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rtc.c

/*
 * linux/arch/sh/boards/sh03/rtc.c -- CTP/PCI-SH03 on-chip RTC support
 *
 *  Copyright (C) 2004  Saito.K & Jeanne(ksaito@interface.co.jp)
 *
 */

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/time.h>
#include <linux/bcd.h>
#include <linux/rtc.h>
#include <linux/spinlock.h>
#include <asm/io.h>
#include <asm/rtc.h>

#define RTC_BASE  0xb0000000
#define RTC_SEC1  (RTC_BASE + 0)
#define RTC_SEC10 (RTC_BASE + 1)
#define RTC_MIN1  (RTC_BASE + 2)
#define RTC_MIN10 (RTC_BASE + 3)
#define RTC_HOU1  (RTC_BASE + 4)
#define RTC_HOU10 (RTC_BASE + 5)
#define RTC_WEE1  (RTC_BASE + 6)
#define RTC_DAY1  (RTC_BASE + 7)
#define RTC_DAY10 (RTC_BASE + 8)
#define RTC_MON1  (RTC_BASE + 9)
#define RTC_MON10 (RTC_BASE + 10)
#define RTC_YEA1  (RTC_BASE + 11)
#define RTC_YEA10 (RTC_BASE + 12)
#define RTC_YEA100      (RTC_BASE + 13)
#define RTC_YEA1000     (RTC_BASE + 14)
#define RTC_CTL         (RTC_BASE + 15)
#define RTC_BUSY  1
#define RTC_STOP  2

extern spinlock_t rtc_lock;

unsigned long get_cmos_time(void)
{
      unsigned int year, mon, day, hour, min, sec;

      spin_lock(&rtc_lock);
 again:
      do {
            sec  = (ctrl_inb(RTC_SEC1) & 0xf) + (ctrl_inb(RTC_SEC10) & 0x7) * 10;
            min  = (ctrl_inb(RTC_MIN1) & 0xf) + (ctrl_inb(RTC_MIN10) & 0xf) * 10;
            hour = (ctrl_inb(RTC_HOU1) & 0xf) + (ctrl_inb(RTC_HOU10) & 0xf) * 10;
            day  = (ctrl_inb(RTC_DAY1) & 0xf) + (ctrl_inb(RTC_DAY10) & 0xf) * 10;
            mon  = (ctrl_inb(RTC_MON1) & 0xf) + (ctrl_inb(RTC_MON10) & 0xf) * 10;
            year = (ctrl_inb(RTC_YEA1) & 0xf) + (ctrl_inb(RTC_YEA10) & 0xf) * 10
                 + (ctrl_inb(RTC_YEA100 ) & 0xf) * 100
                 + (ctrl_inb(RTC_YEA1000) & 0xf) * 1000;
      } while (sec != (ctrl_inb(RTC_SEC1) & 0xf) + (ctrl_inb(RTC_SEC10) & 0x7) * 10);
      if (year == 0 || mon < 1 || mon > 12 || day > 31 || day < 1 ||
          hour > 23 || min > 59 || sec > 59) {
            printk(KERN_ERR
                   "SH-03 RTC: invalid value, resetting to 1 Jan 2000\n");
            printk("year=%d, mon=%d, day=%d, hour=%d, min=%d, sec=%d\n",
                   year, mon, day, hour, min, sec);

            ctrl_outb(0, RTC_SEC1); ctrl_outb(0, RTC_SEC10);
            ctrl_outb(0, RTC_MIN1); ctrl_outb(0, RTC_MIN10);
            ctrl_outb(0, RTC_HOU1); ctrl_outb(0, RTC_HOU10);
            ctrl_outb(6, RTC_WEE1);
            ctrl_outb(1, RTC_DAY1); ctrl_outb(0, RTC_DAY10);
            ctrl_outb(1, RTC_MON1); ctrl_outb(0, RTC_MON10);
            ctrl_outb(0, RTC_YEA1); ctrl_outb(0, RTC_YEA10);
            ctrl_outb(0, RTC_YEA100);
            ctrl_outb(2, RTC_YEA1000);
            ctrl_outb(0, RTC_CTL);
            goto again;
      }

      spin_unlock(&rtc_lock);
      return mktime(year, mon, day, hour, min, sec);
}

void sh03_rtc_gettimeofday(struct timespec *tv)
{

      tv->tv_sec = get_cmos_time();
      tv->tv_nsec = 0;
}

static int set_rtc_mmss(unsigned long nowtime)
{
      int retval = 0;
      int real_seconds, real_minutes, cmos_minutes;
      int i;

      /* gets recalled with irq locally disabled */
      spin_lock(&rtc_lock);
      for (i = 0 ; i < 1000000 ; i++)     /* may take up to 1 second... */
            if (!(ctrl_inb(RTC_CTL) & RTC_BUSY))
                  break;
      cmos_minutes = (ctrl_inb(RTC_MIN1) & 0xf) + (ctrl_inb(RTC_MIN10) & 0xf) * 10;
      real_seconds = nowtime % 60;
      real_minutes = nowtime / 60;
      if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1)
            real_minutes += 30;           /* correct for half hour time zone */
      real_minutes %= 60;

      if (abs(real_minutes - cmos_minutes) < 30) {
            ctrl_outb(real_seconds % 10, RTC_SEC1);
            ctrl_outb(real_seconds / 10, RTC_SEC10);
            ctrl_outb(real_minutes % 10, RTC_MIN1);
            ctrl_outb(real_minutes / 10, RTC_MIN10);
      } else {
            printk(KERN_WARNING
                   "set_rtc_mmss: can't update from %d to %d\n",
                   cmos_minutes, real_minutes);
            retval = -1;
      }
      spin_unlock(&rtc_lock);

      return retval;
}

int sh03_rtc_settimeofday(const time_t secs)
{
      unsigned long nowtime = secs;

      return set_rtc_mmss(nowtime);
}

void sh03_time_init(void)
{
      rtc_sh_get_time = sh03_rtc_gettimeofday;
      rtc_sh_set_time = sh03_rtc_settimeofday;
}

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