MAX44009_REG_CFG
int ret = i2c_smbus_read_byte_data(data->client, MAX44009_REG_CFG);
ret = i2c_smbus_read_byte_data(client, MAX44009_REG_CFG);
return i2c_smbus_write_byte_data(client, MAX44009_REG_CFG, config);
ret = i2c_smbus_read_byte_data(client, MAX44009_REG_CFG);