text: /*
   * Copyright 2018 Jack Humbert <jack.humb@gmail.com>
   * Copyright 2019 Drashna Jaelre (Christopher Courtney) <drashna@live.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 "dip_switch.h"
  
  // for memcpy
  #include <string.h>
  
  #if !defined(DIP_SWITCH_PINS) && !defined(DIP_SWITCH_MATRIX_GRID)
  #    error "Either DIP_SWITCH_PINS or DIP_SWITCH_MATRIX_GRID must be defined."
  #endif
  
  #if defined(DIP_SWITCH_PINS) && defined(DIP_SWITCH_MATRIX_GRID)
  #    error "Both DIP_SWITCH_PINS and DIP_SWITCH_MATRIX_GRID are defined."
  #endif
  
  #ifdef DIP_SWITCH_PINS
  #    define NUMBER_OF_DIP_SWITCHES (sizeof(dip_switch_pad) / sizeof(pin_t))
  static pin_t dip_switch_pad[] = DIP_SWITCH_PINS;
  #endif
  
  #ifdef DIP_SWITCH_MATRIX_GRID
  typedef struct matrix_index_t {
      uint8_t row;
      uint8_t col;
  } matrix_index_t;
  
  #    define NUMBER_OF_DIP_SWITCHES (sizeof(dip_switch_pad) / sizeof(matrix_index_t))
  static matrix_index_t dip_switch_pad[] = DIP_SWITCH_MATRIX_GRID;
  extern bool           peek_matrix(uint8_t row_index, uint8_t col_index, bool read_raw);
  static uint16_t       scan_count;
  #endif /* DIP_SWITCH_MATRIX_GRID */
  
  static bool dip_switch_state[NUMBER_OF_DIP_SWITCHES]      = {0};
  static bool last_dip_switch_state[NUMBER_OF_DIP_SWITCHES] = {0};
  
  __attribute__((weak)) void dip_switch_update_user(uint8_t index, bool active) {}
  
  __attribute__((weak)) void dip_switch_update_kb(uint8_t index, bool active) { dip_switch_update_user(index, active); }
  
  __attribute__((weak)) void dip_switch_update_mask_user(uint32_t state) {}
  
  __attribute__((weak)) void dip_switch_update_mask_kb(uint32_t state) { dip_switch_update_mask_user(state); }
  
  void dip_switch_init(void) {
  #ifdef DIP_SWITCH_PINS
      for (uint8_t i = 0; i < NUMBER_OF_DIP_SWITCHES; i++) {
          setPinInputHigh(dip_switch_pad[i]);
      }
      dip_switch_read(true);
  #endif
  #ifdef DIP_SWITCH_MATRIX_GRID
      scan_count = 0;
  #endif
  }
  
  void dip_switch_read(bool forced) {
      bool     has_dip_state_changed = false;
      uint32_t dip_switch_mask       = 0;
  
  #ifdef DIP_SWITCH_MATRIX_GRID
      bool read_raw = false;
  
      if (scan_count < 500) {
          scan_count++;
          if (scan_count == 10) {
              read_raw = true;
              forced   = true; /* First reading of the dip switch */
          } else {
              return;
          }
      }
  #endif
  
      for (uint8_t i = 0; i < NUMBER_OF_DIP_SWITCHES; i++) {
  #ifdef DIP_SWITCH_PINS
          dip_switch_state[i] = !readPin(dip_switch_pad[i]);
  #endif
  #ifdef DIP_SWITCH_MATRIX_GRID
          dip_switch_state[i] = peek_matrix(dip_switch_pad[i].row, dip_switch_pad[i].col, read_raw);
  #endif
          dip_switch_mask |= dip_switch_state[i] << i;
          if (last_dip_switch_state[i] != dip_switch_state[i] || forced) {
              has_dip_state_changed = true;
              dip_switch_update_kb(i, dip_switch_state[i]);
          }
      }
      if (has_dip_state_changed) {
          dip_switch_update_mask_kb(dip_switch_mask);
          memcpy(last_dip_switch_state, dip_switch_state, sizeof(dip_switch_state));
      }
  }
  