[PATCH] drm/imx: parallel-display: add bridge support

[Philipp Zabel]

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

Signed-off-by: Philipp Zabel <p.zabel at pengutronix.de>
---
 drivers/gpu/drm/imx/parallel-display.c | 71 ++++++++++++++++++++++++++++------
 1 file changed, 59 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/imx/parallel-display.c b/drivers/gpu/drm/imx/parallel-display.c
index 2d1fd02..830e56b 100644
--- a/drivers/gpu/drm/imx/parallel-display.c
+++ b/drivers/gpu/drm/imx/parallel-display.c
@@ -37,6 +37,7 @@ struct imx_parallel_display {
 	u32 bus_format;
 	struct drm_display_mode mode;
 	struct drm_panel *panel;
+	struct drm_bridge *bridge;
 };
 
 static enum drm_connector_status imx_pd_connector_detect(
@@ -103,8 +104,23 @@ static void imx_pd_encoder_dpms(struct drm_encoder *encoder, int mode)
 static void imx_pd_encoder_prepare(struct drm_encoder *encoder)
 {
 	struct imx_parallel_display *imxpd = enc_to_imxpd(encoder);
-	imx_drm_set_bus_config(encoder, imxpd->bus_format, 2, 3,
-			       imxpd->connector.display_info.bus_flags);
+	struct drm_connector *connector;
+	u32 bus_format = imxpd->bus_format;
+	u32 bus_flags;
+
+	drm_for_each_connector(connector, encoder->dev) {
+		struct drm_display_info *di = &connector->display_info;
+
+		if (connector->encoder != encoder)
+			continue;
+
+		bus_flags = di->bus_flags;
+		if (!bus_format && di->num_bus_formats)
+			bus_format = di->bus_formats[0];
+		break;
+	}
+
+	imx_drm_set_bus_config(encoder, bus_format, 2, 3, bus_flags);
 }
 
 static void imx_pd_encoder_commit(struct drm_encoder *encoder)
@@ -174,15 +190,29 @@ static int imx_pd_register(struct drm_device *drm,
 	drm_encoder_init(drm, &imxpd->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, &imxpd->encoder);
+	if (imxpd->bridge) {
+		imxpd->bridge->encoder = &imxpd->encoder;
+		imxpd->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,
+						  &imxpd->encoder);
+	}
 
 	return 0;
 }
@@ -223,13 +253,30 @@ 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;
-- 
2.8.1