[mirror_ubuntu-kernels.git] / drivers / watchdog / it8712f_wdt.c

/*
 *	IT8712F "Smart Guardian" Watchdog support
 *
 *	Copyright (c) 2006-2007 Jorge Boncompte - DTI2 <jorge@dti2.net>
 *
 *	Based on info and code taken from:
 *
 *	drivers/char/watchdog/scx200_wdt.c
 *	drivers/hwmon/it87.c
 *	IT8712F EC-LPC I/O Preliminary Specification 0.8.2
 *	IT8712F EC-LPC I/O Preliminary Specification 0.9.3
 *
 *	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 author(s) of this software shall not be held liable for damages
 *	of any nature resulting due to the use of this software. This
 *	software is provided AS-IS with no warranties.
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/fs.h>
#include <linux/pci.h>
#include <linux/spinlock.h>

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

#define NAME "it8712f_wdt"

MODULE_AUTHOR("Jorge Boncompte - DTI2 <jorge@dti2.net>");
MODULE_DESCRIPTION("IT8712F Watchdog Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);

static int max_units = 255;
static int margin = 60;		/* in seconds */
module_param(margin, int, 0);
MODULE_PARM_DESC(margin, "Watchdog margin in seconds");

static int nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");

static struct semaphore it8712f_wdt_sem;
static unsigned expect_close;
static spinlock_t io_lock;
static unsigned char revision;

/* Dog Food address - We use the game port address */
static unsigned short address;

#define	REG		0x2e	/* The register to read/write */
#define	VAL		0x2f	/* The value to read/write */

#define	LDN		0x07	/* Register: Logical device select */
#define	DEVID		0x20	/* Register: Device ID */
#define	DEVREV		0x22	/* Register: Device Revision */
#define ACT_REG		0x30	/* LDN Register: Activation */
#define BASE_REG	0x60	/* LDN Register: Base address */

#define IT8712F_DEVID	0x8712

#define LDN_GPIO	0x07	/* GPIO and Watch Dog Timer */
#define LDN_GAME 	0x09	/* Game Port */

#define WDT_CONTROL	0x71	/* WDT Register: Control */
#define WDT_CONFIG	0x72	/* WDT Register: Configuration */
#define WDT_TIMEOUT	0x73	/* WDT Register: Timeout Value */

#define WDT_RESET_GAME	0x10
#define WDT_RESET_KBD	0x20
#define WDT_RESET_MOUSE	0x40
#define WDT_RESET_CIR	0x80

#define WDT_UNIT_SEC	0x80	/* If 0 in MINUTES */

#define WDT_OUT_PWROK	0x10
#define WDT_OUT_KRST	0x40

static int
superio_inb(int reg)
{
	outb(reg, REG);
	return inb(VAL);
}

static void
superio_outb(int val, int reg)
{
	outb(reg, REG);
	outb(val, VAL);
}

static int
superio_inw(int reg)
{
	int val;
	outb(reg++, REG);
	val = inb(VAL) << 8;
	outb(reg, REG);
	val |= inb(VAL);
	return val;
}

static void
superio_outw(int val, int reg)
{
	outb(reg++, REG);
	outb((val >> 8) & 0xff, VAL);
	outb(reg, REG);
	outb(val & 0xff, VAL);
}

static inline void
superio_select(int ldn)
{
	outb(LDN, REG);
	outb(ldn, VAL);
}

static inline void
superio_enter(void)
{
	spin_lock(&io_lock);
	outb(0x87, REG);
	outb(0x01, REG);
	outb(0x55, REG);
	outb(0x55, REG);
}

static inline void
superio_exit(void)
{
	outb(0x02, REG);
	outb(0x02, VAL);
	spin_unlock(&io_lock);
}

static inline void
it8712f_wdt_ping(void)
{
	inb(address);
}

static void
it8712f_wdt_update_margin(void)
{
	int config = WDT_OUT_KRST | WDT_OUT_PWROK;
	int units = margin;

	/* Switch to minutes precision if the configured margin
	 * value does not fit within the register width.
	 */
	if (units <= max_units) {
		config |= WDT_UNIT_SEC; /* else UNIT is MINUTES */
		printk(KERN_INFO NAME ": timer margin %d seconds\n", units);
	} else {
		units /= 60;
		printk(KERN_INFO NAME ": timer margin %d minutes\n", units);
	}
	superio_outb(config, WDT_CONFIG);

	if (revision >= 0x08)
		superio_outw(units, WDT_TIMEOUT);
	else
		superio_outb(units, WDT_TIMEOUT);
}

static int
it8712f_wdt_get_status(void)
{
	if (superio_inb(WDT_CONTROL) & 0x01)
		return WDIOF_CARDRESET;
	else
		return 0;
}

static void
it8712f_wdt_enable(void)
{
	printk(KERN_DEBUG NAME ": enabling watchdog timer\n");
	superio_enter();
	superio_select(LDN_GPIO);

	superio_outb(WDT_RESET_GAME, WDT_CONTROL);

	it8712f_wdt_update_margin();

	superio_exit();

	it8712f_wdt_ping();
}

static void
it8712f_wdt_disable(void)
{
	printk(KERN_DEBUG NAME ": disabling watchdog timer\n");

	superio_enter();
	superio_select(LDN_GPIO);

	superio_outb(0, WDT_CONFIG);
	superio_outb(0, WDT_CONTROL);
	superio_outb(0, WDT_TIMEOUT);

	superio_exit();
}

static int
it8712f_wdt_notify(struct notifier_block *this,
		    unsigned long code, void *unused)
{
	if (code == SYS_HALT || code == SYS_POWER_OFF)
		if (!nowayout)
			it8712f_wdt_disable();

	return NOTIFY_DONE;
}

static struct notifier_block it8712f_wdt_notifier = {
	.notifier_call = it8712f_wdt_notify,
};

static ssize_t
it8712f_wdt_write(struct file *file, const char __user *data,
	size_t len, loff_t *ppos)
{
	/* check for a magic close character */
	if (len) {
		size_t i;

		it8712f_wdt_ping();

		expect_close = 0;
		for (i = 0; i < len; ++i) {
			char c;
			if (get_user(c, data+i))
				return -EFAULT;
			if (c == 'V')
				expect_close = 42;
		}
	}

	return len;
}

static int
it8712f_wdt_ioctl(struct inode *inode, struct file *file,
	unsigned int cmd, unsigned long arg)
{
	void __user *argp = (void __user *)arg;
	int __user *p = argp;
	static struct watchdog_info ident = {
		.identity = "IT8712F Watchdog",
		.firmware_version = 1,
		.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
	};
	int value;

	switch (cmd) {
	default:
		return -ENOTTY;
	case WDIOC_GETSUPPORT:
		if (copy_to_user(argp, &ident, sizeof(ident)))
			return -EFAULT;
		return 0;
	case WDIOC_GETSTATUS:
		superio_enter();
		superio_select(LDN_GPIO);

		value = it8712f_wdt_get_status();

		superio_exit();

		return put_user(value, p);
	case WDIOC_GETBOOTSTATUS:
		return put_user(0, p);
	case WDIOC_KEEPALIVE:
		it8712f_wdt_ping();
		return 0;
	case WDIOC_SETTIMEOUT:
		if (get_user(value, p))
			return -EFAULT;
		if (value < 1)
			return -EINVAL;
		if (value > (max_units * 60))
			return -EINVAL;
		margin = value;
		superio_enter();
		superio_select(LDN_GPIO);

		it8712f_wdt_update_margin();

		superio_exit();
		it8712f_wdt_ping();
		/* Fall through */
	case WDIOC_GETTIMEOUT:
		if (put_user(margin, p))
			return -EFAULT;
		return 0;
	}
}

static int
it8712f_wdt_open(struct inode *inode, struct file *file)
{
	/* only allow one at a time */
	if (down_trylock(&it8712f_wdt_sem))
		return -EBUSY;
	it8712f_wdt_enable();

	return nonseekable_open(inode, file);
}

static int
it8712f_wdt_release(struct inode *inode, struct file *file)
{
	if (expect_close != 42) {
		printk(KERN_WARNING NAME
			": watchdog device closed unexpectedly, will not"
			" disable the watchdog timer\n");
	} else if (!nowayout) {
		it8712f_wdt_disable();
	}
	expect_close = 0;
	up(&it8712f_wdt_sem);

	return 0;
}

static const struct file_operations it8712f_wdt_fops = {
	.owner = THIS_MODULE,
	.llseek = no_llseek,
	.write = it8712f_wdt_write,
	.ioctl = it8712f_wdt_ioctl,
	.open = it8712f_wdt_open,
	.release = it8712f_wdt_release,
};

static struct miscdevice it8712f_wdt_miscdev = {
	.minor = WATCHDOG_MINOR,
	.name = "watchdog",
	.fops = &it8712f_wdt_fops,
};

static int __init
it8712f_wdt_find(unsigned short *address)
{
	int err = -ENODEV;
	int chip_type;

	superio_enter();
	chip_type = superio_inw(DEVID);
	if (chip_type != IT8712F_DEVID)
		goto exit;

	superio_select(LDN_GAME);
	superio_outb(1, ACT_REG);
	if (!(superio_inb(ACT_REG) & 0x01)) {
		printk(KERN_ERR NAME ": Device not activated, skipping\n");
		goto exit;
	}

	*address = superio_inw(BASE_REG);
	if (*address == 0) {
		printk(KERN_ERR NAME ": Base address not set, skipping\n");
		goto exit;
	}

	err = 0;
	revision = superio_inb(DEVREV) & 0x0f;

	/* Later revisions have 16-bit values per datasheet 0.9.1 */
	if (revision >= 0x08)
		max_units = 65535;

	if (margin > (max_units * 60))
		margin = (max_units * 60);

	printk(KERN_INFO NAME ": Found IT%04xF chip revision %d - "
		"using DogFood address 0x%x\n",
		chip_type, revision, *address);

exit:
	superio_exit();
	return err;
}

static int __init
it8712f_wdt_init(void)
{
	int err = 0;

	spin_lock_init(&io_lock);

	if (it8712f_wdt_find(&address))
		return -ENODEV;

	if (!request_region(address, 1, "IT8712F Watchdog")) {
		printk(KERN_WARNING NAME ": watchdog I/O region busy\n");
		return -EBUSY;
	}

	it8712f_wdt_disable();

	sema_init(&it8712f_wdt_sem, 1);

	err = register_reboot_notifier(&it8712f_wdt_notifier);
	if (err) {
		printk(KERN_ERR NAME ": unable to register reboot notifier\n");
		goto out;
	}

	err = misc_register(&it8712f_wdt_miscdev);
	if (err) {
		printk(KERN_ERR NAME
			": cannot register miscdev on minor=%d (err=%d)\n",
			WATCHDOG_MINOR, err);
		goto reboot_out;
	}

	return 0;


reboot_out:
	unregister_reboot_notifier(&it8712f_wdt_notifier);
out:
	release_region(address, 1);
	return err;
}

static void __exit
it8712f_wdt_exit(void)
{
	misc_deregister(&it8712f_wdt_miscdev);
	unregister_reboot_notifier(&it8712f_wdt_notifier);
	release_region(address, 1);
}

module_init(it8712f_wdt_init);
module_exit(it8712f_wdt_exit);
Commit	Line	Data
38ff6fd2 JBD	1	/*
	2	* IT8712F "Smart Guardian" Watchdog support
	3	*
	4	* Copyright (c) 2006-2007 Jorge Boncompte - DTI2 <jorge@dti2.net>
	5	*
	6	* Based on info and code taken from:
	7	*
	8	* drivers/char/watchdog/scx200_wdt.c
	9	* drivers/hwmon/it87.c
5e699608 AP	10	* IT8712F EC-LPC I/O Preliminary Specification 0.8.2
5e699608 AP	11	* IT8712F EC-LPC I/O Preliminary Specification 0.9.3
38ff6fd2 JBD	12	*
	13	* This program is free software; you can redistribute it and/or
	14	* modify it under the terms of the GNU General Public License as
	15	* published by the Free Software Foundation; either version 2 of the
	16	* License, or (at your option) any later version.
	17	*
	18	* The author(s) of this software shall not be held liable for damages
	19	* of any nature resulting due to the use of this software. This
	20	* software is provided AS-IS with no warranties.
	21	*/
	22
	23	#include <linux/module.h>
	24	#include <linux/moduleparam.h>
	25	#include <linux/init.h>
	26	#include <linux/miscdevice.h>
	27	#include <linux/watchdog.h>
	28	#include <linux/notifier.h>
	29	#include <linux/reboot.h>
	30	#include <linux/fs.h>
	31	#include <linux/pci.h>
	32	#include <linux/spinlock.h>
	33
	34	#include <asm/uaccess.h>
	35	#include <asm/io.h>
	36
	37	#define NAME "it8712f_wdt"
	38
	39	MODULE_AUTHOR("Jorge Boncompte - DTI2 <jorge@dti2.net>");
	40	MODULE_DESCRIPTION("IT8712F Watchdog Driver");
	41	MODULE_LICENSE("GPL");
	42	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
	43
5e699608	44	static int max_units = 255;
38ff6fd2 JBD	45	static int margin = 60; /* in seconds */
	46	module_param(margin, int, 0);
	47	MODULE_PARM_DESC(margin, "Watchdog margin in seconds");
	48
	49	static int nowayout = WATCHDOG_NOWAYOUT;
	50	module_param(nowayout, int, 0);
	51	MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");
	52
	53	static struct semaphore it8712f_wdt_sem;
	54	static unsigned expect_close;
	55	static spinlock_t io_lock;
5e699608	56	static unsigned char revision;
38ff6fd2 JBD	57
	58	/* Dog Food address - We use the game port address */
	59	static unsigned short address;
	60
	61	#define REG 0x2e /* The register to read/write */
	62	#define VAL 0x2f /* The value to read/write */
	63
	64	#define LDN 0x07 /* Register: Logical device select */
	65	#define DEVID 0x20 /* Register: Device ID */
	66	#define DEVREV 0x22 /* Register: Device Revision */
	67	#define ACT_REG 0x30 /* LDN Register: Activation */
	68	#define BASE_REG 0x60 /* LDN Register: Base address */
	69
	70	#define IT8712F_DEVID 0x8712
	71
	72	#define LDN_GPIO 0x07 /* GPIO and Watch Dog Timer */
	73	#define LDN_GAME 0x09 /* Game Port */
	74
	75	#define WDT_CONTROL 0x71 /* WDT Register: Control */
	76	#define WDT_CONFIG 0x72 /* WDT Register: Configuration */
	77	#define WDT_TIMEOUT 0x73 /* WDT Register: Timeout Value */
	78
	79	#define WDT_RESET_GAME 0x10
	80	#define WDT_RESET_KBD 0x20
	81	#define WDT_RESET_MOUSE 0x40
	82	#define WDT_RESET_CIR 0x80
	83
	84	#define WDT_UNIT_SEC 0x80 /* If 0 in MINUTES */
	85
	86	#define WDT_OUT_PWROK 0x10
	87	#define WDT_OUT_KRST 0x40
	88
	89	static int
	90	superio_inb(int reg)
	91	{
	92	outb(reg, REG);
	93	return inb(VAL);
	94	}
	95
	96	static void
	97	superio_outb(int val, int reg)
	98	{
	99	outb(reg, REG);
	100	outb(val, VAL);
	101	}
	102
	103	static int
	104	superio_inw(int reg)
	105	{
	106	int val;
	107	outb(reg++, REG);
	108	val = inb(VAL) << 8;
	109	outb(reg, REG);
	110	val \|= inb(VAL);
	111	return val;
	112	}
	113
5e699608 AP	114	static void
	115	superio_outw(int val, int reg)
	116	{
	117	outb(reg++, REG);
	118	outb((val >> 8) & 0xff, VAL);
	119	outb(reg, REG);
	120	outb(val & 0xff, VAL);
	121	}
	122
38ff6fd2 JBD	123	static inline void
	124	superio_select(int ldn)
	125	{
	126	outb(LDN, REG);
	127	outb(ldn, VAL);
	128	}
	129
	130	static inline void
	131	superio_enter(void)
	132	{
	133	spin_lock(&io_lock);
	134	outb(0x87, REG);
	135	outb(0x01, REG);
	136	outb(0x55, REG);
	137	outb(0x55, REG);
	138	}
	139
	140	static inline void
	141	superio_exit(void)
	142	{
	143	outb(0x02, REG);
	144	outb(0x02, VAL);
	145	spin_unlock(&io_lock);
	146	}
	147
	148	static inline void
	149	it8712f_wdt_ping(void)
	150	{
	151	inb(address);
	152	}
	153
	154	static void
	155	it8712f_wdt_update_margin(void)
	156	{
	157	int config = WDT_OUT_KRST \| WDT_OUT_PWROK;
5e699608 AP	158	int units = margin;
	159
	160	/* Switch to minutes precision if the configured margin
	161	* value does not fit within the register width.
	162	*/
	163	if (units <= max_units) {
	164	config \|= WDT_UNIT_SEC; /* else UNIT is MINUTES */
	165	printk(KERN_INFO NAME ": timer margin %d seconds\n", units);
	166	} else {
	167	units /= 60;
	168	printk(KERN_INFO NAME ": timer margin %d minutes\n", units);
	169	}
38ff6fd2 JBD	170	superio_outb(config, WDT_CONFIG);
38ff6fd2 JBD	171
5e699608 AP	172	if (revision >= 0x08)
	173	superio_outw(units, WDT_TIMEOUT);
	174	else
	175	superio_outb(units, WDT_TIMEOUT);
	176	}
	177
	178	static int
	179	it8712f_wdt_get_status(void)
	180	{
	181	if (superio_inb(WDT_CONTROL) & 0x01)
	182	return WDIOF_CARDRESET;
	183	else
	184	return 0;
38ff6fd2 JBD	185	}
	186
	187	static void
	188	it8712f_wdt_enable(void)
	189	{
	190	printk(KERN_DEBUG NAME ": enabling watchdog timer\n");
	191	superio_enter();
	192	superio_select(LDN_GPIO);
	193
	194	superio_outb(WDT_RESET_GAME, WDT_CONTROL);
	195
	196	it8712f_wdt_update_margin();
	197
	198	superio_exit();
	199
	200	it8712f_wdt_ping();
	201	}
	202
	203	static void
	204	it8712f_wdt_disable(void)
	205	{
	206	printk(KERN_DEBUG NAME ": disabling watchdog timer\n");
	207
	208	superio_enter();
	209	superio_select(LDN_GPIO);
	210
	211	superio_outb(0, WDT_CONFIG);
	212	superio_outb(0, WDT_CONTROL);
	213	superio_outb(0, WDT_TIMEOUT);
	214
	215	superio_exit();
	216	}
	217
	218	static int
	219	it8712f_wdt_notify(struct notifier_block *this,
	220	unsigned long code, void *unused)
	221	{
	222	if (code == SYS_HALT \|\| code == SYS_POWER_OFF)
	223	if (!nowayout)
	224	it8712f_wdt_disable();
	225
	226	return NOTIFY_DONE;
	227	}
	228
	229	static struct notifier_block it8712f_wdt_notifier = {
	230	.notifier_call = it8712f_wdt_notify,
	231	};
	232
	233	static ssize_t
	234	it8712f_wdt_write(struct file file, const char __user data,
	235	size_t len, loff_t *ppos)
	236	{
	237	/* check for a magic close character */
	238	if (len) {
	239	size_t i;
	240
	241	it8712f_wdt_ping();
	242
	243	expect_close = 0;
	244	for (i = 0; i < len; ++i) {
	245	char c;
	246	if (get_user(c, data+i))
	247	return -EFAULT;
	248	if (c == 'V')
249	expect_close = 42;
250	}
251	}
252
253	return len;
254	}
255
256	static int
257	it8712f_wdt_ioctl(struct inode inode, struct file file,
258	unsigned int cmd, unsigned long arg)
259	{
260	void __user argp = (void __user )arg;
261	int __user *p = argp;
262	static struct watchdog_info ident = {
263	.identity = "IT8712F Watchdog",
264	.firmware_version = 1,
265	.options = WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING,
266	};
5e699608	267	int value;
38ff6fd2 JBD	268
	269	switch (cmd) {
	270	default:
	271	return -ENOTTY;
	272	case WDIOC_GETSUPPORT:
	273	if (copy_to_user(argp, &ident, sizeof(ident)))
	274	return -EFAULT;
	275	return 0;
	276	case WDIOC_GETSTATUS:
5e699608 AP	277	superio_enter();
	278	superio_select(LDN_GPIO);
	279
	280	value = it8712f_wdt_get_status();
	281
	282	superio_exit();
	283
	284	return put_user(value, p);
38ff6fd2 JBD	285	case WDIOC_GETBOOTSTATUS:
	286	return put_user(0, p);
	287	case WDIOC_KEEPALIVE:
	288	it8712f_wdt_ping();
	289	return 0;
	290	case WDIOC_SETTIMEOUT:
5e699608	291	if (get_user(value, p))
38ff6fd2	292	return -EFAULT;
5e699608 AP	293	if (value < 1)
	294	return -EINVAL;
	295	if (value > (max_units * 60))
38ff6fd2	296	return -EINVAL;
5e699608	297	margin = value;
38ff6fd2 JBD	298	superio_enter();
	299	superio_select(LDN_GPIO);
	300
	301	it8712f_wdt_update_margin();
	302
	303	superio_exit();
	304	it8712f_wdt_ping();
5e699608	305	/* Fall through */
38ff6fd2 JBD	306	case WDIOC_GETTIMEOUT:
	307	if (put_user(margin, p))
	308	return -EFAULT;
	309	return 0;
	310	}
	311	}
	312
	313	static int
	314	it8712f_wdt_open(struct inode inode, struct file file)
	315	{
	316	/* only allow one at a time */
	317	if (down_trylock(&it8712f_wdt_sem))
	318	return -EBUSY;
	319	it8712f_wdt_enable();
	320
	321	return nonseekable_open(inode, file);
	322	}
	323
	324	static int
	325	it8712f_wdt_release(struct inode inode, struct file file)
	326	{
	327	if (expect_close != 42) {
	328	printk(KERN_WARNING NAME
	329	": watchdog device closed unexpectedly, will not"
	330	" disable the watchdog timer\n");
	331	} else if (!nowayout) {
	332	it8712f_wdt_disable();
	333	}
	334	expect_close = 0;
	335	up(&it8712f_wdt_sem);
	336
	337	return 0;
	338	}
	339
b47a166e	340	static const struct file_operations it8712f_wdt_fops = {
38ff6fd2 JBD	341	.owner = THIS_MODULE,
	342	.llseek = no_llseek,
	343	.write = it8712f_wdt_write,
	344	.ioctl = it8712f_wdt_ioctl,
	345	.open = it8712f_wdt_open,
	346	.release = it8712f_wdt_release,
	347	};
	348
	349	static struct miscdevice it8712f_wdt_miscdev = {
	350	.minor = WATCHDOG_MINOR,
	351	.name = "watchdog",
	352	.fops = &it8712f_wdt_fops,
	353	};
	354
	355	static int __init
	356	it8712f_wdt_find(unsigned short *address)
	357	{
	358	int err = -ENODEV;
	359	int chip_type;
	360
	361	superio_enter();
	362	chip_type = superio_inw(DEVID);
	363	if (chip_type != IT8712F_DEVID)
	364	goto exit;
	365
	366	superio_select(LDN_GAME);
	367	superio_outb(1, ACT_REG);
	368	if (!(superio_inb(ACT_REG) & 0x01)) {
	369	printk(KERN_ERR NAME ": Device not activated, skipping\n");
	370	goto exit;
	371	}
	372
	373	*address = superio_inw(BASE_REG);
	374	if (*address == 0) {
	375	printk(KERN_ERR NAME ": Base address not set, skipping\n");
	376	goto exit;
	377	}
	378
	379	err = 0;
5e699608 AP	380	revision = superio_inb(DEVREV) & 0x0f;
	381
	382	/* Later revisions have 16-bit values per datasheet 0.9.1 */
	383	if (revision >= 0x08)
	384	max_units = 65535;
	385
	386	if (margin > (max_units * 60))
	387	margin = (max_units * 60);
	388
	389	printk(KERN_INFO NAME ": Found IT%04xF chip revision %d - "
38ff6fd2	390	"using DogFood address 0x%x\n",
5e699608	391	chip_type, revision, *address);
38ff6fd2 JBD	392
	393	exit:
	394	superio_exit();
	395	return err;
	396	}
	397
	398	static int __init
	399	it8712f_wdt_init(void)
	400	{
	401	int err = 0;
	402
	403	spin_lock_init(&io_lock);
	404
	405	if (it8712f_wdt_find(&address))
	406	return -ENODEV;
	407
	408	if (!request_region(address, 1, "IT8712F Watchdog")) {
	409	printk(KERN_WARNING NAME ": watchdog I/O region busy\n");
	410	return -EBUSY;
	411	}
	412
	413	it8712f_wdt_disable();
	414
	415	sema_init(&it8712f_wdt_sem, 1);
	416
	417	err = register_reboot_notifier(&it8712f_wdt_notifier);
	418	if (err) {
	419	printk(KERN_ERR NAME ": unable to register reboot notifier\n");
	420	goto out;
	421	}
	422
	423	err = misc_register(&it8712f_wdt_miscdev);
	424	if (err) {
	425	printk(KERN_ERR NAME
	426	": cannot register miscdev on minor=%d (err=%d)\n",
	427	WATCHDOG_MINOR, err);
	428	goto reboot_out;
	429	}
	430
	431	return 0;
	432
	433
	434	reboot_out:
	435	unregister_reboot_notifier(&it8712f_wdt_notifier);
	436	out:
	437	release_region(address, 1);
	438	return err;
	439	}
	440
	441	static void __exit
	442	it8712f_wdt_exit(void)
	443	{
	444	misc_deregister(&it8712f_wdt_miscdev);
	445	unregister_reboot_notifier(&it8712f_wdt_notifier);
	446	release_region(address, 1);
	447	}
	448
	449	module_init(it8712f_wdt_init);
	450	module_exit(it8712f_wdt_exit);