1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* linux/spi/ads7846.h */
3 
4 /* Touchscreen characteristics vary between boards and models.  The
5  * platform_data for the device's "struct device" holds this information.
6  *
7  * It's OK if the min/max values are zero.
8  */
9 enum ads7846_filter {
10 	ADS7846_FILTER_OK,
11 	ADS7846_FILTER_REPEAT,
12 	ADS7846_FILTER_IGNORE,
13 };
14 
15 struct ads7846_platform_data {
16 	u16	model;			/* 7843, 7845, 7846, 7873. */
17 	u16	vref_delay_usecs;	/* 0 for external vref; etc */
18 	u16	vref_mv;		/* external vref value, milliVolts
19 					 * ads7846: if 0, use internal vref */
20 	bool	keep_vref_on;		/* set to keep vref on for differential
21 					 * measurements as well */
22 	bool	swap_xy;		/* swap x and y axes */
23 
24 	/* Settling time of the analog signals; a function of Vcc and the
25 	 * capacitance on the X/Y drivers.  If set to non-zero, two samples
26 	 * are taken with settle_delay us apart, and the second one is used.
27 	 * ~150 uSec with 0.01uF caps.
28 	 */
29 	u16	settle_delay_usecs;
30 
31 	/* If set to non-zero, after samples are taken this delay is applied
32 	 * and penirq is rechecked, to help avoid false events.  This value
33 	 * is affected by the material used to build the touch layer.
34 	 */
35 	u16	penirq_recheck_delay_usecs;
36 
37 	u16	x_plate_ohms;
38 	u16	y_plate_ohms;
39 
40 	u16	x_min, x_max;
41 	u16	y_min, y_max;
42 	u16	pressure_min, pressure_max;
43 
44 	u16	debounce_max;		/* max number of additional readings
45 					 * per sample */
46 	u16	debounce_tol;		/* tolerance used for filtering */
47 	u16	debounce_rep;		/* additional consecutive good readings
48 					 * required after the first two */
49 	int	gpio_pendown;		/* the GPIO used to decide the pendown
50 					 * state if get_pendown_state == NULL */
51 	int	gpio_pendown_debounce;	/* platform specific debounce time for
52 					 * the gpio_pendown */
53 	int	(*get_pendown_state)(void);
54 	int	(*filter_init)	(const struct ads7846_platform_data *pdata,
55 				 void **filter_data);
56 	int	(*filter)	(void *filter_data, int data_idx, int *val);
57 	void	(*filter_cleanup)(void *filter_data);
58 	void	(*wait_for_sync)(void);
59 	bool	wakeup;
60 	unsigned long irq_flags;
61 };
62 
63