Commit | Line | Data |
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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 | ||
11 | #include <linux/config.h> | |
12 | #include <linux/device.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/errno.h> | |
15 | #include <linux/init.h> | |
16 | #include <linux/string.h> | |
17 | #include "base.h" | |
18 | #include "power/power.h" | |
19 | ||
1da177e4 LT |
20 | #define to_bus_attr(_attr) container_of(_attr, struct bus_attribute, attr) |
21 | #define to_bus(obj) container_of(obj, struct bus_type, subsys.kset.kobj) | |
22 | ||
23 | /* | |
24 | * sysfs bindings for drivers | |
25 | */ | |
26 | ||
27 | #define to_drv_attr(_attr) container_of(_attr, struct driver_attribute, attr) | |
28 | #define to_driver(obj) container_of(obj, struct device_driver, kobj) | |
29 | ||
30 | ||
31 | static ssize_t | |
32 | drv_attr_show(struct kobject * kobj, struct attribute * attr, char * buf) | |
33 | { | |
34 | struct driver_attribute * drv_attr = to_drv_attr(attr); | |
35 | struct device_driver * drv = to_driver(kobj); | |
4a0c20bf | 36 | ssize_t ret = -EIO; |
1da177e4 LT |
37 | |
38 | if (drv_attr->show) | |
39 | ret = drv_attr->show(drv, buf); | |
40 | return ret; | |
41 | } | |
42 | ||
43 | static ssize_t | |
44 | drv_attr_store(struct kobject * kobj, struct attribute * attr, | |
45 | const char * buf, size_t count) | |
46 | { | |
47 | struct driver_attribute * drv_attr = to_drv_attr(attr); | |
48 | struct device_driver * drv = to_driver(kobj); | |
4a0c20bf | 49 | ssize_t ret = -EIO; |
1da177e4 LT |
50 | |
51 | if (drv_attr->store) | |
52 | ret = drv_attr->store(drv, buf, count); | |
53 | return ret; | |
54 | } | |
55 | ||
56 | static struct sysfs_ops driver_sysfs_ops = { | |
57 | .show = drv_attr_show, | |
58 | .store = drv_attr_store, | |
59 | }; | |
60 | ||
61 | ||
62 | static void driver_release(struct kobject * kobj) | |
63 | { | |
64 | struct device_driver * drv = to_driver(kobj); | |
65 | complete(&drv->unloaded); | |
66 | } | |
67 | ||
68 | static struct kobj_type ktype_driver = { | |
69 | .sysfs_ops = &driver_sysfs_ops, | |
70 | .release = driver_release, | |
71 | }; | |
72 | ||
73 | ||
74 | /* | |
75 | * sysfs bindings for buses | |
76 | */ | |
77 | ||
78 | ||
79 | static ssize_t | |
80 | bus_attr_show(struct kobject * kobj, struct attribute * attr, char * buf) | |
81 | { | |
82 | struct bus_attribute * bus_attr = to_bus_attr(attr); | |
83 | struct bus_type * bus = to_bus(kobj); | |
84 | ssize_t ret = 0; | |
85 | ||
86 | if (bus_attr->show) | |
87 | ret = bus_attr->show(bus, buf); | |
88 | return ret; | |
89 | } | |
90 | ||
91 | static ssize_t | |
92 | bus_attr_store(struct kobject * kobj, struct attribute * attr, | |
93 | const char * buf, size_t count) | |
94 | { | |
95 | struct bus_attribute * bus_attr = to_bus_attr(attr); | |
96 | struct bus_type * bus = to_bus(kobj); | |
97 | ssize_t ret = 0; | |
98 | ||
99 | if (bus_attr->store) | |
100 | ret = bus_attr->store(bus, buf, count); | |
101 | return ret; | |
102 | } | |
103 | ||
104 | static struct sysfs_ops bus_sysfs_ops = { | |
105 | .show = bus_attr_show, | |
106 | .store = bus_attr_store, | |
107 | }; | |
108 | ||
109 | int bus_create_file(struct bus_type * bus, struct bus_attribute * attr) | |
110 | { | |
111 | int error; | |
112 | if (get_bus(bus)) { | |
113 | error = sysfs_create_file(&bus->subsys.kset.kobj, &attr->attr); | |
114 | put_bus(bus); | |
115 | } else | |
116 | error = -EINVAL; | |
117 | return error; | |
118 | } | |
119 | ||
120 | void bus_remove_file(struct bus_type * bus, struct bus_attribute * attr) | |
121 | { | |
122 | if (get_bus(bus)) { | |
123 | sysfs_remove_file(&bus->subsys.kset.kobj, &attr->attr); | |
124 | put_bus(bus); | |
125 | } | |
126 | } | |
127 | ||
128 | static struct kobj_type ktype_bus = { | |
129 | .sysfs_ops = &bus_sysfs_ops, | |
130 | ||
131 | }; | |
132 | ||
133 | decl_subsys(bus, &ktype_bus, NULL); | |
134 | ||
1da177e4 | 135 | |
2139bdd5 RK |
136 | #ifdef CONFIG_HOTPLUG |
137 | ||
2b08c8d0 | 138 | /* Manually detach a device from its associated driver. */ |
151ef38f GKH |
139 | static int driver_helper(struct device *dev, void *data) |
140 | { | |
141 | const char *name = data; | |
142 | ||
143 | if (strcmp(name, dev->bus_id) == 0) | |
144 | return 1; | |
145 | return 0; | |
146 | } | |
147 | ||
148 | static ssize_t driver_unbind(struct device_driver *drv, | |
149 | const char *buf, size_t count) | |
150 | { | |
151 | struct bus_type *bus = get_bus(drv->bus); | |
152 | struct device *dev; | |
153 | int err = -ENODEV; | |
154 | ||
155 | dev = bus_find_device(bus, NULL, (void *)buf, driver_helper); | |
2b08c8d0 | 156 | if (dev && dev->driver == drv) { |
bf74ad5b AS |
157 | if (dev->parent) /* Needed for USB */ |
158 | down(&dev->parent->sem); | |
151ef38f | 159 | device_release_driver(dev); |
bf74ad5b AS |
160 | if (dev->parent) |
161 | up(&dev->parent->sem); | |
151ef38f GKH |
162 | err = count; |
163 | } | |
2b08c8d0 AS |
164 | put_device(dev); |
165 | put_bus(bus); | |
166 | return err; | |
151ef38f GKH |
167 | } |
168 | static DRIVER_ATTR(unbind, S_IWUSR, NULL, driver_unbind); | |
169 | ||
afdce75f GKH |
170 | /* |
171 | * Manually attach a device to a driver. | |
172 | * Note: the driver must want to bind to the device, | |
173 | * it is not possible to override the driver's id table. | |
174 | */ | |
175 | static ssize_t driver_bind(struct device_driver *drv, | |
176 | const char *buf, size_t count) | |
177 | { | |
178 | struct bus_type *bus = get_bus(drv->bus); | |
179 | struct device *dev; | |
180 | int err = -ENODEV; | |
181 | ||
182 | dev = bus_find_device(bus, NULL, (void *)buf, driver_helper); | |
2b08c8d0 | 183 | if (dev && dev->driver == NULL) { |
bf74ad5b AS |
184 | if (dev->parent) /* Needed for USB */ |
185 | down(&dev->parent->sem); | |
afdce75f GKH |
186 | down(&dev->sem); |
187 | err = driver_probe_device(drv, dev); | |
188 | up(&dev->sem); | |
bf74ad5b AS |
189 | if (dev->parent) |
190 | up(&dev->parent->sem); | |
37225401 RW |
191 | |
192 | if (err > 0) /* success */ | |
193 | err = count; | |
194 | else if (err == 0) /* driver didn't accept device */ | |
195 | err = -ENODEV; | |
afdce75f | 196 | } |
2b08c8d0 AS |
197 | put_device(dev); |
198 | put_bus(bus); | |
199 | return err; | |
afdce75f GKH |
200 | } |
201 | static DRIVER_ATTR(bind, S_IWUSR, NULL, driver_bind); | |
202 | ||
2139bdd5 | 203 | #endif |
151ef38f | 204 | |
465c7a3a | 205 | static struct device * next_device(struct klist_iter * i) |
206 | { | |
207 | struct klist_node * n = klist_next(i); | |
208 | return n ? container_of(n, struct device, knode_bus) : NULL; | |
209 | } | |
210 | ||
1da177e4 LT |
211 | /** |
212 | * bus_for_each_dev - device iterator. | |
213 | * @bus: bus type. | |
214 | * @start: device to start iterating from. | |
215 | * @data: data for the callback. | |
216 | * @fn: function to be called for each device. | |
217 | * | |
218 | * Iterate over @bus's list of devices, and call @fn for each, | |
219 | * passing it @data. If @start is not NULL, we use that device to | |
220 | * begin iterating from. | |
221 | * | |
222 | * We check the return of @fn each time. If it returns anything | |
223 | * other than 0, we break out and return that value. | |
224 | * | |
225 | * NOTE: The device that returns a non-zero value is not retained | |
226 | * in any way, nor is its refcount incremented. If the caller needs | |
227 | * to retain this data, it should do, and increment the reference | |
228 | * count in the supplied callback. | |
229 | */ | |
230 | ||
231 | int bus_for_each_dev(struct bus_type * bus, struct device * start, | |
232 | void * data, int (*fn)(struct device *, void *)) | |
233 | { | |
465c7a3a | 234 | struct klist_iter i; |
235 | struct device * dev; | |
236 | int error = 0; | |
1da177e4 | 237 | |
465c7a3a | 238 | if (!bus) |
239 | return -EINVAL; | |
240 | ||
241 | klist_iter_init_node(&bus->klist_devices, &i, | |
242 | (start ? &start->knode_bus : NULL)); | |
243 | while ((dev = next_device(&i)) && !error) | |
244 | error = fn(dev, data); | |
245 | klist_iter_exit(&i); | |
246 | return error; | |
1da177e4 LT |
247 | } |
248 | ||
0edb5860 CH |
249 | /** |
250 | * bus_find_device - device iterator for locating a particular device. | |
251 | * @bus: bus type | |
252 | * @start: Device to begin with | |
253 | * @data: Data to pass to match function | |
254 | * @match: Callback function to check device | |
255 | * | |
256 | * This is similar to the bus_for_each_dev() function above, but it | |
257 | * returns a reference to a device that is 'found' for later use, as | |
258 | * determined by the @match callback. | |
259 | * | |
260 | * The callback should return 0 if the device doesn't match and non-zero | |
261 | * if it does. If the callback returns non-zero, this function will | |
262 | * return to the caller and not iterate over any more devices. | |
263 | */ | |
264 | struct device * bus_find_device(struct bus_type *bus, | |
265 | struct device *start, void *data, | |
266 | int (*match)(struct device *, void *)) | |
267 | { | |
268 | struct klist_iter i; | |
269 | struct device *dev; | |
270 | ||
271 | if (!bus) | |
272 | return NULL; | |
273 | ||
274 | klist_iter_init_node(&bus->klist_devices, &i, | |
275 | (start ? &start->knode_bus : NULL)); | |
276 | while ((dev = next_device(&i))) | |
277 | if (match(dev, data) && get_device(dev)) | |
278 | break; | |
279 | klist_iter_exit(&i); | |
280 | return dev; | |
281 | } | |
38fdac3c | 282 | |
283 | ||
284 | static struct device_driver * next_driver(struct klist_iter * i) | |
285 | { | |
286 | struct klist_node * n = klist_next(i); | |
287 | return n ? container_of(n, struct device_driver, knode_bus) : NULL; | |
288 | } | |
289 | ||
1da177e4 LT |
290 | /** |
291 | * bus_for_each_drv - driver iterator | |
292 | * @bus: bus we're dealing with. | |
293 | * @start: driver to start iterating on. | |
294 | * @data: data to pass to the callback. | |
295 | * @fn: function to call for each driver. | |
296 | * | |
297 | * This is nearly identical to the device iterator above. | |
298 | * We iterate over each driver that belongs to @bus, and call | |
299 | * @fn for each. If @fn returns anything but 0, we break out | |
300 | * and return it. If @start is not NULL, we use it as the head | |
301 | * of the list. | |
302 | * | |
303 | * NOTE: we don't return the driver that returns a non-zero | |
304 | * value, nor do we leave the reference count incremented for that | |
305 | * driver. If the caller needs to know that info, it must set it | |
306 | * in the callback. It must also be sure to increment the refcount | |
307 | * so it doesn't disappear before returning to the caller. | |
308 | */ | |
309 | ||
310 | int bus_for_each_drv(struct bus_type * bus, struct device_driver * start, | |
311 | void * data, int (*fn)(struct device_driver *, void *)) | |
312 | { | |
38fdac3c | 313 | struct klist_iter i; |
314 | struct device_driver * drv; | |
315 | int error = 0; | |
1da177e4 | 316 | |
38fdac3c | 317 | if (!bus) |
318 | return -EINVAL; | |
319 | ||
320 | klist_iter_init_node(&bus->klist_drivers, &i, | |
321 | start ? &start->knode_bus : NULL); | |
322 | while ((drv = next_driver(&i)) && !error) | |
323 | error = fn(drv, data); | |
324 | klist_iter_exit(&i); | |
325 | return error; | |
1da177e4 LT |
326 | } |
327 | ||
1da177e4 LT |
328 | static int device_add_attrs(struct bus_type * bus, struct device * dev) |
329 | { | |
330 | int error = 0; | |
331 | int i; | |
332 | ||
333 | if (bus->dev_attrs) { | |
334 | for (i = 0; attr_name(bus->dev_attrs[i]); i++) { | |
335 | error = device_create_file(dev,&bus->dev_attrs[i]); | |
336 | if (error) | |
337 | goto Err; | |
338 | } | |
339 | } | |
340 | Done: | |
341 | return error; | |
342 | Err: | |
343 | while (--i >= 0) | |
344 | device_remove_file(dev,&bus->dev_attrs[i]); | |
345 | goto Done; | |
346 | } | |
347 | ||
348 | ||
349 | static void device_remove_attrs(struct bus_type * bus, struct device * dev) | |
350 | { | |
351 | int i; | |
352 | ||
353 | if (bus->dev_attrs) { | |
354 | for (i = 0; attr_name(bus->dev_attrs[i]); i++) | |
355 | device_remove_file(dev,&bus->dev_attrs[i]); | |
356 | } | |
357 | } | |
358 | ||
359 | ||
360 | /** | |
361 | * bus_add_device - add device to bus | |
362 | * @dev: device being added | |
363 | * | |
364 | * - Add the device to its bus's list of devices. | |
365 | * - Try to attach to driver. | |
366 | * - Create link to device's physical location. | |
367 | */ | |
368 | int bus_add_device(struct device * dev) | |
369 | { | |
370 | struct bus_type * bus = get_bus(dev->bus); | |
371 | int error = 0; | |
372 | ||
373 | if (bus) { | |
1da177e4 | 374 | pr_debug("bus %s: add device %s\n", bus->name, dev->bus_id); |
d377e85b | 375 | device_attach(dev); |
d856f1e3 | 376 | klist_add_tail(&dev->knode_bus, &bus->klist_devices); |
d377e85b | 377 | error = device_add_attrs(bus, dev); |
ca2b94ba HR |
378 | if (!error) { |
379 | sysfs_create_link(&bus->devices.kobj, &dev->kobj, dev->bus_id); | |
380 | sysfs_create_link(&dev->kobj, &dev->bus->subsys.kset.kobj, "bus"); | |
381 | } | |
1da177e4 LT |
382 | } |
383 | return error; | |
384 | } | |
385 | ||
386 | /** | |
387 | * bus_remove_device - remove device from bus | |
388 | * @dev: device to be removed | |
389 | * | |
390 | * - Remove symlink from bus's directory. | |
391 | * - Delete device from bus's list. | |
392 | * - Detach from its driver. | |
393 | * - Drop reference taken in bus_add_device(). | |
394 | */ | |
395 | void bus_remove_device(struct device * dev) | |
396 | { | |
397 | if (dev->bus) { | |
398 | sysfs_remove_link(&dev->kobj, "bus"); | |
399 | sysfs_remove_link(&dev->bus->devices.kobj, dev->bus_id); | |
400 | device_remove_attrs(dev->bus, dev); | |
465c7a3a | 401 | klist_remove(&dev->knode_bus); |
1da177e4 LT |
402 | pr_debug("bus %s: remove device %s\n", dev->bus->name, dev->bus_id); |
403 | device_release_driver(dev); | |
1da177e4 LT |
404 | put_bus(dev->bus); |
405 | } | |
406 | } | |
407 | ||
408 | static int driver_add_attrs(struct bus_type * bus, struct device_driver * drv) | |
409 | { | |
410 | int error = 0; | |
411 | int i; | |
412 | ||
413 | if (bus->drv_attrs) { | |
414 | for (i = 0; attr_name(bus->drv_attrs[i]); i++) { | |
415 | error = driver_create_file(drv, &bus->drv_attrs[i]); | |
416 | if (error) | |
417 | goto Err; | |
418 | } | |
419 | } | |
420 | Done: | |
421 | return error; | |
422 | Err: | |
423 | while (--i >= 0) | |
424 | driver_remove_file(drv, &bus->drv_attrs[i]); | |
425 | goto Done; | |
426 | } | |
427 | ||
428 | ||
429 | static void driver_remove_attrs(struct bus_type * bus, struct device_driver * drv) | |
430 | { | |
431 | int i; | |
432 | ||
433 | if (bus->drv_attrs) { | |
434 | for (i = 0; attr_name(bus->drv_attrs[i]); i++) | |
435 | driver_remove_file(drv, &bus->drv_attrs[i]); | |
436 | } | |
437 | } | |
438 | ||
874c6241 GKH |
439 | #ifdef CONFIG_HOTPLUG |
440 | /* | |
441 | * Thanks to drivers making their tables __devinit, we can't allow manual | |
442 | * bind and unbind from userspace unless CONFIG_HOTPLUG is enabled. | |
443 | */ | |
444 | static void add_bind_files(struct device_driver *drv) | |
445 | { | |
446 | driver_create_file(drv, &driver_attr_unbind); | |
447 | driver_create_file(drv, &driver_attr_bind); | |
448 | } | |
449 | ||
450 | static void remove_bind_files(struct device_driver *drv) | |
451 | { | |
452 | driver_remove_file(drv, &driver_attr_bind); | |
453 | driver_remove_file(drv, &driver_attr_unbind); | |
454 | } | |
455 | #else | |
456 | static inline void add_bind_files(struct device_driver *drv) {} | |
457 | static inline void remove_bind_files(struct device_driver *drv) {} | |
458 | #endif | |
1da177e4 LT |
459 | |
460 | /** | |
461 | * bus_add_driver - Add a driver to the bus. | |
462 | * @drv: driver. | |
463 | * | |
464 | */ | |
465 | int bus_add_driver(struct device_driver * drv) | |
466 | { | |
467 | struct bus_type * bus = get_bus(drv->bus); | |
468 | int error = 0; | |
469 | ||
470 | if (bus) { | |
471 | pr_debug("bus %s: add driver %s\n", bus->name, drv->name); | |
472 | error = kobject_set_name(&drv->kobj, "%s", drv->name); | |
473 | if (error) { | |
474 | put_bus(bus); | |
475 | return error; | |
476 | } | |
477 | drv->kobj.kset = &bus->drivers; | |
478 | if ((error = kobject_register(&drv->kobj))) { | |
479 | put_bus(bus); | |
480 | return error; | |
481 | } | |
482 | ||
1da177e4 | 483 | driver_attach(drv); |
d856f1e3 | 484 | klist_add_tail(&drv->knode_bus, &bus->klist_drivers); |
1da177e4 LT |
485 | module_add_driver(drv->owner, drv); |
486 | ||
487 | driver_add_attrs(bus, drv); | |
874c6241 | 488 | add_bind_files(drv); |
1da177e4 LT |
489 | } |
490 | return error; | |
491 | } | |
492 | ||
493 | ||
494 | /** | |
495 | * bus_remove_driver - delete driver from bus's knowledge. | |
496 | * @drv: driver. | |
497 | * | |
498 | * Detach the driver from the devices it controls, and remove | |
499 | * it from its bus's list of drivers. Finally, we drop the reference | |
500 | * to the bus we took in bus_add_driver(). | |
501 | */ | |
502 | ||
503 | void bus_remove_driver(struct device_driver * drv) | |
504 | { | |
505 | if (drv->bus) { | |
874c6241 | 506 | remove_bind_files(drv); |
1da177e4 | 507 | driver_remove_attrs(drv->bus, drv); |
38fdac3c | 508 | klist_remove(&drv->knode_bus); |
1da177e4 LT |
509 | pr_debug("bus %s: remove driver %s\n", drv->bus->name, drv->name); |
510 | driver_detach(drv); | |
1da177e4 LT |
511 | module_remove_driver(drv); |
512 | kobject_unregister(&drv->kobj); | |
513 | put_bus(drv->bus); | |
514 | } | |
515 | } | |
516 | ||
517 | ||
518 | /* Helper for bus_rescan_devices's iter */ | |
519 | static int bus_rescan_devices_helper(struct device *dev, void *data) | |
520 | { | |
bf74ad5b AS |
521 | if (!dev->driver) { |
522 | if (dev->parent) /* Needed for USB */ | |
523 | down(&dev->parent->sem); | |
23d3d602 | 524 | device_attach(dev); |
bf74ad5b AS |
525 | if (dev->parent) |
526 | up(&dev->parent->sem); | |
527 | } | |
1da177e4 LT |
528 | return 0; |
529 | } | |
530 | ||
1da177e4 | 531 | /** |
23d3d602 GKH |
532 | * bus_rescan_devices - rescan devices on the bus for possible drivers |
533 | * @bus: the bus to scan. | |
1da177e4 | 534 | * |
23d3d602 GKH |
535 | * This function will look for devices on the bus with no driver |
536 | * attached and rescan it against existing drivers to see if it matches | |
537 | * any by calling device_attach() for the unbound devices. | |
1da177e4 | 538 | */ |
23d3d602 | 539 | void bus_rescan_devices(struct bus_type * bus) |
1da177e4 | 540 | { |
23d3d602 | 541 | bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper); |
1da177e4 LT |
542 | } |
543 | ||
e935d5da ME |
544 | /** |
545 | * device_reprobe - remove driver for a device and probe for a new driver | |
546 | * @dev: the device to reprobe | |
547 | * | |
548 | * This function detaches the attached driver (if any) for the given | |
549 | * device and restarts the driver probing process. It is intended | |
550 | * to use if probing criteria changed during a devices lifetime and | |
551 | * driver attachment should change accordingly. | |
552 | */ | |
553 | void device_reprobe(struct device *dev) | |
554 | { | |
555 | if (dev->driver) { | |
556 | if (dev->parent) /* Needed for USB */ | |
557 | down(&dev->parent->sem); | |
558 | device_release_driver(dev); | |
559 | if (dev->parent) | |
560 | up(&dev->parent->sem); | |
561 | } | |
562 | ||
563 | bus_rescan_devices_helper(dev, NULL); | |
564 | } | |
565 | EXPORT_SYMBOL_GPL(device_reprobe); | |
1da177e4 LT |
566 | |
567 | struct bus_type * get_bus(struct bus_type * bus) | |
568 | { | |
569 | return bus ? container_of(subsys_get(&bus->subsys), struct bus_type, subsys) : NULL; | |
570 | } | |
571 | ||
572 | void put_bus(struct bus_type * bus) | |
573 | { | |
574 | subsys_put(&bus->subsys); | |
575 | } | |
576 | ||
577 | ||
578 | /** | |
579 | * find_bus - locate bus by name. | |
580 | * @name: name of bus. | |
581 | * | |
582 | * Call kset_find_obj() to iterate over list of buses to | |
583 | * find a bus by name. Return bus if found. | |
584 | * | |
585 | * Note that kset_find_obj increments bus' reference count. | |
586 | */ | |
587 | ||
588 | struct bus_type * find_bus(char * name) | |
589 | { | |
590 | struct kobject * k = kset_find_obj(&bus_subsys.kset, name); | |
591 | return k ? to_bus(k) : NULL; | |
592 | } | |
593 | ||
594 | ||
595 | /** | |
596 | * bus_add_attrs - Add default attributes for this bus. | |
597 | * @bus: Bus that has just been registered. | |
598 | */ | |
599 | ||
600 | static int bus_add_attrs(struct bus_type * bus) | |
601 | { | |
602 | int error = 0; | |
603 | int i; | |
604 | ||
605 | if (bus->bus_attrs) { | |
606 | for (i = 0; attr_name(bus->bus_attrs[i]); i++) { | |
607 | if ((error = bus_create_file(bus,&bus->bus_attrs[i]))) | |
608 | goto Err; | |
609 | } | |
610 | } | |
611 | Done: | |
612 | return error; | |
613 | Err: | |
614 | while (--i >= 0) | |
615 | bus_remove_file(bus,&bus->bus_attrs[i]); | |
616 | goto Done; | |
617 | } | |
618 | ||
619 | static void bus_remove_attrs(struct bus_type * bus) | |
620 | { | |
621 | int i; | |
622 | ||
623 | if (bus->bus_attrs) { | |
624 | for (i = 0; attr_name(bus->bus_attrs[i]); i++) | |
625 | bus_remove_file(bus,&bus->bus_attrs[i]); | |
626 | } | |
627 | } | |
628 | ||
34bb61f9 JB |
629 | static void klist_devices_get(struct klist_node *n) |
630 | { | |
631 | struct device *dev = container_of(n, struct device, knode_bus); | |
632 | ||
633 | get_device(dev); | |
634 | } | |
635 | ||
636 | static void klist_devices_put(struct klist_node *n) | |
637 | { | |
638 | struct device *dev = container_of(n, struct device, knode_bus); | |
639 | ||
640 | put_device(dev); | |
641 | } | |
642 | ||
643 | static void klist_drivers_get(struct klist_node *n) | |
644 | { | |
645 | struct device_driver *drv = container_of(n, struct device_driver, | |
646 | knode_bus); | |
647 | ||
648 | get_driver(drv); | |
649 | } | |
650 | ||
651 | static void klist_drivers_put(struct klist_node *n) | |
652 | { | |
653 | struct device_driver *drv = container_of(n, struct device_driver, | |
654 | knode_bus); | |
655 | ||
656 | put_driver(drv); | |
657 | } | |
658 | ||
1da177e4 LT |
659 | /** |
660 | * bus_register - register a bus with the system. | |
661 | * @bus: bus. | |
662 | * | |
663 | * Once we have that, we registered the bus with the kobject | |
664 | * infrastructure, then register the children subsystems it has: | |
665 | * the devices and drivers that belong to the bus. | |
666 | */ | |
667 | int bus_register(struct bus_type * bus) | |
668 | { | |
669 | int retval; | |
670 | ||
671 | retval = kobject_set_name(&bus->subsys.kset.kobj, "%s", bus->name); | |
672 | if (retval) | |
673 | goto out; | |
674 | ||
675 | subsys_set_kset(bus, bus_subsys); | |
676 | retval = subsystem_register(&bus->subsys); | |
677 | if (retval) | |
678 | goto out; | |
679 | ||
680 | kobject_set_name(&bus->devices.kobj, "devices"); | |
681 | bus->devices.subsys = &bus->subsys; | |
682 | retval = kset_register(&bus->devices); | |
683 | if (retval) | |
684 | goto bus_devices_fail; | |
685 | ||
686 | kobject_set_name(&bus->drivers.kobj, "drivers"); | |
687 | bus->drivers.subsys = &bus->subsys; | |
688 | bus->drivers.ktype = &ktype_driver; | |
689 | retval = kset_register(&bus->drivers); | |
690 | if (retval) | |
691 | goto bus_drivers_fail; | |
465c7a3a | 692 | |
34bb61f9 JB |
693 | klist_init(&bus->klist_devices, klist_devices_get, klist_devices_put); |
694 | klist_init(&bus->klist_drivers, klist_drivers_get, klist_drivers_put); | |
1da177e4 LT |
695 | bus_add_attrs(bus); |
696 | ||
697 | pr_debug("bus type '%s' registered\n", bus->name); | |
698 | return 0; | |
699 | ||
700 | bus_drivers_fail: | |
701 | kset_unregister(&bus->devices); | |
702 | bus_devices_fail: | |
703 | subsystem_unregister(&bus->subsys); | |
704 | out: | |
705 | return retval; | |
706 | } | |
707 | ||
708 | ||
709 | /** | |
710 | * bus_unregister - remove a bus from the system | |
711 | * @bus: bus. | |
712 | * | |
713 | * Unregister the child subsystems and the bus itself. | |
714 | * Finally, we call put_bus() to release the refcount | |
715 | */ | |
716 | void bus_unregister(struct bus_type * bus) | |
717 | { | |
718 | pr_debug("bus %s: unregistering\n", bus->name); | |
719 | bus_remove_attrs(bus); | |
720 | kset_unregister(&bus->drivers); | |
721 | kset_unregister(&bus->devices); | |
722 | subsystem_unregister(&bus->subsys); | |
723 | } | |
724 | ||
725 | int __init buses_init(void) | |
726 | { | |
727 | return subsystem_register(&bus_subsys); | |
728 | } | |
729 | ||
730 | ||
731 | EXPORT_SYMBOL_GPL(bus_for_each_dev); | |
0edb5860 | 732 | EXPORT_SYMBOL_GPL(bus_find_device); |
1da177e4 LT |
733 | EXPORT_SYMBOL_GPL(bus_for_each_drv); |
734 | ||
1da177e4 LT |
735 | EXPORT_SYMBOL_GPL(bus_add_device); |
736 | EXPORT_SYMBOL_GPL(bus_remove_device); | |
737 | EXPORT_SYMBOL_GPL(bus_register); | |
738 | EXPORT_SYMBOL_GPL(bus_unregister); | |
739 | EXPORT_SYMBOL_GPL(bus_rescan_devices); | |
740 | EXPORT_SYMBOL_GPL(get_bus); | |
741 | EXPORT_SYMBOL_GPL(put_bus); | |
742 | EXPORT_SYMBOL_GPL(find_bus); | |
743 | ||
744 | EXPORT_SYMBOL_GPL(bus_create_file); | |
745 | EXPORT_SYMBOL_GPL(bus_remove_file); |