[media] dt-bindings: add TI VPIF documentation

Acked-by: NRob Herring <robh@kernel.org>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NKevin Hilman <khilman@baylibre.com>
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Documentation/devicetree/bindings/media/ti,da850-vpif.txt

+Texas Instruments VPIF
+----------------------
+
+The TI Video Port InterFace (VPIF) is the primary component for video
+capture and display on the DA850/AM18x family of TI DaVinci/Sitara
+SoCs.
+
+TI Document reference: SPRUH82C, Chapter 35
+http://www.ti.com/lit/pdf/spruh82
+
+Required properties:
+- compatible: must be "ti,da850-vpif"
+- reg: physical base address and length of the registers set for the device;
+- interrupts: should contain IRQ line for the VPIF
+
+Video Capture:
+
+VPIF has a 16-bit parallel bus input, supporting 2 8-bit channels or a
+single 16-bit channel.  It should contain at least one port child node
+with child 'endpoint' node. Please refer to the bindings defined in
+Documentation/devicetree/bindings/media/video-interfaces.txt.
+
+Example using 2 8-bit input channels, one of which is connected to an
+I2C-connected TVP5147 decoder:
+
+	vpif: vpif@217000 {
+		compatible = "ti,da850-vpif";
+		reg = <0x217000 0x1000>;
+		interrupts = <92>;
+
+		port {
+			vpif_ch0: endpoint@0 {
+				  reg = <0>;
+				  bus-width = <8>;
+				  remote-endpoint = <&composite>;
+			};
+
+			vpif_ch1: endpoint@1 {
+				  reg = <1>;
+				  bus-width = <8>;
+				  data-shift = <8>;
+			};
+		};
+	};
+
+[ ... ]
+
+&i2c0 {
+
+	tvp5147@5d {
+		compatible = "ti,tvp5147";
+		reg = <0x5d>;
+		status = "okay";
+
+		port {
+			composite: endpoint {
+				hsync-active = <1>;
+				vsync-active = <1>;
+				pclk-sample = <0>;
+
+				/* VPIF channel 0 (lower 8-bits) */
+				remote-endpoint = <&vpif_ch0>;
+				bus-width = <8>;
+			};
+		};
+	};
+};
+
+
+Alternatively, an example when the bus is configured as a single
+16-bit input (e.g. for raw-capture mode):
+
+	vpif: vpif@217000 {
+		compatible = "ti,da850-vpif";
+		reg = <0x217000 0x1000>;
+		interrupts = <92>;
+
+		port {
+			vpif_ch0: endpoint {
+				  bus-width = <16>;
+			};
+		};
+	};