drm/msm: Add components for MDP5

For MDP5 based platforms, the master device isn't the MDP5 platform
device, but the top level MDSS device, which is a parent to MDP5 and
interface (DSI, HDMI, eDP etc) devices.

In order to add components on MDP5 platforms, we first need to populate
the MDSS children, locate the MDP5 child, and then parse its ports to
get the display interfaces.
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Signed-off-by: NRob Clark <robdclark@gmail.com>

drivers/gpu/drm/msm/msm_drv.c

@@ -834,6 +834,20 @@ static int add_components_mdp(struct device *mdp_dev,
 {
 	struct device_node *np = mdp_dev->of_node;
 	struct device_node *ep_node;
+	struct device *master_dev;
+
+	/*
+	 * on MDP4 based platforms, the MDP platform device is the component
+	 * master that adds other display interface components to itself.
+	 *
+	 * on MDP5 based platforms, the MDSS platform device is the component
+	 * master that adds MDP5 and other display interface components to
+	 * itself.
+	 */
+	if (of_device_is_compatible(np, "qcom,mdp4"))
+		master_dev = mdp_dev;
+	else
+		master_dev = mdp_dev->parent;
 
 	for_each_endpoint_of_node(np, ep_node) {
 		struct device_node *intf;
@@ -868,7 +882,7 @@ static int add_components_mdp(struct device *mdp_dev,
 			continue;
 		}
 
-		component_match_add(mdp_dev, matchptr, compare_of, intf);
+		component_match_add(master_dev, matchptr, compare_of, intf);
 
 		of_node_put(intf);
 		of_node_put(ep_node);
@@ -877,10 +891,52 @@ static int add_components_mdp(struct device *mdp_dev,
 	return 0;
 }
 
+static int compare_name_mdp(struct device *dev, void *data)
+{
+	return (strstr(dev_name(dev), "mdp") != NULL);
+}
+
 static int add_display_components(struct device *dev,
 				  struct component_match **matchptr)
 {
-	return add_components_mdp(dev, matchptr);
+	struct device *mdp_dev;
+	int ret;
+
+	/*
+	 * MDP5 based devices don't have a flat hierarchy. There is a top level
+	 * parent: MDSS, and children: MDP5, DSI, HDMI, eDP etc. Populate the
+	 * children devices, find the MDP5 node, and then add the interfaces
+	 * to our components list.
+	 */
+	if (of_device_is_compatible(dev->of_node, "qcom,mdss")) {
+		ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
+		if (ret) {
+			dev_err(dev, "failed to populate children devices\n");
+			return ret;
+		}
+
+		mdp_dev = device_find_child(dev, NULL, compare_name_mdp);
+		if (!mdp_dev) {
+			dev_err(dev, "failed to find MDSS MDP node\n");
+			of_platform_depopulate(dev);
+			return -ENODEV;
+		}
+
+		put_device(mdp_dev);
+
+		/* add the MDP component itself */
+		component_match_add(dev, matchptr, compare_of,
+				    mdp_dev->of_node);
+	} else {
+		/* MDP4 */
+		mdp_dev = dev;
+	}
+
+	ret = add_components_mdp(mdp_dev, matchptr);
+	if (ret)
+		of_platform_depopulate(dev);
+
+	return ret;
 }
 
 static int add_gpu_components(struct device *dev,
@@ -928,6 +984,7 @@ static int msm_pdev_probe(struct platform_device *pdev)
 static int msm_pdev_remove(struct platform_device *pdev)
 {
 	component_master_del(&pdev->dev, &msm_drm_ops);
+	of_platform_depopulate(&pdev->dev);
 
 	return 0;
 }