Re: [PATCH 0/4] add support for bias pull-disable

[Bartosz Golaszewski <brgl@xxxxxxxx>]

On Tue, Jul 19, 2022 at 10:51 AM Nuno Sá <noname.nuno@xxxxxxxxx> wrote:
>
> On Tue, 2022-07-19 at 10:25 +0200, Bartosz Golaszewski wrote:
> > On Wed, Jul 13, 2022 at 3:13 PM Nuno Sá <nuno.sa@xxxxxxxxxx> wrote:
> > >
> > > The gpio core looks at 'FLAG_BIAS_DISABLE' in preparation of
> > > calling the
> > > gpiochip 'set_config()' hook. However, AFAICT, there's no way that
> > > this
> > > flag is set because there's no support for it in firwmare code.
> > > Moreover,
> > > in 'gpiod_configure_flags()', only pull-ups and pull-downs are
> > > being
> > > handled.
> > >
> > > On top of this, there are some users that are looking at
> > > 'PIN_CONFIG_BIAS_DISABLE' in the 'set_config()' hook. So, unless
> > > I'm
> > > missing something, it looks like this was never working for these
> > > chips.
> > >
> > > Note that the ACPI case is only compiled tested. At first glance,
> > > it seems
> > > the current patch is enough but i'm not really sure...
> > >
> > > As a side note, this came to my attention during this patchset [1]
> > > (and, ofr OF,  was tested with it).
> > >
> > > [1]:
> > > https://lore.kernel.org/linux-input/20220708093448.42617-5-nuno.sa@xxxxxxxxxx/
> > >
> > > Nuno Sá (4):
> > >   gpiolib: add support for bias pull disable
> > >   gpiolib: of: support bias pull disable
> > >   gpiolib: acpi: support bias pull disable
> > >   dt-bindings: gpio: add pull-disable flag
> > >
> > >  drivers/gpio/gpiolib-acpi.c     | 3 +++
> > >  drivers/gpio/gpiolib-of.c       | 7 +++++++
> > >  drivers/gpio/gpiolib.c          | 8 ++++++--
> > >  include/dt-bindings/gpio/gpio.h | 3 +++
> > >  include/linux/gpio/machine.h    | 1 +
> > >  include/linux/of_gpio.h         | 1 +
> > >  6 files changed, 21 insertions(+), 2 deletions(-)
> > >
> > > --
> > > 2.37.0
> > >
> >
> > Series applied, thanks!
>
> Hi Bart,
>
> I was actually planning to spin a v2 with your suggestion for the
> naming of the new define... Did you changed it while applying or should
> I still send it? Or (last option), we just leave it like this :)?
>
> - Nuno Sá

Yeah, I'm alright with it how it is after a second though: uAPI uses
the BIAS_PULL_UP/DOWN/DISABLE notation while the in-kernel API uses
the same scheme but without the BIAS prefix. Unless you want to change
something else - let's keep it as you first submitted it.

Bart