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, 4 insertions, 1 deletions

diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_dev.c b/drivers/gpu/drm/arm/display/komeda/komeda_dev.c
index 5a118984de33..1ff7f4b2c620 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_dev.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_dev.c
@@ -121,11 +121,14 @@ static int komeda_parse_pipe_dt(struct komeda_dev *mdev, struct device_node *np)
 	pipe->pxlclk = clk;
 
 	/* enum ports */
-	pipe->of_output_dev =
+	pipe->of_output_links[0] =
 		of_graph_get_remote_node(np, KOMEDA_OF_PORT_OUTPUT, 0);
+	pipe->of_output_links[1] =
+		of_graph_get_remote_node(np, KOMEDA_OF_PORT_OUTPUT, 1);
 	pipe->of_output_port =
 		of_graph_get_port_by_id(np, KOMEDA_OF_PORT_OUTPUT);
 
+	pipe->dual_link = pipe->of_output_links[0] && pipe->of_output_links[1];
 	pipe->of_node = np;
 
 	return 0;