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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/init.h> | |
17 | #include <linux/string.h> | |
18 | #include "base.h" | |
19 | #include "power/power.h" | |
20 | ||
21 | #define to_bus_attr(_attr) container_of(_attr, struct bus_attribute, attr) | |
22 | #define to_bus(obj) container_of(obj, struct bus_type_private, subsys.kobj) | |
23 | ||
24 | /* | |
25 | * sysfs bindings for drivers | |
26 | */ | |
27 | ||
28 | #define to_drv_attr(_attr) container_of(_attr, struct driver_attribute, attr) | |
29 | ||
30 | ||
31 | static int __must_check bus_rescan_devices_helper(struct device *dev, | |
32 | void *data); | |
33 | ||
34 | static struct bus_type *bus_get(struct bus_type *bus) | |
35 | { | |
36 | if (bus) { | |
37 | kset_get(&bus->p->subsys); | |
38 | return bus; | |
39 | } | |
40 | return NULL; | |
41 | } | |
42 | ||
43 | static void bus_put(struct bus_type *bus) | |
44 | { | |
45 | if (bus) | |
46 | kset_put(&bus->p->subsys); | |
47 | } | |
48 | ||
49 | static ssize_t | |
50 | drv_attr_show(struct kobject * kobj, struct attribute * attr, char * buf) | |
51 | { | |
52 | struct driver_attribute * drv_attr = to_drv_attr(attr); | |
53 | struct driver_private *drv_priv = to_driver(kobj); | |
54 | ssize_t ret = -EIO; | |
55 | ||
56 | if (drv_attr->show) | |
57 | ret = drv_attr->show(drv_priv->driver, buf); | |
58 | return ret; | |
59 | } | |
60 | ||
61 | static ssize_t | |
62 | drv_attr_store(struct kobject * kobj, struct attribute * attr, | |
63 | const char * buf, size_t count) | |
64 | { | |
65 | struct driver_attribute * drv_attr = to_drv_attr(attr); | |
66 | struct driver_private *drv_priv = to_driver(kobj); | |
67 | ssize_t ret = -EIO; | |
68 | ||
69 | if (drv_attr->store) | |
70 | ret = drv_attr->store(drv_priv->driver, buf, count); | |
71 | return ret; | |
72 | } | |
73 | ||
74 | static struct sysfs_ops driver_sysfs_ops = { | |
75 | .show = drv_attr_show, | |
76 | .store = drv_attr_store, | |
77 | }; | |
78 | ||
79 | static void driver_release(struct kobject *kobj) | |
80 | { | |
81 | struct driver_private *drv_priv = to_driver(kobj); | |
82 | ||
83 | pr_debug("driver: '%s': %s\n", kobject_name(kobj), __FUNCTION__); | |
84 | kfree(drv_priv); | |
85 | } | |
86 | ||
87 | static struct kobj_type driver_ktype = { | |
88 | .sysfs_ops = &driver_sysfs_ops, | |
89 | .release = driver_release, | |
90 | }; | |
91 | ||
92 | ||
93 | /* | |
94 | * sysfs bindings for buses | |
95 | */ | |
96 | ||
97 | ||
98 | static ssize_t | |
99 | bus_attr_show(struct kobject * kobj, struct attribute * attr, char * buf) | |
100 | { | |
101 | struct bus_attribute * bus_attr = to_bus_attr(attr); | |
102 | struct bus_type_private *bus_priv = to_bus(kobj); | |
103 | ssize_t ret = 0; | |
104 | ||
105 | if (bus_attr->show) | |
106 | ret = bus_attr->show(bus_priv->bus, buf); | |
107 | return ret; | |
108 | } | |
109 | ||
110 | static ssize_t | |
111 | bus_attr_store(struct kobject * kobj, struct attribute * attr, | |
112 | const char * buf, size_t count) | |
113 | { | |
114 | struct bus_attribute * bus_attr = to_bus_attr(attr); | |
115 | struct bus_type_private *bus_priv = to_bus(kobj); | |
116 | ssize_t ret = 0; | |
117 | ||
118 | if (bus_attr->store) | |
119 | ret = bus_attr->store(bus_priv->bus, buf, count); | |
120 | return ret; | |
121 | } | |
122 | ||
123 | static struct sysfs_ops bus_sysfs_ops = { | |
124 | .show = bus_attr_show, | |
125 | .store = bus_attr_store, | |
126 | }; | |
127 | ||
128 | int bus_create_file(struct bus_type * bus, struct bus_attribute * attr) | |
129 | { | |
130 | int error; | |
131 | if (bus_get(bus)) { | |
132 | error = sysfs_create_file(&bus->p->subsys.kobj, &attr->attr); | |
133 | bus_put(bus); | |
134 | } else | |
135 | error = -EINVAL; | |
136 | return error; | |
137 | } | |
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 | ||
147 | static struct kobj_type bus_ktype = { | |
148 | .sysfs_ops = &bus_sysfs_ops, | |
149 | }; | |
150 | ||
151 | static int bus_uevent_filter(struct kset *kset, struct kobject *kobj) | |
152 | { | |
153 | struct kobj_type *ktype = get_ktype(kobj); | |
154 | ||
155 | if (ktype == &bus_ktype) | |
156 | return 1; | |
157 | return 0; | |
158 | } | |
159 | ||
160 | static struct kset_uevent_ops bus_uevent_ops = { | |
161 | .filter = bus_uevent_filter, | |
162 | }; | |
163 | ||
164 | static struct kset *bus_kset; | |
165 | ||
166 | ||
167 | #ifdef CONFIG_HOTPLUG | |
168 | /* Manually detach a device from its associated driver. */ | |
169 | static int driver_helper(struct device *dev, void *data) | |
170 | { | |
171 | const char *name = data; | |
172 | ||
173 | if (strcmp(name, dev->bus_id) == 0) | |
174 | return 1; | |
175 | return 0; | |
176 | } | |
177 | ||
178 | static ssize_t driver_unbind(struct device_driver *drv, | |
179 | const char *buf, size_t count) | |
180 | { | |
181 | struct bus_type *bus = bus_get(drv->bus); | |
182 | struct device *dev; | |
183 | int err = -ENODEV; | |
184 | ||
185 | dev = bus_find_device(bus, NULL, (void *)buf, driver_helper); | |
186 | if (dev && dev->driver == drv) { | |
187 | if (dev->parent) /* Needed for USB */ | |
188 | down(&dev->parent->sem); | |
189 | device_release_driver(dev); | |
190 | if (dev->parent) | |
191 | up(&dev->parent->sem); | |
192 | err = count; | |
193 | } | |
194 | put_device(dev); | |
195 | bus_put(bus); | |
196 | return err; | |
197 | } | |
198 | static DRIVER_ATTR(unbind, S_IWUSR, NULL, driver_unbind); | |
199 | ||
200 | /* | |
201 | * Manually attach a device to a driver. | |
202 | * Note: the driver must want to bind to the device, | |
203 | * it is not possible to override the driver's id table. | |
204 | */ | |
205 | static ssize_t driver_bind(struct device_driver *drv, | |
206 | const char *buf, size_t count) | |
207 | { | |
208 | struct bus_type *bus = bus_get(drv->bus); | |
209 | struct device *dev; | |
210 | int err = -ENODEV; | |
211 | ||
212 | dev = bus_find_device(bus, NULL, (void *)buf, driver_helper); | |
213 | if (dev && dev->driver == NULL) { | |
214 | if (dev->parent) /* Needed for USB */ | |
215 | down(&dev->parent->sem); | |
216 | down(&dev->sem); | |
217 | err = driver_probe_device(drv, dev); | |
218 | up(&dev->sem); | |
219 | if (dev->parent) | |
220 | up(&dev->parent->sem); | |
221 | ||
222 | if (err > 0) /* success */ | |
223 | err = count; | |
224 | else if (err == 0) /* driver didn't accept device */ | |
225 | err = -ENODEV; | |
226 | } | |
227 | put_device(dev); | |
228 | bus_put(bus); | |
229 | return err; | |
230 | } | |
231 | static DRIVER_ATTR(bind, S_IWUSR, NULL, driver_bind); | |
232 | ||
233 | static ssize_t show_drivers_autoprobe(struct bus_type *bus, char *buf) | |
234 | { | |
235 | return sprintf(buf, "%d\n", bus->p->drivers_autoprobe); | |
236 | } | |
237 | ||
238 | static ssize_t store_drivers_autoprobe(struct bus_type *bus, | |
239 | const char *buf, size_t count) | |
240 | { | |
241 | if (buf[0] == '0') | |
242 | bus->p->drivers_autoprobe = 0; | |
243 | else | |
244 | bus->p->drivers_autoprobe = 1; | |
245 | return count; | |
246 | } | |
247 | ||
248 | static ssize_t store_drivers_probe(struct bus_type *bus, | |
249 | const char *buf, size_t count) | |
250 | { | |
251 | struct device *dev; | |
252 | ||
253 | dev = bus_find_device(bus, NULL, (void *)buf, driver_helper); | |
254 | if (!dev) | |
255 | return -ENODEV; | |
256 | if (bus_rescan_devices_helper(dev, NULL) != 0) | |
257 | return -EINVAL; | |
258 | return count; | |
259 | } | |
260 | #endif | |
261 | ||
262 | static struct device * next_device(struct klist_iter * i) | |
263 | { | |
264 | struct klist_node * n = klist_next(i); | |
265 | return n ? container_of(n, struct device, knode_bus) : NULL; | |
266 | } | |
267 | ||
268 | /** | |
269 | * bus_for_each_dev - device iterator. | |
270 | * @bus: bus type. | |
271 | * @start: device to start iterating from. | |
272 | * @data: data for the callback. | |
273 | * @fn: function to be called for each device. | |
274 | * | |
275 | * Iterate over @bus's list of devices, and call @fn for each, | |
276 | * passing it @data. If @start is not NULL, we use that device to | |
277 | * begin iterating from. | |
278 | * | |
279 | * We check the return of @fn each time. If it returns anything | |
280 | * other than 0, we break out and return that value. | |
281 | * | |
282 | * NOTE: The device that returns a non-zero value is not retained | |
283 | * in any way, nor is its refcount incremented. If the caller needs | |
284 | * to retain this data, it should do, and increment the reference | |
285 | * count in the supplied callback. | |
286 | */ | |
287 | ||
288 | int bus_for_each_dev(struct bus_type * bus, struct device * start, | |
289 | void * data, int (*fn)(struct device *, void *)) | |
290 | { | |
291 | struct klist_iter i; | |
292 | struct device * dev; | |
293 | int error = 0; | |
294 | ||
295 | if (!bus) | |
296 | return -EINVAL; | |
297 | ||
298 | klist_iter_init_node(&bus->p->klist_devices, &i, | |
299 | (start ? &start->knode_bus : NULL)); | |
300 | while ((dev = next_device(&i)) && !error) | |
301 | error = fn(dev, data); | |
302 | klist_iter_exit(&i); | |
303 | return error; | |
304 | } | |
305 | ||
306 | /** | |
307 | * bus_find_device - device iterator for locating a particular device. | |
308 | * @bus: bus type | |
309 | * @start: Device to begin with | |
310 | * @data: Data to pass to match function | |
311 | * @match: Callback function to check device | |
312 | * | |
313 | * This is similar to the bus_for_each_dev() function above, but it | |
314 | * returns a reference to a device that is 'found' for later use, as | |
315 | * determined by the @match callback. | |
316 | * | |
317 | * The callback should return 0 if the device doesn't match and non-zero | |
318 | * if it does. If the callback returns non-zero, this function will | |
319 | * return to the caller and not iterate over any more devices. | |
320 | */ | |
321 | struct device * bus_find_device(struct bus_type *bus, | |
322 | struct device *start, void *data, | |
323 | int (*match)(struct device *, void *)) | |
324 | { | |
325 | struct klist_iter i; | |
326 | struct device *dev; | |
327 | ||
328 | if (!bus) | |
329 | return NULL; | |
330 | ||
331 | klist_iter_init_node(&bus->p->klist_devices, &i, | |
332 | (start ? &start->knode_bus : NULL)); | |
333 | while ((dev = next_device(&i))) | |
334 | if (match(dev, data) && get_device(dev)) | |
335 | break; | |
336 | klist_iter_exit(&i); | |
337 | return dev; | |
338 | } | |
339 | ||
340 | ||
341 | static struct device_driver * next_driver(struct klist_iter * i) | |
342 | { | |
343 | struct klist_node * n = klist_next(i); | |
344 | struct driver_private *drv_priv; | |
345 | ||
346 | if (n) { | |
347 | drv_priv = container_of(n, struct driver_private, knode_bus); | |
348 | return drv_priv->driver; | |
349 | } | |
350 | return NULL; | |
351 | } | |
352 | ||
353 | /** | |
354 | * bus_for_each_drv - driver iterator | |
355 | * @bus: bus we're dealing with. | |
356 | * @start: driver to start iterating on. | |
357 | * @data: data to pass to the callback. | |
358 | * @fn: function to call for each driver. | |
359 | * | |
360 | * This is nearly identical to the device iterator above. | |
361 | * We iterate over each driver that belongs to @bus, and call | |
362 | * @fn for each. If @fn returns anything but 0, we break out | |
363 | * and return it. If @start is not NULL, we use it as the head | |
364 | * of the list. | |
365 | * | |
366 | * NOTE: we don't return the driver that returns a non-zero | |
367 | * value, nor do we leave the reference count incremented for that | |
368 | * driver. If the caller needs to know that info, it must set it | |
369 | * in the callback. It must also be sure to increment the refcount | |
370 | * so it doesn't disappear before returning to the caller. | |
371 | */ | |
372 | ||
373 | int bus_for_each_drv(struct bus_type * bus, struct device_driver * start, | |
374 | void * data, int (*fn)(struct device_driver *, void *)) | |
375 | { | |
376 | struct klist_iter i; | |
377 | struct device_driver * drv; | |
378 | int error = 0; | |
379 | ||
380 | if (!bus) | |
381 | return -EINVAL; | |
382 | ||
383 | klist_iter_init_node(&bus->p->klist_drivers, &i, | |
384 | start ? &start->p->knode_bus : NULL); | |
385 | while ((drv = next_driver(&i)) && !error) | |
386 | error = fn(drv, data); | |
387 | klist_iter_exit(&i); | |
388 | return error; | |
389 | } | |
390 | ||
391 | static int device_add_attrs(struct bus_type *bus, struct device *dev) | |
392 | { | |
393 | int error = 0; | |
394 | int i; | |
395 | ||
396 | if (!bus->dev_attrs) | |
397 | return 0; | |
398 | ||
399 | for (i = 0; attr_name(bus->dev_attrs[i]); i++) { | |
400 | error = device_create_file(dev,&bus->dev_attrs[i]); | |
401 | if (error) { | |
402 | while (--i >= 0) | |
403 | device_remove_file(dev, &bus->dev_attrs[i]); | |
404 | break; | |
405 | } | |
406 | } | |
407 | return error; | |
408 | } | |
409 | ||
410 | static void device_remove_attrs(struct bus_type * bus, struct device * dev) | |
411 | { | |
412 | int i; | |
413 | ||
414 | if (bus->dev_attrs) { | |
415 | for (i = 0; attr_name(bus->dev_attrs[i]); i++) | |
416 | device_remove_file(dev,&bus->dev_attrs[i]); | |
417 | } | |
418 | } | |
419 | ||
420 | #ifdef CONFIG_SYSFS_DEPRECATED | |
421 | static int make_deprecated_bus_links(struct device *dev) | |
422 | { | |
423 | return sysfs_create_link(&dev->kobj, | |
424 | &dev->bus->p->subsys.kobj, "bus"); | |
425 | } | |
426 | ||
427 | static void remove_deprecated_bus_links(struct device *dev) | |
428 | { | |
429 | sysfs_remove_link(&dev->kobj, "bus"); | |
430 | } | |
431 | #else | |
432 | static inline int make_deprecated_bus_links(struct device *dev) { return 0; } | |
433 | static inline void remove_deprecated_bus_links(struct device *dev) { } | |
434 | #endif | |
435 | ||
436 | /** | |
437 | * bus_add_device - add device to bus | |
438 | * @dev: device being added | |
439 | * | |
440 | * - Add the device to its bus's list of devices. | |
441 | * - Create link to device's bus. | |
442 | */ | |
443 | int bus_add_device(struct device * dev) | |
444 | { | |
445 | struct bus_type * bus = bus_get(dev->bus); | |
446 | int error = 0; | |
447 | ||
448 | if (bus) { | |
449 | pr_debug("bus: '%s': add device %s\n", bus->name, dev->bus_id); | |
450 | error = device_add_attrs(bus, dev); | |
451 | if (error) | |
452 | goto out_put; | |
453 | error = sysfs_create_link(&bus->p->devices_kset->kobj, | |
454 | &dev->kobj, dev->bus_id); | |
455 | if (error) | |
456 | goto out_id; | |
457 | error = sysfs_create_link(&dev->kobj, | |
458 | &dev->bus->p->subsys.kobj, "subsystem"); | |
459 | if (error) | |
460 | goto out_subsys; | |
461 | error = make_deprecated_bus_links(dev); | |
462 | if (error) | |
463 | goto out_deprecated; | |
464 | } | |
465 | return 0; | |
466 | ||
467 | out_deprecated: | |
468 | sysfs_remove_link(&dev->kobj, "subsystem"); | |
469 | out_subsys: | |
470 | sysfs_remove_link(&bus->p->devices_kset->kobj, dev->bus_id); | |
471 | out_id: | |
472 | device_remove_attrs(bus, dev); | |
473 | out_put: | |
474 | bus_put(dev->bus); | |
475 | return error; | |
476 | } | |
477 | ||
478 | /** | |
479 | * bus_attach_device - add device to bus | |
480 | * @dev: device tried to attach to a driver | |
481 | * | |
482 | * - Add device to bus's list of devices. | |
483 | * - Try to attach to driver. | |
484 | */ | |
485 | void bus_attach_device(struct device * dev) | |
486 | { | |
487 | struct bus_type *bus = dev->bus; | |
488 | int ret = 0; | |
489 | ||
490 | if (bus) { | |
491 | dev->is_registered = 1; | |
492 | if (bus->p->drivers_autoprobe) | |
493 | ret = device_attach(dev); | |
494 | WARN_ON(ret < 0); | |
495 | if (ret >= 0) | |
496 | klist_add_tail(&dev->knode_bus, &bus->p->klist_devices); | |
497 | else | |
498 | dev->is_registered = 0; | |
499 | } | |
500 | } | |
501 | ||
502 | /** | |
503 | * bus_remove_device - remove device from bus | |
504 | * @dev: device to be removed | |
505 | * | |
506 | * - Remove symlink from bus's directory. | |
507 | * - Delete device from bus's list. | |
508 | * - Detach from its driver. | |
509 | * - Drop reference taken in bus_add_device(). | |
510 | */ | |
511 | void bus_remove_device(struct device * dev) | |
512 | { | |
513 | if (dev->bus) { | |
514 | sysfs_remove_link(&dev->kobj, "subsystem"); | |
515 | remove_deprecated_bus_links(dev); | |
516 | sysfs_remove_link(&dev->bus->p->devices_kset->kobj, dev->bus_id); | |
517 | device_remove_attrs(dev->bus, dev); | |
518 | if (dev->is_registered) { | |
519 | dev->is_registered = 0; | |
520 | klist_del(&dev->knode_bus); | |
521 | } | |
522 | pr_debug("bus: '%s': remove device %s\n", dev->bus->name, dev->bus_id); | |
523 | device_release_driver(dev); | |
524 | bus_put(dev->bus); | |
525 | } | |
526 | } | |
527 | ||
528 | static int driver_add_attrs(struct bus_type * bus, struct device_driver * drv) | |
529 | { | |
530 | int error = 0; | |
531 | int i; | |
532 | ||
533 | if (bus->drv_attrs) { | |
534 | for (i = 0; attr_name(bus->drv_attrs[i]); i++) { | |
535 | error = driver_create_file(drv, &bus->drv_attrs[i]); | |
536 | if (error) | |
537 | goto Err; | |
538 | } | |
539 | } | |
540 | Done: | |
541 | return error; | |
542 | Err: | |
543 | while (--i >= 0) | |
544 | driver_remove_file(drv, &bus->drv_attrs[i]); | |
545 | goto Done; | |
546 | } | |
547 | ||
548 | ||
549 | static void driver_remove_attrs(struct bus_type * bus, struct device_driver * drv) | |
550 | { | |
551 | int i; | |
552 | ||
553 | if (bus->drv_attrs) { | |
554 | for (i = 0; attr_name(bus->drv_attrs[i]); i++) | |
555 | driver_remove_file(drv, &bus->drv_attrs[i]); | |
556 | } | |
557 | } | |
558 | ||
559 | #ifdef CONFIG_HOTPLUG | |
560 | /* | |
561 | * Thanks to drivers making their tables __devinit, we can't allow manual | |
562 | * bind and unbind from userspace unless CONFIG_HOTPLUG is enabled. | |
563 | */ | |
564 | static int __must_check add_bind_files(struct device_driver *drv) | |
565 | { | |
566 | int ret; | |
567 | ||
568 | ret = driver_create_file(drv, &driver_attr_unbind); | |
569 | if (ret == 0) { | |
570 | ret = driver_create_file(drv, &driver_attr_bind); | |
571 | if (ret) | |
572 | driver_remove_file(drv, &driver_attr_unbind); | |
573 | } | |
574 | return ret; | |
575 | } | |
576 | ||
577 | static void remove_bind_files(struct device_driver *drv) | |
578 | { | |
579 | driver_remove_file(drv, &driver_attr_bind); | |
580 | driver_remove_file(drv, &driver_attr_unbind); | |
581 | } | |
582 | ||
583 | static BUS_ATTR(drivers_probe, S_IWUSR, NULL, store_drivers_probe); | |
584 | static BUS_ATTR(drivers_autoprobe, S_IWUSR | S_IRUGO, | |
585 | show_drivers_autoprobe, store_drivers_autoprobe); | |
586 | ||
587 | static int add_probe_files(struct bus_type *bus) | |
588 | { | |
589 | int retval; | |
590 | ||
591 | retval = bus_create_file(bus, &bus_attr_drivers_probe); | |
592 | if (retval) | |
593 | goto out; | |
594 | ||
595 | retval = bus_create_file(bus, &bus_attr_drivers_autoprobe); | |
596 | if (retval) | |
597 | bus_remove_file(bus, &bus_attr_drivers_probe); | |
598 | out: | |
599 | return retval; | |
600 | } | |
601 | ||
602 | static void remove_probe_files(struct bus_type *bus) | |
603 | { | |
604 | bus_remove_file(bus, &bus_attr_drivers_autoprobe); | |
605 | bus_remove_file(bus, &bus_attr_drivers_probe); | |
606 | } | |
607 | #else | |
608 | static inline int add_bind_files(struct device_driver *drv) { return 0; } | |
609 | static inline void remove_bind_files(struct device_driver *drv) {} | |
610 | static inline int add_probe_files(struct bus_type *bus) { return 0; } | |
611 | static inline void remove_probe_files(struct bus_type *bus) {} | |
612 | #endif | |
613 | ||
614 | static ssize_t driver_uevent_store(struct device_driver *drv, | |
615 | const char *buf, size_t count) | |
616 | { | |
617 | enum kobject_action action; | |
618 | ||
619 | if (kobject_action_type(buf, count, &action) == 0) | |
620 | kobject_uevent(&drv->p->kobj, action); | |
621 | return count; | |
622 | } | |
623 | static DRIVER_ATTR(uevent, S_IWUSR, NULL, driver_uevent_store); | |
624 | ||
625 | /** | |
626 | * bus_add_driver - Add a driver to the bus. | |
627 | * @drv: driver. | |
628 | * | |
629 | */ | |
630 | int bus_add_driver(struct device_driver *drv) | |
631 | { | |
632 | struct bus_type *bus; | |
633 | struct driver_private *priv; | |
634 | int error = 0; | |
635 | ||
636 | bus = bus_get(drv->bus); | |
637 | if (!bus) | |
638 | return -EINVAL; | |
639 | ||
640 | pr_debug("bus: '%s': add driver %s\n", bus->name, drv->name); | |
641 | ||
642 | priv = kzalloc(sizeof(*priv), GFP_KERNEL); | |
643 | if (!priv) | |
644 | return -ENOMEM; | |
645 | ||
646 | klist_init(&priv->klist_devices, NULL, NULL); | |
647 | priv->driver = drv; | |
648 | drv->p = priv; | |
649 | priv->kobj.kset = bus->p->drivers_kset; | |
650 | error = kobject_init_and_add(&priv->kobj, &driver_ktype, NULL, | |
651 | "%s", drv->name); | |
652 | if (error) | |
653 | goto out_put_bus; | |
654 | ||
655 | if (drv->bus->p->drivers_autoprobe) { | |
656 | error = driver_attach(drv); | |
657 | if (error) | |
658 | goto out_unregister; | |
659 | } | |
660 | klist_add_tail(&priv->knode_bus, &bus->p->klist_drivers); | |
661 | module_add_driver(drv->owner, drv); | |
662 | ||
663 | error = driver_create_file(drv, &driver_attr_uevent); | |
664 | if (error) { | |
665 | printk(KERN_ERR "%s: uevent attr (%s) failed\n", | |
666 | __FUNCTION__, drv->name); | |
667 | } | |
668 | error = driver_add_attrs(bus, drv); | |
669 | if (error) { | |
670 | /* How the hell do we get out of this pickle? Give up */ | |
671 | printk(KERN_ERR "%s: driver_add_attrs(%s) failed\n", | |
672 | __FUNCTION__, drv->name); | |
673 | } | |
674 | error = add_bind_files(drv); | |
675 | if (error) { | |
676 | /* Ditto */ | |
677 | printk(KERN_ERR "%s: add_bind_files(%s) failed\n", | |
678 | __FUNCTION__, drv->name); | |
679 | } | |
680 | ||
681 | kobject_uevent(&priv->kobj, KOBJ_ADD); | |
682 | return error; | |
683 | out_unregister: | |
684 | kobject_unregister(&priv->kobj); | |
685 | out_put_bus: | |
686 | bus_put(bus); | |
687 | return error; | |
688 | } | |
689 | ||
690 | /** | |
691 | * bus_remove_driver - delete driver from bus's knowledge. | |
692 | * @drv: driver. | |
693 | * | |
694 | * Detach the driver from the devices it controls, and remove | |
695 | * it from its bus's list of drivers. Finally, we drop the reference | |
696 | * to the bus we took in bus_add_driver(). | |
697 | */ | |
698 | ||
699 | void bus_remove_driver(struct device_driver * drv) | |
700 | { | |
701 | if (!drv->bus) | |
702 | return; | |
703 | ||
704 | remove_bind_files(drv); | |
705 | driver_remove_attrs(drv->bus, drv); | |
706 | driver_remove_file(drv, &driver_attr_uevent); | |
707 | klist_remove(&drv->p->knode_bus); | |
708 | pr_debug("bus: '%s': remove driver %s\n", drv->bus->name, drv->name); | |
709 | driver_detach(drv); | |
710 | module_remove_driver(drv); | |
711 | kobject_unregister(&drv->p->kobj); | |
712 | bus_put(drv->bus); | |
713 | } | |
714 | ||
715 | ||
716 | /* Helper for bus_rescan_devices's iter */ | |
717 | static int __must_check bus_rescan_devices_helper(struct device *dev, | |
718 | void *data) | |
719 | { | |
720 | int ret = 0; | |
721 | ||
722 | if (!dev->driver) { | |
723 | if (dev->parent) /* Needed for USB */ | |
724 | down(&dev->parent->sem); | |
725 | ret = device_attach(dev); | |
726 | if (dev->parent) | |
727 | up(&dev->parent->sem); | |
728 | } | |
729 | return ret < 0 ? ret : 0; | |
730 | } | |
731 | ||
732 | /** | |
733 | * bus_rescan_devices - rescan devices on the bus for possible drivers | |
734 | * @bus: the bus to scan. | |
735 | * | |
736 | * This function will look for devices on the bus with no driver | |
737 | * attached and rescan it against existing drivers to see if it matches | |
738 | * any by calling device_attach() for the unbound devices. | |
739 | */ | |
740 | int bus_rescan_devices(struct bus_type * bus) | |
741 | { | |
742 | return bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper); | |
743 | } | |
744 | ||
745 | /** | |
746 | * device_reprobe - remove driver for a device and probe for a new driver | |
747 | * @dev: the device to reprobe | |
748 | * | |
749 | * This function detaches the attached driver (if any) for the given | |
750 | * device and restarts the driver probing process. It is intended | |
751 | * to use if probing criteria changed during a devices lifetime and | |
752 | * driver attachment should change accordingly. | |
753 | */ | |
754 | int device_reprobe(struct device *dev) | |
755 | { | |
756 | if (dev->driver) { | |
757 | if (dev->parent) /* Needed for USB */ | |
758 | down(&dev->parent->sem); | |
759 | device_release_driver(dev); | |
760 | if (dev->parent) | |
761 | up(&dev->parent->sem); | |
762 | } | |
763 | return bus_rescan_devices_helper(dev, NULL); | |
764 | } | |
765 | EXPORT_SYMBOL_GPL(device_reprobe); | |
766 | ||
767 | /** | |
768 | * find_bus - locate bus by name. | |
769 | * @name: name of bus. | |
770 | * | |
771 | * Call kset_find_obj() to iterate over list of buses to | |
772 | * find a bus by name. Return bus if found. | |
773 | * | |
774 | * Note that kset_find_obj increments bus' reference count. | |
775 | */ | |
776 | #if 0 | |
777 | struct bus_type * find_bus(char * name) | |
778 | { | |
779 | struct kobject * k = kset_find_obj(bus_kset, name); | |
780 | return k ? to_bus(k) : NULL; | |
781 | } | |
782 | #endif /* 0 */ | |
783 | ||
784 | ||
785 | /** | |
786 | * bus_add_attrs - Add default attributes for this bus. | |
787 | * @bus: Bus that has just been registered. | |
788 | */ | |
789 | ||
790 | static int bus_add_attrs(struct bus_type * bus) | |
791 | { | |
792 | int error = 0; | |
793 | int i; | |
794 | ||
795 | if (bus->bus_attrs) { | |
796 | for (i = 0; attr_name(bus->bus_attrs[i]); i++) { | |
797 | error = bus_create_file(bus,&bus->bus_attrs[i]); | |
798 | if (error) | |
799 | goto Err; | |
800 | } | |
801 | } | |
802 | Done: | |
803 | return error; | |
804 | Err: | |
805 | while (--i >= 0) | |
806 | bus_remove_file(bus,&bus->bus_attrs[i]); | |
807 | goto Done; | |
808 | } | |
809 | ||
810 | static void bus_remove_attrs(struct bus_type * bus) | |
811 | { | |
812 | int i; | |
813 | ||
814 | if (bus->bus_attrs) { | |
815 | for (i = 0; attr_name(bus->bus_attrs[i]); i++) | |
816 | bus_remove_file(bus,&bus->bus_attrs[i]); | |
817 | } | |
818 | } | |
819 | ||
820 | static void klist_devices_get(struct klist_node *n) | |
821 | { | |
822 | struct device *dev = container_of(n, struct device, knode_bus); | |
823 | ||
824 | get_device(dev); | |
825 | } | |
826 | ||
827 | static void klist_devices_put(struct klist_node *n) | |
828 | { | |
829 | struct device *dev = container_of(n, struct device, knode_bus); | |
830 | ||
831 | put_device(dev); | |
832 | } | |
833 | ||
834 | static ssize_t bus_uevent_store(struct bus_type *bus, | |
835 | const char *buf, size_t count) | |
836 | { | |
837 | enum kobject_action action; | |
838 | ||
839 | if (kobject_action_type(buf, count, &action) == 0) | |
840 | kobject_uevent(&bus->p->subsys.kobj, action); | |
841 | return count; | |
842 | } | |
843 | static BUS_ATTR(uevent, S_IWUSR, NULL, bus_uevent_store); | |
844 | ||
845 | /** | |
846 | * bus_register - register a bus with the system. | |
847 | * @bus: bus. | |
848 | * | |
849 | * Once we have that, we registered the bus with the kobject | |
850 | * infrastructure, then register the children subsystems it has: | |
851 | * the devices and drivers that belong to the bus. | |
852 | */ | |
853 | int bus_register(struct bus_type * bus) | |
854 | { | |
855 | int retval; | |
856 | struct bus_type_private *priv; | |
857 | ||
858 | priv = kzalloc(sizeof(struct bus_type_private), GFP_KERNEL); | |
859 | if (!priv) | |
860 | return -ENOMEM; | |
861 | ||
862 | priv->bus = bus; | |
863 | bus->p = priv; | |
864 | ||
865 | BLOCKING_INIT_NOTIFIER_HEAD(&priv->bus_notifier); | |
866 | ||
867 | retval = kobject_set_name(&priv->subsys.kobj, "%s", bus->name); | |
868 | if (retval) | |
869 | goto out; | |
870 | ||
871 | priv->subsys.kobj.kset = bus_kset; | |
872 | priv->subsys.kobj.ktype = &bus_ktype; | |
873 | priv->drivers_autoprobe = 1; | |
874 | ||
875 | retval = kset_register(&priv->subsys); | |
876 | if (retval) | |
877 | goto out; | |
878 | ||
879 | retval = bus_create_file(bus, &bus_attr_uevent); | |
880 | if (retval) | |
881 | goto bus_uevent_fail; | |
882 | ||
883 | priv->devices_kset = kset_create_and_add("devices", NULL, | |
884 | &priv->subsys.kobj); | |
885 | if (!priv->devices_kset) { | |
886 | retval = -ENOMEM; | |
887 | goto bus_devices_fail; | |
888 | } | |
889 | ||
890 | priv->drivers_kset = kset_create_and_add("drivers", NULL, | |
891 | &priv->subsys.kobj); | |
892 | if (!priv->drivers_kset) { | |
893 | retval = -ENOMEM; | |
894 | goto bus_drivers_fail; | |
895 | } | |
896 | ||
897 | klist_init(&priv->klist_devices, klist_devices_get, klist_devices_put); | |
898 | klist_init(&priv->klist_drivers, NULL, NULL); | |
899 | ||
900 | retval = add_probe_files(bus); | |
901 | if (retval) | |
902 | goto bus_probe_files_fail; | |
903 | ||
904 | retval = bus_add_attrs(bus); | |
905 | if (retval) | |
906 | goto bus_attrs_fail; | |
907 | ||
908 | pr_debug("bus: '%s': registered\n", bus->name); | |
909 | return 0; | |
910 | ||
911 | bus_attrs_fail: | |
912 | remove_probe_files(bus); | |
913 | bus_probe_files_fail: | |
914 | kset_unregister(bus->p->drivers_kset); | |
915 | bus_drivers_fail: | |
916 | kset_unregister(bus->p->devices_kset); | |
917 | bus_devices_fail: | |
918 | bus_remove_file(bus, &bus_attr_uevent); | |
919 | bus_uevent_fail: | |
920 | kset_unregister(&bus->p->subsys); | |
921 | kfree(bus->p); | |
922 | out: | |
923 | return retval; | |
924 | } | |
925 | ||
926 | /** | |
927 | * bus_unregister - remove a bus from the system | |
928 | * @bus: bus. | |
929 | * | |
930 | * Unregister the child subsystems and the bus itself. | |
931 | * Finally, we call bus_put() to release the refcount | |
932 | */ | |
933 | void bus_unregister(struct bus_type * bus) | |
934 | { | |
935 | pr_debug("bus: '%s': unregistering\n", bus->name); | |
936 | bus_remove_attrs(bus); | |
937 | remove_probe_files(bus); | |
938 | kset_unregister(bus->p->drivers_kset); | |
939 | kset_unregister(bus->p->devices_kset); | |
940 | bus_remove_file(bus, &bus_attr_uevent); | |
941 | kset_unregister(&bus->p->subsys); | |
942 | kfree(bus->p); | |
943 | } | |
944 | ||
945 | int bus_register_notifier(struct bus_type *bus, struct notifier_block *nb) | |
946 | { | |
947 | return blocking_notifier_chain_register(&bus->p->bus_notifier, nb); | |
948 | } | |
949 | EXPORT_SYMBOL_GPL(bus_register_notifier); | |
950 | ||
951 | int bus_unregister_notifier(struct bus_type *bus, struct notifier_block *nb) | |
952 | { | |
953 | return blocking_notifier_chain_unregister(&bus->p->bus_notifier, nb); | |
954 | } | |
955 | EXPORT_SYMBOL_GPL(bus_unregister_notifier); | |
956 | ||
957 | struct kset *bus_get_kset(struct bus_type *bus) | |
958 | { | |
959 | return &bus->p->subsys; | |
960 | } | |
961 | EXPORT_SYMBOL_GPL(bus_get_kset); | |
962 | ||
963 | struct klist *bus_get_device_klist(struct bus_type *bus) | |
964 | { | |
965 | return &bus->p->klist_devices; | |
966 | } | |
967 | EXPORT_SYMBOL_GPL(bus_get_device_klist); | |
968 | ||
969 | int __init buses_init(void) | |
970 | { | |
971 | bus_kset = kset_create_and_add("bus", &bus_uevent_ops, NULL); | |
972 | if (!bus_kset) | |
973 | return -ENOMEM; | |
974 | return 0; | |
975 | } | |
976 | ||
977 | ||
978 | EXPORT_SYMBOL_GPL(bus_for_each_dev); | |
979 | EXPORT_SYMBOL_GPL(bus_find_device); | |
980 | EXPORT_SYMBOL_GPL(bus_for_each_drv); | |
981 | ||
982 | EXPORT_SYMBOL_GPL(bus_register); | |
983 | EXPORT_SYMBOL_GPL(bus_unregister); | |
984 | EXPORT_SYMBOL_GPL(bus_rescan_devices); | |
985 | ||
986 | EXPORT_SYMBOL_GPL(bus_create_file); | |
987 | EXPORT_SYMBOL_GPL(bus_remove_file); |