319 lines
8.2 KiB
C
319 lines
8.2 KiB
C
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/*
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* linux/arch/m32r/kernel/time.c
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*
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* Copyright (c) 2001, 2002 Hiroyuki Kondo, Hirokazu Takata,
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* Hitoshi Yamamoto
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* Taken from i386 version.
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* Copyright (C) 1991, 1992, 1995 Linus Torvalds
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* Copyright (C) 1996, 1997, 1998 Ralf Baechle
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*
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* This file contains the time handling details for PC-style clocks as
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* found in some MIPS systems.
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*
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* Some code taken from sh version.
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* Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka
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* Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>
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*/
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#undef DEBUG_TIMER
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#include <linux/config.h>
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#include <linux/errno.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/param.h>
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#include <linux/string.h>
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#include <linux/mm.h>
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#include <linux/interrupt.h>
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#include <linux/profile.h>
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#include <asm/io.h>
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#include <asm/m32r.h>
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#include <asm/hw_irq.h>
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#ifdef CONFIG_SMP
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extern void send_IPI_allbutself(int, int);
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extern void smp_local_timer_interrupt(struct pt_regs *);
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#endif
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u64 jiffies_64 = INITIAL_JIFFIES;
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EXPORT_SYMBOL(jiffies_64);
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extern unsigned long wall_jiffies;
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#define TICK_SIZE (tick_nsec / 1000)
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/*
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* Change this if you have some constant time drift
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*/
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/* This is for machines which generate the exact clock. */
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#define USECS_PER_JIFFY (1000000/HZ)
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static unsigned long latch;
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static unsigned long do_gettimeoffset(void)
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{
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unsigned long elapsed_time = 0; /* [us] */
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#if defined(CONFIG_CHIP_M32102) || defined(CONFIG_CHIP_XNUX2) \
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|| defined(CONFIG_CHIP_VDEC2) || defined(CONFIG_CHIP_M32700) \
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|| defined(CONFIG_CHIP_OPSP)
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#ifndef CONFIG_SMP
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unsigned long count;
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/* timer count may underflow right here */
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count = inl(M32R_MFT2CUT_PORTL);
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if (inl(M32R_ICU_CR18_PORTL) & 0x00000100) /* underflow check */
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count = 0;
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count = (latch - count) * TICK_SIZE;
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elapsed_time = (count + latch / 2) / latch;
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/* NOTE: LATCH is equal to the "interval" value (= reload count). */
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#else /* CONFIG_SMP */
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unsigned long count;
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static unsigned long p_jiffies = -1;
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static unsigned long p_count = 0;
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/* timer count may underflow right here */
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count = inl(M32R_MFT2CUT_PORTL);
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if (jiffies == p_jiffies && count > p_count)
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count = 0;
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p_jiffies = jiffies;
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p_count = count;
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count = (latch - count) * TICK_SIZE;
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elapsed_time = (count + latch / 2) / latch;
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/* NOTE: LATCH is equal to the "interval" value (= reload count). */
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#endif /* CONFIG_SMP */
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#elif defined(CONFIG_CHIP_M32310)
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#warning do_gettimeoffse not implemented
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#else
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#error no chip configuration
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#endif
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return elapsed_time;
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}
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/*
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* This version of gettimeofday has near microsecond resolution.
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*/
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void do_gettimeofday(struct timeval *tv)
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{
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unsigned long seq;
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unsigned long usec, sec;
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unsigned long max_ntp_tick = tick_usec - tickadj;
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do {
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unsigned long lost;
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seq = read_seqbegin(&xtime_lock);
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usec = do_gettimeoffset();
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lost = jiffies - wall_jiffies;
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/*
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* If time_adjust is negative then NTP is slowing the clock
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* so make sure not to go into next possible interval.
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* Better to lose some accuracy than have time go backwards..
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*/
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if (unlikely(time_adjust < 0)) {
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usec = min(usec, max_ntp_tick);
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if (lost)
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usec += lost * max_ntp_tick;
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} else if (unlikely(lost))
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usec += lost * tick_usec;
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sec = xtime.tv_sec;
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usec += (xtime.tv_nsec / 1000);
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} while (read_seqretry(&xtime_lock, seq));
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while (usec >= 1000000) {
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usec -= 1000000;
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sec++;
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}
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tv->tv_sec = sec;
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tv->tv_usec = usec;
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}
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EXPORT_SYMBOL(do_gettimeofday);
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int do_settimeofday(struct timespec *tv)
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{
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time_t wtm_sec, sec = tv->tv_sec;
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long wtm_nsec, nsec = tv->tv_nsec;
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if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
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return -EINVAL;
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write_seqlock_irq(&xtime_lock);
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/*
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* This is revolting. We need to set "xtime" correctly. However, the
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* value in this location is the value at the most recent update of
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* wall time. Discover what correction gettimeofday() would have
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* made, and then undo it!
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*/
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nsec -= do_gettimeoffset() * NSEC_PER_USEC;
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nsec -= (jiffies - wall_jiffies) * TICK_NSEC;
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wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
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wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
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set_normalized_timespec(&xtime, sec, nsec);
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set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
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time_adjust = 0; /* stop active adjtime() */
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time_status |= STA_UNSYNC;
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time_maxerror = NTP_PHASE_LIMIT;
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time_esterror = NTP_PHASE_LIMIT;
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write_sequnlock_irq(&xtime_lock);
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clock_was_set();
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return 0;
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}
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EXPORT_SYMBOL(do_settimeofday);
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/*
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* In order to set the CMOS clock precisely, set_rtc_mmss has to be
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* called 500 ms after the second nowtime has started, because when
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* nowtime is written into the registers of the CMOS clock, it will
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* jump to the next second precisely 500 ms later. Check the Motorola
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* MC146818A or Dallas DS12887 data sheet for details.
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*
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* BUG: This routine does not handle hour overflow properly; it just
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* sets the minutes. Usually you won't notice until after reboot!
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*/
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static inline int set_rtc_mmss(unsigned long nowtime)
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{
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return 0;
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}
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/* last time the cmos clock got updated */
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static long last_rtc_update = 0;
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/*
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* timer_interrupt() needs to keep up the real-time clock,
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* as well as call the "do_timer()" routine every clocktick
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*/
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static inline void
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do_timer_interrupt(int irq, void *dev_id, struct pt_regs * regs)
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{
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#ifndef CONFIG_SMP
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profile_tick(CPU_PROFILING, regs);
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#endif
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do_timer(regs);
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#ifndef CONFIG_SMP
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update_process_times(user_mode(regs));
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#endif
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/*
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* If we have an externally synchronized Linux clock, then update
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* CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
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* called as close as possible to 500 ms before the new second starts.
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*/
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if ((time_status & STA_UNSYNC) == 0
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&& xtime.tv_sec > last_rtc_update + 660
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&& (xtime.tv_nsec / 1000) >= 500000 - ((unsigned)TICK_SIZE) / 2
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&& (xtime.tv_nsec / 1000) <= 500000 + ((unsigned)TICK_SIZE) / 2)
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{
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if (set_rtc_mmss(xtime.tv_sec) == 0)
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last_rtc_update = xtime.tv_sec;
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else /* do it again in 60 s */
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last_rtc_update = xtime.tv_sec - 600;
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}
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/* As we return to user mode fire off the other CPU schedulers..
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this is basically because we don't yet share IRQ's around.
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This message is rigged to be safe on the 386 - basically it's
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a hack, so don't look closely for now.. */
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#ifdef CONFIG_SMP
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smp_local_timer_interrupt(regs);
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#endif
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}
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irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
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{
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write_seqlock(&xtime_lock);
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do_timer_interrupt(irq, NULL, regs);
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write_sequnlock(&xtime_lock);
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return IRQ_HANDLED;
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}
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struct irqaction irq0 = { timer_interrupt, SA_INTERRUPT, CPU_MASK_NONE,
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"MFT2", NULL, NULL };
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void __init time_init(void)
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{
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unsigned int epoch, year, mon, day, hour, min, sec;
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sec = min = hour = day = mon = year = 0;
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epoch = 0;
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year = 23;
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mon = 4;
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day = 17;
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/* Attempt to guess the epoch. This is the same heuristic as in rtc.c
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so no stupid things will happen to timekeeping. Who knows, maybe
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Ultrix also uses 1952 as epoch ... */
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if (year > 10 && year < 44)
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epoch = 1980;
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else if (year < 96)
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epoch = 1952;
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year += epoch;
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xtime.tv_sec = mktime(year, mon, day, hour, min, sec);
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xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
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set_normalized_timespec(&wall_to_monotonic,
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-xtime.tv_sec, -xtime.tv_nsec);
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#if defined(CONFIG_CHIP_M32102) || defined(CONFIG_CHIP_XNUX2) \
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|| defined(CONFIG_CHIP_VDEC2) || defined(CONFIG_CHIP_M32700) \
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|| defined(CONFIG_CHIP_OPSP)
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/* M32102 MFT setup */
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setup_irq(M32R_IRQ_MFT2, &irq0);
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{
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unsigned long bus_clock;
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unsigned short divide;
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bus_clock = boot_cpu_data.bus_clock;
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divide = boot_cpu_data.timer_divide;
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latch = (bus_clock/divide + HZ / 2) / HZ;
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printk("Timer start : latch = %ld\n", latch);
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outl((M32R_MFTMOD_CC_MASK | M32R_MFTMOD_TCCR \
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|M32R_MFTMOD_CSSEL011), M32R_MFT2MOD_PORTL);
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outl(latch, M32R_MFT2RLD_PORTL);
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outl(latch, M32R_MFT2CUT_PORTL);
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outl(0, M32R_MFT2CMPRLD_PORTL);
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outl((M32R_MFTCR_MFT2MSK|M32R_MFTCR_MFT2EN), M32R_MFTCR_PORTL);
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}
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#elif defined(CONFIG_CHIP_M32310)
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#warning time_init not implemented
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#else
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#error no chip configuration
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#endif
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}
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/*
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* Scheduler clock - returns current time in nanosec units.
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*/
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unsigned long long sched_clock(void)
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{
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return (unsigned long long)jiffies * (1000000000 / HZ);
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}
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