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

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