Re: [RFC 2/3] pinctrl: sh-pfc: r8a7795: add support for voltage switching

[Wolfram Sang <wsa@the-dreams.de>]

On Mon, Jun 06, 2016 at 09:23:35AM +0200, Geert Uytterhoeven wrote:
> Hi Wolfram,
> 
> On Mon, Jun 6, 2016 at 8:50 AM, Wolfram Sang <wsa@the-dreams.de> wrote:
> > From: Wolfram Sang <wsa+renesas@sang-engineering.com>
> >
> > Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
> > ---
> >  drivers/pinctrl/sh-pfc/pfc-r8a7795.c | 24 ++++++++++++++++++++++--
> >  1 file changed, 22 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/pinctrl/sh-pfc/pfc-r8a7795.c b/drivers/pinctrl/sh-pfc/pfc-r8a7795.c
> > index 44632b1a5c978c..8e068d8534de00 100644
> > --- a/drivers/pinctrl/sh-pfc/pfc-r8a7795.c
> > +++ b/drivers/pinctrl/sh-pfc/pfc-r8a7795.c
> > @@ -17,8 +17,8 @@
> >         PORT_GP_CFG_16(0, fn, sfx, SH_PFC_PIN_CFG_DRIVE_STRENGTH),      \
> >         PORT_GP_CFG_28(1, fn, sfx, SH_PFC_PIN_CFG_DRIVE_STRENGTH),      \
> >         PORT_GP_CFG_15(2, fn, sfx, SH_PFC_PIN_CFG_DRIVE_STRENGTH),      \
> > -       PORT_GP_CFG_16(3, fn, sfx, SH_PFC_PIN_CFG_DRIVE_STRENGTH),      \
> > -       PORT_GP_CFG_18(4, fn, sfx, SH_PFC_PIN_CFG_DRIVE_STRENGTH),      \
> > +       PORT_GP_CFG_16(3, fn, sfx, SH_PFC_PIN_CFG_DRIVE_STRENGTH | SH_PFC_PIN_CFG_IO_VOLTAGE),  \
> 
> Shouldn't this be split in PORT_GP_CFG_12() with SH_PFC_PIN_CFG_IO_VOLTAGE,
> and PORT_GP_CFG_4() without?

Right. However, PORT_GP_CFG_4 doesn't allow to set an offset for the pin
numbers. Options I see:

a) keep it as is and rely on the checks in pin_to_pocctrl()
b) use PORT_GP_CFG_12 and 4 times PORT_GP_CFG_1 which allow setting the
   pin number
c) introduce (yet another) macro like PORT_GP_CFG_4_OFS

So far, I thought a) was good enough. Now I tend to option b) because it
is indeed more precise. We still can do c) if demand for such a macro
increases.

What do you think?

Thanks,

   Wolfram