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
  43 #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
  44 extern unsigned long do_slow_gettimeoffset(void);
  45 static unsigned long (*do_gettimeoffset)(void) = do_slow_gettimeoffset;
  46
  47 u32 arch_gettimeoffset(void)
  48 {
  49        return do_gettimeoffset() * 1000;
  50 }
  51 #endif
  52
  53 /*
  54  * BUG: This routine does not handle hour overflow properly; it just
  55  *      sets the minutes. Usually you'll only notice that after reboot!
  56  */
  57
  58 int set_rtc_mmss(unsigned long nowtime)
  59 {
  60         int retval = 0;
  61         int real_seconds, real_minutes, cmos_minutes;
  62
  63         printk(KERN_DEBUG "set_rtc_mmss(%lu)\n", nowtime);
  64
  65         if(!have_rtc)
  66                 return 0;
  67
  68         cmos_minutes = CMOS_READ(RTC_MINUTES);
  69         cmos_minutes = bcd2bin(cmos_minutes);
  70
  71         /*
  72          * since we're only adjusting minutes and seconds,
  73          * don't interfere with hour overflow. This avoids
  74          * messing with unknown time zones but requires your
  75          * RTC not to be off by more than 15 minutes
  76          */
  77         real_seconds = nowtime % 60;
  78         real_minutes = nowtime / 60;
  79         if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1)
  80                 real_minutes += 30;             /* correct for half hour time zone */
  81         real_minutes %= 60;
  82
  83         if (abs(real_minutes - cmos_minutes) < 30) {
  84                 real_seconds = bin2bcd(real_seconds);
  85                 real_minutes = bin2bcd(real_minutes);
  86                 CMOS_WRITE(real_seconds,RTC_SECONDS);
  87                 CMOS_WRITE(real_minutes,RTC_MINUTES);
  88         } else {
  89                 printk_once(KERN_NOTICE
  90                        "set_rtc_mmss: can't update from %d to %d\n",
  91                        cmos_minutes, real_minutes);
  92                 retval = -1;
  93         }
  94
  95         return retval;
  96 }
  97
  98 /* grab the time from the RTC chip */
  99
 100 unsigned long
 101 get_cmos_time(void)
 102 {
 103         unsigned int year, mon, day, hour, min, sec;
 104         if(!have_rtc)
 105                 return 0;
 106
 107         sec = CMOS_READ(RTC_SECONDS);
 108         min = CMOS_READ(RTC_MINUTES);
 109         hour = CMOS_READ(RTC_HOURS);
 110         day = CMOS_READ(RTC_DAY_OF_MONTH);
 111         mon = CMOS_READ(RTC_MONTH);
 112         year = CMOS_READ(RTC_YEAR);
 113
 114         sec = bcd2bin(sec);
 115         min = bcd2bin(min);
 116         hour = bcd2bin(hour);
 117         day = bcd2bin(day);
 118         mon = bcd2bin(mon);
 119         year = bcd2bin(year);
 120
 121         if ((year += 1900) < 1970)
 122                 year += 100;
 123
 124         return mktime(year, mon, day, hour, min, sec);
 125 }
 126
 127
 128 int update_persistent_clock(struct timespec now)
 129 {
 130         return set_rtc_mmss(now.tv_sec);
 131 }
 132
 133 void read_persistent_clock(struct timespec *ts)
 134 {
 135         ts->tv_sec = get_cmos_time();
 136         ts->tv_nsec = 0;
 137 }
 138
 139
 140 extern void cris_profile_sample(struct pt_regs* regs);
 141
 142 void
 143 cris_do_profile(struct pt_regs* regs)
 144 {
 145
 146 #ifdef CONFIG_SYSTEM_PROFILER
 147         cris_profile_sample(regs);
 148 #endif
 149
 150 #ifdef CONFIG_PROFILING
 151         profile_tick(CPU_PROFILING);
 152 #endif
 153 }
 154
 155 unsigned long long sched_clock(void)
 156 {
 157         return (unsigned long long)jiffies * (NSEC_PER_SEC / HZ) +
 158                 get_ns_in_jiffie();
 159 }
 160
 161 static int
 162 __init init_udelay(void)
 163 {
 164         loops_per_usec = (loops_per_jiffy * HZ) / 1000000;
 165         return 0;
 166 }
 167
 168 __initcall(init_udelay);