6610e0893b
This patch reworks a large portion of the generic RTC code to in-effect virtualize the rtc interrupt code. The current RTC interface is very much a raw hardware interface. Via the proc, /dev/, or sysfs interfaces, applciations can set the hardware to trigger interrupts in one of three modes: AIE: Alarm interrupt UIE: Update interrupt (ie: once per second) PIE: Periodic interrupt (sub-second irqs) The problem with this interface is that it limits the RTC hardware so it can only be used by one application at a time. The purpose of this patch is to extend the RTC code so that we can multiplex multiple applications event needs onto a single RTC device. This is done by utilizing the timerqueue infrastructure to manage a list of events, which cause the RTC hardware to be programmed to fire an interrupt for the next event in the list. In order to preserve the functionality of the exsting proc,/dev/ and sysfs interfaces, we emulate the different interrupt modes as follows: AIE: We create a rtc_timer dedicated to AIE mode interrupts. There is only one per device, so we don't change existing interface semantics. UIE: Again, a dedicated rtc_timer, set for periodic mode, is used to emulate UIE interrupts. Again, only one per device. PIE: Since PIE mode interrupts fire faster then the RTC's clock read granularity, we emulate PIE mode interrupts using a hrtimer. Again, one per device. With this patch, the rtctest.c application in Documentation/rtc.txt passes fine on x86 hardware. However, there may very well still be bugs, so greatly I'd appreciate any feedback or testing! Signed-off-by: John Stultz <john.stultz@linaro.org> LKML Reference: <1290136329-18291-4-git-send-email-john.stultz@linaro.org> Acked-by: Alessandro Zummo <a.zummo@towertech.it> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> CC: Alessandro Zummo <a.zummo@towertech.it> CC: Thomas Gleixner <tglx@linutronix.de> CC: Richard Cochran <richardcochran@gmail.com>
148 lines
3.3 KiB
C
148 lines
3.3 KiB
C
/*
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* rtc and date/time utility functions
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*
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* Copyright (C) 2005-06 Tower Technologies
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* Author: Alessandro Zummo <a.zummo@towertech.it>
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*
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* based on arch/arm/common/rtctime.c and other bits
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/module.h>
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#include <linux/rtc.h>
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static const unsigned char rtc_days_in_month[] = {
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31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
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};
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static const unsigned short rtc_ydays[2][13] = {
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/* Normal years */
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{ 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
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/* Leap years */
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{ 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
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};
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#define LEAPS_THRU_END_OF(y) ((y)/4 - (y)/100 + (y)/400)
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/*
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* The number of days in the month.
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*/
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int rtc_month_days(unsigned int month, unsigned int year)
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{
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return rtc_days_in_month[month] + (is_leap_year(year) && month == 1);
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}
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EXPORT_SYMBOL(rtc_month_days);
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/*
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* The number of days since January 1. (0 to 365)
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*/
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int rtc_year_days(unsigned int day, unsigned int month, unsigned int year)
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{
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return rtc_ydays[is_leap_year(year)][month] + day-1;
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}
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EXPORT_SYMBOL(rtc_year_days);
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/*
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* Convert seconds since 01-01-1970 00:00:00 to Gregorian date.
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*/
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void rtc_time_to_tm(unsigned long time, struct rtc_time *tm)
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{
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unsigned int month, year;
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int days;
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days = time / 86400;
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time -= (unsigned int) days * 86400;
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/* day of the week, 1970-01-01 was a Thursday */
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tm->tm_wday = (days + 4) % 7;
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year = 1970 + days / 365;
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days -= (year - 1970) * 365
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+ LEAPS_THRU_END_OF(year - 1)
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- LEAPS_THRU_END_OF(1970 - 1);
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if (days < 0) {
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year -= 1;
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days += 365 + is_leap_year(year);
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}
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tm->tm_year = year - 1900;
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tm->tm_yday = days + 1;
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for (month = 0; month < 11; month++) {
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int newdays;
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newdays = days - rtc_month_days(month, year);
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if (newdays < 0)
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break;
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days = newdays;
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}
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tm->tm_mon = month;
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tm->tm_mday = days + 1;
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tm->tm_hour = time / 3600;
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time -= tm->tm_hour * 3600;
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tm->tm_min = time / 60;
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tm->tm_sec = time - tm->tm_min * 60;
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}
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EXPORT_SYMBOL(rtc_time_to_tm);
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/*
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* Does the rtc_time represent a valid date/time?
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*/
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int rtc_valid_tm(struct rtc_time *tm)
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{
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if (tm->tm_year < 70
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|| ((unsigned)tm->tm_mon) >= 12
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|| tm->tm_mday < 1
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|| tm->tm_mday > rtc_month_days(tm->tm_mon, tm->tm_year + 1900)
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|| ((unsigned)tm->tm_hour) >= 24
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|| ((unsigned)tm->tm_min) >= 60
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|| ((unsigned)tm->tm_sec) >= 60)
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return -EINVAL;
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return 0;
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}
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EXPORT_SYMBOL(rtc_valid_tm);
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/*
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* Convert Gregorian date to seconds since 01-01-1970 00:00:00.
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*/
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int rtc_tm_to_time(struct rtc_time *tm, unsigned long *time)
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{
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*time = mktime(tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
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tm->tm_hour, tm->tm_min, tm->tm_sec);
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return 0;
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}
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EXPORT_SYMBOL(rtc_tm_to_time);
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/*
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* Convert rtc_time to ktime
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*/
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ktime_t rtc_tm_to_ktime(struct rtc_time tm)
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{
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time_t time;
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rtc_tm_to_time(&tm, &time);
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return ktime_set(time, 0);
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}
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EXPORT_SYMBOL_GPL(rtc_tm_to_ktime);
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/*
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* Convert ktime to rtc_time
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*/
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struct rtc_time rtc_ktime_to_tm(ktime_t kt)
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{
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struct timespec ts;
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struct rtc_time ret;
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ts = ktime_to_timespec(kt);
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/* Round up any ns */
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if (ts.tv_nsec)
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ts.tv_sec++;
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rtc_time_to_tm(ts.tv_sec, &ret);
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return ret;
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}
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EXPORT_SYMBOL_GPL(rtc_ktime_to_tm);
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MODULE_LICENSE("GPL");
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