Skip to content
Commit 153cca9c authored by Hans de Goede's avatar Hans de Goede
Browse files

platform/x86: Add and use a dual_accel_detect() helper



Various 360 degree hinges (yoga) style 2-in-1 devices use 2 accelerometers
to allow the OS to determine the angle between the display and the base of
the device.

On Windows these are read by a special HingeAngleService process which
calls undocumented ACPI methods, to let the firmware know if the 2-in-1 is
in tablet- or laptop-mode. The firmware may use this to disable the kbd and
touchpad to avoid spurious input in tablet-mode as well as to report
SW_TABLET_MODE info to the OS.

Since Linux does not call these undocumented methods, the SW_TABLET_MODE
info reported by various pdx86 drivers is incorrect on these devices.

Before this commit the intel-hid and thinkpad_acpi code already had 2
hardcoded checks for ACPI hardware-ids of dual-accel sensors to avoid
reporting broken info.

And now we also have a bug-report about the same problem in the intel-vbtn
code. Since there are at least 3 different ACPI hardware-ids in play, add
a new dual_accel_detect() helper which checks for all 3, rather then
adding different hardware-ids to the drivers as bug-reports trickle in.
Having shared code which checks all known hardware-ids is esp. important
for the intel-hid and intel-vbtn drivers as these are generic drivers
which are used on a lot of devices.

The BOSC0200 hardware-id requires special handling, because often it is
used for a single-accelerometer setup. Only in a few cases it refers to
a dual-accel setup, in which case there will be 2 I2cSerialBus resources
in the device's resource-list, so the helper checks for this.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=209011
Reported-and-tested-by: default avatarJulius Lehmann <julius@devpi.de>
Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
Reviewed-by: default avatarAndy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20210729082134.6683-1-hdegoede@redhat.com
parent 2b2c66f6
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment