Re: [PATCH 1/3] gpio / ACPI: add ACPI support

From: Rafael J. Wysocki
Date: Mon Nov 05 2012 - 07:43:51 EST


On Monday, November 05, 2012 02:14:21 PM Mathias Nyman wrote:
> On 11/05/2012 01:53 PM, Linus Walleij wrote:
> > On Sat, Nov 3, 2012 at 8:46 AM, Mika Westerberg
> > <mika.westerberg@xxxxxxxxxxxxxxx> wrote:
> >
> >> +/**
> >> + * acpi_get_gpio() - Translate ACPI GPIO pin to GPIO number usable with GPIO API
> >> + * @path: ACPI GPIO controller full path name, (e.g. "\\_SB.GPO1")
> >> + * @pin: ACPI GPIO pin number (0-based, controller-relative)
> >> + *
> >> + * Returns GPIO number to use with Linux generic GPIO API, or errno error value
> >> + */
> >
> > So by just looking at that we can see that this is yet another
> > instance of papering
> > over the fact that the Linux GPIO numbers are global to the kernel and not
> > per-chip, as would be preferred.
>
> Yes, it is. ACPI5 GPIO resources are numbered per-chip. This is just a
> way for device drivers to find the corresponding Linux GPIO.
>
> per-chip based numbering sounds saner, but this deals with what we
> currently have.

And we need something to hook up drivers to right now.

Thanks,
Rafael


--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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