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/*

 *  linux/arch/m68k/kernel/time.c

 *

 *  Copyright (C) 1991, 1992, 1995  Linus Torvalds

 *

 * This file contains the m68k-specific time handling details.

 * Most of the stuff is located in the machine specific files.

 *

 * 1997-09-10   Updated NTP code according to technical memorandum Jan '96

 *              "A Kernel Model for Precision Timekeeping" by Dave Mills

 */

#include <linux/config.h> /* CONFIG_HEARTBEAT */

#include <linux/errno.h>

#include <linux/sched.h>

#include <linux/kernel.h>

#include <linux/param.h>

#include <linux/string.h>

#include <linux/mm.h>

#include <asm/machdep.h>

#include <asm/io.h>

#include <linux/timex.h>

static inline int set_rtc_mmss(unsigned long nowtime)

{

  if (mach_set_clock_mmss)

    return mach_set_clock_mmss (nowtime);

  return -1;

}

static inline void do_profile (unsigned long pc)

{

        if (prof_buffer && current->pid) {

                extern int _stext;

                pc -= (unsigned long) &_stext;

                pc >>= prof_shift;

                if (pc < prof_len)

                        ++prof_buffer[pc];

                else

                /*

                 * Don't ignore out-of-bounds PC values silently,

                 * put them into the last histogram slot, so if

                 * present, they will show up as a sharp peak.

                 */

                        ++prof_buffer[prof_len-1];

        }

}

/*

 * timer_interrupt() needs to keep up the real-time clock,

 * as well as call the "do_timer()" routine every clocktick

 */

static void timer_interrupt(int irq, void *dummy, struct pt_regs * regs)

{

        do_timer(regs);

        if (!user_mode(regs))

                do_profile(regs->pc);

#ifdef CONFIG_HEARTBEAT

        /* use power LED as a heartbeat instead -- much more useful

           for debugging -- based on the version for PReP by Cort */

        /* acts like an actual heart beat -- ie thump-thump-pause... */

        if (mach_heartbeat) {

            static unsigned cnt = 0, period = 0, dist = 0;

            if (cnt == 0 || cnt == dist)

                mach_heartbeat( 1 );

            else if (cnt == 7 || cnt == dist+7)

                mach_heartbeat( 0 );

            if (++cnt > period) {

                cnt = 0;

                /* The hyperbolic function below modifies the heartbeat period

                 * length in dependency of the current (5min) load. It goes

                 * through the points f(0)=126, f(1)=86, f(5)=51,

                 * f(inf)->30. */

                period = ((672<<FSHIFT)/(5*avenrun[0]+(7<<FSHIFT))) + 30;

                dist = period / 4;

            }

        }

#endif /* CONFIG_HEARTBEAT */

}

void time_init(void)

{

        unsigned int year, mon, day, hour, min, sec;

        extern void arch_gettod(int *year, int *mon, int *day, int *hour,

                                int *min, int *sec);

        arch_gettod (&year, &mon, &day, &hour, &min, &sec);

        if ((year += 1900) < 1970)

                year += 100;

        xtime.tv_sec = mktime(year, mon, day, hour, min, sec);

        xtime.tv_usec = 0;

        mach_sched_init(timer_interrupt);

}

extern rwlock_t xtime_lock;

/*

 * This version of gettimeofday has near microsecond resolution.

 */

void do_gettimeofday(struct timeval *tv)

{

        extern unsigned long wall_jiffies;

        unsigned long flags;

        unsigned long usec, sec, lost;

        read_lock_irqsave(&xtime_lock, flags);

        usec = mach_gettimeoffset();

        lost = jiffies - wall_jiffies;

        if (lost)

                usec += lost * (1000000/HZ);

        sec = xtime.tv_sec;

        usec += xtime.tv_usec;

        read_unlock_irqrestore(&xtime_lock, flags);

        while (usec >= 1000000) {

                usec -= 1000000;

                sec++;

        }

        tv->tv_sec = sec;

        tv->tv_usec = usec;

}

void do_settimeofday(struct timeval *tv)

{

        write_lock_irq(&xtime_lock);

        /* This is revolting. We need to set the xtime.tv_usec

         * correctly. However, the value in this location is

         * is value at the last tick.

         * Discover what correction gettimeofday

         * would have done, and then undo it!

         */

        tv->tv_usec -= mach_gettimeoffset();

        while (tv->tv_usec < 0) {

                tv->tv_usec += 1000000;

                tv->tv_sec--;

        }

        xtime = *tv;

        time_adjust = 0;         /* stop active adjtime() */

        time_status |= STA_UNSYNC;

        time_maxerror = NTP_PHASE_LIMIT;

        time_esterror = NTP_PHASE_LIMIT;

        write_unlock_irq(&xtime_lock);

}