keyboard/hhkb_rn42/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 static bool matrix_power = true;
  39
  40 // matrix state buffer(1:on, 0:off)
  41 static matrix_row_t *matrix;
  42 static matrix_row_t *matrix_prev;
  43 static matrix_row_t _matrix0[MATRIX_ROWS];
  44 static matrix_row_t _matrix1[MATRIX_ROWS];
  45
  46
  47 inline
  48 uint8_t matrix_rows(void)
  49 {
  50     return MATRIX_ROWS;
  51 }
  52
  53 inline
  54 uint8_t matrix_cols(void)
  55 {
  56     return MATRIX_COLS;
  57 }
  58
  59 void matrix_init(void)
  60 {
  61 #ifdef DEBUG
  62     debug_enable = true;
  63     debug_keyboard = true;
  64 #endif
  65
  66     KEY_INIT();
  67
  68     // initialize matrix state: all keys off
  69     for (uint8_t i=0; i < MATRIX_ROWS; i++) _matrix0[i] = 0x00;
  70     for (uint8_t i=0; i < MATRIX_ROWS; i++) _matrix1[i] = 0x00;
  71     matrix = _matrix0;
  72     matrix_prev = _matrix1;
  73 }
  74
  75 uint8_t matrix_scan(void)
  76 {
  77     uint8_t *tmp;
  78
  79     tmp = matrix_prev;
  80     matrix_prev = matrix;
  81     matrix = tmp;
  82
  83     matrix_power_up();
  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     matrix_power_down();
 140     return 1;
 141 }
 142
 143 bool matrix_is_modified(void)
 144 {
 145     for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
 146         if (matrix[i] != matrix_prev[i])
 147             return true;
 148     }
 149     return false;
 150 }
 151
 152 inline
 153 bool matrix_has_ghost(void)
 154 {
 155     return false;
 156 }
 157
 158 inline
 159 bool matrix_is_on(uint8_t row, uint8_t col)
 160 {
 161     return (matrix[row] & (1<<col));
 162 }
 163
 164 inline
 165 matrix_row_t matrix_get_row(uint8_t row)
 166 {
 167     return matrix[row];
 168 }
 169
 170 void matrix_print(void)
 171 {
 172     print("\nr/c 01234567\n");
 173     for (uint8_t row = 0; row < matrix_rows(); row++) {
 174         xprintf("%02X: %08b\n", row, bitrev(matrix_get_row(row)));
 175     }
 176 }
 177
 178 void matrix_power_up(void) {
 179     if (matrix_power) return;
 180     KEY_POWER_ON();
 181     matrix_power = true;
 182 }
 183 void matrix_power_down(void) {
 184     if (!matrix_power) return;
 185     // doesn't power save while USB connection is active
 186     if (USB_DeviceState == DEVICE_STATE_Configured) return;
 187     if (timer_elapsed32(matrix_last_modified) <= MATRIX_POWER_SAVE) return;
 188     KEY_POWER_OFF();
 189     suspend_power_down(WDTO_15MS);
 190     matrix_power = false;
 191 }