drm/komeda: Enable dual-link support

Komeda HW can support dual-link which splits display frame to two halves
(left/link0, right/link1) and output them by two output links.
Due to the halved pixel rate of each link, the pxlclk of dual-link can be
reduced two times compare with single-link.

For enabling dual-link:
- The DT need to configure two output-links for the pipeline node.
- Komeda enable dual-link when both link0 and link1 have been connected.

Example of how the pipeline node will look like for dual-link setup

pipe0: pipeline@0 {
	clocks = <&fpgaosc2>;
	clock-names = "pxclk";
	reg = <0>;

	#address-cells = <1>;
	#size-cells = <0>;

	port@0 {
		reg = <0>;

		#address-cells = <1>;
		#size-cells = <0>;
		dp0_pipe0_link0: endpoint@0 {
			reg = <0>;
			remote-endpoint = <&dlink_connector_in0>;

		};
		dp0_pipe0_link1: endpoint@1 {
			reg = <1>;
			remote-endpoint = <&dlink_connector_in1>;
		};
	};
};

Signed-off-by: James Qian Wang (Arm Technology China) <james.qian.wang@arm.com>
Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190618081013.13638-3-james.qian.wang@arm.com

1 files changed, 5 insertions, 3 deletions

diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_drv.c b/drivers/gpu/drm/arm/display/komeda/komeda_drv.c
index cfa5068d9d1e..69ace6f9055d 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_drv.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_drv.c
@@ -83,11 +83,12 @@ static int compare_of(struct device *dev, void *data)
 
 static void komeda_add_slave(struct device *master,
 			     struct component_match **match,
-			     struct device_node *np, int port)
+			     struct device_node *np,
+			     u32 port, u32 endpoint)
 {
 	struct device_node *remote;
 
-	remote = of_graph_get_remote_node(np, port, 0);
+	remote = of_graph_get_remote_node(np, port, endpoint);
 	if (remote) {
 		drm_of_component_match_add(master, match, compare_of, remote);
 		of_node_put(remote);
@@ -108,7 +109,8 @@ static int komeda_platform_probe(struct platform_device *pdev)
 			continue;
 
 		/* add connector */
-		komeda_add_slave(dev, &match, child, KOMEDA_OF_PORT_OUTPUT);
+		komeda_add_slave(dev, &match, child, KOMEDA_OF_PORT_OUTPUT, 0);
+		komeda_add_slave(dev, &match, child, KOMEDA_OF_PORT_OUTPUT, 1);
 	}
 
 	return component_master_add_with_match(dev, &komeda_master_ops, match);