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-rw-r--r--arch/v850/kernel/time.c198
1 files changed, 198 insertions, 0 deletions
diff --git a/arch/v850/kernel/time.c b/arch/v850/kernel/time.c
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+/*
+ * linux/arch/v850/kernel/time.c -- Arch-dependent timer functions
+ *
+ * Copyright (C) 1991, 1992, 1995, 2001, 2002 Linus Torvalds
+ *
+ * This file contains the v850-specific time handling details.
+ * Most of the stuff is located in the machine specific files.
+ *
+ * 1997-09-10 Updated NTP code according to technical memorandum Jan '96
+ * "A Kernel Model for Precision Timekeeping" by Dave Mills
+ */
+
+#include <linux/config.h> /* CONFIG_HEARTBEAT */
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/param.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <linux/time.h>
+#include <linux/timex.h>
+#include <linux/profile.h>
+
+#include <asm/io.h>
+
+#include "mach.h"
+
+u64 jiffies_64 = INITIAL_JIFFIES;
+
+EXPORT_SYMBOL(jiffies_64);
+
+#define TICK_SIZE (tick_nsec / 1000)
+
+/*
+ * Scheduler clock - returns current time in nanosec units.
+ */
+unsigned long long sched_clock(void)
+{
+ return (unsigned long long)jiffies * (1000000000 / HZ);
+}
+
+/*
+ * timer_interrupt() needs to keep up the real-time clock,
+ * as well as call the "do_timer()" routine every clocktick
+ */
+static irqreturn_t timer_interrupt (int irq, void *dummy, struct pt_regs *regs)
+{
+#if 0
+ /* last time the cmos clock got updated */
+ static long last_rtc_update=0;
+#endif
+
+ /* may need to kick the hardware timer */
+ if (mach_tick)
+ mach_tick ();
+
+ do_timer (regs);
+#ifndef CONFIG_SMP
+ update_process_times(user_mode(regs));
+#endif
+ profile_tick(CPU_PROFILING, regs);
+#if 0
+ /*
+ * 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_status & STA_UNSYNC) == 0 &&
+ 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 */
+ }
+#ifdef CONFIG_HEARTBEAT
+ /* use power LED as a heartbeat instead -- much more useful
+ for debugging -- based on the version for PReP by Cort */
+ /* acts like an actual heart beat -- ie thump-thump-pause... */
+ if (mach_heartbeat) {
+ static unsigned cnt = 0, period = 0, dist = 0;
+
+ if (cnt == 0 || cnt == dist)
+ mach_heartbeat ( 1 );
+ else if (cnt == 7 || cnt == dist+7)
+ mach_heartbeat ( 0 );
+
+ if (++cnt > period) {
+ cnt = 0;
+ /* The hyperbolic function below modifies the heartbeat period
+ * length in dependency of the current (5min) load. It goes
+ * through the points f(0)=126, f(1)=86, f(5)=51,
+ * f(inf)->30. */
+ period = ((672<<FSHIFT)/(5*avenrun[0]+(7<<FSHIFT))) + 30;
+ dist = period / 4;
+ }
+ }
+#endif /* CONFIG_HEARTBEAT */
+#endif /* 0 */
+
+ return IRQ_HANDLED;
+}
+
+/*
+ * This version of gettimeofday has near microsecond resolution.
+ */
+void do_gettimeofday (struct timeval *tv)
+{
+#if 0 /* DAVIDM later if possible */
+ extern volatile unsigned long lost_ticks;
+ unsigned long lost;
+#endif
+ unsigned long flags;
+ unsigned long usec, sec;
+ unsigned long seq;
+
+ do {
+ seq = read_seqbegin_irqsave(&xtime_lock, flags);
+
+#if 0
+ usec = mach_gettimeoffset ? mach_gettimeoffset () : 0;
+#else
+ usec = 0;
+#endif
+#if 0 /* DAVIDM later if possible */
+ lost = lost_ticks;
+ if (lost)
+ usec += lost * (1000000/HZ);
+#endif
+ sec = xtime.tv_sec;
+ usec += xtime.tv_nsec / 1000;
+ } while (read_seqretry_irqrestore(&xtime_lock, seq, 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)
+{
+ 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_nsec
+ * 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 0
+ tv->tv_nsec -= mach_gettimeoffset() * 1000;
+#endif
+
+ while (tv->tv_nsec < 0) {
+ tv->tv_nsec += NSEC_PER_SEC;
+ tv->tv_sec--;
+ }
+
+ xtime.tv_sec = tv->tv_sec;
+ xtime.tv_nsec = tv->tv_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);
+
+static int timer_dev_id;
+static struct irqaction timer_irqaction = {
+ timer_interrupt,
+ SA_INTERRUPT,
+ CPU_MASK_NONE,
+ "timer",
+ &timer_dev_id,
+ NULL
+};
+
+void time_init (void)
+{
+ mach_gettimeofday (&xtime);
+ mach_sched_init (&timer_irqaction);
+}
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