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

Grant Likely grant.likely at secretlab.ca
Wed Nov 21 08:17:04 EST 2012


On Thu, 15 Nov 2012 12:10:59 +0100, Linus Walleij <linus.walleij at linaro.org> wrote:
> On Thu, Nov 15, 2012 at 11:59 AM, Anton Vorontsov
> <anton.vorontsov at linaro.org> wrote:
> > On Thu, Nov 15, 2012 at 11:35:36AM +0100, Linus Walleij wrote:
> >> On Mon, Nov 12, 2012 at 7:58 PM, Stephen Warren <swarren at wwwdotorg.org> 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.
> 
> I agree it's not that big a mess...
> 
> I was more thinking about how to convince the people who can
> test this to fix it up.

+1. Most drivers use the same definitions for flags. New drivers should
be pushed to do the same. And the few that don't can be fixed up
individually.

g.

-- 
Grant Likely, B.Sc, P.Eng.
Secret Lab Technologies, Ltd.



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