[mirror_ubuntu-zesty-kernel.git] / drivers / watchdog / ar7_wdt.c

/*
 * drivers/watchdog/ar7_wdt.c
 *
 * Copyright (C) 2007 Nicolas Thill <nico@openwrt.org>
 * Copyright (c) 2005 Enrik Berkhan <Enrik.Berkhan@akk.org>
 *
 * Some code taken from:
 * National Semiconductor SCx200 Watchdog support
 * Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com>
 *
 * 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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

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

#include <asm/addrspace.h>
#include <asm/ar7/ar7.h>

#define DRVNAME "ar7_wdt"
#define LONGNAME "TI AR7 Watchdog Timer"

MODULE_AUTHOR("Nicolas Thill <nico@openwrt.org>");
MODULE_DESCRIPTION(LONGNAME);
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);

static int margin = 60;
module_param(margin, int, 0);
MODULE_PARM_DESC(margin, "Watchdog margin in seconds");

static int nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");

#define READ_REG(x) readl((void __iomem *)&(x))
#define WRITE_REG(x, v) writel((v), (void __iomem *)&(x))

struct ar7_wdt {
	u32 kick_lock;
	u32 kick;
	u32 change_lock;
	u32 change;
	u32 disable_lock;
	u32 disable;
	u32 prescale_lock;
	u32 prescale;
};

static unsigned long wdt_is_open;
static spinlock_t wdt_lock;
static unsigned expect_close;

/* XXX currently fixed, allows max margin ~68.72 secs */
#define prescale_value 0xffff

/* Offset of the WDT registers */
static unsigned long ar7_regs_wdt;
/* Pointer to the remapped WDT IO space */
static struct ar7_wdt *ar7_wdt;
static void ar7_wdt_get_regs(void)
{
	u16 chip_id = ar7_chip_id();
	switch (chip_id) {
	case AR7_CHIP_7100:
	case AR7_CHIP_7200:
		ar7_regs_wdt = AR7_REGS_WDT;
		break;
	default:
		ar7_regs_wdt = UR8_REGS_WDT;
		break;
	}
}


static void ar7_wdt_kick(u32 value)
{
	WRITE_REG(ar7_wdt->kick_lock, 0x5555);
	if ((READ_REG(ar7_wdt->kick_lock) & 3) == 1) {
		WRITE_REG(ar7_wdt->kick_lock, 0xaaaa);
		if ((READ_REG(ar7_wdt->kick_lock) & 3) == 3) {
			WRITE_REG(ar7_wdt->kick, value);
			return;
		}
	}
	printk(KERN_ERR DRVNAME ": failed to unlock WDT kick reg\n");
}

static void ar7_wdt_prescale(u32 value)
{
	WRITE_REG(ar7_wdt->prescale_lock, 0x5a5a);
	if ((READ_REG(ar7_wdt->prescale_lock) & 3) == 1) {
		WRITE_REG(ar7_wdt->prescale_lock, 0xa5a5);
		if ((READ_REG(ar7_wdt->prescale_lock) & 3) == 3) {
			WRITE_REG(ar7_wdt->prescale, value);
			return;
		}
	}
	printk(KERN_ERR DRVNAME ": failed to unlock WDT prescale reg\n");
}

static void ar7_wdt_change(u32 value)
{
	WRITE_REG(ar7_wdt->change_lock, 0x6666);
	if ((READ_REG(ar7_wdt->change_lock) & 3) == 1) {
		WRITE_REG(ar7_wdt->change_lock, 0xbbbb);
		if ((READ_REG(ar7_wdt->change_lock) & 3) == 3) {
			WRITE_REG(ar7_wdt->change, value);
			return;
		}
	}
	printk(KERN_ERR DRVNAME ": failed to unlock WDT change reg\n");
}

static void ar7_wdt_disable(u32 value)
{
	WRITE_REG(ar7_wdt->disable_lock, 0x7777);
	if ((READ_REG(ar7_wdt->disable_lock) & 3) == 1) {
		WRITE_REG(ar7_wdt->disable_lock, 0xcccc);
		if ((READ_REG(ar7_wdt->disable_lock) & 3) == 2) {
			WRITE_REG(ar7_wdt->disable_lock, 0xdddd);
			if ((READ_REG(ar7_wdt->disable_lock) & 3) == 3) {
				WRITE_REG(ar7_wdt->disable, value);
				return;
			}
		}
	}
	printk(KERN_ERR DRVNAME ": failed to unlock WDT disable reg\n");
}

static void ar7_wdt_update_margin(int new_margin)
{
	u32 change;

	change = new_margin * (ar7_vbus_freq() / prescale_value);
	if (change < 1)
		change = 1;
	if (change > 0xffff)
		change = 0xffff;
	ar7_wdt_change(change);
	margin = change * prescale_value / ar7_vbus_freq();
	printk(KERN_INFO DRVNAME
	       ": timer margin %d seconds (prescale %d, change %d, freq %d)\n",
	       margin, prescale_value, change, ar7_vbus_freq());
}

static void ar7_wdt_enable_wdt(void)
{
	printk(KERN_DEBUG DRVNAME ": enabling watchdog timer\n");
	ar7_wdt_disable(1);
	ar7_wdt_kick(1);
}

static void ar7_wdt_disable_wdt(void)
{
	printk(KERN_DEBUG DRVNAME ": disabling watchdog timer\n");
	ar7_wdt_disable(0);
}

static int ar7_wdt_open(struct inode *inode, struct file *file)
{
	/* only allow one at a time */
	if (test_and_set_bit(0, &wdt_is_open))
		return -EBUSY;
	ar7_wdt_enable_wdt();
	expect_close = 0;

	return nonseekable_open(inode, file);
}

static int ar7_wdt_release(struct inode *inode, struct file *file)
{
	if (!expect_close)
		printk(KERN_WARNING DRVNAME
		": watchdog device closed unexpectedly,"
		"will not disable the watchdog timer\n");
	else if (!nowayout)
		ar7_wdt_disable_wdt();
	clear_bit(0, &wdt_is_open);
	return 0;
}

static int ar7_wdt_notify_sys(struct notifier_block *this,
			      unsigned long code, void *unused)
{
	if (code == SYS_HALT || code == SYS_POWER_OFF)
		if (!nowayout)
			ar7_wdt_disable_wdt();

	return NOTIFY_DONE;
}

static struct notifier_block ar7_wdt_notifier = {
	.notifier_call = ar7_wdt_notify_sys
};

static ssize_t ar7_wdt_write(struct file *file, const char *data,
			     size_t len, loff_t *ppos)
{
	/* check for a magic close character */
	if (len) {
		size_t i;

		spin_lock(&wdt_lock);
		ar7_wdt_kick(1);
		spin_unlock(&wdt_lock);

		expect_close = 0;
		for (i = 0; i < len; ++i) {
			char c;
			if (get_user(c, data+i))
				return -EFAULT;
			if (c == 'V')
				expect_close = 1;
		}

	}
	return len;
}

static long ar7_wdt_ioctl(struct file *file,
					unsigned int cmd, unsigned long arg)
{
	static struct watchdog_info ident = {
		.identity = LONGNAME,
		.firmware_version = 1,
		.options = (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING),
	};
	int new_margin;

	switch (cmd) {
	case WDIOC_GETSUPPORT:
		if (copy_to_user((struct watchdog_info *)arg, &ident,
				sizeof(ident)))
			return -EFAULT;
		return 0;
	case WDIOC_GETSTATUS:
	case WDIOC_GETBOOTSTATUS:
		if (put_user(0, (int *)arg))
			return -EFAULT;
		return 0;
	case WDIOC_KEEPALIVE:
		ar7_wdt_kick(1);
		return 0;
	case WDIOC_SETTIMEOUT:
		if (get_user(new_margin, (int *)arg))
			return -EFAULT;
		if (new_margin < 1)
			return -EINVAL;

		spin_lock(&wdt_lock);
		ar7_wdt_update_margin(new_margin);
		ar7_wdt_kick(1);
		spin_unlock(&wdt_lock);

	case WDIOC_GETTIMEOUT:
		if (put_user(margin, (int *)arg))
			return -EFAULT;
		return 0;
	default:
		return -ENOTTY;
	}
}

static const struct file_operations ar7_wdt_fops = {
	.owner		= THIS_MODULE,
	.write		= ar7_wdt_write,
	.unlocked_ioctl	= ar7_wdt_ioctl,
	.open		= ar7_wdt_open,
	.release	= ar7_wdt_release,
};

static struct miscdevice ar7_wdt_miscdev = {
	.minor		= WATCHDOG_MINOR,
	.name		= "watchdog",
	.fops		= &ar7_wdt_fops,
};

static int __init ar7_wdt_init(void)
{
	int rc;

	spin_lock_init(&wdt_lock);

	ar7_wdt_get_regs();

	if (!request_mem_region(ar7_regs_wdt, sizeof(struct ar7_wdt),
							LONGNAME)) {
		printk(KERN_WARNING DRVNAME ": watchdog I/O region busy\n");
		return -EBUSY;
	}

	ar7_wdt = (struct ar7_wdt *)
			ioremap(ar7_regs_wdt, sizeof(struct ar7_wdt));

	ar7_wdt_disable_wdt();
	ar7_wdt_prescale(prescale_value);
	ar7_wdt_update_margin(margin);

	rc = register_reboot_notifier(&ar7_wdt_notifier);
	if (rc) {
		printk(KERN_ERR DRVNAME
			": unable to register reboot notifier\n");
		goto out_alloc;
	}

	rc = misc_register(&ar7_wdt_miscdev);
	if (rc) {
		printk(KERN_ERR DRVNAME ": unable to register misc device\n");
		goto out_register;
	}
	goto out;

out_register:
	unregister_reboot_notifier(&ar7_wdt_notifier);
out_alloc:
	iounmap(ar7_wdt);
	release_mem_region(ar7_regs_wdt, sizeof(struct ar7_wdt));
out:
	return rc;
}

static void __exit ar7_wdt_cleanup(void)
{
	misc_deregister(&ar7_wdt_miscdev);
	unregister_reboot_notifier(&ar7_wdt_notifier);
	iounmap(ar7_wdt);
	release_mem_region(ar7_regs_wdt, sizeof(struct ar7_wdt));
}

module_init(ar7_wdt_init);
module_exit(ar7_wdt_cleanup);
Commit	Line	Data
c283cf2c MC	1	/*
	2	* drivers/watchdog/ar7_wdt.c
	3	*
	4	* Copyright (C) 2007 Nicolas Thill <nico@openwrt.org>
	5	* Copyright (c) 2005 Enrik Berkhan <Enrik.Berkhan@akk.org>
	6	*
	7	* Some code taken from:
	8	* National Semiconductor SCx200 Watchdog support
	9	* Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com>
	10	*
	11	* This program is free software; you can redistribute it and/or modify
	12	* it under the terms of the GNU General Public License as published by
	13	* the Free Software Foundation; either version 2 of the License, or
	14	* (at your option) any later version.
	15	*
	16	* This program is distributed in the hope that it will be useful,
	17	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	18	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	19	* GNU General Public License for more details.
	20	*
	21	* You should have received a copy of the GNU General Public License
	22	* along with this program; if not, write to the Free Software
	23	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	24	*/
	25
	26	#include <linux/module.h>
	27	#include <linux/moduleparam.h>
	28	#include <linux/errno.h>
	29	#include <linux/init.h>
	30	#include <linux/miscdevice.h>
	31	#include <linux/watchdog.h>
	32	#include <linux/notifier.h>
	33	#include <linux/reboot.h>
	34	#include <linux/fs.h>
	35	#include <linux/ioport.h>
	36	#include <linux/io.h>
	37	#include <linux/uaccess.h>
	38
	39	#include <asm/addrspace.h>
	40	#include <asm/ar7/ar7.h>
	41
	42	#define DRVNAME "ar7_wdt"
	43	#define LONGNAME "TI AR7 Watchdog Timer"
	44
	45	MODULE_AUTHOR("Nicolas Thill <nico@openwrt.org>");
	46	MODULE_DESCRIPTION(LONGNAME);
	47	MODULE_LICENSE("GPL");
	48	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
	49
	50	static int margin = 60;
	51	module_param(margin, int, 0);
	52	MODULE_PARM_DESC(margin, "Watchdog margin in seconds");
	53
	54	static int nowayout = WATCHDOG_NOWAYOUT;
	55	module_param(nowayout, int, 0);
	56	MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");
	57
	58	#define READ_REG(x) readl((void __iomem *)&(x))
	59	#define WRITE_REG(x, v) writel((v), (void __iomem *)&(x))
	60
	61	struct ar7_wdt {
	62	u32 kick_lock;
	63	u32 kick;
	64	u32 change_lock;
65	u32 change;
66	u32 disable_lock;
67	u32 disable;
68	u32 prescale_lock;
69	u32 prescale;
70	};
71
670d59c0 AC	72	static unsigned long wdt_is_open;
670d59c0 AC	73	static spinlock_t wdt_lock;
c283cf2c MC	74	static unsigned expect_close;
	75
	76	/* XXX currently fixed, allows max margin ~68.72 secs */
	77	#define prescale_value 0xffff
	78
	79	/* Offset of the WDT registers */
	80	static unsigned long ar7_regs_wdt;
	81	/* Pointer to the remapped WDT IO space */
	82	static struct ar7_wdt *ar7_wdt;
	83	static void ar7_wdt_get_regs(void)
	84	{
	85	u16 chip_id = ar7_chip_id();
	86	switch (chip_id) {
	87	case AR7_CHIP_7100:
	88	case AR7_CHIP_7200:
	89	ar7_regs_wdt = AR7_REGS_WDT;
	90	break;
	91	default:
	92	ar7_regs_wdt = UR8_REGS_WDT;
	93	break;
	94	}
	95	}
	96
	97
	98	static void ar7_wdt_kick(u32 value)
	99	{
	100	WRITE_REG(ar7_wdt->kick_lock, 0x5555);
	101	if ((READ_REG(ar7_wdt->kick_lock) & 3) == 1) {
	102	WRITE_REG(ar7_wdt->kick_lock, 0xaaaa);
	103	if ((READ_REG(ar7_wdt->kick_lock) & 3) == 3) {
	104	WRITE_REG(ar7_wdt->kick, value);
	105	return;
	106	}
	107	}
	108	printk(KERN_ERR DRVNAME ": failed to unlock WDT kick reg\n");
	109	}
	110
	111	static void ar7_wdt_prescale(u32 value)
	112	{
	113	WRITE_REG(ar7_wdt->prescale_lock, 0x5a5a);
	114	if ((READ_REG(ar7_wdt->prescale_lock) & 3) == 1) {
	115	WRITE_REG(ar7_wdt->prescale_lock, 0xa5a5);
	116	if ((READ_REG(ar7_wdt->prescale_lock) & 3) == 3) {
	117	WRITE_REG(ar7_wdt->prescale, value);
	118	return;
	119	}
	120	}
	121	printk(KERN_ERR DRVNAME ": failed to unlock WDT prescale reg\n");
	122	}
	123
	124	static void ar7_wdt_change(u32 value)
	125	{
	126	WRITE_REG(ar7_wdt->change_lock, 0x6666);
	127	if ((READ_REG(ar7_wdt->change_lock) & 3) == 1) {
	128	WRITE_REG(ar7_wdt->change_lock, 0xbbbb);
	129	if ((READ_REG(ar7_wdt->change_lock) & 3) == 3) {
	130	WRITE_REG(ar7_wdt->change, value);
	131	return;
	132	}
	133	}
	134	printk(KERN_ERR DRVNAME ": failed to unlock WDT change reg\n");
	135	}
	136
	137	static void ar7_wdt_disable(u32 value)
138	{
139	WRITE_REG(ar7_wdt->disable_lock, 0x7777);
140	if ((READ_REG(ar7_wdt->disable_lock) & 3) == 1) {
141	WRITE_REG(ar7_wdt->disable_lock, 0xcccc);
142	if ((READ_REG(ar7_wdt->disable_lock) & 3) == 2) {
143	WRITE_REG(ar7_wdt->disable_lock, 0xdddd);
144	if ((READ_REG(ar7_wdt->disable_lock) & 3) == 3) {
145	WRITE_REG(ar7_wdt->disable, value);
146	return;
147	}
148	}
149	}
150	printk(KERN_ERR DRVNAME ": failed to unlock WDT disable reg\n");
151	}
152
153	static void ar7_wdt_update_margin(int new_margin)
154	{
155	u32 change;
156
157	change = new_margin * (ar7_vbus_freq() / prescale_value);
670d59c0 AC	158	if (change < 1)
	159	change = 1;
	160	if (change > 0xffff)
	161	change = 0xffff;
c283cf2c MC	162	ar7_wdt_change(change);
	163	margin = change * prescale_value / ar7_vbus_freq();
	164	printk(KERN_INFO DRVNAME
	165	": timer margin %d seconds (prescale %d, change %d, freq %d)\n",
	166	margin, prescale_value, change, ar7_vbus_freq());
	167	}
	168
	169	static void ar7_wdt_enable_wdt(void)
	170	{
	171	printk(KERN_DEBUG DRVNAME ": enabling watchdog timer\n");
	172	ar7_wdt_disable(1);
	173	ar7_wdt_kick(1);
	174	}
	175
	176	static void ar7_wdt_disable_wdt(void)
	177	{
	178	printk(KERN_DEBUG DRVNAME ": disabling watchdog timer\n");
	179	ar7_wdt_disable(0);
	180	}
	181
	182	static int ar7_wdt_open(struct inode inode, struct file file)
	183	{
	184	/* only allow one at a time */
670d59c0	185	if (test_and_set_bit(0, &wdt_is_open))
c283cf2c MC	186	return -EBUSY;
	187	ar7_wdt_enable_wdt();
	188	expect_close = 0;
	189
	190	return nonseekable_open(inode, file);
	191	}
	192
	193	static int ar7_wdt_release(struct inode inode, struct file file)
	194	{
	195	if (!expect_close)
	196	printk(KERN_WARNING DRVNAME
	197	": watchdog device closed unexpectedly,"
	198	"will not disable the watchdog timer\n");
	199	else if (!nowayout)
	200	ar7_wdt_disable_wdt();
670d59c0	201	clear_bit(0, &wdt_is_open);
c283cf2c MC	202	return 0;
	203	}
	204
	205	static int ar7_wdt_notify_sys(struct notifier_block *this,
	206	unsigned long code, void *unused)
	207	{
	208	if (code == SYS_HALT \|\| code == SYS_POWER_OFF)
	209	if (!nowayout)
	210	ar7_wdt_disable_wdt();
	211
	212	return NOTIFY_DONE;
	213	}
	214
	215	static struct notifier_block ar7_wdt_notifier = {
	216	.notifier_call = ar7_wdt_notify_sys
	217	};
	218
	219	static ssize_t ar7_wdt_write(struct file file, const char data,
	220	size_t len, loff_t *ppos)
	221	{
	222	/* check for a magic close character */
	223	if (len) {
	224	size_t i;
	225
670d59c0	226	spin_lock(&wdt_lock);
c283cf2c	227	ar7_wdt_kick(1);
670d59c0	228	spin_unlock(&wdt_lock);
c283cf2c MC	229
	230	expect_close = 0;
	231	for (i = 0; i < len; ++i) {
	232	char c;
	233	if (get_user(c, data+i))
	234	return -EFAULT;
	235	if (c == 'V')
	236	expect_close = 1;
	237	}
	238
	239	}
	240	return len;
	241	}
	242
670d59c0 AC	243	static long ar7_wdt_ioctl(struct file *file,
670d59c0 AC	244	unsigned int cmd, unsigned long arg)
c283cf2c MC	245	{
	246	static struct watchdog_info ident = {
	247	.identity = LONGNAME,
	248	.firmware_version = 1,
	249	.options = (WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING),
	250	};
	251	int new_margin;
	252
	253	switch (cmd) {
c283cf2c MC	254	case WDIOC_GETSUPPORT:
	255	if (copy_to_user((struct watchdog_info *)arg, &ident,
	256	sizeof(ident)))
	257	return -EFAULT;
	258	return 0;
	259	case WDIOC_GETSTATUS:
	260	case WDIOC_GETBOOTSTATUS:
	261	if (put_user(0, (int *)arg))
	262	return -EFAULT;
	263	return 0;
	264	case WDIOC_KEEPALIVE:
	265	ar7_wdt_kick(1);
	266	return 0;
	267	case WDIOC_SETTIMEOUT:
	268	if (get_user(new_margin, (int *)arg))
	269	return -EFAULT;
	270	if (new_margin < 1)
	271	return -EINVAL;
	272
670d59c0	273	spin_lock(&wdt_lock);
c283cf2c MC	274	ar7_wdt_update_margin(new_margin);
c283cf2c MC	275	ar7_wdt_kick(1);
670d59c0	276	spin_unlock(&wdt_lock);
c283cf2c MC	277
	278	case WDIOC_GETTIMEOUT:
	279	if (put_user(margin, (int *)arg))
	280	return -EFAULT;
	281	return 0;
0c06090c WVS	282	default:
0c06090c WVS	283	return -ENOTTY;
c283cf2c MC	284	}
	285	}
	286
b47a166e	287	static const struct file_operations ar7_wdt_fops = {
c283cf2c MC	288	.owner = THIS_MODULE,
c283cf2c MC	289	.write = ar7_wdt_write,
670d59c0	290	.unlocked_ioctl = ar7_wdt_ioctl,
c283cf2c MC	291	.open = ar7_wdt_open,
	292	.release = ar7_wdt_release,
	293	};
	294
	295	static struct miscdevice ar7_wdt_miscdev = {
	296	.minor = WATCHDOG_MINOR,
	297	.name = "watchdog",
	298	.fops = &ar7_wdt_fops,
	299	};
	300
	301	static int __init ar7_wdt_init(void)
	302	{
	303	int rc;
	304
670d59c0 AC	305	spin_lock_init(&wdt_lock);
670d59c0 AC	306
c283cf2c MC	307	ar7_wdt_get_regs();
	308
	309	if (!request_mem_region(ar7_regs_wdt, sizeof(struct ar7_wdt),
	310	LONGNAME)) {
	311	printk(KERN_WARNING DRVNAME ": watchdog I/O region busy\n");
	312	return -EBUSY;
	313	}
	314
	315	ar7_wdt = (struct ar7_wdt *)
	316	ioremap(ar7_regs_wdt, sizeof(struct ar7_wdt));
	317
	318	ar7_wdt_disable_wdt();
	319	ar7_wdt_prescale(prescale_value);
	320	ar7_wdt_update_margin(margin);
	321
c283cf2c MC	322	rc = register_reboot_notifier(&ar7_wdt_notifier);
	323	if (rc) {
	324	printk(KERN_ERR DRVNAME
	325	": unable to register reboot notifier\n");
	326	goto out_alloc;
	327	}
	328
	329	rc = misc_register(&ar7_wdt_miscdev);
	330	if (rc) {
	331	printk(KERN_ERR DRVNAME ": unable to register misc device\n");
	332	goto out_register;
	333	}
	334	goto out;
	335
	336	out_register:
	337	unregister_reboot_notifier(&ar7_wdt_notifier);
	338	out_alloc:
	339	iounmap(ar7_wdt);
	340	release_mem_region(ar7_regs_wdt, sizeof(struct ar7_wdt));
	341	out:
	342	return rc;
	343	}
	344
	345	static void __exit ar7_wdt_cleanup(void)
	346	{
	347	misc_deregister(&ar7_wdt_miscdev);
	348	unregister_reboot_notifier(&ar7_wdt_notifier);
	349	iounmap(ar7_wdt);
	350	release_mem_region(ar7_regs_wdt, sizeof(struct ar7_wdt));
	351	}
	352
	353	module_init(ar7_wdt_init);
	354	module_exit(ar7_wdt_cleanup);