wdenk | 0587dd1 | 2002-10-26 17:33:42 +0000 | [diff] [blame] | 1 | /* |
| 2 | * (C) Copyright 2001 |
| 3 | * Wolfgang Denk, DENX Software Engineering, wd@denx.de. |
| 4 | * |
Wolfgang Denk | 1a45966 | 2013-07-08 09:37:19 +0200 | [diff] [blame] | 5 | * SPDX-License-Identifier: GPL-2.0+ |
wdenk | 0587dd1 | 2002-10-26 17:33:42 +0000 | [diff] [blame] | 6 | */ |
| 7 | |
| 8 | /* |
| 9 | * Date & Time support for Philips PCF8563 RTC |
| 10 | */ |
| 11 | |
| 12 | #include <common.h> |
| 13 | #include <command.h> |
| 14 | #include <rtc.h> |
| 15 | |
Jon Loeliger | a593814 | 2007-07-09 18:10:50 -0500 | [diff] [blame] | 16 | #if defined(CONFIG_CMD_DATE) || defined(CONFIG_TIMESTAMP) |
wdenk | 0587dd1 | 2002-10-26 17:33:42 +0000 | [diff] [blame] | 17 | |
| 18 | #define FEBRUARY 2 |
| 19 | #define STARTOFTIME 1970 |
| 20 | #define SECDAY 86400L |
| 21 | #define SECYR (SECDAY * 365) |
| 22 | #define leapyear(year) ((year) % 4 == 0) |
Wolfgang Denk | 53677ef | 2008-05-20 16:00:29 +0200 | [diff] [blame] | 23 | #define days_in_year(a) (leapyear(a) ? 366 : 365) |
| 24 | #define days_in_month(a) (month_days[(a) - 1]) |
wdenk | 0587dd1 | 2002-10-26 17:33:42 +0000 | [diff] [blame] | 25 | |
| 26 | static int month_days[12] = { |
| 27 | 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 |
| 28 | }; |
| 29 | |
| 30 | /* |
| 31 | * This only works for the Gregorian calendar - i.e. after 1752 (in the UK) |
| 32 | */ |
| 33 | void GregorianDay(struct rtc_time * tm) |
| 34 | { |
| 35 | int leapsToDate; |
| 36 | int lastYear; |
| 37 | int day; |
| 38 | int MonthOffset[] = { 0,31,59,90,120,151,181,212,243,273,304,334 }; |
| 39 | |
| 40 | lastYear=tm->tm_year-1; |
| 41 | |
| 42 | /* |
| 43 | * Number of leap corrections to apply up to end of last year |
| 44 | */ |
| 45 | leapsToDate = lastYear/4 - lastYear/100 + lastYear/400; |
| 46 | |
| 47 | /* |
| 48 | * This year is a leap year if it is divisible by 4 except when it is |
| 49 | * divisible by 100 unless it is divisible by 400 |
| 50 | * |
| 51 | * e.g. 1904 was a leap year, 1900 was not, 1996 is, and 2000 will be |
| 52 | */ |
| 53 | if((tm->tm_year%4==0) && |
| 54 | ((tm->tm_year%100!=0) || (tm->tm_year%400==0)) && |
| 55 | (tm->tm_mon>2)) { |
| 56 | /* |
| 57 | * We are past Feb. 29 in a leap year |
| 58 | */ |
| 59 | day=1; |
| 60 | } else { |
| 61 | day=0; |
| 62 | } |
| 63 | |
| 64 | day += lastYear*365 + leapsToDate + MonthOffset[tm->tm_mon-1] + tm->tm_mday; |
| 65 | |
| 66 | tm->tm_wday=day%7; |
| 67 | } |
| 68 | |
| 69 | void to_tm(int tim, struct rtc_time * tm) |
| 70 | { |
| 71 | register int i; |
| 72 | register long hms, day; |
| 73 | |
| 74 | day = tim / SECDAY; |
| 75 | hms = tim % SECDAY; |
| 76 | |
| 77 | /* Hours, minutes, seconds are easy */ |
| 78 | tm->tm_hour = hms / 3600; |
| 79 | tm->tm_min = (hms % 3600) / 60; |
| 80 | tm->tm_sec = (hms % 3600) % 60; |
| 81 | |
| 82 | /* Number of years in days */ |
| 83 | for (i = STARTOFTIME; day >= days_in_year(i); i++) { |
| 84 | day -= days_in_year(i); |
| 85 | } |
| 86 | tm->tm_year = i; |
| 87 | |
| 88 | /* Number of months in days left */ |
| 89 | if (leapyear(tm->tm_year)) { |
| 90 | days_in_month(FEBRUARY) = 29; |
| 91 | } |
| 92 | for (i = 1; day >= days_in_month(i); i++) { |
| 93 | day -= days_in_month(i); |
| 94 | } |
| 95 | days_in_month(FEBRUARY) = 28; |
| 96 | tm->tm_mon = i; |
| 97 | |
| 98 | /* Days are what is left over (+1) from all that. */ |
| 99 | tm->tm_mday = day + 1; |
| 100 | |
| 101 | /* |
| 102 | * Determine the day of week |
| 103 | */ |
| 104 | GregorianDay(tm); |
| 105 | } |
| 106 | |
| 107 | /* Converts Gregorian date to seconds since 1970-01-01 00:00:00. |
| 108 | * Assumes input in normal date format, i.e. 1980-12-31 23:59:59 |
| 109 | * => year=1980, mon=12, day=31, hour=23, min=59, sec=59. |
| 110 | * |
| 111 | * [For the Julian calendar (which was used in Russia before 1917, |
| 112 | * Britain & colonies before 1752, anywhere else before 1582, |
| 113 | * and is still in use by some communities) leave out the |
| 114 | * -year/100+year/400 terms, and add 10.] |
| 115 | * |
| 116 | * This algorithm was first published by Gauss (I think). |
| 117 | * |
| 118 | * WARNING: this function will overflow on 2106-02-07 06:28:16 on |
| 119 | * machines were long is 32-bit! (However, as time_t is signed, we |
| 120 | * will already get problems at other places on 2038-01-19 03:14:08) |
| 121 | */ |
| 122 | unsigned long |
| 123 | mktime (unsigned int year, unsigned int mon, |
| 124 | unsigned int day, unsigned int hour, |
| 125 | unsigned int min, unsigned int sec) |
| 126 | { |
| 127 | if (0 >= (int) (mon -= 2)) { /* 1..12 -> 11,12,1..10 */ |
| 128 | mon += 12; /* Puts Feb last since it has leap day */ |
| 129 | year -= 1; |
| 130 | } |
| 131 | |
| 132 | return ((( |
| 133 | (unsigned long) (year/4 - year/100 + year/400 + 367*mon/12 + day) + |
| 134 | year*365 - 719499 |
| 135 | )*24 + hour /* now have hours */ |
| 136 | )*60 + min /* now have minutes */ |
| 137 | )*60 + sec; /* finally seconds */ |
| 138 | } |
| 139 | |
Jon Loeliger | 068b60a | 2007-07-10 10:27:39 -0500 | [diff] [blame] | 140 | #endif |