The sun4i resisitive touchscreen controller also comes with a built-in
temperature sensor. This commit adds support for it.
This commit also introduces a new "ts-attached" device-tree property,
when this is not set, the input part of the driver won't register. This way
the internal temperature sensor can be used to measure the SoC temperature
independent of there actually being a touchscreen attached to the controller.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Note the sun4i-ts controller is capable of detecting a second touch, but
when a second touch is present then the accuracy becomes so bad the
reported touch location is not useable.
The original android driver contains some complicated heuristics using the
aprox. distance between the 2 touches to see if the user is making a pinch
open / close movement, and then reports emulated multi-touch events around
the last touch coordinate (as the dual-touch coordinates are worthless).
These kinds of heuristics are just asking for trouble (and don't belong in
the kernel). So this driver offers straight forward, reliable single touch
functionality only.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
