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

// SPDX-License-Identifier: GPL-2.0+
/*
 *	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@lxorguk.ukuu.org.uk>,
 *						All Rights Reserved.
 *
 *	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>
 *
 *	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.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#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>


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

/* the watchdog platform device */
static struct platform_device *advwdt_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 bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 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 const 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 through */
	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 stream_open(inode, file);
}

static int advwdt_close(struct inode *inode, struct file *file)
{
	if (adv_expect_close == 42) {
		advwdt_disable();
	} else {
		pr_crit("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 __init advwdt_probe(struct platform_device *dev)
{
	int ret;

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

	if (!request_region(wdt_start, 1, WATCHDOG_NAME)) {
		pr_err("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);
		pr_info("timeout value must be 1<=x<=63, using %d\n", timeout);
	}

	ret = misc_register(&advwdt_miscdev);
	if (ret != 0) {
		pr_err("cannot register miscdev on minor=%d (err=%d)\n",
		       WATCHDOG_MINOR, ret);
		goto unreg_regions;
	}
	pr_info("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 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 = {
	.remove		= advwdt_remove,
	.shutdown	= advwdt_shutdown,
	.driver		= {
		.name	= DRV_NAME,
	},
};

static int __init advwdt_init(void)
{
	int err;

	pr_info("WDT driver for Advantech single board computer initialising\n");

	advwdt_platform_device = platform_device_register_simple(DRV_NAME,
								-1, NULL, 0);
	if (IS_ERR(advwdt_platform_device))
		return PTR_ERR(advwdt_platform_device);

	err = platform_driver_probe(&advwdt_driver, advwdt_probe);
	if (err)
		goto unreg_platform_device;

	return 0;

unreg_platform_device:
	platform_device_unregister(advwdt_platform_device);
	return err;
}

static void __exit advwdt_exit(void)
{
	platform_device_unregister(advwdt_platform_device);
	platform_driver_unregister(&advwdt_driver);
	pr_info("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");
Commit	Line	Data
d0173278	1	// SPDX-License-Identifier: GPL-2.0+
1da177e4 LT	2	/*
	3	* Advantech Single Board Computer WDT driver
	4	*
	5	* (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
	6	*
	7	* Based on acquirewdt.c which is based on wdt.c.
	8	* Original copyright messages:
	9	*
29fa0586 AC	10	* (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
29fa0586 AC	11	* All Rights Reserved.
1da177e4	12	*
1da177e4 LT	13	* Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
	14	* warranty for any of this software. This material is provided
	15	* "AS-IS" and at no charge.
	16	*
29fa0586	17	* (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>
1da177e4 LT	18	*
	19	* 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
	20	* Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
	21	*
	22	* 16-Oct-2002 Rob Radez <rob@osinvestor.com>
	23	* Clean up ioctls, clean up init + exit, add expect close support,
	24	* add wdt_start and wdt_stop as parameters.
	25	*/
	26
27c766aa JP	27	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
27c766aa JP	28
1da177e4 LT	29	#include <linux/module.h>
	30	#include <linux/moduleparam.h>
	31	#include <linux/types.h>
	32	#include <linux/miscdevice.h>
	33	#include <linux/watchdog.h>
	34	#include <linux/fs.h>
	35	#include <linux/ioport.h>
c2bd11c7	36	#include <linux/platform_device.h>
1da177e4	37	#include <linux/init.h>
089ab079 WVS	38	#include <linux/io.h>
089ab079 WVS	39	#include <linux/uaccess.h>
1da177e4	40
1da177e4	41
1d747be6	42	#define DRV_NAME "advantechwdt"
1da177e4	43	#define WATCHDOG_NAME "Advantech WDT"
1da177e4 LT	44	#define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
1da177e4 LT	45
7944d3a5 WVS	46	/* the watchdog platform device */
7944d3a5 WVS	47	static struct platform_device *advwdt_platform_device;
1da177e4 LT	48	static unsigned long advwdt_is_open;
	49	static char adv_expect_close;
	50
	51	/*
	52	* You must set these - there is no sane way to probe for this board.
	53	*
	54	* To enable or restart, write the timeout value in seconds (1 to 63)
	55	* to I/O port wdt_start. To disable, read I/O port wdt_stop.
	56	* Both are 0x443 for most boards (tested on a PCA-6276VE-00B1), but
	57	* check your manual (at least the PCA-6159 seems to be different -
	58	* the manual says wdt_stop is 0x43, not 0x443).
	59	* (0x43 is also a write-only control register for the 8254 timer!)
	60	*/
	61
	62	static int wdt_stop = 0x443;
	63	module_param(wdt_stop, int, 0);
	64	MODULE_PARM_DESC(wdt_stop, "Advantech WDT 'stop' io port (default 0x443)");
	65
	66	static int wdt_start = 0x443;
	67	module_param(wdt_start, int, 0);
	68	MODULE_PARM_DESC(wdt_start, "Advantech WDT 'start' io port (default 0x443)");
	69
	70	static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
	71	module_param(timeout, int, 0);
b6b4d9b8 AC	72	MODULE_PARM_DESC(timeout,
	73	"Watchdog timeout in seconds. 1<= timeout <=63, default="
	74	__MODULE_STRING(WATCHDOG_TIMEOUT) ".");
1da177e4	75
86a1e189 WVS	76	static bool nowayout = WATCHDOG_NOWAYOUT;
86a1e189 WVS	77	module_param(nowayout, bool, 0);
b6b4d9b8 AC	78	MODULE_PARM_DESC(nowayout,
	79	"Watchdog cannot be stopped once started (default="
	80	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
1da177e4 LT	81
1da177e4 LT	82	/*
1d747be6	83	* Watchdog Operations
1da177e4 LT	84	*/
1da177e4 LT	85
b6b4d9b8	86	static void advwdt_ping(void)
1da177e4 LT	87	{
	88	/* Write a watchdog value */
	89	outb_p(timeout, wdt_start);
	90	}
	91
b6b4d9b8	92	static void advwdt_disable(void)
1da177e4 LT	93	{
	94	inb_p(wdt_stop);
	95	}
	96
b6b4d9b8	97	static int advwdt_set_heartbeat(int t)
0349a363	98	{
b6b4d9b8	99	if (t < 1 \|\| t > 63)
0349a363	100	return -EINVAL;
0349a363 WVS	101	timeout = t;
	102	return 0;
	103	}
	104
1d747be6 WVS	105	/*
	106	* /dev/watchdog handling
	107	*/
	108
b6b4d9b8 AC	109	static ssize_t advwdt_write(struct file file, const char __user buf,
b6b4d9b8 AC	110	size_t count, loff_t *ppos)
1da177e4 LT	111	{
	112	if (count) {
	113	if (!nowayout) {
	114	size_t i;
	115
	116	adv_expect_close = 0;
	117
	118	for (i = 0; i != count; i++) {
	119	char c;
7944d3a5	120	if (get_user(c, buf + i))
1da177e4 LT	121	return -EFAULT;
	122	if (c == 'V')
	123	adv_expect_close = 42;
	124	}
	125	}
	126	advwdt_ping();
	127	}
	128	return count;
	129	}
	130
b6b4d9b8	131	static long advwdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1da177e4 LT	132	{
	133	int new_timeout;
	134	void __user argp = (void __user )arg;
	135	int __user *p = argp;
42747d71	136	static const struct watchdog_info ident = {
143a2e54 WVS	137	.options = WDIOF_KEEPALIVEPING \|
	138	WDIOF_SETTIMEOUT \|
	139	WDIOF_MAGICCLOSE,
1da177e4	140	.firmware_version = 1,
1d747be6	141	.identity = WATCHDOG_NAME,
1da177e4 LT	142	};
	143
	144	switch (cmd) {
	145	case WDIOC_GETSUPPORT:
b6b4d9b8 AC	146	if (copy_to_user(argp, &ident, sizeof(ident)))
	147	return -EFAULT;
	148	break;
1da177e4 LT	149
	150	case WDIOC_GETSTATUS:
	151	case WDIOC_GETBOOTSTATUS:
b6b4d9b8	152	return put_user(0, p);
1da177e4	153
1da177e4 LT	154	case WDIOC_SETOPTIONS:
1da177e4 LT	155	{
b6b4d9b8	156	int options, retval = -EINVAL;
1da177e4	157
b6b4d9b8 AC	158	if (get_user(options, p))
	159	return -EFAULT;
	160	if (options & WDIOS_DISABLECARD) {
	161	advwdt_disable();
	162	retval = 0;
	163	}
	164	if (options & WDIOS_ENABLECARD) {
	165	advwdt_ping();
	166	retval = 0;
	167	}
	168	return retval;
1da177e4	169	}
0c06090c WVS	170	case WDIOC_KEEPALIVE:
	171	advwdt_ping();
	172	break;
	173
	174	case WDIOC_SETTIMEOUT:
	175	if (get_user(new_timeout, p))
	176	return -EFAULT;
	177	if (advwdt_set_heartbeat(new_timeout))
	178	return -EINVAL;
	179	advwdt_ping();
083ccebb	180	/* fall through */
0c06090c WVS	181	case WDIOC_GETTIMEOUT:
0c06090c WVS	182	return put_user(timeout, p);
1da177e4	183	default:
b6b4d9b8	184	return -ENOTTY;
1da177e4 LT	185	}
	186	return 0;
	187	}
	188
b6b4d9b8	189	static int advwdt_open(struct inode inode, struct file file)
1da177e4 LT	190	{
	191	if (test_and_set_bit(0, &advwdt_is_open))
	192	return -EBUSY;
	193	/*
	194	* Activate
	195	*/
	196
	197	advwdt_ping();
c5bf68fe	198	return stream_open(inode, file);
1da177e4 LT	199	}
1da177e4 LT	200
7944d3a5	201	static int advwdt_close(struct inode inode, struct file file)
1da177e4 LT	202	{
	203	if (adv_expect_close == 42) {
	204	advwdt_disable();
	205	} else {
27c766aa	206	pr_crit("Unexpected close, not stopping watchdog!\n");
1da177e4 LT	207	advwdt_ping();
	208	}
	209	clear_bit(0, &advwdt_is_open);
	210	adv_expect_close = 0;
	211	return 0;
	212	}
	213
1da177e4 LT	214	/*
	215	* Kernel Interfaces
	216	*/
	217
62322d25	218	static const struct file_operations advwdt_fops = {
1da177e4 LT	219	.owner = THIS_MODULE,
	220	.llseek = no_llseek,
	221	.write = advwdt_write,
b6b4d9b8	222	.unlocked_ioctl = advwdt_ioctl,
1da177e4 LT	223	.open = advwdt_open,
	224	.release = advwdt_close,
	225	};
	226
	227	static struct miscdevice advwdt_miscdev = {
1d747be6 WVS	228	.minor = WATCHDOG_MINOR,
	229	.name = "watchdog",
	230	.fops = &advwdt_fops,
1da177e4 LT	231	};
1da177e4 LT	232
1d747be6 WVS	233	/*
	234	* Init & exit routines
	235	*/
	236
acaaaf62	237	static int __init advwdt_probe(struct platform_device *dev)
1da177e4 LT	238	{
	239	int ret;
	240
1da177e4 LT	241	if (wdt_stop != wdt_start) {
1da177e4 LT	242	if (!request_region(wdt_stop, 1, WATCHDOG_NAME)) {
27c766aa JP	243	pr_err("I/O address 0x%04x already in use\n",
27c766aa JP	244	wdt_stop);
1da177e4 LT	245	ret = -EIO;
	246	goto out;
	247	}
	248	}
	249
	250	if (!request_region(wdt_start, 1, WATCHDOG_NAME)) {
27c766aa	251	pr_err("I/O address 0x%04x already in use\n", wdt_start);
1da177e4 LT	252	ret = -EIO;
	253	goto unreg_stop;
	254	}
	255
143a2e54 WVS	256	/* Check that the heartbeat value is within it's range ;
143a2e54 WVS	257	* if not reset to the default */
0349a363 WVS	258	if (advwdt_set_heartbeat(timeout)) {
0349a363 WVS	259	advwdt_set_heartbeat(WATCHDOG_TIMEOUT);
27c766aa	260	pr_info("timeout value must be 1<=x<=63, using %d\n", timeout);
0349a363 WVS	261	}
0349a363 WVS	262
1da177e4 LT	263	ret = misc_register(&advwdt_miscdev);
1da177e4 LT	264	if (ret != 0) {
27c766aa JP	265	pr_err("cannot register miscdev on minor=%d (err=%d)\n",
27c766aa JP	266	WATCHDOG_MINOR, ret);
2e9c9cf4	267	goto unreg_regions;
1da177e4	268	}
27c766aa	269	pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
1da177e4	270	timeout, nowayout);
1da177e4 LT	271	out:
1da177e4 LT	272	return ret;
1da177e4 LT	273	unreg_regions:
	274	release_region(wdt_start, 1);
	275	unreg_stop:
	276	if (wdt_stop != wdt_start)
	277	release_region(wdt_stop, 1);
	278	goto out;
	279	}
	280
4b12b896	281	static int advwdt_remove(struct platform_device *dev)
1da177e4 LT	282	{
1da177e4 LT	283	misc_deregister(&advwdt_miscdev);
7944d3a5 WVS	284	release_region(wdt_start, 1);
	285	if (wdt_stop != wdt_start)
	286	release_region(wdt_stop, 1);
c2bd11c7 WVS	287
	288	return 0;
	289	}
	290
b6b4d9b8	291	static void advwdt_shutdown(struct platform_device *dev)
2e9c9cf4 WVS	292	{
	293	/* Turn the WDT off if we have a soft shutdown */
	294	advwdt_disable();
	295	}
	296
c2bd11c7	297	static struct platform_driver advwdt_driver = {
82268714	298	.remove = advwdt_remove,
2e9c9cf4	299	.shutdown = advwdt_shutdown,
c2bd11c7	300	.driver = {
c2bd11c7 WVS	301	.name = DRV_NAME,
	302	},
	303	};
	304
b6b4d9b8	305	static int __init advwdt_init(void)
c2bd11c7 WVS	306	{
	307	int err;
	308
27c766aa	309	pr_info("WDT driver for Advantech single board computer initialising\n");
c2bd11c7	310
b6b4d9b8 AC	311	advwdt_platform_device = platform_device_register_simple(DRV_NAME,
b6b4d9b8 AC	312	-1, NULL, 0);
acaaaf62 JD	313	if (IS_ERR(advwdt_platform_device))
	314	return PTR_ERR(advwdt_platform_device);
	315
	316	err = platform_driver_probe(&advwdt_driver, advwdt_probe);
	317	if (err)
	318	goto unreg_platform_device;
c2bd11c7 WVS	319
	320	return 0;
	321
acaaaf62 JD	322	unreg_platform_device:
acaaaf62 JD	323	platform_device_unregister(advwdt_platform_device);
c2bd11c7 WVS	324	return err;
	325	}
	326
b6b4d9b8	327	static void __exit advwdt_exit(void)
c2bd11c7 WVS	328	{
	329	platform_device_unregister(advwdt_platform_device);
	330	platform_driver_unregister(&advwdt_driver);
27c766aa	331	pr_info("Watchdog Module Unloaded\n");
1da177e4 LT	332	}
	333
	334	module_init(advwdt_init);
	335	module_exit(advwdt_exit);
	336
	337	MODULE_LICENSE("GPL");
	338	MODULE_AUTHOR("Marek Michalkiewicz <marekm@linux.org.pl>");
	339	MODULE_DESCRIPTION("Advantech Single Board Computer WDT driver");