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 inline
  47 uint8_t matrix_rows(void)
  48 {
  49     return MATRIX_ROWS;
  50 }
  51
  52 inline
  53 uint8_t matrix_cols(void)
  54 {
  55     return MATRIX_COLS;
  56 }
  57
  58 void matrix_init(void)
  59 {
  60 #ifdef DEBUG
  61     debug_enable = true;
  62     debug_keyboard = true;
  63 #endif
  64
  65     KEY_INIT();
  66
  67     // initialize matrix state: all keys off
  68     for (uint8_t i=0; i < MATRIX_ROWS; i++) _matrix0[i] = 0x00;
  69     for (uint8_t i=0; i < MATRIX_ROWS; i++) _matrix1[i] = 0x00;
  70     matrix = _matrix0;
  71     matrix_prev = _matrix1;
  72 }
  73
  74 uint8_t matrix_scan(void)
  75 {
  76     uint8_t *tmp;
  77
  78     tmp = matrix_prev;
  79     matrix_prev = matrix;
  80     matrix = tmp;
  81
  82     // power on
  83     if (!KEY_POWER_STATE()) KEY_POWER_ON();
  84     for (uint8_t row = 0; row < MATRIX_ROWS; row++) {
  85         for (uint8_t col = 0; col < MATRIX_COLS; col++) {
  86             KEY_SELECT(row, col);
  87             _delay_us(5);
  88
  89             // Not sure this is needed. This just emulates HHKB controller's behaviour.
  90             if (matrix_prev[row] & (1<<col)) {
  91                 KEY_PREV_ON();
  92             }
  93             _delay_us(10);
  94
  95             // NOTE: KEY_STATE is valid only in 20us after KEY_ENABLE.
  96             // If V-USB interrupts in this section we could lose 40us or so
  97             // and would read invalid value from KEY_STATE.
  98             uint8_t last = TIMER_RAW;
  99
 100             KEY_ENABLE();
 101
 102             // Wait for KEY_STATE outputs its value.
 103             // 1us was ok on one HHKB, but not worked on another.
 104             // no   wait doesn't work on Teensy++ with pro(1us works)
 105             // no   wait does    work on tmk PCB(8MHz) with pro2
 106             // 1us  wait does    work on both of above
 107             // 1us  wait doesn't work on tmk(16MHz)
 108             // 5us  wait does    work on tmk(16MHz)
 109             // 5us  wait does    work on tmk(16MHz/2)
 110             // 5us  wait does    work on tmk(8MHz)
 111             // 10us wait does    work on Teensy++ with pro
 112             // 10us wait does    work on 328p+iwrap with pro
 113             // 10us wait doesn't work on tmk PCB(8MHz) with pro2(very lagged scan)
 114             _delay_us(5);
 115
 116             if (KEY_STATE()) {
 117                 matrix[row] &= ~(1<<col);
 118             } else {
 119                 matrix[row] |= (1<<col);
 120             }
 121
 122             // Ignore if this code region execution time elapses more than 20us.
 123             // MEMO: 20[us] * (TIMER_RAW_FREQ / 1000000)[count per us]
 124             // MEMO: then change above using this rule: a/(b/c) = a*1/(b/c) = a*(c/b)
 125             if (TIMER_DIFF_RAW(TIMER_RAW, last) > 20/(1000000/TIMER_RAW_FREQ)) {
 126                 matrix[row] = matrix_prev[row];
 127             }
 128
 129             _delay_us(5);
 130             KEY_PREV_OFF();
 131             KEY_UNABLE();
 132
 133             // NOTE: KEY_STATE keep its state in 20us after KEY_ENABLE.
 134             // This takes 25us or more to make sure KEY_STATE returns to idle state.
 135             _delay_us(75);
 136         }
 137         if (matrix[row] ^ matrix_prev[row]) matrix_last_modified = timer_read32();
 138     }
 139     // power off
 140     if (KEY_POWER_STATE() &&
 141             (USB_DeviceState == DEVICE_STATE_Suspended ||
 142              USB_DeviceState == DEVICE_STATE_Unattached ) &&
 143             timer_elapsed32(matrix_last_modified) > MATRIX_POWER_SAVE) {
 144         KEY_POWER_OFF();
 145         suspend_power_down();
 146     }
 147     return 1;
 148 }
 149
 150 bool matrix_is_modified(void)
 151 {
 152     for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
 153         if (matrix[i] != matrix_prev[i])
 154             return true;
 155     }
 156     return false;
 157 }
 158
 159 inline
 160 bool matrix_has_ghost(void)
 161 {
 162     return false;
 163 }
 164
 165 inline
 166 bool matrix_is_on(uint8_t row, uint8_t col)
 167 {
 168     return (matrix[row] & (1<<col));
 169 }
 170
 171 inline
 172 matrix_row_t matrix_get_row(uint8_t row)
 173 {
 174     return matrix[row];
 175 }
 176
 177 void matrix_print(void)
 178 {
 179     print("\nr/c 01234567\n");
 180     for (uint8_t row = 0; row < matrix_rows(); row++) {
 181         xprintf("%02X: %08b\n", row, bitrev(matrix_get_row(row)));
 182     }
 183 }
 184
 185 void matrix_power_up(void) {
 186     KEY_POWER_ON();
 187 }
 188 void matrix_power_down(void) {
 189     KEY_POWER_OFF();
 190 }