remarkable-linux/include/linux/spi/ad7879.h
Michael Hennerich 6680884a44 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>
2012-07-06 19:12:26 -07:00

42 lines
1.1 KiB
C

/* linux/spi/ad7879.h */
/* Touchscreen characteristics vary between boards and models. The
* platform_data for the device's "struct device" holds this information.
*
* It's OK if the min/max values are zero.
*/
struct ad7879_platform_data {
u16 model; /* 7879 */
u16 x_plate_ohms;
u16 x_min, x_max;
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.
*/
u8 pen_down_acc_interval;
/* [0..15] Starts at 0=128us and goes all the
* way to 4.096ms in steps of 128us.
*/
u8 first_conversion_delay;
/* [0..3] 0 = 2us, 1 = 4us, 2 = 8us, 3 = 16us */
u8 acquisition_time;
/* [0..3] Average X middle samples 0 = 2, 1 = 4, 2 = 8, 3 = 16 */
u8 averaging;
/* [0..3] Perform X measurements 0 = OFF,
* 1 = 4, 2 = 8, 3 = 16 (median > averaging)
*/
u8 median;
/* 1 = AUX/VBAT/GPIO export GPIO to gpiolib
* requires CONFIG_GPIOLIB
*/
bool gpio_export;
/* identifies the first GPIO number handled by this chip;
* or, if negative, requests dynamic ID allocation.
*/
s32 gpio_base;
};