[linux.git] / drivers / watchdog / it8712f_wdt.c

/*
 *	IT8712F "Smart Guardian" Watchdog support
 *
 *	Copyright (c) 2006-2007 Jorge Boncompte - DTI2 <[email protected]>
 *
 *	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.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#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/spinlock.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/ioport.h>

#define DEBUG
#define NAME "it8712f_wdt"

MODULE_AUTHOR("Jorge Boncompte - DTI2 <[email protected]>");
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 bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");

static unsigned long wdt_open;
static unsigned expect_close;
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 int superio_enter(void)
{
	/*
	 * Try to reserve REG and REG + 1 for exclusive access.
	 */
	if (!request_muxed_region(REG, 2, NAME))
		return -EBUSY;

	outb(0x87, REG);
	outb(0x01, REG);
	outb(0x55, REG);
	outb(0x55, REG);
	return 0;
}

static inline void superio_exit(void)
{
	outb(0x02, REG);
	outb(0x02, VAL);
	release_region(REG, 2);
}

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 */
		pr_info("timer margin %d seconds\n", units);
	} else {
		units /= 60;
		pr_info("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 int it8712f_wdt_enable(void)
{
	int ret = superio_enter();
	if (ret)
		return ret;

	pr_debug("enabling watchdog timer\n");
	superio_select(LDN_GPIO);

	superio_outb(wdt_control_reg, WDT_CONTROL);

	it8712f_wdt_update_margin();

	superio_exit();

	it8712f_wdt_ping();

	return 0;
}

static int it8712f_wdt_disable(void)
{
	int ret = superio_enter();
	if (ret)
		return ret;

	pr_debug("disabling watchdog timer\n");
	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();
	return 0;
}

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;
	int ret;

	switch (cmd) {
	case WDIOC_GETSUPPORT:
		if (copy_to_user(argp, &ident, sizeof(ident)))
			return -EFAULT;
		return 0;
	case WDIOC_GETSTATUS:
		ret = superio_enter();
		if (ret)
			return ret;
		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;
		ret = superio_enter();
		if (ret)
			return ret;
		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)
{
	int ret;
	/* only allow one at a time */
	if (test_and_set_bit(0, &wdt_open))
		return -EBUSY;

	ret = it8712f_wdt_enable();
	if (ret)
		return ret;
	return nonseekable_open(inode, file);
}

static int it8712f_wdt_release(struct inode *inode, struct file *file)
{
	if (expect_close != 42) {
		pr_warn("watchdog device closed unexpectedly, will not disable the watchdog timer\n");
	} else if (!nowayout) {
		if (it8712f_wdt_disable())
			pr_warn("Watchdog disable failed\n");
	}
	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;
	int ret = superio_enter();
	if (ret)
		return ret;

	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)) {
		pr_err("Device not activated, skipping\n");
		goto exit;
	}

	*address = superio_inw(BASE_REG);
	if (*address == 0) {
		pr_err("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);

	pr_info("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;

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

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

	err = it8712f_wdt_disable();
	if (err) {
		pr_err("unable to disable watchdog timer\n");
		goto out;
	}

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

	err = misc_register(&it8712f_wdt_miscdev);
	if (err) {
		pr_err("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 <[email protected]>
	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
27c766aa JP	23	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
27c766aa JP	24
38ff6fd2 JBD	25	#include <linux/module.h>
	26	#include <linux/moduleparam.h>
	27	#include <linux/init.h>
	28	#include <linux/miscdevice.h>
	29	#include <linux/watchdog.h>
	30	#include <linux/notifier.h>
	31	#include <linux/reboot.h>
	32	#include <linux/fs.h>
38ff6fd2	33	#include <linux/spinlock.h>
d6547378 AC	34	#include <linux/uaccess.h>
d6547378 AC	35	#include <linux/io.h>
22602868	36	#include <linux/ioport.h>
38ff6fd2	37
27c766aa	38	#define DEBUG
38ff6fd2 JBD	39	#define NAME "it8712f_wdt"
	40
	41	MODULE_AUTHOR("Jorge Boncompte - DTI2 <[email protected]>");
	42	MODULE_DESCRIPTION("IT8712F Watchdog Driver");
	43	MODULE_LICENSE("GPL");
	44	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
	45
5e699608	46	static int max_units = 255;
38ff6fd2 JBD	47	static int margin = 60; /* in seconds */
	48	module_param(margin, int, 0);
	49	MODULE_PARM_DESC(margin, "Watchdog margin in seconds");
	50
86a1e189 WVS	51	static bool nowayout = WATCHDOG_NOWAYOUT;
86a1e189 WVS	52	module_param(nowayout, bool, 0);
38ff6fd2 JBD	53	MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");
38ff6fd2 JBD	54
d6547378	55	static unsigned long wdt_open;
38ff6fd2	56	static unsigned expect_close;
5e699608	57	static unsigned char revision;
38ff6fd2 JBD	58
	59	/* Dog Food address - We use the game port address */
	60	static unsigned short address;
	61
	62	#define REG 0x2e /* The register to read/write */
	63	#define VAL 0x2f /* The value to read/write */
	64
	65	#define LDN 0x07 /* Register: Logical device select */
	66	#define DEVID 0x20 /* Register: Device ID */
	67	#define DEVREV 0x22 /* Register: Device Revision */
	68	#define ACT_REG 0x30 /* LDN Register: Activation */
	69	#define BASE_REG 0x60 /* LDN Register: Base address */
	70
	71	#define IT8712F_DEVID 0x8712
	72
	73	#define LDN_GPIO 0x07 /* GPIO and Watch Dog Timer */
5f3b2756	74	#define LDN_GAME 0x09 /* Game Port */
38ff6fd2 JBD	75
	76	#define WDT_CONTROL 0x71 /* WDT Register: Control */
	77	#define WDT_CONFIG 0x72 /* WDT Register: Configuration */
	78	#define WDT_TIMEOUT 0x73 /* WDT Register: Timeout Value */
	79
f0fc1074 TJL	80	#define WDT_RESET_GAME 0x10 /* Reset timer on read or write to game port */
	81	#define WDT_RESET_KBD 0x20 /* Reset timer on keyboard interrupt */
	82	#define WDT_RESET_MOUSE 0x40 /* Reset timer on mouse interrupt */
	83	#define WDT_RESET_CIR 0x80 /* Reset timer on consumer IR interrupt */
38ff6fd2 JBD	84
	85	#define WDT_UNIT_SEC 0x80 /* If 0 in MINUTES */
	86
f0fc1074 TJL	87	#define WDT_OUT_PWROK 0x10 /* Pulse PWROK on timeout */
f0fc1074 TJL	88	#define WDT_OUT_KRST 0x40 /* Pulse reset on timeout */
38ff6fd2	89
a422088d TJL	90	static int wdt_control_reg = WDT_RESET_GAME;
	91	module_param(wdt_control_reg, int, 0);
	92	MODULE_PARM_DESC(wdt_control_reg, "Value to write to watchdog control "
	93	"register. The default WDT_RESET_GAME resets the timer on "
	94	"game port reads that this driver generates. You can also "
	95	"use KBD, MOUSE or CIR if you have some external way to "
	96	"generate those interrupts.");
	97
d6547378	98	static int superio_inb(int reg)
38ff6fd2 JBD	99	{
	100	outb(reg, REG);
	101	return inb(VAL);
	102	}
	103
d6547378	104	static void superio_outb(int val, int reg)
38ff6fd2 JBD	105	{
	106	outb(reg, REG);
	107	outb(val, VAL);
	108	}
	109
d6547378	110	static int superio_inw(int reg)
38ff6fd2 JBD	111	{
	112	int val;
	113	outb(reg++, REG);
	114	val = inb(VAL) << 8;
	115	outb(reg, REG);
	116	val \|= inb(VAL);
	117	return val;
	118	}
	119
d6547378	120	static inline void superio_select(int ldn)
38ff6fd2 JBD	121	{
	122	outb(LDN, REG);
	123	outb(ldn, VAL);
	124	}
	125
a134b825	126	static inline int superio_enter(void)
38ff6fd2	127	{
a134b825 NG	128	/*
	129	* Try to reserve REG and REG + 1 for exclusive access.
	130	*/
	131	if (!request_muxed_region(REG, 2, NAME))
	132	return -EBUSY;
	133
38ff6fd2 JBD	134	outb(0x87, REG);
	135	outb(0x01, REG);
	136	outb(0x55, REG);
	137	outb(0x55, REG);
a134b825	138	return 0;
38ff6fd2 JBD	139	}
38ff6fd2 JBD	140
d6547378	141	static inline void superio_exit(void)
38ff6fd2 JBD	142	{
	143	outb(0x02, REG);
	144	outb(0x02, VAL);
a134b825	145	release_region(REG, 2);
38ff6fd2 JBD	146	}
38ff6fd2 JBD	147
d6547378	148	static inline void it8712f_wdt_ping(void)
38ff6fd2	149	{
a422088d TJL	150	if (wdt_control_reg & WDT_RESET_GAME)
a422088d TJL	151	inb(address);
38ff6fd2 JBD	152	}
38ff6fd2 JBD	153
d6547378	154	static void it8712f_wdt_update_margin(void)
38ff6fd2 JBD	155	{
38ff6fd2 JBD	156	int config = WDT_OUT_KRST \| WDT_OUT_PWROK;
5e699608 AP	157	int units = margin;
	158
	159	/* Switch to minutes precision if the configured margin
	160	* value does not fit within the register width.
	161	*/
	162	if (units <= max_units) {
	163	config \|= WDT_UNIT_SEC; /* else UNIT is MINUTES */
27c766aa	164	pr_info("timer margin %d seconds\n", units);
5e699608 AP	165	} else {
5e699608 AP	166	units /= 60;
27c766aa	167	pr_info("timer margin %d minutes\n", units);
5e699608	168	}
38ff6fd2 JBD	169	superio_outb(config, WDT_CONFIG);
38ff6fd2 JBD	170
5e699608	171	if (revision >= 0x08)
0e45adb8 OS	172	superio_outb(units >> 8, WDT_TIMEOUT + 1);
0e45adb8 OS	173	superio_outb(units, WDT_TIMEOUT);
5e699608 AP	174	}
5e699608 AP	175
d6547378	176	static int it8712f_wdt_get_status(void)
5e699608 AP	177	{
	178	if (superio_inb(WDT_CONTROL) & 0x01)
	179	return WDIOF_CARDRESET;
	180	else
	181	return 0;
38ff6fd2 JBD	182	}
38ff6fd2 JBD	183
a134b825	184	static int it8712f_wdt_enable(void)
38ff6fd2	185	{
a134b825 NG	186	int ret = superio_enter();
	187	if (ret)
	188	return ret;
	189
27c766aa	190	pr_debug("enabling watchdog timer\n");
38ff6fd2 JBD	191	superio_select(LDN_GPIO);
38ff6fd2 JBD	192
a422088d	193	superio_outb(wdt_control_reg, WDT_CONTROL);
38ff6fd2 JBD	194
	195	it8712f_wdt_update_margin();
	196
	197	superio_exit();
	198
	199	it8712f_wdt_ping();
a134b825 NG	200
a134b825 NG	201	return 0;
38ff6fd2 JBD	202	}
38ff6fd2 JBD	203
a134b825	204	static int it8712f_wdt_disable(void)
38ff6fd2	205	{
a134b825 NG	206	int ret = superio_enter();
	207	if (ret)
	208	return ret;
38ff6fd2	209
27c766aa	210	pr_debug("disabling watchdog timer\n");
38ff6fd2 JBD	211	superio_select(LDN_GPIO);
	212
	213	superio_outb(0, WDT_CONFIG);
	214	superio_outb(0, WDT_CONTROL);
cc1020f1 AP	215	if (revision >= 0x08)
cc1020f1 AP	216	superio_outb(0, WDT_TIMEOUT + 1);
38ff6fd2 JBD	217	superio_outb(0, WDT_TIMEOUT);
	218
	219	superio_exit();
a134b825	220	return 0;
38ff6fd2 JBD	221	}
38ff6fd2 JBD	222
d6547378	223	static int it8712f_wdt_notify(struct notifier_block *this,
38ff6fd2 JBD	224	unsigned long code, void *unused)
	225	{
	226	if (code == SYS_HALT \|\| code == SYS_POWER_OFF)
	227	if (!nowayout)
	228	it8712f_wdt_disable();
	229
	230	return NOTIFY_DONE;
	231	}
	232
	233	static struct notifier_block it8712f_wdt_notifier = {
	234	.notifier_call = it8712f_wdt_notify,
	235	};
	236
d6547378 AC	237	static ssize_t it8712f_wdt_write(struct file file, const char __user data,
d6547378 AC	238	size_t len, loff_t *ppos)
38ff6fd2 JBD	239	{
	240	/* check for a magic close character */
	241	if (len) {
	242	size_t i;
	243
	244	it8712f_wdt_ping();
	245
	246	expect_close = 0;
	247	for (i = 0; i < len; ++i) {
	248	char c;
7944d3a5	249	if (get_user(c, data + i))
38ff6fd2 JBD	250	return -EFAULT;
	251	if (c == 'V')
	252	expect_close = 42;
	253	}
	254	}
	255
	256	return len;
	257	}
	258
d6547378 AC	259	static long it8712f_wdt_ioctl(struct file *file, unsigned int cmd,
d6547378 AC	260	unsigned long arg)
38ff6fd2 JBD	261	{
	262	void __user argp = (void __user )arg;
	263	int __user *p = argp;
42747d71	264	static const struct watchdog_info ident = {
38ff6fd2 JBD	265	.identity = "IT8712F Watchdog",
38ff6fd2 JBD	266	.firmware_version = 1,
e73a7802 WVS	267	.options = WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING \|
e73a7802 WVS	268	WDIOF_MAGICCLOSE,
38ff6fd2	269	};
5e699608	270	int value;
a134b825	271	int ret;
38ff6fd2 JBD	272
38ff6fd2 JBD	273	switch (cmd) {
38ff6fd2 JBD	274	case WDIOC_GETSUPPORT:
	275	if (copy_to_user(argp, &ident, sizeof(ident)))
	276	return -EFAULT;
	277	return 0;
	278	case WDIOC_GETSTATUS:
a134b825 NG	279	ret = superio_enter();
	280	if (ret)
	281	return ret;
5e699608 AP	282	superio_select(LDN_GPIO);
	283
	284	value = it8712f_wdt_get_status();
	285
	286	superio_exit();
	287
	288	return put_user(value, p);
38ff6fd2 JBD	289	case WDIOC_GETBOOTSTATUS:
	290	return put_user(0, p);
	291	case WDIOC_KEEPALIVE:
	292	it8712f_wdt_ping();
	293	return 0;
	294	case WDIOC_SETTIMEOUT:
5e699608	295	if (get_user(value, p))
38ff6fd2	296	return -EFAULT;
5e699608 AP	297	if (value < 1)
	298	return -EINVAL;
	299	if (value > (max_units * 60))
38ff6fd2	300	return -EINVAL;
5e699608	301	margin = value;
a134b825 NG	302	ret = superio_enter();
	303	if (ret)
	304	return ret;
38ff6fd2 JBD	305	superio_select(LDN_GPIO);
	306
	307	it8712f_wdt_update_margin();
	308
	309	superio_exit();
	310	it8712f_wdt_ping();
5e699608	311	/* Fall through */
38ff6fd2 JBD	312	case WDIOC_GETTIMEOUT:
	313	if (put_user(margin, p))
	314	return -EFAULT;
	315	return 0;
0c06090c WVS	316	default:
0c06090c WVS	317	return -ENOTTY;
38ff6fd2 JBD	318	}
	319	}
	320
d6547378	321	static int it8712f_wdt_open(struct inode inode, struct file file)
38ff6fd2	322	{
a134b825	323	int ret;
38ff6fd2	324	/* only allow one at a time */
d6547378	325	if (test_and_set_bit(0, &wdt_open))
38ff6fd2	326	return -EBUSY;
a134b825 NG	327
	328	ret = it8712f_wdt_enable();
	329	if (ret)
	330	return ret;
38ff6fd2 JBD	331	return nonseekable_open(inode, file);
	332	}
	333
d6547378	334	static int it8712f_wdt_release(struct inode inode, struct file file)
38ff6fd2 JBD	335	{
38ff6fd2 JBD	336	if (expect_close != 42) {
27c766aa	337	pr_warn("watchdog device closed unexpectedly, will not disable the watchdog timer\n");
38ff6fd2	338	} else if (!nowayout) {
a134b825	339	if (it8712f_wdt_disable())
27c766aa	340	pr_warn("Watchdog disable failed\n");
38ff6fd2 JBD	341	}
38ff6fd2 JBD	342	expect_close = 0;
d6547378	343	clear_bit(0, &wdt_open);
38ff6fd2 JBD	344
	345	return 0;
	346	}
	347
b47a166e	348	static const struct file_operations it8712f_wdt_fops = {
38ff6fd2 JBD	349	.owner = THIS_MODULE,
	350	.llseek = no_llseek,
	351	.write = it8712f_wdt_write,
d6547378	352	.unlocked_ioctl = it8712f_wdt_ioctl,
38ff6fd2 JBD	353	.open = it8712f_wdt_open,
	354	.release = it8712f_wdt_release,
	355	};
	356
	357	static struct miscdevice it8712f_wdt_miscdev = {
	358	.minor = WATCHDOG_MINOR,
	359	.name = "watchdog",
	360	.fops = &it8712f_wdt_fops,
	361	};
	362
d6547378	363	static int __init it8712f_wdt_find(unsigned short *address)
38ff6fd2 JBD	364	{
	365	int err = -ENODEV;
	366	int chip_type;
a134b825 NG	367	int ret = superio_enter();
	368	if (ret)
	369	return ret;
38ff6fd2	370
38ff6fd2 JBD	371	chip_type = superio_inw(DEVID);
	372	if (chip_type != IT8712F_DEVID)
	373	goto exit;
	374
	375	superio_select(LDN_GAME);
	376	superio_outb(1, ACT_REG);
	377	if (!(superio_inb(ACT_REG) & 0x01)) {
27c766aa	378	pr_err("Device not activated, skipping\n");
38ff6fd2 JBD	379	goto exit;
	380	}
	381
	382	*address = superio_inw(BASE_REG);
	383	if (*address == 0) {
27c766aa	384	pr_err("Base address not set, skipping\n");
38ff6fd2 JBD	385	goto exit;
	386	}
	387
	388	err = 0;
5e699608 AP	389	revision = superio_inb(DEVREV) & 0x0f;
	390
	391	/* Later revisions have 16-bit values per datasheet 0.9.1 */
	392	if (revision >= 0x08)
	393	max_units = 65535;
	394
	395	if (margin > (max_units * 60))
	396	margin = (max_units * 60);
	397
27c766aa	398	pr_info("Found IT%04xF chip revision %d - using DogFood address 0x%x\n",
5e699608	399	chip_type, revision, *address);
38ff6fd2 JBD	400
	401	exit:
	402	superio_exit();
	403	return err;
	404	}
	405
d6547378	406	static int __init it8712f_wdt_init(void)
38ff6fd2 JBD	407	{
	408	int err = 0;
	409
38ff6fd2 JBD	410	if (it8712f_wdt_find(&address))
	411	return -ENODEV;
	412
	413	if (!request_region(address, 1, "IT8712F Watchdog")) {
27c766aa	414	pr_warn("watchdog I/O region busy\n");
38ff6fd2 JBD	415	return -EBUSY;
	416	}
	417
a134b825 NG	418	err = it8712f_wdt_disable();
a134b825 NG	419	if (err) {
27c766aa	420	pr_err("unable to disable watchdog timer\n");
a134b825 NG	421	goto out;
a134b825 NG	422	}
38ff6fd2	423
38ff6fd2 JBD	424	err = register_reboot_notifier(&it8712f_wdt_notifier);
38ff6fd2 JBD	425	if (err) {
27c766aa	426	pr_err("unable to register reboot notifier\n");
38ff6fd2 JBD	427	goto out;
	428	}
	429
	430	err = misc_register(&it8712f_wdt_miscdev);
	431	if (err) {
27c766aa JP	432	pr_err("cannot register miscdev on minor=%d (err=%d)\n",
27c766aa JP	433	WATCHDOG_MINOR, err);
38ff6fd2 JBD	434	goto reboot_out;
	435	}
	436
	437	return 0;
	438
	439
	440	reboot_out:
	441	unregister_reboot_notifier(&it8712f_wdt_notifier);
	442	out:
	443	release_region(address, 1);
	444	return err;
	445	}
	446
d6547378	447	static void __exit it8712f_wdt_exit(void)
38ff6fd2 JBD	448	{
	449	misc_deregister(&it8712f_wdt_miscdev);
	450	unregister_reboot_notifier(&it8712f_wdt_notifier);
	451	release_region(address, 1);
	452	}
	453
	454	module_init(it8712f_wdt_init);
	455	module_exit(it8712f_wdt_exit);