text: /* mbed Microcontroller Library
   * Copyright (c) 2006-2017 ARM Limited
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  #include "min_battery_voltage.h"
  
  /** Defining HAL_MspInit strong function
   * in user defined file as described in documentation
   */
  
  void HAL_MspInit(void)
  {
      set_minimum_battery_voltage();
  }
  
  void set_minimum_battery_voltage()
  {
      i2c_t i2c_obj = {0};
      int data_read;
      i2c_init(&i2c_obj, I2C_SDA_B, I2C_SCL_B);
      i2c_frequency(&i2c_obj, I2C_FREQUENCY);
  
      if (read_from_i2c(BQ24295_I2C_ADDRESS, 0, &data_read, i2c_obj)) {
          data_read = data_read & MIN_BATTERY_VOLTAGE_MASK;
          write_to_i2c(BQ24295_I2C_ADDRESS, 0, data_read, i2c_obj);
              //Battery Voltage is set to 3880mV
      } else {
          // Minimum battery voltage could not be set.  This is not a critical error, no need to stop execution
          // It simply means that longer cabling or USB ports with lower output voltages may cause problems.
      }
  }
  
  char write_to_i2c(int slave_addr, int reg_addr, int data_write, i2c_t i2c_obj)
  {
      char ret_code = 0;
      if (!i2c_start(&i2c_obj)) {
          if ((i2c_byte_write(&i2c_obj, slave_addr << 1) == 1) &&
              (i2c_byte_write(&i2c_obj, reg_addr) == 1) &&
              (i2c_byte_write(&i2c_obj,data_write) ==1)) {
                   ret_code = 1;
          }
          i2c_stop(&i2c_obj);
      }
      return ret_code;
  }
  
  char read_from_i2c(int slave_addr, int reg_addr, int* data_read, i2c_t i2c_obj)
  {
      char ret_code = 0;
      if (!i2c_start(&i2c_obj)) {
          if ((i2c_byte_write(&i2c_obj,(slave_addr << 1))==1) &&
              (i2c_byte_write(&i2c_obj, reg_addr)==1) &&
              (!i2c_start(&i2c_obj)) &&
              (i2c_byte_write(&i2c_obj, ((slave_addr << 1) | 0x01)) == 1)) {
               *data_read = i2c_byte_read(&i2c_obj,1);
               ret_code = 1;
          }
          i2c_stop(&i2c_obj);
      }
      return ret_code;
  }
  