Re: [PATCH v2 01/13] spi: dt-bindings: cdns,qspi-nor: Add Renesas RZ/N1D400 to the list

[Rob Herring]

On Fri, Jan 16, 2026 at 10:39:21AM +0100, Miquel Raynal wrote:
> Hello Geert,
> 
> >> --- a/Documentation/devicetree/bindings/spi/cdns,qspi-nor.yaml
> >> +++ b/Documentation/devicetree/bindings/spi/cdns,qspi-nor.yaml
> >> @@ -80,6 +80,10 @@ properties:
> >>            # controllers are meant to be used with flashes of all kinds,
> >>            # ie. also NAND flashes, not only NOR flashes.
> >>            - const: cdns,qspi-nor
> >> +      - items:
> >> +          - const: renesas,r9a06g032-qspi
> >> +          - const: renesas,rzn1-qspi
> >> +          - const: cdns,qspi-nor
> >
> > Doesn't the need for (at least) the CQSPI_NO_INDIRECT_MODE flag mean
> > that this device is not compatible with cdns,qspi-nor, and thus the
> > cdns,qspi-nor fallback must not be used?
> 
> I understand the question. It is true that I use driver data to limit
> the number of features the IP can use and this data is associated to the
> Renesas compatible, but I believe all other flavours of this IP would
> also not work without driver data attached to their front
> compatible. None of the SoCs with the Cadence QSPI IP actually would run
> without their own driver data. For me the fallback compatible is
> relevant because it describes the hardware as "this is a derivative of
> the Cadence controller" (and it is clearly the case, and this is also
> mentioned in the reference manual), even though I agree using
> cdns,qspi-nor would definitely not work alone. But again, none of the
> other flavours would anyway.

Fallbacks should be usable on their own. We've generally moved away from 
having these generic licensed IP compatibles because they always have 
per platform changes.

Rob