Add bindings to support SGPIO on AST2400 or AST2500.
Signed-off-by: Hongwei Zhang <hongw...@ami.com>
---
.../devicetree/bindings/gpio/sgpio-aspeed.txt | 43 ++++++++++++++++++++++
1 file changed, 43 insertions(+)
create mode 100755 Documentation/devicetree/bindings/gpio/sgpio-aspeed.txt
diff --git a/Documentation/devicetree/bindings/gpio/sgpio-aspeed.txt
b/Documentation/devicetree/bindings/gpio/sgpio-aspeed.txt
new file mode 100755
index 0000000..3ae2b79
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/sgpio-aspeed.txt
@@ -0,0 +1,43 @@
+Aspeed SGPIO controller Device Tree Bindings
+-------------------------------------------
+
+Required properties:
+- compatible : Either "aspeed,ast2400-sgpio" or
"aspeed,ast2500-sgpio"
+
+- #gpio-cells : Should be two
+ - First cell is the GPIO line number
+ - Second cell is used to specify optional
+ parameters (unused)
+
+- reg : Address and length of the register set for the device
+- gpio-controller : Marks the device node as a GPIO controller.
+- interrupts : Interrupt specifier (see interrupt bindings for
+ details)
+
+- interrupt-controller : Mark the GPIO controller as an interrupt-controller
+
+- nr-gpios : number of GPIO pins to serialise. (should be multiple
of 8, up to 80 pins)
+ if not specified, defaults to 80.
+
+- clocks : A phandle to the APB clock for SGPM clock division
+
+- bus-frequency : SGPM CLK frequency, if not specified defaults to 1 MHz
+
+
+The sgpio and interrupt properties are further described in their respective
bindings documentation:
+
+- Documentation/devicetree/bindings/sgpio/gpio.txt
+- Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
+
+ Example:
+ sgpio@1e780200 {
+ #gpio-cells = <2>;
+ compatible = "aspeed,ast2500-sgpio";
+ gpio-controller;
+ interrupts = <40>;
+ reg = <0x1e780200 0x0100>;
+ clocks = <&syscon ASPEED_CLK_APB>;
+ interrupt-controller;
+ nr-gpios = <80>;
+ bus-frequency = <1000000>;
+ };
--
2.7.4
