arch/h8300/kernel/time.c

   1 /*
   2  *  linux/arch/h8300/kernel/time.c
   3  *
   4  *  Yoshinori Sato <ysato@users.sourceforge.jp>
   5  *
   6  *  Copied/hacked from:
   7  *
   8  *  linux/arch/m68k/kernel/time.c
   9  *
  10  *  Copyright (C) 1991, 1992, 1995  Linus Torvalds
  11  *
  12  * This file contains the m68k-specific time handling details.
  13  * Most of the stuff is located in the machine specific files.
  14  *
  15  * 1997-09-10   Updated NTP code according to technical memorandum Jan '96
  16  *              "A Kernel Model for Precision Timekeeping" by Dave Mills
  17  */
  18
  19 #include <linux/config.h> /* CONFIG_HEARTBEAT */
  20 #include <linux/errno.h>
  21 #include <linux/module.h>
  22 #include <linux/sched.h>
  23 #include <linux/kernel.h>
  24 #include <linux/param.h>
  25 #include <linux/string.h>
  26 #include <linux/mm.h>
  27 #include <linux/timex.h>
  28 #include <linux/profile.h>
  29
  30 #include <asm/io.h>
  31 #include <asm/target_time.h>
  32
  33 #define TICK_SIZE (tick_nsec / 1000)
  34
  35 u64 jiffies_64;
  36
  37 EXPORT_SYMBOL(jiffies_64);
  38
  39 /*
  40  * timer_interrupt() needs to keep up the real-time clock,
  41  * as well as call the "do_timer()" routine every clocktick
  42  */
  43 static void timer_interrupt(int irq, void *dummy, struct pt_regs * regs)
  44 {
  45         /* may need to kick the hardware timer */
  46         platform_timer_eoi();
  47
  48         do_timer(regs);
  49 #ifndef CONFIG_SMP
  50         update_process_times(user_mode(regs));
  51 #endif
  52         profile_tick(CPU_PROFILING, regs);
  53 }
  54
  55 void time_init(void)
  56 {
  57         unsigned int year, mon, day, hour, min, sec;
  58
  59         /* FIX by dqg : Set to zero for platforms that don't have tod */
  60         /* without this time is undefined and can overflow time_t, causing  */
  61         /* very stange errors */
  62         year = 1980;
  63         mon = day = 1;
  64         hour = min = sec = 0;
  65         platform_gettod (&year, &mon, &day, &hour, &min, &sec);
  66
  67         if ((year += 1900) < 1970)
  68                 year += 100;
  69         xtime.tv_sec = mktime(year, mon, day, hour, min, sec);
  70         xtime.tv_nsec = 0;
  71
  72         platform_timer_setup(timer_interrupt);
  73 }
  74
  75 /*
  76  * This version of gettimeofday has near microsecond resolution.
  77  */
  78 void do_gettimeofday(struct timeval *tv)
  79 {
  80         unsigned long flags;
  81         unsigned long usec, sec;
  82
  83         read_lock_irqsave(&xtime_lock, flags);
  84         usec = 0;
  85         sec = xtime.tv_sec;
  86         usec += (xtime.tv_nsec / 1000);
  87         read_unlock_irqrestore(&xtime_lock, flags);
  88
  89         while (usec >= 1000000) {
  90                 usec -= 1000000;
  91                 sec++;
  92         }
  93
  94         tv->tv_sec = sec;
  95         tv->tv_usec = usec;
  96 }
  97
  98 EXPORT_SYMBOL(do_gettimeofday);
  99
 100 int do_settimeofday(struct timespec *tv)
 101 {
 102         if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
 103                 return -EINVAL;
 104
 105         write_lock_irq(&xtime_lock);
 106         /* This is revolting. We need to set the xtime.tv_usec
 107          * correctly. However, the value in this location is
 108          * is value at the last tick.
 109          * Discover what correction gettimeofday
 110          * would have done, and then undo it!
 111          */
 112         while (tv->tv_nsec < 0) {
 113                 tv->tv_nsec += NSEC_PER_SEC;
 114                 tv->tv_sec--;
 115         }
 116
 117         xtime.tv_sec = tv->tv_sec;
 118         xtime.tv_nsec = tv->tv_nsec;
 119         time_adjust = 0;                /* stop active adjtime() */
 120         time_status |= STA_UNSYNC;
 121         time_maxerror = NTP_PHASE_LIMIT;
 122         time_esterror = NTP_PHASE_LIMIT;
 123         write_sequnlock_irq(&xtime_lock);
 124         clock_was_set();
 125         return 0;
 126 }
 127
 128 EXPORT_SYMBOL(do_settimeofday);
 129
 130 unsigned long long sched_clock(void)
 131 {
 132         return (unsigned long long)jiffies * (1000000000 / HZ);
 133
 134 }