[net-next-2.6.git] / arch / cris / arch-v10 / drivers / pcf8563.c

/*
 * PCF8563 RTC
 *
 * From Phillips' datasheet:
 *
 * The PCF8563 is a CMOS real-time clock/calendar optimized for low power
 * consumption. A programmable clock output, interrupt output and voltage
 * low detector are also provided. All address and data are transferred
 * serially via two-line bidirectional I2C-bus. Maximum bus speed is
 * 400 kbits/s. The built-in word address register is incremented
 * automatically after each written or read byte.
 *
 * Copyright (c) 2002-2007, Axis Communications AB
 * All rights reserved.
 *
 * Author: Tobias Anderberg <tobiasa@axis.com>.
 *
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/ioctl.h>
#include <linux/delay.h>
#include <linux/bcd.h>
#include <linux/mutex.h>
#include <linux/smp_lock.h>

#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/rtc.h>

#include "i2c.h"

#define PCF8563_MAJOR 121	/* Local major number. */
#define DEVICE_NAME "rtc"	/* Name which is registered in /proc/devices. */
#define PCF8563_NAME "PCF8563"
#define DRIVER_VERSION "$Revision: 1.24 $"

/* I2C bus slave registers. */
#define RTC_I2C_READ		0xa3
#define RTC_I2C_WRITE		0xa2

/* Two simple wrapper macros, saves a few keystrokes. */
#define rtc_read(x) i2c_readreg(RTC_I2C_READ, x)
#define rtc_write(x,y) i2c_writereg(RTC_I2C_WRITE, x, y)

static DEFINE_MUTEX(rtc_lock); /* Protect state etc */

static const unsigned char days_in_month[] =
	{ 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };

static long pcf8563_unlocked_ioctl(struct file *, unsigned int, unsigned long);

/* Cache VL bit value read at driver init since writing the RTC_SECOND
 * register clears the VL status.
 */
static int voltage_low;

static const struct file_operations pcf8563_fops = {
	.owner = THIS_MODULE,
	.unlocked_ioctl = pcf8563_unlocked_ioctl,
};

unsigned char
pcf8563_readreg(int reg)
{
	unsigned char res = rtc_read(reg);

	/* The PCF8563 does not return 0 for unimplemented bits. */
	switch (reg) {
	case RTC_SECONDS:
	case RTC_MINUTES:
		res &= 0x7F;
		break;
	case RTC_HOURS:
	case RTC_DAY_OF_MONTH:
		res &= 0x3F;
		break;
	case RTC_WEEKDAY:
		res &= 0x07;
		break;
	case RTC_MONTH:
		res &= 0x1F;
		break;
	case RTC_CONTROL1:
		res &= 0xA8;
		break;
	case RTC_CONTROL2:
		res &= 0x1F;
		break;
	case RTC_CLOCKOUT_FREQ:
	case RTC_TIMER_CONTROL:
		res &= 0x83;
		break;
	}
	return res;
}

void
pcf8563_writereg(int reg, unsigned char val)
{
	rtc_write(reg, val);
}

void
get_rtc_time(struct rtc_time *tm)
{
	tm->tm_sec  = rtc_read(RTC_SECONDS);
	tm->tm_min  = rtc_read(RTC_MINUTES);
	tm->tm_hour = rtc_read(RTC_HOURS);
	tm->tm_mday = rtc_read(RTC_DAY_OF_MONTH);
	tm->tm_wday = rtc_read(RTC_WEEKDAY);
	tm->tm_mon  = rtc_read(RTC_MONTH);
	tm->tm_year = rtc_read(RTC_YEAR);

	if (tm->tm_sec & 0x80) {
		printk(KERN_ERR "%s: RTC Voltage Low - reliable date/time "
		       "information is no longer guaranteed!\n", PCF8563_NAME);
	}

	tm->tm_year  = bcd2bin(tm->tm_year) +
		       ((tm->tm_mon & 0x80) ? 100 : 0);
	tm->tm_sec  &= 0x7F;
	tm->tm_min  &= 0x7F;
	tm->tm_hour &= 0x3F;
	tm->tm_mday &= 0x3F;
	tm->tm_wday &= 0x07; /* Not coded in BCD. */
	tm->tm_mon  &= 0x1F;

	tm->tm_sec = bcd2bin(tm->tm_sec);
	tm->tm_min = bcd2bin(tm->tm_min);
	tm->tm_hour = bcd2bin(tm->tm_hour);
	tm->tm_mday = bcd2bin(tm->tm_mday);
	tm->tm_mon = bcd2bin(tm->tm_mon);
	tm->tm_mon--; /* Month is 1..12 in RTC but 0..11 in linux */
}

int __init
pcf8563_init(void)
{
	static int res;
	static int first = 1;

	if (!first)
		return res;
	first = 0;

	/* Initiate the i2c protocol. */
	res = i2c_init();
	if (res < 0) {
		printk(KERN_CRIT "pcf8563_init: Failed to init i2c.\n");
		return res;
	}

	/*
	 * First of all we need to reset the chip. This is done by
	 * clearing control1, control2 and clk freq and resetting
	 * all alarms.
	 */
	if (rtc_write(RTC_CONTROL1, 0x00) < 0)
		goto err;

	if (rtc_write(RTC_CONTROL2, 0x00) < 0)
		goto err;

	if (rtc_write(RTC_CLOCKOUT_FREQ, 0x00) < 0)
		goto err;

	if (rtc_write(RTC_TIMER_CONTROL, 0x03) < 0)
		goto err;

	/* Reset the alarms. */
	if (rtc_write(RTC_MINUTE_ALARM, 0x80) < 0)
		goto err;

	if (rtc_write(RTC_HOUR_ALARM, 0x80) < 0)
		goto err;

	if (rtc_write(RTC_DAY_ALARM, 0x80) < 0)
		goto err;

	if (rtc_write(RTC_WEEKDAY_ALARM, 0x80) < 0)
		goto err;

	/* Check for low voltage, and warn about it. */
	if (rtc_read(RTC_SECONDS) & 0x80) {
		voltage_low = 1;
		printk(KERN_WARNING "%s: RTC Voltage Low - reliable "
		       "date/time information is no longer guaranteed!\n",
		       PCF8563_NAME);
	}

	return res;

err:
	printk(KERN_INFO "%s: Error initializing chip.\n", PCF8563_NAME);
	res = -1;
	return res;
}

void __exit
pcf8563_exit(void)
{
	unregister_chrdev(PCF8563_MAJOR, DEVICE_NAME);
}

/*
 * ioctl calls for this driver. Why return -ENOTTY upon error? Because
 * POSIX says so!
 */
static int pcf8563_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
	/* Some sanity checks. */
	if (_IOC_TYPE(cmd) != RTC_MAGIC)
		return -ENOTTY;

	if (_IOC_NR(cmd) > RTC_MAX_IOCTL)
		return -ENOTTY;

	switch (cmd) {
	case RTC_RD_TIME:
	{
		struct rtc_time tm;

		mutex_lock(&rtc_lock);
		memset(&tm, 0, sizeof tm);
		get_rtc_time(&tm);

		if (copy_to_user((struct rtc_time *) arg, &tm,
				 sizeof tm)) {
			mutex_unlock(&rtc_lock);
			return -EFAULT;
		}

		mutex_unlock(&rtc_lock);

		return 0;
	}
	case RTC_SET_TIME:
	{
		int leap;
		int year;
		int century;
		struct rtc_time tm;

		memset(&tm, 0, sizeof tm);
		if (!capable(CAP_SYS_TIME))
			return -EPERM;

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

		/* Convert from struct tm to struct rtc_time. */
		tm.tm_year += 1900;
		tm.tm_mon += 1;

		/*
		 * Check if tm.tm_year is a leap year. A year is a leap
		 * year if it is divisible by 4 but not 100, except
		 * that years divisible by 400 _are_ leap years.
		 */
		year = tm.tm_year;
		leap = (tm.tm_mon == 2) &&
			((year % 4 == 0 && year % 100 != 0) || year % 400 == 0);

		/* Perform some sanity checks. */
		if ((tm.tm_year < 1970) ||
		    (tm.tm_mon > 12) ||
		    (tm.tm_mday == 0) ||
		    (tm.tm_mday > days_in_month[tm.tm_mon] + leap) ||
		    (tm.tm_wday >= 7) ||
		    (tm.tm_hour >= 24) ||
		    (tm.tm_min >= 60) ||
		    (tm.tm_sec >= 60))
			return -EINVAL;

		century = (tm.tm_year >= 2000) ? 0x80 : 0;
		tm.tm_year = tm.tm_year % 100;

		tm.tm_year = bin2bcd(tm.tm_year);
		tm.tm_mon = bin2bcd(tm.tm_mon);
		tm.tm_mday = bin2bcd(tm.tm_mday);
		tm.tm_hour = bin2bcd(tm.tm_hour);
		tm.tm_min = bin2bcd(tm.tm_min);
		tm.tm_sec = bin2bcd(tm.tm_sec);
		tm.tm_mon |= century;

		mutex_lock(&rtc_lock);

		rtc_write(RTC_YEAR, tm.tm_year);
		rtc_write(RTC_MONTH, tm.tm_mon);
		rtc_write(RTC_WEEKDAY, tm.tm_wday); /* Not coded in BCD. */
		rtc_write(RTC_DAY_OF_MONTH, tm.tm_mday);
		rtc_write(RTC_HOURS, tm.tm_hour);
		rtc_write(RTC_MINUTES, tm.tm_min);
		rtc_write(RTC_SECONDS, tm.tm_sec);

		mutex_unlock(&rtc_lock);

		return 0;
	}
	case RTC_VL_READ:
		if (voltage_low) {
			printk(KERN_ERR "%s: RTC Voltage Low - "
			       "reliable date/time information is no "
			       "longer guaranteed!\n", PCF8563_NAME);
		}

		if (copy_to_user((int *) arg, &voltage_low, sizeof(int)))
			return -EFAULT;
		return 0;

	case RTC_VL_CLR:
	{
		/* Clear the VL bit in the seconds register in case
		 * the time has not been set already (which would
		 * have cleared it). This does not really matter
		 * because of the cached voltage_low value but do it
		 * anyway for consistency. */

		int ret = rtc_read(RTC_SECONDS);

		rtc_write(RTC_SECONDS, (ret & 0x7F));

		/* Clear the cached value. */
		voltage_low = 0;

		return 0;
	}
	default:
		return -ENOTTY;
	}

	return 0;
}

static long pcf8563_unlocked_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
	int ret;

	lock_kernel();
	return pcf8563_ioctl(filp, cmd, arg);
	unlock_kernel();

	return ret;
}

static int __init pcf8563_register(void)
{
	if (pcf8563_init() < 0) {
		printk(KERN_INFO "%s: Unable to initialize Real-Time Clock "
		       "Driver, %s\n", PCF8563_NAME, DRIVER_VERSION);
		return -1;
	}

	if (register_chrdev(PCF8563_MAJOR, DEVICE_NAME, &pcf8563_fops) < 0) {
		printk(KERN_INFO "%s: Unable to get major number %d for RTC device.\n",
		       PCF8563_NAME, PCF8563_MAJOR);
		return -1;
	}

	printk(KERN_INFO "%s Real-Time Clock Driver, %s\n", PCF8563_NAME,
	       DRIVER_VERSION);

	/* Check for low voltage, and warn about it. */
	if (voltage_low) {
		printk(KERN_WARNING "%s: RTC Voltage Low - reliable date/time "
		       "information is no longer guaranteed!\n", PCF8563_NAME);
	}

	return 0;
}

module_init(pcf8563_register);
module_exit(pcf8563_exit);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* PCF8563 RTC
	3	*
	4	* From Phillips' datasheet:
	5	*
	6	* The PCF8563 is a CMOS real-time clock/calendar optimized for low power
3a4fa0a2	7	* consumption. A programmable clock output, interrupt output and voltage
1da177e4 LT	8	* low detector are also provided. All address and data are transferred
	9	* serially via two-line bidirectional I2C-bus. Maximum bus speed is
	10	* 400 kbits/s. The built-in word address register is incremented
34a8e501	11	* automatically after each written or read byte.
1da177e4	12	*
34a8e501	13	* Copyright (c) 2002-2007, Axis Communications AB
1da177e4 LT	14	* All rights reserved.
	15	*
	16	* Author: Tobias Anderberg <tobiasa@axis.com>.
	17	*
1da177e4 LT	18	*/
1da177e4 LT	19
1da177e4 LT	20	#include <linux/module.h>
	21	#include <linux/kernel.h>
	22	#include <linux/types.h>
	23	#include <linux/sched.h>
	24	#include <linux/init.h>
	25	#include <linux/fs.h>
	26	#include <linux/ioctl.h>
	27	#include <linux/delay.h>
	28	#include <linux/bcd.h>
34a8e501	29	#include <linux/mutex.h>
f35d7764	30	#include <linux/smp_lock.h>
1da177e4 LT	31
	32	#include <asm/uaccess.h>
	33	#include <asm/system.h>
	34	#include <asm/io.h>
1da177e4	35	#include <asm/rtc.h>
34a8e501	36
1da177e4 LT	37	#include "i2c.h"
1da177e4 LT	38
34a8e501 JN	39	#define PCF8563_MAJOR 121 /* Local major number. */
34a8e501 JN	40	#define DEVICE_NAME "rtc" /* Name which is registered in /proc/devices. */
1da177e4	41	#define PCF8563_NAME "PCF8563"
34a8e501	42	#define DRIVER_VERSION "$Revision: 1.24 $"
1da177e4 LT	43
	44	/* I2C bus slave registers. */
	45	#define RTC_I2C_READ 0xa3
	46	#define RTC_I2C_WRITE 0xa2
	47
	48	/* Two simple wrapper macros, saves a few keystrokes. */
	49	#define rtc_read(x) i2c_readreg(RTC_I2C_READ, x)
	50	#define rtc_write(x,y) i2c_writereg(RTC_I2C_WRITE, x, y)
7e920426	51
34a8e501 JN	52	static DEFINE_MUTEX(rtc_lock); /* Protect state etc */
34a8e501 JN	53
1da177e4 LT	54	static const unsigned char days_in_month[] =
	55	{ 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
	56
f35d7764	57	static long pcf8563_unlocked_ioctl(struct file *, unsigned int, unsigned long);
1da177e4	58
34a8e501 JN	59	/* Cache VL bit value read at driver init since writing the RTC_SECOND
	60	* register clears the VL status.
	61	*/
	62	static int voltage_low;
	63
5dfe4c96	64	static const struct file_operations pcf8563_fops = {
1da177e4	65	.owner = THIS_MODULE,
f35d7764	66	.unlocked_ioctl = pcf8563_unlocked_ioctl,
1da177e4 LT	67	};
	68
	69	unsigned char
34a8e501	70	pcf8563_readreg(int reg)
1da177e4	71	{
34a8e501 JN	72	unsigned char res = rtc_read(reg);
	73
	74	/* The PCF8563 does not return 0 for unimplemented bits. */
	75	switch (reg) {
	76	case RTC_SECONDS:
	77	case RTC_MINUTES:
	78	res &= 0x7F;
	79	break;
	80	case RTC_HOURS:
	81	case RTC_DAY_OF_MONTH:
	82	res &= 0x3F;
	83	break;
	84	case RTC_WEEKDAY:
	85	res &= 0x07;
	86	break;
	87	case RTC_MONTH:
	88	res &= 0x1F;
	89	break;
	90	case RTC_CONTROL1:
	91	res &= 0xA8;
	92	break;
	93	case RTC_CONTROL2:
	94	res &= 0x1F;
	95	break;
	96	case RTC_CLOCKOUT_FREQ:
	97	case RTC_TIMER_CONTROL:
	98	res &= 0x83;
	99	break;
1da177e4 LT	100	}
	101	return res;
	102	}
	103
	104	void
34a8e501	105	pcf8563_writereg(int reg, unsigned char val)
1da177e4	106	{
1da177e4 LT	107	rtc_write(reg, val);
	108	}
	109
	110	void
	111	get_rtc_time(struct rtc_time *tm)
	112	{
34a8e501 JN	113	tm->tm_sec = rtc_read(RTC_SECONDS);
34a8e501 JN	114	tm->tm_min = rtc_read(RTC_MINUTES);
1da177e4 LT	115	tm->tm_hour = rtc_read(RTC_HOURS);
1da177e4 LT	116	tm->tm_mday = rtc_read(RTC_DAY_OF_MONTH);
34a8e501 JN	117	tm->tm_wday = rtc_read(RTC_WEEKDAY);
34a8e501 JN	118	tm->tm_mon = rtc_read(RTC_MONTH);
1da177e4 LT	119	tm->tm_year = rtc_read(RTC_YEAR);
1da177e4 LT	120
34a8e501 JN	121	if (tm->tm_sec & 0x80) {
	122	printk(KERN_ERR "%s: RTC Voltage Low - reliable date/time "
	123	"information is no longer guaranteed!\n", PCF8563_NAME);
	124	}
1da177e4	125
4110a0d6	126	tm->tm_year = bcd2bin(tm->tm_year) +
34a8e501 JN	127	((tm->tm_mon & 0x80) ? 100 : 0);
	128	tm->tm_sec &= 0x7F;
	129	tm->tm_min &= 0x7F;
	130	tm->tm_hour &= 0x3F;
	131	tm->tm_mday &= 0x3F;
	132	tm->tm_wday &= 0x07; /* Not coded in BCD. */
	133	tm->tm_mon &= 0x1F;
1da177e4	134
4110a0d6 AB	135	tm->tm_sec = bcd2bin(tm->tm_sec);
	136	tm->tm_min = bcd2bin(tm->tm_min);
	137	tm->tm_hour = bcd2bin(tm->tm_hour);
	138	tm->tm_mday = bcd2bin(tm->tm_mday);
	139	tm->tm_mon = bcd2bin(tm->tm_mon);
1da177e4 LT	140	tm->tm_mon--; /* Month is 1..12 in RTC but 0..11 in linux */
	141	}
	142
	143	int __init
	144	pcf8563_init(void)
	145	{
34a8e501 JN	146	static int res;
	147	static int first = 1;
	148
	149	if (!first)
	150	return res;
	151	first = 0;
	152
	153	/* Initiate the i2c protocol. */
	154	res = i2c_init();
	155	if (res < 0) {
	156	printk(KERN_CRIT "pcf8563_init: Failed to init i2c.\n");
	157	return res;
7e920426	158	}
1da177e4 LT	159
	160	/*
	161	* First of all we need to reset the chip. This is done by
34a8e501 JN	162	* clearing control1, control2 and clk freq and resetting
34a8e501 JN	163	* all alarms.
1da177e4 LT	164	*/
	165	if (rtc_write(RTC_CONTROL1, 0x00) < 0)
	166	goto err;
	167
	168	if (rtc_write(RTC_CONTROL2, 0x00) < 0)
	169	goto err;
	170
	171	if (rtc_write(RTC_CLOCKOUT_FREQ, 0x00) < 0)
	172	goto err;
	173
34a8e501	174	if (rtc_write(RTC_TIMER_CONTROL, 0x03) < 0)
1da177e4	175	goto err;
34a8e501	176
1da177e4	177	/* Reset the alarms. */
34a8e501	178	if (rtc_write(RTC_MINUTE_ALARM, 0x80) < 0)
1da177e4	179	goto err;
34a8e501 JN	180
34a8e501 JN	181	if (rtc_write(RTC_HOUR_ALARM, 0x80) < 0)
1da177e4	182	goto err;
34a8e501 JN	183
34a8e501 JN	184	if (rtc_write(RTC_DAY_ALARM, 0x80) < 0)
1da177e4	185	goto err;
34a8e501 JN	186
34a8e501 JN	187	if (rtc_write(RTC_WEEKDAY_ALARM, 0x80) < 0)
1da177e4	188	goto err;
34a8e501 JN	189
	190	/* Check for low voltage, and warn about it. */
	191	if (rtc_read(RTC_SECONDS) & 0x80) {
	192	voltage_low = 1;
	193	printk(KERN_WARNING "%s: RTC Voltage Low - reliable "
	194	"date/time information is no longer guaranteed!\n",
	195	PCF8563_NAME);
	196	}
	197
	198	return res;
1da177e4 LT	199
	200	err:
	201	printk(KERN_INFO "%s: Error initializing chip.\n", PCF8563_NAME);
34a8e501 JN	202	res = -1;
34a8e501 JN	203	return res;
1da177e4 LT	204	}
	205
	206	void __exit
	207	pcf8563_exit(void)
	208	{
68fc4fab	209	unregister_chrdev(PCF8563_MAJOR, DEVICE_NAME);
1da177e4 LT	210	}
	211
	212	/*
	213	* ioctl calls for this driver. Why return -ENOTTY upon error? Because
	214	* POSIX says so!
	215	*/
f35d7764	216	static int pcf8563_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1da177e4 LT	217	{
	218	/* Some sanity checks. */
	219	if (_IOC_TYPE(cmd) != RTC_MAGIC)
	220	return -ENOTTY;
	221
	222	if (_IOC_NR(cmd) > RTC_MAX_IOCTL)
	223	return -ENOTTY;
	224
	225	switch (cmd) {
34a8e501 JN	226	case RTC_RD_TIME:
	227	{
	228	struct rtc_time tm;
1da177e4	229
34a8e501 JN	230	mutex_lock(&rtc_lock);
	231	memset(&tm, 0, sizeof tm);
	232	get_rtc_time(&tm);
1da177e4	233
34a8e501 JN	234	if (copy_to_user((struct rtc_time *) arg, &tm,
34a8e501 JN	235	sizeof tm)) {
9be48a94	236	mutex_unlock(&rtc_lock);
34a8e501 JN	237	return -EFAULT;
	238	}
	239
	240	mutex_unlock(&rtc_lock);
1da177e4	241
34a8e501 JN	242	return 0;
	243	}
	244	case RTC_SET_TIME:
	245	{
	246	int leap;
	247	int year;
	248	int century;
	249	struct rtc_time tm;
	250
	251	memset(&tm, 0, sizeof tm);
	252	if (!capable(CAP_SYS_TIME))
	253	return -EPERM;
	254
	255	if (copy_from_user(&tm, (struct rtc_time *) arg, sizeof tm))
	256	return -EFAULT;
	257
	258	/* Convert from struct tm to struct rtc_time. */
	259	tm.tm_year += 1900;
	260	tm.tm_mon += 1;
	261
	262	/*
	263	* Check if tm.tm_year is a leap year. A year is a leap
	264	* year if it is divisible by 4 but not 100, except
	265	* that years divisible by 400 _are_ leap years.
	266	*/
	267	year = tm.tm_year;
	268	leap = (tm.tm_mon == 2) &&
	269	((year % 4 == 0 && year % 100 != 0) \|\| year % 400 == 0);
	270
	271	/* Perform some sanity checks. */
	272	if ((tm.tm_year < 1970) \|\|
	273	(tm.tm_mon > 12) \|\|
	274	(tm.tm_mday == 0) \|\|
	275	(tm.tm_mday > days_in_month[tm.tm_mon] + leap) \|\|
	276	(tm.tm_wday >= 7) \|\|
	277	(tm.tm_hour >= 24) \|\|
	278	(tm.tm_min >= 60) \|\|
	279	(tm.tm_sec >= 60))
	280	return -EINVAL;
	281
	282	century = (tm.tm_year >= 2000) ? 0x80 : 0;
	283	tm.tm_year = tm.tm_year % 100;
	284
4110a0d6 AB	285	tm.tm_year = bin2bcd(tm.tm_year);
	286	tm.tm_mon = bin2bcd(tm.tm_mon);
	287	tm.tm_mday = bin2bcd(tm.tm_mday);
	288	tm.tm_hour = bin2bcd(tm.tm_hour);
	289	tm.tm_min = bin2bcd(tm.tm_min);
	290	tm.tm_sec = bin2bcd(tm.tm_sec);
34a8e501 JN	291	tm.tm_mon \|= century;
	292
	293	mutex_lock(&rtc_lock);
	294
	295	rtc_write(RTC_YEAR, tm.tm_year);
	296	rtc_write(RTC_MONTH, tm.tm_mon);
	297	rtc_write(RTC_WEEKDAY, tm.tm_wday); /* Not coded in BCD. */
	298	rtc_write(RTC_DAY_OF_MONTH, tm.tm_mday);
	299	rtc_write(RTC_HOURS, tm.tm_hour);
	300	rtc_write(RTC_MINUTES, tm.tm_min);
	301	rtc_write(RTC_SECONDS, tm.tm_sec);
	302
	303	mutex_unlock(&rtc_lock);
	304
	305	return 0;
	306	}
	307	case RTC_VL_READ:
	308	if (voltage_low) {
	309	printk(KERN_ERR "%s: RTC Voltage Low - "
	310	"reliable date/time information is no "
	311	"longer guaranteed!\n", PCF8563_NAME);
1da177e4 LT	312	}
1da177e4 LT	313
34a8e501 JN	314	if (copy_to_user((int *) arg, &voltage_low, sizeof(int)))
	315	return -EFAULT;
	316	return 0;
	317
	318	case RTC_VL_CLR:
	319	{
	320	/* Clear the VL bit in the seconds register in case
	321	* the time has not been set already (which would
	322	* have cleared it). This does not really matter
	323	* because of the cached voltage_low value but do it
	324	* anyway for consistency. */
	325
	326	int ret = rtc_read(RTC_SECONDS);
	327
	328	rtc_write(RTC_SECONDS, (ret & 0x7F));
	329
	330	/* Clear the cached value. */
	331	voltage_low = 0;
	332
	333	return 0;
	334	}
	335	default:
	336	return -ENOTTY;
1da177e4 LT	337	}
	338
	339	return 0;
	340	}
	341
f35d7764 AB	342	static long pcf8563_unlocked_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
	343	{
	344	int ret;
	345
	346	lock_kernel();
	347	return pcf8563_ioctl(filp, cmd, arg);
	348	unlock_kernel();
	349
	350	return ret;
	351	}
	352
34a8e501	353	static int __init pcf8563_register(void)
1da177e4	354	{
34a8e501 JN	355	if (pcf8563_init() < 0) {
	356	printk(KERN_INFO "%s: Unable to initialize Real-Time Clock "
	357	"Driver, %s\n", PCF8563_NAME, DRIVER_VERSION);
	358	return -1;
	359	}
	360
1da177e4	361	if (register_chrdev(PCF8563_MAJOR, DEVICE_NAME, &pcf8563_fops) < 0) {
e34f80cd	362	printk(KERN_INFO "%s: Unable to get major number %d for RTC device.\n",
1da177e4 LT	363	PCF8563_NAME, PCF8563_MAJOR);
	364	return -1;
	365	}
	366
34a8e501 JN	367	printk(KERN_INFO "%s Real-Time Clock Driver, %s\n", PCF8563_NAME,
	368	DRIVER_VERSION);
	369
	370	/* Check for low voltage, and warn about it. */
	371	if (voltage_low) {
	372	printk(KERN_WARNING "%s: RTC Voltage Low - reliable date/time "
	373	"information is no longer guaranteed!\n", PCF8563_NAME);
	374	}
	375
	376	return 0;
1da177e4 LT	377	}
	378
	379	module_init(pcf8563_register);
	380	module_exit(pcf8563_exit);