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

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  MachZ ZF-Logic Watchdog Timer driver for Linux
 *
 *  The author does NOT admit liability nor provide warranty for
 *  any of this software. This material is provided "AS-IS" in
 *  the hope that it may be useful for others.
 *
 *  Author: Fernando Fuganti <fuganti@conectiva.com.br>
 *
 *  Based on sbc60xxwdt.c by Jakob Oestergaard
 *
 *  We have two timers (wd#1, wd#2) driven by a 32 KHz clock with the
 *  following periods:
 *      wd#1 - 2 seconds;
 *      wd#2 - 7.2 ms;
 *  After the expiration of wd#1, it can generate a NMI, SCI, SMI, or
 *  a system RESET and it starts wd#2 that unconditionally will RESET
 *  the system when the counter reaches zero.
 *
 *  14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
 *      Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
 */

#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/jiffies.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/fs.h>
#include <linux/ioport.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/uaccess.h>


/* ports */
#define ZF_IOBASE	0x218
#define INDEX		0x218
#define DATA_B		0x219
#define DATA_W		0x21A
#define DATA_D		0x21A

/* indexes */			/* size */
#define ZFL_VERSION	0x02	/* 16   */
#define CONTROL		0x10	/* 16   */
#define STATUS		0x12	/* 8    */
#define COUNTER_1	0x0C	/* 16   */
#define COUNTER_2	0x0E	/* 8    */
#define PULSE_LEN	0x0F	/* 8    */

/* controls */
#define ENABLE_WD1	0x0001
#define ENABLE_WD2	0x0002
#define RESET_WD1	0x0010
#define RESET_WD2	0x0020
#define GEN_SCI		0x0100
#define GEN_NMI		0x0200
#define GEN_SMI		0x0400
#define GEN_RESET	0x0800


/* utilities */

#define WD1	0
#define WD2	1

#define zf_writew(port, data)  { outb(port, INDEX); outw(data, DATA_W); }
#define zf_writeb(port, data)  { outb(port, INDEX); outb(data, DATA_B); }
#define zf_get_ZFL_version()   zf_readw(ZFL_VERSION)


static unsigned short zf_readw(unsigned char port)
{
	outb(port, INDEX);
	return inw(DATA_W);
}


MODULE_AUTHOR("Fernando Fuganti <fuganti@conectiva.com.br>");
MODULE_DESCRIPTION("MachZ ZF-Logic Watchdog driver");
MODULE_LICENSE("GPL");

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) ")");

#define PFX "machzwd"

static const struct watchdog_info zf_info = {
	.options		= WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
	.firmware_version	= 1,
	.identity		= "ZF-Logic watchdog",
};


/*
 * action refers to action taken when watchdog resets
 * 0 = GEN_RESET
 * 1 = GEN_SMI
 * 2 = GEN_NMI
 * 3 = GEN_SCI
 * defaults to GEN_RESET (0)
 */
static int action;
module_param(action, int, 0);
MODULE_PARM_DESC(action, "after watchdog resets, generate: "
				"0 = RESET(*)  1 = SMI  2 = NMI  3 = SCI");

static void zf_ping(struct timer_list *unused);

static int zf_action = GEN_RESET;
static unsigned long zf_is_open;
static char zf_expect_close;
static DEFINE_SPINLOCK(zf_port_lock);
static DEFINE_TIMER(zf_timer, zf_ping);
static unsigned long next_heartbeat;


/* timeout for user land heart beat (10 seconds) */
#define ZF_USER_TIMEO (HZ*10)

/* timeout for hardware watchdog (~500ms) */
#define ZF_HW_TIMEO (HZ/2)

/* number of ticks on WD#1 (driven by a 32KHz clock, 2s) */
#define ZF_CTIMEOUT 0xffff

#ifndef ZF_DEBUG
#define dprintk(format, args...)
#else
#define dprintk(format, args...)					\
	pr_debug(":%s:%d: " format, __func__, __LINE__ , ## args)
#endif


static inline void zf_set_status(unsigned char new)
{
	zf_writeb(STATUS, new);
}


/* CONTROL register functions */

static inline unsigned short zf_get_control(void)
{
	return zf_readw(CONTROL);
}

static inline void zf_set_control(unsigned short new)
{
	zf_writew(CONTROL, new);
}


/* WD#? counter functions */
/*
 *	Just set counter value
 */

static inline void zf_set_timer(unsigned short new, unsigned char n)
{
	switch (n) {
	case WD1:
		zf_writew(COUNTER_1, new);
		/* fall through */
	case WD2:
		zf_writeb(COUNTER_2, new > 0xff ? 0xff : new);
	default:
		return;
	}
}

/*
 * stop hardware timer
 */
static void zf_timer_off(void)
{
	unsigned int ctrl_reg = 0;
	unsigned long flags;

	/* stop internal ping */
	del_timer_sync(&zf_timer);

	spin_lock_irqsave(&zf_port_lock, flags);
	/* stop watchdog timer */
	ctrl_reg = zf_get_control();
	ctrl_reg |= (ENABLE_WD1|ENABLE_WD2);	/* disable wd1 and wd2 */
	ctrl_reg &= ~(ENABLE_WD1|ENABLE_WD2);
	zf_set_control(ctrl_reg);
	spin_unlock_irqrestore(&zf_port_lock, flags);

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


/*
 * start hardware timer
 */
static void zf_timer_on(void)
{
	unsigned int ctrl_reg = 0;
	unsigned long flags;

	spin_lock_irqsave(&zf_port_lock, flags);

	zf_writeb(PULSE_LEN, 0xff);

	zf_set_timer(ZF_CTIMEOUT, WD1);

	/* user land ping */
	next_heartbeat = jiffies + ZF_USER_TIMEO;

	/* start the timer for internal ping */
	mod_timer(&zf_timer, jiffies + ZF_HW_TIMEO);

	/* start watchdog timer */
	ctrl_reg = zf_get_control();
	ctrl_reg |= (ENABLE_WD1|zf_action);
	zf_set_control(ctrl_reg);
	spin_unlock_irqrestore(&zf_port_lock, flags);

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


static void zf_ping(struct timer_list *unused)
{
	unsigned int ctrl_reg = 0;
	unsigned long flags;

	zf_writeb(COUNTER_2, 0xff);

	if (time_before(jiffies, next_heartbeat)) {
		dprintk("time_before: %ld\n", next_heartbeat - jiffies);
		/*
		 * reset event is activated by transition from 0 to 1 on
		 * RESET_WD1 bit and we assume that it is already zero...
		 */

		spin_lock_irqsave(&zf_port_lock, flags);
		ctrl_reg = zf_get_control();
		ctrl_reg |= RESET_WD1;
		zf_set_control(ctrl_reg);

		/* ...and nothing changes until here */
		ctrl_reg &= ~(RESET_WD1);
		zf_set_control(ctrl_reg);
		spin_unlock_irqrestore(&zf_port_lock, flags);

		mod_timer(&zf_timer, jiffies + ZF_HW_TIMEO);
	} else
		pr_crit("I will reset your machine\n");
}

static ssize_t zf_write(struct file *file, const char __user *buf, size_t count,
								loff_t *ppos)
{
	/* See if we got the magic character */
	if (count) {
		/*
		 * no need to check for close confirmation
		 * no way to disable watchdog ;)
		 */
		if (!nowayout) {
			size_t ofs;
			/*
			 * note: just in case someone wrote the magic character
			 * five months ago...
			 */
			zf_expect_close = 0;

			/* now scan */
			for (ofs = 0; ofs != count; ofs++) {
				char c;
				if (get_user(c, buf + ofs))
					return -EFAULT;
				if (c == 'V') {
					zf_expect_close = 42;
					dprintk("zf_expect_close = 42\n");
				}
			}
		}

		/*
		 * Well, anyhow someone wrote to us,
		 * we should return that favour
		 */
		next_heartbeat = jiffies + ZF_USER_TIMEO;
		dprintk("user ping at %ld\n", jiffies);
	}
	return count;
}

static long zf_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	void __user *argp = (void __user *)arg;
	int __user *p = argp;
	switch (cmd) {
	case WDIOC_GETSUPPORT:
		if (copy_to_user(argp, &zf_info, sizeof(zf_info)))
			return -EFAULT;
		break;
	case WDIOC_GETSTATUS:
	case WDIOC_GETBOOTSTATUS:
		return put_user(0, p);
	case WDIOC_KEEPALIVE:
		zf_ping(NULL);
		break;
	default:
		return -ENOTTY;
	}
	return 0;
}

static int zf_open(struct inode *inode, struct file *file)
{
	if (test_and_set_bit(0, &zf_is_open))
		return -EBUSY;
	if (nowayout)
		__module_get(THIS_MODULE);
	zf_timer_on();
	return stream_open(inode, file);
}

static int zf_close(struct inode *inode, struct file *file)
{
	if (zf_expect_close == 42)
		zf_timer_off();
	else {
		del_timer(&zf_timer);
		pr_err("device file closed unexpectedly. Will not stop the WDT!\n");
	}
	clear_bit(0, &zf_is_open);
	zf_expect_close = 0;
	return 0;
}

/*
 * Notifier for system down
 */

static int zf_notify_sys(struct notifier_block *this, unsigned long code,
								void *unused)
{
	if (code == SYS_DOWN || code == SYS_HALT)
		zf_timer_off();
	return NOTIFY_DONE;
}

static const struct file_operations zf_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.write		= zf_write,
	.unlocked_ioctl = zf_ioctl,
	.open		= zf_open,
	.release	= zf_close,
};

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


/*
 * The device needs to learn about soft shutdowns in order to
 * turn the timebomb registers off.
 */
static struct notifier_block zf_notifier = {
	.notifier_call = zf_notify_sys,
};

static void __init zf_show_action(int act)
{
	static const char * const str[] = { "RESET", "SMI", "NMI", "SCI" };

	pr_info("Watchdog using action = %s\n", str[act]);
}

static int __init zf_init(void)
{
	int ret;

	pr_info("MachZ ZF-Logic Watchdog driver initializing\n");

	ret = zf_get_ZFL_version();
	if (!ret || ret == 0xffff) {
		pr_warn("no ZF-Logic found\n");
		return -ENODEV;
	}

	if (action <= 3 && action >= 0)
		zf_action = zf_action >> action;
	else
		action = 0;

	zf_show_action(action);

	if (!request_region(ZF_IOBASE, 3, "MachZ ZFL WDT")) {
		pr_err("cannot reserve I/O ports at %d\n", ZF_IOBASE);
		ret = -EBUSY;
		goto no_region;
	}

	ret = register_reboot_notifier(&zf_notifier);
	if (ret) {
		pr_err("can't register reboot notifier (err=%d)\n", ret);
		goto no_reboot;
	}

	ret = misc_register(&zf_miscdev);
	if (ret) {
		pr_err("can't misc_register on minor=%d\n", WATCHDOG_MINOR);
		goto no_misc;
	}

	zf_set_status(0);
	zf_set_control(0);

	return 0;

no_misc:
	unregister_reboot_notifier(&zf_notifier);
no_reboot:
	release_region(ZF_IOBASE, 3);
no_region:
	return ret;
}


static void __exit zf_exit(void)
{
	zf_timer_off();

	misc_deregister(&zf_miscdev);
	unregister_reboot_notifier(&zf_notifier);
	release_region(ZF_IOBASE, 3);
}

module_init(zf_init);
module_exit(zf_exit);
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
1da177e4 LT	2	/*
	3	* MachZ ZF-Logic Watchdog Timer driver for Linux
	4	*
1da177e4 LT	5	* The author does NOT admit liability nor provide warranty for
	6	* any of this software. This material is provided "AS-IS" in
	7	* the hope that it may be useful for others.
	8	*
	9	* Author: Fernando Fuganti <fuganti@conectiva.com.br>
	10	*
	11	* Based on sbc60xxwdt.c by Jakob Oestergaard
	12	*
1da177e4 LT	13	* We have two timers (wd#1, wd#2) driven by a 32 KHz clock with the
	14	* following periods:
	15	* wd#1 - 2 seconds;
	16	* wd#2 - 7.2 ms;
	17	* After the expiration of wd#1, it can generate a NMI, SCI, SMI, or
af901ca1	18	* a system RESET and it starts wd#2 that unconditionally will RESET
1da177e4 LT	19	* the system when the counter reaches zero.
	20	*
	21	* 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
	22	* Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
	23	*/
	24
27c766aa JP	25	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
27c766aa JP	26
1da177e4 LT	27	#include <linux/module.h>
	28	#include <linux/moduleparam.h>
	29	#include <linux/types.h>
	30	#include <linux/timer.h>
	31	#include <linux/jiffies.h>
	32	#include <linux/miscdevice.h>
	33	#include <linux/watchdog.h>
	34	#include <linux/fs.h>
	35	#include <linux/ioport.h>
	36	#include <linux/notifier.h>
	37	#include <linux/reboot.h>
	38	#include <linux/init.h>
325ea4d3 AC	39	#include <linux/io.h>
325ea4d3 AC	40	#include <linux/uaccess.h>
1da177e4	41
1da177e4 LT	42
	43	/* ports */
	44	#define ZF_IOBASE 0x218
	45	#define INDEX 0x218
	46	#define DATA_B 0x219
	47	#define DATA_W 0x21A
	48	#define DATA_D 0x21A
	49
	50	/* indexes / / size */
	51	#define ZFL_VERSION 0x02 /* 16 */
5f3b2756	52	#define CONTROL 0x10 /* 16 */
1da177e4 LT	53	#define STATUS 0x12 /* 8 */
	54	#define COUNTER_1 0x0C /* 16 */
	55	#define COUNTER_2 0x0E /* 8 */
	56	#define PULSE_LEN 0x0F /* 8 */
	57
	58	/* controls */
	59	#define ENABLE_WD1 0x0001
	60	#define ENABLE_WD2 0x0002
	61	#define RESET_WD1 0x0010
	62	#define RESET_WD2 0x0020
	63	#define GEN_SCI 0x0100
	64	#define GEN_NMI 0x0200
	65	#define GEN_SMI 0x0400
	66	#define GEN_RESET 0x0800
	67
	68
	69	/* utilities */
	70
	71	#define WD1 0
	72	#define WD2 1
	73
	74	#define zf_writew(port, data) { outb(port, INDEX); outw(data, DATA_W); }
	75	#define zf_writeb(port, data) { outb(port, INDEX); outb(data, DATA_B); }
	76	#define zf_get_ZFL_version() zf_readw(ZFL_VERSION)
	77
	78
	79	static unsigned short zf_readw(unsigned char port)
	80	{
	81	outb(port, INDEX);
	82	return inw(DATA_W);
	83	}
	84
	85
	86	MODULE_AUTHOR("Fernando Fuganti <fuganti@conectiva.com.br>");
	87	MODULE_DESCRIPTION("MachZ ZF-Logic Watchdog driver");
	88	MODULE_LICENSE("GPL");
1da177e4	89
86a1e189 WVS	90	static bool nowayout = WATCHDOG_NOWAYOUT;
86a1e189 WVS	91	module_param(nowayout, bool, 0);
325ea4d3 AC	92	MODULE_PARM_DESC(nowayout,
	93	"Watchdog cannot be stopped once started (default="
	94	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
1da177e4 LT	95
	96	#define PFX "machzwd"
	97
42747d71	98	static const struct watchdog_info zf_info = {
1da177e4 LT	99	.options = WDIOF_KEEPALIVEPING \| WDIOF_MAGICCLOSE,
	100	.firmware_version = 1,
	101	.identity = "ZF-Logic watchdog",
	102	};
	103
	104
	105	/*
	106	* action refers to action taken when watchdog resets
	107	* 0 = GEN_RESET
	108	* 1 = GEN_SMI
	109	* 2 = GEN_NMI
	110	* 3 = GEN_SCI
	111	* defaults to GEN_RESET (0)
	112	*/
325ea4d3	113	static int action;
1da177e4	114	module_param(action, int, 0);
a77dba7e WVS	115	MODULE_PARM_DESC(action, "after watchdog resets, generate: "
a77dba7e WVS	116	"0 = RESET(*) 1 = SMI 2 = NMI 3 = SCI");
1da177e4	117
24ed960a	118	static void zf_ping(struct timer_list *unused);
82eb7c50	119
1da177e4 LT	120	static int zf_action = GEN_RESET;
	121	static unsigned long zf_is_open;
	122	static char zf_expect_close;
c7dfd0cc	123	static DEFINE_SPINLOCK(zf_port_lock);
1d27e3e2	124	static DEFINE_TIMER(zf_timer, zf_ping);
325ea4d3	125	static unsigned long next_heartbeat;
1da177e4 LT	126
	127
	128	/* timeout for user land heart beat (10 seconds) */
	129	#define ZF_USER_TIMEO (HZ*10)
	130
	131	/* timeout for hardware watchdog (~500ms) */
	132	#define ZF_HW_TIMEO (HZ/2)
	133
	134	/* number of ticks on WD#1 (driven by a 32KHz clock, 2s) */
	135	#define ZF_CTIMEOUT 0xffff
	136
	137	#ifndef ZF_DEBUG
27c766aa	138	#define dprintk(format, args...)
1da177e4	139	#else
27c766aa JP	140	#define dprintk(format, args...) \
27c766aa JP	141	pr_debug(":%s:%d: " format, __func__, __LINE__ , ## args)
1da177e4 LT	142	#endif
	143
	144
	145	static inline void zf_set_status(unsigned char new)
	146	{
	147	zf_writeb(STATUS, new);
	148	}
	149
	150
	151	/* CONTROL register functions */
	152
	153	static inline unsigned short zf_get_control(void)
	154	{
	155	return zf_readw(CONTROL);
	156	}
	157
	158	static inline void zf_set_control(unsigned short new)
	159	{
	160	zf_writew(CONTROL, new);
	161	}
	162
	163
	164	/* WD#? counter functions */
	165	/*
	166	* Just set counter value
	167	*/
	168
	169	static inline void zf_set_timer(unsigned short new, unsigned char n)
	170	{
325ea4d3 AC	171	switch (n) {
	172	case WD1:
	173	zf_writew(COUNTER_1, new);
0843bdc1	174	/* fall through */
325ea4d3 AC	175	case WD2:
	176	zf_writeb(COUNTER_2, new > 0xff ? 0xff : new);
	177	default:
	178	return;
1da177e4 LT	179	}
	180	}
	181
	182	/*
	183	* stop hardware timer
	184	*/
	185	static void zf_timer_off(void)
	186	{
	187	unsigned int ctrl_reg = 0;
	188	unsigned long flags;
	189
	190	/* stop internal ping */
	191	del_timer_sync(&zf_timer);
	192
	193	spin_lock_irqsave(&zf_port_lock, flags);
	194	/* stop watchdog timer */
	195	ctrl_reg = zf_get_control();
	196	ctrl_reg \|= (ENABLE_WD1\|ENABLE_WD2); /* disable wd1 and wd2 */
	197	ctrl_reg &= ~(ENABLE_WD1\|ENABLE_WD2);
	198	zf_set_control(ctrl_reg);
	199	spin_unlock_irqrestore(&zf_port_lock, flags);
	200
27c766aa	201	pr_info("Watchdog timer is now disabled\n");
1da177e4 LT	202	}
	203
	204
	205	/*
	206	* start hardware timer
	207	*/
	208	static void zf_timer_on(void)
	209	{
	210	unsigned int ctrl_reg = 0;
	211	unsigned long flags;
	212
	213	spin_lock_irqsave(&zf_port_lock, flags);
	214
	215	zf_writeb(PULSE_LEN, 0xff);
	216
	217	zf_set_timer(ZF_CTIMEOUT, WD1);
	218
	219	/* user land ping */
	220	next_heartbeat = jiffies + ZF_USER_TIMEO;
	221
	222	/* start the timer for internal ping */
82eb7c50	223	mod_timer(&zf_timer, jiffies + ZF_HW_TIMEO);
1da177e4 LT	224
	225	/* start watchdog timer */
	226	ctrl_reg = zf_get_control();
	227	ctrl_reg \|= (ENABLE_WD1\|zf_action);
	228	zf_set_control(ctrl_reg);
	229	spin_unlock_irqrestore(&zf_port_lock, flags);
	230
27c766aa	231	pr_info("Watchdog timer is now enabled\n");
1da177e4 LT	232	}
	233
	234
24ed960a	235	static void zf_ping(struct timer_list *unused)
1da177e4 LT	236	{
	237	unsigned int ctrl_reg = 0;
	238	unsigned long flags;
	239
	240	zf_writeb(COUNTER_2, 0xff);
	241
325ea4d3	242	if (time_before(jiffies, next_heartbeat)) {
1da177e4	243	dprintk("time_before: %ld\n", next_heartbeat - jiffies);
1da177e4 LT	244	/*
	245	* reset event is activated by transition from 0 to 1 on
	246	* RESET_WD1 bit and we assume that it is already zero...
	247	*/
	248
	249	spin_lock_irqsave(&zf_port_lock, flags);
	250	ctrl_reg = zf_get_control();
	251	ctrl_reg \|= RESET_WD1;
	252	zf_set_control(ctrl_reg);
	253
	254	/* ...and nothing changes until here */
	255	ctrl_reg &= ~(RESET_WD1);
	256	zf_set_control(ctrl_reg);
	257	spin_unlock_irqrestore(&zf_port_lock, flags);
	258
82eb7c50	259	mod_timer(&zf_timer, jiffies + ZF_HW_TIMEO);
325ea4d3	260	} else
27c766aa	261	pr_crit("I will reset your machine\n");
1da177e4 LT	262	}
	263
	264	static ssize_t zf_write(struct file file, const char __user buf, size_t count,
	265	loff_t *ppos)
	266	{
	267	/* See if we got the magic character */
325ea4d3	268	if (count) {
1da177e4 LT	269	/*
	270	* no need to check for close confirmation
	271	* no way to disable watchdog ;)
	272	*/
	273	if (!nowayout) {
	274	size_t ofs;
1da177e4 LT	275	/*
	276	* note: just in case someone wrote the magic character
	277	* five months ago...
	278	*/
	279	zf_expect_close = 0;
	280
	281	/* now scan */
325ea4d3	282	for (ofs = 0; ofs != count; ofs++) {
1da177e4 LT	283	char c;
	284	if (get_user(c, buf + ofs))
	285	return -EFAULT;
325ea4d3	286	if (c == 'V') {
1da177e4 LT	287	zf_expect_close = 42;
	288	dprintk("zf_expect_close = 42\n");
	289	}
	290	}
	291	}
	292
	293	/*
	294	* Well, anyhow someone wrote to us,
	295	* we should return that favour
	296	*/
	297	next_heartbeat = jiffies + ZF_USER_TIMEO;
	298	dprintk("user ping at %ld\n", jiffies);
1da177e4	299	}
1da177e4 LT	300	return count;
	301	}
	302
325ea4d3	303	static long zf_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1da177e4 LT	304	{
	305	void __user argp = (void __user )arg;
	306	int __user *p = argp;
bad77057 AM	307	switch (cmd) {
	308	case WDIOC_GETSUPPORT:
	309	if (copy_to_user(argp, &zf_info, sizeof(zf_info)))
	310	return -EFAULT;
	311	break;
bad77057	312	case WDIOC_GETSTATUS:
5c4eb61b	313	case WDIOC_GETBOOTSTATUS:
bad77057	314	return put_user(0, p);
bad77057	315	case WDIOC_KEEPALIVE:
33052fbb	316	zf_ping(NULL);
bad77057	317	break;
bad77057 AM	318	default:
bad77057 AM	319	return -ENOTTY;
1da177e4	320	}
1da177e4 LT	321	return 0;
	322	}
	323
	324	static int zf_open(struct inode inode, struct file file)
	325	{
325ea4d3	326	if (test_and_set_bit(0, &zf_is_open))
1da177e4	327	return -EBUSY;
1da177e4 LT	328	if (nowayout)
1da177e4 LT	329	__module_get(THIS_MODULE);
1da177e4	330	zf_timer_on();
c5bf68fe	331	return stream_open(inode, file);
1da177e4 LT	332	}
	333
	334	static int zf_close(struct inode inode, struct file file)
	335	{
325ea4d3	336	if (zf_expect_close == 42)
1da177e4	337	zf_timer_off();
325ea4d3	338	else {
1da177e4	339	del_timer(&zf_timer);
27c766aa	340	pr_err("device file closed unexpectedly. Will not stop the WDT!\n");
1da177e4	341	}
1da177e4	342	clear_bit(0, &zf_is_open);
1da177e4	343	zf_expect_close = 0;
1da177e4 LT	344	return 0;
	345	}
	346
	347	/*
	348	* Notifier for system down
	349	*/
	350
	351	static int zf_notify_sys(struct notifier_block *this, unsigned long code,
	352	void *unused)
	353	{
325ea4d3	354	if (code == SYS_DOWN \|\| code == SYS_HALT)
1da177e4	355	zf_timer_off();
1da177e4 LT	356	return NOTIFY_DONE;
	357	}
	358
62322d25	359	static const struct file_operations zf_fops = {
325ea4d3 AC	360	.owner = THIS_MODULE,
	361	.llseek = no_llseek,
	362	.write = zf_write,
	363	.unlocked_ioctl = zf_ioctl,
	364	.open = zf_open,
	365	.release = zf_close,
1da177e4 LT	366	};
	367
	368	static struct miscdevice zf_miscdev = {
	369	.minor = WATCHDOG_MINOR,
	370	.name = "watchdog",
	371	.fops = &zf_fops,
	372	};
325ea4d3	373
1da177e4 LT	374
	375	/*
	376	* The device needs to learn about soft shutdowns in order to
	377	* turn the timebomb registers off.
	378	*/
	379	static struct notifier_block zf_notifier = {
	380	.notifier_call = zf_notify_sys,
	381	};
	382
	383	static void __init zf_show_action(int act)
	384	{
a2b89cd8	385	static const char * const str[] = { "RESET", "SMI", "NMI", "SCI" };
1da177e4	386
27c766aa	387	pr_info("Watchdog using action = %s\n", str[act]);
1da177e4 LT	388	}
	389
	390	static int __init zf_init(void)
	391	{
	392	int ret;
	393
27c766aa	394	pr_info("MachZ ZF-Logic Watchdog driver initializing\n");
1da177e4 LT	395
1da177e4 LT	396	ret = zf_get_ZFL_version();
325ea4d3	397	if (!ret \|\| ret == 0xffff) {
27c766aa	398	pr_warn("no ZF-Logic found\n");
1da177e4 LT	399	return -ENODEV;
	400	}
	401
325ea4d3 AC	402	if (action <= 3 && action >= 0)
	403	zf_action = zf_action >> action;
	404	else
1da177e4 LT	405	action = 0;
	406
	407	zf_show_action(action);
	408
325ea4d3	409	if (!request_region(ZF_IOBASE, 3, "MachZ ZFL WDT")) {
27c766aa	410	pr_err("cannot reserve I/O ports at %d\n", ZF_IOBASE);
1da177e4 LT	411	ret = -EBUSY;
	412	goto no_region;
	413	}
	414
	415	ret = register_reboot_notifier(&zf_notifier);
325ea4d3	416	if (ret) {
27c766aa	417	pr_err("can't register reboot notifier (err=%d)\n", ret);
1da177e4 LT	418	goto no_reboot;
	419	}
	420
fb8f7ba0	421	ret = misc_register(&zf_miscdev);
325ea4d3	422	if (ret) {
27c766aa	423	pr_err("can't misc_register on minor=%d\n", WATCHDOG_MINOR);
fb8f7ba0 AD	424	goto no_misc;
	425	}
	426
1da177e4 LT	427	zf_set_status(0);
	428	zf_set_control(0);
	429
1da177e4 LT	430	return 0;
1da177e4 LT	431
fb8f7ba0 AD	432	no_misc:
fb8f7ba0 AD	433	unregister_reboot_notifier(&zf_notifier);
1da177e4 LT	434	no_reboot:
	435	release_region(ZF_IOBASE, 3);
	436	no_region:
1da177e4 LT	437	return ret;
	438	}
	439
	440
	441	static void __exit zf_exit(void)
	442	{
	443	zf_timer_off();
	444
	445	misc_deregister(&zf_miscdev);
	446	unregister_reboot_notifier(&zf_notifier);
	447	release_region(ZF_IOBASE, 3);
	448	}
	449
	450	module_init(zf_init);
	451	module_exit(zf_exit);