[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@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>
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#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 bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 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, 0, "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;
}

#ifdef CONFIG_PM
static int mpcore_wdt_suspend(struct platform_device *dev, pm_message_t msg)
{
	struct mpcore_wdt *wdt = platform_get_drvdata(dev);
	mpcore_wdt_stop(wdt);		/* Turn the WDT off */
	return 0;
}

static int mpcore_wdt_resume(struct platform_device *dev)
{
	struct mpcore_wdt *wdt = platform_get_drvdata(dev);
	/* re-activate timer */
	if (test_bit(0, &wdt->timer_alive))
		mpcore_wdt_start(wdt);
	return 0;
}
#else
#define mpcore_wdt_suspend	NULL
#define mpcore_wdt_resume	NULL
#endif

/* 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),
	.suspend	= mpcore_wdt_suspend,
	.resume		= mpcore_wdt_resume,
	.shutdown	= mpcore_wdt_shutdown,
	.driver		= {
		.owner	= THIS_MODULE,
		.name	= "mpcore_wdt",
	},
};

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);
		pr_info("mpcore_margin value must be 0 < mpcore_margin < 65536, using %d\n",
			TIMER_MARGIN);
	}

	pr_info("MPcore Watchdog Timer: 0.1. mpcore_noboot=%d mpcore_margin=%d sec (nowayout= %d)\n",
		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	*/
27c766aa JP	22
	23	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	24
b9d36b85 RK	25	#include <linux/module.h>
b9d36b85 RK	26	#include <linux/moduleparam.h>
b9d36b85 RK	27	#include <linux/types.h>
	28	#include <linux/miscdevice.h>
	29	#include <linux/watchdog.h>
	30	#include <linux/fs.h>
	31	#include <linux/reboot.h>
	32	#include <linux/init.h>
	33	#include <linux/interrupt.h>
d052d1be	34	#include <linux/platform_device.h>
83ab1a53	35	#include <linux/uaccess.h>
5a0e3ad6	36	#include <linux/slab.h>
98af0570	37	#include <linux/io.h>
ad4162f3	38
98af0570	39	#include <asm/smp_twd.h>
b9d36b85 RK	40
	41	struct mpcore_wdt {
	42	unsigned long timer_alive;
	43	struct device *dev;
	44	void __iomem *base;
	45	int irq;
	46	unsigned int perturb;
	47	char expect_close;
	48	};
	49
	50	static struct platform_device *mpcore_wdt_dev;
98af0570	51	static DEFINE_SPINLOCK(wdt_lock);
b9d36b85 RK	52
	53	#define TIMER_MARGIN 60
	54	static int mpcore_margin = TIMER_MARGIN;
	55	module_param(mpcore_margin, int, 0);
83ab1a53 AC	56	MODULE_PARM_DESC(mpcore_margin,
	57	"MPcore timer margin in seconds. (0 < mpcore_margin < 65536, default="
	58	__MODULE_STRING(TIMER_MARGIN) ")");
b9d36b85	59
86a1e189 WVS	60	static bool nowayout = WATCHDOG_NOWAYOUT;
86a1e189 WVS	61	module_param(nowayout, bool, 0);
83ab1a53 AC	62	MODULE_PARM_DESC(nowayout,
	63	"Watchdog cannot be stopped once started (default="
	64	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
b9d36b85 RK	65
	66	#define ONLY_TESTING 0
	67	static int mpcore_noboot = ONLY_TESTING;
	68	module_param(mpcore_noboot, int, 0);
a77dba7e WVS	69	MODULE_PARM_DESC(mpcore_noboot, "MPcore watchdog action, "
	70	"set to 1 to ignore reboots, 0 to reboot (default="
	71	__MODULE_STRING(ONLY_TESTING) ")");
b9d36b85 RK	72
	73	/*
	74	* This is the interrupt handler. Note that we only use this
	75	* in testing mode, so don't actually do a reboot here.
	76	*/
7d12e780	77	static irqreturn_t mpcore_wdt_fire(int irq, void *arg)
b9d36b85 RK	78	{
	79	struct mpcore_wdt *wdt = arg;
	80
	81	/* Check it really was our interrupt */
	82	if (readl(wdt->base + TWD_WDOG_INTSTAT)) {
83ab1a53 AC	83	dev_printk(KERN_CRIT, wdt->dev,
83ab1a53 AC	84	"Triggered - Reboot ignored.\n");
b9d36b85 RK	85	/* Clear the interrupt on the watchdog */
b9d36b85 RK	86	writel(1, wdt->base + TWD_WDOG_INTSTAT);
b9d36b85 RK	87	return IRQ_HANDLED;
b9d36b85 RK	88	}
b9d36b85 RK	89	return IRQ_NONE;
	90	}
	91
	92	/*
	93	* mpcore_wdt_keepalive - reload the timer
	94	*
	95	* Note that the spec says a DIFFERENT value must be written to the reload
	96	* register each time. The "perturb" variable deals with this by adding 1
	97	* to the count every other time the function is called.
	98	*/
	99	static void mpcore_wdt_keepalive(struct mpcore_wdt *wdt)
	100	{
98af0570	101	unsigned long count;
b9d36b85	102
98af0570	103	spin_lock(&wdt_lock);
b9d36b85	104	/* Assume prescale is set to 256 */
98af0570 SK	105	count = __raw_readl(wdt->base + TWD_WDOG_COUNTER);
	106	count = (0xFFFFFFFFU - count) * (HZ / 5);
	107	count = (count / 256) * mpcore_margin;
b9d36b85 RK	108
	109	/* Reload the counter */
	110	writel(count + wdt->perturb, wdt->base + TWD_WDOG_LOAD);
b9d36b85	111	wdt->perturb = wdt->perturb ? 0 : 1;
83ab1a53	112	spin_unlock(&wdt_lock);
b9d36b85 RK	113	}
	114
	115	static void mpcore_wdt_stop(struct mpcore_wdt *wdt)
	116	{
83ab1a53	117	spin_lock(&wdt_lock);
b9d36b85 RK	118	writel(0x12345678, wdt->base + TWD_WDOG_DISABLE);
	119	writel(0x87654321, wdt->base + TWD_WDOG_DISABLE);
	120	writel(0x0, wdt->base + TWD_WDOG_CONTROL);
83ab1a53	121	spin_unlock(&wdt_lock);
b9d36b85 RK	122	}
	123
	124	static void mpcore_wdt_start(struct mpcore_wdt *wdt)
	125	{
	126	dev_printk(KERN_INFO, wdt->dev, "enabling watchdog.\n");
	127
	128	/* This loads the count register but does NOT start the count yet */
	129	mpcore_wdt_keepalive(wdt);
	130
	131	if (mpcore_noboot) {
	132	/* Enable watchdog - prescale=256, watchdog mode=0, enable=1 */
	133	writel(0x0000FF01, wdt->base + TWD_WDOG_CONTROL);
	134	} else {
	135	/* Enable watchdog - prescale=256, watchdog mode=1, enable=1 */
	136	writel(0x0000FF09, wdt->base + TWD_WDOG_CONTROL);
	137	}
	138	}
	139
	140	static int mpcore_wdt_set_heartbeat(int t)
	141	{
	142	if (t < 0x0001 \|\| t > 0xFFFF)
	143	return -EINVAL;
	144
	145	mpcore_margin = t;
	146	return 0;
	147	}
	148
	149	/*
	150	* /dev/watchdog handling
	151	*/
	152	static int mpcore_wdt_open(struct inode inode, struct file file)
	153	{
3ae5eaec	154	struct mpcore_wdt *wdt = platform_get_drvdata(mpcore_wdt_dev);
b9d36b85 RK	155
	156	if (test_and_set_bit(0, &wdt->timer_alive))
	157	return -EBUSY;
	158
	159	if (nowayout)
	160	__module_get(THIS_MODULE);
	161
	162	file->private_data = wdt;
	163
	164	/*
	165	* Activate timer
	166	*/
	167	mpcore_wdt_start(wdt);
	168
	169	return nonseekable_open(inode, file);
	170	}
	171
	172	static int mpcore_wdt_release(struct inode inode, struct file file)
	173	{
	174	struct mpcore_wdt *wdt = file->private_data;
	175
	176	/*
	177	* Shut off the timer.
5f3b2756	178	* Lock it in if it's a module and we set nowayout
b9d36b85	179	*/
83ab1a53	180	if (wdt->expect_close == 42)
b9d36b85	181	mpcore_wdt_stop(wdt);
83ab1a53 AC	182	else {
	183	dev_printk(KERN_CRIT, wdt->dev,
	184	"unexpected close, not stopping watchdog!\n");
b9d36b85 RK	185	mpcore_wdt_keepalive(wdt);
	186	}
	187	clear_bit(0, &wdt->timer_alive);
	188	wdt->expect_close = 0;
	189	return 0;
	190	}
	191
83ab1a53 AC	192	static ssize_t mpcore_wdt_write(struct file file, const char data,
83ab1a53 AC	193	size_t len, loff_t *ppos)
b9d36b85 RK	194	{
	195	struct mpcore_wdt *wdt = file->private_data;
	196
b9d36b85 RK	197	/*
	198	* Refresh the timer.
	199	*/
	200	if (len) {
	201	if (!nowayout) {
	202	size_t i;
	203
	204	/* In case it was set long ago */
	205	wdt->expect_close = 0;
	206
	207	for (i = 0; i != len; i++) {
	208	char c;
	209
	210	if (get_user(c, data + i))
	211	return -EFAULT;
	212	if (c == 'V')
	213	wdt->expect_close = 42;
	214	}
	215	}
	216	mpcore_wdt_keepalive(wdt);
	217	}
	218	return len;
	219	}
	220
42747d71	221	static const struct watchdog_info ident = {
b9d36b85 RK	222	.options = WDIOF_SETTIMEOUT \|
	223	WDIOF_KEEPALIVEPING \|
	224	WDIOF_MAGICCLOSE,
	225	.identity = "MPcore Watchdog",
	226	};
	227
83ab1a53 AC	228	static long mpcore_wdt_ioctl(struct file *file, unsigned int cmd,
83ab1a53 AC	229	unsigned long arg)
b9d36b85 RK	230	{
	231	struct mpcore_wdt *wdt = file->private_data;
	232	int ret;
	233	union {
	234	struct watchdog_info ident;
	235	int i;
	236	} uarg;
	237
	238	if (_IOC_DIR(cmd) && _IOC_SIZE(cmd) > sizeof(uarg))
795b89d2	239	return -ENOTTY;
b9d36b85 RK	240
	241	if (_IOC_DIR(cmd) & _IOC_WRITE) {
	242	ret = copy_from_user(&uarg, (void __user *)arg, _IOC_SIZE(cmd));
	243	if (ret)
	244	return -EFAULT;
	245	}
	246
	247	switch (cmd) {
	248	case WDIOC_GETSUPPORT:
	249	uarg.ident = ident;
	250	ret = 0;
	251	break;
	252
0c06090c WVS	253	case WDIOC_GETSTATUS:
	254	case WDIOC_GETBOOTSTATUS:
	255	uarg.i = 0;
	256	ret = 0;
	257	break;
	258
b9d36b85 RK	259	case WDIOC_SETOPTIONS:
	260	ret = -EINVAL;
	261	if (uarg.i & WDIOS_DISABLECARD) {
	262	mpcore_wdt_stop(wdt);
	263	ret = 0;
	264	}
	265	if (uarg.i & WDIOS_ENABLECARD) {
	266	mpcore_wdt_start(wdt);
	267	ret = 0;
	268	}
	269	break;
	270
b9d36b85 RK	271	case WDIOC_KEEPALIVE:
	272	mpcore_wdt_keepalive(wdt);
	273	ret = 0;
	274	break;
	275
	276	case WDIOC_SETTIMEOUT:
	277	ret = mpcore_wdt_set_heartbeat(uarg.i);
	278	if (ret)
	279	break;
	280
	281	mpcore_wdt_keepalive(wdt);
	282	/* Fall */
	283	case WDIOC_GETTIMEOUT:
	284	uarg.i = mpcore_margin;
	285	ret = 0;
	286	break;
	287
	288	default:
795b89d2	289	return -ENOTTY;
b9d36b85 RK	290	}
	291
	292	if (ret == 0 && _IOC_DIR(cmd) & _IOC_READ) {
	293	ret = copy_to_user((void __user *)arg, &uarg, _IOC_SIZE(cmd));
	294	if (ret)
	295	ret = -EFAULT;
	296	}
	297	return ret;
	298	}
	299
	300	/*
	301	* System shutdown handler. Turn off the watchdog if we're
	302	* restarting or halting the system.
	303	*/
3ae5eaec	304	static void mpcore_wdt_shutdown(struct platform_device *dev)
b9d36b85	305	{
3ae5eaec	306	struct mpcore_wdt *wdt = platform_get_drvdata(dev);
b9d36b85 RK	307
	308	if (system_state == SYSTEM_RESTART \|\| system_state == SYSTEM_HALT)
	309	mpcore_wdt_stop(wdt);
	310	}
	311
	312	/*
	313	* Kernel Interfaces
	314	*/
62322d25	315	static const struct file_operations mpcore_wdt_fops = {
b9d36b85 RK	316	.owner = THIS_MODULE,
	317	.llseek = no_llseek,
	318	.write = mpcore_wdt_write,
83ab1a53	319	.unlocked_ioctl = mpcore_wdt_ioctl,
b9d36b85 RK	320	.open = mpcore_wdt_open,
	321	.release = mpcore_wdt_release,
	322	};
	323
	324	static struct miscdevice mpcore_wdt_miscdev = {
	325	.minor = WATCHDOG_MINOR,
	326	.name = "watchdog",
	327	.fops = &mpcore_wdt_fops,
	328	};
	329
3ae5eaec	330	static int __devinit mpcore_wdt_probe(struct platform_device *dev)
b9d36b85	331	{
b9d36b85 RK	332	struct mpcore_wdt *wdt;
	333	struct resource *res;
	334	int ret;
	335
	336	/* We only accept one device, and it must have an id of -1 */
	337	if (dev->id != -1)
	338	return -ENODEV;
	339
	340	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
	341	if (!res) {
	342	ret = -ENODEV;
	343	goto err_out;
	344	}
	345
dd00cc48	346	wdt = kzalloc(sizeof(struct mpcore_wdt), GFP_KERNEL);
b9d36b85 RK	347	if (!wdt) {
	348	ret = -ENOMEM;
	349	goto err_out;
	350	}
b9d36b85 RK	351
	352	wdt->dev = &dev->dev;
	353	wdt->irq = platform_get_irq(dev, 0);
48944738 DV	354	if (wdt->irq < 0) {
	355	ret = -ENXIO;
	356	goto err_free;
	357	}
b782a563	358	wdt->base = ioremap(res->start, resource_size(res));
b9d36b85 RK	359	if (!wdt->base) {
	360	ret = -ENOMEM;
	361	goto err_free;
	362	}
	363
e0b79e0b	364	mpcore_wdt_miscdev.parent = &dev->dev;
b9d36b85 RK	365	ret = misc_register(&mpcore_wdt_miscdev);
b9d36b85 RK	366	if (ret) {
98af0570	367	dev_printk(KERN_ERR, wdt->dev,
83ab1a53 AC	368	"cannot register miscdev on minor=%d (err=%d)\n",
83ab1a53 AC	369	WATCHDOG_MINOR, ret);
b9d36b85 RK	370	goto err_misc;
	371	}
	372
86b59128	373	ret = request_irq(wdt->irq, mpcore_wdt_fire, 0, "mpcore_wdt", wdt);
b9d36b85	374	if (ret) {
98af0570	375	dev_printk(KERN_ERR, wdt->dev,
83ab1a53	376	"cannot register IRQ%d for watchdog\n", wdt->irq);
b9d36b85 RK	377	goto err_irq;
	378	}
	379
	380	mpcore_wdt_stop(wdt);
98af0570	381	platform_set_drvdata(dev, wdt);
b9d36b85 RK	382	mpcore_wdt_dev = dev;
	383
	384	return 0;
	385
7944d3a5	386	err_irq:
b9d36b85	387	misc_deregister(&mpcore_wdt_miscdev);
7944d3a5	388	err_misc:
b9d36b85	389	iounmap(wdt->base);
7944d3a5	390	err_free:
b9d36b85	391	kfree(wdt);
7944d3a5	392	err_out:
b9d36b85 RK	393	return ret;
	394	}
	395
3ae5eaec	396	static int __devexit mpcore_wdt_remove(struct platform_device *dev)
b9d36b85	397	{
3ae5eaec	398	struct mpcore_wdt *wdt = platform_get_drvdata(dev);
b9d36b85	399
3ae5eaec	400	platform_set_drvdata(dev, NULL);
b9d36b85 RK	401
	402	misc_deregister(&mpcore_wdt_miscdev);
	403
	404	mpcore_wdt_dev = NULL;
	405
	406	free_irq(wdt->irq, wdt);
	407	iounmap(wdt->base);
	408	kfree(wdt);
	409	return 0;
	410	}
	411
641e4f44 PF	412	#ifdef CONFIG_PM
	413	static int mpcore_wdt_suspend(struct platform_device *dev, pm_message_t msg)
	414	{
	415	struct mpcore_wdt *wdt = platform_get_drvdata(dev);
	416	mpcore_wdt_stop(wdt); /* Turn the WDT off */
	417	return 0;
	418	}
	419
	420	static int mpcore_wdt_resume(struct platform_device *dev)
	421	{
	422	struct mpcore_wdt *wdt = platform_get_drvdata(dev);
	423	/* re-activate timer */
	424	if (test_bit(0, &wdt->timer_alive))
	425	mpcore_wdt_start(wdt);
	426	return 0;
	427	}
	428	#else
	429	#define mpcore_wdt_suspend NULL
	430	#define mpcore_wdt_resume NULL
	431	#endif
	432
f37d193c KS	433	/* work with hotplug and coldplug */
	434	MODULE_ALIAS("platform:mpcore_wdt");
	435
3ae5eaec	436	static struct platform_driver mpcore_wdt_driver = {
b9d36b85 RK	437	.probe = mpcore_wdt_probe,
b9d36b85 RK	438	.remove = __devexit_p(mpcore_wdt_remove),
641e4f44 PF	439	.suspend = mpcore_wdt_suspend,
641e4f44 PF	440	.resume = mpcore_wdt_resume,
b9d36b85	441	.shutdown = mpcore_wdt_shutdown,
3ae5eaec RK	442	.driver = {
	443	.owner = THIS_MODULE,
	444	.name = "mpcore_wdt",
	445	},
b9d36b85 RK	446	};
b9d36b85 RK	447
b9d36b85 RK	448	static int __init mpcore_wdt_init(void)
	449	{
	450	/*
	451	* Check that the margin value is within it's range;
	452	* if not reset to the default
	453	*/
	454	if (mpcore_wdt_set_heartbeat(mpcore_margin)) {
	455	mpcore_wdt_set_heartbeat(TIMER_MARGIN);
27c766aa	456	pr_info("mpcore_margin value must be 0 < mpcore_margin < 65536, using %d\n",
b9d36b85 RK	457	TIMER_MARGIN);
	458	}
	459
27c766aa JP	460	pr_info("MPcore Watchdog Timer: 0.1. mpcore_noboot=%d mpcore_margin=%d sec (nowayout= %d)\n",
27c766aa JP	461	mpcore_noboot, mpcore_margin, nowayout);
b9d36b85	462
3ae5eaec	463	return platform_driver_register(&mpcore_wdt_driver);
b9d36b85 RK	464	}
	465
	466	static void __exit mpcore_wdt_exit(void)
	467	{
3ae5eaec	468	platform_driver_unregister(&mpcore_wdt_driver);
b9d36b85 RK	469	}
	470
	471	module_init(mpcore_wdt_init);
	472	module_exit(mpcore_wdt_exit);
	473
	474	MODULE_AUTHOR("ARM Limited");
	475	MODULE_DESCRIPTION("MPcore Watchdog Device Driver");
	476	MODULE_LICENSE("GPL");
	477	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);