31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
};
+static const unsigned short rtc_ydays[2][13] = {
+ /* Normal years */
+ { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
+ /* Leap years */
+ { 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
+};
+
#define LEAPS_THRU_END_OF(y) ((y)/4 - (y)/100 + (y)/400)
#define LEAP_YEAR(year) ((!(year % 4) && (year % 100)) || !(year % 400))
+/*
+ * The number of days in the month.
+ */
int rtc_month_days(unsigned int month, unsigned int year)
{
return rtc_days_in_month[month] + (LEAP_YEAR(year) && month == 1);
}
EXPORT_SYMBOL(rtc_month_days);
+/*
+ * The number of days since January 1. (0 to 365)
+ */
+int rtc_year_days(unsigned int day, unsigned int month, unsigned int year)
+{
+ return rtc_ydays[LEAP_YEAR(year)][month] + day-1;
+}
+EXPORT_SYMBOL(rtc_year_days);
+
/*
* Convert seconds since 01-01-1970 00:00:00 to Gregorian date.
*/
int rtc_valid_tm(struct rtc_time *tm)
{
if (tm->tm_year < 70
- || tm->tm_mon >= 12
+ || ((unsigned)tm->tm_mon) >= 12
|| tm->tm_mday < 1
|| tm->tm_mday > rtc_month_days(tm->tm_mon, tm->tm_year + 1900)
- || tm->tm_hour >= 24
- || tm->tm_min >= 60
- || tm->tm_sec >= 60)
+ || ((unsigned)tm->tm_hour) >= 24
+ || ((unsigned)tm->tm_min) >= 60
+ || ((unsigned)tm->tm_sec) >= 60)
return -EINVAL;
return 0;
}
EXPORT_SYMBOL(rtc_tm_to_time);
+
+/* Merge the valid (i.e. non-negative) fields of alarm into the current
+ * time. If the valid alarm fields are earlier than the equivalent
+ * fields in the time, carry one into the least significant invalid
+ * field, so that the alarm expiry is in the future. It assumes that the
+ * least significant invalid field is more significant than the most
+ * significant valid field, and that the seconds field is valid.
+ *
+ * This is used by alarms that take relative (rather than absolute)
+ * times, and/or have a simple binary second counter instead of
+ * day/hour/minute/sec registers.
+ */
+void rtc_merge_alarm(struct rtc_time *now, struct rtc_time *alarm)
+{
+ int *alarmp = &alarm->tm_sec;
+ int *timep = &now->tm_sec;
+ int carry_into, i;
+
+ /* Ignore everything past the 6th element (tm_year). */
+ for (i = 5; i > 0; i--) {
+ if (alarmp[i] < 0)
+ alarmp[i] = timep[i];
+ else
+ break;
+ }
+
+ /* No carry needed if all fields are valid. */
+ if (i == 5)
+ return;
+
+ for (carry_into = i + 1; i >= 0; i--) {
+ if (alarmp[i] < timep[i])
+ break;
+
+ if (alarmp[i] > timep[i])
+ return;
+ }
+
+ switch (carry_into) {
+ case 1:
+ alarm->tm_min++;
+
+ if (alarm->tm_min < 60)
+ return;
+
+ alarm->tm_min = 0;
+ /* fall-through */
+
+ case 2:
+ alarm->tm_hour++;
+
+ if (alarm->tm_hour < 60)
+ return;
+
+ alarm->tm_hour = 0;
+ /* fall-through */
+
+ case 3:
+ alarm->tm_mday++;
+
+ if (alarm->tm_mday <= rtc_days_in_month[alarm->tm_mon])
+ return;
+
+ alarm->tm_mday = 1;
+ /* fall-through */
+
+ case 4:
+ alarm->tm_mon++;
+
+ if (alarm->tm_mon <= 12)
+ return;
+
+ alarm->tm_mon = 1;
+ /* fall-through */
+
+ case 5:
+ alarm->tm_year++;
+ }
+}
+EXPORT_SYMBOL(rtc_merge_alarm);
+
MODULE_LICENSE("GPL");