Release 4.14 drivers/rtc/rtc-lib.c

/*
 * rtc and date/time utility functions
 *
 * Copyright (C) 2005-06 Tower Technologies
 * Author: Alessandro Zummo <a.zummo@towertech.it>
 *
 * based on arch/arm/common/rtctime.c and other bits
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
*/

#include <linux/export.h>
#include <linux/rtc.h>


static const unsigned char rtc_days_in_month[] = {
	31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
};


static const unsigned short rtc_ydays[2][13] = {
	/* Normal years */
	{ 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
	/* Leap years */
	{ 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
};


#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);
}
Contributors
Person
Tokens
Prop
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CommitProp
Alessandro Zummo
29
96.67%
1
50.00%
Andrew Morton
1
3.33%
1
50.00%
Total
30
100.00%
2
100.00%


EXPORT_SYMBOL(rtc_month_days);

/*
 * The number of days since January 1. (0 to 365)
 */


int rtc_year_days(unsigned int day, unsigned int month, unsigned int year)
{
	return rtc_ydays[is_leap_year(year)][month] + day-1;
}
Contributors
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CommitProp
Andrew Victor
32
96.97%
1
50.00%
Andrew Morton
1
3.03%
1
50.00%
Total
33
100.00%
2
100.00%


EXPORT_SYMBOL(rtc_year_days);


/*
 * rtc_time_to_tm64 - Converts time64_t to rtc_time.
 * Convert seconds since 01-01-1970 00:00:00 to Gregorian date.
 */


void rtc_time64_to_tm(time64_t time, struct rtc_time *tm)
{
	unsigned int month, year;
	unsigned long secs;
	int days;

	/* time must be positive */
	days = div_s64(time, 86400);
	secs = time - (unsigned int) days * 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);
	if (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;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Alessandro Zummo
193
85.40%
1
16.67%
Xunlei Pang
18
7.96%
1
16.67%
Jan Altenberg
7
3.10%
1
16.67%
Mike Waychison
6
2.65%
1
16.67%
Andrew Morton
1
0.44%
1
16.67%
Maciej W. Rozycki
1
0.44%
1
16.67%
Total
226
100.00%
6
100.00%


EXPORT_SYMBOL(rtc_time64_to_tm);

/*
 * Does the rtc_time represent a valid date/time?
 */


int rtc_valid_tm(struct rtc_time *tm)
{
	if (tm->tm_year < 70
		|| ((unsigned)tm->tm_mon) >= 12
		|| tm->tm_mday < 1
		|| tm->tm_mday > rtc_month_days(tm->tm_mon, tm->tm_year + 1900)
		|| ((unsigned)tm->tm_hour) >= 24
		|| ((unsigned)tm->tm_min) >= 60
		|| ((unsigned)tm->tm_sec) >= 60)
		return -EINVAL;

	return 0;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Alessandro Zummo
72
78.26%
1
50.00%
David Brownell
20
21.74%
1
50.00%
Total
92
100.00%
2
100.00%


EXPORT_SYMBOL(rtc_valid_tm);

/*
 * rtc_tm_to_time64 - Converts rtc_time to time64_t.
 * Convert Gregorian date to seconds since 01-01-1970 00:00:00.
 */


time64_t rtc_tm_to_time64(struct rtc_time *tm)
{
	return mktime64(tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
			tm->tm_hour, tm->tm_min, tm->tm_sec);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Alessandro Zummo
38
90.48%
1
50.00%
Xunlei Pang
4
9.52%
1
50.00%
Total
42
100.00%
2
100.00%


EXPORT_SYMBOL(rtc_tm_to_time64);

/*
 * Convert rtc_time to ktime
 */


ktime_t rtc_tm_to_ktime(struct rtc_time tm)
{
	return ktime_set(rtc_tm_to_time64(&tm), 0);
}
Contributors
Person
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CommitProp
John Stultz
17
80.95%
1
50.00%
Xunlei Pang
4
19.05%
1
50.00%
Total
21
100.00%
2
100.00%


EXPORT_SYMBOL_GPL(rtc_tm_to_ktime);

/*
 * Convert ktime to rtc_time
 */


struct rtc_time rtc_ktime_to_tm(ktime_t kt)
{
	struct timespec64 ts;
	struct rtc_time ret;

	ts = ktime_to_timespec64(kt);
	/* Round up any ns */
	if (ts.tv_nsec)
		ts.tv_sec++;
	rtc_time64_to_tm(ts.tv_sec, &ret);
	return ret;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
John Stultz
46
93.88%
1
50.00%
Xunlei Pang
3
6.12%
1
50.00%
Total
49
100.00%
2
100.00%


EXPORT_SYMBOL_GPL(rtc_ktime_to_tm);
Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
Alessandro Zummo
397
60.70%
1
10.00%
Andrew Victor
111
16.97%
1
10.00%
John Stultz
75
11.47%
1
10.00%
Xunlei Pang
33
5.05%
1
10.00%
David Brownell
20
3.06%
1
10.00%
Jan Altenberg
7
1.07%
1
10.00%
Mike Waychison
6
0.92%
1
10.00%
Andrew Morton
3
0.46%
1
10.00%
Paul Gortmaker
1
0.15%
1
10.00%
Maciej W. Rozycki
1
0.15%
1
10.00%
Total
654
100.00%
10
100.00%
Directory: drivers/rtc

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