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/**
 * @file HMC5883_I2C.cpp
 *
 * I2C interface for HMC5883 / HMC 5983
 */

#include <px4_platform_common/px4_config.h>
#include <drivers/device/i2c.h>

#include "hmc5883.h"

#define HMC5883L_ADDRESS		0x1E

device::Device *HMC5883_I2C_interface(int bus, int bus_frequency);

class HMC5883_I2C : public device::I2C
{
public:
	HMC5883_I2C(int bus, int bus_frequency);
	virtual ~HMC5883_I2C() = default;

	virtual int	read(unsigned address, void *data, unsigned count);
	virtual int	write(unsigned address, void *data, unsigned count);

protected:
	virtual int	probe();
};

device::Device *
HMC5883_I2C_interface(int bus, int bus_frequency)
{
	return new HMC5883_I2C(bus, bus_frequency);
}

HMC5883_I2C::HMC5883_I2C(int bus, int bus_frequency) :
	I2C(DRV_MAG_DEVTYPE_HMC5883, MODULE_NAME, bus, HMC5883L_ADDRESS, bus_frequency)
{
}

int HMC5883_I2C::probe()
{
	uint8_t data[3] = {0, 0, 0};

	_retries = 10;

	if (read(ADDR_ID_A, &data[0], 1) ||
	    read(ADDR_ID_B, &data[1], 1) ||
	    read(ADDR_ID_C, &data[2], 1)) {
		DEVICE_DEBUG("read_reg fail");
		return -EIO;
	}

	_retries = 2;

	if ((data[0] != ID_A_WHO_AM_I) ||
	    (data[1] != ID_B_WHO_AM_I) ||
	    (data[2] != ID_C_WHO_AM_I)) {
		DEVICE_DEBUG("ID byte mismatch (%02x,%02x,%02x)", data[0], data[1], data[2]);
		return -EIO;
	}

	return OK;
}

int HMC5883_I2C::write(unsigned address, void *data, unsigned count)
{
	uint8_t buf[32];

	if (sizeof(buf) < (count + 1)) {
		return -EIO;
	}

	buf[0] = address;
	memcpy(&buf[1], data, count);

	return transfer(&buf[0], count + 1, nullptr, 0);
}

int HMC5883_I2C::read(unsigned address, void *data, unsigned count)
{
	uint8_t cmd = address;
	return transfer(&cmd, 1, (uint8_t *)data, count);
}
