staging: imx-drm: Document updated imx-drm device tree bindings

Freescale i.MX DRM master device

================================

The freescale i.MX DRM master device is a virtual device needed to list all

IPU or other display interface nodes that comprise the graphics subsystem.

Required properties:

- compatible: Should be "fsl,imx-display-subsystem"

- ports: Should contain a list of phandles pointing to display interface ports

  of IPU devices

example:

display-subsystem {

	compatible = "fsl,display-subsystem";

	ports = <&ipu_di0>;

};

Freescale i.MX IPUv3

====================

  datasheet

- interrupts: Should contain sync interrupt and error interrupt,

  in this order.

- #crtc-cells: 1, See below

- resets: phandle pointing to the system reset controller and

          reset line index, see reset/fsl,imx-src.txt for details

Optional properties:

- port@[0-3]: Port nodes with endpoint definitions as defined in

  Documentation/devicetree/bindings/media/video-interfaces.txt.

  Ports 0 and 1 should correspond to CSI0 and CSI1,

  ports 2 and 3 should correspond to DI0 and DI1, respectively.

example:

ipu: ipu@18000000 {

	#crtc-cells = <1>;

	#address-cells = <1>;

	#size-cells = <0>;

	compatible = "fsl,imx53-ipu";

	reg = <0x18000000 0x080000000>;

	interrupts = <11 10>;

	resets = <&src 2>;

	ipu_di0: port@2 {

		reg = <2>;

		ipu_di0_disp0: endpoint {

			remote-endpoint = <&display_in>;

		};

	};

};

Parallel display support

Required properties:

- compatible: Should be "fsl,imx-parallel-display"

- crtc: the crtc this display is connected to, see below

Optional properties:

- interface_pix_fmt: How this display is connected to the

  crtc. Currently supported types: "rgb24", "rgb565", "bgr666"

  display interface. Currently supported types: "rgb24", "rgb565", "bgr666"

- edid: verbatim EDID data block describing attached display.

- ddc: phandle describing the i2c bus handling the display data

  channel

- port: A port node with endpoint definitions as defined in

  Documentation/devicetree/bindings/media/video-interfaces.txt.

example:

display@di0 {

	compatible = "fsl,imx-parallel-display";

	edid = [edid-data];

	crtc = <&ipu 0>;

	interface-pix-fmt = "rgb24";

	port {

		display_in: endpoint {

			remote-endpoint = <&ipu_di0_disp0>;

		};

	};

};

Required properties:

 - reg : should be <0> or <1>

 - crtcs : a list of phandles with index pointing to the IPU display interfaces

           that can be used as video source for this channel.

 - fsl,data-mapping : should be "spwg" or "jeida"

                      This describes how the color bits are laid out in the

                      serialized LVDS signal.

 - fsl,data-width : should be <18> or <24>

 - port: A port node with endpoint definitions as defined in

   Documentation/devicetree/bindings/media/video-interfaces.txt.

   On i.MX6, there should be four ports (port@[0-3]) that correspond

   to the four LVDS multiplexer inputs.

example:

	lvds-channel@0 {

		reg = <0>;

		crtcs = <&ipu 0>;

		fsl,data-mapping = "spwg";

		fsl,data-width = <24>;

		display-timings {

			/* ... */

		};

		port {

			lvds0_in: endpoint {

				remote-endpoint = <&ipu_di0_lvds0>;

			};

		};

	};

	lvds-channel@1 {

		reg = <1>;

		crtcs = <&ipu 1>;

		fsl,data-mapping = "spwg";

		fsl,data-width = <24>;

		display-timings {

			/* ... */

		};

		port {

			lvds1_in: endpoint {

				remote-endpoint = <&ipu_di1_lvds1>;

			};

		};

	};

};