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
  12 #include <linux/config.h>
  13 #include <linux/init.h>
  14 #include <linux/kernel.h>
  15 #include <linux/sched.h>
  16 #include <linux/time.h>
  17 #include <linux/delay.h>
  18 #include <linux/spinlock.h>
  19 #include <linux/bcd.h>
  20 #include <asm/rtc.h>
  21
  22 extern spinlock_t rtc_lock;
  23
  24 extern void
  25 rs5c313_set_cmos_time(unsigned int BCD_yr, unsigned int BCD_mon,
  26                       unsigned int BCD_day, unsigned int BCD_hr,
  27                       unsigned int BCD_min, unsigned int BCD_sec);
  28
  29 extern unsigned long
  30 rs5c313_get_cmos_time(unsigned int *BCD_yr, unsigned int *BCD_mon,
  31                       unsigned int *BCD_day, unsigned int *BCD_hr,
  32                       unsigned int *BCD_min, unsigned int *BCD_sec);
  33
  34 void landisk_rtc_gettimeofday(struct timespec *tv)
  35 {
  36         unsigned int BCD_yr, BCD_mon, BCD_day, BCD_hr, BCD_min, BCD_sec;
  37         unsigned long flags;
  38
  39         spin_lock_irqsave(&rtc_lock, flags);
  40         tv->tv_sec = rs5c313_get_cmos_time
  41             (&BCD_yr, &BCD_mon, &BCD_day, &BCD_hr, &BCD_min, &BCD_sec);
  42         tv->tv_nsec = 0;
  43         spin_unlock_irqrestore(&rtc_lock, flags);
  44 }
  45
  46 int landisk_rtc_settimeofday(const time_t secs)
  47 {
  48         int retval = 0;
  49         int real_seconds, real_minutes, cmos_minutes;
  50         unsigned long flags;
  51         unsigned long nowtime = secs;
  52         unsigned int BCD_yr, BCD_mon, BCD_day, BCD_hr, BCD_min, BCD_sec;
  53
  54         spin_lock_irqsave(&rtc_lock, flags);
  55
  56         rs5c313_get_cmos_time
  57           (&BCD_yr, &BCD_mon, &BCD_day, &BCD_hr, &BCD_min, &BCD_sec);
  58         cmos_minutes = BCD_min;
  59         BCD_TO_BIN(cmos_minutes);
  60
  61         /*
  62          * since we're only adjusting minutes and seconds,
  63          * don't interfere with hour overflow. This avoids
  64          * messing with unknown time zones but requires your
  65          * RTC not to be off by more than 15 minutes
  66          */
  67         real_seconds = nowtime % 60;
  68         real_minutes = nowtime / 60;
  69         if (((abs(real_minutes - cmos_minutes) + 15) / 30) & 1)
  70                 real_minutes += 30;     /* correct for half hour time zone */
  71         real_minutes %= 60;
  72
  73         if (abs(real_minutes - cmos_minutes) < 30) {
  74                 BIN_TO_BCD(real_seconds);
  75                 BIN_TO_BCD(real_minutes);
  76                 rs5c313_set_cmos_time(BCD_yr, BCD_mon, BCD_day, BCD_hr,
  77                                       real_minutes, real_seconds);
  78         } else {
  79                 printk(KERN_WARNING
  80                        "set_rtc_time: can't update from %d to %d\n",
  81                        cmos_minutes, real_minutes);
  82                 retval = -1;
  83         }
  84
  85         spin_unlock_irqrestore(&rtc_lock, flags);
  86         return retval;
  87 }
  88
  89 void landisk_time_init(void)
  90 {
  91         rtc_sh_get_time = landisk_rtc_gettimeofday;
  92         rtc_sh_set_time = landisk_rtc_settimeofday;
  93 }