drivers/rtc/rtc-cmos.c - LeafOS-Devices/android_kernel_realme_mt6785 - Gitiles

 /*
  * RTC class driver for "CMOS RTC":  PCs, ACPI, etc
  *
  * Copyright (C) 1996 Paul Gortmaker (drivers/char/rtc.c)
  * Copyright (C) 2006 David Brownell (convert to new framework)
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
  * as published by the Free Software Foundation; either version
  * 2 of the License, or (at your option) any later version.
  */

 /*
  * The original "cmos clock" chip was an MC146818 chip, now obsolete.
  * That defined the register interface now provided by all PCs, some
  * non-PC systems, and incorporated into ACPI.  Modern PC chipsets
  * integrate an MC146818 clone in their southbridge, and boards use
  * that instead of discrete clones like the DS12887 or M48T86.  There
  * are also clones that connect using the LPC bus.
  *
  * That register API is also used directly by various other drivers
  * (notably for integrated NVRAM), infrastructure (x86 has code to
  * bypass the RTC framework, directly reading the RTC during boot
  * and updating minutes/seconds for systems using NTP synch) and
  * utilities (like userspace 'hwclock', if no /dev node exists).
  *
  * So **ALL** calls to CMOS_READ and CMOS_WRITE must be done with
  * interrupts disabled, holding the global rtc_lock, to exclude those
  * other drivers and utilities on correctly configured systems.
  */
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/spinlock.h>
 #include <linux/platform_device.h>
 #include <linux/mod_devicetable.h>

 /* this is for "generic access to PC-style RTC" using CMOS_READ/CMOS_WRITE */
 #include <asm-generic/rtc.h>


 struct cmos_rtc {
 	struct rtc_device	*rtc;
 	struct device		*dev;
 	int			irq;
 	struct resource		*iomem;

 	u8			suspend_ctrl;

 	/* newer hardware extends the original register set */
 	u8			day_alrm;
 	u8			mon_alrm;
 	u8			century;
 };

 /* both platform and pnp busses use negative numbers for invalid irqs */
 #define is_valid_irq(n)		((n) >= 0)

 static const char driver_name[] = "rtc_cmos";

 /*----------------------------------------------------------------*/

 static int cmos_read_time(struct device *dev, struct rtc_time *t)
 {
 	/* REVISIT:  if the clock has a "century" register, use
 	 * that instead of the heuristic in get_rtc_time().
 	 * That'll make Y3K compatility (year > 2070) easy!
 	 */
 	get_rtc_time(t);
 	return 0;
 }

 static int cmos_set_time(struct device *dev, struct rtc_time *t)
 {
 	/* REVISIT:  set the "century" register if available
 	 *
 	 * NOTE: this ignores the issue whereby updating the seconds
 	 * takes effect exactly 500ms after we write the register.
 	 * (Also queueing and other delays before we get this far.)
 	 */
 	return set_rtc_time(t);
 }

 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) {
 		t->time.tm_mday = CMOS_READ(cmos->day_alrm);
 		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 int cmos_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 {
 	struct cmos_rtc	*cmos = dev_get_drvdata(dev);
 	unsigned char	mon, mday, hrs, min, sec;
 	unsigned char	rtc_control, rtc_intr;

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

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

 	/* Writing 0xff means "don't care" or "match all".  */

 	mon = t->time.tm_mon;
 	mon = (mon < 12) ? BIN2BCD(mon) : 0xff;
 	mon++;

 	mday = t->time.tm_mday;
 	mday = (mday >= 1 && mday <= 31) ? BIN2BCD(mday) : 0xff;

 	hrs = t->time.tm_hour;
 	hrs = (hrs < 24) ? BIN2BCD(hrs) : 0xff;

 	min = t->time.tm_min;
 	min = (min < 60) ? BIN2BCD(min) : 0xff;

 	sec = t->time.tm_sec;
 	sec = (sec < 60) ? BIN2BCD(sec) : 0xff;

 	spin_lock_irq(&rtc_lock);

 	/* next rtc irq must not be from previous alarm setting */
 	rtc_control = CMOS_READ(RTC_CONTROL);
 	rtc_control &= ~RTC_AIE;
 	CMOS_WRITE(rtc_control, RTC_CONTROL);
 	rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
 	if (rtc_intr)
 		rtc_update_irq(&cmos->rtc->class_dev, 1, rtc_intr);

 	/* update alarm */
 	CMOS_WRITE(hrs, RTC_HOURS_ALARM);
 	CMOS_WRITE(min, RTC_MINUTES_ALARM);
 	CMOS_WRITE(sec, RTC_SECONDS_ALARM);

 	/* the system may support an "enhanced" alarm */
 	if (cmos->day_alrm) {
 		CMOS_WRITE(mday, cmos->day_alrm);
 		if (cmos->mon_alrm)
 			CMOS_WRITE(mon, cmos->mon_alrm);
 	}

 	if (t->enabled) {
 		rtc_control |= RTC_AIE;
 		CMOS_WRITE(rtc_control, RTC_CONTROL);
 		rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
 		if (rtc_intr)
 			rtc_update_irq(&cmos->rtc->class_dev, 1, rtc_intr);
 	}

 	spin_unlock_irq(&rtc_lock);

 	return 0;
 }

 static int cmos_set_freq(struct device *dev, int freq)
 {
 	struct cmos_rtc	*cmos = dev_get_drvdata(dev);
 	int		f;
 	unsigned long	flags;

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

 	/* 0 = no irqs; 1 = 2^15 Hz ... 15 = 2^0 Hz */
 	f = ffs(freq);
 	if (f != 0) {
 		if (f-- > 16 || freq != (1 << f))
 			return -EINVAL;
 		f = 16 - f;
 	}

 	spin_lock_irqsave(&rtc_lock, flags);
 	CMOS_WRITE(RTC_REF_CLCK_32KHZ | f, RTC_FREQ_SELECT);
 	spin_unlock_irqrestore(&rtc_lock, flags);

 	return 0;
 }

 #if defined(CONFIG_RTC_INTF_DEV) || defined(CONFIG_RTC_INTF_DEV_MODULE)

 static int
 cmos_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 {
 	struct cmos_rtc	*cmos = dev_get_drvdata(dev);
 	unsigned char	rtc_control, rtc_intr;
 	unsigned long	flags;

 	switch (cmd) {
 	case RTC_AIE_OFF:
 	case RTC_AIE_ON:
 	case RTC_UIE_OFF:
 	case RTC_UIE_ON:
 	case RTC_PIE_OFF:
 	case RTC_PIE_ON:
 		if (!is_valid_irq(cmos->irq))
 			return -EINVAL;
 		break;
 	default:
 		return -ENOIOCTLCMD;
 	}

 	spin_lock_irqsave(&rtc_lock, flags);
 	rtc_control = CMOS_READ(RTC_CONTROL);
 	switch (cmd) {
 	case RTC_AIE_OFF:	/* alarm off */
 		rtc_control &= ~RTC_AIE;
 		break;
 	case RTC_AIE_ON:	/* alarm on */
 		rtc_control |= RTC_AIE;
 		break;
 	case RTC_UIE_OFF:	/* update off */
 		rtc_control &= ~RTC_UIE;
 		break;
 	case RTC_UIE_ON:	/* update on */
 		rtc_control |= RTC_UIE;
 		break;
 	case RTC_PIE_OFF:	/* periodic off */
 		rtc_control &= ~RTC_PIE;
 		break;
 	case RTC_PIE_ON:	/* periodic on */
 		rtc_control |= RTC_PIE;
 		break;
 	}
 	CMOS_WRITE(rtc_control, RTC_CONTROL);
 	rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
 	if (rtc_intr)
 		rtc_update_irq(&cmos->rtc->class_dev, 1, rtc_intr);
 	spin_unlock_irqrestore(&rtc_lock, flags);
 	return 0;
 }

 #else
 #define	cmos_rtc_ioctl	NULL
 #endif

 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)

 static int cmos_procfs(struct device *dev, struct seq_file *seq)
 {
 	struct cmos_rtc	*cmos = dev_get_drvdata(dev);
 	unsigned char	rtc_control, valid;

 	spin_lock_irq(&rtc_lock);
 	rtc_control = CMOS_READ(RTC_CONTROL);
 	valid = CMOS_READ(RTC_VALID);
 	spin_unlock_irq(&rtc_lock);

 	/* NOTE:  at least ICH6 reports battery status using a different
 	 * (non-RTC) bit; and SQWE is ignored on many current systems.
 	 */
 	return seq_printf(seq,
 			"periodic_IRQ\t: %s\n"
 			"update_IRQ\t: %s\n"
 			// "square_wave\t: %s\n"
 			// "BCD\t\t: %s\n"
 			"DST_enable\t: %s\n"
 			"periodic_freq\t: %d\n"
 			"batt_status\t: %s\n",
 			(rtc_control & RTC_PIE) ? "yes" : "no",
 			(rtc_control & RTC_UIE) ? "yes" : "no",
 			// (rtc_control & RTC_SQWE) ? "yes" : "no",
 			// (rtc_control & RTC_DM_BINARY) ? "no" : "yes",
 			(rtc_control & RTC_DST_EN) ? "yes" : "no",
 			cmos->rtc->irq_freq,
 			(valid & RTC_VRT) ? "okay" : "dead");
 }

 #else
 #define	cmos_procfs	NULL
 #endif

 static const struct rtc_class_ops cmos_rtc_ops = {
 	.ioctl		= cmos_rtc_ioctl,
 	.read_time	= cmos_read_time,
 	.set_time	= cmos_set_time,
 	.read_alarm	= cmos_read_alarm,
 	.set_alarm	= cmos_set_alarm,
 	.proc		= cmos_procfs,
 	.irq_set_freq	= cmos_set_freq,
 };

 /*----------------------------------------------------------------*/

 static struct cmos_rtc	cmos_rtc;

 static irqreturn_t cmos_interrupt(int irq, void *p)
 {
 	u8		irqstat;

 	spin_lock(&rtc_lock);
 	irqstat = CMOS_READ(RTC_INTR_FLAGS);
 	spin_unlock(&rtc_lock);

 	if (irqstat) {
 		/* NOTE: irqstat may have e.g. RTC_PF set
 		 * even when RTC_PIE is clear...
 		 */
 		rtc_update_irq(p, 1, irqstat);
 		return IRQ_HANDLED;
 	} else
 		return IRQ_NONE;
 }

 #ifdef	CONFIG_PNPACPI
 #define	is_pnpacpi()	1
 #define	INITSECTION

 #else
 #define	is_pnpacpi()	0
 #define	INITSECTION	__init
 #endif

 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 the info comes from the FADT.  On others,
 	 * board specific setup provides it as appropriate.
 	 */
 	if (info) {
 		cmos_rtc.day_alrm = info->rtc_day_alarm;
 		cmos_rtc.mon_alrm = info->rtc_mon_alarm;
 		cmos_rtc.century = info->rtc_century;
 	}

 	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_pnpacpi()) {
 		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->class_dev.class_id);

 	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);

 	spin_unlock_irq(&rtc_lock);

 	/* FIXME teach the alarm code how to handle binary mode;
 	 * <asm-generic/rtc.h> doesn't know 12-hour mode either.
 	 */
 	if (!(rtc_control & RTC_24H) || (rtc_control & (RTC_DM_BINARY))) {
 		dev_dbg(dev, "only 24-hr BCD mode supported\n");
 		retval = -ENXIO;
 		goto cleanup1;
 	}

 	if (is_valid_irq(rtc_irq))
 		retval = request_irq(rtc_irq, cmos_interrupt, IRQF_DISABLED,
 				cmos_rtc.rtc->class_dev.class_id,
 				&cmos_rtc.rtc->class_dev);
 	if (retval < 0) {
 		dev_dbg(dev, "IRQ %d is already in use\n", rtc_irq);
 		goto cleanup1;
 	}

 	/* REVISIT optionally make 50 or 114 bytes NVRAM available,
 	 * like rtc-ds1553, rtc-ds1742 ... this will often include
 	 * registers for century, and day/month alarm.
 	 */

 	pr_info("%s: alarms up to one %s%s\n",
 			cmos_rtc.rtc->class_dev.class_id,
 			is_valid_irq(rtc_irq)
 				?  (cmos_rtc.mon_alrm
 					? "year"
 					: (cmos_rtc.day_alrm
 						? "month" : "day"))
 				: "no",
 			cmos_rtc.century ? ", y3k" : ""
 			);

 	return 0;

 cleanup1:
 	rename_region(ports, NULL);
 cleanup0:
 	rtc_device_unregister(cmos_rtc.rtc);
 	return retval;
 }

 static void cmos_do_shutdown(void)
 {
 	unsigned char	rtc_control;

 	spin_lock_irq(&rtc_lock);
 	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);
 	spin_unlock_irq(&rtc_lock);
 }

 static void __exit cmos_do_remove(struct device *dev)
 {
 	struct cmos_rtc	*cmos = dev_get_drvdata(dev);

 	cmos_do_shutdown();

 	if (is_pnpacpi())
 		release_resource(cmos->iomem);
 	rename_region(cmos->iomem, NULL);

 	if (is_valid_irq(cmos->irq))
 		free_irq(cmos->irq, &cmos_rtc.rtc->class_dev);

 	rtc_device_unregister(cmos_rtc.rtc);

 	cmos_rtc.dev = NULL;
 	dev_set_drvdata(dev, NULL);
 }

 #ifdef	CONFIG_PM

 static int cmos_suspend(struct device *dev, pm_message_t mesg)
 {
 	struct cmos_rtc	*cmos = dev_get_drvdata(dev);
 	int		do_wake = device_may_wakeup(dev);
 	unsigned char	tmp, irqstat;

 	/* only the alarm might be a wakeup event source */
 	spin_lock_irq(&rtc_lock);
 	cmos->suspend_ctrl = tmp = CMOS_READ(RTC_CONTROL);
 	if (tmp & (RTC_PIE|RTC_AIE|RTC_UIE)) {
 		if (do_wake)
 			tmp &= ~(RTC_PIE|RTC_UIE);
 		else
 			tmp &= ~(RTC_PIE|RTC_AIE|RTC_UIE);
 		CMOS_WRITE(tmp, RTC_CONTROL);
 		irqstat = CMOS_READ(RTC_INTR_FLAGS);
 	} else
 		irqstat = 0;
 	spin_unlock_irq(&rtc_lock);

 	if (irqstat)
 		rtc_update_irq(&cmos->rtc->class_dev, 1, irqstat);

 	/* ACPI HOOK:  enable ACPI_EVENT_RTC when (tmp & RTC_AIE)
 	 * ... it'd be best if we could do that under rtc_lock.
 	 */

 	pr_debug("%s: suspend%s, ctrl %02x\n",
 			cmos_rtc.rtc->class_dev.class_id,
 			(tmp & RTC_AIE) ? ", alarm may wake" : "",
 			tmp);

 	return 0;
 }

 static int cmos_resume(struct device *dev)
 {
 	struct cmos_rtc	*cmos = dev_get_drvdata(dev);
 	unsigned char	tmp = cmos->suspend_ctrl;

 	/* REVISIT:  a mechanism to resync the system clock (jiffies)
 	 * on resume should be portable between platforms ...
 	 */

 	/* re-enable any irqs previously active */
 	if (tmp & (RTC_PIE|RTC_AIE|RTC_UIE)) {

 		/* ACPI HOOK:  disable ACPI_EVENT_RTC when (tmp & RTC_AIE) */

 		spin_lock_irq(&rtc_lock);
 		CMOS_WRITE(tmp, RTC_CONTROL);
 		tmp = CMOS_READ(RTC_INTR_FLAGS);
 		spin_unlock_irq(&rtc_lock);
 		if (tmp)
 			rtc_update_irq(&cmos->rtc->class_dev, 1, tmp);
 	}

 	pr_debug("%s: resume, ctrl %02x\n",
 			cmos_rtc.rtc->class_dev.class_id,
 			cmos->suspend_ctrl);


 	return 0;
 }

 #else
 #define	cmos_suspend	NULL
 #define	cmos_resume	NULL
 #endif

 /*----------------------------------------------------------------*/

 /* The "CMOS" RTC normally lives on the platform_bus.  On ACPI systems,
  * the device node may alternatively be created as a PNP device.
  */

 #ifdef	CONFIG_PNPACPI

 #include <linux/pnp.h>

 static int __devinit
 cmos_pnp_probe(struct pnp_dev *pnp, const struct pnp_device_id *id)
 {
 	/* REVISIT paranoia argues for a shutdown notifier, since PNP
 	 * drivers can't provide shutdown() methods to disable IRQs.
 	 * Or better yet, fix PNP to allow those methods...
 	 */
 	return cmos_do_probe(&pnp->dev,
 			&pnp->res.port_resource[0],
 			pnp->res.irq_resource[0].start);
 }

 static void __exit cmos_pnp_remove(struct pnp_dev *pnp)
 {
 	cmos_do_remove(&pnp->dev);
 }

 #ifdef	CONFIG_PM

 static int cmos_pnp_suspend(struct pnp_dev *pnp, pm_message_t mesg)
 {
 	return cmos_suspend(&pnp->dev, mesg);
 }

 static int cmos_pnp_resume(struct pnp_dev *pnp)
 {
 	return cmos_resume(&pnp->dev);
 }

 #else
 #define	cmos_pnp_suspend	NULL
 #define	cmos_pnp_resume		NULL
 #endif


 static const struct pnp_device_id rtc_ids[] = {
 	{ .id = "PNP0b00", },
 	{ .id = "PNP0b01", },
 	{ .id = "PNP0b02", },
 	{ },
 };
 MODULE_DEVICE_TABLE(pnp, rtc_ids);

 static struct pnp_driver cmos_pnp_driver = {
 	.name		= (char *) driver_name,
 	.id_table	= rtc_ids,
 	.probe		= cmos_pnp_probe,
 	.remove		= __exit_p(cmos_pnp_remove),

 	/* flag ensures resume() gets called, and stops syslog spam */
 	.flags		= PNP_DRIVER_RES_DO_NOT_CHANGE,
 	.suspend	= cmos_pnp_suspend,
 	.resume		= cmos_pnp_resume,
 };

 static int __init cmos_init(void)
 {
 	return pnp_register_driver(&cmos_pnp_driver);
 }
 module_init(cmos_init);

 static void __exit cmos_exit(void)
 {
 	pnp_unregister_driver(&cmos_pnp_driver);
 }
 module_exit(cmos_exit);

 #else	/* no PNPACPI */

 /*----------------------------------------------------------------*/

 /* Platform setup should have set up an RTC device, when PNPACPI is
  * unavailable ... this is the normal case, common even on PCs.
  */

 static int __init cmos_platform_probe(struct platform_device *pdev)
 {
 	return cmos_do_probe(&pdev->dev,
 			platform_get_resource(pdev, IORESOURCE_IO, 0),
 			platform_get_irq(pdev, 0));
 }

 static int __exit cmos_platform_remove(struct platform_device *pdev)
 {
 	cmos_do_remove(&pdev->dev);
 	return 0;
 }

 static void cmos_platform_shutdown(struct platform_device *pdev)
 {
 	cmos_do_shutdown();
 }

 static struct platform_driver cmos_platform_driver = {
 	.remove		= __exit_p(cmos_platform_remove),
 	.shutdown	= cmos_platform_shutdown,
 	.driver = {
 		.name		= (char *) driver_name,
 		.suspend	= cmos_suspend,
 		.resume		= cmos_resume,
 	}
 };

 static int __init cmos_init(void)
 {
 	return platform_driver_probe(&cmos_platform_driver,
 			cmos_platform_probe);
 }
 module_init(cmos_init);

 static void __exit cmos_exit(void)
 {
 	platform_driver_unregister(&cmos_platform_driver);
 }
 module_exit(cmos_exit);


 #endif	/* !PNPACPI */

 MODULE_AUTHOR("David Brownell");
 MODULE_DESCRIPTION("Driver for PC-style 'CMOS' RTCs");
 MODULE_LICENSE("GPL");
	/*
	* RTC class driver for "CMOS RTC": PCs, ACPI, etc
	*
	* Copyright (C) 1996 Paul Gortmaker (drivers/char/rtc.c)
	* Copyright (C) 2006 David Brownell (convert to new framework)
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License
	* as published by the Free Software Foundation; either version
	* 2 of the License, or (at your option) any later version.
	*/

	/*
	* The original "cmos clock" chip was an MC146818 chip, now obsolete.
	* That defined the register interface now provided by all PCs, some
	* non-PC systems, and incorporated into ACPI. Modern PC chipsets
	* integrate an MC146818 clone in their southbridge, and boards use
	* that instead of discrete clones like the DS12887 or M48T86. There
	* are also clones that connect using the LPC bus.
	*
	* That register API is also used directly by various other drivers
	* (notably for integrated NVRAM), infrastructure (x86 has code to
	* bypass the RTC framework, directly reading the RTC during boot
	* and updating minutes/seconds for systems using NTP synch) and
	* utilities (like userspace 'hwclock', if no /dev node exists).
	*
	* So ALL calls to CMOS_READ and CMOS_WRITE must be done with
	* interrupts disabled, holding the global rtc_lock, to exclude those
	* other drivers and utilities on correctly configured systems.
	*/
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/interrupt.h>
	#include <linux/spinlock.h>
	#include <linux/platform_device.h>
	#include <linux/mod_devicetable.h>

	/* this is for "generic access to PC-style RTC" using CMOS_READ/CMOS_WRITE */
	#include <asm-generic/rtc.h>


	struct cmos_rtc {
	struct rtc_device *rtc;
	struct device *dev;
	int irq;
	struct resource *iomem;

	u8 suspend_ctrl;

	/* newer hardware extends the original register set */
	u8 day_alrm;
	u8 mon_alrm;
	u8 century;
	};

	/* both platform and pnp busses use negative numbers for invalid irqs */
	#define is_valid_irq(n) ((n) >= 0)

	static const char driver_name[] = "rtc_cmos";

	/----------------------------------------------------------------/

	static int cmos_read_time(struct device dev, struct rtc_time t)
	{
	/* REVISIT: if the clock has a "century" register, use
	* that instead of the heuristic in get_rtc_time().
	* That'll make Y3K compatility (year > 2070) easy!
	*/
	get_rtc_time(t);
	return 0;
	}

	static int cmos_set_time(struct device dev, struct rtc_time t)
	{
	/* REVISIT: set the "century" register if available
	*
	* NOTE: this ignores the issue whereby updating the seconds
	* takes effect exactly 500ms after we write the register.
	* (Also queueing and other delays before we get this far.)
	*/
	return set_rtc_time(t);
	}

	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) {
	t->time.tm_mday = CMOS_READ(cmos->day_alrm);
	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 int cmos_set_alarm(struct device dev, struct rtc_wkalrm t)
	{
	struct cmos_rtc *cmos = dev_get_drvdata(dev);
	unsigned char mon, mday, hrs, min, sec;
	unsigned char rtc_control, rtc_intr;

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

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

	/* Writing 0xff means "don't care" or "match all". */

	mon = t->time.tm_mon;
	mon = (mon < 12) ? BIN2BCD(mon) : 0xff;
	mon++;

	mday = t->time.tm_mday;
	mday = (mday >= 1 && mday <= 31) ? BIN2BCD(mday) : 0xff;

	hrs = t->time.tm_hour;
	hrs = (hrs < 24) ? BIN2BCD(hrs) : 0xff;

	min = t->time.tm_min;
	min = (min < 60) ? BIN2BCD(min) : 0xff;

	sec = t->time.tm_sec;
	sec = (sec < 60) ? BIN2BCD(sec) : 0xff;

	spin_lock_irq(&rtc_lock);

	/* next rtc irq must not be from previous alarm setting */
	rtc_control = CMOS_READ(RTC_CONTROL);
	rtc_control &= ~RTC_AIE;
	CMOS_WRITE(rtc_control, RTC_CONTROL);
	rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
	if (rtc_intr)
	rtc_update_irq(&cmos->rtc->class_dev, 1, rtc_intr);

	/* update alarm */
	CMOS_WRITE(hrs, RTC_HOURS_ALARM);
	CMOS_WRITE(min, RTC_MINUTES_ALARM);
	CMOS_WRITE(sec, RTC_SECONDS_ALARM);

	/* the system may support an "enhanced" alarm */
	if (cmos->day_alrm) {
	CMOS_WRITE(mday, cmos->day_alrm);
	if (cmos->mon_alrm)
	CMOS_WRITE(mon, cmos->mon_alrm);
	}

	if (t->enabled) {
	rtc_control \|= RTC_AIE;
	CMOS_WRITE(rtc_control, RTC_CONTROL);
	rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
	if (rtc_intr)
	rtc_update_irq(&cmos->rtc->class_dev, 1, rtc_intr);
	}

	spin_unlock_irq(&rtc_lock);

	return 0;
	}

	static int cmos_set_freq(struct device *dev, int freq)
	{
	struct cmos_rtc *cmos = dev_get_drvdata(dev);
	int f;
	unsigned long flags;

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

	/* 0 = no irqs; 1 = 2^15 Hz ... 15 = 2^0 Hz */
	f = ffs(freq);
	if (f != 0) {
	if (f-- > 16 \|\| freq != (1 << f))
	return -EINVAL;
	f = 16 - f;
	}

	spin_lock_irqsave(&rtc_lock, flags);
	CMOS_WRITE(RTC_REF_CLCK_32KHZ \| f, RTC_FREQ_SELECT);
	spin_unlock_irqrestore(&rtc_lock, flags);

	return 0;
	}

	#if defined(CONFIG_RTC_INTF_DEV) \|\| defined(CONFIG_RTC_INTF_DEV_MODULE)

	static int
	cmos_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
	{
	struct cmos_rtc *cmos = dev_get_drvdata(dev);
	unsigned char rtc_control, rtc_intr;
	unsigned long flags;

	switch (cmd) {
	case RTC_AIE_OFF:
	case RTC_AIE_ON:
	case RTC_UIE_OFF:
	case RTC_UIE_ON:
	case RTC_PIE_OFF:
	case RTC_PIE_ON:
	if (!is_valid_irq(cmos->irq))
	return -EINVAL;
	break;
	default:
	return -ENOIOCTLCMD;
	}

	spin_lock_irqsave(&rtc_lock, flags);
	rtc_control = CMOS_READ(RTC_CONTROL);
	switch (cmd) {
	case RTC_AIE_OFF: /* alarm off */
	rtc_control &= ~RTC_AIE;
	break;
	case RTC_AIE_ON: /* alarm on */
	rtc_control \|= RTC_AIE;
	break;
	case RTC_UIE_OFF: /* update off */
	rtc_control &= ~RTC_UIE;
	break;
	case RTC_UIE_ON: /* update on */
	rtc_control \|= RTC_UIE;
	break;
	case RTC_PIE_OFF: /* periodic off */
	rtc_control &= ~RTC_PIE;
	break;
	case RTC_PIE_ON: /* periodic on */
	rtc_control \|= RTC_PIE;
	break;
	}
	CMOS_WRITE(rtc_control, RTC_CONTROL);
	rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
	if (rtc_intr)
	rtc_update_irq(&cmos->rtc->class_dev, 1, rtc_intr);
	spin_unlock_irqrestore(&rtc_lock, flags);
	return 0;
	}

	#else
	#define cmos_rtc_ioctl NULL
	#endif

	#if defined(CONFIG_RTC_INTF_PROC) \|\| defined(CONFIG_RTC_INTF_PROC_MODULE)

	static int cmos_procfs(struct device dev, struct seq_file seq)
	{
	struct cmos_rtc *cmos = dev_get_drvdata(dev);
	unsigned char rtc_control, valid;

	spin_lock_irq(&rtc_lock);
	rtc_control = CMOS_READ(RTC_CONTROL);
	valid = CMOS_READ(RTC_VALID);
	spin_unlock_irq(&rtc_lock);

	/* NOTE: at least ICH6 reports battery status using a different
	* (non-RTC) bit; and SQWE is ignored on many current systems.
	*/
	return seq_printf(seq,
	"periodic_IRQ\t: %s\n"
	"update_IRQ\t: %s\n"
	// "square_wave\t: %s\n"
	// "BCD\t\t: %s\n"
	"DST_enable\t: %s\n"
	"periodic_freq\t: %d\n"
	"batt_status\t: %s\n",
	(rtc_control & RTC_PIE) ? "yes" : "no",
	(rtc_control & RTC_UIE) ? "yes" : "no",
	// (rtc_control & RTC_SQWE) ? "yes" : "no",
	// (rtc_control & RTC_DM_BINARY) ? "no" : "yes",
	(rtc_control & RTC_DST_EN) ? "yes" : "no",
	cmos->rtc->irq_freq,
	(valid & RTC_VRT) ? "okay" : "dead");
	}

	#else
	#define cmos_procfs NULL
	#endif

	static const struct rtc_class_ops cmos_rtc_ops = {
	.ioctl = cmos_rtc_ioctl,
	.read_time = cmos_read_time,
	.set_time = cmos_set_time,
	.read_alarm = cmos_read_alarm,
	.set_alarm = cmos_set_alarm,
	.proc = cmos_procfs,
	.irq_set_freq = cmos_set_freq,
	};

	/----------------------------------------------------------------/

	static struct cmos_rtc cmos_rtc;

	static irqreturn_t cmos_interrupt(int irq, void *p)
	{
	u8 irqstat;

	spin_lock(&rtc_lock);
	irqstat = CMOS_READ(RTC_INTR_FLAGS);
	spin_unlock(&rtc_lock);

	if (irqstat) {
	/* NOTE: irqstat may have e.g. RTC_PF set
	* even when RTC_PIE is clear...
	*/
	rtc_update_irq(p, 1, irqstat);
	return IRQ_HANDLED;
	} else
	return IRQ_NONE;
	}

	#ifdef CONFIG_PNPACPI
	#define is_pnpacpi() 1
	#define INITSECTION

	#else
	#define is_pnpacpi() 0
	#define INITSECTION __init
	#endif

	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 the info comes from the FADT. On others,
	* board specific setup provides it as appropriate.
	*/
	if (info) {
	cmos_rtc.day_alrm = info->rtc_day_alarm;
	cmos_rtc.mon_alrm = info->rtc_mon_alarm;
	cmos_rtc.century = info->rtc_century;
	}

	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_pnpacpi()) {
	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->class_dev.class_id);

	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);

	spin_unlock_irq(&rtc_lock);

	/* FIXME teach the alarm code how to handle binary mode;
	* <asm-generic/rtc.h> doesn't know 12-hour mode either.
	*/
	if (!(rtc_control & RTC_24H) \|\| (rtc_control & (RTC_DM_BINARY))) {
	dev_dbg(dev, "only 24-hr BCD mode supported\n");
	retval = -ENXIO;
	goto cleanup1;
	}

	if (is_valid_irq(rtc_irq))
	retval = request_irq(rtc_irq, cmos_interrupt, IRQF_DISABLED,
	cmos_rtc.rtc->class_dev.class_id,
	&cmos_rtc.rtc->class_dev);
	if (retval < 0) {
	dev_dbg(dev, "IRQ %d is already in use\n", rtc_irq);
	goto cleanup1;
	}

	/* REVISIT optionally make 50 or 114 bytes NVRAM available,
	* like rtc-ds1553, rtc-ds1742 ... this will often include
	* registers for century, and day/month alarm.
	*/

	pr_info("%s: alarms up to one %s%s\n",
	cmos_rtc.rtc->class_dev.class_id,
	is_valid_irq(rtc_irq)
	? (cmos_rtc.mon_alrm
	? "year"
	: (cmos_rtc.day_alrm
	? "month" : "day"))
	: "no",
	cmos_rtc.century ? ", y3k" : ""
	);

	return 0;

	cleanup1:
	rename_region(ports, NULL);
	cleanup0:
	rtc_device_unregister(cmos_rtc.rtc);
	return retval;
	}

	static void cmos_do_shutdown(void)
	{
	unsigned char rtc_control;

	spin_lock_irq(&rtc_lock);
	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);
	spin_unlock_irq(&rtc_lock);
	}

	static void __exit cmos_do_remove(struct device *dev)
	{
	struct cmos_rtc *cmos = dev_get_drvdata(dev);

	cmos_do_shutdown();

	if (is_pnpacpi())
	release_resource(cmos->iomem);
	rename_region(cmos->iomem, NULL);

	if (is_valid_irq(cmos->irq))
	free_irq(cmos->irq, &cmos_rtc.rtc->class_dev);

	rtc_device_unregister(cmos_rtc.rtc);

	cmos_rtc.dev = NULL;
	dev_set_drvdata(dev, NULL);
	}

	#ifdef CONFIG_PM

	static int cmos_suspend(struct device *dev, pm_message_t mesg)
	{
	struct cmos_rtc *cmos = dev_get_drvdata(dev);
	int do_wake = device_may_wakeup(dev);
	unsigned char tmp, irqstat;

	/* only the alarm might be a wakeup event source */
	spin_lock_irq(&rtc_lock);
	cmos->suspend_ctrl = tmp = CMOS_READ(RTC_CONTROL);
	if (tmp & (RTC_PIE\|RTC_AIE\|RTC_UIE)) {
	if (do_wake)
	tmp &= ~(RTC_PIE\|RTC_UIE);
	else
	tmp &= ~(RTC_PIE\|RTC_AIE\|RTC_UIE);
	CMOS_WRITE(tmp, RTC_CONTROL);
	irqstat = CMOS_READ(RTC_INTR_FLAGS);
	} else
	irqstat = 0;
	spin_unlock_irq(&rtc_lock);

	if (irqstat)
	rtc_update_irq(&cmos->rtc->class_dev, 1, irqstat);

	/* ACPI HOOK: enable ACPI_EVENT_RTC when (tmp & RTC_AIE)
	* ... it'd be best if we could do that under rtc_lock.
	*/

	pr_debug("%s: suspend%s, ctrl %02x\n",
	cmos_rtc.rtc->class_dev.class_id,
	(tmp & RTC_AIE) ? ", alarm may wake" : "",
	tmp);

	return 0;
	}

	static int cmos_resume(struct device *dev)
	{
	struct cmos_rtc *cmos = dev_get_drvdata(dev);
	unsigned char tmp = cmos->suspend_ctrl;

	/* REVISIT: a mechanism to resync the system clock (jiffies)
	* on resume should be portable between platforms ...
	*/

	/* re-enable any irqs previously active */
	if (tmp & (RTC_PIE\|RTC_AIE\|RTC_UIE)) {

	/* ACPI HOOK: disable ACPI_EVENT_RTC when (tmp & RTC_AIE) */

	spin_lock_irq(&rtc_lock);
	CMOS_WRITE(tmp, RTC_CONTROL);
	tmp = CMOS_READ(RTC_INTR_FLAGS);
	spin_unlock_irq(&rtc_lock);
	if (tmp)
	rtc_update_irq(&cmos->rtc->class_dev, 1, tmp);
	}

	pr_debug("%s: resume, ctrl %02x\n",
	cmos_rtc.rtc->class_dev.class_id,
	cmos->suspend_ctrl);


	return 0;
	}

	#else
	#define cmos_suspend NULL
	#define cmos_resume NULL
	#endif

	/----------------------------------------------------------------/

	/* The "CMOS" RTC normally lives on the platform_bus. On ACPI systems,
	* the device node may alternatively be created as a PNP device.
	*/

	#ifdef CONFIG_PNPACPI

	#include <linux/pnp.h>

	static int __devinit
	cmos_pnp_probe(struct pnp_dev pnp, const struct pnp_device_id id)
	{
	/* REVISIT paranoia argues for a shutdown notifier, since PNP
	* drivers can't provide shutdown() methods to disable IRQs.
	* Or better yet, fix PNP to allow those methods...
	*/
	return cmos_do_probe(&pnp->dev,
	&pnp->res.port_resource[0],
	pnp->res.irq_resource[0].start);
	}

	static void __exit cmos_pnp_remove(struct pnp_dev *pnp)
	{
	cmos_do_remove(&pnp->dev);
	}

	#ifdef CONFIG_PM

	static int cmos_pnp_suspend(struct pnp_dev *pnp, pm_message_t mesg)
	{
	return cmos_suspend(&pnp->dev, mesg);
	}

	static int cmos_pnp_resume(struct pnp_dev *pnp)
	{
	return cmos_resume(&pnp->dev);
	}

	#else
	#define cmos_pnp_suspend NULL
	#define cmos_pnp_resume NULL
	#endif


	static const struct pnp_device_id rtc_ids[] = {
	{ .id = "PNP0b00", },
	{ .id = "PNP0b01", },
	{ .id = "PNP0b02", },
	{ },
	};
	MODULE_DEVICE_TABLE(pnp, rtc_ids);

	static struct pnp_driver cmos_pnp_driver = {
	.name = (char *) driver_name,
	.id_table = rtc_ids,
	.probe = cmos_pnp_probe,
	.remove = __exit_p(cmos_pnp_remove),

	/* flag ensures resume() gets called, and stops syslog spam */
	.flags = PNP_DRIVER_RES_DO_NOT_CHANGE,
	.suspend = cmos_pnp_suspend,
	.resume = cmos_pnp_resume,
	};

	static int __init cmos_init(void)
	{
	return pnp_register_driver(&cmos_pnp_driver);
	}
	module_init(cmos_init);

	static void __exit cmos_exit(void)
	{
	pnp_unregister_driver(&cmos_pnp_driver);
	}
	module_exit(cmos_exit);

	#else /* no PNPACPI */

	/----------------------------------------------------------------/

	/* Platform setup should have set up an RTC device, when PNPACPI is
	* unavailable ... this is the normal case, common even on PCs.
	*/

	static int __init cmos_platform_probe(struct platform_device *pdev)
	{
	return cmos_do_probe(&pdev->dev,
	platform_get_resource(pdev, IORESOURCE_IO, 0),
	platform_get_irq(pdev, 0));
	}

	static int __exit cmos_platform_remove(struct platform_device *pdev)
	{
	cmos_do_remove(&pdev->dev);
	return 0;
	}

	static void cmos_platform_shutdown(struct platform_device *pdev)
	{
	cmos_do_shutdown();
	}

	static struct platform_driver cmos_platform_driver = {
	.remove = __exit_p(cmos_platform_remove),
	.shutdown = cmos_platform_shutdown,
	.driver = {
	.name = (char *) driver_name,
	.suspend = cmos_suspend,
	.resume = cmos_resume,
	}
	};

	static int __init cmos_init(void)
	{
	return platform_driver_probe(&cmos_platform_driver,
	cmos_platform_probe);
	}
	module_init(cmos_init);

	static void __exit cmos_exit(void)
	{
	platform_driver_unregister(&cmos_platform_driver);
	}
	module_exit(cmos_exit);


	#endif /* !PNPACPI */

	MODULE_AUTHOR("David Brownell");
	MODULE_DESCRIPTION("Driver for PC-style 'CMOS' RTCs");
	MODULE_LICENSE("GPL");