release/src-rt-6.x.4708/linux/linux-2.6.36/arch/m68knommu/kernel/time.c

   1 /*
   2  *  linux/arch/m68knommu/kernel/time.c
   3  *
   4  *  Copyright (C) 1991, 1992, 1995  Linus Torvalds
   5  *
   6  * This file contains the m68k-specific time handling details.
   7  * Most of the stuff is located in the machine specific files.
   8  *
   9  * 1997-09-10   Updated NTP code according to technical memorandum Jan '96
  10  *              "A Kernel Model for Precision Timekeeping" by Dave Mills
  11  */
  12
  13 #include <linux/errno.h>
  14 #include <linux/module.h>
  15 #include <linux/sched.h>
  16 #include <linux/kernel.h>
  17 #include <linux/param.h>
  18 #include <linux/string.h>
  19 #include <linux/mm.h>
  20 #include <linux/profile.h>
  21 #include <linux/time.h>
  22 #include <linux/timex.h>
  23
  24 #include <asm/machdep.h>
  25 #include <asm/irq_regs.h>
  26
  27 #define TICK_SIZE (tick_nsec / 1000)
  28
  29 static inline int set_rtc_mmss(unsigned long nowtime)
  30 {
  31         if (mach_set_clock_mmss)
  32                 return mach_set_clock_mmss (nowtime);
  33         return -1;
  34 }
  35
  36 #ifndef CONFIG_GENERIC_CLOCKEVENTS
  37 /*
  38  * timer_interrupt() needs to keep up the real-time clock,
  39  * as well as call the "do_timer()" routine every clocktick
  40  */
  41 irqreturn_t arch_timer_interrupt(int irq, void *dummy)
  42 {
  43
  44         if (current->pid)
  45                 profile_tick(CPU_PROFILING);
  46
  47         write_seqlock(&xtime_lock);
  48
  49         do_timer(1);
  50
  51         write_sequnlock(&xtime_lock);
  52
  53 #ifndef CONFIG_SMP
  54         update_process_times(user_mode(get_irq_regs()));
  55 #endif
  56         return(IRQ_HANDLED);
  57 }
  58 #endif
  59
  60 static unsigned long read_rtc_mmss(void)
  61 {
  62         unsigned int year, mon, day, hour, min, sec;
  63
  64         if (mach_gettod)
  65                 mach_gettod(&year, &mon, &day, &hour, &min, &sec);
  66         else
  67                 year = mon = day = hour = min = sec = 0;
  68
  69         if ((year += 1900) < 1970)
  70                 year += 100;
  71
  72         return  mktime(year, mon, day, hour, min, sec);
  73 }
  74
  75 void read_persistent_clock(struct timespec *ts)
  76 {
  77         ts->tv_sec = read_rtc_mmss();
  78         ts->tv_nsec = 0;
  79 }
  80
  81 int update_persistent_clock(struct timespec now)
  82 {
  83         return set_rtc_mmss(now.tv_sec);
  84 }
  85
  86 void time_init(void)
  87 {
  88         hw_timer_init();
  89 }