1// SPDX-License-Identifier: GPL-2.0+
  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 *
 10 *	(c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
 11 *						All Rights Reserved.
 12 *
 
 
 
 
 
 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 *
 17 *	(c) Copyright 1995    Alan Cox <alan@lxorguk.ukuu.org.uk>
 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
 27#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 28
 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>
 36#include <linux/platform_device.h>
 37#include <linux/init.h>
 38#include <linux/io.h>
 39#include <linux/uaccess.h>
 40
 41
 42#define DRV_NAME "advantechwdt"
 43#define WATCHDOG_NAME "Advantech WDT"
 44#define WATCHDOG_TIMEOUT 60		/* 60 sec default timeout */
 45
 46/* the watchdog platform device */
 47static struct platform_device *advwdt_platform_device;
 48static unsigned long advwdt_is_open;
 49static 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
 62static int wdt_stop = 0x443;
 63module_param(wdt_stop, int, 0);
 64MODULE_PARM_DESC(wdt_stop, "Advantech WDT 'stop' io port (default 0x443)");
 65
 66static int wdt_start = 0x443;
 67module_param(wdt_start, int, 0);
 68MODULE_PARM_DESC(wdt_start, "Advantech WDT 'start' io port (default 0x443)");
 69
 70static int timeout = WATCHDOG_TIMEOUT;	/* in seconds */
 71module_param(timeout, int, 0);
 72MODULE_PARM_DESC(timeout,
 73	"Watchdog timeout in seconds. 1<= timeout <=63, default="
 74		__MODULE_STRING(WATCHDOG_TIMEOUT) ".");
 75
 76static bool nowayout = WATCHDOG_NOWAYOUT;
 77module_param(nowayout, bool, 0);
 78MODULE_PARM_DESC(nowayout,
 79	"Watchdog cannot be stopped once started (default="
 80		__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 81
 82/*
 83 *	Watchdog Operations
 84 */
 85
 86static void advwdt_ping(void)
 87{
 88	/* Write a watchdog value */
 89	outb_p(timeout, wdt_start);
 90}
 91
 92static void advwdt_disable(void)
 93{
 94	inb_p(wdt_stop);
 95}
 96
 97static int advwdt_set_heartbeat(int t)
 98{
 99	if (t < 1 || t > 63)
100		return -EINVAL;
101	timeout = t;
102	return 0;
103}
104
105/*
106 *	/dev/watchdog handling
107 */
108
109static ssize_t advwdt_write(struct file *file, const char __user *buf,
110						size_t count, loff_t *ppos)
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;
120				if (get_user(c, buf + i))
121					return -EFAULT;
122				if (c == 'V')
123					adv_expect_close = 42;
124			}
125		}
126		advwdt_ping();
127	}
128	return count;
129}
130
131static long advwdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
132{
133	int new_timeout;
134	void __user *argp = (void __user *)arg;
135	int __user *p = argp;
136	static const struct watchdog_info ident = {
137		.options = WDIOF_KEEPALIVEPING |
138			   WDIOF_SETTIMEOUT |
139			   WDIOF_MAGICCLOSE,
140		.firmware_version = 1,
141		.identity = WATCHDOG_NAME,
142	};
143
144	switch (cmd) {
145	case WDIOC_GETSUPPORT:
146		if (copy_to_user(argp, &ident, sizeof(ident)))
147			return -EFAULT;
148		break;
149
150	case WDIOC_GETSTATUS:
151	case WDIOC_GETBOOTSTATUS:
152		return put_user(0, p);
153
154	case WDIOC_SETOPTIONS:
155	{
156		int options, retval = -EINVAL;
157
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;
169	}
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();
180		fallthrough;
181	case WDIOC_GETTIMEOUT:
182		return put_user(timeout, p);
183	default:
184		return -ENOTTY;
185	}
186	return 0;
187}
188
189static int advwdt_open(struct inode *inode, struct file *file)
190{
191	if (test_and_set_bit(0, &advwdt_is_open))
192		return -EBUSY;
193	/*
194	 *	Activate
195	 */
196
197	advwdt_ping();
198	return stream_open(inode, file);
199}
200
201static int advwdt_close(struct inode *inode, struct file *file)
202{
203	if (adv_expect_close == 42) {
204		advwdt_disable();
205	} else {
206		pr_crit("Unexpected close, not stopping watchdog!\n");
207		advwdt_ping();
208	}
209	clear_bit(0, &advwdt_is_open);
210	adv_expect_close = 0;
211	return 0;
212}
213
214/*
215 *	Kernel Interfaces
216 */
217
218static const struct file_operations advwdt_fops = {
219	.owner		= THIS_MODULE,
220	.llseek		= no_llseek,
221	.write		= advwdt_write,
222	.unlocked_ioctl	= advwdt_ioctl,
223	.compat_ioctl	= compat_ptr_ioctl,
224	.open		= advwdt_open,
225	.release	= advwdt_close,
226};
227
228static struct miscdevice advwdt_miscdev = {
229	.minor	= WATCHDOG_MINOR,
230	.name	= "watchdog",
231	.fops	= &advwdt_fops,
232};
233
234/*
235 *	Init & exit routines
236 */
237
238static int __init advwdt_probe(struct platform_device *dev)
239{
240	int ret;
241
242	if (wdt_stop != wdt_start) {
243		if (!request_region(wdt_stop, 1, WATCHDOG_NAME)) {
244			pr_err("I/O address 0x%04x already in use\n",
245			       wdt_stop);
246			ret = -EIO;
247			goto out;
248		}
249	}
250
251	if (!request_region(wdt_start, 1, WATCHDOG_NAME)) {
252		pr_err("I/O address 0x%04x already in use\n", wdt_start);
253		ret = -EIO;
254		goto unreg_stop;
255	}
256
257	/* Check that the heartbeat value is within it's range ;
258	 * if not reset to the default */
259	if (advwdt_set_heartbeat(timeout)) {
260		advwdt_set_heartbeat(WATCHDOG_TIMEOUT);
261		pr_info("timeout value must be 1<=x<=63, using %d\n", timeout);
262	}
263
264	ret = misc_register(&advwdt_miscdev);
265	if (ret != 0) {
266		pr_err("cannot register miscdev on minor=%d (err=%d)\n",
267		       WATCHDOG_MINOR, ret);
268		goto unreg_regions;
269	}
270	pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
271		timeout, nowayout);
272out:
273	return ret;
274unreg_regions:
275	release_region(wdt_start, 1);
276unreg_stop:
277	if (wdt_stop != wdt_start)
278		release_region(wdt_stop, 1);
279	goto out;
280}
281
282static int advwdt_remove(struct platform_device *dev)
283{
284	misc_deregister(&advwdt_miscdev);
285	release_region(wdt_start, 1);
286	if (wdt_stop != wdt_start)
287		release_region(wdt_stop, 1);
288
289	return 0;
290}
291
292static void advwdt_shutdown(struct platform_device *dev)
293{
294	/* Turn the WDT off if we have a soft shutdown */
295	advwdt_disable();
296}
297
298static struct platform_driver advwdt_driver = {
299	.remove		= advwdt_remove,
300	.shutdown	= advwdt_shutdown,
301	.driver		= {
302		.name	= DRV_NAME,
303	},
304};
305
306static int __init advwdt_init(void)
307{
308	int err;
309
310	pr_info("WDT driver for Advantech single board computer initialising\n");
311
312	advwdt_platform_device = platform_device_register_simple(DRV_NAME,
313								-1, NULL, 0);
314	if (IS_ERR(advwdt_platform_device))
315		return PTR_ERR(advwdt_platform_device);
316
317	err = platform_driver_probe(&advwdt_driver, advwdt_probe);
318	if (err)
319		goto unreg_platform_device;
320
321	return 0;
322
323unreg_platform_device:
324	platform_device_unregister(advwdt_platform_device);
325	return err;
326}
327
328static void __exit advwdt_exit(void)
329{
330	platform_device_unregister(advwdt_platform_device);
331	platform_driver_unregister(&advwdt_driver);
332	pr_info("Watchdog Module Unloaded\n");
333}
334
335module_init(advwdt_init);
336module_exit(advwdt_exit);
337
338MODULE_LICENSE("GPL");
339MODULE_AUTHOR("Marek Michalkiewicz <marekm@linux.org.pl>");
340MODULE_DESCRIPTION("Advantech Single Board Computer WDT driver");

 
  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@lxorguk.ukuu.org.uk>,
 10 *						All Rights Reserved.
 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@lxorguk.ukuu.org.uk>
 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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 32
 33#include <linux/module.h>
 34#include <linux/moduleparam.h>
 35#include <linux/types.h>
 36#include <linux/miscdevice.h>
 37#include <linux/watchdog.h>
 38#include <linux/fs.h>
 39#include <linux/ioport.h>
 40#include <linux/platform_device.h>
 41#include <linux/init.h>
 42#include <linux/io.h>
 43#include <linux/uaccess.h>
 44
 45
 46#define DRV_NAME "advantechwdt"
 47#define WATCHDOG_NAME "Advantech WDT"
 48#define WATCHDOG_TIMEOUT 60		/* 60 sec default timeout */
 49
 50/* the watchdog platform device */
 51static struct platform_device *advwdt_platform_device;
 52static unsigned long advwdt_is_open;
 53static char adv_expect_close;
 54
 55/*
 56 *	You must set these - there is no sane way to probe for this board.
 57 *
 58 *	To enable or restart, write the timeout value in seconds (1 to 63)
 59 *	to I/O port wdt_start.  To disable, read I/O port wdt_stop.
 60 *	Both are 0x443 for most boards (tested on a PCA-6276VE-00B1), but
 61 *	check your manual (at least the PCA-6159 seems to be different -
 62 *	the manual says wdt_stop is 0x43, not 0x443).
 63 *	(0x43 is also a write-only control register for the 8254 timer!)
 64 */
 65
 66static int wdt_stop = 0x443;
 67module_param(wdt_stop, int, 0);
 68MODULE_PARM_DESC(wdt_stop, "Advantech WDT 'stop' io port (default 0x443)");
 69
 70static int wdt_start = 0x443;
 71module_param(wdt_start, int, 0);
 72MODULE_PARM_DESC(wdt_start, "Advantech WDT 'start' io port (default 0x443)");
 73
 74static int timeout = WATCHDOG_TIMEOUT;	/* in seconds */
 75module_param(timeout, int, 0);
 76MODULE_PARM_DESC(timeout,
 77	"Watchdog timeout in seconds. 1<= timeout <=63, default="
 78		__MODULE_STRING(WATCHDOG_TIMEOUT) ".");
 79
 80static bool nowayout = WATCHDOG_NOWAYOUT;
 81module_param(nowayout, bool, 0);
 82MODULE_PARM_DESC(nowayout,
 83	"Watchdog cannot be stopped once started (default="
 84		__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 85
 86/*
 87 *	Watchdog Operations
 88 */
 89
 90static void advwdt_ping(void)
 91{
 92	/* Write a watchdog value */
 93	outb_p(timeout, wdt_start);
 94}
 95
 96static void advwdt_disable(void)
 97{
 98	inb_p(wdt_stop);
 99}
100
101static int advwdt_set_heartbeat(int t)
102{
103	if (t < 1 || t > 63)
104		return -EINVAL;
105	timeout = t;
106	return 0;
107}
108
109/*
110 *	/dev/watchdog handling
111 */
112
113static ssize_t advwdt_write(struct file *file, const char __user *buf,
114						size_t count, loff_t *ppos)
115{
116	if (count) {
117		if (!nowayout) {
118			size_t i;
119
120			adv_expect_close = 0;
121
122			for (i = 0; i != count; i++) {
123				char c;
124				if (get_user(c, buf + i))
125					return -EFAULT;
126				if (c == 'V')
127					adv_expect_close = 42;
128			}
129		}
130		advwdt_ping();
131	}
132	return count;
133}
134
135static long advwdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
136{
137	int new_timeout;
138	void __user *argp = (void __user *)arg;
139	int __user *p = argp;
140	static const struct watchdog_info ident = {
141		.options = WDIOF_KEEPALIVEPING |
142			   WDIOF_SETTIMEOUT |
143			   WDIOF_MAGICCLOSE,
144		.firmware_version = 1,
145		.identity = WATCHDOG_NAME,
146	};
147
148	switch (cmd) {
149	case WDIOC_GETSUPPORT:
150		if (copy_to_user(argp, &ident, sizeof(ident)))
151			return -EFAULT;
152		break;
153
154	case WDIOC_GETSTATUS:
155	case WDIOC_GETBOOTSTATUS:
156		return put_user(0, p);
157
158	case WDIOC_SETOPTIONS:
159	{
160		int options, retval = -EINVAL;
161
162		if (get_user(options, p))
163			return -EFAULT;
164		if (options & WDIOS_DISABLECARD) {
165			advwdt_disable();
166			retval = 0;
167		}
168		if (options & WDIOS_ENABLECARD) {
169			advwdt_ping();
170			retval = 0;
171		}
172		return retval;
173	}
174	case WDIOC_KEEPALIVE:
175		advwdt_ping();
176		break;
177
178	case WDIOC_SETTIMEOUT:
179		if (get_user(new_timeout, p))
180			return -EFAULT;
181		if (advwdt_set_heartbeat(new_timeout))
182			return -EINVAL;
183		advwdt_ping();
184		/* fall through */
185	case WDIOC_GETTIMEOUT:
186		return put_user(timeout, p);
187	default:
188		return -ENOTTY;
189	}
190	return 0;
191}
192
193static int advwdt_open(struct inode *inode, struct file *file)
194{
195	if (test_and_set_bit(0, &advwdt_is_open))
196		return -EBUSY;
197	/*
198	 *	Activate
199	 */
200
201	advwdt_ping();
202	return nonseekable_open(inode, file);
203}
204
205static int advwdt_close(struct inode *inode, struct file *file)
206{
207	if (adv_expect_close == 42) {
208		advwdt_disable();
209	} else {
210		pr_crit("Unexpected close, not stopping watchdog!\n");
211		advwdt_ping();
212	}
213	clear_bit(0, &advwdt_is_open);
214	adv_expect_close = 0;
215	return 0;
216}
217
218/*
219 *	Kernel Interfaces
220 */
221
222static const struct file_operations advwdt_fops = {
223	.owner		= THIS_MODULE,
224	.llseek		= no_llseek,
225	.write		= advwdt_write,
226	.unlocked_ioctl	= advwdt_ioctl,
 
227	.open		= advwdt_open,
228	.release	= advwdt_close,
229};
230
231static struct miscdevice advwdt_miscdev = {
232	.minor	= WATCHDOG_MINOR,
233	.name	= "watchdog",
234	.fops	= &advwdt_fops,
235};
236
237/*
238 *	Init & exit routines
239 */
240
241static int __init advwdt_probe(struct platform_device *dev)
242{
243	int ret;
244
245	if (wdt_stop != wdt_start) {
246		if (!request_region(wdt_stop, 1, WATCHDOG_NAME)) {
247			pr_err("I/O address 0x%04x already in use\n",
248			       wdt_stop);
249			ret = -EIO;
250			goto out;
251		}
252	}
253
254	if (!request_region(wdt_start, 1, WATCHDOG_NAME)) {
255		pr_err("I/O address 0x%04x already in use\n", wdt_start);
256		ret = -EIO;
257		goto unreg_stop;
258	}
259
260	/* Check that the heartbeat value is within it's range ;
261	 * if not reset to the default */
262	if (advwdt_set_heartbeat(timeout)) {
263		advwdt_set_heartbeat(WATCHDOG_TIMEOUT);
264		pr_info("timeout value must be 1<=x<=63, using %d\n", timeout);
265	}
266
267	ret = misc_register(&advwdt_miscdev);
268	if (ret != 0) {
269		pr_err("cannot register miscdev on minor=%d (err=%d)\n",
270		       WATCHDOG_MINOR, ret);
271		goto unreg_regions;
272	}
273	pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
274		timeout, nowayout);
275out:
276	return ret;
277unreg_regions:
278	release_region(wdt_start, 1);
279unreg_stop:
280	if (wdt_stop != wdt_start)
281		release_region(wdt_stop, 1);
282	goto out;
283}
284
285static int advwdt_remove(struct platform_device *dev)
286{
287	misc_deregister(&advwdt_miscdev);
288	release_region(wdt_start, 1);
289	if (wdt_stop != wdt_start)
290		release_region(wdt_stop, 1);
291
292	return 0;
293}
294
295static void advwdt_shutdown(struct platform_device *dev)
296{
297	/* Turn the WDT off if we have a soft shutdown */
298	advwdt_disable();
299}
300
301static struct platform_driver advwdt_driver = {
302	.remove		= advwdt_remove,
303	.shutdown	= advwdt_shutdown,
304	.driver		= {
305		.name	= DRV_NAME,
306	},
307};
308
309static int __init advwdt_init(void)
310{
311	int err;
312
313	pr_info("WDT driver for Advantech single board computer initialising\n");
314
315	advwdt_platform_device = platform_device_register_simple(DRV_NAME,
316								-1, NULL, 0);
317	if (IS_ERR(advwdt_platform_device))
318		return PTR_ERR(advwdt_platform_device);
319
320	err = platform_driver_probe(&advwdt_driver, advwdt_probe);
321	if (err)
322		goto unreg_platform_device;
323
324	return 0;
325
326unreg_platform_device:
327	platform_device_unregister(advwdt_platform_device);
328	return err;
329}
330
331static void __exit advwdt_exit(void)
332{
333	platform_device_unregister(advwdt_platform_device);
334	platform_driver_unregister(&advwdt_driver);
335	pr_info("Watchdog Module Unloaded\n");
336}
337
338module_init(advwdt_init);
339module_exit(advwdt_exit);
340
341MODULE_LICENSE("GPL");
342MODULE_AUTHOR("Marek Michalkiewicz <marekm@linux.org.pl>");
343MODULE_DESCRIPTION("Advantech Single Board Computer WDT driver");