Re: [PATCH] pinctrl: bcm2835: Make pin freeing behavior configurable

Kent Gibson
2024-05-02T11:05:07Z

On Thu, May 02, 2024 at 12:22:07PM +0200, Stefan Wahren wrote:
> Am 19.04.24 um 22:40 schrieb Stefan Wahren:
> > Until now after a bcm2835 pin was freed its pinmux was set to GPIO_IN.
> > So in case it was configured as GPIO_OUT before the configured output
> > level also get lost. As long as GPIO sysfs was used this wasn't
> > actually a problem because the pins and their possible output level
> > were kept by sysfs.
> >
> > Since more and more Raspberry Pi users start using libgpiod they are
> > confused about this behavior. So make the pin freeing behavior of
> > GPIO_OUT configurable via module parameter. In case
> > pinctrl-bcm2835.strict_gpiod is set to 0, the output level is kept.
> >
> > This patch based on the downstream work of Phil Elwell.
> >
> > Link: https://github.com/raspberrypi/linux/pull/6117
> > Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
> > ---
> > drivers/pinctrl/bcm/pinctrl-bcm2835.c | 20 ++++++++++++++++----
> > 1 file changed, 16 insertions(+), 4 deletions(-)
> Gentle ping ...

I can't comment on the substance of the change as pinctrl is outside my
wheelhouse, but the "strict_gpiod" name could be better.
The point is to make GPIO outputs persist, right?
The name should better reflect that.

Cheers,
Kent.