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