On Fri, 02 Dec 2016, Benjamin Gaignard wrote:
> Define bindings for pwm-stm32
>
> version 2:
> - use parameters instead of compatible of handle the hardware configuration
>
> Signed-off-by: Benjamin Gaignard <[email protected]>
> ---
> .../devicetree/bindings/pwm/pwm-stm32.txt | 38
> ++++++++++++++++++++++
> 1 file changed, 38 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/pwm/pwm-stm32.txt
>
> diff --git a/Documentation/devicetree/bindings/pwm/pwm-stm32.txt
> b/Documentation/devicetree/bindings/pwm/pwm-stm32.txt
> new file mode 100644
> index 0000000..575b9fb
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pwm/pwm-stm32.txt
> @@ -0,0 +1,38 @@
> +STMicroelectronics PWM driver bindings for STM32
> +
> +Must be a sub-node of STM32 general purpose timer driver
> +Parent node properties are describe in ../mfd/stm32-general-purpose-timer.txt
> +
> +Required parameters:
> +- compatible: Must be "st,stm32-pwm"
> +- pinctrl-names: Set to "default".
> +- pinctrl-0: List of phandles pointing to pin configuration
> nodes
> + for PWM module.
> + For Pinctrl properties, please refer to [1].
> +
> +Optional parameters:
> +- st,breakinput: Set if the hardware have break input capabilities
> +- st,breakinput-polarity: Set break input polarity. Default is 0
> + The value define the active polarity:
> + - 0 (active LOW)
> + - 1 (active HIGH)
> +- st,breakinput-polarity-high
Then assume the default if the property is not present.
> +- st,pwm-num-chan: Number of available PWM channels. Default is 0.
What's the point in having a PWM device with no channels?
Best to make this a compulsory property.
> +- st,32bits-counter: Set if the hardware have a 32 bits counter
> +- st,complementary: Set if the hardware have complementary output channels
> +
> +[1] Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
Use relative path.
../pinctrl/pinctrl-bindings.txt
> +Example:
> + gptimer1: gptimer1@40010000 {
> + compatible = "st,stm32-gptimer";
> + reg = <0x40010000 0x400>;
> + clocks = <&rcc 0 160>;
> + clock-names = "clk_int";
> +
> + pwm1@0 {
Don't number the node name.
pwm@xx
> + compatible = "st,stm32-pwm";
> + st,pwm-num-chan = <4>;
> + st,breakinput;
> + st,complementary;
> + };
> + };
--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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