[net-next-2.6.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 <linux/uaccess.h>
#include <linux/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 unsigned long wdt_open;
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	/* Reset timer on read or write to game port */
#define WDT_RESET_KBD	0x20	/* Reset timer on keyboard interrupt */
#define WDT_RESET_MOUSE	0x40	/* Reset timer on mouse interrupt */
#define WDT_RESET_CIR	0x80	/* Reset timer on consumer IR interrupt */

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

#define WDT_OUT_PWROK	0x10	/* Pulse PWROK on timeout */
#define WDT_OUT_KRST	0x40	/* Pulse reset on timeout */

static int wdt_control_reg = WDT_RESET_GAME;
module_param(wdt_control_reg, int, 0);
MODULE_PARM_DESC(wdt_control_reg, "Value to write to watchdog control "
		"register. The default WDT_RESET_GAME resets the timer on "
		"game port reads that this driver generates. You can also "
		"use KBD, MOUSE or CIR if you have some external way to "
		"generate those interrupts.");

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 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)
{
	if (wdt_control_reg & WDT_RESET_GAME)
		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_outb(units >> 8, WDT_TIMEOUT + 1);
	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_control_reg, 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);
	if (revision >= 0x08)
		superio_outb(0, WDT_TIMEOUT + 1);
	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 long it8712f_wdt_ioctl(struct file *file, unsigned int cmd,
							unsigned long arg)
{
	void __user *argp = (void __user *)arg;
	int __user *p = argp;
	static const struct watchdog_info ident = {
		.identity = "IT8712F Watchdog",
		.firmware_version = 1,
		.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
						WDIOF_MAGICCLOSE,
	};
	int value;

	switch (cmd) {
	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;
	default:
		return -ENOTTY;
	}
}

static int it8712f_wdt_open(struct inode *inode, struct file *file)
{
	/* only allow one at a time */
	if (test_and_set_bit(0, &wdt_open))
		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;
	clear_bit(0, &wdt_open);

	return 0;
}

static const struct file_operations it8712f_wdt_fops = {
	.owner = THIS_MODULE,
	.llseek = no_llseek,
	.write = it8712f_wdt_write,
	.unlocked_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();

	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>
d6547378 AC	33	#include <linux/uaccess.h>
d6547378 AC	34	#include <linux/io.h>
38ff6fd2 JBD	35
	36	#define NAME "it8712f_wdt"
	37
	38	MODULE_AUTHOR("Jorge Boncompte - DTI2 <jorge@dti2.net>");
	39	MODULE_DESCRIPTION("IT8712F Watchdog Driver");
	40	MODULE_LICENSE("GPL");
	41	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
	42
5e699608	43	static int max_units = 255;
38ff6fd2 JBD	44	static int margin = 60; /* in seconds */
	45	module_param(margin, int, 0);
	46	MODULE_PARM_DESC(margin, "Watchdog margin in seconds");
	47
	48	static int nowayout = WATCHDOG_NOWAYOUT;
	49	module_param(nowayout, int, 0);
	50	MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");
	51
d6547378	52	static unsigned long wdt_open;
38ff6fd2 JBD	53	static unsigned expect_close;
38ff6fd2 JBD	54	static spinlock_t io_lock;
5e699608	55	static unsigned char revision;
38ff6fd2 JBD	56
	57	/* Dog Food address - We use the game port address */
	58	static unsigned short address;
	59
	60	#define REG 0x2e /* The register to read/write */
	61	#define VAL 0x2f /* The value to read/write */
	62
	63	#define LDN 0x07 /* Register: Logical device select */
	64	#define DEVID 0x20 /* Register: Device ID */
	65	#define DEVREV 0x22 /* Register: Device Revision */
	66	#define ACT_REG 0x30 /* LDN Register: Activation */
	67	#define BASE_REG 0x60 /* LDN Register: Base address */
	68
	69	#define IT8712F_DEVID 0x8712
	70
	71	#define LDN_GPIO 0x07 /* GPIO and Watch Dog Timer */
	72	#define LDN_GAME 0x09 /* Game Port */
	73
	74	#define WDT_CONTROL 0x71 /* WDT Register: Control */
	75	#define WDT_CONFIG 0x72 /* WDT Register: Configuration */
	76	#define WDT_TIMEOUT 0x73 /* WDT Register: Timeout Value */
	77
f0fc1074 TJL	78	#define WDT_RESET_GAME 0x10 /* Reset timer on read or write to game port */
	79	#define WDT_RESET_KBD 0x20 /* Reset timer on keyboard interrupt */
	80	#define WDT_RESET_MOUSE 0x40 /* Reset timer on mouse interrupt */
	81	#define WDT_RESET_CIR 0x80 /* Reset timer on consumer IR interrupt */
38ff6fd2 JBD	82
	83	#define WDT_UNIT_SEC 0x80 /* If 0 in MINUTES */
	84
f0fc1074 TJL	85	#define WDT_OUT_PWROK 0x10 /* Pulse PWROK on timeout */
f0fc1074 TJL	86	#define WDT_OUT_KRST 0x40 /* Pulse reset on timeout */
38ff6fd2	87
a422088d TJL	88	static int wdt_control_reg = WDT_RESET_GAME;
	89	module_param(wdt_control_reg, int, 0);
	90	MODULE_PARM_DESC(wdt_control_reg, "Value to write to watchdog control "
	91	"register. The default WDT_RESET_GAME resets the timer on "
	92	"game port reads that this driver generates. You can also "
	93	"use KBD, MOUSE or CIR if you have some external way to "
	94	"generate those interrupts.");
	95
d6547378	96	static int superio_inb(int reg)
38ff6fd2 JBD	97	{
	98	outb(reg, REG);
	99	return inb(VAL);
	100	}
	101
d6547378	102	static void superio_outb(int val, int reg)
38ff6fd2 JBD	103	{
	104	outb(reg, REG);
	105	outb(val, VAL);
	106	}
	107
d6547378	108	static int superio_inw(int reg)
38ff6fd2 JBD	109	{
	110	int val;
	111	outb(reg++, REG);
	112	val = inb(VAL) << 8;
	113	outb(reg, REG);
	114	val \|= inb(VAL);
	115	return val;
	116	}
	117
d6547378	118	static inline void superio_select(int ldn)
38ff6fd2 JBD	119	{
	120	outb(LDN, REG);
	121	outb(ldn, VAL);
	122	}
	123
d6547378	124	static inline void superio_enter(void)
38ff6fd2 JBD	125	{
	126	spin_lock(&io_lock);
	127	outb(0x87, REG);
	128	outb(0x01, REG);
	129	outb(0x55, REG);
	130	outb(0x55, REG);
	131	}
	132
d6547378	133	static inline void superio_exit(void)
38ff6fd2 JBD	134	{
	135	outb(0x02, REG);
	136	outb(0x02, VAL);
	137	spin_unlock(&io_lock);
	138	}
	139
d6547378	140	static inline void it8712f_wdt_ping(void)
38ff6fd2	141	{
a422088d TJL	142	if (wdt_control_reg & WDT_RESET_GAME)
a422088d TJL	143	inb(address);
38ff6fd2 JBD	144	}
38ff6fd2 JBD	145
d6547378	146	static void it8712f_wdt_update_margin(void)
38ff6fd2 JBD	147	{
38ff6fd2 JBD	148	int config = WDT_OUT_KRST \| WDT_OUT_PWROK;
5e699608 AP	149	int units = margin;
	150
	151	/* Switch to minutes precision if the configured margin
	152	* value does not fit within the register width.
	153	*/
	154	if (units <= max_units) {
	155	config \|= WDT_UNIT_SEC; /* else UNIT is MINUTES */
	156	printk(KERN_INFO NAME ": timer margin %d seconds\n", units);
	157	} else {
	158	units /= 60;
	159	printk(KERN_INFO NAME ": timer margin %d minutes\n", units);
	160	}
38ff6fd2 JBD	161	superio_outb(config, WDT_CONFIG);
38ff6fd2 JBD	162
5e699608	163	if (revision >= 0x08)
0e45adb8 OS	164	superio_outb(units >> 8, WDT_TIMEOUT + 1);
0e45adb8 OS	165	superio_outb(units, WDT_TIMEOUT);
5e699608 AP	166	}
5e699608 AP	167
d6547378	168	static int it8712f_wdt_get_status(void)
5e699608 AP	169	{
	170	if (superio_inb(WDT_CONTROL) & 0x01)
	171	return WDIOF_CARDRESET;
	172	else
	173	return 0;
38ff6fd2 JBD	174	}
38ff6fd2 JBD	175
d6547378	176	static void it8712f_wdt_enable(void)
38ff6fd2 JBD	177	{
	178	printk(KERN_DEBUG NAME ": enabling watchdog timer\n");
	179	superio_enter();
	180	superio_select(LDN_GPIO);
	181
a422088d	182	superio_outb(wdt_control_reg, WDT_CONTROL);
38ff6fd2 JBD	183
	184	it8712f_wdt_update_margin();
	185
	186	superio_exit();
	187
	188	it8712f_wdt_ping();
	189	}
	190
d6547378	191	static void it8712f_wdt_disable(void)
38ff6fd2 JBD	192	{
	193	printk(KERN_DEBUG NAME ": disabling watchdog timer\n");
	194
	195	superio_enter();
	196	superio_select(LDN_GPIO);
	197
	198	superio_outb(0, WDT_CONFIG);
	199	superio_outb(0, WDT_CONTROL);
cc1020f1 AP	200	if (revision >= 0x08)
cc1020f1 AP	201	superio_outb(0, WDT_TIMEOUT + 1);
38ff6fd2 JBD	202	superio_outb(0, WDT_TIMEOUT);
	203
	204	superio_exit();
	205	}
	206
d6547378	207	static int it8712f_wdt_notify(struct notifier_block *this,
38ff6fd2 JBD	208	unsigned long code, void *unused)
	209	{
	210	if (code == SYS_HALT \|\| code == SYS_POWER_OFF)
	211	if (!nowayout)
	212	it8712f_wdt_disable();
	213
	214	return NOTIFY_DONE;
	215	}
	216
	217	static struct notifier_block it8712f_wdt_notifier = {
	218	.notifier_call = it8712f_wdt_notify,
	219	};
	220
d6547378 AC	221	static ssize_t it8712f_wdt_write(struct file file, const char __user data,
d6547378 AC	222	size_t len, loff_t *ppos)
38ff6fd2 JBD	223	{
	224	/* check for a magic close character */
	225	if (len) {
	226	size_t i;
	227
	228	it8712f_wdt_ping();
	229
	230	expect_close = 0;
	231	for (i = 0; i < len; ++i) {
	232	char c;
7944d3a5	233	if (get_user(c, data + i))
38ff6fd2 JBD	234	return -EFAULT;
	235	if (c == 'V')
	236	expect_close = 42;
	237	}
	238	}
	239
	240	return len;
	241	}
	242
d6547378 AC	243	static long it8712f_wdt_ioctl(struct file *file, unsigned int cmd,
d6547378 AC	244	unsigned long arg)
38ff6fd2 JBD	245	{
	246	void __user argp = (void __user )arg;
	247	int __user *p = argp;
42747d71	248	static const struct watchdog_info ident = {
38ff6fd2 JBD	249	.identity = "IT8712F Watchdog",
38ff6fd2 JBD	250	.firmware_version = 1,
e73a7802 WVS	251	.options = WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING \|
e73a7802 WVS	252	WDIOF_MAGICCLOSE,
38ff6fd2	253	};
5e699608	254	int value;
38ff6fd2 JBD	255
38ff6fd2 JBD	256	switch (cmd) {
38ff6fd2 JBD	257	case WDIOC_GETSUPPORT:
	258	if (copy_to_user(argp, &ident, sizeof(ident)))
	259	return -EFAULT;
	260	return 0;
	261	case WDIOC_GETSTATUS:
5e699608 AP	262	superio_enter();
	263	superio_select(LDN_GPIO);
	264
	265	value = it8712f_wdt_get_status();
	266
	267	superio_exit();
	268
	269	return put_user(value, p);
38ff6fd2 JBD	270	case WDIOC_GETBOOTSTATUS:
	271	return put_user(0, p);
	272	case WDIOC_KEEPALIVE:
	273	it8712f_wdt_ping();
	274	return 0;
	275	case WDIOC_SETTIMEOUT:
5e699608	276	if (get_user(value, p))
38ff6fd2	277	return -EFAULT;
5e699608 AP	278	if (value < 1)
	279	return -EINVAL;
	280	if (value > (max_units * 60))
38ff6fd2	281	return -EINVAL;
5e699608	282	margin = value;
38ff6fd2 JBD	283	superio_enter();
	284	superio_select(LDN_GPIO);
	285
	286	it8712f_wdt_update_margin();
	287
	288	superio_exit();
	289	it8712f_wdt_ping();
5e699608	290	/* Fall through */
38ff6fd2 JBD	291	case WDIOC_GETTIMEOUT:
	292	if (put_user(margin, p))
	293	return -EFAULT;
	294	return 0;
0c06090c WVS	295	default:
0c06090c WVS	296	return -ENOTTY;
38ff6fd2 JBD	297	}
	298	}
	299
d6547378	300	static int it8712f_wdt_open(struct inode inode, struct file file)
38ff6fd2 JBD	301	{
38ff6fd2 JBD	302	/* only allow one at a time */
d6547378	303	if (test_and_set_bit(0, &wdt_open))
38ff6fd2 JBD	304	return -EBUSY;
38ff6fd2 JBD	305	it8712f_wdt_enable();
38ff6fd2 JBD	306	return nonseekable_open(inode, file);
	307	}
	308
d6547378	309	static int it8712f_wdt_release(struct inode inode, struct file file)
38ff6fd2 JBD	310	{
	311	if (expect_close != 42) {
	312	printk(KERN_WARNING NAME
	313	": watchdog device closed unexpectedly, will not"
	314	" disable the watchdog timer\n");
	315	} else if (!nowayout) {
	316	it8712f_wdt_disable();
	317	}
	318	expect_close = 0;
d6547378	319	clear_bit(0, &wdt_open);
38ff6fd2 JBD	320
	321	return 0;
	322	}
	323
b47a166e	324	static const struct file_operations it8712f_wdt_fops = {
38ff6fd2 JBD	325	.owner = THIS_MODULE,
	326	.llseek = no_llseek,
	327	.write = it8712f_wdt_write,
d6547378	328	.unlocked_ioctl = it8712f_wdt_ioctl,
38ff6fd2 JBD	329	.open = it8712f_wdt_open,
	330	.release = it8712f_wdt_release,
	331	};
	332
	333	static struct miscdevice it8712f_wdt_miscdev = {
	334	.minor = WATCHDOG_MINOR,
	335	.name = "watchdog",
	336	.fops = &it8712f_wdt_fops,
	337	};
	338
d6547378	339	static int __init it8712f_wdt_find(unsigned short *address)
38ff6fd2 JBD	340	{
	341	int err = -ENODEV;
	342	int chip_type;
	343
	344	superio_enter();
	345	chip_type = superio_inw(DEVID);
	346	if (chip_type != IT8712F_DEVID)
	347	goto exit;
	348
	349	superio_select(LDN_GAME);
	350	superio_outb(1, ACT_REG);
	351	if (!(superio_inb(ACT_REG) & 0x01)) {
	352	printk(KERN_ERR NAME ": Device not activated, skipping\n");
	353	goto exit;
	354	}
	355
	356	*address = superio_inw(BASE_REG);
	357	if (*address == 0) {
	358	printk(KERN_ERR NAME ": Base address not set, skipping\n");
	359	goto exit;
	360	}
	361
	362	err = 0;
5e699608 AP	363	revision = superio_inb(DEVREV) & 0x0f;
	364
	365	/* Later revisions have 16-bit values per datasheet 0.9.1 */
	366	if (revision >= 0x08)
	367	max_units = 65535;
	368
	369	if (margin > (max_units * 60))
	370	margin = (max_units * 60);
	371
	372	printk(KERN_INFO NAME ": Found IT%04xF chip revision %d - "
38ff6fd2	373	"using DogFood address 0x%x\n",
5e699608	374	chip_type, revision, *address);
38ff6fd2 JBD	375
	376	exit:
	377	superio_exit();
	378	return err;
	379	}
	380
d6547378	381	static int __init it8712f_wdt_init(void)
38ff6fd2 JBD	382	{
	383	int err = 0;
	384
	385	spin_lock_init(&io_lock);
	386
	387	if (it8712f_wdt_find(&address))
	388	return -ENODEV;
	389
	390	if (!request_region(address, 1, "IT8712F Watchdog")) {
	391	printk(KERN_WARNING NAME ": watchdog I/O region busy\n");
	392	return -EBUSY;
	393	}
	394
	395	it8712f_wdt_disable();
	396
38ff6fd2 JBD	397	err = register_reboot_notifier(&it8712f_wdt_notifier);
	398	if (err) {
	399	printk(KERN_ERR NAME ": unable to register reboot notifier\n");
	400	goto out;
	401	}
	402
	403	err = misc_register(&it8712f_wdt_miscdev);
	404	if (err) {
	405	printk(KERN_ERR NAME
	406	": cannot register miscdev on minor=%d (err=%d)\n",
	407	WATCHDOG_MINOR, err);
	408	goto reboot_out;
	409	}
	410
	411	return 0;
	412
	413
	414	reboot_out:
	415	unregister_reboot_notifier(&it8712f_wdt_notifier);
	416	out:
	417	release_region(address, 1);
	418	return err;
	419	}
	420
d6547378	421	static void __exit it8712f_wdt_exit(void)
38ff6fd2 JBD	422	{
	423	misc_deregister(&it8712f_wdt_miscdev);
	424	unregister_reboot_notifier(&it8712f_wdt_notifier);
	425	release_region(address, 1);
	426	}
	427
	428	module_init(it8712f_wdt_init);
	429	module_exit(it8712f_wdt_exit);