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Tom Rini83d290c2018-05-06 17:58:06 -04001// SPDX-License-Identifier: GPL-2.0+
wdenk0587dd12002-10-26 17:33:42 +00002/*
3 * (C) Copyright 2001
4 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
wdenk0587dd12002-10-26 17:33:42 +00005 */
6
wdenk0587dd12002-10-26 17:33:42 +00007#include <common.h>
8#include <command.h>
Simon Glass199e87c2015-04-20 12:37:17 -06009#include <errno.h>
wdenk0587dd12002-10-26 17:33:42 +000010#include <rtc.h>
AKASHI Takahiro18723112019-11-13 09:44:50 +090011#include <linux/time.h>
wdenk0587dd12002-10-26 17:33:42 +000012
wdenk0587dd12002-10-26 17:33:42 +000013#define FEBRUARY 2
14#define STARTOFTIME 1970
15#define SECDAY 86400L
16#define SECYR (SECDAY * 365)
17#define leapyear(year) ((year) % 4 == 0)
Wolfgang Denk53677ef2008-05-20 16:00:29 +020018#define days_in_year(a) (leapyear(a) ? 366 : 365)
19#define days_in_month(a) (month_days[(a) - 1])
wdenk0587dd12002-10-26 17:33:42 +000020
Simon Glass36b898b2016-06-19 19:51:00 -060021static int month_offset[] = {
22 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334
23};
24
wdenk0587dd12002-10-26 17:33:42 +000025/*
26 * This only works for the Gregorian calendar - i.e. after 1752 (in the UK)
27 */
Simon Glass199e87c2015-04-20 12:37:17 -060028int rtc_calc_weekday(struct rtc_time *tm)
wdenk0587dd12002-10-26 17:33:42 +000029{
Simon Glass36b898b2016-06-19 19:51:00 -060030 int leaps_to_date;
31 int last_year;
wdenk0587dd12002-10-26 17:33:42 +000032 int day;
wdenk0587dd12002-10-26 17:33:42 +000033
Simon Glass199e87c2015-04-20 12:37:17 -060034 if (tm->tm_year < 1753)
Simon Glass36b898b2016-06-19 19:51:00 -060035 return -1;
36 last_year = tm->tm_year - 1;
wdenk0587dd12002-10-26 17:33:42 +000037
Simon Glass36b898b2016-06-19 19:51:00 -060038 /* Number of leap corrections to apply up to end of last year */
39 leaps_to_date = last_year / 4 - last_year / 100 + last_year / 400;
wdenk0587dd12002-10-26 17:33:42 +000040
41 /*
42 * This year is a leap year if it is divisible by 4 except when it is
43 * divisible by 100 unless it is divisible by 400
44 *
Simon Glass36b898b2016-06-19 19:51:00 -060045 * e.g. 1904 was a leap year, 1900 was not, 1996 is, and 2000 is.
wdenk0587dd12002-10-26 17:33:42 +000046 */
Simon Glass36b898b2016-06-19 19:51:00 -060047 if (tm->tm_year % 4 == 0 &&
48 ((tm->tm_year % 100 != 0) || (tm->tm_year % 400 == 0)) &&
49 tm->tm_mon > 2) {
50 /* We are past Feb. 29 in a leap year */
51 day = 1;
wdenk0587dd12002-10-26 17:33:42 +000052 } else {
Simon Glass36b898b2016-06-19 19:51:00 -060053 day = 0;
wdenk0587dd12002-10-26 17:33:42 +000054 }
55
Simon Glass36b898b2016-06-19 19:51:00 -060056 day += last_year * 365 + leaps_to_date + month_offset[tm->tm_mon - 1] +
57 tm->tm_mday;
58 tm->tm_wday = day % 7;
Simon Glass199e87c2015-04-20 12:37:17 -060059
60 return 0;
wdenk0587dd12002-10-26 17:33:42 +000061}
62
Simon Glass36b898b2016-06-19 19:51:00 -060063/*
64 * Converts Gregorian date to seconds since 1970-01-01 00:00:00.
wdenk0587dd12002-10-26 17:33:42 +000065 * Assumes input in normal date format, i.e. 1980-12-31 23:59:59
66 * => year=1980, mon=12, day=31, hour=23, min=59, sec=59.
67 *
68 * [For the Julian calendar (which was used in Russia before 1917,
69 * Britain & colonies before 1752, anywhere else before 1582,
70 * and is still in use by some communities) leave out the
Simon Glass36b898b2016-06-19 19:51:00 -060071 * -year / 100 + year / 400 terms, and add 10.]
wdenk0587dd12002-10-26 17:33:42 +000072 *
73 * This algorithm was first published by Gauss (I think).
wdenk0587dd12002-10-26 17:33:42 +000074 */
Jan Kiszka90c52422022-04-24 11:34:56 +020075time64_t rtc_mktime(const struct rtc_time *tm)
wdenk0587dd12002-10-26 17:33:42 +000076{
Simon Glass71420982015-04-20 12:37:19 -060077 int mon = tm->tm_mon;
78 int year = tm->tm_year;
Jan Kiszka90c52422022-04-24 11:34:56 +020079 unsigned long days;
80 time64_t hours;
Simon Glass71420982015-04-20 12:37:19 -060081
82 mon -= 2;
Jan Kiszka90c52422022-04-24 11:34:56 +020083 if (0 >= mon) { /* 1..12 -> 11, 12, 1..10 */
Simon Glass36b898b2016-06-19 19:51:00 -060084 mon += 12; /* Puts Feb last since it has leap day */
wdenk0587dd12002-10-26 17:33:42 +000085 year -= 1;
86 }
87
Simon Glass71420982015-04-20 12:37:19 -060088 days = (unsigned long)(year / 4 - year / 100 + year / 400 +
89 367 * mon / 12 + tm->tm_mday) +
90 year * 365 - 719499;
91 hours = days * 24 + tm->tm_hour;
92 return (hours * 60 + tm->tm_min) * 60 + tm->tm_sec;
wdenk0587dd12002-10-26 17:33:42 +000093}
94
AKASHI Takahiro18723112019-11-13 09:44:50 +090095/* for compatibility with linux code */
96time64_t mktime64(const unsigned int year, const unsigned int mon,
97 const unsigned int day, const unsigned int hour,
98 const unsigned int min, const unsigned int sec)
99{
100 struct rtc_time time;
101
102 time.tm_year = year;
103 time.tm_mon = mon;
104 time.tm_mday = day;
105 time.tm_hour = hour;
106 time.tm_min = min;
107 time.tm_sec = sec;
108
Jan Kiszka90c52422022-04-24 11:34:56 +0200109 return rtc_mktime((const struct rtc_time *)&time);
AKASHI Takahiro18723112019-11-13 09:44:50 +0900110}