Re: [PATCH 1/4] dt-bindings: mmc: renesas_sdhi: Add r8a77470 support

[Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>]

Hi Wolfram,

On Tue, Sep 25, 2018 at 10:22 AM Wolfram Sang <wsa@xxxxxxxxxxxxx> wrote:
> > > Perhaps stating the obvious: this feels a lot like the problem we thought
> > > we had with different Gen-3 SoCs/ES versions. And in that case we decided
> > > against using compat strings to differentiate. The main difference here
> > > seems to be that we need to differentiate between different ports on the
> > > same SoC.
>
> Yes, I agree. Our so far agreed solution didn't take into account that
> there are different SDHI versions on the same SoC. Adding a compatible
> might be the easiest solution, but then we have a mix of compatibles,
> soc_device_match, and even version register (deeper in the driver). My
> gut feeling is we should take the time to rethink all this?
>
> > So either
> >   a) SDHI0/2 vs. SDHI1 are different, deserving different compatible values, or
> >   b) SDHI0/1/2 are identical, but SDHI1 is wired different, deserving the same
> >      compatible value, but one or more additional properties describing the
> >      different wiring.
>
> Actually, SDHI2 seems different, too. It doesn't support SDR104. I don't
> have the SDHI specific docs, but from the main docs, all SDHI instances
> are different.

I forgot about the version register.

Fabrizio: can you please check what the 3 instances report in their version
registers? Thanks!

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

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