PX4-Autopilot/src/drivers/lps25h/lps25h_i2c.cpp

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/**
 * @file LPS25H_I2C.cpp
 *
 * I2C interface for LPS25H
 */

/* XXX trim includes */
#include <px4_config.h>

#include <sys/types.h>
#include <stdint.h>
#include <stdbool.h>
#include <string.h>
#include <assert.h>
#include <debug.h>
#include <errno.h>
#include <unistd.h>

#include <arch/board/board.h>

#include <drivers/device/i2c.h>
#include <drivers/drv_mag.h>
#include <drivers/drv_device.h>

#include "lps25h.h"

#include "board_config.h"

#define LPS25H_ADDRESS		0x5D

device::Device *LPS25H_I2C_interface(int bus);

class LPS25H_I2C : public device::I2C
{
public:
	LPS25H_I2C(int bus);
	virtual ~LPS25H_I2C();

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

	virtual int	ioctl(unsigned operation, unsigned &arg);

protected:
	virtual int	probe();

};

device::Device *
LPS25H_I2C_interface(int bus)
{
	return new LPS25H_I2C(bus);
}

LPS25H_I2C::LPS25H_I2C(int bus) :
	I2C("LPS25H_I2C", nullptr, bus, LPS25H_ADDRESS, 400000)
{
}

LPS25H_I2C::~LPS25H_I2C()
{
}

int
LPS25H_I2C::init()
{
	/* this will call probe() */
	return I2C::init();
}

int
LPS25H_I2C::ioctl(unsigned operation, unsigned &arg)
{
	int ret;

	switch (operation) {

	case DEVIOCGDEVICEID:
		return CDev::ioctl(nullptr, operation, arg);

	default:
		ret = -EINVAL;
	}

	return ret;
}

int
LPS25H_I2C::probe()
{
	uint8_t id;

	_retries = 10;

	if (read(ADDR_WHO_AM_I, &id, 1)) {
		DEVICE_DEBUG("read_reg fail");
		return -EIO;
	}

	_retries = 2;

	if (id != ID_WHO_AM_I) {
		DEVICE_DEBUG("ID byte mismatch (%02x != %02x)", ID_WHO_AM_I, id);
		return -EIO;
	}

	return OK;
}

int
LPS25H_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
LPS25H_I2C::read(unsigned address, void *data, unsigned count)
{
	uint8_t cmd = address;
	return transfer(&cmd, 1, (uint8_t *)data, count);
}