[deliverable/linux.git] / drivers / char / 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 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 spinlock_t bfin_wdt_spinlock = SPIN_LOCK_UNLOCKED;

/**
 *	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 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) {
		printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n", ret);
		return ret;
	}

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

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