/*

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 "debounce.h"
#include QMK_KEYBOARD_H
#ifdef DEBUG_MATRIX_SCAN_RATE
#  include "timer.h"
#endif

/*
 * This constant define not debouncing time in msecs, assuming eager_pr.
 *
 * 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 raw_matrix[MATRIX_ROWS];  // raw values
static matrix_row_t matrix[MATRIX_ROWS];      // debounced values

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;
    raw_matrix[i] = 0;    
  }

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

// Reads and stores a row, returning
// whether a change occurred.
static inline bool store_raw_matrix_row(uint8_t index) {
  matrix_row_t temp = read_cols(index);
  if (raw_matrix[index] != temp) {
    raw_matrix[index] = temp;
    return true;
  }
  return false;
}

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
  bool changed = false;  
  for (uint8_t i = 0; i < MATRIX_ROWS_PER_SIDE; i++) {
    // select rows from left and right hands
    uint8_t left_index = i;
    uint8_t right_index = i + MATRIX_ROWS_PER_SIDE;
    select_row(left_index);
    select_row(right_index);

    // we don't need a 30us delay anymore, because selecting a
    // left-hand row requires more than 30us for i2c.
    
    changed |= store_raw_matrix_row(left_index);
    changed |= store_raw_matrix_row(right_index);

    unselect_rows();
  }
  
  debounce(raw_matrix, matrix, MATRIX_ROWS, changed);
  matrix_scan_quantum();

  return (uint8_t)changed;
}

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();
      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();
    }
  } 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 << 2);
        break;
      case 12:
        DDRD |= (1 << 3);
        PORTD &= ~(1 << 3);
        break;
      case 13:
        DDRC |= (1 << 6);
        PORTC &= ~(1 << 6);
        break;
    }
  }
}
