Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 *  linux/arch/or32/kernel/time.c

 *

 *  or32 version

 *

 *  Copied/hacked from:

 *

 *  linux/arch/m68knommu/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.

 */

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/errno.h>

#include <linux/init.h>

#include <linux/sched.h>

#include <linux/param.h>

#include <linux/string.h>

#include <linux/profile.h>

#include <linux/mm.h>

#include <linux/time.h>

#include <linux/timex.h>

#include <linux/interrupt.h>

#include <asm/machdep.h>

#include <asm/segment.h>

#include <asm/io.h>

#include <asm/or32-hf.h>

#define TICK_SIZE (tick_nsec / 1000)

extern unsigned long wall_jiffies;

static inline int set_rtc_mmss(unsigned long nowtime)

{

  if (mach_set_clock_mmss)

    return mach_set_clock_mmss (nowtime);

  return -1;

}

/* last time the RTC clock got updated */

static long last_rtc_update;

/*

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

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

 */

void do_timer_interrupt(struct pt_regs *regs)

{

       /* may need to kick the hardware timer */

       if (mach_tick)

         mach_tick();

       do_timer(1); /*RGD*/

#ifndef CONFIG_SMP

       update_process_times(user_mode(regs));

#endif

       /*profile_tick(CPU_PROFILING); RGD may be broken*/

       /*

        * If we have an externally synchronized Linux clock, then update

        * CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be

        * called as close as possible to 500 ms before the new second starts.

        */

#if 0 /*RGD*/

       if (time_state != TIME_BAD && xtime.tv_sec > last_rtc_update + 660 &&

           (xtime.tv_nsec / 1000) > 500000 - ((unsigned)TICK_SIZE >> 1) &&

           (xtime.tv_nsec / 1000) < 500000 + ((unsigned)TICK_SIZE >> 1)) {

               if (set_rtc_mmss(xtime.tv_sec) == 0)

                       last_rtc_update = xtime.tv_sec;

               else

                       last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */

       }

#endif /*RGD*/

       /*RGD from FRV*/

        /*

         * If we have an externally synchronized Linux clock, then update

         * CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be

         * called as close as possible to 500 ms before the new second starts.

         */

        if (ntp_synced() &&

            xtime.tv_sec > last_rtc_update + 660 &&

            (xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 &&

            (xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2

            ) {

                if (set_rtc_mmss(xtime.tv_sec) == 0)

                        last_rtc_update = xtime.tv_sec;

                else

                        last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */

        }

        /*RGD from FRV*/

}

/*

 * This get called at every clock tick...

 *

 */

irqreturn_t timer_interrupt(struct pt_regs * regs)

{

        check_stack(regs, __FILE__, __FUNCTION__, __LINE__);

        /*

         * Here we are in the timer irq handler. We just have irqs locally

         * disabled but we don't know if the timer_bh is running on the other

         * CPU. We need to avoid to SMP race with it. NOTE: we don' t need

         * the irq version of write_lock because as just said we have irq

         * locally disabled. -arca

         */

        write_seqlock(&xtime_lock);

        do_timer_interrupt(regs);

        write_sequnlock(&xtime_lock);

        return IRQ_HANDLED;

}

/*

 * This version of gettimeofday has near microsecond resolution.

 *

 * Note: Division is quite slow on OR32 and do_gettimeofday is called

 *       rather often. Maybe we should do some kind of approximation here

 *       (a naive approximation would be to divide by 1024).

 */

void do_gettimeofday(struct timeval *tv)

{

        unsigned long flags;

        signed long usec, sec;

        local_irq_save(flags);

        local_irq_disable();

        usec = mach_gettimeoffset ? mach_gettimeoffset() : 0;

#if 0 /*RGD*/

        {

                unsigned long lost = jiffies - wall_jiffies;

                if (lost)

                  usec += lost * (1000000 / HZ);

        }

#endif /*RGD*/  

        /*

         * If time_adjust is negative then NTP is slowing the clock

         * so make sure not to go into next possible interval.

         * Better to lose some accuracy than have time go backwards..

         */

        if (unlikely(time_adjust < 0) && usec > tickadj)

          usec = tickadj;

        sec = xtime.tv_sec;

        usec += xtime.tv_nsec / 1000;

        local_irq_restore(flags);

        while (usec >= 1000000) {

                usec -= 1000000;

                sec++;

        }

        tv->tv_sec = sec;

        tv->tv_usec = usec;

}

EXPORT_SYMBOL(do_gettimeofday);

int do_settimeofday(struct timespec *tv)

{

        time_t wtm_sec, sec = tv->tv_sec;

        long wtm_nsec, nsec = tv->tv_nsec;

        if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)

                return -EINVAL;

        write_seqlock_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!

         */

        if (mach_gettimeoffset)

                nsec -= (mach_gettimeoffset() * 1000);

        wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);

        wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);

        set_normalized_timespec(&xtime, sec, nsec);

        set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);

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

        time_status |= STA_UNSYNC;

        time_maxerror = NTP_PHASE_LIMIT;

        time_esterror = NTP_PHASE_LIMIT;

        write_sequnlock_irq(&xtime_lock);

        clock_was_set();

        return 0;

}

EXPORT_SYMBOL(do_settimeofday);

/*

 * Scheduler clock - returns current time in nanosec units.

 */

unsigned long long sched_clock(void)

{

        return (unsigned long long)jiffies * (1000000000 / HZ);

}

void __init 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_nsec = 0;

        if (mach_sched_init)

                mach_sched_init();

}