[deliverable/linux.git] / drivers / char / watchdog / mpcore_wdt.c

/*
 *	Watchdog driver for the mpcore watchdog timer
 *
 *	(c) Copyright 2004 ARM Limited
 *
 *	Based on the SoftDog driver:
 *	(c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
 *				http://www.redhat.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.
 *
 *	Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
 *	warranty for any of this software. This material is provided
 *	"AS-IS" and at no charge.
 *
 *	(c) Copyright 1995    Alan Cox <alan@lxorguk.ukuu.org.uk>
 *
 */
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/config.h>
#include <linux/types.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/fs.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>

#include <asm/hardware/arm_twd.h>
#include <asm/uaccess.h>

struct mpcore_wdt {
	unsigned long	timer_alive;
	struct device	*dev;
	void __iomem	*base;
	int		irq;
	unsigned int	perturb;
	char		expect_close;
};

static struct platform_device *mpcore_wdt_dev;

extern unsigned int mpcore_timer_rate;

#define TIMER_MARGIN	60
static int mpcore_margin = TIMER_MARGIN;
module_param(mpcore_margin, int, 0);
MODULE_PARM_DESC(mpcore_margin, "MPcore timer margin in seconds. (0<mpcore_margin<65536, default=" __MODULE_STRING(TIMER_MARGIN) ")");

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

#define ONLY_TESTING	0
static int mpcore_noboot = ONLY_TESTING;
module_param(mpcore_noboot, int, 0);
MODULE_PARM_DESC(mpcore_noboot, "MPcore watchdog action, set to 1 to ignore reboots, 0 to reboot (default=" __MODULE_STRING(ONLY_TESTING) ")");

/*
 *	This is the interrupt handler.  Note that we only use this
 *	in testing mode, so don't actually do a reboot here.
 */
static irqreturn_t mpcore_wdt_fire(int irq, void *arg, struct pt_regs *regs)
{
	struct mpcore_wdt *wdt = arg;

	/* Check it really was our interrupt */
	if (readl(wdt->base + TWD_WDOG_INTSTAT)) {
		dev_printk(KERN_CRIT, wdt->dev, "Triggered - Reboot ignored.\n");

		/* Clear the interrupt on the watchdog */
		writel(1, wdt->base + TWD_WDOG_INTSTAT);

		return IRQ_HANDLED;
	}

	return IRQ_NONE;
}

/*
 *	mpcore_wdt_keepalive - reload the timer
 *
 *	Note that the spec says a DIFFERENT value must be written to the reload
 *	register each time.  The "perturb" variable deals with this by adding 1
 *	to the count every other time the function is called.
 */
static void mpcore_wdt_keepalive(struct mpcore_wdt *wdt)
{
	unsigned int count;

	/* Assume prescale is set to 256 */
	count = (mpcore_timer_rate / 256) * mpcore_margin;

	/* Reload the counter */
	writel(count + wdt->perturb, wdt->base + TWD_WDOG_LOAD);

	wdt->perturb = wdt->perturb ? 0 : 1;
}

static void mpcore_wdt_stop(struct mpcore_wdt *wdt)
{
	writel(0x12345678, wdt->base + TWD_WDOG_DISABLE);
	writel(0x87654321, wdt->base + TWD_WDOG_DISABLE);
	writel(0x0, wdt->base + TWD_WDOG_CONTROL);
}

static void mpcore_wdt_start(struct mpcore_wdt *wdt)
{
	dev_printk(KERN_INFO, wdt->dev, "enabling watchdog.\n");

	/* This loads the count register but does NOT start the count yet */
	mpcore_wdt_keepalive(wdt);

	if (mpcore_noboot) {
		/* Enable watchdog - prescale=256, watchdog mode=0, enable=1 */
		writel(0x0000FF01, wdt->base + TWD_WDOG_CONTROL);
	} else {
		/* Enable watchdog - prescale=256, watchdog mode=1, enable=1 */
		writel(0x0000FF09, wdt->base + TWD_WDOG_CONTROL);
	}
}

static int mpcore_wdt_set_heartbeat(int t)
{
	if (t < 0x0001 || t > 0xFFFF)
		return -EINVAL;

	mpcore_margin = t;
	return 0;
}

/*
 *	/dev/watchdog handling
 */
static int mpcore_wdt_open(struct inode *inode, struct file *file)
{
	struct mpcore_wdt *wdt = platform_get_drvdata(mpcore_wdt_dev);

	if (test_and_set_bit(0, &wdt->timer_alive))
		return -EBUSY;

	if (nowayout)
		__module_get(THIS_MODULE);

	file->private_data = wdt;

	/*
	 *	Activate timer
	 */
	mpcore_wdt_start(wdt);

	return nonseekable_open(inode, file);
}

static int mpcore_wdt_release(struct inode *inode, struct file *file)
{
	struct mpcore_wdt *wdt = file->private_data;

	/*
	 *	Shut off the timer.
	 * 	Lock it in if it's a module and we set nowayout
	 */
	if (wdt->expect_close == 42) {
		mpcore_wdt_stop(wdt);
	} else {
		dev_printk(KERN_CRIT, wdt->dev, "unexpected close, not stopping watchdog!\n");
		mpcore_wdt_keepalive(wdt);
	}
	clear_bit(0, &wdt->timer_alive);
	wdt->expect_close = 0;
	return 0;
}

static ssize_t mpcore_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos)
{
	struct mpcore_wdt *wdt = file->private_data;

	/*
	 *	Refresh the timer.
	 */
	if (len) {
		if (!nowayout) {
			size_t i;

			/* In case it was set long ago */
			wdt->expect_close = 0;

			for (i = 0; i != len; i++) {
				char c;

				if (get_user(c, data + i))
					return -EFAULT;
				if (c == 'V')
					wdt->expect_close = 42;
			}
		}
		mpcore_wdt_keepalive(wdt);
	}
	return len;
}

static struct watchdog_info ident = {
	.options		= WDIOF_SETTIMEOUT |
				  WDIOF_KEEPALIVEPING |
				  WDIOF_MAGICCLOSE,
	.identity		= "MPcore Watchdog",
};

static int mpcore_wdt_ioctl(struct inode *inode, struct file *file,
			     unsigned int cmd, unsigned long arg)
{
	struct mpcore_wdt *wdt = file->private_data;
	int ret;
	union {
		struct watchdog_info ident;
		int i;
	} uarg;

	if (_IOC_DIR(cmd) && _IOC_SIZE(cmd) > sizeof(uarg))
		return -ENOIOCTLCMD;

	if (_IOC_DIR(cmd) & _IOC_WRITE) {
		ret = copy_from_user(&uarg, (void __user *)arg, _IOC_SIZE(cmd));
		if (ret)
			return -EFAULT;
	}

	switch (cmd) {
	case WDIOC_GETSUPPORT:
		uarg.ident = ident;
		ret = 0;
		break;

	case WDIOC_SETOPTIONS:
		ret = -EINVAL;
		if (uarg.i & WDIOS_DISABLECARD) {
			mpcore_wdt_stop(wdt);
			ret = 0;
		}
		if (uarg.i & WDIOS_ENABLECARD) {
			mpcore_wdt_start(wdt);
			ret = 0;
		}
		break;

	case WDIOC_GETSTATUS:
	case WDIOC_GETBOOTSTATUS:
		uarg.i = 0;
		ret = 0;
		break;

	case WDIOC_KEEPALIVE:
		mpcore_wdt_keepalive(wdt);
		ret = 0;
		break;

	case WDIOC_SETTIMEOUT:
		ret = mpcore_wdt_set_heartbeat(uarg.i);
		if (ret)
			break;

		mpcore_wdt_keepalive(wdt);
		/* Fall */
	case WDIOC_GETTIMEOUT:
		uarg.i = mpcore_margin;
		ret = 0;
		break;

	default:
		return -ENOIOCTLCMD;
	}

	if (ret == 0 && _IOC_DIR(cmd) & _IOC_READ) {
		ret = copy_to_user((void __user *)arg, &uarg, _IOC_SIZE(cmd));
		if (ret)
			ret = -EFAULT;
	}
	return ret;
}

/*
 *	System shutdown handler.  Turn off the watchdog if we're
 *	restarting or halting the system.
 */
static void mpcore_wdt_shutdown(struct platform_device *dev)
{
	struct mpcore_wdt *wdt = platform_get_drvdata(dev);

	if (system_state == SYSTEM_RESTART || system_state == SYSTEM_HALT)
		mpcore_wdt_stop(wdt);
}

/*
 *	Kernel Interfaces
 */
static struct file_operations mpcore_wdt_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.write		= mpcore_wdt_write,
	.ioctl		= mpcore_wdt_ioctl,
	.open		= mpcore_wdt_open,
	.release	= mpcore_wdt_release,
};

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

static int __devinit mpcore_wdt_probe(struct platform_device *dev)
{
	struct mpcore_wdt *wdt;
	struct resource *res;
	int ret;

	/* We only accept one device, and it must have an id of -1 */
	if (dev->id != -1)
		return -ENODEV;

	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
	if (!res) {
		ret = -ENODEV;
		goto err_out;
	}

	wdt = kmalloc(sizeof(struct mpcore_wdt), GFP_KERNEL);
	if (!wdt) {
		ret = -ENOMEM;
		goto err_out;
	}
	memset(wdt, 0, sizeof(struct mpcore_wdt));

	wdt->dev = &dev->dev;
	wdt->irq = platform_get_irq(dev, 0);
	if (wdt->irq < 0) {
		ret = -ENXIO;
		goto err_free;
	}
	wdt->base = ioremap(res->start, res->end - res->start + 1);
	if (!wdt->base) {
		ret = -ENOMEM;
		goto err_free;
	}

	mpcore_wdt_miscdev.dev = &dev->dev;
	ret = misc_register(&mpcore_wdt_miscdev);
	if (ret) {
		dev_printk(KERN_ERR, _dev, "cannot register miscdev on minor=%d (err=%d)\n",
			   WATCHDOG_MINOR, ret);
		goto err_misc;
	}

	ret = request_irq(wdt->irq, mpcore_wdt_fire, SA_INTERRUPT, "mpcore_wdt", wdt);
	if (ret) {
		dev_printk(KERN_ERR, _dev, "cannot register IRQ%d for watchdog\n", wdt->irq);
		goto err_irq;
	}

	mpcore_wdt_stop(wdt);
	platform_set_drvdata(&dev->dev, wdt);
	mpcore_wdt_dev = dev;

	return 0;

 err_irq:
	misc_deregister(&mpcore_wdt_miscdev);
 err_misc:
	iounmap(wdt->base);
 err_free:
	kfree(wdt);
 err_out:
	return ret;
}

static int __devexit mpcore_wdt_remove(struct platform_device *dev)
{
	struct mpcore_wdt *wdt = platform_get_drvdata(dev);

	platform_set_drvdata(dev, NULL);

	misc_deregister(&mpcore_wdt_miscdev);

	mpcore_wdt_dev = NULL;

	free_irq(wdt->irq, wdt);
	iounmap(wdt->base);
	kfree(wdt);
	return 0;
}

static struct platform_driver mpcore_wdt_driver = {
	.probe		= mpcore_wdt_probe,
	.remove		= __devexit_p(mpcore_wdt_remove),
	.shutdown	= mpcore_wdt_shutdown,
	.driver		= {
		.owner	= THIS_MODULE,
		.name	= "mpcore_wdt",
	},
};

static char banner[] __initdata = KERN_INFO "MPcore Watchdog Timer: 0.1. mpcore_noboot=%d mpcore_margin=%d sec (nowayout= %d)\n";

static int __init mpcore_wdt_init(void)
{
	/*
	 * Check that the margin value is within it's range;
	 * if not reset to the default
	 */
	if (mpcore_wdt_set_heartbeat(mpcore_margin)) {
		mpcore_wdt_set_heartbeat(TIMER_MARGIN);
		printk(KERN_INFO "mpcore_margin value must be 0<mpcore_margin<65536, using %d\n",
			TIMER_MARGIN);
	}

	printk(banner, mpcore_noboot, mpcore_margin, nowayout);

	return platform_driver_register(&mpcore_wdt_driver);
}

static void __exit mpcore_wdt_exit(void)
{
	platform_driver_unregister(&mpcore_wdt_driver);
}

module_init(mpcore_wdt_init);
module_exit(mpcore_wdt_exit);

MODULE_AUTHOR("ARM Limited");
MODULE_DESCRIPTION("MPcore Watchdog Device Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
Commit	Line	Data
b9d36b85 RK	1	/*
	2	* Watchdog driver for the mpcore watchdog timer
	3	*
	4	* (c) Copyright 2004 ARM Limited
	5	*
	6	* Based on the SoftDog driver:
	7	* (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
	8	* http://www.redhat.com
	9	*
	10	* This program is free software; you can redistribute it and/or
	11	* modify it under the terms of the GNU General Public License
	12	* as published by the Free Software Foundation; either version
	13	* 2 of the License, or (at your option) any later version.
	14	*
	15	* Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
	16	* warranty for any of this software. This material is provided
	17	* "AS-IS" and at no charge.
	18	*
	19	* (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>
	20	*
	21	*/
	22	#include <linux/module.h>
	23	#include <linux/moduleparam.h>
	24	#include <linux/config.h>
	25	#include <linux/types.h>
	26	#include <linux/miscdevice.h>
	27	#include <linux/watchdog.h>
	28	#include <linux/fs.h>
	29	#include <linux/reboot.h>
	30	#include <linux/init.h>
	31	#include <linux/interrupt.h>
d052d1be	32	#include <linux/platform_device.h>
ad4162f3 RK	33
ad4162f3 RK	34	#include <asm/hardware/arm_twd.h>
b9d36b85 RK	35	#include <asm/uaccess.h>
	36
	37	struct mpcore_wdt {
	38	unsigned long timer_alive;
	39	struct device *dev;
	40	void __iomem *base;
	41	int irq;
	42	unsigned int perturb;
	43	char expect_close;
	44	};
	45
	46	static struct platform_device *mpcore_wdt_dev;
	47
	48	extern unsigned int mpcore_timer_rate;
	49
	50	#define TIMER_MARGIN 60
	51	static int mpcore_margin = TIMER_MARGIN;
	52	module_param(mpcore_margin, int, 0);
	53	MODULE_PARM_DESC(mpcore_margin, "MPcore timer margin in seconds. (0<mpcore_margin<65536, default=" __MODULE_STRING(TIMER_MARGIN) ")");
	54
	55	static int nowayout = WATCHDOG_NOWAYOUT;
	56	module_param(nowayout, int, 0);
	57	MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
	58
	59	#define ONLY_TESTING 0
	60	static int mpcore_noboot = ONLY_TESTING;
	61	module_param(mpcore_noboot, int, 0);
	62	MODULE_PARM_DESC(mpcore_noboot, "MPcore watchdog action, set to 1 to ignore reboots, 0 to reboot (default=" __MODULE_STRING(ONLY_TESTING) ")");
	63
	64	/*
	65	* This is the interrupt handler. Note that we only use this
	66	* in testing mode, so don't actually do a reboot here.
	67	*/
	68	static irqreturn_t mpcore_wdt_fire(int irq, void arg, struct pt_regs regs)
	69	{
	70	struct mpcore_wdt *wdt = arg;
	71
	72	/* Check it really was our interrupt */
	73	if (readl(wdt->base + TWD_WDOG_INTSTAT)) {
	74	dev_printk(KERN_CRIT, wdt->dev, "Triggered - Reboot ignored.\n");
	75
	76	/* Clear the interrupt on the watchdog */
	77	writel(1, wdt->base + TWD_WDOG_INTSTAT);
	78
	79	return IRQ_HANDLED;
	80	}
	81
	82	return IRQ_NONE;
	83	}
	84
	85	/*
	86	* mpcore_wdt_keepalive - reload the timer
	87	*
	88	* Note that the spec says a DIFFERENT value must be written to the reload
	89	* register each time. The "perturb" variable deals with this by adding 1
	90	* to the count every other time the function is called.
	91	*/
	92	static void mpcore_wdt_keepalive(struct mpcore_wdt *wdt)
	93	{
	94	unsigned int count;
	95
	96	/* Assume prescale is set to 256 */
	97	count = (mpcore_timer_rate / 256) * mpcore_margin;
	98
99	/* Reload the counter */
100	writel(count + wdt->perturb, wdt->base + TWD_WDOG_LOAD);
101
102	wdt->perturb = wdt->perturb ? 0 : 1;
103	}
104
105	static void mpcore_wdt_stop(struct mpcore_wdt *wdt)
106	{
107	writel(0x12345678, wdt->base + TWD_WDOG_DISABLE);
108	writel(0x87654321, wdt->base + TWD_WDOG_DISABLE);
109	writel(0x0, wdt->base + TWD_WDOG_CONTROL);
110	}
111
112	static void mpcore_wdt_start(struct mpcore_wdt *wdt)
113	{
114	dev_printk(KERN_INFO, wdt->dev, "enabling watchdog.\n");
115
116	/* This loads the count register but does NOT start the count yet */
117	mpcore_wdt_keepalive(wdt);
118
119	if (mpcore_noboot) {
120	/* Enable watchdog - prescale=256, watchdog mode=0, enable=1 */
121	writel(0x0000FF01, wdt->base + TWD_WDOG_CONTROL);
122	} else {
123	/* Enable watchdog - prescale=256, watchdog mode=1, enable=1 */
124	writel(0x0000FF09, wdt->base + TWD_WDOG_CONTROL);
125	}
126	}
127
128	static int mpcore_wdt_set_heartbeat(int t)
129	{
130	if (t < 0x0001 \|\| t > 0xFFFF)
131	return -EINVAL;
132
133	mpcore_margin = t;
134	return 0;
135	}
136
137	/*
138	* /dev/watchdog handling
139	*/
140	static int mpcore_wdt_open(struct inode inode, struct file file)
141	{
3ae5eaec	142	struct mpcore_wdt *wdt = platform_get_drvdata(mpcore_wdt_dev);
b9d36b85 RK	143
	144	if (test_and_set_bit(0, &wdt->timer_alive))
	145	return -EBUSY;
	146
	147	if (nowayout)
	148	__module_get(THIS_MODULE);
	149
	150	file->private_data = wdt;
	151
	152	/*
	153	* Activate timer
	154	*/
	155	mpcore_wdt_start(wdt);
	156
	157	return nonseekable_open(inode, file);
	158	}
	159
	160	static int mpcore_wdt_release(struct inode inode, struct file file)
	161	{
	162	struct mpcore_wdt *wdt = file->private_data;
	163
	164	/*
	165	* Shut off the timer.
	166	* Lock it in if it's a module and we set nowayout
	167	*/
	168	if (wdt->expect_close == 42) {
	169	mpcore_wdt_stop(wdt);
	170	} else {
	171	dev_printk(KERN_CRIT, wdt->dev, "unexpected close, not stopping watchdog!\n");
	172	mpcore_wdt_keepalive(wdt);
	173	}
	174	clear_bit(0, &wdt->timer_alive);
	175	wdt->expect_close = 0;
	176	return 0;
	177	}
	178
	179	static ssize_t mpcore_wdt_write(struct file file, const char data, size_t len, loff_t *ppos)
	180	{
	181	struct mpcore_wdt *wdt = file->private_data;
	182
b9d36b85 RK	183	/*
	184	* Refresh the timer.
	185	*/
	186	if (len) {
	187	if (!nowayout) {
	188	size_t i;
	189
	190	/* In case it was set long ago */
	191	wdt->expect_close = 0;
	192
	193	for (i = 0; i != len; i++) {
	194	char c;
	195
	196	if (get_user(c, data + i))
	197	return -EFAULT;
	198	if (c == 'V')
	199	wdt->expect_close = 42;
	200	}
	201	}
	202	mpcore_wdt_keepalive(wdt);
	203	}
	204	return len;
	205	}
	206
	207	static struct watchdog_info ident = {
	208	.options = WDIOF_SETTIMEOUT \|
	209	WDIOF_KEEPALIVEPING \|
	210	WDIOF_MAGICCLOSE,
	211	.identity = "MPcore Watchdog",
	212	};
	213
	214	static int mpcore_wdt_ioctl(struct inode inode, struct file file,
	215	unsigned int cmd, unsigned long arg)
	216	{
	217	struct mpcore_wdt *wdt = file->private_data;
	218	int ret;
	219	union {
	220	struct watchdog_info ident;
	221	int i;
	222	} uarg;
	223
	224	if (_IOC_DIR(cmd) && _IOC_SIZE(cmd) > sizeof(uarg))
	225	return -ENOIOCTLCMD;
	226
	227	if (_IOC_DIR(cmd) & _IOC_WRITE) {
	228	ret = copy_from_user(&uarg, (void __user *)arg, _IOC_SIZE(cmd));
	229	if (ret)
	230	return -EFAULT;
	231	}
	232
	233	switch (cmd) {
	234	case WDIOC_GETSUPPORT:
	235	uarg.ident = ident;
	236	ret = 0;
	237	break;
	238
	239	case WDIOC_SETOPTIONS:
	240	ret = -EINVAL;
	241	if (uarg.i & WDIOS_DISABLECARD) {
	242	mpcore_wdt_stop(wdt);
	243	ret = 0;
	244	}
	245	if (uarg.i & WDIOS_ENABLECARD) {
	246	mpcore_wdt_start(wdt);
247	ret = 0;
248	}
249	break;
250
251	case WDIOC_GETSTATUS:
252	case WDIOC_GETBOOTSTATUS:
253	uarg.i = 0;
254	ret = 0;
255	break;
256
257	case WDIOC_KEEPALIVE:
258	mpcore_wdt_keepalive(wdt);
259	ret = 0;
260	break;
261
262	case WDIOC_SETTIMEOUT:
263	ret = mpcore_wdt_set_heartbeat(uarg.i);
264	if (ret)
265	break;
266
267	mpcore_wdt_keepalive(wdt);
268	/* Fall */
269	case WDIOC_GETTIMEOUT:
270	uarg.i = mpcore_margin;
271	ret = 0;
272	break;
273
274	default:
275	return -ENOIOCTLCMD;
276	}
277
278	if (ret == 0 && _IOC_DIR(cmd) & _IOC_READ) {
279	ret = copy_to_user((void __user *)arg, &uarg, _IOC_SIZE(cmd));
280	if (ret)
281	ret = -EFAULT;
282	}
283	return ret;
284	}
285
286	/*
287	* System shutdown handler. Turn off the watchdog if we're
288	* restarting or halting the system.
289	*/
3ae5eaec	290	static void mpcore_wdt_shutdown(struct platform_device *dev)
b9d36b85	291	{
3ae5eaec	292	struct mpcore_wdt *wdt = platform_get_drvdata(dev);
b9d36b85 RK	293
	294	if (system_state == SYSTEM_RESTART \|\| system_state == SYSTEM_HALT)
	295	mpcore_wdt_stop(wdt);
	296	}
	297
	298	/*
	299	* Kernel Interfaces
	300	*/
	301	static struct file_operations mpcore_wdt_fops = {
	302	.owner = THIS_MODULE,
	303	.llseek = no_llseek,
	304	.write = mpcore_wdt_write,
	305	.ioctl = mpcore_wdt_ioctl,
	306	.open = mpcore_wdt_open,
	307	.release = mpcore_wdt_release,
	308	};
	309
	310	static struct miscdevice mpcore_wdt_miscdev = {
	311	.minor = WATCHDOG_MINOR,
	312	.name = "watchdog",
	313	.fops = &mpcore_wdt_fops,
	314	};
	315
3ae5eaec	316	static int __devinit mpcore_wdt_probe(struct platform_device *dev)
b9d36b85	317	{
b9d36b85 RK	318	struct mpcore_wdt *wdt;
	319	struct resource *res;
	320	int ret;
	321
	322	/* We only accept one device, and it must have an id of -1 */
	323	if (dev->id != -1)
	324	return -ENODEV;
	325
	326	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
	327	if (!res) {
	328	ret = -ENODEV;
	329	goto err_out;
	330	}
	331
	332	wdt = kmalloc(sizeof(struct mpcore_wdt), GFP_KERNEL);
	333	if (!wdt) {
	334	ret = -ENOMEM;
	335	goto err_out;
	336	}
	337	memset(wdt, 0, sizeof(struct mpcore_wdt));
	338
	339	wdt->dev = &dev->dev;
	340	wdt->irq = platform_get_irq(dev, 0);
48944738 DV	341	if (wdt->irq < 0) {
	342	ret = -ENXIO;
	343	goto err_free;
	344	}
b9d36b85 RK	345	wdt->base = ioremap(res->start, res->end - res->start + 1);
	346	if (!wdt->base) {
	347	ret = -ENOMEM;
	348	goto err_free;
	349	}
	350
	351	mpcore_wdt_miscdev.dev = &dev->dev;
	352	ret = misc_register(&mpcore_wdt_miscdev);
	353	if (ret) {
	354	dev_printk(KERN_ERR, _dev, "cannot register miscdev on minor=%d (err=%d)\n",
	355	WATCHDOG_MINOR, ret);
	356	goto err_misc;
	357	}
	358
	359	ret = request_irq(wdt->irq, mpcore_wdt_fire, SA_INTERRUPT, "mpcore_wdt", wdt);
	360	if (ret) {
	361	dev_printk(KERN_ERR, _dev, "cannot register IRQ%d for watchdog\n", wdt->irq);
	362	goto err_irq;
	363	}
	364
	365	mpcore_wdt_stop(wdt);
3ae5eaec	366	platform_set_drvdata(&dev->dev, wdt);
b9d36b85 RK	367	mpcore_wdt_dev = dev;
	368
	369	return 0;
	370
	371	err_irq:
	372	misc_deregister(&mpcore_wdt_miscdev);
	373	err_misc:
	374	iounmap(wdt->base);
	375	err_free:
	376	kfree(wdt);
	377	err_out:
	378	return ret;
	379	}
	380
3ae5eaec	381	static int __devexit mpcore_wdt_remove(struct platform_device *dev)
b9d36b85	382	{
3ae5eaec	383	struct mpcore_wdt *wdt = platform_get_drvdata(dev);
b9d36b85	384
3ae5eaec	385	platform_set_drvdata(dev, NULL);
b9d36b85 RK	386
	387	misc_deregister(&mpcore_wdt_miscdev);
	388
	389	mpcore_wdt_dev = NULL;
	390
	391	free_irq(wdt->irq, wdt);
	392	iounmap(wdt->base);
	393	kfree(wdt);
	394	return 0;
	395	}
	396
3ae5eaec	397	static struct platform_driver mpcore_wdt_driver = {
b9d36b85 RK	398	.probe = mpcore_wdt_probe,
	399	.remove = __devexit_p(mpcore_wdt_remove),
	400	.shutdown = mpcore_wdt_shutdown,
3ae5eaec RK	401	.driver = {
	402	.owner = THIS_MODULE,
	403	.name = "mpcore_wdt",
	404	},
b9d36b85 RK	405	};
	406
	407	static char banner[] __initdata = KERN_INFO "MPcore Watchdog Timer: 0.1. mpcore_noboot=%d mpcore_margin=%d sec (nowayout= %d)\n";
	408
	409	static int __init mpcore_wdt_init(void)
	410	{
	411	/*
	412	* Check that the margin value is within it's range;
	413	* if not reset to the default
	414	*/
	415	if (mpcore_wdt_set_heartbeat(mpcore_margin)) {
	416	mpcore_wdt_set_heartbeat(TIMER_MARGIN);
	417	printk(KERN_INFO "mpcore_margin value must be 0<mpcore_margin<65536, using %d\n",
	418	TIMER_MARGIN);
	419	}
	420
	421	printk(banner, mpcore_noboot, mpcore_margin, nowayout);
	422
3ae5eaec	423	return platform_driver_register(&mpcore_wdt_driver);
b9d36b85 RK	424	}
	425
	426	static void __exit mpcore_wdt_exit(void)
	427	{
3ae5eaec	428	platform_driver_unregister(&mpcore_wdt_driver);
b9d36b85 RK	429	}
	430
	431	module_init(mpcore_wdt_init);
	432	module_exit(mpcore_wdt_exit);
	433
	434	MODULE_AUTHOR("ARM Limited");
	435	MODULE_DESCRIPTION("MPcore Watchdog Device Driver");
	436	MODULE_LICENSE("GPL");
	437	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);