[PATCH 2/5] Documentation: add description of DT binding for the gpio-mvebu driver

Olof Johansson olof at lixom.net
Wed Sep 5 00:51:25 EDT 2012

On Sun, Sep 2, 2012 at 12:33 AM, Linus Walleij <linus.walleij at linaro.org> wrote:
> On Mon, Aug 27, 2012 at 11:53 PM, Olof Johansson <olof at lixom.net> wrote:
>> Hi,
>> On Sat, Aug 11, 2012 at 03:31:43PM +0200, Thomas Petazzoni wrote:
>>> +- gpio-controller: marks the device node as a gpio controller
>>> +
>>> +- ngpios: number of GPIOs this controller has
>>> +
>>> +- #gpio-cells: Should be one. It is the pin number.
>> Most platforms will hit a need to encode polarity of the GPIO, in
>> particular on inputs. Having an extra cell for flags is quite useful.
> Isn't that surplus in this case since this driver has a proper
> pinctrl backend controlling such stuff? I don't really like
> pinctrl portions of GPIOs being showeled into the GPIO
> actually. Or am I just getting this wrong...?

Ah, yes, true. Last time I had to add this was for a platform that
lacked pinctrl bindings (exynos).

I guess it doesn't hurt to add the flag since it might be used on
other OSes that have a gpio driver but not a pinctrl one, but that's a
pretty far corner case, no need to revise for it.


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