devicetree: Add Zynq GPIO devicetree bindings documentation

Add gpio-zynq bindings documentation.

Signed-off-by: Harini Katakam <harinik@xilinx.com>
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/Documentation/devicetree/bindings/gpio/gpio-zynq.txt b/Documentation/devicetree/bindings/gpio/gpio-zynq.txt
new file mode 100644 (file)
index 0000000..986371a
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio-zynq.txt
@@ -0,0 +1,26 @@
+Xilinx Zynq GPIO controller Device Tree Bindings
+-------------------------------------------
+
+Required properties:
+- #gpio-cells          : Should be two
+                         - First cell is the GPIO line number
+                         - Second cell is used to specify optional
+                           parameters (unused)
+- compatible           : Should be "xlnx,zynq-gpio-1.0"
+- clocks               : Clock specifier (see clock bindings for details)
+- gpio-controller      : Marks the device node as a GPIO controller.
+- interrupts           : Interrupt specifier (see interrupt bindings for
+                         details)
+- interrupt-parent     : Must be core interrupt controller
+- reg                  : Address and length of the register set for the device
+
+Example:
+       gpio@e000a000 {
+               #gpio-cells = <2>;
+               compatible = "xlnx,zynq-gpio-1.0";
+               clocks = <&clkc 42>;
+               gpio-controller;
+               interrupt-parent = <&intc>;
+               interrupts = <0 20 4>;
+               reg = <0xe000a000 0x1000>;
+       };