Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <26fd78b9-c074-8341-c99c-4e3b38cd861a@xen0n.name>
Date:   Sun, 21 May 2023 20:21:27 +0800
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0)
 Gecko/20100101 Thunderbird/102.11.0
Subject: Re: [PATCH v14 1/2] drm: add kms driver for loongson display
 controller
Content-Language: en-US
To:     Sui Jingfeng <15330273260@189.cn>,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Maxime Ripard <mripard@kernel.org>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        Sui Jingfeng <suijingfeng@loongson.cn>,
        Li Yi <liyi@loongson.cn>,
        Sumit Semwal <sumit.semwal@linaro.org>,
        Christian Koenig <christian.koenig@amd.com>,
        Emil Velikov <emil.l.velikov@gmail.com>
Cc:     linaro-mm-sig@lists.linaro.org, loongson-kernel@lists.loongnix.cn,
        Geert Uytterhoeven <geert+renesas@glider.be>,
        linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
        Javier Martinez Canillas <javierm@redhat.com>,
        Nathan Chancellor <nathan@kernel.org>,
        Liu Peibao <liupeibao@loongson.cn>, linux-media@vger.kernel.org
References: <20230520105718.325819-1-15330273260@189.cn>
 <20230520105718.325819-2-15330273260@189.cn>
From:   WANG Xuerui <kernel@xen0n.name>
In-Reply-To: <20230520105718.325819-2-15330273260@189.cn>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Precedence: bulk

Hi,

Someone else in a discussion group brought my attention to this series, 
that I've neglected for a long time because loongarch@lists.linux.dev 
isn't on the Cc list and I'm not subscribed to dri-devel.

While I'm reasonably familiar with LoongArch internals and Linux in 
general, I don't regularly tinker with the graphics things, so I'm 
mainly focusing on the natural language usage and general code smells 
for my reviews below. Pardon me if some of the questions seem silly.

(After going through the entirety of this: *please* spell-check your 
comment blocks, and correct obvious grammatical nits as best as you can. 
 From my first impression, although a reader not familiar with LoongArch 
nor Chinese could go a long way in understanding this, some of the rest 
would be misunderstood, or don't make sense at all. And like 90% of the 
sentences are grammatically incorrect, i.e. are obvious "Chinglish". 
Maybe something like those ChatGPT-based services or someone in your 
company would help.)

Also, publicly available documentation and references to them would be 
hugely beneficial. For now we have to trust your description here 
(that's very pictorial and pretty complete with explanations, by the 
way, and thanks for that), but it could be even better to provide more 
citations like "According to Section xx.xx of Loongson 7A1000 User 
Manual v1.0. I don't know how people usually handle the "pre-release 
hardware without docs yet" situation in drm side, though; we should 
adhere to the conventions if my understanding is not aligning with it.

And finally, thanks for your patience all along.

On 2023/5/20 18:57, Sui Jingfeng wrote:
> From: Sui Jingfeng <suijingfeng@loongson.cn>
> 
> Loongson display controller IP has been integrated in both Loongson north
> bridge chipset(ls7a1000/ls7a2000) and Loongson SoCs(ls2k1000/ls2k2000), it
> has been even included in Loongson self-made BMC products.
> 
> This display controller is a PCI device. It has two display pipes and each
> display pipe support a primary plane and a cursor plane. For the DC in the

"supports"

> ls7a1000 and ls2k1000, each display pipe has a DVO output interface which
> provide RGB888 signals, vertical & horizontal synchronisations and pixel

"synchronisation"

> clock. Each CRTC is able to support 1920x1080@60Hz, the maximum resolution

"is capable of" sounds more natural?

> of each display pipe is 2048x2048 according to the hardware spec.
> 
> For the DC in LS7A2000, each display pipe is equipped with a built-in HDMI
> encoder which is compliant with the HDMI 1.4 specification, thus it support

"supporting up to 3840x2160@30Hz"

> 3840x2160@30Hz. The first display pipe is also equipped with a transparent
> vga encoder which is parallel with the HDMI encoder. The DC in LS7A2000 is

"The first display pipe additionally has a transparent VGA encoder"?

> more complete compare with the one in old chips, besides above feature, it
> has two hardware cursors, two hardware vblank counter and two scanout
> position recorders unit. It also support tiled framebuffer format which
> can be scanout the tiled framebuffer rendered by the LoongGPU directly.

"The DC in LS7A2000 is more feature-complete compared with the older 
revision: in addition to the above, it also has two hardware cursors, 
two hardware vblank counters and two scanout position recorders. It also 
supports tiled framebuffer format so the tiled output from the LoongGPU 
can be scanned out directly."

> 
> v1 -> v2:
>   1) Use hpd status reg when polling for ls7a2000
>   2) Fix all warnings emerged when compile with W=1
> 
> v2 -> v3:
>   1) Add COMPILE_TEST in Kconfig and make the driver off by default
>   2) Alphabetical sorting headers (Thomas)
>   3) Untangle register access functions as much as possible (Thomas)
>   4) Switch to TTM based memory manager and prefer cached mapping
>      for Loongson SoC (Thomas)
>   5) Add chip id detection method, now all models are distinguishable.
>   6) Revise builtin HDMI phy driver, nearly all main stream mode
>      below 4K@30Hz is tested, this driver supported these mode very
>      well including clone display mode and extend display mode.
> 
> v3 -> v4:
>   1) Quickly fix a small mistake.
> 
> v4 -> v5:
>   1) Drop potential support for Loongson 2K series SoC temporary,
>      this part should be resend with the DT binding patch in the future.
>   2) Add per display pipe debugfs support to the builtin HDMI encoder.
>   3) Rewrite atomic_update() for hardware cursors plane(Thomas)
>   4) Rewrite encoder and connector initialization part, untangle it
>      according to the chip(Thomas).
> 
> v5 -> v6:
>   1) Remove stray code which didn't get used, say lsdc_of_get_reserved_ram
>   2) Fix all typos I could found, make sentences and code more readable
>   3) Untangle lsdc_hdmi*_connector_detect() function according to the pipe
>   4) After a serious consideration, we rename this driver as loongson.
>      Because we also have drivers toward the LoongGPU IP in LS7A2000 and
>      LS2K2000. Besides, there are also drivers about the external encoder,
>      HDMI audio driver and vbios support etc. This patch only provide DC
>      driver part, my teammate Li Yi believe that loongson will be more
>      suitable for loongson graphics than lsdc in the long run.
> 
>      loongson.ko = LSDC + LoongGPU + encoders driver + vbios/DT ...
> 
> v6 -> v7:
>   1) Add prime support, self-sharing is works. sharing buffer with etnaviv
>      is also tested, and its works with limitation.
>   2) Implement buffer objects tracking with list_head.
>   3) S3(sleep to RAM) is tested on ls3a5000+ls7a2000 evb and it works.
>   4) Rewrite lsdc_bo_move, since ttm core stop allocating resources
>      during BO creation. Patch V1 ~ V6 of this series no longer works
>      on latest kernel. Thus, we send V7 to revival them.
> 
> v7 -> v8:
>   1) Zero a compile warnnings on 32-bit platform, compile with W=1
>   2) Revise lsdc_bo_gpu_offset() and minor cleanup
>   3) Pageflip tested on the virtual terminal with following commands
> 
>      modetest -M loongson -s 32:1920x1080 -v
>      modetest -M loongson -s 34:1920x1080 -v -F tiles
> 
>     It works like a charm, when running pageflip test with dual screnn
>     configuration, another two additional bo created by the modetest
>     emerged, VRAM usage up to 40+MB, well we have at least 64MB, still
>     enough.
> 
>     # cat bos
> 
>         bo[0000]: size:     8112kB VRAM
>         bo[0001]: size:       16kB VRAM
>         bo[0002]: size:       16kB VRAM
>         bo[0003]: size:    16208kB VRAM
>         bo[0004]: size:     8112kB VRAM
>         bo[0005]: size:     8112kB VRAM
> 
> v8 -> v9:
>   1) Select I2C and I2C_ALGOBIT in Kconfig and should depend on MMU.
>   2) Using pci_get_domain_bus_and_slot to get the GPU device.
>   3) Other minor improvements.
> 
>   Those patches are tested on ls3a5000 + ls7a1000 CRB, ls3a5000 + ls7a2000
>   evb, and lemote a1901 board(ls3a4000 + ls7a1000). On loongson mips CPU,
>   the write combine support should be enabled, to get a decent performance
>   for writing framebuffer data to the VRAM.
> 
> v9 -> v10:
>   1) Revise lsdc_drm_freeze() to implement S3 completely and correctly.
>      I suddenly realized that pinned buffer can not move and VRAM lost
>      power when sleep to RAM. Thus, the data in the buffer who is pinned
>      in VRAM will get lost when resume. Yet it's not big problem because
>      we are software rendering solution which relay on the CPU update the
>      front framebuffer. We can see the garbage data when resume from S3,
>      but the screen will show correct image as I move the cursor. This is
>      due to the cpu repaint. v10 of this patch make S3 perfect by unpin
>      all of BOs in VRAM, evict them all to system RAM.
> 
> v10 -> v11:
>   1) On double screen case, the single giant framebuffer is referenced by
>      two GEM object, hence, it will be pinned by prepare_fb() at lease two
>      times. This cause its pin count > 1. V10 of this patch only unpin VRAM
>      BOs once when suspend, which is not correct on double screen case. V11
>      of this patch unpin BOs until its pin count reach to zero when suspend.
>      Then, we make the S3 support complete finally. With v11, I can't see
>      any garbage data after resume. Tested on both ls7a1000 and ls7a2000
>      platform, with single screen and double screen configuration.
>   2) Fix vblank wait timeout when disable CRTC.
>   3) Test against IGT, at least fbdev test and kms_flip test passed.
>   4) Rewrite pixel PLL update function, magic numbers eliminated (Emil)
>   5) Drop a few common hardware features description in lsdc_desc (Emil)
>   6) Drop lsdc_mode_config_mode_valid(), instead add restrictions in dumb
>      create function. (Emil)
>   7) Untangle the ls7a1000 case and ls7a2000 case completely (Thomas)
> 
> v11 -> v12:
>   none
> 
> v12 -> v13:
>   1) Add benchmark to figure out the bandwidth of the hardware platform.
>      Usage:
>      # cd /sys/kernel/debug/dri/0/
>      # cat benchmark
> 
>   2) VRAM is filled with garbage data if uninitialized, add a buffer
>      clearing procedure, clear it on the BO creation time.
>   3) Update copyrights and adjust coding style (Huacai)
> 
> v13 -> v14:
>   1) Trying to add async update support for cursor plane.
> 
> Signed-off-by: Li Yi <liyi@loongson.cn>
> Signed-off-by: Sui Jingfeng <suijingfeng@loongson.cn>
> Tested-by: Liu Peibao <liupeibao@loongson.cn>
> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> Cc: Maxime Ripard <mripard@kernel.org>
> Cc: Thomas Zimmermann <tzimmermann@suse.de>
> Cc: David Airlie <airlied@gmail.com>
> Cc: Daniel Vetter <daniel@ffwll.ch>
> Cc: Sumit Semwal <sumit.semwal@linaro.org>
> Cc: "Christian König" <christian.koenig@amd.com>
> Cc: Nathan Chancellor <nathan@kernel.org>
> Cc: Emil Velikov <emil.l.velikov@gmail.com>
> Cc: Geert Uytterhoeven <geert+renesas@glider.be>
> Cc: Javier Martinez Canillas <javierm@redhat.com>
> ---
>   drivers/gpu/drm/Kconfig                       |    2 +
>   drivers/gpu/drm/Makefile                      |    1 +
>   drivers/gpu/drm/loongson/Kconfig              |   17 +
>   drivers/gpu/drm/loongson/Makefile             |   20 +
>   drivers/gpu/drm/loongson/lsdc_benchmark.c     |  133 ++
>   drivers/gpu/drm/loongson/lsdc_benchmark.h     |   13 +
>   drivers/gpu/drm/loongson/lsdc_crtc.c          | 1066 +++++++++++++++++
>   drivers/gpu/drm/loongson/lsdc_debugfs.c       |   91 ++
>   drivers/gpu/drm/loongson/lsdc_device.c        |  104 ++
>   drivers/gpu/drm/loongson/lsdc_drv.c           |  495 ++++++++
>   drivers/gpu/drm/loongson/lsdc_drv.h           |  451 +++++++
>   drivers/gpu/drm/loongson/lsdc_gem.c           |  324 +++++
>   drivers/gpu/drm/loongson/lsdc_gem.h           |   37 +
>   drivers/gpu/drm/loongson/lsdc_gfxpll.c        |  199 +++
>   drivers/gpu/drm/loongson/lsdc_gfxpll.h        |   52 +
>   drivers/gpu/drm/loongson/lsdc_i2c.c           |  179 +++
>   drivers/gpu/drm/loongson/lsdc_i2c.h           |   29 +
>   drivers/gpu/drm/loongson/lsdc_irq.c           |   71 ++
>   drivers/gpu/drm/loongson/lsdc_irq.h           |   16 +
>   drivers/gpu/drm/loongson/lsdc_output.h        |   21 +
>   drivers/gpu/drm/loongson/lsdc_output_7a1000.c |  161 +++
>   drivers/gpu/drm/loongson/lsdc_output_7a2000.c |  531 ++++++++
>   drivers/gpu/drm/loongson/lsdc_pixpll.c        |  481 ++++++++
>   drivers/gpu/drm/loongson/lsdc_pixpll.h        |   86 ++
>   drivers/gpu/drm/loongson/lsdc_plane.c         |  781 ++++++++++++
>   drivers/gpu/drm/loongson/lsdc_probe.c         |   56 +
>   drivers/gpu/drm/loongson/lsdc_probe.h         |   12 +
>   drivers/gpu/drm/loongson/lsdc_regs.h          |  402 +++++++
>   drivers/gpu/drm/loongson/lsdc_ttm.c           |  610 ++++++++++
>   drivers/gpu/drm/loongson/lsdc_ttm.h           |   99 ++
>   30 files changed, 6540 insertions(+)
>   create mode 100644 drivers/gpu/drm/loongson/Kconfig
>   create mode 100644 drivers/gpu/drm/loongson/Makefile
>   create mode 100644 drivers/gpu/drm/loongson/lsdc_benchmark.c
>   create mode 100644 drivers/gpu/drm/loongson/lsdc_benchmark.h
>   create mode 100644 drivers/gpu/drm/loongson/lsdc_crtc.c
>   create mode 100644 drivers/gpu/drm/loongson/lsdc_debugfs.c
>   create mode 100644 drivers/gpu/drm/loongson/lsdc_device.c
>   create mode 100644 drivers/gpu/drm/loongson/lsdc_drv.c
>   create mode 100644 drivers/gpu/drm/loongson/lsdc_drv.h
>   create mode 100644 drivers/gpu/drm/loongson/lsdc_gem.c
>   create mode 100644 drivers/gpu/drm/loongson/lsdc_gem.h
>   create mode 100644 drivers/gpu/drm/loongson/lsdc_gfxpll.c
>   create mode 100644 drivers/gpu/drm/loongson/lsdc_gfxpll.h
>   create mode 100644 drivers/gpu/drm/loongson/lsdc_i2c.c
>   create mode 100644 drivers/gpu/drm/loongson/lsdc_i2c.h
>   create mode 100644 drivers/gpu/drm/loongson/lsdc_irq.c
>   create mode 100644 drivers/gpu/drm/loongson/lsdc_irq.h
>   create mode 100644 drivers/gpu/drm/loongson/lsdc_output.h
>   create mode 100644 drivers/gpu/drm/loongson/lsdc_output_7a1000.c
>   create mode 100644 drivers/gpu/drm/loongson/lsdc_output_7a2000.c
>   create mode 100644 drivers/gpu/drm/loongson/lsdc_pixpll.c
>   create mode 100644 drivers/gpu/drm/loongson/lsdc_pixpll.h
>   create mode 100644 drivers/gpu/drm/loongson/lsdc_plane.c
>   create mode 100644 drivers/gpu/drm/loongson/lsdc_probe.c
>   create mode 100644 drivers/gpu/drm/loongson/lsdc_probe.h
>   create mode 100644 drivers/gpu/drm/loongson/lsdc_regs.h
>   create mode 100644 drivers/gpu/drm/loongson/lsdc_ttm.c
>   create mode 100644 drivers/gpu/drm/loongson/lsdc_ttm.h
> 
> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> index ba3fb04bb691..d1fa87d2acb7 100644
> --- a/drivers/gpu/drm/Kconfig
> +++ b/drivers/gpu/drm/Kconfig
> @@ -331,6 +331,8 @@ source "drivers/gpu/drm/v3d/Kconfig"
>   
>   source "drivers/gpu/drm/vc4/Kconfig"
>   
> +source "drivers/gpu/drm/loongson/Kconfig"
> +
>   source "drivers/gpu/drm/etnaviv/Kconfig"
>   
>   source "drivers/gpu/drm/hisilicon/Kconfig"
> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> index a33257d2bc7f..131531453b8e 100644
> --- a/drivers/gpu/drm/Makefile
> +++ b/drivers/gpu/drm/Makefile
> @@ -194,3 +194,4 @@ obj-y			+= gud/
>   obj-$(CONFIG_DRM_HYPERV) += hyperv/
>   obj-y			+= solomon/
>   obj-$(CONFIG_DRM_SPRD) += sprd/
> +obj-$(CONFIG_DRM_LOONGSON) += loongson/
> diff --git a/drivers/gpu/drm/loongson/Kconfig b/drivers/gpu/drm/loongson/Kconfig
> new file mode 100644
> index 000000000000..df6946d505fa
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/Kconfig
> @@ -0,0 +1,17 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +config DRM_LOONGSON
> +	tristate "DRM support for Loongson Graphics"
> +	depends on DRM && PCI && MMU
> +	select DRM_KMS_HELPER
> +	select DRM_TTM
> +	select I2C
> +	select I2C_ALGOBIT
> +	help
> +	  This is a DRM driver for Loongson Graphics, it may including

Drop "it may"; "including" should be enough.

> +	  LS7A2000, LS7A1000, LS2K2000 and LS2K1000 etc. Loongson LS7A
> +	  series are bridge chipset, while Loongson LS2K series are SoC.
> +
> +	  If "M" is selected, the module will be called loongson.

Just "loongson"? I know it's like this for ages (at least dating back to 
the MIPS days) but you really don't want to imply Loongson is mainly a 
GPU company. Something like "loongson_drm" or "lsdc" or "gsgpu" could be 
better.

> +
> +	  If in doubt, say "N".
> diff --git a/drivers/gpu/drm/loongson/Makefile b/drivers/gpu/drm/loongson/Makefile
> new file mode 100644
> index 000000000000..9158816ece8e
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/Makefile
> @@ -0,0 +1,20 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +loongson-y := \
> +	lsdc_benchmark.o \
> +	lsdc_crtc.o \
> +	lsdc_debugfs.o \
> +	lsdc_device.o \
> +	lsdc_drv.o \
> +	lsdc_gem.o \
> +	lsdc_gfxpll.o \
> +	lsdc_i2c.o \
> +	lsdc_irq.o \
> +	lsdc_output_7a1000.o \
> +	lsdc_output_7a2000.o \
> +	lsdc_plane.o \
> +	lsdc_pixpll.o \
> +	lsdc_probe.o \
> +	lsdc_ttm.o
> +
> +obj-$(CONFIG_DRM_LOONGSON) += loongson.o
> diff --git a/drivers/gpu/drm/loongson/lsdc_benchmark.c b/drivers/gpu/drm/loongson/lsdc_benchmark.c
> new file mode 100644
> index 000000000000..82961531d84c
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/lsdc_benchmark.c
> @@ -0,0 +1,133 @@
> +// SPDX-License-Identifier: GPL-2.0+

Is it GPL-2.0, GPL-2.0-only, or GPL-2.0+? Please make sure all license 
IDs are consistent.

> +/*
> + * Copyright (C) 2023 Loongson Technology Corporation Limited
> + */
> +
> +#include <drm/drm_debugfs.h>
> +
> +#include "lsdc_benchmark.h"
> +#include "lsdc_drv.h"
> +#include "lsdc_gem.h"
> +#include "lsdc_ttm.h"
> +
> +typedef void (*lsdc_copy_proc_t)(struct lsdc_bo *src_bo,
> +				 struct lsdc_bo *dst_bo,
> +				 unsigned int size,
> +				 int n);
> +
> +static void lsdc_copy_gtt_to_vram_cpu(struct lsdc_bo *src_bo,
> +				      struct lsdc_bo *dst_bo,
> +				      unsigned int size,
> +				      int n)
> +{
> +	lsdc_bo_kmap(src_bo);
> +	lsdc_bo_kmap(dst_bo);
> +
> +	while (n--)
> +		memcpy_toio(dst_bo->kptr, src_bo->kptr, size);
> +
> +	lsdc_bo_kunmap(src_bo);
> +	lsdc_bo_kunmap(dst_bo);
> +}
> +
> +static void lsdc_copy_vram_to_gtt_cpu(struct lsdc_bo *src_bo,
> +				      struct lsdc_bo *dst_bo,
> +				      unsigned int size,
> +				      int n)
> +{
> +	lsdc_bo_kmap(src_bo);
> +	lsdc_bo_kmap(dst_bo);
> +
> +	while (n--)
> +		memcpy_fromio(dst_bo->kptr, src_bo->kptr, size);
> +
> +	lsdc_bo_kunmap(src_bo);
> +	lsdc_bo_kunmap(dst_bo);
> +}
> +
> +static void lsdc_copy_gtt_to_gtt_cpu(struct lsdc_bo *src_bo,
> +				     struct lsdc_bo *dst_bo,
> +				     unsigned int size,
> +				     int n)
> +{
> +	lsdc_bo_kmap(src_bo);
> +	lsdc_bo_kmap(dst_bo);
> +
> +	while (n--)
> +		memcpy(dst_bo->kptr, src_bo->kptr, size);
> +
> +	lsdc_bo_kunmap(src_bo);
> +	lsdc_bo_kunmap(dst_bo);
> +}
> +
> +static void lsdc_benchmark_copy(struct lsdc_device *ldev,
> +				unsigned int size,
> +				unsigned int n,
> +				u32 src_domain,
> +				u32 dst_domain,
> +				lsdc_copy_proc_t copy_proc,
> +				struct drm_printer *p)
> +{
> +	struct drm_device *ddev = &ldev->base;
> +	struct lsdc_bo *src_bo;
> +	struct lsdc_bo *dst_bo;
> +	unsigned long start_jiffies;
> +	unsigned long end_jiffies;
> +	unsigned int throughput;
> +	unsigned int time;
> +
> +	src_bo = lsdc_bo_create_kernel_pinned(ddev, src_domain, size);
> +	dst_bo = lsdc_bo_create_kernel_pinned(ddev, dst_domain, size);
> +
> +	start_jiffies = jiffies;
> +
> +	copy_proc(src_bo, dst_bo, size, n);
> +
> +	end_jiffies = jiffies;
> +
> +	lsdc_bo_free_kernel_pinned(src_bo);
> +	lsdc_bo_free_kernel_pinned(dst_bo);
> +
> +	time = jiffies_to_msecs(end_jiffies - start_jiffies);
> +
> +	throughput = (n * (size >> 10)) / time;
> +
> +	drm_printf(p,
> +		   "Copy bo of %ukB %u times from %s to %s in %ums: %uMB/s\n",
> +		   size >> 10, n,
> +		   lsdc_domain_to_str(src_domain),
> +		   lsdc_domain_to_str(dst_domain),
> +		   time, throughput);
> +}
> +
> +int lsdc_show_benchmark_copy(struct lsdc_device *ldev, struct drm_printer *p)
> +{
> +	unsigned int buffer_size = 1920 * 1080 * 4;
> +	unsigned int iteration = 60;
> +
> +	lsdc_benchmark_copy(ldev,
> +			    buffer_size,
> +			    iteration,
> +			    LSDC_GEM_DOMAIN_GTT,
> +			    LSDC_GEM_DOMAIN_GTT,
> +			    lsdc_copy_gtt_to_gtt_cpu,
> +			    p);
> +
> +	lsdc_benchmark_copy(ldev,
> +			    buffer_size,
> +			    iteration,
> +			    LSDC_GEM_DOMAIN_GTT,
> +			    LSDC_GEM_DOMAIN_VRAM,
> +			    lsdc_copy_gtt_to_vram_cpu,
> +			    p);
> +
> +	lsdc_benchmark_copy(ldev,
> +			    buffer_size,
> +			    iteration,
> +			    LSDC_GEM_DOMAIN_VRAM,
> +			    LSDC_GEM_DOMAIN_GTT,
> +			    lsdc_copy_vram_to_gtt_cpu,
> +			    p);
> +
> +	return 0;
> +}
> diff --git a/drivers/gpu/drm/loongson/lsdc_benchmark.h b/drivers/gpu/drm/loongson/lsdc_benchmark.h
> new file mode 100644
> index 000000000000..2bf9406eae9c
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/lsdc_benchmark.h
> @@ -0,0 +1,13 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2023 Loongson Technology Corporation Limited
> + */
> +
> +#ifndef __LSDC_BENCHMARK_H__
> +#define __LSDC_BENCHMARK_H__
> +
> +#include "lsdc_drv.h"
> +
> +int lsdc_show_benchmark_copy(struct lsdc_device *ldev, struct drm_printer *p);
> +
> +#endif
> diff --git a/drivers/gpu/drm/loongson/lsdc_crtc.c b/drivers/gpu/drm/loongson/lsdc_crtc.c
> new file mode 100644
> index 000000000000..de2c1d514baa
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/lsdc_crtc.c
> @@ -0,0 +1,1066 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2023 Loongson Technology Corporation Limited
> + */
> +
> +#include <linux/delay.h>
> +
> +#include <drm/drm_atomic.h>
> +#include <drm/drm_atomic_helper.h>
> +#include <drm/drm_debugfs.h>
> +#include <drm/drm_vblank.h>
> +
> +#include "lsdc_drv.h"
> +
> +/*
> + * The soft reset cause the vblank counter reset to zero, but the address
> + * and other settings in the crtc register remains.
> + */
> +
> +static void lsdc_crtc0_soft_reset(struct lsdc_crtc *lcrtc)
> +{
> +	struct lsdc_device *ldev = lcrtc->ldev;
> +	u32 val;
> +
> +	val = lsdc_rreg32(ldev, LSDC_CRTC0_CFG_REG);
> +
> +	val &= CFG_VALID_BITS_MASK;
> +
> +	/* soft reset bit, active low */
> +	val &= ~CFG_RESET_N;
> +
> +	val &= ~CFG_PIX_FMT_MASK;
> +
> +	lsdc_wreg32(ldev, LSDC_CRTC0_CFG_REG, val);
> +
> +	udelay(5);
> +
> +	val |= CFG_RESET_N | LSDC_PF_XRGB8888 | CFG_OUTPUT_ENABLE;
> +
> +	lsdc_wreg32(ldev, LSDC_CRTC0_CFG_REG, val);
> +
> +	mdelay(20);
> +}
> +
> +static void lsdc_crtc1_soft_reset(struct lsdc_crtc *lcrtc)
> +{
> +	struct lsdc_device *ldev = lcrtc->ldev;
> +	u32 val;
> +
> +	val = lsdc_rreg32(ldev, LSDC_CRTC1_CFG_REG);
> +
> +	val &= CFG_VALID_BITS_MASK;
> +
> +	/* soft reset bit, active low */
> +	val &= ~CFG_RESET_N;
> +
> +	val &= ~CFG_PIX_FMT_MASK;
> +
> +	lsdc_wreg32(ldev, LSDC_CRTC1_CFG_REG, val);
> +
> +	udelay(5);
> +
> +	val |= CFG_RESET_N | LSDC_PF_XRGB8888 | CFG_OUTPUT_ENABLE;
> +
> +	lsdc_wreg32(ldev, LSDC_CRTC1_CFG_REG, val);
> +
> +	msleep(20);

So many magic sleeps without documentation?

> +}
> +
> +static void lsdc_crtc0_enable(struct lsdc_crtc *lcrtc)
> +{
> +	struct lsdc_device *ldev = lcrtc->ldev;
> +	u32 val;
> +
> +	val = lsdc_rreg32(ldev, LSDC_CRTC0_CFG_REG);
> +
> +	/*
> +	 * This may happens on extremely rare case, luckily, a soft reset

"may happen on extremely rare cases;"

> +	 * can helps to bring it back to normal. We add a warn here, hope

"can help bringing it back to normal. We issue a warning here, hoping to"

> +	 * to catch something if it happens.
> +	 */
> +
> +	if (val & CRTC_ANCHORED) {
> +		drm_warn(&ldev->base, "%s anchored\n", lcrtc->base.name);
> +		return lsdc_crtc0_soft_reset(lcrtc);
> +	}
> +
> +	lsdc_wreg32(ldev, LSDC_CRTC0_CFG_REG, val | CFG_OUTPUT_ENABLE);
> +}
> +
> +static void lsdc_crtc0_disable(struct lsdc_crtc *lcrtc)
> +{
> +	struct lsdc_device *ldev = lcrtc->ldev;
> +
> +	lsdc_ureg32_clr(ldev, LSDC_CRTC0_CFG_REG, CFG_OUTPUT_ENABLE);
> +
> +	udelay(9);
> +}
> +
> +static void lsdc_crtc1_enable(struct lsdc_crtc *lcrtc)
> +{
> +	struct lsdc_device *ldev = lcrtc->ldev;
> +	u32 val;
> +
> +	val = lsdc_rreg32(ldev, LSDC_CRTC1_CFG_REG);
> +	if (val & CRTC_ANCHORED) {
> +		drm_warn(&ldev->base, "%s anchored\n", lcrtc->base.name);
> +		return lsdc_crtc1_soft_reset(lcrtc);
> +	}

Duplication of code? You may want to duplicate the comment here too as 
de-duplication with macro seems too heavy here.

> +
> +	lsdc_wreg32(ldev, LSDC_CRTC1_CFG_REG, val | CFG_OUTPUT_ENABLE);
> +}
> +
> +static void lsdc_crtc1_disable(struct lsdc_crtc *lcrtc)
> +{
> +	struct lsdc_device *ldev = lcrtc->ldev;
> +
> +	lsdc_ureg32_clr(ldev, LSDC_CRTC1_CFG_REG, CFG_OUTPUT_ENABLE);
> +
> +	udelay(9);
> +}
> +
> +/* All loongson display controller support scanout position hardware */

Commit message implies only 7A2000+ LSDC IPs have the "scanout position 
recorders". Either that part or this code would need tweaking...

> +
> +static void lsdc_crtc0_scan_pos(struct lsdc_crtc *lcrtc, int *hpos, int *vpos)
> +{
> +	struct lsdc_device *ldev = lcrtc->ldev;
> +	u32 val;
> +
> +	val = lsdc_rreg32(ldev, LSDC_CRTC0_SCAN_POS_REG);
> +
> +	*hpos = val >> 16;
> +	*vpos = val & 0xffff;
> +}
> +
> +static void lsdc_crtc1_scan_pos(struct lsdc_crtc *lcrtc, int *hpos, int *vpos)
> +{
> +	struct lsdc_device *ldev = lcrtc->ldev;
> +	u32 val;
> +
> +	val = lsdc_rreg32(ldev, LSDC_CRTC1_SCAN_POS_REG);
> +
> +	*hpos = val >> 16;
> +	*vpos = val & 0xffff;
> +}
> +
> +static void lsdc_crtc0_enable_vblank(struct lsdc_crtc *lcrtc)
> +{
> +	struct lsdc_device *ldev = lcrtc->ldev;
> +
> +	lsdc_ureg32_set(ldev, LSDC_INT_REG, INT_CRTC0_VSYNC_EN);
> +}
> +
> +static void lsdc_crtc0_disable_vblank(struct lsdc_crtc *lcrtc)
> +{
> +	struct lsdc_device *ldev = lcrtc->ldev;
> +
> +	lsdc_ureg32_clr(ldev, LSDC_INT_REG, INT_CRTC0_VSYNC_EN);
> +}
> +
> +static void lsdc_crtc1_enable_vblank(struct lsdc_crtc *lcrtc)
> +{
> +	struct lsdc_device *ldev = lcrtc->ldev;
> +
> +	lsdc_ureg32_set(ldev, LSDC_INT_REG, INT_CRTC1_VSYNC_EN);
> +}
> +
> +static void lsdc_crtc1_disable_vblank(struct lsdc_crtc *lcrtc)
> +{
> +	struct lsdc_device *ldev = lcrtc->ldev;
> +
> +	lsdc_ureg32_clr(ldev, LSDC_INT_REG, INT_CRTC1_VSYNC_EN);
> +}
> +
> +static void lsdc_crtc0_flip(struct lsdc_crtc *lcrtc)
> +{
> +	struct lsdc_device *ldev = lcrtc->ldev;
> +
> +	lsdc_ureg32_set(ldev, LSDC_CRTC0_CFG_REG, CFG_PAGE_FLIP);
> +}
> +
> +static void lsdc_crtc1_flip(struct lsdc_crtc *lcrtc)
> +{
> +	struct lsdc_device *ldev = lcrtc->ldev;
> +
> +	lsdc_ureg32_set(ldev, LSDC_CRTC1_CFG_REG, CFG_PAGE_FLIP);
> +}
> +
> +/*
> + * CRTC0 clone from CRTC1 or CRTC1 clone from CRTC0 using hardware logic.

"Hardware-assisted cloning between CRTCs"?

> + * Hardware engineer say this would help to saving bandwidth on clone mode.

"Hardware engineers say this would help save bandwidth in clone mode"

> + *
> + * This may useful on custom clone application.

"This may be useful for custom applications of clone mode"?

> + */
> +
> +static void lsdc_crtc0_clone(struct lsdc_crtc *lcrtc)
> +{
> +	struct lsdc_device *ldev = lcrtc->ldev;
> +
> +	lsdc_ureg32_set(ldev, LSDC_CRTC0_CFG_REG, CFG_HW_CLONE);
> +}
> +
> +static void lsdc_crtc1_clone(struct lsdc_crtc *lcrtc)
> +{
> +	struct lsdc_device *ldev = lcrtc->ldev;
> +
> +	lsdc_ureg32_set(ldev, LSDC_CRTC1_CFG_REG, CFG_HW_CLONE);
> +}
> +
> +static void lsdc_crtc0_set_mode(struct lsdc_crtc *lcrtc,
> +				const struct drm_display_mode *mode)
> +{
> +	struct lsdc_device *ldev = lcrtc->ldev;
> +
> +	lsdc_wreg32(ldev, LSDC_CRTC0_HDISPLAY_REG,
> +		    (mode->crtc_htotal << 16) | mode->crtc_hdisplay);
> +
> +	lsdc_wreg32(ldev, LSDC_CRTC0_VDISPLAY_REG,
> +		    (mode->crtc_vtotal << 16) | mode->crtc_vdisplay);
> +
> +	lsdc_wreg32(ldev, LSDC_CRTC0_HSYNC_REG,
> +		    (mode->crtc_hsync_end << 16) | mode->crtc_hsync_start | HSYNC_EN);
> +
> +	lsdc_wreg32(ldev, LSDC_CRTC0_VSYNC_REG,
> +		    (mode->crtc_vsync_end << 16) | mode->crtc_vsync_start | VSYNC_EN);
> +}
> +
> +static void lsdc_crtc1_set_mode(struct lsdc_crtc *lcrtc,
> +				const struct drm_display_mode *mode)
> +{
> +	struct lsdc_device *ldev = lcrtc->ldev;
> +
> +	lsdc_wreg32(ldev, LSDC_CRTC1_HDISPLAY_REG,
> +		    (mode->crtc_htotal << 16) | mode->crtc_hdisplay);
> +
> +	lsdc_wreg32(ldev, LSDC_CRTC1_VDISPLAY_REG,
> +		    (mode->crtc_vtotal << 16) | mode->crtc_vdisplay);
> +
> +	lsdc_wreg32(ldev, LSDC_CRTC1_HSYNC_REG,
> +		    (mode->crtc_hsync_end << 16) | mode->crtc_hsync_start | HSYNC_EN);
> +
> +	lsdc_wreg32(ldev, LSDC_CRTC1_VSYNC_REG,
> +		    (mode->crtc_vsync_end << 16) | mode->crtc_vsync_start | VSYNC_EN);
> +}
> +
> +/*
> + * This is required for S3 support.
> + *
> + * After resume from suspend, LSDC_CRTCx_CFG_REG (x=0 or 1)is filled with

"resuming", "are filled"

> + * garbarge value which may cause the CRTC completely hang. This function

"to completely hang"

> + * give a minimal setting to the affected registers. This also override

"minimally resets the affected registers"

> + * the firmware's setting on startup, eliminate potential blinding setting.

"This also overrides the boot-time setting by the firmware, eliminating 
potentially blinding settings"?

> + *
> + * Making the CRTC works on our own now, this is similar with the functional

What do you mean by "work on our own"? Do you mean re-initializing the 
CRTC without firmware help?

> + * of GPU POST(Power On Self Test). Only touch CRTC hardware related part.
> + */
> +
> +static void lsdc_crtc0_reset(struct lsdc_crtc *lcrtc)
> +{
> +	struct lsdc_device *ldev = lcrtc->ldev;
> +	struct drm_crtc *crtc = &lcrtc->base;
> +	u32 val;
> +
> +	val = lsdc_rreg32(ldev, LSDC_CRTC0_CFG_REG);
> +
> +	/* This help to see what is it */
> +	drm_dbg(&ldev->base, "value of %s configure register: %x\n",

"config register" should be enough?

> +		crtc->name, val);
> +
> +	/*
> +	 * Help the CRTC get out of soft reset sate, as the CRTC is completely
> +	 * halt on soft reset mode (BIT(20) = 0). It does not event generate
> +	 * vblank, cause vblank wait timeout. This happends when resume from
> +	 * S3.
> +	 *
> +	 * Also give a sane format, after resume from suspend S3, this
> +	 * register is filled with garbarge value. A meaningless value may
> +	 * also cause the CRTC halt or stall.
> +	 */

This block of comment is mostly a duplication of the function's doc 
comment above; I'd suggest removing this block.

> +
> +	val = CFG_RESET_N | LSDC_PF_XRGB8888;
> +
> +	lsdc_wreg32(ldev, LSDC_CRTC0_CFG_REG, val);
> +}
> +
> +static void lsdc_crtc1_reset(struct lsdc_crtc *lcrtc)
> +{
> +	struct lsdc_device *ldev = lcrtc->ldev;
> +	struct drm_crtc *crtc = &lcrtc->base;
> +	u32 val;
> +
> +	val = lsdc_rreg32(ldev, LSDC_CRTC1_CFG_REG);
> +
> +	drm_dbg(&ldev->base, "value of %s configue register: %x\n",

"config"

> +		crtc->name, val);
> +
> +	/*
> +	 * Help the CRTC get out of soft reset sate, give a sane format,
> +	 * Otherwise it will halt or stall there.
> +	 */
> +	val = CFG_RESET_N | LSDC_PF_XRGB8888;
> +
> +	lsdc_wreg32(ldev, LSDC_CRTC1_CFG_REG, val);
> +}
> +
> +static const struct lsdc_crtc_hw_ops ls7a1000_crtc_hw_ops[2] = {
> +	{
> +		.enable = lsdc_crtc0_enable,
> +		.disable = lsdc_crtc0_disable,
> +		.enable_vblank = lsdc_crtc0_enable_vblank,
> +		.disable_vblank = lsdc_crtc0_disable_vblank,
> +		.flip = lsdc_crtc0_flip,
> +		.clone = lsdc_crtc0_clone,
> +		.set_mode = lsdc_crtc0_set_mode,
> +		.get_scan_pos = lsdc_crtc0_scan_pos,
> +		.soft_reset = lsdc_crtc0_soft_reset,
> +		.reset = lsdc_crtc0_reset,
> +	},
> +	{
> +		.enable = lsdc_crtc1_enable,
> +		.disable = lsdc_crtc1_disable,
> +		.enable_vblank = lsdc_crtc1_enable_vblank,
> +		.disable_vblank = lsdc_crtc1_disable_vblank,
> +		.flip = lsdc_crtc1_flip,
> +		.clone = lsdc_crtc1_clone,
> +		.set_mode = lsdc_crtc1_set_mode,
> +		.get_scan_pos = lsdc_crtc1_scan_pos,
> +		.soft_reset = lsdc_crtc1_soft_reset,
> +		.reset = lsdc_crtc1_reset,
> +	},
> +};
> +
> +/*
> + * The 32-bit hardware vblank counter is available since ls7a2000/ls2k2000,
> + * The counter grow up even the CRTC is being disabled, it will got reset

"The counters increase even when the CRTC is disabled, and will be reset 
if the crtc is soft-reset"

I don't think you're describing the transient behavior when the CRTC is 
*being* disabled / soft-reset, i.e. *in the middle of* 
disabling/soft-resetting, hence I've fixed the tenses for you.

Also please change all mentions of lowercase "ls7a2000" or "ls2k2000" in 
comments to consistent uppercase equivalents; it's easier for human eyes 
that way.

> + * if the crtc is being soft reset.
> + *
> + * Those registers are also readable for ls7a1000, but its value does not
> + * change.

"but the values cannot be changed"

> + */
> +
> +static u32 lsdc_crtc0_get_vblank_count(struct lsdc_crtc *lcrtc)
> +{
> +	struct lsdc_device *ldev = lcrtc->ldev;
> +
> +	return lsdc_rreg32(ldev, LSDC_CRTC0_VSYNC_COUNTER_REG);
> +}
> +
> +static u32 lsdc_crtc1_get_vblank_count(struct lsdc_crtc *lcrtc)
> +{
> +	struct lsdc_device *ldev = lcrtc->ldev;
> +
> +	return lsdc_rreg32(ldev, LSDC_CRTC1_VSYNC_COUNTER_REG);
> +}
> +
> +/*
> + * The DMA step bit field is available since ls7a2000/ls2k2000, for support
> + * odd resolutions. But a large DMA step may save bandwidth. Behavior of

"for supporting"; "a larger"

> + * writing thoes bits field on ls7a1000/ls2k1000 is underfined.

"those bitfields"; "undefined"

> + */
> +
> +static void lsdc_crtc0_set_dma_step(struct lsdc_crtc *lcrtc,
> +				    enum lsdc_dma_steps dma_step)
> +{
> +	struct lsdc_device *ldev = lcrtc->ldev;
> +	u32 val = lsdc_rreg32(ldev, LSDC_CRTC0_CFG_REG);
> +
> +	val &= ~CFG_DMA_STEP_MASK;
> +	val |= dma_step << CFG_DMA_STEP_SHIFT;
> +
> +	lsdc_wreg32(ldev, LSDC_CRTC0_CFG_REG, val);
> +}
> +
> +static void lsdc_crtc1_set_dma_step(struct lsdc_crtc *lcrtc,
> +				    enum lsdc_dma_steps dma_step)
> +{
> +	struct lsdc_device *ldev = lcrtc->ldev;
> +	u32 val = lsdc_rreg32(ldev, LSDC_CRTC1_CFG_REG);
> +
> +	val &= ~CFG_DMA_STEP_MASK;
> +	val |= dma_step << CFG_DMA_STEP_SHIFT;
> +
> +	lsdc_wreg32(ldev, LSDC_CRTC1_CFG_REG, val);
> +}
> +
> +static const struct lsdc_crtc_hw_ops ls7a2000_crtc_hw_ops[2] = {
> +	{
> +		.enable = lsdc_crtc0_enable,
> +		.disable = lsdc_crtc0_disable,
> +		.enable_vblank = lsdc_crtc0_enable_vblank,
> +		.disable_vblank = lsdc_crtc0_disable_vblank,
> +		.flip = lsdc_crtc0_flip,
> +		.clone = lsdc_crtc0_clone,
> +		.set_mode = lsdc_crtc0_set_mode,
> +		.soft_reset = lsdc_crtc0_soft_reset,
> +		.get_scan_pos = lsdc_crtc0_scan_pos,
> +		.set_dma_step = lsdc_crtc0_set_dma_step,
> +		.get_vblank_counter = lsdc_crtc0_get_vblank_count,
> +		.reset = lsdc_crtc0_reset,
> +	},
> +	{
> +		.enable = lsdc_crtc1_enable,
> +		.disable = lsdc_crtc1_disable,
> +		.enable_vblank = lsdc_crtc1_enable_vblank,
> +		.disable_vblank = lsdc_crtc1_disable_vblank,
> +		.flip = lsdc_crtc1_flip,
> +		.clone = lsdc_crtc1_clone,
> +		.set_mode = lsdc_crtc1_set_mode,
> +		.get_scan_pos = lsdc_crtc1_scan_pos,
> +		.soft_reset = lsdc_crtc1_soft_reset,
> +		.set_dma_step = lsdc_crtc1_set_dma_step,
> +		.get_vblank_counter = lsdc_crtc1_get_vblank_count,
> +		.reset = lsdc_crtc1_reset,
> +	},
> +};
> +
> +static void lsdc_crtc_reset(struct drm_crtc *crtc)
> +{
> +	struct lsdc_crtc *lcrtc = to_lsdc_crtc(crtc);
> +	const struct lsdc_crtc_hw_ops *ops = lcrtc->hw_ops;
> +	struct lsdc_crtc_state *priv_crtc_state;
> +
> +	if (crtc->state)
> +		crtc->funcs->atomic_destroy_state(crtc, crtc->state);
> +
> +	priv_crtc_state = kzalloc(sizeof(*priv_crtc_state), GFP_KERNEL);
> +
> +	if (!priv_crtc_state)
> +		__drm_atomic_helper_crtc_reset(crtc, NULL);
> +	else
> +		__drm_atomic_helper_crtc_reset(crtc, &priv_crtc_state->base);
> +
> +	/*
> +	 * Reset the crtc hardware, this is need for S3 support,
> +	 * otherwise, wait for vblank timeout may happen.

"Reset the crtc hardware which is needed for S3, otherwise vblank 
timeout may happen"?

> +	 */
> +	ops->reset(lcrtc);
> +}
> +
> +static void lsdc_crtc_atomic_destroy_state(struct drm_crtc *crtc,
> +					   struct drm_crtc_state *state)
> +{
> +	struct lsdc_crtc_state *priv_state = to_lsdc_crtc_state(state);
> +
> +	__drm_atomic_helper_crtc_destroy_state(&priv_state->base);
> +
> +	kfree(priv_state);
> +}
> +
> +static struct drm_crtc_state *
> +lsdc_crtc_atomic_duplicate_state(struct drm_crtc *crtc)
> +{
> +	struct lsdc_crtc_state *new_priv_state;
> +	struct lsdc_crtc_state *old_priv_state;
> +
> +	new_priv_state = kzalloc(sizeof(*new_priv_state), GFP_KERNEL);
> +	if (!new_priv_state)
> +		return NULL;
> +
> +	__drm_atomic_helper_crtc_duplicate_state(crtc, &new_priv_state->base);
> +
> +	old_priv_state = to_lsdc_crtc_state(crtc->state);
> +
> +	memcpy(&new_priv_state->pparms, &old_priv_state->pparms,
> +	       sizeof(new_priv_state->pparms));
> +
> +	return &new_priv_state->base;
> +}
> +
> +static u32 lsdc_crtc_get_vblank_counter(struct drm_crtc *crtc)
> +{
> +	struct lsdc_crtc *lcrtc = to_lsdc_crtc(crtc);
> +	const struct lsdc_crtc_hw_ops *ops = lcrtc->hw_ops;
> +
> +	return ops->get_vblank_counter(lcrtc);
> +}
> +
> +static int lsdc_crtc_enable_vblank(struct drm_crtc *crtc)
> +{
> +	struct lsdc_crtc *lcrtc = to_lsdc_crtc(crtc);
> +	const struct lsdc_crtc_hw_ops *ops = lcrtc->hw_ops;
> +
> +	ops->enable_vblank(lcrtc);
> +
> +	return 0;
> +}
> +
> +static void lsdc_crtc_disable_vblank(struct drm_crtc *crtc)
> +{
> +	struct lsdc_crtc *lcrtc = to_lsdc_crtc(crtc);
> +	const struct lsdc_crtc_hw_ops *ops = lcrtc->hw_ops;
> +
> +	ops->disable_vblank(lcrtc);
> +}
> +
> +/*
> + * CRTC related debugfs
> + *
> + * Primary planes and cursor planes are also belong to the CRTC for our case,

"also belong to the CRTC in our cases"

> + * so also append other registers to here, for sake of convenient.

"so the other registers are also appended here for convenience"

> + */
> +
> +#define REG_DEF(reg) { \
> +	.name = __stringify_1(LSDC_##reg##_REG), \
> +	.offset = LSDC_##reg##_REG, \
> +}
> +
> +static const struct lsdc_reg32 lsdc_crtc_regs_array[2][21] = {
> +	[0] = {
> +		REG_DEF(CRTC0_CFG),
> +		REG_DEF(CRTC0_FB_ORIGIN),
> +		REG_DEF(CRTC0_PANEL_CONF),
> +		REG_DEF(CRTC0_HDISPLAY),
> +		REG_DEF(CRTC0_HSYNC),
> +		REG_DEF(CRTC0_VDISPLAY),
> +		REG_DEF(CRTC0_VSYNC),
> +		REG_DEF(CRTC0_GAMMA_INDEX),
> +		REG_DEF(CRTC0_GAMMA_DATA),
> +		REG_DEF(CRTC0_SYNC_DEVIATION),
> +		REG_DEF(CRTC0_VSYNC_COUNTER),
> +		REG_DEF(CRTC0_SCAN_POS),
> +		REG_DEF(CRTC0_STRIDE),
> +		REG_DEF(CRTC0_FB1_ADDR_HI),
> +		REG_DEF(CRTC0_FB1_ADDR_LO),
> +		REG_DEF(CRTC0_FB0_ADDR_HI),
> +		REG_DEF(CRTC0_FB0_ADDR_LO),
> +		REG_DEF(CURSOR0_CFG),
> +		REG_DEF(CURSOR0_POSITION),
> +		REG_DEF(CURSOR0_BG_COLOR),
> +		REG_DEF(CURSOR0_FG_COLOR),
> +	},
> +	[1] = {
> +		REG_DEF(CRTC1_CFG),
> +		REG_DEF(CRTC1_FB_ORIGIN),
> +		REG_DEF(CRTC1_PANEL_CONF),
> +		REG_DEF(CRTC1_HDISPLAY),
> +		REG_DEF(CRTC1_HSYNC),
> +		REG_DEF(CRTC1_VDISPLAY),
> +		REG_DEF(CRTC1_VSYNC),
> +		REG_DEF(CRTC1_GAMMA_INDEX),
> +		REG_DEF(CRTC1_GAMMA_DATA),
> +		REG_DEF(CRTC1_SYNC_DEVIATION),
> +		REG_DEF(CRTC1_VSYNC_COUNTER),
> +		REG_DEF(CRTC1_SCAN_POS),
> +		REG_DEF(CRTC1_STRIDE),
> +		REG_DEF(CRTC1_FB1_ADDR_HI),
> +		REG_DEF(CRTC1_FB1_ADDR_LO),
> +		REG_DEF(CRTC1_FB0_ADDR_HI),
> +		REG_DEF(CRTC1_FB0_ADDR_LO),
> +		REG_DEF(CURSOR1_CFG),
> +		REG_DEF(CURSOR1_POSITION),
> +		REG_DEF(CURSOR1_BG_COLOR),
> +		REG_DEF(CURSOR1_FG_COLOR),
> +	},
> +};
> +
> +static int lsdc_crtc_show_regs(struct seq_file *m, void *arg)
> +{
> +	struct drm_info_node *node = (struct drm_info_node *)m->private;
> +	struct lsdc_crtc *lcrtc = (struct lsdc_crtc *)node->info_ent->data;
> +	struct lsdc_device *ldev = lcrtc->ldev;
> +	unsigned int i;
> +
> +	for (i = 0; i < lcrtc->nreg; i++) {
> +		const struct lsdc_reg32 *preg = &lcrtc->preg[i];
> +		u32 offset = preg->offset;
> +
> +		seq_printf(m, "%s (0x%04x): 0x%08x\n",
> +			   preg->name, offset, lsdc_rreg32(ldev, offset));
> +	}
> +
> +	return 0;
> +}
> +
> +static int lsdc_crtc_show_scan_position(struct seq_file *m, void *arg)
> +{
> +	struct drm_info_node *node = (struct drm_info_node *)m->private;
> +	struct lsdc_crtc *lcrtc = (struct lsdc_crtc *)node->info_ent->data;
> +	const struct lsdc_crtc_hw_ops *ops = lcrtc->hw_ops;
> +	int x, y;
> +
> +	ops->get_scan_pos(lcrtc, &x, &y);
> +
> +	seq_printf(m, "scanout position: x: %08u, y: %08u\n", x, y);
> +
> +	return 0;
> +}
> +
> +static int lsdc_crtc_show_vblank_counter(struct seq_file *m, void *arg)
> +{
> +	struct drm_info_node *node = (struct drm_info_node *)m->private;
> +	struct lsdc_crtc *lcrtc = (struct lsdc_crtc *)node->info_ent->data;
> +	const struct lsdc_crtc_hw_ops *ops = lcrtc->hw_ops;
> +
> +	if (ops->get_vblank_counter)
> +		seq_printf(m, "%s vblank counter: %08u\n\n",
> +			   lcrtc->base.name,
> +			   ops->get_vblank_counter(lcrtc));
> +
> +	return 0;
> +}
> +
> +static int lsdc_pixpll_show_clock(struct seq_file *m, void *arg)
> +{
> +	struct drm_info_node *node = (struct drm_info_node *)m->private;
> +	struct lsdc_crtc *lcrtc = (struct lsdc_crtc *)node->info_ent->data;
> +	struct lsdc_pixpll *pixpll = &lcrtc->pixpll;
> +	const struct lsdc_pixpll_funcs *funcs = pixpll->funcs;
> +	struct drm_crtc *crtc = &lcrtc->base;
> +	struct drm_display_mode *mode = &crtc->state->mode;
> +	struct drm_printer printer = drm_seq_file_printer(m);
> +	unsigned int out_khz;
> +
> +	out_khz = funcs->get_rate(pixpll);
> +
> +	seq_printf(m, "%s: %dx%d@%d\n", crtc->name,
> +		   mode->hdisplay, mode->vdisplay, drm_mode_vrefresh(mode));
> +
> +	seq_printf(m, "Pixel clock required: %d kHz\n", mode->clock);
> +	seq_printf(m, "Actual frequency output: %u kHz\n", out_khz);
> +	seq_printf(m, "Diff: %d kHz\n", out_khz - mode->clock);
> +
> +	funcs->print(pixpll, &printer);
> +
> +	return 0;
> +}
> +
> +static struct drm_info_list lsdc_crtc_debugfs_list[2][4] = {
> +	[0] = {
> +		{ "regs", lsdc_crtc_show_regs, 0, NULL },
> +		{ "pixclk", lsdc_pixpll_show_clock, 0, NULL },
> +		{ "scanpos", lsdc_crtc_show_scan_position, 0, NULL },
> +		{ "vblanks", lsdc_crtc_show_vblank_counter, 0, NULL },
> +	},
> +	[1] = {
> +		{ "regs", lsdc_crtc_show_regs, 0, NULL },
> +		{ "pixclk", lsdc_pixpll_show_clock, 0, NULL },
> +		{ "scanpos", lsdc_crtc_show_scan_position, 0, NULL },
> +		{ "vblanks", lsdc_crtc_show_vblank_counter, 0, NULL },
> +	},
> +};
> +
> +/* operate manually */
> +
> +static int lsdc_crtc_man_op_show(struct seq_file *m, void *data)
> +{
> +	seq_puts(m, "soft_reset: soft reset this CRTC\n");
> +	seq_puts(m, "enable: enable this CRTC\n");
> +	seq_puts(m, "disable: disable this CRTC\n");
> +	seq_puts(m, "flip: trigger the page flip\n");
> +	seq_puts(m, "clone: clone the another crtc with hardware logic\n");
> +
> +	return 0;
> +}
> +
> +static int lsdc_crtc_man_op_open(struct inode *inode, struct file *file)
> +{
> +	struct drm_crtc *crtc = inode->i_private;
> +
> +	return single_open(file, lsdc_crtc_man_op_show, crtc);
> +}
> +
> +static ssize_t lsdc_crtc_man_op_write(struct file *file,
> +				      const char __user *ubuf,
> +				      size_t len,
> +				      loff_t *offp)
> +{
> +	struct seq_file *m = file->private_data;
> +	struct lsdc_crtc *lcrtc = m->private;
> +	const struct lsdc_crtc_hw_ops *ops = lcrtc->hw_ops;
> +
> +	char buf[16];
> +
> +	if (len > sizeof(buf) - 1)
> +		return -EINVAL;
> +
> +	if (copy_from_user(buf, ubuf, len))
> +		return -EFAULT;
> +
> +	buf[len] = '\0';
> +
> +	if (sysfs_streq(buf, "soft_reset"))
> +		ops->soft_reset(lcrtc);
> +	else if (sysfs_streq(buf, "enable"))
> +		ops->enable(lcrtc);
> +	else if (sysfs_streq(buf, "disable"))
> +		ops->disable(lcrtc);
> +	else if (sysfs_streq(buf, "flip"))
> +		ops->flip(lcrtc);
> +	else if (sysfs_streq(buf, "clone"))
> +		ops->clone(lcrtc);
> +
> +	return len;
> +}
> +
> +static const struct file_operations lsdc_crtc_man_op_fops = {
> +	.owner = THIS_MODULE,
> +	.open = lsdc_crtc_man_op_open,
> +	.read = seq_read,
> +	.llseek = seq_lseek,
> +	.release = single_release,
> +	.write = lsdc_crtc_man_op_write,
> +};
> +
> +static int lsdc_crtc_late_register(struct drm_crtc *crtc)
> +{
> +	struct lsdc_display_pipe *dispipe = crtc_to_display_pipe(crtc);
> +	struct lsdc_crtc *lcrtc = to_lsdc_crtc(crtc);
> +	struct drm_minor *minor = crtc->dev->primary;
> +	unsigned int index = dispipe->index;
> +	unsigned int i;
> +
> +	lcrtc->preg = lsdc_crtc_regs_array[index];
> +	lcrtc->nreg = ARRAY_SIZE(lsdc_crtc_regs_array[index]);
> +	lcrtc->p_info_list = lsdc_crtc_debugfs_list[index];
> +	lcrtc->n_info_list = ARRAY_SIZE(lsdc_crtc_debugfs_list[index]);
> +
> +	for (i = 0; i < lcrtc->n_info_list; ++i)
> +		lcrtc->p_info_list[i].data = lcrtc;
> +
> +	drm_debugfs_create_files(lcrtc->p_info_list,
> +				 lcrtc->n_info_list,
> +				 crtc->debugfs_entry,
> +				 minor);
> +
> +	/* supported manual operations */
> +	debugfs_create_file("ops", 0644, crtc->debugfs_entry, lcrtc,
> +			    &lsdc_crtc_man_op_fops);
> +
> +	return 0;
> +}
> +
> +static void lsdc_crtc_atomic_print_state(struct drm_printer *p,
> +					 const struct drm_crtc_state *state)
> +{
> +	const struct lsdc_crtc_state *priv_state;
> +	const struct lsdc_pixpll_parms *pparms;
> +
> +	priv_state = container_of_const(state, struct lsdc_crtc_state, base);
> +	pparms = &priv_state->pparms;
> +
> +	drm_printf(p, "\tInput clock divider = %u\n", pparms->div_ref);
> +	drm_printf(p, "\tMedium clock Multiplier = %u\n", pparms->loopc);

"multiplier" for consistent casing

> +	drm_printf(p, "\tOutput clock divider = %u\n", pparms->div_out);
> +}
> +
> +static const struct drm_crtc_funcs ls7a1000_crtc_funcs = {
> +	.reset = lsdc_crtc_reset,
> +	.destroy = drm_crtc_cleanup,
> +	.set_config = drm_atomic_helper_set_config,
> +	.page_flip = drm_atomic_helper_page_flip,
> +	.atomic_duplicate_state = lsdc_crtc_atomic_duplicate_state,
> +	.atomic_destroy_state = lsdc_crtc_atomic_destroy_state,
> +	.late_register = lsdc_crtc_late_register,
> +	.enable_vblank = lsdc_crtc_enable_vblank,
> +	.disable_vblank = lsdc_crtc_disable_vblank,
> +	.get_vblank_timestamp = drm_crtc_vblank_helper_get_vblank_timestamp,
> +	.atomic_print_state = lsdc_crtc_atomic_print_state,
> +};
> +
> +static const struct drm_crtc_funcs ls7a2000_crtc_funcs = {
> +	.reset = lsdc_crtc_reset,
> +	.destroy = drm_crtc_cleanup,
> +	.set_config = drm_atomic_helper_set_config,
> +	.page_flip = drm_atomic_helper_page_flip,
> +	.atomic_duplicate_state = lsdc_crtc_atomic_duplicate_state,
> +	.atomic_destroy_state = lsdc_crtc_atomic_destroy_state,
> +	.late_register = lsdc_crtc_late_register,
> +	.get_vblank_counter = lsdc_crtc_get_vblank_counter,
> +	.enable_vblank = lsdc_crtc_enable_vblank,
> +	.disable_vblank = lsdc_crtc_disable_vblank,
> +	.get_vblank_timestamp = drm_crtc_vblank_helper_get_vblank_timestamp,
> +	.atomic_print_state = lsdc_crtc_atomic_print_state,
> +};
> +
> +static enum drm_mode_status
> +lsdc_crtc_mode_valid(struct drm_crtc *crtc, const struct drm_display_mode *mode)
> +{
> +	struct drm_device *ddev = crtc->dev;
> +	struct lsdc_device *ldev = to_lsdc(ddev);
> +	const struct lsdc_desc *descp = ldev->descp;
> +	unsigned int pitch;
> +
> +	if (mode->hdisplay > descp->max_width)
> +		return MODE_BAD_HVALUE;
> +
> +	if (mode->vdisplay > descp->max_height)
> +		return MODE_BAD_VVALUE;
> +
> +	if (mode->clock > descp->max_pixel_clk) {
> +		drm_dbg_kms(ddev, "mode %dx%d, pixel clock=%d is too high\n",
> +			    mode->hdisplay, mode->vdisplay, mode->clock);
> +		return MODE_CLOCK_HIGH;
> +	}
> +
> +	/* 4 for DRM_FORMAT_XRGB8888 */
> +	pitch = mode->hdisplay * 4;
> +
> +	if (pitch % descp->pitch_align) {
> +		drm_dbg_kms(ddev, "aligned to %u bytes is required: %u\n",

"alignment of %u bytes"

> +			    descp->pitch_align, pitch);
> +		return MODE_BAD_WIDTH;
> +	}
> +
> +	return MODE_OK;
> +}
> +
> +static int lsdc_pixpll_atomic_check(struct drm_crtc *crtc,
> +				    struct drm_crtc_state *state)
> +{
> +	struct lsdc_crtc *lcrtc = to_lsdc_crtc(crtc);
> +	struct lsdc_pixpll *pixpll = &lcrtc->pixpll;
> +	const struct lsdc_pixpll_funcs *pfuncs = pixpll->funcs;
> +	struct lsdc_crtc_state *priv_state = to_lsdc_crtc_state(state);
> +	unsigned int clock = state->mode.clock;
> +	int ret;
> +
> +	ret = pfuncs->compute(pixpll, clock, &priv_state->pparms);
> +	if (ret) {
> +		drm_warn(crtc->dev, "find PLL parms for %ukHz failed\n", clock);

"failed to find PLL params for"

> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +static int lsdc_crtc_helper_atomic_check(struct drm_crtc *crtc,
> +					 struct drm_atomic_state *state)
> +{
> +	struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
> +
> +	if (!crtc_state->enable)
> +		return 0;
> +
> +	return lsdc_pixpll_atomic_check(crtc, crtc_state);
> +}
> +
> +static void lsdc_crtc_mode_set_nofb(struct drm_crtc *crtc)
> +{
> +	struct lsdc_crtc *lcrtc = to_lsdc_crtc(crtc);
> +	const struct lsdc_crtc_hw_ops *crtc_hw_ops = lcrtc->hw_ops;
> +	struct lsdc_pixpll *pixpll = &lcrtc->pixpll;
> +	const struct lsdc_pixpll_funcs *pixpll_funcs = pixpll->funcs;
> +	struct drm_crtc_state *state = crtc->state;
> +	struct drm_display_mode *mode = &state->mode;
> +	struct lsdc_crtc_state *priv_state = to_lsdc_crtc_state(state);
> +
> +	pixpll_funcs->update(pixpll, &priv_state->pparms);
> +
> +	if (crtc_hw_ops->set_dma_step) {
> +		unsigned int width_in_bytes = mode->hdisplay * 4;
> +		enum lsdc_dma_steps dma_step;
> +
> +		/*
> +		 * Using large dma step as much as possible, for improving

"Using DMA step as large as possible"

> +		 * hardware DMA efficiency.
> +		 */
> +		if (width_in_bytes % 256 == 0)
> +			dma_step = LSDC_DMA_STEP_256_BYTES;
> +		else if (width_in_bytes % 128 == 0)
> +			dma_step = LSDC_DMA_STEP_128_BYTES;
> +		else if (width_in_bytes % 64 == 0)
> +			dma_step = LSDC_DMA_STEP_64_BYTES;
> +		else  /* width_in_bytes % 32 == 0 */
> +			dma_step = LSDC_DMA_STEP_32_BYTES;
> +
> +		crtc_hw_ops->set_dma_step(lcrtc, dma_step);
> +	}
> +
> +	crtc_hw_ops->set_mode(lcrtc, mode);
> +}
> +
> +static void lsdc_crtc_send_vblank(struct drm_crtc *crtc)
> +{
> +	struct drm_device *ddev = crtc->dev;
> +	unsigned long flags;
> +
> +	if (!crtc->state || !crtc->state->event)
> +		return;
> +
> +	drm_dbg(ddev, "send vblank manually\n");

"manually sending vblank"

> +
> +	spin_lock_irqsave(&ddev->event_lock, flags);
> +	drm_crtc_send_vblank_event(crtc, crtc->state->event);
> +	crtc->state->event = NULL;
> +	spin_unlock_irqrestore(&ddev->event_lock, flags);
> +}
> +
> +static void lsdc_crtc_atomic_enable(struct drm_crtc *crtc,
> +				    struct drm_atomic_state *state)
> +{
> +	struct lsdc_crtc *lcrtc = to_lsdc_crtc(crtc);
> +	const struct lsdc_crtc_hw_ops *ops = lcrtc->hw_ops;
> +
> +	drm_crtc_vblank_on(crtc);
> +
> +	drm_dbg(crtc->dev, "%s enable\n", crtc->name);

"enabling %s\n"

> +
> +	ops->enable(lcrtc);
> +}
> +
> +static void lsdc_crtc_atomic_disable(struct drm_crtc *crtc,
> +				     struct drm_atomic_state *state)
> +{
> +	struct lsdc_crtc *lcrtc = to_lsdc_crtc(crtc);
> +	const struct lsdc_crtc_hw_ops *ops = lcrtc->hw_ops;
> +
> +	drm_crtc_vblank_off(crtc);
> +
> +	ops->disable(lcrtc);
> +
> +	drm_dbg(crtc->dev, "%s disable\n", crtc->name);

"disabling %s\n"

> +
> +	/*
> +	 * Make sure we issue a vblank event after disabling the CRTC if
> +	 * someone was waiting it.

"waiting for"

> +	 */
> +	lsdc_crtc_send_vblank(crtc);
> +}
> +
> +static void lsdc_crtc_atomic_flush(struct drm_crtc *crtc,
> +				   struct drm_atomic_state *state)
> +{
> +	spin_lock_irq(&crtc->dev->event_lock);
> +	if (crtc->state->event) {
> +		if (drm_crtc_vblank_get(crtc) == 0)
> +			drm_crtc_arm_vblank_event(crtc, crtc->state->event);
> +		else
> +			drm_crtc_send_vblank_event(crtc, crtc->state->event);
> +		crtc->state->event = NULL;
> +	}
> +	spin_unlock_irq(&crtc->dev->event_lock);
> +}
> +
> +static bool lsdc_crtc_get_scanout_position(struct drm_crtc *crtc,
> +					   bool in_vblank_irq,
> +					   int *vpos,
> +					   int *hpos,
> +					   ktime_t *stime,
> +					   ktime_t *etime,
> +					   const struct drm_display_mode *mode)
> +{
> +	struct lsdc_crtc *lcrtc = to_lsdc_crtc(crtc);
> +	const struct lsdc_crtc_hw_ops *ops = lcrtc->hw_ops;
> +	int vsw, vbp, vactive_start, vactive_end, vfp_end;
> +	int x, y;
> +
> +	vsw = mode->crtc_vsync_end - mode->crtc_vsync_start;
> +	vbp = mode->crtc_vtotal - mode->crtc_vsync_end;
> +
> +	vactive_start = vsw + vbp + 1;
> +	vactive_end = vactive_start + mode->crtc_vdisplay;
> +
> +	/* last scan line before VSYNC */
> +	vfp_end = mode->crtc_vtotal;
> +
> +	if (stime)
> +		*stime = ktime_get();
> +
> +	ops->get_scan_pos(lcrtc, &x, &y);
> +
> +	if (y > vactive_end)
> +		y = y - vfp_end - vactive_start;
> +	else
> +		y -= vactive_start;
> +
> +	*vpos = y;
> +	*hpos = x;
> +
> +	if (etime)
> +		*etime = ktime_get();
> +
> +	return true;
> +}
> +
> +static const struct drm_crtc_helper_funcs lsdc_crtc_helper_funcs = {
> +	.mode_valid = lsdc_crtc_mode_valid,
> +	.mode_set_nofb = lsdc_crtc_mode_set_nofb,
> +	.atomic_enable = lsdc_crtc_atomic_enable,
> +	.atomic_disable = lsdc_crtc_atomic_disable,
> +	.atomic_check = lsdc_crtc_helper_atomic_check,
> +	.atomic_flush = lsdc_crtc_atomic_flush,
> +	.get_scanout_position = lsdc_crtc_get_scanout_position,
> +};
> +
> +int ls7a1000_crtc_init(struct drm_device *ddev,
> +		       struct drm_crtc *crtc,
> +		       struct drm_plane *primary,
> +		       struct drm_plane *cursor,
> +		       unsigned int index)
> +{
> +	struct lsdc_crtc *lcrtc = to_lsdc_crtc(crtc);
> +	int ret;
> +
> +	ret = lsdc_pixpll_init(&lcrtc->pixpll, ddev, index);
> +	if (ret) {
> +		drm_err(ddev, "crtc init with pll failed: %d\n", ret);

"crtc pll init failed"?

> +		return ret;
> +	}
> +
> +	lcrtc->ldev = to_lsdc(ddev);
> +	lcrtc->hw_ops = &ls7a1000_crtc_hw_ops[index];
> +
> +	ret = drm_crtc_init_with_planes(ddev,
> +					crtc,
> +					primary,
> +					cursor,
> +					&ls7a1000_crtc_funcs,
> +					"CRTC-%d",
> +					index);
> +	if (ret) {
> +		drm_err(ddev, "crtc init with planes failed: %d\n", ret);
> +		return ret;
> +	}
> +
> +	drm_crtc_helper_add(crtc, &lsdc_crtc_helper_funcs);
> +
> +	ret = drm_mode_crtc_set_gamma_size(crtc, 256);
> +	if (ret)
> +		return ret;
> +
> +	drm_crtc_enable_color_mgmt(crtc, 0, false, 256);
> +
> +	return 0;
> +}
> +
> +int ls7a2000_crtc_init(struct drm_device *ddev,
> +		       struct drm_crtc *crtc,
> +		       struct drm_plane *primary,
> +		       struct drm_plane *cursor,
> +		       unsigned int index)
> +{
> +	struct lsdc_crtc *lcrtc = to_lsdc_crtc(crtc);
> +	int ret;
> +
> +	ret = lsdc_pixpll_init(&lcrtc->pixpll, ddev, index);
> +	if (ret) {
> +		drm_err(ddev, "crtc init with pll failed: %d\n", ret);
> +		return ret;
> +	}
> +
> +	lcrtc->ldev = to_lsdc(ddev);
> +	lcrtc->hw_ops = &ls7a2000_crtc_hw_ops[index];
> +
> +	ret = drm_crtc_init_with_planes(ddev,
> +					crtc,
> +					primary,
> +					cursor,
> +					&ls7a2000_crtc_funcs,
> +					"CRTC-%d",
> +					index);
> +	if (ret) {
> +		drm_err(ddev, "crtc init with planes failed: %d\n", ret);
> +		return ret;
> +	}
> +
> +	drm_crtc_helper_add(crtc, &lsdc_crtc_helper_funcs);
> +
> +	ret = drm_mode_crtc_set_gamma_size(crtc, 256);
> +	if (ret)
> +		return ret;
> +
> +	drm_crtc_enable_color_mgmt(crtc, 0, false, 256);
> +
> +	return 0;
> +}
> diff --git a/drivers/gpu/drm/loongson/lsdc_debugfs.c b/drivers/gpu/drm/loongson/lsdc_debugfs.c
> new file mode 100644
> index 000000000000..9ad2c5a0add2
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/lsdc_debugfs.c
> @@ -0,0 +1,91 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2023 Loongson Technology Corporation Limited
> + */
> +
> +#include <drm/drm_debugfs.h>
> +
> +#include "lsdc_benchmark.h"
> +#include "lsdc_drv.h"
> +#include "lsdc_gem.h"
> +#include "lsdc_probe.h"
> +#include "lsdc_ttm.h"
> +
> +/* device level debugfs */
> +
> +static int lsdc_identify(struct seq_file *m, void *arg)
> +{
> +	struct drm_info_node *node = (struct drm_info_node *)m->private;
> +	struct lsdc_device *ldev = (struct lsdc_device *)node->info_ent->data;
> +	const struct loongson_gfx_desc *gfx = to_loongson_gfx(ldev->descp);
> +	u8 impl, rev;
> +
> +	loongson_cpu_get_prid(&impl, &rev);
> +
> +	seq_printf(m, "Running on cpu 0x%x, cpu revision: 0x%x\n",
> +		   impl, rev);

Is this really needed/relevant for LSDC identification? AFAICS the 
loongson_cpu_get_prid helper has only one use (that's here), so if it's 
not absolutely necessary you can just get rid of that function and 
lsdc_probe.h altogether.

> +
> +	seq_printf(m, "Contained in: %s\n", gfx->model);

"model: " would be more appropriate for a piece of info looking like a 
"gfx->model"?

> +
> +	return 0;
> +}
> +
> +static int lsdc_show_mm(struct seq_file *m, void *arg)
> +{
> +	struct drm_info_node *node = (struct drm_info_node *)m->private;
> +	struct drm_device *ddev = node->minor->dev;
> +	struct drm_printer p = drm_seq_file_printer(m);
> +
> +	drm_mm_print(&ddev->vma_offset_manager->vm_addr_space_mm, &p);
> +
> +	return 0;
> +}
> +
> +static int lsdc_show_gfxpll_clock(struct seq_file *m, void *arg)
> +{
> +	struct drm_info_node *node = (struct drm_info_node *)m->private;
> +	struct lsdc_device *ldev = (struct lsdc_device *)node->info_ent->data;
> +	struct drm_printer printer = drm_seq_file_printer(m);
> +	struct loongson_gfxpll *gfxpll = ldev->gfxpll;
> +
> +	gfxpll->funcs->print(gfxpll, &printer, true);
> +
> +	return 0;
> +}
> +
> +static int lsdc_show_benchmark(struct seq_file *m, void *arg)
> +{
> +	struct drm_info_node *node = (struct drm_info_node *)m->private;
> +	struct lsdc_device *ldev = (struct lsdc_device *)node->info_ent->data;
> +	struct drm_printer printer = drm_seq_file_printer(m);
> +
> +	lsdc_show_benchmark_copy(ldev, &printer);
> +
> +	return 0;
> +}
> +
> +static struct drm_info_list lsdc_debugfs_list[] = {
> +	{ "chips",       lsdc_identify, 0, NULL },
> +	{ "clocks",      lsdc_show_gfxpll_clock, 0, NULL },
> +	{ "mm",          lsdc_show_mm, 0, NULL },
> +	{ "bos",         lsdc_show_buffer_object, 0, NULL },
> +	{ "benchmark",   lsdc_show_benchmark, 0, NULL },
> +};
> +
> +void lsdc_debugfs_init(struct drm_minor *minor)
> +{
> +	struct drm_device *ddev = minor->dev;
> +	struct lsdc_device *ldev = to_lsdc(ddev);
> +	unsigned int N = ARRAY_SIZE(lsdc_debugfs_list);

"n" because it's not a macro definition?

> +	unsigned int i;
> +
> +	for (i = 0; i < N; ++i)
> +		lsdc_debugfs_list[i].data = ldev;
> +
> +	drm_debugfs_create_files(lsdc_debugfs_list,
> +				 N,
> +				 minor->debugfs_root,
> +				 minor);
> +
> +	lsdc_ttm_debugfs_init(ldev);
> +}
> diff --git a/drivers/gpu/drm/loongson/lsdc_device.c b/drivers/gpu/drm/loongson/lsdc_device.c
> new file mode 100644
> index 000000000000..b4152f228beb
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/lsdc_device.c
> @@ -0,0 +1,104 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2023 Loongson Technology Corporation Limited
> + */
> +
> +#include <linux/pci.h>
> +
> +#include "lsdc_drv.h"
> +
> +static const struct lsdc_kms_funcs ls7a1000_kms_funcs = {
> +	.create_i2c = lsdc_create_i2c_chan,
> +	.irq_handler = ls7a1000_dc_irq_handler,
> +	.output_init = ls7a1000_output_init,
> +	.cursor_plane_init = ls7a1000_cursor_plane_init,
> +	.primary_plane_init = lsdc_primary_plane_init,
> +	.crtc_init = ls7a1000_crtc_init,
> +};
> +
> +static const struct lsdc_kms_funcs ls7a2000_kms_funcs = {
> +	.create_i2c = lsdc_create_i2c_chan,
> +	.irq_handler = ls7a2000_dc_irq_handler,
> +	.output_init = ls7a2000_output_init,
> +	.cursor_plane_init = ls7a2000_cursor_plane_init,
> +	.primary_plane_init = lsdc_primary_plane_init,
> +	.crtc_init = ls7a2000_crtc_init,
> +};
> +
> +static const struct loongson_gfx_desc ls7a1000_gfx = {
> +	.dc = {
> +		.num_of_crtc = 2,
> +		.max_pixel_clk = 200000,
> +		.max_width = 2048,
> +		.max_height = 2048,
> +		.num_of_hw_cursor = 1,
> +		.hw_cursor_w = 32,
> +		.hw_cursor_h = 32,
> +		.pitch_align = 256,
> +		.mc_bits = 40,
> +		.has_vblank_counter = false,
> +		.funcs = &ls7a1000_kms_funcs,
> +	},
> +	.conf_reg_base = LS7A1000_CONF_REG_BASE,
> +	.gfxpll = {
> +		.reg_offset = LS7A1000_PLL_GFX_REG,
> +		.reg_size = 8,
> +	},
> +	.pixpll = {
> +		[0] = {
> +			.reg_offset = LS7A1000_PIXPLL0_REG,
> +			.reg_size = 8,
> +		},
> +		[1] = {
> +			.reg_offset = LS7A1000_PIXPLL1_REG,
> +			.reg_size = 8,
> +		},
> +	},
> +	.chip_id = CHIP_LS7A1000,
> +	.model = "LS7A1000 bridge chipset",
> +};
> +
> +static const struct loongson_gfx_desc ls7a2000_gfx = {
> +	.dc = {
> +		.num_of_crtc = 2,
> +		.max_pixel_clk = 350000,
> +		.max_width = 4096,
> +		.max_height = 4096,
> +		.num_of_hw_cursor = 2,
> +		.hw_cursor_w = 64,
> +		.hw_cursor_h = 64,
> +		.pitch_align = 64,
> +		.mc_bits = 40, /* Support 48 but using 40 for backward compatibility */

For compatibility with what?

> +		.has_vblank_counter = true,
> +		.funcs = &ls7a2000_kms_funcs,
> +	},
> +	.conf_reg_base = LS7A2000_CONF_REG_BASE,
> +	.gfxpll = {
> +		.reg_offset = LS7A2000_PLL_GFX_REG,
> +		.reg_size = 8,
> +	},
> +	.pixpll = {
> +		[0] = {
> +			.reg_offset = LS7A2000_PIXPLL0_REG,
> +			.reg_size = 8,
> +		},
> +		[1] = {
> +			.reg_offset = LS7A2000_PIXPLL1_REG,
> +			.reg_size = 8,
> +		},
> +	},
> +	.chip_id = CHIP_LS7A2000,
> +	.model = "LS7A2000 bridge chipset",
> +};
> +
> +const struct lsdc_desc *
> +lsdc_device_probe(struct pci_dev *pdev, enum loongson_chip_id chip_id)
> +{
> +	if (chip_id == CHIP_LS7A1000)
> +		return &ls7a1000_gfx.dc;
> +
> +	if (chip_id == CHIP_LS7A2000)
> +		return &ls7a2000_gfx.dc;

I suppose more are to be added later, so better use a switch statement here.

> +
> +	return ERR_PTR(-ENODEV);
> +}
> diff --git a/drivers/gpu/drm/loongson/lsdc_drv.c b/drivers/gpu/drm/loongson/lsdc_drv.c
> new file mode 100644
> index 000000000000..98e2c28f886f
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/lsdc_drv.c
> @@ -0,0 +1,495 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2023 Loongson Technology Corporation Limited
> + */
> +
> +#include <linux/pci.h>
> +
> +#include <video/nomodeset.h>
> +
> +#include <drm/drm_aperture.h>
> +#include <drm/drm_atomic.h>
> +#include <drm/drm_atomic_helper.h>
> +#include <drm/drm_drv.h>
> +#include <drm/drm_fbdev_generic.h>
> +#include <drm/drm_gem_framebuffer_helper.h>
> +#include <drm/drm_ioctl.h>
> +#include <drm/drm_modeset_helper.h>
> +#include <drm/drm_probe_helper.h>
> +#include <drm/drm_vblank.h>
> +
> +#include "lsdc_drv.h"
> +#include "lsdc_gem.h"
> +#include "lsdc_i2c.h"
> +#include "lsdc_irq.h"
> +#include "lsdc_output.h"
> +#include "lsdc_probe.h"
> +#include "lsdc_ttm.h"
> +
> +#define DRIVER_AUTHOR           "Sui Jingfeng <suijingfeng@loongson.cn>"
> +#define DRIVER_NAME             "loongson"

I'd strongly suggest "loongson_drm" or some other name here. See the 
comment on the Kconfig change above.

> +#define DRIVER_DESC             "drm driver for loongson graphics"
> +#define DRIVER_DATE             "20220701"
> +#define DRIVER_MAJOR            1
> +#define DRIVER_MINOR            0
> +#define DRIVER_PATCHLEVEL       0
> +
> +DEFINE_DRM_GEM_FOPS(lsdc_gem_fops);
> +
> +static const struct drm_driver lsdc_drm_driver = {
> +	.driver_features = DRIVER_MODESET | DRIVER_RENDER | DRIVER_GEM | DRIVER_ATOMIC,
> +	.fops = &lsdc_gem_fops,
> +
> +	.name = DRIVER_NAME,
> +	.desc = DRIVER_DESC,
> +	.date = DRIVER_DATE,
> +	.major = DRIVER_MAJOR,
> +	.minor = DRIVER_MINOR,
> +	.patchlevel = DRIVER_PATCHLEVEL,
> +
> +	.debugfs_init = lsdc_debugfs_init,
> +	.dumb_create = lsdc_dumb_create,
> +	.dumb_map_offset = lsdc_dumb_map_offset,
> +	.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
> +	.prime_fd_to_handle = drm_gem_prime_fd_to_handle,
> +	.gem_prime_import_sg_table = lsdc_prime_import_sg_table,
> +	.gem_prime_mmap = drm_gem_prime_mmap,
> +};
> +
> +static const struct drm_mode_config_funcs lsdc_mode_config_funcs = {
> +	.fb_create = drm_gem_fb_create,
> +	.atomic_check = drm_atomic_helper_check,
> +	.atomic_commit = drm_atomic_helper_commit,
> +};
> +
> +/* Display related */
> +
> +static int lsdc_modeset_init(struct lsdc_device *ldev,
> +			     unsigned int num_crtc,
> +			     const struct lsdc_kms_funcs *funcs)
> +{
> +	struct drm_device *ddev = &ldev->base;
> +	struct lsdc_display_pipe *dispipe;
> +	unsigned int i;
> +	int ret;
> +
> +	for (i = 0; i < num_crtc; i++) {
> +		dispipe = &ldev->dispipe[i];
> +
> +		/* We need a index before crtc is initialized */

"an index"

> +		dispipe->index = i;
> +
> +		ret = funcs->create_i2c(ddev, dispipe, i);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	for (i = 0; i < num_crtc; i++) {
> +		struct i2c_adapter *ddc = NULL;
> +
> +		dispipe = &ldev->dispipe[i];
> +		if (dispipe->li2c)
> +			ddc = &dispipe->li2c->adapter;
> +
> +		ret = funcs->output_init(ddev, dispipe, ddc, i);
> +		if (ret)
> +			return ret;
> +
> +		ldev->num_output++;
> +	}
> +
> +	for (i = 0; i < num_crtc; i++) {
> +		dispipe = &ldev->dispipe[i];
> +
> +		ret = funcs->primary_plane_init(ddev, &dispipe->primary.base, i);
> +		if (ret)
> +			return ret;
> +
> +		ret = funcs->cursor_plane_init(ddev, &dispipe->cursor.base, i);
> +		if (ret)
> +			return ret;
> +
> +		ret = funcs->crtc_init(ddev,
> +				       &dispipe->crtc.base,
> +				       &dispipe->primary.base,
> +				       &dispipe->cursor.base,
> +				       i);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	drm_info(ddev, "total %u outputs\n", ldev->num_output);
> +
> +	return 0;
> +}
> +
> +static const struct drm_mode_config_helper_funcs
> +lsdc_mode_config_helper_funcs = {
> +	.atomic_commit_tail = drm_atomic_helper_commit_tail,
> +};
> +
> +static int lsdc_mode_config_init(struct drm_device *ddev,
> +				 const struct lsdc_desc *descp)
> +{
> +	int ret;
> +
> +	ret = drmm_mode_config_init(ddev);
> +	if (ret)
> +		return ret;
> +
> +	ddev->mode_config.funcs = &lsdc_mode_config_funcs;
> +	ddev->mode_config.min_width = 1;
> +	ddev->mode_config.min_height = 1;
> +	ddev->mode_config.max_width = descp->max_width * LSDC_NUM_CRTC;
> +	ddev->mode_config.max_height = descp->max_height * LSDC_NUM_CRTC;
> +	ddev->mode_config.preferred_depth = 24;
> +	ddev->mode_config.prefer_shadow = 1;
> +
> +	ddev->mode_config.cursor_width = descp->hw_cursor_h;
> +	ddev->mode_config.cursor_height = descp->hw_cursor_h;
> +
> +	/* Indicates support for immediate flip */
> +	ddev->mode_config.async_page_flip = true;
> +
> +	ddev->mode_config.helper_private = &lsdc_mode_config_helper_funcs;
> +
> +	if (descp->has_vblank_counter)
> +		ddev->max_vblank_count = 0xffffffff;
> +
> +	return ret;
> +}
> +
> +/*
> + * The GPU and display controller in LS7A1000/LS7A2000 are separated
> + * PCIE devices, they are two devices not one. The DC does not has a

"does not have"

> + * dedicate VRAM bar, because the BIOS engineer choose to assign the

"the firmware people chose to"

> + * VRAM to the GPU device. Sadly, after years application, this form
> + * as a convention for loongson integrated graphics. Bar 2 of the GPU

"this became a convention for Loongson integrated graphics years after"

<rant>Seriously, you *could* change something now, it's 2023 and 
LoongArch is already a thing after all so you're no longer constrained 
by anything else...</rant>

> + * device contain the base address and size of the VRAM, both the GPU
> + * and the DC can access the on-board VRAM as long as the DMA address
> + * emitted fall in [base, base + size).

"the DMA address falls in"? Not very sure what "emitted" is about.

> + */
> +static int lsdc_get_dedicated_vram(struct lsdc_device *ldev,
> +				   struct pci_dev *pdev_dc,
> +				   const struct lsdc_desc *descp)
> +{
> +	struct drm_device *ddev = &ldev->base;
> +	struct pci_dev *pdev_gpu;
> +	resource_size_t base, size;
> +
> +	/*
> +	 * The GPU has 00:06.0 as its BDF, while the DC has 00:06.1,
> +	 * This is sure for LS7A1000, LS7A2000 and LS2K2000.
> +	 */
> +	pdev_gpu = pci_get_domain_bus_and_slot(pci_domain_nr(pdev_dc->bus),
> +					       pdev_dc->bus->number,
> +					       PCI_DEVFN(6, 0));
> +	if (!pdev_gpu) {
> +		drm_err(ddev, "No GPU device, then no VRAM\n");
> +		return -ENODEV;
> +	}
> +
> +	base = pci_resource_start(pdev_gpu, 2);
> +	size = pci_resource_len(pdev_gpu, 2);
> +
> +	ldev->vram_base = base;
> +	ldev->vram_size = size;
> +	ldev->gpu = pdev_gpu;
> +
> +	drm_info(ddev, "dedicated vram start: 0x%llx, size: %uMB\n",
> +		 (u64)base, (u32)(size >> 20));
> +
> +	return 0;
> +}
> +
> +static struct lsdc_device *
> +lsdc_create_device(struct pci_dev *pdev,
> +		   const struct lsdc_desc *descp,
> +		   const struct drm_driver *drv)
> +{
> +	struct lsdc_device *ldev;
> +	struct drm_device *ddev;
> +	int ret;
> +
> +	ldev = devm_drm_dev_alloc(&pdev->dev, drv, struct lsdc_device, base);
> +	if (IS_ERR(ldev))
> +		return ldev;
> +
> +	ddev = &ldev->base;
> +
> +	ldev->descp = descp;
> +
> +	loongson_gfxpll_create(ddev, &ldev->gfxpll);
> +
> +	ret = lsdc_get_dedicated_vram(ldev, pdev, descp);
> +	if (ret) {
> +		drm_err(ddev, "Init VRAM failed: %d\n", ret);

"VRAM init failed"

> +		return ERR_PTR(ret);
> +	}
> +
> +	ret = drm_aperture_remove_conflicting_framebuffers(ldev->vram_base,
> +							   ldev->vram_size,
> +							   drv);
> +	if (ret) {
> +		drm_err(ddev, "remove firmware framebuffers failed: %d\n", ret);
> +		return ERR_PTR(ret);
> +	}
> +
> +	ret = lsdc_ttm_init(ldev);
> +	if (ret) {
> +		drm_err(ddev, "memory manager init failed: %d\n", ret);
> +		return ERR_PTR(ret);
> +	}
> +
> +	lsdc_gem_init(ddev);
> +
> +	/* BAR 0 of the DC device contain registers base address */

"contains"

> +	ldev->reg_base = pcim_iomap(pdev, 0, 0);
> +	if (!ldev->reg_base)
> +		return ERR_PTR(-ENODEV);
> +
> +	spin_lock_init(&ldev->reglock);
> +
> +	ret = lsdc_mode_config_init(ddev, descp);
> +	if (ret)
> +		return ERR_PTR(ret);
> +
> +	ret = lsdc_modeset_init(ldev, descp->num_of_crtc, descp->funcs);
> +	if (ret)
> +		return ERR_PTR(ret);
> +
> +	drm_mode_config_reset(ddev);
> +
> +	ret = drm_vblank_init(ddev, descp->num_of_crtc);
> +	if (ret)
> +		return ERR_PTR(ret);
> +
> +	drm_kms_helper_poll_init(ddev);
> +
> +	return ldev;
> +}
> +
> +static int lsdc_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
> +{
> +	const struct lsdc_desc *descp;
> +	struct drm_device *ddev;
> +	struct lsdc_device *ldev;
> +	int ret;
> +
> +	ret = pcim_enable_device(pdev);
> +	if (ret)
> +		return ret;
> +
> +	pci_set_master(pdev);
> +
> +	ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(40));
> +	if (ret)
> +		return ret;
> +
> +	descp = lsdc_device_probe(pdev, ent->driver_data);
> +	if (IS_ERR_OR_NULL(descp))
> +		return -ENODEV;
> +
> +	dev_info(&pdev->dev, "Found %s, revision: %u",
> +		 to_loongson_gfx(descp)->model, pdev->revision);
> +
> +	ldev = lsdc_create_device(pdev, descp, &lsdc_drm_driver);
> +	if (IS_ERR(ldev))
> +		return PTR_ERR(ldev);
> +
> +	ldev->dc = pdev;
> +
> +	ddev = &ldev->base;
> +
> +	pci_set_drvdata(pdev, ddev);
> +
> +	ret = devm_request_irq(&pdev->dev,
> +			       pdev->irq,
> +			       descp->funcs->irq_handler,
> +			       IRQF_SHARED,
> +			       dev_name(&pdev->dev),
> +			       ddev);
> +	if (ret) {
> +		drm_err(ddev, "Failed to register interrupt: %d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = drm_dev_register(ddev, 0);
> +	if (ret)
> +		return ret;
> +
> +	drm_fbdev_generic_setup(ddev, 32);
> +
> +	return 0;
> +}
> +
> +static void lsdc_pci_remove(struct pci_dev *pdev)
> +{
> +	struct drm_device *ddev = pci_get_drvdata(pdev);
> +
> +	drm_dev_unregister(ddev);
> +	drm_atomic_helper_shutdown(ddev);
> +}
> +
> +static int lsdc_drm_freeze(struct drm_device *ddev)
> +{
> +	struct lsdc_device *ldev = to_lsdc(ddev);
> +	struct lsdc_bo *lbo;
> +	int ret;
> +
> +	/* unpin all of buffers in the vram */
> +	mutex_lock(&ldev->gem.mutex);
> +	list_for_each_entry(lbo, &ldev->gem.objects, list) {
> +		struct ttm_buffer_object *tbo = &lbo->tbo;
> +		struct ttm_resource *resource = tbo->resource;
> +		unsigned int pin_count = tbo->pin_count;
> +
> +		drm_dbg(ddev,
> +			"bo[%p], size: %zuKB, type: %s, pin count: %u\n",

"KiB" for extra clarity?

> +			lbo,
> +			lsdc_bo_size(lbo) >> 10,
> +			lsdc_mem_type_to_str(resource->mem_type),
> +			pin_count);
> +
> +		if (!pin_count)
> +			continue;
> +
> +		if (resource->mem_type == TTM_PL_VRAM) {
> +			ret = lsdc_bo_reserve(lbo);
> +			if (unlikely(ret)) {
> +				drm_err(ddev, "bo reserve failed: %d\n", ret);
> +				continue;
> +			}
> +
> +			/*
> +			 * For double screen usage case, multiple crtc may

"For double screen case, multiple crtcs may reference the single ..."

> +			 * reference to the single giant framebuffer bo.
> +			 * The single giant fb bo get pinned by multiple time.
> +			 * thus, it need to unpin until its pin counter reach
> +			 * zero.

"The single giant fb bo is pinned multiple times, hence it needs to be 
unpinned until ..."

> +			 */
> +			do {
> +				lsdc_bo_unpin(lbo);
> +				--pin_count;
> +			} while (pin_count);
> +
> +			lsdc_bo_unreserve(lbo);
> +		}
> +	}
> +	mutex_unlock(&ldev->gem.mutex);
> +
> +	lsdc_bo_evict_vram(ddev);
> +
> +	ret = drm_mode_config_helper_suspend(ddev);
> +	if (unlikely(ret)) {
> +		drm_err(ddev, "freeze error: %d", ret);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int lsdc_drm_resume(struct device *dev)
> +{
> +	struct pci_dev *pdev = to_pci_dev(dev);
> +	struct drm_device *ddev = pci_get_drvdata(pdev);
> +
> +	return drm_mode_config_helper_resume(ddev);
> +}
> +
> +static int lsdc_pm_freeze(struct device *dev)
> +{
> +	struct pci_dev *pdev = to_pci_dev(dev);
> +	struct drm_device *ddev = pci_get_drvdata(pdev);
> +
> +	return lsdc_drm_freeze(ddev);
> +}
> +
> +static int lsdc_pm_thaw(struct device *dev)
> +{
> +	return lsdc_drm_resume(dev);
> +}
> +
> +static int lsdc_pm_suspend(struct device *dev)
> +{
> +	struct pci_dev *pdev = to_pci_dev(dev);
> +	int error;
> +
> +	error = lsdc_pm_freeze(dev);
> +	if (error)
> +		return error;
> +
> +	pci_save_state(pdev);
> +	/* Shut down the device */
> +	pci_disable_device(pdev);
> +	pci_set_power_state(pdev, PCI_D3hot);
> +
> +	return 0;
> +}
> +
> +static int lsdc_pm_resume(struct device *dev)
> +{
> +	struct pci_dev *pdev = to_pci_dev(dev);
> +
> +	pci_set_power_state(pdev, PCI_D0);
> +
> +	pci_restore_state(pdev);
> +
> +	if (pcim_enable_device(pdev))
> +		return -EIO;
> +
> +	return lsdc_pm_thaw(dev);
> +}
> +
> +static const struct dev_pm_ops lsdc_pm_ops = {
> +	.suspend = lsdc_pm_suspend,
> +	.resume = lsdc_pm_resume,
> +	.freeze = lsdc_pm_freeze,
> +	.thaw = lsdc_pm_thaw,
> +	.poweroff = lsdc_pm_freeze,
> +	.restore = lsdc_pm_resume,
> +};
> +
> +static const struct pci_device_id lsdc_pciid_list[] = {
> +	{PCI_VENDOR_ID_LOONGSON, 0x7a06, PCI_ANY_ID, PCI_ANY_ID, 0, 0, CHIP_LS7A1000},
> +	{PCI_VENDOR_ID_LOONGSON, 0x7a36, PCI_ANY_ID, PCI_ANY_ID, 0, 0, CHIP_LS7A2000},
> +	{0, 0, 0, 0, 0, 0, 0}
> +};
> +
> +static struct pci_driver lsdc_pci_driver = {
> +	.name = DRIVER_NAME,
> +	.id_table = lsdc_pciid_list,
> +	.probe = lsdc_pci_probe,
> +	.remove = lsdc_pci_remove,
> +	.driver.pm = &lsdc_pm_ops,
> +};
> +
> +static int __init loongson_module_init(void)
> +{
> +	struct pci_dev *pdev = NULL;
> +
> +	if (video_firmware_drivers_only())
> +		return -ENODEV;
> +
> +	/* Multiple video card workaround */
> +	while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev))) {
> +		if (pdev->vendor != PCI_VENDOR_ID_LOONGSON) {
> +			pr_info("Discrete graphic card detected, abort\n");

Why is it that the iGPU cannot be used together with a dGPU? I can't see 
why this is technically the case so some more explanations could be 
beneficial to other readers and LoongArch devs.

> +			return 0;
> +		}
> +	}
> +
> +	return pci_register_driver(&lsdc_pci_driver);
> +}
> +module_init(loongson_module_init);
> +
> +static void __exit loongson_module_exit(void)
> +{
> +	pci_unregister_driver(&lsdc_pci_driver);
> +}
> +module_exit(loongson_module_exit);
> +
> +MODULE_DEVICE_TABLE(pci, lsdc_pciid_list);
> +MODULE_AUTHOR(DRIVER_AUTHOR);
> +MODULE_DESCRIPTION(DRIVER_DESC);
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/gpu/drm/loongson/lsdc_drv.h b/drivers/gpu/drm/loongson/lsdc_drv.h
> new file mode 100644
> index 000000000000..25636787191f
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/lsdc_drv.h
> @@ -0,0 +1,451 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2023 Loongson Technology Corporation Limited
> + */
> +
> +#ifndef __LSDC_DRV_H__
> +#define __LSDC_DRV_H__
> +
> +#include <linux/pci.h>
> +
> +#include <drm/drm_connector.h>
> +#include <drm/drm_crtc.h>
> +#include <drm/drm_device.h>
> +#include <drm/drm_encoder.h>
> +#include <drm/drm_file.h>
> +#include <drm/drm_plane.h>
> +#include <drm/ttm/ttm_device.h>
> +
> +#include "lsdc_i2c.h"
> +#include "lsdc_irq.h"
> +#include "lsdc_gfxpll.h"
> +#include "lsdc_output.h"
> +#include "lsdc_pixpll.h"
> +#include "lsdc_regs.h"
> +
> +/* Currently, all loongson display controller has two display pipes */

"... controllers have ..."

> +#define LSDC_NUM_CRTC           2
> +
> +/*
> + * LS7A1000/LS7A2000 bridge chipset function as south & north of the Loongson

"south & north bridges"

> + * LS3A4000/LS3A5000/LS3A6000 CPU, they are equipped with on-board video RAM
> + * typically. While LS2K0500/LS2K1000/LS2K2000 are low cost SoCs which share
> + * the system RAM as video RAM, they don't has a dediacated VRAM.

CPU models are not typically prefixed with "LS", so "Loongson 
3A4000/3A5000/3A6000".

Also the description about the Loongson 2K series is a bit irrelevant 
(we're focusing on VRAM here) so you could simplify the sentence a bit.

> + *
> + * LS7A2000 integrated a 32-bit DDR4@2400 video memtory controller, while

"integrates a 32-bit DDR4-2400 video memory controller"

Maybe you can spell-check your code before submitting... it's getting 
tiresome pointing out every misspelling and unnatural English usage. I'm 
not doing so for the rest of my review.

> + * it is just 16-bit DDR3 for LS7A1000. LS7A2000 integrate Loongson self
> + * maded LoongGPU, LS7A1000 integrate GC1000 due to historical reasons.
> + *
> + * The display controller in LS7A1000 has only two-way DVO interface exported,
> + * thus, external encoder(TX chip) is required except connected with DPI panel
> + * directly.
> + *       ___________________                                     _________
> + *      |            -------|                                   |         |
> + *      |  CRTC0 --> | DVO0 ----> Encoder0 ---> Connector0 ---> | Display |
> + *      |  _   _     -------|        ^             ^            |_________|
> + *      | | | | |  +------+ |        |             |
> + *      | |_| |_|  | i2c6 | <--------+-------------+
> + *      |          +------+ |
> + *      |                   |
> + *      |  DC in LS7A1000   |
> + *      |                   |
> + *      |  _   _   +------+ |
> + *      | | | | |  | i2c7 | <--------+-------------+
> + *      | |_| |_|  +------+ |        |             |             _________
> + *      |            -------|        |             |            |         |
> + *      |  CRTC1 --> | DVO1 ----> Encoder1 ---> Connector1 ---> |  Panel  |
> + *      |            -------|                                   |_________|
> + *      |___________________|
> + *
> + * The display controller in LS7A2000 has two display pipe, yet it has
> + * integrated three encoders, display pipe 0 is attached with a transparent
> + * VGA encoder and a HDMI encoder, they are parallel. Display pipe 1 has
> + * only one HDMI phy connected.
> + *
> + *       ______________________                          _____________
> + *      |             +-----+  |                        |             |
> + *      | CRTC0 -+--> | VGA |  ----> VGA Connector ---> | VGA Monitor |<---+
> + *      |        |    +-----+  |                        |_____________|    |
> + *      |        |             |                         ______________    |
> + *      |        |    +------+ |                        |              |   |
> + *      |        +--> | HDMI | ----> HDMI Connector --> | HDMI Monitor |<--+
> + *      |             +------+ |                        |______________|   |
> + *      |            +------+  |                                           |
> + *      |            | i2c6 |  <-------------------------------------------+
> + *      |            +------+  |
> + *      |                      |
> + *      |    DC in LS7A2000    |
> + *      |                      |
> + *      |            +------+  |
> + *      |            | i2c7 |  <--------------------------------+
> + *      |            +------+  |                                |
> + *      |                      |                          ______|_______
> + *      |            +------+  |                         |              |
> + *      | CRTC1 ---> | HDMI |  ----> HDMI Connector ---> | HDMI Monitor |
> + *      |            +------+  |                         |______________|
> + *      |______________________|
> + *
> + *
> + * There is only a 1:1 mapping of crtcs, encoders and connectors for the DC,
> + * display pipe 0 = crtc0 + dvo0 + encoder0 + connector0 + cursor0 + primary0
> + * display pipe 1 = crtc1 + dvo1 + encoder1 + connectro1 + cursor1 + primary1
> + * Each CRTC has two FB address registers.
> + *
> + * The DC in LS7A1000/LS2K1000 has the pci vendor/device ID: 0x0014:0x7a06,
> + * The DC in LS7A2000/LS2K2000 has the pci vendor/device ID: 0x0014:0x7a36.
> + *
> + * The GPU in LS7A1000 has the pci vendor/device ID: 0x0014:0x7a15,
> + * The GPU in LS7A2000 has the pci vendor/device ID: 0x0014:0x7a25.
> + *
> + * LS7A1000/LS7A2000 can only be used with desktop or server class CPUs, such
> + * as LS3A4000, LS3A5000 and LS3A6000. Thus, CPU PRID can be used to
> + * distinguish Loongson SoC from those the desktop class CPU on the runtime.
> + */
> +enum loongson_chip_id {
> +	CHIP_LS7A1000 = 0,
> +	CHIP_LS7A2000 = 1,
> +	CHIP_LS_LAST,
> +};
> +
> +const struct lsdc_desc *
> +lsdc_device_probe(struct pci_dev *pdev, enum loongson_chip_id chip);
> +
> +struct lsdc_kms_funcs;
> +
> +/* DC specific */
> +
> +struct lsdc_desc {
> +	u32 num_of_crtc;
> +	u32 max_pixel_clk;
> +	u32 max_width;
> +	u32 max_height;
> +	u32 num_of_hw_cursor;
> +	u32 hw_cursor_w;
> +	u32 hw_cursor_h;
> +	u32 pitch_align;         /* CRTC DMA alignment constraint */
> +	u64 mc_bits;             /* physical address bus bit width */
> +	bool has_vblank_counter; /* 32 bit hw vsync counter */
> +
> +	/* device dependent ops, dc side */
> +	const struct lsdc_kms_funcs *funcs;
> +};
> +
> +/* GFX related resources wrangler */
> +
> +struct loongson_gfx_desc {
> +	struct lsdc_desc dc;
> +
> +	u32 conf_reg_base;
> +
> +	/* GFXPLL shared by the DC, GMC and GPU */
> +	struct {
> +		u32 reg_offset;
> +		u32 reg_size;
> +	} gfxpll;
> +
> +	/* Pixel PLL, per display pipe */
> +	struct {
> +		u32 reg_offset;
> +		u32 reg_size;
> +	} pixpll[LSDC_NUM_CRTC];
> +
> +	enum loongson_chip_id chip_id;
> +	char model[64];
> +};
> +
> +static inline const struct loongson_gfx_desc *
> +to_loongson_gfx(const struct lsdc_desc *dcp)
> +{
> +	return container_of_const(dcp, struct loongson_gfx_desc, dc);
> +};
> +
> +struct lsdc_reg32 {
> +	char *name;
> +	u32 offset;
> +};
> +
> +/* crtc hardware related ops */
> +
> +struct lsdc_crtc;
> +
> +struct lsdc_crtc_hw_ops {
> +	void (*enable)(struct lsdc_crtc *lcrtc);
> +	void (*disable)(struct lsdc_crtc *lcrtc);
> +	void (*enable_vblank)(struct lsdc_crtc *lcrtc);
> +	void (*disable_vblank)(struct lsdc_crtc *lcrtc);
> +	void (*flip)(struct lsdc_crtc *lcrtc);
> +	void (*clone)(struct lsdc_crtc *lcrtc);
> +	void (*get_scan_pos)(struct lsdc_crtc *lcrtc, int *hpos, int *vpos);
> +	void (*set_mode)(struct lsdc_crtc *lcrtc, const struct drm_display_mode *mode);
> +	void (*soft_reset)(struct lsdc_crtc *lcrtc);
> +	void (*reset)(struct lsdc_crtc *lcrtc);
> +
> +	u32  (*get_vblank_counter)(struct lsdc_crtc *lcrtc);
> +	void (*set_dma_step)(struct lsdc_crtc *lcrtc, enum lsdc_dma_steps step);
> +};
> +
> +struct lsdc_crtc {
> +	struct drm_crtc base;
> +	struct lsdc_pixpll pixpll;
> +	struct lsdc_device *ldev;
> +	const struct lsdc_crtc_hw_ops *hw_ops;
> +	const struct lsdc_reg32 *preg;
> +	unsigned int nreg;
> +	struct drm_info_list *p_info_list;
> +	unsigned int n_info_list;
> +};
> +
> +/* primary plane hardware related ops */
> +
> +struct lsdc_primary;
> +
> +struct lsdc_primary_plane_ops {
> +	void (*update_fb_addr)(struct lsdc_primary *plane, u64 addr);
> +	void (*update_fb_stride)(struct lsdc_primary *plane, u32 stride);
> +	void (*update_fb_format)(struct lsdc_primary *plane,
> +				 const struct drm_format_info *format);
> +};
> +
> +struct lsdc_primary {
> +	struct drm_plane base;
> +	const struct lsdc_primary_plane_ops *ops;
> +	struct lsdc_device *ldev;
> +};
> +
> +/* cursor plane hardware related ops */
> +
> +struct lsdc_cursor;
> +
> +struct lsdc_cursor_plane_ops {
> +	void (*update_bo_addr)(struct lsdc_cursor *plane, u64 addr);
> +	void (*update_cfg)(struct lsdc_cursor *plane,
> +			   enum lsdc_cursor_size cursor_size,
> +			   enum lsdc_cursor_format);
> +	void (*update_position)(struct lsdc_cursor *plane, int x, int y);
> +};
> +
> +struct lsdc_cursor {
> +	struct drm_plane base;
> +	const struct lsdc_cursor_plane_ops *ops;
> +	struct lsdc_device *ldev;
> +};
> +
> +struct lsdc_output {
> +	struct drm_encoder encoder;
> +	struct drm_connector connector;
> +};
> +
> +static inline struct lsdc_output *
> +connector_to_lsdc_output(struct drm_connector *connector)
> +{
> +	return container_of(connector, struct lsdc_output, connector);
> +}
> +
> +static inline struct lsdc_output *
> +encoder_to_lsdc_output(struct drm_encoder *encoder)
> +{
> +	return container_of(encoder, struct lsdc_output, encoder);
> +}
> +
> +struct lsdc_display_pipe {
> +	struct lsdc_crtc crtc;
> +	struct lsdc_primary primary;
> +	struct lsdc_cursor cursor;
> +	struct lsdc_output output;
> +	struct lsdc_i2c *li2c;
> +	unsigned int index;
> +};
> +
> +static inline struct lsdc_display_pipe *
> +output_to_display_pipe(struct lsdc_output *output)
> +{
> +	return container_of(output, struct lsdc_display_pipe, output);
> +}
> +
> +struct lsdc_kms_funcs {
> +	irqreturn_t (*irq_handler)(int irq, void *arg);
> +
> +	int (*create_i2c)(struct drm_device *ddev,
> +			  struct lsdc_display_pipe *dispipe,
> +			  unsigned int index);
> +
> +	int (*output_init)(struct drm_device *ddev,
> +			   struct lsdc_display_pipe *dispipe,
> +			   struct i2c_adapter *ddc,
> +			   unsigned int index);
> +
> +	int (*cursor_plane_init)(struct drm_device *ddev,
> +				 struct drm_plane *plane,
> +				 unsigned int index);
> +
> +	int (*primary_plane_init)(struct drm_device *ddev,
> +				  struct drm_plane *plane,
> +				  unsigned int index);
> +
> +	int (*crtc_init)(struct drm_device *ddev,
> +			 struct drm_crtc *crtc,
> +			 struct drm_plane *primary,
> +			 struct drm_plane *cursor,
> +			 unsigned int index);
> +};
> +
> +static inline struct lsdc_crtc *
> +to_lsdc_crtc(struct drm_crtc *crtc)
> +{
> +	return container_of(crtc, struct lsdc_crtc, base);
> +}
> +
> +static inline struct lsdc_display_pipe *
> +crtc_to_display_pipe(struct drm_crtc *crtc)
> +{
> +	return container_of(crtc, struct lsdc_display_pipe, crtc.base);
> +}
> +
> +static inline struct lsdc_primary *
> +to_lsdc_primary(struct drm_plane *plane)
> +{
> +	return container_of(plane, struct lsdc_primary, base);
> +}
> +
> +static inline struct lsdc_cursor *
> +to_lsdc_cursor(struct drm_plane *plane)
> +{
> +	return container_of(plane, struct lsdc_cursor, base);
> +}
> +
> +struct lsdc_crtc_state {
> +	struct drm_crtc_state base;
> +	struct lsdc_pixpll_parms pparms;
> +};
> +
> +struct lsdc_gem {
> +	/* @mutex: protect objects list */
> +	struct mutex mutex;
> +	struct list_head objects;
> +};
> +
> +struct lsdc_device {
> +	struct drm_device base;
> +	struct ttm_device bdev;
> +
> +	/* @descp: features description of the DC variant */
> +	const struct lsdc_desc *descp;
> +	struct pci_dev *dc;
> +	struct pci_dev *gpu;
> +
> +	struct loongson_gfxpll *gfxpll;
> +
> +	/* @reglock: protects concurrent access */
> +	spinlock_t reglock;
> +
> +	void __iomem *reg_base;
> +	resource_size_t vram_base;
> +	resource_size_t vram_size;
> +
> +	resource_size_t gtt_base;
> +	resource_size_t gtt_size;
> +
> +	struct lsdc_display_pipe dispipe[LSDC_NUM_CRTC];
> +
> +	struct lsdc_gem gem;
> +
> +	u32 irq_status;
> +
> +	/* tracking pinned memory */
> +	size_t vram_pinned_size;
> +	size_t gtt_pinned_size;
> +
> +	/* @num_output: count the number of active display pipe */
> +	unsigned int num_output;
> +};
> +
> +static inline struct lsdc_device *tdev_to_ldev(struct ttm_device *bdev)
> +{
> +	return container_of(bdev, struct lsdc_device, bdev);
> +}
> +
> +static inline struct lsdc_device *to_lsdc(struct drm_device *ddev)
> +{
> +	return container_of(ddev, struct lsdc_device, base);
> +}
> +
> +static inline struct lsdc_crtc_state *
> +to_lsdc_crtc_state(struct drm_crtc_state *base)
> +{
> +	return container_of(base, struct lsdc_crtc_state, base);
> +}
> +
> +void lsdc_debugfs_init(struct drm_minor *minor);
> +
> +int ls7a1000_crtc_init(struct drm_device *ddev,
> +		       struct drm_crtc *crtc,
> +		       struct drm_plane *primary,
> +		       struct drm_plane *cursor,
> +		       unsigned int index);
> +
> +int ls7a2000_crtc_init(struct drm_device *ddev,
> +		       struct drm_crtc *crtc,
> +		       struct drm_plane *primary,
> +		       struct drm_plane *cursor,
> +		       unsigned int index);
> +
> +int lsdc_primary_plane_init(struct drm_device *ddev,
> +			    struct drm_plane *plane,
> +			    unsigned int index);
> +
> +int ls7a1000_cursor_plane_init(struct drm_device *ddev,
> +			       struct drm_plane *plane,
> +			       unsigned int index);
> +
> +int ls7a2000_cursor_plane_init(struct drm_device *ddev,
> +			       struct drm_plane *plane,
> +			       unsigned int index);
> +
> +/* registers access helpers */
> +
> +static inline u32 lsdc_rreg32(struct lsdc_device *ldev, u32 offset)
> +{
> +	return readl(ldev->reg_base + offset);
> +}
> +
> +static inline void lsdc_wreg32(struct lsdc_device *ldev, u32 offset, u32 val)
> +{
> +	writel(val, ldev->reg_base + offset);
> +}
> +
> +static inline void lsdc_ureg32_set(struct lsdc_device *ldev,
> +				   u32 offset,
> +				   u32 mask)
> +{
> +	void __iomem *addr = ldev->reg_base + offset;
> +	u32 val = readl(addr);
> +
> +	writel(val | mask, addr);
> +}
> +
> +static inline void lsdc_ureg32_clr(struct lsdc_device *ldev,
> +				   u32 offset,
> +				   u32 mask)
> +{
> +	void __iomem *addr = ldev->reg_base + offset;
> +	u32 val = readl(addr);
> +
> +	writel(val & ~mask, addr);
> +}
> +
> +static inline u32 lsdc_pipe_rreg32(struct lsdc_device *ldev,
> +				   u32 offset,
> +				   u32 pipe)
> +{
> +	return readl(ldev->reg_base + offset + pipe * CRTC_PIPE_OFFSET);
> +}
> +
> +static inline void lsdc_pipe_wreg32(struct lsdc_device *ldev,
> +				    u32 offset,
> +				    u32 pipe,
> +				    u32 val)
> +{
> +	writel(val, ldev->reg_base + offset + pipe * CRTC_PIPE_OFFSET);
> +}
> +
> +#endif
> diff --git a/drivers/gpu/drm/loongson/lsdc_gem.c b/drivers/gpu/drm/loongson/lsdc_gem.c
> new file mode 100644
> index 000000000000..f21942b2a3b8
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/lsdc_gem.c
> @@ -0,0 +1,324 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2023 Loongson Technology Corporation Limited
> + */
> +
> +#include <linux/dma-buf.h>
> +
> +#include <drm/drm_debugfs.h>
> +#include <drm/drm_file.h>
> +#include <drm/drm_gem.h>
> +#include <drm/drm_prime.h>
> +
> +#include "lsdc_drv.h"
> +#include "lsdc_gem.h"
> +#include "lsdc_ttm.h"
> +
> +static int lsdc_gem_prime_pin(struct drm_gem_object *obj)
> +{
> +	struct lsdc_bo *lbo = gem_to_lsdc_bo(obj);
> +	int ret;
> +
> +	ret = lsdc_bo_reserve(lbo);
> +	if (unlikely(ret))
> +		return ret;
> +
> +	ret = lsdc_bo_pin(lbo, LSDC_GEM_DOMAIN_GTT, NULL);
> +	if (likely(ret == 0))
> +		lbo->sharing_count++;
> +
> +	lsdc_bo_unreserve(lbo);
> +
> +	return ret;
> +}
> +
> +static void lsdc_gem_prime_unpin(struct drm_gem_object *obj)
> +{
> +	struct lsdc_bo *lbo = gem_to_lsdc_bo(obj);
> +	int ret;
> +
> +	ret = lsdc_bo_reserve(lbo);
> +	if (unlikely(ret))
> +		return;
> +
> +	lsdc_bo_unpin(lbo);
> +	if (lbo->sharing_count)
> +		lbo->sharing_count--;
> +
> +	lsdc_bo_unreserve(lbo);
> +}
> +
> +static struct sg_table *lsdc_gem_prime_get_sg_table(struct drm_gem_object *obj)
> +{
> +	struct ttm_buffer_object *tbo = to_ttm_bo(obj);
> +	struct ttm_tt *tt = tbo->ttm;
> +
> +	if (!tt) {
> +		drm_err(obj->dev, "sharing a buffer without backing memory\n");
> +		return ERR_PTR(-ENOMEM);
> +	}
> +
> +	return drm_prime_pages_to_sg(obj->dev, tt->pages, tt->num_pages);
> +}
> +
> +static void lsdc_gem_object_free(struct drm_gem_object *obj)
> +{
> +	struct ttm_buffer_object *tbo = to_ttm_bo(obj);
> +
> +	if (tbo)
> +		ttm_bo_put(tbo);
> +}
> +
> +static int lsdc_gem_object_vmap(struct drm_gem_object *obj,
> +				struct iosys_map *map)
> +{
> +	struct ttm_buffer_object *tbo = to_ttm_bo(obj);
> +	struct lsdc_bo *lbo = to_lsdc_bo(tbo);
> +	int ret;
> +
> +	if (lbo->vmap_count > 0) {
> +		++lbo->vmap_count;
> +		goto out;
> +	}
> +
> +	ret = lsdc_bo_pin(lbo, 0, NULL);
> +	if (unlikely(ret)) {
> +		drm_err(obj->dev, "pin %p for vmap failed\n", lbo);
> +		return ret;
> +	}
> +
> +	ret = ttm_bo_vmap(tbo, &lbo->map);
> +	if (ret) {
> +		drm_err(obj->dev, "ttm bo vmap failed\n");
> +		lsdc_bo_unpin(lbo);
> +		return ret;
> +	}
> +
> +	lbo->vmap_count = 1;
> +
> +out:
> +	*map = lbo->map;
> +
> +	return 0;
> +}
> +
> +static void lsdc_gem_object_vunmap(struct drm_gem_object *obj,
> +				   struct iosys_map *map)
> +{
> +	struct ttm_buffer_object *tbo = to_ttm_bo(obj);
> +	struct lsdc_bo *lbo = to_lsdc_bo(tbo);
> +
> +	if (unlikely(!lbo->vmap_count)) {
> +		drm_warn(obj->dev, "%p is not mapped\n", lbo);
> +		return;
> +	}
> +
> +	--lbo->vmap_count;
> +	if (lbo->vmap_count == 0) {
> +		ttm_bo_vunmap(tbo, &lbo->map);
> +
> +		lsdc_bo_unpin(lbo);
> +	}
> +}
> +
> +static int lsdc_gem_object_mmap(struct drm_gem_object *obj,
> +				struct vm_area_struct *vma)
> +{
> +	struct ttm_buffer_object *tbo = to_ttm_bo(obj);
> +	int ret;
> +
> +	ret = ttm_bo_mmap_obj(vma, tbo);
> +	if (unlikely(ret)) {
> +		drm_warn(obj->dev, "mmap %p failed\n", tbo);
> +		return ret;
> +	}
> +
> +	drm_gem_object_put(obj);
> +
> +	return 0;
> +}
> +
> +static const struct drm_gem_object_funcs lsdc_gem_object_funcs = {
> +	.free = lsdc_gem_object_free,
> +	.export = drm_gem_prime_export,
> +	.pin = lsdc_gem_prime_pin,
> +	.unpin = lsdc_gem_prime_unpin,
> +	.get_sg_table = lsdc_gem_prime_get_sg_table,
> +	.vmap = lsdc_gem_object_vmap,
> +	.vunmap = lsdc_gem_object_vunmap,
> +	.mmap = lsdc_gem_object_mmap,
> +};
> +
> +struct drm_gem_object *
> +lsdc_gem_object_create(struct drm_device *ddev,
> +		       u32 domain,
> +		       size_t size,
> +		       bool kerenl,
> +		       struct sg_table *sg,
> +		       struct dma_resv *resv)
> +{
> +	struct lsdc_device *ldev = to_lsdc(ddev);
> +	struct drm_gem_object *gobj;
> +	struct lsdc_bo *lbo;
> +	int ret;
> +
> +	lbo = lsdc_bo_create(ddev, domain, size, kerenl, sg, resv);
> +	if (IS_ERR(lbo)) {
> +		ret = PTR_ERR(lbo);
> +		return ERR_PTR(ret);
> +	}
> +
> +	/* VRAM is filled with random data */
> +	lsdc_bo_clear(lbo);
> +
> +	gobj = &lbo->tbo.base;
> +	gobj->funcs = &lsdc_gem_object_funcs;
> +
> +	/* tracking the BOs we created */
> +	mutex_lock(&ldev->gem.mutex);
> +	list_add_tail(&lbo->list, &ldev->gem.objects);
> +	mutex_unlock(&ldev->gem.mutex);
> +
> +	return gobj;
> +}
> +
> +struct drm_gem_object *
> +lsdc_prime_import_sg_table(struct drm_device *ddev,
> +			   struct dma_buf_attachment *attach,
> +			   struct sg_table *sg)
> +{
> +	struct dma_resv *resv = attach->dmabuf->resv;
> +	u64 size = attach->dmabuf->size;
> +	struct drm_gem_object *gobj;
> +	struct lsdc_bo *lbo;
> +
> +	dma_resv_lock(resv, NULL);
> +	gobj = lsdc_gem_object_create(ddev, LSDC_GEM_DOMAIN_GTT, size, false,
> +				      sg, resv);
> +	dma_resv_unlock(resv);
> +
> +	if (IS_ERR(gobj)) {
> +		drm_err(ddev, "Failed to import sg table\n");
> +		return gobj;
> +	}
> +
> +	lbo = gem_to_lsdc_bo(gobj);
> +	lbo->sharing_count = 1;
> +
> +	return gobj;
> +}
> +
> +int lsdc_dumb_create(struct drm_file *file,
> +		     struct drm_device *ddev,
> +		     struct drm_mode_create_dumb *args)
> +{
> +	struct lsdc_device *ldev = to_lsdc(ddev);
> +	const struct lsdc_desc *descp = ldev->descp;
> +	u32 domain = LSDC_GEM_DOMAIN_VRAM;
> +	struct drm_gem_object *gobj;
> +	size_t size;
> +	u32 pitch;
> +	u32 handle;
> +	int ret;
> +
> +	if (!args->width || !args->height)
> +		return -EINVAL;
> +
> +	/* Loongson diaplay controller only support 32-bit and 16-bit FB */
> +	if (args->bpp != 32 && args->bpp != 16)
> +		return -EINVAL;
> +
> +	pitch = args->width * args->bpp / 8;
> +	pitch = ALIGN(pitch, descp->pitch_align);
> +	size = pitch * args->height;
> +	size = ALIGN(size, PAGE_SIZE);
> +
> +	/* Maximum bo size allowed is the half vram size available */
> +	if (size > ldev->vram_size / 2) {
> +		drm_err(ddev, "Requesting(%zuMB) more than owned(%uMB)\n",
> +			size >> 20, (u32)(ldev->vram_size >> 20));
> +		return -ENOMEM;
> +	}
> +
> +	gobj = lsdc_gem_object_create(ddev,
> +				      domain,
> +				      size,
> +				      false,
> +				      NULL,
> +				      NULL);
> +	if (IS_ERR(gobj)) {
> +		drm_err(ddev, "Failed to create gem object\n");
> +		return PTR_ERR(gobj);
> +	}
> +
> +	ret = drm_gem_handle_create(file, gobj, &handle);
> +
> +	/* drop reference from allocate, handle holds it now */
> +	drm_gem_object_put(gobj);
> +	if (ret)
> +		return ret;
> +
> +	args->pitch = pitch;
> +	args->size = size;
> +	args->handle = handle;
> +
> +	return 0;
> +}
> +
> +int lsdc_dumb_map_offset(struct drm_file *filp,
> +			 struct drm_device *ddev,
> +			 u32 handle,
> +			 uint64_t *offset)
> +{
> +	struct drm_gem_object *gobj;
> +
> +	gobj = drm_gem_object_lookup(filp, handle);
> +	if (!gobj)
> +		return -ENOENT;
> +
> +	*offset = drm_vma_node_offset_addr(&gobj->vma_node);
> +
> +	drm_gem_object_put(gobj);
> +
> +	return 0;
> +}
> +
> +void lsdc_gem_init(struct drm_device *ddev)
> +{
> +	struct lsdc_device *ldev = to_lsdc(ddev);
> +
> +	mutex_init(&ldev->gem.mutex);
> +	INIT_LIST_HEAD(&ldev->gem.objects);
> +}
> +
> +int lsdc_show_buffer_object(struct seq_file *m, void *arg)
> +{
> +	struct drm_info_node *node = (struct drm_info_node *)m->private;
> +	struct drm_device *ddev = node->minor->dev;
> +	struct lsdc_device *ldev = to_lsdc(ddev);
> +	struct lsdc_bo *lbo;
> +	unsigned int i;
> +
> +	mutex_lock(&ldev->gem.mutex);
> +
> +	i = 0;
> +
> +	list_for_each_entry(lbo, &ldev->gem.objects, list) {
> +		struct ttm_buffer_object *tbo = &lbo->tbo;
> +		struct ttm_resource *resource = tbo->resource;
> +
> +		seq_printf(m, "bo[%04u][%p]: size: %8zu KB %s offset: %8llx\n",
> +			   i, lbo,
> +			   lsdc_bo_size(lbo) >> 10,
> +			   lsdc_mem_type_to_str(resource->mem_type),
> +			   lsdc_bo_gpu_offset(lbo));
> +		i++;
> +	}
> +
> +	mutex_unlock(&ldev->gem.mutex);
> +
> +	seq_printf(m, "Pinned BO size: VRAM: %zu KB, GTT: %zu KB\n",
> +		   ldev->vram_pinned_size >> 10, ldev->gtt_pinned_size >> 10);
> +
> +	return 0;
> +}
> diff --git a/drivers/gpu/drm/loongson/lsdc_gem.h b/drivers/gpu/drm/loongson/lsdc_gem.h
> new file mode 100644
> index 000000000000..7e05e453b733
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/lsdc_gem.h
> @@ -0,0 +1,37 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2023 Loongson Technology Corporation Limited
> + */
> +
> +#ifndef __LSDC_GEM_H__
> +#define __LSDC_GEM_H__
> +
> +#include <drm/drm_device.h>
> +#include <drm/drm_gem.h>
> +
> +struct drm_gem_object *
> +lsdc_prime_import_sg_table(struct drm_device *ddev,
> +			   struct dma_buf_attachment *attach,
> +			   struct sg_table *sg);
> +
> +int lsdc_dumb_map_offset(struct drm_file *file,
> +			 struct drm_device *dev,
> +			 u32 handle,
> +			 uint64_t *offset);
> +
> +int lsdc_dumb_create(struct drm_file *file,
> +		     struct drm_device *ddev,
> +		     struct drm_mode_create_dumb *args);
> +
> +void lsdc_gem_init(struct drm_device *ddev);
> +int lsdc_show_buffer_object(struct seq_file *m, void *arg);
> +
> +struct drm_gem_object *
> +lsdc_gem_object_create(struct drm_device *ddev,
> +		       u32 domain,
> +		       size_t size,
> +		       bool kerenl,
> +		       struct sg_table *sg,
> +		       struct dma_resv *resv);
> +
> +#endif
> diff --git a/drivers/gpu/drm/loongson/lsdc_gfxpll.c b/drivers/gpu/drm/loongson/lsdc_gfxpll.c
> new file mode 100644
> index 000000000000..977b12dcb73c
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/lsdc_gfxpll.c
> @@ -0,0 +1,199 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2023 Loongson Technology Corporation Limited
> + */
> +
> +#include <linux/delay.h>
> +
> +#include <drm/drm_file.h>
> +#include <drm/drm_managed.h>
> +#include <drm/drm_print.h>
> +
> +#include "lsdc_drv.h"
> +
> +/*
> + * GFX PLL is the PLL used by DC, GMC and GPU, the structure of the GFX PLL
> + * may suffer from change across chip variants.
> + *
> + *
> + *                                            +-------------+  sel_out_dc
> + *                                       +----| / div_out_0 | _____/ _____ DC
> + *                                       |    +-------------+
> + * refclk   +---------+      +-------+   |    +-------------+  sel_out_gmc
> + * ---+---> | div_ref | ---> | loopc | --+--> | / div_out_1 | _____/ _____ GMC
> + *    |     +---------+      +-------+   |    +-------------+
> + *    |          /               *       |    +-------------+  sel_out_gpu
> + *    |                                  +----| / div_out_2 | _____/ _____ GPU
> + *    |                                       +-------------+
> + *    |                                                         ^
> + *    |                                                         |
> + *    +--------------------------- bypass ----------------------+
> + */
> +
> +struct loongson_gfxpll_bitmap {
> +	/* Byte 0 ~ Byte 3 */
> +	unsigned div_out_dc    : 7;  /*  6 : 0    DC output clock divider  */
> +	unsigned div_out_gmc   : 7;  /* 13 : 7    GMC output clock divider */
> +	unsigned div_out_gpu   : 7;  /* 20 : 14   GPU output clock divider */
> +	unsigned loopc         : 9;  /* 29 : 21   clock multiplier         */
> +	unsigned _reserved_1_  : 2;  /* 31 : 30                            */
> +
> +	/* Byte 4 ~ Byte 7 */
> +	unsigned div_ref       : 7;   /* 38 : 32   Input clock divider    */
> +	unsigned locked        : 1;   /* 39        PLL locked indicator   */
> +	unsigned sel_out_dc    : 1;   /* 40        dc output clk enable   */
> +	unsigned sel_out_gmc   : 1;   /* 41        gmc output clk enable  */
> +	unsigned sel_out_gpu   : 1;   /* 42        gpu output clk enable  */
> +	unsigned set_param     : 1;   /* 43        Trigger the update     */
> +	unsigned bypass        : 1;   /* 44                               */
> +	unsigned powerdown     : 1;   /* 45                               */
> +	unsigned _reserved_2_  : 18;  /* 46 : 63   no use                 */
> +};
> +
> +union loongson_gfxpll_reg_bitmap {
> +	struct loongson_gfxpll_bitmap bitmap;
> +	u32 w[2];
> +	u64 d;
> +};
> +
> +static void __gfxpll_rreg(struct loongson_gfxpll *this,
> +			  union loongson_gfxpll_reg_bitmap *reg)
> +{
> +#if defined(CONFIG_64BIT)
> +	reg->d = readq(this->mmio);
> +#else
> +	reg->w[0] = readl(this->mmio);
> +	reg->w[1] = readl(this->mmio + 4);
> +#endif
> +}
> +
> +/* Update new parameters to the hardware */
> +
> +static int loongson_gfxpll_update(struct loongson_gfxpll * const this,
> +				  struct loongson_gfxpll_parms const *pin)
> +{
> +	/* None, TODO */
> +
> +	return 0;
> +}
> +
> +static void loongson_gfxpll_get_rates(struct loongson_gfxpll * const this,
> +				      unsigned int *dc,
> +				      unsigned int *gmc,
> +				      unsigned int *gpu)
> +{
> +	struct loongson_gfxpll_parms *pparms = &this->parms;
> +	union loongson_gfxpll_reg_bitmap gfxpll_reg;
> +	unsigned int pre_output;
> +	unsigned int dc_mhz;
> +	unsigned int gmc_mhz;
> +	unsigned int gpu_mhz;
> +
> +	__gfxpll_rreg(this, &gfxpll_reg);
> +
> +	pparms->div_ref = gfxpll_reg.bitmap.div_ref;
> +	pparms->loopc = gfxpll_reg.bitmap.loopc;
> +
> +	pparms->div_out_dc = gfxpll_reg.bitmap.div_out_dc;
> +	pparms->div_out_gmc = gfxpll_reg.bitmap.div_out_gmc;
> +	pparms->div_out_gpu = gfxpll_reg.bitmap.div_out_gpu;
> +
> +	pre_output = pparms->ref_clock / pparms->div_ref * pparms->loopc;
> +
> +	dc_mhz = pre_output / pparms->div_out_dc / 1000;
> +	gmc_mhz = pre_output / pparms->div_out_gmc / 1000;
> +	gpu_mhz = pre_output / pparms->div_out_gpu / 1000;
> +
> +	if (dc)
> +		*dc = dc_mhz;
> +
> +	if (gmc)
> +		*gmc = gmc_mhz;
> +
> +	if (gpu)
> +		*gpu = gpu_mhz;
> +}
> +
> +static void loongson_gfxpll_print(struct loongson_gfxpll * const this,
> +				  struct drm_printer *p,
> +				  bool verbose)
> +{
> +	struct loongson_gfxpll_parms *parms = &this->parms;
> +	unsigned int dc, gmc, gpu;
> +
> +	if (verbose) {
> +		drm_printf(p, "reference clock: %u\n", parms->ref_clock);
> +		drm_printf(p, "div_ref = %u\n", parms->div_ref);
> +		drm_printf(p, "loopc = %u\n", parms->loopc);
> +
> +		drm_printf(p, "div_out_dc = %u\n", parms->div_out_dc);
> +		drm_printf(p, "div_out_gmc = %u\n", parms->div_out_gmc);
> +		drm_printf(p, "div_out_gpu = %u\n", parms->div_out_gpu);
> +	}
> +
> +	this->funcs->get_rates(this, &dc, &gmc, &gpu);
> +
> +	drm_printf(p, "dc: %uMHz, gmc: %uMHz, gpu: %uMHz\n", dc, gmc, gpu);
> +}
> +
> +/* GFX (DC, GPU, GMC) PLL initialization and destroy function */
> +
> +static void loongson_gfxpll_fini(struct drm_device *ddev, void *data)
> +{
> +	struct loongson_gfxpll *this = (struct loongson_gfxpll *)data;
> +
> +	iounmap(this->mmio);
> +
> +	kfree(this);
> +}
> +
> +static int loongson_gfxpll_init(struct loongson_gfxpll * const this)
> +{
> +	struct loongson_gfxpll_parms *pparms = &this->parms;
> +	struct drm_printer printer = drm_info_printer(this->ddev->dev);
> +
> +	pparms->ref_clock = LSDC_PLL_REF_CLK;
> +
> +	this->mmio = ioremap(this->reg_base, this->reg_size);
> +	if (IS_ERR_OR_NULL(this->mmio))
> +		return -ENOMEM;
> +
> +	this->funcs->print(this, &printer, false);
> +
> +	return 0;
> +}
> +
> +static const struct loongson_gfxpll_funcs lsdc_gmc_gpu_funcs = {
> +	.init = loongson_gfxpll_init,
> +	.update = loongson_gfxpll_update,
> +	.get_rates = loongson_gfxpll_get_rates,
> +	.print = loongson_gfxpll_print,
> +};
> +
> +int loongson_gfxpll_create(struct drm_device *ddev,
> +			   struct loongson_gfxpll **ppout)
> +{
> +	struct lsdc_device *ldev = to_lsdc(ddev);
> +	const struct loongson_gfx_desc *gfx = to_loongson_gfx(ldev->descp);
> +	struct loongson_gfxpll *this;
> +	int ret;
> +
> +	this = kzalloc(sizeof(*this), GFP_KERNEL);
> +	if (IS_ERR_OR_NULL(this))
> +		return -ENOMEM;
> +
> +	this->ddev = ddev;
> +	this->reg_size = gfx->gfxpll.reg_size;
> +	this->reg_base = gfx->conf_reg_base + gfx->gfxpll.reg_offset;
> +	this->funcs = &lsdc_gmc_gpu_funcs;
> +
> +	ret = this->funcs->init(this);
> +	if (unlikely(ret)) {
> +		kfree(this);
> +		return ret;
> +	}
> +
> +	*ppout = this;
> +
> +	return drmm_add_action_or_reset(ddev, loongson_gfxpll_fini, this);
> +}
> diff --git a/drivers/gpu/drm/loongson/lsdc_gfxpll.h b/drivers/gpu/drm/loongson/lsdc_gfxpll.h
> new file mode 100644
> index 000000000000..f5eba6765812
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/lsdc_gfxpll.h
> @@ -0,0 +1,52 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2023 Loongson Technology Corporation Limited
> + */
> +
> +#ifndef __LSDC_GFXPLL_H__
> +#define __LSDC_GFXPLL_H__
> +
> +#include <drm/drm_device.h>
> +
> +struct loongson_gfxpll;
> +
> +struct loongson_gfxpll_parms {
> +	unsigned int ref_clock;
> +	unsigned int div_ref;
> +	unsigned int loopc;
> +	unsigned int div_out_dc;
> +	unsigned int div_out_gmc;
> +	unsigned int div_out_gpu;
> +};
> +
> +struct loongson_gfxpll_funcs {
> +	int (*init)(struct loongson_gfxpll * const this);
> +
> +	int (*update)(struct loongson_gfxpll * const this,
> +		      struct loongson_gfxpll_parms const *pin);
> +
> +	void (*get_rates)(struct loongson_gfxpll * const this,
> +			  unsigned int *dc, unsigned int *gmc, unsigned int *gpu);
> +
> +	void (*print)(struct loongson_gfxpll * const this,
> +		      struct drm_printer *printer, bool verbose);
> +};
> +
> +struct loongson_gfxpll {
> +	struct drm_device *ddev;
> +	void __iomem *mmio;
> +
> +	/* PLL register offset */
> +	u32 reg_base;
> +	/* PLL register size in bytes */
> +	u32 reg_size;
> +
> +	const struct loongson_gfxpll_funcs *funcs;
> +
> +	struct loongson_gfxpll_parms parms;
> +};
> +
> +int loongson_gfxpll_create(struct drm_device *ddev,
> +			   struct loongson_gfxpll **ppout);
> +
> +#endif
> diff --git a/drivers/gpu/drm/loongson/lsdc_i2c.c b/drivers/gpu/drm/loongson/lsdc_i2c.c
> new file mode 100644
> index 000000000000..d64712a46098
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/lsdc_i2c.c
> @@ -0,0 +1,179 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2023 Loongson Technology Corporation Limited
> + */
> +
> +#include <drm/drm_managed.h>
> +
> +#include "lsdc_drv.h"
> +#include "lsdc_output.h"
> +
> +/*
> + * __lsdc_gpio_i2c_set - set the state of a gpio pin indicated by mask
> + * @mask: gpio pin mask
> + * @state: "0" for low, "1" for high
> + */
> +static void __lsdc_gpio_i2c_set(struct lsdc_i2c * const li2c, int mask, int state)
> +{
> +	struct lsdc_device *ldev = to_lsdc(li2c->ddev);
> +	unsigned long flags;
> +	u8 val;
> +
> +	spin_lock_irqsave(&ldev->reglock, flags);
> +
> +	if (state) {
> +		/*
> +		 * Setting this pin as input directly, write 1 for input.
> +		 * The external pull-up resistor will pull the level up
> +		 */
> +		val = readb(li2c->dir_reg);
> +		val |= mask;
> +		writeb(val, li2c->dir_reg);
> +	} else {
> +		/* First set this pin as output, write 0 for output */
> +		val = readb(li2c->dir_reg);
> +		val &= ~mask;
> +		writeb(val, li2c->dir_reg);
> +
> +		/* Then, make this pin output 0 */
> +		val = readb(li2c->dat_reg);
> +		val &= ~mask;
> +		writeb(val, li2c->dat_reg);
> +	}
> +
> +	spin_unlock_irqrestore(&ldev->reglock, flags);
> +}
> +
> +/*
> + * __lsdc_gpio_i2c_get - read value back from the gpio pin indicated by mask
> + * @mask: gpio pin mask
> + * return "0" for low, "1" for high
> + */
> +static int __lsdc_gpio_i2c_get(struct lsdc_i2c * const li2c, int mask)
> +{
> +	struct lsdc_device *ldev = to_lsdc(li2c->ddev);
> +	unsigned long flags;
> +	u8 val;
> +
> +	spin_lock_irqsave(&ldev->reglock, flags);
> +
> +	/* First set this pin as input */
> +	val = readb(li2c->dir_reg);
> +	val |= mask;
> +	writeb(val, li2c->dir_reg);
> +
> +	/* Then get level state from this pin */
> +	val = readb(li2c->dat_reg);
> +
> +	spin_unlock_irqrestore(&ldev->reglock, flags);
> +
> +	return (val & mask) ? 1 : 0;
> +}
> +
> +static void lsdc_gpio_i2c_set_sda(void *i2c, int state)
> +{
> +	struct lsdc_i2c * const li2c = (struct lsdc_i2c *)i2c;
> +	/* set state on the li2c->sda pin */
> +	return __lsdc_gpio_i2c_set(li2c, li2c->sda, state);
> +}
> +
> +static void lsdc_gpio_i2c_set_scl(void *i2c, int state)
> +{
> +	struct lsdc_i2c * const li2c = (struct lsdc_i2c *)i2c;
> +	/* set state on the li2c->scl pin */
> +	return __lsdc_gpio_i2c_set(li2c, li2c->scl, state);
> +}
> +
> +static int lsdc_gpio_i2c_get_sda(void *i2c)
> +{
> +	struct lsdc_i2c * const li2c = (struct lsdc_i2c *)i2c;
> +	/* read value from the li2c->sda pin */
> +	return __lsdc_gpio_i2c_get(li2c, li2c->sda);
> +}
> +
> +static int lsdc_gpio_i2c_get_scl(void *i2c)
> +{
> +	struct lsdc_i2c * const li2c = (struct lsdc_i2c *)i2c;
> +	/* read the value from the li2c->scl pin */
> +	return __lsdc_gpio_i2c_get(li2c, li2c->scl);
> +}
> +
> +static void lsdc_destroy_i2c(struct drm_device *ddev, void *data)
> +{
> +	struct lsdc_i2c *li2c = (struct lsdc_i2c *)data;
> +
> +	if (li2c) {
> +		i2c_del_adapter(&li2c->adapter);
> +		kfree(li2c);
> +	}
> +}
> +
> +/*
> + * The DC in ls7a1000/ls7a2000/ls2k2000 has builtin gpio hardware
> + *
> + * @reg_base: gpio reg base
> + * @index: output channel index, 0 for PIPE0, 1 for PIPE1
> + */
> +int lsdc_create_i2c_chan(struct drm_device *ddev,
> +			 struct lsdc_display_pipe *dispipe,
> +			 unsigned int index)
> +{
> +	struct lsdc_device *ldev = to_lsdc(ddev);
> +	struct i2c_adapter *adapter;
> +	struct lsdc_i2c *li2c;
> +	int ret;
> +
> +	li2c = kzalloc(sizeof(*li2c), GFP_KERNEL);
> +	if (!li2c)
> +		return -ENOMEM;
> +
> +	dispipe->li2c = li2c;
> +
> +	if (index == 0) {
> +		li2c->sda = 0x01;  /* pin 0 */
> +		li2c->scl = 0x02;  /* pin 1 */
> +	} else if (index == 1) {
> +		li2c->sda = 0x04;  /* pin 2 */
> +		li2c->scl = 0x08;  /* pin 3 */
> +	} else {
> +		return -ENOENT;
> +	}
> +
> +	li2c->ddev = ddev;
> +	li2c->dir_reg = ldev->reg_base + LS7A_DC_GPIO_DIR_REG;
> +	li2c->dat_reg = ldev->reg_base + LS7A_DC_GPIO_DAT_REG;
> +
> +	li2c->bit.setsda = lsdc_gpio_i2c_set_sda;
> +	li2c->bit.setscl = lsdc_gpio_i2c_set_scl;
> +	li2c->bit.getsda = lsdc_gpio_i2c_get_sda;
> +	li2c->bit.getscl = lsdc_gpio_i2c_get_scl;
> +	li2c->bit.udelay = 5;
> +	li2c->bit.timeout = usecs_to_jiffies(2200);
> +	li2c->bit.data = li2c;
> +
> +	adapter = &li2c->adapter;
> +	adapter->algo_data = &li2c->bit;
> +	adapter->owner = THIS_MODULE;
> +	adapter->class = I2C_CLASS_DDC;
> +	adapter->dev.parent = ddev->dev;
> +	adapter->nr = -1;
> +
> +	snprintf(adapter->name, sizeof(adapter->name), "lsdc-i2c%u", index);
> +
> +	i2c_set_adapdata(adapter, li2c);
> +
> +	ret = i2c_bit_add_bus(adapter);
> +	if (ret) {
> +		kfree(li2c);
> +		return ret;
> +	}
> +
> +	ret = drmm_add_action_or_reset(ddev, lsdc_destroy_i2c, li2c);
> +	if (ret)
> +		return ret;
> +
> +	drm_info(ddev, "%s(sda pin mask=%u, scl pin mask=%u) created\n",
> +		 adapter->name, li2c->sda, li2c->scl);
> +
> +	return 0;
> +}
> diff --git a/drivers/gpu/drm/loongson/lsdc_i2c.h b/drivers/gpu/drm/loongson/lsdc_i2c.h
> new file mode 100644
> index 000000000000..c3dadc2c423d
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/lsdc_i2c.h
> @@ -0,0 +1,29 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2023 Loongson Technology Corporation Limited
> + */
> +
> +#ifndef __LSDC_I2C_H__
> +#define __LSDC_I2C_H__
> +
> +#include <linux/i2c.h>
> +#include <linux/i2c-algo-bit.h>
> +
> +struct lsdc_i2c {
> +	struct i2c_adapter adapter;
> +	struct i2c_algo_bit_data bit;
> +	struct drm_device *ddev;
> +	void __iomem *dir_reg;
> +	void __iomem *dat_reg;
> +	/* pin bit mask */
> +	u8 sda;
> +	u8 scl;
> +};
> +
> +struct lsdc_display_pipe;
> +
> +int lsdc_create_i2c_chan(struct drm_device *ddev,
> +			 struct lsdc_display_pipe *dispipe,
> +			 unsigned int index);
> +
> +#endif
> diff --git a/drivers/gpu/drm/loongson/lsdc_irq.c b/drivers/gpu/drm/loongson/lsdc_irq.c
> new file mode 100644
> index 000000000000..e4ee0b608023
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/lsdc_irq.c
> @@ -0,0 +1,71 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2023 Loongson Technology Corporation Limited
> + */
> +
> +#include <drm/drm_vblank.h>
> +
> +#include "lsdc_irq.h"
> +
> +/*
> + * For the DC in ls7a2000, clearing interrupt status is achieved by
> + * write "1" to LSDC_INT_REG, For the DC in ls7a1000, clear interrupt
> + * status is achieved by write "0" to LSDC_INT_REG. Two different hardware
> + * engineer of Loongson modify it as their will.
> + */
> +
> +irqreturn_t ls7a2000_dc_irq_handler(int irq, void *arg)
> +{
> +	struct drm_device *ddev = arg;
> +	struct lsdc_device *ldev = to_lsdc(ddev);
> +	u32 val;
> +
> +	/* Read the interrupt status */
> +	val = lsdc_rreg32(ldev, LSDC_INT_REG);
> +	if ((val & INT_STATUS_MASK) == 0) {
> +		drm_warn(ddev, "no interrupt occurs\n");
> +		return IRQ_NONE;
> +	}
> +
> +	ldev->irq_status = val;
> +
> +	/* write "1" to clear the interrupt status */
> +	lsdc_wreg32(ldev, LSDC_INT_REG, val);
> +
> +	if (ldev->irq_status & INT_CRTC0_VSYNC)
> +		drm_handle_vblank(ddev, 0);
> +
> +	if (ldev->irq_status & INT_CRTC1_VSYNC)
> +		drm_handle_vblank(ddev, 1);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +/* For the DC in LS7A1000 and LS2K1000 */
> +irqreturn_t ls7a1000_dc_irq_handler(int irq, void *arg)
> +{
> +	struct drm_device *ddev = arg;
> +	struct lsdc_device *ldev = to_lsdc(ddev);
> +	u32 val;
> +
> +	/* Read the interrupt status */
> +	val = lsdc_rreg32(ldev, LSDC_INT_REG);
> +	if ((val & INT_STATUS_MASK) == 0) {
> +		drm_warn(ddev, "no interrupt occurs\n");
> +		return IRQ_NONE;
> +	}
> +
> +	ldev->irq_status = val;
> +
> +	/* write "0" to clear the interrupt status */
> +	val &= ~(INT_CRTC0_VSYNC | INT_CRTC1_VSYNC);
> +	lsdc_wreg32(ldev, LSDC_INT_REG, val);
> +
> +	if (ldev->irq_status & INT_CRTC0_VSYNC)
> +		drm_handle_vblank(ddev, 0);
> +
> +	if (ldev->irq_status & INT_CRTC1_VSYNC)
> +		drm_handle_vblank(ddev, 1);
> +
> +	return IRQ_HANDLED;
> +}
> diff --git a/drivers/gpu/drm/loongson/lsdc_irq.h b/drivers/gpu/drm/loongson/lsdc_irq.h
> new file mode 100644
> index 000000000000..c7003461051e
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/lsdc_irq.h
> @@ -0,0 +1,16 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2023 Loongson Technology Corporation Limited
> + */
> +
> +#ifndef __LSDC_IRQ_H__
> +#define __LSDC_IRQ_H__
> +
> +#include <linux/irqreturn.h>
> +
> +#include "lsdc_drv.h"
> +
> +irqreturn_t ls7a1000_dc_irq_handler(int irq, void *arg);
> +irqreturn_t ls7a2000_dc_irq_handler(int irq, void *arg);
> +
> +#endif
> diff --git a/drivers/gpu/drm/loongson/lsdc_output.h b/drivers/gpu/drm/loongson/lsdc_output.h
> new file mode 100644
> index 000000000000..e3c375298568
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/lsdc_output.h
> @@ -0,0 +1,21 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2023 Loongson Technology Corporation Limited
> + */
> +
> +#ifndef __LSDC_OUTPUT_H__
> +#define __LSDC_OUTPUT_H__
> +
> +#include "lsdc_drv.h"
> +
> +int ls7a1000_output_init(struct drm_device *ddev,
> +			 struct lsdc_display_pipe *dispipe,
> +			 struct i2c_adapter *ddc,
> +			 unsigned int index);
> +
> +int ls7a2000_output_init(struct drm_device *ldev,
> +			 struct lsdc_display_pipe *dispipe,
> +			 struct i2c_adapter *ddc,
> +			 unsigned int index);
> +
> +#endif
> diff --git a/drivers/gpu/drm/loongson/lsdc_output_7a1000.c b/drivers/gpu/drm/loongson/lsdc_output_7a1000.c
> new file mode 100644
> index 000000000000..45602cc7ccf9
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/lsdc_output_7a1000.c
> @@ -0,0 +1,161 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2023 Loongson Technology Corporation Limited
> + */
> +
> +#include <drm/drm_atomic_helper.h>
> +#include <drm/drm_edid.h>
> +#include <drm/drm_probe_helper.h>
> +
> +#include "lsdc_drv.h"
> +#include "lsdc_output.h"
> +
> +/*
> + * Currently, we assume the external encoders connected with the DVO is
> + * transparent. Loongson DVO interface can directly drive RGB888 panels.
> + *
> + *  TODO: Add support for non-transparent encoders ...
> + */
> +
> +static int ls7a1000_dpi_connector_get_modes(struct drm_connector *conn)
> +{
> +	unsigned int num = 0;
> +	struct edid *edid;
> +
> +	if (conn->ddc) {
> +		edid = drm_get_edid(conn, conn->ddc);
> +		if (edid) {
> +			drm_connector_update_edid_property(conn, edid);
> +			num = drm_add_edid_modes(conn, edid);
> +			kfree(edid);
> +		}
> +
> +		return num;
> +	}
> +
> +	num = drm_add_modes_noedid(conn, 1920, 1200);
> +
> +	drm_set_preferred_mode(conn, 1024, 768);
> +
> +	return num;
> +}
> +
> +static struct drm_encoder *
> +ls7a1000_dpi_connector_get_best_encoder(struct drm_connector *connector,
> +					struct drm_atomic_state *state)
> +{
> +	struct lsdc_output *output = connector_to_lsdc_output(connector);
> +
> +	return &output->encoder;
> +}
> +
> +static const struct drm_connector_helper_funcs
> +ls7a1000_dpi_connector_helpers = {
> +	.atomic_best_encoder = ls7a1000_dpi_connector_get_best_encoder,
> +	.get_modes = ls7a1000_dpi_connector_get_modes,
> +};
> +
> +static enum drm_connector_status
> +ls7a1000_dpi_connector_detect(struct drm_connector *connector, bool force)
> +{
> +	struct i2c_adapter *ddc = connector->ddc;
> +
> +	if (ddc) {
> +		if (drm_probe_ddc(ddc))
> +			return connector_status_connected;
> +
> +		return connector_status_disconnected;
> +	}
> +
> +	return connector_status_unknown;
> +}
> +
> +static const struct drm_connector_funcs ls7a1000_dpi_connector_funcs = {
> +	.detect = ls7a1000_dpi_connector_detect,
> +	.fill_modes = drm_helper_probe_single_connector_modes,
> +	.destroy = drm_connector_cleanup,
> +	.reset = drm_atomic_helper_connector_reset,
> +	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
> +	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state
> +};
> +
> +static void ls7a1000_pipe0_encoder_reset(struct drm_encoder *encoder)
> +{
> +	struct drm_device *ddev = encoder->dev;
> +	struct lsdc_device *ldev = to_lsdc(ddev);
> +
> +	/*
> +	 * We need this, for S3 resume, screen will not lightup if don't set
> +	 * correctly.
> +	 */
> +	lsdc_wreg32(ldev, LSDC_CRTC0_PANEL_CONF_REG,
> +		    PHY_CLOCK_POL | PHY_CLOCK_EN | PHY_DATA_EN);
> +}
> +
> +static void ls7a1000_pipe1_encoder_reset(struct drm_encoder *encoder)
> +{
> +	struct drm_device *ddev = encoder->dev;
> +	struct lsdc_device *ldev = to_lsdc(ddev);
> +
> +	/*
> +	 * We need this, for S3 resume, screen will not light up
> +	 * if we don't set setting this register correctly.
> +	 */
> +	lsdc_wreg32(ldev, LSDC_CRTC1_PANEL_CONF_REG,
> +		    PHY_CLOCK_POL | PHY_CLOCK_EN | PHY_DATA_EN);
> +}
> +
> +static const struct drm_encoder_funcs ls7a1000_encoder_funcs[2] = {
> +	{
> +		.reset = ls7a1000_pipe0_encoder_reset,
> +		.destroy = drm_encoder_cleanup,
> +	},
> +	{
> +		.reset = ls7a1000_pipe1_encoder_reset,
> +		.destroy = drm_encoder_cleanup,
> +	},
> +};
> +
> +int ls7a1000_output_init(struct drm_device *ddev,
> +			 struct lsdc_display_pipe *dispipe,
> +			 struct i2c_adapter *ddc,
> +			 unsigned int index)
> +{
> +	struct lsdc_output *output = &dispipe->output;
> +	struct drm_encoder *encoder = &output->encoder;
> +	struct drm_connector *connector = &output->connector;
> +	int ret;
> +
> +	ret = drm_encoder_init(ddev,
> +			       encoder,
> +			       &ls7a1000_encoder_funcs[index],
> +			       DRM_MODE_ENCODER_TMDS,
> +			       "encoder-%u",
> +			       index);
> +	if (ret)
> +		return ret;
> +
> +	encoder->possible_crtcs = BIT(index);
> +
> +	ret = drm_connector_init_with_ddc(ddev,
> +					  connector,
> +					  &ls7a1000_dpi_connector_funcs,
> +					  DRM_MODE_CONNECTOR_DPI,
> +					  ddc);
> +	if (ret)
> +		return ret;
> +
> +	drm_info(ddev, "display pipe-%u has a DVO\n", index);
> +
> +	drm_connector_helper_add(connector, &ls7a1000_dpi_connector_helpers);
> +
> +	drm_connector_attach_encoder(connector, encoder);
> +
> +	connector->polled = DRM_CONNECTOR_POLL_CONNECT |
> +			    DRM_CONNECTOR_POLL_DISCONNECT;
> +
> +	connector->interlace_allowed = 0;
> +	connector->doublescan_allowed = 0;
> +
> +	return 0;
> +}
> diff --git a/drivers/gpu/drm/loongson/lsdc_output_7a2000.c b/drivers/gpu/drm/loongson/lsdc_output_7a2000.c
> new file mode 100644
> index 000000000000..ccc35283e1dc
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/lsdc_output_7a2000.c
> @@ -0,0 +1,531 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2023 Loongson Technology Corporation Limited
> + */
> +
> +#include <linux/delay.h>
> +
> +#include <drm/drm_atomic_helper.h>
> +#include <drm/drm_debugfs.h>
> +#include <drm/drm_edid.h>
> +#include <drm/drm_probe_helper.h>
> +
> +#include "lsdc_drv.h"
> +#include "lsdc_output.h"
> +
> +static int ls7a2000_connector_get_modes(struct drm_connector *connector)
> +{
> +	unsigned int num = 0;
> +	struct edid *edid;
> +
> +	if (connector->ddc) {
> +		edid = drm_get_edid(connector, connector->ddc);
> +		if (edid) {
> +			drm_connector_update_edid_property(connector, edid);
> +			num = drm_add_edid_modes(connector, edid);
> +			kfree(edid);
> +		}
> +
> +		return num;
> +	}
> +
> +	num = drm_add_modes_noedid(connector, 1920, 1200);
> +
> +	drm_set_preferred_mode(connector, 1024, 768);
> +
> +	return num;
> +}
> +
> +static struct drm_encoder *
> +ls7a2000_connector_get_best_encoder(struct drm_connector *connector,
> +				    struct drm_atomic_state *state)
> +{
> +	struct lsdc_output *output = connector_to_lsdc_output(connector);
> +
> +	return &output->encoder;
> +}
> +
> +static const struct drm_connector_helper_funcs ls7a2000_connector_helpers = {
> +	.atomic_best_encoder = ls7a2000_connector_get_best_encoder,
> +	.get_modes = ls7a2000_connector_get_modes,
> +};
> +
> +/* debugfs */
> +
> +#define LSDC_HDMI_REG(i, reg) {                               \
> +	.name = __stringify_1(LSDC_HDMI##i##_##reg##_REG),    \
> +	.offset = LSDC_HDMI##i##_##reg##_REG,                 \
> +}
> +
> +static const struct lsdc_reg32 ls7a2000_hdmi0_encoder_regs[] = {
> +	LSDC_HDMI_REG(0, ZONE),
> +	LSDC_HDMI_REG(0, INTF_CTRL),
> +	LSDC_HDMI_REG(0, PHY_CTRL),
> +	LSDC_HDMI_REG(0, PHY_PLL),
> +	LSDC_HDMI_REG(0, AVI_INFO_CRTL),
> +	LSDC_HDMI_REG(0, PHY_CAL),
> +	LSDC_HDMI_REG(0, AUDIO_PLL_LO),
> +	LSDC_HDMI_REG(0, AUDIO_PLL_HI),
> +	{NULL, 0},  /* MUST be {NULL, 0} terminated */
> +};
> +
> +static const struct lsdc_reg32 ls7a2000_hdmi1_encoder_regs[] = {
> +	LSDC_HDMI_REG(1, ZONE),
> +	LSDC_HDMI_REG(1, INTF_CTRL),
> +	LSDC_HDMI_REG(1, PHY_CTRL),
> +	LSDC_HDMI_REG(1, PHY_PLL),
> +	LSDC_HDMI_REG(1, AVI_INFO_CRTL),
> +	LSDC_HDMI_REG(1, PHY_CAL),
> +	LSDC_HDMI_REG(1, AUDIO_PLL_LO),
> +	LSDC_HDMI_REG(1, AUDIO_PLL_HI),
> +	{NULL, 0},  /* MUST be {NULL, 0} terminated */
> +};
> +
> +static int ls7a2000_hdmi_encoder_regs_show(struct seq_file *m, void *data)
> +{
> +	struct drm_info_node *node = (struct drm_info_node *)m->private;
> +	struct drm_device *ddev = node->minor->dev;
> +	struct lsdc_device *ldev = to_lsdc(ddev);
> +	const struct lsdc_reg32 *preg;
> +
> +	preg = (const struct lsdc_reg32 *)node->info_ent->data;
> +
> +	while (preg->name) {
> +		u32 offset = preg->offset;
> +
> +		seq_printf(m, "%s (0x%04x): 0x%08x\n",
> +			   preg->name, offset, lsdc_rreg32(ldev, offset));
> +		++preg;
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct drm_info_list ls7a2000_hdmi0_debugfs_files[] = {
> +	{ "regs", ls7a2000_hdmi_encoder_regs_show, 0, (void *)ls7a2000_hdmi0_encoder_regs },
> +};
> +
> +static const struct drm_info_list ls7a2000_hdmi1_debugfs_files[] = {
> +	{ "regs", ls7a2000_hdmi_encoder_regs_show, 0, (void *)ls7a2000_hdmi1_encoder_regs },
> +};
> +
> +static void ls7a2000_hdmi0_late_register(struct drm_connector *connector,
> +					 struct dentry *root)
> +{
> +	struct drm_device *ddev = connector->dev;
> +	struct drm_minor *minor = ddev->primary;
> +
> +	drm_debugfs_create_files(ls7a2000_hdmi0_debugfs_files,
> +				 ARRAY_SIZE(ls7a2000_hdmi0_debugfs_files),
> +				 root,
> +				 minor);
> +}
> +
> +static void ls7a2000_hdmi1_late_register(struct drm_connector *connector,
> +					 struct dentry *root)
> +{
> +	struct drm_device *ddev = connector->dev;
> +	struct drm_minor *minor = ddev->primary;
> +
> +	drm_debugfs_create_files(ls7a2000_hdmi1_debugfs_files,
> +				 ARRAY_SIZE(ls7a2000_hdmi1_debugfs_files),
> +				 root,
> +				 minor);
> +}
> +
> +/* monitor present detection */
> +
> +static enum drm_connector_status
> +ls7a2000_hdmi0_vga_connector_detect(struct drm_connector *connector, bool force)
> +{
> +	struct drm_device *ddev = connector->dev;
> +	struct lsdc_device *ldev = to_lsdc(ddev);
> +	u32 val;
> +
> +	val = lsdc_rreg32(ldev, LSDC_HDMI_HPD_STATUS_REG);
> +
> +	if (val & HDMI0_HPD_FLAG)
> +		return connector_status_connected;
> +
> +	if (connector->ddc) {
> +		if (drm_probe_ddc(connector->ddc))
> +			return connector_status_connected;
> +
> +		return connector_status_disconnected;
> +	}
> +
> +	return connector_status_unknown;
> +}
> +
> +static enum drm_connector_status
> +ls7a2000_hdmi1_connector_detect(struct drm_connector *connector, bool force)
> +{
> +	struct lsdc_device *ldev = to_lsdc(connector->dev);
> +	u32 val;
> +
> +	val = lsdc_rreg32(ldev, LSDC_HDMI_HPD_STATUS_REG);
> +
> +	if (val & HDMI1_HPD_FLAG)
> +		return connector_status_connected;
> +
> +	return connector_status_disconnected;
> +}
> +
> +static const struct drm_connector_funcs ls7a2000_hdmi_connector_funcs[2] = {
> +	{
> +		.detect = ls7a2000_hdmi0_vga_connector_detect,
> +		.fill_modes = drm_helper_probe_single_connector_modes,
> +		.destroy = drm_connector_cleanup,
> +		.reset = drm_atomic_helper_connector_reset,
> +		.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
> +		.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
> +		.debugfs_init = ls7a2000_hdmi0_late_register,
> +	},
> +	{
> +		.detect = ls7a2000_hdmi1_connector_detect,
> +		.fill_modes = drm_helper_probe_single_connector_modes,
> +		.destroy = drm_connector_cleanup,
> +		.reset = drm_atomic_helper_connector_reset,
> +		.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
> +		.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
> +		.debugfs_init = ls7a2000_hdmi1_late_register,
> +	},
> +};
> +
> +/* Even though some board has only one hdmi on display pipe 1,
> + * We still need hook lsdc_encoder_funcs up on display pipe 0,
> + * This is because we need its reset() callback get called, to
> + * set the LSDC_HDMIx_CTRL_REG using software gpio emulated i2c.
> + * Otherwise, the firmware may set LSDC_HDMIx_CTRL_REG blindly.
> + */
> +static void ls7a2000_hdmi0_encoder_reset(struct drm_encoder *encoder)
> +{
> +	struct drm_device *ddev = encoder->dev;
> +	struct lsdc_device *ldev = to_lsdc(ddev);
> +	u32 val;
> +
> +	val = PHY_CLOCK_POL | PHY_CLOCK_EN | PHY_DATA_EN;
> +	lsdc_wreg32(ldev, LSDC_CRTC0_PANEL_CONF_REG, val);
> +
> +	/* using software gpio emulated i2c */
> +	val = lsdc_rreg32(ldev, LSDC_HDMI0_INTF_CTRL_REG);
> +	val &= ~HW_I2C_EN;
> +	lsdc_wreg32(ldev, LSDC_HDMI0_INTF_CTRL_REG, val);
> +
> +	/* help the hdmi phy to get out of reset state */
> +	lsdc_wreg32(ldev, LSDC_HDMI0_PHY_CTRL_REG, HDMI_PHY_RESET_N);
> +
> +	mdelay(20);
> +
> +	drm_dbg(ddev, "HDMI-0 Reset\n");
> +}
> +
> +static void ls7a2000_hdmi1_encoder_reset(struct drm_encoder *encoder)
> +{
> +	struct drm_device *ddev = encoder->dev;
> +	struct lsdc_device *ldev = to_lsdc(ddev);
> +	u32 val;
> +
> +	val = PHY_CLOCK_POL | PHY_CLOCK_EN | PHY_DATA_EN;
> +	lsdc_wreg32(ldev, LSDC_CRTC1_PANEL_CONF_REG, val);
> +
> +	/* using software gpio emulated i2c */
> +	val = lsdc_rreg32(ldev, LSDC_HDMI1_INTF_CTRL_REG);
> +	val &= ~HW_I2C_EN;
> +	lsdc_wreg32(ldev, LSDC_HDMI1_INTF_CTRL_REG, val);
> +
> +	/*  help the hdmi phy to get out of reset state */
> +	lsdc_wreg32(ldev, LSDC_HDMI1_PHY_CTRL_REG, HDMI_PHY_RESET_N);
> +
> +	mdelay(20);
> +
> +	drm_dbg(ddev, "HDMI-1 Reset\n");
> +}
> +
> +static const struct drm_encoder_funcs ls7a2000_encoder_funcs[2] = {
> +	{
> +		.reset = ls7a2000_hdmi0_encoder_reset,
> +		.destroy = drm_encoder_cleanup,
> +	},
> +	{
> +		.reset = ls7a2000_hdmi1_encoder_reset,
> +		.destroy = drm_encoder_cleanup,
> +	},
> +};
> +
> +static int ls7a2000_hdmi_set_avi_infoframe(struct drm_encoder *encoder,
> +					   struct drm_display_mode *mode)
> +{
> +	struct lsdc_output *output = encoder_to_lsdc_output(encoder);
> +	struct lsdc_display_pipe *dispipe = output_to_display_pipe(output);
> +	unsigned int index = dispipe->index;
> +	struct drm_device *ddev = encoder->dev;
> +	struct lsdc_device *ldev = to_lsdc(ddev);
> +	struct hdmi_avi_infoframe infoframe;
> +	u8 buffer[HDMI_INFOFRAME_SIZE(AVI)];
> +	unsigned char *ptr = &buffer[HDMI_INFOFRAME_HEADER_SIZE];
> +	unsigned int content0, content1, content2, content3;
> +	int err;
> +
> +	err = drm_hdmi_avi_infoframe_from_display_mode(&infoframe,
> +						       &output->connector,
> +						       mode);
> +	if (err < 0) {
> +		drm_err(ddev, "failed to setup AVI infoframe: %d\n", err);
> +		return err;
> +	}
> +
> +	/* Fixed infoframe configuration not linked to the mode */
> +	infoframe.colorspace = HDMI_COLORSPACE_RGB;
> +	infoframe.quantization_range = HDMI_QUANTIZATION_RANGE_DEFAULT;
> +	infoframe.colorimetry = HDMI_COLORIMETRY_NONE;
> +
> +	err = hdmi_avi_infoframe_pack(&infoframe, buffer, sizeof(buffer));
> +	if (err < 0) {
> +		drm_err(ddev, "failed to pack AVI infoframe: %d\n", err);
> +			return err;
> +	}
> +
> +	content0 = *(unsigned int *)ptr;
> +	content1 = *(ptr + 4);
> +	content2 = *(unsigned int *)(ptr + 5);
> +	content3 = *(unsigned int *)(ptr + 9);
> +
> +	lsdc_pipe_wreg32(ldev, LSDC_HDMI0_AVI_CONTENT0, index, content0);
> +	lsdc_pipe_wreg32(ldev, LSDC_HDMI0_AVI_CONTENT1, index, content1);
> +	lsdc_pipe_wreg32(ldev, LSDC_HDMI0_AVI_CONTENT2, index, content2);
> +	lsdc_pipe_wreg32(ldev, LSDC_HDMI0_AVI_CONTENT3, index, content3);
> +
> +	lsdc_pipe_wreg32(ldev, LSDC_HDMI0_AVI_INFO_CRTL_REG, index,
> +			 AVI_PKT_ENABLE | AVI_PKT_UPDATE);
> +
> +	drm_dbg(ddev, "Update HDMI-%u avi infoframe\n", index);
> +
> +	return 0;
> +}
> +
> +static void ls7a2000_hdmi_atomic_disable(struct drm_encoder *encoder,
> +					 struct drm_atomic_state *state)
> +{
> +	struct lsdc_output *output = encoder_to_lsdc_output(encoder);
> +	struct lsdc_display_pipe *dispipe = output_to_display_pipe(output);
> +	unsigned int index = dispipe->index;
> +	struct drm_device *ddev = encoder->dev;
> +	struct lsdc_device *ldev = to_lsdc(ddev);
> +	u32 val;
> +
> +	/* Disable the hdmi phy */
> +	val = lsdc_pipe_rreg32(ldev, LSDC_HDMI0_PHY_CTRL_REG, index);
> +	val &= ~HDMI_PHY_EN;
> +	lsdc_pipe_wreg32(ldev, LSDC_HDMI0_PHY_CTRL_REG, index, val);
> +
> +	/* Disable the hdmi interface */
> +	val = lsdc_pipe_rreg32(ldev, LSDC_HDMI0_INTF_CTRL_REG, index);
> +	val &= ~HDMI_INTERFACE_EN;
> +	lsdc_pipe_wreg32(ldev, LSDC_HDMI0_INTF_CTRL_REG, index, val);
> +
> +	drm_dbg(ddev, "HDMI-%u disabled\n", index);
> +}
> +
> +static void ls7a2000_hdmi_atomic_enable(struct drm_encoder *encoder,
> +					struct drm_atomic_state *state)
> +{
> +	struct drm_device *ddev = encoder->dev;
> +	struct lsdc_device *ldev = to_lsdc(ddev);
> +	struct lsdc_output *output = encoder_to_lsdc_output(encoder);
> +	struct lsdc_display_pipe *dispipe = output_to_display_pipe(output);
> +	unsigned int index = dispipe->index;
> +	u32 val;
> +
> +	/* datasheet say it should larger than 48 */
> +	val = 64 << HDMI_H_ZONE_IDLE_SHIFT | 64 << HDMI_V_ZONE_IDLE_SHIFT;
> +
> +	lsdc_pipe_wreg32(ldev, LSDC_HDMI0_ZONE_REG, index, val);
> +
> +	val = HDMI_PHY_TERM_STATUS |
> +	      HDMI_PHY_TERM_DET_EN |
> +	      HDMI_PHY_TERM_H_EN |
> +	      HDMI_PHY_TERM_L_EN |
> +	      HDMI_PHY_RESET_N |
> +	      HDMI_PHY_EN;
> +
> +	lsdc_pipe_wreg32(ldev, LSDC_HDMI0_PHY_CTRL_REG, index, val);
> +
> +	udelay(2);
> +
> +	val = HDMI_CTL_PERIOD_MODE |
> +	      HDMI_AUDIO_EN |
> +	      HDMI_PACKET_EN |
> +	      HDMI_INTERFACE_EN |
> +	      (8 << HDMI_VIDEO_PREAMBLE_SHIFT);
> +
> +	lsdc_pipe_wreg32(ldev, LSDC_HDMI0_INTF_CTRL_REG, index, val);
> +
> +	drm_dbg(ddev, "HDMI-%u enabled\n", index);
> +}
> +
> +/*
> + *  Fout = M * Fin
> + *
> + *  M = (4 * LF) / (IDF * ODF)
> + *
> + *  IDF: Input Division Factor
> + *  ODF: Output Division Factor
> + *   LF: Loop Factor
> + *    M: Required Mult
> + *
> + *  +--------------------------------------------------------+
> + *  |     Fin (kHZ)     | M  | IDF | LF | ODF |   Fout(Mhz)  |
> + *  |-------------------+----+-----+----+-----+--------------|
> + *  |  170000 ~ 340000  | 10 | 16  | 40 |  1  | 1700 ~ 3400  |
> + *  |   85000 ~ 170000  | 10 |  8  | 40 |  2  |  850 ~ 1700  |
> + *  |   42500 ~  85000  | 10 |  4  | 40 |  4  |  425 ~ 850   |
> + *  |   21250 ~  42500  | 10 |  2  | 40 |  8  | 212.5 ~ 425  |
> + *  |   20000 ~  21250  | 10 |  1  | 40 | 16  |  200 ~ 212.5 |
> + *  +--------------------------------------------------------+
> + */
> +static void ls7a2000_hdmi_phy_pll_config(struct lsdc_device *ldev,
> +					 int fin,
> +					 unsigned int index)
> +{
> +	struct drm_device *ddev = &ldev->base;
> +	int count = 0;
> +	u32 val;
> +
> +	/* Firstly, disable phy pll */
> +	lsdc_pipe_wreg32(ldev, LSDC_HDMI0_PHY_PLL_REG, index, 0x0);
> +
> +	/*
> +	 * Most of time, loongson HDMI require M = 10
> +	 * for example, 10 = (4 * 40) / (8 * 2)
> +	 * here, write "1" to the ODF will get "2"
> +	 */
> +
> +	if (fin >= 170000)
> +		val = (16 << HDMI_PLL_IDF_SHIFT) |
> +		      (40 << HDMI_PLL_LF_SHIFT) |
> +		      (0 << HDMI_PLL_ODF_SHIFT);
> +	else if (fin >= 85000)
> +		val = (8 << HDMI_PLL_IDF_SHIFT) |
> +		      (40 << HDMI_PLL_LF_SHIFT) |
> +		      (1 << HDMI_PLL_ODF_SHIFT);
> +	else if (fin >= 42500)
> +		val = (4 << HDMI_PLL_IDF_SHIFT) |
> +		      (40 << HDMI_PLL_LF_SHIFT) |
> +		      (2 << HDMI_PLL_ODF_SHIFT);
> +	else if  (fin >= 21250)
> +		val = (2 << HDMI_PLL_IDF_SHIFT) |
> +		      (40 << HDMI_PLL_LF_SHIFT) |
> +		      (3 << HDMI_PLL_ODF_SHIFT);
> +	else
> +		val = (1 << HDMI_PLL_IDF_SHIFT) |
> +		      (40 << HDMI_PLL_LF_SHIFT) |
> +		      (4 << HDMI_PLL_ODF_SHIFT);
> +
> +	lsdc_pipe_wreg32(ldev, LSDC_HDMI0_PHY_PLL_REG, index, val);
> +
> +	val |= HDMI_PLL_ENABLE;
> +
> +	lsdc_pipe_wreg32(ldev, LSDC_HDMI0_PHY_PLL_REG, index, val);
> +
> +	udelay(2);
> +
> +	drm_dbg(ddev, "Fin of HDMI-%u: %d kHz\n", index, fin);
> +
> +	/* Wait hdmi phy pll lock */
> +	do {
> +		val = lsdc_pipe_rreg32(ldev, LSDC_HDMI0_PHY_PLL_REG, index);
> +
> +		if (val & HDMI_PLL_LOCKED) {
> +			drm_dbg(ddev, "Setting HDMI-%u PLL take %d cycles\n",
> +				index, count);
> +			break;
> +		}
> +		++count;
> +	} while (count < 1000);
> +
> +	lsdc_pipe_wreg32(ldev, LSDC_HDMI0_PHY_CAL_REG, index, 0x0f000ff0);
> +
> +	if (count >= 1000)
> +		drm_err(ddev, "Setting HDMI-%u PLL failed\n", index);
> +}
> +
> +static void ls7a2000_hdmi_atomic_mode_set(struct drm_encoder *encoder,
> +					  struct drm_crtc_state *crtc_state,
> +					  struct drm_connector_state *conn_state)
> +{
> +	struct lsdc_output *output = encoder_to_lsdc_output(encoder);
> +	struct lsdc_display_pipe *dispipe = output_to_display_pipe(output);
> +	unsigned int index = dispipe->index;
> +	struct drm_device *ddev = encoder->dev;
> +	struct lsdc_device *ldev = to_lsdc(ddev);
> +	struct drm_display_mode *mode = &crtc_state->mode;
> +
> +	ls7a2000_hdmi_phy_pll_config(ldev, mode->clock, index);
> +
> +	ls7a2000_hdmi_set_avi_infoframe(encoder, mode);
> +
> +	drm_dbg(ddev, "%s modeset finished\n", encoder->name);
> +}
> +
> +static const struct drm_encoder_helper_funcs ls7a2000_encoder_helper_funcs = {
> +	.atomic_disable = ls7a2000_hdmi_atomic_disable,
> +	.atomic_enable = ls7a2000_hdmi_atomic_enable,
> +	.atomic_mode_set = ls7a2000_hdmi_atomic_mode_set,
> +};
> +
> +/*
> + * For LS7A2000:
> + *
> + * 1) Most of board export one vga + hdmi output interface.
> + * 2) Yet, Some boards export double hdmi output interface.
> + * 3) Still have boards export three output(2 hdmi + 1 vga).
> + *
> + * So let's hook hdmi helper funcs to all display pipe, don't miss.
> + * writing hdmi register do no harms.
> + */
> +int ls7a2000_output_init(struct drm_device *ddev,
> +			 struct lsdc_display_pipe *dispipe,
> +			 struct i2c_adapter *ddc,
> +			 unsigned int pipe)
> +{
> +	struct lsdc_output *output = &dispipe->output;
> +	struct drm_encoder *encoder = &output->encoder;
> +	struct drm_connector *connector = &output->connector;
> +	int ret;
> +
> +	ret = drm_encoder_init(ddev,
> +			       encoder,
> +			       &ls7a2000_encoder_funcs[pipe],
> +			       DRM_MODE_ENCODER_TMDS,
> +			       "encoder-%u",
> +			       pipe);
> +	if (ret)
> +		return ret;
> +
> +	encoder->possible_crtcs = BIT(pipe);
> +
> +	drm_encoder_helper_add(encoder, &ls7a2000_encoder_helper_funcs);
> +
> +	ret = drm_connector_init_with_ddc(ddev,
> +					  connector,
> +					  &ls7a2000_hdmi_connector_funcs[pipe],
> +					  DRM_MODE_CONNECTOR_HDMIA,
> +					  ddc);
> +	if (ret)
> +		return ret;
> +
> +	drm_info(ddev, "display pipe-%u has HDMI %s\n", pipe, pipe ? "" : "and/or VGA");
> +
> +	drm_connector_helper_add(connector, &ls7a2000_connector_helpers);
> +
> +	drm_connector_attach_encoder(connector, encoder);
> +
> +	connector->polled = DRM_CONNECTOR_POLL_CONNECT |
> +			    DRM_CONNECTOR_POLL_DISCONNECT;
> +
> +	connector->interlace_allowed = 0;
> +	connector->doublescan_allowed = 0;
> +
> +	return 0;
> +}
> diff --git a/drivers/gpu/drm/loongson/lsdc_pixpll.c b/drivers/gpu/drm/loongson/lsdc_pixpll.c
> new file mode 100644
> index 000000000000..0364c49585dc
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/lsdc_pixpll.c
> @@ -0,0 +1,481 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2023 Loongson Technology Corporation Limited
> + */
> +
> +#include <linux/delay.h>
> +
> +#include <drm/drm_managed.h>
> +
> +#include "lsdc_drv.h"
> +
> +/*
> + * The structure of the pixel PLL registers is evolved with times,
> + * it can be different across different chip also.
> + */
> +
> +/* size is u64, note that all loongson's cpu is little endian.
> + * This structure is same for ls7a2000, ls7a1000 and ls2k2000.
> + */
> +struct lsdc_pixpll_reg {
> +	/* Byte 0 ~ Byte 3 */
> +	unsigned div_out       : 7;   /*  6 : 0     Output clock divider  */
> +	unsigned _reserved_1_  : 14;  /* 20 : 7                           */
> +	unsigned loopc         : 9;   /* 29 : 21    Clock multiplier      */
> +	unsigned _reserved_2_  : 2;   /* 31 : 30                          */
> +
> +	/* Byte 4 ~ Byte 7 */
> +	unsigned div_ref       : 7;   /* 38 : 32    Input clock divider   */
> +	unsigned locked        : 1;   /* 39         PLL locked indicator  */
> +	unsigned sel_out       : 1;   /* 40         output clk selector   */
> +	unsigned _reserved_3_  : 2;   /* 42 : 41                          */
> +	unsigned set_param     : 1;   /* 43         Trigger the update    */
> +	unsigned bypass        : 1;   /* 44                               */
> +	unsigned powerdown     : 1;   /* 45                               */
> +	unsigned _reserved_4_  : 18;  /* 46 : 63    no use                */
> +};
> +
> +union lsdc_pixpll_reg_bitmap {
> +	struct lsdc_pixpll_reg bitmap;
> +	u32 w[2];
> +	u64 d;
> +};
> +
> +struct clk_to_pixpll_parms_lookup_t {
> +	unsigned int clock;        /* kHz */
> +
> +	unsigned short width;
> +	unsigned short height;
> +	unsigned short vrefresh;
> +
> +	/* Stores parameters for programming the Hardware PLLs */
> +	unsigned short div_out;
> +	unsigned short loopc;
> +	unsigned short div_ref;
> +};
> +
> +static const struct clk_to_pixpll_parms_lookup_t pixpll_parms_table[] = {
> +	{148500, 1920, 1080, 60,  11, 49,  3},   /* 1920x1080@60Hz */
> +	{141750, 1920, 1080, 60,  11, 78,  5},   /* 1920x1080@60Hz */
> +						 /* 1920x1080@50Hz */
> +	{174500, 1920, 1080, 75,  17, 89,  3},   /* 1920x1080@75Hz */
> +	{181250, 2560, 1080, 75,  8,  58,  4},   /* 2560x1080@75Hz */
> +	{297000, 2560, 1080, 30,  8,  95,  4},   /* 3840x2160@30Hz */
> +	{301992, 1920, 1080, 100, 10, 151, 5},   /* 1920x1080@100Hz */
> +	{146250, 1680, 1050, 60,  16, 117, 5},   /* 1680x1050@60Hz */
> +	{135000, 1280, 1024, 75,  10, 54,  4},   /* 1280x1024@75Hz */
> +	{119000, 1680, 1050, 60,  20, 119, 5},   /* 1680x1050@60Hz */
> +	{108000, 1600, 900,  60,  15, 81,  5},   /* 1600x900@60Hz  */
> +						 /* 1280x1024@60Hz */
> +						 /* 1280x960@60Hz */
> +						 /* 1152x864@75Hz */
> +
> +	{106500, 1440, 900,  60,  19, 81,  4},   /* 1440x900@60Hz */
> +	{88750,  1440, 900,  60,  16, 71,  5},   /* 1440x900@60Hz */
> +	{83500,  1280, 800,  60,  17, 71,  5},   /* 1280x800@60Hz */
> +	{71000,  1280, 800,  60,  20, 71,  5},   /* 1280x800@60Hz */
> +
> +	{74250,  1280, 720,  60,  22, 49,  3},   /* 1280x720@60Hz */
> +						 /* 1280x720@50Hz */
> +
> +	{78750,  1024, 768,  75,  16, 63,  5},   /* 1024x768@75Hz */
> +	{75000,  1024, 768,  70,  29, 87,  4},   /* 1024x768@70Hz */
> +	{65000,  1024, 768,  60,  20, 39,  3},   /* 1024x768@60Hz */
> +
> +	{51200,  1024, 600,  60,  25, 64,  5},   /* 1024x600@60Hz */
> +
> +	{57284,  832,  624,  75,  24, 55,  4},   /* 832x624@75Hz */
> +	{49500,  800,  600,  75,  40, 99,  5},   /* 800x600@75Hz */
> +	{50000,  800,  600,  72,  44, 88,  4},   /* 800x600@72Hz */
> +	{40000,  800,  600,  60,  30, 36,  3},   /* 800x600@60Hz */
> +	{36000,  800,  600,  56,  50, 72,  4},   /* 800x600@56Hz */
> +	{31500,  640,  480,  75,  40, 63,  5},   /* 640x480@75Hz */
> +						 /* 640x480@73Hz */
> +
> +	{30240,  640,  480,  67,  62, 75,  4},   /* 640x480@67Hz */
> +	{27000,  720,  576,  50,  50, 54,  4},   /* 720x576@60Hz */
> +	{25175,  640,  480,  60,  85, 107, 5},   /* 640x480@60Hz */
> +	{25200,  640,  480,  60,  50, 63,  5},   /* 640x480@60Hz */
> +						 /* 720x480@60Hz */
> +};
> +
> +static void lsdc_pixel_pll_free(struct drm_device *ddev, void *data)
> +{
> +	struct lsdc_pixpll *this = (struct lsdc_pixpll *)data;
> +
> +	iounmap(this->mmio);
> +
> +	kfree(this->priv);
> +
> +	drm_dbg(ddev, "pixpll private data freed\n");
> +}
> +
> +/*
> + * ioremap the device dependent PLL registers
> + *
> + * @this: point to the object where this function is called from
> + */
> +static int lsdc_pixel_pll_setup(struct lsdc_pixpll * const this)
> +{
> +	struct lsdc_pixpll_parms *pparms;
> +
> +	this->mmio = ioremap(this->reg_base, this->reg_size);
> +	if (IS_ERR_OR_NULL(this->mmio))
> +		return -ENOMEM;
> +
> +	pparms = kzalloc(sizeof(*pparms), GFP_KERNEL);
> +	if (IS_ERR_OR_NULL(pparms))
> +		return -ENOMEM;
> +
> +	pparms->ref_clock = LSDC_PLL_REF_CLK;
> +
> +	this->priv = pparms;
> +
> +	return drmm_add_action_or_reset(this->ddev, lsdc_pixel_pll_free, this);
> +}
> +
> +/*
> + * Find a set of pll parameters from a static local table which avoid
> + * computing the pll parameter eachtime a modeset is triggered.
> + *
> + * @this: point to the object where this function is called from
> + * @clock: the desired output pixel clock, the unit is kHz
> + * @pout: point to where the parameters to store if found
> + *
> + * Return 0 if success, return -1 if not found.
> + */
> +static int lsdc_pixpll_find(struct lsdc_pixpll * const this,
> +			    unsigned int clock,
> +			    struct lsdc_pixpll_parms *pout)
> +{
> +	unsigned int num = ARRAY_SIZE(pixpll_parms_table);
> +	const struct clk_to_pixpll_parms_lookup_t *pt;
> +	unsigned int i;
> +
> +	for (i = 0; i < num; ++i) {
> +		pt = &pixpll_parms_table[i];
> +
> +		if (clock == pt->clock) {
> +			pout->div_ref = pt->div_ref;
> +			pout->loopc   = pt->loopc;
> +			pout->div_out = pt->div_out;
> +
> +			return 0;
> +		}
> +	}
> +
> +	drm_dbg_kms(this->ddev, "pixel clock %u: miss\n", clock);
> +
> +	return -1;
> +}
> +
> +/*
> + * Find a set of pll parameters which have minimal difference with the
> + * desired pixel clock frequency. It does that by computing all of the
> + * possible combination. Compute the diff and find the combination with
> + * minimal diff.
> + *
> + * clock_out = refclk / div_ref * loopc / div_out
> + *
> + * refclk is determined by the oscillator mounted on motherboard(100MHz
> + * in almost all board)
> + *
> + * @this: point to the object from where this function is called
> + * @clock: the desired output pixel clock, the unit is kHz
> + * @pout: point to the out struct of lsdc_pixpll_parms
> + *
> + * Return 0 if a set of parameter is found, otherwise return the error
> + * between clock_kHz we wanted and the most closest candidate with it.
> + */
> +static int lsdc_pixel_pll_compute(struct lsdc_pixpll * const this,
> +				  unsigned int clock,
> +				  struct lsdc_pixpll_parms *pout)
> +{
> +	struct lsdc_pixpll_parms *pparms = this->priv;
> +	unsigned int refclk = pparms->ref_clock;
> +	const unsigned int tolerance = 1000;
> +	unsigned int min = tolerance;
> +	unsigned int div_out, loopc, div_ref;
> +	unsigned int computed;
> +
> +	if (!lsdc_pixpll_find(this, clock, pout))
> +		return 0;
> +
> +	for (div_out = 6; div_out < 64; div_out++) {
> +		for (div_ref = 3; div_ref < 6; div_ref++) {
> +			for (loopc = 6; loopc < 161; loopc++) {
> +				unsigned int diff = 0;
> +
> +				if (loopc < 12 * div_ref)
> +					continue;
> +				if (loopc > 32 * div_ref)
> +					continue;
> +
> +				computed = refclk / div_ref * loopc / div_out;
> +
> +				if (clock >= computed)
> +					diff = clock - computed;
> +				else
> +					diff = computed - clock;
> +
> +				if (diff < min) {
> +					min = diff;
> +					pparms->div_ref = div_ref;
> +					pparms->div_out = div_out;
> +					pparms->loopc = loopc;
> +
> +					if (diff == 0) {
> +						*pout = *pparms;
> +						return 0;
> +					}
> +				}
> +			}
> +		}
> +	}
> +
> +	/* still acceptable */
> +	if (min < tolerance) {
> +		*pout = *pparms;
> +		return 0;
> +	}
> +
> +	drm_dbg(this->ddev, "can't find suitable params for %u khz\n", clock);
> +
> +	return min;
> +}
> +
> +/* Pixel pll hardware related ops, per display pipe */
> +
> +static void __pixpll_rreg(struct lsdc_pixpll *this,
> +			  union lsdc_pixpll_reg_bitmap *dst)
> +{
> +#if defined(CONFIG_64BIT)
> +	dst->d = readq(this->mmio);
> +#else
> +	dst->w[0] = readl(this->mmio);
> +	dst->w[1] = readl(this->mmio + 4);
> +#endif
> +}
> +
> +static void __pixpll_wreg(struct lsdc_pixpll *this,
> +			  union lsdc_pixpll_reg_bitmap *src)
> +{
> +#if defined(CONFIG_64BIT)
> +	writeq(src->d, this->mmio);
> +#else
> +	writel(src->w[0], this->mmio);
> +	writel(src->w[1], this->mmio + 4);
> +#endif
> +}
> +
> +static void __pixpll_ops_powerup(struct lsdc_pixpll * const this)
> +{
> +	union lsdc_pixpll_reg_bitmap pixpll_reg;
> +
> +	__pixpll_rreg(this, &pixpll_reg);
> +
> +	pixpll_reg.bitmap.powerdown = 0;
> +
> +	__pixpll_wreg(this, &pixpll_reg);
> +}
> +
> +static void __pixpll_ops_powerdown(struct lsdc_pixpll * const this)
> +{
> +	union lsdc_pixpll_reg_bitmap pixpll_reg;
> +
> +	__pixpll_rreg(this, &pixpll_reg);
> +
> +	pixpll_reg.bitmap.powerdown = 1;
> +
> +	__pixpll_wreg(this, &pixpll_reg);
> +}
> +
> +static void __pixpll_ops_on(struct lsdc_pixpll * const this)
> +{
> +	union lsdc_pixpll_reg_bitmap pixpll_reg;
> +
> +	__pixpll_rreg(this, &pixpll_reg);
> +
> +	pixpll_reg.bitmap.sel_out = 1;
> +
> +	__pixpll_wreg(this, &pixpll_reg);
> +}
> +
> +static void __pixpll_ops_off(struct lsdc_pixpll * const this)
> +{
> +	union lsdc_pixpll_reg_bitmap pixpll_reg;
> +
> +	__pixpll_rreg(this, &pixpll_reg);
> +
> +	pixpll_reg.bitmap.sel_out = 0;
> +
> +	__pixpll_wreg(this, &pixpll_reg);
> +}
> +
> +static void __pixpll_ops_bypass(struct lsdc_pixpll * const this)
> +{
> +	union lsdc_pixpll_reg_bitmap pixpll_reg;
> +
> +	__pixpll_rreg(this, &pixpll_reg);
> +
> +	pixpll_reg.bitmap.bypass = 1;
> +
> +	__pixpll_wreg(this, &pixpll_reg);
> +}
> +
> +static void __pixpll_ops_unbypass(struct lsdc_pixpll * const this)
> +{
> +	union lsdc_pixpll_reg_bitmap pixpll_reg;
> +
> +	__pixpll_rreg(this, &pixpll_reg);
> +
> +	pixpll_reg.bitmap.bypass = 0;
> +
> +	__pixpll_wreg(this, &pixpll_reg);
> +}
> +
> +static void __pixpll_ops_untoggle_param(struct lsdc_pixpll * const this)
> +{
> +	union lsdc_pixpll_reg_bitmap pixpll_reg;
> +
> +	__pixpll_rreg(this, &pixpll_reg);
> +
> +	pixpll_reg.bitmap.set_param = 0;
> +
> +	__pixpll_wreg(this, &pixpll_reg);
> +}
> +
> +static void __pixpll_ops_set_param(struct lsdc_pixpll * const this,
> +				   struct lsdc_pixpll_parms const *p)
> +{
> +	union lsdc_pixpll_reg_bitmap pixpll_reg;
> +
> +	__pixpll_rreg(this, &pixpll_reg);
> +
> +	pixpll_reg.bitmap.div_ref = p->div_ref;
> +	pixpll_reg.bitmap.loopc = p->loopc;
> +	pixpll_reg.bitmap.div_out = p->div_out;
> +
> +	__pixpll_wreg(this, &pixpll_reg);
> +}
> +
> +static void __pixpll_ops_toggle_param(struct lsdc_pixpll * const this)
> +{
> +	union lsdc_pixpll_reg_bitmap pixpll_reg;
> +
> +	__pixpll_rreg(this, &pixpll_reg);
> +
> +	pixpll_reg.bitmap.set_param = 1;
> +
> +	__pixpll_wreg(this, &pixpll_reg);
> +}
> +
> +static void __pixpll_ops_wait_locked(struct lsdc_pixpll * const this)
> +{
> +	union lsdc_pixpll_reg_bitmap pixpll_reg;
> +	unsigned int counter = 0;
> +
> +	do {
> +		__pixpll_rreg(this, &pixpll_reg);
> +
> +		if (pixpll_reg.bitmap.locked)
> +			break;
> +
> +		++counter;
> +	} while (counter < 2000);
> +
> +	drm_dbg(this->ddev, "%u loop waited\n", counter);
> +}
> +
> +/*
> + * Update the PLL parameters to the PLL hardware
> + *
> + * @this: point to the object from which this function is called
> + * @pin: point to the struct of lsdc_pixpll_parms passed in
> + *
> + * return 0 if successful.
> + */
> +static int lsdc_pixpll_update(struct lsdc_pixpll * const this,
> +			      struct lsdc_pixpll_parms const *pin)
> +{
> +	__pixpll_ops_bypass(this);
> +
> +	__pixpll_ops_off(this);
> +
> +	__pixpll_ops_powerdown(this);
> +
> +	__pixpll_ops_toggle_param(this);
> +
> +	__pixpll_ops_set_param(this, pin);
> +
> +	__pixpll_ops_untoggle_param(this);
> +
> +	__pixpll_ops_powerup(this);
> +
> +	udelay(2);
> +
> +	__pixpll_ops_wait_locked(this);
> +
> +	__pixpll_ops_on(this);
> +
> +	__pixpll_ops_unbypass(this);
> +
> +	return 0;
> +}
> +
> +static unsigned int lsdc_pixpll_get_freq(struct lsdc_pixpll * const this)
> +{
> +	struct lsdc_pixpll_parms *ppar = this->priv;
> +	union lsdc_pixpll_reg_bitmap pix_pll_reg;
> +	unsigned int freq;
> +
> +	__pixpll_rreg(this, &pix_pll_reg);
> +
> +	ppar->div_ref = pix_pll_reg.bitmap.div_ref;
> +	ppar->loopc = pix_pll_reg.bitmap.loopc;
> +	ppar->div_out = pix_pll_reg.bitmap.div_out;
> +
> +	freq = ppar->ref_clock / ppar->div_ref * ppar->loopc / ppar->div_out;
> +
> +	return freq;
> +}
> +
> +static void lsdc_pixpll_print(struct lsdc_pixpll * const this,
> +			      struct drm_printer *p)
> +{
> +	struct lsdc_pixpll_parms *parms = this->priv;
> +
> +	drm_printf(p, "div_ref: %u, loopc: %u, div_out: %u\n",
> +		   parms->div_ref, parms->loopc, parms->div_out);
> +}
> +
> +/*
> + * LS7A1000, LS7A2000 and ls2k2000's pixel pll setting register is same,
> + * we take this as default, create a new instance if a different model is
> + * introduced.
> + */
> +static const struct lsdc_pixpll_funcs __pixpll_default_funcs = {
> +	.setup = lsdc_pixel_pll_setup,
> +	.compute = lsdc_pixel_pll_compute,
> +	.update = lsdc_pixpll_update,
> +	.get_rate = lsdc_pixpll_get_freq,
> +	.print = lsdc_pixpll_print,
> +};
> +
> +/* pixel pll initialization */
> +
> +int lsdc_pixpll_init(struct lsdc_pixpll * const this,
> +		     struct drm_device *ddev,
> +		     unsigned int index)
> +{
> +	struct lsdc_device *ldev = to_lsdc(ddev);
> +	const struct lsdc_desc *descp = ldev->descp;
> +	const struct loongson_gfx_desc *gfx = to_loongson_gfx(descp);
> +
> +	this->ddev = ddev;
> +	this->reg_size = 8;
> +	this->reg_base = gfx->conf_reg_base + gfx->pixpll[index].reg_offset;
> +	this->funcs = &__pixpll_default_funcs;
> +
> +	return this->funcs->setup(this);
> +}
> diff --git a/drivers/gpu/drm/loongson/lsdc_pixpll.h b/drivers/gpu/drm/loongson/lsdc_pixpll.h
> new file mode 100644
> index 000000000000..06ebcdfc1733
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/lsdc_pixpll.h
> @@ -0,0 +1,86 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2023 Loongson Technology Corporation Limited
> + */
> +
> +#ifndef __LSDC_PIXPLL_H__
> +#define __LSDC_PIXPLL_H__
> +
> +#include <drm/drm_device.h>
> +
> +/*
> + * Loongson Pixel PLL hardware structure
> + *
> + * refclk: reference frequency, 100 MHz from external oscillator
> + * outclk: output frequency desired.
> + *
> + *
> + *               L1       Fref                      Fvco     L2
> + * refclk   +-----------+      +------------------+      +---------+   outclk
> + * ---+---> | Prescaler | ---> | Clock Multiplier | ---> | divider | -------->
> + *    |     +-----------+      +------------------+      +---------+     ^
> + *    |           ^                      ^                    ^          |
> + *    |           |                      |                    |          |
> + *    |           |                      |                    |          |
> + *    |        div_ref                 loopc               div_out       |
> + *    |                                                                  |
> + *    +---- bypass (bypass above software configurable clock if set) ----+
> + *
> + *   outclk = refclk / div_ref * loopc / div_out;
> + *
> + *   sel_out: PLL clock output selector(enable).
> + *
> + *   If sel_out == 1, then enable output clock (turn On);
> + *   If sel_out == 0, then disable output clock (turn Off);
> + *
> + * PLL working requirements:
> + *
> + *  1) 20 MHz <= refclk / div_ref <= 40Mhz
> + *  2) 1.2 GHz <= refclk /div_out * loopc <= 3.2 Ghz
> + */
> +
> +struct lsdc_pixpll_parms {
> +	unsigned int ref_clock;
> +	unsigned int div_ref;
> +	unsigned int loopc;
> +	unsigned int div_out;
> +};
> +
> +struct lsdc_pixpll;
> +
> +struct lsdc_pixpll_funcs {
> +	int (*setup)(struct lsdc_pixpll * const this);
> +
> +	int (*compute)(struct lsdc_pixpll * const this,
> +		       unsigned int clock,
> +		       struct lsdc_pixpll_parms *pout);
> +
> +	int (*update)(struct lsdc_pixpll * const this,
> +		      struct lsdc_pixpll_parms const *pin);
> +
> +	unsigned int (*get_rate)(struct lsdc_pixpll * const this);
> +
> +	void (*print)(struct lsdc_pixpll * const this,
> +		      struct drm_printer *printer);
> +};
> +
> +struct lsdc_pixpll {
> +	const struct lsdc_pixpll_funcs *funcs;
> +
> +	struct drm_device *ddev;
> +
> +	/* PLL register offset */
> +	u32 reg_base;
> +	/* PLL register size in bytes */
> +	u32 reg_size;
> +
> +	void __iomem *mmio;
> +
> +	struct lsdc_pixpll_parms *priv;
> +};
> +
> +int lsdc_pixpll_init(struct lsdc_pixpll * const this,
> +		     struct drm_device *ddev,
> +		     unsigned int index);
> +
> +#endif
> diff --git a/drivers/gpu/drm/loongson/lsdc_plane.c b/drivers/gpu/drm/loongson/lsdc_plane.c
> new file mode 100644
> index 000000000000..6d1447c7bff1
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/lsdc_plane.c
> @@ -0,0 +1,781 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2023 Loongson Technology Corporation Limited
> + */
> +
> +#include <linux/delay.h>
> +
> +#include <drm/drm_atomic.h>
> +#include <drm/drm_atomic_helper.h>
> +#include <drm/drm_framebuffer.h>
> +#include <drm/drm_gem_atomic_helper.h>
> +#include <drm/drm_plane_helper.h>
> +
> +#include "lsdc_drv.h"
> +#include "lsdc_regs.h"
> +#include "lsdc_ttm.h"
> +
> +static const u32 lsdc_primary_formats[] = {
> +	DRM_FORMAT_XRGB8888,
> +};
> +
> +static const u32 lsdc_cursor_formats[] = {
> +	DRM_FORMAT_ARGB8888,
> +};
> +
> +static const u64 lsdc_fb_format_modifiers[] = {
> +	DRM_FORMAT_MOD_LINEAR,
> +	DRM_FORMAT_MOD_INVALID
> +};
> +
> +static unsigned int lsdc_get_fb_offset(struct drm_framebuffer *fb,
> +				       struct drm_plane_state *state)
> +{
> +	unsigned int offset = fb->offsets[0];
> +
> +	offset += fb->format->cpp[0] * (state->src_x >> 16);
> +	offset += fb->pitches[0] * (state->src_y >> 16);
> +
> +	return offset;
> +}
> +
> +static u64 lsdc_fb_base_addr(struct drm_framebuffer *fb)
> +{
> +	struct lsdc_device *ldev = to_lsdc(fb->dev);
> +	struct lsdc_bo *lbo = gem_to_lsdc_bo(fb->obj[0]);
> +
> +	return lsdc_bo_gpu_offset(lbo) + ldev->vram_base;
> +}
> +
> +static int lsdc_primary_atomic_check(struct drm_plane *plane,
> +				     struct drm_atomic_state *state)
> +{
> +	struct drm_plane_state *new_plane_state = drm_atomic_get_new_plane_state(state, plane);
> +	struct drm_crtc *crtc = new_plane_state->crtc;
> +	struct drm_crtc_state *new_crtc_state;
> +
> +	if (!crtc)
> +		return 0;
> +
> +	new_crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
> +
> +	return drm_atomic_helper_check_plane_state(new_plane_state,
> +						   new_crtc_state,
> +						   DRM_PLANE_NO_SCALING,
> +						   DRM_PLANE_NO_SCALING,
> +						   false,
> +						   true);
> +}
> +
> +static void lsdc_primary_atomic_update(struct drm_plane *plane,
> +				       struct drm_atomic_state *state)
> +{
> +	struct lsdc_primary *primary = to_lsdc_primary(plane);
> +	const struct lsdc_primary_plane_ops *ops = primary->ops;
> +	struct drm_plane_state *old_plane_state = drm_atomic_get_old_plane_state(state, plane);
> +	struct drm_plane_state *new_plane_state = drm_atomic_get_new_plane_state(state, plane);
> +	struct drm_framebuffer *new_fb = new_plane_state->fb;
> +	struct drm_framebuffer *old_fb = old_plane_state->fb;
> +	u64 fb_addr = lsdc_fb_base_addr(new_fb);
> +
> +	fb_addr += lsdc_get_fb_offset(new_fb, new_plane_state);
> +
> +	drm_dbg(plane->dev, "fb dma addr: %llx\n", fb_addr);
> +
> +	ops->update_fb_addr(primary, fb_addr);
> +	ops->update_fb_stride(primary, new_fb->pitches[0]);
> +
> +	if (!old_fb || old_fb->format != new_fb->format)
> +		ops->update_fb_format(primary, new_fb->format);
> +}
> +
> +static void lsdc_primary_atomic_disable(struct drm_plane *plane,
> +					struct drm_atomic_state *state)
> +{
> +	/* Do nothing, just prevent call into atomic_update().

IIRC block comments should start with the first line being just "/*", 
with the content starting from the next line.

> +	 * Writing the format as LSDC_PF_NONE can disable the primary,
> +	 * But it seems not necessary...
> +	 */
> +	drm_dbg(plane->dev, "%s disabled\n", plane->name);
> +}
> +
> +static int lsdc_plane_prepare_fb(struct drm_plane *plane,
> +				 struct drm_plane_state *new_state)
> +{
> +	struct drm_framebuffer *fb = new_state->fb;
> +	struct lsdc_bo *lbo;
> +	u64 gpu_vaddr;
> +	int ret;
> +
> +	if (!fb)
> +		return 0;
> +
> +	lbo = gem_to_lsdc_bo(fb->obj[0]);
> +
> +	ret = lsdc_bo_reserve(lbo);
> +	if (unlikely(ret)) {
> +		drm_err(plane->dev, "bo %p reserve failed\n", lbo);
> +		return ret;
> +	}
> +
> +	ret = lsdc_bo_pin(lbo, LSDC_GEM_DOMAIN_VRAM, &gpu_vaddr);
> +
> +	lsdc_bo_unreserve(lbo);
> +
> +	if (unlikely(ret)) {
> +		drm_err(plane->dev, "bo %p pin failed\n", lbo);
> +		return ret;
> +	}
> +
> +	lsdc_bo_ref(lbo);
> +
> +	if (plane->type != DRM_PLANE_TYPE_CURSOR)
> +		drm_dbg(plane->dev,
> +			"%s[%p] pin at 0x%llx, bo size: %zu\n",
> +			plane->name, lbo, gpu_vaddr, lsdc_bo_size(lbo));
> +
> +	return drm_gem_plane_helper_prepare_fb(plane, new_state);
> +}
> +
> +static void lsdc_plane_cleanup_fb(struct drm_plane *plane,
> +				  struct drm_plane_state *old_state)
> +{
> +	struct drm_framebuffer *fb = old_state->fb;
> +	struct lsdc_bo *lbo;
> +	int ret;
> +
> +	if (!fb)
> +		return;
> +
> +	lbo = gem_to_lsdc_bo(fb->obj[0]);
> +
> +	ret = lsdc_bo_reserve(lbo);
> +	if (unlikely(ret)) {
> +		drm_err(plane->dev, "%p reserve failed\n", lbo);
> +		return;
> +	}
> +
> +	lsdc_bo_unpin(lbo);
> +
> +	lsdc_bo_unreserve(lbo);
> +
> +	lsdc_bo_unref(lbo);
> +
> +	if (plane->type != DRM_PLANE_TYPE_CURSOR)
> +		drm_dbg(plane->dev, "%s unpin\n", plane->name);
> +}
> +
> +static const struct drm_plane_helper_funcs lsdc_primary_helper_funcs = {
> +	.prepare_fb = lsdc_plane_prepare_fb,
> +	.cleanup_fb = lsdc_plane_cleanup_fb,
> +	.atomic_check = lsdc_primary_atomic_check,
> +	.atomic_update = lsdc_primary_atomic_update,
> +	.atomic_disable = lsdc_primary_atomic_disable,
> +};
> +
> +static int lsdc_cursor_plane_atomic_async_check(struct drm_plane *plane,
> +						struct drm_atomic_state *state)
> +{
> +	struct drm_plane_state *new_state;
> +	struct drm_crtc_state *crtc_state;
> +
> +	new_state = drm_atomic_get_new_plane_state(state, plane);
> +
> +	if (!plane->state || !plane->state->fb) {
> +		drm_dbg(plane->dev, "%s: state is NULL\n", plane->name);
> +		return -EINVAL;
> +	}
> +
> +	if (state) {
> +		crtc_state = drm_atomic_get_existing_crtc_state(state, new_state->crtc);
> +	} else {
> +		crtc_state = plane->crtc->state;
> +		drm_dbg(plane->dev, "%s: atomic state is NULL\n", plane->name);
> +	}
> +
> +	if (!crtc_state->active)
> +		return -EINVAL;
> +
> +	if (plane->state->crtc != new_state->crtc ||
> +	    plane->state->src_w != new_state->src_w ||
> +	    plane->state->src_h != new_state->src_h ||
> +	    plane->state->crtc_w != new_state->crtc_w ||
> +	    plane->state->crtc_h != new_state->crtc_h)
> +		return -EINVAL;
> +
> +	return drm_atomic_helper_check_plane_state(plane->state,
> +						   crtc_state,
> +						   DRM_PLANE_NO_SCALING,
> +						   DRM_PLANE_NO_SCALING,
> +						   true,
> +						   true);
> +}
> +
> +static void lsdc_cursor_plane_atomic_async_update(struct drm_plane *plane,
> +						  struct drm_atomic_state *state)
> +{
> +	struct lsdc_cursor *cursor = to_lsdc_cursor(plane);
> +	const struct lsdc_cursor_plane_ops *ops = cursor->ops;
> +	struct drm_framebuffer *old_fb = plane->state->fb;
> +	struct drm_framebuffer *new_fb;
> +	struct drm_plane_state *new_state;
> +
> +	new_state = drm_atomic_get_new_plane_state(state, plane);
> +
> +	new_fb = plane->state->fb;
> +
> +	plane->state->crtc_x = new_state->crtc_x;
> +	plane->state->crtc_y = new_state->crtc_y;
> +	plane->state->crtc_h = new_state->crtc_h;
> +	plane->state->crtc_w = new_state->crtc_w;
> +	plane->state->src_x = new_state->src_x;
> +	plane->state->src_y = new_state->src_y;
> +	plane->state->src_h = new_state->src_h;
> +	plane->state->src_w = new_state->src_w;
> +	swap(plane->state->fb, new_state->fb);
> +
> +	if (new_state->visible) {
> +		enum lsdc_cursor_size cursor_size;
> +
> +		switch (new_state->crtc_w) {
> +		case 64:
> +			cursor_size = CURSOR_SIZE_64X64;
> +			break;
> +		case 32:
> +			cursor_size = CURSOR_SIZE_32X32;
> +			break;
> +		default:
> +			cursor_size = CURSOR_SIZE_32X32;
> +			break;
> +		}
> +
> +		ops->update_position(cursor, new_state->crtc_x, new_state->crtc_y);
> +
> +		ops->update_cfg(cursor, cursor_size, CURSOR_FORMAT_ARGB8888);
> +
> +		if (!old_fb || old_fb != new_fb)
> +			ops->update_bo_addr(cursor, lsdc_fb_base_addr(new_fb));
> +	}
> +}
> +
> +/* ls7a1000 cursor plane helpers */
> +
> +static int ls7a1000_cursor_plane_atomic_check(struct drm_plane *plane,
> +					      struct drm_atomic_state *state)
> +{
> +	struct drm_plane_state *new_plane_state;
> +	struct drm_crtc_state *new_crtc_state;
> +	struct drm_crtc *crtc;
> +
> +	new_plane_state = drm_atomic_get_new_plane_state(state, plane);
> +
> +	crtc = new_plane_state->crtc;
> +	if (!crtc) {
> +		drm_dbg(plane->dev, "%s is not bind to a crtc\n", plane->name);
> +		return 0;
> +	}
> +
> +	if (new_plane_state->crtc_w > 32 || new_plane_state->crtc_h > 32) {
> +		drm_dbg(plane->dev, "%s is too large %ux%u\n", plane->name,
> +			new_plane_state->crtc_w, new_plane_state->crtc_h);
> +		return -EINVAL;
> +	}
> +
> +	new_crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
> +
> +	return drm_atomic_helper_check_plane_state(new_plane_state,
> +						   new_crtc_state,
> +						   DRM_PLANE_NO_SCALING,
> +						   DRM_PLANE_NO_SCALING,
> +						   true,
> +						   true);
> +}
> +
> +static void ls7a1000_cursor_plane_atomic_update(struct drm_plane *plane,
> +						struct drm_atomic_state *state)
> +{
> +	struct lsdc_cursor *cursor = to_lsdc_cursor(plane);
> +	struct drm_plane_state *old_plane_state = drm_atomic_get_old_plane_state(state, plane);
> +	struct drm_plane_state *new_plane_state = drm_atomic_get_new_plane_state(state, plane);
> +	struct drm_framebuffer *new_fb = new_plane_state->fb;
> +	struct drm_framebuffer *old_fb = old_plane_state->fb;
> +	const struct lsdc_cursor_plane_ops *ops = cursor->ops;
> +	u64 addr = lsdc_fb_base_addr(new_fb);
> +
> +	if (!new_plane_state->visible)
> +		return;
> +
> +	ops->update_position(cursor, new_plane_state->crtc_x, new_plane_state->crtc_y);
> +
> +	if (!old_fb || old_fb != new_fb)
> +		ops->update_bo_addr(cursor, addr);
> +
> +	ops->update_cfg(cursor, CURSOR_SIZE_32X32, CURSOR_FORMAT_ARGB8888);
> +}
> +
> +static void ls7a1000_cursor_plane_atomic_disable(struct drm_plane *plane,
> +						 struct drm_atomic_state *state)
> +{
> +	struct lsdc_cursor *cursor = to_lsdc_cursor(plane);
> +	const struct lsdc_cursor_plane_ops *ops = cursor->ops;
> +
> +	ops->update_cfg(cursor, CURSOR_SIZE_32X32, CURSOR_FORMAT_DISABLE);
> +}
> +
> +static const struct drm_plane_helper_funcs ls7a1000_cursor_plane_helper_funcs = {
> +	.prepare_fb = lsdc_plane_prepare_fb,
> +	.cleanup_fb = lsdc_plane_cleanup_fb,
> +	.atomic_check = ls7a1000_cursor_plane_atomic_check,
> +	.atomic_update = ls7a1000_cursor_plane_atomic_update,
> +	.atomic_disable = ls7a1000_cursor_plane_atomic_disable,
> +	.atomic_async_check = lsdc_cursor_plane_atomic_async_check,
> +	.atomic_async_update = lsdc_cursor_plane_atomic_async_update,
> +};
> +
> +/* ls7a2000 cursor plane helpers */
> +
> +static int ls7a2000_cursor_plane_atomic_check(struct drm_plane *plane,
> +					      struct drm_atomic_state *state)
> +{
> +	struct drm_plane_state *new_plane_state;
> +	struct drm_crtc_state *new_crtc_state;
> +	struct drm_crtc *crtc;
> +
> +	new_plane_state = drm_atomic_get_new_plane_state(state, plane);
> +
> +	crtc = new_plane_state->crtc;
> +	if (!crtc) {
> +		drm_dbg(plane->dev, "%s is not bind to a crtc\n", plane->name);
> +		return 0;
> +	}
> +
> +	if (new_plane_state->crtc_w > 64 || new_plane_state->crtc_h > 64) {
> +		drm_dbg(plane->dev, "%s is too large %ux%u\n", plane->name,
> +			new_plane_state->crtc_w, new_plane_state->crtc_h);
> +		return -EINVAL;
> +	}
> +
> +	new_crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
> +
> +	return drm_atomic_helper_check_plane_state(new_plane_state,
> +						   new_crtc_state,
> +						   DRM_PLANE_NO_SCALING,
> +						   DRM_PLANE_NO_SCALING,
> +						   true,
> +						   true);
> +}
> +
> +/* update the format, size and location of the cursor */
> +
> +static void ls7a2000_cursor_plane_atomic_update(struct drm_plane *plane,
> +						struct drm_atomic_state *state)
> +{
> +	struct lsdc_cursor *cursor = to_lsdc_cursor(plane);
> +	struct drm_plane_state *old_plane_state = drm_atomic_get_old_plane_state(state, plane);
> +	struct drm_plane_state *new_plane_state = drm_atomic_get_new_plane_state(state, plane);
> +	struct drm_framebuffer *new_fb = new_plane_state->fb;
> +	struct drm_framebuffer *old_fb = old_plane_state->fb;
> +	const struct lsdc_cursor_plane_ops *ops = cursor->ops;
> +	u64 addr = lsdc_fb_base_addr(new_fb);
> +
> +	if (!new_plane_state->visible)
> +		return;
> +
> +	ops->update_position(cursor, new_plane_state->crtc_x, new_plane_state->crtc_y);
> +
> +	if (!old_fb || new_fb != old_fb)
> +		ops->update_bo_addr(cursor, addr);
> +
> +	ops->update_cfg(cursor, CURSOR_SIZE_64X64, CURSOR_FORMAT_ARGB8888);
> +}
> +
> +static void ls7a2000_cursor_plane_atomic_disable(struct drm_plane *plane,
> +						 struct drm_atomic_state *state)
> +{
> +	struct lsdc_cursor *cursor = to_lsdc_cursor(plane);
> +	const struct lsdc_cursor_plane_ops *hw_ops = cursor->ops;
> +
> +	hw_ops->update_cfg(cursor, CURSOR_SIZE_64X64, CURSOR_FORMAT_DISABLE);
> +}
> +
> +static const struct drm_plane_helper_funcs ls7a2000_cursor_plane_helper_funcs = {
> +	.prepare_fb = lsdc_plane_prepare_fb,
> +	.cleanup_fb = lsdc_plane_cleanup_fb,
> +	.atomic_check = ls7a2000_cursor_plane_atomic_check,
> +	.atomic_update = ls7a2000_cursor_plane_atomic_update,
> +	.atomic_disable = ls7a2000_cursor_plane_atomic_disable,
> +	.atomic_async_check = lsdc_cursor_plane_atomic_async_check,
> +	.atomic_async_update = lsdc_cursor_plane_atomic_async_update,
> +};
> +
> +static void lsdc_plane_atomic_print_state(struct drm_printer *p,
> +					  const struct drm_plane_state *state)
> +{
> +	struct drm_framebuffer *fb = state->fb;
> +	u64 addr;
> +
> +	if (!fb)
> +		return;
> +
> +	addr = lsdc_fb_base_addr(fb);
> +
> +	drm_printf(p, "\tdma addr=%llx\n", addr);
> +}
> +
> +static const struct drm_plane_funcs lsdc_plane_funcs = {
> +	.update_plane = drm_atomic_helper_update_plane,
> +	.disable_plane = drm_atomic_helper_disable_plane,
> +	.destroy = drm_plane_cleanup,
> +	.reset = drm_atomic_helper_plane_reset,
> +	.atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
> +	.atomic_destroy_state = drm_atomic_helper_plane_destroy_state,
> +	.atomic_print_state = lsdc_plane_atomic_print_state,
> +};
> +
> +/* primary plane 0 hardware related ops  */
> +
> +static void lsdc_primary0_update_fb_addr(struct lsdc_primary *primary, u64 addr)
> +{
> +	struct lsdc_device *ldev = primary->ldev;
> +	u32 status;
> +	u32 lo, hi;
> +
> +	/* 40-bit width physical address bus */
> +	lo = addr & 0xFFFFFFFF;
> +	hi = (addr >> 32) & 0xFF;
> +
> +	status = lsdc_rreg32(ldev, LSDC_CRTC0_CFG_REG);
> +	if (status & FB_REG_IN_USING) {
> +		lsdc_wreg32(ldev, LSDC_CRTC0_FB1_ADDR_LO_REG, lo);
> +		lsdc_wreg32(ldev, LSDC_CRTC0_FB1_ADDR_HI_REG, hi);
> +	} else {
> +		lsdc_wreg32(ldev, LSDC_CRTC0_FB0_ADDR_LO_REG, lo);
> +		lsdc_wreg32(ldev, LSDC_CRTC0_FB0_ADDR_HI_REG, hi);
> +	}
> +}
> +
> +static void lsdc_primary0_update_fb_stride(struct lsdc_primary *primary, u32 stride)
> +{
> +	struct lsdc_device *ldev = primary->ldev;
> +
> +	lsdc_wreg32(ldev, LSDC_CRTC0_STRIDE_REG, stride);
> +}
> +
> +static void lsdc_primary0_update_fb_format(struct lsdc_primary *primary,
> +					   const struct drm_format_info *format)
> +{
> +	struct lsdc_device *ldev = primary->ldev;
> +	u32 status;
> +
> +	status = lsdc_rreg32(ldev, LSDC_CRTC0_CFG_REG);
> +
> +	/*
> +	 * TODO: add RGB565 support, only support XRBG8888 at present
> +	 */
> +	status &= ~CFG_PIX_FMT_MASK;
> +	status |= LSDC_PF_XRGB8888;
> +
> +	lsdc_wreg32(ldev, LSDC_CRTC0_CFG_REG, status);
> +
> +	udelay(9);
> +}
> +
> +/* primary plane 1 hardware related ops */
> +
> +static void lsdc_primary1_update_fb_addr(struct lsdc_primary *primary, u64 addr)
> +{
> +	struct lsdc_device *ldev = primary->ldev;
> +	u32 status;
> +	u32 lo, hi;
> +
> +	/* 40-bit width physical address bus */
> +	lo = addr & 0xFFFFFFFF;
> +	hi = (addr >> 32) & 0xFF;
> +
> +	status = lsdc_rreg32(ldev, LSDC_CRTC1_CFG_REG);
> +	if (status & FB_REG_IN_USING) {
> +		lsdc_wreg32(ldev, LSDC_CRTC1_FB1_ADDR_LO_REG, lo);
> +		lsdc_wreg32(ldev, LSDC_CRTC1_FB1_ADDR_HI_REG, hi);
> +	} else {
> +		lsdc_wreg32(ldev, LSDC_CRTC1_FB0_ADDR_LO_REG, lo);
> +		lsdc_wreg32(ldev, LSDC_CRTC1_FB0_ADDR_HI_REG, hi);
> +	}
> +}
> +
> +static void lsdc_primary1_update_fb_stride(struct lsdc_primary *primary, u32 stride)
> +{
> +	struct lsdc_device *ldev = primary->ldev;
> +
> +	lsdc_wreg32(ldev, LSDC_CRTC1_STRIDE_REG, stride);
> +}
> +
> +static void lsdc_primary1_update_fb_format(struct lsdc_primary *primary,
> +					   const struct drm_format_info *format)
> +{
> +	struct lsdc_device *ldev = primary->ldev;
> +	u32 status;
> +
> +	status = lsdc_rreg32(ldev, LSDC_CRTC1_CFG_REG);
> +
> +	/*
> +	 * TODO: add RGB565 support, only support XRBG8888 at present
> +	 */
> +	status &= ~CFG_PIX_FMT_MASK;
> +	status |= LSDC_PF_XRGB8888;
> +
> +	lsdc_wreg32(ldev, LSDC_CRTC1_CFG_REG, status);
> +
> +	udelay(9);
> +}
> +
> +static const struct lsdc_primary_plane_ops lsdc_primary_plane_hw_ops[2] = {
> +	{
> +		.update_fb_addr = lsdc_primary0_update_fb_addr,
> +		.update_fb_stride = lsdc_primary0_update_fb_stride,
> +		.update_fb_format = lsdc_primary0_update_fb_format,
> +	},
> +	{
> +		.update_fb_addr = lsdc_primary1_update_fb_addr,
> +		.update_fb_stride = lsdc_primary1_update_fb_stride,
> +		.update_fb_format = lsdc_primary1_update_fb_format,
> +	},
> +};
> +
> +/*
> + * Update location, format, enable and disable state of the cursor,
> + * For those who have two hardware cursor, cursor 0 is attach it to CRTC-0,
> + * cursor 1 is attached to CRTC-1. Compositing the primary and cursor plane
> + * is automatically done by hardware, the cursor is alway on the top of the
> + * primary. In other word, z-order is fixed in hardware and cannot be changed.
> + * For those old DC who has only one hardware cursor, we made it shared by
> + * the two screen, this works on extend screen mode.
> + */
> +
> +/* cursor plane 0 (for pipe 0) related hardware ops */
> +
> +static void lsdc_cursor0_update_bo_addr(struct lsdc_cursor *cursor, u64 addr)
> +{
> +	struct lsdc_device *ldev = cursor->ldev;
> +
> +	/* 40-bit width physical address bus */
> +	lsdc_wreg32(ldev, LSDC_CURSOR0_ADDR_HI_REG, (addr >> 32) & 0xFF);
> +	lsdc_wreg32(ldev, LSDC_CURSOR0_ADDR_LO_REG, addr);
> +}
> +
> +static void lsdc_cursor0_update_position(struct lsdc_cursor *cursor, int x, int y)
> +{
> +	struct lsdc_device *ldev = cursor->ldev;
> +
> +	if (x < 0)
> +		x = 0;
> +
> +	if (y < 0)
> +		y = 0;
> +
> +	lsdc_wreg32(ldev, LSDC_CURSOR0_POSITION_REG, (y << 16) | x);
> +}
> +
> +static void lsdc_cursor0_update_cfg(struct lsdc_cursor *cursor,
> +				    enum lsdc_cursor_size cursor_size,
> +				    enum lsdc_cursor_format fmt)
> +{
> +	struct lsdc_device *ldev = cursor->ldev;
> +	u32 cfg;
> +
> +	cfg = CURSOR_ON_CRTC0 << CURSOR_LOCATION_SHIFT |
> +	      cursor_size << CURSOR_SIZE_SHIFT |
> +	      fmt << CURSOR_FORMAT_SHIFT;
> +
> +	lsdc_wreg32(ldev, LSDC_CURSOR0_CFG_REG, cfg);
> +}
> +
> +/* cursor plane 1 (for pipe 1) related hardware ops */
> +
> +static void lsdc_cursor1_update_bo_addr(struct lsdc_cursor *cursor, u64 addr)
> +{
> +	struct lsdc_device *ldev = cursor->ldev;
> +
> +	/* 40-bit width physical address bus */
> +	lsdc_wreg32(ldev, LSDC_CURSOR1_ADDR_HI_REG, (addr >> 32) & 0xFF);
> +	lsdc_wreg32(ldev, LSDC_CURSOR1_ADDR_LO_REG, addr);
> +}
> +
> +static void lsdc_cursor1_update_position(struct lsdc_cursor *cursor, int x, int y)
> +{
> +	struct lsdc_device *ldev = cursor->ldev;
> +
> +	if (x < 0)
> +		x = 0;
> +
> +	if (y < 0)
> +		y = 0;
> +
> +	lsdc_wreg32(ldev, LSDC_CURSOR1_POSITION_REG, (y << 16) | x);
> +}
> +
> +static void lsdc_cursor1_update_cfg(struct lsdc_cursor *cursor,
> +				    enum lsdc_cursor_size cursor_size,
> +				    enum lsdc_cursor_format fmt)
> +{
> +	struct lsdc_device *ldev = cursor->ldev;
> +	u32 cfg;
> +
> +	cfg = CURSOR_ON_CRTC1 << CURSOR_LOCATION_SHIFT |
> +	      cursor_size << CURSOR_SIZE_SHIFT |
> +	      fmt << CURSOR_FORMAT_SHIFT;
> +
> +	lsdc_wreg32(ldev, LSDC_CURSOR1_CFG_REG, cfg);
> +}
> +
> +/* The hardware cursors become normal since ls7a2000/ls2k2000,  */
> +
> +static const struct lsdc_cursor_plane_ops ls7a2000_cursor_hw_ops[2] = {
> +	{
> +		.update_bo_addr = lsdc_cursor0_update_bo_addr,
> +		.update_cfg = lsdc_cursor0_update_cfg,
> +		.update_position = lsdc_cursor0_update_position,
> +	},
> +	{
> +		.update_bo_addr = lsdc_cursor1_update_bo_addr,
> +		.update_cfg = lsdc_cursor1_update_cfg,
> +		.update_position = lsdc_cursor1_update_position,
> +	},
> +};
> +
> +/* quirks for cursor 1, only for old loongson display controller */
> +
> +static void lsdc_cursor1_update_bo_addr_quirk(struct lsdc_cursor *cursor, u64 addr)
> +{
> +	struct lsdc_device *ldev = cursor->ldev;
> +
> +	/* 40-bit width physical address bus */
> +	lsdc_wreg32(ldev, LSDC_CURSOR0_ADDR_HI_REG, (addr >> 32) & 0xFF);
> +	lsdc_wreg32(ldev, LSDC_CURSOR0_ADDR_LO_REG, addr);
> +}
> +
> +static void lsdc_cursor1_update_position_quirk(struct lsdc_cursor *cursor, int x, int y)
> +{
> +	struct lsdc_device *ldev = cursor->ldev;
> +
> +	if (x < 0)
> +		x = 0;
> +
> +	if (y < 0)
> +		y = 0;
> +
> +	lsdc_wreg32(ldev, LSDC_CURSOR0_POSITION_REG, (y << 16) | x);
> +}
> +
> +static void lsdc_cursor1_update_cfg_quirk(struct lsdc_cursor *cursor,
> +					  enum lsdc_cursor_size cursor_size,
> +					  enum lsdc_cursor_format fmt)
> +{
> +	struct lsdc_device *ldev = cursor->ldev;
> +	u32 cfg;
> +
> +	cfg = CURSOR_ON_CRTC1 << CURSOR_LOCATION_SHIFT |
> +	      cursor_size << CURSOR_SIZE_SHIFT |
> +	      fmt << CURSOR_FORMAT_SHIFT;
> +
> +	lsdc_wreg32(ldev, LSDC_CURSOR0_CFG_REG, cfg);
> +}
> +
> +/*
> + * The unforgiving LS7A1000/LS2K1000 has only one hardware cursors plane
> + */
> +static const struct lsdc_cursor_plane_ops ls7a1000_cursor_hw_ops[2] = {
> +	{
> +		.update_bo_addr = lsdc_cursor0_update_bo_addr,
> +		.update_cfg = lsdc_cursor0_update_cfg,
> +		.update_position = lsdc_cursor0_update_position,
> +	},
> +	{
> +		.update_bo_addr = lsdc_cursor1_update_bo_addr_quirk,
> +		.update_cfg = lsdc_cursor1_update_cfg_quirk,
> +		.update_position = lsdc_cursor1_update_position_quirk,
> +	},
> +};
> +
> +int lsdc_primary_plane_init(struct drm_device *ddev,
> +			    struct drm_plane *plane,
> +			    unsigned int index)
> +{
> +	struct lsdc_primary *primary = to_lsdc_primary(plane);
> +	int ret;
> +
> +	ret = drm_universal_plane_init(ddev,
> +				       plane,
> +				       1 << index,
> +				       &lsdc_plane_funcs,
> +				       lsdc_primary_formats,
> +				       ARRAY_SIZE(lsdc_primary_formats),
> +				       lsdc_fb_format_modifiers,
> +				       DRM_PLANE_TYPE_PRIMARY,
> +				       "primary-%u",
> +				       index);
> +	if (ret)
> +		return ret;
> +
> +	drm_plane_helper_add(plane, &lsdc_primary_helper_funcs);
> +
> +	primary->ldev = to_lsdc(ddev);
> +	primary->ops = &lsdc_primary_plane_hw_ops[index];
> +
> +	return 0;
> +}
> +
> +int ls7a1000_cursor_plane_init(struct drm_device *ddev,
> +			       struct drm_plane *plane,
> +			       unsigned int index)
> +{
> +	struct lsdc_cursor *cursor = to_lsdc_cursor(plane);
> +	int ret;
> +
> +	ret = drm_universal_plane_init(ddev,
> +				       plane,
> +				       1 << index,
> +				       &lsdc_plane_funcs,
> +				       lsdc_cursor_formats,
> +				       ARRAY_SIZE(lsdc_cursor_formats),
> +				       lsdc_fb_format_modifiers,
> +				       DRM_PLANE_TYPE_CURSOR,
> +				       "cursor-%u",
> +				       index);
> +	if (ret)
> +		return ret;
> +
> +	cursor->ldev = to_lsdc(ddev);
> +	cursor->ops = &ls7a1000_cursor_hw_ops[index];
> +
> +	drm_plane_helper_add(plane, &ls7a1000_cursor_plane_helper_funcs);
> +
> +	return 0;
> +}
> +
> +int ls7a2000_cursor_plane_init(struct drm_device *ddev,
> +			       struct drm_plane *plane,
> +			       unsigned int index)
> +{
> +	struct lsdc_cursor *cursor = to_lsdc_cursor(plane);
> +	int ret;
> +
> +	ret = drm_universal_plane_init(ddev,
> +				       plane,
> +				       1 << index,
> +				       &lsdc_plane_funcs,
> +				       lsdc_cursor_formats,
> +				       ARRAY_SIZE(lsdc_cursor_formats),
> +				       lsdc_fb_format_modifiers,
> +				       DRM_PLANE_TYPE_CURSOR,
> +				       "cursor-%u",
> +				       index);
> +	if (ret)
> +		return ret;
> +
> +	cursor->ldev = to_lsdc(ddev);
> +	cursor->ops = &ls7a2000_cursor_hw_ops[index];
> +
> +	drm_plane_helper_add(plane, &ls7a2000_cursor_plane_helper_funcs);
> +
> +	return 0;
> +}
> diff --git a/drivers/gpu/drm/loongson/lsdc_probe.c b/drivers/gpu/drm/loongson/lsdc_probe.c
> new file mode 100644
> index 000000000000..48ba69bb8a98
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/lsdc_probe.c
> @@ -0,0 +1,56 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2023 Loongson Technology Corporation Limited
> + */
> +
> +#include "lsdc_drv.h"
> +#include "lsdc_probe.h"
> +
> +/*
> + * Processor ID (implementation) values for bits 15:8 of the PRID register.
> + */
> +#define LOONGSON_CPU_IMP_MASK           0xff00
> +#define LOONGSON_CPU_IMP_SHIFT          8
> +
> +#define LOONGARCH_CPU_IMP_LS2K1000      0xa0
> +#define LOONGARCH_CPU_IMP_LS2K2000      0xb0
> +#define LOONGARCH_CPU_IMP_LS3A5000      0xc0
> +
> +#define LOONGSON_CPU_MIPS_IMP_LS2K      0x61 /* Loongson 2K Mips series SoC */
> +
> +/*
> + * Particular Revision values for bits 7:0 of the PRID register.
> + */
> +#define LOONGSON_CPU_REV_MASK           0x00ff
> +
> +#define LOONGARCH_CPUCFG_PRID_REG       0x0
> +
> +/*
> + * We can achieve fine-grained control with the information about the host.
> + */

As I've noted before, this is actually not used anywhere, except 
seemingly when displaying some debug information. Please consider 
removing this altogether and add back if necessary in the future.

> +
> +unsigned int loongson_cpu_get_prid(u8 *imp, u8 *rev)
> +{
> +	unsigned int prid = 0;
> +
> +#if defined(__loongarch__)
> +	__asm__ volatile("cpucfg %0, %1\n\t"
> +			: "=&r"(prid)
> +			: "r"(LOONGARCH_CPUCFG_PRID_REG)
> +			);
> +#endif
> +
> +#if defined(__mips__)
> +	__asm__ volatile("mfc0\t%0, $15\n\t"
> +			: "=r" (prid)
> +			);
> +#endif
> +
> +	if (imp)
> +		*imp = (prid & LOONGSON_CPU_IMP_MASK) >> LOONGSON_CPU_IMP_SHIFT;
> +
> +	if (rev)
> +		*rev = prid & LOONGSON_CPU_REV_MASK;
> +
> +	return prid;
> +}
> diff --git a/drivers/gpu/drm/loongson/lsdc_probe.h b/drivers/gpu/drm/loongson/lsdc_probe.h
> new file mode 100644
> index 000000000000..7a96bec49ab9
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/lsdc_probe.h
> @@ -0,0 +1,12 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2023 Loongson Technology Corporation Limited
> + */
> +
> +#ifndef __LSDC_PROBE_H__
> +#define __LSDC_PROBE_H__
> +
> +/* Helpers for chip detection */
> +unsigned int loongson_cpu_get_prid(u8 *impl, u8 *rev);
> +
> +#endif
> diff --git a/drivers/gpu/drm/loongson/lsdc_regs.h b/drivers/gpu/drm/loongson/lsdc_regs.h
> new file mode 100644
> index 000000000000..30ff0450ddcd
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/lsdc_regs.h
> @@ -0,0 +1,402 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2023 Loongson Technology Corporation Limited
> + */
> +
> +#ifndef __LSDC_REGS_H__
> +#define __LSDC_REGS_H__
> +
> +#include <linux/bitops.h>
> +#include <linux/types.h>
> +
> +/*
> + * PIXEL PLL Reference clock
> + */
> +#define LSDC_PLL_REF_CLK                100000           /* kHz */

Consider naming it like "LSDC_PLL_REF_CLK_KHZ" for it to be 
self-documenting?

> +
> +/*
> + * Those PLL registers are relative to LSxxxxx_CFG_REG_BASE. xxxxx = 7A1000,
> + * 7A2000, 2K2000, 2K1000 etc.
> + */
> +
> +/* LS7A1000 */
> +
> +#define LS7A1000_PIXPLL0_REG            0x04B0
> +#define LS7A1000_PIXPLL1_REG            0x04C0
> +
> +/* The DC, GPU, Graphic Memory Controller share the single gfxpll */
> +#define LS7A1000_PLL_GFX_REG            0x0490
> +
> +#define LS7A1000_CONF_REG_BASE          0x10010000
> +
> +/* LS7A2000 */
> +
> +#define LS7A2000_PIXPLL0_REG            0x04B0
> +#define LS7A2000_PIXPLL1_REG            0x04C0
> +
> +/* The DC, GPU, Graphic Memory Controller share the single gfxpll */
> +#define LS7A2000_PLL_GFX_REG            0x0490
> +
> +#define LS7A2000_CONF_REG_BASE          0x10010000
> +
> +/* For LSDC_CRTCx_CFG_REG */
> +#define CFG_PIX_FMT_MASK                GENMASK(2, 0)
> +
> +enum lsdc_pixel_format {
> +	LSDC_PF_NONE = 0,
> +	LSDC_PF_XRGB444 = 1,    /* [12 bits] */
> +	LSDC_PF_XRGB555 = 2,    /* [15 bits] */
> +	LSDC_PF_XRGB565 = 3,    /* RGB [16 bits] */
> +	LSDC_PF_XRGB8888 = 4,   /* XRGB [32 bits] */
> +};
> +
> +/*
> + * Each crtc has two set fb address registers usable, FB_REG_IN_USING bit of
> + * LSDC_CRTCx_CFG_REG indicate which fb address register is in using by the
> + * CRTC currently. CFG_PAGE_FLIP is used to trigger the switch, the switching
> + * will be finished at the very next vblank. Trigger it again if you want to
> + * switch back.
> + *
> + * If FB0_ADDR_REG is in using, we write the address to FB0_ADDR_REG,
> + * if FB1_ADDR_REG is in using, we write the address to FB1_ADDR_REG.
> + */
> +#define CFG_PAGE_FLIP                   BIT(7)
> +#define CFG_OUTPUT_ENABLE               BIT(8)
> +#define CFG_HW_CLONE                    BIT(9)
> +/* Indicate witch fb addr reg is in using, currently. read only */
> +#define FB_REG_IN_USING                 BIT(11)
> +#define CFG_GAMMA_EN                    BIT(12)
> +
> +/* The DC get soft reset if this bit changed from "1" to "0", active low */
> +#define CFG_RESET_N                     BIT(20)
> +/* If this bit is set, it say that the CRTC stop working anymore, anchored. */
> +#define CRTC_ANCHORED                   BIT(24)
> +
> +/*
> + * The DMA step of the DC in LS7A2000/LS2K2000 is configurable,
> + * setting those bits on ls7a1000 platform make no effect.
> + */
> +#define CFG_DMA_STEP_MASK              GENMASK(17, 16)
> +#define CFG_DMA_STEP_SHIFT             16
> +enum lsdc_dma_steps {
> +	LSDC_DMA_STEP_256_BYTES = 0,
> +	LSDC_DMA_STEP_128_BYTES = 1,
> +	LSDC_DMA_STEP_64_BYTES = 2,
> +	LSDC_DMA_STEP_32_BYTES = 3,
> +};
> +
> +#define CFG_VALID_BITS_MASK             GENMASK(20, 0)
> +
> +/* For LSDC_CRTCx_PANEL_CONF_REG */
> +#define PHY_CLOCK_POL                   BIT(9)
> +#define PHY_CLOCK_EN                    BIT(8)
> +#define PHY_DE_POL                      BIT(1)
> +#define PHY_DATA_EN                     BIT(0)
> +
> +/* For LSDC_CRTCx_HSYNC_REG */
> +#define HSYNC_INV                       BIT(31)
> +#define HSYNC_EN                        BIT(30)
> +#define HSYNC_END_MASK                  GENMASK(28, 16)
> +#define HSYNC_END_SHIFT                 16
> +#define HSYNC_START_MASK                GENMASK(12, 0)
> +#define HSYNC_START_SHIFT               0
> +
> +/* For LSDC_CRTCx_VSYNC_REG */
> +#define VSYNC_INV                       BIT(31)
> +#define VSYNC_EN                        BIT(30)
> +#define VSYNC_END_MASK                  GENMASK(27, 16)
> +#define VSYNC_END_SHIFT                 16
> +#define VSYNC_START_MASK                GENMASK(11, 0)
> +#define VSYNC_START_SHIFT               0
> +
> +/*********** CRTC0 & DISPLAY PIPE0 ***********/
> +#define LSDC_CRTC0_CFG_REG              0x1240
> +#define LSDC_CRTC0_FB0_ADDR_LO_REG      0x1260
> +#define LSDC_CRTC0_FB0_ADDR_HI_REG      0x15A0
> +#define LSDC_CRTC0_STRIDE_REG           0x1280
> +#define LSDC_CRTC0_FB_ORIGIN_REG        0x1300
> +#define LSDC_CRTC0_PANEL_CONF_REG       0x13C0
> +#define LSDC_CRTC0_HDISPLAY_REG         0x1400
> +#define LSDC_CRTC0_HSYNC_REG            0x1420
> +#define LSDC_CRTC0_VDISPLAY_REG         0x1480
> +#define LSDC_CRTC0_VSYNC_REG            0x14A0
> +#define LSDC_CRTC0_GAMMA_INDEX_REG      0x14E0
> +#define LSDC_CRTC0_GAMMA_DATA_REG       0x1500
> +#define LSDC_CRTC0_FB1_ADDR_LO_REG      0x1580
> +#define LSDC_CRTC0_FB1_ADDR_HI_REG      0x15C0
> +
> +/*********** CTRC1 & DISPLAY PIPE1 ***********/

"CRTC1"

> +#define LSDC_CRTC1_CFG_REG              0x1250
> +#define LSDC_CRTC1_FB0_ADDR_LO_REG      0x1270
> +#define LSDC_CRTC1_FB0_ADDR_HI_REG      0x15B0
> +#define LSDC_CRTC1_STRIDE_REG           0x1290
> +#define LSDC_CRTC1_FB_ORIGIN_REG        0x1310
> +#define LSDC_CRTC1_PANEL_CONF_REG       0x13D0
> +#define LSDC_CRTC1_HDISPLAY_REG         0x1410
> +#define LSDC_CRTC1_HSYNC_REG            0x1430
> +#define LSDC_CRTC1_VDISPLAY_REG         0x1490
> +#define LSDC_CRTC1_VSYNC_REG            0x14B0
> +#define LSDC_CRTC1_GAMMA_INDEX_REG      0x14F0
> +#define LSDC_CRTC1_GAMMA_DATA_REG       0x1510
> +#define LSDC_CRTC1_FB1_ADDR_LO_REG      0x1590
> +#define LSDC_CRTC1_FB1_ADDR_HI_REG      0x15D0
> +
> +/*
> + * All of the DC variants has the hardware which record the scan position
> + * of the CRTC, [31:16] : current X position, [15:0] : current Y position
> + */
> +#define LSDC_CRTC0_SCAN_POS_REG         0x14C0
> +#define LSDC_CRTC1_SCAN_POS_REG         0x14D0
> +
> +/*
> + * LS7A2000 has Sync Deviation register.
> + */
> +#define SYNC_DEVIATION_EN               BIT(31)
> +#define SYNC_DEVIATION_NUM              GENMASK(12, 0)
> +#define LSDC_CRTC0_SYNC_DEVIATION_REG   0x1B80
> +#define LSDC_CRTC1_SYNC_DEVIATION_REG   0x1B90
> +
> +/*
> + * In gross, LSDC_CRTC1_XXX_REG - LSDC_CRTC0_XXX_REG = 0x10, but not all of
> + * the registers obey this rule, LSDC_CURSORx_XXX_REG just don't honor this.
> + * This is the root cause we can't untangle the code by manpulating offset
> + * of the register access simply. Our hardware engineers are lack experiance
> + * when they design this...
> + */
> +#define CRTC_PIPE_OFFSET                0x10
> +
> +/*
> + * There is only one hardware cursor unit in LS7A1000 and LS2K1000, let
> + * CFG_HW_CLONE_EN bit be "1" could eliminate this embarrassment, we made
> + * it on custom clone mode application. While LS7A2000 has two hardware
> + * cursor unit which is good enough.
> + */
> +#define CURSOR_FORMAT_MASK              GENMASK(1, 0)
> +#define CURSOR_FORMAT_SHIFT             0
> +enum lsdc_cursor_format {
> +	CURSOR_FORMAT_DISABLE = 0,
> +	CURSOR_FORMAT_MONOCHROME = 1,   /* masked */
> +	CURSOR_FORMAT_ARGB8888 = 2,     /* A8R8G8B8 */
> +};
> +
> +/*
> + * LS7A1000 and LS2K1000 only support 32x32, LS2K2000 and LS7A2000 support
> + * 64x64, but it seems that setting this bit make no harms on LS7A1000, it
> + * just don't take effects.
> + */
> +#define CURSOR_SIZE_SHIFT               2
> +enum lsdc_cursor_size {
> +	CURSOR_SIZE_32X32 = 0,
> +	CURSOR_SIZE_64X64 = 1,
> +};
> +
> +#define CURSOR_LOCATION_SHIFT           4
> +enum lsdc_cursor_location {
> +	CURSOR_ON_CRTC0 = 0,
> +	CURSOR_ON_CRTC1 = 1,
> +};
> +
> +#define LSDC_CURSOR0_CFG_REG            0x1520
> +#define LSDC_CURSOR0_ADDR_LO_REG        0x1530
> +#define LSDC_CURSOR0_ADDR_HI_REG        0x15e0
> +#define LSDC_CURSOR0_POSITION_REG       0x1540  /* [31:16] Y, [15:0] X */
> +#define LSDC_CURSOR0_BG_COLOR_REG       0x1550  /* background color */
> +#define LSDC_CURSOR0_FG_COLOR_REG       0x1560  /* foreground color */
> +
> +#define LSDC_CURSOR1_CFG_REG            0x1670
> +#define LSDC_CURSOR1_ADDR_LO_REG        0x1680
> +#define LSDC_CURSOR1_ADDR_HI_REG        0x16e0
> +#define LSDC_CURSOR1_POSITION_REG       0x1690  /* [31:16] Y, [15:0] X */
> +#define LSDC_CURSOR1_BG_COLOR_REG       0x16A0  /* background color */
> +#define LSDC_CURSOR1_FG_COLOR_REG       0x16B0  /* foreground color */
> +
> +/*
> + * DC Interrupt Control Register, 32bit, Address Offset: 1570
> + *
> + * Bits 15:0 inidicate the interrupt status
> + * Bits 31:16 control enable interrupts corresponding to bit 15:0 or not
> + * Write 1 to enable, write 0 to disable
> + *
> + * RF: Read Finished
> + * IDBU: Internal Data Buffer Underflow
> + * IDBFU: Internal Data Buffer Fatal Underflow
> + * CBRF: Cursor Buffer Read Finished Flag, no use.
> + * FBRF0: CRTC-0 reading from its framebuffer finished.
> + * FBRF1: CRTC-1 reading from its framebuffer finished.
> + *
> + * +-------+--------------------------+-------+--------+--------+-------+
> + * | 31:27 |         26:16            | 15:11 |   10   |   9    |   8   |
> + * +-------+--------------------------+-------+--------+--------+-------+
> + * |  N/A  | Interrupt Enable Control |  N/A  | IDBFU0 | IDBFU1 | IDBU0 |
> + * +-------+--------------------------+-------+--------+--------+-------+
> + *
> + * +-------+-------+-------+------+--------+--------+--------+--------+
> + * |   7   |   6   |   5   |  4   |   3    |   2    |   1    |   0    |
> + * +-------+-------+-------+------+--------+--------+--------+--------+
> + * | IDBU1 | FBRF0 | FBRF1 | CRRF | HSYNC0 | VSYNC0 | HSYNC1 | VSYNC1 |
> + * +-------+-------+-------+------+--------+--------+--------+--------+
> + *
> + * unfortunately, CRTC0's interrupt is mess with CRTC1's interrupt in one
> + * register again.
> + */
> +
> +#define LSDC_INT_REG                    0x1570
> +
> +#define INT_CRTC0_VSYNC                 BIT(2)
> +#define INT_CRTC0_HSYNC                 BIT(3)
> +#define INT_CRTC0_RF                    BIT(6)
> +#define INT_CRTC0_IDBU                  BIT(8)
> +#define INT_CRTC0_IDBFU                 BIT(10)
> +
> +#define INT_CRTC1_VSYNC                 BIT(0)
> +#define INT_CRTC1_HSYNC                 BIT(1)
> +#define INT_CRTC1_RF                    BIT(5)
> +#define INT_CRTC1_IDBU                  BIT(7)
> +#define INT_CRTC1_IDBFU                 BIT(9)
> +
> +#define INT_CRTC0_VSYNC_EN              BIT(18)
> +#define INT_CRTC0_HSYNC_EN              BIT(19)
> +#define INT_CRTC0_RF_EN                 BIT(22)
> +#define INT_CRTC0_IDBU_EN               BIT(24)
> +#define INT_CRTC0_IDBFU_EN              BIT(26)
> +
> +#define INT_CRTC1_VSYNC_EN              BIT(16)
> +#define INT_CRTC1_HSYNC_EN              BIT(17)
> +#define INT_CRTC1_RF_EN                 BIT(21)
> +#define INT_CRTC1_IDBU_EN               BIT(23)
> +#define INT_CRTC1_IDBFU_EN              BIT(25)
> +
> +#define INT_STATUS_MASK                 GENMASK(15, 0)
> +
> +/*
> + * LS7A1000/LS7A2000 have 4 gpios which are used to emulated I2C.
> + * They are under control of the LS7A_DC_GPIO_DAT_REG and LS7A_DC_GPIO_DIR_REG
> + * register, Those GPIOs has no relationship whth the GPIO hardware on the
> + * bridge chip itself. Those offsets are relative to DC register base address
> + *
> + * LS2k1000 don't have those registers, they use hardware i2c or general GPIO
> + * emulated i2c from linux i2c subsystem.
> + *
> + * GPIO data register, address offset: 0x1650
> + *   +---------------+-----------+-----------+
> + *   | 7 | 6 | 5 | 4 |  3  |  2  |  1  |  0  |
> + *   +---------------+-----------+-----------+
> + *   |               |    DVO1   |    DVO0   |
> + *   +      N/A      +-----------+-----------+
> + *   |               | SCL | SDA | SCL | SDA |
> + *   +---------------+-----------+-----------+
> + */
> +#define LS7A_DC_GPIO_DAT_REG            0x1650
> +
> +/*
> + *  GPIO Input/Output direction control register, address offset: 0x1660
> + */
> +#define LS7A_DC_GPIO_DIR_REG            0x1660
> +
> +/*
> + *  LS7A2000 has two built-in HDMI Encoder and one VGA encoder
> + */
> +
> +/*
> + * Number of continuous packets may be present
> + * in HDMI hblank and vblank zone, should >= 48
> + */
> +#define LSDC_HDMI0_ZONE_REG             0x1700
> +#define LSDC_HDMI1_ZONE_REG             0x1710
> +
> +#define HDMI_H_ZONE_IDLE_SHIFT          0
> +#define HDMI_V_ZONE_IDLE_SHIFT          16
> +
> +/* HDMI Iterface Control Reg */
> +#define HDMI_INTERFACE_EN               BIT(0)
> +#define HDMI_PACKET_EN                  BIT(1)
> +#define HDMI_AUDIO_EN                   BIT(2)
> +/*
> + * Preamble:
> + * Immediately preceding each video data period or data island period is the
> + * preamble. This is a sequence of eight identical control characters that
> + * indicate whether the upcoming data period is a video data period or is a
> + * data island. The values of CTL0, CTL1, CTL2, and CTL3 indicate the type of
> + * data period that follows.
> + */
> +#define HDMI_VIDEO_PREAMBLE_MASK        GENMASK(7, 4)
> +#define HDMI_VIDEO_PREAMBLE_SHIFT       4
> +/* 1: hw i2c, 0: gpio emu i2c, shouldn't put in LSDC_HDMIx_INTF_CTRL_REG */
> +#define HW_I2C_EN                       BIT(8)
> +#define HDMI_CTL_PERIOD_MODE            BIT(9)
> +#define LSDC_HDMI0_INTF_CTRL_REG        0x1720
> +#define LSDC_HDMI1_INTF_CTRL_REG        0x1730
> +
> +#define HDMI_PHY_EN                     BIT(0)
> +#define HDMI_PHY_RESET_N                BIT(1)
> +#define HDMI_PHY_TERM_L_EN              BIT(8)
> +#define HDMI_PHY_TERM_H_EN              BIT(9)
> +#define HDMI_PHY_TERM_DET_EN            BIT(10)
> +#define HDMI_PHY_TERM_STATUS            BIT(11)
> +#define LSDC_HDMI0_PHY_CTRL_REG         0x1800
> +#define LSDC_HDMI1_PHY_CTRL_REG         0x1810
> +
> +/* High level duration need > 1us */
> +#define HDMI_PLL_ENABLE                 BIT(0)
> +#define HDMI_PLL_LOCKED                 BIT(16)
> +/* Bypass the software configured values, using default source from somewhere */
> +#define HDMI_PLL_BYPASS                 BIT(17)
> +
> +#define HDMI_PLL_IDF_SHIFT              1
> +#define HDMI_PLL_IDF_MASK               GENMASK(5, 1)
> +#define HDMI_PLL_LF_SHIFT               6
> +#define HDMI_PLL_LF_MASK                GENMASK(12, 6)
> +#define HDMI_PLL_ODF_SHIFT              13
> +#define HDMI_PLL_ODF_MASK               GENMASK(15, 13)
> +#define LSDC_HDMI0_PHY_PLL_REG          0x1820
> +#define LSDC_HDMI1_PHY_PLL_REG          0x1830
> +
> +/* LS7A2000/LS2K2000 has hpd status reg, while the two hdmi's status
> + * located at the one register again.
> + */
> +#define LSDC_HDMI_HPD_STATUS_REG        0x1BA0
> +#define HDMI0_HPD_FLAG                  BIT(0)
> +#define HDMI1_HPD_FLAG                  BIT(1)
> +
> +#define LSDC_HDMI0_PHY_CAL_REG          0x18C0
> +#define LSDC_HDMI1_PHY_CAL_REG          0x18D0
> +
> +/* AVI InfoFrame */
> +#define LSDC_HDMI0_AVI_CONTENT0         0x18E0
> +#define LSDC_HDMI1_AVI_CONTENT0         0x18D0
> +#define LSDC_HDMI0_AVI_CONTENT1         0x1900
> +#define LSDC_HDMI1_AVI_CONTENT1         0x1910
> +#define LSDC_HDMI0_AVI_CONTENT2         0x1920
> +#define LSDC_HDMI1_AVI_CONTENT2         0x1930
> +#define LSDC_HDMI0_AVI_CONTENT3         0x1940
> +#define LSDC_HDMI1_AVI_CONTENT3         0x1950
> +
> +/* 1: enable avi infoframe packet, 0: disable avi infoframe packet */
> +#define AVI_PKT_ENABLE                  BIT(0)
> +/* 1: send one every two frame, 0: send one each frame */
> +#define AVI_PKT_SEND_FREQ               BIT(1)
> +/*
> + * 1: write 1 to flush avi reg content0 ~ content3 to the packet to be send,
> + * The hardware will clear this bit automatically.
> + */
> +#define AVI_PKT_UPDATE                  BIT(2)
> +
> +#define LSDC_HDMI0_AVI_INFO_CRTL_REG    0x1960
> +#define LSDC_HDMI1_AVI_INFO_CRTL_REG    0x1970
> +
> +/*
> + * LS7A2000 has the hardware which count the number of vblank generated
> + */
> +#define LSDC_CRTC0_VSYNC_COUNTER_REG    0x1A00
> +#define LSDC_CRTC1_VSYNC_COUNTER_REG    0x1A10
> +
> +/*
> + * LS7A2000 has the audio hardware associate with the HDMI encoder.
> + */
> +#define LSDC_HDMI0_AUDIO_PLL_LO_REG     0x1A20
> +#define LSDC_HDMI1_AUDIO_PLL_LO_REG     0x1A30
> +
> +#define LSDC_HDMI0_AUDIO_PLL_HI_REG     0x1A40
> +#define LSDC_HDMI1_AUDIO_PLL_HI_REG     0x1A50
> +
> +#endif
> diff --git a/drivers/gpu/drm/loongson/lsdc_ttm.c b/drivers/gpu/drm/loongson/lsdc_ttm.c
> new file mode 100644
> index 000000000000..fd2ccf5670b1
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/lsdc_ttm.c
> @@ -0,0 +1,610 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2023 Loongson Technology Corporation Limited
> + */
> +
> +#include <drm/drm_drv.h>
> +#include <drm/drm_file.h>
> +#include <drm/drm_gem.h>
> +#include <drm/drm_managed.h>
> +#include <drm/drm_prime.h>
> +
> +#include "lsdc_drv.h"
> +#include "lsdc_ttm.h"
> +
> +const char *lsdc_mem_type_to_str(uint32_t mem_type)
> +{
> +	switch (mem_type) {
> +	case TTM_PL_VRAM:
> +		return "VRAM";
> +	case TTM_PL_TT:
> +		return "GTT";
> +	case TTM_PL_SYSTEM:
> +		return "SYSTEM";
> +	default:
> +		break;
> +	}
> +
> +	return "Unknown";
> +}
> +
> +const char *lsdc_domain_to_str(u32 domain)
> +{
> +	switch (domain) {
> +	case LSDC_GEM_DOMAIN_VRAM:
> +		return "VRAM";
> +	case LSDC_GEM_DOMAIN_GTT:
> +		return "GTT";
> +	case LSDC_GEM_DOMAIN_SYSTEM:
> +		return "SYSTEM";
> +	default:
> +		break;
> +	}
> +
> +	return "Unknown";
> +}
> +
> +static void lsdc_bo_set_placement(struct lsdc_bo *lbo, u32 domain)
> +{
> +	u32 c = 0;
> +	u32 pflags = 0;
> +	u32 i;
> +
> +	if (lbo->tbo.base.size <= PAGE_SIZE)
> +		pflags |= TTM_PL_FLAG_TOPDOWN;
> +
> +	lbo->placement.placement = lbo->placements;
> +	lbo->placement.busy_placement = lbo->placements;
> +
> +	if (domain & LSDC_GEM_DOMAIN_VRAM) {
> +		lbo->placements[c].mem_type = TTM_PL_VRAM;
> +		lbo->placements[c++].flags = pflags;
> +	}
> +
> +	if (domain & LSDC_GEM_DOMAIN_GTT) {
> +		lbo->placements[c].mem_type = TTM_PL_TT;
> +		lbo->placements[c++].flags = pflags;
> +	}
> +
> +	if (domain & LSDC_GEM_DOMAIN_SYSTEM) {
> +		lbo->placements[c].mem_type = TTM_PL_SYSTEM;
> +		lbo->placements[c++].flags = 0;
> +	}
> +
> +	if (!c) {
> +		lbo->placements[c].mem_type = TTM_PL_SYSTEM;
> +		lbo->placements[c++].flags = 0;
> +	}
> +
> +	lbo->placement.num_placement = c;
> +	lbo->placement.num_busy_placement = c;
> +
> +	for (i = 0; i < c; ++i) {
> +		lbo->placements[i].fpfn = 0;
> +		lbo->placements[i].lpfn = 0;
> +	}
> +}
> +
> +static void lsdc_ttm_tt_destroy(struct ttm_device *bdev, struct ttm_tt *tt)
> +{
> +	ttm_tt_fini(tt);
> +	kfree(tt);
> +}
> +
> +static struct ttm_tt *
> +lsdc_ttm_tt_create(struct ttm_buffer_object *tbo, uint32_t page_flags)
> +{
> +	struct ttm_tt *tt;
> +	int ret;
> +
> +	tt = kzalloc(sizeof(*tt), GFP_KERNEL);
> +	if (!tt)
> +		return NULL;
> +
> +	ret = ttm_sg_tt_init(tt, tbo, page_flags, ttm_cached);
> +	if (ret < 0) {
> +		kfree(tt);
> +		return NULL;
> +	}
> +
> +	return tt;
> +}
> +
> +static int lsdc_ttm_tt_populate(struct ttm_device *bdev,
> +				struct ttm_tt *ttm,
> +				struct ttm_operation_ctx *ctx)
> +{
> +	bool slave = !!(ttm->page_flags & TTM_TT_FLAG_EXTERNAL);
> +
> +	if (slave && ttm->sg) {
> +		drm_prime_sg_to_dma_addr_array(ttm->sg,
> +					       ttm->dma_address,
> +					       ttm->num_pages);
> +
> +		return 0;
> +	}
> +
> +	return ttm_pool_alloc(&bdev->pool, ttm, ctx);
> +}
> +
> +static void lsdc_ttm_tt_unpopulate(struct ttm_device *bdev,
> +				   struct ttm_tt *ttm)
> +{
> +	bool slave = !!(ttm->page_flags & TTM_TT_FLAG_EXTERNAL);
> +
> +	if (slave)
> +		return;
> +
> +	return ttm_pool_free(&bdev->pool, ttm);
> +}
> +
> +static void lsdc_bo_evict_flags(struct ttm_buffer_object *tbo,
> +				struct ttm_placement *tplacement)
> +{
> +	struct ttm_resource *resource = tbo->resource;
> +	struct lsdc_bo *lbo = to_lsdc_bo(tbo);
> +
> +	switch (resource->mem_type) {
> +	case TTM_PL_VRAM:
> +		lsdc_bo_set_placement(lbo, LSDC_GEM_DOMAIN_GTT);
> +		break;
> +	case TTM_PL_TT:
> +	default:
> +		lsdc_bo_set_placement(lbo, LSDC_GEM_DOMAIN_SYSTEM);
> +		break;
> +	}
> +
> +	*tplacement = lbo->placement;
> +}
> +
> +static int lsdc_bo_move(struct ttm_buffer_object *tbo,
> +			bool evict,
> +			struct ttm_operation_ctx *ctx,
> +			struct ttm_resource *new_mem,
> +			struct ttm_place *hop)
> +{
> +	struct drm_device *ddev = tbo->base.dev;
> +	struct ttm_resource *old_mem = tbo->resource;
> +	struct lsdc_bo *lbo = to_lsdc_bo(tbo);
> +	int ret;
> +
> +	if (unlikely(tbo->pin_count > 0)) {
> +		drm_warn(ddev, "Can't move a pinned BO\n");
> +		return -EINVAL;
> +	}
> +
> +	ret = ttm_bo_wait_ctx(tbo, ctx);
> +	if (ret)
> +		return ret;
> +
> +	if (!old_mem) {
> +		drm_dbg(ddev, "bo[%p] move: NULL to %s, size: %zu\n",
> +			lbo, lsdc_mem_type_to_str(new_mem->mem_type),
> +			lsdc_bo_size(lbo));
> +		ttm_bo_move_null(tbo, new_mem);
> +		return 0;
> +	}
> +
> +	if (old_mem->mem_type == TTM_PL_SYSTEM && !tbo->ttm) {
> +		ttm_bo_move_null(tbo, new_mem);
> +		drm_dbg(ddev, "bo[%p] move: SYSTEM to NULL, size: %zu\n",
> +			lbo, lsdc_bo_size(lbo));
> +		return 0;
> +	}
> +
> +	if (old_mem->mem_type == TTM_PL_SYSTEM &&
> +	    new_mem->mem_type == TTM_PL_TT) {
> +		drm_dbg(ddev, "bo[%p] move: SYSTEM to GTT, size: %zu\n",
> +			lbo, lsdc_bo_size(lbo));
> +		ttm_bo_move_null(tbo, new_mem);
> +		return 0;
> +	}
> +
> +	if (old_mem->mem_type == TTM_PL_TT &&
> +	    new_mem->mem_type == TTM_PL_SYSTEM) {
> +		drm_dbg(ddev, "bo[%p] move: GTT to SYSTEM, size: %zu\n",
> +			lbo, lsdc_bo_size(lbo));
> +		ttm_resource_free(tbo, &tbo->resource);
> +		ttm_bo_assign_mem(tbo, new_mem);
> +		return 0;
> +	}
> +
> +	drm_dbg(ddev, "bo[%p] move: %s to %s, size: %zu\n",
> +		lbo,
> +		lsdc_mem_type_to_str(old_mem->mem_type),
> +		lsdc_mem_type_to_str(new_mem->mem_type),
> +		lsdc_bo_size(lbo));
> +
> +	return ttm_bo_move_memcpy(tbo, ctx, new_mem);
> +}
> +
> +static int lsdc_bo_reserve_io_mem(struct ttm_device *bdev,
> +				  struct ttm_resource *mem)
> +{
> +	struct lsdc_device *ldev = tdev_to_ldev(bdev);
> +
> +	switch (mem->mem_type) {
> +	case TTM_PL_SYSTEM:
> +		break;
> +	case TTM_PL_TT:
> +		break;
> +	case TTM_PL_VRAM:
> +		mem->bus.offset = (mem->start << PAGE_SHIFT) + ldev->vram_base;
> +		mem->bus.is_iomem = true;
> +		mem->bus.caching = ttm_write_combined;
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +static struct ttm_device_funcs lsdc_bo_driver = {
> +	.ttm_tt_create = lsdc_ttm_tt_create,
> +	.ttm_tt_populate = lsdc_ttm_tt_populate,
> +	.ttm_tt_unpopulate = lsdc_ttm_tt_unpopulate,
> +	.ttm_tt_destroy = lsdc_ttm_tt_destroy,
> +	.eviction_valuable = ttm_bo_eviction_valuable,
> +	.evict_flags = lsdc_bo_evict_flags,
> +	.move = lsdc_bo_move,
> +	.io_mem_reserve = lsdc_bo_reserve_io_mem,
> +};
> +
> +u64 lsdc_bo_gpu_offset(struct lsdc_bo *lbo)
> +{
> +	struct ttm_buffer_object *tbo = &lbo->tbo;
> +	struct drm_device *ddev = tbo->base.dev;
> +	struct ttm_resource *resource = tbo->resource;
> +
> +	if (unlikely(!tbo->pin_count)) {
> +		drm_err(ddev, "unpinned bo, gpu virtual address is invalid\n");
> +		return 0;
> +	}
> +
> +	if (unlikely(resource->mem_type == TTM_PL_SYSTEM))
> +		return 0;
> +
> +	return resource->start << PAGE_SHIFT;
> +}
> +
> +size_t lsdc_bo_size(struct lsdc_bo *lbo)
> +{
> +	struct ttm_buffer_object *tbo = &lbo->tbo;
> +
> +	return tbo->base.size;
> +}
> +
> +int lsdc_bo_reserve(struct lsdc_bo *lbo)
> +{
> +	return ttm_bo_reserve(&lbo->tbo, true, false, NULL);
> +}
> +
> +void lsdc_bo_unreserve(struct lsdc_bo *lbo)
> +{
> +	return ttm_bo_unreserve(&lbo->tbo);
> +}
> +
> +int lsdc_bo_pin(struct lsdc_bo *lbo, u32 domain, u64 *gpu_addr)
> +{
> +	struct ttm_operation_ctx ctx = { false, false };
> +	struct ttm_buffer_object *tbo = &lbo->tbo;
> +	struct lsdc_device *ldev = tdev_to_ldev(tbo->bdev);
> +	int ret;
> +
> +	if (tbo->pin_count)
> +		goto bo_pinned;
> +
> +	if (lbo->sharing_count && domain == LSDC_GEM_DOMAIN_VRAM)
> +		return -EINVAL;
> +
> +	if (domain)
> +		lsdc_bo_set_placement(lbo, domain);
> +
> +	ret = ttm_bo_validate(tbo, &lbo->placement, &ctx);
> +	if (unlikely(ret)) {
> +		drm_err(&ldev->base, "%p validate failed: %d\n", lbo, ret);
> +		return ret;
> +	}
> +
> +	if (domain == LSDC_GEM_DOMAIN_VRAM)
> +		ldev->vram_pinned_size += lsdc_bo_size(lbo);
> +	else if (domain == LSDC_GEM_DOMAIN_GTT)
> +		ldev->gtt_pinned_size += lsdc_bo_size(lbo);
> +
> +bo_pinned:
> +	ttm_bo_pin(tbo);
> +
> +	if (gpu_addr)
> +		*gpu_addr = lsdc_bo_gpu_offset(lbo);
> +
> +	return 0;
> +}
> +
> +void lsdc_bo_unpin(struct lsdc_bo *lbo)
> +{
> +	struct ttm_buffer_object *tbo = &lbo->tbo;
> +	struct lsdc_device *ldev = tdev_to_ldev(tbo->bdev);
> +
> +	if (unlikely(!tbo->pin_count)) {
> +		drm_dbg(&ldev->base, "%p unpin is not necessary\n", lbo);
> +		return;
> +	}
> +
> +	ttm_bo_unpin(tbo);
> +
> +	if (!tbo->pin_count) {
> +		if (tbo->resource->mem_type == TTM_PL_VRAM)
> +			ldev->vram_pinned_size -= lsdc_bo_size(lbo);
> +		else if (tbo->resource->mem_type == TTM_PL_TT)
> +			ldev->gtt_pinned_size -= lsdc_bo_size(lbo);
> +	}
> +}
> +
> +void lsdc_bo_ref(struct lsdc_bo *lbo)
> +{
> +	struct ttm_buffer_object *tbo = &lbo->tbo;
> +
> +	ttm_bo_get(tbo);
> +}
> +
> +void lsdc_bo_unref(struct lsdc_bo *lbo)
> +{
> +	struct ttm_buffer_object *tbo = &lbo->tbo;
> +
> +	ttm_bo_put(tbo);
> +}
> +
> +int lsdc_bo_kmap(struct lsdc_bo *lbo)
> +{
> +	struct ttm_buffer_object *tbo = &lbo->tbo;
> +	struct drm_gem_object *gem = &tbo->base;
> +	struct drm_device *ddev = gem->dev;
> +	long ret;
> +	int err;
> +
> +	ret = dma_resv_wait_timeout(gem->resv,
> +				    DMA_RESV_USAGE_KERNEL,
> +				    false,
> +				    MAX_SCHEDULE_TIMEOUT);
> +	if (ret < 0) {
> +		drm_warn(ddev, "wait fence timeout\n");
> +		return ret;
> +	}
> +
> +	if (lbo->kptr)
> +		return 0;
> +
> +	err = ttm_bo_kmap(tbo, 0, PFN_UP(lsdc_bo_size(lbo)), &lbo->kmap);
> +	if (err) {
> +		drm_err(ddev, "kmap %p failed: %d\n", lbo, err);
> +		return err;
> +	}
> +
> +	lbo->kptr = ttm_kmap_obj_virtual(&lbo->kmap, &lbo->is_iomem);
> +
> +	return 0;
> +}
> +
> +void lsdc_bo_kunmap(struct lsdc_bo *lbo)
> +{
> +	if (!lbo->kptr)
> +		return;
> +
> +	lbo->kptr = NULL;
> +	ttm_bo_kunmap(&lbo->kmap);
> +}
> +
> +void lsdc_bo_clear(struct lsdc_bo *lbo)
> +{
> +	lsdc_bo_kmap(lbo);
> +
> +	if (lbo->is_iomem)
> +		memset_io((void __iomem *)lbo->kptr, 0, lbo->size);
> +	else
> +		memset(lbo->kptr, 0, lbo->size);
> +
> +	lsdc_bo_kunmap(lbo);
> +}
> +
> +int lsdc_bo_evict_vram(struct drm_device *ddev)
> +{
> +	struct lsdc_device *ldev = to_lsdc(ddev);
> +	struct ttm_device *bdev = &ldev->bdev;
> +	struct ttm_resource_manager *man;
> +
> +	man = ttm_manager_type(bdev, TTM_PL_VRAM);
> +	if (unlikely(!man))
> +		return 0;
> +
> +	return ttm_resource_manager_evict_all(bdev, man);
> +}
> +
> +static void lsdc_bo_destroy(struct ttm_buffer_object *tbo)
> +{
> +	struct lsdc_device *ldev = tdev_to_ldev(tbo->bdev);
> +	struct lsdc_bo *lbo = to_lsdc_bo(tbo);
> +
> +	mutex_lock(&ldev->gem.mutex);
> +	list_del_init(&lbo->list);
> +	mutex_unlock(&ldev->gem.mutex);
> +
> +	drm_gem_object_release(&tbo->base);
> +
> +	kfree(lbo);
> +}
> +
> +struct lsdc_bo *lsdc_bo_create(struct drm_device *ddev,
> +			       u32 domain,
> +			       size_t size,
> +			       bool kernel,
> +			       struct sg_table *sg,
> +			       struct dma_resv *resv)
> +{
> +	struct lsdc_device *ldev = to_lsdc(ddev);
> +	struct ttm_device *bdev = &ldev->bdev;
> +	struct ttm_buffer_object *tbo;
> +	struct lsdc_bo *lbo;
> +	enum ttm_bo_type bo_type;
> +	int ret;
> +
> +	lbo = kzalloc(sizeof(*lbo), GFP_KERNEL);
> +	if (!lbo)
> +		return ERR_PTR(-ENOMEM);
> +
> +	INIT_LIST_HEAD(&lbo->list);
> +
> +	lbo->initial_domain = domain & (LSDC_GEM_DOMAIN_VRAM |
> +					LSDC_GEM_DOMAIN_GTT |
> +					LSDC_GEM_DOMAIN_SYSTEM);
> +
> +	tbo = &lbo->tbo;
> +
> +	size = ALIGN(size, PAGE_SIZE);
> +
> +	ret = drm_gem_object_init(ddev, &tbo->base, size);
> +	if (ret) {
> +		kfree(lbo);
> +		return ERR_PTR(ret);
> +	}
> +
> +	tbo->bdev = bdev;
> +
> +	if (kernel)
> +		bo_type = ttm_bo_type_kernel;
> +	else if (sg)
> +		bo_type = ttm_bo_type_sg;
> +	else
> +		bo_type = ttm_bo_type_device;
> +
> +	lsdc_bo_set_placement(lbo, domain);
> +	lbo->size = size;
> +
> +	ret = ttm_bo_init_validate(bdev,
> +				   tbo,
> +				   bo_type,
> +				   &lbo->placement,
> +				   0,
> +				   false,
> +				   sg,
> +				   resv,
> +				   lsdc_bo_destroy);
> +	if (ret) {
> +		kfree(lbo);
> +		return ERR_PTR(ret);
> +	}
> +
> +	return lbo;
> +}
> +
> +struct lsdc_bo *lsdc_bo_create_kernel_pinned(struct drm_device *ddev,
> +					     u32 domain,
> +					     size_t size)
> +{
> +	struct lsdc_bo *lbo;
> +	int ret;
> +
> +	lbo = lsdc_bo_create(ddev, domain, size, true, NULL, NULL);
> +
> +	ret = lsdc_bo_reserve(lbo);
> +	if (unlikely(ret)) {
> +		lsdc_bo_unref(lbo);
> +		return ERR_PTR(ret);
> +	}
> +
> +	ret = lsdc_bo_pin(lbo, domain, NULL);
> +	lsdc_bo_unreserve(lbo);
> +	if (unlikely(ret)) {
> +		lsdc_bo_unref(lbo);
> +		return ERR_PTR(ret);
> +	}
> +
> +	return lbo;
> +}
> +
> +void lsdc_bo_free_kernel_pinned(struct lsdc_bo *lbo)
> +{
> +	int ret;
> +
> +	ret = lsdc_bo_reserve(lbo);
> +	if (unlikely(ret))
> +		return;
> +
> +	lsdc_bo_unpin(lbo);
> +	lsdc_bo_unreserve(lbo);
> +
> +	lsdc_bo_unref(lbo);
> +}
> +
> +static void lsdc_ttm_fini(struct drm_device *ddev, void *data)
> +{
> +	struct lsdc_device *ldev = (struct lsdc_device *)data;
> +
> +	ttm_range_man_fini(&ldev->bdev, TTM_PL_VRAM);
> +	ttm_range_man_fini(&ldev->bdev, TTM_PL_TT);
> +
> +	ttm_device_fini(&ldev->bdev);
> +
> +	drm_dbg(ddev, "ttm finished\n");
> +}
> +
> +int lsdc_ttm_init(struct lsdc_device *ldev)
> +{
> +	struct drm_device *ddev = &ldev->base;
> +	unsigned long num_vram_pages;
> +	unsigned long num_gtt_pages;
> +	int ret;
> +
> +	ret = ttm_device_init(&ldev->bdev,
> +			      &lsdc_bo_driver,
> +			      ddev->dev,
> +			      ddev->anon_inode->i_mapping,
> +			      ddev->vma_offset_manager,
> +			      false,
> +			      false);
> +	if (ret)
> +		return ret;
> +
> +	num_vram_pages = ldev->vram_size >> PAGE_SHIFT;
> +
> +	ret = ttm_range_man_init(&ldev->bdev,
> +				 TTM_PL_VRAM,
> +				 false,
> +				 num_vram_pages);
> +	if (unlikely(ret))
> +		return ret;
> +
> +	drm_info(ddev, "VRAM: %lu pages ready\n", num_vram_pages);
> +
> +	/* 512M is far enough for us now */
> +	ldev->gtt_size = 512 << 20;
> +
> +	num_gtt_pages = ldev->gtt_size >> PAGE_SHIFT;
> +
> +	ret = ttm_range_man_init(&ldev->bdev,
> +				 TTM_PL_TT,
> +				 true,
> +				 num_gtt_pages);
> +	if (unlikely(ret))
> +		return ret;
> +
> +	drm_info(ddev, "GTT: %lu pages ready\n", num_gtt_pages);
> +
> +	return drmm_add_action_or_reset(ddev, lsdc_ttm_fini, ldev);
> +}
> +
> +void lsdc_ttm_debugfs_init(struct lsdc_device *ldev)
> +{
> +	struct ttm_device *bdev = &ldev->bdev;
> +	struct drm_device *ddev = &ldev->base;
> +	struct drm_minor *minor = ddev->primary;
> +	struct dentry *root = minor->debugfs_root;
> +	struct ttm_resource_manager *vram_man;
> +	struct ttm_resource_manager *gtt_man;
> +
> +	vram_man = ttm_manager_type(bdev, TTM_PL_VRAM);
> +	gtt_man = ttm_manager_type(bdev, TTM_PL_TT);
> +
> +	ttm_resource_manager_create_debugfs(vram_man, root, "vram_mm");
> +	ttm_resource_manager_create_debugfs(gtt_man, root, "gtt_mm");
> +}
> diff --git a/drivers/gpu/drm/loongson/lsdc_ttm.h b/drivers/gpu/drm/loongson/lsdc_ttm.h
> new file mode 100644
> index 000000000000..6ef31d702dca
> --- /dev/null
> +++ b/drivers/gpu/drm/loongson/lsdc_ttm.h
> @@ -0,0 +1,99 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2023 Loongson Technology Corporation Limited
> + */
> +
> +#ifndef __LSDC_TTM_H__
> +#define __LSDC_TTM_H__
> +
> +#include <linux/container_of.h>
> +#include <linux/iosys-map.h>
> +#include <linux/list.h>
> +
> +#include <drm/drm_gem.h>
> +#include <drm/ttm/ttm_bo.h>
> +#include <drm/ttm/ttm_placement.h>
> +#include <drm/ttm/ttm_range_manager.h>
> +#include <drm/ttm/ttm_tt.h>
> +
> +#define LSDC_GEM_DOMAIN_SYSTEM          0x1
> +#define LSDC_GEM_DOMAIN_GTT             0x2
> +#define LSDC_GEM_DOMAIN_VRAM            0x4
> +
> +struct lsdc_bo {
> +	struct ttm_buffer_object tbo;
> +
> +	/* Protected by gem.mutex */
> +	struct list_head list;
> +
> +	struct iosys_map map;
> +
> +	unsigned int vmap_count;
> +	/* cross device driver sharing reference count */
> +	unsigned int sharing_count;
> +
> +	struct ttm_bo_kmap_obj kmap;
> +	void *kptr;
> +	bool is_iomem;
> +
> +	size_t size;
> +
> +	u32 initial_domain;
> +
> +	struct ttm_placement placement;
> +	struct ttm_place placements[4];
> +};
> +
> +static inline struct ttm_buffer_object *to_ttm_bo(struct drm_gem_object *gem)
> +{
> +	return container_of(gem, struct ttm_buffer_object, base);
> +}
> +
> +static inline struct lsdc_bo *to_lsdc_bo(struct ttm_buffer_object *tbo)
> +{
> +	return container_of(tbo, struct lsdc_bo, tbo);
> +}
> +
> +static inline struct lsdc_bo *gem_to_lsdc_bo(struct drm_gem_object *gem)
> +{
> +	return container_of(gem, struct lsdc_bo, tbo.base);
> +}
> +
> +const char *lsdc_mem_type_to_str(uint32_t mem_type);
> +const char *lsdc_domain_to_str(u32 domain);
> +
> +struct lsdc_bo *lsdc_bo_create(struct drm_device *ddev,
> +			       u32 domain,
> +			       size_t size,
> +			       bool kernel,
> +			       struct sg_table *sg,
> +			       struct dma_resv *resv);
> +
> +struct lsdc_bo *lsdc_bo_create_kernel_pinned(struct drm_device *ddev,
> +					     u32 domain,
> +					     size_t size);
> +
> +void lsdc_bo_free_kernel_pinned(struct lsdc_bo *lbo);
> +
> +int lsdc_bo_reserve(struct lsdc_bo *lbo);
> +void lsdc_bo_unreserve(struct lsdc_bo *lbo);
> +
> +int lsdc_bo_pin(struct lsdc_bo *lbo, u32 domain, u64 *gpu_addr);
> +void lsdc_bo_unpin(struct lsdc_bo *lbo);
> +
> +void lsdc_bo_ref(struct lsdc_bo *lbo);
> +void lsdc_bo_unref(struct lsdc_bo *lbo);
> +
> +u64 lsdc_bo_gpu_offset(struct lsdc_bo *lbo);
> +size_t lsdc_bo_size(struct lsdc_bo *lbo);
> +
> +int lsdc_bo_kmap(struct lsdc_bo *lbo);
> +void lsdc_bo_kunmap(struct lsdc_bo *lbo);
> +void lsdc_bo_clear(struct lsdc_bo *lbo);
> +
> +int lsdc_bo_evict_vram(struct drm_device *ddev);
> +
> +int lsdc_ttm_init(struct lsdc_device *ldev);
> +void lsdc_ttm_debugfs_init(struct lsdc_device *ldev);
> +
> +#endif

-- 
WANG "xen0n" Xuerui

Linux/LoongArch mailing list: https://lore.kernel.org/loongarch/