lib: move rtc-lib.c to lib
Function rtc_to_tm() is needed for FAT file system support even if we don't
have a real time clock. So move it from drivers/ to lib/.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/lib/Makefile b/lib/Makefile
index 881034f..d8055d3 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -135,6 +135,7 @@
endif
obj-y += date.o
+obj-y += rtc-lib.o
obj-$(CONFIG_LIB_ELF) += elf.o
#
diff --git a/lib/rtc-lib.c b/lib/rtc-lib.c
new file mode 100644
index 0000000..1f7bdad
--- /dev/null
+++ b/lib/rtc-lib.c
@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * rtc and date/time utility functions
+ *
+ * Copyright (C) 2005-06 Tower Technologies
+ * Author: Alessandro Zummo <a.zummo@towertech.it>
+ *
+ * U-Boot rtc_time differs from Linux rtc_time:
+ * - The year field takes the actual value, not year - 1900.
+ * - January is month 1.
+ */
+
+#include <common.h>
+#include <rtc.h>
+#include <linux/math64.h>
+
+static const unsigned char rtc_days_in_month[] = {
+ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
+};
+
+#define LEAPS_THRU_END_OF(y) ((y) / 4 - (y) / 100 + (y) / 400)
+
+/*
+ * The number of days in the month.
+ */
+int rtc_month_days(unsigned int month, unsigned int year)
+{
+ return rtc_days_in_month[month] + (is_leap_year(year) && month == 1);
+}
+
+/*
+ * rtc_to_tm - Converts u64 to rtc_time.
+ * Convert seconds since 01-01-1970 00:00:00 to Gregorian date.
+ *
+ * This function is copied from rtc_time64_to_tm() in the Linux kernel.
+ * But in U-Boot January is month 1 and we do not subtract 1900 from the year.
+ */
+void rtc_to_tm(u64 time, struct rtc_time *tm)
+{
+ unsigned int month, year, secs;
+ int days;
+
+ days = div_u64_rem(time, 86400, &secs);
+
+ /* day of the week, 1970-01-01 was a Thursday */
+ tm->tm_wday = (days + 4) % 7;
+
+ year = 1970 + days / 365;
+ days -= (year - 1970) * 365
+ + LEAPS_THRU_END_OF(year - 1)
+ - LEAPS_THRU_END_OF(1970 - 1);
+ while (days < 0) {
+ year -= 1;
+ days += 365 + is_leap_year(year);
+ }
+ tm->tm_year = year; /* Not year - 1900 */
+ tm->tm_yday = days + 1;
+
+ for (month = 0; month < 11; month++) {
+ int newdays;
+
+ newdays = days - rtc_month_days(month, year);
+ if (newdays < 0)
+ break;
+ days = newdays;
+ }
+ tm->tm_mon = month + 1; /* January = 1 */
+ tm->tm_mday = days + 1;
+
+ tm->tm_hour = secs / 3600;
+ secs -= tm->tm_hour * 3600;
+ tm->tm_min = secs / 60;
+ tm->tm_sec = secs - tm->tm_min * 60;
+
+ /* Zero unused fields */
+ tm->tm_isdst = 0;
+}