drivers/char/watchdog/sbc60xxwdt.c - kernel/msm-4.9 - Gitiles

 /*
  *	60xx Single Board Computer Watchdog Timer driver for Linux 2.2.x
  *
  *      Based on acquirewdt.c by Alan Cox.
  *
  *	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 does 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 2000    Jakob Oestergaard <jakob@unthought.net>
  *
  *           12/4 - 2000      [Initial revision]
  *           25/4 - 2000      Added /dev/watchdog support
  *           09/5 - 2001      [smj@oro.net] fixed fop_write to "return 1" on success
  *           12/4 - 2002      [rob@osinvestor.com] eliminate fop_read
  *                            fix possible wdt_is_open race
  *                            add CONFIG_WATCHDOG_NOWAYOUT support
  *                            remove lock_kernel/unlock_kernel pairs
  *                            added KERN_* to printk's
  *                            got rid of extraneous comments
  *                            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
  *                            use module_param
  *                            made timeout (the emulated heartbeat) a module_param
  *                            made the keepalive ping an internal subroutine
  *                            made wdt_stop and wdt_start module params
  *                            added extra printk's for startup problems
  *                            added MODULE_AUTHOR and MODULE_DESCRIPTION info
  *
  *
  *  This WDT driver is different from the other Linux WDT
  *  drivers in the following ways:
  *  *)  The driver will ping the watchdog by itself, because this
  *      particular WDT has a very short timeout (one second) 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 <asm/io.h>
 #include <asm/uaccess.h>
 #include <asm/system.h>

 #define OUR_NAME "sbc60xxwdt"
 #define PFX OUR_NAME ": "

 /*
  * You must set these - The driver cannot probe for the settings
  */

 static int wdt_stop = 0x45;
 module_param(wdt_stop, int, 0);
 MODULE_PARM_DESC(wdt_stop, "SBC60xx WDT 'stop' io port (default 0x45)");

 static int wdt_start = 0x443;
 module_param(wdt_start, int, 0);
 MODULE_PARM_DESC(wdt_start, "SBC60xx WDT 'start' io port (default 0x443)");

 /*
  * The 60xx board can use watchdog timeout values from one second
  * to several minutes.  The default is one second, so 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.
  * If the daemon pulses us every 25 seconds, we can still afford
  * a 5 second scheduling delay on the (high priority) daemon. That
  * should be sufficient for a box under any load.
  */

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

 #ifdef CONFIG_WATCHDOG_NOWAYOUT
 static int nowayout = 1;
 #else
 static int nowayout = 0;
 #endif

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

 static void wdt_timer_ping(unsigned long);
 static struct timer_list timer;
 static unsigned long next_heartbeat;
 static unsigned long wdt_is_open;
 static char wdt_expect_close;

 /*
  *	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 by reading from wdt_start */
 		inb_p(wdt_start);
 		/* Re-set the timer interval */
 		timer.expires = jiffies + WDT_INTERVAL;
 		add_timer(&timer);
 	} else {
 		printk(KERN_WARNING PFX "Heartbeat lost! Will not ping the watchdog\n");
 	}
 }

 /*
  * Utility routines
  */

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

 	/* Start the timer */
 	timer.expires = jiffies + WDT_INTERVAL;
 	add_timer(&timer);
 	printk(KERN_INFO PFX "Watchdog timer is now enabled.\n");
 }

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

 		/* Well, anyhow someone wrote to us, we should return that favour */
 		wdt_keepalive();
 	}
 	return count;
 }

 static int fop_open(struct inode * inode, struct file * file)
 {
 	nonseekable_open(inode, file);

 	/* Just in case we're already talking to someone... */
 	if(test_and_set_bit(0, &wdt_is_open))
 		return -EBUSY;

 	if (nowayout)
 		__module_get(THIS_MODULE);

 	/* Good, fire up the show */
 	wdt_startup();
 	return 0;
 }

 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 int fop_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
 	unsigned long arg)
 {
 	void __user *argp = (void __user *)arg;
 	int __user *p = argp;
 	static struct watchdog_info ident=
 	{
 		.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
 		.firmware_version = 1,
 		.identity = "SBC60xx",
 	};

 	switch(cmd)
 	{
 		default:
 			return -ENOIOCTLCMD;
 		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_KEEPALIVE:
 			wdt_keepalive();
 			return 0;
 		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_SETTIMEOUT:
 		{
 			int new_timeout;

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

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

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

 static struct file_operations wdt_fops = {
 	.owner		= THIS_MODULE,
 	.llseek		= no_llseek,
 	.write		= fop_write,
 	.open		= fop_open,
 	.release	= fop_close,
 	.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 sbc60xxwdt_unload(void)
 {
 	wdt_turnoff();

 	/* Deregister */
 	misc_deregister(&wdt_miscdev);

 	unregister_reboot_notifier(&wdt_notifier);
 	if ((wdt_stop != 0x45) && (wdt_stop != wdt_start))
 		release_region(wdt_stop,1);
 	release_region(wdt_start,1);
 }

 static int __init sbc60xxwdt_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(wdt_start, 1, "SBC 60XX WDT"))
 	{
 		printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
 			wdt_start);
 		rc = -EIO;
 		goto err_out;
 	}

 	/* We cannot reserve 0x45 - the kernel already has! */
 	if ((wdt_stop != 0x45) && (wdt_stop != wdt_start))
 	{
 		if (!request_region(wdt_stop, 1, "SBC 60XX WDT"))
 		{
 			printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
 				wdt_stop);
 			rc = -EIO;
 			goto err_out_region1;
 		}
 	}

 	init_timer(&timer);
 	timer.function = wdt_timer_ping;
 	timer.data = 0;

 	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_region2;
 	}

 	rc = register_reboot_notifier(&wdt_notifier);
 	if (rc)
 	{
 		printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
 			rc);
 		goto err_out_miscdev;
 	}

 	printk(KERN_INFO PFX "WDT driver for 60XX single board computer initialised. timeout=%d sec (nowayout=%d)\n",
 		timeout, nowayout);

 	return 0;

 err_out_miscdev:
 	misc_deregister(&wdt_miscdev);
 err_out_region2:
 	if ((wdt_stop != 0x45) && (wdt_stop != wdt_start))
 		release_region(wdt_stop,1);
 err_out_region1:
 	release_region(wdt_start,1);
 err_out:
 	return rc;
 }

 module_init(sbc60xxwdt_init);
 module_exit(sbc60xxwdt_unload);

 MODULE_AUTHOR("Jakob Oestergaard <jakob@unthought.net>");
 MODULE_DESCRIPTION("60xx Single Board Computer Watchdog Timer driver");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
	/*
	* 60xx Single Board Computer Watchdog Timer driver for Linux 2.2.x
	*
	* Based on acquirewdt.c by Alan Cox.
	*
	* 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 does 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 2000 Jakob Oestergaard <jakob@unthought.net>
	*
	* 12/4 - 2000 [Initial revision]
	* 25/4 - 2000 Added /dev/watchdog support
	* 09/5 - 2001 [smj@oro.net] fixed fop_write to "return 1" on success
	* 12/4 - 2002 [rob@osinvestor.com] eliminate fop_read
	* fix possible wdt_is_open race
	* add CONFIG_WATCHDOG_NOWAYOUT support
	* remove lock_kernel/unlock_kernel pairs
	* added KERN_* to printk's
	* got rid of extraneous comments
	* 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
	* use module_param
	* made timeout (the emulated heartbeat) a module_param
	* made the keepalive ping an internal subroutine
	* made wdt_stop and wdt_start module params
	* added extra printk's for startup problems
	* added MODULE_AUTHOR and MODULE_DESCRIPTION info
	*
	*
	* This WDT driver is different from the other Linux WDT
	* drivers in the following ways:
	* *) The driver will ping the watchdog by itself, because this
	* particular WDT has a very short timeout (one second) 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 <asm/io.h>
	#include <asm/uaccess.h>
	#include <asm/system.h>

	#define OUR_NAME "sbc60xxwdt"
	#define PFX OUR_NAME ": "

	/*
	* You must set these - The driver cannot probe for the settings
	*/

	static int wdt_stop = 0x45;
	module_param(wdt_stop, int, 0);
	MODULE_PARM_DESC(wdt_stop, "SBC60xx WDT 'stop' io port (default 0x45)");

	static int wdt_start = 0x443;
	module_param(wdt_start, int, 0);
	MODULE_PARM_DESC(wdt_start, "SBC60xx WDT 'start' io port (default 0x443)");

	/*
	* The 60xx board can use watchdog timeout values from one second
	* to several minutes. The default is one second, so 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.
	* If the daemon pulses us every 25 seconds, we can still afford
	* a 5 second scheduling delay on the (high priority) daemon. That
	* should be sufficient for a box under any load.
	*/

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

	#ifdef CONFIG_WATCHDOG_NOWAYOUT
	static int nowayout = 1;
	#else
	static int nowayout = 0;
	#endif

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

	static void wdt_timer_ping(unsigned long);
	static struct timer_list timer;
	static unsigned long next_heartbeat;
	static unsigned long wdt_is_open;
	static char wdt_expect_close;

	/*
	* 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 by reading from wdt_start */
	inb_p(wdt_start);
	/* Re-set the timer interval */
	timer.expires = jiffies + WDT_INTERVAL;
	add_timer(&timer);
	} else {
	printk(KERN_WARNING PFX "Heartbeat lost! Will not ping the watchdog\n");
	}
	}

	/*
	* Utility routines
	*/

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

	/* Start the timer */
	timer.expires = jiffies + WDT_INTERVAL;
	add_timer(&timer);
	printk(KERN_INFO PFX "Watchdog timer is now enabled.\n");
	}

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

	/* Well, anyhow someone wrote to us, we should return that favour */
	wdt_keepalive();
	}
	return count;
	}

	static int fop_open(struct inode * inode, struct file * file)
	{
	nonseekable_open(inode, file);

	/* Just in case we're already talking to someone... */
	if(test_and_set_bit(0, &wdt_is_open))
	return -EBUSY;

	if (nowayout)
	__module_get(THIS_MODULE);

	/* Good, fire up the show */
	wdt_startup();
	return 0;
	}

	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 int fop_ioctl(struct inode inode, struct file file, unsigned int cmd,
	unsigned long arg)
	{
	void __user argp = (void __user )arg;
	int __user *p = argp;
	static struct watchdog_info ident=
	{
	.options = WDIOF_KEEPALIVEPING \| WDIOF_SETTIMEOUT \| WDIOF_MAGICCLOSE,
	.firmware_version = 1,
	.identity = "SBC60xx",
	};

	switch(cmd)
	{
	default:
	return -ENOIOCTLCMD;
	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_KEEPALIVE:
	wdt_keepalive();
	return 0;
	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_SETTIMEOUT:
	{
	int new_timeout;

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

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

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

	static struct file_operations wdt_fops = {
	.owner = THIS_MODULE,
	.llseek = no_llseek,
	.write = fop_write,
	.open = fop_open,
	.release = fop_close,
	.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 sbc60xxwdt_unload(void)
	{
	wdt_turnoff();

	/* Deregister */
	misc_deregister(&wdt_miscdev);

	unregister_reboot_notifier(&wdt_notifier);
	if ((wdt_stop != 0x45) && (wdt_stop != wdt_start))
	release_region(wdt_stop,1);
	release_region(wdt_start,1);
	}

	static int __init sbc60xxwdt_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(wdt_start, 1, "SBC 60XX WDT"))
	{
	printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
	wdt_start);
	rc = -EIO;
	goto err_out;
	}

	/* We cannot reserve 0x45 - the kernel already has! */
	if ((wdt_stop != 0x45) && (wdt_stop != wdt_start))
	{
	if (!request_region(wdt_stop, 1, "SBC 60XX WDT"))
	{
	printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
	wdt_stop);
	rc = -EIO;
	goto err_out_region1;
	}
	}

	init_timer(&timer);
	timer.function = wdt_timer_ping;
	timer.data = 0;

	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_region2;
	}

	rc = register_reboot_notifier(&wdt_notifier);
	if (rc)
	{
	printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
	rc);
	goto err_out_miscdev;
	}

	printk(KERN_INFO PFX "WDT driver for 60XX single board computer initialised. timeout=%d sec (nowayout=%d)\n",
	timeout, nowayout);

	return 0;

	err_out_miscdev:
	misc_deregister(&wdt_miscdev);
	err_out_region2:
	if ((wdt_stop != 0x45) && (wdt_stop != wdt_start))
	release_region(wdt_stop,1);
	err_out_region1:
	release_region(wdt_start,1);
	err_out:
	return rc;
	}

	module_init(sbc60xxwdt_init);
	module_exit(sbc60xxwdt_unload);

	MODULE_AUTHOR("Jakob Oestergaard <jakob@unthought.net>");
	MODULE_DESCRIPTION("60xx Single Board Computer Watchdog Timer driver");
	MODULE_LICENSE("GPL");
	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);