[media] media: et8ek8: add device tree binding documentation

Toshiba et8ek8 5MP sensor

Toshiba et8ek8 5MP sensor is an image sensor found in Nokia N900 device

More detailed documentation can be found in

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

Mandatory properties

--------------------

- compatible: "toshiba,et8ek8"

- reg: I2C address (0x3e, or an alternative address)

- vana-supply: Analogue voltage supply (VANA), 2.8 volts

- clocks: External clock to the sensor

- clock-frequency: Frequency of the external clock to the sensor. Camera

  driver will set this frequency on the external clock. The clock frequency is

  a pre-determined frequency known to be suitable to the board.

- reset-gpios: XSHUTDOWN GPIO. The XSHUTDOWN signal is active low. The sensor

  is in hardware standby mode when the signal is in the low state.

Endpoint node mandatory properties

----------------------------------

- remote-endpoint: A phandle to the bus receiver's endpoint node.

Example

-------

&i2c3 {

	clock-frequency = <400000>;

	cam1: camera@3e {

		compatible = "toshiba,et8ek8";

		reg = <0x3e>;

		vana-supply = <&vaux4>;

		clocks = <&isp 0>;

		clock-frequency = <9600000>;

		reset-gpio = <&gpio4 6 GPIO_ACTIVE_HIGH>; /* 102 */

		port {

			csi_cam1: endpoint {

				remote-endpoint = <&csi_out1>;

			};

		};

	};

};