quantum/debounce/eager_pk.c

   1 /*
   2 Copyright 2017 Alex Ong<the.onga@gmail.com>
   3 This program is free software: you can redistribute it and/or modify
   4 it under the terms of the GNU General Public License as published by
   5 the Free Software Foundation, either version 2 of the License, or
   6 (at your option) any later version.
   7 This program is distributed in the hope that it will be useful,
   8 but WITHOUT ANY WARRANTY; without even the implied warranty of
   9 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10 GNU General Public License for more details.
  11 You should have received a copy of the GNU General Public License
  12 along with this program.  If not, see <http://www.gnu.org/licenses/>.
  13 */
  14
  15 /*
  16 Basic per-key algorithm. Uses an 8-bit counter per key.
  17 After pressing a key, it immediately changes state, and sets a counter.
  18 No further inputs are accepted until DEBOUNCE milliseconds have occurred.
  19 */
  20
  21 #include "matrix.h"
  22 #include "timer.h"
  23 #include "quantum.h"
  24 #include <stdlib.h>
  25
  26 #ifndef DEBOUNCE
  27 #  define DEBOUNCE 5
  28 #endif
  29
  30 #if (MATRIX_COLS <= 8)
  31 #  define ROW_SHIFTER ((uint8_t)1)
  32 #elif (MATRIX_COLS <= 16)
  33 #  define ROW_SHIFTER ((uint16_t)1)
  34 #elif (MATRIX_COLS <= 32)
  35 #  define ROW_SHIFTER ((uint32_t)1)
  36 #endif
  37
  38 #define debounce_counter_t uint8_t
  39
  40 static debounce_counter_t *debounce_counters;
  41 static bool                counters_need_update;
  42
  43 #define DEBOUNCE_ELAPSED 251
  44 #define MAX_DEBOUNCE (DEBOUNCE_ELAPSED - 1)
  45
  46 void update_debounce_counters(uint8_t num_rows, uint8_t current_time);
  47 void transfer_matrix_values(matrix_row_t raw[], matrix_row_t cooked[], uint8_t num_rows, uint8_t current_time);
  48
  49 // we use num_rows rather than MATRIX_ROWS to support split keyboards
  50 void debounce_init(uint8_t num_rows) {
  51   debounce_counters = (debounce_counter_t *)malloc(num_rows * MATRIX_COLS * sizeof(debounce_counter_t));
  52   int i             = 0;
  53   for (uint8_t r = 0; r < num_rows; r++) {
  54     for (uint8_t c = 0; c < MATRIX_COLS; c++) {
  55       debounce_counters[i++] = DEBOUNCE_ELAPSED;
  56     }
  57   }
  58 }
  59
  60 void debounce(matrix_row_t raw[], matrix_row_t cooked[], uint8_t num_rows, bool changed) {
  61   uint8_t current_time = timer_read() % MAX_DEBOUNCE;
  62   if (counters_need_update) {
  63     update_debounce_counters(num_rows, current_time);
  64   }
  65
  66   if (changed) {
  67     transfer_matrix_values(raw, cooked, num_rows, current_time);
  68   }
  69 }
  70
  71 // If the current time is > debounce counter, set the counter to enable input.
  72 void update_debounce_counters(uint8_t num_rows, uint8_t current_time) {
  73   counters_need_update                 = false;
  74   debounce_counter_t *debounce_pointer = debounce_counters;
  75   for (uint8_t row = 0; row < num_rows; row++) {
  76     for (uint8_t col = 0; col < MATRIX_COLS; col++) {
  77       if (*debounce_pointer != DEBOUNCE_ELAPSED) {
  78         if (TIMER_DIFF(current_time, *debounce_pointer, MAX_DEBOUNCE) >= DEBOUNCE) {
  79           *debounce_pointer = DEBOUNCE_ELAPSED;
  80         } else {
  81           counters_need_update = true;
  82         }
  83       }
  84       debounce_pointer++;
  85     }
  86   }
  87 }
  88
  89 // upload from raw_matrix to final matrix;
  90 void transfer_matrix_values(matrix_row_t raw[], matrix_row_t cooked[], uint8_t num_rows, uint8_t current_time) {
  91   debounce_counter_t *debounce_pointer = debounce_counters;
  92   for (uint8_t row = 0; row < num_rows; row++) {
  93     matrix_row_t delta        = raw[row] ^ cooked[row];
  94     matrix_row_t existing_row = cooked[row];
  95     for (uint8_t col = 0; col < MATRIX_COLS; col++) {
  96       matrix_row_t col_mask = (ROW_SHIFTER << col);
  97       if ((delta & col_mask) && *debounce_pointer == DEBOUNCE_ELAPSED) {
  98         *debounce_pointer    = current_time;
  99         counters_need_update = true;
 100         existing_row ^= col_mask;  // flip the bit.
 101       }
 102       debounce_pointer++;
 103     }
 104     cooked[row] = existing_row;
 105   }
 106 }
 107
 108 bool debounce_active(void) { return true; }