drm/sun4i: Add bridge support

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@free-electrons.com>

4 files changed, 87 insertions, 19 deletions

diff --git a/drivers/gpu/drm/sun4i/sun4i_drv.c b/drivers/gpu/drm/sun4i/sun4i_drv.c
index 7092daaf6c43..942f62e2441c 100644
--- a/drivers/gpu/drm/sun4i/sun4i_drv.c
+++ b/drivers/gpu/drm/sun4i/sun4i_drv.c
@@ -257,8 +257,8 @@ 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 d32f08f9ce5f..d4e52522ec53 100644
--- a/drivers/gpu/drm/sun4i/sun4i_rgb.c
+++ b/drivers/gpu/drm/sun4i/sun4i_rgb.c
@@ -151,7 +151,12 @@ 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(encoder->bridge))
+                drm_bridge_enable(encoder->bridge);
+
         sun4i_tcon_channel_enable(tcon, 0);
 }
 
@@ -164,7 +169,12 @@ 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(encoder->bridge))
+                drm_bridge_disable(encoder->bridge);
+
+        if (!IS_ERR(tcon->panel))
+                drm_panel_disable(tcon->panel);
 }
 
 static void sun4i_rgb_encoder_mode_set(struct drm_encoder *encoder,
@@ -203,6 +213,7 @@ int sun4i_rgb_init(struct drm_device *drm)
 {
         struct sun4i_drv *drv = drm->dev_private;
         struct sun4i_tcon *tcon = drv->tcon;
+        struct drm_encoder *encoder;
         struct sun4i_rgb *rgb;
         int ret;
 
@@ -210,10 +221,12 @@ int sun4i_rgb_init(struct drm_device *drm)
         if (!rgb)
                 return -ENOMEM;
         rgb->drv = drv;
+        encoder = &rgb->encoder;
 
         tcon->panel = sun4i_tcon_find_panel(tcon->dev->of_node);
-        if (IS_ERR(tcon->panel)) {
-                dev_info(drm->dev, "No panel found... RGB output disabled\n");
+        encoder->bridge = sun4i_tcon_find_bridge(tcon->dev->of_node);
+        if (IS_ERR(tcon->panel) && IS_ERR(encoder->bridge)) {
+                dev_info(drm->dev, "No panel or bridge found... RGB output disabled\n");
                 return 0;
         }
 
@@ -232,19 +245,36 @@ 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(encoder->bridge)) {
+                encoder->bridge->encoder = &rgb->encoder;
 
-        drm_panel_attach(tcon->panel, &rgb->connector);
+                ret = drm_bridge_attach(drm, encoder->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 d2f7489d29a5..2145ecf2cf5d 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
@@ -432,6 +432,40 @@ struct drm_panel *sun4i_tcon_find_panel(struct device_node *node)
         return of_drm_find_panel(remote) ?: ERR_PTR(-EPROBE_DEFER);
 }
 
+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)
 {
@@ -514,19 +548,22 @@ 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 4f81d86ee5a4..100bfa093277 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.h
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.h
@@ -166,6 +166,7 @@ struct sun4i_tcon {
         struct drm_panel                *panel;
 };
 
+struct drm_bridge *sun4i_tcon_find_bridge(struct device_node *node);
 struct drm_panel *sun4i_tcon_find_panel(struct device_node *node);
 
 /* Global Control */