[media] media: i2c/ov5645: add the device tree binding document

Add the document for ov5645 device tree binding.
Signed-off-by: Todor Tomov <todor.tomov@linaro.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Hans Verkuil <hansverk@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

Documentation/devicetree/bindings/media/i2c/ov5645.txt

+* Omnivision 1/4-Inch 5Mp CMOS Digital Image Sensor
+
+The Omnivision OV5645 is a 1/4-Inch CMOS active pixel digital image sensor with
+an active array size of 2592H x 1944V. It is programmable through a serial I2C
+interface.
+
+Required Properties:
+- compatible: Value should be "ovti,ov5645".
+- clocks: Reference to the xclk clock.
+- clock-names: Should be "xclk".
+- clock-frequency: Frequency of the xclk clock.
+- enable-gpios: Chip enable GPIO. Polarity is GPIO_ACTIVE_HIGH. This corresponds
+  to the hardware pin PWDNB which is physically active low.
+- reset-gpios: Chip reset GPIO. Polarity is GPIO_ACTIVE_LOW. This corresponds to
+  the hardware pin RESETB.
+- vdddo-supply: Chip digital IO regulator.
+- vdda-supply: Chip analog regulator.
+- vddd-supply: Chip digital core regulator.
+
+The device node must contain one 'port' child node for its digital output
+video port, in accordance with the video interface bindings defined in
+Documentation/devicetree/bindings/media/video-interfaces.txt.
+
+Example:
+
+	&i2c1 {
+		...
+
+		ov5645: ov5645@78 {
+			compatible = "ovti,ov5645";
+			reg = <0x78>;
+
+			enable-gpios = <&gpio1 6 GPIO_ACTIVE_HIGH>;
+			reset-gpios = <&gpio5 20 GPIO_ACTIVE_LOW>;
+			pinctrl-names = "default";
+			pinctrl-0 = <&camera_rear_default>;
+
+			clocks = <&clks 200>;
+			clock-names = "xclk";
+			clock-frequency = <23880000>;
+
+			vdddo-supply = <&camera_dovdd_1v8>;
+			vdda-supply = <&camera_avdd_2v8>;
+			vddd-supply = <&camera_dvdd_1v2>;
+
+			port {
+				ov5645_ep: endpoint {
+					clock-lanes = <1>;
+					data-lanes = <0 2>;
+					remote-endpoint = <&csi0_ep>;
+				};
+			};
+		};
+	};