Re: [PATCH 07/11] spi: spi-sh-msiof: RSCR register may absent

[Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>]

Hi Yoshii-san,

On Sun, Dec 1, 2013 at 7:19 PM,  <takasi-y@xxxxxxxxxxxxx> wrote:
> On Ape6, Rcar-H2, and Rcar-M2,
> MSIOF lacks RSCR(Receive Clock Select Register).
> I guess this is a part of .rx_need_dummy_tx case, and use same flag.

Are you sure? I'm under the impression MSIOF on APE6 does have RSCR,
just like on A1, and SH (e.g. 7724).

Given also that:
  - dummy TX is needed during reception for  APE6, R-Car H2/M2, and
     (perhaps --- this is not 100% clear to me) A1,
  - RMDR1[15:0] must be zero on APE6, and R-Car H2/M2.

there are (at least) 4 different variants of MSIOF:
  - SH
  - A1
  - APE6
  - R-Car H2 and M2

And I don't know about SH7372 and SH73A0...

But we indeed may not need to distinguish between all variants.
You just use the value of rx_need_dummy_tx as test condition.
If this works for APE6 and A1, we can add a new platform device name
"spi_sh_mobile_msiof" instead of adding the rx_need_dummy_tx flag
to platform data (struct sh_msiof_spi_info).
This would be in line with the currently defined (but so far unused) DT
compatible values "renesas,sh-msiof" and "renesas,sh-mobile-msiof".

What do you think?

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
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