[linux-2.6-block.git] / drivers / watchdog / alim1535_wdt.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *	Watchdog for the 7101 PMU version found in the ALi M1535 chipsets
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/ioport.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/pci.h>
#include <linux/uaccess.h>
#include <linux/io.h>

#define WATCHDOG_NAME "ALi_M1535"
#define WATCHDOG_TIMEOUT 60	/* 60 sec default timeout */

/* internal variables */
static unsigned long ali_is_open;
static char ali_expect_release;
static struct pci_dev *ali_pci;
static u32 ali_timeout_bits;		/* stores the computed timeout */
static DEFINE_SPINLOCK(ali_lock);	/* Guards the hardware */

/* module parameters */
static int timeout = WATCHDOG_TIMEOUT;
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout,
		"Watchdog timeout in seconds. (0 < timeout < 18000, default="
				__MODULE_STRING(WATCHDOG_TIMEOUT) ")");

static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout,
		"Watchdog cannot be stopped once started (default="
				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

/*
 *	ali_start	-	start watchdog countdown
 *
 *	Starts the timer running providing the timer has a counter
 *	configuration set.
 */

static void ali_start(void)
{
	u32 val;

	spin_lock(&ali_lock);

	pci_read_config_dword(ali_pci, 0xCC, &val);
	val &= ~0x3F;	/* Mask count */
	val |= (1 << 25) | ali_timeout_bits;
	pci_write_config_dword(ali_pci, 0xCC, val);

	spin_unlock(&ali_lock);
}

/*
 *	ali_stop	-	stop the timer countdown
 *
 *	Stop the ALi watchdog countdown
 */

static void ali_stop(void)
{
	u32 val;

	spin_lock(&ali_lock);

	pci_read_config_dword(ali_pci, 0xCC, &val);
	val &= ~0x3F;		/* Mask count to zero (disabled) */
	val &= ~(1 << 25);	/* and for safety mask the reset enable */
	pci_write_config_dword(ali_pci, 0xCC, val);

	spin_unlock(&ali_lock);
}

/*
 *	ali_keepalive	-	send a keepalive to the watchdog
 *
 *	Send a keepalive to the timer (actually we restart the timer).
 */

static void ali_keepalive(void)
{
	ali_start();
}

/*
 *	ali_settimer	-	compute the timer reload value
 *	@t: time in seconds
 *
 *	Computes the timeout values needed
 */

static int ali_settimer(int t)
{
	if (t < 0)
		return -EINVAL;
	else if (t < 60)
		ali_timeout_bits = t|(1 << 6);
	else if (t < 3600)
		ali_timeout_bits = (t / 60)|(1 << 7);
	else if (t < 18000)
		ali_timeout_bits = (t / 300)|(1 << 6)|(1 << 7);
	else
		return -EINVAL;

	timeout = t;
	return 0;
}

/*
 *	/dev/watchdog handling
 */

/*
 *	ali_write	-	writes to ALi watchdog
 *	@file: file from VFS
 *	@data: user address of data
 *	@len: length of data
 *	@ppos: pointer to the file offset
 *
 *	Handle a write to the ALi watchdog. Writing to the file pings
 *	the watchdog and resets it. Writing the magic 'V' sequence allows
 *	the next close to turn off the watchdog.
 */

static ssize_t ali_write(struct file *file, const char __user *data,
						size_t len, loff_t *ppos)
{
	/* See if we got the magic character 'V' and reload the timer */
	if (len) {
		if (!nowayout) {
			size_t i;

			/* note: just in case someone wrote the
			   magic character five months ago... */
			ali_expect_release = 0;

			/* scan to see whether or not we got
			   the magic character */
			for (i = 0; i != len; i++) {
				char c;
				if (get_user(c, data + i))
					return -EFAULT;
				if (c == 'V')
					ali_expect_release = 42;
			}
		}

		/* someone wrote to us, we should reload the timer */
		ali_start();
	}
	return len;
}

/*
 *	ali_ioctl	-	handle watchdog ioctls
 *	@file: VFS file pointer
 *	@cmd: ioctl number
 *	@arg: arguments to the ioctl
 *
 *	Handle the watchdog ioctls supported by the ALi driver. Really
 *	we want an extension to enable irq ack monitoring and the like
 */

static long ali_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	void __user *argp = (void __user *)arg;
	int __user *p = argp;
	static const struct watchdog_info ident = {
		.options =		WDIOF_KEEPALIVEPING |
					WDIOF_SETTIMEOUT |
					WDIOF_MAGICCLOSE,
		.firmware_version =	0,
		.identity =		"ALi M1535 WatchDog Timer",
	};

	switch (cmd) {
	case WDIOC_GETSUPPORT:
		return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;

	case WDIOC_GETSTATUS:
	case WDIOC_GETBOOTSTATUS:
		return put_user(0, p);
	case WDIOC_SETOPTIONS:
	{
		int new_options, retval = -EINVAL;

		if (get_user(new_options, p))
			return -EFAULT;
		if (new_options & WDIOS_DISABLECARD) {
			ali_stop();
			retval = 0;
		}
		if (new_options & WDIOS_ENABLECARD) {
			ali_start();
			retval = 0;
		}
		return retval;
	}
	case WDIOC_KEEPALIVE:
		ali_keepalive();
		return 0;
	case WDIOC_SETTIMEOUT:
	{
		int new_timeout;
		if (get_user(new_timeout, p))
			return -EFAULT;
		if (ali_settimer(new_timeout))
			return -EINVAL;
		ali_keepalive();
	}
		fallthrough;
	case WDIOC_GETTIMEOUT:
		return put_user(timeout, p);
	default:
		return -ENOTTY;
	}
}

/*
 *	ali_open	-	handle open of ali watchdog
 *	@inode: inode from VFS
 *	@file: file from VFS
 *
 *	Open the ALi watchdog device. Ensure only one person opens it
 *	at a time. Also start the watchdog running.
 */

static int ali_open(struct inode *inode, struct file *file)
{
	/* /dev/watchdog can only be opened once */
	if (test_and_set_bit(0, &ali_is_open))
		return -EBUSY;

	/* Activate */
	ali_start();
	return stream_open(inode, file);
}

/*
 *	ali_release	-	close an ALi watchdog
 *	@inode: inode from VFS
 *	@file: file from VFS
 *
 *	Close the ALi watchdog device. Actual shutdown of the timer
 *	only occurs if the magic sequence has been set.
 */

static int ali_release(struct inode *inode, struct file *file)
{
	/*
	 *      Shut off the timer.
	 */
	if (ali_expect_release == 42)
		ali_stop();
	else {
		pr_crit("Unexpected close, not stopping watchdog!\n");
		ali_keepalive();
	}
	clear_bit(0, &ali_is_open);
	ali_expect_release = 0;
	return 0;
}

/*
 *	ali_notify_sys	-	System down notifier
 *
 *	Notifier for system down
 */


static int ali_notify_sys(struct notifier_block *this,
					unsigned long code, void *unused)
{
	if (code == SYS_DOWN || code == SYS_HALT)
		ali_stop();		/* Turn the WDT off */
	return NOTIFY_DONE;
}

/*
 *	Data for PCI driver interface
 *
 *	This data only exists for exporting the supported
 *	PCI ids via MODULE_DEVICE_TABLE.  We do not actually
 *	register a pci_driver, because someone else might one day
 *	want to register another driver on the same PCI id.
 */

static const struct pci_device_id ali_pci_tbl[] __used = {
	{ PCI_VENDOR_ID_AL, 0x1533, PCI_ANY_ID, PCI_ANY_ID,},
	{ PCI_VENDOR_ID_AL, 0x1535, PCI_ANY_ID, PCI_ANY_ID,},
	{ 0, },
};
MODULE_DEVICE_TABLE(pci, ali_pci_tbl);

/*
 *	ali_find_watchdog	-	find a 1535 and 7101
 *
 *	Scans the PCI hardware for a 1535 series bridge and matching 7101
 *	watchdog device. This may be overtight but it is better to be safe
 */

static int __init ali_find_watchdog(void)
{
	struct pci_dev *pdev;
	u32 wdog;

	/* Check for a 1533/1535 series bridge */
	pdev = pci_get_device(PCI_VENDOR_ID_AL, 0x1535, NULL);
	if (pdev == NULL)
		pdev = pci_get_device(PCI_VENDOR_ID_AL, 0x1533, NULL);
	if (pdev == NULL)
		return -ENODEV;
	pci_dev_put(pdev);

	/* Check for the a 7101 PMU */
	pdev = pci_get_device(PCI_VENDOR_ID_AL, 0x7101, NULL);
	if (pdev == NULL)
		return -ENODEV;

	if (pci_enable_device(pdev)) {
		pci_dev_put(pdev);
		return -EIO;
	}

	ali_pci = pdev;

	/*
	 *	Initialize the timer bits
	 */
	pci_read_config_dword(pdev, 0xCC, &wdog);

	/* Timer bits */
	wdog &= ~0x3F;
	/* Issued events */
	wdog &= ~((1 << 27)|(1 << 26)|(1 << 25)|(1 << 24));
	/* No monitor bits */
	wdog &= ~((1 << 16)|(1 << 13)|(1 << 12)|(1 << 11)|(1 << 10)|(1 << 9));

	pci_write_config_dword(pdev, 0xCC, wdog);

	return 0;
}

/*
 *	Kernel Interfaces
 */

static const struct file_operations ali_fops = {
	.owner		=	THIS_MODULE,
	.llseek		=	no_llseek,
	.write		=	ali_write,
	.unlocked_ioctl =	ali_ioctl,
	.compat_ioctl	= 	compat_ptr_ioctl,
	.open		=	ali_open,
	.release	=	ali_release,
};

static struct miscdevice ali_miscdev = {
	.minor =	WATCHDOG_MINOR,
	.name =		"watchdog",
	.fops =		&ali_fops,
};

static struct notifier_block ali_notifier = {
	.notifier_call =	ali_notify_sys,
};

/*
 *	watchdog_init	-	module initialiser
 *
 *	Scan for a suitable watchdog and if so initialize it. Return an error
 *	if we cannot, the error causes the module to unload
 */

static int __init watchdog_init(void)
{
	int ret;

	/* Check whether or not the hardware watchdog is there */
	if (ali_find_watchdog() != 0)
		return -ENODEV;

	/* Check that the timeout value is within it's range;
	   if not reset to the default */
	if (timeout < 1 || timeout >= 18000) {
		timeout = WATCHDOG_TIMEOUT;
		pr_info("timeout value must be 0 < timeout < 18000, using %d\n",
			timeout);
	}

	/* Calculate the watchdog's timeout */
	ali_settimer(timeout);

	ret = register_reboot_notifier(&ali_notifier);
	if (ret != 0) {
		pr_err("cannot register reboot notifier (err=%d)\n", ret);
		goto out;
	}

	ret = misc_register(&ali_miscdev);
	if (ret != 0) {
		pr_err("cannot register miscdev on minor=%d (err=%d)\n",
		       WATCHDOG_MINOR, ret);
		goto unreg_reboot;
	}

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

out:
	return ret;
unreg_reboot:
	unregister_reboot_notifier(&ali_notifier);
	goto out;
}

/*
 *	watchdog_exit	-	module de-initialiser
 *
 *	Called while unloading a successfully installed watchdog module.
 */

static void __exit watchdog_exit(void)
{
	/* Stop the timer before we leave */
	ali_stop();

	/* Deregister */
	misc_deregister(&ali_miscdev);
	unregister_reboot_notifier(&ali_notifier);
	pci_dev_put(ali_pci);
}

module_init(watchdog_init);
module_exit(watchdog_exit);

MODULE_AUTHOR("Alan Cox");
MODULE_DESCRIPTION("ALi M1535 PMU Watchdog Timer driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
1da177e4 LT	2	/*
1da177e4 LT	3	* Watchdog for the 7101 PMU version found in the ALi M1535 chipsets
1da177e4 LT	4	*/
1da177e4 LT	5
27c766aa JP	6	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
27c766aa JP	7
1da177e4 LT	8	#include <linux/module.h>
	9	#include <linux/moduleparam.h>
	10	#include <linux/types.h>
	11	#include <linux/miscdevice.h>
	12	#include <linux/watchdog.h>
	13	#include <linux/ioport.h>
	14	#include <linux/notifier.h>
	15	#include <linux/reboot.h>
	16	#include <linux/init.h>
	17	#include <linux/fs.h>
	18	#include <linux/pci.h>
173d95bc AC	19	#include <linux/uaccess.h>
173d95bc AC	20	#include <linux/io.h>
1da177e4 LT	21
1da177e4 LT	22	#define WATCHDOG_NAME "ALi_M1535"
1da177e4 LT	23	#define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
	24
	25	/* internal variables */
	26	static unsigned long ali_is_open;
	27	static char ali_expect_release;
	28	static struct pci_dev *ali_pci;
173d95bc	29	static u32 ali_timeout_bits; /* stores the computed timeout */
c7dfd0cc	30	static DEFINE_SPINLOCK(ali_lock); /* Guards the hardware */
1da177e4 LT	31
	32	/* module parameters */
	33	static int timeout = WATCHDOG_TIMEOUT;
	34	module_param(timeout, int, 0);
173d95bc AC	35	MODULE_PARM_DESC(timeout,
	36	"Watchdog timeout in seconds. (0 < timeout < 18000, default="
	37	__MODULE_STRING(WATCHDOG_TIMEOUT) ")");
1da177e4	38
86a1e189 WVS	39	static bool nowayout = WATCHDOG_NOWAYOUT;
86a1e189 WVS	40	module_param(nowayout, bool, 0);
173d95bc AC	41	MODULE_PARM_DESC(nowayout,
	42	"Watchdog cannot be stopped once started (default="
	43	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
1da177e4 LT	44
	45	/*
	46	* ali_start - start watchdog countdown
	47	*
	48	* Starts the timer running providing the timer has a counter
	49	* configuration set.
	50	*/
	51
	52	static void ali_start(void)
	53	{
	54	u32 val;
	55
	56	spin_lock(&ali_lock);
	57
	58	pci_read_config_dword(ali_pci, 0xCC, &val);
	59	val &= ~0x3F; /* Mask count */
143a2e54	60	val \|= (1 << 25) \| ali_timeout_bits;
1da177e4 LT	61	pci_write_config_dword(ali_pci, 0xCC, val);
	62
	63	spin_unlock(&ali_lock);
	64	}
	65
	66	/*
	67	* ali_stop - stop the timer countdown
	68	*
	69	* Stop the ALi watchdog countdown
	70	*/
	71
	72	static void ali_stop(void)
	73	{
	74	u32 val;
	75
	76	spin_lock(&ali_lock);
	77
	78	pci_read_config_dword(ali_pci, 0xCC, &val);
143a2e54 WVS	79	val &= ~0x3F; /* Mask count to zero (disabled) */
143a2e54 WVS	80	val &= ~(1 << 25); /* and for safety mask the reset enable */
1da177e4 LT	81	pci_write_config_dword(ali_pci, 0xCC, val);
	82
	83	spin_unlock(&ali_lock);
	84	}
	85
	86	/*
	87	* ali_keepalive - send a keepalive to the watchdog
	88	*
143a2e54	89	* Send a keepalive to the timer (actually we restart the timer).
1da177e4 LT	90	*/
	91
	92	static void ali_keepalive(void)
	93	{
	94	ali_start();
	95	}
	96
	97	/*
	98	* ali_settimer - compute the timer reload value
	99	* @t: time in seconds
	100	*
	101	* Computes the timeout values needed
	102	*/
	103
	104	static int ali_settimer(int t)
	105	{
173d95bc	106	if (t < 0)
1da177e4	107	return -EINVAL;
173d95bc	108	else if (t < 60)
143a2e54	109	ali_timeout_bits = t\|(1 << 6);
173d95bc	110	else if (t < 3600)
143a2e54	111	ali_timeout_bits = (t / 60)\|(1 << 7);
173d95bc	112	else if (t < 18000)
143a2e54	113	ali_timeout_bits = (t / 300)\|(1 << 6)\|(1 << 7);
173d95bc AC	114	else
173d95bc AC	115	return -EINVAL;
1da177e4 LT	116
	117	timeout = t;
	118	return 0;
	119	}
	120
	121	/*
	122	* /dev/watchdog handling
	123	*/
	124
	125	/*
	126	* ali_write - writes to ALi watchdog
	127	* @file: file from VFS
	128	* @data: user address of data
	129	* @len: length of data
	130	* @ppos: pointer to the file offset
	131	*
	132	* Handle a write to the ALi watchdog. Writing to the file pings
	133	* the watchdog and resets it. Writing the magic 'V' sequence allows
	134	* the next close to turn off the watchdog.
	135	*/
	136
	137	static ssize_t ali_write(struct file file, const char __user data,
143a2e54	138	size_t len, loff_t *ppos)
1da177e4 LT	139	{
	140	/* See if we got the magic character 'V' and reload the timer */
	141	if (len) {
	142	if (!nowayout) {
	143	size_t i;
	144
173d95bc AC	145	/* note: just in case someone wrote the
173d95bc AC	146	magic character five months ago... */
1da177e4 LT	147	ali_expect_release = 0;
1da177e4 LT	148
173d95bc AC	149	/* scan to see whether or not we got
173d95bc AC	150	the magic character */
1da177e4 LT	151	for (i = 0; i != len; i++) {
1da177e4 LT	152	char c;
7944d3a5	153	if (get_user(c, data + i))
1da177e4 LT	154	return -EFAULT;
	155	if (c == 'V')
	156	ali_expect_release = 42;
	157	}
	158	}
	159
	160	/* someone wrote to us, we should reload the timer */
	161	ali_start();
	162	}
	163	return len;
	164	}
	165
	166	/*
	167	* ali_ioctl - handle watchdog ioctls
1da177e4 LT	168	* @file: VFS file pointer
	169	* @cmd: ioctl number
	170	* @arg: arguments to the ioctl
	171	*
	172	* Handle the watchdog ioctls supported by the ALi driver. Really
	173	* we want an extension to enable irq ack monitoring and the like
	174	*/
	175
173d95bc	176	static long ali_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1da177e4 LT	177	{
	178	void __user argp = (void __user )arg;
	179	int __user *p = argp;
42747d71	180	static const struct watchdog_info ident = {
1da177e4 LT	181	.options = WDIOF_KEEPALIVEPING \|
	182	WDIOF_SETTIMEOUT \|
	183	WDIOF_MAGICCLOSE,
	184	.firmware_version = 0,
	185	.identity = "ALi M1535 WatchDog Timer",
	186	};
	187
	188	switch (cmd) {
173d95bc AC	189	case WDIOC_GETSUPPORT:
173d95bc AC	190	return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
1da177e4	191
173d95bc AC	192	case WDIOC_GETSTATUS:
	193	case WDIOC_GETBOOTSTATUS:
	194	return put_user(0, p);
173d95bc AC	195	case WDIOC_SETOPTIONS:
	196	{
	197	int new_options, retval = -EINVAL;
	198
	199	if (get_user(new_options, p))
	200	return -EFAULT;
	201	if (new_options & WDIOS_DISABLECARD) {
	202	ali_stop();
	203	retval = 0;
1da177e4	204	}
173d95bc AC	205	if (new_options & WDIOS_ENABLECARD) {
	206	ali_start();
	207	retval = 0;
1da177e4	208	}
173d95bc AC	209	return retval;
173d95bc AC	210	}
0c06090c WVS	211	case WDIOC_KEEPALIVE:
	212	ali_keepalive();
	213	return 0;
173d95bc AC	214	case WDIOC_SETTIMEOUT:
	215	{
	216	int new_timeout;
	217	if (get_user(new_timeout, p))
	218	return -EFAULT;
	219	if (ali_settimer(new_timeout))
	220	return -EINVAL;
	221	ali_keepalive();
173d95bc	222	}
bd490f82	223	fallthrough;
173d95bc AC	224	case WDIOC_GETTIMEOUT:
	225	return put_user(timeout, p);
	226	default:
	227	return -ENOTTY;
1da177e4 LT	228	}
	229	}
	230
	231	/*
	232	* ali_open - handle open of ali watchdog
	233	* @inode: inode from VFS
	234	* @file: file from VFS
	235	*
	236	* Open the ALi watchdog device. Ensure only one person opens it
	237	* at a time. Also start the watchdog running.
	238	*/
	239
	240	static int ali_open(struct inode inode, struct file file)
	241	{
	242	/* /dev/watchdog can only be opened once */
	243	if (test_and_set_bit(0, &ali_is_open))
	244	return -EBUSY;
	245
	246	/* Activate */
	247	ali_start();
c5bf68fe	248	return stream_open(inode, file);
1da177e4 LT	249	}
	250
	251	/*
	252	* ali_release - close an ALi watchdog
	253	* @inode: inode from VFS
	254	* @file: file from VFS
	255	*
	256	* Close the ALi watchdog device. Actual shutdown of the timer
	257	* only occurs if the magic sequence has been set.
	258	*/
	259
	260	static int ali_release(struct inode inode, struct file file)
	261	{
	262	/*
	263	* Shut off the timer.
	264	*/
173d95bc	265	if (ali_expect_release == 42)
1da177e4	266	ali_stop();
173d95bc	267	else {
27c766aa	268	pr_crit("Unexpected close, not stopping watchdog!\n");
1da177e4 LT	269	ali_keepalive();
	270	}
	271	clear_bit(0, &ali_is_open);
	272	ali_expect_release = 0;
	273	return 0;
	274	}
	275
	276	/*
	277	* ali_notify_sys - System down notifier
	278	*
	279	* Notifier for system down
	280	*/
	281
	282
173d95bc AC	283	static int ali_notify_sys(struct notifier_block *this,
173d95bc AC	284	unsigned long code, void *unused)
1da177e4	285	{
173d95bc AC	286	if (code == SYS_DOWN \|\| code == SYS_HALT)
173d95bc AC	287	ali_stop(); /* Turn the WDT off */
1da177e4 LT	288	return NOTIFY_DONE;
	289	}
	290
	291	/*
	292	* Data for PCI driver interface
	293	*
	294	* This data only exists for exporting the supported
	295	* PCI ids via MODULE_DEVICE_TABLE. We do not actually
	296	* register a pci_driver, because someone else might one day
	297	* want to register another driver on the same PCI id.
	298	*/
	299
bc17f9dc	300	static const struct pci_device_id ali_pci_tbl[] __used = {
6e420b7e	301	{ PCI_VENDOR_ID_AL, 0x1533, PCI_ANY_ID, PCI_ANY_ID,},
b7343f01	302	{ PCI_VENDOR_ID_AL, 0x1535, PCI_ANY_ID, PCI_ANY_ID,},
1da177e4 LT	303	{ 0, },
	304	};
	305	MODULE_DEVICE_TABLE(pci, ali_pci_tbl);
	306
	307	/*
	308	* ali_find_watchdog - find a 1535 and 7101
	309	*
	310	* Scans the PCI hardware for a 1535 series bridge and matching 7101
	311	* watchdog device. This may be overtight but it is better to be safe
	312	*/
	313
	314	static int __init ali_find_watchdog(void)
	315	{
	316	struct pci_dev *pdev;
	317	u32 wdog;
	318
6e420b7e	319	/* Check for a 1533/1535 series bridge */
02be2ee9	320	pdev = pci_get_device(PCI_VENDOR_ID_AL, 0x1535, NULL);
6e420b7e AB	321	if (pdev == NULL)
	322	pdev = pci_get_device(PCI_VENDOR_ID_AL, 0x1533, NULL);
	323	if (pdev == NULL)
1da177e4	324	return -ENODEV;
02be2ee9	325	pci_dev_put(pdev);
1da177e4 LT	326
1da177e4 LT	327	/* Check for the a 7101 PMU */
02be2ee9	328	pdev = pci_get_device(PCI_VENDOR_ID_AL, 0x7101, NULL);
173d95bc	329	if (pdev == NULL)
1da177e4 LT	330	return -ENODEV;
1da177e4 LT	331
173d95bc	332	if (pci_enable_device(pdev)) {
02be2ee9	333	pci_dev_put(pdev);
1da177e4	334	return -EIO;
02be2ee9	335	}
1da177e4 LT	336
	337	ali_pci = pdev;
	338
	339	/*
	340	* Initialize the timer bits
	341	*/
	342	pci_read_config_dword(pdev, 0xCC, &wdog);
	343
173d95bc AC	344	/* Timer bits */
	345	wdog &= ~0x3F;
	346	/* Issued events */
143a2e54	347	wdog &= ~((1 << 27)\|(1 << 26)\|(1 << 25)\|(1 << 24));
173d95bc	348	/* No monitor bits */
143a2e54	349	wdog &= ~((1 << 16)\|(1 << 13)\|(1 << 12)\|(1 << 11)\|(1 << 10)\|(1 << 9));
1da177e4 LT	350
	351	pci_write_config_dword(pdev, 0xCC, wdog);
	352
	353	return 0;
	354	}
	355
	356	/*
	357	* Kernel Interfaces
	358	*/
	359
62322d25	360	static const struct file_operations ali_fops = {
5f3b2756 WVS	361	.owner = THIS_MODULE,
5f3b2756 WVS	362	.llseek = no_llseek,
173d95bc AC	363	.write = ali_write,
173d95bc AC	364	.unlocked_ioctl = ali_ioctl,
b6dfb247	365	.compat_ioctl = compat_ptr_ioctl,
5f3b2756 WVS	366	.open = ali_open,
5f3b2756 WVS	367	.release = ali_release,
1da177e4 LT	368	};
	369
	370	static struct miscdevice ali_miscdev = {
	371	.minor = WATCHDOG_MINOR,
	372	.name = "watchdog",
	373	.fops = &ali_fops,
	374	};
	375
	376	static struct notifier_block ali_notifier = {
	377	.notifier_call = ali_notify_sys,
	378	};
	379
	380	/*
	381	* watchdog_init - module initialiser
	382	*
	383	* Scan for a suitable watchdog and if so initialize it. Return an error
	384	* if we cannot, the error causes the module to unload
	385	*/
	386
	387	static int __init watchdog_init(void)
	388	{
	389	int ret;
	390
1da177e4	391	/* Check whether or not the hardware watchdog is there */
173d95bc	392	if (ali_find_watchdog() != 0)
1da177e4	393	return -ENODEV;
1da177e4	394
173d95bc AC	395	/* Check that the timeout value is within it's range;
173d95bc AC	396	if not reset to the default */
1da177e4 LT	397	if (timeout < 1 \|\| timeout >= 18000) {
1da177e4 LT	398	timeout = WATCHDOG_TIMEOUT;
27c766aa JP	399	pr_info("timeout value must be 0 < timeout < 18000, using %d\n",
27c766aa JP	400	timeout);
1da177e4 LT	401	}
	402
	403	/* Calculate the watchdog's timeout */
	404	ali_settimer(timeout);
	405
c6cb13ae	406	ret = register_reboot_notifier(&ali_notifier);
1da177e4	407	if (ret != 0) {
27c766aa	408	pr_err("cannot register reboot notifier (err=%d)\n", ret);
1da177e4 LT	409	goto out;
	410	}
	411
c6cb13ae	412	ret = misc_register(&ali_miscdev);
1da177e4	413	if (ret != 0) {
27c766aa JP	414	pr_err("cannot register miscdev on minor=%d (err=%d)\n",
27c766aa JP	415	WATCHDOG_MINOR, ret);
c6cb13ae	416	goto unreg_reboot;
1da177e4 LT	417	}
1da177e4 LT	418
27c766aa	419	pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
1da177e4 LT	420	timeout, nowayout);
	421
	422	out:
	423	return ret;
c6cb13ae WVS	424	unreg_reboot:
c6cb13ae WVS	425	unregister_reboot_notifier(&ali_notifier);
1da177e4 LT	426	goto out;
	427	}
	428
	429	/*
	430	* watchdog_exit - module de-initialiser
	431	*
	432	* Called while unloading a successfully installed watchdog module.
	433	*/
	434
	435	static void __exit watchdog_exit(void)
	436	{
	437	/* Stop the timer before we leave */
	438	ali_stop();
	439
	440	/* Deregister */
1da177e4	441	misc_deregister(&ali_miscdev);
c6cb13ae	442	unregister_reboot_notifier(&ali_notifier);
02be2ee9	443	pci_dev_put(ali_pci);
1da177e4 LT	444	}
	445
	446	module_init(watchdog_init);
	447	module_exit(watchdog_exit);
	448
	449	MODULE_AUTHOR("Alan Cox");
	450	MODULE_DESCRIPTION("ALi M1535 PMU Watchdog Timer driver");
	451	MODULE_LICENSE("GPL");