[PATCH 0/8] iio: accel: bmc150: Add support for yoga's with dual accelerometers with an ACPI HID of DUAL250E

Andy Shevchenko andy.shevchenko at gmail.com
Sat May 22 20:03:02 CEST 2021


On Sat, May 22, 2021 at 9:00 PM Jonathan Cameron <jic23 at kernel.org> wrote:

> On Fri, 21 May 2021 19:14:10 +0200
> Hans de Goede <hdegoede at redhat.com> wrote:

> > Some 360 degree hinges (yoga) style 2-in-1 devices use 2 bmc150 accels
> > to allow the OS to determine the angle between the display and the base
> > of the device, so that the OS can determine if the 2-in-1 is in laptop
> > or in tablet-mode.
> >
> > We already support this setup on devices using a single ACPI node
> > with a HID of "BOSC0200" to describe both accelerometers. This patch
> > set extends this support to also support the same setup but then
> > using a HID of "DUAL250E".
> >
> > While testing this I found some crashes on rmmod, patches 1-2
> > fix those patches, patch 3 does some refactoring and patch 4
> > adds support for the "DUAL250E" HID.
> >
> > Unfortunately we need some more special handling though, which the
> > rest of the patches are for.
> >
> > On Windows both accelerometers are read (polled) by a special service
> > and this service calls a DSM (Device Specific Method), which in turn
> > translates the angles to one of laptop/tablet/tent/stand mode and then
> > notifies the EC about the new mode and the EC then enables or disables
> > the builtin keyboard and touchpad based in the mode.
> >
> > When the 2-in-1 is powered-on or resumed folded in tablet mode the
> > EC senses this independent of the DSM by using a HALL effect sensor
> > which senses that the keyboard has been folded away behind the display.
> >
> > At power-on or resume the EC disables the keyboard based on this and
> > the only way to get the keyboard to work after this is to call the
> > DSM to re-enable it (similar to how we also need to call a special
> > DSM in the kxcjk-1013.c accel driver to re-enable the keyboard).
> >
> > Patches 5-7 deal with the DSM mess and patch 8 adds labels to the
> > 2 accelerometers specifying which one is which.
>
> Given only thing I'm planning to do is tweak the line wrapping, I'm
> happy to pick this series up.
>
> The two fixes will slow things down a bit though as we should probably
> get those upstream this cycle.
>
> I'm going to leave this on list for a few days before I take anything
> though, to give others time to take a look.

You are, guys, too fast :-)

I have few (minor) comments on a few patches, in general they are okay!
So, after settling on the comments,
Reviewed-by: Andy Shevchenko <andy.shevchenko at gmail.com>
for the entire series.

Thanks, Hans, for doing this!

> One side note, cc list includes a few random choices... Seems you've
> accidentally included alsa people as well as IIO ones.


-- 
With Best Regards,
Andy Shevchenko


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