Newer UC-Logic tablets, such as ones made by Huion have stopped
reporting in-range state, but they're otherwise worthy tablets. The
manufacturer was notified of the problem and promised to fix this in the
future. Meanwhile, detect pen coming in range, and emulate the reports
to the userspace, to make the tablets useable.
Signed-off-by: Nikolai Kondrashov <spbnick@gmail.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>