[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / watchdog / alim7101_wdt.c

/*
 *	ALi M7101 PMU Computer Watchdog Timer driver
 *
 *	Based on w83877f_wdt.c by Scott Jennings <linuxdrivers@oro.net>
 *	and the Cobalt kernel WDT timer driver by Tim Hockin
 *	                                      <thockin@cobaltnet.com>
 *
 *	(c)2002 Steve Hill <steve@navaho.co.uk>
 *
 *  This WDT driver is different from most other Linux WDT
 *  drivers in that the driver will ping the watchdog by itself,
 *  because this particular WDT has a very short timeout (1.6
 *  seconds) and it would be insane to count on any userspace
 *  daemon always getting scheduled within that time frame.
 *
 *  Additions:
 *   Aug 23, 2004 - Added use_gpio module parameter for use on revision a1d PMUs
 *                  found on very old cobalt hardware.
 *                  -- Mike Waychison <michael.waychison@sun.com>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#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/ioport.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/pci.h>
#include <linux/io.h>
#include <linux/uaccess.h>


#define WDT_ENABLE 0x9C
#define WDT_DISABLE 0x8C

#define ALI_7101_WDT    0x92
#define ALI_7101_GPIO   0x7D
#define ALI_7101_GPIO_O 0x7E
#define ALI_WDT_ARM     0x01

/*
 * We're going to use a 1 second timeout.
 * If we reset the watchdog every ~250ms we should be safe.  */

#define WDT_INTERVAL (HZ/4+1)

/*
 * We must not require too good response from the userspace daemon.
 * Here we require the userspace daemon to send us a heartbeat
 * char to /dev/watchdog every 30 seconds.
 */

#define WATCHDOG_TIMEOUT 30            /* 30 sec default timeout */
/* in seconds, will be multiplied by HZ to get seconds to wait for a ping */
static int timeout = WATCHDOG_TIMEOUT;
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout,
		"Watchdog timeout in seconds. (1<=timeout<=3600, default="
				__MODULE_STRING(WATCHDOG_TIMEOUT) ")");

static int use_gpio; /* Use the pic (for a1d revision alim7101) */
module_param(use_gpio, int, 0);
MODULE_PARM_DESC(use_gpio,
		"Use the gpio watchdog (required by old cobalt boards).");

static void wdt_timer_ping(unsigned long);
static DEFINE_TIMER(timer, wdt_timer_ping, 0, 1);
static unsigned long next_heartbeat;
static unsigned long wdt_is_open;
static char wdt_expect_close;
static struct pci_dev *alim7101_pmu;

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) ")");

/*
 *	Whack the dog
 */

static void wdt_timer_ping(unsigned long data)
{
	/* If we got a heartbeat pulse within the WDT_US_INTERVAL
	 * we agree to ping the WDT
	 */
	char tmp;

	if (time_before(jiffies, next_heartbeat)) {
		/* Ping the WDT (this is actually a disarm/arm sequence) */
		pci_read_config_byte(alim7101_pmu, 0x92, &tmp);
		pci_write_config_byte(alim7101_pmu,
					ALI_7101_WDT, (tmp & ~ALI_WDT_ARM));
		pci_write_config_byte(alim7101_pmu,
					ALI_7101_WDT, (tmp | ALI_WDT_ARM));
		if (use_gpio) {
			pci_read_config_byte(alim7101_pmu,
					ALI_7101_GPIO_O, &tmp);
			pci_write_config_byte(alim7101_pmu,
					ALI_7101_GPIO_O, tmp | 0x20);
			pci_write_config_byte(alim7101_pmu,
					ALI_7101_GPIO_O, tmp & ~0x20);
		}
	} else {
		pr_warn("Heartbeat lost! Will not ping the watchdog\n");
	}
	/* Re-set the timer interval */
	mod_timer(&timer, jiffies + WDT_INTERVAL);
}

/*
 * Utility routines
 */

static void wdt_change(int writeval)
{
	char tmp;

	pci_read_config_byte(alim7101_pmu, ALI_7101_WDT, &tmp);
	if (writeval == WDT_ENABLE) {
		pci_write_config_byte(alim7101_pmu,
					ALI_7101_WDT, (tmp | ALI_WDT_ARM));
		if (use_gpio) {
			pci_read_config_byte(alim7101_pmu,
					ALI_7101_GPIO_O, &tmp);
			pci_write_config_byte(alim7101_pmu,
					ALI_7101_GPIO_O, tmp & ~0x20);
		}

	} else {
		pci_write_config_byte(alim7101_pmu,
					ALI_7101_WDT, (tmp & ~ALI_WDT_ARM));
		if (use_gpio) {
			pci_read_config_byte(alim7101_pmu,
					ALI_7101_GPIO_O, &tmp);
			pci_write_config_byte(alim7101_pmu,
					ALI_7101_GPIO_O, tmp | 0x20);
		}
	}
}

static void wdt_startup(void)
{
	next_heartbeat = jiffies + (timeout * HZ);

	/* We must enable before we kick off the timer in case the timer
	   occurs as we ping it */

	wdt_change(WDT_ENABLE);

	/* Start the timer */
	mod_timer(&timer, jiffies + WDT_INTERVAL);

	pr_info("Watchdog timer is now enabled\n");
}

static void wdt_turnoff(void)
{
	/* Stop the timer */
	del_timer_sync(&timer);
	wdt_change(WDT_DISABLE);
	pr_info("Watchdog timer is now disabled...\n");
}

static void wdt_keepalive(void)
{
	/* user land ping */
	next_heartbeat = jiffies + (timeout * HZ);
}

/*
 * /dev/watchdog handling
 */

static ssize_t fop_write(struct file *file, const char __user *buf,
						size_t count, loff_t *ppos)
{
	/* See if we got the magic character 'V' and reload the timer */
	if (count) {
		if (!nowayout) {
			size_t ofs;

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

			/* now scan */
			for (ofs = 0; ofs != count; ofs++) {
				char c;
				if (get_user(c, buf + ofs))
					return -EFAULT;
				if (c == 'V')
					wdt_expect_close = 42;
			}
		}
		/* someone wrote to us, we should restart timer */
		wdt_keepalive();
	}
	return count;
}

static int fop_open(struct inode *inode, struct file *file)
{
	/* Just in case we're already talking to someone... */
	if (test_and_set_bit(0, &wdt_is_open))
		return -EBUSY;
	/* Good, fire up the show */
	wdt_startup();
	return nonseekable_open(inode, file);
}

static int fop_close(struct inode *inode, struct file *file)
{
	if (wdt_expect_close == 42)
		wdt_turnoff();
	else {
		/* wim: shouldn't there be a: del_timer(&timer); */
		pr_crit("device file closed unexpectedly. Will not stop the WDT!\n");
	}
	clear_bit(0, &wdt_is_open);
	wdt_expect_close = 0;
	return 0;
}

static long fop_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 = 1,
		.identity = "ALiM7101",
	};

	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) {
			wdt_turnoff();
			retval = 0;
		}
		if (new_options & WDIOS_ENABLECARD) {
			wdt_startup();
			retval = 0;
		}
		return retval;
	}
	case WDIOC_KEEPALIVE:
		wdt_keepalive();
		return 0;
	case WDIOC_SETTIMEOUT:
	{
		int new_timeout;

		if (get_user(new_timeout, p))
			return -EFAULT;
		/* arbitrary upper limit */
		if (new_timeout < 1 || new_timeout > 3600)
			return -EINVAL;
		timeout = new_timeout;
		wdt_keepalive();
		/* Fall through */
	}
	case WDIOC_GETTIMEOUT:
		return put_user(timeout, p);
	default:
		return -ENOTTY;
	}
}

static const struct file_operations wdt_fops = {
	.owner		=	THIS_MODULE,
	.llseek		=	no_llseek,
	.write		=	fop_write,
	.open		=	fop_open,
	.release	=	fop_close,
	.unlocked_ioctl	=	fop_ioctl,
};

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

/*
 *	Notifier for system down
 */

static int wdt_notify_sys(struct notifier_block *this,
					unsigned long code, void *unused)
{
	if (code == SYS_DOWN || code == SYS_HALT)
		wdt_turnoff();

	if (code == SYS_RESTART) {
		/*
		 * Cobalt devices have no way of rebooting themselves other
		 * than getting the watchdog to pull reset, so we restart the
		 * watchdog on reboot with no heartbeat
		 */
		wdt_change(WDT_ENABLE);
		pr_info("Watchdog timer is now enabled with no heartbeat - should reboot in ~1 second\n");
	}
	return NOTIFY_DONE;
}

/*
 *	The WDT needs to learn about soft shutdowns in order to
 *	turn the timebomb registers off.
 */

static struct notifier_block wdt_notifier = {
	.notifier_call = wdt_notify_sys,
};

static void __exit alim7101_wdt_unload(void)
{
	wdt_turnoff();
	/* Deregister */
	misc_deregister(&wdt_miscdev);
	unregister_reboot_notifier(&wdt_notifier);
	pci_dev_put(alim7101_pmu);
}

static int __init alim7101_wdt_init(void)
{
	int rc = -EBUSY;
	struct pci_dev *ali1543_south;
	char tmp;

	pr_info("Steve Hill <steve@navaho.co.uk>\n");
	alim7101_pmu = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101,
		NULL);
	if (!alim7101_pmu) {
		pr_info("ALi M7101 PMU not present - WDT not set\n");
		return -EBUSY;
	}

	/* Set the WDT in the PMU to 1 second */
	pci_write_config_byte(alim7101_pmu, ALI_7101_WDT, 0x02);

	ali1543_south = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533,
		NULL);
	if (!ali1543_south) {
		pr_info("ALi 1543 South-Bridge not present - WDT not set\n");
		goto err_out;
	}
	pci_read_config_byte(ali1543_south, 0x5e, &tmp);
	pci_dev_put(ali1543_south);
	if ((tmp & 0x1e) == 0x00) {
		if (!use_gpio) {
			pr_info("Detected old alim7101 revision 'a1d'.  If this is a cobalt board, set the 'use_gpio' module parameter.\n");
			goto err_out;
		}
		nowayout = 1;
	} else if ((tmp & 0x1e) != 0x12 && (tmp & 0x1e) != 0x00) {
		pr_info("ALi 1543 South-Bridge does not have the correct revision number (???1001?) - WDT not set\n");
		goto err_out;
	}

	if (timeout < 1 || timeout > 3600) {
		/* arbitrary upper limit */
		timeout = WATCHDOG_TIMEOUT;
		pr_info("timeout value must be 1 <= x <= 3600, using %d\n",
			timeout);
	}

	rc = register_reboot_notifier(&wdt_notifier);
	if (rc) {
		pr_err("cannot register reboot notifier (err=%d)\n", rc);
		goto err_out;
	}

	rc = misc_register(&wdt_miscdev);
	if (rc) {
		pr_err("cannot register miscdev on minor=%d (err=%d)\n",
		       wdt_miscdev.minor, rc);
		goto err_out_reboot;
	}

	if (nowayout)
		__module_get(THIS_MODULE);

	pr_info("WDT driver for ALi M7101 initialised. timeout=%d sec (nowayout=%d)\n",
		timeout, nowayout);
	return 0;

err_out_reboot:
	unregister_reboot_notifier(&wdt_notifier);
err_out:
	pci_dev_put(alim7101_pmu);
	return rc;
}

module_init(alim7101_wdt_init);
module_exit(alim7101_wdt_unload);

static DEFINE_PCI_DEVICE_TABLE(alim7101_pci_tbl) __used = {
	{ PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533) },
	{ PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
	{ }
};

MODULE_DEVICE_TABLE(pci, alim7101_pci_tbl);

MODULE_AUTHOR("Steve Hill");
MODULE_DESCRIPTION("ALi M7101 PMU Computer Watchdog Timer driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
Commit	Line	Data
	1	/*
	2	* ALi M7101 PMU Computer Watchdog Timer driver
	3	*
	4	* Based on w83877f_wdt.c by Scott Jennings <linuxdrivers@oro.net>
	5	* and the Cobalt kernel WDT timer driver by Tim Hockin
	6	* <thockin@cobaltnet.com>
	7	*
	8	* (c)2002 Steve Hill <steve@navaho.co.uk>
	9	*
	10	* This WDT driver is different from most other Linux WDT
	11	* drivers in that the driver will ping the watchdog by itself,
	12	* because this particular WDT has a very short timeout (1.6
	13	* seconds) and it would be insane to count on any userspace
	14	* daemon always getting scheduled within that time frame.
	15	*
	16	* Additions:
	17	* Aug 23, 2004 - Added use_gpio module parameter for use on revision a1d PMUs
	18	* found on very old cobalt hardware.
	19	* -- Mike Waychison <michael.waychison@sun.com>
	20	*/
	21
	22	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	23
	24	#include <linux/module.h>
	25	#include <linux/moduleparam.h>
	26	#include <linux/types.h>
	27	#include <linux/timer.h>
	28	#include <linux/miscdevice.h>
	29	#include <linux/watchdog.h>
	30	#include <linux/ioport.h>
	31	#include <linux/notifier.h>
	32	#include <linux/reboot.h>
	33	#include <linux/init.h>
	34	#include <linux/fs.h>
	35	#include <linux/pci.h>
	36	#include <linux/io.h>
	37	#include <linux/uaccess.h>
	38
	39
	40	#define WDT_ENABLE 0x9C
	41	#define WDT_DISABLE 0x8C
	42
	43	#define ALI_7101_WDT 0x92
	44	#define ALI_7101_GPIO 0x7D
	45	#define ALI_7101_GPIO_O 0x7E
	46	#define ALI_WDT_ARM 0x01
	47
	48	/*
	49	* We're going to use a 1 second timeout.
	50	* If we reset the watchdog every ~250ms we should be safe. */
	51
	52	#define WDT_INTERVAL (HZ/4+1)
	53
	54	/*
	55	* We must not require too good response from the userspace daemon.
	56	* Here we require the userspace daemon to send us a heartbeat
	57	* char to /dev/watchdog every 30 seconds.
	58	*/
	59
	60	#define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */
	61	/* in seconds, will be multiplied by HZ to get seconds to wait for a ping */
	62	static int timeout = WATCHDOG_TIMEOUT;
	63	module_param(timeout, int, 0);
	64	MODULE_PARM_DESC(timeout,
	65	"Watchdog timeout in seconds. (1<=timeout<=3600, default="
	66	__MODULE_STRING(WATCHDOG_TIMEOUT) ")");
	67
	68	static int use_gpio; /* Use the pic (for a1d revision alim7101) */
	69	module_param(use_gpio, int, 0);
	70	MODULE_PARM_DESC(use_gpio,
	71	"Use the gpio watchdog (required by old cobalt boards).");
	72
	73	static void wdt_timer_ping(unsigned long);
	74	static DEFINE_TIMER(timer, wdt_timer_ping, 0, 1);
	75	static unsigned long next_heartbeat;
	76	static unsigned long wdt_is_open;
	77	static char wdt_expect_close;
	78	static struct pci_dev *alim7101_pmu;
	79
	80	static bool nowayout = WATCHDOG_NOWAYOUT;
	81	module_param(nowayout, bool, 0);
	82	MODULE_PARM_DESC(nowayout,
	83	"Watchdog cannot be stopped once started (default="
	84	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
	85
	86	/*
	87	* Whack the dog
	88	*/
	89
	90	static void wdt_timer_ping(unsigned long data)
	91	{
	92	/* If we got a heartbeat pulse within the WDT_US_INTERVAL
	93	* we agree to ping the WDT
	94	*/
	95	char tmp;
	96
	97	if (time_before(jiffies, next_heartbeat)) {
	98	/* Ping the WDT (this is actually a disarm/arm sequence) */
	99	pci_read_config_byte(alim7101_pmu, 0x92, &tmp);
	100	pci_write_config_byte(alim7101_pmu,
	101	ALI_7101_WDT, (tmp & ~ALI_WDT_ARM));
	102	pci_write_config_byte(alim7101_pmu,
	103	ALI_7101_WDT, (tmp \| ALI_WDT_ARM));
	104	if (use_gpio) {
	105	pci_read_config_byte(alim7101_pmu,
	106	ALI_7101_GPIO_O, &tmp);
	107	pci_write_config_byte(alim7101_pmu,
	108	ALI_7101_GPIO_O, tmp \| 0x20);
	109	pci_write_config_byte(alim7101_pmu,
	110	ALI_7101_GPIO_O, tmp & ~0x20);
	111	}
	112	} else {
	113	pr_warn("Heartbeat lost! Will not ping the watchdog\n");
	114	}
	115	/* Re-set the timer interval */
	116	mod_timer(&timer, jiffies + WDT_INTERVAL);
	117	}
	118
	119	/*
	120	* Utility routines
	121	*/
	122
	123	static void wdt_change(int writeval)
	124	{
	125	char tmp;
	126
	127	pci_read_config_byte(alim7101_pmu, ALI_7101_WDT, &tmp);
	128	if (writeval == WDT_ENABLE) {
	129	pci_write_config_byte(alim7101_pmu,
	130	ALI_7101_WDT, (tmp \| ALI_WDT_ARM));
	131	if (use_gpio) {
	132	pci_read_config_byte(alim7101_pmu,
	133	ALI_7101_GPIO_O, &tmp);
	134	pci_write_config_byte(alim7101_pmu,
	135	ALI_7101_GPIO_O, tmp & ~0x20);
	136	}
	137
	138	} else {
	139	pci_write_config_byte(alim7101_pmu,
	140	ALI_7101_WDT, (tmp & ~ALI_WDT_ARM));
	141	if (use_gpio) {
	142	pci_read_config_byte(alim7101_pmu,
	143	ALI_7101_GPIO_O, &tmp);
	144	pci_write_config_byte(alim7101_pmu,
	145	ALI_7101_GPIO_O, tmp \| 0x20);
	146	}
	147	}
	148	}
	149
	150	static void wdt_startup(void)
	151	{
	152	next_heartbeat = jiffies + (timeout * HZ);
	153
	154	/* We must enable before we kick off the timer in case the timer
	155	occurs as we ping it */
	156
	157	wdt_change(WDT_ENABLE);
	158
	159	/* Start the timer */
	160	mod_timer(&timer, jiffies + WDT_INTERVAL);
	161
	162	pr_info("Watchdog timer is now enabled\n");
	163	}
	164
	165	static void wdt_turnoff(void)
	166	{
	167	/* Stop the timer */
	168	del_timer_sync(&timer);
	169	wdt_change(WDT_DISABLE);
	170	pr_info("Watchdog timer is now disabled...\n");
	171	}
	172
	173	static void wdt_keepalive(void)
	174	{
	175	/* user land ping */
	176	next_heartbeat = jiffies + (timeout * HZ);
	177	}
	178
	179	/*
	180	* /dev/watchdog handling
	181	*/
	182
	183	static ssize_t fop_write(struct file file, const char __user buf,
	184	size_t count, loff_t *ppos)
	185	{
	186	/* See if we got the magic character 'V' and reload the timer */
	187	if (count) {
	188	if (!nowayout) {
	189	size_t ofs;
	190
	191	/* note: just in case someone wrote the magic character
	192	* five months ago... */
	193	wdt_expect_close = 0;
	194
	195	/* now scan */
	196	for (ofs = 0; ofs != count; ofs++) {
	197	char c;
	198	if (get_user(c, buf + ofs))
	199	return -EFAULT;
	200	if (c == 'V')
	201	wdt_expect_close = 42;
	202	}
	203	}
	204	/* someone wrote to us, we should restart timer */
	205	wdt_keepalive();
	206	}
	207	return count;
	208	}
	209
	210	static int fop_open(struct inode inode, struct file file)
	211	{
	212	/* Just in case we're already talking to someone... */
	213	if (test_and_set_bit(0, &wdt_is_open))
	214	return -EBUSY;
	215	/* Good, fire up the show */
	216	wdt_startup();
	217	return nonseekable_open(inode, file);
	218	}
	219
	220	static int fop_close(struct inode inode, struct file file)
	221	{
	222	if (wdt_expect_close == 42)
	223	wdt_turnoff();
	224	else {
	225	/* wim: shouldn't there be a: del_timer(&timer); */
	226	pr_crit("device file closed unexpectedly. Will not stop the WDT!\n");
	227	}
	228	clear_bit(0, &wdt_is_open);
	229	wdt_expect_close = 0;
	230	return 0;
	231	}
	232
	233	static long fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
	234	{
	235	void __user argp = (void __user )arg;
	236	int __user *p = argp;
	237	static const struct watchdog_info ident = {
	238	.options = WDIOF_KEEPALIVEPING \| WDIOF_SETTIMEOUT
	239	\| WDIOF_MAGICCLOSE,
	240	.firmware_version = 1,
	241	.identity = "ALiM7101",
	242	};
	243
	244	switch (cmd) {
	245	case WDIOC_GETSUPPORT:
	246	return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
	247	case WDIOC_GETSTATUS:
	248	case WDIOC_GETBOOTSTATUS:
	249	return put_user(0, p);
	250	case WDIOC_SETOPTIONS:
	251	{
	252	int new_options, retval = -EINVAL;
	253
	254	if (get_user(new_options, p))
	255	return -EFAULT;
	256	if (new_options & WDIOS_DISABLECARD) {
	257	wdt_turnoff();
	258	retval = 0;
	259	}
	260	if (new_options & WDIOS_ENABLECARD) {
	261	wdt_startup();
	262	retval = 0;
	263	}
	264	return retval;
	265	}
	266	case WDIOC_KEEPALIVE:
	267	wdt_keepalive();
	268	return 0;
	269	case WDIOC_SETTIMEOUT:
	270	{
	271	int new_timeout;
	272
	273	if (get_user(new_timeout, p))
	274	return -EFAULT;
	275	/* arbitrary upper limit */
	276	if (new_timeout < 1 \|\| new_timeout > 3600)
	277	return -EINVAL;
	278	timeout = new_timeout;
	279	wdt_keepalive();
	280	/* Fall through */
	281	}
	282	case WDIOC_GETTIMEOUT:
	283	return put_user(timeout, p);
	284	default:
	285	return -ENOTTY;
	286	}
	287	}
	288
	289	static const struct file_operations wdt_fops = {
	290	.owner = THIS_MODULE,
	291	.llseek = no_llseek,
	292	.write = fop_write,
	293	.open = fop_open,
	294	.release = fop_close,
	295	.unlocked_ioctl = fop_ioctl,
	296	};
	297
	298	static struct miscdevice wdt_miscdev = {
	299	.minor = WATCHDOG_MINOR,
	300	.name = "watchdog",
	301	.fops = &wdt_fops,
	302	};
	303
	304	/*
	305	* Notifier for system down
	306	*/
	307
	308	static int wdt_notify_sys(struct notifier_block *this,
	309	unsigned long code, void *unused)
	310	{
	311	if (code == SYS_DOWN \|\| code == SYS_HALT)
	312	wdt_turnoff();
	313
	314	if (code == SYS_RESTART) {
	315	/*
	316	* Cobalt devices have no way of rebooting themselves other
	317	* than getting the watchdog to pull reset, so we restart the
	318	* watchdog on reboot with no heartbeat
	319	*/
	320	wdt_change(WDT_ENABLE);
	321	pr_info("Watchdog timer is now enabled with no heartbeat - should reboot in ~1 second\n");
	322	}
	323	return NOTIFY_DONE;
	324	}
	325
	326	/*
	327	* The WDT needs to learn about soft shutdowns in order to
	328	* turn the timebomb registers off.
	329	*/
	330
	331	static struct notifier_block wdt_notifier = {
	332	.notifier_call = wdt_notify_sys,
	333	};
	334
	335	static void __exit alim7101_wdt_unload(void)
	336	{
	337	wdt_turnoff();
	338	/* Deregister */
	339	misc_deregister(&wdt_miscdev);
	340	unregister_reboot_notifier(&wdt_notifier);
	341	pci_dev_put(alim7101_pmu);
	342	}
	343
	344	static int __init alim7101_wdt_init(void)
	345	{
	346	int rc = -EBUSY;
	347	struct pci_dev *ali1543_south;
	348	char tmp;
	349
	350	pr_info("Steve Hill <steve@navaho.co.uk>\n");
	351	alim7101_pmu = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101,
	352	NULL);
	353	if (!alim7101_pmu) {
	354	pr_info("ALi M7101 PMU not present - WDT not set\n");
	355	return -EBUSY;
	356	}
	357
	358	/* Set the WDT in the PMU to 1 second */
	359	pci_write_config_byte(alim7101_pmu, ALI_7101_WDT, 0x02);
	360
	361	ali1543_south = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533,
	362	NULL);
	363	if (!ali1543_south) {
	364	pr_info("ALi 1543 South-Bridge not present - WDT not set\n");
	365	goto err_out;
	366	}
	367	pci_read_config_byte(ali1543_south, 0x5e, &tmp);
	368	pci_dev_put(ali1543_south);
	369	if ((tmp & 0x1e) == 0x00) {
	370	if (!use_gpio) {
	371	pr_info("Detected old alim7101 revision 'a1d'. If this is a cobalt board, set the 'use_gpio' module parameter.\n");
	372	goto err_out;
	373	}
	374	nowayout = 1;
	375	} else if ((tmp & 0x1e) != 0x12 && (tmp & 0x1e) != 0x00) {
	376	pr_info("ALi 1543 South-Bridge does not have the correct revision number (???1001?) - WDT not set\n");
	377	goto err_out;
	378	}
	379
	380	if (timeout < 1 \|\| timeout > 3600) {
	381	/* arbitrary upper limit */
	382	timeout = WATCHDOG_TIMEOUT;
	383	pr_info("timeout value must be 1 <= x <= 3600, using %d\n",
	384	timeout);
	385	}
	386
	387	rc = register_reboot_notifier(&wdt_notifier);
	388	if (rc) {
	389	pr_err("cannot register reboot notifier (err=%d)\n", rc);
	390	goto err_out;
	391	}
	392
	393	rc = misc_register(&wdt_miscdev);
	394	if (rc) {
	395	pr_err("cannot register miscdev on minor=%d (err=%d)\n",
	396	wdt_miscdev.minor, rc);
	397	goto err_out_reboot;
	398	}
	399
	400	if (nowayout)
	401	__module_get(THIS_MODULE);
	402
	403	pr_info("WDT driver for ALi M7101 initialised. timeout=%d sec (nowayout=%d)\n",
	404	timeout, nowayout);
	405	return 0;
	406
	407	err_out_reboot:
	408	unregister_reboot_notifier(&wdt_notifier);
	409	err_out:
	410	pci_dev_put(alim7101_pmu);
	411	return rc;
	412	}
	413
	414	module_init(alim7101_wdt_init);
	415	module_exit(alim7101_wdt_unload);
	416
	417	static DEFINE_PCI_DEVICE_TABLE(alim7101_pci_tbl) __used = {
	418	{ PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533) },
	419	{ PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
	420	{ }
	421	};
	422
	423	MODULE_DEVICE_TABLE(pci, alim7101_pci_tbl);
	424
	425	MODULE_AUTHOR("Steve Hill");
	426	MODULE_DESCRIPTION("ALi M7101 PMU Computer Watchdog Timer driver");
	427	MODULE_LICENSE("GPL");
	428	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);