[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / watchdog / bfin_wdt.c

/*
 * Blackfin On-Chip Watchdog Driver
 *
 * Originally based on softdog.c
 * Copyright 2006-2010 Analog Devices Inc.
 * Copyright 2006-2007 Michele d'Amico
 * Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>
 *
 * Enter bugs at http://blackfin.uclinux.org/
 *
 * Licensed under the GPL-2 or later.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#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/init.h>
#include <linux/interrupt.h>
#include <linux/uaccess.h>
#include <asm/blackfin.h>
#include <asm/bfin_watchdog.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"

/* 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

/* some defaults */
#define WATCHDOG_TIMEOUT 20

static unsigned int timeout = WATCHDOG_TIMEOUT;
static bool nowayout = WATCHDOG_NOWAYOUT;
static const 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, max_t, sclk;
	unsigned long flags;

	sclk = get_sclk();
	max_t = -1 / sclk;
	cnt = t * sclk;
	stamp("maxtimeout=%us newtimeout=%lus (cnt=%#x)", max_t, t, cnt);

	if (t > max_t) {
		pr_warn("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 {
		pr_crit("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
 *	@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 long bfin_wdt_ioctl(struct file *file,
				unsigned int cmd, unsigned long arg)
{
	void __user *argp = (void __user *)arg;
	int __user *p = argp;

	stampit();

	switch (cmd) {
	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_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;
	}
	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);
	default:
		return -ENOTTY;
	}
}

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

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

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

	pr_info("initialized: timeout=%d sec (nowayout=%d)\n",
		timeout, nowayout);

	return 0;
}

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

/**
 *	bfin_wdt_shutdown - Soft Shutdown Handler
 *
 *	Handles the soft shutdown event.
 */
static void bfin_wdt_shutdown(struct platform_device *pdev)
{
	stampit();

	bfin_wdt_stop();
}

static struct platform_device *bfin_wdt_device;

static struct platform_driver bfin_wdt_driver = {
	.probe     = bfin_wdt_probe,
	.remove    = bfin_wdt_remove,
	.shutdown  = bfin_wdt_shutdown,
	.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_err("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_err("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, bool, 0);
MODULE_PARM_DESC(nowayout,
	"Watchdog cannot be stopped once started (default="
		__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
Commit	Line	Data
1e6d320f BW	1	/*
1e6d320f BW	2	* Blackfin On-Chip Watchdog Driver
1e6d320f BW	3	*
1e6d320f BW	4	* Originally based on softdog.c
3dae93ec	5	* Copyright 2006-2010 Analog Devices Inc.
1e6d320f	6	* Copyright 2006-2007 Michele d'Amico
29fa0586	7	* Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>
1e6d320f BW	8	*
	9	* Enter bugs at http://blackfin.uclinux.org/
	10	*
	11	* Licensed under the GPL-2 or later.
	12	*/
	13
27c766aa JP	14	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
27c766aa JP	15
1e6d320f BW	16	#include <linux/platform_device.h>
	17	#include <linux/module.h>
	18	#include <linux/moduleparam.h>
	19	#include <linux/types.h>
	20	#include <linux/timer.h>
	21	#include <linux/miscdevice.h>
	22	#include <linux/watchdog.h>
	23	#include <linux/fs.h>
1e6d320f BW	24	#include <linux/init.h>
1e6d320f BW	25	#include <linux/interrupt.h>
9a5f50d3	26	#include <linux/uaccess.h>
089ab079	27	#include <asm/blackfin.h>
42bd5d49	28	#include <asm/bfin_watchdog.h>
1e6d320f	29
a77dba7e WVS	30	#define stamp(fmt, args...) \
a77dba7e WVS	31	pr_debug("%s:%i: " fmt "\n", __func__, __LINE__, ## args)
1e6d320f BW	32	#define stampit() stamp("here i am")
	33
	34	#define WATCHDOG_NAME "bfin-wdt"
1e6d320f BW	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
1e6d320f BW	48	/* some defaults */
	49	#define WATCHDOG_TIMEOUT 20
	50
	51	static unsigned int timeout = WATCHDOG_TIMEOUT;
86a1e189	52	static bool nowayout = WATCHDOG_NOWAYOUT;
42747d71	53	static const struct watchdog_info bfin_wdt_info;
1e6d320f BW	54	static unsigned long open_check;
1e6d320f BW	55	static char expect_close;
bf6350a3	56	static DEFINE_SPINLOCK(bfin_wdt_spinlock);
1e6d320f BW	57
	58	/**
	59	* bfin_wdt_keepalive - Keep the Userspace Watchdog Alive
	60	*
5f3b2756	61	* The Userspace watchdog got a KeepAlive: schedule the next timeout.
1e6d320f BW	62	*/
	63	static int bfin_wdt_keepalive(void)
	64	{
	65	stampit();
	66	bfin_write_WDOG_STAT(0);
	67	return 0;
	68	}
	69
	70	/**
	71	* bfin_wdt_stop - Stop the Watchdog
	72	*
	73	* Stops the on-chip watchdog.
	74	*/
	75	static int bfin_wdt_stop(void)
	76	{
	77	stampit();
	78	bfin_write_WDOG_CTL(WDEN_DISABLE);
	79	return 0;
	80	}
	81
	82	/**
	83	* bfin_wdt_start - Start the Watchdog
	84	*
	85	* Starts the on-chip watchdog. Automatically loads WDOG_CNT
	86	* into WDOG_STAT for us.
	87	*/
	88	static int bfin_wdt_start(void)
	89	{
	90	stampit();
	91	bfin_write_WDOG_CTL(WDEN_ENABLE \| ICTL_RESET);
	92	return 0;
	93	}
	94
	95	/**
	96	* bfin_wdt_running - Check Watchdog status
	97	*
	98	* See if the watchdog is running.
	99	*/
	100	static int bfin_wdt_running(void)
	101	{
	102	stampit();
	103	return ((bfin_read_WDOG_CTL() & WDEN_MASK) != WDEN_DISABLE);
	104	}
	105
	106	/**
	107	* bfin_wdt_set_timeout - Set the Userspace Watchdog timeout
	108	* @t: new timeout value (in seconds)
	109	*
	110	* Translate the specified timeout in seconds into System Clock
	111	* terms which is what the on-chip Watchdog requires.
	112	*/
	113	static int bfin_wdt_set_timeout(unsigned long t)
	114	{
3dae93ec	115	u32 cnt, max_t, sclk;
1e6d320f BW	116	unsigned long flags;
1e6d320f BW	117
3dae93ec MF	118	sclk = get_sclk();
	119	max_t = -1 / sclk;
	120	cnt = t * sclk;
	121	stamp("maxtimeout=%us newtimeout=%lus (cnt=%#x)", max_t, t, cnt);
1e6d320f	122
3dae93ec	123	if (t > max_t) {
27c766aa	124	pr_warn("timeout value is too large\n");
1e6d320f BW	125	return -EINVAL;
	126	}
	127
	128	spin_lock_irqsave(&bfin_wdt_spinlock, flags);
	129	{
	130	int run = bfin_wdt_running();
	131	bfin_wdt_stop();
	132	bfin_write_WDOG_CNT(cnt);
9a5f50d3 AC	133	if (run)
9a5f50d3 AC	134	bfin_wdt_start();
1e6d320f BW	135	}
	136	spin_unlock_irqrestore(&bfin_wdt_spinlock, flags);
	137
	138	timeout = t;
	139
	140	return 0;
	141	}
	142
	143	/**
	144	* bfin_wdt_open - Open the Device
	145	* @inode: inode of device
	146	* @file: file handle of device
	147	*
	148	* Watchdog device is opened and started.
	149	*/
	150	static int bfin_wdt_open(struct inode inode, struct file file)
	151	{
	152	stampit();
	153
	154	if (test_and_set_bit(0, &open_check))
	155	return -EBUSY;
	156
	157	if (nowayout)
	158	__module_get(THIS_MODULE);
	159
	160	bfin_wdt_keepalive();
	161	bfin_wdt_start();
	162
	163	return nonseekable_open(inode, file);
	164	}
	165
	166	/**
	167	* bfin_wdt_close - Close the Device
	168	* @inode: inode of device
	169	* @file: file handle of device
	170	*
	171	* Watchdog device is closed and stopped.
	172	*/
	173	static int bfin_wdt_release(struct inode inode, struct file file)
	174	{
	175	stampit();
	176
9a5f50d3	177	if (expect_close == 42)
1e6d320f	178	bfin_wdt_stop();
9a5f50d3	179	else {
27c766aa	180	pr_crit("Unexpected close, not stopping watchdog!\n");
1e6d320f BW	181	bfin_wdt_keepalive();
1e6d320f BW	182	}
1e6d320f BW	183	expect_close = 0;
1e6d320f BW	184	clear_bit(0, &open_check);
1e6d320f BW	185	return 0;
	186	}
	187
	188	/**
	189	* bfin_wdt_write - Write to Device
	190	* @file: file handle of device
	191	* @buf: buffer to write
	192	* @count: length of buffer
	193	* @ppos: offset
	194	*
	195	* Pings the watchdog on write.
	196	*/
	197	static ssize_t bfin_wdt_write(struct file file, const char __user data,
9a5f50d3	198	size_t len, loff_t *ppos)
1e6d320f BW	199	{
	200	stampit();
	201
	202	if (len) {
	203	if (!nowayout) {
	204	size_t i;
	205
	206	/* In case it was set long ago */
	207	expect_close = 0;
	208
	209	for (i = 0; i != len; i++) {
	210	char c;
	211	if (get_user(c, data + i))
	212	return -EFAULT;
	213	if (c == 'V')
	214	expect_close = 42;
	215	}
	216	}
	217	bfin_wdt_keepalive();
	218	}
	219
	220	return len;
	221	}
	222
	223	/**
	224	* bfin_wdt_ioctl - Query Device
1e6d320f BW	225	* @file: file handle of device
	226	* @cmd: watchdog command
	227	* @arg: argument
	228	*
	229	* Query basic information from the device or ping it, as outlined by the
	230	* watchdog API.
	231	*/
9a5f50d3 AC	232	static long bfin_wdt_ioctl(struct file *file,
9a5f50d3 AC	233	unsigned int cmd, unsigned long arg)
1e6d320f BW	234	{
	235	void __user argp = (void __user )arg;
	236	int __user *p = argp;
	237
	238	stampit();
	239
	240	switch (cmd) {
9a5f50d3 AC	241	case WDIOC_GETSUPPORT:
	242	if (copy_to_user(argp, &bfin_wdt_info, sizeof(bfin_wdt_info)))
	243	return -EFAULT;
	244	else
1e6d320f	245	return 0;
9a5f50d3 AC	246	case WDIOC_GETSTATUS:
	247	case WDIOC_GETBOOTSTATUS:
	248	return put_user(!!(_bfin_swrst & SWRST_RESET_WDOG), p);
9a5f50d3 AC	249	case WDIOC_SETOPTIONS: {
	250	unsigned long flags;
	251	int options, ret = -EINVAL;
	252
	253	if (get_user(options, p))
	254	return -EFAULT;
	255
	256	spin_lock_irqsave(&bfin_wdt_spinlock, flags);
	257	if (options & WDIOS_DISABLECARD) {
	258	bfin_wdt_stop();
	259	ret = 0;
1e6d320f	260	}
9a5f50d3 AC	261	if (options & WDIOS_ENABLECARD) {
	262	bfin_wdt_start();
	263	ret = 0;
1e6d320f	264	}
9a5f50d3 AC	265	spin_unlock_irqrestore(&bfin_wdt_spinlock, flags);
	266	return ret;
	267	}
0c06090c WVS	268	case WDIOC_KEEPALIVE:
	269	bfin_wdt_keepalive();
	270	return 0;
	271	case WDIOC_SETTIMEOUT: {
	272	int new_timeout;
	273
	274	if (get_user(new_timeout, p))
	275	return -EFAULT;
	276	if (bfin_wdt_set_timeout(new_timeout))
	277	return -EINVAL;
	278	}
	279	/* Fall */
	280	case WDIOC_GETTIMEOUT:
	281	return put_user(timeout, p);
9a5f50d3 AC	282	default:
9a5f50d3 AC	283	return -ENOTTY;
1e6d320f BW	284	}
	285	}
	286
1e6d320f BW	287	#ifdef CONFIG_PM
	288	static int state_before_suspend;
	289
	290	/**
	291	* bfin_wdt_suspend - suspend the watchdog
	292	* @pdev: device being suspended
	293	* @state: requested suspend state
	294	*
	295	* Remember if the watchdog was running and stop it.
	296	* TODO: is this even right? Doesn't seem to be any
	297	* standard in the watchdog world ...
	298	*/
	299	static int bfin_wdt_suspend(struct platform_device *pdev, pm_message_t state)
	300	{
	301	stampit();
	302
	303	state_before_suspend = bfin_wdt_running();
	304	bfin_wdt_stop();
	305
	306	return 0;
	307	}
	308
	309	/**
	310	* bfin_wdt_resume - resume the watchdog
	311	* @pdev: device being resumed
	312	*
	313	* If the watchdog was running, turn it back on.
	314	*/
	315	static int bfin_wdt_resume(struct platform_device *pdev)
	316	{
	317	stampit();
	318
	319	if (state_before_suspend) {
	320	bfin_wdt_set_timeout(timeout);
	321	bfin_wdt_start();
	322	}
	323
	324	return 0;
	325	}
	326	#else
	327	# define bfin_wdt_suspend NULL
	328	# define bfin_wdt_resume NULL
	329	#endif
	330
b47a166e	331	static const struct file_operations bfin_wdt_fops = {
9a5f50d3 AC	332	.owner = THIS_MODULE,
9a5f50d3 AC	333	.llseek = no_llseek,
5f3b2756	334	.write = bfin_wdt_write,
9a5f50d3 AC	335	.unlocked_ioctl = bfin_wdt_ioctl,
	336	.open = bfin_wdt_open,
	337	.release = bfin_wdt_release,
1e6d320f BW	338	};
	339
	340	static struct miscdevice bfin_wdt_miscdev = {
	341	.minor = WATCHDOG_MINOR,
	342	.name = "watchdog",
	343	.fops = &bfin_wdt_fops,
	344	};
	345
42747d71	346	static const struct watchdog_info bfin_wdt_info = {
1e6d320f BW	347	.identity = "Blackfin Watchdog",
1e6d320f BW	348	.options = WDIOF_SETTIMEOUT \|
9a5f50d3 AC	349	WDIOF_KEEPALIVEPING \|
9a5f50d3 AC	350	WDIOF_MAGICCLOSE,
1e6d320f BW	351	};
1e6d320f BW	352
1e6d320f	353	/**
93539b19	354	* bfin_wdt_probe - Initialize module
1e6d320f	355	*
168b5251	356	* Registers the misc device. Actual device
1e6d320f BW	357	* initialization is handled by bfin_wdt_open().
1e6d320f BW	358	*/
2d991a16	359	static int bfin_wdt_probe(struct platform_device *pdev)
93539b19 MF	360	{
	361	int ret;
	362
93539b19 MF	363	ret = misc_register(&bfin_wdt_miscdev);
93539b19 MF	364	if (ret) {
27c766aa JP	365	pr_err("cannot register miscdev on minor=%d (err=%d)\n",
27c766aa JP	366	WATCHDOG_MINOR, ret);
93539b19 MF	367	return ret;
	368	}
	369
27c766aa JP	370	pr_info("initialized: timeout=%d sec (nowayout=%d)\n",
27c766aa JP	371	timeout, nowayout);
93539b19 MF	372
	373	return 0;
	374	}
	375
	376	/**
	377	* bfin_wdt_remove - Initialize module
	378	*
168b5251	379	* Unregisters the misc device. Actual device
93539b19 MF	380	* deinitialization is handled by bfin_wdt_close().
93539b19 MF	381	*/
4b12b896	382	static int bfin_wdt_remove(struct platform_device *pdev)
93539b19 MF	383	{
93539b19 MF	384	misc_deregister(&bfin_wdt_miscdev);
93539b19 MF	385	return 0;
	386	}
	387
168b5251 WVS	388	/**
	389	* bfin_wdt_shutdown - Soft Shutdown Handler
	390	*
	391	* Handles the soft shutdown event.
	392	*/
	393	static void bfin_wdt_shutdown(struct platform_device *pdev)
	394	{
	395	stampit();
	396
	397	bfin_wdt_stop();
	398	}
	399
93539b19 MF	400	static struct platform_device *bfin_wdt_device;
	401
	402	static struct platform_driver bfin_wdt_driver = {
	403	.probe = bfin_wdt_probe,
82268714	404	.remove = bfin_wdt_remove,
168b5251	405	.shutdown = bfin_wdt_shutdown,
93539b19 MF	406	.suspend = bfin_wdt_suspend,
	407	.resume = bfin_wdt_resume,
	408	.driver = {
	409	.name = WATCHDOG_NAME,
	410	.owner = THIS_MODULE,
	411	},
	412	};
	413
	414	/**
	415	* bfin_wdt_init - Initialize module
	416	*
	417	* Checks the module params and registers the platform device & driver.
	418	* Real work is in the platform probe function.
	419	*/
1e6d320f BW	420	static int __init bfin_wdt_init(void)
	421	{
	422	int ret;
	423
	424	stampit();
	425
	426	/* Check that the timeout value is within range */
	427	if (bfin_wdt_set_timeout(timeout))
	428	return -EINVAL;
	429
	430	/* Since this is an on-chip device and needs no board-specific
	431	* resources, we'll handle all the platform device stuff here.
	432	*/
93539b19	433	ret = platform_driver_register(&bfin_wdt_driver);
1e6d320f	434	if (ret) {
27c766aa	435	pr_err("unable to register driver\n");
1e6d320f BW	436	return ret;
	437	}
	438
a77dba7e WVS	439	bfin_wdt_device = platform_device_register_simple(WATCHDOG_NAME,
a77dba7e WVS	440	-1, NULL, 0);
93539b19	441	if (IS_ERR(bfin_wdt_device)) {
27c766aa	442	pr_err("unable to register device\n");
93539b19 MF	443	platform_driver_unregister(&bfin_wdt_driver);
93539b19 MF	444	return PTR_ERR(bfin_wdt_device);
1e6d320f BW	445	}
1e6d320f BW	446
1e6d320f BW	447	return 0;
	448	}
	449
	450	/**
	451	* bfin_wdt_exit - Deinitialize module
	452	*
93539b19 MF	453	* Back out the platform device & driver steps. Real work is in the
93539b19 MF	454	* platform remove function.
1e6d320f BW	455	*/
	456	static void __exit bfin_wdt_exit(void)
	457	{
93539b19 MF	458	platform_device_unregister(bfin_wdt_device);
93539b19 MF	459	platform_driver_unregister(&bfin_wdt_driver);
1e6d320f BW	460	}
	461
	462	module_init(bfin_wdt_init);
	463	module_exit(bfin_wdt_exit);
	464
	465	MODULE_AUTHOR("Michele d'Amico, Mike Frysinger <vapier@gentoo.org>");
	466	MODULE_DESCRIPTION("Blackfin Watchdog Device Driver");
	467	MODULE_LICENSE("GPL");
	468	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
	469
	470	module_param(timeout, uint, 0);
9a5f50d3 AC	471	MODULE_PARM_DESC(timeout,
	472	"Watchdog timeout in seconds. (1<=timeout<=((2^32)/SCLK), default="
	473	__MODULE_STRING(WATCHDOG_TIMEOUT) ")");
1e6d320f	474
86a1e189	475	module_param(nowayout, bool, 0);
9a5f50d3 AC	476	MODULE_PARM_DESC(nowayout,
	477	"Watchdog cannot be stopped once started (default="
	478	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");