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

[Miquel Raynal <miquel.raynal@bootlin.com>]

>> >> +      - 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.

Thanks for settling my doubts. I will drop the cdns,qspi-nor then.

Miquèl