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 //      UNKNOWN: unknown whether input or output
  23 //      PE6,PE7(KEY, UNKNOWN)
  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_ON                  ((PINE&(1<<6)) ? false : true)
  29
  30 // matrix state buffer
  31 static uint8_t *matrix;
  32 static uint8_t *matrix_prev;
  33 static uint8_t _matrix0[MATRIX_ROWS];
  34 static uint8_t _matrix1[MATRIX_ROWS];
  35
  36
  37 inline
  38 int matrix_rows(void)
  39 {
  40     return MATRIX_ROWS;
  41 }
  42
  43 inline
  44 int matrix_cols(void)
  45 {
  46     return MATRIX_COLS;
  47 }
  48
  49 // this must be called once before matrix_scan.
  50 void matrix_init(void)
  51 {
  52     // row & col output(PB0-6)
  53     DDRB = 0xFF;
  54     PORTB = KEY_SELELCT(0, 0);
  55     // KEY & VALID input with pullup(PE6,7)
  56     DDRE = 0x3F;
  57     PORTE = 0xC0;
  58
  59     // initialize matrix state: all keys off
  60     for (int i=0; i < MATRIX_ROWS; i++) _matrix0[i] = 0x00;
  61     for (int i=0; i < MATRIX_ROWS; i++) _matrix1[i] = 0x00;
  62     matrix = _matrix0;
  63     matrix_prev = _matrix1;
  64 }
  65
  66 int matrix_scan(void)
  67 {
  68     uint8_t *tmp;
  69
  70     tmp = matrix_prev;
  71     matrix_prev = matrix;
  72     matrix = tmp;
  73
  74     for (int row = 0; row < MATRIX_ROWS; row++) {
  75         for (int col = 0; col < MATRIX_COLS; col++) {
  76             KEY_SELELCT(row, col);
  77             _delay_us(50);  // from logic analyzer chart
  78             KEY_ENABLE;
  79             _delay_us(10);  // from logic analyzer chart
  80             if (KEY_ON) {
  81                 matrix[row] |= (1<<col);
  82             } else {
  83                 matrix[row] &= ~(1<<col);
  84             }
  85             KEY_UNABLE;
  86             _delay_us(150);  // from logic analyzer chart
  87         }
  88     }
  89     return 1;
  90 }
  91
  92 bool matrix_is_modified(void)
  93 {
  94     for (int i = 0; i < MATRIX_ROWS; i++) {
  95         if (matrix[i] != matrix_prev[i])
  96             return true;
  97     }
  98     return false;
  99 }
 100
 101 inline
 102 bool matrix_has_ghost(void)
 103 {
 104     return false;
 105 }
 106
 107 inline
 108 bool matrix_is_on(int row, int col)
 109 {
 110     return (matrix[row] & (1<<col));
 111 }
 112
 113 inline
 114 uint16_t matrix_get_row(int row)
 115 {
 116     return matrix[row];
 117 }
 118
 119 void matrix_print(void)
 120 {
 121     print("\nr/c 01234567\n");
 122     for (int row = 0; row < matrix_rows(); row++) {
 123         phex(row); print(": ");
 124         pbin_reverse(matrix_get_row(row));
 125         print("\n");
 126     }
 127 }
 128
 129 int matrix_key_count(void)
 130 {
 131     int count = 0;
 132     for (int i = 0; i < MATRIX_ROWS; i++) {
 133         count += bitpop(matrix[i]);
 134     }
 135     return count;
 136 }