hhkb/matrix.c

   1 /*
   2  * scan matrix
   3  */
   4 #include <stdint.h>
   5 #include <stdbool.h>
   6 #include <avr/io.h>
   7 #include <util/delay.h>
   8 #include "print.h"
   9 #include "util.h"
  10 #include "controller.h"
  11 #include "matrix_skel.h"
  12
  13 // matrix is active low. (key on: 0/key off: 1)
  14 //
  15 // HHKB has no ghost and no bounce.
  16 // row: HC4051 select input channel(0-8)
  17 //      PB0, PB1, PB2(A, B, C)
  18 // col: LS145 select low output line(0-8)
  19 //      PB3, PB4, PB5, PB6(A, B, C, D)
  20 //      use D as ENABLE: (enable: 0/unenable: 1)
  21 // key: KEY: (on: 0/ off:1)
  22 //      KEY_PREV: (on: 1/ off: 0)
  23 //      PE6,PE7(KEY, KEY_PREV)
  24 #define COL_ENABLE              (1<<6)
  25 #define KEY_SELELCT(ROW, COL)   (PORTB = COL_ENABLE|(((COL)&0x07)<<3)|((ROW)&0x07))
  26 #define KEY_ENABLE              (PORTB &= ~COL_ENABLE)
  27 #define KEY_UNABLE              (PORTB |=  COL_ENABLE)
  28 #define KEY_STATE               (PINE&(1<<6))
  29 #define KEY_PREV_ON             (PORTE |= (1<<7))
  30 #define KEY_PREV_OFF            (PORTE &= ~(1<<7))
  31
  32 // matrix state buffer
  33 static uint8_t *matrix;
  34 static uint8_t *matrix_prev;
  35 static uint8_t _matrix0[MATRIX_ROWS];
  36 static uint8_t _matrix1[MATRIX_ROWS];
  37
  38
  39 inline
  40 int matrix_rows(void)
  41 {
  42     return MATRIX_ROWS;
  43 }
  44
  45 inline
  46 int matrix_cols(void)
  47 {
  48     return MATRIX_COLS;
  49 }
  50
  51 // this must be called once before matrix_scan.
  52 void matrix_init(void)
  53 {
  54     // row & col output(PB0-6)
  55     DDRB = 0xFF;
  56     PORTB = KEY_SELELCT(0, 0);
  57     // KEY: input with pullup(PE6)
  58     // KEY_PREV: output(PE7)
  59     DDRE = 0xBF;
  60     PORTE = 0x40;
  61
  62     // initialize matrix state: all keys off
  63     for (int i=0; i < MATRIX_ROWS; i++) _matrix0[i] = 0x00;
  64     for (int i=0; i < MATRIX_ROWS; i++) _matrix1[i] = 0x00;
  65     matrix = _matrix0;
  66     matrix_prev = _matrix1;
  67 }
  68
  69 int matrix_scan(void)
  70 {
  71     uint8_t *tmp;
  72
  73     tmp = matrix_prev;
  74     matrix_prev = matrix;
  75     matrix = tmp;
  76
  77     for (int row = 0; row < MATRIX_ROWS; row++) {
  78         for (int col = 0; col < MATRIX_COLS; col++) {
  79             KEY_SELELCT(row, col);
  80             _delay_us(40);  // from logic analyzer chart
  81             if (matrix_prev[row] & (1<<col)) {
  82                 KEY_PREV_ON;
  83             }
  84             _delay_us(7);  // from logic analyzer chart
  85             KEY_ENABLE;
  86             _delay_us(10);  // from logic analyzer chart
  87             if (KEY_STATE) {
  88                 matrix[row] &= ~(1<<col);
  89             } else {
  90                 matrix[row] |= (1<<col);
  91             }
  92             KEY_PREV_OFF;
  93             KEY_UNABLE;
  94             _delay_us(150);  // from logic analyzer chart
  95         }
  96     }
  97     return 1;
  98 }
  99
 100 bool matrix_is_modified(void)
 101 {
 102     for (int i = 0; i < MATRIX_ROWS; i++) {
 103         if (matrix[i] != matrix_prev[i])
 104             return true;
 105     }
 106     return false;
 107 }
 108
 109 inline
 110 bool matrix_has_ghost(void)
 111 {
 112     return false;
 113 }
 114
 115 inline
 116 bool matrix_is_on(int row, int col)
 117 {
 118     return (matrix[row] & (1<<col));
 119 }
 120
 121 inline
 122 uint16_t matrix_get_row(int row)
 123 {
 124     return matrix[row];
 125 }
 126
 127 void matrix_print(void)
 128 {
 129     print("\nr/c 01234567\n");
 130     for (int row = 0; row < matrix_rows(); row++) {
 131         phex(row); print(": ");
 132         pbin_reverse(matrix_get_row(row));
 133         print("\n");
 134     }
 135 }
 136
 137 int matrix_key_count(void)
 138 {
 139     int count = 0;
 140     for (int i = 0; i < MATRIX_ROWS; i++) {
 141         count += bitpop(matrix[i]);
 142     }
 143     return count;
 144 }