/*
Copyright 2011 Jun Wako <[email protected]>

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 "print.h"
#include "debug.h"
#include "util.h"
#include "matrix.h"


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

// bit array of key state(1:on, 0:off)
static matrix_row_t *matrix;
static matrix_row_t *matrix_debounced;
static matrix_row_t _matrix0[MATRIX_ROWS];
static matrix_row_t _matrix1[MATRIX_ROWS];


#define NROW 18
#define NCOL 8
#define _DDRA (uint8_t *const)&DDRA
#define _DDRB (uint8_t *const)&DDRB
#define _DDRC (uint8_t *const)&DDRC
#define _DDRD (uint8_t *const)&DDRD
#define _DDRE (uint8_t *const)&DDRE
#define _DDRF (uint8_t *const)&DDRF

#define _PINA (uint8_t *const)&PINA
#define _PINB (uint8_t *const)&PINB
#define _PINC (uint8_t *const)&PINC
#define _PIND (uint8_t *const)&PIND
#define _PINE (uint8_t *const)&PINE
#define _PINF (uint8_t *const)&PINF

#define _PORTA (uint8_t *const)&PORTA
#define _PORTB (uint8_t *const)&PORTB
#define _PORTC (uint8_t *const)&PORTC
#define _PORTD (uint8_t *const)&PORTD
#define _PORTE (uint8_t *const)&PORTE
#define _PORTF (uint8_t *const)&PORTF

#define _BIT0 0x01
#define _BIT1 0x02
#define _BIT2 0x04
#define _BIT3 0x08
#define _BIT4 0x10
#define _BIT5 0x20
#define _BIT6 0x40
#define _BIT7 0x80

/* Specifies the ports and pin numbers for the rows */
static
uint8_t *const  row_ddr[NROW] = {                                 _DDRB,                  _DDRB,
				                                                  _DDRC,  _DDRC,
				  _DDRD,  _DDRD,  _DDRD,  _DDRD,  _DDRD,  _DDRD,  _DDRD,  _DDRD,
				  _DDRF,  _DDRF,                  _DDRF,  _DDRF,  _DDRF,  _DDRF};

static
uint8_t *const row_port[NROW] = {                                _PORTB,                 _PORTB,
				 _PORTC, _PORTC,
				 _PORTD, _PORTD, _PORTD, _PORTD, _PORTD, _PORTD, _PORTD, _PORTD,
				 _PORTF, _PORTF,                 _PORTF, _PORTF, _PORTF, _PORTF};

static
uint8_t *const  row_pin[NROW] = {                                 _PINB,                  _PINB,
				  _PINC,  _PINC,
				  _PIND,  _PIND,  _PIND,  _PIND,  _PIND,  _PIND,  _PIND,  _PIND,
				  _PINF,  _PINF,                  _PINF,  _PINF,  _PINF,  _PINF};

static
const uint8_t   row_bit[NROW] = {                                 _BIT4,                  _BIT7,
				                                                  _BIT6,  _BIT7,
				  _BIT0,  _BIT1,  _BIT2,  _BIT3,  _BIT4,  _BIT5,  _BIT6,  _BIT7,
				  _BIT0,  _BIT1,                  _BIT4,  _BIT5,  _BIT6,  _BIT7};

static
const uint8_t mask = 0x0E;

/* Specifies the ports and pin numbers for the columns */
static
const uint8_t   col_bit[NCOL] = {  0x00,   0x02,   0x04,   0x06,   0x08,   0x0A,   0x0C,   0x0E};

static
inline void pull_column(int col) {
  PORTB = col_bit[col] | (PORTB & ~mask);
}

static
inline void release_column(int col) {
}

/* PORTB is set as input with pull-up resistors
   PORTC,D,E,F are set to high output */
static
void setup_io_pins(void) {
  uint8_t row;
  DDRB  |=  0x0E;
  PORTB &= ~0x0E;
  for(row = 0; row < NROW; row++) {
    *row_ddr[row]  &= ~row_bit[row];
    *row_port[row] &= ~row_bit[row];
  }
}

static
void setup_leds(void) {
  DDRB  |=  0x60;
  PORTB |=  0x60;
}


inline
uint8_t matrix_rows(void)
{
    return MATRIX_ROWS;
}

inline
uint8_t matrix_cols(void)
{
    return MATRIX_COLS;
}

void matrix_init(void)
{
    // initialize row and col
    setup_io_pins();
    setup_leds();

    // initialize matrix state: all keys off
    for (uint8_t i=0; i < MATRIX_ROWS; i++) _matrix0[i] = 0x00;
    for (uint8_t i=0; i < MATRIX_ROWS; i++) _matrix1[i] = 0x00;
    matrix = _matrix0;
    matrix_debounced = _matrix1;
}

uint8_t matrix_scan(void)
{
    if (!debouncing) {
        uint8_t *tmp = matrix_debounced;
        matrix_debounced = matrix;
        matrix = tmp;
    }

    for (uint8_t col = 0; col < NCOL; col++) {  // 0-7
        pull_column(col);   // output hi on theline
        _delay_us(1);       // without this wait it won't read stable value.
        for (uint8_t row = 0; row < NROW; row++) {  // 0-17
            bool prev_bit = matrix[row] & (1<<col);
            bool curr_bit = *row_pin[row] & row_bit[row];
            if (prev_bit != curr_bit) {
                matrix[row] ^= (1<<col);
                if (debouncing) {
                    debug("bounce!: "); debug_hex(debouncing); print("\n");
                }
                debouncing = DEBOUNCE;
            }
        }
        release_column(col);
    }

    if (debouncing) {
        debouncing--;
    }

    return 1;
}

bool matrix_is_modified(void)
{
    // NOTE: no longer used
    return true;
}

inline
bool matrix_has_ghost(void)
{
    return false;
}

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

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

void matrix_print(void)
{
    print("\nr/c 01234567\n");
    for (uint8_t row = 0; row < MATRIX_ROWS; row++) {
        phex(row); print(": ");
        pbin_reverse(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++) {
        for (uint8_t j = 0; j < MATRIX_COLS; j++) {
            if (matrix_is_on(i, j))
                count++;
        }
    }
    return count;
}