Re: [PATCH 1/4] dt-bindings: pwm: sunxi: add PWM controller for Allwinner H616

[Richard GENOUD]

Hi Krzysztof,

Le 08/12/2025 à 07:52, Krzysztof Kozlowski a écrit :
> On Fri, Dec 05, 2025 at 11:02:36AM +0100, Richard Genoud wrote:
> > Allwinner H616 SoC contains a PWM controller quite different from the A10.
> > It has 6 channels than can generate PWM waveforms or clocks if bypass is
> > enabled.
> >
> > Signed-off-by: Richard Genoud <richard.genoud@xxxxxxxxxxx>
> > ---
> >   .../pwm/allwinner,sun50i-h616-pwm.yaml        | 67 +++++++++++++++++++
> >   1 file changed, 67 insertions(+)
> >   create mode 100644 Documentation/devicetree/bindings/pwm/allwinner,sun50i-h616-pwm.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/pwm/allwinner,sun50i-h616-pwm.yaml b/Documentation/devicetree/bindings/pwm/allwinner,sun50i-h616-pwm.yaml
> > new file mode 100644
> > index 000000000000..b89735ad3a43
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/pwm/allwinner,sun50i-h616-pwm.yaml
> > @@ -0,0 +1,67 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/pwm/allwinner,sun50i-h616-pwm.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Allwinner H616 PWM
> > +
> > +maintainers:
> > +  - Richard Genoud <richard.genoud@xxxxxxxxxxx>
> > +
> > +description: |
>
> Do not need '|' unless you need to preserve formatting.
Ok, I was thinking that it was nicer with the formatting.

> > +  Allwinner H616 PWM can generate standard PWM signals with variable pulse width
> > +  and period.
> > +  Also, instead of a PWM signal, a channel can be used to provide a clock.
> > +
> > +properties:
> > +  compatible:
> > +    const: allwinner,sun50i-h616-pwm
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  clocks:
> > +    items:
> > +      - description: Bus Clock
> > +
>
> Are you sure there is no first clock? Really, really sure? If you add it
> later, I would be pretty sad, because that's unnecessary duplication of
> binidngs....
I surely don't want to make you sad :)

Having a second look at the sun4i binding, I think there's a way to use it.
The sun4i, as you said, has a module clock (OSC24M) and an optional bus 
clock.
Here, the bus clock is mandatory, but the H616 PWM uses OSC24M and APB1 
as clock sources.

So, I guess that if we add something like that:
   clocks:
     minItems: 1
     items:
       - description: Module Clock
       - description: Bus Clock
+      - description: APB Clock

   clock-names:
     minItems: 1
     items:
       - const: mod
       - const: bus
+      - const: apb

   resets:
     maxItems: 1

In the sun4i pwm binding, we could re-use it for the H616 pwm right?
(APB clock is maybe not the best name, could be secondary module clock)

> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxxxxxxxx>
>
> Best regards,
> Krzysztof
Thanks for your review!

Regards,
Richard