drm/sun4i: Don't skip TCONs if they don't have channel 0

TV TCONs (channel 1 only) are always connected to TV or HDMI encoder.
Because of that, all output endpoints on such TCON node will point to a
encoder which is part of component framework.

Correct current graph traversing algorithm in such way that it doesn't
skip output enpoints with id 0 on TV TCONs.
Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180625120304.7543-10-jernej.skrabec@siol.net

drivers/gpu/drm/sun4i/sun4i_drv.c

@@ -198,6 +198,22 @@ static bool sun4i_drv_node_is_tcon(struct device_node *node)
 	return !!of_match_node(sun4i_tcon_of_table, node);
 }
 
+static bool sun4i_drv_node_is_tcon_with_ch0(struct device_node *node)
+{
+	const struct of_device_id *match;
+
+	match = of_match_node(sun4i_tcon_of_table, node);
+	if (match) {
+		struct sun4i_tcon_quirks *quirks;
+
+		quirks = (struct sun4i_tcon_quirks *)match->data;
+
+		return quirks->has_channel_0;
+	}
+
+	return false;
+}
+
 static bool sun4i_drv_node_is_tcon_top(struct device_node *node)
 {
 	return !!of_match_node(sun8i_tcon_top_of_table, node);
@@ -256,14 +272,7 @@ static void sun4i_drv_traverse_endpoints(struct endpoint_list *list,
 			continue;
 		}
 
-		/*
-		 * If the node is our TCON, the first port is used for
-		 * panel or bridges, and will not be part of the
-		 * component framework.
-		 */
 		if (sun4i_drv_node_is_tcon(node)) {
-			struct of_endpoint endpoint;
-
 			/*
 			 * TCON TOP is always probed before TCON. However, TCON
 			 * points back to TCON TOP when it is source for HDMI.
@@ -276,16 +285,25 @@ static void sun4i_drv_traverse_endpoints(struct endpoint_list *list,
 				continue;
 			}
 
-			if (of_graph_parse_endpoint(ep, &endpoint)) {
-				DRM_DEBUG_DRIVER("Couldn't parse endpoint\n");
-				of_node_put(remote);
-				continue;
-			}
-
-			if (!endpoint.id) {
-				DRM_DEBUG_DRIVER("Endpoint is our panel... skipping\n");
-				of_node_put(remote);
-				continue;
+			/*
+			 * If the node is our TCON with channel 0, the first
+			 * port is used for panel or bridges, and will not be
+			 * part of the component framework.
+			 */
+			if (sun4i_drv_node_is_tcon_with_ch0(node)) {
+				struct of_endpoint endpoint;
+
+				if (of_graph_parse_endpoint(ep, &endpoint)) {
+					DRM_DEBUG_DRIVER("Couldn't parse endpoint\n");
+					of_node_put(remote);
+					continue;
+				}
+
+				if (!endpoint.id) {
+					DRM_DEBUG_DRIVER("Endpoint is our panel... skipping\n");
+					of_node_put(remote);
+					continue;
+				}
 			}
 		}