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

[Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>]

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().

> 
> > 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.

Sascha

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