[mirror_ubuntu-bionic-kernel.git] / drivers / watchdog / w83877f_wdt.c

/*
 *	W83877F Computer Watchdog Timer driver
 *
 *      Based on acquirewdt.c by Alan Cox,
 *           and sbc60xxwdt.c by Jakob Oestergaard <jakob@unthought.net>
 *
 *	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 authors do NOT admit liability nor provide warranty for
 *	any of this software. This material is provided "AS-IS" in
 *      the hope that it may be useful for others.
 *
 *	(c) Copyright 2001    Scott Jennings <linuxdrivers@oro.net>
 *
 *           4/19 - 2001      [Initial revision]
 *           9/27 - 2001      Added spinlocking
 *           4/12 - 2002      [rob@osinvestor.com] Eliminate extra comments
 *                            Eliminate fop_read
 *                            Eliminate extra spin_unlock
 *                            Added KERN_* tags to printks
 *                            add CONFIG_WATCHDOG_NOWAYOUT support
 *                            fix possible wdt_is_open race
 *                            changed watchdog_info to correctly reflect what
 *			      the driver offers
 *                            added WDIOC_GETSTATUS, WDIOC_GETBOOTSTATUS,
 *			      WDIOC_SETTIMEOUT,
 *                            WDIOC_GETTIMEOUT, and WDIOC_SETOPTIONS ioctls
 *           09/8 - 2003      [wim@iguana.be] cleanup of trailing spaces
 *                            added extra printk's for startup problems
 *                            use module_param
 *                            made timeout (the emulated heartbeat) a
 *			      module_param
 *                            made the keepalive ping an internal subroutine
 *
 *  This WDT driver is different from most other Linux WDT
 *  drivers in that the driver will ping the watchdog by itself,
 *  because this particular WDT has a very short timeout (1.6
 *  seconds) and it would be insane to count on any userspace
 *  daemon always getting scheduled within that time frame.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/timer.h>
#include <linux/jiffies.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/fs.h>
#include <linux/ioport.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/uaccess.h>

#define OUR_NAME "w83877f_wdt"

#define ENABLE_W83877F_PORT 0x3F0
#define ENABLE_W83877F 0x87
#define DISABLE_W83877F 0xAA
#define WDT_PING 0x443
#define WDT_REGISTER 0x14
#define WDT_ENABLE 0x9C
#define WDT_DISABLE 0x8C

/*
 * The W83877F seems to be fixed at 1.6s timeout (at least on the
 * EMACS PC-104 board I'm using). If we reset the watchdog every
 * ~250ms we should be safe.  */

#define WDT_INTERVAL (HZ/4+1)

/*
 * We must not require too good response from the userspace daemon.
 * Here we require the userspace daemon to send us a heartbeat
 * char to /dev/watchdog every 30 seconds.
 */

#define WATCHDOG_TIMEOUT 30            /* 30 sec default timeout */
/* in seconds, will be multiplied by HZ to get seconds to wait for a ping */
static int timeout = WATCHDOG_TIMEOUT;
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout,
	"Watchdog timeout in seconds. (1<=timeout<=3600, default="
				__MODULE_STRING(WATCHDOG_TIMEOUT) ")");


static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout,
		"Watchdog cannot be stopped once started (default="
				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

static void wdt_timer_ping(struct timer_list *);
static DEFINE_TIMER(timer, wdt_timer_ping);
static unsigned long next_heartbeat;
static unsigned long wdt_is_open;
static char wdt_expect_close;
static DEFINE_SPINLOCK(wdt_spinlock);

/*
 *	Whack the dog
 */

static void wdt_timer_ping(struct timer_list *unused)
{
	/* If we got a heartbeat pulse within the WDT_US_INTERVAL
	 * we agree to ping the WDT
	 */
	if (time_before(jiffies, next_heartbeat)) {
		/* Ping the WDT */
		spin_lock(&wdt_spinlock);

		/* Ping the WDT by reading from WDT_PING */
		inb_p(WDT_PING);

		/* Re-set the timer interval */
		mod_timer(&timer, jiffies + WDT_INTERVAL);

		spin_unlock(&wdt_spinlock);

	} else
		pr_warn("Heartbeat lost! Will not ping the watchdog\n");
}

/*
 * Utility routines
 */

static void wdt_change(int writeval)
{
	unsigned long flags;
	spin_lock_irqsave(&wdt_spinlock, flags);

	/* buy some time */
	inb_p(WDT_PING);

	/* make W83877F available */
	outb_p(ENABLE_W83877F,  ENABLE_W83877F_PORT);
	outb_p(ENABLE_W83877F,  ENABLE_W83877F_PORT);

	/* enable watchdog */
	outb_p(WDT_REGISTER,    ENABLE_W83877F_PORT);
	outb_p(writeval,        ENABLE_W83877F_PORT+1);

	/* lock the W8387FF away */
	outb_p(DISABLE_W83877F, ENABLE_W83877F_PORT);

	spin_unlock_irqrestore(&wdt_spinlock, flags);
}

static void wdt_startup(void)
{
	next_heartbeat = jiffies + (timeout * HZ);

	/* Start the timer */
	mod_timer(&timer, jiffies + WDT_INTERVAL);

	wdt_change(WDT_ENABLE);

	pr_info("Watchdog timer is now enabled\n");
}

static void wdt_turnoff(void)
{
	/* Stop the timer */
	del_timer(&timer);

	wdt_change(WDT_DISABLE);

	pr_info("Watchdog timer is now disabled...\n");
}

static void wdt_keepalive(void)
{
	/* user land ping */
	next_heartbeat = jiffies + (timeout * HZ);
}

/*
 * /dev/watchdog handling
 */

static ssize_t fop_write(struct file *file, const char __user *buf,
						size_t count, loff_t *ppos)
{
	/* See if we got the magic character 'V' and reload the timer */
	if (count) {
		if (!nowayout) {
			size_t ofs;

			/* note: just in case someone wrote the magic
			   character five months ago... */
			wdt_expect_close = 0;

			/* scan to see whether or not we got the
			   magic character */
			for (ofs = 0; ofs != count; ofs++) {
				char c;
				if (get_user(c, buf + ofs))
					return -EFAULT;
				if (c == 'V')
					wdt_expect_close = 42;
			}
		}

		/* someone wrote to us, we should restart timer */
		wdt_keepalive();
	}
	return count;
}

static int fop_open(struct inode *inode, struct file *file)
{
	/* Just in case we're already talking to someone... */
	if (test_and_set_bit(0, &wdt_is_open))
		return -EBUSY;

	/* Good, fire up the show */
	wdt_startup();
	return nonseekable_open(inode, file);
}

static int fop_close(struct inode *inode, struct file *file)
{
	if (wdt_expect_close == 42)
		wdt_turnoff();
	else {
		del_timer(&timer);
		pr_crit("device file closed unexpectedly. Will not stop the WDT!\n");
	}
	clear_bit(0, &wdt_is_open);
	wdt_expect_close = 0;
	return 0;
}

static long fop_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 = {
		.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT
							| WDIOF_MAGICCLOSE,
		.firmware_version = 1,
		.identity = "W83877F",
	};

	switch (cmd) {
	case WDIOC_GETSUPPORT:
		return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
	case WDIOC_GETSTATUS:
	case WDIOC_GETBOOTSTATUS:
		return put_user(0, p);
	case WDIOC_SETOPTIONS:
	{
		int new_options, retval = -EINVAL;

		if (get_user(new_options, p))
			return -EFAULT;

		if (new_options & WDIOS_DISABLECARD) {
			wdt_turnoff();
			retval = 0;
		}

		if (new_options & WDIOS_ENABLECARD) {
			wdt_startup();
			retval = 0;
		}

		return retval;
	}
	case WDIOC_KEEPALIVE:
		wdt_keepalive();
		return 0;
	case WDIOC_SETTIMEOUT:
	{
		int new_timeout;

		if (get_user(new_timeout, p))
			return -EFAULT;

		/* arbitrary upper limit */
		if (new_timeout < 1 || new_timeout > 3600)
			return -EINVAL;

		timeout = new_timeout;
		wdt_keepalive();
		/* Fall through */
	}
	case WDIOC_GETTIMEOUT:
		return put_user(timeout, p);
	default:
		return -ENOTTY;
	}
}

static const struct file_operations wdt_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.write		= fop_write,
	.open		= fop_open,
	.release	= fop_close,
	.unlocked_ioctl	= fop_ioctl,
};

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

/*
 *	Notifier for system down
 */

static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
	void *unused)
{
	if (code == SYS_DOWN || code == SYS_HALT)
		wdt_turnoff();
	return NOTIFY_DONE;
}

/*
 *	The WDT needs to learn about soft shutdowns in order to
 *	turn the timebomb registers off.
 */

static struct notifier_block wdt_notifier = {
	.notifier_call = wdt_notify_sys,
};

static void __exit w83877f_wdt_unload(void)
{
	wdt_turnoff();

	/* Deregister */
	misc_deregister(&wdt_miscdev);

	unregister_reboot_notifier(&wdt_notifier);
	release_region(WDT_PING, 1);
	release_region(ENABLE_W83877F_PORT, 2);
}

static int __init w83877f_wdt_init(void)
{
	int rc = -EBUSY;

	if (timeout < 1 || timeout > 3600) { /* arbitrary upper limit */
		timeout = WATCHDOG_TIMEOUT;
		pr_info("timeout value must be 1 <= x <= 3600, using %d\n",
			timeout);
	}

	if (!request_region(ENABLE_W83877F_PORT, 2, "W83877F WDT")) {
		pr_err("I/O address 0x%04x already in use\n",
		       ENABLE_W83877F_PORT);
		rc = -EIO;
		goto err_out;
	}

	if (!request_region(WDT_PING, 1, "W8387FF WDT")) {
		pr_err("I/O address 0x%04x already in use\n", WDT_PING);
		rc = -EIO;
		goto err_out_region1;
	}

	rc = register_reboot_notifier(&wdt_notifier);
	if (rc) {
		pr_err("cannot register reboot notifier (err=%d)\n", rc);
		goto err_out_region2;
	}

	rc = misc_register(&wdt_miscdev);
	if (rc) {
		pr_err("cannot register miscdev on minor=%d (err=%d)\n",
		       wdt_miscdev.minor, rc);
		goto err_out_reboot;
	}

	pr_info("WDT driver for W83877F initialised. timeout=%d sec (nowayout=%d)\n",
		timeout, nowayout);

	return 0;

err_out_reboot:
	unregister_reboot_notifier(&wdt_notifier);
err_out_region2:
	release_region(WDT_PING, 1);
err_out_region1:
	release_region(ENABLE_W83877F_PORT, 2);
err_out:
	return rc;
}

module_init(w83877f_wdt_init);
module_exit(w83877f_wdt_unload);

MODULE_AUTHOR("Scott and Bill Jennings");
MODULE_DESCRIPTION("Driver for watchdog timer in w83877f chip");
MODULE_LICENSE("GPL");
Commit	Line	Data
1da177e4 LT	1	/*
	2	* W83877F Computer Watchdog Timer driver
	3	*
	4	* Based on acquirewdt.c by Alan Cox,
	5	* and sbc60xxwdt.c by Jakob Oestergaard <jakob@unthought.net>
	6	*
	7	* This program is free software; you can redistribute it and/or
	8	* modify it under the terms of the GNU General Public License
	9	* as published by the Free Software Foundation; either version
	10	* 2 of the License, or (at your option) any later version.
	11	*
	12	* The authors do NOT admit liability nor provide warranty for
	13	* any of this software. This material is provided "AS-IS" in
	14	* the hope that it may be useful for others.
	15	*
	16	* (c) Copyright 2001 Scott Jennings <linuxdrivers@oro.net>
	17	*
	18	* 4/19 - 2001 [Initial revision]
	19	* 9/27 - 2001 Added spinlocking
	20	* 4/12 - 2002 [rob@osinvestor.com] Eliminate extra comments
	21	* Eliminate fop_read
	22	* Eliminate extra spin_unlock
	23	* Added KERN_* tags to printks
	24	* add CONFIG_WATCHDOG_NOWAYOUT support
	25	* fix possible wdt_is_open race
c1cfd1a2 AC	26	* changed watchdog_info to correctly reflect what
	27	* the driver offers
	28	* added WDIOC_GETSTATUS, WDIOC_GETBOOTSTATUS,
	29	* WDIOC_SETTIMEOUT,
1da177e4 LT	30	* WDIOC_GETTIMEOUT, and WDIOC_SETOPTIONS ioctls
	31	* 09/8 - 2003 [wim@iguana.be] cleanup of trailing spaces
	32	* added extra printk's for startup problems
	33	* use module_param
c1cfd1a2 AC	34	* made timeout (the emulated heartbeat) a
c1cfd1a2 AC	35	* module_param
1da177e4 LT	36	* made the keepalive ping an internal subroutine
	37	*
	38	* This WDT driver is different from most other Linux WDT
	39	* drivers in that the driver will ping the watchdog by itself,
	40	* because this particular WDT has a very short timeout (1.6
	41	* seconds) and it would be insane to count on any userspace
	42	* daemon always getting scheduled within that time frame.
	43	*/
	44
27c766aa JP	45	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
27c766aa JP	46
1da177e4 LT	47	#include <linux/module.h>
	48	#include <linux/moduleparam.h>
	49	#include <linux/types.h>
	50	#include <linux/timer.h>
	51	#include <linux/jiffies.h>
	52	#include <linux/miscdevice.h>
	53	#include <linux/watchdog.h>
	54	#include <linux/fs.h>
	55	#include <linux/ioport.h>
	56	#include <linux/notifier.h>
	57	#include <linux/reboot.h>
	58	#include <linux/init.h>
c1cfd1a2 AC	59	#include <linux/io.h>
c1cfd1a2 AC	60	#include <linux/uaccess.h>
1da177e4 LT	61
1da177e4 LT	62	#define OUR_NAME "w83877f_wdt"
1da177e4 LT	63
	64	#define ENABLE_W83877F_PORT 0x3F0
	65	#define ENABLE_W83877F 0x87
	66	#define DISABLE_W83877F 0xAA
	67	#define WDT_PING 0x443
	68	#define WDT_REGISTER 0x14
	69	#define WDT_ENABLE 0x9C
	70	#define WDT_DISABLE 0x8C
	71
	72	/*
	73	* The W83877F seems to be fixed at 1.6s timeout (at least on the
	74	* EMACS PC-104 board I'm using). If we reset the watchdog every
	75	* ~250ms we should be safe. */
	76
	77	#define WDT_INTERVAL (HZ/4+1)
	78
	79	/*
	80	* We must not require too good response from the userspace daemon.
	81	* Here we require the userspace daemon to send us a heartbeat
	82	* char to /dev/watchdog every 30 seconds.
	83	*/
	84
	85	#define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */
c1cfd1a2 AC	86	/* in seconds, will be multiplied by HZ to get seconds to wait for a ping */
c1cfd1a2 AC	87	static int timeout = WATCHDOG_TIMEOUT;
1da177e4	88	module_param(timeout, int, 0);
c1cfd1a2 AC	89	MODULE_PARM_DESC(timeout,
	90	"Watchdog timeout in seconds. (1<=timeout<=3600, default="
	91	__MODULE_STRING(WATCHDOG_TIMEOUT) ")");
1da177e4 LT	92
1da177e4 LT	93
86a1e189 WVS	94	static bool nowayout = WATCHDOG_NOWAYOUT;
86a1e189 WVS	95	module_param(nowayout, bool, 0);
c1cfd1a2 AC	96	MODULE_PARM_DESC(nowayout,
	97	"Watchdog cannot be stopped once started (default="
	98	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
1da177e4	99
24ed960a	100	static void wdt_timer_ping(struct timer_list *);
1d27e3e2	101	static DEFINE_TIMER(timer, wdt_timer_ping);
1da177e4 LT	102	static unsigned long next_heartbeat;
	103	static unsigned long wdt_is_open;
	104	static char wdt_expect_close;
c7dfd0cc	105	static DEFINE_SPINLOCK(wdt_spinlock);
1da177e4 LT	106
	107	/*
	108	* Whack the dog
	109	*/
	110
24ed960a	111	static void wdt_timer_ping(struct timer_list *unused)
1da177e4 LT	112	{
	113	/* If we got a heartbeat pulse within the WDT_US_INTERVAL
	114	* we agree to ping the WDT
	115	*/
c1cfd1a2	116	if (time_before(jiffies, next_heartbeat)) {
1da177e4 LT	117	/* Ping the WDT */
	118	spin_lock(&wdt_spinlock);
	119
	120	/* Ping the WDT by reading from WDT_PING */
	121	inb_p(WDT_PING);
	122
	123	/* Re-set the timer interval */
82eb7c50	124	mod_timer(&timer, jiffies + WDT_INTERVAL);
1da177e4 LT	125
	126	spin_unlock(&wdt_spinlock);
	127
c1cfd1a2	128	} else
27c766aa	129	pr_warn("Heartbeat lost! Will not ping the watchdog\n");
1da177e4 LT	130	}
	131
	132	/*
	133	* Utility routines
	134	*/
	135
	136	static void wdt_change(int writeval)
	137	{
	138	unsigned long flags;
	139	spin_lock_irqsave(&wdt_spinlock, flags);
	140
	141	/* buy some time */
	142	inb_p(WDT_PING);
	143
	144	/* make W83877F available */
	145	outb_p(ENABLE_W83877F, ENABLE_W83877F_PORT);
	146	outb_p(ENABLE_W83877F, ENABLE_W83877F_PORT);
	147
	148	/* enable watchdog */
	149	outb_p(WDT_REGISTER, ENABLE_W83877F_PORT);
	150	outb_p(writeval, ENABLE_W83877F_PORT+1);
	151
	152	/* lock the W8387FF away */
	153	outb_p(DISABLE_W83877F, ENABLE_W83877F_PORT);
	154
	155	spin_unlock_irqrestore(&wdt_spinlock, flags);
	156	}
	157
	158	static void wdt_startup(void)
	159	{
	160	next_heartbeat = jiffies + (timeout * HZ);
	161
	162	/* Start the timer */
82eb7c50	163	mod_timer(&timer, jiffies + WDT_INTERVAL);
1da177e4 LT	164
	165	wdt_change(WDT_ENABLE);
	166
27c766aa	167	pr_info("Watchdog timer is now enabled\n");
1da177e4 LT	168	}
	169
	170	static void wdt_turnoff(void)
	171	{
	172	/* Stop the timer */
	173	del_timer(&timer);
	174
	175	wdt_change(WDT_DISABLE);
	176
27c766aa	177	pr_info("Watchdog timer is now disabled...\n");
1da177e4 LT	178	}
	179
	180	static void wdt_keepalive(void)
	181	{
	182	/* user land ping */
	183	next_heartbeat = jiffies + (timeout * HZ);
	184	}
	185
	186	/*
	187	* /dev/watchdog handling
	188	*/
	189
c1cfd1a2 AC	190	static ssize_t fop_write(struct file file, const char __user buf,
c1cfd1a2 AC	191	size_t count, loff_t *ppos)
1da177e4 LT	192	{
1da177e4 LT	193	/* See if we got the magic character 'V' and reload the timer */
c1cfd1a2 AC	194	if (count) {
c1cfd1a2 AC	195	if (!nowayout) {
1da177e4 LT	196	size_t ofs;
1da177e4 LT	197
c1cfd1a2 AC	198	/* note: just in case someone wrote the magic
c1cfd1a2 AC	199	character five months ago... */
1da177e4 LT	200	wdt_expect_close = 0;
1da177e4 LT	201
c1cfd1a2 AC	202	/* scan to see whether or not we got the
	203	magic character */
	204	for (ofs = 0; ofs != count; ofs++) {
1da177e4 LT	205	char c;
	206	if (get_user(c, buf + ofs))
	207	return -EFAULT;
	208	if (c == 'V')
	209	wdt_expect_close = 42;
	210	}
	211	}
	212
	213	/* someone wrote to us, we should restart timer */
	214	wdt_keepalive();
	215	}
	216	return count;
	217	}
	218
c1cfd1a2	219	static int fop_open(struct inode inode, struct file file)
1da177e4 LT	220	{
1da177e4 LT	221	/* Just in case we're already talking to someone... */
c1cfd1a2	222	if (test_and_set_bit(0, &wdt_is_open))
1da177e4 LT	223	return -EBUSY;
	224
	225	/* Good, fire up the show */
	226	wdt_startup();
	227	return nonseekable_open(inode, file);
	228	}
	229
c1cfd1a2	230	static int fop_close(struct inode inode, struct file file)
1da177e4	231	{
c1cfd1a2	232	if (wdt_expect_close == 42)
1da177e4 LT	233	wdt_turnoff();
	234	else {
	235	del_timer(&timer);
27c766aa	236	pr_crit("device file closed unexpectedly. Will not stop the WDT!\n");
1da177e4 LT	237	}
	238	clear_bit(0, &wdt_is_open);
	239	wdt_expect_close = 0;
	240	return 0;
	241	}
	242
c1cfd1a2	243	static long fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1da177e4 LT	244	{
	245	void __user argp = (void __user )arg;
	246	int __user *p = argp;
c1cfd1a2 AC	247	static const struct watchdog_info ident = {
	248	.options = WDIOF_KEEPALIVEPING \| WDIOF_SETTIMEOUT
	249	\| WDIOF_MAGICCLOSE,
1da177e4 LT	250	.firmware_version = 1,
	251	.identity = "W83877F",
	252	};
	253
c1cfd1a2	254	switch (cmd) {
c1cfd1a2 AC	255	case WDIOC_GETSUPPORT:
	256	return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
	257	case WDIOC_GETSTATUS:
	258	case WDIOC_GETBOOTSTATUS:
	259	return put_user(0, p);
c1cfd1a2	260	case WDIOC_SETOPTIONS:
1da177e4	261	{
c1cfd1a2	262	int new_options, retval = -EINVAL;
1da177e4	263
c1cfd1a2 AC	264	if (get_user(new_options, p))
c1cfd1a2 AC	265	return -EFAULT;
1da177e4	266
c1cfd1a2 AC	267	if (new_options & WDIOS_DISABLECARD) {
	268	wdt_turnoff();
	269	retval = 0;
1da177e4	270	}
1da177e4	271
c1cfd1a2 AC	272	if (new_options & WDIOS_ENABLECARD) {
	273	wdt_startup();
	274	retval = 0;
	275	}
1da177e4	276
c1cfd1a2 AC	277	return retval;
c1cfd1a2 AC	278	}
0c06090c WVS	279	case WDIOC_KEEPALIVE:
	280	wdt_keepalive();
	281	return 0;
c1cfd1a2 AC	282	case WDIOC_SETTIMEOUT:
	283	{
	284	int new_timeout;
1da177e4	285
c1cfd1a2 AC	286	if (get_user(new_timeout, p))
	287	return -EFAULT;
	288
	289	/* arbitrary upper limit */
	290	if (new_timeout < 1 \|\| new_timeout > 3600)
	291	return -EINVAL;
	292
	293	timeout = new_timeout;
	294	wdt_keepalive();
	295	/* Fall through */
	296	}
	297	case WDIOC_GETTIMEOUT:
	298	return put_user(timeout, p);
0c06090c WVS	299	default:
0c06090c WVS	300	return -ENOTTY;
1da177e4 LT	301	}
	302	}
	303
62322d25	304	static const struct file_operations wdt_fops = {
1da177e4 LT	305	.owner = THIS_MODULE,
	306	.llseek = no_llseek,
	307	.write = fop_write,
	308	.open = fop_open,
	309	.release = fop_close,
c1cfd1a2	310	.unlocked_ioctl = fop_ioctl,
1da177e4 LT	311	};
	312
	313	static struct miscdevice wdt_miscdev = {
	314	.minor = WATCHDOG_MINOR,
	315	.name = "watchdog",
	316	.fops = &wdt_fops,
	317	};
	318
	319	/*
	320	* Notifier for system down
	321	*/
	322
	323	static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
	324	void *unused)
	325	{
c1cfd1a2	326	if (code == SYS_DOWN \|\| code == SYS_HALT)
1da177e4 LT	327	wdt_turnoff();
	328	return NOTIFY_DONE;
	329	}
	330
	331	/*
	332	* The WDT needs to learn about soft shutdowns in order to
	333	* turn the timebomb registers off.
	334	*/
	335
c1cfd1a2	336	static struct notifier_block wdt_notifier = {
1da177e4 LT	337	.notifier_call = wdt_notify_sys,
	338	};
	339
	340	static void __exit w83877f_wdt_unload(void)
	341	{
	342	wdt_turnoff();
	343
	344	/* Deregister */
	345	misc_deregister(&wdt_miscdev);
	346
	347	unregister_reboot_notifier(&wdt_notifier);
c1cfd1a2 AC	348	release_region(WDT_PING, 1);
c1cfd1a2 AC	349	release_region(ENABLE_W83877F_PORT, 2);
1da177e4 LT	350	}
	351
	352	static int __init w83877f_wdt_init(void)
	353	{
	354	int rc = -EBUSY;
	355
c1cfd1a2	356	if (timeout < 1 \|\| timeout > 3600) { /* arbitrary upper limit */
1da177e4	357	timeout = WATCHDOG_TIMEOUT;
27c766aa JP	358	pr_info("timeout value must be 1 <= x <= 3600, using %d\n",
27c766aa JP	359	timeout);
1da177e4 LT	360	}
1da177e4 LT	361
c1cfd1a2	362	if (!request_region(ENABLE_W83877F_PORT, 2, "W83877F WDT")) {
27c766aa JP	363	pr_err("I/O address 0x%04x already in use\n",
27c766aa JP	364	ENABLE_W83877F_PORT);
1da177e4 LT	365	rc = -EIO;
	366	goto err_out;
	367	}
	368
c1cfd1a2	369	if (!request_region(WDT_PING, 1, "W8387FF WDT")) {
27c766aa	370	pr_err("I/O address 0x%04x already in use\n", WDT_PING);
1da177e4 LT	371	rc = -EIO;
	372	goto err_out_region1;
	373	}
	374
c6cb13ae	375	rc = register_reboot_notifier(&wdt_notifier);
c1cfd1a2	376	if (rc) {
27c766aa	377	pr_err("cannot register reboot notifier (err=%d)\n", rc);
1da177e4 LT	378	goto err_out_region2;
	379	}
	380
c6cb13ae	381	rc = misc_register(&wdt_miscdev);
c1cfd1a2	382	if (rc) {
27c766aa JP	383	pr_err("cannot register miscdev on minor=%d (err=%d)\n",
27c766aa JP	384	wdt_miscdev.minor, rc);
c6cb13ae	385	goto err_out_reboot;
1da177e4 LT	386	}
1da177e4 LT	387
27c766aa	388	pr_info("WDT driver for W83877F initialised. timeout=%d sec (nowayout=%d)\n",
1da177e4 LT	389	timeout, nowayout);
	390
	391	return 0;
	392
c6cb13ae WVS	393	err_out_reboot:
c6cb13ae WVS	394	unregister_reboot_notifier(&wdt_notifier);
1da177e4	395	err_out_region2:
c1cfd1a2	396	release_region(WDT_PING, 1);
1da177e4	397	err_out_region1:
c1cfd1a2	398	release_region(ENABLE_W83877F_PORT, 2);
1da177e4 LT	399	err_out:
	400	return rc;
	401	}
	402
	403	module_init(w83877f_wdt_init);
	404	module_exit(w83877f_wdt_unload);
	405
	406	MODULE_AUTHOR("Scott and Bill Jennings");
	407	MODULE_DESCRIPTION("Driver for watchdog timer in w83877f chip");
	408	MODULE_LICENSE("GPL");