em3027rtc_read_byte
static int em3027rtc_read_byte(struct em3027rtc_softc *, uint8_t, uint8_t *);
error = em3027rtc_read_byte(sc, EM3027_EEPROM_CTL, &eeprom_ctl);
error = em3027rtc_read_byte(sc, EM3027_STATUS, &status);
error = em3027rtc_read_byte(sc, EM3027_TEMP, &t_raw);