1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
|
/*
* 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/module.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
};
#define LEAPS_THRU_END_OF(y) ((y)/4 - (y)/100 + (y)/400)
#define LEAP_YEAR(year) ((!(year % 4) && (year % 100)) || !(year % 400))
int rtc_month_days(unsigned int month, unsigned int year)
{
return rtc_days_in_month[month] + (LEAP_YEAR(year) && month == 1);
}
EXPORT_SYMBOL(rtc_month_days);
/*
* Convert seconds since 01-01-1970 00:00:00 to Gregorian date.
*/
void rtc_time_to_tm(unsigned long time, struct rtc_time *tm)
{
register int days, month, year;
days = time / 86400;
time -= 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 + 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 = time / 3600;
time -= tm->tm_hour * 3600;
tm->tm_min = time / 60;
tm->tm_sec = time - tm->tm_min * 60;
}
EXPORT_SYMBOL(rtc_time_to_tm);
/*
* Does the rtc_time represent a valid date/time?
*/
int rtc_valid_tm(struct rtc_time *tm)
{
if (tm->tm_year < 70
|| tm->tm_mon >= 12
|| tm->tm_mday < 1
|| tm->tm_mday > rtc_month_days(tm->tm_mon, tm->tm_year + 1900)
|| tm->tm_hour >= 24
|| tm->tm_min >= 60
|| tm->tm_sec >= 60)
return -EINVAL;
return 0;
}
EXPORT_SYMBOL(rtc_valid_tm);
/*
* Convert Gregorian date to seconds since 01-01-1970 00:00:00.
*/
int rtc_tm_to_time(struct rtc_time *tm, unsigned long *time)
{
*time = mktime(tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
tm->tm_hour, tm->tm_min, tm->tm_sec);
return 0;
}
EXPORT_SYMBOL(rtc_tm_to_time);
MODULE_LICENSE("GPL");
|
