/*
Copyright 2014 Kai Ryu <kai1103@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/>.
*/

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

#ifndef DEBOUNCE
#   define DEBOUNCE	5
#endif
static uint8_t debouncing = DEBOUNCE;

/* matrix state(1:on, 0:off) */
static matrix_row_t matrix[MATRIX_ROWS];
static matrix_row_t matrix_debouncing[MATRIX_ROWS];

static matrix_row_t read_cols(void);
static void init_cols(void);
static void unselect_rows(void);
static void select_row(uint8_t row);

#ifdef PS2_MOUSE_ENABLE
static uint8_t ps2_mouse_detected;

uint8_t ps2_enabled(void)
{
    return ps2_mouse_detected;
}
#endif

inline
uint8_t matrix_rows(void)
{
    return MATRIX_ROWS;
}

inline
uint8_t matrix_cols(void)
{
    return MATRIX_COLS;
}

void matrix_init(void)
{
    // disable JTAG
    MCUCR = (1<<JTD);
    MCUCR = (1<<JTD);

    // initialize row and col
    unselect_rows();
    init_cols();

    // initialize matrix state: all keys off
    for (uint8_t i=0; i < MATRIX_ROWS; i++) {
        matrix[i] = 0;
        matrix_debouncing[i] = 0;
    }
}

uint8_t matrix_scan(void)
{
    for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
        select_row(i);
        _delay_us(30);  // without this wait read unstable value.
        matrix_row_t cols = read_cols();
        if (matrix_debouncing[i] != cols) {
            matrix_debouncing[i] = cols;
            if (debouncing) {
                debug("bounce!: "); debug_hex(debouncing); debug("\n");
            }
            debouncing = DEBOUNCE;
        }
        unselect_rows();
    }

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

    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] & ((matrix_row_t)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;
}

/* Column pin configuration
 *  col: 0   1   2   3   4   5
 *  pin: D12 D13 A0  A1  A2  A3  (arduino)
 *       PD6 PC7 PF7 PF6 PF5 PF4
 */
static void  init_cols(void)
{
    // Input with pull-up(DDR:0, PORT:1)
    DDRF  &= ~(1<<PF7 | 1<<PF6 | 1<<PF5 | 1<<PF4);
    PORTF |=  (1<<PF7 | 1<<PF6 | 1<<PF5 | 1<<PF4);
    DDRD  &= ~(1<<PD6);
    PORTD |=  (1<<PD6);
    DDRC  &= ~(1<<PC7);
    PORTC |=  (1<<PC7);
}

static matrix_row_t read_cols(void)
{
    return (PINF&(1<<PD6) ? 0 : (1<<0)) |
           (PINF&(1<<PC7) ? 0 : (1<<1)) |
           (PINE&(1<<PF7) ? 0 : (1<<2)) |
           (PINC&(1<<PF6) ? 0 : (1<<3)) |
           (PINC&(1<<PF5) ? 0 : (1<<4)) |
           (PINB&(1<<PF4) ? 0 : (1<<5));
}

static void unselect_rows(void)
{
    // Hi-Z(DDR:0, PORT:0) to unselect
    DDRB  &= ~(1<<PB4);
    PORTB &= ~(1<<PB4);
    DDRD  &= ~(1<<PD7);
    PORTD &= ~(1<<PD7);
    DDRE  &= ~(1<<PE6);
    PORTE &= ~(1<<PE6);
    // Select 0
    DDRD  |=  (1<<PD3 | 1<<PD2 | 1<<PD0);
    PORTD &= ~(1<<PD3 | 1<<PD2 | 1<<PD0);
    DDRC  |=  (1<<PC6);
    PORTC &= ~(1<<PC6);
}

/* Row pin configuration
 * row:          x  0  1  2  3  4  5  6  7  8  9  10 11 12 13 14 15 16 17
 * pin: D8  PB4  -  0  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1
 *    / TX  PD3  0  0  1  0  1  0  1  0  1  0  1  0  1  0  1  0  1  0  0
 *    | RX  PD2  0  0  0  1  1  0  0  1  1  0  0  1  1  0  0  1  1  0  0
 *    | D3  PD0  0  0  0  0  0  1  1  1  1  0  0  0  0  1  1  1  1  0  0
 *    \ D5  PC6  0  0  0  0  0  0  0  0  0  1  1  1  1  1  1  1  1  0  0
 *      D6  PD7  -  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  0  1
 *      D7  PE6  -  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  0
 */
static void select_row(uint8_t row)
{
    // Output low(DDR:1, PORT:0) to select
    if (row == 0) {
        DDRB |= (1<<PB4);
        PORTB &= ~(1<<PB4);
    }
    else if (row < 16) {
        (row & (1<<0)) ? (PORTD |= (1<<PD3)) : (PORTD &= ~(1<<PD3));
        (row & (1<<1)) ? (PORTD |= (1<<PD2)) : (PORTD &= ~(1<<PD2));
        (row & (1<<2)) ? (PORTD |= (1<<PD0)) : (PORTD &= ~(1<<PD0));
        (row & (1<<3)) ? (PORTC |= (1<<PC6)) : (PORTC &= ~(1<<PC6));
    }
    else if (row == 16) {
        DDRD |= (1<<PD7);
        PORTD &= ~(1<<PD7);
    }
    else if (row == 17) {
        DDRE |= (1<<PE6);
        PORTE &= ~(1<<PE6);
    }
}