drm/omap: Add support for drm_bridge

Hook up drm_bridge support in the omapdrm driver. Despite the recent
extensive preparation work, this is a rather intrusive change, as the
management of outputs needs to be adapted through the driver to handle
both omap_dss_device and drm_bridge.

Connector creation is skipped when using a drm_bridge, as the bridge
creates the connector internally. This creates issues with systems that
split connector operations (such as modes retrieval and hot-plug
detection) across different bridges. These systems can't be supported
using drm_bridge for now (their support through the omap_dss_device
infrastructure is not affected), this will be fixed in subsequent
changes.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Tested-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/gpu/drm/omapdrm/dss/base.c

@@ -19,6 +19,7 @@
 #include <linux/mutex.h>
 #include <linux/of.h>
 #include <linux/of_graph.h>
+#include <linux/platform_device.h>
 
 #include "dss.h"
 #include "omapdss.h"
@@ -156,7 +157,7 @@ struct omap_dss_device *omapdss_device_next_output(struct omap_dss_device *from)
 			goto done;
 		}
 
-		if (dssdev->id && dssdev->next)
+		if (dssdev->id && (dssdev->next || dssdev->bridge))
 			goto done;
 	}
 
@@ -184,7 +185,18 @@ int omapdss_device_connect(struct dss_device *dss,
 {
 	int ret;
 
-	dev_dbg(dst->dev, "connect\n");
+	dev_dbg(&dss->pdev->dev, "connect(%s, %s)\n",
+		src ? dev_name(src->dev) : "NULL",
+		dst ? dev_name(dst->dev) : "NULL");
+
+	if (!dst) {
+		/*
+		 * The destination is NULL when the source is connected to a
+		 * bridge instead of a DSS device. Stop here, we will attach the
+		 * bridge later when we will have a DRM encoder.
+		 */
+		return src && src->bridge ? 0 : -EINVAL;
+	}
 
 	if (omapdss_device_is_connected(dst))
 		return -EBUSY;
@@ -204,7 +216,16 @@ EXPORT_SYMBOL_GPL(omapdss_device_connect);
 void omapdss_device_disconnect(struct omap_dss_device *src,
 			       struct omap_dss_device *dst)
 {
-	dev_dbg(dst->dev, "disconnect\n");
+	struct dss_device *dss = src ? src->dss : dst->dss;
+
+	dev_dbg(&dss->pdev->dev, "disconnect(%s, %s)\n",
+		src ? dev_name(src->dev) : "NULL",
+		dst ? dev_name(dst->dev) : "NULL");
+
+	if (!dst) {
+		WARN_ON(!src->bridge);
+		return;
+	}
 
 	if (!dst->id && !omapdss_device_is_connected(dst)) {
 		WARN_ON(!dst->display);

drivers/gpu/drm/omapdrm/dss/omapdss.h

@@ -410,6 +410,7 @@ struct omap_dss_device {
 
 	struct dss_device *dss;
 	struct omap_dss_device *next;
+	struct drm_bridge *bridge;
 
 	struct list_head list;
 

drivers/gpu/drm/omapdrm/dss/output.c

@@ -20,25 +20,34 @@
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/of.h>
+#include <linux/of_graph.h>
 
 #include "dss.h"
 #include "omapdss.h"
 
 int omapdss_device_init_output(struct omap_dss_device *out)
 {
-	out->next = omapdss_of_find_connected_device(out->dev->of_node, 0);
-	if (IS_ERR(out->next)) {
-		if (PTR_ERR(out->next) != -EPROBE_DEFER)
-			dev_err(out->dev, "failed to find video sink\n");
-		return PTR_ERR(out->next);
+	struct device_node *remote_node;
+
+	remote_node = of_graph_get_remote_node(out->dev->of_node, 0, 0);
+	if (!remote_node) {
+		dev_dbg(out->dev, "failed to find video sink\n");
+		return 0;
 	}
 
+	out->next = omapdss_find_device_by_node(remote_node);
+	out->bridge = of_drm_find_bridge(remote_node);
+
+	of_node_put(remote_node);
+
 	if (out->next && out->type != out->next->type) {
 		dev_err(out->dev, "output type and display type don't match\n");
+		omapdss_device_put(out->next);
+		out->next = NULL;
 		return -EINVAL;
 	}
 
-	return 0;
+	return out->next || out->bridge ? 0 : -EPROBE_DEFER;
 }
 EXPORT_SYMBOL(omapdss_device_init_output);
 

drivers/gpu/drm/omapdrm/omap_connector.c

@@ -299,9 +299,16 @@ static const struct drm_connector_helper_funcs omap_connector_helper_funcs = {
 	.mode_valid = omap_connector_mode_valid,
 };
 
-static int omap_connector_get_type(struct omap_dss_device *display)
+static int omap_connector_get_type(struct omap_dss_device *output)
 {
-	switch (display->type) {
+	struct omap_dss_device *display;
+	enum omap_display_type type;
+
+	display = omapdss_display_get(output);
+	type = display->type;
+	omapdss_device_put(display);
+
+	switch (type) {
 	case OMAP_DISPLAY_TYPE_HDMI:
 		return DRM_MODE_CONNECTOR_HDMIA;
 	case OMAP_DISPLAY_TYPE_DVI:
@@ -324,14 +331,13 @@ static int omap_connector_get_type(struct omap_dss_device *display)
 /* initialize connector */
 struct drm_connector *omap_connector_init(struct drm_device *dev,
 					  struct omap_dss_device *output,
-					  struct omap_dss_device *display,
 					  struct drm_encoder *encoder)
 {
 	struct drm_connector *connector = NULL;
 	struct omap_connector *omap_connector;
 	struct omap_dss_device *dssdev;
 
-	DBG("%s", display->name);
+	DBG("%s", output->name);
 
 	omap_connector = kzalloc(sizeof(*omap_connector), GFP_KERNEL);
 	if (!omap_connector)
@@ -344,7 +350,7 @@ struct drm_connector *omap_connector_init(struct drm_device *dev,
 	connector->doublescan_allowed = 0;
 
 	drm_connector_init(dev, connector, &omap_connector_funcs,
-			   omap_connector_get_type(display));
+			   omap_connector_get_type(output));
 	drm_connector_helper_add(connector, &omap_connector_helper_funcs);
 
 	/*

drivers/gpu/drm/omapdrm/omap_connector.h

@@ -31,7 +31,6 @@ struct omap_dss_device;
 
 struct drm_connector *omap_connector_init(struct drm_device *dev,
 					  struct omap_dss_device *output,
-					  struct omap_dss_device *display,
 					  struct drm_encoder *encoder);
 bool omap_connector_get_hdmi_mode(struct drm_connector *connector);
 void omap_connector_enable_hpd(struct drm_connector *connector);

drivers/gpu/drm/omapdrm/omap_crtc.c

@@ -666,7 +666,7 @@ struct drm_crtc *omap_crtc_init(struct drm_device *dev,
 					&omap_crtc_funcs, NULL);
 	if (ret < 0) {
 		dev_err(dev->dev, "%s(): could not init crtc for: %s\n",
-			__func__, pipe->display->name);
+			__func__, pipe->output->name);
 		kfree(omap_crtc);
 		return ERR_PTR(ret);
 	}

drivers/gpu/drm/omapdrm/omap_drv.c

@@ -140,9 +140,7 @@ static void omap_disconnect_pipelines(struct drm_device *ddev)
 		omapdss_device_disconnect(NULL, pipe->output);
 
 		omapdss_device_put(pipe->output);
-		omapdss_device_put(pipe->display);
 		pipe->output = NULL;
-		pipe->display = NULL;
 	}
 
 	memset(&priv->channels, 0, sizeof(priv->channels));
@@ -169,7 +167,6 @@ static int omap_connect_pipelines(struct drm_device *ddev)
 
 			pipe = &priv->pipes[priv->num_pipes++];
 			pipe->output = omapdss_device_get(output);
-			pipe->display = omapdss_display_get(output);
 
 			if (priv->num_pipes == ARRAY_SIZE(priv->pipes)) {
 				/* To balance the 'for_each_dss_output' loop */
@@ -207,6 +204,28 @@ static int omap_modeset_init_properties(struct drm_device *dev)
 	return 0;
 }
 
+static int omap_display_id(struct omap_dss_device *output)
+{
+	struct device_node *node = NULL;
+
+	if (output->next) {
+		struct omap_dss_device *display;
+
+		display = omapdss_display_get(output);
+		node = display->dev->of_node;
+		omapdss_device_put(display);
+	} else {
+		struct drm_bridge *bridge = output->bridge;
+
+		while (bridge->next)
+			bridge = bridge->next;
+
+		node = bridge->of_node;
+	}
+
+	return node ? of_alias_get_id(node, "display") : -ENODEV;
+}
+
 static int omap_modeset_init(struct drm_device *dev)
 {
 	struct omap_drm_private *priv = dev->dev_private;
@@ -262,7 +281,10 @@ static int omap_modeset_init(struct drm_device *dev)
 		priv->planes[priv->num_planes++] = plane;
 	}
 
-	/* Create the encoders and get the pipelines aliases. */
+	/*
+	 * Create the encoders, attach the bridges and get the pipeline alias
+	 * IDs.
+	 */
 	for (i = 0; i < priv->num_pipes; i++) {
 		struct omap_drm_pipeline *pipe = &priv->pipes[i];
 		int id;
@@ -271,7 +293,14 @@ static int omap_modeset_init(struct drm_device *dev)
 		if (!pipe->encoder)
 			return -ENOMEM;
 
-		id = of_alias_get_id(pipe->display->dev->of_node, "display");
+		if (pipe->output->bridge) {
+			ret = drm_bridge_attach(pipe->encoder,
+						pipe->output->bridge, NULL);
+			if (ret < 0)
+				return ret;
+		}
+
+		id = omap_display_id(pipe->output);
 		pipe->alias_id = id >= 0 ? id : i;
 	}
 
@@ -297,16 +326,16 @@ static int omap_modeset_init(struct drm_device *dev)
 	for (i = 0; i < priv->num_pipes; i++) {
 		struct omap_drm_pipeline *pipe = &priv->pipes[i];
 		struct drm_encoder *encoder = pipe->encoder;
-		struct drm_connector *connector;
 		struct drm_crtc *crtc;
 
-		connector = omap_connector_init(dev, pipe->output,
-						pipe->display, encoder);
-		if (!connector)
-			return -ENOMEM;
+		if (!pipe->output->bridge) {
+			pipe->connector = omap_connector_init(dev, pipe->output,
+							      encoder);
+			if (!pipe->connector)
+				return -ENOMEM;
 
-		drm_connector_attach_encoder(connector, encoder);
-		pipe->connector = connector;
+			drm_connector_attach_encoder(pipe->connector, encoder);
+		}
 
 		crtc = omap_crtc_init(dev, pipe, priv->planes[i]);
 		if (IS_ERR(crtc))
@@ -350,10 +379,12 @@ static int omap_modeset_init(struct drm_device *dev)
 static void omap_modeset_enable_external_hpd(struct drm_device *ddev)
 {
 	struct omap_drm_private *priv = ddev->dev_private;
-	int i;
+	unsigned int i;
 
-	for (i = 0; i < priv->num_pipes; i++)
-		omap_connector_enable_hpd(priv->pipes[i].connector);
+	for (i = 0; i < priv->num_pipes; i++) {
+		if (priv->pipes[i].connector)
+			omap_connector_enable_hpd(priv->pipes[i].connector);
+	}
 }
 
 /*
@@ -362,10 +393,12 @@ static void omap_modeset_enable_external_hpd(struct drm_device *ddev)
 static void omap_modeset_disable_external_hpd(struct drm_device *ddev)
 {
 	struct omap_drm_private *priv = ddev->dev_private;
-	int i;
+	unsigned int i;
 
-	for (i = 0; i < priv->num_pipes; i++)
-		omap_connector_disable_hpd(priv->pipes[i].connector);
+	for (i = 0; i < priv->num_pipes; i++) {
+		if (priv->pipes[i].connector)
+			omap_connector_disable_hpd(priv->pipes[i].connector);
+	}
 }
 
 /*

drivers/gpu/drm/omapdrm/omap_drv.h

@@ -49,7 +49,6 @@ struct omap_drm_pipeline {
 	struct drm_encoder *encoder;
 	struct drm_connector *connector;
 	struct omap_dss_device *output;
-	struct omap_dss_device *display;
 	unsigned int alias_id;
 };