/*

Note for ErgoDox EZ customizers: Here be dragons!
This is not a file you want to be messing with.
All of the interesting stuff for you is under keymaps/ :)
Love, Erez

Copyright 2013 Oleg Kostyuk <cub.uanic@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 "wait.h"
#include "action_layer.h"
#include "print.h"
#include "debug.h"
#include "util.h"
#include "matrix.h"
#include QMK_KEYBOARD_H
#ifdef DEBUG_MATRIX_SCAN_RATE
#include  "timer.h"
#endif

/*
 * This constant define not debouncing time in msecs, but amount of matrix
 * scan loops which should be made to get stable debounced results.
 *
 * On Ergodox matrix scan rate is relatively low, because of slow I2C.
 * Now it's only 317 scans/second, or about 3.15 msec/scan.
 * According to Cherry specs, debouncing time is 5 msec.
 *
 * However, some switches seem to have higher debouncing requirements, or
 * something else might be wrong. (Also, the scan speed has improved since
 * that comment was written.)
 */

#ifndef DEBOUNCE
#   define DEBOUNCE	5
#endif

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

// Debouncing: store for each key the number of scans until it's eligible to
// change.  When scanning the matrix, ignore any changes in keys that have
// already changed in the last DEBOUNCE scans.
static uint8_t debounce_matrix[MATRIX_ROWS * MATRIX_COLS];

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

static uint8_t mcp23018_reset_loop;
// static uint16_t mcp23018_reset_loop;

#ifdef DEBUG_MATRIX_SCAN_RATE
uint32_t matrix_timer;
uint32_t matrix_scan_count;
#endif


__attribute__ ((weak))
void matrix_init_user(void) {}

__attribute__ ((weak))
void matrix_scan_user(void) {}

__attribute__ ((weak))
void matrix_init_kb(void) {
  matrix_init_user();
}

__attribute__ ((weak))
void matrix_scan_kb(void) {
  matrix_scan_user();
}

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

    mcp23018_status = init_mcp23018();


    unselect_rows();
    init_cols();

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

#ifdef DEBUG_MATRIX_SCAN_RATE
    matrix_timer = timer_read32();
    matrix_scan_count = 0;
#endif

    matrix_init_quantum();

}

void matrix_power_up(void) {
    mcp23018_status = init_mcp23018();

    unselect_rows();
    init_cols();

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

#ifdef DEBUG_MATRIX_SCAN_RATE
    matrix_timer = timer_read32();
    matrix_scan_count = 0;
#endif
}

// Returns a matrix_row_t whose bits are set if the corresponding key should be
// eligible to change in this scan.
matrix_row_t debounce_mask(uint8_t row) {
  matrix_row_t result = 0;
  for (uint8_t j=0; j < MATRIX_COLS; ++j) {
    if (debounce_matrix[row * MATRIX_COLS + j]) {
      --debounce_matrix[row * MATRIX_COLS + j];
    } else {
      result |= (1 << j);
    }
  }
  return result;
}

// Report changed keys in the given row.  Resets the debounce countdowns
// corresponding to each set bit in 'change' to DEBOUNCE.
void debounce_report(matrix_row_t change, uint8_t row) {
  for (uint8_t i = 0; i < MATRIX_COLS; ++i) {
    if (change & (1 << i)) {
      debounce_matrix[row * MATRIX_COLS + i] = DEBOUNCE;
    }
  }
}

uint8_t matrix_scan(void)
{
    if (mcp23018_status) { // if there was an error
        if (++mcp23018_reset_loop == 0) {
        // if (++mcp23018_reset_loop >= 1300) {
            // since mcp23018_reset_loop is 8 bit - we'll try to reset once in 255 matrix scans
            // this will be approx bit more frequent than once per second
            print("trying to reset mcp23018\n");
            mcp23018_status = init_mcp23018();
            if (mcp23018_status) {
                print("left side not responding\n");
            } else {
                print("left side attached\n");
                ergodox_blink_all_leds();
            }
        }
    }

#ifdef DEBUG_MATRIX_SCAN_RATE
    matrix_scan_count++;

    uint32_t timer_now = timer_read32();
    if (TIMER_DIFF_32(timer_now, matrix_timer)>1000) {
        print("matrix scan frequency: ");
        pdec(matrix_scan_count);
        print("\n");

        matrix_timer = timer_now;
        matrix_scan_count = 0;
    }
#endif

#ifdef LEFT_LEDS
    mcp23018_status = ergodox_left_leds_update();
#endif // LEFT_LEDS
    for (uint8_t i = 0; i < MATRIX_ROWS_PER_SIDE; i++) {
        select_row(i);
        // and select on left hand
        select_row(i + MATRIX_ROWS_PER_SIDE);
        // we don't need a 30us delay anymore, because selecting a
        // left-hand row requires more than 30us for i2c.
        matrix_row_t mask = debounce_mask(i);
        matrix_row_t cols = (read_cols(i) & mask) | (matrix[i] & ~mask);
        debounce_report(cols ^ matrix[i], i);
        matrix[i] = cols;
        // grab cols from right hand
        mask = debounce_mask(i + MATRIX_ROWS_PER_SIDE);
        cols = (read_cols(i + MATRIX_ROWS_PER_SIDE) & mask) | (matrix[i + MATRIX_ROWS_PER_SIDE] & ~mask);
        debounce_report(cols ^ matrix[i + MATRIX_ROWS_PER_SIDE], i + MATRIX_ROWS_PER_SIDE);
        matrix[i + MATRIX_ROWS_PER_SIDE] = cols;
        unselect_rows();
    }

    matrix_scan_quantum();

    return 1;
}

bool matrix_is_modified(void) // deprecated and evidently not called.
{
    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
 *
 * Teensy
 * col: 0   1   2   3   4   5
 * pin: F0  F1  F4  F5  F6  F7
 *
 * MCP23018
 * col: 0   1   2   3   4   5
 * pin: B5  B4  B3  B2  B1  B0
 */
static void  init_cols(void)
{
    // init on mcp23018
    // not needed, already done as part of init_mcp23018()

    // init on teensy
    // Input with pull-up(DDR:0, PORT:1)
    DDRF  &= ~(1<<7 | 1<<6 | 1<<5 | 1<<4 | 1<<1 | 1<<0);
    PORTF |=  (1<<7 | 1<<6 | 1<<5 | 1<<4 | 1<<1 | 1<<0);
}

static matrix_row_t read_cols(uint8_t row)
{
    if (row < 7) {
        if (mcp23018_status) { // if there was an error
            return 0;
        } else {
            uint8_t data = 0;
            mcp23018_status = i2c_start(I2C_ADDR_WRITE, ERGODOX_EZ_I2C_TIMEOUT);    if (mcp23018_status) goto out;
            mcp23018_status = i2c_write(GPIOB, ERGODOX_EZ_I2C_TIMEOUT);             if (mcp23018_status) goto out;
            mcp23018_status = i2c_start(I2C_ADDR_READ, ERGODOX_EZ_I2C_TIMEOUT);     if (mcp23018_status) goto out;
            mcp23018_status = i2c_read_nack(ERGODOX_EZ_I2C_TIMEOUT);                if (mcp23018_status < 0) goto out;
            data = ~((uint8_t)mcp23018_status);
            mcp23018_status = I2C_STATUS_SUCCESS;
        out:
            i2c_stop(ERGODOX_EZ_I2C_TIMEOUT);
            return data;
        }
    } else {
        /* read from teensy
	 * bitmask is 0b11110011, but we want those all
	 * in the lower six bits.
	 * we'll return 1s for the top two, but that's harmless.
	 */

        return ~((PINF & 0x03) | ((PINF & 0xF0) >> 2));
    }
}

/* Row pin configuration
 *
 * Teensy
 * row: 7   8   9   10  11  12  13
 * pin: B0  B1  B2  B3  D2  D3  C6
 *
 * MCP23018
 * row: 0   1   2   3   4   5   6
 * pin: A0  A1  A2  A3  A4  A5  A6
 */
static void unselect_rows(void)
{
    // no need to unselect on mcp23018, because the select step sets all
    // the other row bits high, and it's not changing to a different
    // direction

    // unselect on teensy
    // Hi-Z(DDR:0, PORT:0) to unselect
    DDRB  &= ~(1<<0 | 1<<1 | 1<<2 | 1<<3);
    PORTB &= ~(1<<0 | 1<<1 | 1<<2 | 1<<3);
    DDRD  &= ~(1<<2 | 1<<3);
    PORTD &= ~(1<<2 | 1<<3);
    DDRC  &= ~(1<<6);
    PORTC &= ~(1<<6);
}

static void select_row(uint8_t row)
{
    if (row < 7) {
        // select on mcp23018
        if (mcp23018_status) { // if there was an error
            // do nothing
        } else {
            // set active row low  : 0
            // set other rows hi-Z : 1
            mcp23018_status = i2c_start(I2C_ADDR_WRITE, ERGODOX_EZ_I2C_TIMEOUT);        if (mcp23018_status) goto out;
            mcp23018_status = i2c_write(GPIOA, ERGODOX_EZ_I2C_TIMEOUT);                 if (mcp23018_status) goto out;
            mcp23018_status = i2c_write(0xFF & ~(1<<row), ERGODOX_EZ_I2C_TIMEOUT);      if (mcp23018_status) goto out;
        out:
            i2c_stop(ERGODOX_EZ_I2C_TIMEOUT);
        }
    } else {
        // select on teensy
        // Output low(DDR:1, PORT:0) to select
        switch (row) {
            case 7:
                DDRB  |= (1<<0);
                PORTB &= ~(1<<0);
                break;
            case 8:
                DDRB  |= (1<<1);
                PORTB &= ~(1<<1);
                break;
            case 9:
                DDRB  |= (1<<2);
                PORTB &= ~(1<<2);
                break;
            case 10:
                DDRB  |= (1<<3);
                PORTB &= ~(1<<3);
                break;
            case 11:
                DDRD  |= (1<<2);
                PORTD &= ~(1<<3);
                break;
            case 12:
                DDRD  |= (1<<3);
                PORTD &= ~(1<<3);
                break;
            case 13:
                DDRC  |= (1<<6);
                PORTC &= ~(1<<6);
                break;
        }
    }
}