[net-next-2.6.git] / drivers / watchdog / f71808e_wdt.c

/***************************************************************************
 *   Copyright (C) 2006 by Hans Edgington <hans@edgington.nl>              *
 *   Copyright (C) 2007-2009 Hans de Goede <hdegoede@redhat.com>           *
 *   Copyright (C) 2010 Giel van Schijndel <me@mortis.eu>                  *
 *                                                                         *
 *   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.                                   *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program; if not, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/

#include <linux/err.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/uaccess.h>
#include <linux/watchdog.h>

#define DRVNAME "f71808e_wdt"

#define SIO_F71808FG_LD_WDT	0x07	/* Watchdog timer logical device */
#define SIO_UNLOCK_KEY		0x87	/* Key to enable Super-I/O */
#define SIO_LOCK_KEY		0xAA	/* Key to diasble Super-I/O */

#define SIO_REG_LDSEL		0x07	/* Logical device select */
#define SIO_REG_DEVID		0x20	/* Device ID (2 bytes) */
#define SIO_REG_DEVREV		0x22	/* Device revision */
#define SIO_REG_MANID		0x23	/* Fintek ID (2 bytes) */
#define SIO_REG_ENABLE		0x30	/* Logical device enable */
#define SIO_REG_ADDR		0x60	/* Logical device address (2 bytes) */

#define SIO_FINTEK_ID		0x1934	/* Manufacturers ID */
#define SIO_F71808_ID		0x0901  /* Chipset ID */
#define SIO_F71858_ID		0x0507  /* Chipset ID */
#define SIO_F71862_ID		0x0601	/* Chipset ID */
#define SIO_F71882_ID		0x0541	/* Chipset ID */
#define SIO_F71889_ID		0x0723	/* Chipset ID */

#define	F71882FG_REG_START		0x01

#define F71808FG_REG_WDO_CONF		0xf0
#define F71808FG_REG_WDT_CONF		0xf5
#define F71808FG_REG_WD_TIME		0xf6

#define F71808FG_FLAG_WDOUT_EN		7

#define F71808FG_FLAG_WDTMOUT_STS	5
#define F71808FG_FLAG_WD_EN		5
#define F71808FG_FLAG_WD_PULSE		4
#define F71808FG_FLAG_WD_UNIT		3

/* Default values */
#define WATCHDOG_TIMEOUT	60	/* 1 minute default timeout */
#define WATCHDOG_MAX_TIMEOUT	(60 * 255)
#define WATCHDOG_PULSE_WIDTH	125	/* 125 ms, default pulse width for
					   watchdog signal */

static unsigned short force_id;
module_param(force_id, ushort, 0);
MODULE_PARM_DESC(force_id, "Override the detected device ID");

static const int max_timeout = WATCHDOG_MAX_TIMEOUT;
static int timeout = 60;	/* default timeout in seconds */
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout,
	"Watchdog timeout in seconds. 1<= timeout <="
			__MODULE_STRING(WATCHDOG_MAX_TIMEOUT) " (default="
			__MODULE_STRING(WATCHDOG_TIMEOUT) ")");

static unsigned int pulse_width = WATCHDOG_PULSE_WIDTH;
module_param(pulse_width, uint, 0);
MODULE_PARM_DESC(pulse_width,
	"Watchdog signal pulse width. 0(=level), 1 ms, 25 ms, 125 ms or 5000 ms"
			" (default=" __MODULE_STRING(WATCHDOG_PULSE_WIDTH) ")");

static int nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0444);
MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");

static unsigned int start_withtimeout;
module_param(start_withtimeout, uint, 0);
MODULE_PARM_DESC(start_withtimeout, "Start watchdog timer on module load with"
	" given initial timeout. Zero (default) disables this feature.");

enum chips { f71808fg, f71858fg, f71862fg, f71882fg, f71889fg };

static const char *f71808e_names[] = {
	"f71808fg",
	"f71858fg",
	"f71862fg",
	"f71882fg",
	"f71889fg",
};

/* Super-I/O Function prototypes */
static inline int superio_inb(int base, int reg);
static inline int superio_inw(int base, int reg);
static inline void superio_outb(int base, int reg, u8 val);
static inline void superio_set_bit(int base, int reg, int bit);
static inline void superio_clear_bit(int base, int reg, int bit);
static inline int superio_enter(int base);
static inline void superio_select(int base, int ld);
static inline void superio_exit(int base);

struct watchdog_data {
	unsigned short	sioaddr;
	enum chips	type;
	unsigned long	opened;
	struct mutex	lock;
	char		expect_close;
	struct watchdog_info ident;

	unsigned short	timeout;
	u8		timer_val;	/* content for the wd_time register */
	char		minutes_mode;
	u8		pulse_val;	/* pulse width flag */
	char		pulse_mode;	/* enable pulse output mode? */
	char		caused_reboot;	/* last reboot was by the watchdog */
};

static struct watchdog_data watchdog = {
	.lock = __MUTEX_INITIALIZER(watchdog.lock),
};

/* Super I/O functions */
static inline int superio_inb(int base, int reg)
{
	outb(reg, base);
	return inb(base + 1);
}

static int superio_inw(int base, int reg)
{
	int val;
	val  = superio_inb(base, reg) << 8;
	val |= superio_inb(base, reg + 1);
	return val;
}

static inline void superio_outb(int base, int reg, u8 val)
{
	outb(reg, base);
	outb(val, base + 1);
}

static inline void superio_set_bit(int base, int reg, int bit)
{
	unsigned long val = superio_inb(base, reg);
	__set_bit(bit, &val);
	superio_outb(base, reg, val);
}

static inline void superio_clear_bit(int base, int reg, int bit)
{
	unsigned long val = superio_inb(base, reg);
	__clear_bit(bit, &val);
	superio_outb(base, reg, val);
}

static inline int superio_enter(int base)
{
	/* Don't step on other drivers' I/O space by accident */
	if (!request_muxed_region(base, 2, DRVNAME)) {
		printk(KERN_ERR DRVNAME ": I/O address 0x%04x already in use\n",
				(int)base);
		return -EBUSY;
	}

	/* according to the datasheet the key must be send twice! */
	outb(SIO_UNLOCK_KEY, base);
	outb(SIO_UNLOCK_KEY, base);

	return 0;
}

static inline void superio_select(int base, int ld)
{
	outb(SIO_REG_LDSEL, base);
	outb(ld, base + 1);
}

static inline void superio_exit(int base)
{
	outb(SIO_LOCK_KEY, base);
	release_region(base, 2);
}

static int watchdog_set_timeout(int timeout)
{
	if (timeout <= 0
	 || timeout >  max_timeout) {
		printk(KERN_ERR DRVNAME ": watchdog timeout out of range\n");
		return -EINVAL;
	}

	mutex_lock(&watchdog.lock);

	watchdog.timeout = timeout;
	if (timeout > 0xff) {
		watchdog.timer_val = DIV_ROUND_UP(timeout, 60);
		watchdog.minutes_mode = true;
	} else {
		watchdog.timer_val = timeout;
		watchdog.minutes_mode = false;
	}

	mutex_unlock(&watchdog.lock);

	return 0;
}

static int watchdog_set_pulse_width(unsigned int pw)
{
	int err = 0;

	mutex_lock(&watchdog.lock);

	if        (pw <=    1) {
		watchdog.pulse_val = 0;
	} else if (pw <=   25) {
		watchdog.pulse_val = 1;
	} else if (pw <=  125) {
		watchdog.pulse_val = 2;
	} else if (pw <= 5000) {
		watchdog.pulse_val = 3;
	} else {
		printk(KERN_ERR DRVNAME ": pulse width out of range\n");
		err = -EINVAL;
		goto exit_unlock;
	}

	watchdog.pulse_mode = pw;

exit_unlock:
	mutex_unlock(&watchdog.lock);
	return err;
}

static int watchdog_keepalive(void)
{
	int err = 0;

	mutex_lock(&watchdog.lock);
	err = superio_enter(watchdog.sioaddr);
	if (err)
		goto exit_unlock;
	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);

	if (watchdog.minutes_mode)
		/* select minutes for timer units */
		superio_set_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
				F71808FG_FLAG_WD_UNIT);
	else
		/* select seconds for timer units */
		superio_clear_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
				F71808FG_FLAG_WD_UNIT);

	/* Set timer value */
	superio_outb(watchdog.sioaddr, F71808FG_REG_WD_TIME,
			   watchdog.timer_val);

	superio_exit(watchdog.sioaddr);

exit_unlock:
	mutex_unlock(&watchdog.lock);
	return err;
}

static int watchdog_start(void)
{
	/* Make sure we don't die as soon as the watchdog is enabled below */
	int err = watchdog_keepalive();
	if (err)
		return err;

	mutex_lock(&watchdog.lock);
	err = superio_enter(watchdog.sioaddr);
	if (err)
		goto exit_unlock;
	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);

	/* Watchdog pin configuration */
	switch (watchdog.type) {
	case f71808fg:
		/* Set pin 21 to GPIO23/WDTRST#, then to WDTRST# */
		superio_clear_bit(watchdog.sioaddr, 0x2a, 3);
		superio_clear_bit(watchdog.sioaddr, 0x2b, 3);
		break;

	case f71882fg:
		/* Set pin 56 to WDTRST# */
		superio_set_bit(watchdog.sioaddr, 0x29, 1);
		break;

	case f71889fg:
		/* set pin 40 to WDTRST# */
		superio_outb(watchdog.sioaddr, 0x2b,
				superio_inb(watchdog.sioaddr, 0x2b) & 0xcf);
		break;

	default:
		/*
		 * 'default' label to shut up the compiler and catch
		 * programmer errors
		 */
		err = -ENODEV;
		goto exit_superio;
	}

	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
	superio_set_bit(watchdog.sioaddr, SIO_REG_ENABLE, 0);
	superio_set_bit(watchdog.sioaddr, F71808FG_REG_WDO_CONF,
			F71808FG_FLAG_WDOUT_EN);

	superio_set_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
			F71808FG_FLAG_WD_EN);

	if (watchdog.pulse_mode) {
		/* Select "pulse" output mode with given duration */
		u8 wdt_conf = superio_inb(watchdog.sioaddr,
				F71808FG_REG_WDT_CONF);

		/* Set WD_PSWIDTH bits (1:0) */
		wdt_conf = (wdt_conf & 0xfc) | (watchdog.pulse_val & 0x03);
		/* Set WD_PULSE to "pulse" mode */
		wdt_conf |= BIT(F71808FG_FLAG_WD_PULSE);

		superio_outb(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
				wdt_conf);
	} else {
		/* Select "level" output mode */
		superio_clear_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
				F71808FG_FLAG_WD_PULSE);
	}

exit_superio:
	superio_exit(watchdog.sioaddr);
exit_unlock:
	mutex_unlock(&watchdog.lock);

	return err;
}

static int watchdog_stop(void)
{
	int err = 0;

	mutex_lock(&watchdog.lock);
	err = superio_enter(watchdog.sioaddr);
	if (err)
		goto exit_unlock;
	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);

	superio_clear_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
			F71808FG_FLAG_WD_EN);

	superio_exit(watchdog.sioaddr);

exit_unlock:
	mutex_unlock(&watchdog.lock);

	return err;
}

static int watchdog_get_status(void)
{
	int status = 0;

	mutex_lock(&watchdog.lock);
	status = (watchdog.caused_reboot) ? WDIOF_CARDRESET : 0;
	mutex_unlock(&watchdog.lock);

	return status;
}

static bool watchdog_is_running(void)
{
	/*
	 * if we fail to determine the watchdog's status assume it to be
	 * running to be on the safe side
	 */
	bool is_running = true;

	mutex_lock(&watchdog.lock);
	if (superio_enter(watchdog.sioaddr))
		goto exit_unlock;
	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);

	is_running = (superio_inb(watchdog.sioaddr, SIO_REG_ENABLE) & BIT(0))
		&& (superio_inb(watchdog.sioaddr, F71808FG_REG_WDT_CONF)
			& F71808FG_FLAG_WD_EN);

	superio_exit(watchdog.sioaddr);

exit_unlock:
	mutex_unlock(&watchdog.lock);
	return is_running;
}

/* /dev/watchdog api */

static int watchdog_open(struct inode *inode, struct file *file)
{
	int err;

	/* If the watchdog is alive we don't need to start it again */
	if (test_and_set_bit(0, &watchdog.opened))
		return -EBUSY;

	err = watchdog_start();
	if (err) {
		clear_bit(0, &watchdog.opened);
		return err;
	}

	if (nowayout)
		__module_get(THIS_MODULE);

	watchdog.expect_close = 0;
	return nonseekable_open(inode, file);
}

static int watchdog_release(struct inode *inode, struct file *file)
{
	clear_bit(0, &watchdog.opened);

	if (!watchdog.expect_close) {
		watchdog_keepalive();
		printk(KERN_CRIT DRVNAME
			": Unexpected close, not stopping watchdog!\n");
	} else if (!nowayout) {
		watchdog_stop();
	}
	return 0;
}

/*
 *      watchdog_write:
 *      @file: file handle to the watchdog
 *      @buf: buffer to write
 *      @count: count of bytes
 *      @ppos: pointer to the position to write. No seeks allowed
 *
 *      A write to a watchdog device is defined as a keepalive signal. Any
 *      write of data will do, as we we don't define content meaning.
 */

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

			/* In case it was set long ago */
			bool expect_close = false;

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

			/* Properly order writes across fork()ed processes */
			mutex_lock(&watchdog.lock);
			watchdog.expect_close = expect_close;
			mutex_unlock(&watchdog.lock);
		}

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

/*
 *      watchdog_ioctl:
 *      @inode: inode of the device
 *      @file: file handle to the device
 *      @cmd: watchdog command
 *      @arg: argument pointer
 *
 *      The watchdog API defines a common set of functions for all watchdogs
 *      according to their available features.
 */
static long watchdog_ioctl(struct file *file, unsigned int cmd,
	unsigned long arg)
{
	int status;
	int new_options;
	int new_timeout;
	union {
		struct watchdog_info __user *ident;
		int __user *i;
	} uarg;

	uarg.i = (int __user *)arg;

	switch (cmd) {
	case WDIOC_GETSUPPORT:
		return copy_to_user(uarg.ident, &watchdog.ident,
			sizeof(watchdog.ident)) ? -EFAULT : 0;

	case WDIOC_GETSTATUS:
		status = watchdog_get_status();
		if (status < 0)
			return status;
		return put_user(status, uarg.i);

	case WDIOC_GETBOOTSTATUS:
		return put_user(0, uarg.i);

	case WDIOC_SETOPTIONS:
		if (get_user(new_options, uarg.i))
			return -EFAULT;

		if (new_options & WDIOS_DISABLECARD)
			watchdog_stop();

		if (new_options & WDIOS_ENABLECARD)
			return watchdog_start();


	case WDIOC_KEEPALIVE:
		watchdog_keepalive();
		return 0;

	case WDIOC_SETTIMEOUT:
		if (get_user(new_timeout, uarg.i))
			return -EFAULT;

		if (watchdog_set_timeout(new_timeout))
			return -EINVAL;

		watchdog_keepalive();
		/* Fall */

	case WDIOC_GETTIMEOUT:
		return put_user(watchdog.timeout, uarg.i);

	default:
		return -ENOTTY;

	}
}

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

static const struct file_operations watchdog_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.open		= watchdog_open,
	.release	= watchdog_release,
	.write		= watchdog_write,
	.unlocked_ioctl	= watchdog_ioctl,
};

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

static struct notifier_block watchdog_notifier = {
	.notifier_call = watchdog_notify_sys,
};

static int __init watchdog_init(int sioaddr)
{
	int wdt_conf, err = 0;

	/* No need to lock watchdog.lock here because no entry points
	 * into the module have been registered yet.
	 */
	watchdog.sioaddr = sioaddr;
	watchdog.ident.options = WDIOC_SETTIMEOUT
				| WDIOF_MAGICCLOSE
				| WDIOF_KEEPALIVEPING;

	snprintf(watchdog.ident.identity,
		sizeof(watchdog.ident.identity), "%s watchdog",
		f71808e_names[watchdog.type]);

	err = superio_enter(sioaddr);
	if (err)
		return err;
	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);

	wdt_conf = superio_inb(sioaddr, F71808FG_REG_WDT_CONF);
	watchdog.caused_reboot = wdt_conf & F71808FG_FLAG_WDTMOUT_STS;

	superio_exit(sioaddr);

	err = watchdog_set_timeout(timeout);
	if (err)
		return err;
	err = watchdog_set_pulse_width(pulse_width);
	if (err)
		return err;

	err = register_reboot_notifier(&watchdog_notifier);
	if (err)
		return err;

	err = misc_register(&watchdog_miscdev);
	if (err) {
		printk(KERN_ERR DRVNAME
			": cannot register miscdev on minor=%d\n",
				watchdog_miscdev.minor);
		goto exit_reboot;
	}

	if (start_withtimeout) {
		if (start_withtimeout <= 0
		 || start_withtimeout >  max_timeout) {
			printk(KERN_ERR DRVNAME
				": starting timeout out of range\n");
			err = -EINVAL;
			goto exit_miscdev;
		}

		err = watchdog_start();
		if (err) {
			printk(KERN_ERR DRVNAME
				": cannot start watchdog timer\n");
			goto exit_miscdev;
		}

		mutex_lock(&watchdog.lock);
		err = superio_enter(sioaddr);
		if (err)
			goto exit_unlock;
		superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);

		if (start_withtimeout > 0xff) {
			/* select minutes for timer units */
			superio_set_bit(sioaddr, F71808FG_REG_WDT_CONF,
				F71808FG_FLAG_WD_UNIT);
			superio_outb(sioaddr, F71808FG_REG_WD_TIME,
				DIV_ROUND_UP(start_withtimeout, 60));
		} else {
			/* select seconds for timer units */
			superio_clear_bit(sioaddr, F71808FG_REG_WDT_CONF,
				F71808FG_FLAG_WD_UNIT);
			superio_outb(sioaddr, F71808FG_REG_WD_TIME,
				start_withtimeout);
		}

		superio_exit(sioaddr);
		mutex_unlock(&watchdog.lock);

		if (nowayout)
			__module_get(THIS_MODULE);

		printk(KERN_INFO DRVNAME
			": watchdog started with initial timeout of %u sec\n",
			start_withtimeout);
	}

	return 0;

exit_unlock:
	mutex_unlock(&watchdog.lock);
exit_miscdev:
	misc_deregister(&watchdog_miscdev);
exit_reboot:
	unregister_reboot_notifier(&watchdog_notifier);

	return err;
}

static int __init f71808e_find(int sioaddr)
{
	u16 devid;
	int err = superio_enter(sioaddr);
	if (err)
		return err;

	devid = superio_inw(sioaddr, SIO_REG_MANID);
	if (devid != SIO_FINTEK_ID) {
		pr_debug(DRVNAME ": Not a Fintek device\n");
		err = -ENODEV;
		goto exit;
	}

	devid = force_id ? force_id : superio_inw(sioaddr, SIO_REG_DEVID);
	switch (devid) {
	case SIO_F71808_ID:
		watchdog.type = f71808fg;
		break;
	case SIO_F71882_ID:
		watchdog.type = f71882fg;
		break;
	case SIO_F71889_ID:
		watchdog.type = f71889fg;
		break;
	case SIO_F71862_ID:
		/* These have a watchdog, though it isn't implemented (yet). */
		err = -ENOSYS;
		goto exit;
	case SIO_F71858_ID:
		/* Confirmed (by datasheet) not to have a watchdog. */
		err = -ENODEV;
		goto exit;
	default:
		printk(KERN_INFO DRVNAME ": Unrecognized Fintek device: %04x\n",
		       (unsigned int)devid);
		err = -ENODEV;
		goto exit;
	}

	printk(KERN_INFO DRVNAME ": Found %s watchdog chip, revision %d\n",
		f71808e_names[watchdog.type],
		(int)superio_inb(sioaddr, SIO_REG_DEVREV));
exit:
	superio_exit(sioaddr);
	return err;
}

static int __init f71808e_init(void)
{
	static const unsigned short addrs[] = { 0x2e, 0x4e };
	int err = -ENODEV;
	int i;

	for (i = 0; i < ARRAY_SIZE(addrs); i++) {
		err = f71808e_find(addrs[i]);
		if (err == 0)
			break;
	}
	if (i == ARRAY_SIZE(addrs))
		return err;

	return watchdog_init(addrs[i]);
}

static void __exit f71808e_exit(void)
{
	if (watchdog_is_running()) {
		printk(KERN_WARNING DRVNAME
			": Watchdog timer still running, stopping it\n");
		watchdog_stop();
	}
	misc_deregister(&watchdog_miscdev);
	unregister_reboot_notifier(&watchdog_notifier);
}

MODULE_DESCRIPTION("F71808E Watchdog Driver");
MODULE_AUTHOR("Giel van Schijndel <me@mortis.eu>");
MODULE_LICENSE("GPL");

module_init(f71808e_init);
module_exit(f71808e_exit);
Commit	Line	Data
96cb4eb0 GS	1	/***************************************************************************
	2	* Copyright (C) 2006 by Hans Edgington <hans@edgington.nl> *
	3	* Copyright (C) 2007-2009 Hans de Goede <hdegoede@redhat.com> *
	4	* Copyright (C) 2010 Giel van Schijndel <me@mortis.eu> *
	5	* *
	6	* This program is free software; you can redistribute it and/or modify *
	7	* it under the terms of the GNU General Public License as published by *
	8	* the Free Software Foundation; either version 2 of the License, or *
	9	* (at your option) any later version. *
	10	* *
	11	* This program is distributed in the hope that it will be useful, *
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of *
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
	14	* GNU General Public License for more details. *
	15	* *
	16	* You should have received a copy of the GNU General Public License *
	17	* along with this program; if not, write to the *
	18	* Free Software Foundation, Inc., *
	19	* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
	20	***************************************************************************/
	21
	22	#include <linux/err.h>
	23	#include <linux/fs.h>
	24	#include <linux/init.h>
	25	#include <linux/io.h>
	26	#include <linux/ioport.h>
	27	#include <linux/miscdevice.h>
	28	#include <linux/module.h>
	29	#include <linux/mutex.h>
	30	#include <linux/notifier.h>
	31	#include <linux/reboot.h>
	32	#include <linux/uaccess.h>
	33	#include <linux/watchdog.h>
	34
	35	#define DRVNAME "f71808e_wdt"
	36
	37	#define SIO_F71808FG_LD_WDT 0x07 /* Watchdog timer logical device */
	38	#define SIO_UNLOCK_KEY 0x87 /* Key to enable Super-I/O */
	39	#define SIO_LOCK_KEY 0xAA /* Key to diasble Super-I/O */
	40
	41	#define SIO_REG_LDSEL 0x07 /* Logical device select */
	42	#define SIO_REG_DEVID 0x20 /* Device ID (2 bytes) */
	43	#define SIO_REG_DEVREV 0x22 /* Device revision */
	44	#define SIO_REG_MANID 0x23 /* Fintek ID (2 bytes) */
	45	#define SIO_REG_ENABLE 0x30 /* Logical device enable */
	46	#define SIO_REG_ADDR 0x60 /* Logical device address (2 bytes) */
	47
	48	#define SIO_FINTEK_ID 0x1934 /* Manufacturers ID */
	49	#define SIO_F71808_ID 0x0901 /* Chipset ID */
	50	#define SIO_F71858_ID 0x0507 /* Chipset ID */
	51	#define SIO_F71862_ID 0x0601 /* Chipset ID */
	52	#define SIO_F71882_ID 0x0541 /* Chipset ID */
	53	#define SIO_F71889_ID 0x0723 /* Chipset ID */
	54
	55	#define F71882FG_REG_START 0x01
	56
	57	#define F71808FG_REG_WDO_CONF 0xf0
	58	#define F71808FG_REG_WDT_CONF 0xf5
	59	#define F71808FG_REG_WD_TIME 0xf6
	60
	61	#define F71808FG_FLAG_WDOUT_EN 7
	62
	63	#define F71808FG_FLAG_WDTMOUT_STS 5
	64	#define F71808FG_FLAG_WD_EN 5
65	#define F71808FG_FLAG_WD_PULSE 4
66	#define F71808FG_FLAG_WD_UNIT 3
67
68	/* Default values */
69	#define WATCHDOG_TIMEOUT 60 /* 1 minute default timeout */
70	#define WATCHDOG_MAX_TIMEOUT (60 * 255)
71	#define WATCHDOG_PULSE_WIDTH 125 /* 125 ms, default pulse width for
72	watchdog signal */
73
74	static unsigned short force_id;
75	module_param(force_id, ushort, 0);
76	MODULE_PARM_DESC(force_id, "Override the detected device ID");
77
78	static const int max_timeout = WATCHDOG_MAX_TIMEOUT;
79	static int timeout = 60; /* default timeout in seconds */
80	module_param(timeout, int, 0);
81	MODULE_PARM_DESC(timeout,
82	"Watchdog timeout in seconds. 1<= timeout <="
83	__MODULE_STRING(WATCHDOG_MAX_TIMEOUT) " (default="
84	__MODULE_STRING(WATCHDOG_TIMEOUT) ")");
85
86	static unsigned int pulse_width = WATCHDOG_PULSE_WIDTH;
87	module_param(pulse_width, uint, 0);
88	MODULE_PARM_DESC(pulse_width,
89	"Watchdog signal pulse width. 0(=level), 1 ms, 25 ms, 125 ms or 5000 ms"
90	" (default=" __MODULE_STRING(WATCHDOG_PULSE_WIDTH) ")");
91
92	static int nowayout = WATCHDOG_NOWAYOUT;
93	module_param(nowayout, bool, 0444);
94	MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");
95
96	static unsigned int start_withtimeout;
97	module_param(start_withtimeout, uint, 0);
98	MODULE_PARM_DESC(start_withtimeout, "Start watchdog timer on module load with"
99	" given initial timeout. Zero (default) disables this feature.");
100
101	enum chips { f71808fg, f71858fg, f71862fg, f71882fg, f71889fg };
102
103	static const char *f71808e_names[] = {
104	"f71808fg",
105	"f71858fg",
106	"f71862fg",
107	"f71882fg",
108	"f71889fg",
109	};
110
111	/* Super-I/O Function prototypes */
112	static inline int superio_inb(int base, int reg);
113	static inline int superio_inw(int base, int reg);
114	static inline void superio_outb(int base, int reg, u8 val);
115	static inline void superio_set_bit(int base, int reg, int bit);
116	static inline void superio_clear_bit(int base, int reg, int bit);
117	static inline int superio_enter(int base);
118	static inline void superio_select(int base, int ld);
119	static inline void superio_exit(int base);
120
121	struct watchdog_data {
122	unsigned short sioaddr;
123	enum chips type;
124	unsigned long opened;
125	struct mutex lock;
126	char expect_close;
127	struct watchdog_info ident;
128
129	unsigned short timeout;
130	u8 timer_val; /* content for the wd_time register */
131	char minutes_mode;
132	u8 pulse_val; /* pulse width flag */
133	char pulse_mode; /* enable pulse output mode? */
134	char caused_reboot; /* last reboot was by the watchdog */
135	};
136
137	static struct watchdog_data watchdog = {
138	.lock = __MUTEX_INITIALIZER(watchdog.lock),
139	};
140
141	/* Super I/O functions */
142	static inline int superio_inb(int base, int reg)
143	{
144	outb(reg, base);
145	return inb(base + 1);
146	}
147
148	static int superio_inw(int base, int reg)
149	{
150	int val;
151	val = superio_inb(base, reg) << 8;
152	val \|= superio_inb(base, reg + 1);
153	return val;
154	}
155
156	static inline void superio_outb(int base, int reg, u8 val)
157	{
158	outb(reg, base);
159	outb(val, base + 1);
160	}
161
162	static inline void superio_set_bit(int base, int reg, int bit)
163	{
164	unsigned long val = superio_inb(base, reg);
165	__set_bit(bit, &val);
166	superio_outb(base, reg, val);
167	}
168
169	static inline void superio_clear_bit(int base, int reg, int bit)
170	{
171	unsigned long val = superio_inb(base, reg);
172	__clear_bit(bit, &val);
173	superio_outb(base, reg, val);
174	}
175
176	static inline int superio_enter(int base)
177	{
178	/* Don't step on other drivers' I/O space by accident */
179	if (!request_muxed_region(base, 2, DRVNAME)) {
180	printk(KERN_ERR DRVNAME ": I/O address 0x%04x already in use\n",
181	(int)base);
182	return -EBUSY;
183	}
184
185	/* according to the datasheet the key must be send twice! */
186	outb(SIO_UNLOCK_KEY, base);
187	outb(SIO_UNLOCK_KEY, base);
188
189	return 0;
190	}
191
192	static inline void superio_select(int base, int ld)
193	{
194	outb(SIO_REG_LDSEL, base);
195	outb(ld, base + 1);
196	}
197
198	static inline void superio_exit(int base)
199	{
200	outb(SIO_LOCK_KEY, base);
201	release_region(base, 2);
202	}
203
204	static int watchdog_set_timeout(int timeout)
205	{
206	if (timeout <= 0
207	\|\| timeout > max_timeout) {
208	printk(KERN_ERR DRVNAME ": watchdog timeout out of range\n");
209	return -EINVAL;
210	}
211
212	mutex_lock(&watchdog.lock);
213
214	watchdog.timeout = timeout;
215	if (timeout > 0xff) {
216	watchdog.timer_val = DIV_ROUND_UP(timeout, 60);
217	watchdog.minutes_mode = true;
218	} else {
219	watchdog.timer_val = timeout;
220	watchdog.minutes_mode = false;
221	}
222
223	mutex_unlock(&watchdog.lock);
224
225	return 0;
226	}
227
228	static int watchdog_set_pulse_width(unsigned int pw)
229	{
230	int err = 0;
231
232	mutex_lock(&watchdog.lock);
233
234	if (pw <= 1) {
235	watchdog.pulse_val = 0;
236	} else if (pw <= 25) {
237	watchdog.pulse_val = 1;
238	} else if (pw <= 125) {
239	watchdog.pulse_val = 2;
240	} else if (pw <= 5000) {
241	watchdog.pulse_val = 3;
242	} else {
243	printk(KERN_ERR DRVNAME ": pulse width out of range\n");
244	err = -EINVAL;
245	goto exit_unlock;
246	}
247
248	watchdog.pulse_mode = pw;
249
250	exit_unlock:
251	mutex_unlock(&watchdog.lock);
252	return err;
253	}
254
255	static int watchdog_keepalive(void)
256	{
257	int err = 0;
258
259	mutex_lock(&watchdog.lock);
260	err = superio_enter(watchdog.sioaddr);
261	if (err)
262	goto exit_unlock;
263	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
264
265	if (watchdog.minutes_mode)
266	/* select minutes for timer units */
267	superio_set_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
268	F71808FG_FLAG_WD_UNIT);
269	else
270	/* select seconds for timer units */
271	superio_clear_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
272	F71808FG_FLAG_WD_UNIT);
273
274	/* Set timer value */
275	superio_outb(watchdog.sioaddr, F71808FG_REG_WD_TIME,
276	watchdog.timer_val);
277
278	superio_exit(watchdog.sioaddr);
279
280	exit_unlock:
281	mutex_unlock(&watchdog.lock);
282	return err;
283	}
284
285	static int watchdog_start(void)
286	{
287	/* Make sure we don't die as soon as the watchdog is enabled below */
288	int err = watchdog_keepalive();
289	if (err)
290	return err;
291
292	mutex_lock(&watchdog.lock);
293	err = superio_enter(watchdog.sioaddr);
294	if (err)
295	goto exit_unlock;
296	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
297
298	/* Watchdog pin configuration */
299	switch (watchdog.type) {
300	case f71808fg:
301	/* Set pin 21 to GPIO23/WDTRST#, then to WDTRST# */
302	superio_clear_bit(watchdog.sioaddr, 0x2a, 3);
303	superio_clear_bit(watchdog.sioaddr, 0x2b, 3);
304	break;
305
306	case f71882fg:
307	/* Set pin 56 to WDTRST# */
308	superio_set_bit(watchdog.sioaddr, 0x29, 1);
309	break;
310
dee00abb GS	311	case f71889fg:
	312	/* set pin 40 to WDTRST# */
	313	superio_outb(watchdog.sioaddr, 0x2b,
	314	superio_inb(watchdog.sioaddr, 0x2b) & 0xcf);
	315	break;
	316
96cb4eb0 GS	317	default:
	318	/*
	319	* 'default' label to shut up the compiler and catch
	320	* programmer errors
	321	*/
	322	err = -ENODEV;
	323	goto exit_superio;
	324	}
	325
	326	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
	327	superio_set_bit(watchdog.sioaddr, SIO_REG_ENABLE, 0);
	328	superio_set_bit(watchdog.sioaddr, F71808FG_REG_WDO_CONF,
	329	F71808FG_FLAG_WDOUT_EN);
	330
	331	superio_set_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
	332	F71808FG_FLAG_WD_EN);
	333
	334	if (watchdog.pulse_mode) {
	335	/* Select "pulse" output mode with given duration */
	336	u8 wdt_conf = superio_inb(watchdog.sioaddr,
	337	F71808FG_REG_WDT_CONF);
	338
	339	/* Set WD_PSWIDTH bits (1:0) */
	340	wdt_conf = (wdt_conf & 0xfc) \| (watchdog.pulse_val & 0x03);
	341	/* Set WD_PULSE to "pulse" mode */
	342	wdt_conf \|= BIT(F71808FG_FLAG_WD_PULSE);
	343
	344	superio_outb(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
	345	wdt_conf);
	346	} else {
	347	/* Select "level" output mode */
	348	superio_clear_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
	349	F71808FG_FLAG_WD_PULSE);
	350	}
	351
	352	exit_superio:
	353	superio_exit(watchdog.sioaddr);
	354	exit_unlock:
	355	mutex_unlock(&watchdog.lock);
	356
	357	return err;
	358	}
	359
	360	static int watchdog_stop(void)
	361	{
	362	int err = 0;
	363
	364	mutex_lock(&watchdog.lock);
	365	err = superio_enter(watchdog.sioaddr);
	366	if (err)
	367	goto exit_unlock;
	368	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
	369
	370	superio_clear_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
	371	F71808FG_FLAG_WD_EN);
	372
	373	superio_exit(watchdog.sioaddr);
	374
	375	exit_unlock:
	376	mutex_unlock(&watchdog.lock);
	377
	378	return err;
	379	}
	380
381	static int watchdog_get_status(void)
382	{
383	int status = 0;
384
385	mutex_lock(&watchdog.lock);
386	status = (watchdog.caused_reboot) ? WDIOF_CARDRESET : 0;
387	mutex_unlock(&watchdog.lock);
388
389	return status;
390	}
391
392	static bool watchdog_is_running(void)
393	{
394	/*
395	* if we fail to determine the watchdog's status assume it to be
396	* running to be on the safe side
397	*/
398	bool is_running = true;
399
400	mutex_lock(&watchdog.lock);
401	if (superio_enter(watchdog.sioaddr))
402	goto exit_unlock;
403	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
404
405	is_running = (superio_inb(watchdog.sioaddr, SIO_REG_ENABLE) & BIT(0))
406	&& (superio_inb(watchdog.sioaddr, F71808FG_REG_WDT_CONF)
407	& F71808FG_FLAG_WD_EN);
408
409	superio_exit(watchdog.sioaddr);
410
411	exit_unlock:
412	mutex_unlock(&watchdog.lock);
413	return is_running;
414	}
415
416	/* /dev/watchdog api */
417
418	static int watchdog_open(struct inode inode, struct file file)
419	{
420	int err;
421
422	/* If the watchdog is alive we don't need to start it again */
423	if (test_and_set_bit(0, &watchdog.opened))
424	return -EBUSY;
425
426	err = watchdog_start();
427	if (err) {
428	clear_bit(0, &watchdog.opened);
429	return err;
430	}
431
432	if (nowayout)
433	__module_get(THIS_MODULE);
434
435	watchdog.expect_close = 0;
436	return nonseekable_open(inode, file);
437	}
438
439	static int watchdog_release(struct inode inode, struct file file)
440	{
441	clear_bit(0, &watchdog.opened);
442
443	if (!watchdog.expect_close) {
444	watchdog_keepalive();
445	printk(KERN_CRIT DRVNAME
446	": Unexpected close, not stopping watchdog!\n");
447	} else if (!nowayout) {
448	watchdog_stop();
449	}
450	return 0;
451	}
452
453	/*
454	* watchdog_write:
455	* @file: file handle to the watchdog
456	* @buf: buffer to write
457	* @count: count of bytes
458	* @ppos: pointer to the position to write. No seeks allowed
459	*
460	* A write to a watchdog device is defined as a keepalive signal. Any
461	* write of data will do, as we we don't define content meaning.
462	*/
463
464	static ssize_t watchdog_write(struct file file, const char __user buf,
465	size_t count, loff_t *ppos)
466	{
467	if (count) {
468	if (!nowayout) {
469	size_t i;
470
471	/* In case it was set long ago */
472	bool expect_close = false;
473
474	for (i = 0; i != count; i++) {
475	char c;
476	if (get_user(c, buf + i))
477	return -EFAULT;
478	expect_close = (c == 'V');
479	}
480
481	/* Properly order writes across fork()ed processes */
482	mutex_lock(&watchdog.lock);
483	watchdog.expect_close = expect_close;
484	mutex_unlock(&watchdog.lock);
485	}
486
487	/* someone wrote to us, we should restart timer */
488	watchdog_keepalive();
489	}
490	return count;
491	}
492
493	/*
494	* watchdog_ioctl:
495	* @inode: inode of the device
496	* @file: file handle to the device
497	* @cmd: watchdog command
498	* @arg: argument pointer
499	*
500	* The watchdog API defines a common set of functions for all watchdogs
501	* according to their available features.
502	*/
503	static long watchdog_ioctl(struct file *file, unsigned int cmd,
504	unsigned long arg)
505	{
506	int status;
507	int new_options;
508	int new_timeout;
509	union {
510	struct watchdog_info __user *ident;
511	int __user *i;
512	} uarg;
513
514	uarg.i = (int __user *)arg;
515
516	switch (cmd) {
517	case WDIOC_GETSUPPORT:
518	return copy_to_user(uarg.ident, &watchdog.ident,
519	sizeof(watchdog.ident)) ? -EFAULT : 0;
520
521	case WDIOC_GETSTATUS:
522	status = watchdog_get_status();
523	if (status < 0)
524	return status;
525	return put_user(status, uarg.i);
526
527	case WDIOC_GETBOOTSTATUS:
528	return put_user(0, uarg.i);
529
530	case WDIOC_SETOPTIONS:
531	if (get_user(new_options, uarg.i))
532	return -EFAULT;
533
534	if (new_options & WDIOS_DISABLECARD)
535	watchdog_stop();
536
537	if (new_options & WDIOS_ENABLECARD)
538	return watchdog_start();
539
540
541	case WDIOC_KEEPALIVE:
542	watchdog_keepalive();
543	return 0;
544
545	case WDIOC_SETTIMEOUT:
546	if (get_user(new_timeout, uarg.i))
547	return -EFAULT;
548
549	if (watchdog_set_timeout(new_timeout))
550	return -EINVAL;
551
552	watchdog_keepalive();
553	/* Fall */
554
555	case WDIOC_GETTIMEOUT:
556	return put_user(watchdog.timeout, uarg.i);
557
558	default:
559	return -ENOTTY;
560
561	}
562	}
563
564	static int watchdog_notify_sys(struct notifier_block *this, unsigned long code,
565	void *unused)
566	{
567	if (code == SYS_DOWN \|\| code == SYS_HALT)
568	watchdog_stop();
569	return NOTIFY_DONE;
570	}
571
572	static const struct file_operations watchdog_fops = {
573	.owner = THIS_MODULE,
574	.llseek = no_llseek,
575	.open = watchdog_open,
576	.release = watchdog_release,
577	.write = watchdog_write,
578	.unlocked_ioctl = watchdog_ioctl,
579	};
580
581	static struct miscdevice watchdog_miscdev = {
582	.minor = WATCHDOG_MINOR,
583	.name = "watchdog",
584	.fops = &watchdog_fops,
585	};
586
587	static struct notifier_block watchdog_notifier = {
588	.notifier_call = watchdog_notify_sys,
589	};
590
591	static int __init watchdog_init(int sioaddr)
592	{
593	int wdt_conf, err = 0;
594
595	/* No need to lock watchdog.lock here because no entry points
596	* into the module have been registered yet.
597	*/
598	watchdog.sioaddr = sioaddr;
599	watchdog.ident.options = WDIOC_SETTIMEOUT
600	\| WDIOF_MAGICCLOSE
601	\| WDIOF_KEEPALIVEPING;
602
603	snprintf(watchdog.ident.identity,
604	sizeof(watchdog.ident.identity), "%s watchdog",
605	f71808e_names[watchdog.type]);
606
607	err = superio_enter(sioaddr);
608	if (err)
609	return err;
610	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
611
612	wdt_conf = superio_inb(sioaddr, F71808FG_REG_WDT_CONF);
613	watchdog.caused_reboot = wdt_conf & F71808FG_FLAG_WDTMOUT_STS;
614
615	superio_exit(sioaddr);
616
617	err = watchdog_set_timeout(timeout);
618	if (err)
619	return err;
620	err = watchdog_set_pulse_width(pulse_width);
621	if (err)
622	return err;
623
624	err = register_reboot_notifier(&watchdog_notifier);
625	if (err)
626	return err;
627
628	err = misc_register(&watchdog_miscdev);
629	if (err) {
630	printk(KERN_ERR DRVNAME
631	": cannot register miscdev on minor=%d\n",
632	watchdog_miscdev.minor);
633	goto exit_reboot;
634	}
635
636	if (start_withtimeout) {
637	if (start_withtimeout <= 0
638	\|\| start_withtimeout > max_timeout) {
639	printk(KERN_ERR DRVNAME
640	": starting timeout out of range\n");
641	err = -EINVAL;
642	goto exit_miscdev;
643	}
644
645	err = watchdog_start();
646	if (err) {
647	printk(KERN_ERR DRVNAME
648	": cannot start watchdog timer\n");
649	goto exit_miscdev;
650	}
651
652	mutex_lock(&watchdog.lock);
653	err = superio_enter(sioaddr);
654	if (err)
655	goto exit_unlock;
656	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
657
658	if (start_withtimeout > 0xff) {
659	/* select minutes for timer units */
660	superio_set_bit(sioaddr, F71808FG_REG_WDT_CONF,
661	F71808FG_FLAG_WD_UNIT);
662	superio_outb(sioaddr, F71808FG_REG_WD_TIME,
663	DIV_ROUND_UP(start_withtimeout, 60));
664	} else {
665	/* select seconds for timer units */
666	superio_clear_bit(sioaddr, F71808FG_REG_WDT_CONF,
667	F71808FG_FLAG_WD_UNIT);
668	superio_outb(sioaddr, F71808FG_REG_WD_TIME,
669	start_withtimeout);
670	}
671
672	superio_exit(sioaddr);
673	mutex_unlock(&watchdog.lock);
674
675	if (nowayout)
676	__module_get(THIS_MODULE);
677
678	printk(KERN_INFO DRVNAME
679	": watchdog started with initial timeout of %u sec\n",
680	start_withtimeout);
681	}
682
683	return 0;
684
685	exit_unlock:
686	mutex_unlock(&watchdog.lock);
687	exit_miscdev:
688	misc_deregister(&watchdog_miscdev);
689	exit_reboot:
690	unregister_reboot_notifier(&watchdog_notifier);
691
692	return err;
693	}
694
695	static int __init f71808e_find(int sioaddr)
696	{
697	u16 devid;
698	int err = superio_enter(sioaddr);
699	if (err)
700	return err;
701
702	devid = superio_inw(sioaddr, SIO_REG_MANID);
703	if (devid != SIO_FINTEK_ID) {
704	pr_debug(DRVNAME ": Not a Fintek device\n");
705	err = -ENODEV;
706	goto exit;
707	}
708
709	devid = force_id ? force_id : superio_inw(sioaddr, SIO_REG_DEVID);
710	switch (devid) {
711	case SIO_F71808_ID:
712	watchdog.type = f71808fg;
713	break;
714	case SIO_F71882_ID:
715	watchdog.type = f71882fg;
716	break;
96cb4eb0	717	case SIO_F71889_ID:
dee00abb GS	718	watchdog.type = f71889fg;
	719	break;
	720	case SIO_F71862_ID:
96cb4eb0 GS	721	/* These have a watchdog, though it isn't implemented (yet). */
	722	err = -ENOSYS;
	723	goto exit;
	724	case SIO_F71858_ID:
	725	/* Confirmed (by datasheet) not to have a watchdog. */
	726	err = -ENODEV;
	727	goto exit;
	728	default:
	729	printk(KERN_INFO DRVNAME ": Unrecognized Fintek device: %04x\n",
	730	(unsigned int)devid);
	731	err = -ENODEV;
	732	goto exit;
	733	}
	734
	735	printk(KERN_INFO DRVNAME ": Found %s watchdog chip, revision %d\n",
	736	f71808e_names[watchdog.type],
	737	(int)superio_inb(sioaddr, SIO_REG_DEVREV));
	738	exit:
	739	superio_exit(sioaddr);
	740	return err;
	741	}
	742
	743	static int __init f71808e_init(void)
	744	{
	745	static const unsigned short addrs[] = { 0x2e, 0x4e };
	746	int err = -ENODEV;
	747	int i;
	748
	749	for (i = 0; i < ARRAY_SIZE(addrs); i++) {
	750	err = f71808e_find(addrs[i]);
	751	if (err == 0)
	752	break;
	753	}
	754	if (i == ARRAY_SIZE(addrs))
	755	return err;
	756
	757	return watchdog_init(addrs[i]);
	758	}
	759
	760	static void __exit f71808e_exit(void)
	761	{
	762	if (watchdog_is_running()) {
	763	printk(KERN_WARNING DRVNAME
	764	": Watchdog timer still running, stopping it\n");
	765	watchdog_stop();
	766	}
	767	misc_deregister(&watchdog_miscdev);
	768	unregister_reboot_notifier(&watchdog_notifier);
	769	}
	770
	771	MODULE_DESCRIPTION("F71808E Watchdog Driver");
	772	MODULE_AUTHOR("Giel van Schijndel <me@mortis.eu>");
	773	MODULE_LICENSE("GPL");
	774
	775	module_init(f71808e_init);
	776	module_exit(f71808e_exit);