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[/] [or1k/] [trunk/] [rc203soc/] [sw/] [uClinux/] [arch/] [or32/] [kernel/] [time.c] - Blame information for rev 1777

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Line No. Rev Author Line
1 1624 jcastillo
/*
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 *  linux/arch/or32/kernel/time.c
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 *
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 *  Copied/hacked from:
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 *
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 *  linux/arch/m68knommu/kernel/time.c
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 *
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 *  Copyright (C) 1991, 1992, 1995  Linus Torvalds
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 *
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 * This file contains the m68k-specific time handling details.
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 * Most of the stuff is located in the machine specific files.
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 */
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#include <linux/config.h>
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#include <linux/errno.h>
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/param.h>
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#include <linux/string.h>
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#include <linux/mm.h>
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#include <asm/machdep.h>
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#include <asm/segment.h>
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#include <asm/io.h>
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#include <linux/timex.h>
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static inline int set_rtc_mmss(unsigned long nowtime)
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{
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  if (mach_set_clock_mmss)
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    return mach_set_clock_mmss (nowtime);
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  return -1;
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}
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/*
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 * timer_interrupt() needs to keep up the real-time clock,
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 * as well as call the "do_timer()" routine every clocktick
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 */
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/* void timer_interrupt(int irq, void *dummy, struct pt_regs * regs)
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*/
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void timer_interrupt(struct pt_regs * regs)
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{
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        /* last time the cmos clock got updated */
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        static long last_rtc_update=0;
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        /* may need to kick the hardware timer */
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        if (mach_tick)
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          mach_tick();
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        do_timer(regs);
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        /*
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         * If we have an externally synchronized Linux clock, then update
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         * CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
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         * called as close as possible to 500 ms before the new second starts.
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         */
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        if (time_state != TIME_BAD && xtime.tv_sec > last_rtc_update + 660 &&
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            xtime.tv_usec > 500000 - (tick >> 1) &&
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            xtime.tv_usec < 500000 + (tick >> 1)) {
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          if (set_rtc_mmss(xtime.tv_sec) == 0)
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            last_rtc_update = xtime.tv_sec;
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          else
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            last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */
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        }
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}
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/* Converts Gregorian date to seconds since 1970-01-01 00:00:00.
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 * Assumes input in normal date format, i.e. 1980-12-31 23:59:59
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 * => year=1980, mon=12, day=31, hour=23, min=59, sec=59.
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 *
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 * [For the Julian calendar (which was used in Russia before 1917,
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 * Britain & colonies before 1752, anywhere else before 1582,
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 * and is still in use by some communities) leave out the
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 * -year/100+year/400 terms, and add 10.]
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 *
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 * This algorithm was first published by Gauss (I think).
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 *
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 * WARNING: this function will overflow on 2106-02-07 06:28:16 on
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 * machines were long is 32-bit! (However, as time_t is signed, we
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 * will already get problems at other places on 2038-01-19 03:14:08)
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 */
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static inline unsigned long mktime(unsigned int year, unsigned int mon,
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        unsigned int day, unsigned int hour,
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        unsigned int min, unsigned int sec)
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{
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        if (0 >= (int) (mon -= 2)) {     /* 1..12 -> 11,12,1..10 */
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                mon += 12;      /* Puts Feb last since it has leap day */
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                year -= 1;
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        }
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        return (((
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            (unsigned long)(year/4 - year/100 + year/400 + 367*mon/12 + day) +
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              year*365 - 719499
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            )*24 + hour /* now have hours */
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           )*60 + min /* now have minutes */
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          )*60 + sec; /* finally seconds */
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}
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void time_init(void)
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{
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        unsigned int year, mon, day, hour, min, sec;
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        extern void arch_gettod(int *year, int *mon, int *day, int *hour,
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                                int *min, int *sec);
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        arch_gettod (&year, &mon, &day, &hour, &min, &sec);
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        if ((year += 1900) < 1970)
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                year += 100;
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        xtime.tv_sec = mktime(year, mon, day, hour, min, sec);
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        xtime.tv_usec = 0;
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        if (mach_sched_init)
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                mach_sched_init(timer_interrupt);
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}
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/*
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 * This version of gettimeofday has near microsecond resolution.
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 */
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void do_gettimeofday(struct timeval *tv)
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{
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        unsigned long flags;
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        save_flags(flags);
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        cli();
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        *tv = xtime;
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        if (mach_gettimeoffset) {
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          tv->tv_usec += mach_gettimeoffset();
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          if (tv->tv_usec >= 1000000) {
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            tv->tv_usec -= 1000000;
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            tv->tv_sec++;
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          }
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        }
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        restore_flags(flags);
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}
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void do_settimeofday(struct timeval *tv)
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{
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        cli();
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        /* This is revolting. We need to set the xtime.tv_usec
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         * correctly. However, the value in this location is
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         * is value at the last tick.
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         * Discover what correction gettimeofday
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         * would have done, and then undo it!
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         */
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        if (mach_gettimeoffset)
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          tv->tv_usec -= mach_gettimeoffset();
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        if (tv->tv_usec < 0) {
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                tv->tv_usec += 1000000;
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                tv->tv_sec--;
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        }
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        xtime = *tv;
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        time_state = TIME_BAD;
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        time_maxerror = MAXPHASE;
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        time_esterror = MAXPHASE;
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        sti();
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}
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