[mirror_ubuntu-zesty-kernel.git] / drivers / watchdog / machzwd.c

/*
 *  MachZ ZF-Logic Watchdog Timer driver for Linux
 *
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  as published by the Free Software Foundation; either version
 *  2 of the License, or (at your option) any later version.
 *
 *  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 unconditionaly 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
 */

#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>

#include <asm/system.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");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);

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

#define PFX "machzwd"

static 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(unsigned long data);

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, 0, 0);
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...) printk(KERN_DEBUG PFX ":%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);
	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);

	printk(KERN_INFO PFX ": 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);

	printk(KERN_INFO PFX ": Watchdog timer is now enabled\n");
}


static void zf_ping(unsigned long data)
{
	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
		printk(KERN_CRIT PFX ": 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(0);
		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 nonseekable_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);
		printk(KERN_ERR PFX ": 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)
{
	char *str[] = { "RESET", "SMI", "NMI", "SCI" };

	printk(KERN_INFO PFX ": Watchdog using action = %s\n", str[act]);
}

static int __init zf_init(void)
{
	int ret;

	printk(KERN_INFO PFX
		": MachZ ZF-Logic Watchdog driver initializing.\n");

	ret = zf_get_ZFL_version();
	if (!ret || ret == 0xffff) {
		printk(KERN_WARNING PFX ": 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")) {
		printk(KERN_ERR "cannot reserve I/O ports at %d\n",
							ZF_IOBASE);
		ret = -EBUSY;
		goto no_region;
	}

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

	ret = misc_register(&zf_miscdev);
	if (ret) {
		printk(KERN_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
1da177e4 LT	1	/*
	2	* MachZ ZF-Logic Watchdog Timer driver for Linux
	3	*
	4	*
	5	* This program is free software; you can redistribute it and/or
	6	* modify it under the terms of the GNU General Public License
	7	* as published by the Free Software Foundation; either version
	8	* 2 of the License, or (at your option) any later version.
	9	*
	10	* The author does NOT admit liability nor provide warranty for
	11	* any of this software. This material is provided "AS-IS" in
	12	* the hope that it may be useful for others.
	13	*
	14	* Author: Fernando Fuganti <fuganti@conectiva.com.br>
	15	*
	16	* Based on sbc60xxwdt.c by Jakob Oestergaard
	17	*
	18	*
	19	* We have two timers (wd#1, wd#2) driven by a 32 KHz clock with the
	20	* following periods:
	21	* wd#1 - 2 seconds;
	22	* wd#2 - 7.2 ms;
	23	* After the expiration of wd#1, it can generate a NMI, SCI, SMI, or
	24	* a system RESET and it starts wd#2 that unconditionaly will RESET
	25	* the system when the counter reaches zero.
	26	*
	27	* 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
	28	* Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
	29	*/
	30
1da177e4 LT	31	#include <linux/module.h>
	32	#include <linux/moduleparam.h>
	33	#include <linux/types.h>
	34	#include <linux/timer.h>
	35	#include <linux/jiffies.h>
	36	#include <linux/miscdevice.h>
	37	#include <linux/watchdog.h>
	38	#include <linux/fs.h>
	39	#include <linux/ioport.h>
	40	#include <linux/notifier.h>
	41	#include <linux/reboot.h>
	42	#include <linux/init.h>
325ea4d3 AC	43	#include <linux/io.h>
325ea4d3 AC	44	#include <linux/uaccess.h>
1da177e4	45
1da177e4 LT	46	#include <asm/system.h>
	47
	48	/* ports */
	49	#define ZF_IOBASE 0x218
	50	#define INDEX 0x218
	51	#define DATA_B 0x219
	52	#define DATA_W 0x21A
	53	#define DATA_D 0x21A
	54
	55	/* indexes / / size */
	56	#define ZFL_VERSION 0x02 /* 16 */
	57	#define CONTROL 0x10 /* 16 */
	58	#define STATUS 0x12 /* 8 */
	59	#define COUNTER_1 0x0C /* 16 */
	60	#define COUNTER_2 0x0E /* 8 */
	61	#define PULSE_LEN 0x0F /* 8 */
	62
	63	/* controls */
	64	#define ENABLE_WD1 0x0001
	65	#define ENABLE_WD2 0x0002
	66	#define RESET_WD1 0x0010
	67	#define RESET_WD2 0x0020
	68	#define GEN_SCI 0x0100
	69	#define GEN_NMI 0x0200
	70	#define GEN_SMI 0x0400
	71	#define GEN_RESET 0x0800
	72
	73
	74	/* utilities */
	75
	76	#define WD1 0
	77	#define WD2 1
	78
	79	#define zf_writew(port, data) { outb(port, INDEX); outw(data, DATA_W); }
	80	#define zf_writeb(port, data) { outb(port, INDEX); outb(data, DATA_B); }
	81	#define zf_get_ZFL_version() zf_readw(ZFL_VERSION)
	82
	83
	84	static unsigned short zf_readw(unsigned char port)
	85	{
	86	outb(port, INDEX);
	87	return inw(DATA_W);
	88	}
	89
	90
	91	MODULE_AUTHOR("Fernando Fuganti <fuganti@conectiva.com.br>");
	92	MODULE_DESCRIPTION("MachZ ZF-Logic Watchdog driver");
	93	MODULE_LICENSE("GPL");
	94	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
	95
4bfdf378	96	static int nowayout = WATCHDOG_NOWAYOUT;
1da177e4	97	module_param(nowayout, int, 0);
325ea4d3 AC	98	MODULE_PARM_DESC(nowayout,
	99	"Watchdog cannot be stopped once started (default="
	100	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
1da177e4 LT	101
	102	#define PFX "machzwd"
	103
	104	static struct watchdog_info zf_info = {
	105	.options = WDIOF_KEEPALIVEPING \| WDIOF_MAGICCLOSE,
	106	.firmware_version = 1,
	107	.identity = "ZF-Logic watchdog",
	108	};
	109
	110
	111	/*
	112	* action refers to action taken when watchdog resets
	113	* 0 = GEN_RESET
	114	* 1 = GEN_SMI
	115	* 2 = GEN_NMI
	116	* 3 = GEN_SCI
	117	* defaults to GEN_RESET (0)
	118	*/
325ea4d3	119	static int action;
1da177e4 LT	120	module_param(action, int, 0);
	121	MODULE_PARM_DESC(action, "after watchdog resets, generate: 0 = RESET(*) 1 = SMI 2 = NMI 3 = SCI");
	122
82eb7c50 JS	123	static void zf_ping(unsigned long data);
82eb7c50 JS	124
1da177e4 LT	125	static int zf_action = GEN_RESET;
	126	static unsigned long zf_is_open;
	127	static char zf_expect_close;
c7dfd0cc	128	static DEFINE_SPINLOCK(zf_port_lock);
82eb7c50	129	static DEFINE_TIMER(zf_timer, zf_ping, 0, 0);
325ea4d3	130	static unsigned long next_heartbeat;
1da177e4 LT	131
	132
	133	/* timeout for user land heart beat (10 seconds) */
	134	#define ZF_USER_TIMEO (HZ*10)
	135
	136	/* timeout for hardware watchdog (~500ms) */
	137	#define ZF_HW_TIMEO (HZ/2)
	138
	139	/* number of ticks on WD#1 (driven by a 32KHz clock, 2s) */
	140	#define ZF_CTIMEOUT 0xffff
	141
	142	#ifndef ZF_DEBUG
	143	# define dprintk(format, args...)
	144	#else
fa9363c5	145	# define dprintk(format, args...) printk(KERN_DEBUG PFX ":%s:%d: " format, __func__, __LINE__ , ## args)
1da177e4 LT	146	#endif
	147
	148
	149	static inline void zf_set_status(unsigned char new)
	150	{
	151	zf_writeb(STATUS, new);
	152	}
	153
	154
	155	/* CONTROL register functions */
	156
	157	static inline unsigned short zf_get_control(void)
	158	{
	159	return zf_readw(CONTROL);
	160	}
	161
	162	static inline void zf_set_control(unsigned short new)
	163	{
	164	zf_writew(CONTROL, new);
	165	}
	166
	167
	168	/* WD#? counter functions */
	169	/*
	170	* Just set counter value
	171	*/
	172
	173	static inline void zf_set_timer(unsigned short new, unsigned char n)
	174	{
325ea4d3 AC	175	switch (n) {
	176	case WD1:
	177	zf_writew(COUNTER_1, new);
	178	case WD2:
	179	zf_writeb(COUNTER_2, new > 0xff ? 0xff : new);
	180	default:
	181	return;
1da177e4 LT	182	}
	183	}
	184
	185	/*
	186	* stop hardware timer
	187	*/
	188	static void zf_timer_off(void)
	189	{
	190	unsigned int ctrl_reg = 0;
	191	unsigned long flags;
	192
	193	/* stop internal ping */
	194	del_timer_sync(&zf_timer);
	195
	196	spin_lock_irqsave(&zf_port_lock, flags);
	197	/* stop watchdog timer */
	198	ctrl_reg = zf_get_control();
	199	ctrl_reg \|= (ENABLE_WD1\|ENABLE_WD2); /* disable wd1 and wd2 */
	200	ctrl_reg &= ~(ENABLE_WD1\|ENABLE_WD2);
	201	zf_set_control(ctrl_reg);
	202	spin_unlock_irqrestore(&zf_port_lock, flags);
	203
	204	printk(KERN_INFO PFX ": Watchdog timer is now disabled\n");
	205	}
	206
	207
	208	/*
	209	* start hardware timer
	210	*/
	211	static void zf_timer_on(void)
	212	{
	213	unsigned int ctrl_reg = 0;
	214	unsigned long flags;
	215
	216	spin_lock_irqsave(&zf_port_lock, flags);
	217
	218	zf_writeb(PULSE_LEN, 0xff);
	219
	220	zf_set_timer(ZF_CTIMEOUT, WD1);
	221
	222	/* user land ping */
	223	next_heartbeat = jiffies + ZF_USER_TIMEO;
	224
	225	/* start the timer for internal ping */
82eb7c50	226	mod_timer(&zf_timer, jiffies + ZF_HW_TIMEO);
1da177e4 LT	227
	228	/* start watchdog timer */
	229	ctrl_reg = zf_get_control();
	230	ctrl_reg \|= (ENABLE_WD1\|zf_action);
	231	zf_set_control(ctrl_reg);
	232	spin_unlock_irqrestore(&zf_port_lock, flags);
	233
	234	printk(KERN_INFO PFX ": Watchdog timer is now enabled\n");
	235	}
	236
	237
	238	static void zf_ping(unsigned long data)
	239	{
	240	unsigned int ctrl_reg = 0;
	241	unsigned long flags;
	242
	243	zf_writeb(COUNTER_2, 0xff);
	244
325ea4d3	245	if (time_before(jiffies, next_heartbeat)) {
1da177e4	246	dprintk("time_before: %ld\n", next_heartbeat - jiffies);
1da177e4 LT	247	/*
	248	* reset event is activated by transition from 0 to 1 on
	249	* RESET_WD1 bit and we assume that it is already zero...
	250	*/
	251
	252	spin_lock_irqsave(&zf_port_lock, flags);
	253	ctrl_reg = zf_get_control();
	254	ctrl_reg \|= RESET_WD1;
	255	zf_set_control(ctrl_reg);
	256
	257	/* ...and nothing changes until here */
	258	ctrl_reg &= ~(RESET_WD1);
	259	zf_set_control(ctrl_reg);
	260	spin_unlock_irqrestore(&zf_port_lock, flags);
	261
82eb7c50	262	mod_timer(&zf_timer, jiffies + ZF_HW_TIMEO);
325ea4d3	263	} else
1da177e4	264	printk(KERN_CRIT PFX ": I will reset your machine\n");
1da177e4 LT	265	}
	266
	267	static ssize_t zf_write(struct file file, const char __user buf, size_t count,
	268	loff_t *ppos)
	269	{
	270	/* See if we got the magic character */
325ea4d3	271	if (count) {
1da177e4 LT	272	/*
	273	* no need to check for close confirmation
	274	* no way to disable watchdog ;)
	275	*/
	276	if (!nowayout) {
	277	size_t ofs;
1da177e4 LT	278	/*
	279	* note: just in case someone wrote the magic character
	280	* five months ago...
	281	*/
	282	zf_expect_close = 0;
	283
	284	/* now scan */
325ea4d3	285	for (ofs = 0; ofs != count; ofs++) {
1da177e4 LT	286	char c;
	287	if (get_user(c, buf + ofs))
	288	return -EFAULT;
325ea4d3	289	if (c == 'V') {
1da177e4 LT	290	zf_expect_close = 42;
	291	dprintk("zf_expect_close = 42\n");
	292	}
	293	}
	294	}
	295
	296	/*
	297	* Well, anyhow someone wrote to us,
	298	* we should return that favour
	299	*/
	300	next_heartbeat = jiffies + ZF_USER_TIMEO;
	301	dprintk("user ping at %ld\n", jiffies);
1da177e4	302	}
1da177e4 LT	303	return count;
	304	}
	305
325ea4d3	306	static long zf_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1da177e4 LT	307	{
	308	void __user argp = (void __user )arg;
	309	int __user *p = argp;
bad77057 AM	310	switch (cmd) {
	311	case WDIOC_GETSUPPORT:
	312	if (copy_to_user(argp, &zf_info, sizeof(zf_info)))
	313	return -EFAULT;
	314	break;
bad77057	315	case WDIOC_GETSTATUS:
5c4eb61b	316	case WDIOC_GETBOOTSTATUS:
bad77057	317	return put_user(0, p);
bad77057 AM	318	case WDIOC_KEEPALIVE:
	319	zf_ping(0);
	320	break;
bad77057 AM	321	default:
bad77057 AM	322	return -ENOTTY;
1da177e4	323	}
1da177e4 LT	324	return 0;
	325	}
	326
	327	static int zf_open(struct inode inode, struct file file)
	328	{
325ea4d3	329	if (test_and_set_bit(0, &zf_is_open))
1da177e4	330	return -EBUSY;
1da177e4 LT	331	if (nowayout)
1da177e4 LT	332	__module_get(THIS_MODULE);
1da177e4	333	zf_timer_on();
1da177e4 LT	334	return nonseekable_open(inode, file);
	335	}
	336
	337	static int zf_close(struct inode inode, struct file file)
	338	{
325ea4d3	339	if (zf_expect_close == 42)
1da177e4	340	zf_timer_off();
325ea4d3	341	else {
1da177e4 LT	342	del_timer(&zf_timer);
	343	printk(KERN_ERR PFX ": device file closed unexpectedly. Will not stop the WDT!\n");
	344	}
1da177e4	345	clear_bit(0, &zf_is_open);
1da177e4	346	zf_expect_close = 0;
1da177e4 LT	347	return 0;
	348	}
	349
	350	/*
	351	* Notifier for system down
	352	*/
	353
	354	static int zf_notify_sys(struct notifier_block *this, unsigned long code,
	355	void *unused)
	356	{
325ea4d3	357	if (code == SYS_DOWN \|\| code == SYS_HALT)
1da177e4	358	zf_timer_off();
1da177e4 LT	359	return NOTIFY_DONE;
	360	}
	361
62322d25	362	static const struct file_operations zf_fops = {
325ea4d3 AC	363	.owner = THIS_MODULE,
	364	.llseek = no_llseek,
	365	.write = zf_write,
	366	.unlocked_ioctl = zf_ioctl,
	367	.open = zf_open,
	368	.release = zf_close,
1da177e4 LT	369	};
	370
	371	static struct miscdevice zf_miscdev = {
	372	.minor = WATCHDOG_MINOR,
	373	.name = "watchdog",
	374	.fops = &zf_fops,
	375	};
325ea4d3	376
1da177e4 LT	377
	378	/*
	379	* The device needs to learn about soft shutdowns in order to
	380	* turn the timebomb registers off.
	381	*/
	382	static struct notifier_block zf_notifier = {
	383	.notifier_call = zf_notify_sys,
	384	};
	385
	386	static void __init zf_show_action(int act)
	387	{
	388	char *str[] = { "RESET", "SMI", "NMI", "SCI" };
	389
	390	printk(KERN_INFO PFX ": Watchdog using action = %s\n", str[act]);
	391	}
	392
	393	static int __init zf_init(void)
	394	{
	395	int ret;
	396
325ea4d3 AC	397	printk(KERN_INFO PFX
325ea4d3 AC	398	": MachZ ZF-Logic Watchdog driver initializing.\n");
1da177e4 LT	399
1da177e4 LT	400	ret = zf_get_ZFL_version();
325ea4d3	401	if (!ret \|\| ret == 0xffff) {
1da177e4 LT	402	printk(KERN_WARNING PFX ": no ZF-Logic found\n");
	403	return -ENODEV;
	404	}
	405
325ea4d3 AC	406	if (action <= 3 && action >= 0)
	407	zf_action = zf_action >> action;
	408	else
1da177e4 LT	409	action = 0;
	410
	411	zf_show_action(action);
	412
325ea4d3	413	if (!request_region(ZF_IOBASE, 3, "MachZ ZFL WDT")) {
1da177e4 LT	414	printk(KERN_ERR "cannot reserve I/O ports at %d\n",
	415	ZF_IOBASE);
	416	ret = -EBUSY;
	417	goto no_region;
	418	}
	419
	420	ret = register_reboot_notifier(&zf_notifier);
325ea4d3	421	if (ret) {
1da177e4 LT	422	printk(KERN_ERR "can't register reboot notifier (err=%d)\n",
	423	ret);
	424	goto no_reboot;
	425	}
	426
fb8f7ba0	427	ret = misc_register(&zf_miscdev);
325ea4d3	428	if (ret) {
fb8f7ba0 AD	429	printk(KERN_ERR "can't misc_register on minor=%d\n",
	430	WATCHDOG_MINOR);
	431	goto no_misc;
	432	}
	433
1da177e4 LT	434	zf_set_status(0);
	435	zf_set_control(0);
	436
1da177e4 LT	437	return 0;
1da177e4 LT	438
fb8f7ba0 AD	439	no_misc:
fb8f7ba0 AD	440	unregister_reboot_notifier(&zf_notifier);
1da177e4 LT	441	no_reboot:
	442	release_region(ZF_IOBASE, 3);
	443	no_region:
1da177e4 LT	444	return ret;
	445	}
	446
	447
	448	static void __exit zf_exit(void)
	449	{
	450	zf_timer_off();
	451
	452	misc_deregister(&zf_miscdev);
	453	unregister_reboot_notifier(&zf_notifier);
	454	release_region(ZF_IOBASE, 3);
	455	}
	456
	457	module_init(zf_init);
	458	module_exit(zf_exit);