pwm: rockchip: document device tree bindings

This adds binding documentation for Rockchip SoC PWM driver.

Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

diff --git a/Documentation/devicetree/bindings/pwm/pwm-rockchip.txt b/Documentation/devicetree/bindings/pwm/pwm-rockchip.txt
new file mode 100644 (file)
index 0000000..3182126
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/pwm-rockchip.txt
@@ -0,0 +1,17 @@
+Rockchip PWM controller
+
+Required properties:
+ - compatible: should be "rockchip,rk2928-pwm"
+ - reg: physical base address and length of the controller's registers
+ - clocks: phandle and clock specifier of the PWM reference clock
+ - #pwm-cells: should be 2. See pwm.txt in this directory for a
+   description of the cell format.
+
+Example:
+
+       pwm0: pwm@20030000 {
+               compatible = "rockchip,rk2928-pwm";
+               reg = <0x20030000 0x10>;
+               clocks = <&cru PCLK_PWM01>;
+               #pwm-cells = <2>;
+       };