keyboard/hhkb/matrix.c

   1 /*
   2 Copyright 2011 Jun Wako <wakojun@gmail.com>
   3
   4 This program is free software: you can redistribute it and/or modify
   5 it under the terms of the GNU General Public License as published by
   6 the Free Software Foundation, either version 2 of the License, or
   7 (at your option) any later version.
   8
   9 This program is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 GNU General Public License for more details.
  13
  14 You should have received a copy of the GNU General Public License
  15 along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16 */
  17
  18 /*
  19  * scan matrix
  20  */
  21 #include <stdint.h>
  22 #include <stdbool.h>
  23 #include <util/delay.h>
  24 #include "print.h"
  25 #include "debug.h"
  26 #include "util.h"
  27 #include "timer.h"
  28 #include "matrix.h"
  29 #include "hhkb_avr.h"
  30
  31
  32 // matrix state buffer(1:on, 0:off)
  33 static matrix_row_t *matrix;
  34 static matrix_row_t *matrix_prev;
  35 static matrix_row_t _matrix0[MATRIX_ROWS];
  36 static matrix_row_t _matrix1[MATRIX_ROWS];
  37
  38
  39 inline
  40 uint8_t matrix_rows(void)
  41 {
  42     return MATRIX_ROWS;
  43 }
  44
  45 inline
  46 uint8_t matrix_cols(void)
  47 {
  48     return MATRIX_COLS;
  49 }
  50
  51 void matrix_init(void)
  52 {
  53 #ifdef DEBUG
  54     debug_enable = true;
  55     debug_keyboard = true;
  56 #endif
  57
  58     KEY_INIT();
  59
  60     // initialize matrix state: all keys off
  61     for (uint8_t i=0; i < MATRIX_ROWS; i++) _matrix0[i] = 0x00;
  62     for (uint8_t i=0; i < MATRIX_ROWS; i++) _matrix1[i] = 0x00;
  63     matrix = _matrix0;
  64     matrix_prev = _matrix1;
  65 }
  66
  67 uint8_t matrix_scan(void)
  68 {
  69     uint8_t *tmp;
  70
  71     tmp = matrix_prev;
  72     matrix_prev = matrix;
  73     matrix = tmp;
  74
  75     KEY_POWER_ON();
  76     for (uint8_t row = 0; row < MATRIX_ROWS; row++) {
  77         for (uint8_t col = 0; col < MATRIX_COLS; col++) {
  78             KEY_SELECT(row, col);
  79             _delay_us(5);
  80
  81             // Not sure this is needed. This just emulates HHKB controller's behaviour.
  82             if (matrix_prev[row] & (1<<col)) {
  83                 KEY_PREV_ON();
  84             }
  85             _delay_us(10);
  86
  87             // NOTE: KEY_STATE is valid only in 20us after KEY_ENABLE.
  88             // If V-USB interrupts in this section we could lose 40us or so
  89             // and would read invalid value from KEY_STATE.
  90             uint8_t last = TIMER_RAW;
  91
  92             KEY_ENABLE();
  93
  94             // Wait for KEY_STATE outputs its value.
  95             // 1us was ok on one HHKB, but not worked on another.
  96             // no   wait doesn't work on Teensy++ with pro(1us works)
  97             // no   wait does    work on tmk PCB(8MHz) with pro2
  98             // 1us  wait does    work on both of above
  99             // 1us  wait doesn't work on tmk(16MHz)
 100             // 5us  wait does    work on tmk(16MHz)
 101             // 5us  wait does    work on tmk(16MHz/2)
 102             // 5us  wait does    work on tmk(8MHz)
 103             // 10us wait does    work on Teensy++ with pro
 104             // 10us wait does    work on 328p+iwrap with pro
 105             // 10us wait doesn't work on tmk PCB(8MHz) with pro2(very lagged scan)
 106             _delay_us(5);
 107
 108             if (KEY_STATE()) {
 109                 matrix[row] &= ~(1<<col);
 110             } else {
 111                 matrix[row] |= (1<<col);
 112             }
 113
 114             // Ignore if this code region execution time elapses more than 20us.
 115             // MEMO: 20[us] * (TIMER_RAW_FREQ / 1000000)[count per us]
 116             // MEMO: then change above using this rule: a/(b/c) = a*1/(b/c) = a*(c/b)
 117             if (TIMER_DIFF_RAW(TIMER_RAW, last) > 20/(1000000/TIMER_RAW_FREQ)) {
 118                 matrix[row] = matrix_prev[row];
 119             }
 120
 121             _delay_us(5);
 122             KEY_PREV_OFF();
 123             KEY_UNABLE();
 124
 125             // NOTE: KEY_STATE keep its state in 20us after KEY_ENABLE.
 126             // This takes 25us or more to make sure KEY_STATE returns to idle state.
 127             _delay_us(75);
 128         }
 129     }
 130     KEY_POWER_OFF();
 131     return 1;
 132 }
 133
 134 bool matrix_is_modified(void)
 135 {
 136     for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
 137         if (matrix[i] != matrix_prev[i])
 138             return true;
 139     }
 140     return false;
 141 }
 142
 143 inline
 144 bool matrix_has_ghost(void)
 145 {
 146     return false;
 147 }
 148
 149 inline
 150 bool matrix_is_on(uint8_t row, uint8_t col)
 151 {
 152     return (matrix[row] & (1<<col));
 153 }
 154
 155 inline
 156 matrix_row_t matrix_get_row(uint8_t row)
 157 {
 158     return matrix[row];
 159 }
 160
 161 void matrix_print(void)
 162 {
 163     print("\nr/c 01234567\n");
 164     for (uint8_t row = 0; row < matrix_rows(); row++) {
 165         xprintf("%02X: %08b\n", row, bitrev(matrix_get_row(row)));
 166     }
 167 }