[net-next-2.6.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/platform_device.h>
#include <linux/watchdog.h>
#include <linux/fs.h>
#include <linux/ioport.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include <linux/clk.h>

#include <asm/addrspace.h>
#include <asm/mach-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

/* Resource of the WDT registers */
static struct resource *ar7_regs_wdt;
/* Pointer to the remapped WDT IO space */
static struct ar7_wdt *ar7_wdt;

static struct clk *vbus_clk;

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;
	u32 vbus_rate;

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

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 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 const struct watchdog_info ident = {
		.identity = LONGNAME,
		.firmware_version = 1,
		.options = (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
						WDIOF_MAGICCLOSE),
	};
	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,
	.llseek		= no_llseek,
};

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

static int __devinit ar7_wdt_probe(struct platform_device *pdev)
{
	int rc;

	spin_lock_init(&wdt_lock);

	ar7_regs_wdt =
		platform_get_resource_byname(pdev, IORESOURCE_MEM, "regs");
	if (!ar7_regs_wdt) {
		printk(KERN_ERR DRVNAME ": could not get registers resource\n");
		rc = -ENODEV;
		goto out;
	}

	if (!request_mem_region(ar7_regs_wdt->start,
				resource_size(ar7_regs_wdt), LONGNAME)) {
		printk(KERN_WARNING DRVNAME ": watchdog I/O region busy\n");
		rc = -EBUSY;
		goto out;
	}

	ar7_wdt = ioremap(ar7_regs_wdt->start, resource_size(ar7_regs_wdt));
	if (!ar7_wdt) {
		printk(KERN_ERR DRVNAME ": could not ioremap registers\n");
		rc = -ENXIO;
		goto out_mem_region;
	}

	vbus_clk = clk_get(NULL, "vbus");
	if (IS_ERR(vbus_clk)) {
		printk(KERN_ERR DRVNAME ": could not get vbus clock\n");
		rc = PTR_ERR(vbus_clk);
		goto out_mem_region;
	}

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

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

out_alloc:
	iounmap(ar7_wdt);
out_mem_region:
	release_mem_region(ar7_regs_wdt->start, resource_size(ar7_regs_wdt));
out:
	return rc;
}

static int __devexit ar7_wdt_remove(struct platform_device *pdev)
{
	misc_deregister(&ar7_wdt_miscdev);
	iounmap(ar7_wdt);
	release_mem_region(ar7_regs_wdt->start, resource_size(ar7_regs_wdt));

	return 0;
}

static void ar7_wdt_shutdown(struct platform_device *pdev)
{
	if (!nowayout)
		ar7_wdt_disable_wdt();
}

static struct platform_driver ar7_wdt_driver = {
	.probe = ar7_wdt_probe,
	.remove = __devexit_p(ar7_wdt_remove),
	.shutdown = ar7_wdt_shutdown,
	.driver = {
		.owner = THIS_MODULE,
		.name = "ar7_wdt",
	},
};

static int __init ar7_wdt_init(void)
{
	return platform_driver_register(&ar7_wdt_driver);
}

static void __exit ar7_wdt_cleanup(void)
{
	platform_driver_unregister(&ar7_wdt_driver);
}

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>
64d4062a	31	#include <linux/platform_device.h>
c283cf2c	32	#include <linux/watchdog.h>
c283cf2c MC	33	#include <linux/fs.h>
	34	#include <linux/ioport.h>
	35	#include <linux/io.h>
	36	#include <linux/uaccess.h>
780019dd	37	#include <linux/clk.h>
c283cf2c MC	38
c283cf2c MC	39	#include <asm/addrspace.h>
c5e7f5a3	40	#include <asm/mach-ar7/ar7.h>
c283cf2c MC	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
64d4062a FF	79	/* Resource of the WDT registers */
64d4062a FF	80	static struct resource *ar7_regs_wdt;
c283cf2c MC	81	/* Pointer to the remapped WDT IO space */
c283cf2c MC	82	static struct ar7_wdt *ar7_wdt;
c283cf2c	83
780019dd FF	84	static struct clk *vbus_clk;
780019dd FF	85
c283cf2c MC	86	static void ar7_wdt_kick(u32 value)
	87	{
	88	WRITE_REG(ar7_wdt->kick_lock, 0x5555);
	89	if ((READ_REG(ar7_wdt->kick_lock) & 3) == 1) {
	90	WRITE_REG(ar7_wdt->kick_lock, 0xaaaa);
	91	if ((READ_REG(ar7_wdt->kick_lock) & 3) == 3) {
	92	WRITE_REG(ar7_wdt->kick, value);
	93	return;
	94	}
	95	}
	96	printk(KERN_ERR DRVNAME ": failed to unlock WDT kick reg\n");
	97	}
	98
	99	static void ar7_wdt_prescale(u32 value)
	100	{
	101	WRITE_REG(ar7_wdt->prescale_lock, 0x5a5a);
	102	if ((READ_REG(ar7_wdt->prescale_lock) & 3) == 1) {
	103	WRITE_REG(ar7_wdt->prescale_lock, 0xa5a5);
	104	if ((READ_REG(ar7_wdt->prescale_lock) & 3) == 3) {
	105	WRITE_REG(ar7_wdt->prescale, value);
	106	return;
	107	}
	108	}
	109	printk(KERN_ERR DRVNAME ": failed to unlock WDT prescale reg\n");
	110	}
	111
	112	static void ar7_wdt_change(u32 value)
	113	{
	114	WRITE_REG(ar7_wdt->change_lock, 0x6666);
	115	if ((READ_REG(ar7_wdt->change_lock) & 3) == 1) {
	116	WRITE_REG(ar7_wdt->change_lock, 0xbbbb);
	117	if ((READ_REG(ar7_wdt->change_lock) & 3) == 3) {
	118	WRITE_REG(ar7_wdt->change, value);
	119	return;
	120	}
	121	}
	122	printk(KERN_ERR DRVNAME ": failed to unlock WDT change reg\n");
	123	}
	124
	125	static void ar7_wdt_disable(u32 value)
	126	{
	127	WRITE_REG(ar7_wdt->disable_lock, 0x7777);
	128	if ((READ_REG(ar7_wdt->disable_lock) & 3) == 1) {
	129	WRITE_REG(ar7_wdt->disable_lock, 0xcccc);
	130	if ((READ_REG(ar7_wdt->disable_lock) & 3) == 2) {
	131	WRITE_REG(ar7_wdt->disable_lock, 0xdddd);
	132	if ((READ_REG(ar7_wdt->disable_lock) & 3) == 3) {
	133	WRITE_REG(ar7_wdt->disable, value);
	134	return;
	135	}
	136	}
	137	}
	138	printk(KERN_ERR DRVNAME ": failed to unlock WDT disable reg\n");
	139	}
	140
	141	static void ar7_wdt_update_margin(int new_margin)
	142	{
	143	u32 change;
780019dd	144	u32 vbus_rate;
c283cf2c	145
780019dd FF	146	vbus_rate = clk_get_rate(vbus_clk);
780019dd FF	147	change = new_margin * (vbus_rate / prescale_value);
670d59c0 AC	148	if (change < 1)
	149	change = 1;
	150	if (change > 0xffff)
	151	change = 0xffff;
c283cf2c	152	ar7_wdt_change(change);
780019dd	153	margin = change * prescale_value / vbus_rate;
c283cf2c MC	154	printk(KERN_INFO DRVNAME
c283cf2c MC	155	": timer margin %d seconds (prescale %d, change %d, freq %d)\n",
780019dd	156	margin, prescale_value, change, vbus_rate);
c283cf2c MC	157	}
	158
	159	static void ar7_wdt_enable_wdt(void)
	160	{
	161	printk(KERN_DEBUG DRVNAME ": enabling watchdog timer\n");
	162	ar7_wdt_disable(1);
	163	ar7_wdt_kick(1);
	164	}
	165
	166	static void ar7_wdt_disable_wdt(void)
	167	{
	168	printk(KERN_DEBUG DRVNAME ": disabling watchdog timer\n");
	169	ar7_wdt_disable(0);
	170	}
	171
	172	static int ar7_wdt_open(struct inode inode, struct file file)
	173	{
	174	/* only allow one at a time */
670d59c0	175	if (test_and_set_bit(0, &wdt_is_open))
c283cf2c MC	176	return -EBUSY;
	177	ar7_wdt_enable_wdt();
	178	expect_close = 0;
	179
	180	return nonseekable_open(inode, file);
	181	}
	182
	183	static int ar7_wdt_release(struct inode inode, struct file file)
	184	{
	185	if (!expect_close)
	186	printk(KERN_WARNING DRVNAME
	187	": watchdog device closed unexpectedly,"
	188	"will not disable the watchdog timer\n");
	189	else if (!nowayout)
	190	ar7_wdt_disable_wdt();
670d59c0	191	clear_bit(0, &wdt_is_open);
c283cf2c MC	192	return 0;
	193	}
	194
c283cf2c MC	195	static ssize_t ar7_wdt_write(struct file file, const char data,
	196	size_t len, loff_t *ppos)
	197	{
	198	/* check for a magic close character */
	199	if (len) {
	200	size_t i;
	201
670d59c0	202	spin_lock(&wdt_lock);
c283cf2c	203	ar7_wdt_kick(1);
670d59c0	204	spin_unlock(&wdt_lock);
c283cf2c MC	205
	206	expect_close = 0;
	207	for (i = 0; i < len; ++i) {
	208	char c;
7944d3a5	209	if (get_user(c, data + i))
c283cf2c MC	210	return -EFAULT;
	211	if (c == 'V')
	212	expect_close = 1;
	213	}
	214
	215	}
	216	return len;
	217	}
	218
670d59c0 AC	219	static long ar7_wdt_ioctl(struct file *file,
670d59c0 AC	220	unsigned int cmd, unsigned long arg)
c283cf2c	221	{
42747d71	222	static const struct watchdog_info ident = {
c283cf2c MC	223	.identity = LONGNAME,
c283cf2c MC	224	.firmware_version = 1,
e73a7802 WVS	225	.options = (WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING \|
e73a7802 WVS	226	WDIOF_MAGICCLOSE),
c283cf2c MC	227	};
	228	int new_margin;
	229
	230	switch (cmd) {
c283cf2c MC	231	case WDIOC_GETSUPPORT:
	232	if (copy_to_user((struct watchdog_info *)arg, &ident,
	233	sizeof(ident)))
	234	return -EFAULT;
	235	return 0;
	236	case WDIOC_GETSTATUS:
	237	case WDIOC_GETBOOTSTATUS:
	238	if (put_user(0, (int *)arg))
	239	return -EFAULT;
	240	return 0;
	241	case WDIOC_KEEPALIVE:
	242	ar7_wdt_kick(1);
	243	return 0;
	244	case WDIOC_SETTIMEOUT:
	245	if (get_user(new_margin, (int *)arg))
	246	return -EFAULT;
	247	if (new_margin < 1)
	248	return -EINVAL;
	249
670d59c0	250	spin_lock(&wdt_lock);
c283cf2c MC	251	ar7_wdt_update_margin(new_margin);
c283cf2c MC	252	ar7_wdt_kick(1);
670d59c0	253	spin_unlock(&wdt_lock);
c283cf2c MC	254
	255	case WDIOC_GETTIMEOUT:
	256	if (put_user(margin, (int *)arg))
	257	return -EFAULT;
	258	return 0;
0c06090c WVS	259	default:
0c06090c WVS	260	return -ENOTTY;
c283cf2c MC	261	}
	262	}
	263
b47a166e	264	static const struct file_operations ar7_wdt_fops = {
c283cf2c MC	265	.owner = THIS_MODULE,
c283cf2c MC	266	.write = ar7_wdt_write,
670d59c0	267	.unlocked_ioctl = ar7_wdt_ioctl,
c283cf2c MC	268	.open = ar7_wdt_open,
c283cf2c MC	269	.release = ar7_wdt_release,
6038f373	270	.llseek = no_llseek,
c283cf2c MC	271	};
	272
	273	static struct miscdevice ar7_wdt_miscdev = {
	274	.minor = WATCHDOG_MINOR,
	275	.name = "watchdog",
	276	.fops = &ar7_wdt_fops,
	277	};
	278
64d4062a	279	static int __devinit ar7_wdt_probe(struct platform_device *pdev)
c283cf2c MC	280	{
	281	int rc;
	282
670d59c0 AC	283	spin_lock_init(&wdt_lock);
670d59c0 AC	284
64d4062a FF	285	ar7_regs_wdt =
	286	platform_get_resource_byname(pdev, IORESOURCE_MEM, "regs");
	287	if (!ar7_regs_wdt) {
	288	printk(KERN_ERR DRVNAME ": could not get registers resource\n");
	289	rc = -ENODEV;
	290	goto out;
	291	}
c283cf2c	292
64d4062a FF	293	if (!request_mem_region(ar7_regs_wdt->start,
64d4062a FF	294	resource_size(ar7_regs_wdt), LONGNAME)) {
c283cf2c	295	printk(KERN_WARNING DRVNAME ": watchdog I/O region busy\n");
64d4062a FF	296	rc = -EBUSY;
64d4062a FF	297	goto out;
c283cf2c MC	298	}
c283cf2c MC	299
64d4062a FF	300	ar7_wdt = ioremap(ar7_regs_wdt->start, resource_size(ar7_regs_wdt));
	301	if (!ar7_wdt) {
	302	printk(KERN_ERR DRVNAME ": could not ioremap registers\n");
	303	rc = -ENXIO;
d7e9791b	304	goto out_mem_region;
64d4062a	305	}
c283cf2c	306
780019dd FF	307	vbus_clk = clk_get(NULL, "vbus");
	308	if (IS_ERR(vbus_clk)) {
	309	printk(KERN_ERR DRVNAME ": could not get vbus clock\n");
	310	rc = PTR_ERR(vbus_clk);
	311	goto out_mem_region;
	312	}
	313
c283cf2c MC	314	ar7_wdt_disable_wdt();
	315	ar7_wdt_prescale(prescale_value);
	316	ar7_wdt_update_margin(margin);
	317
c283cf2c MC	318	rc = misc_register(&ar7_wdt_miscdev);
	319	if (rc) {
	320	printk(KERN_ERR DRVNAME ": unable to register misc device\n");
64d4062a	321	goto out_alloc;
c283cf2c MC	322	}
	323	goto out;
	324
c283cf2c MC	325	out_alloc:
c283cf2c MC	326	iounmap(ar7_wdt);
d7e9791b	327	out_mem_region:
64d4062a	328	release_mem_region(ar7_regs_wdt->start, resource_size(ar7_regs_wdt));
c283cf2c MC	329	out:
	330	return rc;
	331	}
	332
64d4062a	333	static int __devexit ar7_wdt_remove(struct platform_device *pdev)
c283cf2c MC	334	{
c283cf2c MC	335	misc_deregister(&ar7_wdt_miscdev);
c283cf2c	336	iounmap(ar7_wdt);
64d4062a FF	337	release_mem_region(ar7_regs_wdt->start, resource_size(ar7_regs_wdt));
	338
	339	return 0;
	340	}
	341
	342	static void ar7_wdt_shutdown(struct platform_device *pdev)
	343	{
	344	if (!nowayout)
	345	ar7_wdt_disable_wdt();
	346	}
	347
	348	static struct platform_driver ar7_wdt_driver = {
	349	.probe = ar7_wdt_probe,
	350	.remove = __devexit_p(ar7_wdt_remove),
	351	.shutdown = ar7_wdt_shutdown,
	352	.driver = {
	353	.owner = THIS_MODULE,
	354	.name = "ar7_wdt",
	355	},
	356	};
	357
	358	static int __init ar7_wdt_init(void)
	359	{
	360	return platform_driver_register(&ar7_wdt_driver);
	361	}
	362
	363	static void __exit ar7_wdt_cleanup(void)
	364	{
	365	platform_driver_unregister(&ar7_wdt_driver);
c283cf2c MC	366	}
	367
	368	module_init(ar7_wdt_init);
	369	module_exit(ar7_wdt_cleanup);