can: Allwinner A10/A20 CAN Controller support - Devicetree bindings

Devicetree bindings for Allwinner A10/A20 CAN controller.
Signed-off-by: NGerhard Bertelsmann <info@gerhard-bertelsmann.de>
Acked-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

Documentation/devicetree/bindings/net/can/sun4i_can.txt

+Allwinner A10/A20 CAN controller Device Tree Bindings
+-----------------------------------------------------
+
+Required properties:
+- compatible: "allwinner,sun4i-a10-can"
+- reg: physical base address and size of the Allwinner A10/A20 CAN register map.
+- interrupts: interrupt specifier for the sole interrupt.
+- clock: phandle and clock specifier.
+
+Example
+-------
+
+SoC common .dtsi file:
+
+	can0_pins_a: can0@0 {
+		allwinner,pins = "PH20","PH21";
+		allwinner,function = "can";
+		allwinner,drive = <0>;
+		allwinner,pull = <0>;
+	};
+...
+	can0: can@01c2bc00 {
+		compatible = "allwinner,sun4i-a10-can";
+		reg = <0x01c2bc00 0x400>;
+		interrupts = <0 26 4>;
+		clocks = <&apb1_gates 4>;
+		status = "disabled";
+	};
+
+Board specific .dts file:
+
+	can0: can@01c2bc00 {
+		pinctrl-names = "default";
+		pinctrl-0 = <&can0_pins_a>;
+		status = "okay";
+	};