Subject: [PATCH 1/3] gpio: Add simple poweroff-gpio driver

From: [email-masked] (Anton Vorontsov)
Date: Thu, 15 Nov 2012 02:59:55 -0800

On Thu, Nov 15, 2012 at 11:35:36AM +0100, Linus Walleij wrote:
> On Mon, Nov 12, 2012 at 7:58 PM, Stephen Warren <[email-masked]> wrote:
> > On 11/12/2012 11:43 AM, Anton Vorontsov wrote:
> 
> >> Should the gpio driver fix its bindings then?.. Polarity is a quite
> >> generic concept of a GPIO, and flags are there for a reason. I'd rather
> >> prefer having
> >
> > There is no "GPIO driver" to fix; each GPIO driver has its own bindings,
> > and unfortunately, some of the GPIO binding authors chose not to include
> > any flags cell in the GPIO specifier (e.g. Samsung ARM SoCs IIRC, but
> > there are probably more).
> 
> So can I read this something like we have been too liberal with the
> GPIO DT bindings and they are now a bit messy and need to be shaped
> up? I don't know how to achieve that :-(

I guess there's really no reason to panic. :)

'git grep gpio-cells Documentation/' shows just mrvl-gpio.txt and
twl6040.txt having the wrong gpio-cells (i.e. 1).

But even these can use one cells for both flags and pin number (unless you
really have 4294967295 GPIOs per controller).

FWIW, current Samsung SOCs use 3 and even 4 cells for a GPIO specifier,
which is absolutely fine. Plus, the Samsung bindings do specify the
inversion flag. So, unless we have a lot of other [undocumented] bindings,
I don't see a big mess. And everything I currently see is fixable.

Thanks,
Anton.