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