[net-next-2.6.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.
 */

#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>

#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 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) {
		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
 *	@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 __devinit bfin_wdt_probe(struct platform_device *pdev)
{
	int 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);
		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.  Actual device
 *	deinitialization is handled by bfin_wdt_close().
 */
static int __devexit 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    = __devexit_p(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_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	/*
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
	14	#include <linux/platform_device.h>
	15	#include <linux/module.h>
	16	#include <linux/moduleparam.h>
	17	#include <linux/types.h>
	18	#include <linux/timer.h>
	19	#include <linux/miscdevice.h>
	20	#include <linux/watchdog.h>
	21	#include <linux/fs.h>
1e6d320f BW	22	#include <linux/init.h>
1e6d320f BW	23	#include <linux/interrupt.h>
9a5f50d3	24	#include <linux/uaccess.h>
089ab079	25	#include <asm/blackfin.h>
1e6d320f	26
a77dba7e WVS	27	#define stamp(fmt, args...) \
a77dba7e WVS	28	pr_debug("%s:%i: " fmt "\n", __func__, __LINE__, ## args)
1e6d320f	29	#define stampit() stamp("here i am")
a77dba7e WVS	30	#define pr_devinit(fmt, args...) \
	31	({ static const __devinitconst char __fmt[] = fmt; \
	32	printk(__fmt, ## args); })
	33	#define pr_init(fmt, args...) \
	34	({ static const __initconst char __fmt[] = fmt; \
	35	printk(__fmt, ## args); })
1e6d320f BW	36
	37	#define WATCHDOG_NAME "bfin-wdt"
	38	#define PFX WATCHDOG_NAME ": "
	39
	40	/* The BF561 has two watchdogs (one per core), but since Linux
	41	* only runs on core A, we'll just work with that one.
	42	*/
	43	#ifdef BF561_FAMILY
	44	# define bfin_read_WDOG_CTL() bfin_read_WDOGA_CTL()
	45	# define bfin_read_WDOG_CNT() bfin_read_WDOGA_CNT()
	46	# define bfin_read_WDOG_STAT() bfin_read_WDOGA_STAT()
	47	# define bfin_write_WDOG_CTL(x) bfin_write_WDOGA_CTL(x)
	48	# define bfin_write_WDOG_CNT(x) bfin_write_WDOGA_CNT(x)
	49	# define bfin_write_WDOG_STAT(x) bfin_write_WDOGA_STAT(x)
	50	#endif
	51
	52	/* Bit in SWRST that indicates boot caused by watchdog */
	53	#define SWRST_RESET_WDOG 0x4000
	54
	55	/* Bit in WDOG_CTL that indicates watchdog has expired (WDR0) */
	56	#define WDOG_EXPIRED 0x8000
	57
	58	/* Masks for WDEV field in WDOG_CTL register */
	59	#define ICTL_RESET 0x0
	60	#define ICTL_NMI 0x2
	61	#define ICTL_GPI 0x4
	62	#define ICTL_NONE 0x6
	63	#define ICTL_MASK 0x6
	64
	65	/* Masks for WDEN field in WDOG_CTL register */
	66	#define WDEN_MASK 0x0FF0
	67	#define WDEN_ENABLE 0x0000
	68	#define WDEN_DISABLE 0x0AD0
	69
	70	/* some defaults */
	71	#define WATCHDOG_TIMEOUT 20
	72
	73	static unsigned int timeout = WATCHDOG_TIMEOUT;
	74	static int nowayout = WATCHDOG_NOWAYOUT;
42747d71	75	static const struct watchdog_info bfin_wdt_info;
1e6d320f BW	76	static unsigned long open_check;
1e6d320f BW	77	static char expect_close;
bf6350a3	78	static DEFINE_SPINLOCK(bfin_wdt_spinlock);
1e6d320f BW	79
	80	/**
	81	* bfin_wdt_keepalive - Keep the Userspace Watchdog Alive
	82	*
	83	* The Userspace watchdog got a KeepAlive: schedule the next timeout.
	84	*/
	85	static int bfin_wdt_keepalive(void)
	86	{
	87	stampit();
	88	bfin_write_WDOG_STAT(0);
	89	return 0;
	90	}
	91
	92	/**
	93	* bfin_wdt_stop - Stop the Watchdog
	94	*
	95	* Stops the on-chip watchdog.
	96	*/
	97	static int bfin_wdt_stop(void)
	98	{
	99	stampit();
	100	bfin_write_WDOG_CTL(WDEN_DISABLE);
	101	return 0;
	102	}
	103
	104	/**
	105	* bfin_wdt_start - Start the Watchdog
	106	*
	107	* Starts the on-chip watchdog. Automatically loads WDOG_CNT
	108	* into WDOG_STAT for us.
	109	*/
	110	static int bfin_wdt_start(void)
	111	{
	112	stampit();
	113	bfin_write_WDOG_CTL(WDEN_ENABLE \| ICTL_RESET);
	114	return 0;
	115	}
	116
	117	/**
	118	* bfin_wdt_running - Check Watchdog status
	119	*
	120	* See if the watchdog is running.
	121	*/
	122	static int bfin_wdt_running(void)
	123	{
	124	stampit();
	125	return ((bfin_read_WDOG_CTL() & WDEN_MASK) != WDEN_DISABLE);
	126	}
	127
	128	/**
	129	* bfin_wdt_set_timeout - Set the Userspace Watchdog timeout
	130	* @t: new timeout value (in seconds)
	131	*
	132	* Translate the specified timeout in seconds into System Clock
	133	* terms which is what the on-chip Watchdog requires.
	134	*/
	135	static int bfin_wdt_set_timeout(unsigned long t)
	136	{
3dae93ec	137	u32 cnt, max_t, sclk;
1e6d320f BW	138	unsigned long flags;
1e6d320f BW	139
3dae93ec MF	140	sclk = get_sclk();
	141	max_t = -1 / sclk;
	142	cnt = t * sclk;
	143	stamp("maxtimeout=%us newtimeout=%lus (cnt=%#x)", max_t, t, cnt);
1e6d320f	144
3dae93ec	145	if (t > max_t) {
1e6d320f BW	146	printk(KERN_WARNING PFX "timeout value is too large\n");
	147	return -EINVAL;
	148	}
	149
	150	spin_lock_irqsave(&bfin_wdt_spinlock, flags);
	151	{
	152	int run = bfin_wdt_running();
	153	bfin_wdt_stop();
	154	bfin_write_WDOG_CNT(cnt);
9a5f50d3 AC	155	if (run)
9a5f50d3 AC	156	bfin_wdt_start();
1e6d320f BW	157	}
	158	spin_unlock_irqrestore(&bfin_wdt_spinlock, flags);
	159
	160	timeout = t;
	161
	162	return 0;
	163	}
	164
	165	/**
	166	* bfin_wdt_open - Open the Device
	167	* @inode: inode of device
	168	* @file: file handle of device
	169	*
	170	* Watchdog device is opened and started.
	171	*/
	172	static int bfin_wdt_open(struct inode inode, struct file file)
	173	{
	174	stampit();
	175
	176	if (test_and_set_bit(0, &open_check))
	177	return -EBUSY;
	178
	179	if (nowayout)
	180	__module_get(THIS_MODULE);
	181
	182	bfin_wdt_keepalive();
	183	bfin_wdt_start();
	184
	185	return nonseekable_open(inode, file);
	186	}
	187
	188	/**
	189	* bfin_wdt_close - Close the Device
	190	* @inode: inode of device
	191	* @file: file handle of device
	192	*
	193	* Watchdog device is closed and stopped.
	194	*/
	195	static int bfin_wdt_release(struct inode inode, struct file file)
	196	{
	197	stampit();
	198
9a5f50d3	199	if (expect_close == 42)
1e6d320f	200	bfin_wdt_stop();
9a5f50d3 AC	201	else {
	202	printk(KERN_CRIT PFX
	203	"Unexpected close, not stopping watchdog!\n");
1e6d320f BW	204	bfin_wdt_keepalive();
1e6d320f BW	205	}
1e6d320f BW	206	expect_close = 0;
1e6d320f BW	207	clear_bit(0, &open_check);
1e6d320f BW	208	return 0;
	209	}
	210
	211	/**
	212	* bfin_wdt_write - Write to Device
	213	* @file: file handle of device
	214	* @buf: buffer to write
	215	* @count: length of buffer
	216	* @ppos: offset
	217	*
	218	* Pings the watchdog on write.
	219	*/
	220	static ssize_t bfin_wdt_write(struct file file, const char __user data,
9a5f50d3	221	size_t len, loff_t *ppos)
1e6d320f BW	222	{
	223	stampit();
	224
	225	if (len) {
	226	if (!nowayout) {
	227	size_t i;
	228
	229	/* In case it was set long ago */
	230	expect_close = 0;
	231
	232	for (i = 0; i != len; i++) {
	233	char c;
	234	if (get_user(c, data + i))
	235	return -EFAULT;
	236	if (c == 'V')
	237	expect_close = 42;
	238	}
	239	}
	240	bfin_wdt_keepalive();
	241	}
	242
	243	return len;
	244	}
	245
	246	/**
	247	* bfin_wdt_ioctl - Query Device
1e6d320f BW	248	* @file: file handle of device
	249	* @cmd: watchdog command
	250	* @arg: argument
	251	*
	252	* Query basic information from the device or ping it, as outlined by the
	253	* watchdog API.
	254	*/
9a5f50d3 AC	255	static long bfin_wdt_ioctl(struct file *file,
9a5f50d3 AC	256	unsigned int cmd, unsigned long arg)
1e6d320f BW	257	{
	258	void __user argp = (void __user )arg;
	259	int __user *p = argp;
	260
	261	stampit();
	262
	263	switch (cmd) {
9a5f50d3 AC	264	case WDIOC_GETSUPPORT:
	265	if (copy_to_user(argp, &bfin_wdt_info, sizeof(bfin_wdt_info)))
	266	return -EFAULT;
	267	else
1e6d320f	268	return 0;
9a5f50d3 AC	269	case WDIOC_GETSTATUS:
	270	case WDIOC_GETBOOTSTATUS:
	271	return put_user(!!(_bfin_swrst & SWRST_RESET_WDOG), p);
9a5f50d3 AC	272	case WDIOC_SETOPTIONS: {
	273	unsigned long flags;
	274	int options, ret = -EINVAL;
	275
	276	if (get_user(options, p))
	277	return -EFAULT;
	278
	279	spin_lock_irqsave(&bfin_wdt_spinlock, flags);
	280	if (options & WDIOS_DISABLECARD) {
	281	bfin_wdt_stop();
	282	ret = 0;
1e6d320f	283	}
9a5f50d3 AC	284	if (options & WDIOS_ENABLECARD) {
	285	bfin_wdt_start();
	286	ret = 0;
1e6d320f	287	}
9a5f50d3 AC	288	spin_unlock_irqrestore(&bfin_wdt_spinlock, flags);
	289	return ret;
	290	}
0c06090c WVS	291	case WDIOC_KEEPALIVE:
	292	bfin_wdt_keepalive();
	293	return 0;
	294	case WDIOC_SETTIMEOUT: {
	295	int new_timeout;
	296
	297	if (get_user(new_timeout, p))
	298	return -EFAULT;
	299	if (bfin_wdt_set_timeout(new_timeout))
	300	return -EINVAL;
	301	}
	302	/* Fall */
	303	case WDIOC_GETTIMEOUT:
	304	return put_user(timeout, p);
9a5f50d3 AC	305	default:
9a5f50d3 AC	306	return -ENOTTY;
1e6d320f BW	307	}
	308	}
	309
1e6d320f BW	310	#ifdef CONFIG_PM
	311	static int state_before_suspend;
	312
	313	/**
	314	* bfin_wdt_suspend - suspend the watchdog
	315	* @pdev: device being suspended
	316	* @state: requested suspend state
	317	*
	318	* Remember if the watchdog was running and stop it.
	319	* TODO: is this even right? Doesn't seem to be any
	320	* standard in the watchdog world ...
	321	*/
	322	static int bfin_wdt_suspend(struct platform_device *pdev, pm_message_t state)
	323	{
	324	stampit();
	325
	326	state_before_suspend = bfin_wdt_running();
	327	bfin_wdt_stop();
	328
	329	return 0;
	330	}
	331
	332	/**
	333	* bfin_wdt_resume - resume the watchdog
	334	* @pdev: device being resumed
	335	*
	336	* If the watchdog was running, turn it back on.
	337	*/
	338	static int bfin_wdt_resume(struct platform_device *pdev)
	339	{
	340	stampit();
	341
	342	if (state_before_suspend) {
	343	bfin_wdt_set_timeout(timeout);
	344	bfin_wdt_start();
	345	}
	346
	347	return 0;
	348	}
	349	#else
	350	# define bfin_wdt_suspend NULL
	351	# define bfin_wdt_resume NULL
	352	#endif
	353
b47a166e	354	static const struct file_operations bfin_wdt_fops = {
9a5f50d3 AC	355	.owner = THIS_MODULE,
	356	.llseek = no_llseek,
	357	.write = bfin_wdt_write,
	358	.unlocked_ioctl = bfin_wdt_ioctl,
	359	.open = bfin_wdt_open,
	360	.release = bfin_wdt_release,
1e6d320f BW	361	};
	362
	363	static struct miscdevice bfin_wdt_miscdev = {
	364	.minor = WATCHDOG_MINOR,
	365	.name = "watchdog",
	366	.fops = &bfin_wdt_fops,
	367	};
	368
42747d71	369	static const struct watchdog_info bfin_wdt_info = {
1e6d320f BW	370	.identity = "Blackfin Watchdog",
1e6d320f BW	371	.options = WDIOF_SETTIMEOUT \|
9a5f50d3 AC	372	WDIOF_KEEPALIVEPING \|
9a5f50d3 AC	373	WDIOF_MAGICCLOSE,
1e6d320f BW	374	};
1e6d320f BW	375
1e6d320f	376	/**
93539b19	377	* bfin_wdt_probe - Initialize module
1e6d320f	378	*
168b5251	379	* Registers the misc device. Actual device
1e6d320f BW	380	* initialization is handled by bfin_wdt_open().
1e6d320f BW	381	*/
93539b19 MF	382	static int __devinit bfin_wdt_probe(struct platform_device *pdev)
	383	{
	384	int ret;
	385
93539b19 MF	386	ret = misc_register(&bfin_wdt_miscdev);
93539b19 MF	387	if (ret) {
9a5f50d3 AC	388	pr_devinit(KERN_ERR PFX
	389	"cannot register miscdev on minor=%d (err=%d)\n",
	390	WATCHDOG_MINOR, ret);
93539b19 MF	391	return ret;
	392	}
	393
	394	pr_devinit(KERN_INFO PFX "initialized: timeout=%d sec (nowayout=%d)\n",
	395	timeout, nowayout);
	396
	397	return 0;
	398	}
	399
	400	/**
	401	* bfin_wdt_remove - Initialize module
	402	*
168b5251	403	* Unregisters the misc device. Actual device
93539b19 MF	404	* deinitialization is handled by bfin_wdt_close().
	405	*/
	406	static int __devexit bfin_wdt_remove(struct platform_device *pdev)
	407	{
	408	misc_deregister(&bfin_wdt_miscdev);
93539b19 MF	409	return 0;
	410	}
	411
168b5251 WVS	412	/**
	413	* bfin_wdt_shutdown - Soft Shutdown Handler
	414	*
	415	* Handles the soft shutdown event.
	416	*/
	417	static void bfin_wdt_shutdown(struct platform_device *pdev)
	418	{
	419	stampit();
	420
	421	bfin_wdt_stop();
	422	}
	423
93539b19 MF	424	static struct platform_device *bfin_wdt_device;
	425
	426	static struct platform_driver bfin_wdt_driver = {
	427	.probe = bfin_wdt_probe,
	428	.remove = __devexit_p(bfin_wdt_remove),
168b5251	429	.shutdown = bfin_wdt_shutdown,
93539b19 MF	430	.suspend = bfin_wdt_suspend,
	431	.resume = bfin_wdt_resume,
	432	.driver = {
	433	.name = WATCHDOG_NAME,
	434	.owner = THIS_MODULE,
	435	},
	436	};
	437
	438	/**
	439	* bfin_wdt_init - Initialize module
	440	*
	441	* Checks the module params and registers the platform device & driver.
	442	* Real work is in the platform probe function.
	443	*/
1e6d320f BW	444	static int __init bfin_wdt_init(void)
	445	{
	446	int ret;
	447
	448	stampit();
	449
	450	/* Check that the timeout value is within range */
	451	if (bfin_wdt_set_timeout(timeout))
	452	return -EINVAL;
	453
	454	/* Since this is an on-chip device and needs no board-specific
	455	* resources, we'll handle all the platform device stuff here.
	456	*/
93539b19	457	ret = platform_driver_register(&bfin_wdt_driver);
1e6d320f	458	if (ret) {
93539b19	459	pr_init(KERN_ERR PFX "unable to register driver\n");
1e6d320f BW	460	return ret;
	461	}
	462
a77dba7e WVS	463	bfin_wdt_device = platform_device_register_simple(WATCHDOG_NAME,
a77dba7e WVS	464	-1, NULL, 0);
93539b19 MF	465	if (IS_ERR(bfin_wdt_device)) {
	466	pr_init(KERN_ERR PFX "unable to register device\n");
	467	platform_driver_unregister(&bfin_wdt_driver);
	468	return PTR_ERR(bfin_wdt_device);
1e6d320f BW	469	}
1e6d320f BW	470
1e6d320f BW	471	return 0;
	472	}
	473
	474	/**
	475	* bfin_wdt_exit - Deinitialize module
	476	*
93539b19 MF	477	* Back out the platform device & driver steps. Real work is in the
93539b19 MF	478	* platform remove function.
1e6d320f BW	479	*/
	480	static void __exit bfin_wdt_exit(void)
	481	{
93539b19 MF	482	platform_device_unregister(bfin_wdt_device);
93539b19 MF	483	platform_driver_unregister(&bfin_wdt_driver);
1e6d320f BW	484	}
	485
	486	module_init(bfin_wdt_init);
	487	module_exit(bfin_wdt_exit);
	488
	489	MODULE_AUTHOR("Michele d'Amico, Mike Frysinger <vapier@gentoo.org>");
	490	MODULE_DESCRIPTION("Blackfin Watchdog Device Driver");
	491	MODULE_LICENSE("GPL");
	492	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
	493
	494	module_param(timeout, uint, 0);
9a5f50d3 AC	495	MODULE_PARM_DESC(timeout,
	496	"Watchdog timeout in seconds. (1<=timeout<=((2^32)/SCLK), default="
	497	__MODULE_STRING(WATCHDOG_TIMEOUT) ")");
1e6d320f BW	498
1e6d320f BW	499	module_param(nowayout, int, 0);
9a5f50d3 AC	500	MODULE_PARM_DESC(nowayout,
	501	"Watchdog cannot be stopped once started (default="
	502	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");