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