[periperi] How to set default GPIO pin ?

[Laurent Pinchart]

Hi Linus and Morimoto-san,

On Tuesday 23 September 2014 17:06:28 Linus Walleij wrote:
> On Wed, Sep 10, 2014 at 10:55 AM, Laurent Pinchart wrote:
> > On Sunday 31 August 2014 22:08:52 Kuninori Morimoto wrote:
> >> I know we can use "defalt" PFC settings on DT.
> >> But, how to use "defalt" GPIO pin settings on DT ?
> >> 
> >> We would like to use GPIO 7-17 as Low output,
> >> and do nothing after boot.
> > 
> > From a DT point of view I believe this is supposed to be done by
> > specifying the output-low or output-high properties in the pinctrl
> > configuration node. However, these properties are not supported by the PFC
> > driver, and there's no easy way for the PFC driver to configure GPIOs
> > handled by a different driver such as the gpio-rcar driver for instance.
> > 
> > Linus, do you have any hindsight on how this should be implemented ?
> 
> I have suggested adding GPIO hogs, so that a GPIO node can specify
> that some GPIO's specified on the local ship be hogged high or
> low at probe. Generic DT bindings and generic code in gpiolib.c.
> 
> gpios-hog-high = <....>;
> gpios-hog-low = <....>;

How about just a gpios-hog property, with a list of gpio specifiers + flags ? 
That's bikeshedding I suppose.

Morimoto-san, would you like to implement that ? :-)

-- 
Regards,

Laurent Pinchart