Re: [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