acrtc_read_reg
dt->dt_sec = FROMBCD(acrtc_read_reg(sc, RTC_SEC) & RTC_SEC_MASK);
dt->dt_min = FROMBCD(acrtc_read_reg(sc, RTC_MIN) & RTC_MIN_MASK);
dt->dt_hour = FROMBCD(acrtc_read_reg(sc, RTC_HOU) & RTC_HOU_MASK);
dt->dt_day = FROMBCD(acrtc_read_reg(sc, RTC_DAY) & RTC_DAY_MASK);
dt->dt_mon = FROMBCD(acrtc_read_reg(sc, RTC_MON) & RTC_MON_MASK);
dt->dt_year = FROMBCD(acrtc_read_reg(sc, RTC_YEA) & RTC_YEA_MASK);
ctrl = acrtc_read_reg(sc, RTC_CTRL);
reg = acrtc_read_reg(sc, CK32K_OUT_CTRL1 + idx);