[v6 1/4] dt-bindings: pwm: Add ASPEED PWM Control documentation

[Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>]

On 08/06/2023 10:21, Billy Tsai wrote:
>         On 08/06/2023 09:47, Billy Tsai wrote:
>         >>
>         >>   >> +
>         >>   >> +allOf:
>         >>   >> +  - $ref: pwm.yaml#
>         >>   >> +
>         >>   >> +properties:
>         >>   >> +  compatible:
>         >>   >> +    enum:
>         >>   >> +      - aspeed,ast2600-pwm
>         >>   >> +
>         >>   >> +  "#pwm-cells":
>         >>   >> +    const: 3
>         >>
>         >>   > 3 cells? For one PWM? What are they?
>         >>
>         >> channel, period and polarity.
> 
>         > Don't cut my responses. You wrote you have one PWM output, so only one
>         > channel. What do you put then in the channel?
> 
> You need to put 0 in the cell of the channel, the example of the dts usage will like following:
> 
> pwm0: pwm0 at 1e610000 {
>         compatible = "aspeed,ast2600-pwm";
>         reg = <0x1e610000 0x8>;
>         #pwm-cells = <3>;
>         #address-cells = <1>;
>         #size-cells = <0>;
>         pinctrl-names = "default";
>         pinctrl-0 = <&pinctrl_pwm0_default>;
>         clocks = <&syscon ASPEED_CLK_AHB>;
>         resets = <&syscon ASPEED_RESET_PWM>;
>         status = "okay";
> };
> 
> pwm1: pwm1 at 1e610010 {
>         compatible = "aspeed,ast2600-pwm";
>         reg = <0x1e610010 0x8>;
>         #pwm-cells = <3>;
>         #address-cells = <1>;
>         #size-cells = <0>;
>         pinctrl-names = "default";
>         pinctrl-0 = <&pinctrl_pwm1_default>;
>         clocks = <&syscon ASPEED_CLK_AHB>;
>         resets = <&syscon ASPEED_RESET_PWM>;
>         status = "okay";

BTW, these are not two PWM devices but one. I don't understand why you
changed previous design into something like this, but this is not
representing your hardware.

Best regards,
Krzysztof