[net-next-2.6.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.
 */

#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>
#include <asm/system.h>

#define OUR_NAME "w83877f_wdt"
#define PFX OUR_NAME ": "

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

static void wdt_timer_ping(unsigned long);
static DEFINE_TIMER(timer, wdt_timer_ping, 0, 0);
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(unsigned long data)
{
	/* 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
		printk(KERN_WARNING PFX
			"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);

	printk(KERN_INFO PFX "Watchdog timer is now enabled.\n");
}

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

	wdt_change(WDT_DISABLE);

	printk(KERN_INFO PFX "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);
		printk(KERN_CRIT PFX
		  "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;
		printk(KERN_INFO PFX
			"timeout value must be 1 <= x <= 3600, using %d\n",
							timeout);
	}

	if (!request_region(ENABLE_W83877F_PORT, 2, "W83877F WDT")) {
		printk(KERN_ERR PFX "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")) {
		printk(KERN_ERR PFX "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) {
		printk(KERN_ERR PFX
			"cannot register reboot notifier (err=%d)\n", rc);
		goto err_out_region2;
	}

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

	printk(KERN_INFO PFX
	  "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");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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
	45	#include <linux/module.h>
	46	#include <linux/moduleparam.h>
	47	#include <linux/types.h>
	48	#include <linux/timer.h>
	49	#include <linux/jiffies.h>
	50	#include <linux/miscdevice.h>
	51	#include <linux/watchdog.h>
	52	#include <linux/fs.h>
	53	#include <linux/ioport.h>
	54	#include <linux/notifier.h>
	55	#include <linux/reboot.h>
	56	#include <linux/init.h>
c1cfd1a2 AC	57	#include <linux/io.h>
c1cfd1a2 AC	58	#include <linux/uaccess.h>
1da177e4 LT	59	#include <asm/system.h>
	60
	61	#define OUR_NAME "w83877f_wdt"
	62	#define PFX OUR_NAME ": "
	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
4bfdf378	94	static int nowayout = WATCHDOG_NOWAYOUT;
1da177e4	95	module_param(nowayout, int, 0);
c1cfd1a2 AC	96	MODULE_PARM_DESC(nowayout,
	97	"Watchdog cannot be stopped once started (default="
	98	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
1da177e4 LT	99
1da177e4 LT	100	static void wdt_timer_ping(unsigned long);
82eb7c50	101	static DEFINE_TIMER(timer, wdt_timer_ping, 0, 0);
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
	111	static void wdt_timer_ping(unsigned long data)
	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 AC	128	} else
	129	printk(KERN_WARNING PFX
	130	"Heartbeat lost! Will not ping the watchdog\n");
1da177e4 LT	131	}
	132
	133	/*
	134	* Utility routines
	135	*/
	136
	137	static void wdt_change(int writeval)
	138	{
	139	unsigned long flags;
	140	spin_lock_irqsave(&wdt_spinlock, flags);
	141
	142	/* buy some time */
	143	inb_p(WDT_PING);
	144
	145	/* make W83877F available */
	146	outb_p(ENABLE_W83877F, ENABLE_W83877F_PORT);
	147	outb_p(ENABLE_W83877F, ENABLE_W83877F_PORT);
	148
	149	/* enable watchdog */
	150	outb_p(WDT_REGISTER, ENABLE_W83877F_PORT);
	151	outb_p(writeval, ENABLE_W83877F_PORT+1);
	152
	153	/* lock the W8387FF away */
	154	outb_p(DISABLE_W83877F, ENABLE_W83877F_PORT);
	155
	156	spin_unlock_irqrestore(&wdt_spinlock, flags);
	157	}
	158
	159	static void wdt_startup(void)
	160	{
	161	next_heartbeat = jiffies + (timeout * HZ);
	162
	163	/* Start the timer */
82eb7c50	164	mod_timer(&timer, jiffies + WDT_INTERVAL);
1da177e4 LT	165
	166	wdt_change(WDT_ENABLE);
	167
	168	printk(KERN_INFO PFX "Watchdog timer is now enabled.\n");
	169	}
	170
	171	static void wdt_turnoff(void)
	172	{
	173	/* Stop the timer */
	174	del_timer(&timer);
	175
	176	wdt_change(WDT_DISABLE);
	177
	178	printk(KERN_INFO PFX "Watchdog timer is now disabled...\n");
	179	}
	180
	181	static void wdt_keepalive(void)
	182	{
	183	/* user land ping */
	184	next_heartbeat = jiffies + (timeout * HZ);
	185	}
	186
	187	/*
	188	* /dev/watchdog handling
	189	*/
	190
c1cfd1a2 AC	191	static ssize_t fop_write(struct file file, const char __user buf,
c1cfd1a2 AC	192	size_t count, loff_t *ppos)
1da177e4 LT	193	{
1da177e4 LT	194	/* See if we got the magic character 'V' and reload the timer */
c1cfd1a2 AC	195	if (count) {
c1cfd1a2 AC	196	if (!nowayout) {
1da177e4 LT	197	size_t ofs;
1da177e4 LT	198
c1cfd1a2 AC	199	/* note: just in case someone wrote the magic
c1cfd1a2 AC	200	character five months ago... */
1da177e4 LT	201	wdt_expect_close = 0;
1da177e4 LT	202
c1cfd1a2 AC	203	/* scan to see whether or not we got the
	204	magic character */
	205	for (ofs = 0; ofs != count; ofs++) {
1da177e4 LT	206	char c;
	207	if (get_user(c, buf + ofs))
	208	return -EFAULT;
	209	if (c == 'V')
	210	wdt_expect_close = 42;
	211	}
	212	}
	213
	214	/* someone wrote to us, we should restart timer */
	215	wdt_keepalive();
	216	}
	217	return count;
	218	}
	219
c1cfd1a2	220	static int fop_open(struct inode inode, struct file file)
1da177e4 LT	221	{
1da177e4 LT	222	/* Just in case we're already talking to someone... */
c1cfd1a2	223	if (test_and_set_bit(0, &wdt_is_open))
1da177e4 LT	224	return -EBUSY;
	225
	226	/* Good, fire up the show */
	227	wdt_startup();
	228	return nonseekable_open(inode, file);
	229	}
	230
c1cfd1a2	231	static int fop_close(struct inode inode, struct file file)
1da177e4	232	{
c1cfd1a2	233	if (wdt_expect_close == 42)
1da177e4 LT	234	wdt_turnoff();
	235	else {
	236	del_timer(&timer);
c1cfd1a2 AC	237	printk(KERN_CRIT PFX
c1cfd1a2 AC	238	"device file closed unexpectedly. Will not stop the WDT!\n");
1da177e4 LT	239	}
	240	clear_bit(0, &wdt_is_open);
	241	wdt_expect_close = 0;
	242	return 0;
	243	}
	244
c1cfd1a2	245	static long fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1da177e4 LT	246	{
	247	void __user argp = (void __user )arg;
	248	int __user *p = argp;
c1cfd1a2 AC	249	static const struct watchdog_info ident = {
	250	.options = WDIOF_KEEPALIVEPING \| WDIOF_SETTIMEOUT
	251	\| WDIOF_MAGICCLOSE,
1da177e4 LT	252	.firmware_version = 1,
	253	.identity = "W83877F",
	254	};
	255
c1cfd1a2	256	switch (cmd) {
c1cfd1a2 AC	257	case WDIOC_GETSUPPORT:
	258	return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
	259	case WDIOC_GETSTATUS:
	260	case WDIOC_GETBOOTSTATUS:
	261	return put_user(0, p);
c1cfd1a2	262	case WDIOC_SETOPTIONS:
1da177e4	263	{
c1cfd1a2	264	int new_options, retval = -EINVAL;
1da177e4	265
c1cfd1a2 AC	266	if (get_user(new_options, p))
c1cfd1a2 AC	267	return -EFAULT;
1da177e4	268
c1cfd1a2 AC	269	if (new_options & WDIOS_DISABLECARD) {
	270	wdt_turnoff();
	271	retval = 0;
1da177e4	272	}
1da177e4	273
c1cfd1a2 AC	274	if (new_options & WDIOS_ENABLECARD) {
	275	wdt_startup();
	276	retval = 0;
	277	}
1da177e4	278
c1cfd1a2 AC	279	return retval;
c1cfd1a2 AC	280	}
0c06090c WVS	281	case WDIOC_KEEPALIVE:
	282	wdt_keepalive();
	283	return 0;
c1cfd1a2 AC	284	case WDIOC_SETTIMEOUT:
	285	{
	286	int new_timeout;
1da177e4	287
c1cfd1a2 AC	288	if (get_user(new_timeout, p))
	289	return -EFAULT;
	290
	291	/* arbitrary upper limit */
	292	if (new_timeout < 1 \|\| new_timeout > 3600)
	293	return -EINVAL;
	294
	295	timeout = new_timeout;
	296	wdt_keepalive();
	297	/* Fall through */
	298	}
	299	case WDIOC_GETTIMEOUT:
	300	return put_user(timeout, p);
0c06090c WVS	301	default:
0c06090c WVS	302	return -ENOTTY;
1da177e4 LT	303	}
	304	}
	305
62322d25	306	static const struct file_operations wdt_fops = {
1da177e4 LT	307	.owner = THIS_MODULE,
	308	.llseek = no_llseek,
	309	.write = fop_write,
	310	.open = fop_open,
	311	.release = fop_close,
c1cfd1a2	312	.unlocked_ioctl = fop_ioctl,
1da177e4 LT	313	};
	314
	315	static struct miscdevice wdt_miscdev = {
	316	.minor = WATCHDOG_MINOR,
	317	.name = "watchdog",
	318	.fops = &wdt_fops,
	319	};
	320
	321	/*
	322	* Notifier for system down
	323	*/
	324
	325	static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
	326	void *unused)
	327	{
c1cfd1a2	328	if (code == SYS_DOWN \|\| code == SYS_HALT)
1da177e4 LT	329	wdt_turnoff();
	330	return NOTIFY_DONE;
	331	}
	332
	333	/*
	334	* The WDT needs to learn about soft shutdowns in order to
	335	* turn the timebomb registers off.
	336	*/
	337
c1cfd1a2	338	static struct notifier_block wdt_notifier = {
1da177e4 LT	339	.notifier_call = wdt_notify_sys,
	340	};
	341
	342	static void __exit w83877f_wdt_unload(void)
	343	{
	344	wdt_turnoff();
	345
	346	/* Deregister */
	347	misc_deregister(&wdt_miscdev);
	348
	349	unregister_reboot_notifier(&wdt_notifier);
c1cfd1a2 AC	350	release_region(WDT_PING, 1);
c1cfd1a2 AC	351	release_region(ENABLE_W83877F_PORT, 2);
1da177e4 LT	352	}
	353
	354	static int __init w83877f_wdt_init(void)
	355	{
	356	int rc = -EBUSY;
	357
c1cfd1a2	358	if (timeout < 1 \|\| timeout > 3600) { /* arbitrary upper limit */
1da177e4	359	timeout = WATCHDOG_TIMEOUT;
c1cfd1a2 AC	360	printk(KERN_INFO PFX
	361	"timeout value must be 1 <= x <= 3600, using %d\n",
	362	timeout);
1da177e4 LT	363	}
1da177e4 LT	364
c1cfd1a2	365	if (!request_region(ENABLE_W83877F_PORT, 2, "W83877F WDT")) {
1da177e4 LT	366	printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
	367	ENABLE_W83877F_PORT);
	368	rc = -EIO;
	369	goto err_out;
	370	}
	371
c1cfd1a2	372	if (!request_region(WDT_PING, 1, "W8387FF WDT")) {
1da177e4 LT	373	printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
	374	WDT_PING);
	375	rc = -EIO;
	376	goto err_out_region1;
	377	}
	378
c6cb13ae	379	rc = register_reboot_notifier(&wdt_notifier);
c1cfd1a2 AC	380	if (rc) {
	381	printk(KERN_ERR PFX
	382	"cannot register reboot notifier (err=%d)\n", rc);
1da177e4 LT	383	goto err_out_region2;
	384	}
	385
c6cb13ae	386	rc = misc_register(&wdt_miscdev);
c1cfd1a2 AC	387	if (rc) {
	388	printk(KERN_ERR PFX
	389	"cannot register miscdev on minor=%d (err=%d)\n",
	390	wdt_miscdev.minor, rc);
c6cb13ae	391	goto err_out_reboot;
1da177e4 LT	392	}
1da177e4 LT	393
c1cfd1a2 AC	394	printk(KERN_INFO PFX
c1cfd1a2 AC	395	"WDT driver for W83877F initialised. timeout=%d sec (nowayout=%d)\n",
1da177e4 LT	396	timeout, nowayout);
	397
	398	return 0;
	399
c6cb13ae WVS	400	err_out_reboot:
c6cb13ae WVS	401	unregister_reboot_notifier(&wdt_notifier);
1da177e4	402	err_out_region2:
c1cfd1a2	403	release_region(WDT_PING, 1);
1da177e4	404	err_out_region1:
c1cfd1a2	405	release_region(ENABLE_W83877F_PORT, 2);
1da177e4 LT	406	err_out:
	407	return rc;
	408	}
	409
	410	module_init(w83877f_wdt_init);
	411	module_exit(w83877f_wdt_unload);
	412
	413	MODULE_AUTHOR("Scott and Bill Jennings");
	414	MODULE_DESCRIPTION("Driver for watchdog timer in w83877f chip");
	415	MODULE_LICENSE("GPL");
	416	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);