[deliverable/linux.git] / drivers / watchdog / wafer5823wdt.c

/*
 *	ICP Wafer 5823 Single Board Computer WDT driver
 *      http://www.icpamerica.com/wafer_5823.php
 *      May also work on other similar models
 *
 *	(c) Copyright 2002 Justin Cormack <justin@street-vision.com>
 *
 *      Release 0.02
 *
 *	Based on advantechwdt.c which is based on wdt.c.
 *	Original copyright messages:
 *
 *	(c) Copyright 1996-1997 Alan Cox <alan@redhat.com>, All Rights Reserved.
 *				http://www.redhat.com
 *
 *	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.
 *
 *	Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
 *	warranty for any of this software. This material is provided
 *	"AS-IS" and at no charge.
 *
 *	(c) Copyright 1995    Alan Cox <alan@lxorguk.ukuu.org.uk>
 *
 */

#include <linux/module.h>
#include <linux/moduleparam.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/spinlock.h>
#include <linux/io.h>
#include <linux/uaccess.h>

#define WATCHDOG_NAME "Wafer 5823 WDT"
#define PFX WATCHDOG_NAME ": "
#define WD_TIMO 60			/* 60 sec default timeout */

static unsigned long wafwdt_is_open;
static char expect_close;
static DEFINE_SPINLOCK(wafwdt_lock);

/*
 *	You must set these - there is no sane way to probe for this board.
 *
 *      To enable, write the timeout value in seconds (1 to 255) to I/O
 *      port WDT_START, then read the port to start the watchdog. To pat
 *      the dog, read port WDT_STOP to stop the timer, then read WDT_START
 *      to restart it again.
 */

static int wdt_stop = 0x843;
static int wdt_start = 0x443;

static int timeout = WD_TIMO;  /* in seconds */
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout,
		"Watchdog timeout in seconds. 1 <= timeout <= 255, default="
				__MODULE_STRING(WD_TIMO) ".");

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) ")");

static void wafwdt_ping(void)
{
	/* pat watchdog */
	spin_lock(&wafwdt_lock);
	inb_p(wdt_stop);
	inb_p(wdt_start);
	spin_unlock(&wafwdt_lock);
}

static void wafwdt_start(void)
{
	/* start up watchdog */
	outb_p(timeout, wdt_start);
	inb_p(wdt_start);
}

static void
wafwdt_stop(void)
{
	/* stop watchdog */
	inb_p(wdt_stop);
}

static ssize_t wafwdt_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 i;

			/* In case it was set long ago */
			expect_close = 0;

			/* scan to see whether or not we got the magic
			   character */
			for (i = 0; i != count; i++) {
				char c;
				if (get_user(c, buf + i))
					return -EFAULT;
				if (c == 'V')
					expect_close = 42;
			}
		}
		/* Well, anyhow someone wrote to us, we should
		   return that favour */
		wafwdt_ping();
	}
	return count;
}

static long wafwdt_ioctl(struct file *file, unsigned int cmd,
							unsigned long arg)
{
	int new_timeout;
	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 = "Wafer 5823 WDT",
	};

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

	case WDIOC_GETSTATUS:
	case WDIOC_GETBOOTSTATUS:
		return put_user(0, p);

	case WDIOC_SETOPTIONS:
	{
		int options, retval = -EINVAL;

		if (get_user(options, p))
			return -EFAULT;

		if (options & WDIOS_DISABLECARD) {
			wafwdt_start();
			retval = 0;
		}

		if (options & WDIOS_ENABLECARD) {
			wafwdt_stop();
			retval = 0;
		}

		return retval;
	}

	case WDIOC_KEEPALIVE:
		wafwdt_ping();
		break;

	case WDIOC_SETTIMEOUT:
		if (get_user(new_timeout, p))
			return -EFAULT;
		if ((new_timeout < 1) || (new_timeout > 255))
			return -EINVAL;
		timeout = new_timeout;
		wafwdt_stop();
		wafwdt_start();
		/* Fall */
	case WDIOC_GETTIMEOUT:
		return put_user(timeout, p);

	default:
		return -ENOTTY;
	}
	return 0;
}

static int wafwdt_open(struct inode *inode, struct file *file)
{
	if (test_and_set_bit(0, &wafwdt_is_open))
		return -EBUSY;

	/*
	 *      Activate
	 */
	wafwdt_start();
	return nonseekable_open(inode, file);
}

static int
wafwdt_close(struct inode *inode, struct file *file)
{
	if (expect_close == 42)
		wafwdt_stop();
	else {
		printk(KERN_CRIT PFX
		    "WDT device closed unexpectedly.  WDT will not stop!\n");
		wafwdt_ping();
	}
	clear_bit(0, &wafwdt_is_open);
	expect_close = 0;
	return 0;
}

/*
 *	Notifier for system down
 */

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

/*
 *	Kernel Interfaces
 */

static const struct file_operations wafwdt_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.write		= wafwdt_write,
	.unlocked_ioctl	= wafwdt_ioctl,
	.open		= wafwdt_open,
	.release	= wafwdt_close,
};

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

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

static struct notifier_block wafwdt_notifier = {
	.notifier_call = wafwdt_notify_sys,
};

static int __init wafwdt_init(void)
{
	int ret;

	printk(KERN_INFO
	  "WDT driver for Wafer 5823 single board computer initialising.\n");

	if (timeout < 1 || timeout > 255) {
		timeout = WD_TIMO;
		printk(KERN_INFO PFX
			"timeout value must be 1 <= x <= 255, using %d\n",
								timeout);
	}

	if (wdt_stop != wdt_start) {
		if (!request_region(wdt_stop, 1, "Wafer 5823 WDT")) {
			printk(KERN_ERR PFX
				"I/O address 0x%04x already in use\n",
								wdt_stop);
			ret = -EIO;
			goto error;
		}
	}

	if (!request_region(wdt_start, 1, "Wafer 5823 WDT")) {
		printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
			wdt_start);
		ret = -EIO;
		goto error2;
	}

	ret = register_reboot_notifier(&wafwdt_notifier);
	if (ret != 0) {
		printk(KERN_ERR PFX
			"cannot register reboot notifier (err=%d)\n", ret);
		goto error3;
	}

	ret = misc_register(&wafwdt_miscdev);
	if (ret != 0) {
		printk(KERN_ERR PFX
			"cannot register miscdev on minor=%d (err=%d)\n",
						WATCHDOG_MINOR, ret);
		goto error4;
	}

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

	return ret;
error4:
	unregister_reboot_notifier(&wafwdt_notifier);
error3:
	release_region(wdt_start, 1);
error2:
	if (wdt_stop != wdt_start)
		release_region(wdt_stop, 1);
error:
	return ret;
}

static void __exit wafwdt_exit(void)
{
	misc_deregister(&wafwdt_miscdev);
	unregister_reboot_notifier(&wafwdt_notifier);
	if (wdt_stop != wdt_start)
		release_region(wdt_stop, 1);
	release_region(wdt_start, 1);
}

module_init(wafwdt_init);
module_exit(wafwdt_exit);

MODULE_AUTHOR("Justin Cormack");
MODULE_DESCRIPTION("ICP Wafer 5823 Single Board Computer WDT driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);

/* end of wafer5823wdt.c */
Commit	Line	Data
1da177e4 LT	1	/*
	2	* ICP Wafer 5823 Single Board Computer WDT driver
	3	* http://www.icpamerica.com/wafer_5823.php
	4	* May also work on other similar models
	5	*
	6	* (c) Copyright 2002 Justin Cormack <justin@street-vision.com>
	7	*
	8	* Release 0.02
	9	*
	10	* Based on advantechwdt.c which is based on wdt.c.
	11	* Original copyright messages:
	12	*
	13	* (c) Copyright 1996-1997 Alan Cox <alan@redhat.com>, All Rights Reserved.
	14	* http://www.redhat.com
	15	*
	16	* This program is free software; you can redistribute it and/or
	17	* modify it under the terms of the GNU General Public License
	18	* as published by the Free Software Foundation; either version
	19	* 2 of the License, or (at your option) any later version.
	20	*
	21	* Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
	22	* warranty for any of this software. This material is provided
	23	* "AS-IS" and at no charge.
	24	*
	25	* (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>
	26	*
	27	*/
	28
	29	#include <linux/module.h>
	30	#include <linux/moduleparam.h>
	31	#include <linux/miscdevice.h>
	32	#include <linux/watchdog.h>
	33	#include <linux/fs.h>
	34	#include <linux/ioport.h>
	35	#include <linux/notifier.h>
	36	#include <linux/reboot.h>
	37	#include <linux/init.h>
	38	#include <linux/spinlock.h>
694b16b2 AC	39	#include <linux/io.h>
694b16b2 AC	40	#include <linux/uaccess.h>
1da177e4 LT	41
	42	#define WATCHDOG_NAME "Wafer 5823 WDT"
	43	#define PFX WATCHDOG_NAME ": "
	44	#define WD_TIMO 60 /* 60 sec default timeout */
	45
	46	static unsigned long wafwdt_is_open;
	47	static char expect_close;
c7dfd0cc	48	static DEFINE_SPINLOCK(wafwdt_lock);
1da177e4 LT	49
	50	/*
	51	* You must set these - there is no sane way to probe for this board.
	52	*
	53	* To enable, write the timeout value in seconds (1 to 255) to I/O
	54	* port WDT_START, then read the port to start the watchdog. To pat
	55	* the dog, read port WDT_STOP to stop the timer, then read WDT_START
	56	* to restart it again.
	57	*/
	58
	59	static int wdt_stop = 0x843;
	60	static int wdt_start = 0x443;
	61
	62	static int timeout = WD_TIMO; /* in seconds */
	63	module_param(timeout, int, 0);
694b16b2 AC	64	MODULE_PARM_DESC(timeout,
	65	"Watchdog timeout in seconds. 1 <= timeout <= 255, default="
	66	__MODULE_STRING(WD_TIMO) ".");
1da177e4	67
4bfdf378	68	static int nowayout = WATCHDOG_NOWAYOUT;
1da177e4	69	module_param(nowayout, int, 0);
694b16b2 AC	70	MODULE_PARM_DESC(nowayout,
	71	"Watchdog cannot be stopped once started (default="
	72	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
1da177e4 LT	73
	74	static void wafwdt_ping(void)
	75	{
	76	/* pat watchdog */
	77	spin_lock(&wafwdt_lock);
	78	inb_p(wdt_stop);
	79	inb_p(wdt_start);
	80	spin_unlock(&wafwdt_lock);
	81	}
	82
	83	static void wafwdt_start(void)
	84	{
	85	/* start up watchdog */
	86	outb_p(timeout, wdt_start);
	87	inb_p(wdt_start);
	88	}
	89
	90	static void
	91	wafwdt_stop(void)
	92	{
	93	/* stop watchdog */
	94	inb_p(wdt_stop);
	95	}
	96
694b16b2 AC	97	static ssize_t wafwdt_write(struct file file, const char __user buf,
694b16b2 AC	98	size_t count, loff_t *ppos)
1da177e4 LT	99	{
	100	/* See if we got the magic character 'V' and reload the timer */
	101	if (count) {
	102	if (!nowayout) {
	103	size_t i;
	104
	105	/* In case it was set long ago */
	106	expect_close = 0;
	107
694b16b2 AC	108	/* scan to see whether or not we got the magic
694b16b2 AC	109	character */
1da177e4 LT	110	for (i = 0; i != count; i++) {
	111	char c;
	112	if (get_user(c, buf + i))
	113	return -EFAULT;
	114	if (c == 'V')
	115	expect_close = 42;
	116	}
	117	}
694b16b2 AC	118	/* Well, anyhow someone wrote to us, we should
694b16b2 AC	119	return that favour */
1da177e4 LT	120	wafwdt_ping();
	121	}
	122	return count;
	123	}
	124
694b16b2 AC	125	static long wafwdt_ioctl(struct file *file, unsigned int cmd,
694b16b2 AC	126	unsigned long arg)
1da177e4 LT	127	{
	128	int new_timeout;
	129	void __user argp = (void __user )arg;
	130	int __user *p = argp;
694b16b2 AC	131	static const struct watchdog_info ident = {
	132	.options = WDIOF_KEEPALIVEPING \| WDIOF_SETTIMEOUT \|
	133	WDIOF_MAGICCLOSE,
1da177e4 LT	134	.firmware_version = 1,
	135	.identity = "Wafer 5823 WDT",
	136	};
	137
	138	switch (cmd) {
	139	case WDIOC_GETSUPPORT:
694b16b2	140	if (copy_to_user(argp, &ident, sizeof(ident)))
1da177e4 LT	141	return -EFAULT;
	142	break;
	143
	144	case WDIOC_GETSTATUS:
	145	case WDIOC_GETBOOTSTATUS:
	146	return put_user(0, p);
	147
1da177e4 LT	148	case WDIOC_SETOPTIONS:
	149	{
	150	int options, retval = -EINVAL;
	151
	152	if (get_user(options, p))
	153	return -EFAULT;
	154
	155	if (options & WDIOS_DISABLECARD) {
	156	wafwdt_start();
	157	retval = 0;
	158	}
	159
	160	if (options & WDIOS_ENABLECARD) {
	161	wafwdt_stop();
	162	retval = 0;
	163	}
	164
	165	return retval;
	166	}
	167
0c06090c WVS	168	case WDIOC_KEEPALIVE:
	169	wafwdt_ping();
	170	break;
	171
	172	case WDIOC_SETTIMEOUT:
	173	if (get_user(new_timeout, p))
	174	return -EFAULT;
	175	if ((new_timeout < 1) \|\| (new_timeout > 255))
	176	return -EINVAL;
	177	timeout = new_timeout;
	178	wafwdt_stop();
	179	wafwdt_start();
	180	/* Fall */
	181	case WDIOC_GETTIMEOUT:
	182	return put_user(timeout, p);
	183
1da177e4	184	default:
795b89d2	185	return -ENOTTY;
1da177e4 LT	186	}
	187	return 0;
	188	}
	189
	190	static int wafwdt_open(struct inode inode, struct file file)
	191	{
	192	if (test_and_set_bit(0, &wafwdt_is_open))
	193	return -EBUSY;
	194
	195	/*
	196	* Activate
	197	*/
	198	wafwdt_start();
	199	return nonseekable_open(inode, file);
	200	}
	201
	202	static int
	203	wafwdt_close(struct inode inode, struct file file)
	204	{
694b16b2	205	if (expect_close == 42)
1da177e4	206	wafwdt_stop();
694b16b2 AC	207	else {
	208	printk(KERN_CRIT PFX
	209	"WDT device closed unexpectedly. WDT will not stop!\n");
1da177e4 LT	210	wafwdt_ping();
	211	}
	212	clear_bit(0, &wafwdt_is_open);
	213	expect_close = 0;
	214	return 0;
	215	}
	216
	217	/*
	218	* Notifier for system down
	219	*/
	220
694b16b2 AC	221	static int wafwdt_notify_sys(struct notifier_block *this, unsigned long code,
694b16b2 AC	222	void *unused)
1da177e4	223	{
694b16b2	224	if (code == SYS_DOWN \|\| code == SYS_HALT)
1da177e4	225	wafwdt_stop();
1da177e4 LT	226	return NOTIFY_DONE;
	227	}
	228
	229	/*
	230	* Kernel Interfaces
	231	*/
	232
62322d25	233	static const struct file_operations wafwdt_fops = {
1da177e4 LT	234	.owner = THIS_MODULE,
	235	.llseek = no_llseek,
	236	.write = wafwdt_write,
694b16b2	237	.unlocked_ioctl = wafwdt_ioctl,
1da177e4 LT	238	.open = wafwdt_open,
	239	.release = wafwdt_close,
	240	};
	241
	242	static struct miscdevice wafwdt_miscdev = {
	243	.minor = WATCHDOG_MINOR,
	244	.name = "watchdog",
	245	.fops = &wafwdt_fops,
	246	};
	247
	248	/*
	249	* The WDT needs to learn about soft shutdowns in order to
	250	* turn the timebomb registers off.
	251	*/
	252
	253	static struct notifier_block wafwdt_notifier = {
	254	.notifier_call = wafwdt_notify_sys,
	255	};
	256
	257	static int __init wafwdt_init(void)
	258	{
	259	int ret;
	260
694b16b2 AC	261	printk(KERN_INFO
694b16b2 AC	262	"WDT driver for Wafer 5823 single board computer initialising.\n");
1da177e4	263
1da177e4 LT	264	if (timeout < 1 \|\| timeout > 255) {
1da177e4 LT	265	timeout = WD_TIMO;
694b16b2 AC	266	printk(KERN_INFO PFX
	267	"timeout value must be 1 <= x <= 255, using %d\n",
	268	timeout);
1da177e4 LT	269	}
	270
	271	if (wdt_stop != wdt_start) {
694b16b2 AC	272	if (!request_region(wdt_stop, 1, "Wafer 5823 WDT")) {
	273	printk(KERN_ERR PFX
	274	"I/O address 0x%04x already in use\n",
	275	wdt_stop);
1da177e4 LT	276	ret = -EIO;
	277	goto error;
	278	}
	279	}
	280
694b16b2 AC	281	if (!request_region(wdt_start, 1, "Wafer 5823 WDT")) {
694b16b2 AC	282	printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
1da177e4 LT	283	wdt_start);
	284	ret = -EIO;
	285	goto error2;
	286	}
	287
	288	ret = register_reboot_notifier(&wafwdt_notifier);
	289	if (ret != 0) {
694b16b2 AC	290	printk(KERN_ERR PFX
694b16b2 AC	291	"cannot register reboot notifier (err=%d)\n", ret);
1da177e4 LT	292	goto error3;
	293	}
	294
	295	ret = misc_register(&wafwdt_miscdev);
	296	if (ret != 0) {
694b16b2 AC	297	printk(KERN_ERR PFX
	298	"cannot register miscdev on minor=%d (err=%d)\n",
	299	WATCHDOG_MINOR, ret);
1da177e4 LT	300	goto error4;
	301	}
	302
694b16b2	303	printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
1da177e4 LT	304	timeout, nowayout);
	305
	306	return ret;
	307	error4:
	308	unregister_reboot_notifier(&wafwdt_notifier);
	309	error3:
	310	release_region(wdt_start, 1);
	311	error2:
	312	if (wdt_stop != wdt_start)
	313	release_region(wdt_stop, 1);
	314	error:
	315	return ret;
	316	}
	317
	318	static void __exit wafwdt_exit(void)
	319	{
	320	misc_deregister(&wafwdt_miscdev);
	321	unregister_reboot_notifier(&wafwdt_notifier);
694b16b2	322	if (wdt_stop != wdt_start)
1da177e4 LT	323	release_region(wdt_stop, 1);
	324	release_region(wdt_start, 1);
	325	}
	326
	327	module_init(wafwdt_init);
	328	module_exit(wafwdt_exit);
	329
	330	MODULE_AUTHOR("Justin Cormack");
	331	MODULE_DESCRIPTION("ICP Wafer 5823 Single Board Computer WDT driver");
	332	MODULE_LICENSE("GPL");
	333	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
	334
	335	/* end of wafer5823wdt.c */