[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 = 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 = {
	.owner		= THIS_MODULE,
	.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>
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	{
142	struct mpcore_wdt *wdt = dev_get_drvdata(&mpcore_wdt_dev->dev);
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
183	/* Can't seek (pwrite) on this device */
184	if (ppos != &file->f_pos)
185	return -ESPIPE;
186
187	/*
188	* Refresh the timer.
189	*/
190	if (len) {
191	if (!nowayout) {
192	size_t i;
193
194	/* In case it was set long ago */
195	wdt->expect_close = 0;
196
197	for (i = 0; i != len; i++) {
198	char c;
199
200	if (get_user(c, data + i))
201	return -EFAULT;
202	if (c == 'V')
203	wdt->expect_close = 42;
204	}
205	}
206	mpcore_wdt_keepalive(wdt);
207	}
208	return len;
209	}
210
211	static struct watchdog_info ident = {
212	.options = WDIOF_SETTIMEOUT \|
213	WDIOF_KEEPALIVEPING \|
214	WDIOF_MAGICCLOSE,
215	.identity = "MPcore Watchdog",
216	};
217
218	static int mpcore_wdt_ioctl(struct inode inode, struct file file,
219	unsigned int cmd, unsigned long arg)
220	{
221	struct mpcore_wdt *wdt = file->private_data;
222	int ret;
223	union {
224	struct watchdog_info ident;
225	int i;
226	} uarg;
227
228	if (_IOC_DIR(cmd) && _IOC_SIZE(cmd) > sizeof(uarg))
229	return -ENOIOCTLCMD;
230
231	if (_IOC_DIR(cmd) & _IOC_WRITE) {
232	ret = copy_from_user(&uarg, (void __user *)arg, _IOC_SIZE(cmd));
233	if (ret)
234	return -EFAULT;
235	}
236
237	switch (cmd) {
238	case WDIOC_GETSUPPORT:
239	uarg.ident = ident;
240	ret = 0;
241	break;
242
243	case WDIOC_SETOPTIONS:
244	ret = -EINVAL;
245	if (uarg.i & WDIOS_DISABLECARD) {
246	mpcore_wdt_stop(wdt);
247	ret = 0;
248	}
249	if (uarg.i & WDIOS_ENABLECARD) {
250	mpcore_wdt_start(wdt);
251	ret = 0;
252	}
253	break;
254
255	case WDIOC_GETSTATUS:
256	case WDIOC_GETBOOTSTATUS:
257	uarg.i = 0;
258	ret = 0;
259	break;
260
261	case WDIOC_KEEPALIVE:
262	mpcore_wdt_keepalive(wdt);
263	ret = 0;
264	break;
265
266	case WDIOC_SETTIMEOUT:
267	ret = mpcore_wdt_set_heartbeat(uarg.i);
268	if (ret)
269	break;
270
271	mpcore_wdt_keepalive(wdt);
272	/* Fall */
273	case WDIOC_GETTIMEOUT:
274	uarg.i = mpcore_margin;
275	ret = 0;
276	break;
277
278	default:
279	return -ENOIOCTLCMD;
280	}
281
282	if (ret == 0 && _IOC_DIR(cmd) & _IOC_READ) {
283	ret = copy_to_user((void __user *)arg, &uarg, _IOC_SIZE(cmd));
284	if (ret)
285	ret = -EFAULT;
286	}
287	return ret;
288	}
289
290	/*
291	* System shutdown handler. Turn off the watchdog if we're
292	* restarting or halting the system.
293	*/
294	static void mpcore_wdt_shutdown(struct device *_dev)
295	{
296	struct mpcore_wdt *wdt = dev_get_drvdata(_dev);
297
298	if (system_state == SYSTEM_RESTART \|\| system_state == SYSTEM_HALT)
299	mpcore_wdt_stop(wdt);
300	}
301
302	/*
303	* Kernel Interfaces
304	*/
305	static struct file_operations mpcore_wdt_fops = {
306	.owner = THIS_MODULE,
307	.llseek = no_llseek,
308	.write = mpcore_wdt_write,
309	.ioctl = mpcore_wdt_ioctl,
310	.open = mpcore_wdt_open,
311	.release = mpcore_wdt_release,
312	};
313
314	static struct miscdevice mpcore_wdt_miscdev = {
315	.minor = WATCHDOG_MINOR,
316	.name = "watchdog",
317	.fops = &mpcore_wdt_fops,
318	};
319
320	static int __devinit mpcore_wdt_probe(struct device *_dev)
321	{
322	struct platform_device *dev = to_platform_device(_dev);
323	struct mpcore_wdt *wdt;
324	struct resource *res;
325	int ret;
326
327	/* We only accept one device, and it must have an id of -1 */
328	if (dev->id != -1)
329	return -ENODEV;
330
331	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
332	if (!res) {
333	ret = -ENODEV;
334	goto err_out;
335	}
336
337	wdt = kmalloc(sizeof(struct mpcore_wdt), GFP_KERNEL);
338	if (!wdt) {
339	ret = -ENOMEM;
340	goto err_out;
341	}
342	memset(wdt, 0, sizeof(struct mpcore_wdt));
343
344	wdt->dev = &dev->dev;
345	wdt->irq = platform_get_irq(dev, 0);
346	wdt->base = ioremap(res->start, res->end - res->start + 1);
347	if (!wdt->base) {
348	ret = -ENOMEM;
349	goto err_free;
350	}
351
352	mpcore_wdt_miscdev.dev = &dev->dev;
353	ret = misc_register(&mpcore_wdt_miscdev);
354	if (ret) {
355	dev_printk(KERN_ERR, _dev, "cannot register miscdev on minor=%d (err=%d)\n",
356	WATCHDOG_MINOR, ret);
357	goto err_misc;
358	}
359
360	ret = request_irq(wdt->irq, mpcore_wdt_fire, SA_INTERRUPT, "mpcore_wdt", wdt);
361	if (ret) {
362	dev_printk(KERN_ERR, _dev, "cannot register IRQ%d for watchdog\n", wdt->irq);
363	goto err_irq;
364	}
365
366	mpcore_wdt_stop(wdt);
367	dev_set_drvdata(&dev->dev, wdt);
368	mpcore_wdt_dev = dev;
369
370	return 0;
371
372	err_irq:
373	misc_deregister(&mpcore_wdt_miscdev);
374	err_misc:
375	iounmap(wdt->base);
376	err_free:
377	kfree(wdt);
378	err_out:
379	return ret;
380	}
381
382	static int __devexit mpcore_wdt_remove(struct device *dev)
383	{
384	struct mpcore_wdt *wdt = dev_get_drvdata(dev);
385
386	dev_set_drvdata(dev, NULL);
387
388	misc_deregister(&mpcore_wdt_miscdev);
389
390	mpcore_wdt_dev = NULL;
391
392	free_irq(wdt->irq, wdt);
393	iounmap(wdt->base);
394	kfree(wdt);
395	return 0;
396	}
397
398	static struct device_driver mpcore_wdt_driver = {
de4ae58f	399	.owner = THIS_MODULE,
b9d36b85 RK	400	.name = "mpcore_wdt",
	401	.bus = &platform_bus_type,
	402	.probe = mpcore_wdt_probe,
	403	.remove = __devexit_p(mpcore_wdt_remove),
	404	.shutdown = mpcore_wdt_shutdown,
	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
	423	return driver_register(&mpcore_wdt_driver);
	424	}
	425
	426	static void __exit mpcore_wdt_exit(void)
	427	{
	428	driver_unregister(&mpcore_wdt_driver);
	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);