rtc_tm_sub
if (!alarm->enabled || rtc_tm_sub(alarm_tm, &rtc_tm) <= 0)
if (!alarm->enabled || rtc_tm_sub(alarm_tm, &rtc_tm) <= 0)
if (rtc_tm_sub(tm, &tm_now) > 59 || tm->tm_min != tm_now.tm_min)
if (!rtc->rtc->aie_timer.enabled || rtc_tm_sub(&aie_time, &alrm->time))
diff = rtc_tm_sub(alrm_tm, &tm_now);