[SPARC64]: Synchronize RTC clock via timer just like x86.

#define TICK_SIZE (tick_nsec / 1000)

static inline void timer_check_rtc(void)

#define USEC_AFTER	500000

#define USEC_BEFORE	500000

static void sync_cmos_clock(unsigned long dummy);

static DEFINE_TIMER(sync_cmos_timer, sync_cmos_clock, 0, 0);

static void sync_cmos_clock(unsigned long dummy)

{

	/* last time the cmos clock got updated */

	static long last_rtc_update;

	/* Determine when to update the Mostek clock. */

	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;

	struct timeval now, next;

	int fail = 1;

	/*

	 * 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.

	 * This code is run on a timer.  If the clock is set, that timer

	 * may not expire at the correct time.  Thus, we adjust...

	 */

	if (!ntp_synced())

		/*

		 * Not synced, exit, do not restart a timer (if one is

		 * running, let it run out).

		 */

		return;

	do_gettimeofday(&now);

	if (now.tv_usec >= USEC_AFTER - ((unsigned) TICK_SIZE) / 2 &&

	    now.tv_usec <= USEC_BEFORE + ((unsigned) TICK_SIZE) / 2)

		fail = set_rtc_mmss(now.tv_sec);

	next.tv_usec = USEC_AFTER - now.tv_usec;

	if (next.tv_usec <= 0)

		next.tv_usec += USEC_PER_SEC;

	if (!fail)

		next.tv_sec = 659;

	else

			last_rtc_update = xtime.tv_sec - 600;

			/* do it again in 60 s */

		next.tv_sec = 0;

	if (next.tv_usec >= USEC_PER_SEC) {

		next.tv_sec++;

		next.tv_usec -= USEC_PER_SEC;

	}

	mod_timer(&sync_cmos_timer, jiffies + timeval_to_jiffies(&next));

}

void notify_arch_cmos_timer(void)

{

	mod_timer(&sync_cmos_timer, jiffies + 1);

}

irqreturn_t timer_interrupt(int irq, void *dev_id)

				     : "r" (pstate));

	} while (time_after_eq(ticks, compare));

	timer_check_rtc();

	write_sequnlock(&xtime_lock);

	return IRQ_HANDLED;

	do_timer(1);

	timer_check_rtc();

	write_sequnlock(&xtime_lock);

}

#endif