Input: ads7846 - debouncing and rudimentary sample filtering

Some touchscreens seem to oscillate heavily for a while after touching
the screen.  Implement support for sampling the screen until we get two
consecutive values that are close enough.

Signed-off-by: Imre Deak <imre.deak@nokia.com>
Signed-off-by: Juha Yrjola <juha.yrjola@nokia.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

1 files changed, 3 insertions, 0 deletions

diff --git a/include/linux/spi/ads7846.h b/include/linux/spi/ads7846.h
index 72261e0f2ac1..3f7664951256 100644
--- a/include/linux/spi/ads7846.h
+++ b/include/linux/spi/ads7846.h
@@ -14,5 +14,8 @@ struct ads7846_platform_data {
         u16     x_min, x_max;
         u16     y_min, y_max;
         u16     pressure_min, pressure_max;
+
+        u16     debounce_max;           /* max number of readings per sample */
+        u16     debounce_tol;           /* tolerance used for filtering */
 };