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 "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 #if defined(__AVR_AT90USB1286__)
  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
  94 #elif defined(__AVR_ATmega328P__)
  95 // Ports for V-USB
  96 // key:     PB0(pull-uped)
  97 // prev:    PB1
  98 // row:     PB2-4
  99 // col:     PC0-2,3
 100 // power:   PB5(Low:on/Hi-z:off)
 101 #define KEY_INIT()              do {    \
 102     DDRB  |= 0x3E;                      \
 103     DDRB  &= ~(1<<0);                   \
 104     PORTB |= 1<<0;                      \
 105     DDRC  |= 0x0F;                      \
 106     KEY_UNABLE();                       \
 107     KEY_PREV_OFF();                     \
 108 } while (0)
 109 #define KEY_SELECT(ROW, COL)    do {    \
 110     PORTB = (PORTB & 0xE3) | ((ROW) & 0x07)<<2; \
 111     PORTC = (PORTC & 0xF8) | ((COL) & 0x07);    \
 112 } while (0)
 113 #define KEY_ENABLE()            (PORTC &= ~(1<<3))
 114 #define KEY_UNABLE()            (PORTC |=  (1<<3))
 115 #define KEY_STATE()             (PINB & (1<<0))
 116 #define KEY_PREV_ON()           (PORTB |=  (1<<1))
 117 #define KEY_PREV_OFF()          (PORTB &= ~(1<<1))
 118 // Power supply switching
 119 #define KEY_POWER_ON()          do {    \
 120     KEY_INIT();                         \
 121     PORTB &= ~(1<<5);                   \
 122     _delay_us(200);                     \
 123 } while (0)
 124 #define KEY_POWER_OFF()         do {    \
 125     DDRB  &= ~0x3F;                     \
 126     PORTB &= ~0x3F;                     \
 127     DDRC  &= ~0x0F;                     \
 128     PORTC &= ~0x0F;                     \
 129 } while (0)
 130
 131 #else
 132 #   error "define code for matrix scan"
 133 #endif
 134
 135
 136 inline
 137 uint8_t matrix_rows(void)
 138 {
 139     return MATRIX_ROWS;
 140 }
 141
 142 inline
 143 uint8_t matrix_cols(void)
 144 {
 145     return MATRIX_COLS;
 146 }
 147
 148 void matrix_init(void)
 149 {
 150     KEY_INIT();
 151
 152     // initialize matrix state: all keys off
 153     for (uint8_t i=0; i < MATRIX_ROWS; i++) _matrix0[i] = 0x00;
 154     for (uint8_t i=0; i < MATRIX_ROWS; i++) _matrix1[i] = 0x00;
 155     matrix = _matrix0;
 156     matrix_prev = _matrix1;
 157 }
 158
 159 uint8_t matrix_scan(void)
 160 {
 161     uint8_t *tmp;
 162
 163     tmp = matrix_prev;
 164     matrix_prev = matrix;
 165     matrix = tmp;
 166
 167     KEY_POWER_ON();
 168     for (uint8_t row = 0; row < MATRIX_ROWS; row++) {
 169         for (uint8_t col = 0; col < MATRIX_COLS; col++) {
 170             KEY_SELECT(row, col);
 171             _delay_us(40);
 172
 173             // Not sure this is needed. This just emulates HHKB controller's behaviour.
 174             if (matrix_prev[row] & (1<<col)) {
 175                 KEY_PREV_ON();
 176             }
 177             _delay_us(7);
 178
 179             // NOTE: KEY_STATE is valid only in 20us after KEY_ENABLE.
 180             // If V-USB interrupts in this section we could lose 40us or so
 181             // and would read invalid value from KEY_STATE.
 182             uint8_t last = TIMER_RAW;
 183
 184             KEY_ENABLE();
 185             // Wait for KEY_STATE outputs its value.
 186             // 1us was ok on one HHKB, but not worked on another.
 187             _delay_us(10);
 188             if (KEY_STATE()) {
 189                 matrix[row] &= ~(1<<col);
 190             } else {
 191                 matrix[row] |= (1<<col);
 192             }
 193
 194             // Ignore if this code region execution time elapses more than 20us.
 195             if (TIMER_DIFF_RAW(TIMER_RAW, last) > 20/(1000000/TIMER_RAW_FREQ)) {
 196                 matrix[row] = matrix_prev[row];
 197             }
 198
 199             KEY_PREV_OFF();
 200             KEY_UNABLE();
 201             // NOTE: KEY_STATE keep its state in 20us after KEY_ENABLE.
 202             // This takes 25us or more to make sure KEY_STATE returns to idle state.
 203             _delay_us(150);
 204         }
 205     }
 206     KEY_POWER_OFF();
 207     return 1;
 208 }
 209
 210 bool matrix_is_modified(void)
 211 {
 212     for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
 213         if (matrix[i] != matrix_prev[i])
 214             return true;
 215     }
 216     return false;
 217 }
 218
 219 inline
 220 bool matrix_has_ghost(void)
 221 {
 222 #ifdef MATRIX_HAS_GHOST
 223     for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
 224         if (matrix_has_ghost_in_row(i))
 225             return true;
 226     }
 227 #endif
 228     return false;
 229 }
 230
 231 inline
 232 bool matrix_is_on(uint8_t row, uint8_t col)
 233 {
 234     return (matrix[row] & (1<<col));
 235 }
 236
 237 inline
 238 #if (MATRIX_COLS <= 8)
 239 uint8_t matrix_get_row(uint8_t row)
 240 #else
 241 uint16_t matrix_get_row(uint8_t row)
 242 #endif
 243 {
 244     return matrix[row];
 245 }
 246
 247 void matrix_print(void)
 248 {
 249 #if (MATRIX_COLS <= 8)
 250     print("\nr/c 01234567\n");
 251 #else
 252     print("\nr/c 0123456789ABCDEF\n");
 253 #endif
 254     for (uint8_t row = 0; row < matrix_rows(); row++) {
 255         phex(row); print(": ");
 256 #if (MATRIX_COLS <= 8)
 257         pbin_reverse(matrix_get_row(row));
 258 #else
 259         pbin_reverse16(matrix_get_row(row));
 260 #endif
 261 #ifdef MATRIX_HAS_GHOST
 262         if (matrix_has_ghost_in_row(row)) {
 263             print(" <ghost");
 264         }
 265 #endif
 266         print("\n");
 267     }
 268 }
 269
 270 uint8_t matrix_key_count(void)
 271 {
 272     uint8_t count = 0;
 273     for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
 274 #if (MATRIX_COLS <= 8)
 275         count += bitpop(matrix[i]);
 276 #else
 277         count += bitpop16(matrix[i]);
 278 #endif
 279     }
 280     return count;
 281 }
 282
 283 #ifdef MATRIX_HAS_GHOST
 284 inline
 285 static bool matrix_has_ghost_in_row(uint8_t row)
 286 {
 287     // no ghost exists in case less than 2 keys on
 288     if (((matrix[row] - 1) & matrix[row]) == 0)
 289         return false;
 290
 291     // ghost exists in case same state as other row
 292     for (uint8_t i=0; i < MATRIX_ROWS; i++) {
 293         if (i != row && (matrix[i] & matrix[row]) == matrix[row])
 294             return true;
 295     }
 296     return false;
 297 }
 298 #endif