[net-next-2.6.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@lxorguk.ukuu.org.uk>,
 *						All Rights Reserved.
 *
 *	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 <linux/slab.h>
#include <linux/io.h>

#include <asm/smp_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;
static DEFINE_SPINLOCK(wdt_lock);

#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 long count;

	spin_lock(&wdt_lock);
	/* Assume prescale is set to 256 */
	count =  __raw_readl(wdt->base + TWD_WDOG_COUNTER);
	count = (0xFFFFFFFFU - count) * (HZ / 5);
	count = (count / 256) * mpcore_margin;

	/* Reload the counter */
	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");

	/* 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 const 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, resource_size(res));
	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, wdt->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, wdt->dev,
			"cannot register IRQ%d for watchdog\n", wdt->irq);
		goto err_irq;
	}

	mpcore_wdt_stop(wdt);
	platform_set_drvdata(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:
29fa0586	7	* (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
143a2e54	8	* All Rights Reserved.
b9d36b85 RK	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>
5a0e3ad6	33	#include <linux/slab.h>
98af0570	34	#include <linux/io.h>
ad4162f3	35
98af0570	36	#include <asm/smp_twd.h>
b9d36b85 RK	37
	38	struct mpcore_wdt {
	39	unsigned long timer_alive;
	40	struct device *dev;
	41	void __iomem *base;
	42	int irq;
	43	unsigned int perturb;
	44	char expect_close;
	45	};
	46
	47	static struct platform_device *mpcore_wdt_dev;
98af0570	48	static DEFINE_SPINLOCK(wdt_lock);
b9d36b85 RK	49
	50	#define TIMER_MARGIN 60
	51	static int mpcore_margin = TIMER_MARGIN;
	52	module_param(mpcore_margin, int, 0);
83ab1a53 AC	53	MODULE_PARM_DESC(mpcore_margin,
	54	"MPcore timer margin in seconds. (0 < mpcore_margin < 65536, default="
	55	__MODULE_STRING(TIMER_MARGIN) ")");
b9d36b85 RK	56
	57	static int nowayout = WATCHDOG_NOWAYOUT;
	58	module_param(nowayout, int, 0);
83ab1a53 AC	59	MODULE_PARM_DESC(nowayout,
	60	"Watchdog cannot be stopped once started (default="
	61	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
b9d36b85 RK	62
	63	#define ONLY_TESTING 0
	64	static int mpcore_noboot = ONLY_TESTING;
	65	module_param(mpcore_noboot, int, 0);
a77dba7e WVS	66	MODULE_PARM_DESC(mpcore_noboot, "MPcore watchdog action, "
	67	"set to 1 to ignore reboots, 0 to reboot (default="
	68	__MODULE_STRING(ONLY_TESTING) ")");
b9d36b85 RK	69
	70	/*
	71	* This is the interrupt handler. Note that we only use this
	72	* in testing mode, so don't actually do a reboot here.
	73	*/
7d12e780	74	static irqreturn_t mpcore_wdt_fire(int irq, void *arg)
b9d36b85 RK	75	{
	76	struct mpcore_wdt *wdt = arg;
	77
	78	/* Check it really was our interrupt */
	79	if (readl(wdt->base + TWD_WDOG_INTSTAT)) {
83ab1a53 AC	80	dev_printk(KERN_CRIT, wdt->dev,
83ab1a53 AC	81	"Triggered - Reboot ignored.\n");
b9d36b85 RK	82	/* Clear the interrupt on the watchdog */
b9d36b85 RK	83	writel(1, wdt->base + TWD_WDOG_INTSTAT);
b9d36b85 RK	84	return IRQ_HANDLED;
b9d36b85 RK	85	}
b9d36b85 RK	86	return IRQ_NONE;
	87	}
	88
	89	/*
	90	* mpcore_wdt_keepalive - reload the timer
	91	*
	92	* Note that the spec says a DIFFERENT value must be written to the reload
	93	* register each time. The "perturb" variable deals with this by adding 1
	94	* to the count every other time the function is called.
	95	*/
	96	static void mpcore_wdt_keepalive(struct mpcore_wdt *wdt)
	97	{
98af0570	98	unsigned long count;
b9d36b85	99
98af0570	100	spin_lock(&wdt_lock);
b9d36b85	101	/* Assume prescale is set to 256 */
98af0570 SK	102	count = __raw_readl(wdt->base + TWD_WDOG_COUNTER);
	103	count = (0xFFFFFFFFU - count) * (HZ / 5);
	104	count = (count / 256) * mpcore_margin;
b9d36b85 RK	105
	106	/* Reload the counter */
	107	writel(count + wdt->perturb, wdt->base + TWD_WDOG_LOAD);
b9d36b85	108	wdt->perturb = wdt->perturb ? 0 : 1;
83ab1a53	109	spin_unlock(&wdt_lock);
b9d36b85 RK	110	}
	111
	112	static void mpcore_wdt_stop(struct mpcore_wdt *wdt)
	113	{
83ab1a53	114	spin_lock(&wdt_lock);
b9d36b85 RK	115	writel(0x12345678, wdt->base + TWD_WDOG_DISABLE);
	116	writel(0x87654321, wdt->base + TWD_WDOG_DISABLE);
	117	writel(0x0, wdt->base + TWD_WDOG_CONTROL);
83ab1a53	118	spin_unlock(&wdt_lock);
b9d36b85 RK	119	}
	120
	121	static void mpcore_wdt_start(struct mpcore_wdt *wdt)
	122	{
	123	dev_printk(KERN_INFO, wdt->dev, "enabling watchdog.\n");
	124
	125	/* This loads the count register but does NOT start the count yet */
	126	mpcore_wdt_keepalive(wdt);
	127
	128	if (mpcore_noboot) {
	129	/* Enable watchdog - prescale=256, watchdog mode=0, enable=1 */
	130	writel(0x0000FF01, wdt->base + TWD_WDOG_CONTROL);
	131	} else {
	132	/* Enable watchdog - prescale=256, watchdog mode=1, enable=1 */
	133	writel(0x0000FF09, wdt->base + TWD_WDOG_CONTROL);
	134	}
	135	}
	136
	137	static int mpcore_wdt_set_heartbeat(int t)
	138	{
	139	if (t < 0x0001 \|\| t > 0xFFFF)
	140	return -EINVAL;
	141
	142	mpcore_margin = t;
	143	return 0;
	144	}
	145
	146	/*
	147	* /dev/watchdog handling
	148	*/
	149	static int mpcore_wdt_open(struct inode inode, struct file file)
	150	{
3ae5eaec	151	struct mpcore_wdt *wdt = platform_get_drvdata(mpcore_wdt_dev);
b9d36b85 RK	152
	153	if (test_and_set_bit(0, &wdt->timer_alive))
	154	return -EBUSY;
	155
	156	if (nowayout)
	157	__module_get(THIS_MODULE);
	158
	159	file->private_data = wdt;
	160
	161	/*
	162	* Activate timer
	163	*/
	164	mpcore_wdt_start(wdt);
	165
	166	return nonseekable_open(inode, file);
	167	}
	168
	169	static int mpcore_wdt_release(struct inode inode, struct file file)
	170	{
	171	struct mpcore_wdt *wdt = file->private_data;
	172
	173	/*
	174	* Shut off the timer.
	175	* Lock it in if it's a module and we set nowayout
	176	*/
83ab1a53	177	if (wdt->expect_close == 42)
b9d36b85	178	mpcore_wdt_stop(wdt);
83ab1a53 AC	179	else {
	180	dev_printk(KERN_CRIT, wdt->dev,
	181	"unexpected close, not stopping watchdog!\n");
b9d36b85 RK	182	mpcore_wdt_keepalive(wdt);
	183	}
	184	clear_bit(0, &wdt->timer_alive);
	185	wdt->expect_close = 0;
	186	return 0;
	187	}
	188
83ab1a53 AC	189	static ssize_t mpcore_wdt_write(struct file file, const char data,
83ab1a53 AC	190	size_t len, loff_t *ppos)
b9d36b85 RK	191	{
	192	struct mpcore_wdt *wdt = file->private_data;
	193
b9d36b85 RK	194	/*
	195	* Refresh the timer.
	196	*/
	197	if (len) {
	198	if (!nowayout) {
	199	size_t i;
	200
	201	/* In case it was set long ago */
	202	wdt->expect_close = 0;
	203
	204	for (i = 0; i != len; i++) {
	205	char c;
	206
	207	if (get_user(c, data + i))
	208	return -EFAULT;
	209	if (c == 'V')
	210	wdt->expect_close = 42;
	211	}
	212	}
	213	mpcore_wdt_keepalive(wdt);
	214	}
	215	return len;
	216	}
	217
42747d71	218	static const struct watchdog_info ident = {
b9d36b85 RK	219	.options = WDIOF_SETTIMEOUT \|
	220	WDIOF_KEEPALIVEPING \|
	221	WDIOF_MAGICCLOSE,
	222	.identity = "MPcore Watchdog",
	223	};
	224
83ab1a53 AC	225	static long mpcore_wdt_ioctl(struct file *file, unsigned int cmd,
83ab1a53 AC	226	unsigned long arg)
b9d36b85 RK	227	{
	228	struct mpcore_wdt *wdt = file->private_data;
	229	int ret;
	230	union {
	231	struct watchdog_info ident;
	232	int i;
	233	} uarg;
	234
	235	if (_IOC_DIR(cmd) && _IOC_SIZE(cmd) > sizeof(uarg))
795b89d2	236	return -ENOTTY;
b9d36b85 RK	237
	238	if (_IOC_DIR(cmd) & _IOC_WRITE) {
	239	ret = copy_from_user(&uarg, (void __user *)arg, _IOC_SIZE(cmd));
	240	if (ret)
	241	return -EFAULT;
	242	}
	243
	244	switch (cmd) {
	245	case WDIOC_GETSUPPORT:
	246	uarg.ident = ident;
	247	ret = 0;
	248	break;
	249
0c06090c WVS	250	case WDIOC_GETSTATUS:
	251	case WDIOC_GETBOOTSTATUS:
	252	uarg.i = 0;
	253	ret = 0;
	254	break;
	255
b9d36b85 RK	256	case WDIOC_SETOPTIONS:
	257	ret = -EINVAL;
	258	if (uarg.i & WDIOS_DISABLECARD) {
	259	mpcore_wdt_stop(wdt);
	260	ret = 0;
	261	}
	262	if (uarg.i & WDIOS_ENABLECARD) {
	263	mpcore_wdt_start(wdt);
	264	ret = 0;
	265	}
	266	break;
	267
b9d36b85 RK	268	case WDIOC_KEEPALIVE:
	269	mpcore_wdt_keepalive(wdt);
	270	ret = 0;
	271	break;
	272
	273	case WDIOC_SETTIMEOUT:
	274	ret = mpcore_wdt_set_heartbeat(uarg.i);
	275	if (ret)
	276	break;
	277
	278	mpcore_wdt_keepalive(wdt);
	279	/* Fall */
	280	case WDIOC_GETTIMEOUT:
	281	uarg.i = mpcore_margin;
	282	ret = 0;
	283	break;
	284
	285	default:
795b89d2	286	return -ENOTTY;
b9d36b85 RK	287	}
	288
	289	if (ret == 0 && _IOC_DIR(cmd) & _IOC_READ) {
	290	ret = copy_to_user((void __user *)arg, &uarg, _IOC_SIZE(cmd));
	291	if (ret)
	292	ret = -EFAULT;
	293	}
	294	return ret;
	295	}
	296
	297	/*
	298	* System shutdown handler. Turn off the watchdog if we're
	299	* restarting or halting the system.
	300	*/
3ae5eaec	301	static void mpcore_wdt_shutdown(struct platform_device *dev)
b9d36b85	302	{
3ae5eaec	303	struct mpcore_wdt *wdt = platform_get_drvdata(dev);
b9d36b85 RK	304
	305	if (system_state == SYSTEM_RESTART \|\| system_state == SYSTEM_HALT)
	306	mpcore_wdt_stop(wdt);
	307	}
	308
	309	/*
	310	* Kernel Interfaces
	311	*/
62322d25	312	static const struct file_operations mpcore_wdt_fops = {
b9d36b85 RK	313	.owner = THIS_MODULE,
	314	.llseek = no_llseek,
	315	.write = mpcore_wdt_write,
83ab1a53	316	.unlocked_ioctl = mpcore_wdt_ioctl,
b9d36b85 RK	317	.open = mpcore_wdt_open,
	318	.release = mpcore_wdt_release,
	319	};
	320
	321	static struct miscdevice mpcore_wdt_miscdev = {
	322	.minor = WATCHDOG_MINOR,
	323	.name = "watchdog",
	324	.fops = &mpcore_wdt_fops,
	325	};
	326
3ae5eaec	327	static int __devinit mpcore_wdt_probe(struct platform_device *dev)
b9d36b85	328	{
b9d36b85 RK	329	struct mpcore_wdt *wdt;
	330	struct resource *res;
	331	int ret;
	332
	333	/* We only accept one device, and it must have an id of -1 */
	334	if (dev->id != -1)
	335	return -ENODEV;
	336
	337	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
	338	if (!res) {
	339	ret = -ENODEV;
	340	goto err_out;
	341	}
	342
dd00cc48	343	wdt = kzalloc(sizeof(struct mpcore_wdt), GFP_KERNEL);
b9d36b85 RK	344	if (!wdt) {
	345	ret = -ENOMEM;
	346	goto err_out;
	347	}
b9d36b85 RK	348
	349	wdt->dev = &dev->dev;
	350	wdt->irq = platform_get_irq(dev, 0);
48944738 DV	351	if (wdt->irq < 0) {
	352	ret = -ENXIO;
	353	goto err_free;
	354	}
b782a563	355	wdt->base = ioremap(res->start, resource_size(res));
b9d36b85 RK	356	if (!wdt->base) {
	357	ret = -ENOMEM;
	358	goto err_free;
	359	}
	360
e0b79e0b	361	mpcore_wdt_miscdev.parent = &dev->dev;
b9d36b85 RK	362	ret = misc_register(&mpcore_wdt_miscdev);
b9d36b85 RK	363	if (ret) {
98af0570	364	dev_printk(KERN_ERR, wdt->dev,
83ab1a53 AC	365	"cannot register miscdev on minor=%d (err=%d)\n",
83ab1a53 AC	366	WATCHDOG_MINOR, ret);
b9d36b85 RK	367	goto err_misc;
	368	}
	369
83ab1a53 AC	370	ret = request_irq(wdt->irq, mpcore_wdt_fire, IRQF_DISABLED,
83ab1a53 AC	371	"mpcore_wdt", wdt);
b9d36b85	372	if (ret) {
98af0570	373	dev_printk(KERN_ERR, wdt->dev,
83ab1a53	374	"cannot register IRQ%d for watchdog\n", wdt->irq);
b9d36b85 RK	375	goto err_irq;
	376	}
	377
	378	mpcore_wdt_stop(wdt);
98af0570	379	platform_set_drvdata(dev, wdt);
b9d36b85 RK	380	mpcore_wdt_dev = dev;
	381
	382	return 0;
	383
7944d3a5	384	err_irq:
b9d36b85	385	misc_deregister(&mpcore_wdt_miscdev);
7944d3a5	386	err_misc:
b9d36b85	387	iounmap(wdt->base);
7944d3a5	388	err_free:
b9d36b85	389	kfree(wdt);
7944d3a5	390	err_out:
b9d36b85 RK	391	return ret;
	392	}
	393
3ae5eaec	394	static int __devexit mpcore_wdt_remove(struct platform_device *dev)
b9d36b85	395	{
3ae5eaec	396	struct mpcore_wdt *wdt = platform_get_drvdata(dev);
b9d36b85	397
3ae5eaec	398	platform_set_drvdata(dev, NULL);
b9d36b85 RK	399
	400	misc_deregister(&mpcore_wdt_miscdev);
	401
	402	mpcore_wdt_dev = NULL;
	403
	404	free_irq(wdt->irq, wdt);
	405	iounmap(wdt->base);
	406	kfree(wdt);
	407	return 0;
	408	}
	409
f37d193c KS	410	/* work with hotplug and coldplug */
	411	MODULE_ALIAS("platform:mpcore_wdt");
	412
3ae5eaec	413	static struct platform_driver mpcore_wdt_driver = {
b9d36b85 RK	414	.probe = mpcore_wdt_probe,
	415	.remove = __devexit_p(mpcore_wdt_remove),
	416	.shutdown = mpcore_wdt_shutdown,
3ae5eaec RK	417	.driver = {
	418	.owner = THIS_MODULE,
	419	.name = "mpcore_wdt",
	420	},
b9d36b85 RK	421	};
b9d36b85 RK	422
a77dba7e WVS	423	static char banner[] __initdata = KERN_INFO "MPcore Watchdog Timer: 0.1. "
a77dba7e WVS	424	"mpcore_noboot=%d mpcore_margin=%d sec (nowayout= %d)\n";
b9d36b85 RK	425
	426	static int __init mpcore_wdt_init(void)
	427	{
	428	/*
	429	* Check that the margin value is within it's range;
	430	* if not reset to the default
	431	*/
	432	if (mpcore_wdt_set_heartbeat(mpcore_margin)) {
	433	mpcore_wdt_set_heartbeat(TIMER_MARGIN);
83ab1a53	434	printk(KERN_INFO "mpcore_margin value must be 0 < mpcore_margin < 65536, using %d\n",
b9d36b85 RK	435	TIMER_MARGIN);
	436	}
	437
	438	printk(banner, mpcore_noboot, mpcore_margin, nowayout);
	439
3ae5eaec	440	return platform_driver_register(&mpcore_wdt_driver);
b9d36b85 RK	441	}
	442
	443	static void __exit mpcore_wdt_exit(void)
	444	{
3ae5eaec	445	platform_driver_unregister(&mpcore_wdt_driver);
b9d36b85 RK	446	}
	447
	448	module_init(mpcore_wdt_init);
	449	module_exit(mpcore_wdt_exit);
	450
	451	MODULE_AUTHOR("ARM Limited");
	452	MODULE_DESCRIPTION("MPcore Watchdog Device Driver");
	453	MODULE_LICENSE("GPL");
	454	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);