lis3mdl_i2c.cpp

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/**
 * @file lis3mdl_i2c.cpp
 *
 * I2C interface for LIS3MDL
 */

#include <px4_platform_common/px4_config.h>

#include <assert.h>
#include <debug.h>
#include <errno.h>
#include <stdint.h>
#include <stdbool.h>
#include <string.h>
#include <sys/types.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 "board_config.h"
#include "lis3mdl.h"

#if defined(PX4_I2C_BUS_ONBOARD) || defined(PX4_I2C_BUS_EXPANSION)

#define LIS3MDLL_ADDRESS        0x1e

class LIS3MDL_I2C : public device::I2C
{
public:
    LIS3MDL_I2C(int bus);
    virtual ~LIS3MDL_I2C() = default;

    virtual int     ioctl(unsigned operation, unsigned &arg);
    virtual int     read(unsigned address, void *data, unsigned count);
    virtual int     write(unsigned address, void *data, unsigned count);

protected:
    virtual int     probe();

};

device::Device *
LIS3MDL_I2C_interface(int bus);

device::Device *
LIS3MDL_I2C_interface(int bus)
{
    return new LIS3MDL_I2C(bus);
}

LIS3MDL_I2C::LIS3MDL_I2C(int bus) :
    I2C("LIS3MDL_I2C", nullptr, bus, LIS3MDLL_ADDRESS, 400000)
{
    _device_id.devid_s.devtype = DRV_MAG_DEVTYPE_LIS3MDL;
}

int
LIS3MDL_I2C::ioctl(unsigned operation, unsigned &arg)
{
    switch (operation) {

    case MAGIOCGEXTERNAL:
        return external();

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

    default:
        return  -EINVAL;
    }
}

int
LIS3MDL_I2C::probe()
{
    uint8_t data = 0;

    _retries = 10;

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

    _retries = 2;

    if (data != ID_WHO_AM_I) {
        DEVICE_DEBUG("LIS3MDL bad ID: %02x", data);
        return -EIO;
    }

    return OK;
}

int
LIS3MDL_I2C::read(unsigned address, void *data, unsigned count)
{
    uint8_t cmd = address;
    return transfer(&cmd, 1, (uint8_t *)data, count);
}

int
LIS3MDL_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);
}

#endif /* PX4_I2C_OBDEV_LIS3MDL */