[PATCH v5 01/17] spi: dt-bindings: add spi-max-post-config-frequency-hz property

[Santhosh Kumar K]

On 20/07/26 13:10, Krzysztof Kozlowski wrote:
> On 20/07/2026 09:38, Santhosh Kumar K wrote:
>>>> diff --git a/Documentation/devicetree/bindings/spi/spi-peripheral-props.yaml b/Documentation/devicetree/bindings/spi/spi-peripheral-props.yaml
>>>> index 880a9f624566..12211f8c9f7d 100644
>>>> --- a/Documentation/devicetree/bindings/spi/spi-peripheral-props.yaml
>>>> +++ b/Documentation/devicetree/bindings/spi/spi-peripheral-props.yaml
>>>> @@ -45,6 +45,11 @@ properties:
>>>>        description:
>>>>          Maximum SPI clocking speed of the device in Hz.
>>>>    
>>>> +  spi-max-post-config-frequency-hz:
>>>> +    description:
>>>> +      Maximum SPI clock frequency in Hz achievable after controller-side
>>>> +      configuration.
>>>
>>> How did you implement my feedback?
>>
>> Three points from your feedback:
>>
>> 1. -hz suffix: added
>>
>> 2. Array property: I still lean towards keeping this as a scalar for
>> now, as we don't have a concrete use case for multiple values today, and
>> supporting two frequencies should be sufficient for the foreseeable
>> future. I had responded to this in the v4 discussion as well, you may
>> have missed that response.
>>
>> 3. maxItems: Since the property remains a scalar, I have not added maxItems.
> 
> So how did you make this property scalar?

The -hz suffix constraints the property to a uint32 scalar through the
DT schema framework's property-units.yaml.

Adding an explicit $ref or maxItems for a unit-suffixed property is
rejected by dtbs_check with:
  - "Standard unit suffix properties don't need a type $ref"
  - "Scalar properties should not have array keywords"

Thanks,
Santhosh.

> 
> Best regards,
> Krzysztof