1 /* linux/spi/ads7846.h */
2 
3 /* Touchscreen characteristics vary between boards and models.  The
4  * platform_data for the device's "struct device" holds this information.
5  *
6  * It's OK if the min/max values are zero.
7  */
8 enum ads7846_filter {
9 	ADS7846_FILTER_OK,
10 	ADS7846_FILTER_REPEAT,
11 	ADS7846_FILTER_IGNORE,
12 };
13 
14 struct ads7846_platform_data {
15 	u16	model;			/* 7843, 7845, 7846, 7873. */
16 	u16	vref_delay_usecs;	/* 0 for external vref; etc */
17 	u16	vref_mv;		/* external vref value, milliVolts */
18 	bool	keep_vref_on;		/* set to keep vref on for differential
19 					 * measurements as well */
20 	bool	swap_xy;		/* swap x and y axes */
21 
22 	/* Settling time of the analog signals; a function of Vcc and the
23 	 * capacitance on the X/Y drivers.  If set to non-zero, two samples
24 	 * are taken with settle_delay us apart, and the second one is used.
25 	 * ~150 uSec with 0.01uF caps.
26 	 */
27 	u16	settle_delay_usecs;
28 
29 	/* If set to non-zero, after samples are taken this delay is applied
30 	 * and penirq is rechecked, to help avoid false events.  This value
31 	 * is affected by the material used to build the touch layer.
32 	 */
33 	u16	penirq_recheck_delay_usecs;
34 
35 	u16	x_plate_ohms;
36 	u16	y_plate_ohms;
37 
38 	u16	x_min, x_max;
39 	u16	y_min, y_max;
40 	u16	pressure_min, pressure_max;
41 
42 	u16	debounce_max;		/* max number of additional readings
43 					 * per sample */
44 	u16	debounce_tol;		/* tolerance used for filtering */
45 	u16	debounce_rep;		/* additional consecutive good readings
46 					 * required after the first two */
47 	int	gpio_pendown;		/* the GPIO used to decide the pendown
48 					 * state if get_pendown_state == NULL
49 					 */
50 	int	(*get_pendown_state)(void);
51 	int	(*filter_init)	(const struct ads7846_platform_data *pdata,
52 				 void **filter_data);
53 	int	(*filter)	(void *filter_data, int data_idx, int *val);
54 	void	(*filter_cleanup)(void *filter_data);
55 	void	(*wait_for_sync)(void);
56 	bool	wakeup;
57 	unsigned long irq_flags;
58 };
59 
60