[PATCH 1/7] gpiolib: gpiolib-of: Implement device tree gpio-names based lookup

Chen-Yu Tsai wens at csie.org
Wed Apr 16 02:56:54 PDT 2014


On Wed, Apr 16, 2014 at 3:06 PM, Alexandre Courbot <gnurou at gmail.com> wrote:
> On Wed, Apr 16, 2014 at 3:12 PM, Alexandre Courbot <gnurou at gmail.com> wrote:
>> On Tue, Apr 15, 2014 at 11:20 PM, Maxime Ripard
>> <maxime.ripard at free-electrons.com> wrote:
>>> Hi Chen-Yu,
>>> On Tue, Apr 15, 2014 at 02:41:35PM +0800, Chen-Yu Tsai wrote:
>>>> This patch provides of_get_gpiod_flags_by_name(), which looks up GPIO
>>>> phandles by name only, through gpios/gpio-names, and not by index.
>>> IIRC, gpios only uses the *-gpios properties, and not gpios/gpio-names
>>> pattern seen on various other things.
>>> Is it some new property you introduce? If so, please add it to the
>>> documentation.
>>> Now, I'm not sure that having two distinct representations of GPIOs in
>>> the DT is a good thing. Yes, it's looking odd compared to other
>>> similar bindings, but it's what we have to deal with.
>> Mmmm I *think* I somehow remember a discussion about this topic
>> recently, but I cannot find it. Maybe Chen-yu could point us to the
>> conclusion of this discussion and the rationale for (re)implementing
>> named GPIOs this way?
> Aha, here maybe:
> https://lkml.org/lkml/2014/1/21/164

They're also mentioned in:


> However I don't see a clear conclusion that we should implement that
> scheme. Not that I am strongly against it, but I'd like to see a
> practical purpose for it.

Again no clear conclusion on this. I wrote this as it was one possible
way out of the index-based GPIO stuff.

Hopefully others will chime in and we can decide whether this is what
we want or not.


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