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+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2020 Unisoc Inc.
+ */
+
+#ifndef TST_RTCTIME
+#define TST_RTCTIME
+
+#include <linux/rtc.h>
+
+int tst_rtc_gettime(char *rtc_dev, struct rtc_time *rtc_tm);
+
+int tst_rtc_settime(char *rtc_dev, struct rtc_time *rtc_tm);
+
+#endif /* TST_RTCTIME */
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+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2020 Unisoc Communications Inc.
+ *
+ * Filename : tst_rtctime.c
+ * Abstract : This file is a implementation for rtc set read,covert to tm functions
+ */
+
+#include <linux/rtc.h>
+#include <stdbool.h>
+#include <limits.h>
+#define TST_NO_DEFAULT_MAIN
+#include "tst_test.h"
+#include "tst_rtctime.h"
+
+#define LEAPS_THRU_END_OF(y) ((y) / 4 - (y) / 100 + (y) / 400)
+
+static const unsigned char rtc_days_in_month[] = {
+ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
+};
+
+static inline bool is_leap_year(unsigned int year)
+{
+ return (!(year % 4) && (year % 100)) || !(year % 400);
+}
+
+static long long tst_mktime(const unsigned int year0, const unsigned int mon0,
+ const unsigned int day, const unsigned int hour,
+ const unsigned int min, const unsigned int sec)
+{
+ unsigned int mon = mon0, year = year0;
+
+ /* 1..12 -> 11,12,1..10 */
+ mon -= 2;
+ if (0 >= (int) (mon)) {
+ mon += 12; /* Puts Feb last since it has leap day */
+ year -= 1;
+ }
+
+ return ((((long long)
+ (year/4 - year/100 + year/400 + 367*mon/12 + day) +
+ year*365 - 719499
+ )*24 + hour /* now have hours - midnight tomorrow handled here */
+ )*60 + min /* now have minutes */
+ )*60 + sec; /* finally seconds */
+}
+
+/*
+ * The number of days in the month.
+ */
+static int rtc_month_days(unsigned int month, unsigned int year)
+{
+ return rtc_days_in_month[month] + (is_leap_year(year) && month == 1);
+}
+
+/*
+ * tst_rtc_time_to_tm - Converts time_t to rtc_time.
+ * Convert seconds since 01-01-1970 00:00:00 to Gregorian date.
+ */
+void tst_rtc_time_to_tm(long long time, struct rtc_time *tm)
+{
+ unsigned int month, year, secs;
+ int days;
+
+ /* time must be positive */
+ days = time / 86400;
+ secs = time % 86400;
+
+ /* 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 - 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;
+ 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;
+
+ tm->tm_isdst = 0;
+}
+
+/*
+ * tst_rtc_tm_to_time - Converts rtc_time to time_t.
+ * Convert Gregorian date to seconds since 01-01-1970 00:00:00.
+ */
+long long tst_rtc_tm_to_time(struct rtc_time *tm)
+{
+ return tst_mktime(((unsigned int)tm->tm_year + 1900), tm->tm_mon + 1,
+ tm->tm_mday, tm->tm_hour, tm->tm_min, tm->tm_sec);
+}
+
+static int rtc_supported_by_kernel(const char *rtc_dev)
+{
+ int exists = access(rtc_dev, F_OK);
+
+ if (exists < 0)
+ tst_brk(TCONF, "RTC device %s not available", rtc_dev);
+ return 0;
+}
+
+static int tst_rtc_ioctl(char *rtc_dev, unsigned long request, struct rtc_time *rtc_tm)
+{
+ int ret;
+ int rtc_fd = -1;
+
+ rtc_fd = SAFE_OPEN(rtc_dev, O_RDONLY);
+
+ ret = ioctl(rtc_fd, request, rtc_tm);
+
+ if (ret != 0)
+ return -1;
+
+ if (rtc_fd > 0)
+ SAFE_CLOSE(rtc_fd);
+
+ return 0;
+}
+
+int tst_rtc_gettime(char *rtc_dev, struct rtc_time *rtc_tm)
+{
+ int ret;
+
+ ret = tst_rtc_ioctl(rtc_dev, RTC_RD_TIME, rtc_tm);
+
+ if (ret != 0)
+ return -1;
+ return 0;
+}
+
+int tst_rtc_settime(char *rtc_dev, struct rtc_time *rtc_tm)
+{
+ int ret;
+
+ ret = tst_rtc_ioctl(rtc_dev, RTC_SET_TIME, rtc_tm);
+
+ if (ret != 0)
+ return -1;
+ return 0;
+}