[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>
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2 changed files with 20 additions and 0 deletions
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@ -18,15 +18,34 @@ static const unsigned char rtc_days_in_month[] = {
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31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
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};
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static const unsigned short rtc_ydays[2][13] = {
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/* Normal years */
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{ 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
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/* Leap years */
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{ 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
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};
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#define LEAPS_THRU_END_OF(y) ((y)/4 - (y)/100 + (y)/400)
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#define LEAP_YEAR(year) ((!(year % 4) && (year % 100)) || !(year % 400))
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/*
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* The number of days in the month.
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*/
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int rtc_month_days(unsigned int month, unsigned int year)
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{
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return rtc_days_in_month[month] + (LEAP_YEAR(year) && month == 1);
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}
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EXPORT_SYMBOL(rtc_month_days);
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/*
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* The number of days since January 1. (0 to 365)
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*/
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int rtc_year_days(unsigned int day, unsigned int month, unsigned int year)
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{
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return rtc_ydays[LEAP_YEAR(year)][month] + day-1;
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}
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EXPORT_SYMBOL(rtc_year_days);
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/*
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* Convert seconds since 01-01-1970 00:00:00 to Gregorian date.
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*/
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@ -102,6 +102,7 @@ struct rtc_pll_info {
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#include <linux/interrupt.h>
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extern int rtc_month_days(unsigned int month, unsigned int year);
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extern int rtc_year_days(unsigned int day, unsigned int month, unsigned int year);
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extern int rtc_valid_tm(struct rtc_time *tm);
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extern int rtc_tm_to_time(struct rtc_time *tm, unsigned long *time);
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extern void rtc_time_to_tm(unsigned long time, struct rtc_time *tm);
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