[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,
	.llseek		= noop_llseek,
};

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,
6038f373	67	.llseek = noop_llseek,
1da177e4 LT	68	};
	69
	70	unsigned char
34a8e501	71	pcf8563_readreg(int reg)
1da177e4	72	{
34a8e501 JN	73	unsigned char res = rtc_read(reg);
	74
	75	/* The PCF8563 does not return 0 for unimplemented bits. */
	76	switch (reg) {
	77	case RTC_SECONDS:
	78	case RTC_MINUTES:
	79	res &= 0x7F;
	80	break;
	81	case RTC_HOURS:
	82	case RTC_DAY_OF_MONTH:
	83	res &= 0x3F;
	84	break;
	85	case RTC_WEEKDAY:
	86	res &= 0x07;
	87	break;
	88	case RTC_MONTH:
	89	res &= 0x1F;
	90	break;
	91	case RTC_CONTROL1:
	92	res &= 0xA8;
	93	break;
	94	case RTC_CONTROL2:
	95	res &= 0x1F;
	96	break;
	97	case RTC_CLOCKOUT_FREQ:
	98	case RTC_TIMER_CONTROL:
	99	res &= 0x83;
	100	break;
1da177e4 LT	101	}
	102	return res;
	103	}
	104
	105	void
34a8e501	106	pcf8563_writereg(int reg, unsigned char val)
1da177e4	107	{
1da177e4 LT	108	rtc_write(reg, val);
	109	}
	110
	111	void
	112	get_rtc_time(struct rtc_time *tm)
	113	{
34a8e501 JN	114	tm->tm_sec = rtc_read(RTC_SECONDS);
34a8e501 JN	115	tm->tm_min = rtc_read(RTC_MINUTES);
1da177e4 LT	116	tm->tm_hour = rtc_read(RTC_HOURS);
1da177e4 LT	117	tm->tm_mday = rtc_read(RTC_DAY_OF_MONTH);
34a8e501 JN	118	tm->tm_wday = rtc_read(RTC_WEEKDAY);
34a8e501 JN	119	tm->tm_mon = rtc_read(RTC_MONTH);
1da177e4 LT	120	tm->tm_year = rtc_read(RTC_YEAR);
1da177e4 LT	121
34a8e501 JN	122	if (tm->tm_sec & 0x80) {
	123	printk(KERN_ERR "%s: RTC Voltage Low - reliable date/time "
	124	"information is no longer guaranteed!\n", PCF8563_NAME);
	125	}
1da177e4	126
4110a0d6	127	tm->tm_year = bcd2bin(tm->tm_year) +
34a8e501 JN	128	((tm->tm_mon & 0x80) ? 100 : 0);
	129	tm->tm_sec &= 0x7F;
	130	tm->tm_min &= 0x7F;
	131	tm->tm_hour &= 0x3F;
	132	tm->tm_mday &= 0x3F;
	133	tm->tm_wday &= 0x07; /* Not coded in BCD. */
	134	tm->tm_mon &= 0x1F;
1da177e4	135
4110a0d6 AB	136	tm->tm_sec = bcd2bin(tm->tm_sec);
	137	tm->tm_min = bcd2bin(tm->tm_min);
	138	tm->tm_hour = bcd2bin(tm->tm_hour);
	139	tm->tm_mday = bcd2bin(tm->tm_mday);
	140	tm->tm_mon = bcd2bin(tm->tm_mon);
1da177e4 LT	141	tm->tm_mon--; /* Month is 1..12 in RTC but 0..11 in linux */
	142	}
	143
	144	int __init
	145	pcf8563_init(void)
	146	{
34a8e501 JN	147	static int res;
	148	static int first = 1;
	149
	150	if (!first)
	151	return res;
	152	first = 0;
	153
	154	/* Initiate the i2c protocol. */
	155	res = i2c_init();
	156	if (res < 0) {
	157	printk(KERN_CRIT "pcf8563_init: Failed to init i2c.\n");
	158	return res;
7e920426	159	}
1da177e4 LT	160
	161	/*
	162	* First of all we need to reset the chip. This is done by
34a8e501 JN	163	* clearing control1, control2 and clk freq and resetting
34a8e501 JN	164	* all alarms.
1da177e4 LT	165	*/
	166	if (rtc_write(RTC_CONTROL1, 0x00) < 0)
	167	goto err;
	168
	169	if (rtc_write(RTC_CONTROL2, 0x00) < 0)
	170	goto err;
	171
	172	if (rtc_write(RTC_CLOCKOUT_FREQ, 0x00) < 0)
	173	goto err;
	174
34a8e501	175	if (rtc_write(RTC_TIMER_CONTROL, 0x03) < 0)
1da177e4	176	goto err;
34a8e501	177
1da177e4	178	/* Reset the alarms. */
34a8e501	179	if (rtc_write(RTC_MINUTE_ALARM, 0x80) < 0)
1da177e4	180	goto err;
34a8e501 JN	181
34a8e501 JN	182	if (rtc_write(RTC_HOUR_ALARM, 0x80) < 0)
1da177e4	183	goto err;
34a8e501 JN	184
34a8e501 JN	185	if (rtc_write(RTC_DAY_ALARM, 0x80) < 0)
1da177e4	186	goto err;
34a8e501 JN	187
34a8e501 JN	188	if (rtc_write(RTC_WEEKDAY_ALARM, 0x80) < 0)
1da177e4	189	goto err;
34a8e501 JN	190
	191	/* Check for low voltage, and warn about it. */
	192	if (rtc_read(RTC_SECONDS) & 0x80) {
	193	voltage_low = 1;
	194	printk(KERN_WARNING "%s: RTC Voltage Low - reliable "
	195	"date/time information is no longer guaranteed!\n",
	196	PCF8563_NAME);
	197	}
	198
	199	return res;
1da177e4 LT	200
	201	err:
	202	printk(KERN_INFO "%s: Error initializing chip.\n", PCF8563_NAME);
34a8e501 JN	203	res = -1;
34a8e501 JN	204	return res;
1da177e4 LT	205	}
	206
	207	void __exit
	208	pcf8563_exit(void)
	209	{
68fc4fab	210	unregister_chrdev(PCF8563_MAJOR, DEVICE_NAME);
1da177e4 LT	211	}
	212
	213	/*
	214	* ioctl calls for this driver. Why return -ENOTTY upon error? Because
	215	* POSIX says so!
	216	*/
f35d7764	217	static int pcf8563_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1da177e4 LT	218	{
	219	/* Some sanity checks. */
	220	if (_IOC_TYPE(cmd) != RTC_MAGIC)
	221	return -ENOTTY;
	222
	223	if (_IOC_NR(cmd) > RTC_MAX_IOCTL)
	224	return -ENOTTY;
	225
	226	switch (cmd) {
34a8e501 JN	227	case RTC_RD_TIME:
	228	{
	229	struct rtc_time tm;
1da177e4	230
34a8e501 JN	231	mutex_lock(&rtc_lock);
	232	memset(&tm, 0, sizeof tm);
	233	get_rtc_time(&tm);
1da177e4	234
34a8e501 JN	235	if (copy_to_user((struct rtc_time *) arg, &tm,
34a8e501 JN	236	sizeof tm)) {
9be48a94	237	mutex_unlock(&rtc_lock);
34a8e501 JN	238	return -EFAULT;
	239	}
	240
	241	mutex_unlock(&rtc_lock);
1da177e4	242
34a8e501 JN	243	return 0;
	244	}
	245	case RTC_SET_TIME:
	246	{
	247	int leap;
	248	int year;
	249	int century;
	250	struct rtc_time tm;
	251
	252	memset(&tm, 0, sizeof tm);
	253	if (!capable(CAP_SYS_TIME))
	254	return -EPERM;
	255
	256	if (copy_from_user(&tm, (struct rtc_time *) arg, sizeof tm))
	257	return -EFAULT;
	258
	259	/* Convert from struct tm to struct rtc_time. */
	260	tm.tm_year += 1900;
	261	tm.tm_mon += 1;
	262
	263	/*
	264	* Check if tm.tm_year is a leap year. A year is a leap
	265	* year if it is divisible by 4 but not 100, except
	266	* that years divisible by 400 _are_ leap years.
	267	*/
	268	year = tm.tm_year;
	269	leap = (tm.tm_mon == 2) &&
	270	((year % 4 == 0 && year % 100 != 0) \|\| year % 400 == 0);
	271
	272	/* Perform some sanity checks. */
	273	if ((tm.tm_year < 1970) \|\|
	274	(tm.tm_mon > 12) \|\|
	275	(tm.tm_mday == 0) \|\|
	276	(tm.tm_mday > days_in_month[tm.tm_mon] + leap) \|\|
	277	(tm.tm_wday >= 7) \|\|
	278	(tm.tm_hour >= 24) \|\|
	279	(tm.tm_min >= 60) \|\|
	280	(tm.tm_sec >= 60))
	281	return -EINVAL;
	282
	283	century = (tm.tm_year >= 2000) ? 0x80 : 0;
	284	tm.tm_year = tm.tm_year % 100;
	285
4110a0d6 AB	286	tm.tm_year = bin2bcd(tm.tm_year);
	287	tm.tm_mon = bin2bcd(tm.tm_mon);
	288	tm.tm_mday = bin2bcd(tm.tm_mday);
	289	tm.tm_hour = bin2bcd(tm.tm_hour);
	290	tm.tm_min = bin2bcd(tm.tm_min);
	291	tm.tm_sec = bin2bcd(tm.tm_sec);
34a8e501 JN	292	tm.tm_mon \|= century;
	293
	294	mutex_lock(&rtc_lock);
	295
	296	rtc_write(RTC_YEAR, tm.tm_year);
	297	rtc_write(RTC_MONTH, tm.tm_mon);
	298	rtc_write(RTC_WEEKDAY, tm.tm_wday); /* Not coded in BCD. */
	299	rtc_write(RTC_DAY_OF_MONTH, tm.tm_mday);
	300	rtc_write(RTC_HOURS, tm.tm_hour);
	301	rtc_write(RTC_MINUTES, tm.tm_min);
	302	rtc_write(RTC_SECONDS, tm.tm_sec);
	303
	304	mutex_unlock(&rtc_lock);
	305
	306	return 0;
	307	}
	308	case RTC_VL_READ:
	309	if (voltage_low) {
	310	printk(KERN_ERR "%s: RTC Voltage Low - "
	311	"reliable date/time information is no "
	312	"longer guaranteed!\n", PCF8563_NAME);
1da177e4 LT	313	}
1da177e4 LT	314
34a8e501 JN	315	if (copy_to_user((int *) arg, &voltage_low, sizeof(int)))
	316	return -EFAULT;
	317	return 0;
	318
	319	case RTC_VL_CLR:
	320	{
	321	/* Clear the VL bit in the seconds register in case
	322	* the time has not been set already (which would
	323	* have cleared it). This does not really matter
	324	* because of the cached voltage_low value but do it
	325	* anyway for consistency. */
	326
	327	int ret = rtc_read(RTC_SECONDS);
	328
	329	rtc_write(RTC_SECONDS, (ret & 0x7F));
	330
	331	/* Clear the cached value. */
	332	voltage_low = 0;
	333
	334	return 0;
	335	}
	336	default:
	337	return -ENOTTY;
1da177e4 LT	338	}
	339
	340	return 0;
	341	}
	342
f35d7764 AB	343	static long pcf8563_unlocked_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
	344	{
	345	int ret;
	346
	347	lock_kernel();
	348	return pcf8563_ioctl(filp, cmd, arg);
	349	unlock_kernel();
	350
	351	return ret;
	352	}
	353
34a8e501	354	static int __init pcf8563_register(void)
1da177e4	355	{
34a8e501 JN	356	if (pcf8563_init() < 0) {
	357	printk(KERN_INFO "%s: Unable to initialize Real-Time Clock "
	358	"Driver, %s\n", PCF8563_NAME, DRIVER_VERSION);
	359	return -1;
	360	}
	361
1da177e4	362	if (register_chrdev(PCF8563_MAJOR, DEVICE_NAME, &pcf8563_fops) < 0) {
e34f80cd	363	printk(KERN_INFO "%s: Unable to get major number %d for RTC device.\n",
1da177e4 LT	364	PCF8563_NAME, PCF8563_MAJOR);
	365	return -1;
	366	}
	367
34a8e501 JN	368	printk(KERN_INFO "%s Real-Time Clock Driver, %s\n", PCF8563_NAME,
	369	DRIVER_VERSION);
	370
	371	/* Check for low voltage, and warn about it. */
	372	if (voltage_low) {
	373	printk(KERN_WARNING "%s: RTC Voltage Low - reliable date/time "
	374	"information is no longer guaranteed!\n", PCF8563_NAME);
	375	}
	376
	377	return 0;
1da177e4 LT	378	}
	379
	380	module_init(pcf8563_register);
	381	module_exit(pcf8563_exit);