video: exynos_dp: device tree documentation

The Exynos display port interface should be configured based on

the type of panel connected to it.

We use two nodes:

	-dp-controller node

	-dptx-phy node(defined inside dp-controller node)

For the DP-PHY initialization, we use the dptx-phy node.

Required properties for dptx-phy:

	-reg:

		Base address of DP PHY register.

	-samsung,enable-mask:

		The bit-mask used to enable/disable DP PHY.

For the Panel initialization, we read data from dp-controller node.

Required properties for dp-controller:

	-compatible:

		should be "samsung,exynos5-dp".

	-reg:

		physical base address of the controller and length

		of memory mapped region.

	-interrupts:

		interrupt combiner values.

	-interrupt-parent:

		phandle to Interrupt combiner node.

	-samsung,color-space:

		input video data format.

			COLOR_RGB = 0, COLOR_YCBCR422 = 1, COLOR_YCBCR444 = 2

	-samsung,dynamic-range:

		dynamic range for input video data.

			VESA = 0, CEA = 1

	-samsung,ycbcr-coeff:

		YCbCr co-efficients for input video.

			COLOR_YCBCR601 = 0, COLOR_YCBCR709 = 1

	-samsung,color-depth:

		number of bits per colour component.

			COLOR_6 = 0, COLOR_8 = 1, COLOR_10 = 2, COLOR_12 = 3

	-samsung,link-rate:

		link rate supported by the panel.

			LINK_RATE_1_62GBPS = 0x6, LINK_RATE_2_70GBPS = 0x0A

	-samsung,lane-count:

		number of lanes supported by the panel.

			LANE_COUNT1 = 1, LANE_COUNT2 = 2, LANE_COUNT4 = 4

Optional properties for dp-controller:

	-interlaced:

		interlace scan mode.

			Progressive if defined, Interlaced if not defined

	-vsync-active-high:

		VSYNC polarity configuration.

			High if defined, Low if not defined

	-hsync-active-high:

		HSYNC polarity configuration.

			High if defined, Low if not defined

Example:

SOC specific portion:

	dp-controller {

		compatible = "samsung,exynos5-dp";

		reg = <0x145b0000 0x10000>;

		interrupts = <10 3>;

		interrupt-parent = <&combiner>;

		dptx-phy {

			reg = <0x10040720>;

			samsung,enable-mask = <1>;

		};

	};

Board Specific portion:

	dp-controller {

		samsung,color-space = <0>;

		samsung,dynamic-range = <0>;

		samsung,ycbcr-coeff = <0>;

		samsung,color-depth = <1>;

		samsung,link-rate = <0x0a>;

		samsung,lane-count = <4>;

	};