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 = { |
1da177e4 LT |
75 | .show = class_attr_show, |
76 | .store = class_attr_store, | |
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 | ||
4a3ad20c | 89 | int class_create_file(struct class *cls, const struct class_attribute *attr) |
1da177e4 LT |
90 | { |
91 | int error; | |
4a3ad20c | 92 | if (cls) |
6b6e39a6 | 93 | error = sysfs_create_file(&cls->p->subsys.kobj, |
1fbfee6c | 94 | &attr->attr); |
4a3ad20c | 95 | else |
1da177e4 LT |
96 | error = -EINVAL; |
97 | return error; | |
98 | } | |
99 | ||
4a3ad20c | 100 | void class_remove_file(struct class *cls, const struct class_attribute *attr) |
1da177e4 LT |
101 | { |
102 | if (cls) | |
6b6e39a6 | 103 | sysfs_remove_file(&cls->p->subsys.kobj, &attr->attr); |
1da177e4 LT |
104 | } |
105 | ||
1740757e | 106 | static struct class *class_get(struct class *cls) |
1da177e4 LT |
107 | { |
108 | if (cls) | |
6b6e39a6 | 109 | kset_get(&cls->p->subsys); |
7c71448b | 110 | return cls; |
1da177e4 LT |
111 | } |
112 | ||
4a3ad20c | 113 | static void class_put(struct class *cls) |
1da177e4 | 114 | { |
51d172d5 | 115 | if (cls) |
6b6e39a6 | 116 | kset_put(&cls->p->subsys); |
1da177e4 LT |
117 | } |
118 | ||
4a3ad20c | 119 | static int add_class_attrs(struct class *cls) |
1da177e4 LT |
120 | { |
121 | int i; | |
122 | int error = 0; | |
123 | ||
124 | if (cls->class_attrs) { | |
125 | for (i = 0; attr_name(cls->class_attrs[i]); i++) { | |
4a3ad20c | 126 | error = class_create_file(cls, &cls->class_attrs[i]); |
1da177e4 | 127 | if (error) |
4a3ad20c | 128 | goto error; |
1da177e4 LT |
129 | } |
130 | } | |
4a3ad20c | 131 | done: |
1da177e4 | 132 | return error; |
4a3ad20c | 133 | error: |
1da177e4 | 134 | while (--i >= 0) |
4a3ad20c GKH |
135 | class_remove_file(cls, &cls->class_attrs[i]); |
136 | goto done; | |
1da177e4 LT |
137 | } |
138 | ||
4a3ad20c | 139 | static void remove_class_attrs(struct class *cls) |
1da177e4 LT |
140 | { |
141 | int i; | |
142 | ||
143 | if (cls->class_attrs) { | |
144 | for (i = 0; attr_name(cls->class_attrs[i]); i++) | |
4a3ad20c | 145 | class_remove_file(cls, &cls->class_attrs[i]); |
1da177e4 LT |
146 | } |
147 | } | |
148 | ||
5a3ceb86 TH |
149 | static void klist_class_dev_get(struct klist_node *n) |
150 | { | |
151 | struct device *dev = container_of(n, struct device, knode_class); | |
152 | ||
153 | get_device(dev); | |
154 | } | |
155 | ||
156 | static void klist_class_dev_put(struct klist_node *n) | |
157 | { | |
158 | struct device *dev = container_of(n, struct device, knode_class); | |
159 | ||
160 | put_device(dev); | |
161 | } | |
162 | ||
d2a3b914 | 163 | int __class_register(struct class *cls, struct lock_class_key *key) |
1da177e4 | 164 | { |
6b6e39a6 | 165 | struct subsys_private *cp; |
1da177e4 LT |
166 | int error; |
167 | ||
168 | pr_debug("device class '%s': registering\n", cls->name); | |
169 | ||
7c71448b GKH |
170 | cp = kzalloc(sizeof(*cp), GFP_KERNEL); |
171 | if (!cp) | |
172 | return -ENOMEM; | |
6b6e39a6 | 173 | klist_init(&cp->klist_devices, klist_class_dev_get, klist_class_dev_put); |
184f1f77 | 174 | INIT_LIST_HEAD(&cp->class_interfaces); |
6b6e39a6 | 175 | kset_init(&cp->glue_dirs); |
f75b1c60 | 176 | __mutex_init(&cp->class_mutex, "struct class mutex", key); |
6b6e39a6 | 177 | error = kobject_set_name(&cp->subsys.kobj, "%s", cls->name); |
7c71448b GKH |
178 | if (error) { |
179 | kfree(cp); | |
1da177e4 | 180 | return error; |
7c71448b | 181 | } |
1da177e4 | 182 | |
e105b8bf DW |
183 | /* set the default /sys/dev directory for devices of this class */ |
184 | if (!cls->dev_kobj) | |
185 | cls->dev_kobj = sysfs_dev_char_kobj; | |
186 | ||
e52eec13 | 187 | #if defined(CONFIG_BLOCK) |
edfaa7c3 | 188 | /* let the block class directory show up in the root of sysfs */ |
e52eec13 | 189 | if (!sysfs_deprecated || cls != &block_class) |
6b6e39a6 | 190 | cp->subsys.kobj.kset = class_kset; |
edfaa7c3 | 191 | #else |
6b6e39a6 | 192 | cp->subsys.kobj.kset = class_kset; |
edfaa7c3 | 193 | #endif |
6b6e39a6 | 194 | cp->subsys.kobj.ktype = &class_ktype; |
7c71448b GKH |
195 | cp->class = cls; |
196 | cls->p = cp; | |
1da177e4 | 197 | |
6b6e39a6 | 198 | error = kset_register(&cp->subsys); |
7c71448b GKH |
199 | if (error) { |
200 | kfree(cp); | |
201 | return error; | |
1da177e4 | 202 | } |
7c71448b GKH |
203 | error = add_class_attrs(class_get(cls)); |
204 | class_put(cls); | |
1da177e4 LT |
205 | return error; |
206 | } | |
d2a3b914 | 207 | EXPORT_SYMBOL_GPL(__class_register); |
1da177e4 | 208 | |
4a3ad20c | 209 | void class_unregister(struct class *cls) |
1da177e4 LT |
210 | { |
211 | pr_debug("device class '%s': unregistering\n", cls->name); | |
212 | remove_class_attrs(cls); | |
6b6e39a6 | 213 | kset_unregister(&cls->p->subsys); |
1da177e4 LT |
214 | } |
215 | ||
e9ba6365 GKH |
216 | static void class_create_release(struct class *cls) |
217 | { | |
2b3a302a | 218 | pr_debug("%s called for %s\n", __func__, cls->name); |
e9ba6365 GKH |
219 | kfree(cls); |
220 | } | |
221 | ||
2fc68447 GKH |
222 | /** |
223 | * class_create - create a struct class structure | |
224 | * @owner: pointer to the module that is to "own" this struct class | |
225 | * @name: pointer to a string for the name of this class. | |
0e241ffd | 226 | * @key: the lock_class_key for this class; used by mutex lock debugging |
2fc68447 GKH |
227 | * |
228 | * This is used to create a struct class pointer that can then be used | |
c3b19ff0 | 229 | * in calls to device_create(). |
2fc68447 | 230 | * |
f0eae0ed JN |
231 | * Returns &struct class pointer on success, or ERR_PTR() on error. |
232 | * | |
2fc68447 GKH |
233 | * Note, the pointer created here is to be destroyed when finished by |
234 | * making a call to class_destroy(). | |
235 | */ | |
d2a3b914 MW |
236 | struct class *__class_create(struct module *owner, const char *name, |
237 | struct lock_class_key *key) | |
e9ba6365 GKH |
238 | { |
239 | struct class *cls; | |
240 | int retval; | |
241 | ||
4aed0644 | 242 | cls = kzalloc(sizeof(*cls), GFP_KERNEL); |
e9ba6365 GKH |
243 | if (!cls) { |
244 | retval = -ENOMEM; | |
245 | goto error; | |
246 | } | |
e9ba6365 GKH |
247 | |
248 | cls->name = name; | |
249 | cls->owner = owner; | |
250 | cls->class_release = class_create_release; | |
e9ba6365 | 251 | |
d2a3b914 | 252 | retval = __class_register(cls, key); |
e9ba6365 GKH |
253 | if (retval) |
254 | goto error; | |
255 | ||
256 | return cls; | |
257 | ||
258 | error: | |
259 | kfree(cls); | |
260 | return ERR_PTR(retval); | |
261 | } | |
d2a3b914 | 262 | EXPORT_SYMBOL_GPL(__class_create); |
e9ba6365 | 263 | |
2fc68447 GKH |
264 | /** |
265 | * class_destroy - destroys a struct class structure | |
92a0f861 | 266 | * @cls: pointer to the struct class that is to be destroyed |
2fc68447 GKH |
267 | * |
268 | * Note, the pointer to be destroyed must have been created with a call | |
269 | * to class_create(). | |
270 | */ | |
e9ba6365 GKH |
271 | void class_destroy(struct class *cls) |
272 | { | |
273 | if ((cls == NULL) || (IS_ERR(cls))) | |
274 | return; | |
275 | ||
276 | class_unregister(cls); | |
277 | } | |
1da177e4 | 278 | |
5a3ceb86 TH |
279 | /** |
280 | * class_dev_iter_init - initialize class device iterator | |
281 | * @iter: class iterator to initialize | |
282 | * @class: the class we wanna iterate over | |
283 | * @start: the device to start iterating from, if any | |
284 | * @type: device_type of the devices to iterate over, NULL for all | |
285 | * | |
286 | * Initialize class iterator @iter such that it iterates over devices | |
287 | * of @class. If @start is set, the list iteration will start there, | |
288 | * otherwise if it is NULL, the iteration starts at the beginning of | |
289 | * the list. | |
290 | */ | |
291 | void class_dev_iter_init(struct class_dev_iter *iter, struct class *class, | |
292 | struct device *start, const struct device_type *type) | |
293 | { | |
294 | struct klist_node *start_knode = NULL; | |
295 | ||
296 | if (start) | |
297 | start_knode = &start->knode_class; | |
6b6e39a6 | 298 | klist_iter_init_node(&class->p->klist_devices, &iter->ki, start_knode); |
5a3ceb86 TH |
299 | iter->type = type; |
300 | } | |
301 | EXPORT_SYMBOL_GPL(class_dev_iter_init); | |
302 | ||
303 | /** | |
304 | * class_dev_iter_next - iterate to the next device | |
305 | * @iter: class iterator to proceed | |
306 | * | |
307 | * Proceed @iter to the next device and return it. Returns NULL if | |
308 | * iteration is complete. | |
309 | * | |
310 | * The returned device is referenced and won't be released till | |
311 | * iterator is proceed to the next device or exited. The caller is | |
312 | * free to do whatever it wants to do with the device including | |
313 | * calling back into class code. | |
314 | */ | |
315 | struct device *class_dev_iter_next(struct class_dev_iter *iter) | |
316 | { | |
317 | struct klist_node *knode; | |
318 | struct device *dev; | |
319 | ||
320 | while (1) { | |
321 | knode = klist_next(&iter->ki); | |
322 | if (!knode) | |
323 | return NULL; | |
324 | dev = container_of(knode, struct device, knode_class); | |
325 | if (!iter->type || iter->type == dev->type) | |
326 | return dev; | |
327 | } | |
328 | } | |
329 | EXPORT_SYMBOL_GPL(class_dev_iter_next); | |
330 | ||
331 | /** | |
332 | * class_dev_iter_exit - finish iteration | |
333 | * @iter: class iterator to finish | |
334 | * | |
335 | * Finish an iteration. Always call this function after iteration is | |
336 | * complete whether the iteration ran till the end or not. | |
337 | */ | |
338 | void class_dev_iter_exit(struct class_dev_iter *iter) | |
339 | { | |
340 | klist_iter_exit(&iter->ki); | |
341 | } | |
342 | EXPORT_SYMBOL_GPL(class_dev_iter_exit); | |
343 | ||
fd04897b DY |
344 | /** |
345 | * class_for_each_device - device iterator | |
346 | * @class: the class we're iterating | |
93562b53 | 347 | * @start: the device to start with in the list, if any. |
fd04897b DY |
348 | * @data: data for the callback |
349 | * @fn: function to be called for each device | |
350 | * | |
351 | * Iterate over @class's list of devices, and call @fn for each, | |
93562b53 GKH |
352 | * passing it @data. If @start is set, the list iteration will start |
353 | * there, otherwise if it is NULL, the iteration starts at the | |
354 | * beginning of the list. | |
fd04897b DY |
355 | * |
356 | * We check the return of @fn each time. If it returns anything | |
357 | * other than 0, we break out and return that value. | |
358 | * | |
5a3ceb86 TH |
359 | * @fn is allowed to do anything including calling back into class |
360 | * code. There's no locking restriction. | |
fd04897b | 361 | */ |
93562b53 GKH |
362 | int class_for_each_device(struct class *class, struct device *start, |
363 | void *data, int (*fn)(struct device *, void *)) | |
fd04897b | 364 | { |
5a3ceb86 | 365 | struct class_dev_iter iter; |
fd04897b DY |
366 | struct device *dev; |
367 | int error = 0; | |
368 | ||
369 | if (!class) | |
370 | return -EINVAL; | |
7c225035 DB |
371 | if (!class->p) { |
372 | WARN(1, "%s called for class '%s' before it was initialized", | |
373 | __func__, class->name); | |
374 | return -EINVAL; | |
375 | } | |
376 | ||
5a3ceb86 TH |
377 | class_dev_iter_init(&iter, class, start, NULL); |
378 | while ((dev = class_dev_iter_next(&iter))) { | |
93562b53 | 379 | error = fn(dev, data); |
fd04897b DY |
380 | if (error) |
381 | break; | |
382 | } | |
5a3ceb86 | 383 | class_dev_iter_exit(&iter); |
fd04897b DY |
384 | |
385 | return error; | |
386 | } | |
387 | EXPORT_SYMBOL_GPL(class_for_each_device); | |
388 | ||
389 | /** | |
390 | * class_find_device - device iterator for locating a particular device | |
391 | * @class: the class we're iterating | |
695794ae | 392 | * @start: Device to begin with |
fd04897b DY |
393 | * @data: data for the match function |
394 | * @match: function to check device | |
395 | * | |
396 | * This is similar to the class_for_each_dev() function above, but it | |
397 | * returns a reference to a device that is 'found' for later use, as | |
398 | * determined by the @match callback. | |
399 | * | |
400 | * The callback should return 0 if the device doesn't match and non-zero | |
401 | * if it does. If the callback returns non-zero, this function will | |
402 | * return to the caller and not iterate over any more devices. | |
a63ca8f6 | 403 | * |
fd04897b DY |
404 | * Note, you will need to drop the reference with put_device() after use. |
405 | * | |
5a3ceb86 TH |
406 | * @fn is allowed to do anything including calling back into class |
407 | * code. There's no locking restriction. | |
fd04897b | 408 | */ |
695794ae GKH |
409 | struct device *class_find_device(struct class *class, struct device *start, |
410 | void *data, | |
411 | int (*match)(struct device *, void *)) | |
fd04897b | 412 | { |
5a3ceb86 | 413 | struct class_dev_iter iter; |
fd04897b | 414 | struct device *dev; |
fd04897b DY |
415 | |
416 | if (!class) | |
417 | return NULL; | |
7c225035 DB |
418 | if (!class->p) { |
419 | WARN(1, "%s called for class '%s' before it was initialized", | |
420 | __func__, class->name); | |
421 | return NULL; | |
422 | } | |
fd04897b | 423 | |
5a3ceb86 TH |
424 | class_dev_iter_init(&iter, class, start, NULL); |
425 | while ((dev = class_dev_iter_next(&iter))) { | |
695794ae | 426 | if (match(dev, data)) { |
5a3ceb86 | 427 | get_device(dev); |
fd04897b | 428 | break; |
5a3ceb86 | 429 | } |
fd04897b | 430 | } |
5a3ceb86 | 431 | class_dev_iter_exit(&iter); |
fd04897b | 432 | |
5a3ceb86 | 433 | return dev; |
fd04897b DY |
434 | } |
435 | EXPORT_SYMBOL_GPL(class_find_device); | |
436 | ||
1da177e4 LT |
437 | int class_interface_register(struct class_interface *class_intf) |
438 | { | |
439 | struct class *parent; | |
5a3ceb86 | 440 | struct class_dev_iter iter; |
c47ed219 | 441 | struct device *dev; |
1da177e4 LT |
442 | |
443 | if (!class_intf || !class_intf->class) | |
444 | return -ENODEV; | |
445 | ||
446 | parent = class_get(class_intf->class); | |
447 | if (!parent) | |
448 | return -EINVAL; | |
449 | ||
f75b1c60 | 450 | mutex_lock(&parent->p->class_mutex); |
184f1f77 | 451 | list_add_tail(&class_intf->node, &parent->p->class_interfaces); |
c47ed219 | 452 | if (class_intf->add_dev) { |
5a3ceb86 TH |
453 | class_dev_iter_init(&iter, parent, NULL, NULL); |
454 | while ((dev = class_dev_iter_next(&iter))) | |
c47ed219 | 455 | class_intf->add_dev(dev, class_intf); |
5a3ceb86 | 456 | class_dev_iter_exit(&iter); |
c47ed219 | 457 | } |
f75b1c60 | 458 | mutex_unlock(&parent->p->class_mutex); |
1da177e4 LT |
459 | |
460 | return 0; | |
461 | } | |
462 | ||
463 | void class_interface_unregister(struct class_interface *class_intf) | |
464 | { | |
4a3ad20c | 465 | struct class *parent = class_intf->class; |
5a3ceb86 | 466 | struct class_dev_iter iter; |
c47ed219 | 467 | struct device *dev; |
1da177e4 LT |
468 | |
469 | if (!parent) | |
470 | return; | |
471 | ||
f75b1c60 | 472 | mutex_lock(&parent->p->class_mutex); |
1da177e4 | 473 | list_del_init(&class_intf->node); |
c47ed219 | 474 | if (class_intf->remove_dev) { |
5a3ceb86 TH |
475 | class_dev_iter_init(&iter, parent, NULL, NULL); |
476 | while ((dev = class_dev_iter_next(&iter))) | |
c47ed219 | 477 | class_intf->remove_dev(dev, class_intf); |
5a3ceb86 | 478 | class_dev_iter_exit(&iter); |
c47ed219 | 479 | } |
f75b1c60 | 480 | mutex_unlock(&parent->p->class_mutex); |
1da177e4 LT |
481 | |
482 | class_put(parent); | |
483 | } | |
484 | ||
319684b1 BP |
485 | ssize_t show_class_attr_string(struct class *class, |
486 | struct class_attribute *attr, char *buf) | |
869dfc87 AK |
487 | { |
488 | struct class_attribute_string *cs; | |
489 | cs = container_of(attr, struct class_attribute_string, attr); | |
490 | return snprintf(buf, PAGE_SIZE, "%s\n", cs->str); | |
491 | } | |
492 | ||
493 | EXPORT_SYMBOL_GPL(show_class_attr_string); | |
494 | ||
46227094 JD |
495 | struct class_compat { |
496 | struct kobject *kobj; | |
497 | }; | |
498 | ||
499 | /** | |
500 | * class_compat_register - register a compatibility class | |
501 | * @name: the name of the class | |
502 | * | |
503 | * Compatibility class are meant as a temporary user-space compatibility | |
504 | * workaround when converting a family of class devices to a bus devices. | |
505 | */ | |
506 | struct class_compat *class_compat_register(const char *name) | |
507 | { | |
508 | struct class_compat *cls; | |
509 | ||
510 | cls = kmalloc(sizeof(struct class_compat), GFP_KERNEL); | |
511 | if (!cls) | |
512 | return NULL; | |
513 | cls->kobj = kobject_create_and_add(name, &class_kset->kobj); | |
514 | if (!cls->kobj) { | |
515 | kfree(cls); | |
516 | return NULL; | |
517 | } | |
518 | return cls; | |
519 | } | |
520 | EXPORT_SYMBOL_GPL(class_compat_register); | |
521 | ||
522 | /** | |
523 | * class_compat_unregister - unregister a compatibility class | |
524 | * @cls: the class to unregister | |
525 | */ | |
526 | void class_compat_unregister(struct class_compat *cls) | |
527 | { | |
528 | kobject_put(cls->kobj); | |
529 | kfree(cls); | |
530 | } | |
531 | EXPORT_SYMBOL_GPL(class_compat_unregister); | |
532 | ||
533 | /** | |
534 | * class_compat_create_link - create a compatibility class device link to | |
535 | * a bus device | |
536 | * @cls: the compatibility class | |
537 | * @dev: the target bus device | |
538 | * @device_link: an optional device to which a "device" link should be created | |
539 | */ | |
540 | int class_compat_create_link(struct class_compat *cls, struct device *dev, | |
541 | struct device *device_link) | |
542 | { | |
543 | int error; | |
544 | ||
545 | error = sysfs_create_link(cls->kobj, &dev->kobj, dev_name(dev)); | |
546 | if (error) | |
547 | return error; | |
548 | ||
549 | /* | |
550 | * Optionally add a "device" link (typically to the parent), as a | |
551 | * class device would have one and we want to provide as much | |
552 | * backwards compatibility as possible. | |
553 | */ | |
554 | if (device_link) { | |
555 | error = sysfs_create_link(&dev->kobj, &device_link->kobj, | |
556 | "device"); | |
557 | if (error) | |
558 | sysfs_remove_link(cls->kobj, dev_name(dev)); | |
559 | } | |
560 | ||
561 | return error; | |
562 | } | |
563 | EXPORT_SYMBOL_GPL(class_compat_create_link); | |
564 | ||
565 | /** | |
566 | * class_compat_remove_link - remove a compatibility class device link to | |
567 | * a bus device | |
568 | * @cls: the compatibility class | |
569 | * @dev: the target bus device | |
570 | * @device_link: an optional device to which a "device" link was previously | |
571 | * created | |
572 | */ | |
573 | void class_compat_remove_link(struct class_compat *cls, struct device *dev, | |
574 | struct device *device_link) | |
575 | { | |
576 | if (device_link) | |
577 | sysfs_remove_link(&dev->kobj, "device"); | |
578 | sysfs_remove_link(cls->kobj, dev_name(dev)); | |
579 | } | |
580 | EXPORT_SYMBOL_GPL(class_compat_remove_link); | |
581 | ||
1da177e4 LT |
582 | int __init classes_init(void) |
583 | { | |
443dbf90 GKH |
584 | class_kset = kset_create_and_add("class", NULL, NULL); |
585 | if (!class_kset) | |
586 | return -ENOMEM; | |
1da177e4 LT |
587 | return 0; |
588 | } | |
589 | ||
590 | EXPORT_SYMBOL_GPL(class_create_file); | |
591 | EXPORT_SYMBOL_GPL(class_remove_file); | |
1da177e4 | 592 | EXPORT_SYMBOL_GPL(class_unregister); |
e9ba6365 | 593 | EXPORT_SYMBOL_GPL(class_destroy); |
1da177e4 | 594 | |
1da177e4 LT |
595 | EXPORT_SYMBOL_GPL(class_interface_register); |
596 | EXPORT_SYMBOL_GPL(class_interface_unregister); |