[mirror_ubuntu-jammy-kernel.git] / drivers / watchdog / wafer5823wdt.c

// SPDX-License-Identifier: GPL-2.0+
/*
 *	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@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>
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#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 bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 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_stop();
			retval = 0;
		}

		if (options & WDIOS_ENABLECARD) {
			wafwdt_start();
			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();
		fallthrough;
	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 stream_open(inode, file);
}

static int wafwdt_close(struct inode *inode, struct file *file)
{
	if (expect_close == 42)
		wafwdt_stop();
	else {
		pr_crit("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,
	.compat_ioctl	= compat_ptr_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;

	pr_info("WDT driver for Wafer 5823 single board computer initialising\n");

	if (timeout < 1 || timeout > 255) {
		timeout = WD_TIMO;
		pr_info("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")) {
			pr_err("I/O address 0x%04x already in use\n", wdt_stop);
			ret = -EIO;
			goto error;
		}
	}

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

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

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

	pr_info("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");

/* end of wafer5823wdt.c */
Commit	Line	Data
d0173278	1	// SPDX-License-Identifier: GPL-2.0+
1da177e4 LT	2	/*
1da177e4 LT	3	* ICP Wafer 5823 Single Board Computer WDT driver
7944d3a5 WVS	4	* http://www.icpamerica.com/wafer_5823.php
7944d3a5 WVS	5	* May also work on other similar models
1da177e4 LT	6	*
	7	* (c) Copyright 2002 Justin Cormack <justin@street-vision.com>
	8	*
7944d3a5	9	* Release 0.02
1da177e4 LT	10	*
	11	* Based on advantechwdt.c which is based on wdt.c.
	12	* Original copyright messages:
	13	*
29fa0586 AC	14	* (c) Copyright 1996-1997 Alan Cox <alan@lxorguk.ukuu.org.uk>,
29fa0586 AC	15	* All Rights Reserved.
1da177e4	16	*
1da177e4 LT	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@lxorguk.ukuu.org.uk>
	22	*
	23	*/
	24
27c766aa JP	25	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
27c766aa JP	26
1da177e4 LT	27	#include <linux/module.h>
	28	#include <linux/moduleparam.h>
	29	#include <linux/miscdevice.h>
	30	#include <linux/watchdog.h>
	31	#include <linux/fs.h>
	32	#include <linux/ioport.h>
	33	#include <linux/notifier.h>
	34	#include <linux/reboot.h>
	35	#include <linux/init.h>
	36	#include <linux/spinlock.h>
694b16b2 AC	37	#include <linux/io.h>
694b16b2 AC	38	#include <linux/uaccess.h>
1da177e4 LT	39
	40	#define WATCHDOG_NAME "Wafer 5823 WDT"
	41	#define PFX WATCHDOG_NAME ": "
	42	#define WD_TIMO 60 /* 60 sec default timeout */
	43
	44	static unsigned long wafwdt_is_open;
	45	static char expect_close;
c7dfd0cc	46	static DEFINE_SPINLOCK(wafwdt_lock);
1da177e4 LT	47
	48	/*
	49	* You must set these - there is no sane way to probe for this board.
	50	*
7944d3a5 WVS	51	* To enable, write the timeout value in seconds (1 to 255) to I/O
	52	* port WDT_START, then read the port to start the watchdog. To pat
	53	* the dog, read port WDT_STOP to stop the timer, then read WDT_START
	54	* to restart it again.
1da177e4 LT	55	*/
	56
	57	static int wdt_stop = 0x843;
	58	static int wdt_start = 0x443;
	59
	60	static int timeout = WD_TIMO; /* in seconds */
	61	module_param(timeout, int, 0);
694b16b2 AC	62	MODULE_PARM_DESC(timeout,
	63	"Watchdog timeout in seconds. 1 <= timeout <= 255, default="
	64	__MODULE_STRING(WD_TIMO) ".");
1da177e4	65
86a1e189 WVS	66	static bool nowayout = WATCHDOG_NOWAYOUT;
86a1e189 WVS	67	module_param(nowayout, bool, 0);
694b16b2 AC	68	MODULE_PARM_DESC(nowayout,
	69	"Watchdog cannot be stopped once started (default="
	70	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
1da177e4 LT	71
	72	static void wafwdt_ping(void)
	73	{
	74	/* pat watchdog */
	75	spin_lock(&wafwdt_lock);
	76	inb_p(wdt_stop);
	77	inb_p(wdt_start);
	78	spin_unlock(&wafwdt_lock);
	79	}
	80
	81	static void wafwdt_start(void)
	82	{
	83	/* start up watchdog */
	84	outb_p(timeout, wdt_start);
	85	inb_p(wdt_start);
	86	}
	87
7944d3a5	88	static void wafwdt_stop(void)
1da177e4 LT	89	{
	90	/* stop watchdog */
	91	inb_p(wdt_stop);
	92	}
	93
694b16b2 AC	94	static ssize_t wafwdt_write(struct file file, const char __user buf,
694b16b2 AC	95	size_t count, loff_t *ppos)
1da177e4 LT	96	{
	97	/* See if we got the magic character 'V' and reload the timer */
	98	if (count) {
	99	if (!nowayout) {
	100	size_t i;
	101
	102	/* In case it was set long ago */
	103	expect_close = 0;
	104
694b16b2 AC	105	/* scan to see whether or not we got the magic
694b16b2 AC	106	character */
1da177e4 LT	107	for (i = 0; i != count; i++) {
	108	char c;
	109	if (get_user(c, buf + i))
	110	return -EFAULT;
	111	if (c == 'V')
	112	expect_close = 42;
	113	}
	114	}
694b16b2 AC	115	/* Well, anyhow someone wrote to us, we should
694b16b2 AC	116	return that favour */
1da177e4 LT	117	wafwdt_ping();
	118	}
	119	return count;
	120	}
	121
694b16b2 AC	122	static long wafwdt_ioctl(struct file *file, unsigned int cmd,
694b16b2 AC	123	unsigned long arg)
1da177e4 LT	124	{
	125	int new_timeout;
	126	void __user argp = (void __user )arg;
	127	int __user *p = argp;
694b16b2 AC	128	static const struct watchdog_info ident = {
	129	.options = WDIOF_KEEPALIVEPING \| WDIOF_SETTIMEOUT \|
	130	WDIOF_MAGICCLOSE,
1da177e4 LT	131	.firmware_version = 1,
	132	.identity = "Wafer 5823 WDT",
	133	};
	134
	135	switch (cmd) {
	136	case WDIOC_GETSUPPORT:
694b16b2	137	if (copy_to_user(argp, &ident, sizeof(ident)))
1da177e4 LT	138	return -EFAULT;
	139	break;
	140
	141	case WDIOC_GETSTATUS:
	142	case WDIOC_GETBOOTSTATUS:
	143	return put_user(0, p);
	144
1da177e4 LT	145	case WDIOC_SETOPTIONS:
	146	{
	147	int options, retval = -EINVAL;
	148
	149	if (get_user(options, p))
	150	return -EFAULT;
	151
	152	if (options & WDIOS_DISABLECARD) {
8a062ac6	153	wafwdt_stop();
1da177e4 LT	154	retval = 0;
	155	}
	156
	157	if (options & WDIOS_ENABLECARD) {
8a062ac6	158	wafwdt_start();
1da177e4 LT	159	retval = 0;
	160	}
	161
	162	return retval;
	163	}
	164
0c06090c WVS	165	case WDIOC_KEEPALIVE:
	166	wafwdt_ping();
	167	break;
	168
	169	case WDIOC_SETTIMEOUT:
	170	if (get_user(new_timeout, p))
	171	return -EFAULT;
	172	if ((new_timeout < 1) \|\| (new_timeout > 255))
	173	return -EINVAL;
	174	timeout = new_timeout;
	175	wafwdt_stop();
	176	wafwdt_start();
bd490f82	177	fallthrough;
0c06090c WVS	178	case WDIOC_GETTIMEOUT:
	179	return put_user(timeout, p);
	180
1da177e4	181	default:
795b89d2	182	return -ENOTTY;
1da177e4 LT	183	}
	184	return 0;
	185	}
	186
	187	static int wafwdt_open(struct inode inode, struct file file)
	188	{
	189	if (test_and_set_bit(0, &wafwdt_is_open))
	190	return -EBUSY;
	191
	192	/*
	193	* Activate
	194	*/
	195	wafwdt_start();
c5bf68fe	196	return stream_open(inode, file);
1da177e4 LT	197	}
1da177e4 LT	198
7944d3a5	199	static int wafwdt_close(struct inode inode, struct file file)
1da177e4	200	{
694b16b2	201	if (expect_close == 42)
1da177e4	202	wafwdt_stop();
694b16b2	203	else {
27c766aa	204	pr_crit("WDT device closed unexpectedly. WDT will not stop!\n");
1da177e4 LT	205	wafwdt_ping();
	206	}
	207	clear_bit(0, &wafwdt_is_open);
	208	expect_close = 0;
	209	return 0;
	210	}
	211
	212	/*
	213	* Notifier for system down
	214	*/
	215
694b16b2 AC	216	static int wafwdt_notify_sys(struct notifier_block *this, unsigned long code,
694b16b2 AC	217	void *unused)
1da177e4	218	{
694b16b2	219	if (code == SYS_DOWN \|\| code == SYS_HALT)
1da177e4	220	wafwdt_stop();
1da177e4 LT	221	return NOTIFY_DONE;
	222	}
	223
	224	/*
	225	* Kernel Interfaces
	226	*/
	227
62322d25	228	static const struct file_operations wafwdt_fops = {
1da177e4 LT	229	.owner = THIS_MODULE,
	230	.llseek = no_llseek,
	231	.write = wafwdt_write,
694b16b2	232	.unlocked_ioctl = wafwdt_ioctl,
b6dfb247	233	.compat_ioctl = compat_ptr_ioctl,
1da177e4 LT	234	.open = wafwdt_open,
	235	.release = wafwdt_close,
	236	};
	237
	238	static struct miscdevice wafwdt_miscdev = {
	239	.minor = WATCHDOG_MINOR,
	240	.name = "watchdog",
	241	.fops = &wafwdt_fops,
	242	};
	243
	244	/*
	245	* The WDT needs to learn about soft shutdowns in order to
	246	* turn the timebomb registers off.
	247	*/
	248
	249	static struct notifier_block wafwdt_notifier = {
	250	.notifier_call = wafwdt_notify_sys,
	251	};
	252
	253	static int __init wafwdt_init(void)
	254	{
	255	int ret;
	256
27c766aa	257	pr_info("WDT driver for Wafer 5823 single board computer initialising\n");
1da177e4	258
1da177e4 LT	259	if (timeout < 1 \|\| timeout > 255) {
1da177e4 LT	260	timeout = WD_TIMO;
27c766aa JP	261	pr_info("timeout value must be 1 <= x <= 255, using %d\n",
27c766aa JP	262	timeout);
1da177e4 LT	263	}
	264
	265	if (wdt_stop != wdt_start) {
694b16b2	266	if (!request_region(wdt_stop, 1, "Wafer 5823 WDT")) {
27c766aa	267	pr_err("I/O address 0x%04x already in use\n", wdt_stop);
1da177e4 LT	268	ret = -EIO;
	269	goto error;
	270	}
	271	}
	272
694b16b2	273	if (!request_region(wdt_start, 1, "Wafer 5823 WDT")) {
27c766aa	274	pr_err("I/O address 0x%04x already in use\n", wdt_start);
1da177e4 LT	275	ret = -EIO;
	276	goto error2;
	277	}
	278
	279	ret = register_reboot_notifier(&wafwdt_notifier);
	280	if (ret != 0) {
27c766aa	281	pr_err("cannot register reboot notifier (err=%d)\n", ret);
1da177e4 LT	282	goto error3;
	283	}
	284
	285	ret = misc_register(&wafwdt_miscdev);
	286	if (ret != 0) {
27c766aa JP	287	pr_err("cannot register miscdev on minor=%d (err=%d)\n",
27c766aa JP	288	WATCHDOG_MINOR, ret);
1da177e4 LT	289	goto error4;
	290	}
	291
27c766aa	292	pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
1da177e4 LT	293	timeout, nowayout);
	294
	295	return ret;
	296	error4:
	297	unregister_reboot_notifier(&wafwdt_notifier);
	298	error3:
	299	release_region(wdt_start, 1);
	300	error2:
	301	if (wdt_stop != wdt_start)
	302	release_region(wdt_stop, 1);
	303	error:
	304	return ret;
	305	}
	306
	307	static void __exit wafwdt_exit(void)
	308	{
	309	misc_deregister(&wafwdt_miscdev);
	310	unregister_reboot_notifier(&wafwdt_notifier);
694b16b2	311	if (wdt_stop != wdt_start)
1da177e4 LT	312	release_region(wdt_stop, 1);
	313	release_region(wdt_start, 1);
	314	}
	315
	316	module_init(wafwdt_init);
	317	module_exit(wafwdt_exit);
	318
	319	MODULE_AUTHOR("Justin Cormack");
	320	MODULE_DESCRIPTION("ICP Wafer 5823 Single Board Computer WDT driver");
	321	MODULE_LICENSE("GPL");
1da177e4 LT	322
1da177e4 LT	323	/* end of wafer5823wdt.c */