Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * class.c - basic device class management | |
3 | * | |
4 | * Copyright (c) 2002-3 Patrick Mochel | |
5 | * Copyright (c) 2002-3 Open Source Development Labs | |
6 | * Copyright (c) 2003-2004 Greg Kroah-Hartman | |
7 | * Copyright (c) 2003-2004 IBM Corp. | |
8 | * | |
9 | * This file is released under the GPLv2 | |
10 | * | |
11 | */ | |
12 | ||
1da177e4 LT |
13 | #include <linux/device.h> |
14 | #include <linux/module.h> | |
15 | #include <linux/init.h> | |
16 | #include <linux/string.h> | |
17 | #include <linux/kdev_t.h> | |
e9ba6365 | 18 | #include <linux/err.h> |
4e57b681 | 19 | #include <linux/slab.h> |
edfaa7c3 | 20 | #include <linux/genhd.h> |
f75b1c60 | 21 | #include <linux/mutex.h> |
1da177e4 LT |
22 | #include "base.h" |
23 | ||
24 | #define to_class_attr(_attr) container_of(_attr, struct class_attribute, attr) | |
1da177e4 | 25 | |
4a3ad20c GKH |
26 | static ssize_t class_attr_show(struct kobject *kobj, struct attribute *attr, |
27 | char *buf) | |
1da177e4 | 28 | { |
4a3ad20c | 29 | struct class_attribute *class_attr = to_class_attr(attr); |
6b6e39a6 | 30 | struct subsys_private *cp = to_subsys_private(kobj); |
4a0c20bf | 31 | ssize_t ret = -EIO; |
1da177e4 LT |
32 | |
33 | if (class_attr->show) | |
28812fe1 | 34 | ret = class_attr->show(cp->class, class_attr, buf); |
1da177e4 LT |
35 | return ret; |
36 | } | |
37 | ||
4a3ad20c GKH |
38 | static ssize_t class_attr_store(struct kobject *kobj, struct attribute *attr, |
39 | const char *buf, size_t count) | |
1da177e4 | 40 | { |
4a3ad20c | 41 | struct class_attribute *class_attr = to_class_attr(attr); |
6b6e39a6 | 42 | struct subsys_private *cp = to_subsys_private(kobj); |
4a0c20bf | 43 | ssize_t ret = -EIO; |
1da177e4 LT |
44 | |
45 | if (class_attr->store) | |
28812fe1 | 46 | ret = class_attr->store(cp->class, class_attr, buf, count); |
1da177e4 LT |
47 | return ret; |
48 | } | |
49 | ||
4a3ad20c | 50 | static void class_release(struct kobject *kobj) |
1da177e4 | 51 | { |
6b6e39a6 | 52 | struct subsys_private *cp = to_subsys_private(kobj); |
7c71448b | 53 | struct class *class = cp->class; |
1da177e4 LT |
54 | |
55 | pr_debug("class '%s': release.\n", class->name); | |
56 | ||
57 | if (class->class_release) | |
58 | class->class_release(class); | |
59 | else | |
60 | pr_debug("class '%s' does not have a release() function, " | |
61 | "be careful\n", class->name); | |
18d19c96 LP |
62 | |
63 | kfree(cp); | |
1da177e4 LT |
64 | } |
65 | ||
bc451f20 EB |
66 | static const struct kobj_ns_type_operations *class_child_ns_type(struct kobject *kobj) |
67 | { | |
6b6e39a6 | 68 | struct subsys_private *cp = to_subsys_private(kobj); |
bc451f20 EB |
69 | struct class *class = cp->class; |
70 | ||
71 | return class->ns_type; | |
72 | } | |
73 | ||
52cf25d0 | 74 | static const struct sysfs_ops class_sysfs_ops = { |
672d82c1 EB |
75 | .show = class_attr_show, |
76 | .store = class_attr_store, | |
1da177e4 LT |
77 | }; |
78 | ||
adc56808 | 79 | static struct kobj_type class_ktype = { |
1da177e4 LT |
80 | .sysfs_ops = &class_sysfs_ops, |
81 | .release = class_release, | |
bc451f20 | 82 | .child_ns_type = class_child_ns_type, |
1da177e4 LT |
83 | }; |
84 | ||
6b6e39a6 | 85 | /* Hotplug events for classes go to the class subsys */ |
443dbf90 | 86 | static struct kset *class_kset; |
1da177e4 LT |
87 | |
88 | ||
58292cbe TH |
89 | int class_create_file_ns(struct class *cls, const struct class_attribute *attr, |
90 | const void *ns) | |
1da177e4 LT |
91 | { |
92 | int error; | |
4a3ad20c | 93 | if (cls) |
58292cbe TH |
94 | error = sysfs_create_file_ns(&cls->p->subsys.kobj, |
95 | &attr->attr, ns); | |
4a3ad20c | 96 | else |
1da177e4 LT |
97 | error = -EINVAL; |
98 | return error; | |
99 | } | |
100 | ||
58292cbe TH |
101 | void class_remove_file_ns(struct class *cls, const struct class_attribute *attr, |
102 | const void *ns) | |
1da177e4 LT |
103 | { |
104 | if (cls) | |
58292cbe | 105 | sysfs_remove_file_ns(&cls->p->subsys.kobj, &attr->attr, ns); |
1da177e4 LT |
106 | } |
107 | ||
1740757e | 108 | static struct class *class_get(struct class *cls) |
1da177e4 LT |
109 | { |
110 | if (cls) | |
6b6e39a6 | 111 | kset_get(&cls->p->subsys); |
7c71448b | 112 | return cls; |
1da177e4 LT |
113 | } |
114 | ||
4a3ad20c | 115 | static void class_put(struct class *cls) |
1da177e4 | 116 | { |
51d172d5 | 117 | if (cls) |
6b6e39a6 | 118 | kset_put(&cls->p->subsys); |
1da177e4 LT |
119 | } |
120 | ||
4a3ad20c | 121 | static int add_class_attrs(struct class *cls) |
1da177e4 LT |
122 | { |
123 | int i; | |
124 | int error = 0; | |
125 | ||
126 | if (cls->class_attrs) { | |
3e1026b3 | 127 | for (i = 0; cls->class_attrs[i].attr.name; i++) { |
4a3ad20c | 128 | error = class_create_file(cls, &cls->class_attrs[i]); |
1da177e4 | 129 | if (error) |
4a3ad20c | 130 | goto error; |
1da177e4 LT |
131 | } |
132 | } | |
4a3ad20c | 133 | done: |
1da177e4 | 134 | return error; |
4a3ad20c | 135 | error: |
1da177e4 | 136 | while (--i >= 0) |
4a3ad20c GKH |
137 | class_remove_file(cls, &cls->class_attrs[i]); |
138 | goto done; | |
1da177e4 LT |
139 | } |
140 | ||
4a3ad20c | 141 | static void remove_class_attrs(struct class *cls) |
1da177e4 LT |
142 | { |
143 | int i; | |
144 | ||
145 | if (cls->class_attrs) { | |
3e1026b3 | 146 | for (i = 0; cls->class_attrs[i].attr.name; i++) |
4a3ad20c | 147 | class_remove_file(cls, &cls->class_attrs[i]); |
1da177e4 LT |
148 | } |
149 | } | |
150 | ||
5a3ceb86 TH |
151 | static void klist_class_dev_get(struct klist_node *n) |
152 | { | |
153 | struct device *dev = container_of(n, struct device, knode_class); | |
154 | ||
155 | get_device(dev); | |
156 | } | |
157 | ||
158 | static void klist_class_dev_put(struct klist_node *n) | |
159 | { | |
160 | struct device *dev = container_of(n, struct device, knode_class); | |
161 | ||
162 | put_device(dev); | |
163 | } | |
164 | ||
d2a3b914 | 165 | int __class_register(struct class *cls, struct lock_class_key *key) |
1da177e4 | 166 | { |
6b6e39a6 | 167 | struct subsys_private *cp; |
1da177e4 LT |
168 | int error; |
169 | ||
170 | pr_debug("device class '%s': registering\n", cls->name); | |
171 | ||
7c71448b GKH |
172 | cp = kzalloc(sizeof(*cp), GFP_KERNEL); |
173 | if (!cp) | |
174 | return -ENOMEM; | |
6b6e39a6 | 175 | klist_init(&cp->klist_devices, klist_class_dev_get, klist_class_dev_put); |
ca22e56d | 176 | INIT_LIST_HEAD(&cp->interfaces); |
6b6e39a6 | 177 | kset_init(&cp->glue_dirs); |
ca22e56d | 178 | __mutex_init(&cp->mutex, "subsys mutex", key); |
6b6e39a6 | 179 | error = kobject_set_name(&cp->subsys.kobj, "%s", cls->name); |
7c71448b GKH |
180 | if (error) { |
181 | kfree(cp); | |
1da177e4 | 182 | return error; |
7c71448b | 183 | } |
1da177e4 | 184 | |
e105b8bf DW |
185 | /* set the default /sys/dev directory for devices of this class */ |
186 | if (!cls->dev_kobj) | |
187 | cls->dev_kobj = sysfs_dev_char_kobj; | |
188 | ||
e52eec13 | 189 | #if defined(CONFIG_BLOCK) |
edfaa7c3 | 190 | /* let the block class directory show up in the root of sysfs */ |
e52eec13 | 191 | if (!sysfs_deprecated || cls != &block_class) |
6b6e39a6 | 192 | cp->subsys.kobj.kset = class_kset; |
edfaa7c3 | 193 | #else |
6b6e39a6 | 194 | cp->subsys.kobj.kset = class_kset; |
edfaa7c3 | 195 | #endif |
6b6e39a6 | 196 | cp->subsys.kobj.ktype = &class_ktype; |
7c71448b GKH |
197 | cp->class = cls; |
198 | cls->p = cp; | |
1da177e4 | 199 | |
6b6e39a6 | 200 | error = kset_register(&cp->subsys); |
7c71448b GKH |
201 | if (error) { |
202 | kfree(cp); | |
203 | return error; | |
1da177e4 | 204 | } |
7c71448b GKH |
205 | error = add_class_attrs(class_get(cls)); |
206 | class_put(cls); | |
1da177e4 LT |
207 | return error; |
208 | } | |
d2a3b914 | 209 | EXPORT_SYMBOL_GPL(__class_register); |
1da177e4 | 210 | |
4a3ad20c | 211 | void class_unregister(struct class *cls) |
1da177e4 LT |
212 | { |
213 | pr_debug("device class '%s': unregistering\n", cls->name); | |
214 | remove_class_attrs(cls); | |
6b6e39a6 | 215 | kset_unregister(&cls->p->subsys); |
1da177e4 LT |
216 | } |
217 | ||
e9ba6365 | 218 | static void class_create_release(struct class *cls) |
219 | { | |
2b3a302a | 220 | pr_debug("%s called for %s\n", __func__, cls->name); |
e9ba6365 | 221 | kfree(cls); |
222 | } | |
223 | ||
2fc68447 | 224 | /** |
225 | * class_create - create a struct class structure | |
226 | * @owner: pointer to the module that is to "own" this struct class | |
227 | * @name: pointer to a string for the name of this class. | |
0e241ffd | 228 | * @key: the lock_class_key for this class; used by mutex lock debugging |
2fc68447 | 229 | * |
230 | * This is used to create a struct class pointer that can then be used | |
c3b19ff0 | 231 | * in calls to device_create(). |
2fc68447 | 232 | * |
f0eae0ed JN |
233 | * Returns &struct class pointer on success, or ERR_PTR() on error. |
234 | * | |
2fc68447 | 235 | * Note, the pointer created here is to be destroyed when finished by |
236 | * making a call to class_destroy(). | |
237 | */ | |
d2a3b914 MW |
238 | struct class *__class_create(struct module *owner, const char *name, |
239 | struct lock_class_key *key) | |
e9ba6365 | 240 | { |
241 | struct class *cls; | |
242 | int retval; | |
243 | ||
4aed0644 | 244 | cls = kzalloc(sizeof(*cls), GFP_KERNEL); |
e9ba6365 | 245 | if (!cls) { |
246 | retval = -ENOMEM; | |
247 | goto error; | |
248 | } | |
e9ba6365 | 249 | |
250 | cls->name = name; | |
251 | cls->owner = owner; | |
252 | cls->class_release = class_create_release; | |
e9ba6365 | 253 | |
d2a3b914 | 254 | retval = __class_register(cls, key); |
e9ba6365 | 255 | if (retval) |
256 | goto error; | |
257 | ||
258 | return cls; | |
259 | ||
260 | error: | |
261 | kfree(cls); | |
262 | return ERR_PTR(retval); | |
263 | } | |
d2a3b914 | 264 | EXPORT_SYMBOL_GPL(__class_create); |
e9ba6365 | 265 | |
2fc68447 | 266 | /** |
267 | * class_destroy - destroys a struct class structure | |
92a0f861 | 268 | * @cls: pointer to the struct class that is to be destroyed |
2fc68447 | 269 | * |
270 | * Note, the pointer to be destroyed must have been created with a call | |
271 | * to class_create(). | |
272 | */ | |
e9ba6365 | 273 | void class_destroy(struct class *cls) |
274 | { | |
275 | if ((cls == NULL) || (IS_ERR(cls))) | |
276 | return; | |
277 | ||
278 | class_unregister(cls); | |
279 | } | |
1da177e4 | 280 | |
5a3ceb86 TH |
281 | /** |
282 | * class_dev_iter_init - initialize class device iterator | |
283 | * @iter: class iterator to initialize | |
284 | * @class: the class we wanna iterate over | |
285 | * @start: the device to start iterating from, if any | |
286 | * @type: device_type of the devices to iterate over, NULL for all | |
287 | * | |
288 | * Initialize class iterator @iter such that it iterates over devices | |
289 | * of @class. If @start is set, the list iteration will start there, | |
290 | * otherwise if it is NULL, the iteration starts at the beginning of | |
291 | * the list. | |
292 | */ | |
293 | void class_dev_iter_init(struct class_dev_iter *iter, struct class *class, | |
294 | struct device *start, const struct device_type *type) | |
295 | { | |
296 | struct klist_node *start_knode = NULL; | |
297 | ||
298 | if (start) | |
299 | start_knode = &start->knode_class; | |
6b6e39a6 | 300 | klist_iter_init_node(&class->p->klist_devices, &iter->ki, start_knode); |
5a3ceb86 TH |
301 | iter->type = type; |
302 | } | |
303 | EXPORT_SYMBOL_GPL(class_dev_iter_init); | |
304 | ||
305 | /** | |
306 | * class_dev_iter_next - iterate to the next device | |
307 | * @iter: class iterator to proceed | |
308 | * | |
309 | * Proceed @iter to the next device and return it. Returns NULL if | |
310 | * iteration is complete. | |
311 | * | |
312 | * The returned device is referenced and won't be released till | |
313 | * iterator is proceed to the next device or exited. The caller is | |
314 | * free to do whatever it wants to do with the device including | |
315 | * calling back into class code. | |
316 | */ | |
317 | struct device *class_dev_iter_next(struct class_dev_iter *iter) | |
318 | { | |
319 | struct klist_node *knode; | |
320 | struct device *dev; | |
321 | ||
322 | while (1) { | |
323 | knode = klist_next(&iter->ki); | |
324 | if (!knode) | |
325 | return NULL; | |
326 | dev = container_of(knode, struct device, knode_class); | |
327 | if (!iter->type || iter->type == dev->type) | |
328 | return dev; | |
329 | } | |
330 | } | |
331 | EXPORT_SYMBOL_GPL(class_dev_iter_next); | |
332 | ||
333 | /** | |
334 | * class_dev_iter_exit - finish iteration | |
335 | * @iter: class iterator to finish | |
336 | * | |
337 | * Finish an iteration. Always call this function after iteration is | |
338 | * complete whether the iteration ran till the end or not. | |
339 | */ | |
340 | void class_dev_iter_exit(struct class_dev_iter *iter) | |
341 | { | |
342 | klist_iter_exit(&iter->ki); | |
343 | } | |
344 | EXPORT_SYMBOL_GPL(class_dev_iter_exit); | |
345 | ||
fd04897b DY |
346 | /** |
347 | * class_for_each_device - device iterator | |
348 | * @class: the class we're iterating | |
93562b53 | 349 | * @start: the device to start with in the list, if any. |
fd04897b DY |
350 | * @data: data for the callback |
351 | * @fn: function to be called for each device | |
352 | * | |
353 | * Iterate over @class's list of devices, and call @fn for each, | |
93562b53 GKH |
354 | * passing it @data. If @start is set, the list iteration will start |
355 | * there, otherwise if it is NULL, the iteration starts at the | |
356 | * beginning of the list. | |
fd04897b DY |
357 | * |
358 | * We check the return of @fn each time. If it returns anything | |
359 | * other than 0, we break out and return that value. | |
360 | * | |
5a3ceb86 TH |
361 | * @fn is allowed to do anything including calling back into class |
362 | * code. There's no locking restriction. | |
fd04897b | 363 | */ |
93562b53 GKH |
364 | int class_for_each_device(struct class *class, struct device *start, |
365 | void *data, int (*fn)(struct device *, void *)) | |
fd04897b | 366 | { |
5a3ceb86 | 367 | struct class_dev_iter iter; |
fd04897b DY |
368 | struct device *dev; |
369 | int error = 0; | |
370 | ||
371 | if (!class) | |
372 | return -EINVAL; | |
7c225035 DB |
373 | if (!class->p) { |
374 | WARN(1, "%s called for class '%s' before it was initialized", | |
375 | __func__, class->name); | |
376 | return -EINVAL; | |
377 | } | |
378 | ||
5a3ceb86 TH |
379 | class_dev_iter_init(&iter, class, start, NULL); |
380 | while ((dev = class_dev_iter_next(&iter))) { | |
93562b53 | 381 | error = fn(dev, data); |
fd04897b DY |
382 | if (error) |
383 | break; | |
384 | } | |
5a3ceb86 | 385 | class_dev_iter_exit(&iter); |
fd04897b DY |
386 | |
387 | return error; | |
388 | } | |
389 | EXPORT_SYMBOL_GPL(class_for_each_device); | |
390 | ||
391 | /** | |
392 | * class_find_device - device iterator for locating a particular device | |
393 | * @class: the class we're iterating | |
695794ae | 394 | * @start: Device to begin with |
fd04897b DY |
395 | * @data: data for the match function |
396 | * @match: function to check device | |
397 | * | |
398 | * This is similar to the class_for_each_dev() function above, but it | |
399 | * returns a reference to a device that is 'found' for later use, as | |
400 | * determined by the @match callback. | |
401 | * | |
402 | * The callback should return 0 if the device doesn't match and non-zero | |
403 | * if it does. If the callback returns non-zero, this function will | |
404 | * return to the caller and not iterate over any more devices. | |
a63ca8f6 | 405 | * |
fd04897b DY |
406 | * Note, you will need to drop the reference with put_device() after use. |
407 | * | |
5a3ceb86 TH |
408 | * @fn is allowed to do anything including calling back into class |
409 | * code. There's no locking restriction. | |
fd04897b | 410 | */ |
695794ae | 411 | struct device *class_find_device(struct class *class, struct device *start, |
9f3b795a MM |
412 | const void *data, |
413 | int (*match)(struct device *, const void *)) | |
fd04897b | 414 | { |
5a3ceb86 | 415 | struct class_dev_iter iter; |
fd04897b | 416 | struct device *dev; |
fd04897b DY |
417 | |
418 | if (!class) | |
419 | return NULL; | |
7c225035 DB |
420 | if (!class->p) { |
421 | WARN(1, "%s called for class '%s' before it was initialized", | |
422 | __func__, class->name); | |
423 | return NULL; | |
424 | } | |
fd04897b | 425 | |
5a3ceb86 TH |
426 | class_dev_iter_init(&iter, class, start, NULL); |
427 | while ((dev = class_dev_iter_next(&iter))) { | |
695794ae | 428 | if (match(dev, data)) { |
5a3ceb86 | 429 | get_device(dev); |
fd04897b | 430 | break; |
5a3ceb86 | 431 | } |
fd04897b | 432 | } |
5a3ceb86 | 433 | class_dev_iter_exit(&iter); |
fd04897b | 434 | |
5a3ceb86 | 435 | return dev; |
fd04897b DY |
436 | } |
437 | EXPORT_SYMBOL_GPL(class_find_device); | |
438 | ||
1da177e4 LT |
439 | int class_interface_register(struct class_interface *class_intf) |
440 | { | |
441 | struct class *parent; | |
5a3ceb86 | 442 | struct class_dev_iter iter; |
c47ed219 | 443 | struct device *dev; |
1da177e4 LT |
444 | |
445 | if (!class_intf || !class_intf->class) | |
446 | return -ENODEV; | |
447 | ||
448 | parent = class_get(class_intf->class); | |
449 | if (!parent) | |
450 | return -EINVAL; | |
451 | ||
ca22e56d KS |
452 | mutex_lock(&parent->p->mutex); |
453 | list_add_tail(&class_intf->node, &parent->p->interfaces); | |
c47ed219 | 454 | if (class_intf->add_dev) { |
5a3ceb86 TH |
455 | class_dev_iter_init(&iter, parent, NULL, NULL); |
456 | while ((dev = class_dev_iter_next(&iter))) | |
c47ed219 | 457 | class_intf->add_dev(dev, class_intf); |
5a3ceb86 | 458 | class_dev_iter_exit(&iter); |
c47ed219 | 459 | } |
ca22e56d | 460 | mutex_unlock(&parent->p->mutex); |
1da177e4 LT |
461 | |
462 | return 0; | |
463 | } | |
464 | ||
465 | void class_interface_unregister(struct class_interface *class_intf) | |
466 | { | |
4a3ad20c | 467 | struct class *parent = class_intf->class; |
5a3ceb86 | 468 | struct class_dev_iter iter; |
c47ed219 | 469 | struct device *dev; |
1da177e4 LT |
470 | |
471 | if (!parent) | |
472 | return; | |
473 | ||
ca22e56d | 474 | mutex_lock(&parent->p->mutex); |
1da177e4 | 475 | list_del_init(&class_intf->node); |
c47ed219 | 476 | if (class_intf->remove_dev) { |
5a3ceb86 TH |
477 | class_dev_iter_init(&iter, parent, NULL, NULL); |
478 | while ((dev = class_dev_iter_next(&iter))) | |
c47ed219 | 479 | class_intf->remove_dev(dev, class_intf); |
5a3ceb86 | 480 | class_dev_iter_exit(&iter); |
c47ed219 | 481 | } |
ca22e56d | 482 | mutex_unlock(&parent->p->mutex); |
1da177e4 LT |
483 | |
484 | class_put(parent); | |
485 | } | |
486 | ||
319684b1 BP |
487 | ssize_t show_class_attr_string(struct class *class, |
488 | struct class_attribute *attr, char *buf) | |
869dfc87 AK |
489 | { |
490 | struct class_attribute_string *cs; | |
491 | cs = container_of(attr, struct class_attribute_string, attr); | |
492 | return snprintf(buf, PAGE_SIZE, "%s\n", cs->str); | |
493 | } | |
494 | ||
495 | EXPORT_SYMBOL_GPL(show_class_attr_string); | |
496 | ||
46227094 JD |
497 | struct class_compat { |
498 | struct kobject *kobj; | |
499 | }; | |
500 | ||
501 | /** | |
502 | * class_compat_register - register a compatibility class | |
503 | * @name: the name of the class | |
504 | * | |
505 | * Compatibility class are meant as a temporary user-space compatibility | |
506 | * workaround when converting a family of class devices to a bus devices. | |
507 | */ | |
508 | struct class_compat *class_compat_register(const char *name) | |
509 | { | |
510 | struct class_compat *cls; | |
511 | ||
512 | cls = kmalloc(sizeof(struct class_compat), GFP_KERNEL); | |
513 | if (!cls) | |
514 | return NULL; | |
515 | cls->kobj = kobject_create_and_add(name, &class_kset->kobj); | |
516 | if (!cls->kobj) { | |
517 | kfree(cls); | |
518 | return NULL; | |
519 | } | |
520 | return cls; | |
521 | } | |
522 | EXPORT_SYMBOL_GPL(class_compat_register); | |
523 | ||
524 | /** | |
525 | * class_compat_unregister - unregister a compatibility class | |
526 | * @cls: the class to unregister | |
527 | */ | |
528 | void class_compat_unregister(struct class_compat *cls) | |
529 | { | |
530 | kobject_put(cls->kobj); | |
531 | kfree(cls); | |
532 | } | |
533 | EXPORT_SYMBOL_GPL(class_compat_unregister); | |
534 | ||
535 | /** | |
536 | * class_compat_create_link - create a compatibility class device link to | |
537 | * a bus device | |
538 | * @cls: the compatibility class | |
539 | * @dev: the target bus device | |
540 | * @device_link: an optional device to which a "device" link should be created | |
541 | */ | |
542 | int class_compat_create_link(struct class_compat *cls, struct device *dev, | |
543 | struct device *device_link) | |
544 | { | |
545 | int error; | |
546 | ||
547 | error = sysfs_create_link(cls->kobj, &dev->kobj, dev_name(dev)); | |
548 | if (error) | |
549 | return error; | |
550 | ||
551 | /* | |
552 | * Optionally add a "device" link (typically to the parent), as a | |
553 | * class device would have one and we want to provide as much | |
554 | * backwards compatibility as possible. | |
555 | */ | |
556 | if (device_link) { | |
557 | error = sysfs_create_link(&dev->kobj, &device_link->kobj, | |
558 | "device"); | |
559 | if (error) | |
560 | sysfs_remove_link(cls->kobj, dev_name(dev)); | |
561 | } | |
562 | ||
563 | return error; | |
564 | } | |
565 | EXPORT_SYMBOL_GPL(class_compat_create_link); | |
566 | ||
567 | /** | |
568 | * class_compat_remove_link - remove a compatibility class device link to | |
569 | * a bus device | |
570 | * @cls: the compatibility class | |
571 | * @dev: the target bus device | |
572 | * @device_link: an optional device to which a "device" link was previously | |
573 | * created | |
574 | */ | |
575 | void class_compat_remove_link(struct class_compat *cls, struct device *dev, | |
576 | struct device *device_link) | |
577 | { | |
578 | if (device_link) | |
579 | sysfs_remove_link(&dev->kobj, "device"); | |
580 | sysfs_remove_link(cls->kobj, dev_name(dev)); | |
581 | } | |
582 | EXPORT_SYMBOL_GPL(class_compat_remove_link); | |
583 | ||
1da177e4 LT |
584 | int __init classes_init(void) |
585 | { | |
443dbf90 GKH |
586 | class_kset = kset_create_and_add("class", NULL, NULL); |
587 | if (!class_kset) | |
588 | return -ENOMEM; | |
1da177e4 LT |
589 | return 0; |
590 | } | |
591 | ||
58292cbe TH |
592 | EXPORT_SYMBOL_GPL(class_create_file_ns); |
593 | EXPORT_SYMBOL_GPL(class_remove_file_ns); | |
1da177e4 | 594 | EXPORT_SYMBOL_GPL(class_unregister); |
e9ba6365 | 595 | EXPORT_SYMBOL_GPL(class_destroy); |
1da177e4 | 596 | |
1da177e4 LT |
597 | EXPORT_SYMBOL_GPL(class_interface_register); |
598 | EXPORT_SYMBOL_GPL(class_interface_unregister); |