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References: <20200417150614.2631786-1-enric.balletbo@collabora.com> <20200417150614.2631786-5-enric.balletbo@collabora.com>
In-Reply-To: <20200417150614.2631786-5-enric.balletbo@collabora.com>
From:   Chun-Kuang Hu <chunkuang.hu@kernel.org>
Date:   Fri, 1 May 2020 21:21:48 +0800
Message-ID: <CAAOTY_-nzdS-jg2pgpM1ksrsQVewB2AEB8TihHcCB-MJd+qFfw@mail.gmail.com>
Subject: Re: [PATCH v3 4/7] drm/mediatek: mtk_dsi: Convert to bridge driver
To:     Enric Balletbo i Serra <enric.balletbo@collabora.com>
Cc:     linux-kernel <linux-kernel@vger.kernel.org>,
        Collabora Kernel ML <kernel@collabora.com>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Nicolas Boichat <drinkcat@chromium.org>,
        Hsin-Yi Wang <hsinyi@chromium.org>,
        Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        Chun-Kuang Hu <chunkuang.hu@kernel.org>,
        Daniel Vetter <daniel@ffwll.ch>,
        David Airlie <airlied@linux.ie>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        DRI Development <dri-devel@lists.freedesktop.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        "moderated list:ARM/Mediatek SoC support" 
        <linux-mediatek@lists.infradead.org>
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Sender: linux-kernel-owner@vger.kernel.org
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Hi, Enric:

Enric Balletbo i Serra <enric.balletbo@collabora.com> =E6=96=BC 2020=E5=B9=
=B44=E6=9C=8817=E6=97=A5 =E9=80=B1=E4=BA=94 =E4=B8=8B=E5=8D=8811:06=E5=AF=
=AB=E9=81=93=EF=BC=9A
>
> Convert mtk_dsi to a bridge driver with built-in encoder support for
> compatibility with existing component drivers.
>
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
> ---
>
> Changes in v3:
> - Add the bridge.type. (Laurent Pinchart)
>
> Changes in v2: None
>
>  drivers/gpu/drm/mediatek/mtk_dsi.c | 93 ++++++++++++++++++++++--------
>  1 file changed, 69 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediate=
k/mtk_dsi.c
> index 37b8d7ffd835..869ae0a2e9f8 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> @@ -180,6 +180,7 @@ struct mtk_dsi {
>         struct device *dev;
>         struct mipi_dsi_host host;
>         struct drm_encoder encoder;
> +       struct drm_bridge bridge;
>         struct drm_connector conn;
>         struct drm_panel *panel;
>         struct drm_bridge *next_bridge;
> @@ -205,9 +206,9 @@ struct mtk_dsi {
>         const struct mtk_dsi_driver_data *driver_data;
>  };
>
> -static inline struct mtk_dsi *encoder_to_dsi(struct drm_encoder *e)
> +static inline struct mtk_dsi *bridge_to_dsi(struct drm_bridge *b)
>  {
> -       return container_of(e, struct mtk_dsi, encoder);
> +       return container_of(b, struct mtk_dsi, bridge);
>  }
>
>  static inline struct mtk_dsi *connector_to_dsi(struct drm_connector *c)
> @@ -796,32 +797,43 @@ static const struct drm_encoder_funcs mtk_dsi_encod=
er_funcs =3D {
>         .destroy =3D mtk_dsi_encoder_destroy,
>  };
>
> -static bool mtk_dsi_encoder_mode_fixup(struct drm_encoder *encoder,
> -                                      const struct drm_display_mode *mod=
e,
> -                                      struct drm_display_mode *adjusted_=
mode)
> +static int mtk_dsi_create_conn_enc(struct drm_device *drm, struct mtk_ds=
i *dsi);
> +static void mtk_dsi_destroy_conn_enc(struct mtk_dsi *dsi);
> +
> +static int mtk_dsi_bridge_attach(struct drm_bridge *bridge,
> +                                enum drm_bridge_attach_flags flags)
> +{
> +       struct mtk_dsi *dsi =3D bridge_to_dsi(bridge);
> +
> +       return mtk_dsi_create_conn_enc(bridge->dev, dsi);
> +}
> +
> +static void mtk_dsi_bridge_detach(struct drm_bridge *bridge)
>  {
> -       return true;
> +       struct mtk_dsi *dsi =3D bridge_to_dsi(bridge);
> +
> +       mtk_dsi_destroy_conn_enc(dsi);
>  }
>
> -static void mtk_dsi_encoder_mode_set(struct drm_encoder *encoder,
> -                                    struct drm_display_mode *mode,
> -                                    struct drm_display_mode *adjusted)
> +static void mtk_dsi_bridge_mode_set(struct drm_bridge *bridge,
> +                                   const struct drm_display_mode *mode,
> +                                   const struct drm_display_mode *adjust=
ed)
>  {
> -       struct mtk_dsi *dsi =3D encoder_to_dsi(encoder);
> +       struct mtk_dsi *dsi =3D bridge_to_dsi(bridge);
>
>         drm_display_mode_to_videomode(adjusted, &dsi->vm);
>  }
>
> -static void mtk_dsi_encoder_disable(struct drm_encoder *encoder)
> +static void mtk_dsi_bridge_disable(struct drm_bridge *bridge)
>  {
> -       struct mtk_dsi *dsi =3D encoder_to_dsi(encoder);
> +       struct mtk_dsi *dsi =3D bridge_to_dsi(bridge);
>
>         mtk_output_dsi_disable(dsi);
>  }
>
> -static void mtk_dsi_encoder_enable(struct drm_encoder *encoder)
> +static void mtk_dsi_bridge_enable(struct drm_bridge *bridge)
>  {
> -       struct mtk_dsi *dsi =3D encoder_to_dsi(encoder);
> +       struct mtk_dsi *dsi =3D bridge_to_dsi(bridge);
>
>         mtk_output_dsi_enable(dsi);
>  }
> @@ -833,11 +845,12 @@ static int mtk_dsi_connector_get_modes(struct drm_c=
onnector *connector)
>         return drm_panel_get_modes(dsi->panel, connector);
>  }
>
> -static const struct drm_encoder_helper_funcs mtk_dsi_encoder_helper_func=
s =3D {
> -       .mode_fixup =3D mtk_dsi_encoder_mode_fixup,
> -       .mode_set =3D mtk_dsi_encoder_mode_set,
> -       .disable =3D mtk_dsi_encoder_disable,
> -       .enable =3D mtk_dsi_encoder_enable,
> +static const struct drm_bridge_funcs mtk_dsi_bridge_funcs =3D {
> +       .attach =3D mtk_dsi_bridge_attach,
> +       .detach =3D mtk_dsi_bridge_detach,
> +       .disable =3D mtk_dsi_bridge_disable,
> +       .enable =3D mtk_dsi_bridge_enable,
> +       .mode_set =3D mtk_dsi_bridge_mode_set,
>  };
>
>  static const struct drm_connector_funcs mtk_dsi_connector_funcs =3D {
> @@ -1123,6 +1136,34 @@ static const struct mipi_dsi_host_ops mtk_dsi_ops =
=3D {
>         .transfer =3D mtk_dsi_host_transfer,
>  };
>
> +static int mtk_dsi_encoder_init(struct drm_device *drm, struct mtk_dsi *=
dsi)
> +{
> +       int ret;
> +
> +       ret =3D drm_encoder_init(drm, &dsi->encoder, &mtk_dsi_encoder_fun=
cs,
> +                              DRM_MODE_ENCODER_DSI, NULL);

I'm a bit confused here. drm_encoder_init() exist here and in
mtk_dsi_create_conn_enc(). Do you plan to init encodr twice?

> +       if (ret) {
> +               DRM_ERROR("Failed to encoder init to drm\n");
> +               return ret;
> +       }
> +
> +       /*
> +        * Currently display data paths are statically assigned to a crtc=
 each.
> +        * crtc 0 is OVL0 -> COLOR0 -> AAL -> OD -> RDMA0 -> UFOE -> DSI0
> +        */
> +       dsi->encoder.possible_crtcs =3D 1;
> +
> +       ret =3D drm_bridge_attach(&dsi->encoder, &dsi->bridge, NULL, 0);
> +       if (ret)
> +               goto err_cleanup_encoder;
> +
> +       return 0;
> +
> +err_cleanup_encoder:
> +       drm_encoder_cleanup(&dsi->encoder);
> +       return ret;
> +}
> +
>  static int mtk_dsi_bind(struct device *dev, struct device *master, void =
*data)
>  {
>         int ret;
> @@ -1136,11 +1177,9 @@ static int mtk_dsi_bind(struct device *dev, struct=
 device *master, void *data)
>                 return ret;
>         }
>
> -       ret =3D mtk_dsi_create_conn_enc(drm, dsi);
> -       if (ret) {
> -               DRM_ERROR("Encoder create failed with %d\n", ret);
> +       ret =3D mtk_dsi_encoder_init(drm, dsi);
> +       if (ret)
>                 goto err_unregister;
> -       }
>
>         return 0;
>
> @@ -1155,7 +1194,6 @@ static void mtk_dsi_unbind(struct device *dev, stru=
ct device *master,
>         struct drm_device *drm =3D data;
>         struct mtk_dsi *dsi =3D dev_get_drvdata(dev);
>
> -       mtk_dsi_destroy_conn_enc(dsi);

There is mtk_dsi_encoder_init() in bind(), why no mtk_dsi_encoder_uninit() =
here?

Regards,
Chun-Kuang.

>         mtk_ddp_comp_unregister(drm, &dsi->ddp_comp);
>  }
>
> @@ -1265,6 +1303,12 @@ static int mtk_dsi_probe(struct platform_device *p=
dev)
>
>         platform_set_drvdata(pdev, dsi);
>
> +       dsi->bridge.funcs =3D &mtk_dsi_bridge_funcs;
> +       dsi->bridge.of_node =3D dev->of_node;
> +       dsi->bridge.type =3D DRM_MODE_CONNECTOR_DSI;
> +
> +       drm_bridge_add(&dsi->bridge);
> +
>         ret =3D component_add(&pdev->dev, &mtk_dsi_component_ops);
>         if (ret) {
>                 dev_err(&pdev->dev, "failed to add component: %d\n", ret)=
;
> @@ -1283,6 +1327,7 @@ static int mtk_dsi_remove(struct platform_device *p=
dev)
>         struct mtk_dsi *dsi =3D platform_get_drvdata(pdev);
>
>         mtk_output_dsi_disable(dsi);
> +       drm_bridge_remove(&dsi->bridge);
>         component_del(&pdev->dev, &mtk_dsi_component_ops);
>         mipi_dsi_host_unregister(&dsi->host);
>
> --
> 2.25.1
>