android_kernel_motorola_sm6225/include/linux/spi/ads7846.h
David Brownell 7c6d0ee14c Input: ads7846 - simplify support of external vREF (and ads7843)
This updates the ads7846 driver to handle external vREF (required
on boards using ads7843 chips) without module parameters, and also
removes a needless variable with its associated bogus gcc warning.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2008-04-02 00:43:01 -04:00

52 lines
1.6 KiB
C

/* linux/spi/ads7846.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.
*/
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 */
u16 vref_mv; /* external vref value, milliVolts */
bool keep_vref_on; /* set to keep vref on for differential
* measurements as well */
/* Settling time of the analog signals; a function of Vcc and the
* capacitance on the X/Y drivers. If set to non-zero, two samples
* are taken with settle_delay us apart, and the second one is used.
* ~150 uSec with 0.01uF caps.
*/
u16 settle_delay_usecs;
/* If set to non-zero, after samples are taken this delay is applied
* and penirq is rechecked, to help avoid false events. This value
* is affected by the material used to build the touch layer.
*/
u16 penirq_recheck_delay_usecs;
u16 x_plate_ohms;
u16 y_plate_ohms;
u16 x_min, x_max;
u16 y_min, y_max;
u16 pressure_min, pressure_max;
u16 debounce_max; /* max number of additional readings
* per sample */
u16 debounce_tol; /* tolerance used for filtering */
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);
};