openwrtv4/target/linux/ramips/patches-4.3/0026-DT-Add-documentation-for-gpio-ralink.patch

From d410e5478c622c01fcf31427533df5f433df9146 Mon Sep 17 00:00:00 2001
From: John Crispin <blogic@openwrt.org>
Date: Sun, 28 Jul 2013 19:45:30 +0200
Subject: [PATCH 26/53] DT: Add documentation for gpio-ralink

Describe gpio-ralink binding.

Signed-off-by: John Crispin <blogic@openwrt.org>
Cc: linux-mips@linux-mips.org
Cc: devicetree@vger.kernel.org
Cc: linux-gpio@vger.kernel.org
---
 .../devicetree/bindings/gpio/gpio-ralink.txt       |   40 ++++++++++++++++++++
 1 file changed, 40 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/gpio/gpio-ralink.txt

--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio-ralink.txt
@@ -0,0 +1,40 @@
+Ralink SoC GPIO controller bindings
+
+Required properties:
+- compatible:
+  - "ralink,rt2880-gpio" for Ralink controllers
+- #gpio-cells : Should be two.
+  - first cell is the pin number
+  - second cell is used to specify optional parameters (unused)
+- gpio-controller : Marks the device node as a GPIO controller
+- reg : Physical base address and length of the controller's registers
+- interrupt-parent: phandle to the INTC device node
+- interrupts : Specify the INTC interrupt number
+- ralink,num-gpios : Specify the number of GPIOs
+- ralink,register-map : The register layout depends on the GPIO bank and actual
+		SoC type. Register offsets need to be in this order.
+		[ INT, EDGE, RENA, FENA, DATA, DIR, POL, SET, RESET, TOGGLE ]
+
+Optional properties:
+- ralink,gpio-base : Specify the GPIO chips base number
+
+Example:
+
+	gpio0: gpio@600 {
+		compatible = "ralink,rt5350-gpio", "ralink,rt2880-gpio";
+
+		#gpio-cells = <2>;
+		gpio-controller;
+
+		reg = <0x600 0x34>;
+
+		interrupt-parent = <&intc>;
+		interrupts = <6>;
+
+		ralink,gpio-base = <0>;
+		ralink,num-gpios = <24>;
+		ralink,register-map = [ 00 04 08 0c
+				20 24 28 2c
+				30 34 ];
+
+	};