[PATCH 2/4] drm: Add DT bindings documentation for ARC PGU display controller

[Alexey.Brodkin@synopsys.com (Alexey Brodkin)]

This add DT bindings documentation for ARC PGU display controller.

Signed-off-by: Alexey Brodkin <abrodkin at synopsys.com>
Cc: Rob Herring <robh+dt at kernel.org>
Cc: Pawel Moll <pawel.moll at arm.com>
Cc: Mark Rutland <mark.rutland at arm.com>
Cc: Ian Campbell <ijc+devicetree at hellion.org.uk>
Cc: Kumar Gala <galak at codeaurora.org>
Cc: devicetree at vger.kernel.org
Cc: linux-snps-arc at lists.infradead.org
---
 .../devicetree/bindings/display/snps,arcpgu.txt    | 74 ++++++++++++++++++++++
 1 file changed, 74 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/display/snps,arcpgu.txt

diff --git a/Documentation/devicetree/bindings/display/snps,arcpgu.txt b/Documentation/devicetree/bindings/display/snps,arcpgu.txt
new file mode 100644
index 0000000..c8382fb
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/snps,arcpgu.txt
@@ -0,0 +1,74 @@
+ARC PGU
+
+This is a display controller found on several development boards produced
+by Synopsys. The ARC PGU is an RGB streamer that reads the data from a
+framebuffer and sends it to a single digital encoder (usually HDMI).
+
+Required properties:
+  - compatible: "snps,arcpgu"
+  - reg: Physical base address and length of the controller's registers.
+  - clocks: A list of phandle + clock-specifier pairs, one for each
+    entry in 'clock-names'.
+  - clock-names: A list of clock names. For ARC PGU it should contain:
+      - "pxlclk" for the clock feeding the output PLL of the controller.
+  - encoder-slave: Phandle of encoder chip.
+
+Required sub-nodes:
+  - port: The PGU connection to an encoder chip. The connection is modelled
+    using the OF graph bindings specified in
+    Documentation/devicetree/bindings/graph.txt.
+
+Example:
+
+/ {
+	...
+
+	pgu at 0xXXXXXXXX {
+		compatible = "snps,arcpgu";
+		reg = <0xXXXXXXXX 0x400>;
+		clocks = <&clock_node>;
+		clock-names = "pxlclk";
+		encoder-slave = <&encoder_node>;
+
+		port {
+			pgu_output: endpoint {
+				remote-endpoint = <&hdmi_enc_input>;
+			};
+		};
+	};
+
+	/* HDMI encoder on I2C bus */
+	i2c at 0xXXXXXXXX {
+		compatible = "...";
+
+		encoder_node:encoder_node at 0xXXXXXXXX{
+			compatible="...";
+
+			ports {
+				port at 0 {
+					reg = <0>;
+					hdmi_enc_input:endpoint {
+						remote-endpoint = <&pgu_output>;
+					};
+				};
+
+				port at 1 {
+					reg = <1>;
+					hdmi_enc_output:endpoint {
+						remote-endpoint = <&hdmi_connector_in>;
+					};
+				};
+			};
+		};
+	}
+
+	hdmi0: connector {
+		compatible = "hdmi-connector";
+
+		port {
+			hdmi_connector_in: endpoint {
+				remote-endpoint = <&hdmi_enc_output>;
+			};
+		};
+	};
+};
-- 
2.5.0