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 /*
  36  * timer_interrupt() needs to keep up the real-time clock,
  37  * as well as call the "do_timer()" routine every clocktick
  38  */
  39 static void timer_interrupt(int irq, void *dummy, struct pt_regs * regs)
  40 {
  41         /* may need to kick the hardware timer */
  42         platform_timer_eoi();
  43
  44         do_timer(regs);
  45 #ifndef CONFIG_SMP
  46         update_process_times(user_mode(regs));
  47 #endif
  48         profile_tick(CPU_PROFILING, regs);
  49 }
  50
  51 void time_init(void)
  52 {
  53         unsigned int year, mon, day, hour, min, sec;
  54
  55         /* FIX by dqg : Set to zero for platforms that don't have tod */
  56         /* without this time is undefined and can overflow time_t, causing  */
  57         /* very stange errors */
  58         year = 1980;
  59         mon = day = 1;
  60         hour = min = sec = 0;
  61         platform_gettod (&year, &mon, &day, &hour, &min, &sec);
  62
  63         if ((year += 1900) < 1970)
  64                 year += 100;
  65         xtime.tv_sec = mktime(year, mon, day, hour, min, sec);
  66         xtime.tv_nsec = 0;
  67
  68         platform_timer_setup(timer_interrupt);
  69 }
  70
  71 /*
  72  * This version of gettimeofday has near microsecond resolution.
  73  */
  74 void do_gettimeofday(struct timeval *tv)
  75 {
  76         unsigned long flags;
  77         unsigned long usec, sec;
  78
  79         read_lock_irqsave(&xtime_lock, flags);
  80         usec = 0;
  81         sec = xtime.tv_sec;
  82         usec += (xtime.tv_nsec / 1000);
  83         read_unlock_irqrestore(&xtime_lock, flags);
  84
  85         while (usec >= 1000000) {
  86                 usec -= 1000000;
  87                 sec++;
  88         }
  89
  90         tv->tv_sec = sec;
  91         tv->tv_usec = usec;
  92 }
  93
  94 EXPORT_SYMBOL(do_gettimeofday);
  95
  96 int do_settimeofday(struct timespec *tv)
  97 {
  98         if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
  99                 return -EINVAL;
 100
 101         write_lock_irq(&xtime_lock);
 102         /* This is revolting. We need to set the xtime.tv_usec
 103          * correctly. However, the value in this location is
 104          * is value at the last tick.
 105          * Discover what correction gettimeofday
 106          * would have done, and then undo it!
 107          */
 108         while (tv->tv_nsec < 0) {
 109                 tv->tv_nsec += NSEC_PER_SEC;
 110                 tv->tv_sec--;
 111         }
 112
 113         xtime.tv_sec = tv->tv_sec;
 114         xtime.tv_nsec = tv->tv_nsec;
 115         ntp_clear();
 116         write_sequnlock_irq(&xtime_lock);
 117         clock_was_set();
 118         return 0;
 119 }
 120
 121 EXPORT_SYMBOL(do_settimeofday);
 122
 123 unsigned long long sched_clock(void)
 124 {
 125         return (unsigned long long)jiffies * (1000000000 / HZ);
 126
 127 }