C++ CMOS_READ函数代码示例

static int dec_timer_state(void)
{
	return (CMOS_READ(RTC_REG_C) & RTC_PF) != 0;
}

static int cmos_read_alarm(struct device *dev, struct rtc_wkalrm *t)
{
	struct cmos_rtc	*cmos = dev_get_drvdata(dev);
	unsigned char	rtc_control;

	if (!is_valid_irq(cmos->irq))
		return -EIO;

	/* Basic alarms only support hour, minute, and seconds fields.
	 * Some also support day and month, for alarms up to a year in
	 * the future.
	 */
	t->time.tm_mday = -1;
	t->time.tm_mon = -1;

	spin_lock_irq(&rtc_lock);
	t->time.tm_sec = CMOS_READ(RTC_SECONDS_ALARM);
	t->time.tm_min = CMOS_READ(RTC_MINUTES_ALARM);
	t->time.tm_hour = CMOS_READ(RTC_HOURS_ALARM);

	if (cmos->day_alrm) {
		/* ignore upper bits on readback per ACPI spec */
		t->time.tm_mday = CMOS_READ(cmos->day_alrm) & 0x3f;
		if (!t->time.tm_mday)
			t->time.tm_mday = -1;

		if (cmos->mon_alrm) {
			t->time.tm_mon = CMOS_READ(cmos->mon_alrm);
			if (!t->time.tm_mon)
				t->time.tm_mon = -1;
		}
	}

	rtc_control = CMOS_READ(RTC_CONTROL);
	spin_unlock_irq(&rtc_lock);

	/* REVISIT this assumes PC style usage:  always BCD */

	if (((unsigned)t->time.tm_sec) < 0x60)
		t->time.tm_sec = bcd2bin(t->time.tm_sec);
	else
		t->time.tm_sec = -1;
	if (((unsigned)t->time.tm_min) < 0x60)
		t->time.tm_min = bcd2bin(t->time.tm_min);
	else
		t->time.tm_min = -1;
	if (((unsigned)t->time.tm_hour) < 0x24)
		t->time.tm_hour = bcd2bin(t->time.tm_hour);
	else
		t->time.tm_hour = -1;

	if (cmos->day_alrm) {
		if (((unsigned)t->time.tm_mday) <= 0x31)
			t->time.tm_mday = bcd2bin(t->time.tm_mday);
		else
			t->time.tm_mday = -1;
		if (cmos->mon_alrm) {
			if (((unsigned)t->time.tm_mon) <= 0x12)
				t->time.tm_mon = bcd2bin(t->time.tm_mon) - 1;
			else
				t->time.tm_mon = -1;
		}
	}
	t->time.tm_year = -1;

	t->enabled = !!(rtc_control & RTC_AIE);
	t->pending = 0;

	return 0;
}

static unsigned long __init get_isa_cmos_time(void)
{
	unsigned int year, mon, day, hour, min, sec;
	int i;

	// check to see if the RTC makes sense.....
	if ((CMOS_READ(RTC_VALID) & RTC_VRT) == 0)
		return mktime(1970, 1, 1, 0, 0, 0);

	/* The Linux interpretation of the CMOS clock register contents:
	 * When the Update-In-Progress (UIP) flag goes from 1 to 0, the
	 * RTC registers show the second which has precisely just started.
	 * Let's hope other operating systems interpret the RTC the same way.
	 */
	/* read RTC exactly on falling edge of update flag */
	for (i = 0 ; i < 1000000 ; i++) /* may take up to 1 second... */
		if (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP)
			break;

	for (i = 0 ; i < 1000000 ; i++) /* must try at least 2.228 ms */
		if (!(CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP))
			break;

	do { /* Isn't this overkill ? UIP above should guarantee consistency */
		sec  = CMOS_READ(RTC_SECONDS);
		min  = CMOS_READ(RTC_MINUTES);
		hour = CMOS_READ(RTC_HOURS);
		day  = CMOS_READ(RTC_DAY_OF_MONTH);
		mon  = CMOS_READ(RTC_MONTH);
		year = CMOS_READ(RTC_YEAR);
	} while (sec != CMOS_READ(RTC_SECONDS));

	if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
		BCD_TO_BIN(sec);
		BCD_TO_BIN(min);
		BCD_TO_BIN(hour);
		BCD_TO_BIN(day);
		BCD_TO_BIN(mon);
		BCD_TO_BIN(year);
	}
	if ((year += 1900) < 1970)
		year += 100;
	return mktime(year, mon, day, hour, min, sec);
}

static int
sm_osl_proc_read_alarm (
	char                    *page,
	char                    **start,
	off_t                   off,
	int                     count,
	int                     *eof,
	void                    *context)
{
	char *str = page;
	int len;
	u32 sec,min,hr;
	u32 day,mo,yr;

	if (off != 0) goto out;

	spin_lock(&rtc_lock);
	sec = CMOS_READ(RTC_SECONDS_ALARM);
	min = CMOS_READ(RTC_MINUTES_ALARM);
	hr = CMOS_READ(RTC_HOURS_ALARM);

#if 0
	/* if I ever get an FACP with proper values, maybe I'll enable this code */
	if (acpi_gbl_FADT->day_alrm)
		day = CMOS_READ(acpi_gbl_FADT->day_alrm);
	else
		day =  CMOS_READ(RTC_DAY_OF_MONTH);
	if (acpi_gbl_FADT->mon_alrm)
		mo = CMOS_READ(acpi_gbl_FADT->mon_alrm);
	else
		mo = CMOS_READ(RTC_MONTH);;
	if (acpi_gbl_FADT->century)
		yr = CMOS_READ(acpi_gbl_FADT->century) * 100 + CMOS_READ(RTC_YEAR);
	else
		yr = CMOS_READ(RTC_YEAR);
#else
	day = CMOS_READ(RTC_DAY_OF_MONTH);
	mo = CMOS_READ(RTC_MONTH);
	yr = CMOS_READ(RTC_YEAR);
#endif
	spin_unlock(&rtc_lock);

	BCD_TO_BIN(sec);
	BCD_TO_BIN(min);
	BCD_TO_BIN(hr);
	BCD_TO_BIN(day);
	BCD_TO_BIN(mo);
	BCD_TO_BIN(yr);

	str += sprintf(str,"%4.4u-",yr);

	str += (mo > 12) ?
		sprintf(str,"**-") :
		sprintf(str,"%2.2u-",mo);

	str += (day > 31) ?
		sprintf(str,"** ") :
		sprintf(str,"%2.2u ",day);

	str += (hr > 23) ?
		sprintf(str,"**:") :
		sprintf(str,"%2.2u:",hr);

	str += (min > 59) ?
		sprintf(str,"**:") :
		sprintf(str,"%2.2u:",min);

	str += (sec > 59) ?
		sprintf(str,"**\n") :
		sprintf(str,"%2.2u\n",sec);

 out:
	len = str - page;

	if (len < count) *eof = 1;
	else if (len > count) len = count;

	if (len < 0) len = 0;

	*start = page;

	return len;
}

//.........这里部分代码省略.........
		return 0;
	}
#endif
	case RTC_ALM_READ:	/* Read the present alarm time */
	{
		/*
		 * This returns a struct rtc_time. Reading >= 0xc0
		 * means "don't care" or "match all". Only the tm_hour,
		 * tm_min, and tm_sec values are filled in.
		 */
		memset(&wtime, 0, sizeof(struct rtc_time));
		get_rtc_alm_time(&wtime);
		break; 
	}
	case RTC_ALM_SET:	/* Store a time into the alarm */
	{
		/*
		 * This expects a struct rtc_time. Writing 0xff means
		 * "don't care" or "match all". Only the tm_hour,
		 * tm_min and tm_sec are used.
		 */
		unsigned char hrs, min, sec;
		struct rtc_time alm_tm;

		if (copy_from_user(&alm_tm, (struct rtc_time*)arg,
				   sizeof(struct rtc_time)))
			return -EFAULT;

		hrs = alm_tm.tm_hour;
		min = alm_tm.tm_min;
		sec = alm_tm.tm_sec;

		spin_lock_irq(&rtc_lock);
		if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) ||
		    RTC_ALWAYS_BCD)
		{
			if (sec < 60) BIN_TO_BCD(sec);
			else sec = 0xff;

			if (min < 60) BIN_TO_BCD(min);
			else min = 0xff;

			if (hrs < 24) BIN_TO_BCD(hrs);
			else hrs = 0xff;
		}
		CMOS_WRITE(hrs, RTC_HOURS_ALARM);
		CMOS_WRITE(min, RTC_MINUTES_ALARM);
		CMOS_WRITE(sec, RTC_SECONDS_ALARM);
		spin_unlock_irq(&rtc_lock);

		return 0;
	}
	case RTC_RD_TIME:	/* Read the time/date from RTC	*/
	{
		memset(&wtime, 0, sizeof(struct rtc_time));
		get_rtc_time(&wtime);
		break;
	}
	case RTC_SET_TIME:	/* Set the RTC */
	{
		struct rtc_time rtc_tm;
		unsigned char mon, day, hrs, min, sec, leap_yr;
		unsigned char save_control, save_freq_select;
		unsigned int yrs;
#ifdef CONFIG_DECSTATION
		unsigned int real_yrs;

static int rtc_proc_output (char *buf)
{
#define YN(bit) ((ctrl & bit) ? "yes" : "no")
#define NY(bit) ((ctrl & bit) ? "no" : "yes")
	char *p;
	struct rtc_time tm;
	unsigned char batt, ctrl;
	unsigned long freq;

	spin_lock_irq(&rtc_lock);
	batt = CMOS_READ(RTC_VALID) & RTC_VRT;
	ctrl = CMOS_READ(RTC_CONTROL);
	freq = rtc_freq;
	spin_unlock_irq(&rtc_lock);

	p = buf;

	get_rtc_time(&tm);

	/*
	 * There is no way to tell if the luser has the RTC set for local
	 * time or for Universal Standard Time (GMT). Probably local though.
	 */
	p += sprintf(p,
		     "rtc_time\t: %02d:%02d:%02d\n"
		     "rtc_date\t: %04d-%02d-%02d\n"
	 	     "rtc_epoch\t: %04lu\n",
		     tm.tm_hour, tm.tm_min, tm.tm_sec,
		     tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, epoch);

	get_rtc_alm_time(&tm);

	/*
	 * We implicitly assume 24hr mode here. Alarm values >= 0xc0 will
	 * match any value for that particular field. Values that are
	 * greater than a valid time, but less than 0xc0 shouldn't appear.
	 */
	p += sprintf(p, "alarm\t\t: ");
	if (tm.tm_hour <= 24)
		p += sprintf(p, "%02d:", tm.tm_hour);
	else
		p += sprintf(p, "**:");

	if (tm.tm_min <= 59)
		p += sprintf(p, "%02d:", tm.tm_min);
	else
		p += sprintf(p, "**:");

	if (tm.tm_sec <= 59)
		p += sprintf(p, "%02d\n", tm.tm_sec);
	else
		p += sprintf(p, "**\n");

	p += sprintf(p,
		     "DST_enable\t: %s\n"
		     "BCD\t\t: %s\n"
		     "24hr\t\t: %s\n"
		     "square_wave\t: %s\n"
		     "alarm_IRQ\t: %s\n"
		     "update_IRQ\t: %s\n"
		     "periodic_IRQ\t: %s\n"
		     "periodic_freq\t: %ld\n"
		     "batt_status\t: %s\n",
		     YN(RTC_DST_EN),
		     NY(RTC_DM_BINARY),
		     YN(RTC_24H),
		     YN(RTC_SQWE),
		     YN(RTC_AIE),
		     YN(RTC_UIE),
		     YN(RTC_PIE),
		     freq,
		     batt ? "okay" : "dead");

	return  p - buf;
#undef YN
#undef NY
}

static int acpi_system_alarm_seq_show(struct seq_file *seq, void *offset)
{
	u32			sec, min, hr;
	u32			day, mo, yr;

	ACPI_FUNCTION_TRACE("acpi_system_alarm_seq_show");

	spin_lock(&rtc_lock);

	sec = CMOS_READ(RTC_SECONDS_ALARM);
	min = CMOS_READ(RTC_MINUTES_ALARM);
	hr = CMOS_READ(RTC_HOURS_ALARM);

#if 0	/* If we ever get an FACP with proper values... */
	if (acpi_gbl_FADT->day_alrm)
		day = CMOS_READ(acpi_gbl_FADT->day_alrm);
	else
		day =  CMOS_READ(RTC_DAY_OF_MONTH);
	if (acpi_gbl_FADT->mon_alrm)
		mo = CMOS_READ(acpi_gbl_FADT->mon_alrm);
	else
		mo = CMOS_READ(RTC_MONTH);
	if (acpi_gbl_FADT->century)
		yr = CMOS_READ(acpi_gbl_FADT->century) * 100 + CMOS_READ(RTC_YEAR);
	else
		yr = CMOS_READ(RTC_YEAR);
#else
	day = CMOS_READ(RTC_DAY_OF_MONTH);
	mo = CMOS_READ(RTC_MONTH);
	yr = CMOS_READ(RTC_YEAR);
#endif

	spin_unlock(&rtc_lock);

	BCD_TO_BIN(sec);
	BCD_TO_BIN(min);
	BCD_TO_BIN(hr);
	BCD_TO_BIN(day);
	BCD_TO_BIN(mo);
	BCD_TO_BIN(yr);

#if 0
	/* we're trusting the FADT (see above)*/
#else
	/* If we're not trusting the FADT, we should at least make it
	 * right for _this_ century... ehm, what is _this_ century?
	 *
	 * TBD:
	 *  ASAP: find piece of code in the kernel, e.g. star tracker driver,
	 *        which we can trust to determine the century correctly. Atom
	 *        watch driver would be nice, too...
	 *
	 *  if that has not happened, change for first release in 2050:
 	 *        if (yr<50)
	 *                yr += 2100;
	 *        else
	 *                yr += 2000;   // current line of code
	 *
	 *  if that has not happened either, please do on 2099/12/31:23:59:59
	 *        s/2000/2100
	 *
	 */
	yr += 2000;
#endif

	seq_printf(seq,"%4.4u-", yr);
	(mo > 12)  ? seq_puts(seq, "**-")  : seq_printf(seq, "%2.2u-", mo);
	(day > 31) ? seq_puts(seq, "** ")  : seq_printf(seq, "%2.2u ", day);
	(hr > 23)  ? seq_puts(seq, "**:")  : seq_printf(seq, "%2.2u:", hr);
	(min > 59) ? seq_puts(seq, "**:")  : seq_printf(seq, "%2.2u:", min);
	(sec > 59) ? seq_puts(seq, "**\n") : seq_printf(seq, "%2.2u\n", sec);

	return 0;
}

static int __init hd_init(void)
{
	int drive;

	if (register_blkdev(MAJOR_NR,"hd"))
		return -1;

	hd_queue = blk_init_queue(do_hd_request, &hd_lock);
	if (!hd_queue) {
		unregister_blkdev(MAJOR_NR,"hd");
		return -ENOMEM;
	}

	blk_queue_max_sectors(hd_queue, 255);
	init_timer(&device_timer);
	device_timer.function = hd_times_out;
	blk_queue_hardsect_size(hd_queue, 512);

#ifdef __i386__
	if (!NR_HD) {
		extern struct drive_info drive_info;
		unsigned char *BIOS = (unsigned char *) &drive_info;
		unsigned long flags;
		int cmos_disks;

		for (drive=0 ; drive<2 ; drive++) {
			hd_info[drive].cyl = *(unsigned short *) BIOS;
			hd_info[drive].head = *(2+BIOS);
			hd_info[drive].wpcom = *(unsigned short *) (5+BIOS);
			hd_info[drive].ctl = *(8+BIOS);
			hd_info[drive].lzone = *(unsigned short *) (12+BIOS);
			hd_info[drive].sect = *(14+BIOS);
#ifdef does_not_work_for_everybody_with_scsi_but_helps_ibm_vp
			if (hd_info[drive].cyl && NR_HD == drive)
				NR_HD++;
#endif
			BIOS += 16;
		}

	/*
		We query CMOS about hard disks : it could be that 
		we have a SCSI/ESDI/etc controller that is BIOS
		compatible with ST-506, and thus showing up in our
		BIOS table, but not register compatible, and therefore
		not present in CMOS.

		Furthermore, we will assume that our ST-506 drives
		<if any> are the primary drives in the system, and 
		the ones reflected as drive 1 or 2.

		The first drive is stored in the high nibble of CMOS
		byte 0x12, the second in the low nibble.  This will be
		either a 4 bit drive type or 0xf indicating use byte 0x19 
		for an 8 bit type, drive 1, 0x1a for drive 2 in CMOS.

		Needless to say, a non-zero value means we have 
		an AT controller hard disk for that drive.

		Currently the rtc_lock is a bit academic since this
		driver is non-modular, but someday... ?         Paul G.
	*/

		spin_lock_irqsave(&rtc_lock, flags);
		cmos_disks = CMOS_READ(0x12);
		spin_unlock_irqrestore(&rtc_lock, flags);

		if (cmos_disks & 0xf0) {
			if (cmos_disks & 0x0f)
				NR_HD = 2;
			else
				NR_HD = 1;
		}
	}
#endif /* __i386__ */
#ifdef __arm__
	if (!NR_HD) {
		/* We don't know anything about the drive.  This means
		 * that you *MUST* specify the drive parameters to the
		 * kernel yourself.
		 */
		printk("hd: no drives specified - use hd=cyl,head,sectors"
			" on kernel command line\n");
	}
#endif
	if (!NR_HD)
		goto out;

	for (drive=0 ; drive < NR_HD ; drive++) {
		struct gendisk *disk = alloc_disk(64);
		struct hd_i_struct *p = &hd_info[drive];
		if (!disk)
			goto Enomem;
		disk->major = MAJOR_NR;
		disk->first_minor = drive << 6;
		disk->fops = &hd_fops;
		sprintf(disk->disk_name, "hd%c", 'a'+drive);
		disk->private_data = p;
		set_capacity(disk, p->head * p->sect * p->cyl);
		disk->queue = hd_queue;
		p->unit = drive;
//.........这里部分代码省略.........

void date()
{
	int year=2012;
	printf("\n %d - %s - %d\n",CMOS_READ(7),month[CMOS_READ(8)-1],year);  
    
}

int ds1287_timer_state(void)
{
	return (CMOS_READ(RTC_REG_C) & RTC_PF) != 0;
}

void dayOfWeek() 
{ 
     printf("\n %s \n", day[CMOS_READ(6)-1]); 
		        
} 

static unsigned long dec_rtc_get_time(void)
{
	unsigned int year, mon, day, hour, min, sec, real_year;
	int i;

	/* The Linux interpretation of the DS1287 clock register contents:
	 * When the Update-In-Progress (UIP) flag goes from 1 to 0, the
	 * RTC registers show the second which has precisely just started.
	 * Let's hope other operating systems interpret the RTC the same way.
	 */
	/* read RTC exactly on falling edge of update flag */
	for (i = 0; i < 1000000; i++)	/* may take up to 1 second... */
		if (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP)
			break;
	for (i = 0; i < 1000000; i++)	/* must try at least 2.228 ms */
		if (!(CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP))
			break;
	/* Isn't this overkill?  UIP above should guarantee consistency */
	do {
		sec = CMOS_READ(RTC_SECONDS);
		min = CMOS_READ(RTC_MINUTES);
		hour = CMOS_READ(RTC_HOURS);
		day = CMOS_READ(RTC_DAY_OF_MONTH);
		mon = CMOS_READ(RTC_MONTH);
		year = CMOS_READ(RTC_YEAR);
	} while (sec != CMOS_READ(RTC_SECONDS));
	if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
		sec = BCD2BIN(sec);
		min = BCD2BIN(min);
		hour = BCD2BIN(hour);
		day = BCD2BIN(day);
		mon = BCD2BIN(mon);
		year = BCD2BIN(year);
	}
	/*
	 * The PROM will reset the year to either '72 or '73.
	 * Therefore we store the real year separately, in one
	 * of unused BBU RAM locations.
	 */
	real_year = CMOS_READ(RTC_DEC_YEAR);
	year += real_year - 72 + 2000;

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

static void dec_timer_ack(void)
{
	CMOS_READ(RTC_REG_C);			/* Ack the RTC interrupt.  */
}

static int
acpi_system_write_alarm (
	struct file		*file,
	const char		*buffer,
	unsigned long		count,
	void			*data)
{
	int			result = 0;
	char			alarm_string[30] = {'\0'};
	char			*p = alarm_string;
	u32			sec, min, hr, day, mo, yr;
	int			adjust = 0;
	unsigned char		rtc_control = 0;

	ACPI_FUNCTION_TRACE("acpi_system_write_alarm");

	if (count > sizeof(alarm_string) - 1)
		return_VALUE(-EINVAL);
	
	if (copy_from_user(alarm_string, buffer, count))
		return_VALUE(-EFAULT);

	alarm_string[count] = '\0';

	/* check for time adjustment */
	if (alarm_string[0] == '+') {
		p++;
		adjust = 1;
	}

	if ((result = get_date_field(&p, &yr)))
		goto end;
	if ((result = get_date_field(&p, &mo)))
		goto end;
	if ((result = get_date_field(&p, &day)))
		goto end;
	if ((result = get_date_field(&p, &hr)))
		goto end;
	if ((result = get_date_field(&p, &min)))
		goto end;
	if ((result = get_date_field(&p, &sec)))
		goto end;

	if (sec > 59) {
		min += 1;
		sec -= 60;
	}
	if (min > 59) {
		hr += 1;
		min -= 60;
	}
	if (hr > 23) {
		day += 1;
		hr -= 24;
	}
	if (day > 31) {
		mo += 1;
		day -= 31;
	}
	if (mo > 12) {
		yr += 1;
		mo -= 12;
	}

	spin_lock_irq(&rtc_lock);

	rtc_control = CMOS_READ(RTC_CONTROL);
	if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
		BIN_TO_BCD(yr);
		BIN_TO_BCD(mo);
		BIN_TO_BCD(day);
		BIN_TO_BCD(hr);
		BIN_TO_BCD(min);
		BIN_TO_BCD(sec);
	}

	if (adjust) {
		yr  += CMOS_READ(RTC_YEAR);
		mo  += CMOS_READ(RTC_MONTH);
		day += CMOS_READ(RTC_DAY_OF_MONTH);
		hr  += CMOS_READ(RTC_HOURS);
		min += CMOS_READ(RTC_MINUTES);
		sec += CMOS_READ(RTC_SECONDS);
	}

	spin_unlock_irq(&rtc_lock);

	if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
		BCD_TO_BIN(yr);
		BCD_TO_BIN(mo);
		BCD_TO_BIN(day);
		BCD_TO_BIN(hr);
		BCD_TO_BIN(min);
		BCD_TO_BIN(sec);
	}

	if (sec > 59) {
		min++;
		sec -= 60;
	}
//.........这里部分代码省略.........

static int INITSECTION
cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq)
{
	struct cmos_rtc_board_info	*info = dev->platform_data;
	int				retval = 0;
	unsigned char			rtc_control;

	/* there can be only one ... */
	if (cmos_rtc.dev)
		return -EBUSY;

	if (!ports)
		return -ENODEV;

	cmos_rtc.irq = rtc_irq;
	cmos_rtc.iomem = ports;

	/* For ACPI systems extension info comes from the FADT.  On others,
	 * board specific setup provides it as appropriate.  Systems where
	 * the alarm IRQ isn't automatically a wakeup IRQ (like ACPI, and
	 * some almost-clones) can provide hooks to make that behave.
	 */
	if (info) {
		cmos_rtc.day_alrm = info->rtc_day_alarm;
		cmos_rtc.mon_alrm = info->rtc_mon_alarm;
		cmos_rtc.century = info->rtc_century;

		if (info->wake_on && info->wake_off) {
			cmos_rtc.wake_on = info->wake_on;
			cmos_rtc.wake_off = info->wake_off;
		}
	}

	cmos_rtc.rtc = rtc_device_register(driver_name, dev,
				&cmos_rtc_ops, THIS_MODULE);
	if (IS_ERR(cmos_rtc.rtc))
		return PTR_ERR(cmos_rtc.rtc);

	cmos_rtc.dev = dev;
	dev_set_drvdata(dev, &cmos_rtc);

	/* platform and pnp busses handle resources incompatibly.
	 *
	 * REVISIT for non-x86 systems we may need to handle io memory
	 * resources: ioremap them, and request_mem_region().
	 */
	if (is_pnp()) {
		retval = request_resource(&ioport_resource, ports);
		if (retval < 0) {
			dev_dbg(dev, "i/o registers already in use\n");
			goto cleanup0;
		}
	}
	rename_region(ports, cmos_rtc.rtc->dev.bus_id);

#ifdef CONFIG_ARCH_GEN3
        /* MOSAIC WORKAROUND
         * some of our boxes shipped with unexpected CMOS RTC mode bits
         * if this is detected, reset the RTC to a known point
         */
	spin_lock_irq(&rtc_lock);
	rtc_control = CMOS_READ(RTC_CONTROL);
        if (!(rtc_control & RTC_24H) || (rtc_control & (RTC_DM_BINARY))) {
                struct rtc_time t;

                printk(KERN_INFO "Fixing bogus CMOS RTC mode\n");
                rtc_control |= RTC_24H;
                rtc_control &= ~RTC_DM_BINARY;
                CMOS_WRITE(rtc_control, RTC_CONTROL);

                memset(&t, 0, sizeof(t));
                t.tm_mday = 1;
                t.tm_year = 109;
                spin_unlock_irq(&rtc_lock);
                set_rtc_time(&t);
        } else {
                spin_unlock_irq(&rtc_lock);
        }
#endif

	spin_lock_irq(&rtc_lock);

	/* force periodic irq to CMOS reset default of 1024Hz;
	 *
	 * REVISIT it's been reported that at least one x86_64 ALI mobo
	 * doesn't use 32KHz here ... for portability we might need to
	 * do something about other clock frequencies.
	 */
	CMOS_WRITE(RTC_REF_CLCK_32KHZ | 0x06, RTC_FREQ_SELECT);
	cmos_rtc.rtc->irq_freq = 1024;

	/* disable irqs.
	 *
	 * NOTE after changing RTC_xIE bits we always read INTR_FLAGS;
	 * allegedly some older rtcs need that to handle irqs properly
	 */
	rtc_control = CMOS_READ(RTC_CONTROL);
	rtc_control &= ~(RTC_PIE | RTC_AIE | RTC_UIE);
	CMOS_WRITE(rtc_control, RTC_CONTROL);
	CMOS_READ(RTC_INTR_FLAGS);
//.........这里部分代码省略.........