[media] dt-bindings: add TI VPIF documentation

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>;

			};

		};

	};