/* *  linux/arch/m68knommu/kernel/time.c * *  Copyright (C) 1998  D. Jeff Dionne <jeff@ryeham.ee.ryerson.ca>, *                      Kenneth Albanowski <kjahds@kjahds.com>, *                      The Silver Hammer Group, Ltd. * *  Copied/hacked from: * *  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. */#include <linux/config.h>#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/segment.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;}/* * timer_interrupt() needs to keep up the real-time clock, * as well as call the "do_timer()" routine every clocktick */void timer_interrupt(int irq, void *dummy, struct pt_regs * regs){	/* last time the cmos clock got updated */	static long last_rtc_update=0;	/* may need to kick the hardware timer */	if (mach_tick)	  mach_tick();	do_timer(regs);	/*	 * 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 (time_state != TIME_BAD && xtime.tv_sec > last_rtc_update + 660 &&	    xtime.tv_usec > 500000 - (tick >> 1) &&	    xtime.tv_usec < 500000 + (tick >> 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 */}/* Converts Gregorian date to seconds since 1970-01-01 00:00:00. * Assumes input in normal date format, i.e. 1980-12-31 23:59:59 * => year=1980, mon=12, day=31, hour=23, min=59, sec=59. * * [For the Julian calendar (which was used in Russia before 1917, * Britain & colonies before 1752, anywhere else before 1582, * and is still in use by some communities) leave out the * -year/100+year/400 terms, and add 10.] * * This algorithm was first published by Gauss (I think). * * WARNING: this function will overflow on 2106-02-07 06:28:16 on * machines were long is 32-bit! (However, as time_t is signed, we * will already get problems at other places on 2038-01-19 03:14:08) */static inline unsigned long mktime(unsigned int year, unsigned int mon,	unsigned int day, unsigned int hour,	unsigned int min, unsigned int sec){	if (0 >= (int) (mon -= 2)) {	/* 1..12 -> 11,12,1..10 */		mon += 12;	/* Puts Feb last since it has leap day */		year -= 1;	}	return (((	    (unsigned long)(year/4 - year/100 + year/400 + 367*mon/12 + day) +	      year*365 - 719499	    )*24 + hour /* now have hours */	   )*60 + min /* now have minutes */	  )*60 + sec; /* finally seconds */}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;#ifdef CONFIG_M68332	*(volatile unsigned short *)0xfffa22 = 0x0140;  /* ipl 6, vec 0x40 */	*(volatile unsigned short *)0xfffa24 = 0x00a3;  /* 50 Hz */#endif	if (mach_sched_init)		mach_sched_init(timer_interrupt);}/* * This version of gettimeofday has near microsecond resolution. */void do_gettimeofday(struct timeval *tv){	unsigned long flags;		save_flags(flags);	cli();	*tv = xtime;	if (mach_gettimeoffset) {	  tv->tv_usec += mach_gettimeoffset();	  if (tv->tv_usec >= 1000000) {	    tv->tv_usec -= 1000000;	    tv->tv_sec++;	  }	}	restore_flags(flags);}void do_settimeofday(struct timeval *tv){	cli();	/* 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)	  tv->tv_usec -= mach_gettimeoffset();	if (tv->tv_usec < 0) {		tv->tv_usec += 1000000;		tv->tv_sec--;	}	xtime = *tv;	time_state = TIME_BAD;	time_maxerror = MAXPHASE;	time_esterror = MAXPHASE;	sti();}