[net-next-2.6.git] / drivers / watchdog / advantechwdt.c

/*
 *	Advantech Single Board Computer WDT driver
 *
 *	(c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
 *
 *	Based on acquirewdt.c which is based on wdt.c.
 *	Original copyright messages:
 *
 *	(c) Copyright 1996 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@redhat.com>
 *
 *	14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
 *	    Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
 *
 *	16-Oct-2002 Rob Radez <rob@osinvestor.com>
 *	    Clean up ioctls, clean up init + exit, add expect close support,
 *	    add wdt_start and wdt_stop as parameters.
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/fs.h>
#include <linux/ioport.h>
#include <linux/platform_device.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/uaccess.h>

#include <asm/system.h>

#define DRV_NAME "advantechwdt"
#define PFX DRV_NAME ": "
#define WATCHDOG_NAME "Advantech WDT"
#define WATCHDOG_TIMEOUT 60		/* 60 sec default timeout */

static struct platform_device *advwdt_platform_device;	/* the watchdog platform device */
static unsigned long advwdt_is_open;
static char adv_expect_close;

/*
 *	You must set these - there is no sane way to probe for this board.
 *
 *	To enable or restart, write the timeout value in seconds (1 to 63)
 *	to I/O port wdt_start.  To disable, read I/O port wdt_stop.
 *	Both are 0x443 for most boards (tested on a PCA-6276VE-00B1), but
 *	check your manual (at least the PCA-6159 seems to be different -
 *	the manual says wdt_stop is 0x43, not 0x443).
 *	(0x43 is also a write-only control register for the 8254 timer!)
 */

static int wdt_stop = 0x443;
module_param(wdt_stop, int, 0);
MODULE_PARM_DESC(wdt_stop, "Advantech WDT 'stop' io port (default 0x443)");

static int wdt_start = 0x443;
module_param(wdt_start, int, 0);
MODULE_PARM_DESC(wdt_start, "Advantech WDT 'start' io port (default 0x443)");

static int timeout = WATCHDOG_TIMEOUT;	/* in seconds */
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout,
	"Watchdog timeout in seconds. 1<= timeout <=63, default="
		__MODULE_STRING(WATCHDOG_TIMEOUT) ".");

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) ")");

/*
 *	Watchdog Operations
 */

static void advwdt_ping(void)
{
	/* Write a watchdog value */
	outb_p(timeout, wdt_start);
}

static void advwdt_disable(void)
{
	inb_p(wdt_stop);
}

static int advwdt_set_heartbeat(int t)
{
	if (t < 1 || t > 63)
		return -EINVAL;
	timeout = t;
	return 0;
}

/*
 *	/dev/watchdog handling
 */

static ssize_t advwdt_write(struct file *file, const char __user *buf,
						size_t count, loff_t *ppos)
{
	if (count) {
		if (!nowayout) {
			size_t i;

			adv_expect_close = 0;

			for (i = 0; i != count; i++) {
				char c;
				if (get_user(c, buf+i))
					return -EFAULT;
				if (c == 'V')
					adv_expect_close = 42;
			}
		}
		advwdt_ping();
	}
	return count;
}

static long advwdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	int new_timeout;
	void __user *argp = (void __user *)arg;
	int __user *p = argp;
	static struct watchdog_info ident = {
		.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
		.firmware_version = 1,
		.identity = WATCHDOG_NAME,
	};

	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) {
			advwdt_disable();
			retval = 0;
		}
		if (options & WDIOS_ENABLECARD) {
			advwdt_ping();
			retval = 0;
		}
		return retval;
	}
	case WDIOC_KEEPALIVE:
		advwdt_ping();
		break;

	case WDIOC_SETTIMEOUT:
		if (get_user(new_timeout, p))
			return -EFAULT;
		if (advwdt_set_heartbeat(new_timeout))
			return -EINVAL;
		advwdt_ping();
		/* Fall */
	case WDIOC_GETTIMEOUT:
		return put_user(timeout, p);
	default:
		return -ENOTTY;
	}
	return 0;
}

static int advwdt_open(struct inode *inode, struct file *file)
{
	if (test_and_set_bit(0, &advwdt_is_open))
		return -EBUSY;
	/*
	 *	Activate
	 */

	advwdt_ping();
	return nonseekable_open(inode, file);
}

static int
advwdt_close(struct inode *inode, struct file *file)
{
	if (adv_expect_close == 42) {
		advwdt_disable();
	} else {
		printk(KERN_CRIT PFX
				"Unexpected close, not stopping watchdog!\n");
		advwdt_ping();
	}
	clear_bit(0, &advwdt_is_open);
	adv_expect_close = 0;
	return 0;
}

/*
 *	Kernel Interfaces
 */

static const struct file_operations advwdt_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.write		= advwdt_write,
	.unlocked_ioctl	= advwdt_ioctl,
	.open		= advwdt_open,
	.release	= advwdt_close,
};

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

/*
 *	Init & exit routines
 */

static int __devinit advwdt_probe(struct platform_device *dev)
{
	int ret;

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

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

	/* Check that the heartbeat value is within it's range ; if not reset to the default */
	if (advwdt_set_heartbeat(timeout)) {
		advwdt_set_heartbeat(WATCHDOG_TIMEOUT);
		printk(KERN_INFO PFX
			"timeout value must be 1<=x<=63, using %d\n", timeout);
	}

	ret = misc_register(&advwdt_miscdev);
	if (ret != 0) {
		printk(KERN_ERR PFX
			"cannot register miscdev on minor=%d (err=%d)\n",
							WATCHDOG_MINOR, ret);
		goto unreg_regions;
	}
	printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
		timeout, nowayout);
out:
	return ret;
unreg_regions:
	release_region(wdt_start, 1);
unreg_stop:
	if (wdt_stop != wdt_start)
		release_region(wdt_stop, 1);
	goto out;
}

static int __devexit advwdt_remove(struct platform_device *dev)
{
	misc_deregister(&advwdt_miscdev);
	release_region(wdt_start,1);
	if(wdt_stop != wdt_start)
		release_region(wdt_stop,1);

	return 0;
}

static void advwdt_shutdown(struct platform_device *dev)
{
	/* Turn the WDT off if we have a soft shutdown */
	advwdt_disable();
}

static struct platform_driver advwdt_driver = {
	.probe		= advwdt_probe,
	.remove		= __devexit_p(advwdt_remove),
	.shutdown	= advwdt_shutdown,
	.driver		= {
		.owner	= THIS_MODULE,
		.name	= DRV_NAME,
	},
};

static int __init advwdt_init(void)
{
	int err;

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

	err = platform_driver_register(&advwdt_driver);
	if (err)
		return err;

	advwdt_platform_device = platform_device_register_simple(DRV_NAME,
								-1, NULL, 0);
	if (IS_ERR(advwdt_platform_device)) {
		err = PTR_ERR(advwdt_platform_device);
		goto unreg_platform_driver;
	}

	return 0;

unreg_platform_driver:
	platform_driver_unregister(&advwdt_driver);
	return err;
}

static void __exit advwdt_exit(void)
{
	platform_device_unregister(advwdt_platform_device);
	platform_driver_unregister(&advwdt_driver);
	printk(KERN_INFO PFX "Watchdog Module Unloaded.\n");
}

module_init(advwdt_init);
module_exit(advwdt_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Marek Michalkiewicz <marekm@linux.org.pl>");
MODULE_DESCRIPTION("Advantech Single Board Computer WDT driver");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Advantech Single Board Computer WDT driver
	3	*
	4	* (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
	5	*
	6	* Based on acquirewdt.c which is based on wdt.c.
	7	* Original copyright messages:
	8	*
	9	* (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
	10	* http://www.redhat.com
	11	*
	12	* This program is free software; you can redistribute it and/or
	13	* modify it under the terms of the GNU General Public License
	14	* as published by the Free Software Foundation; either version
	15	* 2 of the License, or (at your option) any later version.
	16	*
	17	* Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
	18	* warranty for any of this software. This material is provided
	19	* "AS-IS" and at no charge.
	20	*
	21	* (c) Copyright 1995 Alan Cox <alan@redhat.com>
	22	*
	23	* 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
	24	* Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
	25	*
	26	* 16-Oct-2002 Rob Radez <rob@osinvestor.com>
	27	* Clean up ioctls, clean up init + exit, add expect close support,
	28	* add wdt_start and wdt_stop as parameters.
	29	*/
	30
	31	#include <linux/module.h>
	32	#include <linux/moduleparam.h>
	33	#include <linux/types.h>
	34	#include <linux/miscdevice.h>
	35	#include <linux/watchdog.h>
	36	#include <linux/fs.h>
	37	#include <linux/ioport.h>
c2bd11c7	38	#include <linux/platform_device.h>
1da177e4	39	#include <linux/init.h>
089ab079 WVS	40	#include <linux/io.h>
089ab079 WVS	41	#include <linux/uaccess.h>
1da177e4	42
1da177e4 LT	43	#include <asm/system.h>
1da177e4 LT	44
1d747be6 WVS	45	#define DRV_NAME "advantechwdt"
1d747be6 WVS	46	#define PFX DRV_NAME ": "
1da177e4	47	#define WATCHDOG_NAME "Advantech WDT"
1da177e4 LT	48	#define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
1da177e4 LT	49
c2bd11c7	50	static struct platform_device advwdt_platform_device; / the watchdog platform device */
1da177e4 LT	51	static unsigned long advwdt_is_open;
	52	static char adv_expect_close;
	53
	54	/*
	55	* You must set these - there is no sane way to probe for this board.
	56	*
	57	* To enable or restart, write the timeout value in seconds (1 to 63)
	58	* to I/O port wdt_start. To disable, read I/O port wdt_stop.
	59	* Both are 0x443 for most boards (tested on a PCA-6276VE-00B1), but
	60	* check your manual (at least the PCA-6159 seems to be different -
	61	* the manual says wdt_stop is 0x43, not 0x443).
	62	* (0x43 is also a write-only control register for the 8254 timer!)
	63	*/
	64
	65	static int wdt_stop = 0x443;
	66	module_param(wdt_stop, int, 0);
	67	MODULE_PARM_DESC(wdt_stop, "Advantech WDT 'stop' io port (default 0x443)");
	68
	69	static int wdt_start = 0x443;
	70	module_param(wdt_start, int, 0);
	71	MODULE_PARM_DESC(wdt_start, "Advantech WDT 'start' io port (default 0x443)");
	72
	73	static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
	74	module_param(timeout, int, 0);
b6b4d9b8 AC	75	MODULE_PARM_DESC(timeout,
	76	"Watchdog timeout in seconds. 1<= timeout <=63, default="
	77	__MODULE_STRING(WATCHDOG_TIMEOUT) ".");
1da177e4	78
4bfdf378	79	static int nowayout = WATCHDOG_NOWAYOUT;
1da177e4	80	module_param(nowayout, int, 0);
b6b4d9b8 AC	81	MODULE_PARM_DESC(nowayout,
	82	"Watchdog cannot be stopped once started (default="
	83	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
1da177e4 LT	84
1da177e4 LT	85	/*
1d747be6	86	* Watchdog Operations
1da177e4 LT	87	*/
1da177e4 LT	88
b6b4d9b8	89	static void advwdt_ping(void)
1da177e4 LT	90	{
	91	/* Write a watchdog value */
	92	outb_p(timeout, wdt_start);
	93	}
	94
b6b4d9b8	95	static void advwdt_disable(void)
1da177e4 LT	96	{
	97	inb_p(wdt_stop);
	98	}
	99
b6b4d9b8	100	static int advwdt_set_heartbeat(int t)
0349a363	101	{
b6b4d9b8	102	if (t < 1 \|\| t > 63)
0349a363	103	return -EINVAL;
0349a363 WVS	104	timeout = t;
	105	return 0;
	106	}
	107
1d747be6 WVS	108	/*
	109	* /dev/watchdog handling
	110	*/
	111
b6b4d9b8 AC	112	static ssize_t advwdt_write(struct file file, const char __user buf,
b6b4d9b8 AC	113	size_t count, loff_t *ppos)
1da177e4 LT	114	{
	115	if (count) {
	116	if (!nowayout) {
	117	size_t i;
	118
	119	adv_expect_close = 0;
	120
	121	for (i = 0; i != count; i++) {
	122	char c;
	123	if (get_user(c, buf+i))
	124	return -EFAULT;
	125	if (c == 'V')
	126	adv_expect_close = 42;
	127	}
	128	}
	129	advwdt_ping();
	130	}
	131	return count;
	132	}
	133
b6b4d9b8	134	static long advwdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1da177e4 LT	135	{
	136	int new_timeout;
	137	void __user argp = (void __user )arg;
	138	int __user *p = argp;
	139	static struct watchdog_info ident = {
	140	.options = WDIOF_KEEPALIVEPING \| WDIOF_SETTIMEOUT \| WDIOF_MAGICCLOSE,
	141	.firmware_version = 1,
1d747be6	142	.identity = WATCHDOG_NAME,
1da177e4 LT	143	};
	144
	145	switch (cmd) {
	146	case WDIOC_GETSUPPORT:
b6b4d9b8 AC	147	if (copy_to_user(argp, &ident, sizeof(ident)))
	148	return -EFAULT;
	149	break;
1da177e4 LT	150
	151	case WDIOC_GETSTATUS:
	152	case WDIOC_GETBOOTSTATUS:
b6b4d9b8	153	return put_user(0, p);
1da177e4	154
1da177e4 LT	155	case WDIOC_SETOPTIONS:
1da177e4 LT	156	{
b6b4d9b8	157	int options, retval = -EINVAL;
1da177e4	158
b6b4d9b8 AC	159	if (get_user(options, p))
	160	return -EFAULT;
	161	if (options & WDIOS_DISABLECARD) {
	162	advwdt_disable();
	163	retval = 0;
	164	}
	165	if (options & WDIOS_ENABLECARD) {
	166	advwdt_ping();
	167	retval = 0;
	168	}
	169	return retval;
1da177e4	170	}
0c06090c WVS	171	case WDIOC_KEEPALIVE:
	172	advwdt_ping();
	173	break;
	174
	175	case WDIOC_SETTIMEOUT:
	176	if (get_user(new_timeout, p))
	177	return -EFAULT;
	178	if (advwdt_set_heartbeat(new_timeout))
	179	return -EINVAL;
	180	advwdt_ping();
	181	/* Fall */
	182	case WDIOC_GETTIMEOUT:
	183	return put_user(timeout, p);
1da177e4	184	default:
b6b4d9b8	185	return -ENOTTY;
1da177e4 LT	186	}
	187	return 0;
	188	}
	189
b6b4d9b8	190	static int advwdt_open(struct inode inode, struct file file)
1da177e4 LT	191	{
	192	if (test_and_set_bit(0, &advwdt_is_open))
	193	return -EBUSY;
	194	/*
	195	* Activate
	196	*/
	197
	198	advwdt_ping();
	199	return nonseekable_open(inode, file);
	200	}
	201
	202	static int
	203	advwdt_close(struct inode inode, struct file file)
	204	{
	205	if (adv_expect_close == 42) {
	206	advwdt_disable();
	207	} else {
b6b4d9b8 AC	208	printk(KERN_CRIT PFX
b6b4d9b8 AC	209	"Unexpected close, not stopping watchdog!\n");
1da177e4 LT	210	advwdt_ping();
	211	}
	212	clear_bit(0, &advwdt_is_open);
	213	adv_expect_close = 0;
	214	return 0;
	215	}
	216
1da177e4 LT	217	/*
	218	* Kernel Interfaces
	219	*/
	220
62322d25	221	static const struct file_operations advwdt_fops = {
1da177e4 LT	222	.owner = THIS_MODULE,
	223	.llseek = no_llseek,
	224	.write = advwdt_write,
b6b4d9b8	225	.unlocked_ioctl = advwdt_ioctl,
1da177e4 LT	226	.open = advwdt_open,
	227	.release = advwdt_close,
	228	};
	229
	230	static struct miscdevice advwdt_miscdev = {
1d747be6 WVS	231	.minor = WATCHDOG_MINOR,
	232	.name = "watchdog",
	233	.fops = &advwdt_fops,
1da177e4 LT	234	};
1da177e4 LT	235
1d747be6 WVS	236	/*
	237	* Init & exit routines
	238	*/
	239
b6b4d9b8	240	static int __devinit advwdt_probe(struct platform_device *dev)
1da177e4 LT	241	{
	242	int ret;
	243
1da177e4 LT	244	if (wdt_stop != wdt_start) {
1da177e4 LT	245	if (!request_region(wdt_stop, 1, WATCHDOG_NAME)) {
b6b4d9b8 AC	246	printk(KERN_ERR PFX
	247	"I/O address 0x%04x already in use\n",
	248	wdt_stop);
1da177e4 LT	249	ret = -EIO;
	250	goto out;
	251	}
	252	}
	253
	254	if (!request_region(wdt_start, 1, WATCHDOG_NAME)) {
b6b4d9b8 AC	255	printk(KERN_ERR PFX
	256	"I/O address 0x%04x already in use\n",
	257	wdt_start);
1da177e4 LT	258	ret = -EIO;
	259	goto unreg_stop;
	260	}
	261
0349a363 WVS	262	/* Check that the heartbeat value is within it's range ; if not reset to the default */
	263	if (advwdt_set_heartbeat(timeout)) {
	264	advwdt_set_heartbeat(WATCHDOG_TIMEOUT);
b6b4d9b8 AC	265	printk(KERN_INFO PFX
b6b4d9b8 AC	266	"timeout value must be 1<=x<=63, using %d\n", timeout);
0349a363 WVS	267	}
0349a363 WVS	268
1da177e4 LT	269	ret = misc_register(&advwdt_miscdev);
1da177e4 LT	270	if (ret != 0) {
b6b4d9b8 AC	271	printk(KERN_ERR PFX
	272	"cannot register miscdev on minor=%d (err=%d)\n",
	273	WATCHDOG_MINOR, ret);
2e9c9cf4	274	goto unreg_regions;
1da177e4	275	}
b6b4d9b8	276	printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
1da177e4	277	timeout, nowayout);
1da177e4 LT	278	out:
1da177e4 LT	279	return ret;
1da177e4 LT	280	unreg_regions:
	281	release_region(wdt_start, 1);
	282	unreg_stop:
	283	if (wdt_stop != wdt_start)
	284	release_region(wdt_stop, 1);
	285	goto out;
	286	}
	287
b6b4d9b8	288	static int __devexit advwdt_remove(struct platform_device *dev)
1da177e4 LT	289	{
1da177e4 LT	290	misc_deregister(&advwdt_miscdev);
1d747be6	291	release_region(wdt_start,1);
1da177e4 LT	292	if(wdt_stop != wdt_start)
1da177e4 LT	293	release_region(wdt_stop,1);
c2bd11c7 WVS	294
	295	return 0;
	296	}
	297
b6b4d9b8	298	static void advwdt_shutdown(struct platform_device *dev)
2e9c9cf4 WVS	299	{
	300	/* Turn the WDT off if we have a soft shutdown */
	301	advwdt_disable();
	302	}
	303
c2bd11c7 WVS	304	static struct platform_driver advwdt_driver = {
	305	.probe = advwdt_probe,
	306	.remove = __devexit_p(advwdt_remove),
2e9c9cf4	307	.shutdown = advwdt_shutdown,
c2bd11c7 WVS	308	.driver = {
	309	.owner = THIS_MODULE,
	310	.name = DRV_NAME,
	311	},
	312	};
	313
b6b4d9b8	314	static int __init advwdt_init(void)
c2bd11c7 WVS	315	{
	316	int err;
	317
	318	printk(KERN_INFO "WDT driver for Advantech single board computer initialising.\n");
	319
	320	err = platform_driver_register(&advwdt_driver);
	321	if (err)
	322	return err;
	323
b6b4d9b8 AC	324	advwdt_platform_device = platform_device_register_simple(DRV_NAME,
b6b4d9b8 AC	325	-1, NULL, 0);
c2bd11c7 WVS	326	if (IS_ERR(advwdt_platform_device)) {
	327	err = PTR_ERR(advwdt_platform_device);
	328	goto unreg_platform_driver;
	329	}
	330
	331	return 0;
	332
	333	unreg_platform_driver:
	334	platform_driver_unregister(&advwdt_driver);
	335	return err;
	336	}
	337
b6b4d9b8	338	static void __exit advwdt_exit(void)
c2bd11c7 WVS	339	{
	340	platform_device_unregister(advwdt_platform_device);
	341	platform_driver_unregister(&advwdt_driver);
	342	printk(KERN_INFO PFX "Watchdog Module Unloaded.\n");
1da177e4 LT	343	}
	344
	345	module_init(advwdt_init);
	346	module_exit(advwdt_exit);
	347
	348	MODULE_LICENSE("GPL");
	349	MODULE_AUTHOR("Marek Michalkiewicz <marekm@linux.org.pl>");
	350	MODULE_DESCRIPTION("Advantech Single Board Computer WDT driver");
	351	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);