Input: ads7846 - pluggable filtering logic

Some LCDs like the LS041Y3 require a customized filtering
logic for reliable readings, so make the filtering function
replacable through platform specific hooks.

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

1 files changed, 10 insertions, 0 deletions

diff --git a/include/linux/spi/ads7846.h b/include/linux/spi/ads7846.h
index adb3dafd33e9..1663f940ca11 100644
--- a/include/linux/spi/ads7846.h
+++ b/include/linux/spi/ads7846.h
@@ -5,6 +5,12 @@
  *
  * It's OK if the min/max values are zero.
  */
+enum ads7846_filter {
+        ADS7846_FILTER_OK,
+        ADS7846_FILTER_REPEAT,
+        ADS7846_FILTER_IGNORE,
+};
+
 struct ads7846_platform_data {
         u16     model;                  /* 7843, 7845, 7846. */
         u16     vref_delay_usecs;       /* 0 for external vref; etc */
@@ -21,5 +27,9 @@ struct ads7846_platform_data {
         u16     debounce_rep;           /* additional consecutive good readings
                                          * required after the first two */
         int     (*get_pendown_state)(void);
+        int     (*filter_init)  (struct ads7846_platform_data *pdata,
+                                 void **filter_data);
+        int     (*filter)       (void *filter_data, int data_idx, int *val);
+        void    (*filter_cleanup)(void *filter_data);
 };