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

From: Jean Delvare
Date: Tue Sep 11 2012 - 06:56:22 EST


On Tue, 11 Sep 2012 12:41:16 +0200, Samuel Ortiz wrote:
> Hi Jean,
>
> On Mon, Jul 23, 2012 at 05:34:15PM +0200, Jean Delvare 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@xxxxxxxxxxxx>
> > Cc: Peter Tyser <ptyser@xxxxxxxxxxx>
> > Cc: Aaron Sierra <asierra@xxxxxxxxxxx>
> > Cc: Grant Likely <grant.likely@xxxxxxxxxxxx>
> > Cc: Samuel Ortiz <sameo@xxxxxxxxxxxxxxx>
> > ---
> > 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.
> >
> > drivers/gpio/gpio-ich.c | 79 +++++++++++++++++++++++++++++++++++++------
> > drivers/mfd/lpc_ich.c | 29 ++++++++++++++-
> > include/linux/mfd/lpc_ich.h | 1
> > 3 files changed, 97 insertions(+), 12 deletions(-)
> Applied (finally) to my for-next branch, thanks.

Excellent, thank you!

--
Jean Delvare
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