+static int cmos_validate_alarm(struct device *dev, struct rtc_wkalrm *t)
+{
+ struct cmos_rtc *cmos = dev_get_drvdata(dev);
+ struct rtc_time now;
+
+ cmos_read_time(dev, &now);
+
+ if (!cmos->day_alrm) {
+ time64_t t_max_date;
+ time64_t t_alrm;
+
+ t_max_date = rtc_tm_to_time64(&now);
+ t_max_date += 24 * 60 * 60 - 1;
+ t_alrm = rtc_tm_to_time64(&t->time);
+ if (t_alrm > t_max_date) {
+ dev_err(dev,
+ "Alarms can be up to one day in the future\n");
+ return -EINVAL;
+ }
+ } else if (!cmos->mon_alrm) {
+ struct rtc_time max_date = now;
+ time64_t t_max_date;
+ time64_t t_alrm;
+ int max_mday;
+
+ if (max_date.tm_mon == 11) {
+ max_date.tm_mon = 0;
+ max_date.tm_year += 1;
+ } else {
+ max_date.tm_mon += 1;
+ }
+ max_mday = rtc_month_days(max_date.tm_mon, max_date.tm_year);
+ if (max_date.tm_mday > max_mday)
+ max_date.tm_mday = max_mday;
+
+ t_max_date = rtc_tm_to_time64(&max_date);
+ t_max_date -= 1;
+ t_alrm = rtc_tm_to_time64(&t->time);
+ if (t_alrm > t_max_date) {
+ dev_err(dev,
+ "Alarms can be up to one month in the future\n");
+ return -EINVAL;
+ }
+ } else {
+ struct rtc_time max_date = now;
+ time64_t t_max_date;
+ time64_t t_alrm;
+ int max_mday;
+
+ max_date.tm_year += 1;
+ max_mday = rtc_month_days(max_date.tm_mon, max_date.tm_year);
+ if (max_date.tm_mday > max_mday)
+ max_date.tm_mday = max_mday;
+
+ t_max_date = rtc_tm_to_time64(&max_date);
+ t_max_date -= 1;
+ t_alrm = rtc_tm_to_time64(&t->time);
+ if (t_alrm > t_max_date) {
+ dev_err(dev,
+ "Alarms can be up to one year in the future\n");
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+