Input: ad7877 - filter events where pressure is beyond the maximum

Suppress events where pressure > pressure_max.
These events come typically along with inaccurate X and Y samples.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/input/touchscreen/ad7877.c b/drivers/input/touchscreen/ad7877.c
index 96c0a0d4b69c..b7de78e82737 100644
--- a/drivers/input/touchscreen/ad7877.c
+++ b/drivers/input/touchscreen/ad7877.c
@@ -360,6 +360,13 @@ static int ad7877_rx(struct ad7877 *ts)
                 Rt /= z1;
                 Rt = (Rt + 2047) >> 12;
 
+                /*
+                 * Sample found inconsistent, pressure is beyond
+                 * the maximum. Don't report it to user space.
+                 */
+                if (Rt > ts->pressure_max)
+                        return -EINVAL;
+
                 if (!timer_pending(&ts->timer))
                         input_report_key(input_dev, BTN_TOUCH, 1);