drivers/watchdog/w83697hf_wdt.c - arm/linux-arm-legacy - Git at Google

 /*
  *	w83697hf/hg WDT driver
  *
  *	(c) Copyright 2006 Samuel Tardieu <sam@rfc1149.net>
  *	(c) Copyright 2006 Marcus Junker <junker@anduras.de>
  *
  *	Based on w83627hf_wdt.c which is based on advantechwdt.c
  *	which is based on wdt.c.
  *	Original copyright messages:
  *
  *	(c) Copyright 2003 Pádraig Brady <P@draigBrady.com>
  *
  *	(c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
  *
  *	(c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
  *						All Rights Reserved.
  *
  *	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.
  *
  *	Neither Marcus Junker nor ANDURAS AG admit liability nor provide
  *	warranty for any of this software. This material is provided
  *	"AS-IS" and at no charge.
  */

 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/types.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/spinlock.h>
 #include <linux/io.h>
 #include <linux/uaccess.h>


 #define WATCHDOG_NAME "w83697hf/hg WDT"
 #define WATCHDOG_TIMEOUT 60		/* 60 sec default timeout */
 #define WATCHDOG_EARLY_DISABLE 1	/* Disable until userland kicks in */

 static unsigned long wdt_is_open;
 static char expect_close;
 static DEFINE_SPINLOCK(io_lock);

 /* You must set this - there is no sane way to probe for this board. */
 static int wdt_io = 0x2e;
 module_param(wdt_io, int, 0);
 MODULE_PARM_DESC(wdt_io,
 		"w83697hf/hg WDT io port (default 0x2e, 0 = autodetect)");

 static int timeout = WATCHDOG_TIMEOUT;	/* in seconds */
 module_param(timeout, int, 0);
 MODULE_PARM_DESC(timeout,
 	"Watchdog timeout in seconds. 1<= timeout <=255 (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 int early_disable = WATCHDOG_EARLY_DISABLE;
 module_param(early_disable, int, 0);
 MODULE_PARM_DESC(early_disable,
 	"Watchdog gets disabled at boot time (default="
 				__MODULE_STRING(WATCHDOG_EARLY_DISABLE) ")");

 /*
  *	Kernel methods.
  */

 #define W83697HF_EFER (wdt_io + 0)  /* Extended Function Enable Register */
 #define W83697HF_EFIR (wdt_io + 0)  /* Extended Function Index Register
 							(same as EFER) */
 #define W83697HF_EFDR (wdt_io + 1)  /* Extended Function Data Register */

 static inline void w83697hf_unlock(void)
 {
 	outb_p(0x87, W83697HF_EFER);	/* Enter extended function mode */
 	outb_p(0x87, W83697HF_EFER);	/* Again according to manual */
 }

 static inline void w83697hf_lock(void)
 {
 	outb_p(0xAA, W83697HF_EFER);	/* Leave extended function mode */
 }

 /*
  *	The three functions w83697hf_get_reg(), w83697hf_set_reg() and
  *	w83697hf_write_timeout() must be called with the device unlocked.
  */

 static unsigned char w83697hf_get_reg(unsigned char reg)
 {
 	outb_p(reg, W83697HF_EFIR);
 	return inb_p(W83697HF_EFDR);
 }

 static void w83697hf_set_reg(unsigned char reg, unsigned char data)
 {
 	outb_p(reg, W83697HF_EFIR);
 	outb_p(data, W83697HF_EFDR);
 }

 static void w83697hf_write_timeout(int timeout)
 {
 	/* Write Timeout counter to CRF4 */
 	w83697hf_set_reg(0xF4, timeout);
 }

 static void w83697hf_select_wdt(void)
 {
 	w83697hf_unlock();
 	w83697hf_set_reg(0x07, 0x08);	/* Switch to logic device 8 (GPIO2) */
 }

 static inline void w83697hf_deselect_wdt(void)
 {
 	w83697hf_lock();
 }

 static void w83697hf_init(void)
 {
 	unsigned char bbuf;

 	w83697hf_select_wdt();

 	bbuf = w83697hf_get_reg(0x29);
 	bbuf &= ~0x60;
 	bbuf |= 0x20;

 	/* Set pin 119 to WDTO# mode (= CR29, WDT0) */
 	w83697hf_set_reg(0x29, bbuf);

 	bbuf = w83697hf_get_reg(0xF3);
 	bbuf &= ~0x04;
 	w83697hf_set_reg(0xF3, bbuf);	/* Count mode is seconds */

 	w83697hf_deselect_wdt();
 }

 static void wdt_ping(void)
 {
 	spin_lock(&io_lock);
 	w83697hf_select_wdt();

 	w83697hf_write_timeout(timeout);

 	w83697hf_deselect_wdt();
 	spin_unlock(&io_lock);
 }

 static void wdt_enable(void)
 {
 	spin_lock(&io_lock);
 	w83697hf_select_wdt();

 	w83697hf_write_timeout(timeout);
 	w83697hf_set_reg(0x30, 1);	/* Enable timer */

 	w83697hf_deselect_wdt();
 	spin_unlock(&io_lock);
 }

 static void wdt_disable(void)
 {
 	spin_lock(&io_lock);
 	w83697hf_select_wdt();

 	w83697hf_set_reg(0x30, 0);	/* Disable timer */
 	w83697hf_write_timeout(0);

 	w83697hf_deselect_wdt();
 	spin_unlock(&io_lock);
 }

 static unsigned char wdt_running(void)
 {
 	unsigned char t;

 	spin_lock(&io_lock);
 	w83697hf_select_wdt();

 	t = w83697hf_get_reg(0xF4);	/* Read timer */

 	w83697hf_deselect_wdt();
 	spin_unlock(&io_lock);

 	return t;
 }

 static int wdt_set_heartbeat(int t)
 {
 	if (t < 1 || t > 255)
 		return -EINVAL;

 	timeout = t;
 	return 0;
 }

 static ssize_t wdt_write(struct file *file, const char __user *buf,
 						size_t count, loff_t *ppos)
 {
 	if (count) {
 		if (!nowayout) {
 			size_t i;

 			expect_close = 0;

 			for (i = 0; i != count; i++) {
 				char c;
 				if (get_user(c, buf + i))
 					return -EFAULT;
 				if (c == 'V')
 					expect_close = 42;
 			}
 		}
 		wdt_ping();
 	}
 	return count;
 }

 static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
 	void __user *argp = (void __user *)arg;
 	int __user *p = argp;
 	int new_timeout;
 	static const struct watchdog_info ident = {
 		.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT
 							| WDIOF_MAGICCLOSE,
 		.firmware_version = 1,
 		.identity = "W83697HF WDT",
 	};

 	switch (cmd) {
 	case WDIOC_GETSUPPORT:
 		if (copy_to_user(argp, &ident, sizeof(ident)))
 			return -EFAULT;
 		break;

 	case WDIOC_GETSTATUS:
 	case WDIOC_GETBOOTSTATUS:
 		return put_user(0, p);

 	case WDIOC_SETOPTIONS:
 	{
 		int options, retval = -EINVAL;

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

 		if (options & WDIOS_DISABLECARD) {
 			wdt_disable();
 			retval = 0;
 		}

 		if (options & WDIOS_ENABLECARD) {
 			wdt_enable();
 			retval = 0;
 		}

 		return retval;
 	}

 	case WDIOC_KEEPALIVE:
 		wdt_ping();
 		break;

 	case WDIOC_SETTIMEOUT:
 		if (get_user(new_timeout, p))
 			return -EFAULT;
 		if (wdt_set_heartbeat(new_timeout))
 			return -EINVAL;
 		wdt_ping();
 		/* Fall */

 	case WDIOC_GETTIMEOUT:
 		return put_user(timeout, p);

 	default:
 		return -ENOTTY;
 	}
 	return 0;
 }

 static int wdt_open(struct inode *inode, struct file *file)
 {
 	if (test_and_set_bit(0, &wdt_is_open))
 		return -EBUSY;
 	/*
 	 *	Activate
 	 */

 	wdt_enable();
 	return nonseekable_open(inode, file);
 }

 static int wdt_close(struct inode *inode, struct file *file)
 {
 	if (expect_close == 42)
 		wdt_disable();
 	else {
 		pr_crit("Unexpected close, not stopping watchdog!\n");
 		wdt_ping();
 	}
 	expect_close = 0;
 	clear_bit(0, &wdt_is_open);
 	return 0;
 }

 /*
  *	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_disable();	/* Turn the WDT off */

 	return NOTIFY_DONE;
 }

 /*
  *	Kernel Interfaces
  */

 static const struct file_operations wdt_fops = {
 	.owner		= THIS_MODULE,
 	.llseek		= no_llseek,
 	.write		= wdt_write,
 	.unlocked_ioctl	= wdt_ioctl,
 	.open		= wdt_open,
 	.release	= wdt_close,
 };

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

 /*
  *	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 int w83697hf_check_wdt(void)
 {
 	if (!request_region(wdt_io, 2, WATCHDOG_NAME)) {
 		pr_err("I/O address 0x%x already in use\n", wdt_io);
 		return -EIO;
 	}

 	pr_debug("Looking for watchdog at address 0x%x\n", wdt_io);
 	w83697hf_unlock();
 	if (w83697hf_get_reg(0x20) == 0x60) {
 		pr_info("watchdog found at address 0x%x\n", wdt_io);
 		w83697hf_lock();
 		return 0;
 	}
 	/* Reprotect in case it was a compatible device */
 	w83697hf_lock();

 	pr_info("watchdog not found at address 0x%x\n", wdt_io);
 	release_region(wdt_io, 2);
 	return -EIO;
 }

 static int w83697hf_ioports[] = { 0x2e, 0x4e, 0x00 };

 static int __init wdt_init(void)
 {
 	int ret, i, found = 0;

 	pr_info("WDT driver for W83697HF/HG initializing\n");

 	if (wdt_io == 0) {
 		/* we will autodetect the W83697HF/HG watchdog */
 		for (i = 0; ((!found) && (w83697hf_ioports[i] != 0)); i++) {
 			wdt_io = w83697hf_ioports[i];
 			if (!w83697hf_check_wdt())
 				found++;
 		}
 	} else {
 		if (!w83697hf_check_wdt())
 			found++;
 	}

 	if (!found) {
 		pr_err("No W83697HF/HG could be found\n");
 		ret = -EIO;
 		goto out;
 	}

 	w83697hf_init();
 	if (early_disable) {
 		if (wdt_running())
 			pr_warn("Stopping previously enabled watchdog until userland kicks in\n");
 		wdt_disable();
 	}

 	if (wdt_set_heartbeat(timeout)) {
 		wdt_set_heartbeat(WATCHDOG_TIMEOUT);
 		pr_info("timeout value must be 1 <= timeout <= 255, using %d\n",
 			WATCHDOG_TIMEOUT);
 	}

 	ret = register_reboot_notifier(&wdt_notifier);
 	if (ret != 0) {
 		pr_err("cannot register reboot notifier (err=%d)\n", ret);
 		goto unreg_regions;
 	}

 	ret = misc_register(&wdt_miscdev);
 	if (ret != 0) {
 		pr_err("cannot register miscdev on minor=%d (err=%d)\n",
 		       WATCHDOG_MINOR, ret);
 		goto unreg_reboot;
 	}

 	pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
 		timeout, nowayout);

 out:
 	return ret;
 unreg_reboot:
 	unregister_reboot_notifier(&wdt_notifier);
 unreg_regions:
 	release_region(wdt_io, 2);
 	goto out;
 }

 static void __exit wdt_exit(void)
 {
 	misc_deregister(&wdt_miscdev);
 	unregister_reboot_notifier(&wdt_notifier);
 	release_region(wdt_io, 2);
 }

 module_init(wdt_init);
 module_exit(wdt_exit);

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Marcus Junker <junker@anduras.de>, "
 		"Samuel Tardieu <sam@rfc1149.net>");
 MODULE_DESCRIPTION("w83697hf/hg WDT driver");
	/*
	* w83697hf/hg WDT driver
	*
	* (c) Copyright 2006 Samuel Tardieu <sam@rfc1149.net>
	* (c) Copyright 2006 Marcus Junker <junker@anduras.de>
	*
	* Based on w83627hf_wdt.c which is based on advantechwdt.c
	* which is based on wdt.c.
	* Original copyright messages:
	*
	* (c) Copyright 2003 Pádraig Brady <P@draigBrady.com>
	*
	* (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
	*
	* (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
	* All Rights Reserved.
	*
	* 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.
	*
	* Neither Marcus Junker nor ANDURAS AG admit liability nor provide
	* warranty for any of this software. This material is provided
	* "AS-IS" and at no charge.
	*/

	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

	#include <linux/module.h>
	#include <linux/moduleparam.h>
	#include <linux/types.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/spinlock.h>
	#include <linux/io.h>
	#include <linux/uaccess.h>


	#define WATCHDOG_NAME "w83697hf/hg WDT"
	#define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
	#define WATCHDOG_EARLY_DISABLE 1 /* Disable until userland kicks in */

	static unsigned long wdt_is_open;
	static char expect_close;
	static DEFINE_SPINLOCK(io_lock);

	/* You must set this - there is no sane way to probe for this board. */
	static int wdt_io = 0x2e;
	module_param(wdt_io, int, 0);
	MODULE_PARM_DESC(wdt_io,
	"w83697hf/hg WDT io port (default 0x2e, 0 = autodetect)");

	static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
	module_param(timeout, int, 0);
	MODULE_PARM_DESC(timeout,
	"Watchdog timeout in seconds. 1<= timeout <=255 (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 int early_disable = WATCHDOG_EARLY_DISABLE;
	module_param(early_disable, int, 0);
	MODULE_PARM_DESC(early_disable,
	"Watchdog gets disabled at boot time (default="
	__MODULE_STRING(WATCHDOG_EARLY_DISABLE) ")");

	/*
	* Kernel methods.
	*/

	#define W83697HF_EFER (wdt_io + 0) /* Extended Function Enable Register */
	#define W83697HF_EFIR (wdt_io + 0) /* Extended Function Index Register
	(same as EFER) */
	#define W83697HF_EFDR (wdt_io + 1) /* Extended Function Data Register */

	static inline void w83697hf_unlock(void)
	{
	outb_p(0x87, W83697HF_EFER); /* Enter extended function mode */
	outb_p(0x87, W83697HF_EFER); /* Again according to manual */
	}

	static inline void w83697hf_lock(void)
	{
	outb_p(0xAA, W83697HF_EFER); /* Leave extended function mode */
	}

	/*
	* The three functions w83697hf_get_reg(), w83697hf_set_reg() and
	* w83697hf_write_timeout() must be called with the device unlocked.
	*/

	static unsigned char w83697hf_get_reg(unsigned char reg)
	{
	outb_p(reg, W83697HF_EFIR);
	return inb_p(W83697HF_EFDR);
	}

	static void w83697hf_set_reg(unsigned char reg, unsigned char data)
	{
	outb_p(reg, W83697HF_EFIR);
	outb_p(data, W83697HF_EFDR);
	}

	static void w83697hf_write_timeout(int timeout)
	{
	/* Write Timeout counter to CRF4 */
	w83697hf_set_reg(0xF4, timeout);
	}

	static void w83697hf_select_wdt(void)
	{
	w83697hf_unlock();
	w83697hf_set_reg(0x07, 0x08); /* Switch to logic device 8 (GPIO2) */
	}

	static inline void w83697hf_deselect_wdt(void)
	{
	w83697hf_lock();
	}

	static void w83697hf_init(void)
	{
	unsigned char bbuf;

	w83697hf_select_wdt();

	bbuf = w83697hf_get_reg(0x29);
	bbuf &= ~0x60;
	bbuf \|= 0x20;

	/* Set pin 119 to WDTO# mode (= CR29, WDT0) */
	w83697hf_set_reg(0x29, bbuf);

	bbuf = w83697hf_get_reg(0xF3);
	bbuf &= ~0x04;
	w83697hf_set_reg(0xF3, bbuf); /* Count mode is seconds */

	w83697hf_deselect_wdt();
	}

	static void wdt_ping(void)
	{
	spin_lock(&io_lock);
	w83697hf_select_wdt();

	w83697hf_write_timeout(timeout);

	w83697hf_deselect_wdt();
	spin_unlock(&io_lock);
	}

	static void wdt_enable(void)
	{
	spin_lock(&io_lock);
	w83697hf_select_wdt();

	w83697hf_write_timeout(timeout);
	w83697hf_set_reg(0x30, 1); /* Enable timer */

	w83697hf_deselect_wdt();
	spin_unlock(&io_lock);
	}

	static void wdt_disable(void)
	{
	spin_lock(&io_lock);
	w83697hf_select_wdt();

	w83697hf_set_reg(0x30, 0); /* Disable timer */
	w83697hf_write_timeout(0);

	w83697hf_deselect_wdt();
	spin_unlock(&io_lock);
	}

	static unsigned char wdt_running(void)
	{
	unsigned char t;

	spin_lock(&io_lock);
	w83697hf_select_wdt();

	t = w83697hf_get_reg(0xF4); /* Read timer */

	w83697hf_deselect_wdt();
	spin_unlock(&io_lock);

	return t;
	}

	static int wdt_set_heartbeat(int t)
	{
	if (t < 1 \|\| t > 255)
	return -EINVAL;

	timeout = t;
	return 0;
	}

	static ssize_t wdt_write(struct file file, const char __user buf,
	size_t count, loff_t *ppos)
	{
	if (count) {
	if (!nowayout) {
	size_t i;

	expect_close = 0;

	for (i = 0; i != count; i++) {
	char c;
	if (get_user(c, buf + i))
	return -EFAULT;
	if (c == 'V')
	expect_close = 42;
	}
	}
	wdt_ping();
	}
	return count;
	}

	static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
	{
	void __user argp = (void __user )arg;
	int __user *p = argp;
	int new_timeout;
	static const struct watchdog_info ident = {
	.options = WDIOF_KEEPALIVEPING \| WDIOF_SETTIMEOUT
	\| WDIOF_MAGICCLOSE,
	.firmware_version = 1,
	.identity = "W83697HF WDT",
	};

	switch (cmd) {
	case WDIOC_GETSUPPORT:
	if (copy_to_user(argp, &ident, sizeof(ident)))
	return -EFAULT;
	break;

	case WDIOC_GETSTATUS:
	case WDIOC_GETBOOTSTATUS:
	return put_user(0, p);

	case WDIOC_SETOPTIONS:
	{
	int options, retval = -EINVAL;

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

	if (options & WDIOS_DISABLECARD) {
	wdt_disable();
	retval = 0;
	}

	if (options & WDIOS_ENABLECARD) {
	wdt_enable();
	retval = 0;
	}

	return retval;
	}

	case WDIOC_KEEPALIVE:
	wdt_ping();
	break;

	case WDIOC_SETTIMEOUT:
	if (get_user(new_timeout, p))
	return -EFAULT;
	if (wdt_set_heartbeat(new_timeout))
	return -EINVAL;
	wdt_ping();
	/* Fall */

	case WDIOC_GETTIMEOUT:
	return put_user(timeout, p);

	default:
	return -ENOTTY;
	}
	return 0;
	}

	static int wdt_open(struct inode inode, struct file file)
	{
	if (test_and_set_bit(0, &wdt_is_open))
	return -EBUSY;
	/*
	* Activate
	*/

	wdt_enable();
	return nonseekable_open(inode, file);
	}

	static int wdt_close(struct inode inode, struct file file)
	{
	if (expect_close == 42)
	wdt_disable();
	else {
	pr_crit("Unexpected close, not stopping watchdog!\n");
	wdt_ping();
	}
	expect_close = 0;
	clear_bit(0, &wdt_is_open);
	return 0;
	}

	/*
	* 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_disable(); /* Turn the WDT off */

	return NOTIFY_DONE;
	}

	/*
	* Kernel Interfaces
	*/

	static const struct file_operations wdt_fops = {
	.owner = THIS_MODULE,
	.llseek = no_llseek,
	.write = wdt_write,
	.unlocked_ioctl = wdt_ioctl,
	.open = wdt_open,
	.release = wdt_close,
	};

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

	/*
	* 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 int w83697hf_check_wdt(void)
	{
	if (!request_region(wdt_io, 2, WATCHDOG_NAME)) {
	pr_err("I/O address 0x%x already in use\n", wdt_io);
	return -EIO;
	}

	pr_debug("Looking for watchdog at address 0x%x\n", wdt_io);
	w83697hf_unlock();
	if (w83697hf_get_reg(0x20) == 0x60) {
	pr_info("watchdog found at address 0x%x\n", wdt_io);
	w83697hf_lock();
	return 0;
	}
	/* Reprotect in case it was a compatible device */
	w83697hf_lock();

	pr_info("watchdog not found at address 0x%x\n", wdt_io);
	release_region(wdt_io, 2);
	return -EIO;
	}

	static int w83697hf_ioports[] = { 0x2e, 0x4e, 0x00 };

	static int __init wdt_init(void)
	{
	int ret, i, found = 0;

	pr_info("WDT driver for W83697HF/HG initializing\n");

	if (wdt_io == 0) {
	/* we will autodetect the W83697HF/HG watchdog */
	for (i = 0; ((!found) && (w83697hf_ioports[i] != 0)); i++) {
	wdt_io = w83697hf_ioports[i];
	if (!w83697hf_check_wdt())
	found++;
	}
	} else {
	if (!w83697hf_check_wdt())
	found++;
	}

	if (!found) {
	pr_err("No W83697HF/HG could be found\n");
	ret = -EIO;
	goto out;
	}

	w83697hf_init();
	if (early_disable) {
	if (wdt_running())
	pr_warn("Stopping previously enabled watchdog until userland kicks in\n");
	wdt_disable();
	}

	if (wdt_set_heartbeat(timeout)) {
	wdt_set_heartbeat(WATCHDOG_TIMEOUT);
	pr_info("timeout value must be 1 <= timeout <= 255, using %d\n",
	WATCHDOG_TIMEOUT);
	}

	ret = register_reboot_notifier(&wdt_notifier);
	if (ret != 0) {
	pr_err("cannot register reboot notifier (err=%d)\n", ret);
	goto unreg_regions;
	}

	ret = misc_register(&wdt_miscdev);
	if (ret != 0) {
	pr_err("cannot register miscdev on minor=%d (err=%d)\n",
	WATCHDOG_MINOR, ret);
	goto unreg_reboot;
	}

	pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
	timeout, nowayout);

	out:
	return ret;
	unreg_reboot:
	unregister_reboot_notifier(&wdt_notifier);
	unreg_regions:
	release_region(wdt_io, 2);
	goto out;
	}

	static void __exit wdt_exit(void)
	{
	misc_deregister(&wdt_miscdev);
	unregister_reboot_notifier(&wdt_notifier);
	release_region(wdt_io, 2);
	}

	module_init(wdt_init);
	module_exit(wdt_exit);

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Marcus Junker <junker@anduras.de>, "
	"Samuel Tardieu <sam@rfc1149.net>");
	MODULE_DESCRIPTION("w83697hf/hg WDT driver");