[media] atmel-isc: DT binding for Image Sensor Controller driver

DT binding documentation for ISC driver.
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Songjun Wu <songjun.wu@microchip.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

Documentation/devicetree/bindings/media/atmel-isc.txt

+Atmel Image Sensor Controller (ISC)
+----------------------------------------------
+
+Required properties for ISC:
+- compatible
+	Must be "atmel,sama5d2-isc".
+- reg
+	Physical base address and length of the registers set for the device.
+- interrupts
+	Should contain IRQ line for the ISC.
+- clocks
+	List of clock specifiers, corresponding to entries in
+	the clock-names property;
+	Please refer to clock-bindings.txt.
+- clock-names
+	Required elements: "hclock", "iscck", "gck".
+- #clock-cells
+	Should be 0.
+- clock-output-names
+	Should be "isc-mck".
+- pinctrl-names, pinctrl-0
+	Please refer to pinctrl-bindings.txt.
+
+ISC supports a single port node with parallel bus. It should contain one
+'port' child node with child 'endpoint' node. Please refer to the bindings
+defined in Documentation/devicetree/bindings/media/video-interfaces.txt.
+
+Example:
+isc: isc@f0008000 {
+	compatible = "atmel,sama5d2-isc";
+	reg = <0xf0008000 0x4000>;
+	interrupts = <46 IRQ_TYPE_LEVEL_HIGH 5>;
+	clocks = <&isc_clk>, <&iscck>, <&isc_gclk>;
+	clock-names = "hclock", "iscck", "gck";
+	#clock-cells = <0>;
+	clock-output-names = "isc-mck";
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_isc_base &pinctrl_isc_data_8bit &pinctrl_isc_data_9_10 &pinctrl_isc_data_11_12>;
+
+	port {
+		isc_0: endpoint {
+			remote-endpoint = <&ov7740_0>;
+			hsync-active = <1>;
+			vsync-active = <0>;
+			pclk-sample = <1>;
+		};
+	};
+};
+
+i2c1: i2c@fc028000 {
+	ov7740: camera@21 {
+		compatible = "ovti,ov7740";
+		reg = <0x21>;
+		clocks = <&isc>;
+		clock-names = "xvclk";
+		assigned-clocks = <&isc>;
+		assigned-clock-rates = <24000000>;
+
+		port {
+			ov7740_0: endpoint {
+				remote-endpoint = <&isc_0>;
+			};
+		};
+	};
+};