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 #include <avr/wdt.h>
  31 #include "suspend.h"
  32 #include "lufa.h"
  33
  34
  35 // matrix power saving
  36 #define MATRIX_POWER_SAVE       10000
  37 static uint32_t matrix_last_modified = 0;
  38
  39 // matrix state buffer(1:on, 0:off)
  40 static matrix_row_t *matrix;
  41 static matrix_row_t *matrix_prev;
  42 static matrix_row_t _matrix0[MATRIX_ROWS];
  43 static matrix_row_t _matrix1[MATRIX_ROWS];
  44
  45
  46 void matrix_init(void)
  47 {
  48 #ifdef DEBUG
  49     debug_enable = true;
  50     debug_keyboard = true;
  51 #endif
  52
  53     KEY_INIT();
  54
  55     // initialize matrix state: all keys off
  56     for (uint8_t i=0; i < MATRIX_ROWS; i++) _matrix0[i] = 0x00;
  57     for (uint8_t i=0; i < MATRIX_ROWS; i++) _matrix1[i] = 0x00;
  58     matrix = _matrix0;
  59     matrix_prev = _matrix1;
  60 }
  61
  62 uint8_t matrix_scan(void)
  63 {
  64     uint8_t *tmp;
  65
  66     tmp = matrix_prev;
  67     matrix_prev = matrix;
  68     matrix = tmp;
  69
  70     // power on
  71     if (!KEY_POWER_STATE()) KEY_POWER_ON();
  72     for (uint8_t row = 0; row < MATRIX_ROWS; row++) {
  73         for (uint8_t col = 0; col < MATRIX_COLS; col++) {
  74             KEY_SELECT(row, col);
  75             _delay_us(5);
  76
  77             // Not sure this is needed. This just emulates HHKB controller's behaviour.
  78             if (matrix_prev[row] & (1<<col)) {
  79                 KEY_PREV_ON();
  80             }
  81             _delay_us(10);
  82
  83             // NOTE: KEY_STATE is valid only in 20us after KEY_ENABLE.
  84             // If V-USB interrupts in this section we could lose 40us or so
  85             // and would read invalid value from KEY_STATE.
  86             uint8_t last = TIMER_RAW;
  87
  88             KEY_ENABLE();
  89
  90             // Wait for KEY_STATE outputs its value.
  91             // 1us was ok on one HHKB, but not worked on another.
  92             // no   wait doesn't work on Teensy++ with pro(1us works)
  93             // no   wait does    work on tmk PCB(8MHz) with pro2
  94             // 1us  wait does    work on both of above
  95             // 1us  wait doesn't work on tmk(16MHz)
  96             // 5us  wait does    work on tmk(16MHz)
  97             // 5us  wait does    work on tmk(16MHz/2)
  98             // 5us  wait does    work on tmk(8MHz)
  99             // 10us wait does    work on Teensy++ with pro
 100             // 10us wait does    work on 328p+iwrap with pro
 101             // 10us wait doesn't work on tmk PCB(8MHz) with pro2(very lagged scan)
 102             _delay_us(5);
 103
 104             if (KEY_STATE()) {
 105                 matrix[row] &= ~(1<<col);
 106             } else {
 107                 matrix[row] |= (1<<col);
 108             }
 109
 110             // Ignore if this code region execution time elapses more than 20us.
 111             // MEMO: 20[us] * (TIMER_RAW_FREQ / 1000000)[count per us]
 112             // MEMO: then change above using this rule: a/(b/c) = a*1/(b/c) = a*(c/b)
 113             if (TIMER_DIFF_RAW(TIMER_RAW, last) > 20/(1000000/TIMER_RAW_FREQ)) {
 114                 matrix[row] = matrix_prev[row];
 115             }
 116
 117             _delay_us(5);
 118             KEY_PREV_OFF();
 119             KEY_UNABLE();
 120
 121             // NOTE: KEY_STATE keep its state in 20us after KEY_ENABLE.
 122             // This takes 25us or more to make sure KEY_STATE returns to idle state.
 123 #ifdef HHKB_JP
 124             // Looks like JP needs faster scan due to its twice larger matrix
 125             // or it can drop keys in fast key typing
 126             _delay_us(30);
 127 #else
 128             _delay_us(75);
 129 #endif
 130         }
 131         if (matrix[row] ^ matrix_prev[row]) matrix_last_modified = timer_read32();
 132     }
 133     // power off
 134     if (KEY_POWER_STATE() &&
 135             (USB_DeviceState == DEVICE_STATE_Suspended ||
 136              USB_DeviceState == DEVICE_STATE_Unattached ) &&
 137             timer_elapsed32(matrix_last_modified) > MATRIX_POWER_SAVE) {
 138         KEY_POWER_OFF();
 139         suspend_power_down();
 140     }
 141     return 1;
 142 }
 143
 144 inline
 145 matrix_row_t matrix_get_row(uint8_t row)
 146 {
 147     return matrix[row];
 148 }
 149
 150 void matrix_power_up(void) {
 151     KEY_POWER_ON();
 152 }
 153 void matrix_power_down(void) {
 154     KEY_POWER_OFF();
 155 }