rockchip: video: vop: Use endpoint compatible string to find VOP mode

The current code is using an hard coded enum and the of node reg value of
endpoint to find out if the endpoint is mipi/hdmi/lvds/edp/dp. The order
is different between rk3288, rk3399 vop little, rk3399 vop big.

A possible solution would be to make sure that the rk3288.dtsi and
rk3399.dtsi files have "expected" reg value or an other solution is
to find the kind of endpoint by comparing the endpoint compatible value.

This patch is implementing the more flexible second solution.

Signed-off-by: Arnaud Patard <arnaud.patard@rtp-net.org>
Tested-by: Peter Robinson <pbrobinson@gmail.com>
diff --git a/arch/arm/include/asm/arch-rockchip/vop_rk3288.h b/arch/arm/include/asm/arch-rockchip/vop_rk3288.h
index 52446e9..49a7141 100644
--- a/arch/arm/include/asm/arch-rockchip/vop_rk3288.h
+++ b/arch/arm/include/asm/arch-rockchip/vop_rk3288.h
@@ -85,26 +85,13 @@
 	LB_RGB_1280X8 = 0x5
 };
 
-#if defined(CONFIG_ROCKCHIP_RK3399)
 enum vop_modes {
 	VOP_MODE_EDP = 0,
 	VOP_MODE_MIPI,
 	VOP_MODE_HDMI,
-	VOP_MODE_MIPI1,
-	VOP_MODE_DP,
-	VOP_MODE_NONE,
-};
-#else
-enum vop_modes {
-	VOP_MODE_EDP = 0,
-	VOP_MODE_HDMI,
 	VOP_MODE_LVDS,
-	VOP_MODE_MIPI,
-	VOP_MODE_NONE,
-	VOP_MODE_AUTO_DETECT,
-	VOP_MODE_UNKNOWN,
+	VOP_MODE_DP,
 };
-#endif
 
 /* VOP_VERSION_INFO */
 #define M_FPGA_VERSION (0xffff << 16)
diff --git a/drivers/video/rockchip/rk_vop.c b/drivers/video/rockchip/rk_vop.c
index 145c333..145a340 100644
--- a/drivers/video/rockchip/rk_vop.c
+++ b/drivers/video/rockchip/rk_vop.c
@@ -236,12 +236,11 @@
 	struct clk clk;
 	enum video_log2_bpp l2bpp;
 	ofnode remote;
+	const char *compat;
 
 	debug("%s(%s, %lu, %s)\n", __func__,
 	      dev_read_name(dev), fbbase, ofnode_get_name(ep_node));
 
-	vop_id = ofnode_read_s32_default(ep_node, "reg", -1);
-	debug("vop_id=%d\n", vop_id);
 	ret = ofnode_read_u32(ep_node, "remote-endpoint", &remote_phandle);
 	if (ret)
 		return ret;
@@ -283,6 +282,28 @@
 		if (disp)
 			break;
 	};
+	compat = ofnode_get_property(remote, "compatible", NULL);
+	if (!compat) {
+		debug("%s(%s): Failed to find compatible property\n",
+		      __func__, dev_read_name(dev));
+		return -EINVAL;
+	}
+	if (strstr(compat, "edp")) {
+		vop_id = VOP_MODE_EDP;
+	} else if (strstr(compat, "mipi")) {
+		vop_id = VOP_MODE_MIPI;
+	} else if (strstr(compat, "hdmi")) {
+		vop_id = VOP_MODE_HDMI;
+	} else if (strstr(compat, "cdn-dp")) {
+		vop_id = VOP_MODE_DP;
+	} else if (strstr(compat, "lvds")) {
+		vop_id = VOP_MODE_LVDS;
+	} else {
+		debug("%s(%s): Failed to find vop mode for %s\n",
+		      __func__, dev_read_name(dev), compat);
+		return -EINVAL;
+	}
+	debug("vop_id=%d\n", vop_id);
 
 	disp_uc_plat = dev_get_uclass_plat(disp);
 	debug("Found device '%s', disp_uc_priv=%p\n", disp->name, disp_uc_plat);