arch/cris/kernel/time.c

   1 /*
   2  *  linux/arch/cris/kernel/time.c
   3  *
   4  *  Copyright (C) 1991, 1992, 1995  Linus Torvalds
   5  *  Copyright (C) 1999, 2000, 2001 Axis Communications AB
   6  *
   7  * 1994-07-02    Alan Modra
   8  *      fixed set_rtc_mmss, fixed time.year for >= 2000, new mktime
   9  * 1995-03-26    Markus Kuhn
  10  *      fixed 500 ms bug at call to set_rtc_mmss, fixed DS12887
  11  *      precision CMOS clock update
  12  * 1996-05-03    Ingo Molnar
  13  *      fixed time warps in do_[slow|fast]_gettimeoffset()
  14  * 1997-09-10   Updated NTP code according to technical memorandum Jan '96
  15  *              "A Kernel Model for Precision Timekeeping" by Dave Mills
  16  *
  17  * Linux/CRIS specific code:
  18  *
  19  * Authors:    Bjorn Wesen
  20  *             Johan Adolfsson
  21  *
  22  */
  23
  24 #include <asm/rtc.h>
  25 #include <linux/errno.h>
  26 #include <linux/module.h>
  27 #include <linux/param.h>
  28 #include <linux/jiffies.h>
  29 #include <linux/bcd.h>
  30 #include <linux/timex.h>
  31 #include <linux/init.h>
  32 #include <linux/profile.h>
  33 #include <linux/sched.h>        /* just for sched_clock() - funny that */
  34
  35 int have_rtc;  /* used to remember if we have an RTC or not */;
  36
  37 #define TICK_SIZE tick
  38
  39 extern unsigned long loops_per_jiffy; /* init/main.c */
  40 unsigned long loops_per_usec;
  41
  42 extern unsigned long do_slow_gettimeoffset(void);
  43 static unsigned long (*do_gettimeoffset)(void) = do_slow_gettimeoffset;
  44
  45 u32 arch_gettimeoffset(void)
  46 {
  47         return do_gettimeoffset() * 1000;
  48 }
  49
  50 /*
  51  * BUG: This routine does not handle hour overflow properly; it just
  52  *      sets the minutes. Usually you'll only notice that after reboot!
  53  */
  54
  55 int set_rtc_mmss(unsigned long nowtime)
  56 {
  57         int retval = 0;
  58         int real_seconds, real_minutes, cmos_minutes;
  59
  60         printk(KERN_DEBUG "set_rtc_mmss(%lu)\n", nowtime);
  61
  62         if(!have_rtc)
  63                 return 0;
  64
  65         cmos_minutes = CMOS_READ(RTC_MINUTES);
  66         cmos_minutes = bcd2bin(cmos_minutes);
  67
  68         /*
  69          * since we're only adjusting minutes and seconds,
  70          * don't interfere with hour overflow. This avoids
  71          * messing with unknown time zones but requires your
  72          * RTC not to be off by more than 15 minutes
  73          */
  74         real_seconds = nowtime % 60;
  75         real_minutes = nowtime / 60;
  76         if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1)
  77                 real_minutes += 30;             /* correct for half hour time zone */
  78         real_minutes %= 60;
  79
  80         if (abs(real_minutes - cmos_minutes) < 30) {
  81                 real_seconds = bin2bcd(real_seconds);
  82                 real_minutes = bin2bcd(real_minutes);
  83                 CMOS_WRITE(real_seconds,RTC_SECONDS);
  84                 CMOS_WRITE(real_minutes,RTC_MINUTES);
  85         } else {
  86                 printk(KERN_WARNING
  87                        "set_rtc_mmss: can't update from %d to %d\n",
  88                        cmos_minutes, real_minutes);
  89                 retval = -1;
  90         }
  91
  92         return retval;
  93 }
  94
  95 /* grab the time from the RTC chip */
  96
  97 unsigned long
  98 get_cmos_time(void)
  99 {
 100         unsigned int year, mon, day, hour, min, sec;
 101
 102         sec = CMOS_READ(RTC_SECONDS);
 103         min = CMOS_READ(RTC_MINUTES);
 104         hour = CMOS_READ(RTC_HOURS);
 105         day = CMOS_READ(RTC_DAY_OF_MONTH);
 106         mon = CMOS_READ(RTC_MONTH);
 107         year = CMOS_READ(RTC_YEAR);
 108
 109         sec = bcd2bin(sec);
 110         min = bcd2bin(min);
 111         hour = bcd2bin(hour);
 112         day = bcd2bin(day);
 113         mon = bcd2bin(mon);
 114         year = bcd2bin(year);
 115
 116         if ((year += 1900) < 1970)
 117                 year += 100;
 118
 119         return mktime(year, mon, day, hour, min, sec);
 120 }
 121
 122 /* update xtime from the CMOS settings. used when /dev/rtc gets a SET_TIME.
 123  * TODO: this doesn't reset the fancy NTP phase stuff as do_settimeofday does.
 124  */
 125
 126 void
 127 update_xtime_from_cmos(void)
 128 {
 129         if(have_rtc) {
 130                 xtime.tv_sec = get_cmos_time();
 131                 xtime.tv_nsec = 0;
 132         }
 133 }
 134
 135 extern void cris_profile_sample(struct pt_regs* regs);
 136
 137 void
 138 cris_do_profile(struct pt_regs* regs)
 139 {
 140
 141 #ifdef CONFIG_SYSTEM_PROFILER
 142         cris_profile_sample(regs);
 143 #endif
 144
 145 #ifdef CONFIG_PROFILING
 146         profile_tick(CPU_PROFILING);
 147 #endif
 148 }
 149
 150 unsigned long long sched_clock(void)
 151 {
 152         return (unsigned long long)jiffies * (1000000000 / HZ) +
 153                 get_ns_in_jiffie();
 154 }
 155
 156 static int
 157 __init init_udelay(void)
 158 {
 159         loops_per_usec = (loops_per_jiffy * HZ) / 1000000;
 160         return 0;
 161 }
 162
 163 __initcall(init_udelay);