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

From: Krzysztof Kozlowski

Date: Mon Jul 20 2026 - 06:36:41 EST


On 20/07/2026 10:48, Santhosh Kumar K wrote:
>
>
> 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.

Hm, where? I completely missed that, can you point me to the specific
line? I see clearly that it is not a scalar.


>
> 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"

This I did not propose - the type is fixed.

> - "Scalar properties should not have array keywords"

Cannot reproduce it.

Best regards,
Krzysztof