FROMLIST: dt-bindings: Document the Rockchip MIPI RX D-PHY bindings

Add DT bindings documentation for Rockchip MIPI D-PHY RX

Signed-off-by: Jacob Chen <jacob2.chen@rock-chips.com>
Reviewed-by: Rob Herring <robh@kernel.org>

BUG=b:36227021
TEST=Camera works on Scarlet with the whole series
(am from https://patchwork.linuxtv.org/patch/46239/)

Change-Id: If7ca96f97f3c2f2b475d2a918fdcde1684846701
Signed-off-by: Jacob Chen <jacob2.chen@rock-chips.com>

Documentation/devicetree/bindings/media/rockchip-mipi-dphy.txt

@@ -0,0 +1,88 @@
+Rockchip SoC MIPI RX D-PHY
+-------------------------------------------------------------
+
+Required properties:
+- compatible: value should be one of the following
+	"rockchip,rk3288-mipi-dphy"
+	"rockchip,rk3399-mipi-dphy"
+- clocks : list of clock specifiers, corresponding to entries in
+	clock-names property;
+- clock-names: required clock name.
+
+MIPI RX0 D-PHY use registers in "general register files", it
+should be a child of the GRF.
+MIPI TXRX D-PHY have its own registers, it must have a reg property.
+
+Optional properties:
+- reg: offset and length of the register set for the device.
+
+port node
+-------------------
+
+The device node should contain two 'port' child nodes, according to the bindings
+defined in Documentation/devicetree/bindings/media/video-interfaces.txt.
+
+The first port show the sensors connected in this mipi-dphy.
+- endpoint:
+	- remote-endpoint: Linked to a sensor with a MIPI CSI-2 video bus.
+	- data-lanes : (required) an array specifying active physical MIPI-CSI2
+			data input lanes and their mapping to logical lanes; the
+			D-PHY can't reroute lanes, so the array's content should
+			be consecutive and only its length is meaningful.
+
+The port node must contain at least one endpoint. It could have multiple endpoints
+linked to different sensors, but please note that they are not supposed to be
+actived at the same time.
+
+The second port should be connected to isp node.
+- endpoint:
+	- remote-endpoint:  Linked to Rockchip ISP1, which is defined
+		in rockchip-isp1.txt.
+
+Device node example
+-------------------
+
+grf: syscon@ff770000 {
+	compatible = "rockchip,rk3288-grf", "syscon", "simple-mfd";
+
+...
+
+	mipi_dphy_rx0: mipi-dphy-rx0 {
+		compatible = "rockchip,rk3399-mipi-dphy";
+		clocks = <&cru SCLK_MIPIDPHY_REF>,
+			<&cru SCLK_DPHY_RX0_CFG>,
+			<&cru PCLK_VIO_GRF>;
+		clock-names = "dphy-ref", "dphy-cfg", "grf";
+		power-domains = <&power RK3399_PD_VIO>;
+
+		ports {
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			port@0 {
+				reg = <0>;
+				#address-cells = <1>;
+				#size-cells = <0>;
+
+				mipi_in_wcam: endpoint@0 {
+					reg = <0>;
+					remote-endpoint = <&wcam_out>;
+					data-lanes = <1 2>;
+				};
+				mipi_in_ucam: endpoint@1 {
+					reg = <1>;
+					remote-endpoint = <&ucam_out>;
+					data-lanes = <1>;
+				};
+			};
+
+			port@1 {
+				reg = <1>;
+
+				dphy_rx0_out: endpoint {
+					remote-endpoint = <&isp0_mipi_in>;
+				};
+			};
+		};
+	};
+};