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Commit cb7efc02c6dbc3bfe9d5d1509ed790fc757e05a9

Authored by H Hartley Sweeten
Committed by Wim Van Sebroeck
1 parent 9d037a7776
Exists in master and in 6 other branches imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga, smarc-l5.0.0_1.0.0-ga

watchdog: WatchDog Timer Driver Core - use passed watchdog_device 

Use the passed watchdog_device instead of the static global variable when
testing and setting the status in watchdog_ping, watchdog_start, and
watchdog_stop.  Note that the callers of these functions are actually
passing the static global variable.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

Showing 1 changed file with 7 additions and 7 deletions Inline Diff

drivers/watchdog/watchdog_dev.c
Diff comments   View file @ cb7efc0
1 /* 1 /*
2 * watchdog_dev.c 2 * watchdog_dev.c
3 * 3 *
4 * (c) Copyright 2008-2011 Alan Cox <alan@lxorguk.ukuu.org.uk>, 4 * (c) Copyright 2008-2011 Alan Cox <alan@lxorguk.ukuu.org.uk>,
5 * All Rights Reserved. 5 * All Rights Reserved.
6 * 6 *
7 * (c) Copyright 2008-2011 Wim Van Sebroeck <wim@iguana.be>. 7 * (c) Copyright 2008-2011 Wim Van Sebroeck <wim@iguana.be>.
8 * 8 *
9 * 9 *
10 * This source code is part of the generic code that can be used 10 * This source code is part of the generic code that can be used
11 * by all the watchdog timer drivers. 11 * by all the watchdog timer drivers.
12 * 12 *
13 * This part of the generic code takes care of the following 13 * This part of the generic code takes care of the following
14 * misc device: /dev/watchdog. 14 * misc device: /dev/watchdog.
15 * 15 *
16 * Based on source code of the following authors: 16 * Based on source code of the following authors:
17 * Matt Domsch <Matt_Domsch@dell.com>, 17 * Matt Domsch <Matt_Domsch@dell.com>,
18 * Rob Radez <rob@osinvestor.com>, 18 * Rob Radez <rob@osinvestor.com>,
19 * Rusty Lynch <rusty@linux.co.intel.com> 19 * Rusty Lynch <rusty@linux.co.intel.com>
20 * Satyam Sharma <satyam@infradead.org> 20 * Satyam Sharma <satyam@infradead.org>
21 * Randy Dunlap <randy.dunlap@oracle.com> 21 * Randy Dunlap <randy.dunlap@oracle.com>
22 * 22 *
23 * This program is free software; you can redistribute it and/or 23 * This program is free software; you can redistribute it and/or
24 * modify it under the terms of the GNU General Public License 24 * modify it under the terms of the GNU General Public License
25 * as published by the Free Software Foundation; either version 25 * as published by the Free Software Foundation; either version
26 * 2 of the License, or (at your option) any later version. 26 * 2 of the License, or (at your option) any later version.
27 * 27 *
28 * Neither Alan Cox, CymruNet Ltd., Wim Van Sebroeck nor Iguana vzw. 28 * Neither Alan Cox, CymruNet Ltd., Wim Van Sebroeck nor Iguana vzw.
29 * admit liability nor provide warranty for any of this software. 29 * admit liability nor provide warranty for any of this software.
30 * This material is provided "AS-IS" and at no charge. 30 * This material is provided "AS-IS" and at no charge.
31 */ 31 */
32 32
33 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 33 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
34 34
35 #include <linux/module.h> /* For module stuff/... */ 35 #include <linux/module.h> /* For module stuff/... */
36 #include <linux/types.h> /* For standard types (like size_t) */ 36 #include <linux/types.h> /* For standard types (like size_t) */
37 #include <linux/errno.h> /* For the -ENODEV/... values */ 37 #include <linux/errno.h> /* For the -ENODEV/... values */
38 #include <linux/kernel.h> /* For printk/panic/... */ 38 #include <linux/kernel.h> /* For printk/panic/... */
39 #include <linux/fs.h> /* For file operations */ 39 #include <linux/fs.h> /* For file operations */
40 #include <linux/watchdog.h> /* For watchdog specific items */ 40 #include <linux/watchdog.h> /* For watchdog specific items */
41 #include <linux/miscdevice.h> /* For handling misc devices */ 41 #include <linux/miscdevice.h> /* For handling misc devices */
42 #include <linux/init.h> /* For __init/__exit/... */ 42 #include <linux/init.h> /* For __init/__exit/... */
43 #include <linux/uaccess.h> /* For copy_to_user/put_user/... */ 43 #include <linux/uaccess.h> /* For copy_to_user/put_user/... */
44 44
45 /* make sure we only register one /dev/watchdog device */ 45 /* make sure we only register one /dev/watchdog device */
46 static unsigned long watchdog_dev_busy; 46 static unsigned long watchdog_dev_busy;
47 /* the watchdog device behind /dev/watchdog */ 47 /* the watchdog device behind /dev/watchdog */
48 static struct watchdog_device *wdd; 48 static struct watchdog_device *wdd;
49 49
50 /* 50 /*
51 * watchdog_ping: ping the watchdog. 51 * watchdog_ping: ping the watchdog.
52 * @wddev: the watchdog device to ping 52 * @wddev: the watchdog device to ping
53 * 53 *
54 * If the watchdog has no own ping operation then it needs to be 54 * If the watchdog has no own ping operation then it needs to be
55 * restarted via the start operation. This wrapper function does 55 * restarted via the start operation. This wrapper function does
56 * exactly that. 56 * exactly that.
57 * We only ping when the watchdog device is running. 57 * We only ping when the watchdog device is running.
58 */ 58 */
59 59
60 static int watchdog_ping(struct watchdog_device *wddev) 60 static int watchdog_ping(struct watchdog_device *wddev)
61 { 61 {
62 if (test_bit(WDOG_ACTIVE, &wdd->status)) { 62 if (test_bit(WDOG_ACTIVE, &wddev->status)) {
63 if (wddev->ops->ping) 63 if (wddev->ops->ping)
64 return wddev->ops->ping(wddev); /* ping the watchdog */ 64 return wddev->ops->ping(wddev); /* ping the watchdog */
65 else 65 else
66 return wddev->ops->start(wddev); /* restart watchdog */ 66 return wddev->ops->start(wddev); /* restart watchdog */
67 } 67 }
68 return 0; 68 return 0;
69 } 69 }
70 70
71 /* 71 /*
72 * watchdog_start: wrapper to start the watchdog. 72 * watchdog_start: wrapper to start the watchdog.
73 * @wddev: the watchdog device to start 73 * @wddev: the watchdog device to start
74 * 74 *
75 * Start the watchdog if it is not active and mark it active. 75 * Start the watchdog if it is not active and mark it active.
76 * This function returns zero on success or a negative errno code for 76 * This function returns zero on success or a negative errno code for
77 * failure. 77 * failure.
78 */ 78 */
79 79
80 static int watchdog_start(struct watchdog_device *wddev) 80 static int watchdog_start(struct watchdog_device *wddev)
81 { 81 {
82 int err; 82 int err;
83 83
84 if (!test_bit(WDOG_ACTIVE, &wdd->status)) { 84 if (!test_bit(WDOG_ACTIVE, &wddev->status)) {
85 err = wddev->ops->start(wddev); 85 err = wddev->ops->start(wddev);
86 if (err < 0) 86 if (err < 0)
87 return err; 87 return err;
88 88
89 set_bit(WDOG_ACTIVE, &wdd->status); 89 set_bit(WDOG_ACTIVE, &wddev->status);
90 } 90 }
91 return 0; 91 return 0;
92 } 92 }
93 93
94 /* 94 /*
95 * watchdog_stop: wrapper to stop the watchdog. 95 * watchdog_stop: wrapper to stop the watchdog.
96 * @wddev: the watchdog device to stop 96 * @wddev: the watchdog device to stop
97 * 97 *
98 * Stop the watchdog if it is still active and unmark it active. 98 * Stop the watchdog if it is still active and unmark it active.
99 * This function returns zero on success or a negative errno code for 99 * This function returns zero on success or a negative errno code for
100 * failure. 100 * failure.
101 * If the 'nowayout' feature was set, the watchdog cannot be stopped. 101 * If the 'nowayout' feature was set, the watchdog cannot be stopped.
102 */ 102 */
103 103
104 static int watchdog_stop(struct watchdog_device *wddev) 104 static int watchdog_stop(struct watchdog_device *wddev)
105 { 105 {
106 int err = -EBUSY; 106 int err = -EBUSY;
107 107
108 if (test_bit(WDOG_NO_WAY_OUT, &wdd->status)) { 108 if (test_bit(WDOG_NO_WAY_OUT, &wddev->status)) {
109 pr_info("%s: nowayout prevents watchdog to be stopped!\n", 109 pr_info("%s: nowayout prevents watchdog to be stopped!\n",
110 wdd->info->identity); 110 wddev->info->identity);
111 return err; 111 return err;
112 } 112 }
113 113
114 if (test_bit(WDOG_ACTIVE, &wdd->status)) { 114 if (test_bit(WDOG_ACTIVE, &wddev->status)) {
115 err = wddev->ops->stop(wddev); 115 err = wddev->ops->stop(wddev);
116 if (err < 0) 116 if (err < 0)
117 return err; 117 return err;
118 118
119 clear_bit(WDOG_ACTIVE, &wdd->status); 119 clear_bit(WDOG_ACTIVE, &wddev->status);
120 } 120 }
121 return 0; 121 return 0;
122 } 122 }
123 123
124 /* 124 /*
125 * watchdog_write: writes to the watchdog. 125 * watchdog_write: writes to the watchdog.
126 * @file: file from VFS 126 * @file: file from VFS
127 * @data: user address of data 127 * @data: user address of data
128 * @len: length of data 128 * @len: length of data
129 * @ppos: pointer to the file offset 129 * @ppos: pointer to the file offset
130 * 130 *
131 * A write to a watchdog device is defined as a keepalive ping. 131 * A write to a watchdog device is defined as a keepalive ping.
132 * Writing the magic 'V' sequence allows the next close to turn 132 * Writing the magic 'V' sequence allows the next close to turn
133 * off the watchdog (if 'nowayout' is not set). 133 * off the watchdog (if 'nowayout' is not set).
134 */ 134 */
135 135
136 static ssize_t watchdog_write(struct file *file, const char __user *data, 136 static ssize_t watchdog_write(struct file *file, const char __user *data,
137 size_t len, loff_t *ppos) 137 size_t len, loff_t *ppos)
138 { 138 {
139 size_t i; 139 size_t i;
140 char c; 140 char c;
141 141
142 if (len == 0) 142 if (len == 0)
143 return 0; 143 return 0;
144 144
145 /* 145 /*
146 * Note: just in case someone wrote the magic character 146 * Note: just in case someone wrote the magic character
147 * five months ago... 147 * five months ago...
148 */ 148 */
149 clear_bit(WDOG_ALLOW_RELEASE, &wdd->status); 149 clear_bit(WDOG_ALLOW_RELEASE, &wdd->status);
150 150
151 /* scan to see whether or not we got the magic character */ 151 /* scan to see whether or not we got the magic character */
152 for (i = 0; i != len; i++) { 152 for (i = 0; i != len; i++) {
153 if (get_user(c, data + i)) 153 if (get_user(c, data + i))
154 return -EFAULT; 154 return -EFAULT;
155 if (c == 'V') 155 if (c == 'V')
156 set_bit(WDOG_ALLOW_RELEASE, &wdd->status); 156 set_bit(WDOG_ALLOW_RELEASE, &wdd->status);
157 } 157 }
158 158
159 /* someone wrote to us, so we send the watchdog a keepalive ping */ 159 /* someone wrote to us, so we send the watchdog a keepalive ping */
160 watchdog_ping(wdd); 160 watchdog_ping(wdd);
161 161
162 return len; 162 return len;
163 } 163 }
164 164
165 /* 165 /*
166 * watchdog_ioctl: handle the different ioctl's for the watchdog device. 166 * watchdog_ioctl: handle the different ioctl's for the watchdog device.
167 * @file: file handle to the device 167 * @file: file handle to the device
168 * @cmd: watchdog command 168 * @cmd: watchdog command
169 * @arg: argument pointer 169 * @arg: argument pointer
170 * 170 *
171 * The watchdog API defines a common set of functions for all watchdogs 171 * The watchdog API defines a common set of functions for all watchdogs
172 * according to their available features. 172 * according to their available features.
173 */ 173 */
174 174
175 static long watchdog_ioctl(struct file *file, unsigned int cmd, 175 static long watchdog_ioctl(struct file *file, unsigned int cmd,
176 unsigned long arg) 176 unsigned long arg)
177 { 177 {
178 void __user *argp = (void __user *)arg; 178 void __user *argp = (void __user *)arg;
179 int __user *p = argp; 179 int __user *p = argp;
180 unsigned int val; 180 unsigned int val;
181 int err; 181 int err;
182 182
183 if (wdd->ops->ioctl) { 183 if (wdd->ops->ioctl) {
184 err = wdd->ops->ioctl(wdd, cmd, arg); 184 err = wdd->ops->ioctl(wdd, cmd, arg);
185 if (err != -ENOIOCTLCMD) 185 if (err != -ENOIOCTLCMD)
186 return err; 186 return err;
187 } 187 }
188 188
189 switch (cmd) { 189 switch (cmd) {
190 case WDIOC_GETSUPPORT: 190 case WDIOC_GETSUPPORT:
191 return copy_to_user(argp, wdd->info, 191 return copy_to_user(argp, wdd->info,
192 sizeof(struct watchdog_info)) ? -EFAULT : 0; 192 sizeof(struct watchdog_info)) ? -EFAULT : 0;
193 case WDIOC_GETSTATUS: 193 case WDIOC_GETSTATUS:
194 val = wdd->ops->status ? wdd->ops->status(wdd) : 0; 194 val = wdd->ops->status ? wdd->ops->status(wdd) : 0;
195 return put_user(val, p); 195 return put_user(val, p);
196 case WDIOC_GETBOOTSTATUS: 196 case WDIOC_GETBOOTSTATUS:
197 return put_user(wdd->bootstatus, p); 197 return put_user(wdd->bootstatus, p);
198 case WDIOC_SETOPTIONS: 198 case WDIOC_SETOPTIONS:
199 if (get_user(val, p)) 199 if (get_user(val, p))
200 return -EFAULT; 200 return -EFAULT;
201 if (val & WDIOS_DISABLECARD) { 201 if (val & WDIOS_DISABLECARD) {
202 err = watchdog_stop(wdd); 202 err = watchdog_stop(wdd);
203 if (err < 0) 203 if (err < 0)
204 return err; 204 return err;
205 } 205 }
206 if (val & WDIOS_ENABLECARD) { 206 if (val & WDIOS_ENABLECARD) {
207 err = watchdog_start(wdd); 207 err = watchdog_start(wdd);
208 if (err < 0) 208 if (err < 0)
209 return err; 209 return err;
210 } 210 }
211 return 0; 211 return 0;
212 case WDIOC_KEEPALIVE: 212 case WDIOC_KEEPALIVE:
213 if (!(wdd->info->options & WDIOF_KEEPALIVEPING)) 213 if (!(wdd->info->options & WDIOF_KEEPALIVEPING))
214 return -EOPNOTSUPP; 214 return -EOPNOTSUPP;
215 watchdog_ping(wdd); 215 watchdog_ping(wdd);
216 return 0; 216 return 0;
217 case WDIOC_SETTIMEOUT: 217 case WDIOC_SETTIMEOUT:
218 if ((wdd->ops->set_timeout == NULL) || 218 if ((wdd->ops->set_timeout == NULL) ||
219 !(wdd->info->options & WDIOF_SETTIMEOUT)) 219 !(wdd->info->options & WDIOF_SETTIMEOUT))
220 return -EOPNOTSUPP; 220 return -EOPNOTSUPP;
221 if (get_user(val, p)) 221 if (get_user(val, p))
222 return -EFAULT; 222 return -EFAULT;
223 if ((wdd->max_timeout != 0) && 223 if ((wdd->max_timeout != 0) &&
224 (val < wdd->min_timeout || val > wdd->max_timeout)) 224 (val < wdd->min_timeout || val > wdd->max_timeout))
225 return -EINVAL; 225 return -EINVAL;
226 err = wdd->ops->set_timeout(wdd, val); 226 err = wdd->ops->set_timeout(wdd, val);
227 if (err < 0) 227 if (err < 0)
228 return err; 228 return err;
229 wdd->timeout = val; 229 wdd->timeout = val;
230 /* If the watchdog is active then we send a keepalive ping 230 /* If the watchdog is active then we send a keepalive ping
231 * to make sure that the watchdog keep's running (and if 231 * to make sure that the watchdog keep's running (and if
232 * possible that it takes the new timeout) */ 232 * possible that it takes the new timeout) */
233 watchdog_ping(wdd); 233 watchdog_ping(wdd);
234 /* Fall */ 234 /* Fall */
235 case WDIOC_GETTIMEOUT: 235 case WDIOC_GETTIMEOUT:
236 /* timeout == 0 means that we don't know the timeout */ 236 /* timeout == 0 means that we don't know the timeout */
237 if (wdd->timeout == 0) 237 if (wdd->timeout == 0)
238 return -EOPNOTSUPP; 238 return -EOPNOTSUPP;
239 return put_user(wdd->timeout, p); 239 return put_user(wdd->timeout, p);
240 default: 240 default:
241 return -ENOTTY; 241 return -ENOTTY;
242 } 242 }
243 } 243 }
244 244
245 /* 245 /*
246 * watchdog_open: open the /dev/watchdog device. 246 * watchdog_open: open the /dev/watchdog device.
247 * @inode: inode of device 247 * @inode: inode of device
248 * @file: file handle to device 248 * @file: file handle to device
249 * 249 *
250 * When the /dev/watchdog device gets opened, we start the watchdog. 250 * When the /dev/watchdog device gets opened, we start the watchdog.
251 * Watch out: the /dev/watchdog device is single open, so we make sure 251 * Watch out: the /dev/watchdog device is single open, so we make sure
252 * it can only be opened once. 252 * it can only be opened once.
253 */ 253 */
254 254
255 static int watchdog_open(struct inode *inode, struct file *file) 255 static int watchdog_open(struct inode *inode, struct file *file)
256 { 256 {
257 int err = -EBUSY; 257 int err = -EBUSY;
258 258
259 /* the watchdog is single open! */ 259 /* the watchdog is single open! */
260 if (test_and_set_bit(WDOG_DEV_OPEN, &wdd->status)) 260 if (test_and_set_bit(WDOG_DEV_OPEN, &wdd->status))
261 return -EBUSY; 261 return -EBUSY;
262 262
263 /* 263 /*
264 * If the /dev/watchdog device is open, we don't want the module 264 * If the /dev/watchdog device is open, we don't want the module
265 * to be unloaded. 265 * to be unloaded.
266 */ 266 */
267 if (!try_module_get(wdd->ops->owner)) 267 if (!try_module_get(wdd->ops->owner))
268 goto out; 268 goto out;
269 269
270 err = watchdog_start(wdd); 270 err = watchdog_start(wdd);
271 if (err < 0) 271 if (err < 0)
272 goto out_mod; 272 goto out_mod;
273 273
274 /* dev/watchdog is a virtual (and thus non-seekable) filesystem */ 274 /* dev/watchdog is a virtual (and thus non-seekable) filesystem */
275 return nonseekable_open(inode, file); 275 return nonseekable_open(inode, file);
276 276
277 out_mod: 277 out_mod:
278 module_put(wdd->ops->owner); 278 module_put(wdd->ops->owner);
279 out: 279 out:
280 clear_bit(WDOG_DEV_OPEN, &wdd->status); 280 clear_bit(WDOG_DEV_OPEN, &wdd->status);
281 return err; 281 return err;
282 } 282 }
283 283
284 /* 284 /*
285 * watchdog_release: release the /dev/watchdog device. 285 * watchdog_release: release the /dev/watchdog device.
286 * @inode: inode of device 286 * @inode: inode of device
287 * @file: file handle to device 287 * @file: file handle to device
288 * 288 *
289 * This is the code for when /dev/watchdog gets closed. We will only 289 * This is the code for when /dev/watchdog gets closed. We will only
290 * stop the watchdog when we have received the magic char (and nowayout 290 * stop the watchdog when we have received the magic char (and nowayout
291 * was not set), else the watchdog will keep running. 291 * was not set), else the watchdog will keep running.
292 */ 292 */
293 293
294 static int watchdog_release(struct inode *inode, struct file *file) 294 static int watchdog_release(struct inode *inode, struct file *file)
295 { 295 {
296 int err = -EBUSY; 296 int err = -EBUSY;
297 297
298 /* 298 /*
299 * We only stop the watchdog if we received the magic character 299 * We only stop the watchdog if we received the magic character
300 * or if WDIOF_MAGICCLOSE is not set. If nowayout was set then 300 * or if WDIOF_MAGICCLOSE is not set. If nowayout was set then
301 * watchdog_stop will fail. 301 * watchdog_stop will fail.
302 */ 302 */
303 if (test_and_clear_bit(WDOG_ALLOW_RELEASE, &wdd->status) || 303 if (test_and_clear_bit(WDOG_ALLOW_RELEASE, &wdd->status) ||
304 !(wdd->info->options & WDIOF_MAGICCLOSE)) 304 !(wdd->info->options & WDIOF_MAGICCLOSE))
305 err = watchdog_stop(wdd); 305 err = watchdog_stop(wdd);
306 306
307 /* If the watchdog was not stopped, send a keepalive ping */ 307 /* If the watchdog was not stopped, send a keepalive ping */
308 if (err < 0) { 308 if (err < 0) {
309 pr_crit("%s: watchdog did not stop!\n", wdd->info->identity); 309 pr_crit("%s: watchdog did not stop!\n", wdd->info->identity);
310 watchdog_ping(wdd); 310 watchdog_ping(wdd);
311 } 311 }
312 312
313 /* Allow the owner module to be unloaded again */ 313 /* Allow the owner module to be unloaded again */
314 module_put(wdd->ops->owner); 314 module_put(wdd->ops->owner);
315 315
316 /* make sure that /dev/watchdog can be re-opened */ 316 /* make sure that /dev/watchdog can be re-opened */
317 clear_bit(WDOG_DEV_OPEN, &wdd->status); 317 clear_bit(WDOG_DEV_OPEN, &wdd->status);
318 318
319 return 0; 319 return 0;
320 } 320 }
321 321
322 static const struct file_operations watchdog_fops = { 322 static const struct file_operations watchdog_fops = {
323 .owner = THIS_MODULE, 323 .owner = THIS_MODULE,
324 .write = watchdog_write, 324 .write = watchdog_write,
325 .unlocked_ioctl = watchdog_ioctl, 325 .unlocked_ioctl = watchdog_ioctl,
326 .open = watchdog_open, 326 .open = watchdog_open,
327 .release = watchdog_release, 327 .release = watchdog_release,
328 }; 328 };
329 329
330 static struct miscdevice watchdog_miscdev = { 330 static struct miscdevice watchdog_miscdev = {
331 .minor = WATCHDOG_MINOR, 331 .minor = WATCHDOG_MINOR,
332 .name = "watchdog", 332 .name = "watchdog",
333 .fops = &watchdog_fops, 333 .fops = &watchdog_fops,
334 }; 334 };
335 335
336 /* 336 /*
337 * watchdog_dev_register: 337 * watchdog_dev_register:
338 * @watchdog: watchdog device 338 * @watchdog: watchdog device
339 * 339 *
340 * Register a watchdog device as /dev/watchdog. /dev/watchdog 340 * Register a watchdog device as /dev/watchdog. /dev/watchdog
341 * is actually a miscdevice and thus we set it up like that. 341 * is actually a miscdevice and thus we set it up like that.
342 */ 342 */
343 343
344 int watchdog_dev_register(struct watchdog_device *watchdog) 344 int watchdog_dev_register(struct watchdog_device *watchdog)
345 { 345 {
346 int err; 346 int err;
347 347
348 /* Only one device can register for /dev/watchdog */ 348 /* Only one device can register for /dev/watchdog */
349 if (test_and_set_bit(0, &watchdog_dev_busy)) { 349 if (test_and_set_bit(0, &watchdog_dev_busy)) {
350 pr_err("only one watchdog can use /dev/watchdog.\n"); 350 pr_err("only one watchdog can use /dev/watchdog.\n");
351 return -EBUSY; 351 return -EBUSY;
352 } 352 }
353 353
354 wdd = watchdog; 354 wdd = watchdog;
355 355
356 err = misc_register(&watchdog_miscdev); 356 err = misc_register(&watchdog_miscdev);
357 if (err != 0) { 357 if (err != 0) {
358 pr_err("%s: cannot register miscdev on minor=%d (err=%d).\n", 358 pr_err("%s: cannot register miscdev on minor=%d (err=%d).\n",
359 watchdog->info->identity, WATCHDOG_MINOR, err); 359 watchdog->info->identity, WATCHDOG_MINOR, err);
360 goto out; 360 goto out;
361 } 361 }
362 362
363 return 0; 363 return 0;
364 364
365 out: 365 out:
366 wdd = NULL; 366 wdd = NULL;
367 clear_bit(0, &watchdog_dev_busy); 367 clear_bit(0, &watchdog_dev_busy);
368 return err; 368 return err;
369 } 369 }
370 370
371 /* 371 /*
372 * watchdog_dev_unregister: 372 * watchdog_dev_unregister:
373 * @watchdog: watchdog device 373 * @watchdog: watchdog device
374 * 374 *
375 * Deregister the /dev/watchdog device. 375 * Deregister the /dev/watchdog device.
376 */ 376 */
377 377
378 int watchdog_dev_unregister(struct watchdog_device *watchdog) 378 int watchdog_dev_unregister(struct watchdog_device *watchdog)
379 { 379 {
380 /* Check that a watchdog device was registered in the past */ 380 /* Check that a watchdog device was registered in the past */
381 if (!test_bit(0, &watchdog_dev_busy) || !wdd) 381 if (!test_bit(0, &watchdog_dev_busy) || !wdd)
382 return -ENODEV; 382 return -ENODEV;
383 383
384 /* We can only unregister the watchdog device that was registered */ 384 /* We can only unregister the watchdog device that was registered */
385 if (watchdog != wdd) { 385 if (watchdog != wdd) {
386 pr_err("%s: watchdog was not registered as /dev/watchdog.\n", 386 pr_err("%s: watchdog was not registered as /dev/watchdog.\n",
387 watchdog->info->identity); 387 watchdog->info->identity);
388 return -ENODEV; 388 return -ENODEV;
389 } 389 }
390 390
391 misc_deregister(&watchdog_miscdev); 391 misc_deregister(&watchdog_miscdev);
392 wdd = NULL; 392 wdd = NULL;
393 clear_bit(0, &watchdog_dev_busy); 393 clear_bit(0, &watchdog_dev_busy);
394 return 0; 394 return 0;
395 } 395 }
396 396