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1 | /* | |
2 | * bus.c - bus driver management | |
3 | * | |
4 | * Copyright (c) 2002-3 Patrick Mochel | |
5 | * Copyright (c) 2002-3 Open Source Development Labs | |
6 | * Copyright (c) 2007 Greg Kroah-Hartman <gregkh@suse.de> | |
7 | * Copyright (c) 2007 Novell Inc. | |
8 | * | |
9 | * This file is released under the GPLv2 | |
10 | * | |
11 | */ | |
12 | ||
13 | #include <linux/device.h> | |
14 | #include <linux/module.h> | |
15 | #include <linux/errno.h> | |
16 | #include <linux/slab.h> | |
17 | #include <linux/init.h> | |
18 | #include <linux/string.h> | |
19 | #include <linux/mutex.h> | |
20 | #include "base.h" | |
21 | #include "power/power.h" | |
22 | ||
23 | /* /sys/devices/system */ | |
24 | static struct kset *system_kset; | |
25 | ||
26 | #define to_bus_attr(_attr) container_of(_attr, struct bus_attribute, attr) | |
27 | ||
28 | /* | |
29 | * sysfs bindings for drivers | |
30 | */ | |
31 | ||
32 | #define to_drv_attr(_attr) container_of(_attr, struct driver_attribute, attr) | |
33 | ||
34 | ||
35 | static int __must_check bus_rescan_devices_helper(struct device *dev, | |
36 | void *data); | |
37 | ||
38 | static struct bus_type *bus_get(struct bus_type *bus) | |
39 | { | |
40 | if (bus) { | |
41 | kset_get(&bus->p->subsys); | |
42 | return bus; | |
43 | } | |
44 | return NULL; | |
45 | } | |
46 | ||
47 | static void bus_put(struct bus_type *bus) | |
48 | { | |
49 | if (bus) | |
50 | kset_put(&bus->p->subsys); | |
51 | } | |
52 | ||
53 | static ssize_t drv_attr_show(struct kobject *kobj, struct attribute *attr, | |
54 | char *buf) | |
55 | { | |
56 | struct driver_attribute *drv_attr = to_drv_attr(attr); | |
57 | struct driver_private *drv_priv = to_driver(kobj); | |
58 | ssize_t ret = -EIO; | |
59 | ||
60 | if (drv_attr->show) | |
61 | ret = drv_attr->show(drv_priv->driver, buf); | |
62 | return ret; | |
63 | } | |
64 | ||
65 | static ssize_t drv_attr_store(struct kobject *kobj, struct attribute *attr, | |
66 | const char *buf, size_t count) | |
67 | { | |
68 | struct driver_attribute *drv_attr = to_drv_attr(attr); | |
69 | struct driver_private *drv_priv = to_driver(kobj); | |
70 | ssize_t ret = -EIO; | |
71 | ||
72 | if (drv_attr->store) | |
73 | ret = drv_attr->store(drv_priv->driver, buf, count); | |
74 | return ret; | |
75 | } | |
76 | ||
77 | static const struct sysfs_ops driver_sysfs_ops = { | |
78 | .show = drv_attr_show, | |
79 | .store = drv_attr_store, | |
80 | }; | |
81 | ||
82 | static void driver_release(struct kobject *kobj) | |
83 | { | |
84 | struct driver_private *drv_priv = to_driver(kobj); | |
85 | ||
86 | pr_debug("driver: '%s': %s\n", kobject_name(kobj), __func__); | |
87 | kfree(drv_priv); | |
88 | } | |
89 | ||
90 | static struct kobj_type driver_ktype = { | |
91 | .sysfs_ops = &driver_sysfs_ops, | |
92 | .release = driver_release, | |
93 | }; | |
94 | ||
95 | /* | |
96 | * sysfs bindings for buses | |
97 | */ | |
98 | static ssize_t bus_attr_show(struct kobject *kobj, struct attribute *attr, | |
99 | char *buf) | |
100 | { | |
101 | struct bus_attribute *bus_attr = to_bus_attr(attr); | |
102 | struct subsys_private *subsys_priv = to_subsys_private(kobj); | |
103 | ssize_t ret = 0; | |
104 | ||
105 | if (bus_attr->show) | |
106 | ret = bus_attr->show(subsys_priv->bus, buf); | |
107 | return ret; | |
108 | } | |
109 | ||
110 | static ssize_t bus_attr_store(struct kobject *kobj, struct attribute *attr, | |
111 | const char *buf, size_t count) | |
112 | { | |
113 | struct bus_attribute *bus_attr = to_bus_attr(attr); | |
114 | struct subsys_private *subsys_priv = to_subsys_private(kobj); | |
115 | ssize_t ret = 0; | |
116 | ||
117 | if (bus_attr->store) | |
118 | ret = bus_attr->store(subsys_priv->bus, buf, count); | |
119 | return ret; | |
120 | } | |
121 | ||
122 | static const struct sysfs_ops bus_sysfs_ops = { | |
123 | .show = bus_attr_show, | |
124 | .store = bus_attr_store, | |
125 | }; | |
126 | ||
127 | int bus_create_file(struct bus_type *bus, struct bus_attribute *attr) | |
128 | { | |
129 | int error; | |
130 | if (bus_get(bus)) { | |
131 | error = sysfs_create_file(&bus->p->subsys.kobj, &attr->attr); | |
132 | bus_put(bus); | |
133 | } else | |
134 | error = -EINVAL; | |
135 | return error; | |
136 | } | |
137 | EXPORT_SYMBOL_GPL(bus_create_file); | |
138 | ||
139 | void bus_remove_file(struct bus_type *bus, struct bus_attribute *attr) | |
140 | { | |
141 | if (bus_get(bus)) { | |
142 | sysfs_remove_file(&bus->p->subsys.kobj, &attr->attr); | |
143 | bus_put(bus); | |
144 | } | |
145 | } | |
146 | EXPORT_SYMBOL_GPL(bus_remove_file); | |
147 | ||
148 | static struct kobj_type bus_ktype = { | |
149 | .sysfs_ops = &bus_sysfs_ops, | |
150 | }; | |
151 | ||
152 | static int bus_uevent_filter(struct kset *kset, struct kobject *kobj) | |
153 | { | |
154 | struct kobj_type *ktype = get_ktype(kobj); | |
155 | ||
156 | if (ktype == &bus_ktype) | |
157 | return 1; | |
158 | return 0; | |
159 | } | |
160 | ||
161 | static const struct kset_uevent_ops bus_uevent_ops = { | |
162 | .filter = bus_uevent_filter, | |
163 | }; | |
164 | ||
165 | static struct kset *bus_kset; | |
166 | ||
167 | /* Manually detach a device from its associated driver. */ | |
168 | static ssize_t driver_unbind(struct device_driver *drv, | |
169 | const char *buf, size_t count) | |
170 | { | |
171 | struct bus_type *bus = bus_get(drv->bus); | |
172 | struct device *dev; | |
173 | int err = -ENODEV; | |
174 | ||
175 | dev = bus_find_device_by_name(bus, NULL, buf); | |
176 | if (dev && dev->driver == drv) { | |
177 | if (dev->parent) /* Needed for USB */ | |
178 | device_lock(dev->parent); | |
179 | device_release_driver(dev); | |
180 | if (dev->parent) | |
181 | device_unlock(dev->parent); | |
182 | err = count; | |
183 | } | |
184 | put_device(dev); | |
185 | bus_put(bus); | |
186 | return err; | |
187 | } | |
188 | static DRIVER_ATTR(unbind, S_IWUSR, NULL, driver_unbind); | |
189 | ||
190 | /* | |
191 | * Manually attach a device to a driver. | |
192 | * Note: the driver must want to bind to the device, | |
193 | * it is not possible to override the driver's id table. | |
194 | */ | |
195 | static ssize_t driver_bind(struct device_driver *drv, | |
196 | const char *buf, size_t count) | |
197 | { | |
198 | struct bus_type *bus = bus_get(drv->bus); | |
199 | struct device *dev; | |
200 | int err = -ENODEV; | |
201 | ||
202 | dev = bus_find_device_by_name(bus, NULL, buf); | |
203 | if (dev && dev->driver == NULL && driver_match_device(drv, dev)) { | |
204 | if (dev->parent) /* Needed for USB */ | |
205 | device_lock(dev->parent); | |
206 | device_lock(dev); | |
207 | err = driver_probe_device(drv, dev); | |
208 | device_unlock(dev); | |
209 | if (dev->parent) | |
210 | device_unlock(dev->parent); | |
211 | ||
212 | if (err > 0) { | |
213 | /* success */ | |
214 | err = count; | |
215 | } else if (err == 0) { | |
216 | /* driver didn't accept device */ | |
217 | err = -ENODEV; | |
218 | } | |
219 | } | |
220 | put_device(dev); | |
221 | bus_put(bus); | |
222 | return err; | |
223 | } | |
224 | static DRIVER_ATTR(bind, S_IWUSR, NULL, driver_bind); | |
225 | ||
226 | static ssize_t show_drivers_autoprobe(struct bus_type *bus, char *buf) | |
227 | { | |
228 | return sprintf(buf, "%d\n", bus->p->drivers_autoprobe); | |
229 | } | |
230 | ||
231 | static ssize_t store_drivers_autoprobe(struct bus_type *bus, | |
232 | const char *buf, size_t count) | |
233 | { | |
234 | if (buf[0] == '0') | |
235 | bus->p->drivers_autoprobe = 0; | |
236 | else | |
237 | bus->p->drivers_autoprobe = 1; | |
238 | return count; | |
239 | } | |
240 | ||
241 | static ssize_t store_drivers_probe(struct bus_type *bus, | |
242 | const char *buf, size_t count) | |
243 | { | |
244 | struct device *dev; | |
245 | ||
246 | dev = bus_find_device_by_name(bus, NULL, buf); | |
247 | if (!dev) | |
248 | return -ENODEV; | |
249 | if (bus_rescan_devices_helper(dev, NULL) != 0) | |
250 | return -EINVAL; | |
251 | return count; | |
252 | } | |
253 | ||
254 | static struct device *next_device(struct klist_iter *i) | |
255 | { | |
256 | struct klist_node *n = klist_next(i); | |
257 | struct device *dev = NULL; | |
258 | struct device_private *dev_prv; | |
259 | ||
260 | if (n) { | |
261 | dev_prv = to_device_private_bus(n); | |
262 | dev = dev_prv->device; | |
263 | } | |
264 | return dev; | |
265 | } | |
266 | ||
267 | /** | |
268 | * bus_for_each_dev - device iterator. | |
269 | * @bus: bus type. | |
270 | * @start: device to start iterating from. | |
271 | * @data: data for the callback. | |
272 | * @fn: function to be called for each device. | |
273 | * | |
274 | * Iterate over @bus's list of devices, and call @fn for each, | |
275 | * passing it @data. If @start is not NULL, we use that device to | |
276 | * begin iterating from. | |
277 | * | |
278 | * We check the return of @fn each time. If it returns anything | |
279 | * other than 0, we break out and return that value. | |
280 | * | |
281 | * NOTE: The device that returns a non-zero value is not retained | |
282 | * in any way, nor is its refcount incremented. If the caller needs | |
283 | * to retain this data, it should do so, and increment the reference | |
284 | * count in the supplied callback. | |
285 | */ | |
286 | int bus_for_each_dev(struct bus_type *bus, struct device *start, | |
287 | void *data, int (*fn)(struct device *, void *)) | |
288 | { | |
289 | struct klist_iter i; | |
290 | struct device *dev; | |
291 | int error = 0; | |
292 | ||
293 | if (!bus || !bus->p) | |
294 | return -EINVAL; | |
295 | ||
296 | klist_iter_init_node(&bus->p->klist_devices, &i, | |
297 | (start ? &start->p->knode_bus : NULL)); | |
298 | while ((dev = next_device(&i)) && !error) | |
299 | error = fn(dev, data); | |
300 | klist_iter_exit(&i); | |
301 | return error; | |
302 | } | |
303 | EXPORT_SYMBOL_GPL(bus_for_each_dev); | |
304 | ||
305 | /** | |
306 | * bus_find_device - device iterator for locating a particular device. | |
307 | * @bus: bus type | |
308 | * @start: Device to begin with | |
309 | * @data: Data to pass to match function | |
310 | * @match: Callback function to check device | |
311 | * | |
312 | * This is similar to the bus_for_each_dev() function above, but it | |
313 | * returns a reference to a device that is 'found' for later use, as | |
314 | * determined by the @match callback. | |
315 | * | |
316 | * The callback should return 0 if the device doesn't match and non-zero | |
317 | * if it does. If the callback returns non-zero, this function will | |
318 | * return to the caller and not iterate over any more devices. | |
319 | */ | |
320 | struct device *bus_find_device(struct bus_type *bus, | |
321 | struct device *start, void *data, | |
322 | int (*match)(struct device *dev, void *data)) | |
323 | { | |
324 | struct klist_iter i; | |
325 | struct device *dev; | |
326 | ||
327 | if (!bus || !bus->p) | |
328 | return NULL; | |
329 | ||
330 | klist_iter_init_node(&bus->p->klist_devices, &i, | |
331 | (start ? &start->p->knode_bus : NULL)); | |
332 | while ((dev = next_device(&i))) | |
333 | if (match(dev, data) && get_device(dev)) | |
334 | break; | |
335 | klist_iter_exit(&i); | |
336 | return dev; | |
337 | } | |
338 | EXPORT_SYMBOL_GPL(bus_find_device); | |
339 | ||
340 | static int match_name(struct device *dev, void *data) | |
341 | { | |
342 | const char *name = data; | |
343 | ||
344 | return sysfs_streq(name, dev_name(dev)); | |
345 | } | |
346 | ||
347 | /** | |
348 | * bus_find_device_by_name - device iterator for locating a particular device of a specific name | |
349 | * @bus: bus type | |
350 | * @start: Device to begin with | |
351 | * @name: name of the device to match | |
352 | * | |
353 | * This is similar to the bus_find_device() function above, but it handles | |
354 | * searching by a name automatically, no need to write another strcmp matching | |
355 | * function. | |
356 | */ | |
357 | struct device *bus_find_device_by_name(struct bus_type *bus, | |
358 | struct device *start, const char *name) | |
359 | { | |
360 | return bus_find_device(bus, start, (void *)name, match_name); | |
361 | } | |
362 | EXPORT_SYMBOL_GPL(bus_find_device_by_name); | |
363 | ||
364 | /** | |
365 | * subsys_find_device_by_id - find a device with a specific enumeration number | |
366 | * @subsys: subsystem | |
367 | * @id: index 'id' in struct device | |
368 | * @hint: device to check first | |
369 | * | |
370 | * Check the hint's next object and if it is a match return it directly, | |
371 | * otherwise, fall back to a full list search. Either way a reference for | |
372 | * the returned object is taken. | |
373 | */ | |
374 | struct device *subsys_find_device_by_id(struct bus_type *subsys, unsigned int id, | |
375 | struct device *hint) | |
376 | { | |
377 | struct klist_iter i; | |
378 | struct device *dev; | |
379 | ||
380 | if (!subsys) | |
381 | return NULL; | |
382 | ||
383 | if (hint) { | |
384 | klist_iter_init_node(&subsys->p->klist_devices, &i, &hint->p->knode_bus); | |
385 | dev = next_device(&i); | |
386 | if (dev && dev->id == id && get_device(dev)) { | |
387 | klist_iter_exit(&i); | |
388 | return dev; | |
389 | } | |
390 | klist_iter_exit(&i); | |
391 | } | |
392 | ||
393 | klist_iter_init_node(&subsys->p->klist_devices, &i, NULL); | |
394 | while ((dev = next_device(&i))) { | |
395 | if (dev->id == id && get_device(dev)) { | |
396 | klist_iter_exit(&i); | |
397 | return dev; | |
398 | } | |
399 | } | |
400 | klist_iter_exit(&i); | |
401 | return NULL; | |
402 | } | |
403 | EXPORT_SYMBOL_GPL(subsys_find_device_by_id); | |
404 | ||
405 | static struct device_driver *next_driver(struct klist_iter *i) | |
406 | { | |
407 | struct klist_node *n = klist_next(i); | |
408 | struct driver_private *drv_priv; | |
409 | ||
410 | if (n) { | |
411 | drv_priv = container_of(n, struct driver_private, knode_bus); | |
412 | return drv_priv->driver; | |
413 | } | |
414 | return NULL; | |
415 | } | |
416 | ||
417 | /** | |
418 | * bus_for_each_drv - driver iterator | |
419 | * @bus: bus we're dealing with. | |
420 | * @start: driver to start iterating on. | |
421 | * @data: data to pass to the callback. | |
422 | * @fn: function to call for each driver. | |
423 | * | |
424 | * This is nearly identical to the device iterator above. | |
425 | * We iterate over each driver that belongs to @bus, and call | |
426 | * @fn for each. If @fn returns anything but 0, we break out | |
427 | * and return it. If @start is not NULL, we use it as the head | |
428 | * of the list. | |
429 | * | |
430 | * NOTE: we don't return the driver that returns a non-zero | |
431 | * value, nor do we leave the reference count incremented for that | |
432 | * driver. If the caller needs to know that info, it must set it | |
433 | * in the callback. It must also be sure to increment the refcount | |
434 | * so it doesn't disappear before returning to the caller. | |
435 | */ | |
436 | int bus_for_each_drv(struct bus_type *bus, struct device_driver *start, | |
437 | void *data, int (*fn)(struct device_driver *, void *)) | |
438 | { | |
439 | struct klist_iter i; | |
440 | struct device_driver *drv; | |
441 | int error = 0; | |
442 | ||
443 | if (!bus) | |
444 | return -EINVAL; | |
445 | ||
446 | klist_iter_init_node(&bus->p->klist_drivers, &i, | |
447 | start ? &start->p->knode_bus : NULL); | |
448 | while ((drv = next_driver(&i)) && !error) | |
449 | error = fn(drv, data); | |
450 | klist_iter_exit(&i); | |
451 | return error; | |
452 | } | |
453 | EXPORT_SYMBOL_GPL(bus_for_each_drv); | |
454 | ||
455 | static int device_add_attrs(struct bus_type *bus, struct device *dev) | |
456 | { | |
457 | int error = 0; | |
458 | int i; | |
459 | ||
460 | if (!bus->dev_attrs) | |
461 | return 0; | |
462 | ||
463 | for (i = 0; attr_name(bus->dev_attrs[i]); i++) { | |
464 | error = device_create_file(dev, &bus->dev_attrs[i]); | |
465 | if (error) { | |
466 | while (--i >= 0) | |
467 | device_remove_file(dev, &bus->dev_attrs[i]); | |
468 | break; | |
469 | } | |
470 | } | |
471 | return error; | |
472 | } | |
473 | ||
474 | static void device_remove_attrs(struct bus_type *bus, struct device *dev) | |
475 | { | |
476 | int i; | |
477 | ||
478 | if (bus->dev_attrs) { | |
479 | for (i = 0; attr_name(bus->dev_attrs[i]); i++) | |
480 | device_remove_file(dev, &bus->dev_attrs[i]); | |
481 | } | |
482 | } | |
483 | ||
484 | /** | |
485 | * bus_add_device - add device to bus | |
486 | * @dev: device being added | |
487 | * | |
488 | * - Add device's bus attributes. | |
489 | * - Create links to device's bus. | |
490 | * - Add the device to its bus's list of devices. | |
491 | */ | |
492 | int bus_add_device(struct device *dev) | |
493 | { | |
494 | struct bus_type *bus = bus_get(dev->bus); | |
495 | int error = 0; | |
496 | ||
497 | if (bus) { | |
498 | pr_debug("bus: '%s': add device %s\n", bus->name, dev_name(dev)); | |
499 | error = device_add_attrs(bus, dev); | |
500 | if (error) | |
501 | goto out_put; | |
502 | error = sysfs_create_link(&bus->p->devices_kset->kobj, | |
503 | &dev->kobj, dev_name(dev)); | |
504 | if (error) | |
505 | goto out_id; | |
506 | error = sysfs_create_link(&dev->kobj, | |
507 | &dev->bus->p->subsys.kobj, "subsystem"); | |
508 | if (error) | |
509 | goto out_subsys; | |
510 | klist_add_tail(&dev->p->knode_bus, &bus->p->klist_devices); | |
511 | } | |
512 | return 0; | |
513 | ||
514 | out_subsys: | |
515 | sysfs_remove_link(&bus->p->devices_kset->kobj, dev_name(dev)); | |
516 | out_id: | |
517 | device_remove_attrs(bus, dev); | |
518 | out_put: | |
519 | bus_put(dev->bus); | |
520 | return error; | |
521 | } | |
522 | ||
523 | /** | |
524 | * bus_probe_device - probe drivers for a new device | |
525 | * @dev: device to probe | |
526 | * | |
527 | * - Automatically probe for a driver if the bus allows it. | |
528 | */ | |
529 | void bus_probe_device(struct device *dev) | |
530 | { | |
531 | struct bus_type *bus = dev->bus; | |
532 | struct subsys_interface *sif; | |
533 | int ret; | |
534 | ||
535 | if (!bus) | |
536 | return; | |
537 | ||
538 | if (bus->p->drivers_autoprobe) { | |
539 | ret = device_attach(dev); | |
540 | WARN_ON(ret < 0); | |
541 | } | |
542 | ||
543 | mutex_lock(&bus->p->mutex); | |
544 | list_for_each_entry(sif, &bus->p->interfaces, node) | |
545 | if (sif->add_dev) | |
546 | sif->add_dev(dev, sif); | |
547 | mutex_unlock(&bus->p->mutex); | |
548 | } | |
549 | ||
550 | /** | |
551 | * bus_remove_device - remove device from bus | |
552 | * @dev: device to be removed | |
553 | * | |
554 | * - Remove device from all interfaces. | |
555 | * - Remove symlink from bus' directory. | |
556 | * - Delete device from bus's list. | |
557 | * - Detach from its driver. | |
558 | * - Drop reference taken in bus_add_device(). | |
559 | */ | |
560 | void bus_remove_device(struct device *dev) | |
561 | { | |
562 | struct bus_type *bus = dev->bus; | |
563 | struct subsys_interface *sif; | |
564 | ||
565 | if (!bus) | |
566 | return; | |
567 | ||
568 | mutex_lock(&bus->p->mutex); | |
569 | list_for_each_entry(sif, &bus->p->interfaces, node) | |
570 | if (sif->remove_dev) | |
571 | sif->remove_dev(dev, sif); | |
572 | mutex_unlock(&bus->p->mutex); | |
573 | ||
574 | sysfs_remove_link(&dev->kobj, "subsystem"); | |
575 | sysfs_remove_link(&dev->bus->p->devices_kset->kobj, | |
576 | dev_name(dev)); | |
577 | device_remove_attrs(dev->bus, dev); | |
578 | if (klist_node_attached(&dev->p->knode_bus)) | |
579 | klist_del(&dev->p->knode_bus); | |
580 | ||
581 | pr_debug("bus: '%s': remove device %s\n", | |
582 | dev->bus->name, dev_name(dev)); | |
583 | device_release_driver(dev); | |
584 | bus_put(dev->bus); | |
585 | } | |
586 | ||
587 | static int driver_add_attrs(struct bus_type *bus, struct device_driver *drv) | |
588 | { | |
589 | int error = 0; | |
590 | int i; | |
591 | ||
592 | if (bus->drv_attrs) { | |
593 | for (i = 0; attr_name(bus->drv_attrs[i]); i++) { | |
594 | error = driver_create_file(drv, &bus->drv_attrs[i]); | |
595 | if (error) | |
596 | goto err; | |
597 | } | |
598 | } | |
599 | done: | |
600 | return error; | |
601 | err: | |
602 | while (--i >= 0) | |
603 | driver_remove_file(drv, &bus->drv_attrs[i]); | |
604 | goto done; | |
605 | } | |
606 | ||
607 | static void driver_remove_attrs(struct bus_type *bus, | |
608 | struct device_driver *drv) | |
609 | { | |
610 | int i; | |
611 | ||
612 | if (bus->drv_attrs) { | |
613 | for (i = 0; attr_name(bus->drv_attrs[i]); i++) | |
614 | driver_remove_file(drv, &bus->drv_attrs[i]); | |
615 | } | |
616 | } | |
617 | ||
618 | static int __must_check add_bind_files(struct device_driver *drv) | |
619 | { | |
620 | int ret; | |
621 | ||
622 | ret = driver_create_file(drv, &driver_attr_unbind); | |
623 | if (ret == 0) { | |
624 | ret = driver_create_file(drv, &driver_attr_bind); | |
625 | if (ret) | |
626 | driver_remove_file(drv, &driver_attr_unbind); | |
627 | } | |
628 | return ret; | |
629 | } | |
630 | ||
631 | static void remove_bind_files(struct device_driver *drv) | |
632 | { | |
633 | driver_remove_file(drv, &driver_attr_bind); | |
634 | driver_remove_file(drv, &driver_attr_unbind); | |
635 | } | |
636 | ||
637 | static BUS_ATTR(drivers_probe, S_IWUSR, NULL, store_drivers_probe); | |
638 | static BUS_ATTR(drivers_autoprobe, S_IWUSR | S_IRUGO, | |
639 | show_drivers_autoprobe, store_drivers_autoprobe); | |
640 | ||
641 | static int add_probe_files(struct bus_type *bus) | |
642 | { | |
643 | int retval; | |
644 | ||
645 | retval = bus_create_file(bus, &bus_attr_drivers_probe); | |
646 | if (retval) | |
647 | goto out; | |
648 | ||
649 | retval = bus_create_file(bus, &bus_attr_drivers_autoprobe); | |
650 | if (retval) | |
651 | bus_remove_file(bus, &bus_attr_drivers_probe); | |
652 | out: | |
653 | return retval; | |
654 | } | |
655 | ||
656 | static void remove_probe_files(struct bus_type *bus) | |
657 | { | |
658 | bus_remove_file(bus, &bus_attr_drivers_autoprobe); | |
659 | bus_remove_file(bus, &bus_attr_drivers_probe); | |
660 | } | |
661 | ||
662 | static ssize_t driver_uevent_store(struct device_driver *drv, | |
663 | const char *buf, size_t count) | |
664 | { | |
665 | enum kobject_action action; | |
666 | ||
667 | if (kobject_action_type(buf, count, &action) == 0) | |
668 | kobject_uevent(&drv->p->kobj, action); | |
669 | return count; | |
670 | } | |
671 | static DRIVER_ATTR(uevent, S_IWUSR, NULL, driver_uevent_store); | |
672 | ||
673 | /** | |
674 | * bus_add_driver - Add a driver to the bus. | |
675 | * @drv: driver. | |
676 | */ | |
677 | int bus_add_driver(struct device_driver *drv) | |
678 | { | |
679 | struct bus_type *bus; | |
680 | struct driver_private *priv; | |
681 | int error = 0; | |
682 | ||
683 | bus = bus_get(drv->bus); | |
684 | if (!bus) | |
685 | return -EINVAL; | |
686 | ||
687 | pr_debug("bus: '%s': add driver %s\n", bus->name, drv->name); | |
688 | ||
689 | priv = kzalloc(sizeof(*priv), GFP_KERNEL); | |
690 | if (!priv) { | |
691 | error = -ENOMEM; | |
692 | goto out_put_bus; | |
693 | } | |
694 | klist_init(&priv->klist_devices, NULL, NULL); | |
695 | priv->driver = drv; | |
696 | drv->p = priv; | |
697 | priv->kobj.kset = bus->p->drivers_kset; | |
698 | error = kobject_init_and_add(&priv->kobj, &driver_ktype, NULL, | |
699 | "%s", drv->name); | |
700 | if (error) | |
701 | goto out_unregister; | |
702 | ||
703 | klist_add_tail(&priv->knode_bus, &bus->p->klist_drivers); | |
704 | if (drv->bus->p->drivers_autoprobe) { | |
705 | error = driver_attach(drv); | |
706 | if (error) | |
707 | goto out_unregister; | |
708 | } | |
709 | module_add_driver(drv->owner, drv); | |
710 | ||
711 | error = driver_create_file(drv, &driver_attr_uevent); | |
712 | if (error) { | |
713 | printk(KERN_ERR "%s: uevent attr (%s) failed\n", | |
714 | __func__, drv->name); | |
715 | } | |
716 | error = driver_add_attrs(bus, drv); | |
717 | if (error) { | |
718 | /* How the hell do we get out of this pickle? Give up */ | |
719 | printk(KERN_ERR "%s: driver_add_attrs(%s) failed\n", | |
720 | __func__, drv->name); | |
721 | } | |
722 | ||
723 | if (!drv->suppress_bind_attrs) { | |
724 | error = add_bind_files(drv); | |
725 | if (error) { | |
726 | /* Ditto */ | |
727 | printk(KERN_ERR "%s: add_bind_files(%s) failed\n", | |
728 | __func__, drv->name); | |
729 | } | |
730 | } | |
731 | ||
732 | return 0; | |
733 | ||
734 | out_unregister: | |
735 | kobject_put(&priv->kobj); | |
736 | kfree(drv->p); | |
737 | drv->p = NULL; | |
738 | out_put_bus: | |
739 | bus_put(bus); | |
740 | return error; | |
741 | } | |
742 | ||
743 | /** | |
744 | * bus_remove_driver - delete driver from bus's knowledge. | |
745 | * @drv: driver. | |
746 | * | |
747 | * Detach the driver from the devices it controls, and remove | |
748 | * it from its bus's list of drivers. Finally, we drop the reference | |
749 | * to the bus we took in bus_add_driver(). | |
750 | */ | |
751 | void bus_remove_driver(struct device_driver *drv) | |
752 | { | |
753 | if (!drv->bus) | |
754 | return; | |
755 | ||
756 | if (!drv->suppress_bind_attrs) | |
757 | remove_bind_files(drv); | |
758 | driver_remove_attrs(drv->bus, drv); | |
759 | driver_remove_file(drv, &driver_attr_uevent); | |
760 | klist_remove(&drv->p->knode_bus); | |
761 | pr_debug("bus: '%s': remove driver %s\n", drv->bus->name, drv->name); | |
762 | driver_detach(drv); | |
763 | module_remove_driver(drv); | |
764 | kobject_put(&drv->p->kobj); | |
765 | bus_put(drv->bus); | |
766 | } | |
767 | ||
768 | /* Helper for bus_rescan_devices's iter */ | |
769 | static int __must_check bus_rescan_devices_helper(struct device *dev, | |
770 | void *data) | |
771 | { | |
772 | int ret = 0; | |
773 | ||
774 | if (!dev->driver) { | |
775 | if (dev->parent) /* Needed for USB */ | |
776 | device_lock(dev->parent); | |
777 | ret = device_attach(dev); | |
778 | if (dev->parent) | |
779 | device_unlock(dev->parent); | |
780 | } | |
781 | return ret < 0 ? ret : 0; | |
782 | } | |
783 | ||
784 | /** | |
785 | * bus_rescan_devices - rescan devices on the bus for possible drivers | |
786 | * @bus: the bus to scan. | |
787 | * | |
788 | * This function will look for devices on the bus with no driver | |
789 | * attached and rescan it against existing drivers to see if it matches | |
790 | * any by calling device_attach() for the unbound devices. | |
791 | */ | |
792 | int bus_rescan_devices(struct bus_type *bus) | |
793 | { | |
794 | return bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper); | |
795 | } | |
796 | EXPORT_SYMBOL_GPL(bus_rescan_devices); | |
797 | ||
798 | /** | |
799 | * device_reprobe - remove driver for a device and probe for a new driver | |
800 | * @dev: the device to reprobe | |
801 | * | |
802 | * This function detaches the attached driver (if any) for the given | |
803 | * device and restarts the driver probing process. It is intended | |
804 | * to use if probing criteria changed during a devices lifetime and | |
805 | * driver attachment should change accordingly. | |
806 | */ | |
807 | int device_reprobe(struct device *dev) | |
808 | { | |
809 | if (dev->driver) { | |
810 | if (dev->parent) /* Needed for USB */ | |
811 | device_lock(dev->parent); | |
812 | device_release_driver(dev); | |
813 | if (dev->parent) | |
814 | device_unlock(dev->parent); | |
815 | } | |
816 | return bus_rescan_devices_helper(dev, NULL); | |
817 | } | |
818 | EXPORT_SYMBOL_GPL(device_reprobe); | |
819 | ||
820 | /** | |
821 | * find_bus - locate bus by name. | |
822 | * @name: name of bus. | |
823 | * | |
824 | * Call kset_find_obj() to iterate over list of buses to | |
825 | * find a bus by name. Return bus if found. | |
826 | * | |
827 | * Note that kset_find_obj increments bus' reference count. | |
828 | */ | |
829 | #if 0 | |
830 | struct bus_type *find_bus(char *name) | |
831 | { | |
832 | struct kobject *k = kset_find_obj(bus_kset, name); | |
833 | return k ? to_bus(k) : NULL; | |
834 | } | |
835 | #endif /* 0 */ | |
836 | ||
837 | ||
838 | /** | |
839 | * bus_add_attrs - Add default attributes for this bus. | |
840 | * @bus: Bus that has just been registered. | |
841 | */ | |
842 | ||
843 | static int bus_add_attrs(struct bus_type *bus) | |
844 | { | |
845 | int error = 0; | |
846 | int i; | |
847 | ||
848 | if (bus->bus_attrs) { | |
849 | for (i = 0; attr_name(bus->bus_attrs[i]); i++) { | |
850 | error = bus_create_file(bus, &bus->bus_attrs[i]); | |
851 | if (error) | |
852 | goto err; | |
853 | } | |
854 | } | |
855 | done: | |
856 | return error; | |
857 | err: | |
858 | while (--i >= 0) | |
859 | bus_remove_file(bus, &bus->bus_attrs[i]); | |
860 | goto done; | |
861 | } | |
862 | ||
863 | static void bus_remove_attrs(struct bus_type *bus) | |
864 | { | |
865 | int i; | |
866 | ||
867 | if (bus->bus_attrs) { | |
868 | for (i = 0; attr_name(bus->bus_attrs[i]); i++) | |
869 | bus_remove_file(bus, &bus->bus_attrs[i]); | |
870 | } | |
871 | } | |
872 | ||
873 | static void klist_devices_get(struct klist_node *n) | |
874 | { | |
875 | struct device_private *dev_prv = to_device_private_bus(n); | |
876 | struct device *dev = dev_prv->device; | |
877 | ||
878 | get_device(dev); | |
879 | } | |
880 | ||
881 | static void klist_devices_put(struct klist_node *n) | |
882 | { | |
883 | struct device_private *dev_prv = to_device_private_bus(n); | |
884 | struct device *dev = dev_prv->device; | |
885 | ||
886 | put_device(dev); | |
887 | } | |
888 | ||
889 | static ssize_t bus_uevent_store(struct bus_type *bus, | |
890 | const char *buf, size_t count) | |
891 | { | |
892 | enum kobject_action action; | |
893 | ||
894 | if (kobject_action_type(buf, count, &action) == 0) | |
895 | kobject_uevent(&bus->p->subsys.kobj, action); | |
896 | return count; | |
897 | } | |
898 | static BUS_ATTR(uevent, S_IWUSR, NULL, bus_uevent_store); | |
899 | ||
900 | /** | |
901 | * bus_register - register a driver-core subsystem | |
902 | * @bus: bus to register | |
903 | * | |
904 | * Once we have that, we register the bus with the kobject | |
905 | * infrastructure, then register the children subsystems it has: | |
906 | * the devices and drivers that belong to the subsystem. | |
907 | */ | |
908 | int bus_register(struct bus_type *bus) | |
909 | { | |
910 | int retval; | |
911 | struct subsys_private *priv; | |
912 | struct lock_class_key *key = &bus->lock_key; | |
913 | ||
914 | priv = kzalloc(sizeof(struct subsys_private), GFP_KERNEL); | |
915 | if (!priv) | |
916 | return -ENOMEM; | |
917 | ||
918 | priv->bus = bus; | |
919 | bus->p = priv; | |
920 | ||
921 | BLOCKING_INIT_NOTIFIER_HEAD(&priv->bus_notifier); | |
922 | ||
923 | retval = kobject_set_name(&priv->subsys.kobj, "%s", bus->name); | |
924 | if (retval) | |
925 | goto out; | |
926 | ||
927 | priv->subsys.kobj.kset = bus_kset; | |
928 | priv->subsys.kobj.ktype = &bus_ktype; | |
929 | priv->drivers_autoprobe = 1; | |
930 | ||
931 | retval = kset_register(&priv->subsys); | |
932 | if (retval) | |
933 | goto out; | |
934 | ||
935 | retval = bus_create_file(bus, &bus_attr_uevent); | |
936 | if (retval) | |
937 | goto bus_uevent_fail; | |
938 | ||
939 | priv->devices_kset = kset_create_and_add("devices", NULL, | |
940 | &priv->subsys.kobj); | |
941 | if (!priv->devices_kset) { | |
942 | retval = -ENOMEM; | |
943 | goto bus_devices_fail; | |
944 | } | |
945 | ||
946 | priv->drivers_kset = kset_create_and_add("drivers", NULL, | |
947 | &priv->subsys.kobj); | |
948 | if (!priv->drivers_kset) { | |
949 | retval = -ENOMEM; | |
950 | goto bus_drivers_fail; | |
951 | } | |
952 | ||
953 | INIT_LIST_HEAD(&priv->interfaces); | |
954 | __mutex_init(&priv->mutex, "subsys mutex", key); | |
955 | klist_init(&priv->klist_devices, klist_devices_get, klist_devices_put); | |
956 | klist_init(&priv->klist_drivers, NULL, NULL); | |
957 | ||
958 | retval = add_probe_files(bus); | |
959 | if (retval) | |
960 | goto bus_probe_files_fail; | |
961 | ||
962 | retval = bus_add_attrs(bus); | |
963 | if (retval) | |
964 | goto bus_attrs_fail; | |
965 | ||
966 | pr_debug("bus: '%s': registered\n", bus->name); | |
967 | return 0; | |
968 | ||
969 | bus_attrs_fail: | |
970 | remove_probe_files(bus); | |
971 | bus_probe_files_fail: | |
972 | kset_unregister(bus->p->drivers_kset); | |
973 | bus_drivers_fail: | |
974 | kset_unregister(bus->p->devices_kset); | |
975 | bus_devices_fail: | |
976 | bus_remove_file(bus, &bus_attr_uevent); | |
977 | bus_uevent_fail: | |
978 | kset_unregister(&bus->p->subsys); | |
979 | out: | |
980 | kfree(bus->p); | |
981 | bus->p = NULL; | |
982 | return retval; | |
983 | } | |
984 | EXPORT_SYMBOL_GPL(bus_register); | |
985 | ||
986 | /** | |
987 | * bus_unregister - remove a bus from the system | |
988 | * @bus: bus. | |
989 | * | |
990 | * Unregister the child subsystems and the bus itself. | |
991 | * Finally, we call bus_put() to release the refcount | |
992 | */ | |
993 | void bus_unregister(struct bus_type *bus) | |
994 | { | |
995 | pr_debug("bus: '%s': unregistering\n", bus->name); | |
996 | if (bus->dev_root) | |
997 | device_unregister(bus->dev_root); | |
998 | bus_remove_attrs(bus); | |
999 | remove_probe_files(bus); | |
1000 | kset_unregister(bus->p->drivers_kset); | |
1001 | kset_unregister(bus->p->devices_kset); | |
1002 | bus_remove_file(bus, &bus_attr_uevent); | |
1003 | kset_unregister(&bus->p->subsys); | |
1004 | kfree(bus->p); | |
1005 | bus->p = NULL; | |
1006 | } | |
1007 | EXPORT_SYMBOL_GPL(bus_unregister); | |
1008 | ||
1009 | int bus_register_notifier(struct bus_type *bus, struct notifier_block *nb) | |
1010 | { | |
1011 | return blocking_notifier_chain_register(&bus->p->bus_notifier, nb); | |
1012 | } | |
1013 | EXPORT_SYMBOL_GPL(bus_register_notifier); | |
1014 | ||
1015 | int bus_unregister_notifier(struct bus_type *bus, struct notifier_block *nb) | |
1016 | { | |
1017 | return blocking_notifier_chain_unregister(&bus->p->bus_notifier, nb); | |
1018 | } | |
1019 | EXPORT_SYMBOL_GPL(bus_unregister_notifier); | |
1020 | ||
1021 | struct kset *bus_get_kset(struct bus_type *bus) | |
1022 | { | |
1023 | return &bus->p->subsys; | |
1024 | } | |
1025 | EXPORT_SYMBOL_GPL(bus_get_kset); | |
1026 | ||
1027 | struct klist *bus_get_device_klist(struct bus_type *bus) | |
1028 | { | |
1029 | return &bus->p->klist_devices; | |
1030 | } | |
1031 | EXPORT_SYMBOL_GPL(bus_get_device_klist); | |
1032 | ||
1033 | /* | |
1034 | * Yes, this forcibly breaks the klist abstraction temporarily. It | |
1035 | * just wants to sort the klist, not change reference counts and | |
1036 | * take/drop locks rapidly in the process. It does all this while | |
1037 | * holding the lock for the list, so objects can't otherwise be | |
1038 | * added/removed while we're swizzling. | |
1039 | */ | |
1040 | static void device_insertion_sort_klist(struct device *a, struct list_head *list, | |
1041 | int (*compare)(const struct device *a, | |
1042 | const struct device *b)) | |
1043 | { | |
1044 | struct list_head *pos; | |
1045 | struct klist_node *n; | |
1046 | struct device_private *dev_prv; | |
1047 | struct device *b; | |
1048 | ||
1049 | list_for_each(pos, list) { | |
1050 | n = container_of(pos, struct klist_node, n_node); | |
1051 | dev_prv = to_device_private_bus(n); | |
1052 | b = dev_prv->device; | |
1053 | if (compare(a, b) <= 0) { | |
1054 | list_move_tail(&a->p->knode_bus.n_node, | |
1055 | &b->p->knode_bus.n_node); | |
1056 | return; | |
1057 | } | |
1058 | } | |
1059 | list_move_tail(&a->p->knode_bus.n_node, list); | |
1060 | } | |
1061 | ||
1062 | void bus_sort_breadthfirst(struct bus_type *bus, | |
1063 | int (*compare)(const struct device *a, | |
1064 | const struct device *b)) | |
1065 | { | |
1066 | LIST_HEAD(sorted_devices); | |
1067 | struct list_head *pos, *tmp; | |
1068 | struct klist_node *n; | |
1069 | struct device_private *dev_prv; | |
1070 | struct device *dev; | |
1071 | struct klist *device_klist; | |
1072 | ||
1073 | device_klist = bus_get_device_klist(bus); | |
1074 | ||
1075 | spin_lock(&device_klist->k_lock); | |
1076 | list_for_each_safe(pos, tmp, &device_klist->k_list) { | |
1077 | n = container_of(pos, struct klist_node, n_node); | |
1078 | dev_prv = to_device_private_bus(n); | |
1079 | dev = dev_prv->device; | |
1080 | device_insertion_sort_klist(dev, &sorted_devices, compare); | |
1081 | } | |
1082 | list_splice(&sorted_devices, &device_klist->k_list); | |
1083 | spin_unlock(&device_klist->k_lock); | |
1084 | } | |
1085 | EXPORT_SYMBOL_GPL(bus_sort_breadthfirst); | |
1086 | ||
1087 | /** | |
1088 | * subsys_dev_iter_init - initialize subsys device iterator | |
1089 | * @iter: subsys iterator to initialize | |
1090 | * @subsys: the subsys we wanna iterate over | |
1091 | * @start: the device to start iterating from, if any | |
1092 | * @type: device_type of the devices to iterate over, NULL for all | |
1093 | * | |
1094 | * Initialize subsys iterator @iter such that it iterates over devices | |
1095 | * of @subsys. If @start is set, the list iteration will start there, | |
1096 | * otherwise if it is NULL, the iteration starts at the beginning of | |
1097 | * the list. | |
1098 | */ | |
1099 | void subsys_dev_iter_init(struct subsys_dev_iter *iter, struct bus_type *subsys, | |
1100 | struct device *start, const struct device_type *type) | |
1101 | { | |
1102 | struct klist_node *start_knode = NULL; | |
1103 | ||
1104 | if (start) | |
1105 | start_knode = &start->p->knode_bus; | |
1106 | klist_iter_init_node(&subsys->p->klist_devices, &iter->ki, start_knode); | |
1107 | iter->type = type; | |
1108 | } | |
1109 | EXPORT_SYMBOL_GPL(subsys_dev_iter_init); | |
1110 | ||
1111 | /** | |
1112 | * subsys_dev_iter_next - iterate to the next device | |
1113 | * @iter: subsys iterator to proceed | |
1114 | * | |
1115 | * Proceed @iter to the next device and return it. Returns NULL if | |
1116 | * iteration is complete. | |
1117 | * | |
1118 | * The returned device is referenced and won't be released till | |
1119 | * iterator is proceed to the next device or exited. The caller is | |
1120 | * free to do whatever it wants to do with the device including | |
1121 | * calling back into subsys code. | |
1122 | */ | |
1123 | struct device *subsys_dev_iter_next(struct subsys_dev_iter *iter) | |
1124 | { | |
1125 | struct klist_node *knode; | |
1126 | struct device *dev; | |
1127 | ||
1128 | for (;;) { | |
1129 | knode = klist_next(&iter->ki); | |
1130 | if (!knode) | |
1131 | return NULL; | |
1132 | dev = container_of(knode, struct device_private, knode_bus)->device; | |
1133 | if (!iter->type || iter->type == dev->type) | |
1134 | return dev; | |
1135 | } | |
1136 | } | |
1137 | EXPORT_SYMBOL_GPL(subsys_dev_iter_next); | |
1138 | ||
1139 | /** | |
1140 | * subsys_dev_iter_exit - finish iteration | |
1141 | * @iter: subsys iterator to finish | |
1142 | * | |
1143 | * Finish an iteration. Always call this function after iteration is | |
1144 | * complete whether the iteration ran till the end or not. | |
1145 | */ | |
1146 | void subsys_dev_iter_exit(struct subsys_dev_iter *iter) | |
1147 | { | |
1148 | klist_iter_exit(&iter->ki); | |
1149 | } | |
1150 | EXPORT_SYMBOL_GPL(subsys_dev_iter_exit); | |
1151 | ||
1152 | int subsys_interface_register(struct subsys_interface *sif) | |
1153 | { | |
1154 | struct bus_type *subsys; | |
1155 | struct subsys_dev_iter iter; | |
1156 | struct device *dev; | |
1157 | ||
1158 | if (!sif || !sif->subsys) | |
1159 | return -ENODEV; | |
1160 | ||
1161 | subsys = bus_get(sif->subsys); | |
1162 | if (!subsys) | |
1163 | return -EINVAL; | |
1164 | ||
1165 | mutex_lock(&subsys->p->mutex); | |
1166 | list_add_tail(&sif->node, &subsys->p->interfaces); | |
1167 | if (sif->add_dev) { | |
1168 | subsys_dev_iter_init(&iter, subsys, NULL, NULL); | |
1169 | while ((dev = subsys_dev_iter_next(&iter))) | |
1170 | sif->add_dev(dev, sif); | |
1171 | subsys_dev_iter_exit(&iter); | |
1172 | } | |
1173 | mutex_unlock(&subsys->p->mutex); | |
1174 | ||
1175 | return 0; | |
1176 | } | |
1177 | EXPORT_SYMBOL_GPL(subsys_interface_register); | |
1178 | ||
1179 | void subsys_interface_unregister(struct subsys_interface *sif) | |
1180 | { | |
1181 | struct bus_type *subsys; | |
1182 | struct subsys_dev_iter iter; | |
1183 | struct device *dev; | |
1184 | ||
1185 | if (!sif || !sif->subsys) | |
1186 | return; | |
1187 | ||
1188 | subsys = sif->subsys; | |
1189 | ||
1190 | mutex_lock(&subsys->p->mutex); | |
1191 | list_del_init(&sif->node); | |
1192 | if (sif->remove_dev) { | |
1193 | subsys_dev_iter_init(&iter, subsys, NULL, NULL); | |
1194 | while ((dev = subsys_dev_iter_next(&iter))) | |
1195 | sif->remove_dev(dev, sif); | |
1196 | subsys_dev_iter_exit(&iter); | |
1197 | } | |
1198 | mutex_unlock(&subsys->p->mutex); | |
1199 | ||
1200 | bus_put(subsys); | |
1201 | } | |
1202 | EXPORT_SYMBOL_GPL(subsys_interface_unregister); | |
1203 | ||
1204 | static void system_root_device_release(struct device *dev) | |
1205 | { | |
1206 | kfree(dev); | |
1207 | } | |
1208 | ||
1209 | static int subsys_register(struct bus_type *subsys, | |
1210 | const struct attribute_group **groups, | |
1211 | struct kobject *parent_of_root) | |
1212 | { | |
1213 | struct device *dev; | |
1214 | int err; | |
1215 | ||
1216 | err = bus_register(subsys); | |
1217 | if (err < 0) | |
1218 | return err; | |
1219 | ||
1220 | dev = kzalloc(sizeof(struct device), GFP_KERNEL); | |
1221 | if (!dev) { | |
1222 | err = -ENOMEM; | |
1223 | goto err_dev; | |
1224 | } | |
1225 | ||
1226 | err = dev_set_name(dev, "%s", subsys->name); | |
1227 | if (err < 0) | |
1228 | goto err_name; | |
1229 | ||
1230 | dev->kobj.parent = parent_of_root; | |
1231 | dev->groups = groups; | |
1232 | dev->release = system_root_device_release; | |
1233 | ||
1234 | err = device_register(dev); | |
1235 | if (err < 0) | |
1236 | goto err_dev_reg; | |
1237 | ||
1238 | subsys->dev_root = dev; | |
1239 | return 0; | |
1240 | ||
1241 | err_dev_reg: | |
1242 | put_device(dev); | |
1243 | dev = NULL; | |
1244 | err_name: | |
1245 | kfree(dev); | |
1246 | err_dev: | |
1247 | bus_unregister(subsys); | |
1248 | return err; | |
1249 | } | |
1250 | ||
1251 | /** | |
1252 | * subsys_system_register - register a subsystem at /sys/devices/system/ | |
1253 | * @subsys: system subsystem | |
1254 | * @groups: default attributes for the root device | |
1255 | * | |
1256 | * All 'system' subsystems have a /sys/devices/system/<name> root device | |
1257 | * with the name of the subsystem. The root device can carry subsystem- | |
1258 | * wide attributes. All registered devices are below this single root | |
1259 | * device and are named after the subsystem with a simple enumeration | |
1260 | * number appended. The registered devices are not explicitely named; | |
1261 | * only 'id' in the device needs to be set. | |
1262 | * | |
1263 | * Do not use this interface for anything new, it exists for compatibility | |
1264 | * with bad ideas only. New subsystems should use plain subsystems; and | |
1265 | * add the subsystem-wide attributes should be added to the subsystem | |
1266 | * directory itself and not some create fake root-device placed in | |
1267 | * /sys/devices/system/<name>. | |
1268 | */ | |
1269 | int subsys_system_register(struct bus_type *subsys, | |
1270 | const struct attribute_group **groups) | |
1271 | { | |
1272 | return subsys_register(subsys, groups, &system_kset->kobj); | |
1273 | } | |
1274 | EXPORT_SYMBOL_GPL(subsys_system_register); | |
1275 | ||
1276 | /** | |
1277 | * subsys_virtual_register - register a subsystem at /sys/devices/virtual/ | |
1278 | * @subsys: virtual subsystem | |
1279 | * @groups: default attributes for the root device | |
1280 | * | |
1281 | * All 'virtual' subsystems have a /sys/devices/system/<name> root device | |
1282 | * with the name of the subystem. The root device can carry subsystem-wide | |
1283 | * attributes. All registered devices are below this single root device. | |
1284 | * There's no restriction on device naming. This is for kernel software | |
1285 | * constructs which need sysfs interface. | |
1286 | */ | |
1287 | int subsys_virtual_register(struct bus_type *subsys, | |
1288 | const struct attribute_group **groups) | |
1289 | { | |
1290 | struct kobject *virtual_dir; | |
1291 | ||
1292 | virtual_dir = virtual_device_parent(NULL); | |
1293 | if (!virtual_dir) | |
1294 | return -ENOMEM; | |
1295 | ||
1296 | return subsys_register(subsys, groups, virtual_dir); | |
1297 | } | |
1298 | ||
1299 | int __init buses_init(void) | |
1300 | { | |
1301 | bus_kset = kset_create_and_add("bus", &bus_uevent_ops, NULL); | |
1302 | if (!bus_kset) | |
1303 | return -ENOMEM; | |
1304 | ||
1305 | system_kset = kset_create_and_add("system", NULL, &devices_kset->kobj); | |
1306 | if (!system_kset) | |
1307 | return -ENOMEM; | |
1308 | ||
1309 | return 0; | |
1310 | } |