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 "util.h"
  28 #include "timer.h"
  29 #include "matrix.h"
  30
  31
  32 // Timer resolution check
  33 #if (1000000/TIMER_RAW_FREQ > 20)
  34 #   error "Timer resolution(>20us) is not enough for HHKB matrix scan tweak on V-USB."
  35 #endif
  36
  37 #if (MATRIX_COLS > 16)
  38 #   error "MATRIX_COLS must not exceed 16"
  39 #endif
  40 #if (MATRIX_ROWS > 255)
  41 #   error "MATRIX_ROWS must not exceed 255"
  42 #endif
  43
  44
  45 // matrix state buffer(1:on, 0:off)
  46 #if (MATRIX_COLS <= 8)
  47 static uint8_t *matrix;
  48 static uint8_t *matrix_prev;
  49 static uint8_t _matrix0[MATRIX_ROWS];
  50 static uint8_t _matrix1[MATRIX_ROWS];
  51 #else
  52 static uint16_t *matrix;
  53 static uint16_t *matrix_prev;
  54 static uint16_t _matrix0[MATRIX_ROWS];
  55 static uint16_t _matrix1[MATRIX_ROWS];
  56 #endif
  57
  58 // HHKB has no ghost and no bounce.
  59 #ifdef MATRIX_HAS_GHOST
  60 static bool matrix_has_ghost_in_row(uint8_t row);
  61 #endif
  62
  63
  64 // Matrix I/O ports
  65 //
  66 // row:     HC4051[A,B,C]  selects scan row0-7
  67 // col:     LS145[A,B,C,D] selects scan col0-7 and enable(D)
  68 // key:     on: 0/off: 1
  69 // prev:    unknown: output previous key state(negated)?
  70
  71 #ifdef HOST_PJRC
  72 // Ports for Teensy
  73 // row:     PB0-2
  74 // col:     PB3-5,6
  75 // key:     PE6(pull-uped)
  76 // prev:    PE7
  77 #define KEY_INIT()              do {    \
  78     DDRB |= 0x7F;                       \
  79     DDRE |=  (1<<7);                    \
  80     DDRE &= ~(1<<6);                    \
  81     PORTE |= (1<<6);                    \
  82 } while (0)
  83 #define KEY_SELECT(ROW, COL)    (PORTB = (PORTB & 0xC0) |       \
  84                                          (((COL) & 0x07)<<3) |    \
  85                                          ((ROW) & 0x07))
  86 #define KEY_ENABLE()            (PORTB &= ~(1<<6))
  87 #define KEY_UNABLE()            (PORTB |=  (1<<6))
  88 #define KEY_STATE()             (PINE & (1<<6))
  89 #define KEY_PREV_ON()           (PORTE |=  (1<<7))
  90 #define KEY_PREV_OFF()          (PORTE &= ~(1<<7))
  91 #define KEY_POWER_ON()
  92 #define KEY_POWER_OFF()
  93 #else
  94 // Ports for V-USB
  95 // key:     PB0(pull-uped)
  96 // prev:    PB1
  97 // row:     PB2-4
  98 // col:     PC0-2,3
  99 // power:   PB5(Low:on/Hi-z:off)
 100 #define KEY_INIT()              do {    \
 101     DDRB  |= 0x3E;                      \
 102     DDRB  &= ~(1<<0);                   \
 103     PORTB |= 1<<0;                      \
 104     DDRC  |= 0x0F;                      \
 105     KEY_UNABLE();                       \
 106     KEY_PREV_OFF();                     \
 107 } while (0)
 108 #define KEY_SELECT(ROW, COL)    do {    \
 109     PORTB = (PORTB & 0xE3) | ((ROW) & 0x07)<<2; \
 110     PORTC = (PORTC & 0xF8) | ((COL) & 0x07);    \
 111 } while (0)
 112 #define KEY_ENABLE()            (PORTC &= ~(1<<3))
 113 #define KEY_UNABLE()            (PORTC |=  (1<<3))
 114 #define KEY_STATE()             (PINB & (1<<0))
 115 #define KEY_PREV_ON()           (PORTB |=  (1<<1))
 116 #define KEY_PREV_OFF()          (PORTB &= ~(1<<1))
 117 // Power supply switching
 118 #define KEY_POWER_ON()          do {    \
 119     KEY_INIT();                         \
 120     PORTB &= ~(1<<5);                   \
 121     _delay_us(200);                     \
 122 } while (0)
 123 #define KEY_POWER_OFF()         do {    \
 124     DDRB  &= ~0x3F;                     \
 125     PORTB &= ~0x3F;                     \
 126     DDRC  &= ~0x0F;                     \
 127     PORTC &= ~0x0F;                     \
 128 } while (0)
 129 #endif
 130
 131
 132 inline
 133 uint8_t matrix_rows(void)
 134 {
 135     return MATRIX_ROWS;
 136 }
 137
 138 inline
 139 uint8_t matrix_cols(void)
 140 {
 141     return MATRIX_COLS;
 142 }
 143
 144 void matrix_init(void)
 145 {
 146     KEY_INIT();
 147
 148     // initialize matrix state: all keys off
 149     for (uint8_t i=0; i < MATRIX_ROWS; i++) _matrix0[i] = 0x00;
 150     for (uint8_t i=0; i < MATRIX_ROWS; i++) _matrix1[i] = 0x00;
 151     matrix = _matrix0;
 152     matrix_prev = _matrix1;
 153 }
 154
 155 uint8_t matrix_scan(void)
 156 {
 157     uint8_t *tmp;
 158
 159     tmp = matrix_prev;
 160     matrix_prev = matrix;
 161     matrix = tmp;
 162
 163     KEY_POWER_ON();
 164     for (uint8_t row = 0; row < MATRIX_ROWS; row++) {
 165         for (uint8_t col = 0; col < MATRIX_COLS; col++) {
 166             KEY_SELECT(row, col);
 167             _delay_us(40);
 168
 169             // Not sure this is needed. This just emulates HHKB controller's behaviour.
 170             if (matrix_prev[row] & (1<<col)) {
 171                 KEY_PREV_ON();
 172             }
 173             _delay_us(7);
 174
 175             // NOTE: KEY_STATE is valid only in 20us after KEY_ENABLE.
 176             // If V-USB interrupts in this section we could lose 40us or so
 177             // and would read invalid value from KEY_STATE.
 178             uint8_t last = TIMER_RAW;
 179
 180             KEY_ENABLE();
 181             // Wait for KEY_STATE outputs its value.
 182             // 1us was ok on one HHKB, but not worked on another.
 183             _delay_us(10);
 184             if (KEY_STATE()) {
 185                 matrix[row] &= ~(1<<col);
 186             } else {
 187                 matrix[row] |= (1<<col);
 188             }
 189
 190             // Ignore if this code region execution time elapses more than 20us.
 191             if (TIMER_DIFF_RAW(TIMER_RAW, last) > 20/(1000000/TIMER_RAW_FREQ)) {
 192                 matrix[row] = matrix_prev[row];
 193             }
 194
 195             KEY_PREV_OFF();
 196             KEY_UNABLE();
 197             // NOTE: KEY_STATE keep its state in 20us after KEY_ENABLE.
 198             // This takes 25us or more to make sure KEY_STATE returns to idle state.
 199             _delay_us(150);
 200         }
 201     }
 202     KEY_POWER_OFF();
 203     return 1;
 204 }
 205
 206 bool matrix_is_modified(void)
 207 {
 208     for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
 209         if (matrix[i] != matrix_prev[i])
 210             return true;
 211     }
 212     return false;
 213 }
 214
 215 inline
 216 bool matrix_has_ghost(void)
 217 {
 218 #ifdef MATRIX_HAS_GHOST
 219     for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
 220         if (matrix_has_ghost_in_row(i))
 221             return true;
 222     }
 223 #endif
 224     return false;
 225 }
 226
 227 inline
 228 bool matrix_is_on(uint8_t row, uint8_t col)
 229 {
 230     return (matrix[row] & (1<<col));
 231 }
 232
 233 inline
 234 #if (MATRIX_COLS <= 8)
 235 uint8_t matrix_get_row(uint8_t row)
 236 #else
 237 uint16_t matrix_get_row(uint8_t row)
 238 #endif
 239 {
 240     return matrix[row];
 241 }
 242
 243 void matrix_print(void)
 244 {
 245 #if (MATRIX_COLS <= 8)
 246     print("\nr/c 01234567\n");
 247 #else
 248     print("\nr/c 0123456789ABCDEF\n");
 249 #endif
 250     for (uint8_t row = 0; row < matrix_rows(); row++) {
 251         phex(row); print(": ");
 252 #if (MATRIX_COLS <= 8)
 253         pbin_reverse(matrix_get_row(row));
 254 #else
 255         pbin_reverse16(matrix_get_row(row));
 256 #endif
 257 #ifdef MATRIX_HAS_GHOST
 258         if (matrix_has_ghost_in_row(row)) {
 259             print(" <ghost");
 260         }
 261 #endif
 262         print("\n");
 263     }
 264 }
 265
 266 uint8_t matrix_key_count(void)
 267 {
 268     uint8_t count = 0;
 269     for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
 270 #if (MATRIX_COLS <= 8)
 271         count += bitpop(matrix[i]);
 272 #else
 273         count += bitpop16(matrix[i]);
 274 #endif
 275     }
 276     return count;
 277 }
 278
 279 #ifdef MATRIX_HAS_GHOST
 280 inline
 281 static bool matrix_has_ghost_in_row(uint8_t row)
 282 {
 283     // no ghost exists in case less than 2 keys on
 284     if (((matrix[row] - 1) & matrix[row]) == 0)
 285         return false;
 286
 287     // ghost exists in case same state as other row
 288     for (uint8_t i=0; i < MATRIX_ROWS; i++) {
 289         if (i != row && (matrix[i] & matrix[row]) == matrix[row])
 290             return true;
 291     }
 292     return false;
 293 }
 294 #endif