media: dt-bindings: media: Add Cadence MIPI-CSI2 TX Device Tree bindings

The Cadence MIPI-CSI2 TX controller is a CSI2 bridge that supports up to 4
video streams and can output on up to 4 CSI-2 lanes, depending on the
hardware implementation.

It can operate with an external D-PHY, an internal one or no D-PHY at all
in some configurations.
Acked-by: Benoit Parrot <bparrot@ti.com>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

Documentation/devicetree/bindings/media/cdns,csi2tx.txt

+Cadence MIPI-CSI2 TX controller
+===============================
+
+The Cadence MIPI-CSI2 TX controller is a CSI-2 bridge supporting up to
+4 CSI lanes in output, and up to 4 different pixel streams in input.
+
+Required properties:
+  - compatible: must be set to "cdns,csi2tx"
+  - reg: base address and size of the memory mapped region
+  - clocks: phandles to the clocks driving the controller
+  - clock-names: must contain:
+    * esc_clk: escape mode clock
+    * p_clk: register bank clock
+    * pixel_if[0-3]_clk: pixel stream output clock, one for each stream
+                         implemented in hardware, between 0 and 3
+
+Optional properties
+  - phys: phandle to the D-PHY. If it is set, phy-names need to be set
+  - phy-names: must contain "dphy"
+
+Required subnodes:
+  - ports: A ports node with one port child node per device input and output
+           port, in accordance with the video interface bindings defined in
+           Documentation/devicetree/bindings/media/video-interfaces.txt. The
+           port nodes are numbered as follows.
+
+           Port Description
+           -----------------------------
+           0    CSI-2 output
+           1    Stream 0 input
+           2    Stream 1 input
+           3    Stream 2 input
+           4    Stream 3 input
+
+           The stream input port nodes are optional if they are not
+           connected to anything at the hardware level or implemented
+           in the design. Since there is only one endpoint per port,
+           the endpoints are not numbered.
+
+Example:
+
+csi2tx: csi-bridge@0d0e1000 {
+	compatible = "cdns,csi2tx";
+	reg = <0x0d0e1000 0x1000>;
+	clocks = <&byteclock>, <&byteclock>,
+		 <&coreclock>, <&coreclock>,
+		 <&coreclock>, <&coreclock>;
+	clock-names = "p_clk", "esc_clk",
+		      "pixel_if0_clk", "pixel_if1_clk",
+		      "pixel_if2_clk", "pixel_if3_clk";
+
+	ports {
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		port@0 {
+			reg = <0>;
+
+			csi2tx_out: endpoint {
+				remote-endpoint = <&remote_in>;
+				clock-lanes = <0>;
+				data-lanes = <1 2>;
+			};
+		};
+
+		port@1 {
+			reg = <1>;
+
+			csi2tx_in_stream0: endpoint {
+				remote-endpoint = <&stream0_out>;
+			};
+		};
+
+		port@2 {
+			reg = <2>;
+
+			csi2tx_in_stream1: endpoint {
+				remote-endpoint = <&stream1_out>;
+			};
+		};
+
+		port@3 {
+			reg = <3>;
+
+			csi2tx_in_stream2: endpoint {
+				remote-endpoint = <&stream2_out>;
+			};
+		};
+
+		port@4 {
+			reg = <4>;
+
+			csi2tx_in_stream3: endpoint {
+				remote-endpoint = <&stream3_out>;
+			};
+		};
+	};
+};