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Message-ID: <3eaa4c05-f8f2-9e18-e6d9-a627fe5e1e40@collabora.com>
Date:   Thu, 3 Mar 2022 15:27:27 +0100
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Subject: Re: [PATCH v2, 04/10] media: mtk-vcodec: Enable venc dual core usage
Content-Language: en-US
To:     Irui Wang <irui.wang@mediatek.com>,
        Hans Verkuil <hverkuil-cisco@xs4all.nl>,
        Tzung-Bi Shih <tzungbi@chromium.org>,
        Alexandre Courbot <acourbot@chromium.org>,
        Tiffany Lin <tiffany.lin@mediatek.com>,
        Andrew-CT Chen <andrew-ct.chen@mediatek.com>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Tomasz Figa <tfiga@google.com>, Yong Wu <yong.wu@mediatek.com>
Cc:     Hsin-Yi Wang <hsinyi@chromium.org>,
        Maoguang Meng <maoguang.meng@mediatek.com>,
        Longfei Wang <longfei.wang@mediatek.com>,
        Yunfei Dong <yunfei.dong@mediatek.com>,
        Fritz Koenig <frkoenig@chromium.org>,
        linux-media@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        srv_heupstream@mediatek.com, linux-mediatek@lists.infradead.org,
        Project_Global_Chrome_Upstream_Group@mediatek.com
References: <20220117120615.21687-1-irui.wang@mediatek.com>
 <20220117120615.21687-5-irui.wang@mediatek.com>
From:   AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>
In-Reply-To: <20220117120615.21687-5-irui.wang@mediatek.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
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Precedence: bulk

Il 17/01/22 13:06, Irui Wang ha scritto:
> Adds new venc core mode to indicate different venc hardware mode:
> VENC_SINGLE_CORE_MODE means only one core, the device has its own
> power/clk/irq, init_clk/request_irq helper can be used.
> 
> VENC_DUAL_CORE_MODE means more than one core inside, the core device
> can use the init_clk/request_irq helper to initialize their own
> power/clk/irq. And the main device doesn't need use these helper anymore.
> 
> MT8195 has two H264 venc cores, enable dual_core_mode for it.
> 
> Signed-off-by: Irui Wang <irui.wang@mediatek.com>
> ---
>   drivers/media/platform/mtk-vcodec/Makefile    |   4 +-
>   .../platform/mtk-vcodec/mtk_vcodec_drv.h      |  22 +++
>   .../platform/mtk-vcodec/mtk_vcodec_enc_core.c | 153 ++++++++++++++++++
>   .../platform/mtk-vcodec/mtk_vcodec_enc_core.h |  36 +++++
>   .../platform/mtk-vcodec/mtk_vcodec_enc_drv.c  |  88 +++++-----
>   5 files changed, 266 insertions(+), 37 deletions(-)
>   create mode 100644 drivers/media/platform/mtk-vcodec/mtk_vcodec_enc_core.c
>   create mode 100644 drivers/media/platform/mtk-vcodec/mtk_vcodec_enc_core.h
> 
> diff --git a/drivers/media/platform/mtk-vcodec/Makefile b/drivers/media/platform/mtk-vcodec/Makefile
> index 93e7a343b5b0..c472b221bd6b 100644
> --- a/drivers/media/platform/mtk-vcodec/Makefile
> +++ b/drivers/media/platform/mtk-vcodec/Makefile
> @@ -3,7 +3,8 @@
>   obj-$(CONFIG_VIDEO_MEDIATEK_VCODEC) += mtk-vcodec-dec.o \
>   				       mtk-vcodec-enc.o \
>   				       mtk-vcodec-common.o \
> -				       mtk-vcodec-dec-hw.o
> +				       mtk-vcodec-dec-hw.o \
> +				       mtk-vcodec-enc-core.o
>   
>   mtk-vcodec-dec-y := vdec/vdec_h264_if.o \
>   		vdec/vdec_vp8_if.o \
> @@ -32,6 +33,7 @@ mtk-vcodec-enc-y := venc/venc_vp8_if.o \
>   		venc_drv_if.o \
>   		venc_vpu_if.o \
>   
> +mtk-vcodec-enc-core-y := mtk_vcodec_enc_core.o
>   
>   mtk-vcodec-common-y := mtk_vcodec_intr.o \
>   		mtk_vcodec_util.o \
> diff --git a/drivers/media/platform/mtk-vcodec/mtk_vcodec_drv.h b/drivers/media/platform/mtk-vcodec/mtk_vcodec_drv.h
> index f78463ff4551..9e4e4290a69a 100644
> --- a/drivers/media/platform/mtk-vcodec/mtk_vcodec_drv.h
> +++ b/drivers/media/platform/mtk-vcodec/mtk_vcodec_drv.h
> @@ -117,6 +117,23 @@ enum mtk_vdec_hw_count {
>   	MTK_VDEC_MAX_HW_COUNT,
>   };
>   
> +/*
> + * enum mtk_venc_core_id -- encoder core id
> + */
> +enum mtk_venc_core_id {
> +	MTK_VENC_CORE0 = 0,
> +	MTK_VENC_CORE1 = 1,

You don't have to say "= 1" for core1, just...

	MTK_VENC_CORE0 = 0,
	MTK_VENC_CORE1,

...is fine, and better.

> +	MTK_VENC_CORE_MAX,
> +};
> +
> +/**
> + * enmu mtk_venc_core_mode - Used to indicate different encode mode
> + */
> +enum mtk_venc_core_mode {
> +	VENC_SINGLE_CORE_MODE = 0,
> +	VENC_DUAL_CORE_MODE = 1,
> +};
> +
>   /*
>    * struct mtk_video_fmt - Structure used to store information about pixelformats
>    */
> @@ -420,6 +437,7 @@ struct mtk_vcodec_dec_pdata {
>    * @output_formats: array of supported output formats
>    * @num_output_formats: number of entries in output_formats
>    * @core_type: stand for h264 or vp8 encode
> + * @core_mode: indicate encode core mode
>    */
>   struct mtk_vcodec_enc_pdata {
>   	bool uses_ext;
> @@ -430,6 +448,7 @@ struct mtk_vcodec_enc_pdata {
>   	const struct mtk_video_fmt *output_formats;
>   	size_t num_output_formats;
>   	int core_type;
> +	enum mtk_venc_core_mode core_mode;
>   };
>   
>   #define MTK_ENC_CTX_IS_EXT(ctx) ((ctx)->dev->venc_pdata->uses_ext)
> @@ -479,6 +498,7 @@ struct mtk_vcodec_enc_pdata {
>    * @subdev_dev: subdev hardware device
>    * @subdev_prob_done: check whether all used hw device is prob done
>    * @subdev_bitmap: used to record hardware is ready or not
> + * @enc_core_dev: used to store venc core device
>    */
>   struct mtk_vcodec_dev {
>   	struct v4l2_device v4l2_dev;
> @@ -524,6 +544,8 @@ struct mtk_vcodec_dev {
>   	void *subdev_dev[MTK_VDEC_HW_MAX];
>   	int (*subdev_prob_done)(struct mtk_vcodec_dev *vdec_dev);
>   	DECLARE_BITMAP(subdev_bitmap, MTK_VDEC_HW_MAX);
> +
> +	void *enc_core_dev[MTK_VENC_CORE_MAX];
>   };
>   
>   static inline struct mtk_vcodec_ctx *fh_to_ctx(struct v4l2_fh *fh)
> diff --git a/drivers/media/platform/mtk-vcodec/mtk_vcodec_enc_core.c b/drivers/media/platform/mtk-vcodec/mtk_vcodec_enc_core.c
> new file mode 100644
> index 000000000000..d84914f615a5
> --- /dev/null
> +++ b/drivers/media/platform/mtk-vcodec/mtk_vcodec_enc_core.c
> @@ -0,0 +1,153 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2021 MediaTek Inc.
> + */
> +
> +#include <linux/interrupt.h>
> +#include <linux/irq.h>
> +#include <linux/module.h>
> +#include <linux/of_platform.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/slab.h>
> +
> +#include "mtk_vcodec_drv.h"
> +#include "mtk_vcodec_enc.h"
> +#include "mtk_vcodec_enc_core.h"
> +
> +static const struct of_device_id mtk_venc_core_ids[] = {
> +	{
> +		.compatible = "mediatek,mtk-venc-core0",
> +		.data = (void *)MTK_VENC_CORE0,
> +	},
> +	{
> +		.compatible = "mediatek,mtk-venc-core1",
> +		.data = (void *)MTK_VENC_CORE1,
> +	},
> +	{},
> +};

Hello Irui,

You don't need a different compatible for the different cores, as in the
declaration, there's nothing special that differentiates them that much.

I understand that there may be a need to differentiate the core number, as
in, CORE0 always has to be the leader, while CORE1 would be the follower,
but this is not a good reason to give them a different compatible string.

I want to make you aware that Kyrie Wu did the same thing as you did here
and in my review on his patch I was able to give an extensive example of
how this should look; the exactly same logic would apply to this patch.

Please have a look here: https://patchwork.kernel.org/comment/24726607/

P.S.: In short, you should have only one "mediatek,mtk-venc-hw" compatible
       used for probing both cores.

> +MODULE_DEVICE_TABLE(of, mtk_venc_core_ids);
> +
> +static void clean_irq_status(unsigned int irq_status, void __iomem *addr)
> +{
> +	if (irq_status & MTK_VENC_IRQ_STATUS_PAUSE)
> +		writel(MTK_VENC_IRQ_STATUS_PAUSE, addr);
> +
> +	if (irq_status & MTK_VENC_IRQ_STATUS_SWITCH)
> +		writel(MTK_VENC_IRQ_STATUS_SWITCH, addr);
> +
> +	if (irq_status & MTK_VENC_IRQ_STATUS_DRAM)
> +		writel(MTK_VENC_IRQ_STATUS_DRAM, addr);
> +
> +	if (irq_status & MTK_VENC_IRQ_STATUS_SPS)
> +		writel(MTK_VENC_IRQ_STATUS_SPS, addr);
> +
> +	if (irq_status & MTK_VENC_IRQ_STATUS_PPS)
> +		writel(MTK_VENC_IRQ_STATUS_PPS, addr);
> +
> +	if (irq_status & MTK_VENC_IRQ_STATUS_FRM)
> +		writel(MTK_VENC_IRQ_STATUS_FRM, addr);
> +}
> +
> +static irqreturn_t mtk_enc_core_irq_handler(int irq, void *priv)
> +{
> +	struct mtk_venc_core_dev *core = priv;
> +	struct mtk_vcodec_ctx *ctx;
> +	unsigned long flags;
> +	void __iomem *addr;
> +
> +	spin_lock_irqsave(&core->main_dev->irqlock, flags);
> +	ctx = core->curr_ctx;
> +	spin_unlock_irqrestore(&core->main_dev->irqlock, flags);
> +	if (!ctx)
> +		return IRQ_HANDLED;
> +
> +	mtk_v4l2_debug(1, "id=%d core :%d", ctx->id, core->core_id);
> +
> +	addr = core->reg_base + MTK_VENC_IRQ_ACK_OFFSET;
> +	ctx->irq_status = readl(core->reg_base + MTK_VENC_IRQ_STATUS_OFFSET);
> +	clean_irq_status(ctx->irq_status, addr);
> +
> +	wake_up_ctx(ctx, MTK_INST_IRQ_RECEIVED, 0);
> +	return IRQ_HANDLED;
> +}
> +
> +static int mtk_venc_core_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct mtk_venc_core_dev *core;
> +	struct mtk_vcodec_dev *main_dev;
> +	int ret;
> +
> +	if (!dev->parent) {
> +		dev_err(dev, "No parent for venc core device\n");
> +		return -ENODEV;
> +	}

Please, use dev_err_probe(), here and everywhere else.

> +
> +	main_dev = dev_get_drvdata(dev->parent);
> +	if (!main_dev) {
> +		dev_err(dev, "Failed to get parent driver data");
> +		return -EINVAL;
> +	}
> +
> +	core = devm_kzalloc(&pdev->dev, sizeof(*core), GFP_KERNEL);
> +	if (!core)
> +		return -ENOMEM;
> +
> +	core->plat_dev = pdev;
> +
> +	core->reg_base = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(core->reg_base)) {
> +		dev_err(&pdev->dev, "Failed to get reg base");
> +		ret = PTR_ERR(core->reg_base);
> +		goto err;

You don't need the "err" label. Also, you can return dev_err_probe here too.
Example:

		return dev_err_probe(&pdev->dev, PTR_ERR(core->reg_base),
				     "Failed to get reg base\n");

> +	}
> +
> +	core->enc_irq = platform_get_irq(pdev, 0);
> +	if (core->enc_irq < 0) {
> +		dev_err(&pdev->dev, "Failed to get irq resource");
> +		ret = core->enc_irq;
> +		goto err;
> +	}
> +
> +	ret = devm_request_irq(&pdev->dev, core->enc_irq,
> +			       mtk_enc_core_irq_handler, 0,
> +			       pdev->name, core);
> +	if (ret) {
> +		dev_err(&pdev->dev,
> +			"Failed to install core->enc_irq %d (%d)",
> +			core->enc_irq, ret);
> +		ret = -EINVAL;
> +		goto err;
> +	}
> +
> +	core->core_id =

core_id would be 0 if "mediatek,hw-leader", N if it's not a mediatek,hw-leader.

> +		(enum mtk_venc_core_id)of_device_get_match_data(&pdev->dev);
> +	if (core->core_id < 0 || core->core_id >= MTK_VENC_CORE_MAX) {
> +		ret = -EINVAL;
> +		goto err;
> +	}
> +
> +	main_dev->enc_core_dev[core->core_id] = core;
> +	core->main_dev = main_dev;
> +
> +	platform_set_drvdata(pdev, core);
> +
> +	dev_info(dev, "Venc core :%d probe done\n", core->core_id);

Please change this to dev_dbg().

> +
> +	return 0;
> +
> +err:
> +	return ret;
> +}
> +
> +static struct platform_driver mtk_venc_core_driver = {
> +	.probe  = mtk_venc_core_probe,
> +	.driver = {
> +		.name	 = "mtk-venc-core",
> +		.of_match_table = mtk_venc_core_ids,
> +	},
> +};
> +module_platform_driver(mtk_venc_core_driver);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("Mediatek video encoder core driver");
> diff --git a/drivers/media/platform/mtk-vcodec/mtk_vcodec_enc_core.h b/drivers/media/platform/mtk-vcodec/mtk_vcodec_enc_core.h
> new file mode 100644
> index 000000000000..856681989869
> --- /dev/null
> +++ b/drivers/media/platform/mtk-vcodec/mtk_vcodec_enc_core.h
> @@ -0,0 +1,36 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (c) 2021 MediaTek Inc.
> + */
> +
> +#ifndef _MTK_VCODEC_ENC_CORE_H_
> +#define _MTK_VCODEC_ENC_CORE_H_
> +
> +#include <linux/platform_device.h>
> +#include "mtk_vcodec_drv.h"
> +
> +/*

I love when developers try to write kerneldoc, this is something that
should really be done *always*, so thank you for this!!!!

....but you missed something here: for this to be parsed by kerneldoc,
you need to do:

/**
^^^ this one :))

  * struct mtk_venc_core_dev - driver data

P.S.: https://docs.kernel.org/doc-guide/kernel-doc.html

> + * struct mtk_venc_core_dev - driver data
> + * @plat_dev: platform_device
> + * @main_dev: main device
> + * @pm: power management data
> + * @curr_ctx: the context that is waiting for venc hardware
> + * @reg_base: mapped address of venc registers
> + * @irq_status: venc core irq status
> + * @enc_irq: venc device irq
> + * @core id: for venc core id: core#0, core#1...
> + */
> +struct mtk_venc_core_dev {
> +	struct platform_device *plat_dev;
> +	struct mtk_vcodec_dev *main_dev;
> +
> +	struct mtk_vcodec_pm pm;
> +	struct mtk_vcodec_ctx *curr_ctx;
> +
> +	void __iomem *reg_base;
> +	unsigned int irq_status;
> +	int enc_irq;
> +	int core_id;
> +};
> +
> +#endif /* _MTK_VCODEC_ENC_CORE_H_ */


Thanks,
Angelo