Commit | Line | Data |
---|---|---|
1da177e4 LT |
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 | * | |
7 | * This file is released under the GPLv2 | |
8 | * | |
9 | */ | |
10 | ||
1da177e4 LT |
11 | #include <linux/device.h> |
12 | #include <linux/module.h> | |
13 | #include <linux/errno.h> | |
14 | #include <linux/init.h> | |
15 | #include <linux/string.h> | |
16 | #include "base.h" | |
17 | #include "power/power.h" | |
18 | ||
1da177e4 LT |
19 | #define to_bus_attr(_attr) container_of(_attr, struct bus_attribute, attr) |
20 | #define to_bus(obj) container_of(obj, struct bus_type, subsys.kset.kobj) | |
21 | ||
22 | /* | |
23 | * sysfs bindings for drivers | |
24 | */ | |
25 | ||
26 | #define to_drv_attr(_attr) container_of(_attr, struct driver_attribute, attr) | |
27 | #define to_driver(obj) container_of(obj, struct device_driver, kobj) | |
28 | ||
29 | ||
b8c5cec2 KS |
30 | static int __must_check bus_rescan_devices_helper(struct device *dev, |
31 | void *data); | |
32 | ||
1da177e4 LT |
33 | static ssize_t |
34 | drv_attr_show(struct kobject * kobj, struct attribute * attr, char * buf) | |
35 | { | |
36 | struct driver_attribute * drv_attr = to_drv_attr(attr); | |
37 | struct device_driver * drv = to_driver(kobj); | |
4a0c20bf | 38 | ssize_t ret = -EIO; |
1da177e4 LT |
39 | |
40 | if (drv_attr->show) | |
41 | ret = drv_attr->show(drv, buf); | |
42 | return ret; | |
43 | } | |
44 | ||
45 | static ssize_t | |
46 | drv_attr_store(struct kobject * kobj, struct attribute * attr, | |
47 | const char * buf, size_t count) | |
48 | { | |
49 | struct driver_attribute * drv_attr = to_drv_attr(attr); | |
50 | struct device_driver * drv = to_driver(kobj); | |
4a0c20bf | 51 | ssize_t ret = -EIO; |
1da177e4 LT |
52 | |
53 | if (drv_attr->store) | |
54 | ret = drv_attr->store(drv, buf, count); | |
55 | return ret; | |
56 | } | |
57 | ||
58 | static struct sysfs_ops driver_sysfs_ops = { | |
59 | .show = drv_attr_show, | |
60 | .store = drv_attr_store, | |
61 | }; | |
62 | ||
63 | ||
64 | static void driver_release(struct kobject * kobj) | |
65 | { | |
66 | struct device_driver * drv = to_driver(kobj); | |
67 | complete(&drv->unloaded); | |
68 | } | |
69 | ||
70 | static struct kobj_type ktype_driver = { | |
71 | .sysfs_ops = &driver_sysfs_ops, | |
72 | .release = driver_release, | |
73 | }; | |
74 | ||
75 | ||
76 | /* | |
77 | * sysfs bindings for buses | |
78 | */ | |
79 | ||
80 | ||
81 | static ssize_t | |
82 | bus_attr_show(struct kobject * kobj, struct attribute * attr, char * buf) | |
83 | { | |
84 | struct bus_attribute * bus_attr = to_bus_attr(attr); | |
85 | struct bus_type * bus = to_bus(kobj); | |
86 | ssize_t ret = 0; | |
87 | ||
88 | if (bus_attr->show) | |
89 | ret = bus_attr->show(bus, buf); | |
90 | return ret; | |
91 | } | |
92 | ||
93 | static ssize_t | |
94 | bus_attr_store(struct kobject * kobj, struct attribute * attr, | |
95 | const char * buf, size_t count) | |
96 | { | |
97 | struct bus_attribute * bus_attr = to_bus_attr(attr); | |
98 | struct bus_type * bus = to_bus(kobj); | |
99 | ssize_t ret = 0; | |
100 | ||
101 | if (bus_attr->store) | |
102 | ret = bus_attr->store(bus, buf, count); | |
103 | return ret; | |
104 | } | |
105 | ||
106 | static struct sysfs_ops bus_sysfs_ops = { | |
107 | .show = bus_attr_show, | |
108 | .store = bus_attr_store, | |
109 | }; | |
110 | ||
111 | int bus_create_file(struct bus_type * bus, struct bus_attribute * attr) | |
112 | { | |
113 | int error; | |
114 | if (get_bus(bus)) { | |
115 | error = sysfs_create_file(&bus->subsys.kset.kobj, &attr->attr); | |
116 | put_bus(bus); | |
117 | } else | |
118 | error = -EINVAL; | |
119 | return error; | |
120 | } | |
121 | ||
122 | void bus_remove_file(struct bus_type * bus, struct bus_attribute * attr) | |
123 | { | |
124 | if (get_bus(bus)) { | |
125 | sysfs_remove_file(&bus->subsys.kset.kobj, &attr->attr); | |
126 | put_bus(bus); | |
127 | } | |
128 | } | |
129 | ||
130 | static struct kobj_type ktype_bus = { | |
131 | .sysfs_ops = &bus_sysfs_ops, | |
132 | ||
133 | }; | |
134 | ||
7e4ef085 | 135 | static decl_subsys(bus, &ktype_bus, NULL); |
1da177e4 | 136 | |
1da177e4 | 137 | |
2139bdd5 | 138 | #ifdef CONFIG_HOTPLUG |
2b08c8d0 | 139 | /* Manually detach a device from its associated driver. */ |
151ef38f GKH |
140 | static int driver_helper(struct device *dev, void *data) |
141 | { | |
142 | const char *name = data; | |
143 | ||
144 | if (strcmp(name, dev->bus_id) == 0) | |
145 | return 1; | |
146 | return 0; | |
147 | } | |
148 | ||
149 | static ssize_t driver_unbind(struct device_driver *drv, | |
150 | const char *buf, size_t count) | |
151 | { | |
152 | struct bus_type *bus = get_bus(drv->bus); | |
153 | struct device *dev; | |
154 | int err = -ENODEV; | |
155 | ||
156 | dev = bus_find_device(bus, NULL, (void *)buf, driver_helper); | |
2b08c8d0 | 157 | if (dev && dev->driver == drv) { |
bf74ad5b AS |
158 | if (dev->parent) /* Needed for USB */ |
159 | down(&dev->parent->sem); | |
151ef38f | 160 | device_release_driver(dev); |
bf74ad5b AS |
161 | if (dev->parent) |
162 | up(&dev->parent->sem); | |
151ef38f GKH |
163 | err = count; |
164 | } | |
2b08c8d0 AS |
165 | put_device(dev); |
166 | put_bus(bus); | |
167 | return err; | |
151ef38f GKH |
168 | } |
169 | static DRIVER_ATTR(unbind, S_IWUSR, NULL, driver_unbind); | |
170 | ||
afdce75f GKH |
171 | /* |
172 | * Manually attach a device to a driver. | |
173 | * Note: the driver must want to bind to the device, | |
174 | * it is not possible to override the driver's id table. | |
175 | */ | |
176 | static ssize_t driver_bind(struct device_driver *drv, | |
177 | const char *buf, size_t count) | |
178 | { | |
179 | struct bus_type *bus = get_bus(drv->bus); | |
180 | struct device *dev; | |
181 | int err = -ENODEV; | |
182 | ||
183 | dev = bus_find_device(bus, NULL, (void *)buf, driver_helper); | |
2b08c8d0 | 184 | if (dev && dev->driver == NULL) { |
bf74ad5b AS |
185 | if (dev->parent) /* Needed for USB */ |
186 | down(&dev->parent->sem); | |
afdce75f GKH |
187 | down(&dev->sem); |
188 | err = driver_probe_device(drv, dev); | |
189 | up(&dev->sem); | |
bf74ad5b AS |
190 | if (dev->parent) |
191 | up(&dev->parent->sem); | |
37225401 RW |
192 | |
193 | if (err > 0) /* success */ | |
194 | err = count; | |
195 | else if (err == 0) /* driver didn't accept device */ | |
196 | err = -ENODEV; | |
afdce75f | 197 | } |
2b08c8d0 AS |
198 | put_device(dev); |
199 | put_bus(bus); | |
200 | return err; | |
afdce75f GKH |
201 | } |
202 | static DRIVER_ATTR(bind, S_IWUSR, NULL, driver_bind); | |
203 | ||
b8c5cec2 KS |
204 | static ssize_t show_drivers_autoprobe(struct bus_type *bus, char *buf) |
205 | { | |
206 | return sprintf(buf, "%d\n", bus->drivers_autoprobe); | |
207 | } | |
208 | ||
209 | static ssize_t store_drivers_autoprobe(struct bus_type *bus, | |
210 | const char *buf, size_t count) | |
211 | { | |
212 | if (buf[0] == '0') | |
213 | bus->drivers_autoprobe = 0; | |
214 | else | |
215 | bus->drivers_autoprobe = 1; | |
216 | return count; | |
217 | } | |
218 | ||
219 | static ssize_t store_drivers_probe(struct bus_type *bus, | |
220 | const char *buf, size_t count) | |
221 | { | |
222 | struct device *dev; | |
223 | ||
224 | dev = bus_find_device(bus, NULL, (void *)buf, driver_helper); | |
225 | if (!dev) | |
226 | return -ENODEV; | |
227 | if (bus_rescan_devices_helper(dev, NULL) != 0) | |
228 | return -EINVAL; | |
229 | return count; | |
230 | } | |
2139bdd5 | 231 | #endif |
151ef38f | 232 | |
465c7a3a | 233 | static struct device * next_device(struct klist_iter * i) |
234 | { | |
235 | struct klist_node * n = klist_next(i); | |
236 | return n ? container_of(n, struct device, knode_bus) : NULL; | |
237 | } | |
238 | ||
1da177e4 LT |
239 | /** |
240 | * bus_for_each_dev - device iterator. | |
241 | * @bus: bus type. | |
242 | * @start: device to start iterating from. | |
243 | * @data: data for the callback. | |
244 | * @fn: function to be called for each device. | |
245 | * | |
246 | * Iterate over @bus's list of devices, and call @fn for each, | |
247 | * passing it @data. If @start is not NULL, we use that device to | |
248 | * begin iterating from. | |
249 | * | |
250 | * We check the return of @fn each time. If it returns anything | |
251 | * other than 0, we break out and return that value. | |
252 | * | |
253 | * NOTE: The device that returns a non-zero value is not retained | |
254 | * in any way, nor is its refcount incremented. If the caller needs | |
255 | * to retain this data, it should do, and increment the reference | |
256 | * count in the supplied callback. | |
257 | */ | |
258 | ||
259 | int bus_for_each_dev(struct bus_type * bus, struct device * start, | |
260 | void * data, int (*fn)(struct device *, void *)) | |
261 | { | |
465c7a3a | 262 | struct klist_iter i; |
263 | struct device * dev; | |
264 | int error = 0; | |
1da177e4 | 265 | |
465c7a3a | 266 | if (!bus) |
267 | return -EINVAL; | |
268 | ||
269 | klist_iter_init_node(&bus->klist_devices, &i, | |
270 | (start ? &start->knode_bus : NULL)); | |
271 | while ((dev = next_device(&i)) && !error) | |
272 | error = fn(dev, data); | |
273 | klist_iter_exit(&i); | |
274 | return error; | |
1da177e4 LT |
275 | } |
276 | ||
0edb5860 CH |
277 | /** |
278 | * bus_find_device - device iterator for locating a particular device. | |
279 | * @bus: bus type | |
280 | * @start: Device to begin with | |
281 | * @data: Data to pass to match function | |
282 | * @match: Callback function to check device | |
283 | * | |
284 | * This is similar to the bus_for_each_dev() function above, but it | |
285 | * returns a reference to a device that is 'found' for later use, as | |
286 | * determined by the @match callback. | |
287 | * | |
288 | * The callback should return 0 if the device doesn't match and non-zero | |
289 | * if it does. If the callback returns non-zero, this function will | |
290 | * return to the caller and not iterate over any more devices. | |
291 | */ | |
292 | struct device * bus_find_device(struct bus_type *bus, | |
293 | struct device *start, void *data, | |
294 | int (*match)(struct device *, void *)) | |
295 | { | |
296 | struct klist_iter i; | |
297 | struct device *dev; | |
298 | ||
299 | if (!bus) | |
300 | return NULL; | |
301 | ||
302 | klist_iter_init_node(&bus->klist_devices, &i, | |
303 | (start ? &start->knode_bus : NULL)); | |
304 | while ((dev = next_device(&i))) | |
305 | if (match(dev, data) && get_device(dev)) | |
306 | break; | |
307 | klist_iter_exit(&i); | |
308 | return dev; | |
309 | } | |
38fdac3c | 310 | |
311 | ||
312 | static struct device_driver * next_driver(struct klist_iter * i) | |
313 | { | |
314 | struct klist_node * n = klist_next(i); | |
315 | return n ? container_of(n, struct device_driver, knode_bus) : NULL; | |
316 | } | |
317 | ||
1da177e4 LT |
318 | /** |
319 | * bus_for_each_drv - driver iterator | |
320 | * @bus: bus we're dealing with. | |
321 | * @start: driver to start iterating on. | |
322 | * @data: data to pass to the callback. | |
323 | * @fn: function to call for each driver. | |
324 | * | |
325 | * This is nearly identical to the device iterator above. | |
326 | * We iterate over each driver that belongs to @bus, and call | |
327 | * @fn for each. If @fn returns anything but 0, we break out | |
328 | * and return it. If @start is not NULL, we use it as the head | |
329 | * of the list. | |
330 | * | |
331 | * NOTE: we don't return the driver that returns a non-zero | |
332 | * value, nor do we leave the reference count incremented for that | |
333 | * driver. If the caller needs to know that info, it must set it | |
334 | * in the callback. It must also be sure to increment the refcount | |
335 | * so it doesn't disappear before returning to the caller. | |
336 | */ | |
337 | ||
338 | int bus_for_each_drv(struct bus_type * bus, struct device_driver * start, | |
339 | void * data, int (*fn)(struct device_driver *, void *)) | |
340 | { | |
38fdac3c | 341 | struct klist_iter i; |
342 | struct device_driver * drv; | |
343 | int error = 0; | |
1da177e4 | 344 | |
38fdac3c | 345 | if (!bus) |
346 | return -EINVAL; | |
347 | ||
348 | klist_iter_init_node(&bus->klist_drivers, &i, | |
349 | start ? &start->knode_bus : NULL); | |
350 | while ((drv = next_driver(&i)) && !error) | |
351 | error = fn(drv, data); | |
352 | klist_iter_exit(&i); | |
353 | return error; | |
1da177e4 LT |
354 | } |
355 | ||
4aca67e5 | 356 | static int device_add_attrs(struct bus_type *bus, struct device *dev) |
1da177e4 LT |
357 | { |
358 | int error = 0; | |
359 | int i; | |
360 | ||
4aca67e5 AM |
361 | if (!bus->dev_attrs) |
362 | return 0; | |
363 | ||
364 | for (i = 0; attr_name(bus->dev_attrs[i]); i++) { | |
365 | error = device_create_file(dev,&bus->dev_attrs[i]); | |
366 | if (error) { | |
367 | while (--i >= 0) | |
368 | device_remove_file(dev, &bus->dev_attrs[i]); | |
369 | break; | |
1da177e4 LT |
370 | } |
371 | } | |
1da177e4 | 372 | return error; |
1da177e4 LT |
373 | } |
374 | ||
1da177e4 LT |
375 | static void device_remove_attrs(struct bus_type * bus, struct device * dev) |
376 | { | |
377 | int i; | |
378 | ||
379 | if (bus->dev_attrs) { | |
380 | for (i = 0; attr_name(bus->dev_attrs[i]); i++) | |
381 | device_remove_file(dev,&bus->dev_attrs[i]); | |
382 | } | |
383 | } | |
384 | ||
b9cafc7d KS |
385 | #ifdef CONFIG_SYSFS_DEPRECATED |
386 | static int make_deprecated_bus_links(struct device *dev) | |
387 | { | |
388 | return sysfs_create_link(&dev->kobj, | |
389 | &dev->bus->subsys.kset.kobj, "bus"); | |
390 | } | |
391 | ||
392 | static void remove_deprecated_bus_links(struct device *dev) | |
393 | { | |
394 | sysfs_remove_link(&dev->kobj, "bus"); | |
395 | } | |
396 | #else | |
397 | static inline int make_deprecated_bus_links(struct device *dev) { return 0; } | |
398 | static inline void remove_deprecated_bus_links(struct device *dev) { } | |
399 | #endif | |
1da177e4 LT |
400 | |
401 | /** | |
402 | * bus_add_device - add device to bus | |
403 | * @dev: device being added | |
404 | * | |
405 | * - Add the device to its bus's list of devices. | |
53877d06 | 406 | * - Create link to device's bus. |
1da177e4 LT |
407 | */ |
408 | int bus_add_device(struct device * dev) | |
409 | { | |
410 | struct bus_type * bus = get_bus(dev->bus); | |
411 | int error = 0; | |
412 | ||
413 | if (bus) { | |
1da177e4 | 414 | pr_debug("bus %s: add device %s\n", bus->name, dev->bus_id); |
d377e85b | 415 | error = device_add_attrs(bus, dev); |
f86db396 | 416 | if (error) |
513e7337 | 417 | goto out_put; |
f86db396 AM |
418 | error = sysfs_create_link(&bus->devices.kobj, |
419 | &dev->kobj, dev->bus_id); | |
420 | if (error) | |
513e7337 | 421 | goto out_id; |
f86db396 AM |
422 | error = sysfs_create_link(&dev->kobj, |
423 | &dev->bus->subsys.kset.kobj, "subsystem"); | |
424 | if (error) | |
513e7337 | 425 | goto out_subsys; |
b9cafc7d | 426 | error = make_deprecated_bus_links(dev); |
513e7337 CH |
427 | if (error) |
428 | goto out_deprecated; | |
1da177e4 | 429 | } |
513e7337 CH |
430 | return 0; |
431 | ||
432 | out_deprecated: | |
433 | sysfs_remove_link(&dev->kobj, "subsystem"); | |
434 | out_subsys: | |
435 | sysfs_remove_link(&bus->devices.kobj, dev->bus_id); | |
436 | out_id: | |
437 | device_remove_attrs(bus, dev); | |
438 | out_put: | |
439 | put_bus(dev->bus); | |
1da177e4 LT |
440 | return error; |
441 | } | |
442 | ||
53877d06 KS |
443 | /** |
444 | * bus_attach_device - add device to bus | |
445 | * @dev: device tried to attach to a driver | |
446 | * | |
f2eaae19 | 447 | * - Add device to bus's list of devices. |
53877d06 KS |
448 | * - Try to attach to driver. |
449 | */ | |
f86db396 | 450 | int bus_attach_device(struct device * dev) |
53877d06 | 451 | { |
f86db396 AM |
452 | struct bus_type *bus = dev->bus; |
453 | int ret = 0; | |
53877d06 KS |
454 | |
455 | if (bus) { | |
f2eaae19 | 456 | dev->is_registered = 1; |
b8c5cec2 KS |
457 | if (bus->drivers_autoprobe) |
458 | ret = device_attach(dev); | |
f86db396 AM |
459 | if (ret >= 0) { |
460 | klist_add_tail(&dev->knode_bus, &bus->klist_devices); | |
461 | ret = 0; | |
f2eaae19 AS |
462 | } else |
463 | dev->is_registered = 0; | |
53877d06 | 464 | } |
f86db396 | 465 | return ret; |
53877d06 KS |
466 | } |
467 | ||
1da177e4 LT |
468 | /** |
469 | * bus_remove_device - remove device from bus | |
470 | * @dev: device to be removed | |
471 | * | |
472 | * - Remove symlink from bus's directory. | |
473 | * - Delete device from bus's list. | |
474 | * - Detach from its driver. | |
475 | * - Drop reference taken in bus_add_device(). | |
476 | */ | |
477 | void bus_remove_device(struct device * dev) | |
478 | { | |
479 | if (dev->bus) { | |
b9d9c82b | 480 | sysfs_remove_link(&dev->kobj, "subsystem"); |
b9cafc7d | 481 | remove_deprecated_bus_links(dev); |
1da177e4 LT |
482 | sysfs_remove_link(&dev->bus->devices.kobj, dev->bus_id); |
483 | device_remove_attrs(dev->bus, dev); | |
f70fa629 AS |
484 | if (dev->is_registered) { |
485 | dev->is_registered = 0; | |
486 | klist_del(&dev->knode_bus); | |
487 | } | |
1da177e4 LT |
488 | pr_debug("bus %s: remove device %s\n", dev->bus->name, dev->bus_id); |
489 | device_release_driver(dev); | |
1da177e4 LT |
490 | put_bus(dev->bus); |
491 | } | |
492 | } | |
493 | ||
494 | static int driver_add_attrs(struct bus_type * bus, struct device_driver * drv) | |
495 | { | |
496 | int error = 0; | |
497 | int i; | |
498 | ||
499 | if (bus->drv_attrs) { | |
500 | for (i = 0; attr_name(bus->drv_attrs[i]); i++) { | |
501 | error = driver_create_file(drv, &bus->drv_attrs[i]); | |
502 | if (error) | |
503 | goto Err; | |
504 | } | |
505 | } | |
506 | Done: | |
507 | return error; | |
508 | Err: | |
509 | while (--i >= 0) | |
510 | driver_remove_file(drv, &bus->drv_attrs[i]); | |
511 | goto Done; | |
512 | } | |
513 | ||
514 | ||
515 | static void driver_remove_attrs(struct bus_type * bus, struct device_driver * drv) | |
516 | { | |
517 | int i; | |
518 | ||
519 | if (bus->drv_attrs) { | |
520 | for (i = 0; attr_name(bus->drv_attrs[i]); i++) | |
521 | driver_remove_file(drv, &bus->drv_attrs[i]); | |
522 | } | |
523 | } | |
524 | ||
874c6241 GKH |
525 | #ifdef CONFIG_HOTPLUG |
526 | /* | |
527 | * Thanks to drivers making their tables __devinit, we can't allow manual | |
528 | * bind and unbind from userspace unless CONFIG_HOTPLUG is enabled. | |
529 | */ | |
f86db396 | 530 | static int __must_check add_bind_files(struct device_driver *drv) |
874c6241 | 531 | { |
f86db396 AM |
532 | int ret; |
533 | ||
534 | ret = driver_create_file(drv, &driver_attr_unbind); | |
535 | if (ret == 0) { | |
536 | ret = driver_create_file(drv, &driver_attr_bind); | |
537 | if (ret) | |
538 | driver_remove_file(drv, &driver_attr_unbind); | |
539 | } | |
540 | return ret; | |
874c6241 GKH |
541 | } |
542 | ||
543 | static void remove_bind_files(struct device_driver *drv) | |
544 | { | |
545 | driver_remove_file(drv, &driver_attr_bind); | |
546 | driver_remove_file(drv, &driver_attr_unbind); | |
547 | } | |
b8c5cec2 KS |
548 | |
549 | static int add_probe_files(struct bus_type *bus) | |
550 | { | |
551 | int retval; | |
552 | ||
553 | bus->drivers_probe_attr.attr.name = "drivers_probe"; | |
554 | bus->drivers_probe_attr.attr.mode = S_IWUSR; | |
555 | bus->drivers_probe_attr.attr.owner = bus->owner; | |
556 | bus->drivers_probe_attr.store = store_drivers_probe; | |
557 | retval = bus_create_file(bus, &bus->drivers_probe_attr); | |
558 | if (retval) | |
559 | goto out; | |
560 | ||
561 | bus->drivers_autoprobe_attr.attr.name = "drivers_autoprobe"; | |
562 | bus->drivers_autoprobe_attr.attr.mode = S_IWUSR | S_IRUGO; | |
563 | bus->drivers_autoprobe_attr.attr.owner = bus->owner; | |
564 | bus->drivers_autoprobe_attr.show = show_drivers_autoprobe; | |
565 | bus->drivers_autoprobe_attr.store = store_drivers_autoprobe; | |
566 | retval = bus_create_file(bus, &bus->drivers_autoprobe_attr); | |
567 | if (retval) | |
568 | bus_remove_file(bus, &bus->drivers_probe_attr); | |
569 | out: | |
570 | return retval; | |
571 | } | |
572 | ||
573 | static void remove_probe_files(struct bus_type *bus) | |
574 | { | |
575 | bus_remove_file(bus, &bus->drivers_autoprobe_attr); | |
576 | bus_remove_file(bus, &bus->drivers_probe_attr); | |
577 | } | |
874c6241 | 578 | #else |
35acfdd7 | 579 | static inline int add_bind_files(struct device_driver *drv) { return 0; } |
874c6241 | 580 | static inline void remove_bind_files(struct device_driver *drv) {} |
b8c5cec2 KS |
581 | static inline int add_probe_files(struct bus_type *bus) { return 0; } |
582 | static inline void remove_probe_files(struct bus_type *bus) {} | |
874c6241 | 583 | #endif |
1da177e4 LT |
584 | |
585 | /** | |
586 | * bus_add_driver - Add a driver to the bus. | |
587 | * @drv: driver. | |
588 | * | |
589 | */ | |
f86db396 | 590 | int bus_add_driver(struct device_driver *drv) |
1da177e4 LT |
591 | { |
592 | struct bus_type * bus = get_bus(drv->bus); | |
593 | int error = 0; | |
594 | ||
d9fd4d3b JG |
595 | if (!bus) |
596 | return 0; | |
597 | ||
598 | pr_debug("bus %s: add driver %s\n", bus->name, drv->name); | |
599 | error = kobject_set_name(&drv->kobj, "%s", drv->name); | |
600 | if (error) | |
601 | goto out_put_bus; | |
602 | drv->kobj.kset = &bus->drivers; | |
603 | if ((error = kobject_register(&drv->kobj))) | |
604 | goto out_put_bus; | |
605 | ||
b8c5cec2 KS |
606 | if (drv->bus->drivers_autoprobe) { |
607 | error = driver_attach(drv); | |
608 | if (error) | |
609 | goto out_unregister; | |
610 | } | |
d9fd4d3b JG |
611 | klist_add_tail(&drv->knode_bus, &bus->klist_drivers); |
612 | module_add_driver(drv->owner, drv); | |
613 | ||
614 | error = driver_add_attrs(bus, drv); | |
615 | if (error) { | |
616 | /* How the hell do we get out of this pickle? Give up */ | |
617 | printk(KERN_ERR "%s: driver_add_attrs(%s) failed\n", | |
618 | __FUNCTION__, drv->name); | |
619 | } | |
620 | error = add_bind_files(drv); | |
621 | if (error) { | |
622 | /* Ditto */ | |
623 | printk(KERN_ERR "%s: add_bind_files(%s) failed\n", | |
624 | __FUNCTION__, drv->name); | |
1da177e4 | 625 | } |
d9fd4d3b | 626 | |
1da177e4 | 627 | return error; |
f86db396 AM |
628 | out_unregister: |
629 | kobject_unregister(&drv->kobj); | |
630 | out_put_bus: | |
631 | put_bus(bus); | |
632 | return error; | |
1da177e4 LT |
633 | } |
634 | ||
1da177e4 LT |
635 | /** |
636 | * bus_remove_driver - delete driver from bus's knowledge. | |
637 | * @drv: driver. | |
638 | * | |
639 | * Detach the driver from the devices it controls, and remove | |
640 | * it from its bus's list of drivers. Finally, we drop the reference | |
641 | * to the bus we took in bus_add_driver(). | |
642 | */ | |
643 | ||
644 | void bus_remove_driver(struct device_driver * drv) | |
645 | { | |
d9fd4d3b JG |
646 | if (!drv->bus) |
647 | return; | |
648 | ||
649 | remove_bind_files(drv); | |
650 | driver_remove_attrs(drv->bus, drv); | |
651 | klist_remove(&drv->knode_bus); | |
652 | pr_debug("bus %s: remove driver %s\n", drv->bus->name, drv->name); | |
653 | driver_detach(drv); | |
654 | module_remove_driver(drv); | |
655 | kobject_unregister(&drv->kobj); | |
656 | put_bus(drv->bus); | |
1da177e4 LT |
657 | } |
658 | ||
659 | ||
660 | /* Helper for bus_rescan_devices's iter */ | |
f86db396 AM |
661 | static int __must_check bus_rescan_devices_helper(struct device *dev, |
662 | void *data) | |
1da177e4 | 663 | { |
f86db396 AM |
664 | int ret = 0; |
665 | ||
bf74ad5b AS |
666 | if (!dev->driver) { |
667 | if (dev->parent) /* Needed for USB */ | |
668 | down(&dev->parent->sem); | |
f86db396 | 669 | ret = device_attach(dev); |
bf74ad5b AS |
670 | if (dev->parent) |
671 | up(&dev->parent->sem); | |
f86db396 AM |
672 | if (ret > 0) |
673 | ret = 0; | |
bf74ad5b | 674 | } |
f86db396 | 675 | return ret < 0 ? ret : 0; |
1da177e4 LT |
676 | } |
677 | ||
1da177e4 | 678 | /** |
23d3d602 GKH |
679 | * bus_rescan_devices - rescan devices on the bus for possible drivers |
680 | * @bus: the bus to scan. | |
1da177e4 | 681 | * |
23d3d602 GKH |
682 | * This function will look for devices on the bus with no driver |
683 | * attached and rescan it against existing drivers to see if it matches | |
684 | * any by calling device_attach() for the unbound devices. | |
1da177e4 | 685 | */ |
f86db396 | 686 | int bus_rescan_devices(struct bus_type * bus) |
1da177e4 | 687 | { |
f86db396 | 688 | return bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper); |
1da177e4 LT |
689 | } |
690 | ||
e935d5da ME |
691 | /** |
692 | * device_reprobe - remove driver for a device and probe for a new driver | |
693 | * @dev: the device to reprobe | |
694 | * | |
695 | * This function detaches the attached driver (if any) for the given | |
696 | * device and restarts the driver probing process. It is intended | |
697 | * to use if probing criteria changed during a devices lifetime and | |
698 | * driver attachment should change accordingly. | |
699 | */ | |
f86db396 | 700 | int device_reprobe(struct device *dev) |
e935d5da ME |
701 | { |
702 | if (dev->driver) { | |
703 | if (dev->parent) /* Needed for USB */ | |
704 | down(&dev->parent->sem); | |
705 | device_release_driver(dev); | |
706 | if (dev->parent) | |
707 | up(&dev->parent->sem); | |
708 | } | |
f86db396 | 709 | return bus_rescan_devices_helper(dev, NULL); |
e935d5da ME |
710 | } |
711 | EXPORT_SYMBOL_GPL(device_reprobe); | |
1da177e4 | 712 | |
f86db396 | 713 | struct bus_type *get_bus(struct bus_type *bus) |
1da177e4 | 714 | { |
f86db396 AM |
715 | return bus ? container_of(subsys_get(&bus->subsys), |
716 | struct bus_type, subsys) : NULL; | |
1da177e4 LT |
717 | } |
718 | ||
719 | void put_bus(struct bus_type * bus) | |
720 | { | |
721 | subsys_put(&bus->subsys); | |
722 | } | |
723 | ||
724 | ||
725 | /** | |
726 | * find_bus - locate bus by name. | |
727 | * @name: name of bus. | |
728 | * | |
729 | * Call kset_find_obj() to iterate over list of buses to | |
730 | * find a bus by name. Return bus if found. | |
731 | * | |
732 | * Note that kset_find_obj increments bus' reference count. | |
733 | */ | |
7e4ef085 | 734 | #if 0 |
1da177e4 LT |
735 | struct bus_type * find_bus(char * name) |
736 | { | |
737 | struct kobject * k = kset_find_obj(&bus_subsys.kset, name); | |
738 | return k ? to_bus(k) : NULL; | |
739 | } | |
7e4ef085 | 740 | #endif /* 0 */ |
1da177e4 LT |
741 | |
742 | ||
743 | /** | |
744 | * bus_add_attrs - Add default attributes for this bus. | |
745 | * @bus: Bus that has just been registered. | |
746 | */ | |
747 | ||
748 | static int bus_add_attrs(struct bus_type * bus) | |
749 | { | |
750 | int error = 0; | |
751 | int i; | |
752 | ||
753 | if (bus->bus_attrs) { | |
754 | for (i = 0; attr_name(bus->bus_attrs[i]); i++) { | |
755 | if ((error = bus_create_file(bus,&bus->bus_attrs[i]))) | |
756 | goto Err; | |
757 | } | |
758 | } | |
759 | Done: | |
760 | return error; | |
761 | Err: | |
762 | while (--i >= 0) | |
763 | bus_remove_file(bus,&bus->bus_attrs[i]); | |
764 | goto Done; | |
765 | } | |
766 | ||
767 | static void bus_remove_attrs(struct bus_type * bus) | |
768 | { | |
769 | int i; | |
770 | ||
771 | if (bus->bus_attrs) { | |
772 | for (i = 0; attr_name(bus->bus_attrs[i]); i++) | |
773 | bus_remove_file(bus,&bus->bus_attrs[i]); | |
774 | } | |
775 | } | |
776 | ||
34bb61f9 JB |
777 | static void klist_devices_get(struct klist_node *n) |
778 | { | |
779 | struct device *dev = container_of(n, struct device, knode_bus); | |
780 | ||
781 | get_device(dev); | |
782 | } | |
783 | ||
784 | static void klist_devices_put(struct klist_node *n) | |
785 | { | |
786 | struct device *dev = container_of(n, struct device, knode_bus); | |
787 | ||
788 | put_device(dev); | |
789 | } | |
790 | ||
1da177e4 LT |
791 | /** |
792 | * bus_register - register a bus with the system. | |
793 | * @bus: bus. | |
794 | * | |
795 | * Once we have that, we registered the bus with the kobject | |
796 | * infrastructure, then register the children subsystems it has: | |
797 | * the devices and drivers that belong to the bus. | |
798 | */ | |
799 | int bus_register(struct bus_type * bus) | |
800 | { | |
801 | int retval; | |
802 | ||
116af378 BH |
803 | BLOCKING_INIT_NOTIFIER_HEAD(&bus->bus_notifier); |
804 | ||
1da177e4 LT |
805 | retval = kobject_set_name(&bus->subsys.kset.kobj, "%s", bus->name); |
806 | if (retval) | |
807 | goto out; | |
808 | ||
809 | subsys_set_kset(bus, bus_subsys); | |
810 | retval = subsystem_register(&bus->subsys); | |
811 | if (retval) | |
812 | goto out; | |
813 | ||
814 | kobject_set_name(&bus->devices.kobj, "devices"); | |
815 | bus->devices.subsys = &bus->subsys; | |
816 | retval = kset_register(&bus->devices); | |
817 | if (retval) | |
818 | goto bus_devices_fail; | |
819 | ||
820 | kobject_set_name(&bus->drivers.kobj, "drivers"); | |
821 | bus->drivers.subsys = &bus->subsys; | |
822 | bus->drivers.ktype = &ktype_driver; | |
823 | retval = kset_register(&bus->drivers); | |
824 | if (retval) | |
825 | goto bus_drivers_fail; | |
465c7a3a | 826 | |
34bb61f9 | 827 | klist_init(&bus->klist_devices, klist_devices_get, klist_devices_put); |
81107bf5 | 828 | klist_init(&bus->klist_drivers, NULL, NULL); |
b8c5cec2 KS |
829 | |
830 | bus->drivers_autoprobe = 1; | |
831 | retval = add_probe_files(bus); | |
832 | if (retval) | |
833 | goto bus_probe_files_fail; | |
834 | ||
1bb6881a CH |
835 | retval = bus_add_attrs(bus); |
836 | if (retval) | |
837 | goto bus_attrs_fail; | |
1da177e4 LT |
838 | |
839 | pr_debug("bus type '%s' registered\n", bus->name); | |
840 | return 0; | |
841 | ||
1bb6881a | 842 | bus_attrs_fail: |
b8c5cec2 KS |
843 | remove_probe_files(bus); |
844 | bus_probe_files_fail: | |
1bb6881a | 845 | kset_unregister(&bus->drivers); |
1da177e4 LT |
846 | bus_drivers_fail: |
847 | kset_unregister(&bus->devices); | |
848 | bus_devices_fail: | |
849 | subsystem_unregister(&bus->subsys); | |
850 | out: | |
851 | return retval; | |
852 | } | |
853 | ||
1da177e4 LT |
854 | /** |
855 | * bus_unregister - remove a bus from the system | |
856 | * @bus: bus. | |
857 | * | |
858 | * Unregister the child subsystems and the bus itself. | |
859 | * Finally, we call put_bus() to release the refcount | |
860 | */ | |
861 | void bus_unregister(struct bus_type * bus) | |
862 | { | |
863 | pr_debug("bus %s: unregistering\n", bus->name); | |
864 | bus_remove_attrs(bus); | |
b8c5cec2 | 865 | remove_probe_files(bus); |
1da177e4 LT |
866 | kset_unregister(&bus->drivers); |
867 | kset_unregister(&bus->devices); | |
868 | subsystem_unregister(&bus->subsys); | |
869 | } | |
870 | ||
116af378 BH |
871 | int bus_register_notifier(struct bus_type *bus, struct notifier_block *nb) |
872 | { | |
873 | return blocking_notifier_chain_register(&bus->bus_notifier, nb); | |
874 | } | |
875 | EXPORT_SYMBOL_GPL(bus_register_notifier); | |
876 | ||
877 | int bus_unregister_notifier(struct bus_type *bus, struct notifier_block *nb) | |
878 | { | |
879 | return blocking_notifier_chain_unregister(&bus->bus_notifier, nb); | |
880 | } | |
881 | EXPORT_SYMBOL_GPL(bus_unregister_notifier); | |
882 | ||
1da177e4 LT |
883 | int __init buses_init(void) |
884 | { | |
885 | return subsystem_register(&bus_subsys); | |
886 | } | |
887 | ||
888 | ||
889 | EXPORT_SYMBOL_GPL(bus_for_each_dev); | |
0edb5860 | 890 | EXPORT_SYMBOL_GPL(bus_find_device); |
1da177e4 LT |
891 | EXPORT_SYMBOL_GPL(bus_for_each_drv); |
892 | ||
1da177e4 LT |
893 | EXPORT_SYMBOL_GPL(bus_register); |
894 | EXPORT_SYMBOL_GPL(bus_unregister); | |
895 | EXPORT_SYMBOL_GPL(bus_rescan_devices); | |
1da177e4 LT |
896 | |
897 | EXPORT_SYMBOL_GPL(bus_create_file); | |
898 | EXPORT_SYMBOL_GPL(bus_remove_file); |