[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_init(fmt, args...) ({ static const __initdata 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 struct platform_device bfin_wdt_device = {
	.name          = WATCHDOG_NAME,
	.id            = -1,
};

static struct platform_driver bfin_wdt_driver = {
	.driver    = {
		.name  = WATCHDOG_NAME,
		.owner = THIS_MODULE,
	},
	.suspend   = bfin_wdt_suspend,
	.resume    = bfin_wdt_resume,
};

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_init - Initialize module
 *
 *	Registers the device and notifier handler. Actual device
 *	initialization is handled by bfin_wdt_open().
 */
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_device_register(&bfin_wdt_device);
	if (ret)
		return ret;

	ret = platform_driver_probe(&bfin_wdt_driver, NULL);
	if (ret)
		return ret;

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

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

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

	return 0;
}

/**
 *	bfin_wdt_exit - Deinitialize module
 *
 *	Unregisters the device and notifier handler. Actual device
 *	deinitialization is handled by bfin_wdt_close().
 */
static void __exit bfin_wdt_exit(void)
{
	misc_deregister(&bfin_wdt_miscdev);
	unregister_reboot_notifier(&bfin_wdt_notifier);
}

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")
bb59b557	32	#define pr_init(fmt, args...) ({ static const __initdata char __fmt[] = fmt; printk(__fmt, ## args); })
1e6d320f BW	33
	34	#define WATCHDOG_NAME "bfin-wdt"
	35	#define PFX WATCHDOG_NAME ": "
	36
	37	/* The BF561 has two watchdogs (one per core), but since Linux
	38	* only runs on core A, we'll just work with that one.
	39	*/
	40	#ifdef BF561_FAMILY
	41	# define bfin_read_WDOG_CTL() bfin_read_WDOGA_CTL()
	42	# define bfin_read_WDOG_CNT() bfin_read_WDOGA_CNT()
	43	# define bfin_read_WDOG_STAT() bfin_read_WDOGA_STAT()
	44	# define bfin_write_WDOG_CTL(x) bfin_write_WDOGA_CTL(x)
	45	# define bfin_write_WDOG_CNT(x) bfin_write_WDOGA_CNT(x)
	46	# define bfin_write_WDOG_STAT(x) bfin_write_WDOGA_STAT(x)
	47	#endif
	48
	49	/* Bit in SWRST that indicates boot caused by watchdog */
	50	#define SWRST_RESET_WDOG 0x4000
	51
	52	/* Bit in WDOG_CTL that indicates watchdog has expired (WDR0) */
	53	#define WDOG_EXPIRED 0x8000
	54
	55	/* Masks for WDEV field in WDOG_CTL register */
	56	#define ICTL_RESET 0x0
	57	#define ICTL_NMI 0x2
	58	#define ICTL_GPI 0x4
	59	#define ICTL_NONE 0x6
	60	#define ICTL_MASK 0x6
	61
	62	/* Masks for WDEN field in WDOG_CTL register */
	63	#define WDEN_MASK 0x0FF0
	64	#define WDEN_ENABLE 0x0000
	65	#define WDEN_DISABLE 0x0AD0
	66
	67	/* some defaults */
	68	#define WATCHDOG_TIMEOUT 20
	69
	70	static unsigned int timeout = WATCHDOG_TIMEOUT;
	71	static int nowayout = WATCHDOG_NOWAYOUT;
	72	static struct watchdog_info bfin_wdt_info;
	73	static unsigned long open_check;
	74	static char expect_close;
bf6350a3	75	static DEFINE_SPINLOCK(bfin_wdt_spinlock);
1e6d320f BW	76
	77	/**
	78	* bfin_wdt_keepalive - Keep the Userspace Watchdog Alive
	79	*
	80	* The Userspace watchdog got a KeepAlive: schedule the next timeout.
	81	*/
	82	static int bfin_wdt_keepalive(void)
	83	{
	84	stampit();
	85	bfin_write_WDOG_STAT(0);
	86	return 0;
	87	}
	88
	89	/**
	90	* bfin_wdt_stop - Stop the Watchdog
	91	*
	92	* Stops the on-chip watchdog.
	93	*/
	94	static int bfin_wdt_stop(void)
	95	{
	96	stampit();
	97	bfin_write_WDOG_CTL(WDEN_DISABLE);
	98	return 0;
	99	}
	100
	101	/**
	102	* bfin_wdt_start - Start the Watchdog
	103	*
	104	* Starts the on-chip watchdog. Automatically loads WDOG_CNT
	105	* into WDOG_STAT for us.
	106	*/
	107	static int bfin_wdt_start(void)
	108	{
	109	stampit();
	110	bfin_write_WDOG_CTL(WDEN_ENABLE \| ICTL_RESET);
	111	return 0;
	112	}
	113
	114	/**
	115	* bfin_wdt_running - Check Watchdog status
	116	*
	117	* See if the watchdog is running.
	118	*/
	119	static int bfin_wdt_running(void)
	120	{
	121	stampit();
	122	return ((bfin_read_WDOG_CTL() & WDEN_MASK) != WDEN_DISABLE);
	123	}
	124
	125	/**
	126	* bfin_wdt_set_timeout - Set the Userspace Watchdog timeout
	127	* @t: new timeout value (in seconds)
	128	*
	129	* Translate the specified timeout in seconds into System Clock
	130	* terms which is what the on-chip Watchdog requires.
	131	*/
	132	static int bfin_wdt_set_timeout(unsigned long t)
	133	{
	134	u32 cnt;
	135	unsigned long flags;
	136
	137	stampit();
	138
	139	cnt = t * get_sclk();
140	if (cnt < get_sclk()) {
141	printk(KERN_WARNING PFX "timeout value is too large\n");
142	return -EINVAL;
143	}
144
145	spin_lock_irqsave(&bfin_wdt_spinlock, flags);
146	{
147	int run = bfin_wdt_running();
148	bfin_wdt_stop();
149	bfin_write_WDOG_CNT(cnt);
150	if (run) bfin_wdt_start();
151	}
152	spin_unlock_irqrestore(&bfin_wdt_spinlock, flags);
153
154	timeout = t;
155
156	return 0;
157	}
158
159	/**
160	* bfin_wdt_open - Open the Device
161	* @inode: inode of device
162	* @file: file handle of device
163	*
164	* Watchdog device is opened and started.
165	*/
166	static int bfin_wdt_open(struct inode inode, struct file file)
167	{
168	stampit();
169
170	if (test_and_set_bit(0, &open_check))
171	return -EBUSY;
172
173	if (nowayout)
174	__module_get(THIS_MODULE);
175
176	bfin_wdt_keepalive();
177	bfin_wdt_start();
178
179	return nonseekable_open(inode, file);
180	}
181
182	/**
183	* bfin_wdt_close - Close the Device
184	* @inode: inode of device
185	* @file: file handle of device
186	*
187	* Watchdog device is closed and stopped.
188	*/
189	static int bfin_wdt_release(struct inode inode, struct file file)
190	{
191	stampit();
192
193	if (expect_close == 42) {
194	bfin_wdt_stop();
195	} else {
196	printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
197	bfin_wdt_keepalive();
198	}
199
200	expect_close = 0;
201	clear_bit(0, &open_check);
202
203	return 0;
204	}
205
206	/**
207	* bfin_wdt_write - Write to Device
208	* @file: file handle of device
209	* @buf: buffer to write
210	* @count: length of buffer
211	* @ppos: offset
212	*
213	* Pings the watchdog on write.
214	*/
215	static ssize_t bfin_wdt_write(struct file file, const char __user data,
216	size_t len, loff_t *ppos)
217	{
218	stampit();
219
220	if (len) {
221	if (!nowayout) {
222	size_t i;
223
224	/* In case it was set long ago */
225	expect_close = 0;
226
227	for (i = 0; i != len; i++) {
228	char c;
229	if (get_user(c, data + i))
230	return -EFAULT;
231	if (c == 'V')
232	expect_close = 42;
233	}
234	}
235	bfin_wdt_keepalive();
236	}
237
238	return len;
239	}
240
241	/**
242	* bfin_wdt_ioctl - Query Device
243	* @inode: inode of device
244	* @file: file handle of device
245	* @cmd: watchdog command
246	* @arg: argument
247	*
248	* Query basic information from the device or ping it, as outlined by the
249	* watchdog API.
250	*/
251	static int bfin_wdt_ioctl(struct inode inode, struct file file,
252	unsigned int cmd, unsigned long arg)
253	{
254	void __user argp = (void __user )arg;
255	int __user *p = argp;
256
257	stampit();
258
259	switch (cmd) {
260	default:
261	return -ENOTTY;
262
263	case WDIOC_GETSUPPORT:
264	if (copy_to_user(argp, &bfin_wdt_info, sizeof(bfin_wdt_info)))
265	return -EFAULT;
266	else
267	return 0;
268
269	case WDIOC_GETSTATUS:
270	case WDIOC_GETBOOTSTATUS:
271	return put_user(!!(_bfin_swrst & SWRST_RESET_WDOG), p);
272
273	case WDIOC_KEEPALIVE:
274	bfin_wdt_keepalive();
275	return 0;
276
277	case WDIOC_SETTIMEOUT: {
278	int new_timeout;
279
280	if (get_user(new_timeout, p))
281	return -EFAULT;
282
283	if (bfin_wdt_set_timeout(new_timeout))
284	return -EINVAL;
285	}
286	/* Fall */
287	case WDIOC_GETTIMEOUT:
288	return put_user(timeout, p);
289
290	case WDIOC_SETOPTIONS: {
291	unsigned long flags;
292	int options, ret = -EINVAL;
293
294	if (get_user(options, p))
295	return -EFAULT;
296
297	spin_lock_irqsave(&bfin_wdt_spinlock, flags);
298
299	if (options & WDIOS_DISABLECARD) {
300	bfin_wdt_stop();
301	ret = 0;
302	}
303
304	if (options & WDIOS_ENABLECARD) {
305	bfin_wdt_start();
306	ret = 0;
307	}
308
309	spin_unlock_irqrestore(&bfin_wdt_spinlock, flags);
310
311	return ret;
312	}
313	}
314	}
315
316	/**
317	* bfin_wdt_notify_sys - Notifier Handler
318	* @this: notifier block
319	* @code: notifier event
320	* @unused: unused
321	*
322	* Handles specific events, such as turning off the watchdog during a
323	* shutdown event.
324	*/
325	static int bfin_wdt_notify_sys(struct notifier_block *this, unsigned long code,
326	void *unused)
327	{
328	stampit();
329
330	if (code == SYS_DOWN \|\| code == SYS_HALT)
331	bfin_wdt_stop();
332
333	return NOTIFY_DONE;
334	}
335
336	#ifdef CONFIG_PM
337	static int state_before_suspend;
338
339	/**
340	* bfin_wdt_suspend - suspend the watchdog
341	* @pdev: device being suspended
342	* @state: requested suspend state
343	*
344	* Remember if the watchdog was running and stop it.
345	* TODO: is this even right? Doesn't seem to be any
346	* standard in the watchdog world ...
347	*/
348	static int bfin_wdt_suspend(struct platform_device *pdev, pm_message_t state)
349	{
350	stampit();
351
352	state_before_suspend = bfin_wdt_running();
353	bfin_wdt_stop();
354
355	return 0;
356	}
357
358	/**
359	* bfin_wdt_resume - resume the watchdog
360	* @pdev: device being resumed
361	*
362	* If the watchdog was running, turn it back on.
363	*/
364	static int bfin_wdt_resume(struct platform_device *pdev)
365	{
366	stampit();
367
368	if (state_before_suspend) {
369	bfin_wdt_set_timeout(timeout);
370	bfin_wdt_start();
371	}
372
373	return 0;
374	}
375	#else
376	# define bfin_wdt_suspend NULL
377	# define bfin_wdt_resume NULL
378	#endif
379
380	static struct platform_device bfin_wdt_device = {
381	.name = WATCHDOG_NAME,
382	.id = -1,
383	};
384
385	static struct platform_driver bfin_wdt_driver = {
386	.driver = {
387	.name = WATCHDOG_NAME,
388	.owner = THIS_MODULE,
389	},
390	.suspend = bfin_wdt_suspend,
391	.resume = bfin_wdt_resume,
392	};
393
b47a166e	394	static const struct file_operations bfin_wdt_fops = {
1e6d320f BW	395	.owner = THIS_MODULE,
	396	.llseek = no_llseek,
	397	.write = bfin_wdt_write,
	398	.ioctl = bfin_wdt_ioctl,
	399	.open = bfin_wdt_open,
	400	.release = bfin_wdt_release,
	401	};
	402
	403	static struct miscdevice bfin_wdt_miscdev = {
	404	.minor = WATCHDOG_MINOR,
	405	.name = "watchdog",
	406	.fops = &bfin_wdt_fops,
	407	};
	408
	409	static struct watchdog_info bfin_wdt_info = {
	410	.identity = "Blackfin Watchdog",
	411	.options = WDIOF_SETTIMEOUT \|
	412	WDIOF_KEEPALIVEPING \|
	413	WDIOF_MAGICCLOSE,
	414	};
	415
	416	static struct notifier_block bfin_wdt_notifier = {
	417	.notifier_call = bfin_wdt_notify_sys,
	418	};
	419
	420	/**
	421	* bfin_wdt_init - Initialize module
	422	*
	423	* Registers the device and notifier handler. Actual device
	424	* initialization is handled by bfin_wdt_open().
	425	*/
	426	static int __init bfin_wdt_init(void)
	427	{
	428	int ret;
	429
	430	stampit();
	431
	432	/* Check that the timeout value is within range */
	433	if (bfin_wdt_set_timeout(timeout))
	434	return -EINVAL;
	435
	436	/* Since this is an on-chip device and needs no board-specific
	437	* resources, we'll handle all the platform device stuff here.
	438	*/
	439	ret = platform_device_register(&bfin_wdt_device);
	440	if (ret)
	441	return ret;
	442
	443	ret = platform_driver_probe(&bfin_wdt_driver, NULL);
	444	if (ret)
	445	return ret;
	446
	447	ret = register_reboot_notifier(&bfin_wdt_notifier);
	448	if (ret) {
bb59b557	449	pr_init(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n", ret);
1e6d320f BW	450	return ret;
	451	}
	452
	453	ret = misc_register(&bfin_wdt_miscdev);
	454	if (ret) {
bb59b557	455	pr_init(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
1e6d320f BW	456	WATCHDOG_MINOR, ret);
	457	unregister_reboot_notifier(&bfin_wdt_notifier);
	458	return ret;
	459	}
	460
bb59b557	461	pr_init(KERN_INFO PFX "initialized: timeout=%d sec (nowayout=%d)\n",
1e6d320f BW	462	timeout, nowayout);
	463
	464	return 0;
	465	}
	466
	467	/**
	468	* bfin_wdt_exit - Deinitialize module
	469	*
	470	* Unregisters the device and notifier handler. Actual device
	471	* deinitialization is handled by bfin_wdt_close().
	472	*/
	473	static void __exit bfin_wdt_exit(void)
	474	{
	475	misc_deregister(&bfin_wdt_miscdev);
	476	unregister_reboot_notifier(&bfin_wdt_notifier);
	477	}
	478
	479	module_init(bfin_wdt_init);
	480	module_exit(bfin_wdt_exit);
	481
	482	MODULE_AUTHOR("Michele d'Amico, Mike Frysinger <vapier@gentoo.org>");
	483	MODULE_DESCRIPTION("Blackfin Watchdog Device Driver");
	484	MODULE_LICENSE("GPL");
	485	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
	486
	487	module_param(timeout, uint, 0);
	488	MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. (1<=timeout<=((2^32)/SCLK), default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ")");
	489
	490	module_param(nowayout, int, 0);
	491	MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");