aboutsummaryrefslogtreecommitdiff
path: root/arch/m68k/kernel/time.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/m68k/kernel/time.c')
-rw-r--r--arch/m68k/kernel/time.c187
1 files changed, 187 insertions, 0 deletions
diff --git a/arch/m68k/kernel/time.c b/arch/m68k/kernel/time.c
new file mode 100644
index 00000000000..e47e1958852
--- /dev/null
+++ b/arch/m68k/kernel/time.c
@@ -0,0 +1,187 @@
+/*
+ * 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.
+ *
+ * 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/module.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/param.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/rtc.h>
+
+#include <asm/machdep.h>
+#include <asm/io.h>
+
+#include <linux/time.h>
+#include <linux/timex.h>
+#include <linux/profile.h>
+
+u64 jiffies_64 = INITIAL_JIFFIES;
+
+EXPORT_SYMBOL(jiffies_64);
+
+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
+ */
+static irqreturn_t timer_interrupt(int irq, void *dummy, struct pt_regs * regs)
+{
+ do_timer(regs);
+#ifndef CONFIG_SMP
+ update_process_times(user_mode(regs));
+#endif
+ profile_tick(CPU_PROFILING, regs);
+
+#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 */
+ return IRQ_HANDLED;
+}
+
+void time_init(void)
+{
+ struct rtc_time time;
+
+ if (mach_hwclk) {
+ mach_hwclk(0, &time);
+
+ if ((time.tm_year += 1900) < 1970)
+ time.tm_year += 100;
+ xtime.tv_sec = mktime(time.tm_year, time.tm_mon, time.tm_mday,
+ time.tm_hour, time.tm_min, time.tm_sec);
+ xtime.tv_nsec = 0;
+ }
+ wall_to_monotonic.tv_sec = -xtime.tv_sec;
+
+ mach_sched_init(timer_interrupt);
+}
+
+/*
+ * This version of gettimeofday has near microsecond resolution.
+ */
+void do_gettimeofday(struct timeval *tv)
+{
+ unsigned long flags;
+ extern unsigned long wall_jiffies;
+ unsigned long seq;
+ unsigned long usec, sec, lost;
+ unsigned long max_ntp_tick = tick_usec - tickadj;
+
+ do {
+ seq = read_seqbegin_irqsave(&xtime_lock, flags);
+
+ usec = mach_gettimeoffset();
+ lost = jiffies - wall_jiffies;
+
+ /*
+ * If time_adjust is negative then NTP is slowing the clock
+ * so make sure not to go into next possible interval.
+ * Better to lose some accuracy than have time go backwards..
+ */
+ if (unlikely(time_adjust < 0)) {
+ usec = min(usec, max_ntp_tick);
+
+ if (lost)
+ usec += lost * max_ntp_tick;
+ }
+ else if (unlikely(lost))
+ usec += lost * tick_usec;
+
+ 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)
+{
+ time_t wtm_sec, sec = tv->tv_sec;
+ long wtm_nsec, nsec = tv->tv_nsec;
+ extern unsigned long wall_jiffies;
+
+ 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!
+ */
+ nsec -= 1000 * (mach_gettimeoffset() +
+ (jiffies - wall_jiffies) * (1000000 / HZ));
+
+ wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
+ wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
+
+ set_normalized_timespec(&xtime, sec, nsec);
+ set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_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);
+
+/*
+ * Scheduler clock - returns current time in ns units.
+ */
+unsigned long long sched_clock(void)
+{
+ return (unsigned long long)jiffies*(1000000000/HZ);
+}
+