[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	/*
1da177e4 LT	2	* ICP Wafer 5823 Single Board Computer WDT driver
7944d3a5 WVS	3	* http://www.icpamerica.com/wafer_5823.php
7944d3a5 WVS	4	* May also work on other similar models
1da177e4 LT	5	*
	6	* (c) Copyright 2002 Justin Cormack <justin@street-vision.com>
	7	*
7944d3a5	8	* Release 0.02
1da177e4 LT	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	*
7944d3a5 WVS	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.
1da177e4 LT	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
7944d3a5	90	static void wafwdt_stop(void)
1da177e4 LT	91	{
	92	/* stop watchdog */
	93	inb_p(wdt_stop);
	94	}
	95
694b16b2 AC	96	static ssize_t wafwdt_write(struct file file, const char __user buf,
694b16b2 AC	97	size_t count, loff_t *ppos)
1da177e4 LT	98	{
	99	/* See if we got the magic character 'V' and reload the timer */
	100	if (count) {
	101	if (!nowayout) {
	102	size_t i;
	103
	104	/* In case it was set long ago */
	105	expect_close = 0;
	106
694b16b2 AC	107	/* scan to see whether or not we got the magic
694b16b2 AC	108	character */
1da177e4 LT	109	for (i = 0; i != count; i++) {
	110	char c;
	111	if (get_user(c, buf + i))
	112	return -EFAULT;
	113	if (c == 'V')
	114	expect_close = 42;
	115	}
	116	}
694b16b2 AC	117	/* Well, anyhow someone wrote to us, we should
694b16b2 AC	118	return that favour */
1da177e4 LT	119	wafwdt_ping();
	120	}
	121	return count;
	122	}
	123
694b16b2 AC	124	static long wafwdt_ioctl(struct file *file, unsigned int cmd,
694b16b2 AC	125	unsigned long arg)
1da177e4 LT	126	{
	127	int new_timeout;
	128	void __user argp = (void __user )arg;
	129	int __user *p = argp;
694b16b2 AC	130	static const struct watchdog_info ident = {
	131	.options = WDIOF_KEEPALIVEPING \| WDIOF_SETTIMEOUT \|
	132	WDIOF_MAGICCLOSE,
1da177e4 LT	133	.firmware_version = 1,
	134	.identity = "Wafer 5823 WDT",
	135	};
	136
	137	switch (cmd) {
	138	case WDIOC_GETSUPPORT:
694b16b2	139	if (copy_to_user(argp, &ident, sizeof(ident)))
1da177e4 LT	140	return -EFAULT;
	141	break;
	142
	143	case WDIOC_GETSTATUS:
	144	case WDIOC_GETBOOTSTATUS:
	145	return put_user(0, p);
	146
1da177e4 LT	147	case WDIOC_SETOPTIONS:
	148	{
	149	int options, retval = -EINVAL;
	150
	151	if (get_user(options, p))
	152	return -EFAULT;
	153
	154	if (options & WDIOS_DISABLECARD) {
	155	wafwdt_start();
	156	retval = 0;
	157	}
	158
	159	if (options & WDIOS_ENABLECARD) {
	160	wafwdt_stop();
	161	retval = 0;
	162	}
	163
	164	return retval;
	165	}
	166
0c06090c WVS	167	case WDIOC_KEEPALIVE:
	168	wafwdt_ping();
	169	break;
	170
	171	case WDIOC_SETTIMEOUT:
	172	if (get_user(new_timeout, p))
	173	return -EFAULT;
	174	if ((new_timeout < 1) \|\| (new_timeout > 255))
	175	return -EINVAL;
	176	timeout = new_timeout;
	177	wafwdt_stop();
	178	wafwdt_start();
	179	/* Fall */
	180	case WDIOC_GETTIMEOUT:
	181	return put_user(timeout, p);
	182
1da177e4	183	default:
795b89d2	184	return -ENOTTY;
1da177e4 LT	185	}
	186	return 0;
	187	}
	188
	189	static int wafwdt_open(struct inode inode, struct file file)
	190	{
	191	if (test_and_set_bit(0, &wafwdt_is_open))
	192	return -EBUSY;
	193
	194	/*
	195	* Activate
	196	*/
	197	wafwdt_start();
	198	return nonseekable_open(inode, file);
	199	}
	200
7944d3a5	201	static int wafwdt_close(struct inode inode, struct file file)
1da177e4	202	{
694b16b2	203	if (expect_close == 42)
1da177e4	204	wafwdt_stop();
694b16b2 AC	205	else {
	206	printk(KERN_CRIT PFX
	207	"WDT device closed unexpectedly. WDT will not stop!\n");
1da177e4 LT	208	wafwdt_ping();
	209	}
	210	clear_bit(0, &wafwdt_is_open);
	211	expect_close = 0;
	212	return 0;
	213	}
	214
	215	/*
	216	* Notifier for system down
	217	*/
	218
694b16b2 AC	219	static int wafwdt_notify_sys(struct notifier_block *this, unsigned long code,
694b16b2 AC	220	void *unused)
1da177e4	221	{
694b16b2	222	if (code == SYS_DOWN \|\| code == SYS_HALT)
1da177e4	223	wafwdt_stop();
1da177e4 LT	224	return NOTIFY_DONE;
	225	}
	226
	227	/*
	228	* Kernel Interfaces
	229	*/
	230
62322d25	231	static const struct file_operations wafwdt_fops = {
1da177e4 LT	232	.owner = THIS_MODULE,
	233	.llseek = no_llseek,
	234	.write = wafwdt_write,
694b16b2	235	.unlocked_ioctl = wafwdt_ioctl,
1da177e4 LT	236	.open = wafwdt_open,
	237	.release = wafwdt_close,
	238	};
	239
	240	static struct miscdevice wafwdt_miscdev = {
	241	.minor = WATCHDOG_MINOR,
	242	.name = "watchdog",
	243	.fops = &wafwdt_fops,
	244	};
	245
	246	/*
	247	* The WDT needs to learn about soft shutdowns in order to
	248	* turn the timebomb registers off.
	249	*/
	250
	251	static struct notifier_block wafwdt_notifier = {
	252	.notifier_call = wafwdt_notify_sys,
	253	};
	254
	255	static int __init wafwdt_init(void)
	256	{
	257	int ret;
	258
694b16b2 AC	259	printk(KERN_INFO
694b16b2 AC	260	"WDT driver for Wafer 5823 single board computer initialising.\n");
1da177e4	261
1da177e4 LT	262	if (timeout < 1 \|\| timeout > 255) {
1da177e4 LT	263	timeout = WD_TIMO;
694b16b2 AC	264	printk(KERN_INFO PFX
	265	"timeout value must be 1 <= x <= 255, using %d\n",
	266	timeout);
1da177e4 LT	267	}
	268
	269	if (wdt_stop != wdt_start) {
694b16b2 AC	270	if (!request_region(wdt_stop, 1, "Wafer 5823 WDT")) {
	271	printk(KERN_ERR PFX
	272	"I/O address 0x%04x already in use\n",
	273	wdt_stop);
1da177e4 LT	274	ret = -EIO;
	275	goto error;
	276	}
	277	}
	278
694b16b2 AC	279	if (!request_region(wdt_start, 1, "Wafer 5823 WDT")) {
694b16b2 AC	280	printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
1da177e4 LT	281	wdt_start);
	282	ret = -EIO;
	283	goto error2;
	284	}
	285
	286	ret = register_reboot_notifier(&wafwdt_notifier);
	287	if (ret != 0) {
694b16b2 AC	288	printk(KERN_ERR PFX
694b16b2 AC	289	"cannot register reboot notifier (err=%d)\n", ret);
1da177e4 LT	290	goto error3;
	291	}
	292
	293	ret = misc_register(&wafwdt_miscdev);
	294	if (ret != 0) {
694b16b2 AC	295	printk(KERN_ERR PFX
	296	"cannot register miscdev on minor=%d (err=%d)\n",
	297	WATCHDOG_MINOR, ret);
1da177e4 LT	298	goto error4;
	299	}
	300
694b16b2	301	printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
1da177e4 LT	302	timeout, nowayout);
	303
	304	return ret;
	305	error4:
	306	unregister_reboot_notifier(&wafwdt_notifier);
	307	error3:
	308	release_region(wdt_start, 1);
	309	error2:
	310	if (wdt_stop != wdt_start)
	311	release_region(wdt_stop, 1);
	312	error:
	313	return ret;
	314	}
	315
	316	static void __exit wafwdt_exit(void)
	317	{
	318	misc_deregister(&wafwdt_miscdev);
	319	unregister_reboot_notifier(&wafwdt_notifier);
694b16b2	320	if (wdt_stop != wdt_start)
1da177e4 LT	321	release_region(wdt_stop, 1);
	322	release_region(wdt_start, 1);
	323	}
	324
	325	module_init(wafwdt_init);
	326	module_exit(wafwdt_exit);
	327
	328	MODULE_AUTHOR("Justin Cormack");
	329	MODULE_DESCRIPTION("ICP Wafer 5823 Single Board Computer WDT driver");
	330	MODULE_LICENSE("GPL");
	331	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
	332
	333	/* end of wafer5823wdt.c */