diff options
| author | Andrew Victor <andrew@sanpeople.com> | 2006-06-25 05:48:25 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-06-25 10:01:14 -0700 |
| commit | 8232212e0b4ee4eb3e407f5a9b098f6377820164 (patch) | |
| tree | 427b2c0a935e880d0a949f22072af207ade1e793 /drivers | |
| parent | 362600fe60fd18a25b4de8ec544b9e24e77e1484 (diff) | |
[PATCH] RTC: Add rtc_year_days() to calculate tm_yday
RTC: Add exported function rtc_year_days() to calculate the tm_yday value.
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'drivers')
| -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 cfedc1d28ee..9812120f3a7 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) |