[deliverable/linux.git] / drivers / watchdog / bfin_wdt.c

/*
 * Blackfin On-Chip Watchdog Driver
 *  Supports BF53[123]/BF53[467]/BF54[2489]/BF561
 *
 * Originally based on softdog.c
 * Copyright 2006-2007 Analog Devices Inc.
 * Copyright 2006-2007 Michele d'Amico
 * Copyright 1996 Alan Cox <alan@redhat.com>
 *
 * Enter bugs at http://blackfin.uclinux.org/
 *
 * Licensed under the GPL-2 or later.
 */

#include <linux/platform_device.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/timer.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/fs.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <asm/blackfin.h>
#include <asm/uaccess.h>

#define stamp(fmt, args...) pr_debug("%s:%i: " fmt "\n", __func__, __LINE__, ## args)
#define stampit() stamp("here i am")
#define pr_devinit(fmt, args...) ({ static const __devinitconst char __fmt[] = fmt; printk(__fmt, ## args); })
#define pr_init(fmt, args...) ({ static const __initconst char __fmt[] = fmt; printk(__fmt, ## args); })

#define WATCHDOG_NAME "bfin-wdt"
#define PFX WATCHDOG_NAME ": "

/* The BF561 has two watchdogs (one per core), but since Linux
 * only runs on core A, we'll just work with that one.
 */
#ifdef BF561_FAMILY
# define bfin_read_WDOG_CTL()    bfin_read_WDOGA_CTL()
# define bfin_read_WDOG_CNT()    bfin_read_WDOGA_CNT()
# define bfin_read_WDOG_STAT()   bfin_read_WDOGA_STAT()
# define bfin_write_WDOG_CTL(x)  bfin_write_WDOGA_CTL(x)
# define bfin_write_WDOG_CNT(x)  bfin_write_WDOGA_CNT(x)
# define bfin_write_WDOG_STAT(x) bfin_write_WDOGA_STAT(x)
#endif

/* Bit in SWRST that indicates boot caused by watchdog */
#define SWRST_RESET_WDOG 0x4000

/* Bit in WDOG_CTL that indicates watchdog has expired (WDR0) */
#define WDOG_EXPIRED 0x8000

/* Masks for WDEV field in WDOG_CTL register */
#define ICTL_RESET   0x0
#define ICTL_NMI     0x2
#define ICTL_GPI     0x4
#define ICTL_NONE    0x6
#define ICTL_MASK    0x6

/* Masks for WDEN field in WDOG_CTL register */
#define WDEN_MASK    0x0FF0
#define WDEN_ENABLE  0x0000
#define WDEN_DISABLE 0x0AD0

/* some defaults */
#define WATCHDOG_TIMEOUT 20

static unsigned int timeout = WATCHDOG_TIMEOUT;
static int nowayout = WATCHDOG_NOWAYOUT;
static struct watchdog_info bfin_wdt_info;
static unsigned long open_check;
static char expect_close;
static DEFINE_SPINLOCK(bfin_wdt_spinlock);

/**
 *	bfin_wdt_keepalive - Keep the Userspace Watchdog Alive
 *
 * 	The Userspace watchdog got a KeepAlive: schedule the next timeout.
 */
static int bfin_wdt_keepalive(void)
{
	stampit();
	bfin_write_WDOG_STAT(0);
	return 0;
}

/**
 *	bfin_wdt_stop - Stop the Watchdog
 *
 *	Stops the on-chip watchdog.
 */
static int bfin_wdt_stop(void)
{
	stampit();
	bfin_write_WDOG_CTL(WDEN_DISABLE);
	return 0;
}

/**
 *	bfin_wdt_start - Start the Watchdog
 *
 *	Starts the on-chip watchdog.  Automatically loads WDOG_CNT
 *	into WDOG_STAT for us.
 */
static int bfin_wdt_start(void)
{
	stampit();
	bfin_write_WDOG_CTL(WDEN_ENABLE | ICTL_RESET);
	return 0;
}

/**
 *	bfin_wdt_running - Check Watchdog status
 *
 *	See if the watchdog is running.
 */
static int bfin_wdt_running(void)
{
	stampit();
	return ((bfin_read_WDOG_CTL() & WDEN_MASK) != WDEN_DISABLE);
}

/**
 *	bfin_wdt_set_timeout - Set the Userspace Watchdog timeout
 *	@t: new timeout value (in seconds)
 *
 *	Translate the specified timeout in seconds into System Clock
 *	terms which is what the on-chip Watchdog requires.
 */
static int bfin_wdt_set_timeout(unsigned long t)
{
	u32 cnt;
	unsigned long flags;

	stampit();

	cnt = t * get_sclk();
	if (cnt < get_sclk()) {
		printk(KERN_WARNING PFX "timeout value is too large\n");
		return -EINVAL;
	}

	spin_lock_irqsave(&bfin_wdt_spinlock, flags);
	{
		int run = bfin_wdt_running();
		bfin_wdt_stop();
		bfin_write_WDOG_CNT(cnt);
		if (run) bfin_wdt_start();
	}
	spin_unlock_irqrestore(&bfin_wdt_spinlock, flags);

	timeout = t;

	return 0;
}

/**
 *	bfin_wdt_open - Open the Device
 *	@inode: inode of device
 *	@file: file handle of device
 *
 *	Watchdog device is opened and started.
 */
static int bfin_wdt_open(struct inode *inode, struct file *file)
{
	stampit();

	if (test_and_set_bit(0, &open_check))
		return -EBUSY;

	if (nowayout)
		__module_get(THIS_MODULE);

	bfin_wdt_keepalive();
	bfin_wdt_start();

	return nonseekable_open(inode, file);
}

/**
 *	bfin_wdt_close - Close the Device
 *	@inode: inode of device
 *	@file: file handle of device
 *
 *	Watchdog device is closed and stopped.
 */
static int bfin_wdt_release(struct inode *inode, struct file *file)
{
	stampit();

	if (expect_close == 42) {
		bfin_wdt_stop();
	} else {
		printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
		bfin_wdt_keepalive();
	}

	expect_close = 0;
	clear_bit(0, &open_check);

	return 0;
}

/**
 *	bfin_wdt_write - Write to Device
 *	@file: file handle of device
 *	@buf: buffer to write
 *	@count: length of buffer
 *	@ppos: offset
 *
 *	Pings the watchdog on write.
 */
static ssize_t bfin_wdt_write(struct file *file, const char __user *data,
                              size_t len, loff_t *ppos)
{
	stampit();

	if (len) {
		if (!nowayout) {
			size_t i;

			/* In case it was set long ago */
			expect_close = 0;

			for (i = 0; i != len; i++) {
				char c;
				if (get_user(c, data + i))
					return -EFAULT;
				if (c == 'V')
					expect_close = 42;
			}
		}
		bfin_wdt_keepalive();
	}

	return len;
}

/**
 *	bfin_wdt_ioctl - Query Device
 *	@inode: inode of device
 *	@file: file handle of device
 *	@cmd: watchdog command
 *	@arg: argument
 *
 *	Query basic information from the device or ping it, as outlined by the
 *	watchdog API.
 */
static int bfin_wdt_ioctl(struct inode *inode, struct file *file,
                          unsigned int cmd, unsigned long arg)
{
	void __user *argp = (void __user *)arg;
	int __user *p = argp;

	stampit();

	switch (cmd) {
		default:
			return -ENOTTY;

		case WDIOC_GETSUPPORT:
			if (copy_to_user(argp, &bfin_wdt_info, sizeof(bfin_wdt_info)))
				return -EFAULT;
			else
				return 0;

		case WDIOC_GETSTATUS:
		case WDIOC_GETBOOTSTATUS:
			return put_user(!!(_bfin_swrst & SWRST_RESET_WDOG), p);

		case WDIOC_KEEPALIVE:
			bfin_wdt_keepalive();
			return 0;

		case WDIOC_SETTIMEOUT: {
			int new_timeout;

			if (get_user(new_timeout, p))
				return -EFAULT;

			if (bfin_wdt_set_timeout(new_timeout))
				return -EINVAL;
		}
			/* Fall */
		case WDIOC_GETTIMEOUT:
			return put_user(timeout, p);

		case WDIOC_SETOPTIONS: {
			unsigned long flags;
			int options, ret = -EINVAL;

			if (get_user(options, p))
				return -EFAULT;

			spin_lock_irqsave(&bfin_wdt_spinlock, flags);

			if (options & WDIOS_DISABLECARD) {
				bfin_wdt_stop();
				ret = 0;
			}

			if (options & WDIOS_ENABLECARD) {
				bfin_wdt_start();
				ret = 0;
			}

			spin_unlock_irqrestore(&bfin_wdt_spinlock, flags);

			return ret;
		}
	}
}

/**
 *	bfin_wdt_notify_sys - Notifier Handler
 *	@this: notifier block
 *	@code: notifier event
 *	@unused: unused
 *
 *	Handles specific events, such as turning off the watchdog during a
 *	shutdown event.
 */
static int bfin_wdt_notify_sys(struct notifier_block *this, unsigned long code,
                               void *unused)
{
	stampit();

	if (code == SYS_DOWN || code == SYS_HALT)
		bfin_wdt_stop();

	return NOTIFY_DONE;
}

#ifdef CONFIG_PM
static int state_before_suspend;

/**
 *	bfin_wdt_suspend - suspend the watchdog
 *	@pdev: device being suspended
 *	@state: requested suspend state
 *
 *	Remember if the watchdog was running and stop it.
 *	TODO: is this even right?  Doesn't seem to be any
 *	      standard in the watchdog world ...
 */
static int bfin_wdt_suspend(struct platform_device *pdev, pm_message_t state)
{
	stampit();

	state_before_suspend = bfin_wdt_running();
	bfin_wdt_stop();

	return 0;
}

/**
 *	bfin_wdt_resume - resume the watchdog
 *	@pdev: device being resumed
 *
 *	If the watchdog was running, turn it back on.
 */
static int bfin_wdt_resume(struct platform_device *pdev)
{
	stampit();

	if (state_before_suspend) {
		bfin_wdt_set_timeout(timeout);
		bfin_wdt_start();
	}

	return 0;
}
#else
# define bfin_wdt_suspend NULL
# define bfin_wdt_resume NULL
#endif

static const struct file_operations bfin_wdt_fops = {
	.owner    = THIS_MODULE,
	.llseek   = no_llseek,
	.write    = bfin_wdt_write,
	.ioctl    = bfin_wdt_ioctl,
	.open     = bfin_wdt_open,
	.release  = bfin_wdt_release,
};

static struct miscdevice bfin_wdt_miscdev = {
	.minor    = WATCHDOG_MINOR,
	.name     = "watchdog",
	.fops     = &bfin_wdt_fops,
};

static struct watchdog_info bfin_wdt_info = {
	.identity = "Blackfin Watchdog",
	.options  = WDIOF_SETTIMEOUT |
	            WDIOF_KEEPALIVEPING |
	            WDIOF_MAGICCLOSE,
};

static struct notifier_block bfin_wdt_notifier = {
	.notifier_call = bfin_wdt_notify_sys,
};

/**
 *	bfin_wdt_probe - Initialize module
 *
 *	Registers the misc device and notifier handler.  Actual device
 *	initialization is handled by bfin_wdt_open().
 */
static int __devinit bfin_wdt_probe(struct platform_device *pdev)
{
	int ret;

	ret = register_reboot_notifier(&bfin_wdt_notifier);
	if (ret) {
		pr_devinit(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n", ret);
		return ret;
	}

	ret = misc_register(&bfin_wdt_miscdev);
	if (ret) {
		pr_devinit(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
		       WATCHDOG_MINOR, ret);
		unregister_reboot_notifier(&bfin_wdt_notifier);
		return ret;
	}

	pr_devinit(KERN_INFO PFX "initialized: timeout=%d sec (nowayout=%d)\n",
	       timeout, nowayout);

	return 0;
}

/**
 *	bfin_wdt_remove - Initialize module
 *
 *	Unregisters the misc device and notifier handler.  Actual device
 *	deinitialization is handled by bfin_wdt_close().
 */
static int __devexit bfin_wdt_remove(struct platform_device *pdev)
{
	misc_deregister(&bfin_wdt_miscdev);
	unregister_reboot_notifier(&bfin_wdt_notifier);
	return 0;
}

static struct platform_device *bfin_wdt_device;

static struct platform_driver bfin_wdt_driver = {
	.probe     = bfin_wdt_probe,
	.remove    = __devexit_p(bfin_wdt_remove),
	.suspend   = bfin_wdt_suspend,
	.resume    = bfin_wdt_resume,
	.driver    = {
		.name  = WATCHDOG_NAME,
		.owner = THIS_MODULE,
	},
};

/**
 *	bfin_wdt_init - Initialize module
 *
 *	Checks the module params and registers the platform device & driver.
 *	Real work is in the platform probe function.
 */
static int __init bfin_wdt_init(void)
{
	int ret;

	stampit();

	/* Check that the timeout value is within range */
	if (bfin_wdt_set_timeout(timeout))
		return -EINVAL;

	/* Since this is an on-chip device and needs no board-specific
	 * resources, we'll handle all the platform device stuff here.
	 */
	ret = platform_driver_register(&bfin_wdt_driver);
	if (ret) {
		pr_init(KERN_ERR PFX "unable to register driver\n");
		return ret;
	}

	bfin_wdt_device = platform_device_register_simple(WATCHDOG_NAME, -1, NULL, 0);
	if (IS_ERR(bfin_wdt_device)) {
		pr_init(KERN_ERR PFX "unable to register device\n");
		platform_driver_unregister(&bfin_wdt_driver);
		return PTR_ERR(bfin_wdt_device);
	}

	return 0;
}

/**
 *	bfin_wdt_exit - Deinitialize module
 *
 *	Back out the platform device & driver steps.  Real work is in the
 *	platform remove function.
 */
static void __exit bfin_wdt_exit(void)
{
	platform_device_unregister(bfin_wdt_device);
	platform_driver_unregister(&bfin_wdt_driver);
}

module_init(bfin_wdt_init);
module_exit(bfin_wdt_exit);

MODULE_AUTHOR("Michele d'Amico, Mike Frysinger <vapier@gentoo.org>");
MODULE_DESCRIPTION("Blackfin Watchdog Device Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);

module_param(timeout, uint, 0);
MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. (1<=timeout<=((2^32)/SCLK), default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ")");

module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
Commit	Line	Data
1e6d320f BW	1	/*
	2	* Blackfin On-Chip Watchdog Driver
	3	* Supports BF53[123]/BF53[467]/BF54[2489]/BF561
	4	*
	5	* Originally based on softdog.c
	6	* Copyright 2006-2007 Analog Devices Inc.
	7	* Copyright 2006-2007 Michele d'Amico
	8	* Copyright 1996 Alan Cox <alan@redhat.com>
	9	*
	10	* Enter bugs at http://blackfin.uclinux.org/
	11	*
	12	* Licensed under the GPL-2 or later.
	13	*/
	14
	15	#include <linux/platform_device.h>
	16	#include <linux/module.h>
	17	#include <linux/moduleparam.h>
	18	#include <linux/types.h>
	19	#include <linux/timer.h>
	20	#include <linux/miscdevice.h>
	21	#include <linux/watchdog.h>
	22	#include <linux/fs.h>
	23	#include <linux/notifier.h>
	24	#include <linux/reboot.h>
	25	#include <linux/init.h>
	26	#include <linux/interrupt.h>
	27	#include <asm/blackfin.h>
	28	#include <asm/uaccess.h>
	29
	30	#define stamp(fmt, args...) pr_debug("%s:%i: " fmt "\n", __func__, __LINE__, ## args)
	31	#define stampit() stamp("here i am")
93539b19 MF	32	#define pr_devinit(fmt, args...) ({ static const __devinitconst char __fmt[] = fmt; printk(__fmt, ## args); })
93539b19 MF	33	#define pr_init(fmt, args...) ({ static const __initconst char __fmt[] = fmt; printk(__fmt, ## args); })
1e6d320f BW	34
	35	#define WATCHDOG_NAME "bfin-wdt"
	36	#define PFX WATCHDOG_NAME ": "
	37
	38	/* The BF561 has two watchdogs (one per core), but since Linux
	39	* only runs on core A, we'll just work with that one.
	40	*/
	41	#ifdef BF561_FAMILY
	42	# define bfin_read_WDOG_CTL() bfin_read_WDOGA_CTL()
	43	# define bfin_read_WDOG_CNT() bfin_read_WDOGA_CNT()
	44	# define bfin_read_WDOG_STAT() bfin_read_WDOGA_STAT()
	45	# define bfin_write_WDOG_CTL(x) bfin_write_WDOGA_CTL(x)
	46	# define bfin_write_WDOG_CNT(x) bfin_write_WDOGA_CNT(x)
	47	# define bfin_write_WDOG_STAT(x) bfin_write_WDOGA_STAT(x)
	48	#endif
	49
	50	/* Bit in SWRST that indicates boot caused by watchdog */
	51	#define SWRST_RESET_WDOG 0x4000
	52
	53	/* Bit in WDOG_CTL that indicates watchdog has expired (WDR0) */
	54	#define WDOG_EXPIRED 0x8000
	55
	56	/* Masks for WDEV field in WDOG_CTL register */
	57	#define ICTL_RESET 0x0
	58	#define ICTL_NMI 0x2
	59	#define ICTL_GPI 0x4
	60	#define ICTL_NONE 0x6
	61	#define ICTL_MASK 0x6
	62
	63	/* Masks for WDEN field in WDOG_CTL register */
	64	#define WDEN_MASK 0x0FF0
	65	#define WDEN_ENABLE 0x0000
	66	#define WDEN_DISABLE 0x0AD0
	67
	68	/* some defaults */
	69	#define WATCHDOG_TIMEOUT 20
	70
	71	static unsigned int timeout = WATCHDOG_TIMEOUT;
	72	static int nowayout = WATCHDOG_NOWAYOUT;
	73	static struct watchdog_info bfin_wdt_info;
	74	static unsigned long open_check;
	75	static char expect_close;
bf6350a3	76	static DEFINE_SPINLOCK(bfin_wdt_spinlock);
1e6d320f BW	77
	78	/**
	79	* bfin_wdt_keepalive - Keep the Userspace Watchdog Alive
	80	*
	81	* The Userspace watchdog got a KeepAlive: schedule the next timeout.
	82	*/
	83	static int bfin_wdt_keepalive(void)
	84	{
	85	stampit();
	86	bfin_write_WDOG_STAT(0);
	87	return 0;
	88	}
	89
	90	/**
	91	* bfin_wdt_stop - Stop the Watchdog
	92	*
	93	* Stops the on-chip watchdog.
	94	*/
	95	static int bfin_wdt_stop(void)
	96	{
	97	stampit();
	98	bfin_write_WDOG_CTL(WDEN_DISABLE);
	99	return 0;
	100	}
	101
	102	/**
	103	* bfin_wdt_start - Start the Watchdog
	104	*
	105	* Starts the on-chip watchdog. Automatically loads WDOG_CNT
	106	* into WDOG_STAT for us.
	107	*/
	108	static int bfin_wdt_start(void)
	109	{
	110	stampit();
	111	bfin_write_WDOG_CTL(WDEN_ENABLE \| ICTL_RESET);
	112	return 0;
	113	}
	114
	115	/**
	116	* bfin_wdt_running - Check Watchdog status
	117	*
	118	* See if the watchdog is running.
	119	*/
	120	static int bfin_wdt_running(void)
	121	{
	122	stampit();
	123	return ((bfin_read_WDOG_CTL() & WDEN_MASK) != WDEN_DISABLE);
	124	}
	125
	126	/**
	127	* bfin_wdt_set_timeout - Set the Userspace Watchdog timeout
	128	* @t: new timeout value (in seconds)
	129	*
	130	* Translate the specified timeout in seconds into System Clock
	131	* terms which is what the on-chip Watchdog requires.
	132	*/
	133	static int bfin_wdt_set_timeout(unsigned long t)
	134	{
	135	u32 cnt;
	136	unsigned long flags;
	137
	138	stampit();
	139
	140	cnt = t * get_sclk();
141	if (cnt < get_sclk()) {
142	printk(KERN_WARNING PFX "timeout value is too large\n");
143	return -EINVAL;
144	}
145
146	spin_lock_irqsave(&bfin_wdt_spinlock, flags);
147	{
148	int run = bfin_wdt_running();
149	bfin_wdt_stop();
150	bfin_write_WDOG_CNT(cnt);
151	if (run) bfin_wdt_start();
152	}
153	spin_unlock_irqrestore(&bfin_wdt_spinlock, flags);
154
155	timeout = t;
156
157	return 0;
158	}
159
160	/**
161	* bfin_wdt_open - Open the Device
162	* @inode: inode of device
163	* @file: file handle of device
164	*
165	* Watchdog device is opened and started.
166	*/
167	static int bfin_wdt_open(struct inode inode, struct file file)
168	{
169	stampit();
170
171	if (test_and_set_bit(0, &open_check))
172	return -EBUSY;
173
174	if (nowayout)
175	__module_get(THIS_MODULE);
176
177	bfin_wdt_keepalive();
178	bfin_wdt_start();
179
180	return nonseekable_open(inode, file);
181	}
182
183	/**
184	* bfin_wdt_close - Close the Device
185	* @inode: inode of device
186	* @file: file handle of device
187	*
188	* Watchdog device is closed and stopped.
189	*/
190	static int bfin_wdt_release(struct inode inode, struct file file)
191	{
192	stampit();
193
194	if (expect_close == 42) {
195	bfin_wdt_stop();
196	} else {
197	printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
198	bfin_wdt_keepalive();
199	}
200
201	expect_close = 0;
202	clear_bit(0, &open_check);
203
204	return 0;
205	}
206
207	/**
208	* bfin_wdt_write - Write to Device
209	* @file: file handle of device
210	* @buf: buffer to write
211	* @count: length of buffer
212	* @ppos: offset
213	*
214	* Pings the watchdog on write.
215	*/
216	static ssize_t bfin_wdt_write(struct file file, const char __user data,
217	size_t len, loff_t *ppos)
218	{
219	stampit();
220
221	if (len) {
222	if (!nowayout) {
223	size_t i;
224
225	/* In case it was set long ago */
226	expect_close = 0;
227
228	for (i = 0; i != len; i++) {
229	char c;
230	if (get_user(c, data + i))
231	return -EFAULT;
232	if (c == 'V')
233	expect_close = 42;
234	}
235	}
236	bfin_wdt_keepalive();
237	}
238
239	return len;
240	}
241
242	/**
243	* bfin_wdt_ioctl - Query Device
244	* @inode: inode of device
245	* @file: file handle of device
246	* @cmd: watchdog command
247	* @arg: argument
248	*
249	* Query basic information from the device or ping it, as outlined by the
250	* watchdog API.
251	*/
252	static int bfin_wdt_ioctl(struct inode inode, struct file file,
253	unsigned int cmd, unsigned long arg)
254	{
255	void __user argp = (void __user )arg;
256	int __user *p = argp;
257
258	stampit();
259
260	switch (cmd) {
261	default:
262	return -ENOTTY;
263
264	case WDIOC_GETSUPPORT:
265	if (copy_to_user(argp, &bfin_wdt_info, sizeof(bfin_wdt_info)))
266	return -EFAULT;
267	else
268	return 0;
269
270	case WDIOC_GETSTATUS:
271	case WDIOC_GETBOOTSTATUS:
272	return put_user(!!(_bfin_swrst & SWRST_RESET_WDOG), p);
273
274	case WDIOC_KEEPALIVE:
275	bfin_wdt_keepalive();
276	return 0;
277
278	case WDIOC_SETTIMEOUT: {
279	int new_timeout;
280
281	if (get_user(new_timeout, p))
282	return -EFAULT;
283
284	if (bfin_wdt_set_timeout(new_timeout))
285	return -EINVAL;
286	}
287	/* Fall */
288	case WDIOC_GETTIMEOUT:
289	return put_user(timeout, p);
290
291	case WDIOC_SETOPTIONS: {
292	unsigned long flags;
293	int options, ret = -EINVAL;
294
295	if (get_user(options, p))
296	return -EFAULT;
297
298	spin_lock_irqsave(&bfin_wdt_spinlock, flags);
299
300	if (options & WDIOS_DISABLECARD) {
301	bfin_wdt_stop();
302	ret = 0;
303	}
304
305	if (options & WDIOS_ENABLECARD) {
306	bfin_wdt_start();
307	ret = 0;
308	}
309
310	spin_unlock_irqrestore(&bfin_wdt_spinlock, flags);
311
312	return ret;
313	}
314	}
315	}
316
317	/**
318	* bfin_wdt_notify_sys - Notifier Handler
319	* @this: notifier block
320	* @code: notifier event
321	* @unused: unused
322	*
323	* Handles specific events, such as turning off the watchdog during a
324	* shutdown event.
325	*/
326	static int bfin_wdt_notify_sys(struct notifier_block *this, unsigned long code,
327	void *unused)
328	{
329	stampit();
330
331	if (code == SYS_DOWN \|\| code == SYS_HALT)
332	bfin_wdt_stop();
333
334	return NOTIFY_DONE;
335	}
336
337	#ifdef CONFIG_PM
338	static int state_before_suspend;
339
340	/**
341	* bfin_wdt_suspend - suspend the watchdog
342	* @pdev: device being suspended
343	* @state: requested suspend state
344	*
345	* Remember if the watchdog was running and stop it.
346	* TODO: is this even right? Doesn't seem to be any
347	* standard in the watchdog world ...
348	*/
349	static int bfin_wdt_suspend(struct platform_device *pdev, pm_message_t state)
350	{
351	stampit();
352
353	state_before_suspend = bfin_wdt_running();
354	bfin_wdt_stop();
355
356	return 0;
357	}
358
359	/**
360	* bfin_wdt_resume - resume the watchdog
361	* @pdev: device being resumed
362	*
363	* If the watchdog was running, turn it back on.
364	*/
365	static int bfin_wdt_resume(struct platform_device *pdev)
366	{
367	stampit();
368
369	if (state_before_suspend) {
370	bfin_wdt_set_timeout(timeout);
371	bfin_wdt_start();
372	}
373
374	return 0;
375	}
376	#else
377	# define bfin_wdt_suspend NULL
378	# define bfin_wdt_resume NULL
379	#endif
380
b47a166e	381	static const struct file_operations bfin_wdt_fops = {
1e6d320f BW	382	.owner = THIS_MODULE,
	383	.llseek = no_llseek,
	384	.write = bfin_wdt_write,
	385	.ioctl = bfin_wdt_ioctl,
	386	.open = bfin_wdt_open,
	387	.release = bfin_wdt_release,
	388	};
	389
	390	static struct miscdevice bfin_wdt_miscdev = {
	391	.minor = WATCHDOG_MINOR,
	392	.name = "watchdog",
	393	.fops = &bfin_wdt_fops,
	394	};
	395
	396	static struct watchdog_info bfin_wdt_info = {
	397	.identity = "Blackfin Watchdog",
	398	.options = WDIOF_SETTIMEOUT \|
	399	WDIOF_KEEPALIVEPING \|
	400	WDIOF_MAGICCLOSE,
	401	};
	402
	403	static struct notifier_block bfin_wdt_notifier = {
	404	.notifier_call = bfin_wdt_notify_sys,
	405	};
	406
	407	/**
93539b19	408	* bfin_wdt_probe - Initialize module
1e6d320f	409	*
93539b19	410	* Registers the misc device and notifier handler. Actual device
1e6d320f BW	411	* initialization is handled by bfin_wdt_open().
1e6d320f BW	412	*/
93539b19 MF	413	static int __devinit bfin_wdt_probe(struct platform_device *pdev)
	414	{
	415	int ret;
	416
	417	ret = register_reboot_notifier(&bfin_wdt_notifier);
	418	if (ret) {
	419	pr_devinit(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n", ret);
	420	return ret;
	421	}
	422
	423	ret = misc_register(&bfin_wdt_miscdev);
	424	if (ret) {
	425	pr_devinit(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
	426	WATCHDOG_MINOR, ret);
	427	unregister_reboot_notifier(&bfin_wdt_notifier);
	428	return ret;
	429	}
	430
	431	pr_devinit(KERN_INFO PFX "initialized: timeout=%d sec (nowayout=%d)\n",
	432	timeout, nowayout);
	433
	434	return 0;
	435	}
	436
	437	/**
	438	* bfin_wdt_remove - Initialize module
	439	*
	440	* Unregisters the misc device and notifier handler. Actual device
	441	* deinitialization is handled by bfin_wdt_close().
	442	*/
	443	static int __devexit bfin_wdt_remove(struct platform_device *pdev)
	444	{
	445	misc_deregister(&bfin_wdt_miscdev);
	446	unregister_reboot_notifier(&bfin_wdt_notifier);
	447	return 0;
	448	}
	449
	450	static struct platform_device *bfin_wdt_device;
	451
	452	static struct platform_driver bfin_wdt_driver = {
	453	.probe = bfin_wdt_probe,
	454	.remove = __devexit_p(bfin_wdt_remove),
	455	.suspend = bfin_wdt_suspend,
	456	.resume = bfin_wdt_resume,
	457	.driver = {
	458	.name = WATCHDOG_NAME,
	459	.owner = THIS_MODULE,
	460	},
	461	};
	462
	463	/**
	464	* bfin_wdt_init - Initialize module
	465	*
	466	* Checks the module params and registers the platform device & driver.
	467	* Real work is in the platform probe function.
	468	*/
1e6d320f BW	469	static int __init bfin_wdt_init(void)
	470	{
	471	int ret;
	472
	473	stampit();
	474
	475	/* Check that the timeout value is within range */
	476	if (bfin_wdt_set_timeout(timeout))
	477	return -EINVAL;
	478
	479	/* Since this is an on-chip device and needs no board-specific
	480	* resources, we'll handle all the platform device stuff here.
	481	*/
93539b19	482	ret = platform_driver_register(&bfin_wdt_driver);
1e6d320f	483	if (ret) {
93539b19	484	pr_init(KERN_ERR PFX "unable to register driver\n");
1e6d320f BW	485	return ret;
	486	}
	487
93539b19 MF	488	bfin_wdt_device = platform_device_register_simple(WATCHDOG_NAME, -1, NULL, 0);
	489	if (IS_ERR(bfin_wdt_device)) {
	490	pr_init(KERN_ERR PFX "unable to register device\n");
	491	platform_driver_unregister(&bfin_wdt_driver);
	492	return PTR_ERR(bfin_wdt_device);
1e6d320f BW	493	}
1e6d320f BW	494
1e6d320f BW	495	return 0;
	496	}
	497
	498	/**
	499	* bfin_wdt_exit - Deinitialize module
	500	*
93539b19 MF	501	* Back out the platform device & driver steps. Real work is in the
93539b19 MF	502	* platform remove function.
1e6d320f BW	503	*/
	504	static void __exit bfin_wdt_exit(void)
	505	{
93539b19 MF	506	platform_device_unregister(bfin_wdt_device);
93539b19 MF	507	platform_driver_unregister(&bfin_wdt_driver);
1e6d320f BW	508	}
	509
	510	module_init(bfin_wdt_init);
	511	module_exit(bfin_wdt_exit);
	512
	513	MODULE_AUTHOR("Michele d'Amico, Mike Frysinger <vapier@gentoo.org>");
	514	MODULE_DESCRIPTION("Blackfin Watchdog Device Driver");
	515	MODULE_LICENSE("GPL");
	516	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
	517
	518	module_param(timeout, uint, 0);
	519	MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. (1<=timeout<=((2^32)/SCLK), default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ")");
	520
	521	module_param(nowayout, int, 0);
	522	MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");