Simon Glass | 2cf99e1 | 2016-06-10 20:58:24 -0600 | [diff] [blame] | 1 | /* |
| 2 | * This file is part of the coreboot project. |
| 3 | * |
Simon Glass | 2cf99e1 | 2016-06-10 20:58:24 -0600 | [diff] [blame] | 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License as published by |
| 7 | * the Free Software Foundation; version 2 of the License or (at your |
| 8 | * option) any later version. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | * |
| 15 | * From U-Boot 2016.05 |
| 16 | */ |
| 17 | |
| 18 | #include <console/console.h> |
| 19 | #include <rtc.h> |
| 20 | |
| 21 | #define FEBRUARY 2 |
| 22 | #define STARTOFTIME 1970 |
| 23 | #define SECDAY 86400L |
| 24 | #define SECYR (SECDAY * 365) |
| 25 | #define LEAP_YEAR(year) ((year) % 4 == 0) |
| 26 | #define DAYS_IN_YEAR(a) (LEAP_YEAR(a) ? 366 : 365) |
| 27 | #define DAYS_IN_MONTH(a) (month_days[(a) - 1]) |
| 28 | |
Elyes HAOUAS | c92f5f2 | 2018-07-08 12:36:18 +0200 | [diff] [blame] | 29 | static const char *const weekdays[] = { |
Tim Wawrzynczak | b47c633 | 2019-02-21 15:02:26 -0700 | [diff] [blame] | 30 | "Sun", "Mon", "Tues", "Wednes", "Thurs", "Fri", "Satur" |
Simon Glass | 2cf99e1 | 2016-06-10 20:58:24 -0600 | [diff] [blame] | 31 | }; |
| 32 | |
Tim Wawrzynczak | b47c633 | 2019-02-21 15:02:26 -0700 | [diff] [blame] | 33 | /* Zeller's rule */ |
Simon Glass | 2cf99e1 | 2016-06-10 20:58:24 -0600 | [diff] [blame] | 34 | static int rtc_calc_weekday(struct rtc_time *tm) |
| 35 | { |
Simon Glass | 2cf99e1 | 2016-06-10 20:58:24 -0600 | [diff] [blame] | 36 | if (tm->year < 1971) |
| 37 | return -1; |
| 38 | |
Tim Wawrzynczak | b47c633 | 2019-02-21 15:02:26 -0700 | [diff] [blame] | 39 | /* In Zeller's rule, January and February are treated as if they |
| 40 | are months 13 and 14 of the previous year (March is still month 3) */ |
| 41 | const int zyear = ((tm->mon < 3) ? tm->year - 1 : tm->year); |
| 42 | const int q = tm->mday; |
| 43 | const int m = (tm->mon < 3) ? tm->mon + 12 : tm->mon; |
| 44 | const int K = zyear % 100; |
| 45 | const int J = zyear / 100; |
Simon Glass | 2cf99e1 | 2016-06-10 20:58:24 -0600 | [diff] [blame] | 46 | |
| 47 | /* |
Tim Wawrzynczak | b47c633 | 2019-02-21 15:02:26 -0700 | [diff] [blame] | 48 | * Because of the way the modulo operator works with negative numbers, |
| 49 | * the traditional formulation of Zeller's rule must be modified |
| 50 | * slightly to make the numerator positive (i.e., add 5J instead of |
| 51 | * subtracting 2J). Also subtract 1 so that Sunday is day 0. |
Simon Glass | 2cf99e1 | 2016-06-10 20:58:24 -0600 | [diff] [blame] | 52 | */ |
Tim Wawrzynczak | b47c633 | 2019-02-21 15:02:26 -0700 | [diff] [blame] | 53 | const int h = (q + (13 * (m + 1)) / 5 |
| 54 | + K + (K / 4) + (J / 4) + (5 * J) - 1) % 7; |
Simon Glass | 2cf99e1 | 2016-06-10 20:58:24 -0600 | [diff] [blame] | 55 | |
Tim Wawrzynczak | b47c633 | 2019-02-21 15:02:26 -0700 | [diff] [blame] | 56 | tm->wday = h; |
Simon Glass | 2cf99e1 | 2016-06-10 20:58:24 -0600 | [diff] [blame] | 57 | return 0; |
| 58 | } |
| 59 | |
| 60 | int rtc_to_tm(int tim, struct rtc_time *tm) |
| 61 | { |
| 62 | int month_days[12] = { |
Tim Wawrzynczak | b47c633 | 2019-02-21 15:02:26 -0700 | [diff] [blame] | 63 | 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 |
Simon Glass | 2cf99e1 | 2016-06-10 20:58:24 -0600 | [diff] [blame] | 64 | }; |
| 65 | register int i; |
| 66 | register long hms, day; |
| 67 | |
| 68 | day = tim / SECDAY; |
| 69 | hms = tim % SECDAY; |
| 70 | |
| 71 | /* Hours, minutes, seconds are easy */ |
| 72 | tm->hour = hms / 3600; |
| 73 | tm->min = (hms % 3600) / 60; |
| 74 | tm->sec = (hms % 3600) % 60; |
| 75 | |
| 76 | /* Number of years in days */ |
| 77 | for (i = STARTOFTIME; day >= DAYS_IN_YEAR(i); i++) |
| 78 | day -= DAYS_IN_YEAR(i); |
| 79 | tm->year = i; |
| 80 | |
| 81 | /* Number of months in days left */ |
| 82 | if (LEAP_YEAR(tm->year)) |
| 83 | DAYS_IN_MONTH(FEBRUARY) = 29; |
| 84 | for (i = 1; day >= DAYS_IN_MONTH(i); i++) |
| 85 | day -= DAYS_IN_MONTH(i); |
| 86 | DAYS_IN_MONTH(FEBRUARY) = 28; |
| 87 | tm->mon = i; |
| 88 | |
| 89 | /* Days are what is left over (+1) from all that */ |
| 90 | tm->mday = day + 1; |
| 91 | |
| 92 | /* Determine the day of week */ |
| 93 | return rtc_calc_weekday(tm); |
| 94 | } |
| 95 | |
| 96 | /* |
| 97 | * Converts Gregorian date to seconds since 1970-01-01 00:00:00. |
Tim Wawrzynczak | b47c633 | 2019-02-21 15:02:26 -0700 | [diff] [blame] | 98 | * Assumes input in normal date format, i.e. 1980-12-31 23:59:59 |
Simon Glass | 2cf99e1 | 2016-06-10 20:58:24 -0600 | [diff] [blame] | 99 | * => year=1980, mon=12, day=31, hour=23, min=59, sec=59. |
| 100 | * |
| 101 | * [For the Julian calendar (which was used in Russia before 1917, |
| 102 | * Britain & colonies before 1752, anywhere else before 1582, |
| 103 | * and is still in use by some communities) leave out the |
| 104 | * -year / 100 + year / 400 terms, and add 10.] |
| 105 | * |
| 106 | * This algorithm was first published by Gauss (I think). |
| 107 | * |
| 108 | * WARNING: this function will overflow on 2106-02-07 06:28:16 on |
| 109 | * machines where long is 32-bit! (However, as time_t is signed, we |
| 110 | * will already get problems at other places on 2038-01-19 03:14:08) |
| 111 | */ |
| 112 | unsigned long rtc_mktime(const struct rtc_time *tm) |
| 113 | { |
| 114 | int mon = tm->mon; |
| 115 | int year = tm->year; |
Tim Wawrzynczak | b47c633 | 2019-02-21 15:02:26 -0700 | [diff] [blame] | 116 | int days, hours; |
Simon Glass | 2cf99e1 | 2016-06-10 20:58:24 -0600 | [diff] [blame] | 117 | |
| 118 | mon -= 2; |
| 119 | if (0 >= (int)mon) { /* 1..12 -> 11, 12, 1..10 */ |
| 120 | mon += 12; /* Puts Feb last since it has leap day */ |
| 121 | year -= 1; |
| 122 | } |
| 123 | |
| 124 | days = (unsigned long)(year / 4 - year / 100 + year / 400 + |
Tim Wawrzynczak | b47c633 | 2019-02-21 15:02:26 -0700 | [diff] [blame] | 125 | 367 * mon / 12 + tm->mday) + |
| 126 | year * 365 - 719499; |
Simon Glass | 2cf99e1 | 2016-06-10 20:58:24 -0600 | [diff] [blame] | 127 | hours = days * 24 + tm->hour; |
| 128 | return (hours * 60 + tm->min) * 60 + tm->sec; |
| 129 | } |
| 130 | |
| 131 | void rtc_display(const struct rtc_time *tm) |
| 132 | { |
Tim Wawrzynczak | b47c633 | 2019-02-21 15:02:26 -0700 | [diff] [blame] | 133 | printk(BIOS_INFO, "Date: %5d-%02d-%02d (%sday) Time: %2d:%02d:%02d\n", |
Simon Glass | 2cf99e1 | 2016-06-10 20:58:24 -0600 | [diff] [blame] | 134 | tm->year, tm->mon, tm->mday, |
| 135 | (tm->wday < 0 || tm->wday > 6) ? "unknown " : weekdays[tm->wday], |
| 136 | tm->hour, tm->min, tm->sec); |
| 137 | } |