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 | ||
30 | static ssize_t | |
31 | drv_attr_show(struct kobject * kobj, struct attribute * attr, char * buf) | |
32 | { | |
33 | struct driver_attribute * drv_attr = to_drv_attr(attr); | |
34 | struct device_driver * drv = to_driver(kobj); | |
4a0c20bf | 35 | ssize_t ret = -EIO; |
1da177e4 LT |
36 | |
37 | if (drv_attr->show) | |
38 | ret = drv_attr->show(drv, buf); | |
39 | return ret; | |
40 | } | |
41 | ||
42 | static ssize_t | |
43 | drv_attr_store(struct kobject * kobj, struct attribute * attr, | |
44 | const char * buf, size_t count) | |
45 | { | |
46 | struct driver_attribute * drv_attr = to_drv_attr(attr); | |
47 | struct device_driver * drv = to_driver(kobj); | |
4a0c20bf | 48 | ssize_t ret = -EIO; |
1da177e4 LT |
49 | |
50 | if (drv_attr->store) | |
51 | ret = drv_attr->store(drv, buf, count); | |
52 | return ret; | |
53 | } | |
54 | ||
55 | static struct sysfs_ops driver_sysfs_ops = { | |
56 | .show = drv_attr_show, | |
57 | .store = drv_attr_store, | |
58 | }; | |
59 | ||
60 | ||
61 | static void driver_release(struct kobject * kobj) | |
62 | { | |
63 | struct device_driver * drv = to_driver(kobj); | |
64 | complete(&drv->unloaded); | |
65 | } | |
66 | ||
67 | static struct kobj_type ktype_driver = { | |
68 | .sysfs_ops = &driver_sysfs_ops, | |
69 | .release = driver_release, | |
70 | }; | |
71 | ||
72 | ||
73 | /* | |
74 | * sysfs bindings for buses | |
75 | */ | |
76 | ||
77 | ||
78 | static ssize_t | |
79 | bus_attr_show(struct kobject * kobj, struct attribute * attr, char * buf) | |
80 | { | |
81 | struct bus_attribute * bus_attr = to_bus_attr(attr); | |
82 | struct bus_type * bus = to_bus(kobj); | |
83 | ssize_t ret = 0; | |
84 | ||
85 | if (bus_attr->show) | |
86 | ret = bus_attr->show(bus, buf); | |
87 | return ret; | |
88 | } | |
89 | ||
90 | static ssize_t | |
91 | bus_attr_store(struct kobject * kobj, struct attribute * attr, | |
92 | const char * buf, size_t count) | |
93 | { | |
94 | struct bus_attribute * bus_attr = to_bus_attr(attr); | |
95 | struct bus_type * bus = to_bus(kobj); | |
96 | ssize_t ret = 0; | |
97 | ||
98 | if (bus_attr->store) | |
99 | ret = bus_attr->store(bus, buf, count); | |
100 | return ret; | |
101 | } | |
102 | ||
103 | static struct sysfs_ops bus_sysfs_ops = { | |
104 | .show = bus_attr_show, | |
105 | .store = bus_attr_store, | |
106 | }; | |
107 | ||
108 | int bus_create_file(struct bus_type * bus, struct bus_attribute * attr) | |
109 | { | |
110 | int error; | |
111 | if (get_bus(bus)) { | |
112 | error = sysfs_create_file(&bus->subsys.kset.kobj, &attr->attr); | |
113 | put_bus(bus); | |
114 | } else | |
115 | error = -EINVAL; | |
116 | return error; | |
117 | } | |
118 | ||
119 | void bus_remove_file(struct bus_type * bus, struct bus_attribute * attr) | |
120 | { | |
121 | if (get_bus(bus)) { | |
122 | sysfs_remove_file(&bus->subsys.kset.kobj, &attr->attr); | |
123 | put_bus(bus); | |
124 | } | |
125 | } | |
126 | ||
127 | static struct kobj_type ktype_bus = { | |
128 | .sysfs_ops = &bus_sysfs_ops, | |
129 | ||
130 | }; | |
131 | ||
7e4ef085 | 132 | static decl_subsys(bus, &ktype_bus, NULL); |
1da177e4 | 133 | |
1da177e4 | 134 | |
2139bdd5 RK |
135 | #ifdef CONFIG_HOTPLUG |
136 | ||
2b08c8d0 | 137 | /* Manually detach a device from its associated driver. */ |
151ef38f GKH |
138 | static int driver_helper(struct device *dev, void *data) |
139 | { | |
140 | const char *name = data; | |
141 | ||
142 | if (strcmp(name, dev->bus_id) == 0) | |
143 | return 1; | |
144 | return 0; | |
145 | } | |
146 | ||
147 | static ssize_t driver_unbind(struct device_driver *drv, | |
148 | const char *buf, size_t count) | |
149 | { | |
150 | struct bus_type *bus = get_bus(drv->bus); | |
151 | struct device *dev; | |
152 | int err = -ENODEV; | |
153 | ||
154 | dev = bus_find_device(bus, NULL, (void *)buf, driver_helper); | |
2b08c8d0 | 155 | if (dev && dev->driver == drv) { |
bf74ad5b AS |
156 | if (dev->parent) /* Needed for USB */ |
157 | down(&dev->parent->sem); | |
151ef38f | 158 | device_release_driver(dev); |
bf74ad5b AS |
159 | if (dev->parent) |
160 | up(&dev->parent->sem); | |
151ef38f GKH |
161 | err = count; |
162 | } | |
2b08c8d0 AS |
163 | put_device(dev); |
164 | put_bus(bus); | |
165 | return err; | |
151ef38f GKH |
166 | } |
167 | static DRIVER_ATTR(unbind, S_IWUSR, NULL, driver_unbind); | |
168 | ||
afdce75f GKH |
169 | /* |
170 | * Manually attach a device to a driver. | |
171 | * Note: the driver must want to bind to the device, | |
172 | * it is not possible to override the driver's id table. | |
173 | */ | |
174 | static ssize_t driver_bind(struct device_driver *drv, | |
175 | const char *buf, size_t count) | |
176 | { | |
177 | struct bus_type *bus = get_bus(drv->bus); | |
178 | struct device *dev; | |
179 | int err = -ENODEV; | |
180 | ||
181 | dev = bus_find_device(bus, NULL, (void *)buf, driver_helper); | |
2b08c8d0 | 182 | if (dev && dev->driver == NULL) { |
bf74ad5b AS |
183 | if (dev->parent) /* Needed for USB */ |
184 | down(&dev->parent->sem); | |
afdce75f GKH |
185 | down(&dev->sem); |
186 | err = driver_probe_device(drv, dev); | |
187 | up(&dev->sem); | |
bf74ad5b AS |
188 | if (dev->parent) |
189 | up(&dev->parent->sem); | |
37225401 RW |
190 | |
191 | if (err > 0) /* success */ | |
192 | err = count; | |
193 | else if (err == 0) /* driver didn't accept device */ | |
194 | err = -ENODEV; | |
afdce75f | 195 | } |
2b08c8d0 AS |
196 | put_device(dev); |
197 | put_bus(bus); | |
198 | return err; | |
afdce75f GKH |
199 | } |
200 | static DRIVER_ATTR(bind, S_IWUSR, NULL, driver_bind); | |
201 | ||
2139bdd5 | 202 | #endif |
151ef38f | 203 | |
465c7a3a | 204 | static struct device * next_device(struct klist_iter * i) |
205 | { | |
206 | struct klist_node * n = klist_next(i); | |
207 | return n ? container_of(n, struct device, knode_bus) : NULL; | |
208 | } | |
209 | ||
1da177e4 LT |
210 | /** |
211 | * bus_for_each_dev - device iterator. | |
212 | * @bus: bus type. | |
213 | * @start: device to start iterating from. | |
214 | * @data: data for the callback. | |
215 | * @fn: function to be called for each device. | |
216 | * | |
217 | * Iterate over @bus's list of devices, and call @fn for each, | |
218 | * passing it @data. If @start is not NULL, we use that device to | |
219 | * begin iterating from. | |
220 | * | |
221 | * We check the return of @fn each time. If it returns anything | |
222 | * other than 0, we break out and return that value. | |
223 | * | |
224 | * NOTE: The device that returns a non-zero value is not retained | |
225 | * in any way, nor is its refcount incremented. If the caller needs | |
226 | * to retain this data, it should do, and increment the reference | |
227 | * count in the supplied callback. | |
228 | */ | |
229 | ||
230 | int bus_for_each_dev(struct bus_type * bus, struct device * start, | |
231 | void * data, int (*fn)(struct device *, void *)) | |
232 | { | |
465c7a3a | 233 | struct klist_iter i; |
234 | struct device * dev; | |
235 | int error = 0; | |
1da177e4 | 236 | |
465c7a3a | 237 | if (!bus) |
238 | return -EINVAL; | |
239 | ||
240 | klist_iter_init_node(&bus->klist_devices, &i, | |
241 | (start ? &start->knode_bus : NULL)); | |
242 | while ((dev = next_device(&i)) && !error) | |
243 | error = fn(dev, data); | |
244 | klist_iter_exit(&i); | |
245 | return error; | |
1da177e4 LT |
246 | } |
247 | ||
0edb5860 CH |
248 | /** |
249 | * bus_find_device - device iterator for locating a particular device. | |
250 | * @bus: bus type | |
251 | * @start: Device to begin with | |
252 | * @data: Data to pass to match function | |
253 | * @match: Callback function to check device | |
254 | * | |
255 | * This is similar to the bus_for_each_dev() function above, but it | |
256 | * returns a reference to a device that is 'found' for later use, as | |
257 | * determined by the @match callback. | |
258 | * | |
259 | * The callback should return 0 if the device doesn't match and non-zero | |
260 | * if it does. If the callback returns non-zero, this function will | |
261 | * return to the caller and not iterate over any more devices. | |
262 | */ | |
263 | struct device * bus_find_device(struct bus_type *bus, | |
264 | struct device *start, void *data, | |
265 | int (*match)(struct device *, void *)) | |
266 | { | |
267 | struct klist_iter i; | |
268 | struct device *dev; | |
269 | ||
270 | if (!bus) | |
271 | return NULL; | |
272 | ||
273 | klist_iter_init_node(&bus->klist_devices, &i, | |
274 | (start ? &start->knode_bus : NULL)); | |
275 | while ((dev = next_device(&i))) | |
276 | if (match(dev, data) && get_device(dev)) | |
277 | break; | |
278 | klist_iter_exit(&i); | |
279 | return dev; | |
280 | } | |
38fdac3c | 281 | |
282 | ||
283 | static struct device_driver * next_driver(struct klist_iter * i) | |
284 | { | |
285 | struct klist_node * n = klist_next(i); | |
286 | return n ? container_of(n, struct device_driver, knode_bus) : NULL; | |
287 | } | |
288 | ||
1da177e4 LT |
289 | /** |
290 | * bus_for_each_drv - driver iterator | |
291 | * @bus: bus we're dealing with. | |
292 | * @start: driver to start iterating on. | |
293 | * @data: data to pass to the callback. | |
294 | * @fn: function to call for each driver. | |
295 | * | |
296 | * This is nearly identical to the device iterator above. | |
297 | * We iterate over each driver that belongs to @bus, and call | |
298 | * @fn for each. If @fn returns anything but 0, we break out | |
299 | * and return it. If @start is not NULL, we use it as the head | |
300 | * of the list. | |
301 | * | |
302 | * NOTE: we don't return the driver that returns a non-zero | |
303 | * value, nor do we leave the reference count incremented for that | |
304 | * driver. If the caller needs to know that info, it must set it | |
305 | * in the callback. It must also be sure to increment the refcount | |
306 | * so it doesn't disappear before returning to the caller. | |
307 | */ | |
308 | ||
309 | int bus_for_each_drv(struct bus_type * bus, struct device_driver * start, | |
310 | void * data, int (*fn)(struct device_driver *, void *)) | |
311 | { | |
38fdac3c | 312 | struct klist_iter i; |
313 | struct device_driver * drv; | |
314 | int error = 0; | |
1da177e4 | 315 | |
38fdac3c | 316 | if (!bus) |
317 | return -EINVAL; | |
318 | ||
319 | klist_iter_init_node(&bus->klist_drivers, &i, | |
320 | start ? &start->knode_bus : NULL); | |
321 | while ((drv = next_driver(&i)) && !error) | |
322 | error = fn(drv, data); | |
323 | klist_iter_exit(&i); | |
324 | return error; | |
1da177e4 LT |
325 | } |
326 | ||
1da177e4 LT |
327 | static int device_add_attrs(struct bus_type * bus, struct device * dev) |
328 | { | |
329 | int error = 0; | |
330 | int i; | |
331 | ||
332 | if (bus->dev_attrs) { | |
333 | for (i = 0; attr_name(bus->dev_attrs[i]); i++) { | |
334 | error = device_create_file(dev,&bus->dev_attrs[i]); | |
335 | if (error) | |
336 | goto Err; | |
337 | } | |
338 | } | |
339 | Done: | |
340 | return error; | |
341 | Err: | |
342 | while (--i >= 0) | |
343 | device_remove_file(dev,&bus->dev_attrs[i]); | |
344 | goto Done; | |
345 | } | |
346 | ||
347 | ||
348 | static void device_remove_attrs(struct bus_type * bus, struct device * dev) | |
349 | { | |
350 | int i; | |
351 | ||
352 | if (bus->dev_attrs) { | |
353 | for (i = 0; attr_name(bus->dev_attrs[i]); i++) | |
354 | device_remove_file(dev,&bus->dev_attrs[i]); | |
355 | } | |
356 | } | |
357 | ||
358 | ||
359 | /** | |
360 | * bus_add_device - add device to bus | |
361 | * @dev: device being added | |
362 | * | |
363 | * - Add the device to its bus's list of devices. | |
53877d06 | 364 | * - Create link to device's bus. |
1da177e4 LT |
365 | */ |
366 | int bus_add_device(struct device * dev) | |
367 | { | |
368 | struct bus_type * bus = get_bus(dev->bus); | |
369 | int error = 0; | |
370 | ||
371 | if (bus) { | |
1da177e4 | 372 | pr_debug("bus %s: add device %s\n", bus->name, dev->bus_id); |
d377e85b | 373 | error = device_add_attrs(bus, dev); |
f86db396 AM |
374 | if (error) |
375 | goto out; | |
376 | error = sysfs_create_link(&bus->devices.kobj, | |
377 | &dev->kobj, dev->bus_id); | |
378 | if (error) | |
379 | goto out; | |
380 | error = sysfs_create_link(&dev->kobj, | |
381 | &dev->bus->subsys.kset.kobj, "subsystem"); | |
382 | if (error) | |
383 | goto out; | |
384 | error = sysfs_create_link(&dev->kobj, | |
385 | &dev->bus->subsys.kset.kobj, "bus"); | |
1da177e4 | 386 | } |
f86db396 | 387 | out: |
1da177e4 LT |
388 | return error; |
389 | } | |
390 | ||
53877d06 KS |
391 | /** |
392 | * bus_attach_device - add device to bus | |
393 | * @dev: device tried to attach to a driver | |
394 | * | |
f2eaae19 | 395 | * - Add device to bus's list of devices. |
53877d06 KS |
396 | * - Try to attach to driver. |
397 | */ | |
f86db396 | 398 | int bus_attach_device(struct device * dev) |
53877d06 | 399 | { |
f86db396 AM |
400 | struct bus_type *bus = dev->bus; |
401 | int ret = 0; | |
53877d06 KS |
402 | |
403 | if (bus) { | |
f2eaae19 | 404 | dev->is_registered = 1; |
f86db396 AM |
405 | ret = device_attach(dev); |
406 | if (ret >= 0) { | |
407 | klist_add_tail(&dev->knode_bus, &bus->klist_devices); | |
408 | ret = 0; | |
f2eaae19 AS |
409 | } else |
410 | dev->is_registered = 0; | |
53877d06 | 411 | } |
f86db396 | 412 | return ret; |
53877d06 KS |
413 | } |
414 | ||
1da177e4 LT |
415 | /** |
416 | * bus_remove_device - remove device from bus | |
417 | * @dev: device to be removed | |
418 | * | |
419 | * - Remove symlink from bus's directory. | |
420 | * - Delete device from bus's list. | |
421 | * - Detach from its driver. | |
422 | * - Drop reference taken in bus_add_device(). | |
423 | */ | |
424 | void bus_remove_device(struct device * dev) | |
425 | { | |
426 | if (dev->bus) { | |
b9d9c82b | 427 | sysfs_remove_link(&dev->kobj, "subsystem"); |
1da177e4 LT |
428 | sysfs_remove_link(&dev->kobj, "bus"); |
429 | sysfs_remove_link(&dev->bus->devices.kobj, dev->bus_id); | |
430 | device_remove_attrs(dev->bus, dev); | |
f2eaae19 AS |
431 | dev->is_registered = 0; |
432 | klist_del(&dev->knode_bus); | |
1da177e4 LT |
433 | pr_debug("bus %s: remove device %s\n", dev->bus->name, dev->bus_id); |
434 | device_release_driver(dev); | |
1da177e4 LT |
435 | put_bus(dev->bus); |
436 | } | |
437 | } | |
438 | ||
439 | static int driver_add_attrs(struct bus_type * bus, struct device_driver * drv) | |
440 | { | |
441 | int error = 0; | |
442 | int i; | |
443 | ||
444 | if (bus->drv_attrs) { | |
445 | for (i = 0; attr_name(bus->drv_attrs[i]); i++) { | |
446 | error = driver_create_file(drv, &bus->drv_attrs[i]); | |
447 | if (error) | |
448 | goto Err; | |
449 | } | |
450 | } | |
451 | Done: | |
452 | return error; | |
453 | Err: | |
454 | while (--i >= 0) | |
455 | driver_remove_file(drv, &bus->drv_attrs[i]); | |
456 | goto Done; | |
457 | } | |
458 | ||
459 | ||
460 | static void driver_remove_attrs(struct bus_type * bus, struct device_driver * drv) | |
461 | { | |
462 | int i; | |
463 | ||
464 | if (bus->drv_attrs) { | |
465 | for (i = 0; attr_name(bus->drv_attrs[i]); i++) | |
466 | driver_remove_file(drv, &bus->drv_attrs[i]); | |
467 | } | |
468 | } | |
469 | ||
874c6241 GKH |
470 | #ifdef CONFIG_HOTPLUG |
471 | /* | |
472 | * Thanks to drivers making their tables __devinit, we can't allow manual | |
473 | * bind and unbind from userspace unless CONFIG_HOTPLUG is enabled. | |
474 | */ | |
f86db396 | 475 | static int __must_check add_bind_files(struct device_driver *drv) |
874c6241 | 476 | { |
f86db396 AM |
477 | int ret; |
478 | ||
479 | ret = driver_create_file(drv, &driver_attr_unbind); | |
480 | if (ret == 0) { | |
481 | ret = driver_create_file(drv, &driver_attr_bind); | |
482 | if (ret) | |
483 | driver_remove_file(drv, &driver_attr_unbind); | |
484 | } | |
485 | return ret; | |
874c6241 GKH |
486 | } |
487 | ||
488 | static void remove_bind_files(struct device_driver *drv) | |
489 | { | |
490 | driver_remove_file(drv, &driver_attr_bind); | |
491 | driver_remove_file(drv, &driver_attr_unbind); | |
492 | } | |
493 | #else | |
35acfdd7 | 494 | static inline int add_bind_files(struct device_driver *drv) { return 0; } |
874c6241 GKH |
495 | static inline void remove_bind_files(struct device_driver *drv) {} |
496 | #endif | |
1da177e4 LT |
497 | |
498 | /** | |
499 | * bus_add_driver - Add a driver to the bus. | |
500 | * @drv: driver. | |
501 | * | |
502 | */ | |
f86db396 | 503 | int bus_add_driver(struct device_driver *drv) |
1da177e4 LT |
504 | { |
505 | struct bus_type * bus = get_bus(drv->bus); | |
506 | int error = 0; | |
507 | ||
508 | if (bus) { | |
509 | pr_debug("bus %s: add driver %s\n", bus->name, drv->name); | |
510 | error = kobject_set_name(&drv->kobj, "%s", drv->name); | |
f86db396 AM |
511 | if (error) |
512 | goto out_put_bus; | |
1da177e4 | 513 | drv->kobj.kset = &bus->drivers; |
f86db396 AM |
514 | if ((error = kobject_register(&drv->kobj))) |
515 | goto out_put_bus; | |
1da177e4 | 516 | |
f86db396 AM |
517 | error = driver_attach(drv); |
518 | if (error) | |
519 | goto out_unregister; | |
d856f1e3 | 520 | klist_add_tail(&drv->knode_bus, &bus->klist_drivers); |
1da177e4 LT |
521 | module_add_driver(drv->owner, drv); |
522 | ||
f86db396 AM |
523 | error = driver_add_attrs(bus, drv); |
524 | if (error) { | |
525 | /* How the hell do we get out of this pickle? Give up */ | |
526 | printk(KERN_ERR "%s: driver_add_attrs(%s) failed\n", | |
527 | __FUNCTION__, drv->name); | |
528 | } | |
529 | error = add_bind_files(drv); | |
530 | if (error) { | |
531 | /* Ditto */ | |
532 | printk(KERN_ERR "%s: add_bind_files(%s) failed\n", | |
533 | __FUNCTION__, drv->name); | |
534 | } | |
1da177e4 LT |
535 | } |
536 | return error; | |
f86db396 AM |
537 | out_unregister: |
538 | kobject_unregister(&drv->kobj); | |
539 | out_put_bus: | |
540 | put_bus(bus); | |
541 | return error; | |
1da177e4 LT |
542 | } |
543 | ||
1da177e4 LT |
544 | /** |
545 | * bus_remove_driver - delete driver from bus's knowledge. | |
546 | * @drv: driver. | |
547 | * | |
548 | * Detach the driver from the devices it controls, and remove | |
549 | * it from its bus's list of drivers. Finally, we drop the reference | |
550 | * to the bus we took in bus_add_driver(). | |
551 | */ | |
552 | ||
553 | void bus_remove_driver(struct device_driver * drv) | |
554 | { | |
555 | if (drv->bus) { | |
874c6241 | 556 | remove_bind_files(drv); |
1da177e4 | 557 | driver_remove_attrs(drv->bus, drv); |
38fdac3c | 558 | klist_remove(&drv->knode_bus); |
1da177e4 LT |
559 | pr_debug("bus %s: remove driver %s\n", drv->bus->name, drv->name); |
560 | driver_detach(drv); | |
1da177e4 LT |
561 | module_remove_driver(drv); |
562 | kobject_unregister(&drv->kobj); | |
563 | put_bus(drv->bus); | |
564 | } | |
565 | } | |
566 | ||
567 | ||
568 | /* Helper for bus_rescan_devices's iter */ | |
f86db396 AM |
569 | static int __must_check bus_rescan_devices_helper(struct device *dev, |
570 | void *data) | |
1da177e4 | 571 | { |
f86db396 AM |
572 | int ret = 0; |
573 | ||
bf74ad5b AS |
574 | if (!dev->driver) { |
575 | if (dev->parent) /* Needed for USB */ | |
576 | down(&dev->parent->sem); | |
f86db396 | 577 | ret = device_attach(dev); |
bf74ad5b AS |
578 | if (dev->parent) |
579 | up(&dev->parent->sem); | |
f86db396 AM |
580 | if (ret > 0) |
581 | ret = 0; | |
bf74ad5b | 582 | } |
f86db396 | 583 | return ret < 0 ? ret : 0; |
1da177e4 LT |
584 | } |
585 | ||
1da177e4 | 586 | /** |
23d3d602 GKH |
587 | * bus_rescan_devices - rescan devices on the bus for possible drivers |
588 | * @bus: the bus to scan. | |
1da177e4 | 589 | * |
23d3d602 GKH |
590 | * This function will look for devices on the bus with no driver |
591 | * attached and rescan it against existing drivers to see if it matches | |
592 | * any by calling device_attach() for the unbound devices. | |
1da177e4 | 593 | */ |
f86db396 | 594 | int bus_rescan_devices(struct bus_type * bus) |
1da177e4 | 595 | { |
f86db396 | 596 | return bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper); |
1da177e4 LT |
597 | } |
598 | ||
e935d5da ME |
599 | /** |
600 | * device_reprobe - remove driver for a device and probe for a new driver | |
601 | * @dev: the device to reprobe | |
602 | * | |
603 | * This function detaches the attached driver (if any) for the given | |
604 | * device and restarts the driver probing process. It is intended | |
605 | * to use if probing criteria changed during a devices lifetime and | |
606 | * driver attachment should change accordingly. | |
607 | */ | |
f86db396 | 608 | int device_reprobe(struct device *dev) |
e935d5da ME |
609 | { |
610 | if (dev->driver) { | |
611 | if (dev->parent) /* Needed for USB */ | |
612 | down(&dev->parent->sem); | |
613 | device_release_driver(dev); | |
614 | if (dev->parent) | |
615 | up(&dev->parent->sem); | |
616 | } | |
f86db396 | 617 | return bus_rescan_devices_helper(dev, NULL); |
e935d5da ME |
618 | } |
619 | EXPORT_SYMBOL_GPL(device_reprobe); | |
1da177e4 | 620 | |
f86db396 | 621 | struct bus_type *get_bus(struct bus_type *bus) |
1da177e4 | 622 | { |
f86db396 AM |
623 | return bus ? container_of(subsys_get(&bus->subsys), |
624 | struct bus_type, subsys) : NULL; | |
1da177e4 LT |
625 | } |
626 | ||
627 | void put_bus(struct bus_type * bus) | |
628 | { | |
629 | subsys_put(&bus->subsys); | |
630 | } | |
631 | ||
632 | ||
633 | /** | |
634 | * find_bus - locate bus by name. | |
635 | * @name: name of bus. | |
636 | * | |
637 | * Call kset_find_obj() to iterate over list of buses to | |
638 | * find a bus by name. Return bus if found. | |
639 | * | |
640 | * Note that kset_find_obj increments bus' reference count. | |
641 | */ | |
7e4ef085 | 642 | #if 0 |
1da177e4 LT |
643 | struct bus_type * find_bus(char * name) |
644 | { | |
645 | struct kobject * k = kset_find_obj(&bus_subsys.kset, name); | |
646 | return k ? to_bus(k) : NULL; | |
647 | } | |
7e4ef085 | 648 | #endif /* 0 */ |
1da177e4 LT |
649 | |
650 | ||
651 | /** | |
652 | * bus_add_attrs - Add default attributes for this bus. | |
653 | * @bus: Bus that has just been registered. | |
654 | */ | |
655 | ||
656 | static int bus_add_attrs(struct bus_type * bus) | |
657 | { | |
658 | int error = 0; | |
659 | int i; | |
660 | ||
661 | if (bus->bus_attrs) { | |
662 | for (i = 0; attr_name(bus->bus_attrs[i]); i++) { | |
663 | if ((error = bus_create_file(bus,&bus->bus_attrs[i]))) | |
664 | goto Err; | |
665 | } | |
666 | } | |
667 | Done: | |
668 | return error; | |
669 | Err: | |
670 | while (--i >= 0) | |
671 | bus_remove_file(bus,&bus->bus_attrs[i]); | |
672 | goto Done; | |
673 | } | |
674 | ||
675 | static void bus_remove_attrs(struct bus_type * bus) | |
676 | { | |
677 | int i; | |
678 | ||
679 | if (bus->bus_attrs) { | |
680 | for (i = 0; attr_name(bus->bus_attrs[i]); i++) | |
681 | bus_remove_file(bus,&bus->bus_attrs[i]); | |
682 | } | |
683 | } | |
684 | ||
34bb61f9 JB |
685 | static void klist_devices_get(struct klist_node *n) |
686 | { | |
687 | struct device *dev = container_of(n, struct device, knode_bus); | |
688 | ||
689 | get_device(dev); | |
690 | } | |
691 | ||
692 | static void klist_devices_put(struct klist_node *n) | |
693 | { | |
694 | struct device *dev = container_of(n, struct device, knode_bus); | |
695 | ||
696 | put_device(dev); | |
697 | } | |
698 | ||
1da177e4 LT |
699 | /** |
700 | * bus_register - register a bus with the system. | |
701 | * @bus: bus. | |
702 | * | |
703 | * Once we have that, we registered the bus with the kobject | |
704 | * infrastructure, then register the children subsystems it has: | |
705 | * the devices and drivers that belong to the bus. | |
706 | */ | |
707 | int bus_register(struct bus_type * bus) | |
708 | { | |
709 | int retval; | |
710 | ||
711 | retval = kobject_set_name(&bus->subsys.kset.kobj, "%s", bus->name); | |
712 | if (retval) | |
713 | goto out; | |
714 | ||
715 | subsys_set_kset(bus, bus_subsys); | |
716 | retval = subsystem_register(&bus->subsys); | |
717 | if (retval) | |
718 | goto out; | |
719 | ||
720 | kobject_set_name(&bus->devices.kobj, "devices"); | |
721 | bus->devices.subsys = &bus->subsys; | |
722 | retval = kset_register(&bus->devices); | |
723 | if (retval) | |
724 | goto bus_devices_fail; | |
725 | ||
726 | kobject_set_name(&bus->drivers.kobj, "drivers"); | |
727 | bus->drivers.subsys = &bus->subsys; | |
728 | bus->drivers.ktype = &ktype_driver; | |
729 | retval = kset_register(&bus->drivers); | |
730 | if (retval) | |
731 | goto bus_drivers_fail; | |
465c7a3a | 732 | |
34bb61f9 | 733 | klist_init(&bus->klist_devices, klist_devices_get, klist_devices_put); |
81107bf5 | 734 | klist_init(&bus->klist_drivers, NULL, NULL); |
1bb6881a CH |
735 | retval = bus_add_attrs(bus); |
736 | if (retval) | |
737 | goto bus_attrs_fail; | |
1da177e4 LT |
738 | |
739 | pr_debug("bus type '%s' registered\n", bus->name); | |
740 | return 0; | |
741 | ||
1bb6881a CH |
742 | bus_attrs_fail: |
743 | kset_unregister(&bus->drivers); | |
1da177e4 LT |
744 | bus_drivers_fail: |
745 | kset_unregister(&bus->devices); | |
746 | bus_devices_fail: | |
747 | subsystem_unregister(&bus->subsys); | |
748 | out: | |
749 | return retval; | |
750 | } | |
751 | ||
752 | ||
753 | /** | |
754 | * bus_unregister - remove a bus from the system | |
755 | * @bus: bus. | |
756 | * | |
757 | * Unregister the child subsystems and the bus itself. | |
758 | * Finally, we call put_bus() to release the refcount | |
759 | */ | |
760 | void bus_unregister(struct bus_type * bus) | |
761 | { | |
762 | pr_debug("bus %s: unregistering\n", bus->name); | |
763 | bus_remove_attrs(bus); | |
764 | kset_unregister(&bus->drivers); | |
765 | kset_unregister(&bus->devices); | |
766 | subsystem_unregister(&bus->subsys); | |
767 | } | |
768 | ||
769 | int __init buses_init(void) | |
770 | { | |
771 | return subsystem_register(&bus_subsys); | |
772 | } | |
773 | ||
774 | ||
775 | EXPORT_SYMBOL_GPL(bus_for_each_dev); | |
0edb5860 | 776 | EXPORT_SYMBOL_GPL(bus_find_device); |
1da177e4 LT |
777 | EXPORT_SYMBOL_GPL(bus_for_each_drv); |
778 | ||
1da177e4 LT |
779 | EXPORT_SYMBOL_GPL(bus_register); |
780 | EXPORT_SYMBOL_GPL(bus_unregister); | |
781 | EXPORT_SYMBOL_GPL(bus_rescan_devices); | |
1da177e4 LT |
782 | |
783 | EXPORT_SYMBOL_GPL(bus_create_file); | |
784 | EXPORT_SYMBOL_GPL(bus_remove_file); |