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

[Santhosh Kumar K]

On 20/07/26 15:39, Krzysztof Kozlowski wrote:
> 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.

I overlooked this. You are right, and I apologize for the incorrect
explanation.

The -hz suffix maps to uint32-matrix in property-units.yaml, not a
scalar. Without 'maxItems: 1', the property can accept multiple values.
I should have verified this before responding. Sorry again!

I'll add 'maxItems: 1' in the next version.

Thanks,
Santhosh.

> Best regards,
> Krzysztof