Re: [RFC PATCH 0/3] New Atmel PIO4 pinctrl/gpio driver

From: Ludovic Desroches
Date: Thu Aug 20 2015 - 08:46:35 EST


On Thu, Aug 20, 2015 at 09:05:07AM +0200, Sascha Hauer wrote:
> On Mon, Aug 10, 2015 at 08:53:34AM +0200, Ludovic Desroches wrote:
> > Hi Sascha,
> >
> > On Wed, Aug 05, 2015 at 09:31:17AM +0200, Sascha Hauer wrote:
> > > On Fri, Jul 31, 2015 at 05:08:07PM +0200, Ludovic Desroches wrote:
> > > > Hi,
> > > >
> > > > Following our discussion, I send an RFC version of my driver. RFC because it is
> > > > not totally achieved, some cleanup and feature addition is needed.
> > > >
> > > > At least, we could discuss about the 'core' part. I have used the pinmux
> > > > property as Mediatek driver. Patch 3 is the internal dt files we are using.
> > >
> > > As you can imagine I am fine with the binding, so I can add my acked-by
> > > once you send a non-RFC version.
> > >
> >
> > Great, I'm glad to hear that.
> >
> > > The only thing I never understood is what's so special about GPIOs that
> > > they have to bypass the pinctrl framework and instead a gpio_request
> > > magically translates a gpio into a pin.
> >
> > Not sure to really understand your concern here... Do you mean I could
> > get rid of gpio_request_enable()?
>
> I would expect a gpio to be a pin like every other pin, hence configured
> via the pinctrl framework and not implicitly via gpio_request().
>

It is not an issue to get rid of gpio_request_*(). I was thinking it was
a bonus to provide it.

> >
> > > Wouldn't it make sense to at
> > > least add the pins in their GPIO mode to
> > > arch/arm/boot/dts/sama5d2-pinfunc.h?
> >
> > It is done, PIN_PA0 could be used for this purpose.
>
> I would expect a define like:
>
> #define PIN_PA3__GPIO PINMUX_PIN(PIN_PA3, 0, 2)
>
> PIN_PAx only contains the pin number, but not the function.

Ok I can do this change for v2.


Ludovic
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