[mirror_ubuntu-hirsute-kernel.git] / drivers / watchdog / it8712f_wdt.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *	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
 *
 *	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 <jorge@dti2.net>");
MODULE_DESCRIPTION("IT8712F Watchdog Driver");
MODULE_LICENSE("GPL");

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();
		fallthrough;
	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 stream_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,
	.compat_ioctl = compat_ptr_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
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
38ff6fd2 JBD	2	/*
	3	* IT8712F "Smart Guardian" Watchdog support
	4	*
	5	* Copyright (c) 2006-2007 Jorge Boncompte - DTI2 <jorge@dti2.net>
	6	*
	7	* Based on info and code taken from:
	8	*
	9	* drivers/char/watchdog/scx200_wdt.c
	10	* drivers/hwmon/it87.c
5e699608 AP	11	* IT8712F EC-LPC I/O Preliminary Specification 0.8.2
5e699608 AP	12	* IT8712F EC-LPC I/O Preliminary Specification 0.9.3
38ff6fd2	13	*
38ff6fd2 JBD	14	* The author(s) of this software shall not be held liable for damages
	15	* of any nature resulting due to the use of this software. This
	16	* software is provided AS-IS with no warranties.
	17	*/
	18
27c766aa JP	19	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
27c766aa JP	20
38ff6fd2 JBD	21	#include <linux/module.h>
	22	#include <linux/moduleparam.h>
	23	#include <linux/init.h>
	24	#include <linux/miscdevice.h>
	25	#include <linux/watchdog.h>
	26	#include <linux/notifier.h>
	27	#include <linux/reboot.h>
	28	#include <linux/fs.h>
38ff6fd2	29	#include <linux/spinlock.h>
d6547378 AC	30	#include <linux/uaccess.h>
d6547378 AC	31	#include <linux/io.h>
22602868	32	#include <linux/ioport.h>
38ff6fd2	33
27c766aa	34	#define DEBUG
38ff6fd2 JBD	35	#define NAME "it8712f_wdt"
	36
	37	MODULE_AUTHOR("Jorge Boncompte - DTI2 <jorge@dti2.net>");
	38	MODULE_DESCRIPTION("IT8712F Watchdog Driver");
	39	MODULE_LICENSE("GPL");
38ff6fd2	40
5e699608	41	static int max_units = 255;
38ff6fd2 JBD	42	static int margin = 60; /* in seconds */
	43	module_param(margin, int, 0);
	44	MODULE_PARM_DESC(margin, "Watchdog margin in seconds");
	45
86a1e189 WVS	46	static bool nowayout = WATCHDOG_NOWAYOUT;
86a1e189 WVS	47	module_param(nowayout, bool, 0);
38ff6fd2 JBD	48	MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");
38ff6fd2 JBD	49
d6547378	50	static unsigned long wdt_open;
38ff6fd2	51	static unsigned expect_close;
5e699608	52	static unsigned char revision;
38ff6fd2 JBD	53
	54	/* Dog Food address - We use the game port address */
	55	static unsigned short address;
	56
	57	#define REG 0x2e /* The register to read/write */
	58	#define VAL 0x2f /* The value to read/write */
	59
	60	#define LDN 0x07 /* Register: Logical device select */
	61	#define DEVID 0x20 /* Register: Device ID */
	62	#define DEVREV 0x22 /* Register: Device Revision */
	63	#define ACT_REG 0x30 /* LDN Register: Activation */
	64	#define BASE_REG 0x60 /* LDN Register: Base address */
	65
	66	#define IT8712F_DEVID 0x8712
	67
	68	#define LDN_GPIO 0x07 /* GPIO and Watch Dog Timer */
5f3b2756	69	#define LDN_GAME 0x09 /* Game Port */
38ff6fd2 JBD	70
	71	#define WDT_CONTROL 0x71 /* WDT Register: Control */
	72	#define WDT_CONFIG 0x72 /* WDT Register: Configuration */
	73	#define WDT_TIMEOUT 0x73 /* WDT Register: Timeout Value */
	74
f0fc1074 TJL	75	#define WDT_RESET_GAME 0x10 /* Reset timer on read or write to game port */
	76	#define WDT_RESET_KBD 0x20 /* Reset timer on keyboard interrupt */
	77	#define WDT_RESET_MOUSE 0x40 /* Reset timer on mouse interrupt */
	78	#define WDT_RESET_CIR 0x80 /* Reset timer on consumer IR interrupt */
38ff6fd2 JBD	79
	80	#define WDT_UNIT_SEC 0x80 /* If 0 in MINUTES */
	81
f0fc1074 TJL	82	#define WDT_OUT_PWROK 0x10 /* Pulse PWROK on timeout */
f0fc1074 TJL	83	#define WDT_OUT_KRST 0x40 /* Pulse reset on timeout */
38ff6fd2	84
a422088d TJL	85	static int wdt_control_reg = WDT_RESET_GAME;
	86	module_param(wdt_control_reg, int, 0);
	87	MODULE_PARM_DESC(wdt_control_reg, "Value to write to watchdog control "
	88	"register. The default WDT_RESET_GAME resets the timer on "
	89	"game port reads that this driver generates. You can also "
	90	"use KBD, MOUSE or CIR if you have some external way to "
	91	"generate those interrupts.");
	92
d6547378	93	static int superio_inb(int reg)
38ff6fd2 JBD	94	{
	95	outb(reg, REG);
	96	return inb(VAL);
	97	}
	98
d6547378	99	static void superio_outb(int val, int reg)
38ff6fd2 JBD	100	{
	101	outb(reg, REG);
	102	outb(val, VAL);
	103	}
	104
d6547378	105	static int superio_inw(int reg)
38ff6fd2 JBD	106	{
	107	int val;
	108	outb(reg++, REG);
	109	val = inb(VAL) << 8;
	110	outb(reg, REG);
	111	val \|= inb(VAL);
	112	return val;
	113	}
	114
d6547378	115	static inline void superio_select(int ldn)
38ff6fd2 JBD	116	{
	117	outb(LDN, REG);
	118	outb(ldn, VAL);
	119	}
	120
a134b825	121	static inline int superio_enter(void)
38ff6fd2	122	{
a134b825 NG	123	/*
	124	* Try to reserve REG and REG + 1 for exclusive access.
	125	*/
	126	if (!request_muxed_region(REG, 2, NAME))
	127	return -EBUSY;
	128
38ff6fd2 JBD	129	outb(0x87, REG);
	130	outb(0x01, REG);
	131	outb(0x55, REG);
	132	outb(0x55, REG);
a134b825	133	return 0;
38ff6fd2 JBD	134	}
38ff6fd2 JBD	135
d6547378	136	static inline void superio_exit(void)
38ff6fd2 JBD	137	{
	138	outb(0x02, REG);
	139	outb(0x02, VAL);
a134b825	140	release_region(REG, 2);
38ff6fd2 JBD	141	}
38ff6fd2 JBD	142
d6547378	143	static inline void it8712f_wdt_ping(void)
38ff6fd2	144	{
a422088d TJL	145	if (wdt_control_reg & WDT_RESET_GAME)
a422088d TJL	146	inb(address);
38ff6fd2 JBD	147	}
38ff6fd2 JBD	148
d6547378	149	static void it8712f_wdt_update_margin(void)
38ff6fd2 JBD	150	{
38ff6fd2 JBD	151	int config = WDT_OUT_KRST \| WDT_OUT_PWROK;
5e699608 AP	152	int units = margin;
	153
	154	/* Switch to minutes precision if the configured margin
	155	* value does not fit within the register width.
	156	*/
	157	if (units <= max_units) {
	158	config \|= WDT_UNIT_SEC; /* else UNIT is MINUTES */
27c766aa	159	pr_info("timer margin %d seconds\n", units);
5e699608 AP	160	} else {
5e699608 AP	161	units /= 60;
27c766aa	162	pr_info("timer margin %d minutes\n", units);
5e699608	163	}
38ff6fd2 JBD	164	superio_outb(config, WDT_CONFIG);
38ff6fd2 JBD	165
5e699608	166	if (revision >= 0x08)
0e45adb8 OS	167	superio_outb(units >> 8, WDT_TIMEOUT + 1);
0e45adb8 OS	168	superio_outb(units, WDT_TIMEOUT);
5e699608 AP	169	}
5e699608 AP	170
d6547378	171	static int it8712f_wdt_get_status(void)
5e699608 AP	172	{
	173	if (superio_inb(WDT_CONTROL) & 0x01)
	174	return WDIOF_CARDRESET;
	175	else
	176	return 0;
38ff6fd2 JBD	177	}
38ff6fd2 JBD	178
a134b825	179	static int it8712f_wdt_enable(void)
38ff6fd2	180	{
a134b825 NG	181	int ret = superio_enter();
	182	if (ret)
	183	return ret;
	184
27c766aa	185	pr_debug("enabling watchdog timer\n");
38ff6fd2 JBD	186	superio_select(LDN_GPIO);
38ff6fd2 JBD	187
a422088d	188	superio_outb(wdt_control_reg, WDT_CONTROL);
38ff6fd2 JBD	189
	190	it8712f_wdt_update_margin();
	191
	192	superio_exit();
	193
	194	it8712f_wdt_ping();
a134b825 NG	195
a134b825 NG	196	return 0;
38ff6fd2 JBD	197	}
38ff6fd2 JBD	198
a134b825	199	static int it8712f_wdt_disable(void)
38ff6fd2	200	{
a134b825 NG	201	int ret = superio_enter();
	202	if (ret)
	203	return ret;
38ff6fd2	204
27c766aa	205	pr_debug("disabling watchdog timer\n");
38ff6fd2 JBD	206	superio_select(LDN_GPIO);
	207
	208	superio_outb(0, WDT_CONFIG);
	209	superio_outb(0, WDT_CONTROL);
cc1020f1 AP	210	if (revision >= 0x08)
cc1020f1 AP	211	superio_outb(0, WDT_TIMEOUT + 1);
38ff6fd2 JBD	212	superio_outb(0, WDT_TIMEOUT);
	213
	214	superio_exit();
a134b825	215	return 0;
38ff6fd2 JBD	216	}
38ff6fd2 JBD	217
d6547378	218	static int it8712f_wdt_notify(struct notifier_block *this,
38ff6fd2 JBD	219	unsigned long code, void *unused)
	220	{
	221	if (code == SYS_HALT \|\| code == SYS_POWER_OFF)
	222	if (!nowayout)
	223	it8712f_wdt_disable();
	224
	225	return NOTIFY_DONE;
	226	}
	227
	228	static struct notifier_block it8712f_wdt_notifier = {
	229	.notifier_call = it8712f_wdt_notify,
	230	};
	231
d6547378 AC	232	static ssize_t it8712f_wdt_write(struct file file, const char __user data,
d6547378 AC	233	size_t len, loff_t *ppos)
38ff6fd2 JBD	234	{
	235	/* check for a magic close character */
	236	if (len) {
	237	size_t i;
	238
	239	it8712f_wdt_ping();
	240
	241	expect_close = 0;
	242	for (i = 0; i < len; ++i) {
	243	char c;
7944d3a5	244	if (get_user(c, data + i))
38ff6fd2 JBD	245	return -EFAULT;
	246	if (c == 'V')
	247	expect_close = 42;
	248	}
	249	}
	250
	251	return len;
	252	}
	253
d6547378 AC	254	static long it8712f_wdt_ioctl(struct file *file, unsigned int cmd,
d6547378 AC	255	unsigned long arg)
38ff6fd2 JBD	256	{
	257	void __user argp = (void __user )arg;
	258	int __user *p = argp;
42747d71	259	static const struct watchdog_info ident = {
38ff6fd2 JBD	260	.identity = "IT8712F Watchdog",
38ff6fd2 JBD	261	.firmware_version = 1,
e73a7802 WVS	262	.options = WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING \|
e73a7802 WVS	263	WDIOF_MAGICCLOSE,
38ff6fd2	264	};
5e699608	265	int value;
a134b825	266	int ret;
38ff6fd2 JBD	267
38ff6fd2 JBD	268	switch (cmd) {
38ff6fd2 JBD	269	case WDIOC_GETSUPPORT:
	270	if (copy_to_user(argp, &ident, sizeof(ident)))
	271	return -EFAULT;
	272	return 0;
	273	case WDIOC_GETSTATUS:
a134b825 NG	274	ret = superio_enter();
	275	if (ret)
	276	return ret;
5e699608 AP	277	superio_select(LDN_GPIO);
	278
	279	value = it8712f_wdt_get_status();
	280
	281	superio_exit();
	282
	283	return put_user(value, p);
38ff6fd2 JBD	284	case WDIOC_GETBOOTSTATUS:
	285	return put_user(0, p);
	286	case WDIOC_KEEPALIVE:
	287	it8712f_wdt_ping();
	288	return 0;
	289	case WDIOC_SETTIMEOUT:
5e699608	290	if (get_user(value, p))
38ff6fd2	291	return -EFAULT;
5e699608 AP	292	if (value < 1)
	293	return -EINVAL;
	294	if (value > (max_units * 60))
38ff6fd2	295	return -EINVAL;
5e699608	296	margin = value;
a134b825 NG	297	ret = superio_enter();
	298	if (ret)
	299	return ret;
38ff6fd2 JBD	300	superio_select(LDN_GPIO);
	301
	302	it8712f_wdt_update_margin();
	303
	304	superio_exit();
	305	it8712f_wdt_ping();
bd490f82	306	fallthrough;
38ff6fd2 JBD	307	case WDIOC_GETTIMEOUT:
	308	if (put_user(margin, p))
	309	return -EFAULT;
	310	return 0;
0c06090c WVS	311	default:
0c06090c WVS	312	return -ENOTTY;
38ff6fd2 JBD	313	}
	314	}
	315
d6547378	316	static int it8712f_wdt_open(struct inode inode, struct file file)
38ff6fd2	317	{
a134b825	318	int ret;
38ff6fd2	319	/* only allow one at a time */
d6547378	320	if (test_and_set_bit(0, &wdt_open))
38ff6fd2	321	return -EBUSY;
a134b825 NG	322
	323	ret = it8712f_wdt_enable();
	324	if (ret)
	325	return ret;
c5bf68fe	326	return stream_open(inode, file);
38ff6fd2 JBD	327	}
38ff6fd2 JBD	328
d6547378	329	static int it8712f_wdt_release(struct inode inode, struct file file)
38ff6fd2 JBD	330	{
38ff6fd2 JBD	331	if (expect_close != 42) {
27c766aa	332	pr_warn("watchdog device closed unexpectedly, will not disable the watchdog timer\n");
38ff6fd2	333	} else if (!nowayout) {
a134b825	334	if (it8712f_wdt_disable())
27c766aa	335	pr_warn("Watchdog disable failed\n");
38ff6fd2 JBD	336	}
38ff6fd2 JBD	337	expect_close = 0;
d6547378	338	clear_bit(0, &wdt_open);
38ff6fd2 JBD	339
	340	return 0;
	341	}
	342
b47a166e	343	static const struct file_operations it8712f_wdt_fops = {
38ff6fd2 JBD	344	.owner = THIS_MODULE,
	345	.llseek = no_llseek,
	346	.write = it8712f_wdt_write,
d6547378	347	.unlocked_ioctl = it8712f_wdt_ioctl,
b6dfb247	348	.compat_ioctl = compat_ptr_ioctl,
38ff6fd2 JBD	349	.open = it8712f_wdt_open,
	350	.release = it8712f_wdt_release,
	351	};
	352
	353	static struct miscdevice it8712f_wdt_miscdev = {
	354	.minor = WATCHDOG_MINOR,
	355	.name = "watchdog",
	356	.fops = &it8712f_wdt_fops,
	357	};
	358
d6547378	359	static int __init it8712f_wdt_find(unsigned short *address)
38ff6fd2 JBD	360	{
	361	int err = -ENODEV;
	362	int chip_type;
a134b825 NG	363	int ret = superio_enter();
	364	if (ret)
	365	return ret;
38ff6fd2	366
38ff6fd2 JBD	367	chip_type = superio_inw(DEVID);
	368	if (chip_type != IT8712F_DEVID)
	369	goto exit;
	370
	371	superio_select(LDN_GAME);
	372	superio_outb(1, ACT_REG);
	373	if (!(superio_inb(ACT_REG) & 0x01)) {
27c766aa	374	pr_err("Device not activated, skipping\n");
38ff6fd2 JBD	375	goto exit;
	376	}
	377
	378	*address = superio_inw(BASE_REG);
	379	if (*address == 0) {
27c766aa	380	pr_err("Base address not set, skipping\n");
38ff6fd2 JBD	381	goto exit;
	382	}
	383
	384	err = 0;
5e699608 AP	385	revision = superio_inb(DEVREV) & 0x0f;
	386
	387	/* Later revisions have 16-bit values per datasheet 0.9.1 */
	388	if (revision >= 0x08)
	389	max_units = 65535;
	390
	391	if (margin > (max_units * 60))
	392	margin = (max_units * 60);
	393
27c766aa	394	pr_info("Found IT%04xF chip revision %d - using DogFood address 0x%x\n",
5e699608	395	chip_type, revision, *address);
38ff6fd2 JBD	396
	397	exit:
	398	superio_exit();
	399	return err;
	400	}
	401
d6547378	402	static int __init it8712f_wdt_init(void)
38ff6fd2 JBD	403	{
	404	int err = 0;
	405
38ff6fd2 JBD	406	if (it8712f_wdt_find(&address))
	407	return -ENODEV;
	408
	409	if (!request_region(address, 1, "IT8712F Watchdog")) {
27c766aa	410	pr_warn("watchdog I/O region busy\n");
38ff6fd2 JBD	411	return -EBUSY;
	412	}
	413
a134b825 NG	414	err = it8712f_wdt_disable();
a134b825 NG	415	if (err) {
27c766aa	416	pr_err("unable to disable watchdog timer\n");
a134b825 NG	417	goto out;
a134b825 NG	418	}
38ff6fd2	419
38ff6fd2 JBD	420	err = register_reboot_notifier(&it8712f_wdt_notifier);
38ff6fd2 JBD	421	if (err) {
27c766aa	422	pr_err("unable to register reboot notifier\n");
38ff6fd2 JBD	423	goto out;
	424	}
	425
	426	err = misc_register(&it8712f_wdt_miscdev);
	427	if (err) {
27c766aa JP	428	pr_err("cannot register miscdev on minor=%d (err=%d)\n",
27c766aa JP	429	WATCHDOG_MINOR, err);
38ff6fd2 JBD	430	goto reboot_out;
	431	}
	432
	433	return 0;
	434
	435
	436	reboot_out:
	437	unregister_reboot_notifier(&it8712f_wdt_notifier);
	438	out:
	439	release_region(address, 1);
	440	return err;
	441	}
	442
d6547378	443	static void __exit it8712f_wdt_exit(void)
38ff6fd2 JBD	444	{
	445	misc_deregister(&it8712f_wdt_miscdev);
	446	unregister_reboot_notifier(&it8712f_wdt_notifier);
	447	release_region(address, 1);
	448	}
	449
	450	module_init(it8712f_wdt_init);
	451	module_exit(it8712f_wdt_exit);