Re: [PATCH 03/12] dt-bindings: soc: renesas: Document RZ/G3E SMARC SoM and Carrier-II EVK

Geert Uytterhoeven
2024-11-28T08:50:10Z

Hi Biju,

On Thu, Nov 28, 2024 at 7:52 AM Biju Das <biju.das.jz@bp.renesas.com> wrote:
> > From: Conor Dooley <conor@kernel.org>
> > On Wed, Nov 27, 2024 at 05:18:56PM +0000, Biju Das wrote:
> > > > -----Original Message-----
> > > > From: Conor Dooley <conor@kernel.org>
> > > > Sent: 27 November 2024 16:33
> > > > Subject: Re: [PATCH 03/12] dt-bindings: soc: renesas: Document
> > > > RZ/G3E SMARC SoM and Carrier-II EVK
> > > >
> > > > On Wed, Nov 27, 2024 at 12:34:42PM +0000, Biju Das wrote:
> > > > > Hi Conor Dooley,
> > > > >
> > > > > Thanks for the feedback.
> > > > >
> > > > > > -----Original Message-----
> > > > > > From: Conor Dooley <conor@kernel.org>
> > > > > > Sent: 25 November 2024 18:52
> > > > > > Subject: Re: [PATCH 03/12] dt-bindings: soc: renesas: Document
> > > > > > RZ/G3E SMARC SoM and Carrier-II EVK
> > > > > >
> > > > > > On Fri, Nov 22, 2024 at 12:45:39PM +0000, Biju Das wrote:
> > > > > > > Document the Renesas RZ/G3E SMARC Carrier-II EVK board which
> > > > > > > is based on the Renesas RZ/G3E SMARC SoM. The RZ/G3E SMARC
> > > > > > > Carrier-II EVK consists of an RZ/G3E SoM module and a SMARC Carrier-II carrier board.
> > > > > > > The SoM module sits on top of the carrier board.
> > > > > > >
> > > > > > > Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> > > > > > > ---
> > > > > > > Documentation/devicetree/bindings/soc/renesas/renesas.yaml |
> > > > > > > 4
> > > > > > > ++++
> > > > > > > 1 file changed, 4 insertions(+)
> > > > > > >
> > > > > > > diff --git
> > > > > > > a/Documentation/devicetree/bindings/soc/renesas/renesas.yaml
> > > > > > > b/Documentation/devicetree/bindings/soc/renesas/renesas.yaml
> > > > > > > index 7cc2bb97db13..1785142fc8da 100644
> > > > > > > ---
> > > > > > > a/Documentation/devicetree/bindings/soc/renesas/renesas.yaml
> > > > > > > +++ b/Documentation/devicetree/bindings/soc/renesas/renesas.ya
> > > > > > > +++ ml
> > > > > > > @@ -527,6 +527,10 @@ properties:
> > > > > > >
> > > > > > > - description: RZ/G3E (R9A09G047)
> > > > > > > items:
> > > > > > > + - enum:
> > > > > > > + - renesas,smarc2-evk # RZ SMARC Carrier-II EVK
> > > > > > > + - enum:
> > > > > > > + - renesas,rzg3e-smarcm # RZ/G3E SMARC Module
> > > > > > > + (SoM)
> > > > > >
> > > > > > Why are these enums, when you have a single item in each?
> > > > >
> > > > > I just followed the style used in [1]
> > > > >
> > > > > [1]
> > > > > https://elixir.bootlin.com/linux/v6.12.1/source/Documentation/devi
> > > > > cetr
> > > > > ee/bindings/soc/renesas/renesas.yaml#L531
> > > >
> > > > It ain't the same though, since you additionally have the SoM.
> > > >
> > > > > Other than that,
> > > > >
> > > > > In future some vendors can add their RZ/G3E SoM's here
> > > >
> > > > Only makes sense if their SoM is compatible with the smarc2-evk.
> > >
> > > All our SMARC Modules and SMARC Carrier boards are SMARC compliant.
> >
> > All of yours might be, but what you said was "some vendors".
>
> FYI, In the past, we have a requirement to validate smarc-evk before RZ/G2L SMARC
> SoM available.
>
> So, we just used a SMARC SoM based on RZ/G2N and tested smarc-evk ethernet interface(of course with small hw mods)

Cool!

> > > So, if anyone have a RZ/G3E SMARC SoM, that should work with SMARC2-EVK.
> > >
> > > > >
> > > > > They can use Renesas RZ/G3E SMARC module and use their custom carrier boards.
> > > >
> > > > But allowing this part does make sense.
> > >
> > > We already have a use case for this example.
> > >
> > > Renesas RZ/G3E SoM can work on both Renesas smarc-evk and smarc2-evk.
> > >
> > > But we only officially support RZ/G3E SoM with SMARC2-EVK as it has multiple display support.
> > >
> > > So, can I use const for both SoM and Carrier EVK as at the moment
> > > there is only one?
> >
> > That is what I would do.
>
> Geert, Please share your thoughts.

I prefer the enum, as it causes less churn when adding more entries
later. Cfr. using a comma after the last entry in a C array, so new
entries can be appended later, without touching existing lines.

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds