[net-next-2.6.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 <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 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
 *	@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;
	}
}

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

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

	return NOTIFY_DONE;
}

#ifdef CONFIG_PM
static int state_before_suspend;

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

	state_before_suspend = bfin_wdt_running();
	bfin_wdt_stop();

	return 0;
}

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

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

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

static const struct file_operations bfin_wdt_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.write    	= bfin_wdt_write,
	.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 struct watchdog_info bfin_wdt_info = {
	.identity = "Blackfin Watchdog",
	.options  = WDIOF_SETTIMEOUT |
		    WDIOF_KEEPALIVEPING |
		    WDIOF_MAGICCLOSE,
};

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

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

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

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

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

	return 0;
}

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

static struct platform_device *bfin_wdt_device;

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

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

	stampit();

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

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

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

	return 0;
}

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

module_init(bfin_wdt_init);
module_exit(bfin_wdt_exit);

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

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

module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout,
	"Watchdog cannot be stopped once started (default="
		__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
Commit	Line	Data
1e6d320f BW	1	/*
	2	* Blackfin On-Chip Watchdog Driver
	3	* Supports BF53[123]/BF53[467]/BF54[2489]/BF561
	4	*
	5	* Originally based on softdog.c
	6	* Copyright 2006-2007 Analog Devices Inc.
	7	* Copyright 2006-2007 Michele d'Amico
	8	* Copyright 1996 Alan Cox <alan@redhat.com>
	9	*
	10	* Enter bugs at http://blackfin.uclinux.org/
	11	*
	12	* Licensed under the GPL-2 or later.
	13	*/
	14
	15	#include <linux/platform_device.h>
	16	#include <linux/module.h>
	17	#include <linux/moduleparam.h>
	18	#include <linux/types.h>
	19	#include <linux/timer.h>
	20	#include <linux/miscdevice.h>
	21	#include <linux/watchdog.h>
	22	#include <linux/fs.h>
	23	#include <linux/notifier.h>
	24	#include <linux/reboot.h>
	25	#include <linux/init.h>
	26	#include <linux/interrupt.h>
9a5f50d3	27	#include <linux/uaccess.h>
089ab079	28	#include <asm/blackfin.h>
1e6d320f BW	29
	30	#define stamp(fmt, args...) pr_debug("%s:%i: " fmt "\n", __func__, __LINE__, ## args)
	31	#define stampit() stamp("here i am")
93539b19 MF	32	#define pr_devinit(fmt, args...) ({ static const __devinitconst char __fmt[] = fmt; printk(__fmt, ## args); })
93539b19 MF	33	#define pr_init(fmt, args...) ({ static const __initconst char __fmt[] = fmt; printk(__fmt, ## args); })
1e6d320f BW	34
	35	#define WATCHDOG_NAME "bfin-wdt"
	36	#define PFX WATCHDOG_NAME ": "
	37
	38	/* The BF561 has two watchdogs (one per core), but since Linux
	39	* only runs on core A, we'll just work with that one.
	40	*/
	41	#ifdef BF561_FAMILY
	42	# define bfin_read_WDOG_CTL() bfin_read_WDOGA_CTL()
	43	# define bfin_read_WDOG_CNT() bfin_read_WDOGA_CNT()
	44	# define bfin_read_WDOG_STAT() bfin_read_WDOGA_STAT()
	45	# define bfin_write_WDOG_CTL(x) bfin_write_WDOGA_CTL(x)
	46	# define bfin_write_WDOG_CNT(x) bfin_write_WDOGA_CNT(x)
	47	# define bfin_write_WDOG_STAT(x) bfin_write_WDOGA_STAT(x)
	48	#endif
	49
	50	/* Bit in SWRST that indicates boot caused by watchdog */
	51	#define SWRST_RESET_WDOG 0x4000
	52
	53	/* Bit in WDOG_CTL that indicates watchdog has expired (WDR0) */
	54	#define WDOG_EXPIRED 0x8000
	55
	56	/* Masks for WDEV field in WDOG_CTL register */
	57	#define ICTL_RESET 0x0
	58	#define ICTL_NMI 0x2
	59	#define ICTL_GPI 0x4
	60	#define ICTL_NONE 0x6
	61	#define ICTL_MASK 0x6
	62
	63	/* Masks for WDEN field in WDOG_CTL register */
	64	#define WDEN_MASK 0x0FF0
	65	#define WDEN_ENABLE 0x0000
	66	#define WDEN_DISABLE 0x0AD0
	67
	68	/* some defaults */
	69	#define WATCHDOG_TIMEOUT 20
	70
	71	static unsigned int timeout = WATCHDOG_TIMEOUT;
	72	static int nowayout = WATCHDOG_NOWAYOUT;
	73	static struct watchdog_info bfin_wdt_info;
	74	static unsigned long open_check;
	75	static char expect_close;
bf6350a3	76	static DEFINE_SPINLOCK(bfin_wdt_spinlock);
1e6d320f BW	77
	78	/**
	79	* bfin_wdt_keepalive - Keep the Userspace Watchdog Alive
	80	*
	81	* The Userspace watchdog got a KeepAlive: schedule the next timeout.
	82	*/
	83	static int bfin_wdt_keepalive(void)
	84	{
	85	stampit();
	86	bfin_write_WDOG_STAT(0);
	87	return 0;
	88	}
	89
	90	/**
	91	* bfin_wdt_stop - Stop the Watchdog
	92	*
	93	* Stops the on-chip watchdog.
	94	*/
	95	static int bfin_wdt_stop(void)
	96	{
	97	stampit();
	98	bfin_write_WDOG_CTL(WDEN_DISABLE);
	99	return 0;
	100	}
	101
	102	/**
	103	* bfin_wdt_start - Start the Watchdog
	104	*
	105	* Starts the on-chip watchdog. Automatically loads WDOG_CNT
	106	* into WDOG_STAT for us.
	107	*/
	108	static int bfin_wdt_start(void)
	109	{
	110	stampit();
	111	bfin_write_WDOG_CTL(WDEN_ENABLE \| ICTL_RESET);
	112	return 0;
	113	}
	114
	115	/**
	116	* bfin_wdt_running - Check Watchdog status
	117	*
	118	* See if the watchdog is running.
	119	*/
	120	static int bfin_wdt_running(void)
	121	{
	122	stampit();
	123	return ((bfin_read_WDOG_CTL() & WDEN_MASK) != WDEN_DISABLE);
	124	}
	125
	126	/**
	127	* bfin_wdt_set_timeout - Set the Userspace Watchdog timeout
	128	* @t: new timeout value (in seconds)
	129	*
	130	* Translate the specified timeout in seconds into System Clock
	131	* terms which is what the on-chip Watchdog requires.
	132	*/
	133	static int bfin_wdt_set_timeout(unsigned long t)
	134	{
	135	u32 cnt;
	136	unsigned long flags;
	137
	138	stampit();
	139
	140	cnt = t * get_sclk();
141	if (cnt < get_sclk()) {
142	printk(KERN_WARNING PFX "timeout value is too large\n");
143	return -EINVAL;
144	}
145
146	spin_lock_irqsave(&bfin_wdt_spinlock, flags);
147	{
148	int run = bfin_wdt_running();
149	bfin_wdt_stop();
150	bfin_write_WDOG_CNT(cnt);
9a5f50d3 AC	151	if (run)
9a5f50d3 AC	152	bfin_wdt_start();
1e6d320f BW	153	}
	154	spin_unlock_irqrestore(&bfin_wdt_spinlock, flags);
	155
	156	timeout = t;
	157
	158	return 0;
	159	}
	160
	161	/**
	162	* bfin_wdt_open - Open the Device
	163	* @inode: inode of device
	164	* @file: file handle of device
	165	*
	166	* Watchdog device is opened and started.
	167	*/
	168	static int bfin_wdt_open(struct inode inode, struct file file)
	169	{
	170	stampit();
	171
	172	if (test_and_set_bit(0, &open_check))
	173	return -EBUSY;
	174
	175	if (nowayout)
	176	__module_get(THIS_MODULE);
	177
	178	bfin_wdt_keepalive();
	179	bfin_wdt_start();
	180
	181	return nonseekable_open(inode, file);
	182	}
	183
	184	/**
	185	* bfin_wdt_close - Close the Device
	186	* @inode: inode of device
	187	* @file: file handle of device
	188	*
	189	* Watchdog device is closed and stopped.
	190	*/
	191	static int bfin_wdt_release(struct inode inode, struct file file)
	192	{
	193	stampit();
	194
9a5f50d3	195	if (expect_close == 42)
1e6d320f	196	bfin_wdt_stop();
9a5f50d3 AC	197	else {
	198	printk(KERN_CRIT PFX
	199	"Unexpected close, not stopping watchdog!\n");
1e6d320f BW	200	bfin_wdt_keepalive();
1e6d320f BW	201	}
1e6d320f BW	202	expect_close = 0;
1e6d320f BW	203	clear_bit(0, &open_check);
1e6d320f BW	204	return 0;
	205	}
	206
	207	/**
	208	* bfin_wdt_write - Write to Device
	209	* @file: file handle of device
	210	* @buf: buffer to write
	211	* @count: length of buffer
	212	* @ppos: offset
	213	*
	214	* Pings the watchdog on write.
	215	*/
	216	static ssize_t bfin_wdt_write(struct file file, const char __user data,
9a5f50d3	217	size_t len, loff_t *ppos)
1e6d320f BW	218	{
	219	stampit();
	220
	221	if (len) {
	222	if (!nowayout) {
	223	size_t i;
	224
	225	/* In case it was set long ago */
	226	expect_close = 0;
	227
	228	for (i = 0; i != len; i++) {
	229	char c;
	230	if (get_user(c, data + i))
	231	return -EFAULT;
	232	if (c == 'V')
	233	expect_close = 42;
	234	}
	235	}
	236	bfin_wdt_keepalive();
	237	}
	238
	239	return len;
	240	}
	241
	242	/**
	243	* bfin_wdt_ioctl - Query Device
1e6d320f BW	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	*/
9a5f50d3 AC	251	static long bfin_wdt_ioctl(struct file *file,
9a5f50d3 AC	252	unsigned int cmd, unsigned long arg)
1e6d320f BW	253	{
	254	void __user argp = (void __user )arg;
	255	int __user *p = argp;
	256
	257	stampit();
	258
	259	switch (cmd) {
9a5f50d3 AC	260	case WDIOC_GETSUPPORT:
	261	if (copy_to_user(argp, &bfin_wdt_info, sizeof(bfin_wdt_info)))
	262	return -EFAULT;
	263	else
1e6d320f	264	return 0;
9a5f50d3 AC	265	case WDIOC_GETSTATUS:
	266	case WDIOC_GETBOOTSTATUS:
	267	return put_user(!!(_bfin_swrst & SWRST_RESET_WDOG), p);
9a5f50d3 AC	268	case WDIOC_SETOPTIONS: {
	269	unsigned long flags;
	270	int options, ret = -EINVAL;
	271
	272	if (get_user(options, p))
	273	return -EFAULT;
	274
	275	spin_lock_irqsave(&bfin_wdt_spinlock, flags);
	276	if (options & WDIOS_DISABLECARD) {
	277	bfin_wdt_stop();
	278	ret = 0;
1e6d320f	279	}
9a5f50d3 AC	280	if (options & WDIOS_ENABLECARD) {
	281	bfin_wdt_start();
	282	ret = 0;
1e6d320f	283	}
9a5f50d3 AC	284	spin_unlock_irqrestore(&bfin_wdt_spinlock, flags);
	285	return ret;
	286	}
0c06090c WVS	287	case WDIOC_KEEPALIVE:
	288	bfin_wdt_keepalive();
	289	return 0;
	290	case WDIOC_SETTIMEOUT: {
	291	int new_timeout;
	292
	293	if (get_user(new_timeout, p))
	294	return -EFAULT;
	295	if (bfin_wdt_set_timeout(new_timeout))
	296	return -EINVAL;
	297	}
	298	/* Fall */
	299	case WDIOC_GETTIMEOUT:
	300	return put_user(timeout, p);
9a5f50d3 AC	301	default:
9a5f50d3 AC	302	return -ENOTTY;
1e6d320f BW	303	}
	304	}
	305
	306	/**
	307	* bfin_wdt_notify_sys - Notifier Handler
	308	* @this: notifier block
	309	* @code: notifier event
	310	* @unused: unused
	311	*
	312	* Handles specific events, such as turning off the watchdog during a
	313	* shutdown event.
	314	*/
9a5f50d3 AC	315	static int bfin_wdt_notify_sys(struct notifier_block *this,
9a5f50d3 AC	316	unsigned long code, void *unused)
1e6d320f BW	317	{
	318	stampit();
	319
	320	if (code == SYS_DOWN \|\| code == SYS_HALT)
	321	bfin_wdt_stop();
	322
	323	return NOTIFY_DONE;
	324	}
	325
	326	#ifdef CONFIG_PM
	327	static int state_before_suspend;
	328
	329	/**
	330	* bfin_wdt_suspend - suspend the watchdog
	331	* @pdev: device being suspended
	332	* @state: requested suspend state
	333	*
	334	* Remember if the watchdog was running and stop it.
	335	* TODO: is this even right? Doesn't seem to be any
	336	* standard in the watchdog world ...
	337	*/
	338	static int bfin_wdt_suspend(struct platform_device *pdev, pm_message_t state)
	339	{
	340	stampit();
	341
	342	state_before_suspend = bfin_wdt_running();
	343	bfin_wdt_stop();
	344
	345	return 0;
	346	}
	347
	348	/**
	349	* bfin_wdt_resume - resume the watchdog
	350	* @pdev: device being resumed
	351	*
	352	* If the watchdog was running, turn it back on.
	353	*/
	354	static int bfin_wdt_resume(struct platform_device *pdev)
	355	{
	356	stampit();
	357
	358	if (state_before_suspend) {
	359	bfin_wdt_set_timeout(timeout);
	360	bfin_wdt_start();
	361	}
	362
	363	return 0;
	364	}
	365	#else
	366	# define bfin_wdt_suspend NULL
	367	# define bfin_wdt_resume NULL
	368	#endif
	369
b47a166e	370	static const struct file_operations bfin_wdt_fops = {
9a5f50d3 AC	371	.owner = THIS_MODULE,
	372	.llseek = no_llseek,
	373	.write = bfin_wdt_write,
	374	.unlocked_ioctl = bfin_wdt_ioctl,
	375	.open = bfin_wdt_open,
	376	.release = bfin_wdt_release,
1e6d320f BW	377	};
	378
	379	static struct miscdevice bfin_wdt_miscdev = {
	380	.minor = WATCHDOG_MINOR,
	381	.name = "watchdog",
	382	.fops = &bfin_wdt_fops,
	383	};
	384
	385	static struct watchdog_info bfin_wdt_info = {
	386	.identity = "Blackfin Watchdog",
	387	.options = WDIOF_SETTIMEOUT \|
9a5f50d3 AC	388	WDIOF_KEEPALIVEPING \|
9a5f50d3 AC	389	WDIOF_MAGICCLOSE,
1e6d320f BW	390	};
	391
	392	static struct notifier_block bfin_wdt_notifier = {
	393	.notifier_call = bfin_wdt_notify_sys,
	394	};
	395
	396	/**
93539b19	397	* bfin_wdt_probe - Initialize module
1e6d320f	398	*
93539b19	399	* Registers the misc device and notifier handler. Actual device
1e6d320f BW	400	* initialization is handled by bfin_wdt_open().
1e6d320f BW	401	*/
93539b19 MF	402	static int __devinit bfin_wdt_probe(struct platform_device *pdev)
	403	{
	404	int ret;
	405
	406	ret = register_reboot_notifier(&bfin_wdt_notifier);
	407	if (ret) {
9a5f50d3 AC	408	pr_devinit(KERN_ERR PFX
9a5f50d3 AC	409	"cannot register reboot notifier (err=%d)\n", ret);
93539b19 MF	410	return ret;
	411	}
	412
	413	ret = misc_register(&bfin_wdt_miscdev);
	414	if (ret) {
9a5f50d3 AC	415	pr_devinit(KERN_ERR PFX
	416	"cannot register miscdev on minor=%d (err=%d)\n",
	417	WATCHDOG_MINOR, ret);
93539b19 MF	418	unregister_reboot_notifier(&bfin_wdt_notifier);
	419	return ret;
	420	}
	421
	422	pr_devinit(KERN_INFO PFX "initialized: timeout=%d sec (nowayout=%d)\n",
	423	timeout, nowayout);
	424
	425	return 0;
	426	}
	427
	428	/**
	429	* bfin_wdt_remove - Initialize module
	430	*
	431	* Unregisters the misc device and notifier handler. Actual device
	432	* deinitialization is handled by bfin_wdt_close().
	433	*/
	434	static int __devexit bfin_wdt_remove(struct platform_device *pdev)
	435	{
	436	misc_deregister(&bfin_wdt_miscdev);
	437	unregister_reboot_notifier(&bfin_wdt_notifier);
	438	return 0;
	439	}
	440
	441	static struct platform_device *bfin_wdt_device;
	442
	443	static struct platform_driver bfin_wdt_driver = {
	444	.probe = bfin_wdt_probe,
	445	.remove = __devexit_p(bfin_wdt_remove),
	446	.suspend = bfin_wdt_suspend,
	447	.resume = bfin_wdt_resume,
	448	.driver = {
	449	.name = WATCHDOG_NAME,
	450	.owner = THIS_MODULE,
	451	},
	452	};
	453
	454	/**
	455	* bfin_wdt_init - Initialize module
	456	*
	457	* Checks the module params and registers the platform device & driver.
	458	* Real work is in the platform probe function.
	459	*/
1e6d320f BW	460	static int __init bfin_wdt_init(void)
	461	{
	462	int ret;
	463
	464	stampit();
	465
	466	/* Check that the timeout value is within range */
	467	if (bfin_wdt_set_timeout(timeout))
	468	return -EINVAL;
	469
	470	/* Since this is an on-chip device and needs no board-specific
	471	* resources, we'll handle all the platform device stuff here.
	472	*/
93539b19	473	ret = platform_driver_register(&bfin_wdt_driver);
1e6d320f	474	if (ret) {
93539b19	475	pr_init(KERN_ERR PFX "unable to register driver\n");
1e6d320f BW	476	return ret;
	477	}
	478
93539b19 MF	479	bfin_wdt_device = platform_device_register_simple(WATCHDOG_NAME, -1, NULL, 0);
	480	if (IS_ERR(bfin_wdt_device)) {
	481	pr_init(KERN_ERR PFX "unable to register device\n");
	482	platform_driver_unregister(&bfin_wdt_driver);
	483	return PTR_ERR(bfin_wdt_device);
1e6d320f BW	484	}
1e6d320f BW	485
1e6d320f BW	486	return 0;
	487	}
	488
	489	/**
	490	* bfin_wdt_exit - Deinitialize module
	491	*
93539b19 MF	492	* Back out the platform device & driver steps. Real work is in the
93539b19 MF	493	* platform remove function.
1e6d320f BW	494	*/
	495	static void __exit bfin_wdt_exit(void)
	496	{
93539b19 MF	497	platform_device_unregister(bfin_wdt_device);
93539b19 MF	498	platform_driver_unregister(&bfin_wdt_driver);
1e6d320f BW	499	}
	500
	501	module_init(bfin_wdt_init);
	502	module_exit(bfin_wdt_exit);
	503
	504	MODULE_AUTHOR("Michele d'Amico, Mike Frysinger <vapier@gentoo.org>");
	505	MODULE_DESCRIPTION("Blackfin Watchdog Device Driver");
	506	MODULE_LICENSE("GPL");
	507	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
	508
	509	module_param(timeout, uint, 0);
9a5f50d3 AC	510	MODULE_PARM_DESC(timeout,
	511	"Watchdog timeout in seconds. (1<=timeout<=((2^32)/SCLK), default="
	512	__MODULE_STRING(WATCHDOG_TIMEOUT) ")");
1e6d320f BW	513
1e6d320f BW	514	module_param(nowayout, int, 0);
9a5f50d3 AC	515	MODULE_PARM_DESC(nowayout,
	516	"Watchdog cannot be stopped once started (default="
	517	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");