>From c5a48c772f3564211dcd1ec71004de1d6dbb0307 Mon Sep 17 00:00:00 2001
From: Heiko Stuebner <heiko@sntech.de>
Date: Sat, 25 Aug 2018 19:05:21 +0200
Subject: [PATCH 1/2] drm/tockchip: add function to check if endpoint is a
 subdriver

To be able to have both internal subdrivers and external bridge
drivers as output endpoints of vops, add a function to be able
to distinguish these.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
---
 drivers/gpu/drm/rockchip/rockchip_drm_drv.c | 27 +++++++++++++++++++++
 drivers/gpu/drm/rockchip/rockchip_drm_drv.h |  1 +
 2 files changed, 28 insertions(+)

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_drv.c b/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
index 1d9c4a9201c8..d18f7f85aa23 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
@@ -24,6 +24,7 @@
 #include <linux/pm_runtime.h>
 #include <linux/module.h>
 #include <linux/of_graph.h>
+#include <linux/of_platform.h>
 #include <linux/component.h>
 #include <linux/console.h>
 #include <linux/iommu.h>
@@ -267,6 +268,32 @@ static const struct dev_pm_ops rockchip_drm_pm_ops = {
 static struct platform_driver *rockchip_sub_drivers[MAX_ROCKCHIP_SUB_DRIVERS];
 static int num_rockchip_sub_drivers;
 
+/*
+ * check if a vop output-endpoint is a subdriver or bridge.
+ */
+bool rockchip_drm_endpoint_is_subdriver(struct device_node *ep)
+{
+	struct device_node *node = of_graph_get_remote_port_parent(ep);
+	struct platform_device *pdev;
+	int i;
+
+	if (!node)
+		return false;
+
+	pdev = of_find_device_by_node(node);
+	if (!pdev)
+		return false;
+
+	for (i = 0; i < num_rockchip_sub_drivers; i++) {
+		struct device_driver *drv = pdev->dev.driver;
+
+		if (rockchip_sub_drivers[i] == to_platform_driver(drv))
+			return true;
+	}
+
+	return false;
+}
+
 static int compare_dev(struct device *dev, void *data)
 {
 	return dev == (struct device *)data;
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_drv.h b/drivers/gpu/drm/rockchip/rockchip_drm_drv.h
index d67ad0a3cf36..305b4858c522 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_drv.h
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_drv.h
@@ -64,6 +64,7 @@ void rockchip_drm_dma_detach_device(struct drm_device *drm_dev,
 				    struct device *dev);
 int rockchip_drm_wait_vact_end(struct drm_crtc *crtc, unsigned int mstimeout);
 
+bool rockchip_drm_endpoint_is_subdriver(struct device_node *ep);
 extern struct platform_driver cdn_dp_driver;
 extern struct platform_driver dw_hdmi_rockchip_pltfm_driver;
 extern struct platform_driver dw_mipi_dsi_driver;
-- 
2.17.0