rtcget
error = rtcget(rtc, rtc->sec, &ct.sec);
error = rtcget(rtc, rtc->min, &ct.min);
error = rtcget(rtc, hour, &ct.hour);
error = rtcget(rtc, rtc->day_of_month, &ct.day);
error = rtcget(rtc, rtc->month, &ct.mon);
error = rtcget(rtc, rtc->year, &year);
error = rtcget(rtc, rtc->century, ¢ury);