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); |
ca2b94ba HR |
374 | if (!error) { |
375 | sysfs_create_link(&bus->devices.kobj, &dev->kobj, dev->bus_id); | |
b9d9c82b | 376 | sysfs_create_link(&dev->kobj, &dev->bus->subsys.kset.kobj, "subsystem"); |
ca2b94ba HR |
377 | sysfs_create_link(&dev->kobj, &dev->bus->subsys.kset.kobj, "bus"); |
378 | } | |
1da177e4 LT |
379 | } |
380 | return error; | |
381 | } | |
382 | ||
53877d06 KS |
383 | /** |
384 | * bus_attach_device - add device to bus | |
385 | * @dev: device tried to attach to a driver | |
386 | * | |
387 | * - Try to attach to driver. | |
388 | */ | |
389 | void bus_attach_device(struct device * dev) | |
390 | { | |
391 | struct bus_type * bus = dev->bus; | |
392 | ||
393 | if (bus) { | |
394 | device_attach(dev); | |
395 | klist_add_tail(&dev->knode_bus, &bus->klist_devices); | |
396 | } | |
397 | } | |
398 | ||
1da177e4 LT |
399 | /** |
400 | * bus_remove_device - remove device from bus | |
401 | * @dev: device to be removed | |
402 | * | |
403 | * - Remove symlink from bus's directory. | |
404 | * - Delete device from bus's list. | |
405 | * - Detach from its driver. | |
406 | * - Drop reference taken in bus_add_device(). | |
407 | */ | |
408 | void bus_remove_device(struct device * dev) | |
409 | { | |
410 | if (dev->bus) { | |
b9d9c82b | 411 | sysfs_remove_link(&dev->kobj, "subsystem"); |
1da177e4 LT |
412 | sysfs_remove_link(&dev->kobj, "bus"); |
413 | sysfs_remove_link(&dev->bus->devices.kobj, dev->bus_id); | |
414 | device_remove_attrs(dev->bus, dev); | |
465c7a3a | 415 | klist_remove(&dev->knode_bus); |
1da177e4 LT |
416 | pr_debug("bus %s: remove device %s\n", dev->bus->name, dev->bus_id); |
417 | device_release_driver(dev); | |
1da177e4 LT |
418 | put_bus(dev->bus); |
419 | } | |
420 | } | |
421 | ||
422 | static int driver_add_attrs(struct bus_type * bus, struct device_driver * drv) | |
423 | { | |
424 | int error = 0; | |
425 | int i; | |
426 | ||
427 | if (bus->drv_attrs) { | |
428 | for (i = 0; attr_name(bus->drv_attrs[i]); i++) { | |
429 | error = driver_create_file(drv, &bus->drv_attrs[i]); | |
430 | if (error) | |
431 | goto Err; | |
432 | } | |
433 | } | |
434 | Done: | |
435 | return error; | |
436 | Err: | |
437 | while (--i >= 0) | |
438 | driver_remove_file(drv, &bus->drv_attrs[i]); | |
439 | goto Done; | |
440 | } | |
441 | ||
442 | ||
443 | static void driver_remove_attrs(struct bus_type * bus, struct device_driver * drv) | |
444 | { | |
445 | int i; | |
446 | ||
447 | if (bus->drv_attrs) { | |
448 | for (i = 0; attr_name(bus->drv_attrs[i]); i++) | |
449 | driver_remove_file(drv, &bus->drv_attrs[i]); | |
450 | } | |
451 | } | |
452 | ||
874c6241 GKH |
453 | #ifdef CONFIG_HOTPLUG |
454 | /* | |
455 | * Thanks to drivers making their tables __devinit, we can't allow manual | |
456 | * bind and unbind from userspace unless CONFIG_HOTPLUG is enabled. | |
457 | */ | |
458 | static void add_bind_files(struct device_driver *drv) | |
459 | { | |
460 | driver_create_file(drv, &driver_attr_unbind); | |
461 | driver_create_file(drv, &driver_attr_bind); | |
462 | } | |
463 | ||
464 | static void remove_bind_files(struct device_driver *drv) | |
465 | { | |
466 | driver_remove_file(drv, &driver_attr_bind); | |
467 | driver_remove_file(drv, &driver_attr_unbind); | |
468 | } | |
469 | #else | |
35acfdd7 | 470 | static inline int add_bind_files(struct device_driver *drv) { return 0; } |
874c6241 GKH |
471 | static inline void remove_bind_files(struct device_driver *drv) {} |
472 | #endif | |
1da177e4 LT |
473 | |
474 | /** | |
475 | * bus_add_driver - Add a driver to the bus. | |
476 | * @drv: driver. | |
477 | * | |
478 | */ | |
479 | int bus_add_driver(struct device_driver * drv) | |
480 | { | |
481 | struct bus_type * bus = get_bus(drv->bus); | |
482 | int error = 0; | |
483 | ||
484 | if (bus) { | |
485 | pr_debug("bus %s: add driver %s\n", bus->name, drv->name); | |
486 | error = kobject_set_name(&drv->kobj, "%s", drv->name); | |
487 | if (error) { | |
488 | put_bus(bus); | |
489 | return error; | |
490 | } | |
491 | drv->kobj.kset = &bus->drivers; | |
492 | if ((error = kobject_register(&drv->kobj))) { | |
493 | put_bus(bus); | |
494 | return error; | |
495 | } | |
496 | ||
1da177e4 | 497 | driver_attach(drv); |
d856f1e3 | 498 | klist_add_tail(&drv->knode_bus, &bus->klist_drivers); |
1da177e4 LT |
499 | module_add_driver(drv->owner, drv); |
500 | ||
501 | driver_add_attrs(bus, drv); | |
874c6241 | 502 | add_bind_files(drv); |
1da177e4 LT |
503 | } |
504 | return error; | |
505 | } | |
506 | ||
507 | ||
508 | /** | |
509 | * bus_remove_driver - delete driver from bus's knowledge. | |
510 | * @drv: driver. | |
511 | * | |
512 | * Detach the driver from the devices it controls, and remove | |
513 | * it from its bus's list of drivers. Finally, we drop the reference | |
514 | * to the bus we took in bus_add_driver(). | |
515 | */ | |
516 | ||
517 | void bus_remove_driver(struct device_driver * drv) | |
518 | { | |
519 | if (drv->bus) { | |
874c6241 | 520 | remove_bind_files(drv); |
1da177e4 | 521 | driver_remove_attrs(drv->bus, drv); |
38fdac3c | 522 | klist_remove(&drv->knode_bus); |
1da177e4 LT |
523 | pr_debug("bus %s: remove driver %s\n", drv->bus->name, drv->name); |
524 | driver_detach(drv); | |
1da177e4 LT |
525 | module_remove_driver(drv); |
526 | kobject_unregister(&drv->kobj); | |
527 | put_bus(drv->bus); | |
528 | } | |
529 | } | |
530 | ||
531 | ||
532 | /* Helper for bus_rescan_devices's iter */ | |
533 | static int bus_rescan_devices_helper(struct device *dev, void *data) | |
534 | { | |
bf74ad5b AS |
535 | if (!dev->driver) { |
536 | if (dev->parent) /* Needed for USB */ | |
537 | down(&dev->parent->sem); | |
23d3d602 | 538 | device_attach(dev); |
bf74ad5b AS |
539 | if (dev->parent) |
540 | up(&dev->parent->sem); | |
541 | } | |
1da177e4 LT |
542 | return 0; |
543 | } | |
544 | ||
1da177e4 | 545 | /** |
23d3d602 GKH |
546 | * bus_rescan_devices - rescan devices on the bus for possible drivers |
547 | * @bus: the bus to scan. | |
1da177e4 | 548 | * |
23d3d602 GKH |
549 | * This function will look for devices on the bus with no driver |
550 | * attached and rescan it against existing drivers to see if it matches | |
551 | * any by calling device_attach() for the unbound devices. | |
1da177e4 | 552 | */ |
23d3d602 | 553 | void bus_rescan_devices(struct bus_type * bus) |
1da177e4 | 554 | { |
23d3d602 | 555 | bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper); |
1da177e4 LT |
556 | } |
557 | ||
e935d5da ME |
558 | /** |
559 | * device_reprobe - remove driver for a device and probe for a new driver | |
560 | * @dev: the device to reprobe | |
561 | * | |
562 | * This function detaches the attached driver (if any) for the given | |
563 | * device and restarts the driver probing process. It is intended | |
564 | * to use if probing criteria changed during a devices lifetime and | |
565 | * driver attachment should change accordingly. | |
566 | */ | |
567 | void device_reprobe(struct device *dev) | |
568 | { | |
569 | if (dev->driver) { | |
570 | if (dev->parent) /* Needed for USB */ | |
571 | down(&dev->parent->sem); | |
572 | device_release_driver(dev); | |
573 | if (dev->parent) | |
574 | up(&dev->parent->sem); | |
575 | } | |
576 | ||
577 | bus_rescan_devices_helper(dev, NULL); | |
578 | } | |
579 | EXPORT_SYMBOL_GPL(device_reprobe); | |
1da177e4 LT |
580 | |
581 | struct bus_type * get_bus(struct bus_type * bus) | |
582 | { | |
583 | return bus ? container_of(subsys_get(&bus->subsys), struct bus_type, subsys) : NULL; | |
584 | } | |
585 | ||
586 | void put_bus(struct bus_type * bus) | |
587 | { | |
588 | subsys_put(&bus->subsys); | |
589 | } | |
590 | ||
591 | ||
592 | /** | |
593 | * find_bus - locate bus by name. | |
594 | * @name: name of bus. | |
595 | * | |
596 | * Call kset_find_obj() to iterate over list of buses to | |
597 | * find a bus by name. Return bus if found. | |
598 | * | |
599 | * Note that kset_find_obj increments bus' reference count. | |
600 | */ | |
7e4ef085 | 601 | #if 0 |
1da177e4 LT |
602 | struct bus_type * find_bus(char * name) |
603 | { | |
604 | struct kobject * k = kset_find_obj(&bus_subsys.kset, name); | |
605 | return k ? to_bus(k) : NULL; | |
606 | } | |
7e4ef085 | 607 | #endif /* 0 */ |
1da177e4 LT |
608 | |
609 | ||
610 | /** | |
611 | * bus_add_attrs - Add default attributes for this bus. | |
612 | * @bus: Bus that has just been registered. | |
613 | */ | |
614 | ||
615 | static int bus_add_attrs(struct bus_type * bus) | |
616 | { | |
617 | int error = 0; | |
618 | int i; | |
619 | ||
620 | if (bus->bus_attrs) { | |
621 | for (i = 0; attr_name(bus->bus_attrs[i]); i++) { | |
622 | if ((error = bus_create_file(bus,&bus->bus_attrs[i]))) | |
623 | goto Err; | |
624 | } | |
625 | } | |
626 | Done: | |
627 | return error; | |
628 | Err: | |
629 | while (--i >= 0) | |
630 | bus_remove_file(bus,&bus->bus_attrs[i]); | |
631 | goto Done; | |
632 | } | |
633 | ||
634 | static void bus_remove_attrs(struct bus_type * bus) | |
635 | { | |
636 | int i; | |
637 | ||
638 | if (bus->bus_attrs) { | |
639 | for (i = 0; attr_name(bus->bus_attrs[i]); i++) | |
640 | bus_remove_file(bus,&bus->bus_attrs[i]); | |
641 | } | |
642 | } | |
643 | ||
34bb61f9 JB |
644 | static void klist_devices_get(struct klist_node *n) |
645 | { | |
646 | struct device *dev = container_of(n, struct device, knode_bus); | |
647 | ||
648 | get_device(dev); | |
649 | } | |
650 | ||
651 | static void klist_devices_put(struct klist_node *n) | |
652 | { | |
653 | struct device *dev = container_of(n, struct device, knode_bus); | |
654 | ||
655 | put_device(dev); | |
656 | } | |
657 | ||
658 | static void klist_drivers_get(struct klist_node *n) | |
659 | { | |
660 | struct device_driver *drv = container_of(n, struct device_driver, | |
661 | knode_bus); | |
662 | ||
663 | get_driver(drv); | |
664 | } | |
665 | ||
666 | static void klist_drivers_put(struct klist_node *n) | |
667 | { | |
668 | struct device_driver *drv = container_of(n, struct device_driver, | |
669 | knode_bus); | |
670 | ||
671 | put_driver(drv); | |
672 | } | |
673 | ||
1da177e4 LT |
674 | /** |
675 | * bus_register - register a bus with the system. | |
676 | * @bus: bus. | |
677 | * | |
678 | * Once we have that, we registered the bus with the kobject | |
679 | * infrastructure, then register the children subsystems it has: | |
680 | * the devices and drivers that belong to the bus. | |
681 | */ | |
682 | int bus_register(struct bus_type * bus) | |
683 | { | |
684 | int retval; | |
685 | ||
686 | retval = kobject_set_name(&bus->subsys.kset.kobj, "%s", bus->name); | |
687 | if (retval) | |
688 | goto out; | |
689 | ||
690 | subsys_set_kset(bus, bus_subsys); | |
691 | retval = subsystem_register(&bus->subsys); | |
692 | if (retval) | |
693 | goto out; | |
694 | ||
695 | kobject_set_name(&bus->devices.kobj, "devices"); | |
696 | bus->devices.subsys = &bus->subsys; | |
697 | retval = kset_register(&bus->devices); | |
698 | if (retval) | |
699 | goto bus_devices_fail; | |
700 | ||
701 | kobject_set_name(&bus->drivers.kobj, "drivers"); | |
702 | bus->drivers.subsys = &bus->subsys; | |
703 | bus->drivers.ktype = &ktype_driver; | |
704 | retval = kset_register(&bus->drivers); | |
705 | if (retval) | |
706 | goto bus_drivers_fail; | |
465c7a3a | 707 | |
34bb61f9 JB |
708 | klist_init(&bus->klist_devices, klist_devices_get, klist_devices_put); |
709 | klist_init(&bus->klist_drivers, klist_drivers_get, klist_drivers_put); | |
1da177e4 LT |
710 | bus_add_attrs(bus); |
711 | ||
712 | pr_debug("bus type '%s' registered\n", bus->name); | |
713 | return 0; | |
714 | ||
715 | bus_drivers_fail: | |
716 | kset_unregister(&bus->devices); | |
717 | bus_devices_fail: | |
718 | subsystem_unregister(&bus->subsys); | |
719 | out: | |
720 | return retval; | |
721 | } | |
722 | ||
723 | ||
724 | /** | |
725 | * bus_unregister - remove a bus from the system | |
726 | * @bus: bus. | |
727 | * | |
728 | * Unregister the child subsystems and the bus itself. | |
729 | * Finally, we call put_bus() to release the refcount | |
730 | */ | |
731 | void bus_unregister(struct bus_type * bus) | |
732 | { | |
733 | pr_debug("bus %s: unregistering\n", bus->name); | |
734 | bus_remove_attrs(bus); | |
735 | kset_unregister(&bus->drivers); | |
736 | kset_unregister(&bus->devices); | |
737 | subsystem_unregister(&bus->subsys); | |
738 | } | |
739 | ||
740 | int __init buses_init(void) | |
741 | { | |
742 | return subsystem_register(&bus_subsys); | |
743 | } | |
744 | ||
745 | ||
746 | EXPORT_SYMBOL_GPL(bus_for_each_dev); | |
0edb5860 | 747 | EXPORT_SYMBOL_GPL(bus_find_device); |
1da177e4 LT |
748 | EXPORT_SYMBOL_GPL(bus_for_each_drv); |
749 | ||
1da177e4 LT |
750 | EXPORT_SYMBOL_GPL(bus_register); |
751 | EXPORT_SYMBOL_GPL(bus_unregister); | |
752 | EXPORT_SYMBOL_GPL(bus_rescan_devices); | |
1da177e4 LT |
753 | |
754 | EXPORT_SYMBOL_GPL(bus_create_file); | |
755 | EXPORT_SYMBOL_GPL(bus_remove_file); |