[PATCH] gpio: vt8500: Export dedicated GPIO before multifunction pins.

Tony Prisk linux at prisktech.co.nz
Thu Jan 10 13:44:33 EST 2013

On Thu, 2013-01-10 at 11:49 +0100, Linus Walleij wrote:
> On Sun, Dec 30, 2012 at 9:29 PM, Tony Prisk <linux at prisktech.co.nz> wrote:
> > The vendor does not provide numbering for gpio pins. Vendor source
> > exports dedicated gpio pins first, followed by multifunction pins.
> > As this is what end users expect, this patch changes vt8500 and wm8505
> > to do the same.
> >
> > Signed-off-by: Tony Prisk <linux at prisktech.co.nz>
> So how many existing userspace applications does this patch
> break? Has this system been widely deployed so a kernel
> upgrade will cause problems for people?
> But applied anyway, unless someone screams about it real
> soon now. That seems to be the only way to get people to tell
> us about their use cases.
> Could you consider adding names to the exported GPIO pins
> on the vt8500 series please? Then userspace can atleast
> try to locate the right pin.
> Yours,
> Linus Walleij

In terms of userspace apps, my best guess would be 'I dunno'. This was
requested by the only end-user to ask a question since mainline support
was added - He couldn't find the external GPIO's in the 200+ that were

This also makes all the platforms the same now - external GPIO's are now
exported first (0..x) which is better in the long term for userspace.

The names is a bit of a problem, but I will try my best. We have limited
datasheets etc from the vendor, so knowing what things do is a bit of a
mystery sometimes.

Tony P

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