TMP451_REG_CONALERT
val = lm90_read_reg(client, TMP451_REG_CONALERT);
reg = i2c_smbus_read_byte_data(client, TMP451_REG_CONALERT);
TMP451_REG_CONALERT);
err = lm90_write_reg(data->client, TMP451_REG_CONALERT,