This patch refactors the Mainstone accelerated touch code a little and
adds support for interrupt driven touchscreen on Palm LifeDrive, TX and
Tungsten T5.
Signed-off-by: Marek Vasut <marek.vasut@gmail.com> Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>