diff options
Diffstat (limited to 'drivers/rtc/rtc-lib.c')
| -rw-r--r-- | drivers/rtc/rtc-lib.c | 19 |
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) |