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>
This commit is contained in:
Michael Hennerich 2012-07-06 10:44:19 -07:00 committed by Dmitry Torokhov
parent f2bb26b9b7
commit 6680884a44
2 changed files with 7 additions and 0 deletions

View file

@ -118,6 +118,7 @@ struct ad7879 {
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 @@ static int ad7879_report(struct ad7879 *ts)
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 @@ struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned int irq,
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);

View file

@ -12,6 +12,8 @@ struct ad7879_platform_data {
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.
*/