ads7846.h

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/* 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, 7873. */
    u16 vref_delay_usecs;   /* 0 for external vref; etc */
    u16 vref_mv;        /* external vref value, milliVolts
                     * ads7846: if 0, use internal vref */
    bool    keep_vref_on;       /* set to keep vref on for differential
                     * measurements as well */
    bool    swap_xy;        /* swap x and y axes */

    /* 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 gpio_pendown_debounce;  /* platform specific debounce time for
                     * the gpio_pendown */
    int (*get_pendown_state)(void);
    int (*filter_init)  (const 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);
    bool    wakeup;
    unsigned long irq_flags;
};