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path: root/drivers/rtc/rtc-lib.c
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Diffstat (limited to 'drivers/rtc/rtc-lib.c')
-rw-r--r--drivers/rtc/rtc-lib.c19
1 files changed, 19 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-lib.c b/drivers/rtc/rtc-lib.c
index cfedc1d28ee1..9812120f3a7c 100644
--- a/drivers/rtc/rtc-lib.c
+++ b/drivers/rtc/rtc-lib.c
@@ -18,9 +18,19 @@ static const unsigned char rtc_days_in_month[] = {
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);
@@ -28,6 +38,15 @@ int rtc_month_days(unsigned int month, unsigned int year)
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.
*/
void rtc_time_to_tm(unsigned long time, struct rtc_time *tm)