pwm: add DT bindings documentation for atmel-hlcdc-pwm driver

The HLCDC IP available in some Atmel SoCs (i.e. at91sam9x5, at91sam9n12
or sama5d3 families for instance) provides a PWM device.

The DT bindings used for this PWM device is following the default 3 cells
bindings described in Documentation/devicetree/bindings/pwm/pwm.txt.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

diff --git a/Documentation/devicetree/bindings/pwm/atmel-hlcdc-pwm.txt b/Documentation/devicetree/bindings/pwm/atmel-hlcdc-pwm.txt
new file mode 100644 (file)
index 0000000..cfda0d5
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/atmel-hlcdc-pwm.txt
@@ -0,0 +1,29 @@
+Device-Tree bindings for Atmel's HLCDC (High-end LCD Controller) PWM driver
+
+The Atmel HLCDC PWM is subdevice of the HLCDC MFD device.
+See ../mfd/atmel-hlcdc.txt for more details.
+
+Required properties:
+ - compatible: value should be one of the following:
+   "atmel,hlcdc-pwm"
+ - pinctr-names: the pin control state names. Should contain "default".
+ - pinctrl-0: should contain the pinctrl states described by pinctrl
+   default.
+ - #pwm-cells: should be set to 3. This PWM chip use the default 3 cells
+   bindings defined in pwm.txt in this directory.
+
+Example:
+
+       hlcdc: hlcdc@f0030000 {
+               compatible = "atmel,sama5d3-hlcdc";
+               reg = <0xf0030000 0x2000>;
+               clocks = <&lcdc_clk>, <&lcdck>, <&clk32k>;
+               clock-names = "periph_clk","sys_clk", "slow_clk";
+
+               hlcdc_pwm: hlcdc-pwm {
+                       compatible = "atmel,hlcdc-pwm";
+                       pinctrl-names = "default";
+                       pinctrl-0 = <&pinctrl_lcd_pwm>;
+                       #pwm-cells = <3>;
+               };
+       };