Input: ad7879 - add option to correct xy axis
Sebastian Zenker reported that driver swaps x and y samples when the
touchscreen leads are connected in accordance with the datasheet
specification. Transposed axis can be typically corrected by touch
screen calibration however this bug also negatively influences touch
pressure measurements.
Add an option to correct x and y axis.
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Reported-and-tested-by: Sebastian Zenker <sebastian.zenker@gmx.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
diff --git a/drivers/input/touchscreen/ad7879.c b/drivers/input/touchscreen/ad7879.c
index e2482b4..e607092 100644
--- a/drivers/input/touchscreen/ad7879.c
+++ b/drivers/input/touchscreen/ad7879.c
@@ -118,6 +118,7 @@
unsigned int irq;
bool disabled; /* P: input->mutex */
bool suspended; /* P: input->mutex */
+ bool swap_xy;
u16 conversion_data[AD7879_NR_SENSE];
char phys[32];
u8 first_conversion_delay;
@@ -161,6 +162,9 @@
z1 = ts->conversion_data[AD7879_SEQ_Z1] & MAX_12BIT;
z2 = ts->conversion_data[AD7879_SEQ_Z2] & MAX_12BIT;
+ if (ts->swap_xy)
+ swap(x, y);
+
/*
* The samples processed here are already preprocessed by the AD7879.
* The preprocessing function consists of a median and an averaging
@@ -520,6 +524,7 @@
ts->dev = dev;
ts->input = input_dev;
ts->irq = irq;
+ ts->swap_xy = pdata->swap_xy;
setup_timer(&ts->timer, ad7879_timer, (unsigned long) ts);
diff --git a/include/linux/spi/ad7879.h b/include/linux/spi/ad7879.h
index 6334cee..58368be 100644
--- a/include/linux/spi/ad7879.h
+++ b/include/linux/spi/ad7879.h
@@ -12,6 +12,8 @@
u16 y_min, y_max;
u16 pressure_min, pressure_max;
+ bool swap_xy; /* swap x and y axes */
+
/* [0..255] 0=OFF Starts at 1=550us and goes
* all the way to 9.440ms in steps of 35us.
*/