drm/imx: parallel-display: add bridge support

Add support for bridge chips connected externally to the i.MX
DISP0/DISP1 DPI interfaces.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

1 files changed, 41 insertions, 9 deletions

diff --git a/drivers/gpu/drm/imx/parallel-display.c b/drivers/gpu/drm/imx/parallel-display.c
index 4abac21c5c9b..1dad297b01fd 100644
--- a/drivers/gpu/drm/imx/parallel-display.c
+++ b/drivers/gpu/drm/imx/parallel-display.c
@@ -35,6 +35,7 @@ struct imx_parallel_display {
         u32 bus_format;
         struct drm_display_mode mode;
         struct drm_panel *panel;
+        struct drm_bridge *bridge;
 };
 
 static inline struct imx_parallel_display *con_to_imxpd(struct drm_connector *c)
@@ -181,15 +182,29 @@ static int imx_pd_register(struct drm_device *drm,
         drm_encoder_init(drm, encoder, &imx_pd_encoder_funcs,
                          DRM_MODE_ENCODER_NONE, NULL);
 
-        drm_connector_helper_add(&imxpd->connector,
-                        &imx_pd_connector_helper_funcs);
-        drm_connector_init(drm, &imxpd->connector, &imx_pd_connector_funcs,
-                           DRM_MODE_CONNECTOR_VGA);
+        if (!imxpd->bridge) {
+                drm_connector_helper_add(&imxpd->connector,
+                                &imx_pd_connector_helper_funcs);
+                drm_connector_init(drm, &imxpd->connector,
+                                   &imx_pd_connector_funcs,
+                                   DRM_MODE_CONNECTOR_VGA);
+        }
 
         if (imxpd->panel)
                 drm_panel_attach(imxpd->panel, &imxpd->connector);
 
-        drm_mode_connector_attach_encoder(&imxpd->connector, encoder);
+        if (imxpd->bridge) {
+                imxpd->bridge->encoder = encoder;
+                encoder->bridge = imxpd->bridge;
+                ret = drm_bridge_attach(drm, imxpd->bridge);
+                if (ret < 0) {
+                        dev_err(imxpd->dev, "failed to attach bridge: %d\n",
+                                ret);
+                        return ret;
+                }
+        } else {
+                drm_mode_connector_attach_encoder(&imxpd->connector, encoder);
+        }
 
         return 0;
 }
@@ -232,13 +247,30 @@ static int imx_pd_bind(struct device *dev, struct device *master, void *data)
                 struct device_node *remote;
 
                 remote = of_graph_get_remote_port_parent(ep);
+                if (!remote) {
+                        dev_warn(dev, "endpoint %s not connected\n",
+                                 ep->full_name);
+                        of_node_put(ep);
+                        return -ENODEV;
+                }
                 of_node_put(ep);
-                if (remote) {
-                        imxpd->panel = of_drm_find_panel(remote);
-                        of_node_put(remote);
+
+                imxpd->panel = of_drm_find_panel(remote);
+                if (imxpd->panel) {
+                        dev_dbg(dev, "found panel %s\n", remote->full_name);
+                } else {
+                        imxpd->bridge = of_drm_find_bridge(remote);
+                        if (imxpd->bridge)
+                                dev_dbg(dev, "found bridge %s\n",
+                                        remote->full_name);
                 }
-                if (!imxpd->panel)
+                if (!imxpd->panel && !imxpd->bridge) {
+                        dev_dbg(dev, "waiting for panel or bridge %s\n",
+                                remote->full_name);
+                        of_node_put(remote);
                         return -EPROBE_DEFER;
+                }
+                of_node_put(remote);
         }
 
         imxpd->dev = dev;