lps25h_i2c.cpp

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

#include "lps25h.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() = default;

    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)
{
}

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);
}