text: /****************************************************************************
   *
   *   Copyright (c) 2019 PX4 Development Team. All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   * 3. Neither the name PX4 nor the names of its contributors may be
   *    used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
   * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
   * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
   * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
   * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
   * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
   * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
   * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   *
   ****************************************************************************/
  
  #pragma once
  
  
  #include <px4_config.h>
  #include <lib/perf/perf_counter.h>
  #include <systemlib/conversions.h>
  #include <drivers/drv_hrt.h>
  #include <drivers/device/i2c.h>
  #include <px4_platform_common/px4_work_queue/ScheduledWorkItem.hpp>
  #include <lib/drivers/magnetometer/PX4Magnetometer.hpp>
  
  #define AK09916_DEVICE_PATH_MAG              "/dev/ak09916_i2c_int"
  #define AK09916_DEVICE_PATH_MAG_EXT          "/dev/ak09916_i2c_ext"
  
  /* in 16-bit sampling mode the mag resolution is 1.5 milli Gauss per bit */
  static constexpr float AK09916_MAG_RANGE_GA{1.5e-3f};
  
  /* ak09916 deviating register addresses and bit definitions */
  #define AK09916_I2C_ADDR         0x0C
  
  #define AK09916_DEVICE_ID_A		0x48
  #define AK09916_DEVICE_ID_B		0x09	// additional ID byte ("INFO" on AK9063 without content specification.)
  
  #define AK09916REG_WIA           0x00
  
  #define AK09916REG_ST1        0x10
  #define AK09916REG_CNTL2          0x31
  #define AK09916REG_CNTL3          0x32
  
  #define AK09916_RESET				0x01
  #define AK09916_CNTL2_SINGLE_MODE               0x01 /* default */
  #define AK09916_CNTL2_CONTINOUS_MODE_100HZ      0x08
  
  #pragma pack(push, 1)
  struct ak09916_regs {
  	uint8_t st1;
  	int16_t x;
  	int16_t y;
  	int16_t z;
  	uint8_t tmps;
  	uint8_t st2;
  };
  #pragma pack(pop)
  
  /**
   * Helper class implementing the magnetometer driver node.
   */
  class AK09916 : public device::I2C, px4::ScheduledWorkItem
  {
  public:
  	AK09916(int bus, const char *path, enum Rotation rotation);
  	~AK09916();
  
  	virtual int init();
  
  	void read_block(uint8_t reg, uint8_t *val, uint8_t count);
  
  	int reset(void);
  	int probe(void);
  	int setup(void);
  	void print_info(void);
  	int setup_master_i2c(void);
  	bool check_id(uint8_t &id);
  
  	void Run();
  
  	void start(void);
  	void stop(void);
  
  protected:
  
  	/* Directly measure from the _interface if possible */
  	void measure();
  
  	uint8_t read_reg(uint8_t reg);
  	void write_reg(uint8_t reg, uint8_t value);
  
  private:
  
  	PX4Magnetometer _px4_mag;
  
  	uint32_t _measure_interval{0};
  
  	perf_counter_t _mag_reads;
  	perf_counter_t _mag_errors;
  	perf_counter_t _mag_overruns;
  	perf_counter_t _mag_overflows;
  	perf_counter_t _mag_duplicates;
  
  	bool check_duplicate(uint8_t *mag_data);
  
  	// keep last mag reading for duplicate detection
  	uint8_t			_last_mag_data[6] {};
  
  	/* do not allow to copy this class due to pointer data members */
  	AK09916(const AK09916 &);
  	AK09916 operator=(const AK09916 &);
  };
  