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

[Kent Gibson]

On Thu, May 02, 2024 at 01:11:06PM +0200, Stefan Wahren wrote:
> Hi Kent,
>
> Am 02.05.24 um 13:04 schrieb Kent Gibson:
> > 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 at 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?
> Yes, correct.
> > The name should better reflect that.
> Finding good and short names is hard, do you have a suggestion?
>

How about "persist_gpio_outputs"?

Cheers,
Kent.