Re: [PATCH v3 1/1] pinctrl: add Intel BayTrail GPIO/pinctrl support

From: Linus Walleij
Date: Fri Apr 25 2014 - 06:37:59 EST


On Fri, Apr 25, 2014 at 9:41 AM, Westerberg, Mika
<mika.westerberg@xxxxxxxxx> wrote:
> On Thu, Apr 24, 2014 at 10:25:56AM -0500, Timur Tabi wrote:
>> On 04/24/2014 06:58 AM, Westerberg, Mika wrote:
>> >>>No, that's my point. I was expecting the pinmux functions of the
>> >>>pinctrl driver are used by ACPI, but apparently they aren't, and
>> >>>that's why I'm asking.
>>
>> >Which functions?
>>
>> The functions in struct pinmux_ops, like get_function_groups. Will
>> these functions ever be called on an ACPI system?
>
> Well, if you have an ACPI system (like normal PC) it is perfectly fine to
> have pin controller/mux hardware there which is not dependent at all on
> ACPI.
>
> If you happen to have pin controller/mux driver that drives that hardware,
> I'm sure your pinmux functions gets called.

True as far as the driver itself goes.

Pin controllers are however configured into a certain state with
platform data or device tree data. This configuration would need
to be stored in ACPI to fill the equivalent role in such a system,
and that in turn implies some thought given to it during design
of any ACPI-pinctrl bindings.

Yours,
Linus Walleij
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