Input: goodix - add pen support
Some Goodix touchscreens have support for a (Goodix) active pen, add
support for this. The info on how to detect when a pen is down and to
detect when the stylus buttons are pressed was lifted from the out
of tree Goodix driver with pen support written by Adya:
https://gitlab.com/AdyaAdya/goodix-touchscreen-linux-driver/
Since there is no way to tell if pen support is present, the registering
of the pen input_dev is delayed till the first pen event is detected.
This has been tested on a Trekstor Surftab duo W1, a Chuwi Hi13 and
a Cyberbook T116 tablet.
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=202161
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=204513
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20211207100754.31155-3-hdegoede@redhat.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>