Commit | Line | Data |
---|---|---|
989d42e8 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * class.c - basic device class management | |
4 | * | |
5 | * Copyright (c) 2002-3 Patrick Mochel | |
6 | * Copyright (c) 2002-3 Open Source Development Labs | |
7 | * Copyright (c) 2003-2004 Greg Kroah-Hartman | |
8 | * Copyright (c) 2003-2004 IBM Corp. | |
1da177e4 LT |
9 | */ |
10 | ||
1da177e4 LT |
11 | #include <linux/device.h> |
12 | #include <linux/module.h> | |
13 | #include <linux/init.h> | |
14 | #include <linux/string.h> | |
15 | #include <linux/kdev_t.h> | |
e9ba6365 | 16 | #include <linux/err.h> |
4e57b681 | 17 | #include <linux/slab.h> |
edfaa7c3 | 18 | #include <linux/genhd.h> |
f75b1c60 | 19 | #include <linux/mutex.h> |
1da177e4 LT |
20 | #include "base.h" |
21 | ||
22 | #define to_class_attr(_attr) container_of(_attr, struct class_attribute, attr) | |
1da177e4 | 23 | |
4a3ad20c GKH |
24 | static ssize_t class_attr_show(struct kobject *kobj, struct attribute *attr, |
25 | char *buf) | |
1da177e4 | 26 | { |
4a3ad20c | 27 | struct class_attribute *class_attr = to_class_attr(attr); |
6b6e39a6 | 28 | struct subsys_private *cp = to_subsys_private(kobj); |
4a0c20bf | 29 | ssize_t ret = -EIO; |
1da177e4 LT |
30 | |
31 | if (class_attr->show) | |
28812fe1 | 32 | ret = class_attr->show(cp->class, class_attr, buf); |
1da177e4 LT |
33 | return ret; |
34 | } | |
35 | ||
4a3ad20c GKH |
36 | static ssize_t class_attr_store(struct kobject *kobj, struct attribute *attr, |
37 | const char *buf, size_t count) | |
1da177e4 | 38 | { |
4a3ad20c | 39 | struct class_attribute *class_attr = to_class_attr(attr); |
6b6e39a6 | 40 | struct subsys_private *cp = to_subsys_private(kobj); |
4a0c20bf | 41 | ssize_t ret = -EIO; |
1da177e4 LT |
42 | |
43 | if (class_attr->store) | |
28812fe1 | 44 | ret = class_attr->store(cp->class, class_attr, buf, count); |
1da177e4 LT |
45 | return ret; |
46 | } | |
47 | ||
4a3ad20c | 48 | static void class_release(struct kobject *kobj) |
1da177e4 | 49 | { |
6b6e39a6 | 50 | struct subsys_private *cp = to_subsys_private(kobj); |
7c71448b | 51 | struct class *class = cp->class; |
1da177e4 LT |
52 | |
53 | pr_debug("class '%s': release.\n", class->name); | |
54 | ||
55 | if (class->class_release) | |
56 | class->class_release(class); | |
57 | else | |
58 | pr_debug("class '%s' does not have a release() function, " | |
59 | "be careful\n", class->name); | |
18d19c96 LP |
60 | |
61 | kfree(cp); | |
1da177e4 LT |
62 | } |
63 | ||
bc451f20 EB |
64 | static const struct kobj_ns_type_operations *class_child_ns_type(struct kobject *kobj) |
65 | { | |
6b6e39a6 | 66 | struct subsys_private *cp = to_subsys_private(kobj); |
bc451f20 EB |
67 | struct class *class = cp->class; |
68 | ||
69 | return class->ns_type; | |
70 | } | |
71 | ||
52cf25d0 | 72 | static const struct sysfs_ops class_sysfs_ops = { |
672d82c1 EB |
73 | .show = class_attr_show, |
74 | .store = class_attr_store, | |
1da177e4 LT |
75 | }; |
76 | ||
adc56808 | 77 | static struct kobj_type class_ktype = { |
1da177e4 LT |
78 | .sysfs_ops = &class_sysfs_ops, |
79 | .release = class_release, | |
bc451f20 | 80 | .child_ns_type = class_child_ns_type, |
1da177e4 LT |
81 | }; |
82 | ||
6b6e39a6 | 83 | /* Hotplug events for classes go to the class subsys */ |
443dbf90 | 84 | static struct kset *class_kset; |
1da177e4 LT |
85 | |
86 | ||
58292cbe TH |
87 | int class_create_file_ns(struct class *cls, const struct class_attribute *attr, |
88 | const void *ns) | |
1da177e4 LT |
89 | { |
90 | int error; | |
d34898de | 91 | |
4a3ad20c | 92 | if (cls) |
58292cbe TH |
93 | error = sysfs_create_file_ns(&cls->p->subsys.kobj, |
94 | &attr->attr, ns); | |
4a3ad20c | 95 | else |
1da177e4 LT |
96 | error = -EINVAL; |
97 | return error; | |
98 | } | |
99 | ||
58292cbe TH |
100 | void class_remove_file_ns(struct class *cls, const struct class_attribute *attr, |
101 | const void *ns) | |
1da177e4 LT |
102 | { |
103 | if (cls) | |
58292cbe | 104 | sysfs_remove_file_ns(&cls->p->subsys.kobj, &attr->attr, ns); |
1da177e4 LT |
105 | } |
106 | ||
1740757e | 107 | static struct class *class_get(struct class *cls) |
1da177e4 LT |
108 | { |
109 | if (cls) | |
6b6e39a6 | 110 | kset_get(&cls->p->subsys); |
7c71448b | 111 | return cls; |
1da177e4 LT |
112 | } |
113 | ||
4a3ad20c | 114 | static void class_put(struct class *cls) |
1da177e4 | 115 | { |
51d172d5 | 116 | if (cls) |
6b6e39a6 | 117 | kset_put(&cls->p->subsys); |
1da177e4 LT |
118 | } |
119 | ||
570d0200 WY |
120 | static struct device *klist_class_to_dev(struct klist_node *n) |
121 | { | |
122 | struct device_private *p = to_device_private_class(n); | |
123 | return p->device; | |
124 | } | |
125 | ||
5a3ceb86 TH |
126 | static void klist_class_dev_get(struct klist_node *n) |
127 | { | |
570d0200 | 128 | struct device *dev = klist_class_to_dev(n); |
5a3ceb86 TH |
129 | |
130 | get_device(dev); | |
131 | } | |
132 | ||
133 | static void klist_class_dev_put(struct klist_node *n) | |
134 | { | |
570d0200 | 135 | struct device *dev = klist_class_to_dev(n); |
5a3ceb86 TH |
136 | |
137 | put_device(dev); | |
138 | } | |
139 | ||
ced6473e GKH |
140 | static int class_add_groups(struct class *cls, |
141 | const struct attribute_group **groups) | |
142 | { | |
143 | return sysfs_create_groups(&cls->p->subsys.kobj, groups); | |
144 | } | |
145 | ||
146 | static void class_remove_groups(struct class *cls, | |
147 | const struct attribute_group **groups) | |
148 | { | |
149 | return sysfs_remove_groups(&cls->p->subsys.kobj, groups); | |
150 | } | |
151 | ||
d2a3b914 | 152 | int __class_register(struct class *cls, struct lock_class_key *key) |
1da177e4 | 153 | { |
6b6e39a6 | 154 | struct subsys_private *cp; |
1da177e4 LT |
155 | int error; |
156 | ||
157 | pr_debug("device class '%s': registering\n", cls->name); | |
158 | ||
7c71448b GKH |
159 | cp = kzalloc(sizeof(*cp), GFP_KERNEL); |
160 | if (!cp) | |
161 | return -ENOMEM; | |
6b6e39a6 | 162 | klist_init(&cp->klist_devices, klist_class_dev_get, klist_class_dev_put); |
ca22e56d | 163 | INIT_LIST_HEAD(&cp->interfaces); |
6b6e39a6 | 164 | kset_init(&cp->glue_dirs); |
ca22e56d | 165 | __mutex_init(&cp->mutex, "subsys mutex", key); |
6b6e39a6 | 166 | error = kobject_set_name(&cp->subsys.kobj, "%s", cls->name); |
7c71448b GKH |
167 | if (error) { |
168 | kfree(cp); | |
1da177e4 | 169 | return error; |
7c71448b | 170 | } |
1da177e4 | 171 | |
e105b8bf DW |
172 | /* set the default /sys/dev directory for devices of this class */ |
173 | if (!cls->dev_kobj) | |
174 | cls->dev_kobj = sysfs_dev_char_kobj; | |
175 | ||
e52eec13 | 176 | #if defined(CONFIG_BLOCK) |
edfaa7c3 | 177 | /* let the block class directory show up in the root of sysfs */ |
e52eec13 | 178 | if (!sysfs_deprecated || cls != &block_class) |
6b6e39a6 | 179 | cp->subsys.kobj.kset = class_kset; |
edfaa7c3 | 180 | #else |
6b6e39a6 | 181 | cp->subsys.kobj.kset = class_kset; |
edfaa7c3 | 182 | #endif |
6b6e39a6 | 183 | cp->subsys.kobj.ktype = &class_ktype; |
7c71448b GKH |
184 | cp->class = cls; |
185 | cls->p = cp; | |
1da177e4 | 186 | |
6b6e39a6 | 187 | error = kset_register(&cp->subsys); |
7c71448b GKH |
188 | if (error) { |
189 | kfree(cp); | |
190 | return error; | |
1da177e4 | 191 | } |
ced6473e GKH |
192 | error = class_add_groups(class_get(cls), cls->class_groups); |
193 | class_put(cls); | |
1da177e4 LT |
194 | return error; |
195 | } | |
d2a3b914 | 196 | EXPORT_SYMBOL_GPL(__class_register); |
1da177e4 | 197 | |
4a3ad20c | 198 | void class_unregister(struct class *cls) |
1da177e4 LT |
199 | { |
200 | pr_debug("device class '%s': unregistering\n", cls->name); | |
ced6473e | 201 | class_remove_groups(cls, cls->class_groups); |
6b6e39a6 | 202 | kset_unregister(&cls->p->subsys); |
1da177e4 LT |
203 | } |
204 | ||
e9ba6365 | 205 | static void class_create_release(struct class *cls) |
206 | { | |
2b3a302a | 207 | pr_debug("%s called for %s\n", __func__, cls->name); |
e9ba6365 | 208 | kfree(cls); |
209 | } | |
210 | ||
2fc68447 | 211 | /** |
212 | * class_create - create a struct class structure | |
213 | * @owner: pointer to the module that is to "own" this struct class | |
214 | * @name: pointer to a string for the name of this class. | |
0e241ffd | 215 | * @key: the lock_class_key for this class; used by mutex lock debugging |
2fc68447 | 216 | * |
217 | * This is used to create a struct class pointer that can then be used | |
c3b19ff0 | 218 | * in calls to device_create(). |
2fc68447 | 219 | * |
f0eae0ed JN |
220 | * Returns &struct class pointer on success, or ERR_PTR() on error. |
221 | * | |
2fc68447 | 222 | * Note, the pointer created here is to be destroyed when finished by |
223 | * making a call to class_destroy(). | |
224 | */ | |
d2a3b914 MW |
225 | struct class *__class_create(struct module *owner, const char *name, |
226 | struct lock_class_key *key) | |
e9ba6365 | 227 | { |
228 | struct class *cls; | |
229 | int retval; | |
230 | ||
4aed0644 | 231 | cls = kzalloc(sizeof(*cls), GFP_KERNEL); |
e9ba6365 | 232 | if (!cls) { |
233 | retval = -ENOMEM; | |
234 | goto error; | |
235 | } | |
e9ba6365 | 236 | |
237 | cls->name = name; | |
238 | cls->owner = owner; | |
239 | cls->class_release = class_create_release; | |
e9ba6365 | 240 | |
d2a3b914 | 241 | retval = __class_register(cls, key); |
e9ba6365 | 242 | if (retval) |
243 | goto error; | |
244 | ||
245 | return cls; | |
246 | ||
247 | error: | |
248 | kfree(cls); | |
249 | return ERR_PTR(retval); | |
250 | } | |
d2a3b914 | 251 | EXPORT_SYMBOL_GPL(__class_create); |
e9ba6365 | 252 | |
2fc68447 | 253 | /** |
254 | * class_destroy - destroys a struct class structure | |
92a0f861 | 255 | * @cls: pointer to the struct class that is to be destroyed |
2fc68447 | 256 | * |
257 | * Note, the pointer to be destroyed must have been created with a call | |
258 | * to class_create(). | |
259 | */ | |
e9ba6365 | 260 | void class_destroy(struct class *cls) |
261 | { | |
262 | if ((cls == NULL) || (IS_ERR(cls))) | |
263 | return; | |
264 | ||
265 | class_unregister(cls); | |
266 | } | |
1da177e4 | 267 | |
5a3ceb86 TH |
268 | /** |
269 | * class_dev_iter_init - initialize class device iterator | |
270 | * @iter: class iterator to initialize | |
271 | * @class: the class we wanna iterate over | |
272 | * @start: the device to start iterating from, if any | |
273 | * @type: device_type of the devices to iterate over, NULL for all | |
274 | * | |
275 | * Initialize class iterator @iter such that it iterates over devices | |
276 | * of @class. If @start is set, the list iteration will start there, | |
277 | * otherwise if it is NULL, the iteration starts at the beginning of | |
278 | * the list. | |
279 | */ | |
280 | void class_dev_iter_init(struct class_dev_iter *iter, struct class *class, | |
281 | struct device *start, const struct device_type *type) | |
282 | { | |
283 | struct klist_node *start_knode = NULL; | |
284 | ||
285 | if (start) | |
570d0200 | 286 | start_knode = &start->p->knode_class; |
6b6e39a6 | 287 | klist_iter_init_node(&class->p->klist_devices, &iter->ki, start_knode); |
5a3ceb86 TH |
288 | iter->type = type; |
289 | } | |
290 | EXPORT_SYMBOL_GPL(class_dev_iter_init); | |
291 | ||
292 | /** | |
293 | * class_dev_iter_next - iterate to the next device | |
294 | * @iter: class iterator to proceed | |
295 | * | |
296 | * Proceed @iter to the next device and return it. Returns NULL if | |
297 | * iteration is complete. | |
298 | * | |
299 | * The returned device is referenced and won't be released till | |
300 | * iterator is proceed to the next device or exited. The caller is | |
301 | * free to do whatever it wants to do with the device including | |
302 | * calling back into class code. | |
303 | */ | |
304 | struct device *class_dev_iter_next(struct class_dev_iter *iter) | |
305 | { | |
306 | struct klist_node *knode; | |
307 | struct device *dev; | |
308 | ||
309 | while (1) { | |
310 | knode = klist_next(&iter->ki); | |
311 | if (!knode) | |
312 | return NULL; | |
570d0200 | 313 | dev = klist_class_to_dev(knode); |
5a3ceb86 TH |
314 | if (!iter->type || iter->type == dev->type) |
315 | return dev; | |
316 | } | |
317 | } | |
318 | EXPORT_SYMBOL_GPL(class_dev_iter_next); | |
319 | ||
320 | /** | |
321 | * class_dev_iter_exit - finish iteration | |
322 | * @iter: class iterator to finish | |
323 | * | |
324 | * Finish an iteration. Always call this function after iteration is | |
325 | * complete whether the iteration ran till the end or not. | |
326 | */ | |
327 | void class_dev_iter_exit(struct class_dev_iter *iter) | |
328 | { | |
329 | klist_iter_exit(&iter->ki); | |
330 | } | |
331 | EXPORT_SYMBOL_GPL(class_dev_iter_exit); | |
332 | ||
fd04897b DY |
333 | /** |
334 | * class_for_each_device - device iterator | |
335 | * @class: the class we're iterating | |
93562b53 | 336 | * @start: the device to start with in the list, if any. |
fd04897b DY |
337 | * @data: data for the callback |
338 | * @fn: function to be called for each device | |
339 | * | |
340 | * Iterate over @class's list of devices, and call @fn for each, | |
93562b53 GKH |
341 | * passing it @data. If @start is set, the list iteration will start |
342 | * there, otherwise if it is NULL, the iteration starts at the | |
343 | * beginning of the list. | |
fd04897b DY |
344 | * |
345 | * We check the return of @fn each time. If it returns anything | |
346 | * other than 0, we break out and return that value. | |
347 | * | |
5a3ceb86 TH |
348 | * @fn is allowed to do anything including calling back into class |
349 | * code. There's no locking restriction. | |
fd04897b | 350 | */ |
93562b53 GKH |
351 | int class_for_each_device(struct class *class, struct device *start, |
352 | void *data, int (*fn)(struct device *, void *)) | |
fd04897b | 353 | { |
5a3ceb86 | 354 | struct class_dev_iter iter; |
fd04897b DY |
355 | struct device *dev; |
356 | int error = 0; | |
357 | ||
358 | if (!class) | |
359 | return -EINVAL; | |
7c225035 DB |
360 | if (!class->p) { |
361 | WARN(1, "%s called for class '%s' before it was initialized", | |
362 | __func__, class->name); | |
363 | return -EINVAL; | |
364 | } | |
365 | ||
5a3ceb86 TH |
366 | class_dev_iter_init(&iter, class, start, NULL); |
367 | while ((dev = class_dev_iter_next(&iter))) { | |
93562b53 | 368 | error = fn(dev, data); |
fd04897b DY |
369 | if (error) |
370 | break; | |
371 | } | |
5a3ceb86 | 372 | class_dev_iter_exit(&iter); |
fd04897b DY |
373 | |
374 | return error; | |
375 | } | |
376 | EXPORT_SYMBOL_GPL(class_for_each_device); | |
377 | ||
378 | /** | |
379 | * class_find_device - device iterator for locating a particular device | |
380 | * @class: the class we're iterating | |
695794ae | 381 | * @start: Device to begin with |
fd04897b DY |
382 | * @data: data for the match function |
383 | * @match: function to check device | |
384 | * | |
385 | * This is similar to the class_for_each_dev() function above, but it | |
386 | * returns a reference to a device that is 'found' for later use, as | |
387 | * determined by the @match callback. | |
388 | * | |
389 | * The callback should return 0 if the device doesn't match and non-zero | |
390 | * if it does. If the callback returns non-zero, this function will | |
391 | * return to the caller and not iterate over any more devices. | |
a63ca8f6 | 392 | * |
fd04897b DY |
393 | * Note, you will need to drop the reference with put_device() after use. |
394 | * | |
12077754 | 395 | * @match is allowed to do anything including calling back into class |
5a3ceb86 | 396 | * code. There's no locking restriction. |
fd04897b | 397 | */ |
695794ae | 398 | struct device *class_find_device(struct class *class, struct device *start, |
9f3b795a MM |
399 | const void *data, |
400 | int (*match)(struct device *, const void *)) | |
fd04897b | 401 | { |
5a3ceb86 | 402 | struct class_dev_iter iter; |
fd04897b | 403 | struct device *dev; |
fd04897b DY |
404 | |
405 | if (!class) | |
406 | return NULL; | |
7c225035 DB |
407 | if (!class->p) { |
408 | WARN(1, "%s called for class '%s' before it was initialized", | |
409 | __func__, class->name); | |
410 | return NULL; | |
411 | } | |
fd04897b | 412 | |
5a3ceb86 TH |
413 | class_dev_iter_init(&iter, class, start, NULL); |
414 | while ((dev = class_dev_iter_next(&iter))) { | |
695794ae | 415 | if (match(dev, data)) { |
5a3ceb86 | 416 | get_device(dev); |
fd04897b | 417 | break; |
5a3ceb86 | 418 | } |
fd04897b | 419 | } |
5a3ceb86 | 420 | class_dev_iter_exit(&iter); |
fd04897b | 421 | |
5a3ceb86 | 422 | return dev; |
fd04897b DY |
423 | } |
424 | EXPORT_SYMBOL_GPL(class_find_device); | |
425 | ||
1da177e4 LT |
426 | int class_interface_register(struct class_interface *class_intf) |
427 | { | |
428 | struct class *parent; | |
5a3ceb86 | 429 | struct class_dev_iter iter; |
c47ed219 | 430 | struct device *dev; |
1da177e4 LT |
431 | |
432 | if (!class_intf || !class_intf->class) | |
433 | return -ENODEV; | |
434 | ||
435 | parent = class_get(class_intf->class); | |
436 | if (!parent) | |
437 | return -EINVAL; | |
438 | ||
ca22e56d KS |
439 | mutex_lock(&parent->p->mutex); |
440 | list_add_tail(&class_intf->node, &parent->p->interfaces); | |
c47ed219 | 441 | if (class_intf->add_dev) { |
5a3ceb86 TH |
442 | class_dev_iter_init(&iter, parent, NULL, NULL); |
443 | while ((dev = class_dev_iter_next(&iter))) | |
c47ed219 | 444 | class_intf->add_dev(dev, class_intf); |
5a3ceb86 | 445 | class_dev_iter_exit(&iter); |
c47ed219 | 446 | } |
ca22e56d | 447 | mutex_unlock(&parent->p->mutex); |
1da177e4 LT |
448 | |
449 | return 0; | |
450 | } | |
451 | ||
452 | void class_interface_unregister(struct class_interface *class_intf) | |
453 | { | |
4a3ad20c | 454 | struct class *parent = class_intf->class; |
5a3ceb86 | 455 | struct class_dev_iter iter; |
c47ed219 | 456 | struct device *dev; |
1da177e4 LT |
457 | |
458 | if (!parent) | |
459 | return; | |
460 | ||
ca22e56d | 461 | mutex_lock(&parent->p->mutex); |
1da177e4 | 462 | list_del_init(&class_intf->node); |
c47ed219 | 463 | if (class_intf->remove_dev) { |
5a3ceb86 TH |
464 | class_dev_iter_init(&iter, parent, NULL, NULL); |
465 | while ((dev = class_dev_iter_next(&iter))) | |
c47ed219 | 466 | class_intf->remove_dev(dev, class_intf); |
5a3ceb86 | 467 | class_dev_iter_exit(&iter); |
c47ed219 | 468 | } |
ca22e56d | 469 | mutex_unlock(&parent->p->mutex); |
1da177e4 LT |
470 | |
471 | class_put(parent); | |
472 | } | |
473 | ||
319684b1 BP |
474 | ssize_t show_class_attr_string(struct class *class, |
475 | struct class_attribute *attr, char *buf) | |
869dfc87 AK |
476 | { |
477 | struct class_attribute_string *cs; | |
d34898de | 478 | |
869dfc87 AK |
479 | cs = container_of(attr, struct class_attribute_string, attr); |
480 | return snprintf(buf, PAGE_SIZE, "%s\n", cs->str); | |
481 | } | |
482 | ||
483 | EXPORT_SYMBOL_GPL(show_class_attr_string); | |
484 | ||
46227094 JD |
485 | struct class_compat { |
486 | struct kobject *kobj; | |
487 | }; | |
488 | ||
489 | /** | |
490 | * class_compat_register - register a compatibility class | |
491 | * @name: the name of the class | |
492 | * | |
493 | * Compatibility class are meant as a temporary user-space compatibility | |
494 | * workaround when converting a family of class devices to a bus devices. | |
495 | */ | |
496 | struct class_compat *class_compat_register(const char *name) | |
497 | { | |
498 | struct class_compat *cls; | |
499 | ||
500 | cls = kmalloc(sizeof(struct class_compat), GFP_KERNEL); | |
501 | if (!cls) | |
502 | return NULL; | |
503 | cls->kobj = kobject_create_and_add(name, &class_kset->kobj); | |
504 | if (!cls->kobj) { | |
505 | kfree(cls); | |
506 | return NULL; | |
507 | } | |
508 | return cls; | |
509 | } | |
510 | EXPORT_SYMBOL_GPL(class_compat_register); | |
511 | ||
512 | /** | |
513 | * class_compat_unregister - unregister a compatibility class | |
514 | * @cls: the class to unregister | |
515 | */ | |
516 | void class_compat_unregister(struct class_compat *cls) | |
517 | { | |
518 | kobject_put(cls->kobj); | |
519 | kfree(cls); | |
520 | } | |
521 | EXPORT_SYMBOL_GPL(class_compat_unregister); | |
522 | ||
523 | /** | |
524 | * class_compat_create_link - create a compatibility class device link to | |
525 | * a bus device | |
526 | * @cls: the compatibility class | |
527 | * @dev: the target bus device | |
528 | * @device_link: an optional device to which a "device" link should be created | |
529 | */ | |
530 | int class_compat_create_link(struct class_compat *cls, struct device *dev, | |
531 | struct device *device_link) | |
532 | { | |
533 | int error; | |
534 | ||
535 | error = sysfs_create_link(cls->kobj, &dev->kobj, dev_name(dev)); | |
536 | if (error) | |
537 | return error; | |
538 | ||
539 | /* | |
540 | * Optionally add a "device" link (typically to the parent), as a | |
541 | * class device would have one and we want to provide as much | |
542 | * backwards compatibility as possible. | |
543 | */ | |
544 | if (device_link) { | |
545 | error = sysfs_create_link(&dev->kobj, &device_link->kobj, | |
546 | "device"); | |
547 | if (error) | |
548 | sysfs_remove_link(cls->kobj, dev_name(dev)); | |
549 | } | |
550 | ||
551 | return error; | |
552 | } | |
553 | EXPORT_SYMBOL_GPL(class_compat_create_link); | |
554 | ||
555 | /** | |
556 | * class_compat_remove_link - remove a compatibility class device link to | |
557 | * a bus device | |
558 | * @cls: the compatibility class | |
559 | * @dev: the target bus device | |
560 | * @device_link: an optional device to which a "device" link was previously | |
561 | * created | |
562 | */ | |
563 | void class_compat_remove_link(struct class_compat *cls, struct device *dev, | |
564 | struct device *device_link) | |
565 | { | |
566 | if (device_link) | |
567 | sysfs_remove_link(&dev->kobj, "device"); | |
568 | sysfs_remove_link(cls->kobj, dev_name(dev)); | |
569 | } | |
570 | EXPORT_SYMBOL_GPL(class_compat_remove_link); | |
571 | ||
1da177e4 LT |
572 | int __init classes_init(void) |
573 | { | |
443dbf90 GKH |
574 | class_kset = kset_create_and_add("class", NULL, NULL); |
575 | if (!class_kset) | |
576 | return -ENOMEM; | |
1da177e4 LT |
577 | return 0; |
578 | } | |
579 | ||
58292cbe TH |
580 | EXPORT_SYMBOL_GPL(class_create_file_ns); |
581 | EXPORT_SYMBOL_GPL(class_remove_file_ns); | |
1da177e4 | 582 | EXPORT_SYMBOL_GPL(class_unregister); |
e9ba6365 | 583 | EXPORT_SYMBOL_GPL(class_destroy); |
1da177e4 | 584 | |
1da177e4 LT |
585 | EXPORT_SYMBOL_GPL(class_interface_register); |
586 | EXPORT_SYMBOL_GPL(class_interface_unregister); |