include/linux/input/matrix_keypad.h

   1 #ifndef _MATRIX_KEYPAD_H
   2 #define _MATRIX_KEYPAD_H
   3
   4 #include <linux/types.h>
   5 #include <linux/input.h>
   6
   7 #define MATRIX_MAX_ROWS         16
   8 #define MATRIX_MAX_COLS         16
   9
  10 #define KEY(row, col, val)      ((((row) & (MATRIX_MAX_ROWS - 1)) << 24) |\
  11                                  (((col) & (MATRIX_MAX_COLS - 1)) << 16) |\
  12                                  (val & 0xffff))
  13
  14 #define KEY_ROW(k)              (((k) >> 24) & 0xff)
  15 #define KEY_COL(k)              (((k) >> 16) & 0xff)
  16 #define KEY_VAL(k)              ((k) & 0xffff)
  17
  18 #define MATRIX_SCAN_CODE(row, col, row_shift)   (((row) << (row_shift)) + (col))
  19
  20 /**
  21  * struct matrix_keymap_data - keymap for matrix keyboards
  22  * @keymap: pointer to array of uint32 values encoded with KEY() macro
  23  *      representing keymap
  24  * @keymap_size: number of entries (initialized) in this keymap
  25  *
  26  * This structure is supposed to be used by platform code to supply
  27  * keymaps to drivers that implement matrix-like keypads/keyboards.
  28  */
  29 struct matrix_keymap_data {
  30         const uint32_t *keymap;
  31         unsigned int    keymap_size;
  32 };
  33
  34 /**
  35  * struct matrix_keypad_platform_data - platform-dependent keypad data
  36  * @keymap_data: pointer to &matrix_keymap_data
  37  * @row_gpios: pointer to array of gpio numbers representing rows
  38  * @col_gpios: pointer to array of gpio numbers reporesenting colums
  39  * @num_row_gpios: actual number of row gpios used by device
  40  * @num_col_gpios: actual number of col gpios used by device
  41  * @col_scan_delay_us: delay, measured in microseconds, that is
  42  *      needed before we can keypad after activating column gpio
  43  * @debounce_ms: debounce interval in milliseconds
  44  *
  45  * This structure represents platform-specific data that use used by
  46  * matrix_keypad driver to perform proper initialization.
  47  */
  48 struct matrix_keypad_platform_data {
  49         const struct matrix_keymap_data *keymap_data;
  50
  51         const unsigned int *row_gpios;
  52         const unsigned int *col_gpios;
  53
  54         unsigned int    num_row_gpios;
  55         unsigned int    num_col_gpios;
  56
  57         unsigned int    col_scan_delay_us;
  58
  59         /* key debounce interval in milli-second */
  60         unsigned int    debounce_ms;
  61
  62         bool            active_low;
  63         bool            wakeup;
  64 };
  65
  66 /**
  67  * matrix_keypad_build_keymap - convert platform keymap into matrix keymap
  68  * @keymap_data: keymap supplied by the platform code
  69  * @row_shift: number of bits to shift row value by to advance to the next
  70  * line in the keymap
  71  * @keymap: expanded version of keymap that is suitable for use by
  72  * matrix keyboad driver
  73  * @keybit: pointer to bitmap of keys supported by input device
  74  *
  75  * This function converts platform keymap (encoded with KEY() macro) into
  76  * an array of keycodes that is suitable for using in a standard matrix
  77  * keyboard driver that uses row and col as indices.
  78  */
  79 static inline void
  80 matrix_keypad_build_keymap(const struct matrix_keymap_data *keymap_data,
  81                            unsigned int row_shift,
  82                            unsigned short *keymap, unsigned long *keybit)
  83 {
  84         int i;
  85
  86         for (i = 0; i < keymap_data->keymap_size; i++) {
  87                 unsigned int key = keymap_data->keymap[i];
  88                 unsigned int row = KEY_ROW(key);
  89                 unsigned int col = KEY_COL(key);
  90                 unsigned short code = KEY_VAL(key);
  91
  92                 keymap[MATRIX_SCAN_CODE(row, col, row_shift)] = code;
  93                 __set_bit(code, keybit);
  94         }
  95         __clear_bit(KEY_RESERVED, keybit);
  96 }
  97
  98 #endif /* _MATRIX_KEYPAD_H */