diff options
Diffstat (limited to 'src/lib')
| -rw-r--r-- | src/lib/Makefile.inc | 1 | ||||
| -rw-r--r-- | src/lib/rtc.c | 154 |
2 files changed, 155 insertions, 0 deletions
diff --git a/src/lib/Makefile.inc b/src/lib/Makefile.inc index 49720a71e6..10289176fb 100644 --- a/src/lib/Makefile.inc +++ b/src/lib/Makefile.inc @@ -79,6 +79,7 @@ ramstage-$(CONFIG_PRIMITIVE_MEMTEST) += primitive_memtest.c romstage-$(CONFIG_CACHE_AS_RAM) += ramtest.c romstage-$(CONFIG_GENERIC_GPIO_LIB) += gpio.c romstage-y += stack.c +ramstage-y += rtc.c ifeq ($(CONFIG_EARLY_CBMEM_INIT),y) romstage-$(CONFIG_COLLECT_TIMESTAMPS) += timestamp.c diff --git a/src/lib/rtc.c b/src/lib/rtc.c new file mode 100644 index 0000000000..bd98590d96 --- /dev/null +++ b/src/lib/rtc.c @@ -0,0 +1,154 @@ +/* + * This file is part of the coreboot project. + * + * (C) Copyright 2001 Wolfgang Denk, DENX Software Engineering, wd@denx.de. + * + * 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; 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. + * + * From U-Boot 2016.05 + */ + +#include <console/console.h> +#include <rtc.h> + +#define FEBRUARY 2 +#define STARTOFTIME 1970 +#define SECDAY 86400L +#define SECYR (SECDAY * 365) +#define LEAP_YEAR(year) ((year) % 4 == 0) +#define DAYS_IN_YEAR(a) (LEAP_YEAR(a) ? 366 : 365) +#define DAYS_IN_MONTH(a) (month_days[(a) - 1]) + +static const int month_offset[] = { + 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 +}; + +static const char * const weekdays[] = { + "Sun", "Mon", "Tues", "Wednes", "Thurs", "Fri", "Satur", +}; + +static int leaps_to_year(int year) +{ + return year / 4 - year / 100 + year / 400; +} + +/* This only works for the Gregorian calendar after Jan 1 1971. */ +static int rtc_calc_weekday(struct rtc_time *tm) +{ + int leaps_to_date; + int day; + + if (tm->year < 1971) + return -1; + + day = 4; /* Jan 1 1970 was a Thursday. */ + + /* Number of leap corrections to apply up to end of last year */ + leaps_to_date = leaps_to_year(tm->year - 1) - leaps_to_year(1970); + + /* + * 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 is. + */ + if ((tm->year % 4) && + ((tm->year % 100 != 0) || (tm->year % 400 == 0)) && + (tm->mon > 2)) { + /* We are past Feb. 29 in a leap year */ + day++; + } + + day += (tm->year - 1970) * 365 + leaps_to_date + + month_offset[tm->mon-1] + tm->mday; + tm->wday = day % 7; + + return 0; +} + +int rtc_to_tm(int tim, struct rtc_time *tm) +{ + int month_days[12] = { + 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 + }; + register int i; + register long hms, day; + + day = tim / SECDAY; + hms = tim % SECDAY; + + /* Hours, minutes, seconds are easy */ + tm->hour = hms / 3600; + tm->min = (hms % 3600) / 60; + 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->year = i; + + /* Number of months in days left */ + if (LEAP_YEAR(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->mon = i; + + /* Days are what is left over (+1) from all that */ + tm->mday = day + 1; + + /* Determine the day of week */ + return rtc_calc_weekday(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 where 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 rtc_mktime(const struct rtc_time *tm) +{ + int mon = tm->mon; + int year = tm->year; + int days, hours; + + mon -= 2; + if (0 >= (int)mon) { /* 1..12 -> 11, 12, 1..10 */ + mon += 12; /* Puts Feb last since it has leap day */ + year -= 1; + } + + days = (unsigned long)(year / 4 - year / 100 + year / 400 + + 367 * mon / 12 + tm->mday) + + year * 365 - 719499; + hours = days * 24 + tm->hour; + return (hours * 60 + tm->min) * 60 + tm->sec; +} + +void rtc_display(const struct rtc_time *tm) +{ + printk(BIOS_INFO, "Date: %4d-%02d-%02d (%sday) Time: %2d:%02d:%02d\n", + tm->year, tm->mon, tm->mday, + (tm->wday < 0 || tm->wday > 6) ? "unknown " : weekdays[tm->wday], + tm->hour, tm->min, tm->sec); +} |