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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/cris/kernel/time.c
downloadlinux-stericsson-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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diff --git a/arch/cris/kernel/time.c b/arch/cris/kernel/time.c
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+/* $Id: time.c,v 1.14 2004/06/01 05:38:11 starvik Exp $
+ *
+ * linux/arch/cris/kernel/time.c
+ *
+ * Copyright (C) 1991, 1992, 1995 Linus Torvalds
+ * Copyright (C) 1999, 2000, 2001 Axis Communications AB
+ *
+ * 1994-07-02 Alan Modra
+ * fixed set_rtc_mmss, fixed time.year for >= 2000, new mktime
+ * 1995-03-26 Markus Kuhn
+ * fixed 500 ms bug at call to set_rtc_mmss, fixed DS12887
+ * precision CMOS clock update
+ * 1996-05-03 Ingo Molnar
+ * fixed time warps in do_[slow|fast]_gettimeoffset()
+ * 1997-09-10 Updated NTP code according to technical memorandum Jan '96
+ * "A Kernel Model for Precision Timekeeping" by Dave Mills
+ *
+ * Linux/CRIS specific code:
+ *
+ * Authors: Bjorn Wesen
+ * Johan Adolfsson
+ *
+ */
+
+#include <asm/rtc.h>
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/param.h>
+#include <linux/jiffies.h>
+#include <linux/bcd.h>
+#include <linux/timex.h>
+#include <linux/init.h>
+
+u64 jiffies_64 = INITIAL_JIFFIES;
+
+EXPORT_SYMBOL(jiffies_64);
+
+int have_rtc; /* used to remember if we have an RTC or not */;
+
+#define TICK_SIZE tick
+
+extern unsigned long wall_jiffies;
+extern unsigned long loops_per_jiffy; /* init/main.c */
+unsigned long loops_per_usec;
+
+extern unsigned long do_slow_gettimeoffset(void);
+static unsigned long (*do_gettimeoffset)(void) = do_slow_gettimeoffset;
+
+/*
+ * This version of gettimeofday has near microsecond resolution.
+ *
+ * Note: Division is quite slow on CRIS and do_gettimeofday is called
+ * rather often. Maybe we should do some kind of approximation here
+ * (a naive approximation would be to divide by 1024).
+ */
+void do_gettimeofday(struct timeval *tv)
+{
+ unsigned long flags;
+ signed long usec, sec;
+ local_irq_save(flags);
+ local_irq_disable();
+ usec = do_gettimeoffset();
+ {
+ unsigned long lost = jiffies - wall_jiffies;
+ if (lost)
+ usec += lost * (1000000 / HZ);
+ }
+
+ /*
+ * 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 > tickadj)
+ usec = tickadj;
+
+ sec = xtime.tv_sec;
+ usec += xtime.tv_nsec / 1000;
+ local_irq_restore(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;
+
+ if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
+ return -EINVAL;
+
+ write_seqlock_irq(&xtime_lock);
+ /*
+ * This is revolting. We need to set "xtime" correctly. However, the
+ * value in this location is the value at the most recent update of
+ * wall time. Discover what correction gettimeofday() would have
+ * made, and then undo it!
+ */
+ nsec -= do_gettimeoffset() * NSEC_PER_USEC;
+ nsec -= (jiffies - wall_jiffies) * TICK_NSEC;
+
+ 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);
+
+
+/*
+ * BUG: This routine does not handle hour overflow properly; it just
+ * sets the minutes. Usually you'll only notice that after reboot!
+ */
+
+int set_rtc_mmss(unsigned long nowtime)
+{
+ int retval = 0;
+ int real_seconds, real_minutes, cmos_minutes;
+
+ printk(KERN_DEBUG "set_rtc_mmss(%lu)\n", nowtime);
+
+ if(!have_rtc)
+ return 0;
+
+ cmos_minutes = CMOS_READ(RTC_MINUTES);
+ BCD_TO_BIN(cmos_minutes);
+
+ /*
+ * since we're only adjusting minutes and seconds,
+ * don't interfere with hour overflow. This avoids
+ * messing with unknown time zones but requires your
+ * RTC not to be off by more than 15 minutes
+ */
+ real_seconds = nowtime % 60;
+ real_minutes = nowtime / 60;
+ if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1)
+ real_minutes += 30; /* correct for half hour time zone */
+ real_minutes %= 60;
+
+ if (abs(real_minutes - cmos_minutes) < 30) {
+ BIN_TO_BCD(real_seconds);
+ BIN_TO_BCD(real_minutes);
+ CMOS_WRITE(real_seconds,RTC_SECONDS);
+ CMOS_WRITE(real_minutes,RTC_MINUTES);
+ } else {
+ printk(KERN_WARNING
+ "set_rtc_mmss: can't update from %d to %d\n",
+ cmos_minutes, real_minutes);
+ retval = -1;
+ }
+
+ return retval;
+}
+
+/* grab the time from the RTC chip */
+
+unsigned long
+get_cmos_time(void)
+{
+ unsigned int year, mon, day, hour, min, sec;
+
+ sec = CMOS_READ(RTC_SECONDS);
+ min = CMOS_READ(RTC_MINUTES);
+ hour = CMOS_READ(RTC_HOURS);
+ day = CMOS_READ(RTC_DAY_OF_MONTH);
+ mon = CMOS_READ(RTC_MONTH);
+ year = CMOS_READ(RTC_YEAR);
+
+ printk(KERN_DEBUG
+ "rtc: sec 0x%x min 0x%x hour 0x%x day 0x%x mon 0x%x year 0x%x\n",
+ sec, min, hour, day, mon, year);
+
+ BCD_TO_BIN(sec);
+ BCD_TO_BIN(min);
+ BCD_TO_BIN(hour);
+ BCD_TO_BIN(day);
+ BCD_TO_BIN(mon);
+ BCD_TO_BIN(year);
+
+ if ((year += 1900) < 1970)
+ year += 100;
+
+ return mktime(year, mon, day, hour, min, sec);
+}
+
+/* update xtime from the CMOS settings. used when /dev/rtc gets a SET_TIME.
+ * TODO: this doesn't reset the fancy NTP phase stuff as do_settimeofday does.
+ */
+
+void
+update_xtime_from_cmos(void)
+{
+ if(have_rtc) {
+ xtime.tv_sec = get_cmos_time();
+ xtime.tv_nsec = 0;
+ }
+}
+
+/*
+ * Scheduler clock - returns current time in nanosec units.
+ */
+unsigned long long sched_clock(void)
+{
+ return (unsigned long long)jiffies * (1000000000 / HZ);
+}
+
+static int
+__init init_udelay(void)
+{
+ loops_per_usec = (loops_per_jiffy * HZ) / 1000000;
+ return 0;
+}
+
+__initcall(init_udelay);