[linux-2.6-block.git] / drivers / 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/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 <linux/uaccess.h>

#include <asm/hardware/arm_twd.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 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 */
	spin_lock(&wdt_lock);
	writel(count + wdt->perturb, wdt->base + TWD_WDOG_LOAD);
	wdt->perturb = wdt->perturb ? 0 : 1;
	spin_unlock(&wdt_lock);
}

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

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

	spin_lock(&wdt_lock);
	/* 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);
	}
	spin_unlock(&wdt_lock);
}

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 long mpcore_wdt_ioctl(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 -ENOTTY;

	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_GETSTATUS:
	case WDIOC_GETBOOTSTATUS:
		uarg.i = 0;
		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_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 -ENOTTY;
	}

	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 const struct file_operations mpcore_wdt_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.write		= mpcore_wdt_write,
	.unlocked_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 = kzalloc(sizeof(struct mpcore_wdt), GFP_KERNEL);
	if (!wdt) {
		ret = -ENOMEM;
		goto err_out;
	}

	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.parent = &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, IRQF_DISABLED,
							"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;
}

/* work with hotplug and coldplug */
MODULE_ALIAS("platform:mpcore_wdt");

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>
b9d36b85 RK	24	#include <linux/types.h>
	25	#include <linux/miscdevice.h>
	26	#include <linux/watchdog.h>
	27	#include <linux/fs.h>
	28	#include <linux/reboot.h>
	29	#include <linux/init.h>
	30	#include <linux/interrupt.h>
d052d1be	31	#include <linux/platform_device.h>
83ab1a53	32	#include <linux/uaccess.h>
ad4162f3 RK	33
ad4162f3 RK	34	#include <asm/hardware/arm_twd.h>
b9d36b85 RK	35
	36	struct mpcore_wdt {
	37	unsigned long timer_alive;
	38	struct device *dev;
	39	void __iomem *base;
	40	int irq;
	41	unsigned int perturb;
	42	char expect_close;
	43	};
	44
	45	static struct platform_device *mpcore_wdt_dev;
b9d36b85 RK	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);
83ab1a53 AC	51	MODULE_PARM_DESC(mpcore_margin,
	52	"MPcore timer margin in seconds. (0 < mpcore_margin < 65536, default="
	53	__MODULE_STRING(TIMER_MARGIN) ")");
b9d36b85 RK	54
	55	static int nowayout = WATCHDOG_NOWAYOUT;
	56	module_param(nowayout, int, 0);
83ab1a53 AC	57	MODULE_PARM_DESC(nowayout,
	58	"Watchdog cannot be stopped once started (default="
	59	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
b9d36b85 RK	60
	61	#define ONLY_TESTING 0
	62	static int mpcore_noboot = ONLY_TESTING;
	63	module_param(mpcore_noboot, int, 0);
	64	MODULE_PARM_DESC(mpcore_noboot, "MPcore watchdog action, set to 1 to ignore reboots, 0 to reboot (default=" __MODULE_STRING(ONLY_TESTING) ")");
	65
	66	/*
	67	* This is the interrupt handler. Note that we only use this
	68	* in testing mode, so don't actually do a reboot here.
	69	*/
7d12e780	70	static irqreturn_t mpcore_wdt_fire(int irq, void *arg)
b9d36b85 RK	71	{
	72	struct mpcore_wdt *wdt = arg;
	73
	74	/* Check it really was our interrupt */
	75	if (readl(wdt->base + TWD_WDOG_INTSTAT)) {
83ab1a53 AC	76	dev_printk(KERN_CRIT, wdt->dev,
83ab1a53 AC	77	"Triggered - Reboot ignored.\n");
b9d36b85 RK	78	/* Clear the interrupt on the watchdog */
b9d36b85 RK	79	writel(1, wdt->base + TWD_WDOG_INTSTAT);
b9d36b85 RK	80	return IRQ_HANDLED;
b9d36b85 RK	81	}
b9d36b85 RK	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 */
83ab1a53	100	spin_lock(&wdt_lock);
b9d36b85	101	writel(count + wdt->perturb, wdt->base + TWD_WDOG_LOAD);
b9d36b85	102	wdt->perturb = wdt->perturb ? 0 : 1;
83ab1a53	103	spin_unlock(&wdt_lock);
b9d36b85 RK	104	}
	105
	106	static void mpcore_wdt_stop(struct mpcore_wdt *wdt)
	107	{
83ab1a53	108	spin_lock(&wdt_lock);
b9d36b85 RK	109	writel(0x12345678, wdt->base + TWD_WDOG_DISABLE);
	110	writel(0x87654321, wdt->base + TWD_WDOG_DISABLE);
	111	writel(0x0, wdt->base + TWD_WDOG_CONTROL);
83ab1a53	112	spin_unlock(&wdt_lock);
b9d36b85 RK	113	}
	114
	115	static void mpcore_wdt_start(struct mpcore_wdt *wdt)
	116	{
	117	dev_printk(KERN_INFO, wdt->dev, "enabling watchdog.\n");
	118
83ab1a53	119	spin_lock(&wdt_lock);
b9d36b85 RK	120	/* This loads the count register but does NOT start the count yet */
	121	mpcore_wdt_keepalive(wdt);
	122
	123	if (mpcore_noboot) {
	124	/* Enable watchdog - prescale=256, watchdog mode=0, enable=1 */
	125	writel(0x0000FF01, wdt->base + TWD_WDOG_CONTROL);
	126	} else {
	127	/* Enable watchdog - prescale=256, watchdog mode=1, enable=1 */
	128	writel(0x0000FF09, wdt->base + TWD_WDOG_CONTROL);
	129	}
83ab1a53	130	spin_unlock(&wdt_lock);
b9d36b85 RK	131	}
	132
	133	static int mpcore_wdt_set_heartbeat(int t)
	134	{
	135	if (t < 0x0001 \|\| t > 0xFFFF)
	136	return -EINVAL;
	137
	138	mpcore_margin = t;
	139	return 0;
	140	}
	141
	142	/*
	143	* /dev/watchdog handling
	144	*/
	145	static int mpcore_wdt_open(struct inode inode, struct file file)
	146	{
3ae5eaec	147	struct mpcore_wdt *wdt = platform_get_drvdata(mpcore_wdt_dev);
b9d36b85 RK	148
	149	if (test_and_set_bit(0, &wdt->timer_alive))
	150	return -EBUSY;
	151
	152	if (nowayout)
	153	__module_get(THIS_MODULE);
	154
	155	file->private_data = wdt;
	156
	157	/*
	158	* Activate timer
	159	*/
	160	mpcore_wdt_start(wdt);
	161
	162	return nonseekable_open(inode, file);
	163	}
	164
	165	static int mpcore_wdt_release(struct inode inode, struct file file)
	166	{
	167	struct mpcore_wdt *wdt = file->private_data;
	168
	169	/*
	170	* Shut off the timer.
	171	* Lock it in if it's a module and we set nowayout
	172	*/
83ab1a53	173	if (wdt->expect_close == 42)
b9d36b85	174	mpcore_wdt_stop(wdt);
83ab1a53 AC	175	else {
	176	dev_printk(KERN_CRIT, wdt->dev,
	177	"unexpected close, not stopping watchdog!\n");
b9d36b85 RK	178	mpcore_wdt_keepalive(wdt);
	179	}
	180	clear_bit(0, &wdt->timer_alive);
	181	wdt->expect_close = 0;
	182	return 0;
	183	}
	184
83ab1a53 AC	185	static ssize_t mpcore_wdt_write(struct file file, const char data,
83ab1a53 AC	186	size_t len, loff_t *ppos)
b9d36b85 RK	187	{
	188	struct mpcore_wdt *wdt = file->private_data;
	189
b9d36b85 RK	190	/*
	191	* Refresh the timer.
	192	*/
	193	if (len) {
	194	if (!nowayout) {
	195	size_t i;
	196
	197	/* In case it was set long ago */
	198	wdt->expect_close = 0;
	199
	200	for (i = 0; i != len; i++) {
	201	char c;
	202
	203	if (get_user(c, data + i))
	204	return -EFAULT;
	205	if (c == 'V')
	206	wdt->expect_close = 42;
	207	}
	208	}
	209	mpcore_wdt_keepalive(wdt);
	210	}
	211	return len;
	212	}
	213
	214	static struct watchdog_info ident = {
	215	.options = WDIOF_SETTIMEOUT \|
	216	WDIOF_KEEPALIVEPING \|
	217	WDIOF_MAGICCLOSE,
	218	.identity = "MPcore Watchdog",
	219	};
	220
83ab1a53 AC	221	static long mpcore_wdt_ioctl(struct file *file, unsigned int cmd,
83ab1a53 AC	222	unsigned long arg)
b9d36b85 RK	223	{
	224	struct mpcore_wdt *wdt = file->private_data;
	225	int ret;
	226	union {
	227	struct watchdog_info ident;
	228	int i;
	229	} uarg;
	230
	231	if (_IOC_DIR(cmd) && _IOC_SIZE(cmd) > sizeof(uarg))
795b89d2	232	return -ENOTTY;
b9d36b85 RK	233
	234	if (_IOC_DIR(cmd) & _IOC_WRITE) {
	235	ret = copy_from_user(&uarg, (void __user *)arg, _IOC_SIZE(cmd));
	236	if (ret)
	237	return -EFAULT;
	238	}
	239
	240	switch (cmd) {
	241	case WDIOC_GETSUPPORT:
	242	uarg.ident = ident;
	243	ret = 0;
	244	break;
	245
0c06090c WVS	246	case WDIOC_GETSTATUS:
	247	case WDIOC_GETBOOTSTATUS:
	248	uarg.i = 0;
	249	ret = 0;
	250	break;
	251
b9d36b85 RK	252	case WDIOC_SETOPTIONS:
	253	ret = -EINVAL;
	254	if (uarg.i & WDIOS_DISABLECARD) {
	255	mpcore_wdt_stop(wdt);
	256	ret = 0;
	257	}
	258	if (uarg.i & WDIOS_ENABLECARD) {
	259	mpcore_wdt_start(wdt);
	260	ret = 0;
	261	}
	262	break;
	263
b9d36b85 RK	264	case WDIOC_KEEPALIVE:
	265	mpcore_wdt_keepalive(wdt);
	266	ret = 0;
	267	break;
	268
	269	case WDIOC_SETTIMEOUT:
	270	ret = mpcore_wdt_set_heartbeat(uarg.i);
	271	if (ret)
	272	break;
	273
	274	mpcore_wdt_keepalive(wdt);
	275	/* Fall */
	276	case WDIOC_GETTIMEOUT:
	277	uarg.i = mpcore_margin;
	278	ret = 0;
	279	break;
	280
	281	default:
795b89d2	282	return -ENOTTY;
b9d36b85 RK	283	}
	284
	285	if (ret == 0 && _IOC_DIR(cmd) & _IOC_READ) {
	286	ret = copy_to_user((void __user *)arg, &uarg, _IOC_SIZE(cmd));
	287	if (ret)
	288	ret = -EFAULT;
	289	}
	290	return ret;
	291	}
	292
	293	/*
	294	* System shutdown handler. Turn off the watchdog if we're
	295	* restarting or halting the system.
	296	*/
3ae5eaec	297	static void mpcore_wdt_shutdown(struct platform_device *dev)
b9d36b85	298	{
3ae5eaec	299	struct mpcore_wdt *wdt = platform_get_drvdata(dev);
b9d36b85 RK	300
	301	if (system_state == SYSTEM_RESTART \|\| system_state == SYSTEM_HALT)
	302	mpcore_wdt_stop(wdt);
	303	}
	304
	305	/*
	306	* Kernel Interfaces
	307	*/
62322d25	308	static const struct file_operations mpcore_wdt_fops = {
b9d36b85 RK	309	.owner = THIS_MODULE,
	310	.llseek = no_llseek,
	311	.write = mpcore_wdt_write,
83ab1a53	312	.unlocked_ioctl = mpcore_wdt_ioctl,
b9d36b85 RK	313	.open = mpcore_wdt_open,
	314	.release = mpcore_wdt_release,
	315	};
	316
	317	static struct miscdevice mpcore_wdt_miscdev = {
	318	.minor = WATCHDOG_MINOR,
	319	.name = "watchdog",
	320	.fops = &mpcore_wdt_fops,
	321	};
	322
3ae5eaec	323	static int __devinit mpcore_wdt_probe(struct platform_device *dev)
b9d36b85	324	{
b9d36b85 RK	325	struct mpcore_wdt *wdt;
	326	struct resource *res;
	327	int ret;
	328
	329	/* We only accept one device, and it must have an id of -1 */
	330	if (dev->id != -1)
	331	return -ENODEV;
	332
	333	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
	334	if (!res) {
	335	ret = -ENODEV;
	336	goto err_out;
	337	}
	338
dd00cc48	339	wdt = kzalloc(sizeof(struct mpcore_wdt), GFP_KERNEL);
b9d36b85 RK	340	if (!wdt) {
	341	ret = -ENOMEM;
	342	goto err_out;
	343	}
b9d36b85 RK	344
	345	wdt->dev = &dev->dev;
	346	wdt->irq = platform_get_irq(dev, 0);
48944738 DV	347	if (wdt->irq < 0) {
	348	ret = -ENXIO;
	349	goto err_free;
	350	}
b9d36b85 RK	351	wdt->base = ioremap(res->start, res->end - res->start + 1);
	352	if (!wdt->base) {
	353	ret = -ENOMEM;
	354	goto err_free;
	355	}
	356
e0b79e0b	357	mpcore_wdt_miscdev.parent = &dev->dev;
b9d36b85 RK	358	ret = misc_register(&mpcore_wdt_miscdev);
b9d36b85 RK	359	if (ret) {
83ab1a53 AC	360	dev_printk(KERN_ERR, _dev,
	361	"cannot register miscdev on minor=%d (err=%d)\n",
	362	WATCHDOG_MINOR, ret);
b9d36b85 RK	363	goto err_misc;
	364	}
	365
83ab1a53 AC	366	ret = request_irq(wdt->irq, mpcore_wdt_fire, IRQF_DISABLED,
83ab1a53 AC	367	"mpcore_wdt", wdt);
b9d36b85	368	if (ret) {
83ab1a53 AC	369	dev_printk(KERN_ERR, _dev,
83ab1a53 AC	370	"cannot register IRQ%d for watchdog\n", wdt->irq);
b9d36b85 RK	371	goto err_irq;
	372	}
	373
	374	mpcore_wdt_stop(wdt);
3ae5eaec	375	platform_set_drvdata(&dev->dev, wdt);
b9d36b85 RK	376	mpcore_wdt_dev = dev;
	377
	378	return 0;
	379
	380	err_irq:
	381	misc_deregister(&mpcore_wdt_miscdev);
	382	err_misc:
	383	iounmap(wdt->base);
	384	err_free:
	385	kfree(wdt);
	386	err_out:
	387	return ret;
	388	}
	389
3ae5eaec	390	static int __devexit mpcore_wdt_remove(struct platform_device *dev)
b9d36b85	391	{
3ae5eaec	392	struct mpcore_wdt *wdt = platform_get_drvdata(dev);
b9d36b85	393
3ae5eaec	394	platform_set_drvdata(dev, NULL);
b9d36b85 RK	395
	396	misc_deregister(&mpcore_wdt_miscdev);
	397
	398	mpcore_wdt_dev = NULL;
	399
	400	free_irq(wdt->irq, wdt);
	401	iounmap(wdt->base);
	402	kfree(wdt);
	403	return 0;
	404	}
	405
f37d193c KS	406	/* work with hotplug and coldplug */
	407	MODULE_ALIAS("platform:mpcore_wdt");
	408
3ae5eaec	409	static struct platform_driver mpcore_wdt_driver = {
b9d36b85 RK	410	.probe = mpcore_wdt_probe,
	411	.remove = __devexit_p(mpcore_wdt_remove),
	412	.shutdown = mpcore_wdt_shutdown,
3ae5eaec RK	413	.driver = {
	414	.owner = THIS_MODULE,
	415	.name = "mpcore_wdt",
	416	},
b9d36b85 RK	417	};
	418
	419	static char banner[] __initdata = KERN_INFO "MPcore Watchdog Timer: 0.1. mpcore_noboot=%d mpcore_margin=%d sec (nowayout= %d)\n";
	420
	421	static int __init mpcore_wdt_init(void)
	422	{
	423	/*
	424	* Check that the margin value is within it's range;
	425	* if not reset to the default
	426	*/
	427	if (mpcore_wdt_set_heartbeat(mpcore_margin)) {
	428	mpcore_wdt_set_heartbeat(TIMER_MARGIN);
83ab1a53	429	printk(KERN_INFO "mpcore_margin value must be 0 < mpcore_margin < 65536, using %d\n",
b9d36b85 RK	430	TIMER_MARGIN);
	431	}
	432
	433	printk(banner, mpcore_noboot, mpcore_margin, nowayout);
	434
3ae5eaec	435	return platform_driver_register(&mpcore_wdt_driver);
b9d36b85 RK	436	}
	437
	438	static void __exit mpcore_wdt_exit(void)
	439	{
3ae5eaec	440	platform_driver_unregister(&mpcore_wdt_driver);
b9d36b85 RK	441	}
	442
	443	module_init(mpcore_wdt_init);
	444	module_exit(mpcore_wdt_exit);
	445
	446	MODULE_AUTHOR("ARM Limited");
	447	MODULE_DESCRIPTION("MPcore Watchdog Device Driver");
	448	MODULE_LICENSE("GPL");
	449	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);