LXR linux/include/linux/spi/ads7846.h

   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 */
   9enum ads7846_filter {
  10        ADS7846_FILTER_OK,
  11        ADS7846_FILTER_REPEAT,
  12        ADS7846_FILTER_IGNORE,
  13};
  14
  15struct 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