Re: [PATCH] gpio-ich: Share ownership of GPIO groups

Linus Walleij
2012-08-05T10:02:26Z

On Mon, Jul 23, 2012 at 5:34 PM, Jean Delvare <khali@linux-fr.org> wrote:

> The ICH chips have their GPIO pins organized in 2 or 3 independent
> groups of 32 GPIO pins. It can happen that the ACPI BIOS wants to make
> use of pins in one group, preventing the OS to access these. This does
> not prevent the OS from accessing the other group(s).
>
> This is the case for example on my Asus Z8NA-D6 board. The ACPI BIOS
> wants to control GPIO 18 (group 1), while I (the OS) need to control
> GPIO 52 and 53 (group 2) for SMBus multiplexing.
>
> So instead of checking for ACPI resource conflict on the whole I/O
> range, check on a per-group basis, and consider it a success if at
> least one of the groups is available for the OS to use.
>
> Signed-off-by: Jean Delvare <khali@linux-fr.org>
> Cc: Peter Tyser <ptyser@xes-inc.com>
> Cc: Aaron Sierra <asierra@xes-inc.com>
> Cc: Grant Likely <grant.likely@secretlab.ca>
> Cc: Samuel Ortiz <sameo@linux.intel.com>
> ---
> That's probably not the nicest code you've seen, but everything else I
> could think of either couldn't work or was looking worse. If anyone can
> think of a better approach, I'm all ears.

I'm not very good at Intel and SMBus so cannot really help either.

Acked-by: Linus Walleij <linus.walleij@linaro.org>

I guess you're bringing this through Sam's tree.

Yours,
Linus Walleij