Re: [PATCH] pinctrl: cherryview: Configure HiZ pins to be input when requested as GPIOs

From: Mika Westerberg
Date: Wed Feb 04 2015 - 10:38:10 EST


On Wed, Feb 04, 2015 at 10:01:49AM +0100, Linus Walleij wrote:
> On Thu, Jan 29, 2015 at 11:44 AM, Mika Westerberg
> <mika.westerberg@xxxxxxxxxxxxxxx> wrote:
>
> > If the pin is in HiZ mode when it is requested as GPIO its value cannot be
> > read (it always returns 0). In order to cope with the Linux GPIO subsystem
> > where we do not have such state at all, turn the pin to be input instead.
> >
> > Reported-by: Jerome Blin <jerome.blin@xxxxxxxxx>
> > Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
>
> Patch applied.

Thanks.

> Since putting a pin into GPIO mode start poking around in essentially pin
> control registers, we may need to revisit the issue of the pin control subsystem
> not denying simultaneous use of a pin for a device muxing and GPIO.
> Maybe the "strict" setting forcing a pin to be either one or the other on
> a per-driver basis would enforce a better policy on this driver (and some
> others).

Yes, something like that sounds reasonable.
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