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References: <20220120083357.1541262-1-narmstrong@baylibre.com> <20220120083357.1541262-6-narmstrong@baylibre.com>
In-Reply-To: <20220120083357.1541262-6-narmstrong@baylibre.com>
From:   Jagan Teki <jagan@amarulasolutions.com>
Date:   Thu, 20 Jan 2022 19:52:54 +0530
Message-ID: <CAMty3ZCrcQchnne1KU1RQA6MfwRQS8dObJQcOF_H7fEQ57wa0w@mail.gmail.com>
Subject: Re: [PATCH v2 5/6] drm/meson: add DSI encoder
To:     Neil Armstrong <narmstrong@baylibre.com>
Cc:     dri-devel@lists.freedesktop.org,
        martin.blumenstingl@googlemail.com,
        linux-amlogic@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org
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On Thu, Jan 20, 2022 at 2:04 PM Neil Armstrong <narmstrong@baylibre.com> wrote:
>
> This adds an encoder bridge designed to drive a MIPI-DSI display
> by using the ENCL encoder through the internal MIPI DSI transceiver
> connected to the output of the ENCL pixel encoder.
>
> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
> ---
>  drivers/gpu/drm/meson/Makefile            |   2 +-
>  drivers/gpu/drm/meson/meson_drv.c         |   7 +
>  drivers/gpu/drm/meson/meson_encoder_dsi.c | 160 ++++++++++++++++++++++
>  drivers/gpu/drm/meson/meson_encoder_dsi.h |  12 ++
>  4 files changed, 180 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/gpu/drm/meson/meson_encoder_dsi.c
>  create mode 100644 drivers/gpu/drm/meson/meson_encoder_dsi.h
>
> diff --git a/drivers/gpu/drm/meson/Makefile b/drivers/gpu/drm/meson/Makefile
> index 3afa31bdc950..833e18c20603 100644
> --- a/drivers/gpu/drm/meson/Makefile
> +++ b/drivers/gpu/drm/meson/Makefile
> @@ -2,7 +2,7 @@
>  meson-drm-y := meson_drv.o meson_plane.o meson_crtc.o meson_encoder_cvbs.o
>  meson-drm-y += meson_viu.o meson_vpp.o meson_venc.o meson_vclk.o meson_overlay.o
>  meson-drm-y += meson_rdma.o meson_osd_afbcd.o
> -meson-drm-y += meson_encoder_hdmi.o
> +meson-drm-y += meson_encoder_hdmi.o meson_encoder_dsi.o
>
>  obj-$(CONFIG_DRM_MESON) += meson-drm.o
>  obj-$(CONFIG_DRM_MESON_DW_HDMI) += meson_dw_hdmi.o
> diff --git a/drivers/gpu/drm/meson/meson_drv.c b/drivers/gpu/drm/meson/meson_drv.c
> index 26aeaf0ab86e..15344cf9f913 100644
> --- a/drivers/gpu/drm/meson/meson_drv.c
> +++ b/drivers/gpu/drm/meson/meson_drv.c
> @@ -33,6 +33,7 @@
>  #include "meson_registers.h"
>  #include "meson_encoder_cvbs.h"
>  #include "meson_encoder_hdmi.h"
> +#include "meson_encoder_dsi.h"
>  #include "meson_viu.h"
>  #include "meson_vpp.h"
>  #include "meson_rdma.h"
> @@ -323,6 +324,12 @@ static int meson_drv_bind_master(struct device *dev, bool has_components)
>         if (ret)
>                 goto exit_afbcd;
>
> +       if (meson_vpu_is_compatible(priv, VPU_COMPATIBLE_G12A)) {
> +               ret = meson_encoder_dsi_init(priv);
> +               if (ret)
> +                       goto free_drm;
> +       }
> +
>         ret = meson_plane_create(priv);
>         if (ret)
>                 goto exit_afbcd;
> diff --git a/drivers/gpu/drm/meson/meson_encoder_dsi.c b/drivers/gpu/drm/meson/meson_encoder_dsi.c
> new file mode 100644
> index 000000000000..12a586316183
> --- /dev/null
> +++ b/drivers/gpu/drm/meson/meson_encoder_dsi.c
> @@ -0,0 +1,160 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (C) 2016 BayLibre, SAS
> + * Author: Neil Armstrong <narmstrong@baylibre.com>
> + * Copyright (C) 2015 Amlogic, Inc. All rights reserved.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/of_graph.h>
> +
> +#include <drm/drm_atomic_helper.h>
> +#include <drm/drm_simple_kms_helper.h>
> +#include <drm/drm_bridge.h>
> +#include <drm/drm_bridge_connector.h>
> +#include <drm/drm_device.h>
> +#include <drm/drm_probe_helper.h>
> +
> +#include "meson_drv.h"
> +#include "meson_encoder_dsi.h"
> +#include "meson_registers.h"
> +#include "meson_venc.h"
> +#include "meson_vclk.h"
> +
> +struct meson_encoder_dsi {
> +       struct drm_encoder encoder;
> +       struct drm_bridge bridge;
> +       struct drm_bridge *next_bridge;
> +       struct meson_drm *priv;
> +};
> +
> +#define bridge_to_meson_encoder_dsi(x) \
> +       container_of(x, struct meson_encoder_dsi, bridge)
> +
> +static int meson_encoder_dsi_attach(struct drm_bridge *bridge,
> +                                   enum drm_bridge_attach_flags flags)
> +{
> +       struct meson_encoder_dsi *encoder_dsi = bridge_to_meson_encoder_dsi(bridge);
> +
> +       return drm_bridge_attach(bridge->encoder, encoder_dsi->next_bridge,
> +                                &encoder_dsi->bridge, flags);
> +}
> +
> +static void meson_encoder_dsi_mode_set(struct drm_bridge *bridge,
> +                                      const struct drm_display_mode *mode,
> +                                      const struct drm_display_mode *adjusted_mode)
> +{
> +       struct meson_encoder_dsi *encoder_dsi = bridge_to_meson_encoder_dsi(bridge);
> +       struct meson_drm *priv = encoder_dsi->priv;
> +
> +       meson_vclk_setup(priv, MESON_VCLK_TARGET_DSI, mode->clock, 0, 0, 0, false);
> +
> +       meson_venc_mipi_dsi_mode_set(priv, mode);
> +       meson_encl_load_gamma(priv);
> +
> +       writel_relaxed(0, priv->io_base + _REG(ENCL_VIDEO_EN));
> +
> +       writel_bits_relaxed(ENCL_VIDEO_MODE_ADV_VFIFO_EN, ENCL_VIDEO_MODE_ADV_VFIFO_EN,
> +                           priv->io_base + _REG(ENCL_VIDEO_MODE_ADV));
> +       writel_relaxed(0, priv->io_base + _REG(ENCL_TST_EN));
> +}
> +
> +static void meson_encoder_dsi_atomic_enable(struct drm_bridge *bridge,
> +                                           struct drm_bridge_state *bridge_state)
> +{
> +       struct meson_encoder_dsi *encoder_dsi = bridge_to_meson_encoder_dsi(bridge);
> +       struct meson_drm *priv = encoder_dsi->priv;
> +
> +       writel_bits_relaxed(BIT(0), 0, priv->io_base + _REG(VPP_WRAP_OSD1_MATRIX_EN_CTRL));
> +
> +       writel_relaxed(1, priv->io_base + _REG(ENCL_VIDEO_EN));
> +}
> +
> +static void meson_encoder_dsi_atomic_disable(struct drm_bridge *bridge,
> +                                            struct drm_bridge_state *bridge_state)
> +{
> +       struct meson_encoder_dsi *meson_encoder_dsi =
> +                                       bridge_to_meson_encoder_dsi(bridge);
> +       struct meson_drm *priv = meson_encoder_dsi->priv;
> +
> +       writel_relaxed(0, priv->io_base + _REG(ENCL_VIDEO_EN));
> +
> +       writel_bits_relaxed(BIT(0), BIT(0), priv->io_base + _REG(VPP_WRAP_OSD1_MATRIX_EN_CTRL));
> +}
> +
> +static const struct drm_bridge_funcs meson_encoder_dsi_bridge_funcs = {
> +       .attach = meson_encoder_dsi_attach,
> +       /*
> +        * TOFIX: remove when dw-mipi-dsi moves out of mode_set
> +        * We should get rid of mode_set, but until dw-mipi-dsi uses it
> +        * we need to setup the pixel clock before the following
> +        * bridge tries to setup the HW.
> +        */
> +       .mode_set = meson_encoder_dsi_mode_set,
> +       .atomic_enable = meson_encoder_dsi_atomic_enable,
> +       .atomic_disable = meson_encoder_dsi_atomic_disable,
> +       .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
> +       .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
> +       .atomic_reset = drm_atomic_helper_bridge_reset,
> +};
> +
> +int meson_encoder_dsi_init(struct meson_drm *priv)
> +{
> +       struct meson_encoder_dsi *meson_encoder_dsi;
> +       struct device_node *remote;
> +       int ret;
> +
> +       meson_encoder_dsi = devm_kzalloc(priv->dev, sizeof(*meson_encoder_dsi), GFP_KERNEL);
> +       if (!meson_encoder_dsi)
> +               return -ENOMEM;
> +
> +       /* DSI Transceiver Bridge */
> +       remote = of_graph_get_remote_node(priv->dev->of_node, 2, 0);
> +       if (!remote) {
> +               dev_err(priv->dev, "DSI transceiver device is disabled");
> +               return 0;
> +       }
> +
> +       meson_encoder_dsi->next_bridge = of_drm_find_bridge(remote);
> +       if (!meson_encoder_dsi->next_bridge) {
> +               dev_dbg(priv->dev, "Failed to find DSI transceiver bridge: %d\n", ret);
> +               return -EPROBE_DEFER;
> +       }
> +
> +       /* DSI Encoder Bridge */
> +       meson_encoder_dsi->bridge.funcs = &meson_encoder_dsi_bridge_funcs;
> +       meson_encoder_dsi->bridge.of_node = priv->dev->of_node;
> +       meson_encoder_dsi->bridge.type = DRM_MODE_CONNECTOR_DSI;
> +
> +       drm_bridge_add(&meson_encoder_dsi->bridge);
> +
> +       meson_encoder_dsi->priv = priv;
> +
> +       /* Encoder */
> +       ret = drm_simple_encoder_init(priv->drm, &meson_encoder_dsi->encoder,
> +                                     DRM_MODE_ENCODER_DSI);
> +       if (ret) {
> +               dev_err(priv->dev, "Failed to init DSI encoder: %d\n", ret);
> +               return ret;
> +       }
> +
> +       meson_encoder_dsi->encoder.possible_crtcs = BIT(0);
> +
> +       /* Attach DSI Encoder Bridge to Encoder */
> +       ret = drm_bridge_attach(&meson_encoder_dsi->encoder, &meson_encoder_dsi->bridge, NULL, 0);
> +       if (ret) {
> +               dev_err(priv->dev, "Failed to attach bridge: %d\n", ret);
> +               return ret;
> +       }
> +
> +       /*
> +        * We should have now in place:
> +        * encoder->[dsi encoder bridge]->[dw-mipi-dsi bridge]->[panel bridge]->[panel]
> +        */

Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>