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[/] [or1k/] [trunk/] [uclinux/] [uClinux-2.0.x/] [arch/] [m68knommu/] [kernel/] [time.c] - Rev 1775
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/* * 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; 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(); }
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