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 <avr/io.h>
  24 #include <avr/interrupt.h>
  25 #include <util/delay.h>
  26 #include "print.h"
  27 #include "debug.h"
  28 #include "util.h"
  29 #include "timer.h"
  30 #include "matrix.h"
  31
  32
  33 // Timer resolution check
  34 #if (1000000/TIMER_RAW_FREQ > 20)
  35 #   error "Timer resolution(>20us) is not enough for HHKB matrix scan tweak on V-USB."
  36 #endif
  37
  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 // Matrix I/O ports
  47 //
  48 // row:     HC4051[A,B,C]  selects scan row0-7
  49 // col:     LS145[A,B,C,D] selects scan col0-7 and enable(D)
  50 // key:     on: 0/off: 1
  51 // prev:    unknown: output previous key state(negated)?
  52
  53 #if defined(__AVR_AT90USB1286__)
  54 // Ports for Teensy++
  55 // row:     PB0-2
  56 // col:     PB3-5,6
  57 // key:     PE6(pull-uped)
  58 // prev:    PE7
  59 #define KEY_INIT()              do {    \
  60     DDRB |= 0x7F;                       \
  61     DDRE |=  (1<<7);                    \
  62     DDRE &= ~(1<<6);                    \
  63     PORTE |= (1<<6);                    \
  64 } while (0)
  65 #define KEY_SELECT(ROW, COL)    (PORTB = (PORTB & 0xC0) |       \
  66                                          (((COL) & 0x07)<<3) |    \
  67                                          ((ROW) & 0x07))
  68 #define KEY_ENABLE()            (PORTB &= ~(1<<6))
  69 #define KEY_UNABLE()            (PORTB |=  (1<<6))
  70 #define KEY_STATE()             (PINE & (1<<6))
  71 #define KEY_PREV_ON()           (PORTE |=  (1<<7))
  72 #define KEY_PREV_OFF()          (PORTE &= ~(1<<7))
  73 #define KEY_POWER_ON()
  74 #define KEY_POWER_OFF()
  75
  76 #elif defined(__AVR_ATmega328P__)
  77 // Ports for V-USB
  78 // key:     PB0(pull-uped)
  79 // prev:    PB1
  80 // row:     PB2-4
  81 // col:     PC0-2,3
  82 // power:   PB5(Low:on/Hi-z:off)
  83 #define KEY_INIT()              do {    \
  84     DDRB  |= 0x3E;                      \
  85     DDRB  &= ~(1<<0);                   \
  86     PORTB |= 1<<0;                      \
  87     DDRC  |= 0x0F;                      \
  88     KEY_UNABLE();                       \
  89     KEY_PREV_OFF();                     \
  90 } while (0)
  91 #define KEY_SELECT(ROW, COL)    do {    \
  92     PORTB = (PORTB & 0xE3) | ((ROW) & 0x07)<<2; \
  93     PORTC = (PORTC & 0xF8) | ((COL) & 0x07);    \
  94 } while (0)
  95 #define KEY_ENABLE()            (PORTC &= ~(1<<3))
  96 #define KEY_UNABLE()            (PORTC |=  (1<<3))
  97 #define KEY_STATE()             (PINB & (1<<0))
  98 #define KEY_PREV_ON()           (PORTB |=  (1<<1))
  99 #define KEY_PREV_OFF()          (PORTB &= ~(1<<1))
 100 // Power supply switching
 101 #define KEY_POWER_ON()          do {    \
 102     KEY_INIT();                         \
 103     PORTB &= ~(1<<5);                   \
 104     _delay_ms(1);                       \
 105 } while (0)
 106 #define KEY_POWER_OFF()         do {    \
 107     DDRB  &= ~0x3F;                     \
 108     PORTB &= ~0x3F;                     \
 109     DDRC  &= ~0x0F;                     \
 110     PORTC &= ~0x0F;                     \
 111 } while (0)
 112
 113 #else
 114 #   error "define code for matrix scan"
 115 #endif
 116
 117
 118 inline
 119 uint8_t matrix_rows(void)
 120 {
 121     return MATRIX_ROWS;
 122 }
 123
 124 inline
 125 uint8_t matrix_cols(void)
 126 {
 127     return MATRIX_COLS;
 128 }
 129
 130 void matrix_init(void)
 131 {
 132 #ifdef DEBUG
 133     print_enable = true;
 134     debug_enable = true;
 135     debug_keyboard = true;
 136 #endif
 137
 138     KEY_INIT();
 139
 140     // initialize matrix state: all keys off
 141     for (uint8_t i=0; i < MATRIX_ROWS; i++) _matrix0[i] = 0x00;
 142     for (uint8_t i=0; i < MATRIX_ROWS; i++) _matrix1[i] = 0x00;
 143     matrix = _matrix0;
 144     matrix_prev = _matrix1;
 145 }
 146
 147 uint8_t matrix_scan(void)
 148 {
 149     uint8_t *tmp;
 150
 151     tmp = matrix_prev;
 152     matrix_prev = matrix;
 153     matrix = tmp;
 154
 155     KEY_POWER_ON();
 156     for (uint8_t row = 0; row < MATRIX_ROWS; row++) {
 157         for (uint8_t col = 0; col < MATRIX_COLS; col++) {
 158             KEY_SELECT(row, col);
 159             _delay_us(40);
 160
 161             // Not sure this is needed. This just emulates HHKB controller's behaviour.
 162             if (matrix_prev[row] & (1<<col)) {
 163                 KEY_PREV_ON();
 164             }
 165             _delay_us(7);
 166
 167             // NOTE: KEY_STATE is valid only in 20us after KEY_ENABLE.
 168             // If V-USB interrupts in this section we could lose 40us or so
 169             // and would read invalid value from KEY_STATE.
 170             uint8_t last = TIMER_RAW;
 171
 172             KEY_ENABLE();
 173             // Wait for KEY_STATE outputs its value.
 174             // 1us was ok on one HHKB, but not worked on another.
 175             _delay_us(10);
 176             if (KEY_STATE()) {
 177                 matrix[row] &= ~(1<<col);
 178             } else {
 179                 matrix[row] |= (1<<col);
 180             }
 181
 182             // Ignore if this code region execution time elapses more than 20us.
 183             // MEMO: 20[us] * (TIMER_RAW_FREQ / 1000000)[count per us]
 184             // MEMO: then change above using this rule: a/(b/c) = a*1/(b/c) = a*(c/b)
 185             if (TIMER_DIFF_RAW(TIMER_RAW, last) > 20/(1000000/TIMER_RAW_FREQ)) {
 186                 matrix[row] = matrix_prev[row];
 187             }
 188
 189             KEY_PREV_OFF();
 190             KEY_UNABLE();
 191             // NOTE: KEY_STATE keep its state in 20us after KEY_ENABLE.
 192             // This takes 25us or more to make sure KEY_STATE returns to idle state.
 193             _delay_us(150);
 194         }
 195     }
 196     KEY_POWER_OFF();
 197     return 1;
 198 }
 199
 200 bool matrix_is_modified(void)
 201 {
 202     for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
 203         if (matrix[i] != matrix_prev[i])
 204             return true;
 205     }
 206     return false;
 207 }
 208
 209 inline
 210 bool matrix_has_ghost(void)
 211 {
 212     return false;
 213 }
 214
 215 inline
 216 bool matrix_is_on(uint8_t row, uint8_t col)
 217 {
 218     return (matrix[row] & (1<<col));
 219 }
 220
 221 inline
 222 matrix_row_t matrix_get_row(uint8_t row)
 223 {
 224     return matrix[row];
 225 }
 226
 227 void matrix_print(void)
 228 {
 229     print("\nr/c 01234567\n");
 230     for (uint8_t row = 0; row < matrix_rows(); row++) {
 231         xprintf("%02X: %08b\n", row, bitrev(matrix_get_row(row)));
 232     }
 233 }