kernel-fxtec-pro1x/include/linux/spi/ads7846.h
Eric Miao fd746d540a Input: ads7846 - introduce platform specific way to synchronize sampling
Noises can be introduced when LCD signals are being driven, some platforms
provide a signal to assist the synchronization of this sampling procedure.

Signed-off-by: Eric Miao <eric.miao@marvell.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2009-04-11 17:09:15 -07:00

56 lines
1.8 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 gpio_pendown; /* the GPIO used to decide the pendown
* state if get_pendown_state == NULL
*/
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);
void (*wait_for_sync)(void);
};