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

[Richard GENOUD <richard.genoud@bootlin.com>]

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@bootlin.com>
>> ---
>>   .../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@bootlin.com>
>> +
>> +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@oss.qualcomm.com>
> 
> Best regards,
> Krzysztof
> 
Thanks for your review!

Regards,
Richard