Re: [PATCH] Input: cros_ec_keyb: Add support for a front proximity switch

[Doug Anderson <dianders@chromium.org>]

Hi,

On Wed, Jan 6, 2021 at 6:22 PM Dmitry Torokhov
<dmitry.torokhov@gmail.com> wrote:
>
> Hi Doug, Stephen,
>
> On Wed, Jan 06, 2021 at 05:16:10PM -0800, Doug Anderson wrote:
> > Hi,
> >
> > On Fri, Dec 4, 2020 at 4:48 PM Stephen Boyd <swboyd@chromium.org> wrote:
> > >
> > > Some cros ECs support a front proximity MKBP event via
> > > 'EC_MKBP_FRONT_PROXIMITY'. Map this to the 'SW_FRONT_PROXIMITY' input
> > > event code so it can be reported up to userspace.
> > >
> > > Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> > > Cc: Benson Leung <bleung@chromium.org>
> > > Cc: Guenter Roeck <groeck@chromium.org>
> > > Signed-off-by: Stephen Boyd <swboyd@chromium.org>
> > > ---
> > >  drivers/input/keyboard/cros_ec_keyb.c          | 5 +++++
> > >  include/linux/platform_data/cros_ec_commands.h | 1 +
> > >  2 files changed, 6 insertions(+)
> >
> > This seems really straightforward.
> >
> > Reviewed-by: Douglas Anderson <dianders@chromium.org>
> >
> > Given that it touches a header file owned by the Chrome OS maintainers
> > and a driver owned by input, how should it land?  One maintainer Acks
> > and the other lands?
>
> Sorry about missing this one, however the "front proximity" switch has
> been introduced for the benefit of phone devices, to be emitted when a
> device is raised to user's ear, and I do not think we should be using
> this here.
>
> We have just recently had similar discussion with regard to palm- and
> lap-mode sensors and whether they should be reported over input or IIO
> as true proximity sensors:
>
> https://lore.kernel.org/linux-iio/9f9b0ff6-3bf1-63c4-eb36-901cecd7c4d9@redhat.com/
>
> Based on what we are doing for other Chrome OS devices that expose
> proximity sensors (for example trogdor) we have decided that we all
> should be using IIO as it will allow not only on/off, but true proximity
> reporting with potential of implementing smarter policies by userspace.
>
> Because of that we should do the same here and export this as IIO
> proximity sensor as well.

For devices with a true proximity sensor that's exactly what we're
doing.  I've only been involved in the periphery of the discussion,
but as I understand it there are some models of laptop for which we
don't have a true proximity sensor.  On these devices, the EC is in
charge of deciding about proximity based on a number of factors.
Unfortunately, it's not a public bug, but since you're at Google I
think you can look at b/168714440 to find the relevant discussion.
These are the models that Stephen is trying to add support for here...

-Doug