Re: [PATCH 1/6] gpiolib: Allow GPIO chips to request their own GPIOs

[Linus Walleij]

On Tue, Feb 25, 2014 at 12:00 AM, Mika Westerberg
<mika.westerberg@xxxxxxxxxxxxxxx> wrote:

> Sometimes it is useful to allow GPIO chips themselves to request GPIOs they
> own through gpiolib API. One usecase is ACPI ASL code that should be able
> to toggle GPIOs through GPIO operation regions.
>
> We can't really use gpio_request() and its counterparts because it will pin
> the module to the kernel forever (as it calls module_get()). Instead we
> provide a gpiolib internal functions gpiochip_request/free_own_desc() that
> work the same as gpio_request() but don't manipulate module refrence count.
>
> Since it's the GPIO chip driver who requests the GPIOs in the first place
> we can be sure that it cannot be unloaded without the driver knowing about
> that. Furthermore we only limit this functionality to be available only
> inside gpiolib.
>
> Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>

I fully trust you in doing the ACPI stuff in patches 2-n but on this patch
in particular I want Alexandre's review tag as well, as he's working
actively with the descriptor API and I don't want to add too many quirks
without his consent.

So Alexandre, what do you say about this?

Yours,
Linus Walleij
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/