/* * (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 */ /* * Date & Time support for Philips PCF8563 RTC */ #include <common.h> #include <command.h> #include <rtc.h> #if defined(CONFIG_CMD_DATE) || defined(CONFIG_TIMESTAMP) #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); } /* 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 */ } #endif