arch/sh/boards/landisk/rtc.c

   1 /*
   2  * arch/sh/boards/landisk/rtc.c --  RTC support
   3  *
   4  *  Copyright (C) 2000  Philipp Rumpf <prumpf@tux.org>
   5  *  Copyright (C) 1999  Tetsuya Okada & Niibe Yutaka
   6  */
   7 /*
   8  * modifed by kogiidena
   9  * 2005.09.16
  10  */
  11 #include <linux/init.h>
  12 #include <linux/kernel.h>
  13 #include <linux/sched.h>
  14 #include <linux/time.h>
  15 #include <linux/delay.h>
  16 #include <linux/spinlock.h>
  17 #include <linux/bcd.h>
  18 #include <asm/rtc.h>
  19
  20 extern spinlock_t rtc_lock;
  21
  22 extern void
  23 rs5c313_set_cmos_time(unsigned int BCD_yr, unsigned int BCD_mon,
  24                       unsigned int BCD_day, unsigned int BCD_hr,
  25                       unsigned int BCD_min, unsigned int BCD_sec);
  26
  27 extern unsigned long
  28 rs5c313_get_cmos_time(unsigned int *BCD_yr, unsigned int *BCD_mon,
  29                       unsigned int *BCD_day, unsigned int *BCD_hr,
  30                       unsigned int *BCD_min, unsigned int *BCD_sec);
  31
  32 void landisk_rtc_gettimeofday(struct timespec *tv)
  33 {
  34         unsigned int BCD_yr, BCD_mon, BCD_day, BCD_hr, BCD_min, BCD_sec;
  35         unsigned long flags;
  36
  37         spin_lock_irqsave(&rtc_lock, flags);
  38         tv->tv_sec = rs5c313_get_cmos_time
  39             (&BCD_yr, &BCD_mon, &BCD_day, &BCD_hr, &BCD_min, &BCD_sec);
  40         tv->tv_nsec = 0;
  41         spin_unlock_irqrestore(&rtc_lock, flags);
  42 }
  43
  44 int landisk_rtc_settimeofday(const time_t secs)
  45 {
  46         int retval = 0;
  47         int real_seconds, real_minutes, cmos_minutes;
  48         unsigned long flags;
  49         unsigned long nowtime = secs;
  50         unsigned int BCD_yr, BCD_mon, BCD_day, BCD_hr, BCD_min, BCD_sec;
  51
  52         spin_lock_irqsave(&rtc_lock, flags);
  53
  54         rs5c313_get_cmos_time
  55           (&BCD_yr, &BCD_mon, &BCD_day, &BCD_hr, &BCD_min, &BCD_sec);
  56         cmos_minutes = BCD_min;
  57         BCD_TO_BIN(cmos_minutes);
  58
  59         /*
  60          * since we're only adjusting minutes and seconds,
  61          * don't interfere with hour overflow. This avoids
  62          * messing with unknown time zones but requires your
  63          * RTC not to be off by more than 15 minutes
  64          */
  65         real_seconds = nowtime % 60;
  66         real_minutes = nowtime / 60;
  67         if (((abs(real_minutes - cmos_minutes) + 15) / 30) & 1)
  68                 real_minutes += 30;     /* correct for half hour time zone */
  69         real_minutes %= 60;
  70
  71         if (abs(real_minutes - cmos_minutes) < 30) {
  72                 BIN_TO_BCD(real_seconds);
  73                 BIN_TO_BCD(real_minutes);
  74                 rs5c313_set_cmos_time(BCD_yr, BCD_mon, BCD_day, BCD_hr,
  75                                       real_minutes, real_seconds);
  76         } else {
  77                 printk(KERN_WARNING
  78                        "set_rtc_time: can't update from %d to %d\n",
  79                        cmos_minutes, real_minutes);
  80                 retval = -1;
  81         }
  82
  83         spin_unlock_irqrestore(&rtc_lock, flags);
  84         return retval;
  85 }
  86
  87 void landisk_time_init(void)
  88 {
  89         rtc_sh_get_time = landisk_rtc_gettimeofday;
  90         rtc_sh_set_time = landisk_rtc_settimeofday;
  91 }