keyboard/alps64/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 /*
  19  * scan matrix
  20  */
  21 #include <stdint.h>
  22 #include <stdbool.h>
  23 #include <avr/io.h>
  24 #include <util/delay.h>
  25 #include "print.h"
  26 #include "debug.h"
  27 #include "util.h"
  28 #include "matrix.h"
  29
  30
  31 #ifndef DEBOUNCE
  32 #   define DEBOUNCE     5
  33 #endif
  34 static uint8_t debouncing = DEBOUNCE;
  35
  36 /* matrix state(1:on, 0:off) */
  37 static matrix_row_t matrix[MATRIX_ROWS];
  38 static matrix_row_t matrix_debouncing[MATRIX_ROWS];
  39
  40 static matrix_row_t read_cols(void);
  41 static void init_cols(void);
  42 static void unselect_rows(void);
  43 static void select_row(uint8_t row);
  44
  45
  46 inline
  47 uint8_t matrix_rows(void)
  48 {
  49     return MATRIX_ROWS;
  50 }
  51
  52 inline
  53 uint8_t matrix_cols(void)
  54 {
  55     return MATRIX_COLS;
  56 }
  57
  58 void matrix_init(void)
  59 {
  60     // initialize row and col
  61     unselect_rows();
  62     init_cols();
  63
  64     // initialize matrix state: all keys off
  65     for (uint8_t i=0; i < MATRIX_ROWS; i++) {
  66         matrix[i] = 0;
  67         matrix_debouncing[i] = 0;
  68     }
  69 }
  70
  71 uint8_t matrix_scan(void)
  72 {
  73     for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
  74         select_row(i);
  75         _delay_us(30);  // without this wait read unstable value.
  76         matrix_row_t cols = read_cols();
  77         if (matrix_debouncing[i] != cols) {
  78             matrix_debouncing[i] = cols;
  79             if (debouncing) {
  80                 debug("bounce!: "); debug_hex(debouncing); debug("\n");
  81             }
  82             debouncing = DEBOUNCE;
  83         }
  84         unselect_rows();
  85     }
  86
  87     if (debouncing) {
  88         if (--debouncing) {
  89             _delay_ms(1);
  90         } else {
  91             for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
  92                 matrix[i] = matrix_debouncing[i];
  93             }
  94         }
  95     }
  96
  97     return 1;
  98 }
  99
 100 inline
 101 bool matrix_is_on(uint8_t row, uint8_t col)
 102 {
 103     return (matrix[row] & ((matrix_row_t)1<<col));
 104 }
 105
 106 inline
 107 matrix_row_t matrix_get_row(uint8_t row)
 108 {
 109     return matrix[row];
 110 }
 111
 112 void matrix_print(void)
 113 {
 114     print("\nr/c 0123456789ABCDEF\n");
 115     for (uint8_t row = 0; row < MATRIX_ROWS; row++) {
 116         phex(row); print(": ");
 117         pbin_reverse16(matrix_get_row(row));
 118         print("\n");
 119     }
 120 }
 121
 122 /* Column pin configuration
 123  * col: 0   1   2   3   4   5   6   7
 124  * pin: B0  B1  B2  B3  B4  B5  B6  B7
 125  */
 126 static void  init_cols(void)
 127 {
 128     // Input with pull-up(DDR:0, PORT:1)
 129     DDRB  &= ~0b11111111;
 130     PORTB |=  0b11111111;
 131 }
 132
 133 /* Returns status of switches(1:on, 0:off) */
 134 static matrix_row_t read_cols(void)
 135 {
 136     // Invert because PIN indicates 'switch on' with low(0) and 'off' with high(1)
 137     return ~PINB;
 138 }
 139
 140 /* Row pin configuration
 141  * row: 0   1   2   3   4   5   6   7
 142  * pin: D0  D1  D2  D3  D4  D5  D6  C2
 143  */
 144 static void unselect_rows(void)
 145 {
 146     // Hi-Z(DDR:0, PORT:0) to unselect
 147     DDRD  &= ~0b01111111;
 148     PORTD &= ~0b01111111;
 149     DDRC  &= ~0b00000100;
 150     PORTD &= ~0b00000100;
 151 }
 152
 153 static void select_row(uint8_t row)
 154 {
 155     // Output low(DDR:1, PORT:0) to select
 156     switch (row) {
 157         case 0:
 158             DDRD  |= (1<<0);
 159             PORTD &= ~(1<<0);
 160             break;
 161         case 1:
 162             DDRD  |= (1<<1);
 163             PORTD &= ~(1<<1);
 164             break;
 165         case 2:
 166             DDRD  |= (1<<2);
 167             PORTD &= ~(1<<2);
 168             break;
 169         case 3:
 170             DDRD  |= (1<<3);
 171             PORTD &= ~(1<<3);
 172             break;
 173         case 4:
 174             DDRD  |= (1<<4);
 175             PORTD &= ~(1<<4);
 176             break;
 177         case 5:
 178             DDRD  |= (1<<5);
 179             PORTD &= ~(1<<5);
 180             break;
 181         case 6:
 182             DDRD  |= (1<<6);
 183             PORTD &= ~(1<<6);
 184             break;
 185         case 7:
 186             DDRC  |= (1<<2);
 187             PORTC &= ~(1<<2);
 188             break;
 189     }
 190 }