arch/sh/boards/mach-sh03/rtc.c

   1 /*
   2  * linux/arch/sh/boards/sh03/rtc.c -- CTP/PCI-SH03 on-chip RTC support
   3  *
   4  *  Copyright (C) 2004  Saito.K & Jeanne(ksaito@interface.co.jp)
   5  *
   6  */
   7
   8 #include <linux/init.h>
   9 #include <linux/kernel.h>
  10 #include <linux/sched.h>
  11 #include <linux/time.h>
  12 #include <linux/bcd.h>
  13 #include <linux/rtc.h>
  14 #include <linux/spinlock.h>
  15 #include <asm/io.h>
  16 #include <asm/rtc.h>
  17
  18 #define RTC_BASE        0xb0000000
  19 #define RTC_SEC1        (RTC_BASE + 0)
  20 #define RTC_SEC10       (RTC_BASE + 1)
  21 #define RTC_MIN1        (RTC_BASE + 2)
  22 #define RTC_MIN10       (RTC_BASE + 3)
  23 #define RTC_HOU1        (RTC_BASE + 4)
  24 #define RTC_HOU10       (RTC_BASE + 5)
  25 #define RTC_WEE1        (RTC_BASE + 6)
  26 #define RTC_DAY1        (RTC_BASE + 7)
  27 #define RTC_DAY10       (RTC_BASE + 8)
  28 #define RTC_MON1        (RTC_BASE + 9)
  29 #define RTC_MON10       (RTC_BASE + 10)
  30 #define RTC_YEA1        (RTC_BASE + 11)
  31 #define RTC_YEA10       (RTC_BASE + 12)
  32 #define RTC_YEA100      (RTC_BASE + 13)
  33 #define RTC_YEA1000     (RTC_BASE + 14)
  34 #define RTC_CTL         (RTC_BASE + 15)
  35 #define RTC_BUSY        1
  36 #define RTC_STOP        2
  37
  38 static DEFINE_SPINLOCK(sh03_rtc_lock);
  39
  40 unsigned long get_cmos_time(void)
  41 {
  42         unsigned int year, mon, day, hour, min, sec;
  43
  44         spin_lock(&sh03_rtc_lock);
  45  again:
  46         do {
  47                 sec  = (__raw_readb(RTC_SEC1) & 0xf) + (__raw_readb(RTC_SEC10) & 0x7) * 10;
  48                 min  = (__raw_readb(RTC_MIN1) & 0xf) + (__raw_readb(RTC_MIN10) & 0xf) * 10;
  49                 hour = (__raw_readb(RTC_HOU1) & 0xf) + (__raw_readb(RTC_HOU10) & 0xf) * 10;
  50                 day  = (__raw_readb(RTC_DAY1) & 0xf) + (__raw_readb(RTC_DAY10) & 0xf) * 10;
  51                 mon  = (__raw_readb(RTC_MON1) & 0xf) + (__raw_readb(RTC_MON10) & 0xf) * 10;
  52                 year = (__raw_readb(RTC_YEA1) & 0xf) + (__raw_readb(RTC_YEA10) & 0xf) * 10
  53                      + (__raw_readb(RTC_YEA100 ) & 0xf) * 100
  54                      + (__raw_readb(RTC_YEA1000) & 0xf) * 1000;
  55         } while (sec != (__raw_readb(RTC_SEC1) & 0xf) + (__raw_readb(RTC_SEC10) & 0x7) * 10);
  56         if (year == 0 || mon < 1 || mon > 12 || day > 31 || day < 1 ||
  57             hour > 23 || min > 59 || sec > 59) {
  58                 printk(KERN_ERR
  59                        "SH-03 RTC: invalid value, resetting to 1 Jan 2000\n");
  60                 printk("year=%d, mon=%d, day=%d, hour=%d, min=%d, sec=%d\n",
  61                        year, mon, day, hour, min, sec);
  62
  63                 __raw_writeb(0, RTC_SEC1); __raw_writeb(0, RTC_SEC10);
  64                 __raw_writeb(0, RTC_MIN1); __raw_writeb(0, RTC_MIN10);
  65                 __raw_writeb(0, RTC_HOU1); __raw_writeb(0, RTC_HOU10);
  66                 __raw_writeb(6, RTC_WEE1);
  67                 __raw_writeb(1, RTC_DAY1); __raw_writeb(0, RTC_DAY10);
  68                 __raw_writeb(1, RTC_MON1); __raw_writeb(0, RTC_MON10);
  69                 __raw_writeb(0, RTC_YEA1); __raw_writeb(0, RTC_YEA10);
  70                 __raw_writeb(0, RTC_YEA100);
  71                 __raw_writeb(2, RTC_YEA1000);
  72                 __raw_writeb(0, RTC_CTL);
  73                 goto again;
  74         }
  75
  76         spin_unlock(&sh03_rtc_lock);
  77         return mktime(year, mon, day, hour, min, sec);
  78 }
  79
  80 void sh03_rtc_gettimeofday(struct timespec *tv)
  81 {
  82
  83         tv->tv_sec = get_cmos_time();
  84         tv->tv_nsec = 0;
  85 }
  86
  87 static int set_rtc_mmss(unsigned long nowtime)
  88 {
  89         int retval = 0;
  90         int real_seconds, real_minutes, cmos_minutes;
  91         int i;
  92
  93         /* gets recalled with irq locally disabled */
  94         spin_lock(&sh03_rtc_lock);
  95         for (i = 0 ; i < 1000000 ; i++) /* may take up to 1 second... */
  96                 if (!(__raw_readb(RTC_CTL) & RTC_BUSY))
  97                         break;
  98         cmos_minutes = (__raw_readb(RTC_MIN1) & 0xf) + (__raw_readb(RTC_MIN10) & 0xf) * 10;
  99         real_seconds = nowtime % 60;
 100         real_minutes = nowtime / 60;
 101         if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1)
 102                 real_minutes += 30;             /* correct for half hour time zone */
 103         real_minutes %= 60;
 104
 105         if (abs(real_minutes - cmos_minutes) < 30) {
 106                 __raw_writeb(real_seconds % 10, RTC_SEC1);
 107                 __raw_writeb(real_seconds / 10, RTC_SEC10);
 108                 __raw_writeb(real_minutes % 10, RTC_MIN1);
 109                 __raw_writeb(real_minutes / 10, RTC_MIN10);
 110         } else {
 111                 printk(KERN_WARNING
 112                        "set_rtc_mmss: can't update from %d to %d\n",
 113                        cmos_minutes, real_minutes);
 114                 retval = -1;
 115         }
 116         spin_unlock(&sh03_rtc_lock);
 117
 118         return retval;
 119 }
 120
 121 int sh03_rtc_settimeofday(const time_t secs)
 122 {
 123         unsigned long nowtime = secs;
 124
 125         return set_rtc_mmss(nowtime);
 126 }
 127
 128 void sh03_time_init(void)
 129 {
 130         rtc_sh_get_time = sh03_rtc_gettimeofday;
 131         rtc_sh_set_time = sh03_rtc_settimeofday;
 132 }