Commit | Line | Data |
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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 | ||
a8ae6085 | 11 | #include <linux/device/class.h> |
1da177e4 LT |
12 | #include <linux/device.h> |
13 | #include <linux/module.h> | |
14 | #include <linux/init.h> | |
15 | #include <linux/string.h> | |
16 | #include <linux/kdev_t.h> | |
e9ba6365 | 17 | #include <linux/err.h> |
4e57b681 | 18 | #include <linux/slab.h> |
322cbb50 | 19 | #include <linux/blkdev.h> |
f75b1c60 | 20 | #include <linux/mutex.h> |
1da177e4 LT |
21 | #include "base.h" |
22 | ||
23 | #define to_class_attr(_attr) container_of(_attr, struct class_attribute, attr) | |
1da177e4 | 24 | |
4a3ad20c GKH |
25 | static ssize_t class_attr_show(struct kobject *kobj, struct attribute *attr, |
26 | char *buf) | |
1da177e4 | 27 | { |
4a3ad20c | 28 | struct class_attribute *class_attr = to_class_attr(attr); |
6b6e39a6 | 29 | struct subsys_private *cp = to_subsys_private(kobj); |
4a0c20bf | 30 | ssize_t ret = -EIO; |
1da177e4 LT |
31 | |
32 | if (class_attr->show) | |
28812fe1 | 33 | ret = class_attr->show(cp->class, class_attr, buf); |
1da177e4 LT |
34 | return ret; |
35 | } | |
36 | ||
4a3ad20c GKH |
37 | static ssize_t class_attr_store(struct kobject *kobj, struct attribute *attr, |
38 | const char *buf, size_t count) | |
1da177e4 | 39 | { |
4a3ad20c | 40 | struct class_attribute *class_attr = to_class_attr(attr); |
6b6e39a6 | 41 | struct subsys_private *cp = to_subsys_private(kobj); |
4a0c20bf | 42 | ssize_t ret = -EIO; |
1da177e4 LT |
43 | |
44 | if (class_attr->store) | |
28812fe1 | 45 | ret = class_attr->store(cp->class, class_attr, buf, count); |
1da177e4 LT |
46 | return ret; |
47 | } | |
48 | ||
4a3ad20c | 49 | static void class_release(struct kobject *kobj) |
1da177e4 | 50 | { |
6b6e39a6 | 51 | struct subsys_private *cp = to_subsys_private(kobj); |
7c71448b | 52 | struct class *class = cp->class; |
1da177e4 LT |
53 | |
54 | pr_debug("class '%s': release.\n", class->name); | |
55 | ||
0b2a1a39 RW |
56 | class->p = NULL; |
57 | ||
1da177e4 LT |
58 | if (class->class_release) |
59 | class->class_release(class); | |
60 | else | |
61 | pr_debug("class '%s' does not have a release() function, " | |
62 | "be careful\n", class->name); | |
18d19c96 LP |
63 | |
64 | kfree(cp); | |
1da177e4 LT |
65 | } |
66 | ||
02a476d9 | 67 | static const struct kobj_ns_type_operations *class_child_ns_type(const struct kobject *kobj) |
bc451f20 | 68 | { |
7bbb89b4 | 69 | const struct subsys_private *cp = to_subsys_private(kobj); |
bc451f20 EB |
70 | struct class *class = cp->class; |
71 | ||
72 | return class->ns_type; | |
73 | } | |
74 | ||
52cf25d0 | 75 | static const struct sysfs_ops class_sysfs_ops = { |
672d82c1 EB |
76 | .show = class_attr_show, |
77 | .store = class_attr_store, | |
1da177e4 LT |
78 | }; |
79 | ||
c83d9ab4 | 80 | static const struct kobj_type class_ktype = { |
1da177e4 LT |
81 | .sysfs_ops = &class_sysfs_ops, |
82 | .release = class_release, | |
bc451f20 | 83 | .child_ns_type = class_child_ns_type, |
1da177e4 LT |
84 | }; |
85 | ||
6b6e39a6 | 86 | /* Hotplug events for classes go to the class subsys */ |
443dbf90 | 87 | static struct kset *class_kset; |
1da177e4 LT |
88 | |
89 | ||
58292cbe TH |
90 | int class_create_file_ns(struct class *cls, const struct class_attribute *attr, |
91 | const void *ns) | |
1da177e4 LT |
92 | { |
93 | int error; | |
d34898de | 94 | |
4a3ad20c | 95 | if (cls) |
58292cbe TH |
96 | error = sysfs_create_file_ns(&cls->p->subsys.kobj, |
97 | &attr->attr, ns); | |
4a3ad20c | 98 | else |
1da177e4 LT |
99 | error = -EINVAL; |
100 | return error; | |
101 | } | |
779aeb73 | 102 | EXPORT_SYMBOL_GPL(class_create_file_ns); |
1da177e4 | 103 | |
58292cbe TH |
104 | void class_remove_file_ns(struct class *cls, const struct class_attribute *attr, |
105 | const void *ns) | |
1da177e4 LT |
106 | { |
107 | if (cls) | |
58292cbe | 108 | sysfs_remove_file_ns(&cls->p->subsys.kobj, &attr->attr, ns); |
1da177e4 | 109 | } |
779aeb73 | 110 | EXPORT_SYMBOL_GPL(class_remove_file_ns); |
1da177e4 | 111 | |
1740757e | 112 | static struct class *class_get(struct class *cls) |
1da177e4 LT |
113 | { |
114 | if (cls) | |
6b6e39a6 | 115 | kset_get(&cls->p->subsys); |
7c71448b | 116 | return cls; |
1da177e4 LT |
117 | } |
118 | ||
4a3ad20c | 119 | static void class_put(struct class *cls) |
1da177e4 | 120 | { |
51d172d5 | 121 | if (cls) |
6b6e39a6 | 122 | kset_put(&cls->p->subsys); |
1da177e4 LT |
123 | } |
124 | ||
570d0200 WY |
125 | static struct device *klist_class_to_dev(struct klist_node *n) |
126 | { | |
127 | struct device_private *p = to_device_private_class(n); | |
128 | return p->device; | |
129 | } | |
130 | ||
5a3ceb86 TH |
131 | static void klist_class_dev_get(struct klist_node *n) |
132 | { | |
570d0200 | 133 | struct device *dev = klist_class_to_dev(n); |
5a3ceb86 TH |
134 | |
135 | get_device(dev); | |
136 | } | |
137 | ||
138 | static void klist_class_dev_put(struct klist_node *n) | |
139 | { | |
570d0200 | 140 | struct device *dev = klist_class_to_dev(n); |
5a3ceb86 TH |
141 | |
142 | put_device(dev); | |
143 | } | |
144 | ||
ced6473e GKH |
145 | static int class_add_groups(struct class *cls, |
146 | const struct attribute_group **groups) | |
147 | { | |
148 | return sysfs_create_groups(&cls->p->subsys.kobj, groups); | |
149 | } | |
150 | ||
151 | static void class_remove_groups(struct class *cls, | |
152 | const struct attribute_group **groups) | |
153 | { | |
154 | return sysfs_remove_groups(&cls->p->subsys.kobj, groups); | |
155 | } | |
156 | ||
d2a3b914 | 157 | int __class_register(struct class *cls, struct lock_class_key *key) |
1da177e4 | 158 | { |
6b6e39a6 | 159 | struct subsys_private *cp; |
1da177e4 LT |
160 | int error; |
161 | ||
162 | pr_debug("device class '%s': registering\n", cls->name); | |
163 | ||
7c71448b GKH |
164 | cp = kzalloc(sizeof(*cp), GFP_KERNEL); |
165 | if (!cp) | |
166 | return -ENOMEM; | |
6b6e39a6 | 167 | klist_init(&cp->klist_devices, klist_class_dev_get, klist_class_dev_put); |
ca22e56d | 168 | INIT_LIST_HEAD(&cp->interfaces); |
6b6e39a6 | 169 | kset_init(&cp->glue_dirs); |
ca22e56d | 170 | __mutex_init(&cp->mutex, "subsys mutex", key); |
6b6e39a6 | 171 | error = kobject_set_name(&cp->subsys.kobj, "%s", cls->name); |
7c71448b GKH |
172 | if (error) { |
173 | kfree(cp); | |
1da177e4 | 174 | return error; |
7c71448b | 175 | } |
1da177e4 | 176 | |
e105b8bf DW |
177 | /* set the default /sys/dev directory for devices of this class */ |
178 | if (!cls->dev_kobj) | |
179 | cls->dev_kobj = sysfs_dev_char_kobj; | |
180 | ||
e52eec13 | 181 | #if defined(CONFIG_BLOCK) |
edfaa7c3 | 182 | /* let the block class directory show up in the root of sysfs */ |
e52eec13 | 183 | if (!sysfs_deprecated || cls != &block_class) |
6b6e39a6 | 184 | cp->subsys.kobj.kset = class_kset; |
edfaa7c3 | 185 | #else |
6b6e39a6 | 186 | cp->subsys.kobj.kset = class_kset; |
edfaa7c3 | 187 | #endif |
6b6e39a6 | 188 | cp->subsys.kobj.ktype = &class_ktype; |
7c71448b GKH |
189 | cp->class = cls; |
190 | cls->p = cp; | |
1da177e4 | 191 | |
6b6e39a6 | 192 | error = kset_register(&cp->subsys); |
0b2a1a39 RW |
193 | if (error) |
194 | goto err_out; | |
195 | ||
ced6473e GKH |
196 | error = class_add_groups(class_get(cls), cls->class_groups); |
197 | class_put(cls); | |
8c3e8a6b YY |
198 | if (error) { |
199 | kobject_del(&cp->subsys.kobj); | |
200 | kfree_const(cp->subsys.kobj.name); | |
0b2a1a39 | 201 | goto err_out; |
8c3e8a6b | 202 | } |
0b2a1a39 RW |
203 | return 0; |
204 | ||
205 | err_out: | |
206 | kfree(cp); | |
207 | cls->p = NULL; | |
1da177e4 LT |
208 | return error; |
209 | } | |
d2a3b914 | 210 | EXPORT_SYMBOL_GPL(__class_register); |
1da177e4 | 211 | |
4a3ad20c | 212 | void class_unregister(struct class *cls) |
1da177e4 LT |
213 | { |
214 | pr_debug("device class '%s': unregistering\n", cls->name); | |
ced6473e | 215 | class_remove_groups(cls, cls->class_groups); |
6b6e39a6 | 216 | kset_unregister(&cls->p->subsys); |
1da177e4 | 217 | } |
779aeb73 | 218 | EXPORT_SYMBOL_GPL(class_unregister); |
1da177e4 | 219 | |
e9ba6365 | 220 | static void class_create_release(struct class *cls) |
221 | { | |
2b3a302a | 222 | pr_debug("%s called for %s\n", __func__, cls->name); |
e9ba6365 | 223 | kfree(cls); |
224 | } | |
225 | ||
2fc68447 | 226 | /** |
33c0c9bd | 227 | * __class_create - create a struct class structure |
2fc68447 | 228 | * @owner: pointer to the module that is to "own" this struct class |
229 | * @name: pointer to a string for the name of this class. | |
0e241ffd | 230 | * @key: the lock_class_key for this class; used by mutex lock debugging |
2fc68447 | 231 | * |
232 | * This is used to create a struct class pointer that can then be used | |
c3b19ff0 | 233 | * in calls to device_create(). |
2fc68447 | 234 | * |
f0eae0ed JN |
235 | * Returns &struct class pointer on success, or ERR_PTR() on error. |
236 | * | |
2fc68447 | 237 | * Note, the pointer created here is to be destroyed when finished by |
238 | * making a call to class_destroy(). | |
239 | */ | |
d2a3b914 MW |
240 | struct class *__class_create(struct module *owner, const char *name, |
241 | struct lock_class_key *key) | |
e9ba6365 | 242 | { |
243 | struct class *cls; | |
244 | int retval; | |
245 | ||
4aed0644 | 246 | cls = kzalloc(sizeof(*cls), GFP_KERNEL); |
e9ba6365 | 247 | if (!cls) { |
248 | retval = -ENOMEM; | |
249 | goto error; | |
250 | } | |
e9ba6365 | 251 | |
252 | cls->name = name; | |
253 | cls->owner = owner; | |
254 | cls->class_release = class_create_release; | |
e9ba6365 | 255 | |
d2a3b914 | 256 | retval = __class_register(cls, key); |
e9ba6365 | 257 | if (retval) |
258 | goto error; | |
259 | ||
260 | return cls; | |
261 | ||
262 | error: | |
263 | kfree(cls); | |
264 | return ERR_PTR(retval); | |
265 | } | |
d2a3b914 | 266 | EXPORT_SYMBOL_GPL(__class_create); |
e9ba6365 | 267 | |
2fc68447 | 268 | /** |
269 | * class_destroy - destroys a struct class structure | |
92a0f861 | 270 | * @cls: pointer to the struct class that is to be destroyed |
2fc68447 | 271 | * |
272 | * Note, the pointer to be destroyed must have been created with a call | |
273 | * to class_create(). | |
274 | */ | |
e9ba6365 | 275 | void class_destroy(struct class *cls) |
276 | { | |
e9628e01 | 277 | if (IS_ERR_OR_NULL(cls)) |
e9ba6365 | 278 | return; |
279 | ||
280 | class_unregister(cls); | |
281 | } | |
779aeb73 | 282 | EXPORT_SYMBOL_GPL(class_destroy); |
1da177e4 | 283 | |
5a3ceb86 TH |
284 | /** |
285 | * class_dev_iter_init - initialize class device iterator | |
286 | * @iter: class iterator to initialize | |
287 | * @class: the class we wanna iterate over | |
288 | * @start: the device to start iterating from, if any | |
289 | * @type: device_type of the devices to iterate over, NULL for all | |
290 | * | |
291 | * Initialize class iterator @iter such that it iterates over devices | |
292 | * of @class. If @start is set, the list iteration will start there, | |
293 | * otherwise if it is NULL, the iteration starts at the beginning of | |
294 | * the list. | |
295 | */ | |
296 | void class_dev_iter_init(struct class_dev_iter *iter, struct class *class, | |
297 | struct device *start, const struct device_type *type) | |
298 | { | |
299 | struct klist_node *start_knode = NULL; | |
300 | ||
301 | if (start) | |
570d0200 | 302 | start_knode = &start->p->knode_class; |
6b6e39a6 | 303 | klist_iter_init_node(&class->p->klist_devices, &iter->ki, start_knode); |
5a3ceb86 TH |
304 | iter->type = type; |
305 | } | |
306 | EXPORT_SYMBOL_GPL(class_dev_iter_init); | |
307 | ||
308 | /** | |
309 | * class_dev_iter_next - iterate to the next device | |
310 | * @iter: class iterator to proceed | |
311 | * | |
312 | * Proceed @iter to the next device and return it. Returns NULL if | |
313 | * iteration is complete. | |
314 | * | |
315 | * The returned device is referenced and won't be released till | |
316 | * iterator is proceed to the next device or exited. The caller is | |
317 | * free to do whatever it wants to do with the device including | |
318 | * calling back into class code. | |
319 | */ | |
320 | struct device *class_dev_iter_next(struct class_dev_iter *iter) | |
321 | { | |
322 | struct klist_node *knode; | |
323 | struct device *dev; | |
324 | ||
325 | while (1) { | |
326 | knode = klist_next(&iter->ki); | |
327 | if (!knode) | |
328 | return NULL; | |
570d0200 | 329 | dev = klist_class_to_dev(knode); |
5a3ceb86 TH |
330 | if (!iter->type || iter->type == dev->type) |
331 | return dev; | |
332 | } | |
333 | } | |
334 | EXPORT_SYMBOL_GPL(class_dev_iter_next); | |
335 | ||
336 | /** | |
337 | * class_dev_iter_exit - finish iteration | |
338 | * @iter: class iterator to finish | |
339 | * | |
340 | * Finish an iteration. Always call this function after iteration is | |
341 | * complete whether the iteration ran till the end or not. | |
342 | */ | |
343 | void class_dev_iter_exit(struct class_dev_iter *iter) | |
344 | { | |
345 | klist_iter_exit(&iter->ki); | |
346 | } | |
347 | EXPORT_SYMBOL_GPL(class_dev_iter_exit); | |
348 | ||
fd04897b DY |
349 | /** |
350 | * class_for_each_device - device iterator | |
351 | * @class: the class we're iterating | |
93562b53 | 352 | * @start: the device to start with in the list, if any. |
fd04897b DY |
353 | * @data: data for the callback |
354 | * @fn: function to be called for each device | |
355 | * | |
356 | * Iterate over @class's list of devices, and call @fn for each, | |
93562b53 GKH |
357 | * passing it @data. If @start is set, the list iteration will start |
358 | * there, otherwise if it is NULL, the iteration starts at the | |
359 | * beginning of the list. | |
fd04897b DY |
360 | * |
361 | * We check the return of @fn each time. If it returns anything | |
362 | * other than 0, we break out and return that value. | |
363 | * | |
5a3ceb86 TH |
364 | * @fn is allowed to do anything including calling back into class |
365 | * code. There's no locking restriction. | |
fd04897b | 366 | */ |
93562b53 GKH |
367 | int class_for_each_device(struct class *class, struct device *start, |
368 | void *data, int (*fn)(struct device *, void *)) | |
fd04897b | 369 | { |
5a3ceb86 | 370 | struct class_dev_iter iter; |
fd04897b DY |
371 | struct device *dev; |
372 | int error = 0; | |
373 | ||
374 | if (!class) | |
375 | return -EINVAL; | |
7c225035 DB |
376 | if (!class->p) { |
377 | WARN(1, "%s called for class '%s' before it was initialized", | |
378 | __func__, class->name); | |
379 | return -EINVAL; | |
380 | } | |
381 | ||
5a3ceb86 TH |
382 | class_dev_iter_init(&iter, class, start, NULL); |
383 | while ((dev = class_dev_iter_next(&iter))) { | |
93562b53 | 384 | error = fn(dev, data); |
fd04897b DY |
385 | if (error) |
386 | break; | |
387 | } | |
5a3ceb86 | 388 | class_dev_iter_exit(&iter); |
fd04897b DY |
389 | |
390 | return error; | |
391 | } | |
392 | EXPORT_SYMBOL_GPL(class_for_each_device); | |
393 | ||
394 | /** | |
395 | * class_find_device - device iterator for locating a particular device | |
396 | * @class: the class we're iterating | |
695794ae | 397 | * @start: Device to begin with |
fd04897b DY |
398 | * @data: data for the match function |
399 | * @match: function to check device | |
400 | * | |
401 | * This is similar to the class_for_each_dev() function above, but it | |
402 | * returns a reference to a device that is 'found' for later use, as | |
403 | * determined by the @match callback. | |
404 | * | |
405 | * The callback should return 0 if the device doesn't match and non-zero | |
406 | * if it does. If the callback returns non-zero, this function will | |
407 | * return to the caller and not iterate over any more devices. | |
a63ca8f6 | 408 | * |
fd04897b DY |
409 | * Note, you will need to drop the reference with put_device() after use. |
410 | * | |
12077754 | 411 | * @match is allowed to do anything including calling back into class |
5a3ceb86 | 412 | * code. There's no locking restriction. |
fd04897b | 413 | */ |
695794ae | 414 | struct device *class_find_device(struct class *class, struct device *start, |
9f3b795a MM |
415 | const void *data, |
416 | int (*match)(struct device *, const void *)) | |
fd04897b | 417 | { |
5a3ceb86 | 418 | struct class_dev_iter iter; |
fd04897b | 419 | struct device *dev; |
fd04897b DY |
420 | |
421 | if (!class) | |
422 | return NULL; | |
7c225035 DB |
423 | if (!class->p) { |
424 | WARN(1, "%s called for class '%s' before it was initialized", | |
425 | __func__, class->name); | |
426 | return NULL; | |
427 | } | |
fd04897b | 428 | |
5a3ceb86 TH |
429 | class_dev_iter_init(&iter, class, start, NULL); |
430 | while ((dev = class_dev_iter_next(&iter))) { | |
695794ae | 431 | if (match(dev, data)) { |
5a3ceb86 | 432 | get_device(dev); |
fd04897b | 433 | break; |
5a3ceb86 | 434 | } |
fd04897b | 435 | } |
5a3ceb86 | 436 | class_dev_iter_exit(&iter); |
fd04897b | 437 | |
5a3ceb86 | 438 | return dev; |
fd04897b DY |
439 | } |
440 | EXPORT_SYMBOL_GPL(class_find_device); | |
441 | ||
1da177e4 LT |
442 | int class_interface_register(struct class_interface *class_intf) |
443 | { | |
444 | struct class *parent; | |
5a3ceb86 | 445 | struct class_dev_iter iter; |
c47ed219 | 446 | struct device *dev; |
1da177e4 LT |
447 | |
448 | if (!class_intf || !class_intf->class) | |
449 | return -ENODEV; | |
450 | ||
451 | parent = class_get(class_intf->class); | |
452 | if (!parent) | |
453 | return -EINVAL; | |
454 | ||
ca22e56d KS |
455 | mutex_lock(&parent->p->mutex); |
456 | list_add_tail(&class_intf->node, &parent->p->interfaces); | |
c47ed219 | 457 | if (class_intf->add_dev) { |
5a3ceb86 TH |
458 | class_dev_iter_init(&iter, parent, NULL, NULL); |
459 | while ((dev = class_dev_iter_next(&iter))) | |
c47ed219 | 460 | class_intf->add_dev(dev, class_intf); |
5a3ceb86 | 461 | class_dev_iter_exit(&iter); |
c47ed219 | 462 | } |
ca22e56d | 463 | mutex_unlock(&parent->p->mutex); |
1da177e4 LT |
464 | |
465 | return 0; | |
466 | } | |
779aeb73 | 467 | EXPORT_SYMBOL_GPL(class_interface_register); |
1da177e4 LT |
468 | |
469 | void class_interface_unregister(struct class_interface *class_intf) | |
470 | { | |
4a3ad20c | 471 | struct class *parent = class_intf->class; |
5a3ceb86 | 472 | struct class_dev_iter iter; |
c47ed219 | 473 | struct device *dev; |
1da177e4 LT |
474 | |
475 | if (!parent) | |
476 | return; | |
477 | ||
ca22e56d | 478 | mutex_lock(&parent->p->mutex); |
1da177e4 | 479 | list_del_init(&class_intf->node); |
c47ed219 | 480 | if (class_intf->remove_dev) { |
5a3ceb86 TH |
481 | class_dev_iter_init(&iter, parent, NULL, NULL); |
482 | while ((dev = class_dev_iter_next(&iter))) | |
c47ed219 | 483 | class_intf->remove_dev(dev, class_intf); |
5a3ceb86 | 484 | class_dev_iter_exit(&iter); |
c47ed219 | 485 | } |
ca22e56d | 486 | mutex_unlock(&parent->p->mutex); |
1da177e4 LT |
487 | |
488 | class_put(parent); | |
489 | } | |
779aeb73 | 490 | EXPORT_SYMBOL_GPL(class_interface_unregister); |
1da177e4 | 491 | |
319684b1 BP |
492 | ssize_t show_class_attr_string(struct class *class, |
493 | struct class_attribute *attr, char *buf) | |
869dfc87 AK |
494 | { |
495 | struct class_attribute_string *cs; | |
d34898de | 496 | |
869dfc87 | 497 | cs = container_of(attr, struct class_attribute_string, attr); |
948b3edb | 498 | return sysfs_emit(buf, "%s\n", cs->str); |
869dfc87 AK |
499 | } |
500 | ||
501 | EXPORT_SYMBOL_GPL(show_class_attr_string); | |
502 | ||
46227094 JD |
503 | struct class_compat { |
504 | struct kobject *kobj; | |
505 | }; | |
506 | ||
507 | /** | |
508 | * class_compat_register - register a compatibility class | |
509 | * @name: the name of the class | |
510 | * | |
511 | * Compatibility class are meant as a temporary user-space compatibility | |
512 | * workaround when converting a family of class devices to a bus devices. | |
513 | */ | |
514 | struct class_compat *class_compat_register(const char *name) | |
515 | { | |
516 | struct class_compat *cls; | |
517 | ||
518 | cls = kmalloc(sizeof(struct class_compat), GFP_KERNEL); | |
519 | if (!cls) | |
520 | return NULL; | |
521 | cls->kobj = kobject_create_and_add(name, &class_kset->kobj); | |
522 | if (!cls->kobj) { | |
523 | kfree(cls); | |
524 | return NULL; | |
525 | } | |
526 | return cls; | |
527 | } | |
528 | EXPORT_SYMBOL_GPL(class_compat_register); | |
529 | ||
530 | /** | |
531 | * class_compat_unregister - unregister a compatibility class | |
532 | * @cls: the class to unregister | |
533 | */ | |
534 | void class_compat_unregister(struct class_compat *cls) | |
535 | { | |
536 | kobject_put(cls->kobj); | |
537 | kfree(cls); | |
538 | } | |
539 | EXPORT_SYMBOL_GPL(class_compat_unregister); | |
540 | ||
541 | /** | |
542 | * class_compat_create_link - create a compatibility class device link to | |
543 | * a bus device | |
544 | * @cls: the compatibility class | |
545 | * @dev: the target bus device | |
546 | * @device_link: an optional device to which a "device" link should be created | |
547 | */ | |
548 | int class_compat_create_link(struct class_compat *cls, struct device *dev, | |
549 | struct device *device_link) | |
550 | { | |
551 | int error; | |
552 | ||
553 | error = sysfs_create_link(cls->kobj, &dev->kobj, dev_name(dev)); | |
554 | if (error) | |
555 | return error; | |
556 | ||
557 | /* | |
558 | * Optionally add a "device" link (typically to the parent), as a | |
559 | * class device would have one and we want to provide as much | |
560 | * backwards compatibility as possible. | |
561 | */ | |
562 | if (device_link) { | |
563 | error = sysfs_create_link(&dev->kobj, &device_link->kobj, | |
564 | "device"); | |
565 | if (error) | |
566 | sysfs_remove_link(cls->kobj, dev_name(dev)); | |
567 | } | |
568 | ||
569 | return error; | |
570 | } | |
571 | EXPORT_SYMBOL_GPL(class_compat_create_link); | |
572 | ||
573 | /** | |
574 | * class_compat_remove_link - remove a compatibility class device link to | |
575 | * a bus device | |
576 | * @cls: the compatibility class | |
577 | * @dev: the target bus device | |
578 | * @device_link: an optional device to which a "device" link was previously | |
579 | * created | |
580 | */ | |
581 | void class_compat_remove_link(struct class_compat *cls, struct device *dev, | |
582 | struct device *device_link) | |
583 | { | |
584 | if (device_link) | |
585 | sysfs_remove_link(&dev->kobj, "device"); | |
586 | sysfs_remove_link(cls->kobj, dev_name(dev)); | |
587 | } | |
588 | EXPORT_SYMBOL_GPL(class_compat_remove_link); | |
589 | ||
1da177e4 LT |
590 | int __init classes_init(void) |
591 | { | |
443dbf90 GKH |
592 | class_kset = kset_create_and_add("class", NULL, NULL); |
593 | if (!class_kset) | |
594 | return -ENOMEM; | |
1da177e4 LT |
595 | return 0; |
596 | } |