diff options
Diffstat (limited to 'drivers/rtc')
| -rw-r--r-- | drivers/rtc/rtc-lib.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-lib.c b/drivers/rtc/rtc-lib.c index 0d6acde3e0..1b23458a57 100644 --- a/drivers/rtc/rtc-lib.c +++ b/drivers/rtc/rtc-lib.c @@ -39,6 +39,51 @@ int rtc_month_days(unsigned int month, unsigned int year) 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) +{ + unsigned int month, year; + int days; + + days = time / 86400; + 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 = time / 3600; + time -= tm->tm_hour * 3600; + tm->tm_min = time / 60; + tm->tm_sec = time - tm->tm_min * 60; + + tm->tm_isdst = 0; +} +EXPORT_SYMBOL(rtc_time_to_tm); + +/* * Does the rtc_time represent a valid date/time? */ int rtc_valid_tm(struct rtc_time *tm) |