[media] atmel-isi: update device tree bindings documentation

The original bindings documentation was incomplete (missing pinctrl-names,
missing endpoint node properties) and the example was out of date.

Add the missing information and tidy up the text.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

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

-Atmel Image Sensor Interface (ISI) SoC Camera Subsystem
-----------------------------------------------
-
-Required properties:
-- compatible: must be "atmel,at91sam9g45-isi"
-- reg: physical base address and length of the registers set for the device;
-- interrupts: should contain IRQ line for the ISI;
-- clocks: list of clock specifiers, corresponding to entries in
-          the clock-names property;
-- clock-names: must contain "isi_clk", which is the isi peripherial clock.
-
-ISI supports a single port node with parallel bus. It should contain one
+Atmel Image Sensor Interface (ISI)
+----------------------------------
+
+Required properties for ISI:
+- compatible: must be "atmel,at91sam9g45-isi".
+- reg: physical base address and length of the registers set for the device.
+- interrupts: should contain IRQ line for the ISI.
+- clocks: list of clock specifiers, corresponding to entries in the clock-names
+	property; please refer to clock-bindings.txt.
+- clock-names: required elements: "isi_clk".
+- pinctrl-names, pinctrl-0: please refer to pinctrl-bindings.txt.
+
+ISI supports a single port node with parallel bus. It shall contain one
 'port' child node with child 'endpoint' node. Please refer to the bindings
 defined in Documentation/devicetree/bindings/media/video-interfaces.txt.
 
-Example:
-	isi: isi@f0034000 {
-		compatible = "atmel,at91sam9g45-isi";
-		reg = <0xf0034000 0x4000>;
-		interrupts = <37 IRQ_TYPE_LEVEL_HIGH 5>;
-
-		clocks = <&isi_clk>;
-		clock-names = "isi_clk";
+Endpoint node properties
+------------------------
 
-		pinctrl-names = "default";
-		pinctrl-0 = <&pinctrl_isi>;
+- bus-width: <8> or <10> (mandatory)
+- hsync-active (default: active high)
+- vsync-active (default: active high)
+- pclk-sample (default: sample on falling edge)
+- remote-endpoint: A phandle to the bus receiver's endpoint node (mandatory).
 
-		port {
-			#address-cells = <1>;
-			#size-cells = <0>;
+Example:
 
-			isi_0: endpoint {
-				remote-endpoint = <&ov2640_0>;
-				bus-width = <8>;
-			};
+isi: isi@f0034000 {
+	compatible = "atmel,at91sam9g45-isi";
+	reg = <0xf0034000 0x4000>;
+	interrupts = <37 IRQ_TYPE_LEVEL_HIGH 5>;
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_isi_data_0_7>;
+	clocks = <&isi_clk>;
+	clock-names = "isi_clk";
+	port {
+		isi_0: endpoint {
+			remote-endpoint = <&ov2640_0>;
+			bus-width = <8>;
+			vsync-active = <1>;
+			hsync-active = <1>;
 		};
 	};
+};
 
-	i2c1: i2c@f0018000 {
-		ov2640: camera@0x30 {
-			compatible = "ovti,ov2640";
-			reg = <0x30>;
+i2c1: i2c@f0018000 {
+	ov2640: camera@30 {
+		compatible = "ovti,ov2640";
+		reg = <0x30>;
+		pinctrl-names = "default";
+		pinctrl-0 = <&pinctrl_pck0_as_isi_mck &pinctrl_sensor_power &pinctrl_sensor_reset>;
+		resetb-gpios = <&pioE 11 GPIO_ACTIVE_LOW>;
+		pwdn-gpios = <&pioE 13 GPIO_ACTIVE_HIGH>;
+		clocks = <&pck0>;
+		clock-names = "xvclk";
+		assigned-clocks = <&pck0>;
+		assigned-clock-rates = <25000000>;
 
-			port {
-				ov2640_0: endpoint {
-					remote-endpoint = <&isi_0>;
-					bus-width = <8>;
-				};
+		port {
+			ov2640_0: endpoint {
+				remote-endpoint = <&isi_0>;
+				bus-width = <8>;
 			};
 		};
 	};
+};