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 "debug.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 static matrix_row_t *matrix;
  47 static matrix_row_t *matrix_prev;
  48 static matrix_row_t _matrix0[MATRIX_ROWS];
  49 static matrix_row_t _matrix1[MATRIX_ROWS];
  50
  51
  52 // Matrix I/O ports
  53 //
  54 // row:     HC4051[A,B,C]  selects scan row0-7
  55 // col:     LS145[A,B,C,D] selects scan col0-7 and enable(D)
  56 // key:     on: 0/off: 1
  57 // prev:    unknown: output previous key state(negated)?
  58
  59 #if defined(__AVR_AT90USB1286__)
  60 // Ports for Teensy++
  61 // row:     PB0-2
  62 // col:     PB3-5,6
  63 // key:     PE6(pull-uped)
  64 // prev:    PE7
  65 #define KEY_INIT()              do {    \
  66     DDRB |= 0x7F;                       \
  67     DDRE |=  (1<<7);                    \
  68     DDRE &= ~(1<<6);                    \
  69     PORTE |= (1<<6);                    \
  70 } while (0)
  71 #define KEY_SELECT(ROW, COL)    (PORTB = (PORTB & 0xC0) |       \
  72                                          (((COL) & 0x07)<<3) |    \
  73                                          ((ROW) & 0x07))
  74 #define KEY_ENABLE()            (PORTB &= ~(1<<6))
  75 #define KEY_UNABLE()            (PORTB |=  (1<<6))
  76 #define KEY_STATE()             (PINE & (1<<6))
  77 #define KEY_PREV_ON()           (PORTE |=  (1<<7))
  78 #define KEY_PREV_OFF()          (PORTE &= ~(1<<7))
  79 #define KEY_POWER_ON()
  80 #define KEY_POWER_OFF()
  81
  82 #elif defined(__AVR_ATmega328P__)
  83 // Ports for V-USB
  84 // key:     PB0(pull-uped)
  85 // prev:    PB1
  86 // row:     PB2-4
  87 // col:     PC0-2,3
  88 // power:   PB5(Low:on/Hi-z:off)
  89 #define KEY_INIT()              do {    \
  90     DDRB  |= 0x3E;                      \
  91     DDRB  &= ~(1<<0);                   \
  92     PORTB |= 1<<0;                      \
  93     DDRC  |= 0x0F;                      \
  94     KEY_UNABLE();                       \
  95     KEY_PREV_OFF();                     \
  96 } while (0)
  97 #define KEY_SELECT(ROW, COL)    do {    \
  98     PORTB = (PORTB & 0xE3) | ((ROW) & 0x07)<<2; \
  99     PORTC = (PORTC & 0xF8) | ((COL) & 0x07);    \
 100 } while (0)
 101 #define KEY_ENABLE()            (PORTC &= ~(1<<3))
 102 #define KEY_UNABLE()            (PORTC |=  (1<<3))
 103 #define KEY_STATE()             (PINB & (1<<0))
 104 #define KEY_PREV_ON()           (PORTB |=  (1<<1))
 105 #define KEY_PREV_OFF()          (PORTB &= ~(1<<1))
 106 // Power supply switching
 107 #define KEY_POWER_ON()          do {    \
 108     KEY_INIT();                         \
 109     PORTB &= ~(1<<5);                   \
 110     _delay_ms(1);                       \
 111 } while (0)
 112 #define KEY_POWER_OFF()         do {    \
 113     DDRB  &= ~0x3F;                     \
 114     PORTB &= ~0x3F;                     \
 115     DDRC  &= ~0x0F;                     \
 116     PORTC &= ~0x0F;                     \
 117 } while (0)
 118
 119 #else
 120 #   error "define code for matrix scan"
 121 #endif
 122
 123
 124 inline
 125 uint8_t matrix_rows(void)
 126 {
 127     return MATRIX_ROWS;
 128 }
 129
 130 inline
 131 uint8_t matrix_cols(void)
 132 {
 133     return MATRIX_COLS;
 134 }
 135
 136 void matrix_init(void)
 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 #if (MATRIX_COLS <= 8)
 223 uint8_t matrix_get_row(uint8_t row)
 224 #else
 225 uint16_t matrix_get_row(uint8_t row)
 226 #endif
 227 {
 228     return matrix[row];
 229 }
 230
 231 void matrix_debug(void)
 232 {
 233     if (!debug_matrix)
 234         return;
 235
 236 #if (MATRIX_COLS <= 8)
 237     debug("\nr/c 01234567\n");
 238 #else
 239     debug("\nr/c 0123456789ABCDEF\n");
 240 #endif
 241     for (uint8_t row = 0; row < matrix_rows(); row++) {
 242         debug_hex(row); debug(": ");
 243 #if (MATRIX_COLS <= 8)
 244         debug_bin_reverse(matrix_get_row(row));
 245 #else
 246         debug_bin_reverse16(matrix_get_row(row));
 247 #endif
 248         debug("\n");
 249     }
 250 }
 251
 252 uint8_t matrix_key_count(void)
 253 {
 254     uint8_t count = 0;
 255     for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
 256 #if (MATRIX_COLS <= 8)
 257         count += bitpop(matrix[i]);
 258 #else
 259         count += bitpop16(matrix[i]);
 260 #endif
 261     }
 262     return count;
 263 }