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); |
7c71448b | 30 | struct class_private *cp = to_class(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); |
7c71448b | 42 | struct class_private *cp = to_class(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 | { |
7c71448b GKH |
52 | struct class_private *cp = to_class(kobj); |
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 | ||
52cf25d0 | 66 | static const struct sysfs_ops class_sysfs_ops = { |
1da177e4 LT |
67 | .show = class_attr_show, |
68 | .store = class_attr_store, | |
69 | }; | |
70 | ||
adc56808 | 71 | static struct kobj_type class_ktype = { |
1da177e4 LT |
72 | .sysfs_ops = &class_sysfs_ops, |
73 | .release = class_release, | |
74 | }; | |
75 | ||
1fbfee6c | 76 | /* Hotplug events for classes go to the class class_subsys */ |
443dbf90 | 77 | static struct kset *class_kset; |
1da177e4 LT |
78 | |
79 | ||
4a3ad20c | 80 | int class_create_file(struct class *cls, const struct class_attribute *attr) |
1da177e4 LT |
81 | { |
82 | int error; | |
4a3ad20c | 83 | if (cls) |
1fbfee6c GKH |
84 | error = sysfs_create_file(&cls->p->class_subsys.kobj, |
85 | &attr->attr); | |
4a3ad20c | 86 | else |
1da177e4 LT |
87 | error = -EINVAL; |
88 | return error; | |
89 | } | |
90 | ||
4a3ad20c | 91 | void class_remove_file(struct class *cls, const struct class_attribute *attr) |
1da177e4 LT |
92 | { |
93 | if (cls) | |
1fbfee6c | 94 | sysfs_remove_file(&cls->p->class_subsys.kobj, &attr->attr); |
1da177e4 LT |
95 | } |
96 | ||
1740757e | 97 | static struct class *class_get(struct class *cls) |
1da177e4 LT |
98 | { |
99 | if (cls) | |
1fbfee6c | 100 | kset_get(&cls->p->class_subsys); |
7c71448b | 101 | return cls; |
1da177e4 LT |
102 | } |
103 | ||
4a3ad20c | 104 | static void class_put(struct class *cls) |
1da177e4 | 105 | { |
51d172d5 | 106 | if (cls) |
1fbfee6c | 107 | kset_put(&cls->p->class_subsys); |
1da177e4 LT |
108 | } |
109 | ||
4a3ad20c | 110 | static int add_class_attrs(struct class *cls) |
1da177e4 LT |
111 | { |
112 | int i; | |
113 | int error = 0; | |
114 | ||
115 | if (cls->class_attrs) { | |
116 | for (i = 0; attr_name(cls->class_attrs[i]); i++) { | |
4a3ad20c | 117 | error = class_create_file(cls, &cls->class_attrs[i]); |
1da177e4 | 118 | if (error) |
4a3ad20c | 119 | goto error; |
1da177e4 LT |
120 | } |
121 | } | |
4a3ad20c | 122 | done: |
1da177e4 | 123 | return error; |
4a3ad20c | 124 | error: |
1da177e4 | 125 | while (--i >= 0) |
4a3ad20c GKH |
126 | class_remove_file(cls, &cls->class_attrs[i]); |
127 | goto done; | |
1da177e4 LT |
128 | } |
129 | ||
4a3ad20c | 130 | static void remove_class_attrs(struct class *cls) |
1da177e4 LT |
131 | { |
132 | int i; | |
133 | ||
134 | if (cls->class_attrs) { | |
135 | for (i = 0; attr_name(cls->class_attrs[i]); i++) | |
4a3ad20c | 136 | class_remove_file(cls, &cls->class_attrs[i]); |
1da177e4 LT |
137 | } |
138 | } | |
139 | ||
5a3ceb86 TH |
140 | static void klist_class_dev_get(struct klist_node *n) |
141 | { | |
142 | struct device *dev = container_of(n, struct device, knode_class); | |
143 | ||
144 | get_device(dev); | |
145 | } | |
146 | ||
147 | static void klist_class_dev_put(struct klist_node *n) | |
148 | { | |
149 | struct device *dev = container_of(n, struct device, knode_class); | |
150 | ||
151 | put_device(dev); | |
152 | } | |
153 | ||
d2a3b914 | 154 | int __class_register(struct class *cls, struct lock_class_key *key) |
1da177e4 | 155 | { |
7c71448b | 156 | struct class_private *cp; |
1da177e4 LT |
157 | int error; |
158 | ||
159 | pr_debug("device class '%s': registering\n", cls->name); | |
160 | ||
7c71448b GKH |
161 | cp = kzalloc(sizeof(*cp), GFP_KERNEL); |
162 | if (!cp) | |
163 | return -ENOMEM; | |
5a3ceb86 | 164 | klist_init(&cp->class_devices, klist_class_dev_get, klist_class_dev_put); |
184f1f77 | 165 | INIT_LIST_HEAD(&cp->class_interfaces); |
7c71448b | 166 | kset_init(&cp->class_dirs); |
f75b1c60 | 167 | __mutex_init(&cp->class_mutex, "struct class mutex", key); |
1fbfee6c | 168 | error = kobject_set_name(&cp->class_subsys.kobj, "%s", cls->name); |
7c71448b GKH |
169 | if (error) { |
170 | kfree(cp); | |
1da177e4 | 171 | return error; |
7c71448b | 172 | } |
1da177e4 | 173 | |
e105b8bf DW |
174 | /* set the default /sys/dev directory for devices of this class */ |
175 | if (!cls->dev_kobj) | |
176 | cls->dev_kobj = sysfs_dev_char_kobj; | |
177 | ||
4e886c29 | 178 | #if defined(CONFIG_SYSFS_DEPRECATED) && defined(CONFIG_BLOCK) |
edfaa7c3 KS |
179 | /* let the block class directory show up in the root of sysfs */ |
180 | if (cls != &block_class) | |
1fbfee6c | 181 | cp->class_subsys.kobj.kset = class_kset; |
edfaa7c3 | 182 | #else |
1fbfee6c | 183 | cp->class_subsys.kobj.kset = class_kset; |
edfaa7c3 | 184 | #endif |
1fbfee6c | 185 | cp->class_subsys.kobj.ktype = &class_ktype; |
7c71448b GKH |
186 | cp->class = cls; |
187 | cls->p = cp; | |
1da177e4 | 188 | |
1fbfee6c | 189 | error = kset_register(&cp->class_subsys); |
7c71448b GKH |
190 | if (error) { |
191 | kfree(cp); | |
192 | return error; | |
1da177e4 | 193 | } |
7c71448b GKH |
194 | error = add_class_attrs(class_get(cls)); |
195 | class_put(cls); | |
1da177e4 LT |
196 | return error; |
197 | } | |
d2a3b914 | 198 | EXPORT_SYMBOL_GPL(__class_register); |
1da177e4 | 199 | |
4a3ad20c | 200 | void class_unregister(struct class *cls) |
1da177e4 LT |
201 | { |
202 | pr_debug("device class '%s': unregistering\n", cls->name); | |
203 | remove_class_attrs(cls); | |
1fbfee6c | 204 | kset_unregister(&cls->p->class_subsys); |
1da177e4 LT |
205 | } |
206 | ||
e9ba6365 GKH |
207 | static void class_create_release(struct class *cls) |
208 | { | |
2b3a302a | 209 | pr_debug("%s called for %s\n", __func__, cls->name); |
e9ba6365 GKH |
210 | kfree(cls); |
211 | } | |
212 | ||
2fc68447 GKH |
213 | /** |
214 | * class_create - create a struct class structure | |
215 | * @owner: pointer to the module that is to "own" this struct class | |
216 | * @name: pointer to a string for the name of this class. | |
0e241ffd | 217 | * @key: the lock_class_key for this class; used by mutex lock debugging |
2fc68447 GKH |
218 | * |
219 | * This is used to create a struct class pointer that can then be used | |
c3b19ff0 | 220 | * in calls to device_create(). |
2fc68447 | 221 | * |
f0eae0ed JN |
222 | * Returns &struct class pointer on success, or ERR_PTR() on error. |
223 | * | |
2fc68447 GKH |
224 | * Note, the pointer created here is to be destroyed when finished by |
225 | * making a call to class_destroy(). | |
226 | */ | |
d2a3b914 MW |
227 | struct class *__class_create(struct module *owner, const char *name, |
228 | struct lock_class_key *key) | |
e9ba6365 GKH |
229 | { |
230 | struct class *cls; | |
231 | int retval; | |
232 | ||
4aed0644 | 233 | cls = kzalloc(sizeof(*cls), GFP_KERNEL); |
e9ba6365 GKH |
234 | if (!cls) { |
235 | retval = -ENOMEM; | |
236 | goto error; | |
237 | } | |
e9ba6365 GKH |
238 | |
239 | cls->name = name; | |
240 | cls->owner = owner; | |
241 | cls->class_release = class_create_release; | |
e9ba6365 | 242 | |
d2a3b914 | 243 | retval = __class_register(cls, key); |
e9ba6365 GKH |
244 | if (retval) |
245 | goto error; | |
246 | ||
247 | return cls; | |
248 | ||
249 | error: | |
250 | kfree(cls); | |
251 | return ERR_PTR(retval); | |
252 | } | |
d2a3b914 | 253 | EXPORT_SYMBOL_GPL(__class_create); |
e9ba6365 | 254 | |
2fc68447 GKH |
255 | /** |
256 | * class_destroy - destroys a struct class structure | |
92a0f861 | 257 | * @cls: pointer to the struct class that is to be destroyed |
2fc68447 GKH |
258 | * |
259 | * Note, the pointer to be destroyed must have been created with a call | |
260 | * to class_create(). | |
261 | */ | |
e9ba6365 GKH |
262 | void class_destroy(struct class *cls) |
263 | { | |
264 | if ((cls == NULL) || (IS_ERR(cls))) | |
265 | return; | |
266 | ||
267 | class_unregister(cls); | |
268 | } | |
1da177e4 | 269 | |
805fab47 KS |
270 | #ifdef CONFIG_SYSFS_DEPRECATED |
271 | char *make_class_name(const char *name, struct kobject *kobj) | |
272 | { | |
273 | char *class_name; | |
274 | int size; | |
275 | ||
276 | size = strlen(name) + strlen(kobject_name(kobj)) + 2; | |
277 | ||
278 | class_name = kmalloc(size, GFP_KERNEL); | |
279 | if (!class_name) | |
cb360bbf | 280 | return NULL; |
805fab47 KS |
281 | |
282 | strcpy(class_name, name); | |
283 | strcat(class_name, ":"); | |
284 | strcat(class_name, kobject_name(kobj)); | |
285 | return class_name; | |
286 | } | |
805fab47 KS |
287 | #endif |
288 | ||
5a3ceb86 TH |
289 | /** |
290 | * class_dev_iter_init - initialize class device iterator | |
291 | * @iter: class iterator to initialize | |
292 | * @class: the class we wanna iterate over | |
293 | * @start: the device to start iterating from, if any | |
294 | * @type: device_type of the devices to iterate over, NULL for all | |
295 | * | |
296 | * Initialize class iterator @iter such that it iterates over devices | |
297 | * of @class. If @start is set, the list iteration will start there, | |
298 | * otherwise if it is NULL, the iteration starts at the beginning of | |
299 | * the list. | |
300 | */ | |
301 | void class_dev_iter_init(struct class_dev_iter *iter, struct class *class, | |
302 | struct device *start, const struct device_type *type) | |
303 | { | |
304 | struct klist_node *start_knode = NULL; | |
305 | ||
306 | if (start) | |
307 | start_knode = &start->knode_class; | |
308 | klist_iter_init_node(&class->p->class_devices, &iter->ki, start_knode); | |
309 | iter->type = type; | |
310 | } | |
311 | EXPORT_SYMBOL_GPL(class_dev_iter_init); | |
312 | ||
313 | /** | |
314 | * class_dev_iter_next - iterate to the next device | |
315 | * @iter: class iterator to proceed | |
316 | * | |
317 | * Proceed @iter to the next device and return it. Returns NULL if | |
318 | * iteration is complete. | |
319 | * | |
320 | * The returned device is referenced and won't be released till | |
321 | * iterator is proceed to the next device or exited. The caller is | |
322 | * free to do whatever it wants to do with the device including | |
323 | * calling back into class code. | |
324 | */ | |
325 | struct device *class_dev_iter_next(struct class_dev_iter *iter) | |
326 | { | |
327 | struct klist_node *knode; | |
328 | struct device *dev; | |
329 | ||
330 | while (1) { | |
331 | knode = klist_next(&iter->ki); | |
332 | if (!knode) | |
333 | return NULL; | |
334 | dev = container_of(knode, struct device, knode_class); | |
335 | if (!iter->type || iter->type == dev->type) | |
336 | return dev; | |
337 | } | |
338 | } | |
339 | EXPORT_SYMBOL_GPL(class_dev_iter_next); | |
340 | ||
341 | /** | |
342 | * class_dev_iter_exit - finish iteration | |
343 | * @iter: class iterator to finish | |
344 | * | |
345 | * Finish an iteration. Always call this function after iteration is | |
346 | * complete whether the iteration ran till the end or not. | |
347 | */ | |
348 | void class_dev_iter_exit(struct class_dev_iter *iter) | |
349 | { | |
350 | klist_iter_exit(&iter->ki); | |
351 | } | |
352 | EXPORT_SYMBOL_GPL(class_dev_iter_exit); | |
353 | ||
fd04897b DY |
354 | /** |
355 | * class_for_each_device - device iterator | |
356 | * @class: the class we're iterating | |
93562b53 | 357 | * @start: the device to start with in the list, if any. |
fd04897b DY |
358 | * @data: data for the callback |
359 | * @fn: function to be called for each device | |
360 | * | |
361 | * Iterate over @class's list of devices, and call @fn for each, | |
93562b53 GKH |
362 | * passing it @data. If @start is set, the list iteration will start |
363 | * there, otherwise if it is NULL, the iteration starts at the | |
364 | * beginning of the list. | |
fd04897b DY |
365 | * |
366 | * We check the return of @fn each time. If it returns anything | |
367 | * other than 0, we break out and return that value. | |
368 | * | |
5a3ceb86 TH |
369 | * @fn is allowed to do anything including calling back into class |
370 | * code. There's no locking restriction. | |
fd04897b | 371 | */ |
93562b53 GKH |
372 | int class_for_each_device(struct class *class, struct device *start, |
373 | void *data, int (*fn)(struct device *, void *)) | |
fd04897b | 374 | { |
5a3ceb86 | 375 | struct class_dev_iter iter; |
fd04897b DY |
376 | struct device *dev; |
377 | int error = 0; | |
378 | ||
379 | if (!class) | |
380 | return -EINVAL; | |
7c225035 DB |
381 | if (!class->p) { |
382 | WARN(1, "%s called for class '%s' before it was initialized", | |
383 | __func__, class->name); | |
384 | return -EINVAL; | |
385 | } | |
386 | ||
5a3ceb86 TH |
387 | class_dev_iter_init(&iter, class, start, NULL); |
388 | while ((dev = class_dev_iter_next(&iter))) { | |
93562b53 | 389 | error = fn(dev, data); |
fd04897b DY |
390 | if (error) |
391 | break; | |
392 | } | |
5a3ceb86 | 393 | class_dev_iter_exit(&iter); |
fd04897b DY |
394 | |
395 | return error; | |
396 | } | |
397 | EXPORT_SYMBOL_GPL(class_for_each_device); | |
398 | ||
399 | /** | |
400 | * class_find_device - device iterator for locating a particular device | |
401 | * @class: the class we're iterating | |
695794ae | 402 | * @start: Device to begin with |
fd04897b DY |
403 | * @data: data for the match function |
404 | * @match: function to check device | |
405 | * | |
406 | * This is similar to the class_for_each_dev() function above, but it | |
407 | * returns a reference to a device that is 'found' for later use, as | |
408 | * determined by the @match callback. | |
409 | * | |
410 | * The callback should return 0 if the device doesn't match and non-zero | |
411 | * if it does. If the callback returns non-zero, this function will | |
412 | * return to the caller and not iterate over any more devices. | |
a63ca8f6 | 413 | * |
fd04897b DY |
414 | * Note, you will need to drop the reference with put_device() after use. |
415 | * | |
5a3ceb86 TH |
416 | * @fn is allowed to do anything including calling back into class |
417 | * code. There's no locking restriction. | |
fd04897b | 418 | */ |
695794ae GKH |
419 | struct device *class_find_device(struct class *class, struct device *start, |
420 | void *data, | |
421 | int (*match)(struct device *, void *)) | |
fd04897b | 422 | { |
5a3ceb86 | 423 | struct class_dev_iter iter; |
fd04897b | 424 | struct device *dev; |
fd04897b DY |
425 | |
426 | if (!class) | |
427 | return NULL; | |
7c225035 DB |
428 | if (!class->p) { |
429 | WARN(1, "%s called for class '%s' before it was initialized", | |
430 | __func__, class->name); | |
431 | return NULL; | |
432 | } | |
fd04897b | 433 | |
5a3ceb86 TH |
434 | class_dev_iter_init(&iter, class, start, NULL); |
435 | while ((dev = class_dev_iter_next(&iter))) { | |
695794ae | 436 | if (match(dev, data)) { |
5a3ceb86 | 437 | get_device(dev); |
fd04897b | 438 | break; |
5a3ceb86 | 439 | } |
fd04897b | 440 | } |
5a3ceb86 | 441 | class_dev_iter_exit(&iter); |
fd04897b | 442 | |
5a3ceb86 | 443 | return dev; |
fd04897b DY |
444 | } |
445 | EXPORT_SYMBOL_GPL(class_find_device); | |
446 | ||
1da177e4 LT |
447 | int class_interface_register(struct class_interface *class_intf) |
448 | { | |
449 | struct class *parent; | |
5a3ceb86 | 450 | struct class_dev_iter iter; |
c47ed219 | 451 | struct device *dev; |
1da177e4 LT |
452 | |
453 | if (!class_intf || !class_intf->class) | |
454 | return -ENODEV; | |
455 | ||
456 | parent = class_get(class_intf->class); | |
457 | if (!parent) | |
458 | return -EINVAL; | |
459 | ||
f75b1c60 | 460 | mutex_lock(&parent->p->class_mutex); |
184f1f77 | 461 | list_add_tail(&class_intf->node, &parent->p->class_interfaces); |
c47ed219 | 462 | if (class_intf->add_dev) { |
5a3ceb86 TH |
463 | class_dev_iter_init(&iter, parent, NULL, NULL); |
464 | while ((dev = class_dev_iter_next(&iter))) | |
c47ed219 | 465 | class_intf->add_dev(dev, class_intf); |
5a3ceb86 | 466 | class_dev_iter_exit(&iter); |
c47ed219 | 467 | } |
f75b1c60 | 468 | mutex_unlock(&parent->p->class_mutex); |
1da177e4 LT |
469 | |
470 | return 0; | |
471 | } | |
472 | ||
473 | void class_interface_unregister(struct class_interface *class_intf) | |
474 | { | |
4a3ad20c | 475 | struct class *parent = class_intf->class; |
5a3ceb86 | 476 | struct class_dev_iter iter; |
c47ed219 | 477 | struct device *dev; |
1da177e4 LT |
478 | |
479 | if (!parent) | |
480 | return; | |
481 | ||
f75b1c60 | 482 | mutex_lock(&parent->p->class_mutex); |
1da177e4 | 483 | list_del_init(&class_intf->node); |
c47ed219 | 484 | if (class_intf->remove_dev) { |
5a3ceb86 TH |
485 | class_dev_iter_init(&iter, parent, NULL, NULL); |
486 | while ((dev = class_dev_iter_next(&iter))) | |
c47ed219 | 487 | class_intf->remove_dev(dev, class_intf); |
5a3ceb86 | 488 | class_dev_iter_exit(&iter); |
c47ed219 | 489 | } |
f75b1c60 | 490 | mutex_unlock(&parent->p->class_mutex); |
1da177e4 LT |
491 | |
492 | class_put(parent); | |
493 | } | |
494 | ||
869dfc87 AK |
495 | ssize_t show_class_attr_string(struct class *class, struct class_attribute *attr, |
496 | char *buf) | |
497 | { | |
498 | struct class_attribute_string *cs; | |
499 | cs = container_of(attr, struct class_attribute_string, attr); | |
500 | return snprintf(buf, PAGE_SIZE, "%s\n", cs->str); | |
501 | } | |
502 | ||
503 | EXPORT_SYMBOL_GPL(show_class_attr_string); | |
504 | ||
46227094 JD |
505 | struct class_compat { |
506 | struct kobject *kobj; | |
507 | }; | |
508 | ||
509 | /** | |
510 | * class_compat_register - register a compatibility class | |
511 | * @name: the name of the class | |
512 | * | |
513 | * Compatibility class are meant as a temporary user-space compatibility | |
514 | * workaround when converting a family of class devices to a bus devices. | |
515 | */ | |
516 | struct class_compat *class_compat_register(const char *name) | |
517 | { | |
518 | struct class_compat *cls; | |
519 | ||
520 | cls = kmalloc(sizeof(struct class_compat), GFP_KERNEL); | |
521 | if (!cls) | |
522 | return NULL; | |
523 | cls->kobj = kobject_create_and_add(name, &class_kset->kobj); | |
524 | if (!cls->kobj) { | |
525 | kfree(cls); | |
526 | return NULL; | |
527 | } | |
528 | return cls; | |
529 | } | |
530 | EXPORT_SYMBOL_GPL(class_compat_register); | |
531 | ||
532 | /** | |
533 | * class_compat_unregister - unregister a compatibility class | |
534 | * @cls: the class to unregister | |
535 | */ | |
536 | void class_compat_unregister(struct class_compat *cls) | |
537 | { | |
538 | kobject_put(cls->kobj); | |
539 | kfree(cls); | |
540 | } | |
541 | EXPORT_SYMBOL_GPL(class_compat_unregister); | |
542 | ||
543 | /** | |
544 | * class_compat_create_link - create a compatibility class device link to | |
545 | * a bus device | |
546 | * @cls: the compatibility class | |
547 | * @dev: the target bus device | |
548 | * @device_link: an optional device to which a "device" link should be created | |
549 | */ | |
550 | int class_compat_create_link(struct class_compat *cls, struct device *dev, | |
551 | struct device *device_link) | |
552 | { | |
553 | int error; | |
554 | ||
555 | error = sysfs_create_link(cls->kobj, &dev->kobj, dev_name(dev)); | |
556 | if (error) | |
557 | return error; | |
558 | ||
559 | /* | |
560 | * Optionally add a "device" link (typically to the parent), as a | |
561 | * class device would have one and we want to provide as much | |
562 | * backwards compatibility as possible. | |
563 | */ | |
564 | if (device_link) { | |
565 | error = sysfs_create_link(&dev->kobj, &device_link->kobj, | |
566 | "device"); | |
567 | if (error) | |
568 | sysfs_remove_link(cls->kobj, dev_name(dev)); | |
569 | } | |
570 | ||
571 | return error; | |
572 | } | |
573 | EXPORT_SYMBOL_GPL(class_compat_create_link); | |
574 | ||
575 | /** | |
576 | * class_compat_remove_link - remove a compatibility class device link to | |
577 | * a bus device | |
578 | * @cls: the compatibility class | |
579 | * @dev: the target bus device | |
580 | * @device_link: an optional device to which a "device" link was previously | |
581 | * created | |
582 | */ | |
583 | void class_compat_remove_link(struct class_compat *cls, struct device *dev, | |
584 | struct device *device_link) | |
585 | { | |
586 | if (device_link) | |
587 | sysfs_remove_link(&dev->kobj, "device"); | |
588 | sysfs_remove_link(cls->kobj, dev_name(dev)); | |
589 | } | |
590 | EXPORT_SYMBOL_GPL(class_compat_remove_link); | |
591 | ||
1da177e4 LT |
592 | int __init classes_init(void) |
593 | { | |
443dbf90 GKH |
594 | class_kset = kset_create_and_add("class", NULL, NULL); |
595 | if (!class_kset) | |
596 | return -ENOMEM; | |
1da177e4 LT |
597 | return 0; |
598 | } | |
599 | ||
600 | EXPORT_SYMBOL_GPL(class_create_file); | |
601 | EXPORT_SYMBOL_GPL(class_remove_file); | |
1da177e4 | 602 | EXPORT_SYMBOL_GPL(class_unregister); |
e9ba6365 | 603 | EXPORT_SYMBOL_GPL(class_destroy); |
1da177e4 | 604 | |
1da177e4 LT |
605 | EXPORT_SYMBOL_GPL(class_interface_register); |
606 | EXPORT_SYMBOL_GPL(class_interface_unregister); |