| /* |
| * (C) Copyright 2001 |
| * Wolfgang Denk, DENX Software Engineering, wd@denx.de. |
| * |
| * See file CREDITS for list of people who contributed to this |
| * project. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License as |
| * published by the Free Software Foundation; either version 2 of |
| * the License, or (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, |
| * MA 02111-1307 USA |
| */ |
| |
| /** |
| * @file |
| * @brief Date & Time support |
| */ |
| |
| #include <common.h> |
| #include <command.h> |
| #include <rtc.h> |
| |
| #define FEBRUARY 2 |
| #define STARTOFTIME 1970 |
| #define SECDAY 86400L |
| #define SECYR (SECDAY * 365) |
| #define leapyear(year) ((year) % 4 == 0) |
| #define days_in_year(a) (leapyear(a) ? 366 : 365) |
| #define days_in_month(a) (month_days[(a) - 1]) |
| |
| static int month_days[12] = { |
| 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 |
| }; |
| |
| /* |
| * This only works for the Gregorian calendar - i.e. after 1752 (in the UK) |
| */ |
| void GregorianDay(struct rtc_time * tm) |
| { |
| int leapsToDate; |
| int lastYear; |
| int day; |
| int MonthOffset[] = { 0,31,59,90,120,151,181,212,243,273,304,334 }; |
| |
| lastYear=tm->tm_year-1; |
| |
| /* |
| * Number of leap corrections to apply up to end of last year |
| */ |
| leapsToDate = lastYear/4 - lastYear/100 + lastYear/400; |
| |
| /* |
| * This year is a leap year if it is divisible by 4 except when it is |
| * divisible by 100 unless it is divisible by 400 |
| * |
| * e.g. 1904 was a leap year, 1900 was not, 1996 is, and 2000 will be |
| */ |
| if((tm->tm_year%4==0) && |
| ((tm->tm_year%100!=0) || (tm->tm_year%400==0)) && |
| (tm->tm_mon>2)) { |
| /* |
| * We are past Feb. 29 in a leap year |
| */ |
| day=1; |
| } else { |
| day=0; |
| } |
| |
| day += lastYear*365 + leapsToDate + MonthOffset[tm->tm_mon-1] + tm->tm_mday; |
| |
| tm->tm_wday=day%7; |
| } |
| |
| void to_tm(int tim, struct rtc_time * tm) |
| { |
| register int i; |
| register long hms, day; |
| |
| day = tim / SECDAY; |
| hms = tim % SECDAY; |
| |
| /* Hours, minutes, seconds are easy */ |
| tm->tm_hour = hms / 3600; |
| tm->tm_min = (hms % 3600) / 60; |
| tm->tm_sec = (hms % 3600) % 60; |
| |
| /* Number of years in days */ |
| for (i = STARTOFTIME; day >= days_in_year(i); i++) { |
| day -= days_in_year(i); |
| } |
| tm->tm_year = i; |
| |
| /* Number of months in days left */ |
| if (leapyear(tm->tm_year)) { |
| days_in_month(FEBRUARY) = 29; |
| } |
| for (i = 1; day >= days_in_month(i); i++) { |
| day -= days_in_month(i); |
| } |
| days_in_month(FEBRUARY) = 28; |
| tm->tm_mon = i; |
| |
| /* Days are what is left over (+1) from all that. */ |
| tm->tm_mday = day + 1; |
| |
| /* |
| * Determine the day of week |
| */ |
| GregorianDay(tm); |
| } |
| EXPORT_SYMBOL(to_tm); |
| |
| /* Converts Gregorian date to seconds since 1970-01-01 00:00:00. |
| * Assumes input in normal date format, i.e. 1980-12-31 23:59:59 |
| * => year=1980, mon=12, day=31, hour=23, min=59, sec=59. |
| * |
| * [For the Julian calendar (which was used in Russia before 1917, |
| * Britain & colonies before 1752, anywhere else before 1582, |
| * and is still in use by some communities) leave out the |
| * -year/100+year/400 terms, and add 10.] |
| * |
| * This algorithm was first published by Gauss (I think). |
| * |
| * WARNING: this function will overflow on 2106-02-07 06:28:16 on |
| * machines were long is 32-bit! (However, as time_t is signed, we |
| * will already get problems at other places on 2038-01-19 03:14:08) |
| */ |
| unsigned long |
| mktime (unsigned int year, unsigned int mon, |
| unsigned int day, unsigned int hour, |
| unsigned int min, unsigned int sec) |
| { |
| if (0 >= (int) (mon -= 2)) { /* 1..12 -> 11,12,1..10 */ |
| mon += 12; /* Puts Feb last since it has leap day */ |
| year -= 1; |
| } |
| |
| return ((( |
| (unsigned long) (year/4 - year/100 + year/400 + 367*mon/12 + day) + |
| year*365 - 719499 |
| )*24 + hour /* now have hours */ |
| )*60 + min /* now have minutes */ |
| )*60 + sec; /* finally seconds */ |
| } |