drm/rockchip: Add device links for master and components

Since we are trying to access components' resources in the master's
suspend/resume PM callbacks(e.g. panel), add device links to correct
the suspend/resume and shutdown ordering.
Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20180207175309.21095-1-enric.balletbo@collabora.com

drivers/gpu/drm/rockchip/rockchip_drm_drv.c

@@ -314,6 +314,14 @@ static int compare_dev(struct device *dev, void *data)
 	return dev == (struct device *)data;
 }
 
+static void rockchip_drm_match_remove(struct device *dev)
+{
+	struct device_link *link;
+
+	list_for_each_entry(link, &dev->links.consumers, s_node)
+		device_link_del(link);
+}
+
 static struct component_match *rockchip_drm_match_add(struct device *dev)
 {
 	struct component_match *match = NULL;
@@ -331,10 +339,15 @@ static struct component_match *rockchip_drm_match_add(struct device *dev)
 
 			if (!d)
 				break;
+
+			device_link_add(dev, d, DL_FLAG_STATELESS);
 			component_match_add(dev, &match, compare_dev, d);
 		} while (true);
 	}
 
+	if (IS_ERR(match))
+		rockchip_drm_match_remove(dev);
+
 	return match ?: ERR_PTR(-ENODEV);
 }
 
@@ -411,13 +424,21 @@ static int rockchip_drm_platform_probe(struct platform_device *pdev)
 	if (IS_ERR(match))
 		return PTR_ERR(match);
 
-	return component_master_add_with_match(dev, &rockchip_drm_ops, match);
+	ret = component_master_add_with_match(dev, &rockchip_drm_ops, match);
+	if (ret < 0) {
+		rockchip_drm_match_remove(dev);
+		return ret;
+	}
+
+	return 0;
 }
 
 static int rockchip_drm_platform_remove(struct platform_device *pdev)
 {
 	component_master_del(&pdev->dev, &rockchip_drm_ops);
 
+	rockchip_drm_match_remove(&pdev->dev);
+
 	return 0;
 }