On Mon, Nov 26, 2018 at 12:18:59AM +0800, Hao Zhang wrote:
> This patch adds Allwinner sun8i pwm binding document.
> 
> Signed-off-by: Hao Zhang <hao5781286-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> ---
>  .../devicetree/bindings/pwm/pwm-sun8i.txt          | 24 ++++++++++++++++++++++
>  1 file changed, 24 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/pwm/pwm-sun8i.txt
> 
> diff --git a/Documentation/devicetree/bindings/pwm/pwm-sun8i.txt b/Documentation/devicetree/bindings/pwm/pwm-sun8i.txt
> new file mode 100644
> index 0000000..7531d85
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pwm/pwm-sun8i.txt
> @@ -0,0 +1,24 @@
> +Allwinner sun8i R40/V40/T3 SoC PWM controller
> +
> +Required properties:
> +  - compatible: Should be one of:
> +    - "allwinner,sun8i-r40-pwm"
> +  - reg: Physical base address and length of the controller's registers
> +  - interrupts: Should contain interrupt.
> +  - clocks: From common clock binding, handle to the parent clock.
> +  - clock-names: Must contain the clock names described just above.
> +  - pwm-channels: PWM channels of the controller.

Why do you need this? In the cover letter you say:

	"The sun8i R40/T3/V40 PWM has 8 PWM channals ..."

Why does this need to be specified in the DT?

Thierry