matrix.c

/*
Copyright 2014 Ralf Schmitt <ralf@bunkertor.net>
Copyright 2016 Daniel Svensson <dsvensson@gmail.com>

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include <stdint.h>
#include <stdbool.h>
#include <avr/io.h>
#include <util/delay.h>
#include "wait.h"
#include "print.h"
#include "debug.h"
#include "util.h"
#include "matrix.h"

static uint8_t debouncing = DEBOUNCING_DELAY;
static matrix_row_t matrix[MATRIX_ROWS];
static matrix_row_t matrix_debouncing[MATRIX_ROWS];

static matrix_row_t read_cols(void);
static void select_row(uint8_t col);

inline uint8_t matrix_rows(void)
{
	return MATRIX_ROWS;
}

inline uint8_t matrix_cols(void)
{
	return MATRIX_COLS;
}

void matrix_init(void)
{
	/* Column output pins */
	DDRD  |=  0b01111011;
	/* Row input pins */
	DDRC  &= ~0b10000000;
	DDRB  &= ~0b01111111;
	PORTC |=  0b10000000;
	PORTB |=  0b01111111;

	for (uint8_t i=0; i < MATRIX_ROWS; i++)  {
		matrix[i] = 0;
		matrix_debouncing[i] = 0;
	}

	matrix_init_quantum();
}

uint8_t matrix_scan(void)
{
	for (uint8_t col = 0; col < MATRIX_COLS; col++) {
		select_row(col);
		wait_us(30);
		matrix_row_t rows = read_cols();
		for (uint8_t row = 0; row < MATRIX_ROWS; row++) {
			bool prev_bit = matrix_debouncing[row] & ((matrix_row_t)1<<col);
			bool curr_bit = rows & (1<<row);
			if (prev_bit != curr_bit) {
				matrix_debouncing[row] ^= (matrix_row_t) 1 << col;
				debouncing = DEBOUNCING_DELAY;
			}
		}
	}

	if (debouncing) {
		if (--debouncing) {
			wait_ms(1);
		} else {
			for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
				matrix[i] = matrix_debouncing[i];
			}
		}
	}

	matrix_scan_quantum();

	return 1;
}

bool matrix_is_modified(void)
{
	if (debouncing)
		return false;
	return true;
}

inline
bool matrix_is_on(uint8_t row, uint8_t col)
{
	return matrix[row] & 1 << col;
}

inline
matrix_row_t matrix_get_row(uint8_t row)
{
	return matrix[row];
}

void matrix_print(void)
{
	print("\nr/c 0123456789ABCDEF\n");
	for (uint8_t row = 0; row < MATRIX_ROWS; row++) {
		phex(row); print(": ");
		pbin_reverse16(matrix_get_row(row));
		print("\n");
	}
}

uint8_t matrix_key_count(void)
{
	uint8_t count = 0;
	for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
		count += bitpop16(matrix[i]);
	}
	return count;
}

static matrix_row_t read_cols(void)
{
	return
		(PINB & (1 << 5) ? 0 : 1 << 0) |
		(PINC & (1 << 7) ? 0 : 1 << 1) |
		(PINB & (1 << 4) ? 0 : 1 << 2) |
		(PINB & (1 << 6) ? 0 : 1 << 3) |
		(PINB & (1 << 1) ? 0 : 1 << 4) |
		(PINB & (1 << 0) ? 0 : 1 << 5) |
		(PINB & (1 << 3) ? 0 : 1 << 6) |
		(PINB & (1 << 2) ? 0 : 1 << 7);
}

static void select_row(uint8_t col)
{
	switch (col) {
		case 0:
			PORTD = (PORTD & ~0b01111011) | 0b00110011;
			break;
		case 1:
			PORTD = (PORTD & ~0b01111011) | 0b01110000;
			break;
		case 2:
			PORTD = (PORTD & ~0b01111011) | 0b00010011;
			break;
		case 3:
			PORTD = (PORTD & ~0b01111011) | 0b01101000;
			break;
		case 4:
			PORTD = (PORTD & ~0b01111011) | 0b00001011;
			break;
		case 5:
			PORTD = (PORTD & ~0b01111011) | 0b00111011;
			break;
		case 6:
			PORTD = (PORTD & ~0b01111011) | 0b01111000;
			break;
		case 7:
			PORTD = (PORTD & ~0b01111011) | 0b01100001;
			break;
		case 8:
			PORTD = (PORTD & ~0b01111011) | 0b01101001;
			break;
		case 9:
			PORTD = (PORTD & ~0b01111011) | 0b01110001;
			break;
		case 10:
			PORTD = (PORTD & ~0b01111011) | 0b01101010;
			break;
		case 11:
			PORTD = (PORTD & ~0b01111011) | 0b01100010;
			break;
		case 12:
			PORTD = (PORTD & ~0b01111011) | 0b01111001;
			break;
		case 13:
			PORTD = (PORTD & ~0b01111011) | 0b01100000;
			break;
		case 14:
			PORTD = (PORTD & ~0b01111011) | 0b01000011;
			break;
		case 15:
			PORTD = (PORTD & ~0b01111011) | 0b00011011;
			break;
		case 16:
			PORTD = (PORTD & ~0b01111011) | 0b00100011;
			break;
		case 17:
			PORTD = (PORTD & ~0b01111011) | 0b00101011;
			break;
	}
}