diff options
Diffstat (limited to 'drivers/rtc')
| -rw-r--r-- | drivers/rtc/Kconfig | 6 | ||||
| -rw-r--r-- | drivers/rtc/Makefile | 5 | ||||
| -rw-r--r-- | drivers/rtc/rtc-lib.c | 101 |
3 files changed, 112 insertions, 0 deletions
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig new file mode 100644 index 0000000..15df7c1 --- /dev/null +++ b/drivers/rtc/Kconfig @@ -0,0 +1,6 @@ +# +# RTC class/drivers configuration +# + +config RTC_LIB + tristate
\ No newline at end of file diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile new file mode 100644 index 0000000..eb9ad77 --- /dev/null +++ b/drivers/rtc/Makefile @@ -0,0 +1,5 @@ +# +# Makefile for RTC class/drivers. +# + +obj-$(CONFIG_RTC_LIB) += rtc-lib.o diff --git a/drivers/rtc/rtc-lib.c b/drivers/rtc/rtc-lib.c new file mode 100644 index 0000000..cfedc1d --- /dev/null +++ b/drivers/rtc/rtc-lib.c @@ -0,0 +1,101 @@ +/* + * 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"); |
