keyboard/hbkb/matrix.c

   1 /*
   2 Copyright 2012 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 #include <stdint.h>
  19 #include <stdbool.h>
  20 #include <avr/io.h>
  21 #include <util/delay.h>
  22 #include "print.h"
  23 #include "debug.h"
  24 #include "util.h"
  25 #include "matrix.h"
  26
  27
  28 /*
  29  * Happy Buckling Keyboard(IBM Model M mod)
  30  *
  31  * Pin usage:
  32  *   COL: PD0-7
  33  *   ROW: PB0-7, PF4-7
  34  */
  35 #ifndef DEBOUNCE
  36 #   define DEBOUNCE     10
  37 #endif
  38 static uint8_t debouncing = DEBOUNCE;
  39
  40 /* matrix state(1:on, 0:off) */
  41 static matrix_row_t matrix[MATRIX_ROWS];
  42 static matrix_row_t matrix_debouncing[MATRIX_ROWS];
  43
  44 #ifdef MATRIX_HAS_GHOST
  45 static bool matrix_has_ghost_in_row(uint8_t row);
  46 #endif
  47 static matrix_row_t read_cols(void);
  48 static void unselect_rows(void);
  49 static void select_row(uint8_t row);
  50
  51
  52 inline
  53 uint8_t matrix_rows(void)
  54 {
  55     return MATRIX_ROWS;
  56 }
  57
  58 inline
  59 uint8_t matrix_cols(void)
  60 {
  61     return MATRIX_COLS;
  62 }
  63
  64 void matrix_init(void)
  65 {
  66     // JTAG disable for PORT F. write JTD bit twice within four cycles.
  67     MCUCR |= (1<<JTD);
  68     MCUCR |= (1<<JTD);
  69
  70     // initialize rows
  71     unselect_rows();
  72
  73     // initialize columns to input with pull-up(DDR:0, PORT:1)
  74     DDRD = 0x00;
  75     PORTD = 0xFF;
  76
  77     // initialize matrix state: all keys off
  78     for (uint8_t i=0; i < MATRIX_ROWS; i++) {
  79         matrix[i] = 0;
  80         matrix_debouncing[i] = 0;
  81     }
  82 }
  83
  84 uint8_t matrix_scan(void)
  85 {
  86     for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
  87         select_row(i);
  88         _delay_us(30);  // without this wait read unstable value.
  89         matrix_row_t cols = read_cols();
  90         if (matrix_debouncing[i] != cols) {
  91             matrix_debouncing[i] = cols;
  92             if (debouncing) {
  93                 debug("bounce!: "); debug_hex(debouncing); debug("\n");
  94             }
  95             debouncing = DEBOUNCE;
  96         }
  97         unselect_rows();
  98     }
  99
 100     if (debouncing) {
 101         if (--debouncing) {
 102             _delay_ms(1);
 103         } else {
 104             for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
 105                 matrix[i] = matrix_debouncing[i];
 106             }
 107         }
 108     }
 109
 110     return 1;
 111 }
 112
 113 bool matrix_is_modified(void)
 114 {
 115     if (debouncing) return false;
 116     return true;
 117 }
 118
 119 inline
 120 bool matrix_is_on(uint8_t row, uint8_t col)
 121 {
 122     return (matrix[row] & ((matrix_row_t)1<<col));
 123 }
 124
 125 inline
 126 matrix_row_t matrix_get_row(uint8_t row)
 127 {
 128     return matrix[row];
 129 }
 130
 131 void matrix_print(void)
 132 {
 133     print("\nr/c 01234567\n");
 134     for (uint8_t row = 0; row < matrix_rows(); row++) {
 135         phex(row); print(": ");
 136         pbin_reverse(matrix_get_row(row));
 137 #ifdef MATRIX_HAS_GHOST
 138         if (matrix_has_ghost_in_row(row)) {
 139             print(" <ghost");
 140         }
 141 #endif
 142         print("\n");
 143     }
 144 }
 145
 146 #ifdef MATRIX_HAS_GHOST
 147 inline
 148 static bool matrix_has_ghost_in_row(uint8_t row)
 149 {
 150     // no ghost exists in case less than 2 keys on
 151     if (((matrix[row] - 1) & matrix[row]) == 0)
 152         return false;
 153
 154     // ghost exists in case same state as other row
 155     for (uint8_t i=0; i < MATRIX_ROWS; i++) {
 156         if (i != row && (matrix[i] & matrix[row]))
 157             return true;
 158     }
 159     return false;
 160 }
 161 #endif
 162
 163 inline
 164 static matrix_row_t read_cols(void)
 165 {
 166     return ~PIND;
 167 }
 168
 169 inline
 170 static void unselect_rows(void)
 171 {
 172     // Hi-Z(DDR:0, PORT:0) to unselect
 173     DDRB  &= ~0b11111111;
 174     PORTB &= ~0b11111111;
 175     DDRF  &= ~0b11110000;
 176     PORTF &= ~0b11110000;
 177 }
 178
 179 inline
 180 static void select_row(uint8_t row)
 181 {
 182     // Output low(DDR:1, PORT:0) to select
 183     switch (row) {
 184         case 0:
 185         case 1:
 186         case 2:
 187         case 3:
 188         case 4:
 189         case 5:
 190         case 6:
 191         case 7:
 192             DDRB  |=  (1<<row);
 193             PORTB &= ~(1<<row);
 194             break;
 195         case 8:
 196             DDRF  |=  (1<<4);
 197             PORTF &= ~(1<<4);
 198             break;
 199         case 9:
 200         case 10:
 201         case 11:
 202             DDRF  |=  (1<<(row-4));
 203             PORTF &= ~(1<<(row-4));
 204             break;
 205     }
 206 }