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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 | * @key: lockdep class key |
904 | * |
905 | * Once we have that, we register the bus with the kobject |
906 | * infrastructure, then register the children subsystems it has: |
907 | * the devices and drivers that belong to the subsystem. |
908 | */ |
909 | int __bus_register(struct bus_type *bus, struct lock_class_key *key) |
910 | { |
911 | int retval; |
912 | struct subsys_private *priv; |
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 | * subsys_system_register - register a subsystem at /sys/devices/system/ |
1210 | * @subsys: system subsystem |
1211 | * @groups: default attributes for the root device |
1212 | * |
1213 | * All 'system' subsystems have a /sys/devices/system/<name> root device |
1214 | * with the name of the subsystem. The root device can carry subsystem- |
1215 | * wide attributes. All registered devices are below this single root |
1216 | * device and are named after the subsystem with a simple enumeration |
1217 | * number appended. The registered devices are not explicitely named; |
1218 | * only 'id' in the device needs to be set. |
1219 | * |
1220 | * Do not use this interface for anything new, it exists for compatibility |
1221 | * with bad ideas only. New subsystems should use plain subsystems; and |
1222 | * add the subsystem-wide attributes should be added to the subsystem |
1223 | * directory itself and not some create fake root-device placed in |
1224 | * /sys/devices/system/<name>. |
1225 | */ |
1226 | int subsys_system_register(struct bus_type *subsys, |
1227 | const struct attribute_group **groups) |
1228 | { |
1229 | struct device *dev; |
1230 | int err; |
1231 | |
1232 | err = bus_register(subsys); |
1233 | if (err < 0) |
1234 | return err; |
1235 | |
1236 | dev = kzalloc(sizeof(struct device), GFP_KERNEL); |
1237 | if (!dev) { |
1238 | err = -ENOMEM; |
1239 | goto err_dev; |
1240 | } |
1241 | |
1242 | err = dev_set_name(dev, "%s", subsys->name); |
1243 | if (err < 0) |
1244 | goto err_name; |
1245 | |
1246 | dev->kobj.parent = &system_kset->kobj; |
1247 | dev->groups = groups; |
1248 | dev->release = system_root_device_release; |
1249 | |
1250 | err = device_register(dev); |
1251 | if (err < 0) |
1252 | goto err_dev_reg; |
1253 | |
1254 | subsys->dev_root = dev; |
1255 | return 0; |
1256 | |
1257 | err_dev_reg: |
1258 | put_device(dev); |
1259 | dev = NULL; |
1260 | err_name: |
1261 | kfree(dev); |
1262 | err_dev: |
1263 | bus_unregister(subsys); |
1264 | return err; |
1265 | } |
1266 | EXPORT_SYMBOL_GPL(subsys_system_register); |
1267 | |
1268 | int __init buses_init(void) |
1269 | { |
1270 | bus_kset = kset_create_and_add("bus", &bus_uevent_ops, NULL); |
1271 | if (!bus_kset) |
1272 | return -ENOMEM; |
1273 | |
1274 | system_kset = kset_create_and_add("system", NULL, &devices_kset->kobj); |
1275 | if (!system_kset) |
1276 | return -ENOMEM; |
1277 | |
1278 | return 0; |
1279 | } |
1280 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9