]>
Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * drivers/base/core.c - core driver model code (device registration, etc) | |
3 | * | |
4 | * Copyright (c) 2002-3 Patrick Mochel | |
5 | * Copyright (c) 2002-3 Open Source Development Labs | |
6 | * | |
7 | * This file is released under the GPLv2 | |
8 | * | |
9 | */ | |
10 | ||
1da177e4 LT |
11 | #include <linux/device.h> |
12 | #include <linux/err.h> | |
13 | #include <linux/init.h> | |
14 | #include <linux/module.h> | |
15 | #include <linux/slab.h> | |
16 | #include <linux/string.h> | |
23681e47 | 17 | #include <linux/kdev_t.h> |
1da177e4 LT |
18 | |
19 | #include <asm/semaphore.h> | |
20 | ||
21 | #include "base.h" | |
22 | #include "power/power.h" | |
23 | ||
24 | int (*platform_notify)(struct device * dev) = NULL; | |
25 | int (*platform_notify_remove)(struct device * dev) = NULL; | |
26 | ||
27 | /* | |
28 | * sysfs bindings for devices. | |
29 | */ | |
30 | ||
3e95637a AS |
31 | /** |
32 | * dev_driver_string - Return a device's driver name, if at all possible | |
33 | * @dev: struct device to get the name of | |
34 | * | |
35 | * Will return the device's driver's name if it is bound to a device. If | |
36 | * the device is not bound to a device, it will return the name of the bus | |
37 | * it is attached to. If it is not attached to a bus either, an empty | |
38 | * string will be returned. | |
39 | */ | |
40 | const char *dev_driver_string(struct device *dev) | |
41 | { | |
42 | return dev->driver ? dev->driver->name : | |
43 | (dev->bus ? dev->bus->name : ""); | |
44 | } | |
45 | EXPORT_SYMBOL_GPL(dev_driver_string); | |
46 | ||
1da177e4 LT |
47 | #define to_dev(obj) container_of(obj, struct device, kobj) |
48 | #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr) | |
49 | ||
1da177e4 LT |
50 | static ssize_t |
51 | dev_attr_show(struct kobject * kobj, struct attribute * attr, char * buf) | |
52 | { | |
53 | struct device_attribute * dev_attr = to_dev_attr(attr); | |
54 | struct device * dev = to_dev(kobj); | |
4a0c20bf | 55 | ssize_t ret = -EIO; |
1da177e4 LT |
56 | |
57 | if (dev_attr->show) | |
54b6f35c | 58 | ret = dev_attr->show(dev, dev_attr, buf); |
1da177e4 LT |
59 | return ret; |
60 | } | |
61 | ||
62 | static ssize_t | |
63 | dev_attr_store(struct kobject * kobj, struct attribute * attr, | |
64 | const char * buf, size_t count) | |
65 | { | |
66 | struct device_attribute * dev_attr = to_dev_attr(attr); | |
67 | struct device * dev = to_dev(kobj); | |
4a0c20bf | 68 | ssize_t ret = -EIO; |
1da177e4 LT |
69 | |
70 | if (dev_attr->store) | |
54b6f35c | 71 | ret = dev_attr->store(dev, dev_attr, buf, count); |
1da177e4 LT |
72 | return ret; |
73 | } | |
74 | ||
75 | static struct sysfs_ops dev_sysfs_ops = { | |
76 | .show = dev_attr_show, | |
77 | .store = dev_attr_store, | |
78 | }; | |
79 | ||
80 | ||
81 | /** | |
82 | * device_release - free device structure. | |
83 | * @kobj: device's kobject. | |
84 | * | |
85 | * This is called once the reference count for the object | |
86 | * reaches 0. We forward the call to the device's release | |
87 | * method, which should handle actually freeing the structure. | |
88 | */ | |
89 | static void device_release(struct kobject * kobj) | |
90 | { | |
91 | struct device * dev = to_dev(kobj); | |
92 | ||
93 | if (dev->release) | |
94 | dev->release(dev); | |
95 | else { | |
96 | printk(KERN_ERR "Device '%s' does not have a release() function, " | |
97 | "it is broken and must be fixed.\n", | |
98 | dev->bus_id); | |
99 | WARN_ON(1); | |
100 | } | |
101 | } | |
102 | ||
103 | static struct kobj_type ktype_device = { | |
104 | .release = device_release, | |
105 | .sysfs_ops = &dev_sysfs_ops, | |
1da177e4 LT |
106 | }; |
107 | ||
108 | ||
312c004d | 109 | static int dev_uevent_filter(struct kset *kset, struct kobject *kobj) |
1da177e4 LT |
110 | { |
111 | struct kobj_type *ktype = get_ktype(kobj); | |
112 | ||
113 | if (ktype == &ktype_device) { | |
114 | struct device *dev = to_dev(kobj); | |
115 | if (dev->bus) | |
116 | return 1; | |
23681e47 GKH |
117 | if (dev->class) |
118 | return 1; | |
1da177e4 LT |
119 | } |
120 | return 0; | |
121 | } | |
122 | ||
312c004d | 123 | static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj) |
1da177e4 LT |
124 | { |
125 | struct device *dev = to_dev(kobj); | |
126 | ||
23681e47 GKH |
127 | if (dev->bus) |
128 | return dev->bus->name; | |
129 | if (dev->class) | |
130 | return dev->class->name; | |
131 | return NULL; | |
1da177e4 LT |
132 | } |
133 | ||
312c004d | 134 | static int dev_uevent(struct kset *kset, struct kobject *kobj, char **envp, |
1da177e4 LT |
135 | int num_envp, char *buffer, int buffer_size) |
136 | { | |
137 | struct device *dev = to_dev(kobj); | |
138 | int i = 0; | |
139 | int length = 0; | |
140 | int retval = 0; | |
141 | ||
23681e47 GKH |
142 | /* add the major/minor if present */ |
143 | if (MAJOR(dev->devt)) { | |
144 | add_uevent_var(envp, num_envp, &i, | |
145 | buffer, buffer_size, &length, | |
146 | "MAJOR=%u", MAJOR(dev->devt)); | |
147 | add_uevent_var(envp, num_envp, &i, | |
148 | buffer, buffer_size, &length, | |
149 | "MINOR=%u", MINOR(dev->devt)); | |
150 | } | |
151 | ||
1da177e4 LT |
152 | /* add bus name of physical device */ |
153 | if (dev->bus) | |
312c004d KS |
154 | add_uevent_var(envp, num_envp, &i, |
155 | buffer, buffer_size, &length, | |
156 | "PHYSDEVBUS=%s", dev->bus->name); | |
1da177e4 LT |
157 | |
158 | /* add driver name of physical device */ | |
159 | if (dev->driver) | |
312c004d KS |
160 | add_uevent_var(envp, num_envp, &i, |
161 | buffer, buffer_size, &length, | |
162 | "PHYSDEVDRIVER=%s", dev->driver->name); | |
1da177e4 LT |
163 | |
164 | /* terminate, set to next free slot, shrink available space */ | |
165 | envp[i] = NULL; | |
166 | envp = &envp[i]; | |
167 | num_envp -= i; | |
168 | buffer = &buffer[length]; | |
169 | buffer_size -= length; | |
170 | ||
312c004d | 171 | if (dev->bus && dev->bus->uevent) { |
1da177e4 | 172 | /* have the bus specific function add its stuff */ |
312c004d | 173 | retval = dev->bus->uevent(dev, envp, num_envp, buffer, buffer_size); |
1da177e4 | 174 | if (retval) { |
312c004d | 175 | pr_debug ("%s - uevent() returned %d\n", |
1da177e4 LT |
176 | __FUNCTION__, retval); |
177 | } | |
178 | } | |
179 | ||
180 | return retval; | |
181 | } | |
182 | ||
312c004d KS |
183 | static struct kset_uevent_ops device_uevent_ops = { |
184 | .filter = dev_uevent_filter, | |
185 | .name = dev_uevent_name, | |
186 | .uevent = dev_uevent, | |
1da177e4 LT |
187 | }; |
188 | ||
a7fd6706 KS |
189 | static ssize_t store_uevent(struct device *dev, struct device_attribute *attr, |
190 | const char *buf, size_t count) | |
191 | { | |
312c004d | 192 | kobject_uevent(&dev->kobj, KOBJ_ADD); |
a7fd6706 KS |
193 | return count; |
194 | } | |
195 | ||
23681e47 GKH |
196 | static ssize_t show_dev(struct device *dev, struct device_attribute *attr, |
197 | char *buf) | |
198 | { | |
199 | return print_dev_t(buf, dev->devt); | |
200 | } | |
201 | ||
0863afb3 MW |
202 | /* |
203 | * devices_subsys - structure to be registered with kobject core. | |
1da177e4 LT |
204 | */ |
205 | ||
312c004d | 206 | decl_subsys(devices, &ktype_device, &device_uevent_ops); |
1da177e4 LT |
207 | |
208 | ||
209 | /** | |
210 | * device_create_file - create sysfs attribute file for device. | |
211 | * @dev: device. | |
212 | * @attr: device attribute descriptor. | |
213 | */ | |
214 | ||
215 | int device_create_file(struct device * dev, struct device_attribute * attr) | |
216 | { | |
217 | int error = 0; | |
218 | if (get_device(dev)) { | |
219 | error = sysfs_create_file(&dev->kobj, &attr->attr); | |
220 | put_device(dev); | |
221 | } | |
222 | return error; | |
223 | } | |
224 | ||
225 | /** | |
226 | * device_remove_file - remove sysfs attribute file. | |
227 | * @dev: device. | |
228 | * @attr: device attribute descriptor. | |
229 | */ | |
230 | ||
231 | void device_remove_file(struct device * dev, struct device_attribute * attr) | |
232 | { | |
233 | if (get_device(dev)) { | |
234 | sysfs_remove_file(&dev->kobj, &attr->attr); | |
235 | put_device(dev); | |
236 | } | |
237 | } | |
238 | ||
34bb61f9 JB |
239 | static void klist_children_get(struct klist_node *n) |
240 | { | |
241 | struct device *dev = container_of(n, struct device, knode_parent); | |
242 | ||
243 | get_device(dev); | |
244 | } | |
245 | ||
246 | static void klist_children_put(struct klist_node *n) | |
247 | { | |
248 | struct device *dev = container_of(n, struct device, knode_parent); | |
249 | ||
250 | put_device(dev); | |
251 | } | |
252 | ||
1da177e4 LT |
253 | |
254 | /** | |
255 | * device_initialize - init device structure. | |
256 | * @dev: device. | |
257 | * | |
258 | * This prepares the device for use by other layers, | |
259 | * including adding it to the device hierarchy. | |
260 | * It is the first half of device_register(), if called by | |
261 | * that, though it can also be called separately, so one | |
262 | * may use @dev's fields (e.g. the refcount). | |
263 | */ | |
264 | ||
265 | void device_initialize(struct device *dev) | |
266 | { | |
267 | kobj_set_kset_s(dev, devices_subsys); | |
268 | kobject_init(&dev->kobj); | |
34bb61f9 JB |
269 | klist_init(&dev->klist_children, klist_children_get, |
270 | klist_children_put); | |
1da177e4 | 271 | INIT_LIST_HEAD(&dev->dma_pools); |
23681e47 | 272 | INIT_LIST_HEAD(&dev->node); |
af70316a | 273 | init_MUTEX(&dev->sem); |
0ac85241 | 274 | device_init_wakeup(dev, 0); |
1da177e4 LT |
275 | } |
276 | ||
277 | /** | |
278 | * device_add - add device to device hierarchy. | |
279 | * @dev: device. | |
280 | * | |
281 | * This is part 2 of device_register(), though may be called | |
282 | * separately _iff_ device_initialize() has been called separately. | |
283 | * | |
284 | * This adds it to the kobject hierarchy via kobject_add(), adds it | |
285 | * to the global and sibling lists for the device, then | |
286 | * adds it to the other relevant subsystems of the driver model. | |
287 | */ | |
288 | int device_add(struct device *dev) | |
289 | { | |
290 | struct device *parent = NULL; | |
e9a7d305 | 291 | char *class_name = NULL; |
1da177e4 LT |
292 | int error = -EINVAL; |
293 | ||
294 | dev = get_device(dev); | |
295 | if (!dev || !strlen(dev->bus_id)) | |
296 | goto Error; | |
297 | ||
298 | parent = get_device(dev->parent); | |
299 | ||
300 | pr_debug("DEV: registering device: ID = '%s'\n", dev->bus_id); | |
301 | ||
302 | /* first, register with generic layer. */ | |
303 | kobject_set_name(&dev->kobj, "%s", dev->bus_id); | |
304 | if (parent) | |
305 | dev->kobj.parent = &parent->kobj; | |
306 | ||
307 | if ((error = kobject_add(&dev->kobj))) | |
308 | goto Error; | |
a7fd6706 KS |
309 | |
310 | dev->uevent_attr.attr.name = "uevent"; | |
311 | dev->uevent_attr.attr.mode = S_IWUSR; | |
312 | if (dev->driver) | |
313 | dev->uevent_attr.attr.owner = dev->driver->owner; | |
314 | dev->uevent_attr.store = store_uevent; | |
315 | device_create_file(dev, &dev->uevent_attr); | |
316 | ||
23681e47 GKH |
317 | if (MAJOR(dev->devt)) { |
318 | struct device_attribute *attr; | |
319 | attr = kzalloc(sizeof(*attr), GFP_KERNEL); | |
320 | if (!attr) { | |
321 | error = -ENOMEM; | |
322 | goto PMError; | |
323 | } | |
324 | attr->attr.name = "dev"; | |
325 | attr->attr.mode = S_IRUGO; | |
326 | if (dev->driver) | |
327 | attr->attr.owner = dev->driver->owner; | |
328 | attr->show = show_dev; | |
329 | error = device_create_file(dev, attr); | |
330 | if (error) { | |
331 | kfree(attr); | |
332 | goto attrError; | |
333 | } | |
334 | ||
335 | dev->devt_attr = attr; | |
336 | } | |
337 | ||
b9d9c82b KS |
338 | if (dev->class) { |
339 | sysfs_create_link(&dev->kobj, &dev->class->subsys.kset.kobj, | |
340 | "subsystem"); | |
23681e47 GKH |
341 | sysfs_create_link(&dev->class->subsys.kset.kobj, &dev->kobj, |
342 | dev->bus_id); | |
e9a7d305 GKH |
343 | |
344 | sysfs_create_link(&dev->kobj, &dev->parent->kobj, "device"); | |
345 | class_name = make_class_name(dev->class->name, &dev->kobj); | |
346 | sysfs_create_link(&dev->parent->kobj, &dev->kobj, class_name); | |
b9d9c82b | 347 | } |
23681e47 | 348 | |
1da177e4 LT |
349 | if ((error = device_pm_add(dev))) |
350 | goto PMError; | |
351 | if ((error = bus_add_device(dev))) | |
352 | goto BusError; | |
53877d06 KS |
353 | kobject_uevent(&dev->kobj, KOBJ_ADD); |
354 | bus_attach_device(dev); | |
1da177e4 | 355 | if (parent) |
d856f1e3 | 356 | klist_add_tail(&dev->knode_parent, &parent->klist_children); |
1da177e4 | 357 | |
5d9fd169 GKH |
358 | if (dev->class) { |
359 | /* tie the class to the device */ | |
360 | down(&dev->class->sem); | |
361 | list_add_tail(&dev->node, &dev->class->devices); | |
362 | up(&dev->class->sem); | |
363 | } | |
364 | ||
1da177e4 LT |
365 | /* notify platform of device entry */ |
366 | if (platform_notify) | |
367 | platform_notify(dev); | |
368 | Done: | |
e9a7d305 | 369 | kfree(class_name); |
1da177e4 LT |
370 | put_device(dev); |
371 | return error; | |
372 | BusError: | |
373 | device_pm_remove(dev); | |
374 | PMError: | |
23681e47 GKH |
375 | if (dev->devt_attr) { |
376 | device_remove_file(dev, dev->devt_attr); | |
377 | kfree(dev->devt_attr); | |
378 | } | |
379 | attrError: | |
312c004d | 380 | kobject_uevent(&dev->kobj, KOBJ_REMOVE); |
1da177e4 LT |
381 | kobject_del(&dev->kobj); |
382 | Error: | |
383 | if (parent) | |
384 | put_device(parent); | |
385 | goto Done; | |
386 | } | |
387 | ||
388 | ||
389 | /** | |
390 | * device_register - register a device with the system. | |
391 | * @dev: pointer to the device structure | |
392 | * | |
393 | * This happens in two clean steps - initialize the device | |
394 | * and add it to the system. The two steps can be called | |
395 | * separately, but this is the easiest and most common. | |
396 | * I.e. you should only call the two helpers separately if | |
397 | * have a clearly defined need to use and refcount the device | |
398 | * before it is added to the hierarchy. | |
399 | */ | |
400 | ||
401 | int device_register(struct device *dev) | |
402 | { | |
403 | device_initialize(dev); | |
404 | return device_add(dev); | |
405 | } | |
406 | ||
407 | ||
408 | /** | |
409 | * get_device - increment reference count for device. | |
410 | * @dev: device. | |
411 | * | |
412 | * This simply forwards the call to kobject_get(), though | |
413 | * we do take care to provide for the case that we get a NULL | |
414 | * pointer passed in. | |
415 | */ | |
416 | ||
417 | struct device * get_device(struct device * dev) | |
418 | { | |
419 | return dev ? to_dev(kobject_get(&dev->kobj)) : NULL; | |
420 | } | |
421 | ||
422 | ||
423 | /** | |
424 | * put_device - decrement reference count. | |
425 | * @dev: device in question. | |
426 | */ | |
427 | void put_device(struct device * dev) | |
428 | { | |
429 | if (dev) | |
430 | kobject_put(&dev->kobj); | |
431 | } | |
432 | ||
433 | ||
434 | /** | |
435 | * device_del - delete device from system. | |
436 | * @dev: device. | |
437 | * | |
438 | * This is the first part of the device unregistration | |
439 | * sequence. This removes the device from the lists we control | |
440 | * from here, has it removed from the other driver model | |
441 | * subsystems it was added to in device_add(), and removes it | |
442 | * from the kobject hierarchy. | |
443 | * | |
444 | * NOTE: this should be called manually _iff_ device_add() was | |
445 | * also called manually. | |
446 | */ | |
447 | ||
448 | void device_del(struct device * dev) | |
449 | { | |
450 | struct device * parent = dev->parent; | |
e9a7d305 | 451 | char *class_name = NULL; |
1da177e4 | 452 | |
1da177e4 | 453 | if (parent) |
d62c0f9f | 454 | klist_del(&dev->knode_parent); |
23681e47 GKH |
455 | if (dev->devt_attr) |
456 | device_remove_file(dev, dev->devt_attr); | |
b9d9c82b KS |
457 | if (dev->class) { |
458 | sysfs_remove_link(&dev->kobj, "subsystem"); | |
23681e47 | 459 | sysfs_remove_link(&dev->class->subsys.kset.kobj, dev->bus_id); |
e9a7d305 GKH |
460 | class_name = make_class_name(dev->class->name, &dev->kobj); |
461 | sysfs_remove_link(&dev->kobj, "device"); | |
462 | sysfs_remove_link(&dev->parent->kobj, class_name); | |
463 | kfree(class_name); | |
5d9fd169 GKH |
464 | down(&dev->class->sem); |
465 | list_del_init(&dev->node); | |
466 | up(&dev->class->sem); | |
b9d9c82b | 467 | } |
a7fd6706 | 468 | device_remove_file(dev, &dev->uevent_attr); |
1da177e4 LT |
469 | |
470 | /* Notify the platform of the removal, in case they | |
471 | * need to do anything... | |
472 | */ | |
473 | if (platform_notify_remove) | |
474 | platform_notify_remove(dev); | |
475 | bus_remove_device(dev); | |
476 | device_pm_remove(dev); | |
312c004d | 477 | kobject_uevent(&dev->kobj, KOBJ_REMOVE); |
1da177e4 LT |
478 | kobject_del(&dev->kobj); |
479 | if (parent) | |
480 | put_device(parent); | |
481 | } | |
482 | ||
483 | /** | |
484 | * device_unregister - unregister device from system. | |
485 | * @dev: device going away. | |
486 | * | |
487 | * We do this in two parts, like we do device_register(). First, | |
488 | * we remove it from all the subsystems with device_del(), then | |
489 | * we decrement the reference count via put_device(). If that | |
490 | * is the final reference count, the device will be cleaned up | |
491 | * via device_release() above. Otherwise, the structure will | |
492 | * stick around until the final reference to the device is dropped. | |
493 | */ | |
494 | void device_unregister(struct device * dev) | |
495 | { | |
496 | pr_debug("DEV: Unregistering device. ID = '%s'\n", dev->bus_id); | |
497 | device_del(dev); | |
498 | put_device(dev); | |
499 | } | |
500 | ||
501 | ||
36239577 PM |
502 | static struct device * next_device(struct klist_iter * i) |
503 | { | |
504 | struct klist_node * n = klist_next(i); | |
505 | return n ? container_of(n, struct device, knode_parent) : NULL; | |
506 | } | |
507 | ||
1da177e4 LT |
508 | /** |
509 | * device_for_each_child - device child iterator. | |
c41455fb | 510 | * @parent: parent struct device. |
1da177e4 LT |
511 | * @data: data for the callback. |
512 | * @fn: function to be called for each device. | |
513 | * | |
c41455fb | 514 | * Iterate over @parent's child devices, and call @fn for each, |
1da177e4 LT |
515 | * passing it @data. |
516 | * | |
517 | * We check the return of @fn each time. If it returns anything | |
518 | * other than 0, we break out and return that value. | |
519 | */ | |
36239577 | 520 | int device_for_each_child(struct device * parent, void * data, |
1da177e4 LT |
521 | int (*fn)(struct device *, void *)) |
522 | { | |
36239577 | 523 | struct klist_iter i; |
1da177e4 LT |
524 | struct device * child; |
525 | int error = 0; | |
526 | ||
36239577 PM |
527 | klist_iter_init(&parent->klist_children, &i); |
528 | while ((child = next_device(&i)) && !error) | |
529 | error = fn(child, data); | |
530 | klist_iter_exit(&i); | |
1da177e4 LT |
531 | return error; |
532 | } | |
533 | ||
1da177e4 LT |
534 | int __init devices_init(void) |
535 | { | |
536 | return subsystem_register(&devices_subsys); | |
537 | } | |
538 | ||
539 | EXPORT_SYMBOL_GPL(device_for_each_child); | |
540 | ||
541 | EXPORT_SYMBOL_GPL(device_initialize); | |
542 | EXPORT_SYMBOL_GPL(device_add); | |
543 | EXPORT_SYMBOL_GPL(device_register); | |
544 | ||
545 | EXPORT_SYMBOL_GPL(device_del); | |
546 | EXPORT_SYMBOL_GPL(device_unregister); | |
547 | EXPORT_SYMBOL_GPL(get_device); | |
548 | EXPORT_SYMBOL_GPL(put_device); | |
1da177e4 LT |
549 | |
550 | EXPORT_SYMBOL_GPL(device_create_file); | |
551 | EXPORT_SYMBOL_GPL(device_remove_file); | |
23681e47 GKH |
552 | |
553 | ||
554 | static void device_create_release(struct device *dev) | |
555 | { | |
556 | pr_debug("%s called for %s\n", __FUNCTION__, dev->bus_id); | |
557 | kfree(dev); | |
558 | } | |
559 | ||
560 | /** | |
561 | * device_create - creates a device and registers it with sysfs | |
42734daf HK |
562 | * @class: pointer to the struct class that this device should be registered to |
563 | * @parent: pointer to the parent struct device of this new device, if any | |
564 | * @devt: the dev_t for the char device to be added | |
565 | * @fmt: string for the device's name | |
566 | * | |
567 | * This function can be used by char device classes. A struct device | |
568 | * will be created in sysfs, registered to the specified class. | |
23681e47 | 569 | * |
23681e47 GKH |
570 | * A "dev" file will be created, showing the dev_t for the device, if |
571 | * the dev_t is not 0,0. | |
42734daf HK |
572 | * If a pointer to a parent struct device is passed in, the newly created |
573 | * struct device will be a child of that device in sysfs. | |
574 | * The pointer to the struct device will be returned from the call. | |
575 | * Any further sysfs files that might be required can be created using this | |
23681e47 GKH |
576 | * pointer. |
577 | * | |
578 | * Note: the struct class passed to this function must have previously | |
579 | * been created with a call to class_create(). | |
580 | */ | |
581 | struct device *device_create(struct class *class, struct device *parent, | |
582 | dev_t devt, char *fmt, ...) | |
583 | { | |
584 | va_list args; | |
585 | struct device *dev = NULL; | |
586 | int retval = -ENODEV; | |
587 | ||
588 | if (class == NULL || IS_ERR(class)) | |
589 | goto error; | |
590 | if (parent == NULL) { | |
591 | printk(KERN_WARNING "%s does not work yet for NULL parents\n", __FUNCTION__); | |
592 | goto error; | |
593 | } | |
594 | ||
595 | dev = kzalloc(sizeof(*dev), GFP_KERNEL); | |
596 | if (!dev) { | |
597 | retval = -ENOMEM; | |
598 | goto error; | |
599 | } | |
600 | ||
601 | dev->devt = devt; | |
602 | dev->class = class; | |
603 | dev->parent = parent; | |
604 | dev->release = device_create_release; | |
605 | ||
606 | va_start(args, fmt); | |
607 | vsnprintf(dev->bus_id, BUS_ID_SIZE, fmt, args); | |
608 | va_end(args); | |
609 | retval = device_register(dev); | |
610 | if (retval) | |
611 | goto error; | |
612 | ||
23681e47 GKH |
613 | return dev; |
614 | ||
615 | error: | |
616 | kfree(dev); | |
617 | return ERR_PTR(retval); | |
618 | } | |
619 | EXPORT_SYMBOL_GPL(device_create); | |
620 | ||
621 | /** | |
622 | * device_destroy - removes a device that was created with device_create() | |
42734daf HK |
623 | * @class: pointer to the struct class that this device was registered with |
624 | * @devt: the dev_t of the device that was previously registered | |
23681e47 | 625 | * |
42734daf HK |
626 | * This call unregisters and cleans up a device that was created with a |
627 | * call to device_create(). | |
23681e47 GKH |
628 | */ |
629 | void device_destroy(struct class *class, dev_t devt) | |
630 | { | |
631 | struct device *dev = NULL; | |
632 | struct device *dev_tmp; | |
633 | ||
634 | down(&class->sem); | |
635 | list_for_each_entry(dev_tmp, &class->devices, node) { | |
636 | if (dev_tmp->devt == devt) { | |
637 | dev = dev_tmp; | |
638 | break; | |
639 | } | |
640 | } | |
641 | up(&class->sem); | |
642 | ||
5d9fd169 | 643 | if (dev) |
23681e47 | 644 | device_unregister(dev); |
23681e47 GKH |
645 | } |
646 | EXPORT_SYMBOL_GPL(device_destroy); |