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 #define LED_ON()    do { DDRC |= (1<<5); PORTC |= (1<<5); } while (0)
  47 #define LED_OFF()   do { DDRC &= ~(1<<5); PORTC &= ~(1<<5); } while (0)
  48 #define LED_TGL()   do { DDRC |= (1<<5); PINC |= (1<<5); } while (0)
  49
  50 void matrix_init(void)
  51 {
  52     // initialize row and col
  53     unselect_rows();
  54     init_cols();
  55
  56     // initialize matrix state: all keys off
  57     for (uint8_t i=0; i < MATRIX_ROWS; i++) {
  58         matrix[i] = 0;
  59         matrix_debouncing[i] = 0;
  60     }
  61
  62     //debug
  63     debug_matrix = true;
  64     LED_ON();
  65     _delay_ms(500);
  66     LED_OFF();
  67 }
  68
  69 uint8_t matrix_scan(void)
  70 {
  71     for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
  72         select_row(i);
  73         _delay_us(30);  // without this wait read unstable value.
  74         matrix_row_t cols = read_cols();
  75         if (matrix_debouncing[i] != cols) {
  76             matrix_debouncing[i] = cols;
  77             if (debouncing) {
  78                 debug("bounce!: "); debug_hex(debouncing); debug("\n");
  79             }
  80             debouncing = DEBOUNCE;
  81         }
  82         unselect_rows();
  83     }
  84
  85     if (debouncing) {
  86         if (--debouncing) {
  87             _delay_ms(1);
  88         } else {
  89             for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
  90                 matrix[i] = matrix_debouncing[i];
  91             }
  92         }
  93     }
  94
  95     return 1;
  96 }
  97
  98 inline
  99 matrix_row_t matrix_get_row(uint8_t row)
 100 {
 101     return matrix[row];
 102 }
 103
 104 /* Column pin configuration
 105  * col: 0   1   2   3   4   5   6   7
 106  * pin: B0  B1  B2  B3  B4  B5  B6  B7
 107  */
 108 static void  init_cols(void)
 109 {
 110     // Input with pull-up(DDR:0, PORT:1)
 111     DDRB  &= ~0b11111111;
 112     PORTB |=  0b11111111;
 113 }
 114
 115 /* Returns status of switches(1:on, 0:off) */
 116 static matrix_row_t read_cols(void)
 117 {
 118     // Invert because PIN indicates 'switch on' with low(0) and 'off' with high(1)
 119     return ~PINB;
 120 }
 121
 122 /* Row pin configuration
 123  * row: 0   1   2   3   4   5   6   7
 124  * pin: D0  D1  D2  D3  D4  D5  D6  C2
 125  */
 126 static void unselect_rows(void)
 127 {
 128     // Hi-Z(DDR:0, PORT:0) to unselect
 129     DDRD  &= ~0b01111111;
 130     PORTD &= ~0b01111111;
 131     DDRC  &= ~0b00000100;
 132     PORTC &= ~0b00000100;
 133 }
 134
 135 static void select_row(uint8_t row)
 136 {
 137     // Output low(DDR:1, PORT:0) to select
 138     switch (row) {
 139         case 0:
 140             DDRD  |= (1<<0);
 141             PORTD &= ~(1<<0);
 142             break;
 143         case 1:
 144             DDRD  |= (1<<1);
 145             PORTD &= ~(1<<1);
 146             break;
 147         case 2:
 148             DDRD  |= (1<<2);
 149             PORTD &= ~(1<<2);
 150             break;
 151         case 3:
 152             DDRD  |= (1<<3);
 153             PORTD &= ~(1<<3);
 154             break;
 155         case 4:
 156             DDRD  |= (1<<4);
 157             PORTD &= ~(1<<4);
 158             break;
 159         case 5:
 160             DDRD  |= (1<<5);
 161             PORTD &= ~(1<<5);
 162             break;
 163         case 6:
 164             DDRD  |= (1<<6);
 165             PORTD &= ~(1<<6);
 166             break;
 167         case 7:
 168             DDRC  |= (1<<2);
 169             PORTC &= ~(1<<2);
 170             break;
 171     }
 172 }