Re: [PATCH v3 1/2] spi: cadence: add dt-bindings documentation for Cadence XSPI controller

From: Pratyush Yadav
Date: Wed Sep 08 2021 - 07:32:26 EST

On 08/09/21 06:52AM, Parshuram Raju Thombare wrote:
> >This needs to be a "subclass" of the spi-controller.yaml binding.
> >
> >allOf:
> > - $ref: spi-controller.yaml#
> Isn't stating that validation need against spi-controller.yaml as well as
> this schema sufficient ? Can you please point an example how to make
> controller binding a "subclass" of spi-controller.yaml binding ?

I just showed you. You need to add the below lines:

- $ref: spi-controller.yaml#

See cdns,qspi-nor.yaml or nvidia,tegra210-quad.yaml or any of the
multiple controller bindings we already have.

By "subclass" I did not mean a programming construct, I just meant it
should logically be a subclass of the spi-controller.yaml binding, which
can be done by the allOf.

> >Node name should be flash@0.
> I think spi-controller.yaml uses wildcard for the name of a device node,
> so anything in string@hexvalue: should work.

Sure, but mtd.yaml (which the SPI NOR binding depends on) requires it.

> >> + compatible = "spi-nor", "micron,mt35xu512";
> >
> >These compatibles are arbitrary and undocumented. You probably just need
> >"jedec,spi-nor". If you need anything else, you need to justify why.
> Although just "spi-nor" also works, I agree to use "jedec, spi-nor" and drop
> device name.

Does it? I see "jedec,spi-nor" compatible documented, but not just
"spi-nor". And I don't see "micron,mt35xu512" compatible documented
anywhere either.

Anyway, please just use "jedec,spi-nor".

Pratyush Yadav
Texas Instruments Inc.