Input: add support for touchscreen on W90P910 ARM platform

The touchscreen works in two modes, wait trigger mode and auto-semi
mode. The device starts in wait trigger mode and waits until pressure
is detected, then device sets WT_INT bit and raises an interrupt.
The driver should put the device into auto-semi mode and prepare for
reading first X and then Y coordinates. When coordinate data is ready
the driver sets ADC_INT bit and raises interrupt again.

[dtor@mail.ru: various cleanups]
Signed-off-by: Wan ZongShun <mcuos.com@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 1b4a167..72e2712 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -490,4 +490,12 @@
 	  To compile this driver as a module, choose M here: the
 	  module will be called tsc2007.
 
+config TOUCHSCREEN_W90X900
+	tristate "W90P910 touchscreen driver"
+	help
+	  Say Y here if you have a W90P910 based touchscreen.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called w90p910_ts.
+
 endif