NAU7802_REG_CTRL1
ret = i2c_smbus_read_byte_data(st->client, NAU7802_REG_CTRL1);
ret = i2c_smbus_write_byte_data(st->client, NAU7802_REG_CTRL1,
ret = i2c_smbus_read_byte_data(st->client, NAU7802_REG_CTRL1);
ret = i2c_smbus_write_byte_data(st->client, NAU7802_REG_CTRL1,