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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#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>
38#include <linux/platform_device.h>
39#include <linux/init.h>
40#include <linux/io.h>
41#include <linux/uaccess.h>
42
43#include <asm/system.h>
44
45#define DRV_NAME "advantechwdt"
46#define PFX DRV_NAME ": "
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 int nowayout = WATCHDOG_NOWAYOUT;
81module_param(nowayout, int, 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 */
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 printk(KERN_CRIT PFX
211 "Unexpected close, not stopping watchdog!\n");
212 advwdt_ping();
213 }
214 clear_bit(0, &advwdt_is_open);
215 adv_expect_close = 0;
216 return 0;
217}
218
219/*
220 * Kernel Interfaces
221 */
222
223static const struct file_operations advwdt_fops = {
224 .owner = THIS_MODULE,
225 .llseek = no_llseek,
226 .write = advwdt_write,
227 .unlocked_ioctl = advwdt_ioctl,
228 .open = advwdt_open,
229 .release = advwdt_close,
230};
231
232static struct miscdevice advwdt_miscdev = {
233 .minor = WATCHDOG_MINOR,
234 .name = "watchdog",
235 .fops = &advwdt_fops,
236};
237
238/*
239 * Init & exit routines
240 */
241
242static int __devinit advwdt_probe(struct platform_device *dev)
243{
244 int ret;
245
246 if (wdt_stop != wdt_start) {
247 if (!request_region(wdt_stop, 1, WATCHDOG_NAME)) {
248 printk(KERN_ERR PFX
249 "I/O address 0x%04x already in use\n",
250 wdt_stop);
251 ret = -EIO;
252 goto out;
253 }
254 }
255
256 if (!request_region(wdt_start, 1, WATCHDOG_NAME)) {
257 printk(KERN_ERR PFX
258 "I/O address 0x%04x already in use\n",
259 wdt_start);
260 ret = -EIO;
261 goto unreg_stop;
262 }
263
264 /* Check that the heartbeat value is within it's range ;
265 * if not reset to the default */
266 if (advwdt_set_heartbeat(timeout)) {
267 advwdt_set_heartbeat(WATCHDOG_TIMEOUT);
268 printk(KERN_INFO PFX
269 "timeout value must be 1<=x<=63, using %d\n", timeout);
270 }
271
272 ret = misc_register(&advwdt_miscdev);
273 if (ret != 0) {
274 printk(KERN_ERR PFX
275 "cannot register miscdev on minor=%d (err=%d)\n",
276 WATCHDOG_MINOR, ret);
277 goto unreg_regions;
278 }
279 printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
280 timeout, nowayout);
281out:
282 return ret;
283unreg_regions:
284 release_region(wdt_start, 1);
285unreg_stop:
286 if (wdt_stop != wdt_start)
287 release_region(wdt_stop, 1);
288 goto out;
289}
290
291static int __devexit advwdt_remove(struct platform_device *dev)
292{
293 misc_deregister(&advwdt_miscdev);
294 release_region(wdt_start, 1);
295 if (wdt_stop != wdt_start)
296 release_region(wdt_stop, 1);
297
298 return 0;
299}
300
301static void advwdt_shutdown(struct platform_device *dev)
302{
303 /* Turn the WDT off if we have a soft shutdown */
304 advwdt_disable();
305}
306
307static struct platform_driver advwdt_driver = {
308 .probe = advwdt_probe,
309 .remove = __devexit_p(advwdt_remove),
310 .shutdown = advwdt_shutdown,
311 .driver = {
312 .owner = THIS_MODULE,
313 .name = DRV_NAME,
314 },
315};
316
317static int __init advwdt_init(void)
318{
319 int err;
320
321 printk(KERN_INFO
322 "WDT driver for Advantech single board computer initialising.\n");
323
324 err = platform_driver_register(&advwdt_driver);
325 if (err)
326 return err;
327
328 advwdt_platform_device = platform_device_register_simple(DRV_NAME,
329 -1, NULL, 0);
330 if (IS_ERR(advwdt_platform_device)) {
331 err = PTR_ERR(advwdt_platform_device);
332 goto unreg_platform_driver;
333 }
334
335 return 0;
336
337unreg_platform_driver:
338 platform_driver_unregister(&advwdt_driver);
339 return err;
340}
341
342static void __exit advwdt_exit(void)
343{
344 platform_device_unregister(advwdt_platform_device);
345 platform_driver_unregister(&advwdt_driver);
346 printk(KERN_INFO PFX "Watchdog Module Unloaded.\n");
347}
348
349module_init(advwdt_init);
350module_exit(advwdt_exit);
351
352MODULE_LICENSE("GPL");
353MODULE_AUTHOR("Marek Michalkiewicz <marekm@linux.org.pl>");
354MODULE_DESCRIPTION("Advantech Single Board Computer WDT driver");
355MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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");