gpio: add ETRAXFS GPIO driver

Add a GPIO driver for the General I/O block on Axis ETRAX FS SoCs.

Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 21 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/gpio/gpio-etraxfs.txt b/Documentation/devicetree/bindings/gpio/gpio-etraxfs.txt
new file mode 100644
index 0000000..abf4db7
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio-etraxfs.txt
@@ -0,0 +1,21 @@
+Axis ETRAX FS General I/O controller bindings
+
+Required properties:
+
+- compatible:
+  - "axis,etraxfs-gio"
+- reg: Physical base address and length of the controller's registers.
+- #gpio-cells: Should be 3
+  - The first cell is the gpio offset number.
+  - The second cell is reserved and is currently unused.
+  - The third cell is the port number (hex).
+- gpio-controller: Marks the device node as a GPIO controller.
+
+Example:
+
+	gio: gpio@b001a000 {
+		compatible = "axis,etraxfs-gio";
+		reg = <0xb001a000 0x1000>;
+		gpio-controller;
+		#gpio-cells = <3>;
+	};