[PATCH 12/20] drm/sun4i: Add bridge support

Daniel Vetter daniel at ffwll.ch
Mon May 16 13:12:15 UTC 2016


On Mon, May 16, 2016 at 2:47 PM, Maxime Ripard
<maxime.ripard at free-electrons.com> wrote:
> Our RGB bus can be either connected to a bridge or a panel. While the panel
> support was already there, the bridge was not.
>
> Fix that.
>
> Signed-off-by: Maxime Ripard <maxime.ripard at free-electrons.com>

For bridge support the only thing you need is to set
drm_encoder->bridge. Why do you need to hand-roll your own bridge
support? That pretty muchmeans you'll do it slightly differently (e.g.
you don't bother with a lot of the calls), which will make sharing
bridge drivers ever so harder. And also reviewing code, since using
shared code but slightly differently is really confusing.
-Daniel

> ---
>  drivers/gpu/drm/sun4i/sun4i_drv.c  |  4 +--
>  drivers/gpu/drm/sun4i/sun4i_rgb.c  | 56 +++++++++++++++++++++++++++-----------
>  drivers/gpu/drm/sun4i/sun4i_tcon.c | 48 ++++++++++++++++++++++++++++----
>  drivers/gpu/drm/sun4i/sun4i_tcon.h |  1 +
>  4 files changed, 86 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/gpu/drm/sun4i/sun4i_drv.c b/drivers/gpu/drm/sun4i/sun4i_drv.c
> index 257d2b4f3645..1f9e00db747d 100644
> --- a/drivers/gpu/drm/sun4i/sun4i_drv.c
> +++ b/drivers/gpu/drm/sun4i/sun4i_drv.c
> @@ -268,8 +268,8 @@ static int sun4i_drv_add_endpoints(struct device *dev,
>                 }
>
>                 /*
> -                * If the node is our TCON, the first port is used for our
> -                * panel, and will not be part of the
> +                * If the node is our TCON, the first port is used for
> +                * panel or bridges, and will not be part of the
>                  * component framework.
>                  */
>                 if (sun4i_drv_node_is_tcon(node)) {
> diff --git a/drivers/gpu/drm/sun4i/sun4i_rgb.c b/drivers/gpu/drm/sun4i/sun4i_rgb.c
> index b46d2c15dc95..c3c611b08269 100644
> --- a/drivers/gpu/drm/sun4i/sun4i_rgb.c
> +++ b/drivers/gpu/drm/sun4i/sun4i_rgb.c
> @@ -161,7 +161,12 @@ static void sun4i_rgb_encoder_enable(struct drm_encoder *encoder)
>
>         DRM_DEBUG_DRIVER("Enabling RGB output\n");
>
> -       drm_panel_enable(tcon->panel);
> +       if (!IS_ERR(tcon->panel))
> +               drm_panel_enable(tcon->panel);
> +
> +       if (!IS_ERR(tcon->bridge))
> +               drm_bridge_enable(tcon->bridge);
> +
>         sun4i_tcon_channel_enable(tcon, 0);
>  }
>
> @@ -174,7 +179,12 @@ static void sun4i_rgb_encoder_disable(struct drm_encoder *encoder)
>         DRM_DEBUG_DRIVER("Disabling RGB output\n");
>
>         sun4i_tcon_channel_disable(tcon, 0);
> -       drm_panel_disable(tcon->panel);
> +
> +       if (!IS_ERR(tcon->bridge))
> +               drm_bridge_disable(tcon->bridge);
> +
> +       if (!IS_ERR(tcon->panel))
> +               drm_panel_disable(tcon->panel);
>  }
>
>  static void sun4i_rgb_encoder_mode_set(struct drm_encoder *encoder,
> @@ -216,10 +226,6 @@ int sun4i_rgb_init(struct drm_device *drm)
>         struct sun4i_rgb *rgb;
>         int ret;
>
> -       /* If we don't have a panel, there's no point in going on */
> -       if (IS_ERR(tcon->panel))
> -               return -ENODEV;
> -
>         rgb = devm_kzalloc(drm->dev, sizeof(*rgb), GFP_KERNEL);
>         if (!rgb)
>                 return -ENOMEM;
> @@ -240,19 +246,37 @@ int sun4i_rgb_init(struct drm_device *drm)
>         /* The RGB encoder can only work with the TCON channel 0 */
>         rgb->encoder.possible_crtcs = BIT(0);
>
> -       drm_connector_helper_add(&rgb->connector,
> -                                &sun4i_rgb_con_helper_funcs);
> -       ret = drm_connector_init(drm, &rgb->connector,
> -                                &sun4i_rgb_con_funcs,
> -                                DRM_MODE_CONNECTOR_Unknown);
> -       if (ret) {
> -               dev_err(drm->dev, "Couldn't initialise the rgb connector\n");
> -               goto err_cleanup_connector;
> +       if (!IS_ERR(tcon->panel)) {
> +               drm_connector_helper_add(&rgb->connector,
> +                                        &sun4i_rgb_con_helper_funcs);
> +               ret = drm_connector_init(drm, &rgb->connector,
> +                                        &sun4i_rgb_con_funcs,
> +                                        DRM_MODE_CONNECTOR_Unknown);
> +               if (ret) {
> +                       dev_err(drm->dev, "Couldn't initialise the rgb connector\n");
> +                       goto err_cleanup_connector;
> +               }
> +
> +               drm_mode_connector_attach_encoder(&rgb->connector,
> +                                                 &rgb->encoder);
> +
> +               ret = drm_panel_attach(tcon->panel, &rgb->connector);
> +               if (ret) {
> +                       dev_err(drm->dev, "Couldn't attach our panel\n");
> +                       goto err_cleanup_connector;
> +               }
>         }
>
> -       drm_mode_connector_attach_encoder(&rgb->connector, &rgb->encoder);
> +       if (!IS_ERR(tcon->bridge)) {
> +               rgb->encoder.bridge = tcon->bridge;
> +               tcon->bridge->encoder = &rgb->encoder;
>
> -       drm_panel_attach(tcon->panel, &rgb->connector);
> +               ret = drm_bridge_attach(drm, tcon->bridge);
> +               if (ret) {
> +                       dev_err(drm->dev, "Couldn't attach our bridge\n");
> +                       goto err_cleanup_connector;
> +               }
> +       }
>
>         return 0;
>
> diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> index eed6a9e8d9a6..4618d98913b4 100644
> --- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
> +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> @@ -432,6 +432,40 @@ static struct drm_panel *sun4i_tcon_find_panel(struct device_node *node)
>         return of_drm_find_panel(remote) ?: ERR_PTR(-EPROBE_DEFER);
>  }
>
> +static struct drm_bridge *sun4i_tcon_find_bridge(struct device_node *node)
> +{
> +       struct device_node *port, *remote, *child;
> +       struct device_node *end_node = NULL;
> +
> +       /* Inputs are listed first, then outputs */
> +       port = of_graph_get_port_by_id(node, 1);
> +
> +       /*
> +        * Our first output is the RGB interface where the panel will
> +        * be connected.
> +        */
> +       for_each_child_of_node(port, child) {
> +               u32 reg;
> +
> +               of_property_read_u32(child, "reg", &reg);
> +               if (reg == 0)
> +                       end_node = child;
> +       }
> +
> +       if (!end_node) {
> +               DRM_DEBUG_DRIVER("Missing bridge endpoint\n");
> +               return ERR_PTR(-ENODEV);
> +       }
> +
> +       remote = of_graph_get_remote_port_parent(end_node);
> +       if (!remote) {
> +               DRM_DEBUG_DRIVER("Enable to parse remote node\n");
> +               return ERR_PTR(-EINVAL);
> +       }
> +
> +       return of_drm_find_bridge(remote) ?: ERR_PTR(-EPROBE_DEFER);
> +}
> +
>  static int sun4i_tcon_bind(struct device *dev, struct device *master,
>                            void *data)
>  {
> @@ -485,8 +519,9 @@ static int sun4i_tcon_bind(struct device *dev, struct device *master,
>         }
>
>         tcon->panel = sun4i_tcon_find_panel(dev->of_node);
> -       if (IS_ERR(tcon->panel)) {
> -               dev_info(dev, "No panel found... RGB output disabled\n");
> +       tcon->bridge = sun4i_tcon_find_bridge(dev->of_node);
> +       if (IS_ERR(tcon->panel) && IS_ERR(tcon->bridge)) {
> +               dev_info(dev, "No panel or bridge found... RGB output disabled\n");
>                 return 0;
>         }
>
> @@ -515,19 +550,22 @@ static struct component_ops sun4i_tcon_ops = {
>  static int sun4i_tcon_probe(struct platform_device *pdev)
>  {
>         struct device_node *node = pdev->dev.of_node;
> +       struct drm_bridge *bridge;
>         struct drm_panel *panel;
>
>         /*
> -        * The panel is not ready.
> +        * Neither the bridge or the panel is ready.
>          * Defer the probe.
>          */
>         panel = sun4i_tcon_find_panel(node);
> +       bridge = sun4i_tcon_find_bridge(node);
>
>         /*
>          * If we don't have a panel endpoint, just go on
>          */
> -       if (PTR_ERR(panel) == -EPROBE_DEFER) {
> -               DRM_DEBUG_DRIVER("Still waiting for our panel. Deferring...\n");
> +       if ((PTR_ERR(panel) == -EPROBE_DEFER) &&
> +           (PTR_ERR(bridge) == -EPROBE_DEFER)) {
> +               DRM_DEBUG_DRIVER("Still waiting for our panel/bridge. Deferring...\n");
>                 return -EPROBE_DEFER;
>         }
>
> diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.h b/drivers/gpu/drm/sun4i/sun4i_tcon.h
> index 0e0b11db401b..31069027d7fb 100644
> --- a/drivers/gpu/drm/sun4i/sun4i_tcon.h
> +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.h
> @@ -162,6 +162,7 @@ struct sun4i_tcon {
>         /* Platform adjustments */
>         bool                            has_mux;
>
> +       struct drm_bridge               *bridge;
>         struct drm_panel                *panel;
>  };
>
> --
> 2.8.2
>
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> dri-devel at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel



-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch


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