[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/device.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 = dev_get_drvdata(&mpcore_wdt_dev->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;

	/*  Can't seek (pwrite) on this device  */
	if (ppos != &file->f_pos)
		return -ESPIPE;

	/*
	 *	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 device *_dev)
{
	struct mpcore_wdt *wdt = dev_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 device *_dev)
{
	struct platform_device *dev = to_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);
	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);
	dev_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 device *dev)
{
	struct mpcore_wdt *wdt = dev_get_drvdata(dev);

	dev_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 device_driver mpcore_wdt_driver = {
	.name		= "mpcore_wdt",
	.bus		= &platform_bus_type,
	.probe		= mpcore_wdt_probe,
	.remove		= __devexit_p(mpcore_wdt_remove),
	.shutdown	= mpcore_wdt_shutdown,
};

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 driver_register(&mpcore_wdt_driver);
}

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