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authorSimon Glass <sjg@chromium.org>2016-06-10 20:58:24 -0600
committerMartin Roth <martinroth@google.com>2016-06-24 20:22:05 +0200
commit2cf99e1655ea2f10bcd5a0f494bbad4db4d46bee (patch)
treeccf4150f9b9861f041f4c68aaf6c67323a093629 /src/lib
parent9482cf6c0956f2184c499a125348b09365fcc593 (diff)
downloadcoreboot-2cf99e1655ea2f10bcd5a0f494bbad4db4d46bee.tar.xz
lib: Add real-time-clock functions
Add functions to convert between seconds and a struct rtc_time. Also add a function that can display the time on the console. BUG=chrome-os-partner:52220 BRANCH=none TEST=(partial) with future commits and after setting RTC on the EC: boot on gru into linux shell, check firmware log: localhost ~ # grep Date: /sys/firmware/log Date: 2016-06-20 (Monday) Time: 18:01:44 Then reboot ~10 seconds and check again: localhost ~ # grep Date: /sys/firmware/log Date: 2016-06-20 (Monday) Time: 18:01:54 Change-Id: Id148ccb7a18a05865b903307358666ff6c7b4a3d Signed-off-by: Martin Roth <martinroth@chromium.org> Original-Commit-Id: 3b02dbcd7d9023ce0acabebcf904e70007428d27 Original-Change-Id: I344c385e2e4cb995d3a374025c205f01c38b660d Original-Signed-off-by: Simon Glass <sjg@chromium.org> Original-Reviewed-on: https://chromium-review.googlesource.com/351782 Original-Commit-Ready: Vadim Bendebury <vbendeb@chromium.org> Original-Tested-by: Vadim Bendebury <vbendeb@chromium.org> Original-Reviewed-by: Vadim Bendebury <vbendeb@chromium.org> Reviewed-on: https://review.coreboot.org/15301 Tested-by: build bot (Jenkins) Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Diffstat (limited to 'src/lib')
-rw-r--r--src/lib/Makefile.inc1
-rw-r--r--src/lib/rtc.c154
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);
+}