hhkb/matrix.c

   1 /*
   2  * scan matrix
   3  */
   4 #include <avr/io.h>
   5 #include <util/delay.h>
   6 #include "keymap.h"
   7 #include "matrix.h"
   8 #include "print.h"
   9
  10 // matrix is active low. (key on: 0/key off: 1)
  11 //
  12 // HHKB has no ghost and no bounce.
  13 // row: HC4051 select input channel(0-8)
  14 //      PB0, PB1, PB2(A, B, C)
  15 // col: LS145 select low output line(0-8)
  16 //      PB3, PB4, PB5, PB6(A, B, C, D)
  17 //      use D as ENABLE: (enable: 0/unenable: 1)
  18 // key: KEY: (on: 0/ off:1)
  19 //      UNKNOWN: unknown whether input or output
  20 //      PE6,PE7(KEY, UNKNOWN)
  21 #define COL_ENABLE              (1<<6)
  22 #define KEY_SELELCT(ROW, COL)   (PORTB = COL_ENABLE|(((COL)&0x07)<<3)|((ROW)&0x07))
  23 #define KEY_ENABLE              (PORTB &= ~COL_ENABLE)
  24 #define KEY_UNABLE              (PORTB |=  COL_ENABLE)
  25 #define KEY_ON                  ((PINE&(1<<6)) ? false : true)
  26
  27 // matrix state buffer
  28 uint8_t *matrix;
  29 uint8_t *matrix_prev;
  30 static uint8_t _matrix0[MATRIX_ROWS];
  31 static uint8_t _matrix1[MATRIX_ROWS];
  32
  33
  34 static bool matrix_has_ghost_in_row(int row);
  35
  36
  37 inline
  38 int matrix_rows(void) {
  39     return MATRIX_ROWS;
  40 }
  41
  42 inline
  43 int matrix_cols(void) {
  44     return MATRIX_COLS;
  45 }
  46
  47 // this must be called once before matrix_scan.
  48 void matrix_init(void)
  49 {
  50     // row & col output(PB0-6)
  51     DDRB = 0xFF;
  52     PORTB = KEY_SELELCT(0, 0);
  53     // KEY & VALID input with pullup(PE6,7)
  54     DDRE = 0x3F;
  55     PORTE = 0xC0;
  56
  57     // initialize matrix state: all keys off
  58     for (int i=0; i < MATRIX_ROWS; i++) _matrix0[i] = 0xFF;
  59     for (int i=0; i < MATRIX_ROWS; i++) _matrix1[i] = 0xFF;
  60     matrix = _matrix0;
  61     matrix_prev = _matrix1;
  62 }
  63
  64 int matrix_scan(void)
  65 {
  66     uint8_t *tmp;
  67
  68     tmp = matrix_prev;
  69     matrix_prev = matrix;
  70     matrix = tmp;
  71
  72     for (int row = 0; row < MATRIX_ROWS; row++) {
  73         for (int col = 0; col < MATRIX_COLS; col++) {
  74             KEY_SELELCT(row, col);
  75             _delay_us(50);  // from logic analyzer chart
  76             KEY_ENABLE;
  77             _delay_us(10);  // from logic analyzer chart
  78             if (KEY_ON) {
  79                 matrix[row] &= ~(1<<col);
  80             } else {
  81                 matrix[row] |= (1<<col);
  82             }
  83             KEY_UNABLE;
  84             _delay_us(150);  // from logic analyzer chart
  85         }
  86     }
  87     return 1;
  88 }
  89
  90 bool matrix_is_modified(void) {
  91     for (int i=0; i <MATRIX_ROWS; i++) {
  92         if (matrix[i] != matrix_prev[i])
  93             return true;
  94     }
  95     return false;
  96 }
  97
  98 inline
  99 bool matrix_has_ghost(void) {
 100     return false;
 101 }
 102
 103 inline
 104 uint16_t matrix_get_row(int row) {
 105     return matrix[row];
 106 }
 107
 108 void matrix_print(void) {
 109     print("\nr/c 01234567\n");
 110     for (int row = 0; row < matrix_rows(); row++) {
 111         phex(row); print(": ");
 112         pbin_reverse(matrix_get_row(row));
 113         if (matrix_has_ghost_in_row(row)) {
 114             print(" <ghost");
 115         }
 116         print("\n");
 117     }
 118 }
 119
 120 inline
 121 static bool matrix_has_ghost_in_row(int row) {
 122     return false;
 123 }