Re: [PATCH v11 1/2] dt-bindings: spi: add loongson spi

[zhuyinbo]

在 2023/6/1 下午11:30, Krzysztof Kozlowski 写道:
> On 01/06/2023 11:51, zhuyinbo wrote:
> > > > Yes, it is make sense as it can reduce the workload of the community.
> > > > For the Loongson platform, the versions of spi peripherals are almost
> > > > the same, except for a few  or individual SoCs.  And we have also
> > > > discussed compatible internally, and we tend to define it this way.
> > >
> > > So you have chosen different path than what's clearly recommended by
> > > community, existing experience and documentation:
> > >
> > > https://elixir.bootlin.com/linux/v6.1-rc1/source/Documentation/devicetree/bindings/writing-bindings.rst#L42
> > >
> > > Family names are not accepted as specific compatibles. Whenever they
> > > were accepted, it lead to problems. All the time.
> >
> >
> > Thank you for your documentation and advice and the Loongson platform
> > have loongson-2h (ls2h), loongson-2k (ls2k), loongson-2p (ls2p) or other
> > series SoC, which loongson-2 seems to be the family name you mentioned
> > and the "loongson,ls2k-spi" should be a speific compatible name.
> >
> > > https://lore.kernel.org/all/20220822181701.GA89665-robh@xxxxxxxxxx/
> > > https://lore.kernel.org/all/78651e07-6b3e-4243-8e1f-fcd1dfb3ffe1@xxxxxxxxxxxxxxxx/
> > > https://lore.kernel.org/all/288f56ba9cfad46354203b7698babe91@xxxxxxxx/
> > > https://lore.kernel.org/all/106e443a-e765-51fe-b556-e4e7e2aa771c@xxxxxxxxxx/
> > > and many many more discussions.
> > >
> > > You should choose carefully, because we will keep NAK-ing adding
> > > properties to circumvent missing compatibles.
> >
> >
> > I have read the documention and patch link that you mentioned and it
> > seems to advice that We don't have wildcard names in the compatible
> > string and use wildcard names that will cause issue. and the compatible
> > "loongson,ls2k-spi" that wasn't a wildcard names, and if the loongson-2k
> > spi controller hardware upgraded or changed the I will use
> > "loongson,ls2k-spi-version" as a compatible, such as,
> > "loongson,ls2k-spi-v1.1", "loongson,ls2k-spi-v1.1a" or other.
>
> Versions? Why? They received a lot of comments in the past, let me just
> paste to avoid repeating the same:
>
> https://lore.kernel.org/all/20220926231238.GA3132756-robh@xxxxxxxxxx/
>
> (and many more discussions on devicetree mailing list)


I didn't notice the following words earlier about compatible in
documention and I will use "loongson,ls2k1000-spi" as ls2k1000 SoC spi
compatible, which is a very specific compatible.

"For sub-blocks/components of bigger device (e.g. SoC blocks) use rather
device-based compatible (e.g. SoC-based compatible), instead of custom
versioning of that component.For example use "vendor,soc1234-i2c"
instead of "vendor,i2c-v2".

> > > > > Or am I misunderstanding and all ls2k SoCs do work with this driver and
> > > > > you were talking about other, future products?
> > > >
> > > > Actually, in 2k500 has one special type spi was only one cs and their's
> > > > register definition was different from common type spi thus this driver
> > > > doesn't support but this driver can support another common type spi in
> > > > 2k500.  for this special type spi I will add support as needed in the
> > > > future.
> > >
> > > Bindings are for hardware, not driver. What does your driver support or
> > > does not, matters less.
> >
> >
> > okay, I got it, and the loongson spi bindings was for loongson spi
> > controller hardware. if the spi controller hardware not changed in
> > different ls2k SoC and the spi compatible should be same thus loongson
> > spi compatible seems to be adhere to the bindings aggrement.
>
> Specific compatible - yes. Unspecific - not, because you disregard the
> clear message in the guideline.

okay, I got it.

Thanks.