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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 | ||
20 | #define to_dev(node) container_of(node, struct device, bus_list) | |
21 | #define to_drv(node) container_of(node, struct device_driver, kobj.entry) | |
22 | ||
23 | #define to_bus_attr(_attr) container_of(_attr, struct bus_attribute, attr) | |
24 | #define to_bus(obj) container_of(obj, struct bus_type, subsys.kset.kobj) | |
25 | ||
26 | /* | |
27 | * sysfs bindings for drivers | |
28 | */ | |
29 | ||
30 | #define to_drv_attr(_attr) container_of(_attr, struct driver_attribute, attr) | |
31 | #define to_driver(obj) container_of(obj, struct device_driver, kobj) | |
32 | ||
33 | ||
34 | static ssize_t | |
35 | drv_attr_show(struct kobject * kobj, struct attribute * attr, char * buf) | |
36 | { | |
37 | struct driver_attribute * drv_attr = to_drv_attr(attr); | |
38 | struct device_driver * drv = to_driver(kobj); | |
39 | ssize_t ret = 0; | |
40 | ||
41 | if (drv_attr->show) | |
42 | ret = drv_attr->show(drv, buf); | |
43 | return ret; | |
44 | } | |
45 | ||
46 | static ssize_t | |
47 | drv_attr_store(struct kobject * kobj, struct attribute * attr, | |
48 | const char * buf, size_t count) | |
49 | { | |
50 | struct driver_attribute * drv_attr = to_drv_attr(attr); | |
51 | struct device_driver * drv = to_driver(kobj); | |
52 | ssize_t ret = 0; | |
53 | ||
54 | if (drv_attr->store) | |
55 | ret = drv_attr->store(drv, buf, count); | |
56 | return ret; | |
57 | } | |
58 | ||
59 | static struct sysfs_ops driver_sysfs_ops = { | |
60 | .show = drv_attr_show, | |
61 | .store = drv_attr_store, | |
62 | }; | |
63 | ||
64 | ||
65 | static void driver_release(struct kobject * kobj) | |
66 | { | |
67 | struct device_driver * drv = to_driver(kobj); | |
68 | complete(&drv->unloaded); | |
69 | } | |
70 | ||
71 | static struct kobj_type ktype_driver = { | |
72 | .sysfs_ops = &driver_sysfs_ops, | |
73 | .release = driver_release, | |
74 | }; | |
75 | ||
76 | ||
77 | /* | |
78 | * sysfs bindings for buses | |
79 | */ | |
80 | ||
81 | ||
82 | static ssize_t | |
83 | bus_attr_show(struct kobject * kobj, struct attribute * attr, char * buf) | |
84 | { | |
85 | struct bus_attribute * bus_attr = to_bus_attr(attr); | |
86 | struct bus_type * bus = to_bus(kobj); | |
87 | ssize_t ret = 0; | |
88 | ||
89 | if (bus_attr->show) | |
90 | ret = bus_attr->show(bus, buf); | |
91 | return ret; | |
92 | } | |
93 | ||
94 | static ssize_t | |
95 | bus_attr_store(struct kobject * kobj, struct attribute * attr, | |
96 | const char * buf, size_t count) | |
97 | { | |
98 | struct bus_attribute * bus_attr = to_bus_attr(attr); | |
99 | struct bus_type * bus = to_bus(kobj); | |
100 | ssize_t ret = 0; | |
101 | ||
102 | if (bus_attr->store) | |
103 | ret = bus_attr->store(bus, buf, count); | |
104 | return ret; | |
105 | } | |
106 | ||
107 | static struct sysfs_ops bus_sysfs_ops = { | |
108 | .show = bus_attr_show, | |
109 | .store = bus_attr_store, | |
110 | }; | |
111 | ||
112 | int bus_create_file(struct bus_type * bus, struct bus_attribute * attr) | |
113 | { | |
114 | int error; | |
115 | if (get_bus(bus)) { | |
116 | error = sysfs_create_file(&bus->subsys.kset.kobj, &attr->attr); | |
117 | put_bus(bus); | |
118 | } else | |
119 | error = -EINVAL; | |
120 | return error; | |
121 | } | |
122 | ||
123 | void bus_remove_file(struct bus_type * bus, struct bus_attribute * attr) | |
124 | { | |
125 | if (get_bus(bus)) { | |
126 | sysfs_remove_file(&bus->subsys.kset.kobj, &attr->attr); | |
127 | put_bus(bus); | |
128 | } | |
129 | } | |
130 | ||
131 | static struct kobj_type ktype_bus = { | |
132 | .sysfs_ops = &bus_sysfs_ops, | |
133 | ||
134 | }; | |
135 | ||
136 | decl_subsys(bus, &ktype_bus, NULL); | |
137 | ||
138 | static int __bus_for_each_dev(struct bus_type *bus, struct device *start, | |
139 | void *data, int (*fn)(struct device *, void *)) | |
140 | { | |
141 | struct list_head *head; | |
142 | struct device *dev; | |
143 | int error = 0; | |
144 | ||
145 | if (!(bus = get_bus(bus))) | |
146 | return -EINVAL; | |
147 | ||
148 | head = &bus->devices.list; | |
149 | dev = list_prepare_entry(start, head, bus_list); | |
150 | list_for_each_entry_continue(dev, head, bus_list) { | |
151 | get_device(dev); | |
152 | error = fn(dev, data); | |
153 | put_device(dev); | |
154 | if (error) | |
155 | break; | |
156 | } | |
157 | put_bus(bus); | |
158 | return error; | |
159 | } | |
160 | ||
161 | static int __bus_for_each_drv(struct bus_type *bus, struct device_driver *start, | |
162 | void * data, int (*fn)(struct device_driver *, void *)) | |
163 | { | |
164 | struct list_head *head; | |
165 | struct device_driver *drv; | |
166 | int error = 0; | |
167 | ||
168 | if (!(bus = get_bus(bus))) | |
169 | return -EINVAL; | |
170 | ||
171 | head = &bus->drivers.list; | |
172 | drv = list_prepare_entry(start, head, kobj.entry); | |
173 | list_for_each_entry_continue(drv, head, kobj.entry) { | |
174 | get_driver(drv); | |
175 | error = fn(drv, data); | |
176 | put_driver(drv); | |
177 | if (error) | |
178 | break; | |
179 | } | |
180 | put_bus(bus); | |
181 | return error; | |
182 | } | |
183 | ||
184 | /** | |
185 | * bus_for_each_dev - device iterator. | |
186 | * @bus: bus type. | |
187 | * @start: device to start iterating from. | |
188 | * @data: data for the callback. | |
189 | * @fn: function to be called for each device. | |
190 | * | |
191 | * Iterate over @bus's list of devices, and call @fn for each, | |
192 | * passing it @data. If @start is not NULL, we use that device to | |
193 | * begin iterating from. | |
194 | * | |
195 | * We check the return of @fn each time. If it returns anything | |
196 | * other than 0, we break out and return that value. | |
197 | * | |
198 | * NOTE: The device that returns a non-zero value is not retained | |
199 | * in any way, nor is its refcount incremented. If the caller needs | |
200 | * to retain this data, it should do, and increment the reference | |
201 | * count in the supplied callback. | |
202 | */ | |
203 | ||
204 | int bus_for_each_dev(struct bus_type * bus, struct device * start, | |
205 | void * data, int (*fn)(struct device *, void *)) | |
206 | { | |
207 | int ret; | |
208 | ||
209 | down_read(&bus->subsys.rwsem); | |
210 | ret = __bus_for_each_dev(bus, start, data, fn); | |
211 | up_read(&bus->subsys.rwsem); | |
212 | return ret; | |
213 | } | |
214 | ||
215 | /** | |
216 | * bus_for_each_drv - driver iterator | |
217 | * @bus: bus we're dealing with. | |
218 | * @start: driver to start iterating on. | |
219 | * @data: data to pass to the callback. | |
220 | * @fn: function to call for each driver. | |
221 | * | |
222 | * This is nearly identical to the device iterator above. | |
223 | * We iterate over each driver that belongs to @bus, and call | |
224 | * @fn for each. If @fn returns anything but 0, we break out | |
225 | * and return it. If @start is not NULL, we use it as the head | |
226 | * of the list. | |
227 | * | |
228 | * NOTE: we don't return the driver that returns a non-zero | |
229 | * value, nor do we leave the reference count incremented for that | |
230 | * driver. If the caller needs to know that info, it must set it | |
231 | * in the callback. It must also be sure to increment the refcount | |
232 | * so it doesn't disappear before returning to the caller. | |
233 | */ | |
234 | ||
235 | int bus_for_each_drv(struct bus_type * bus, struct device_driver * start, | |
236 | void * data, int (*fn)(struct device_driver *, void *)) | |
237 | { | |
238 | int ret; | |
239 | ||
240 | down_read(&bus->subsys.rwsem); | |
241 | ret = __bus_for_each_drv(bus, start, data, fn); | |
242 | up_read(&bus->subsys.rwsem); | |
243 | return ret; | |
244 | } | |
245 | ||
246 | /** | |
247 | * device_bind_driver - bind a driver to one device. | |
248 | * @dev: device. | |
249 | * | |
250 | * Allow manual attachment of a driver to a device. | |
251 | * Caller must have already set @dev->driver. | |
252 | * | |
253 | * Note that this does not modify the bus reference count | |
254 | * nor take the bus's rwsem. Please verify those are accounted | |
255 | * for before calling this. (It is ok to call with no other effort | |
256 | * from a driver's probe() method.) | |
257 | */ | |
258 | ||
259 | void device_bind_driver(struct device * dev) | |
260 | { | |
261 | pr_debug("bound device '%s' to driver '%s'\n", | |
262 | dev->bus_id, dev->driver->name); | |
263 | list_add_tail(&dev->driver_list, &dev->driver->devices); | |
264 | sysfs_create_link(&dev->driver->kobj, &dev->kobj, | |
265 | kobject_name(&dev->kobj)); | |
266 | sysfs_create_link(&dev->kobj, &dev->driver->kobj, "driver"); | |
267 | } | |
268 | ||
269 | ||
270 | /** | |
271 | * driver_probe_device - attempt to bind device & driver. | |
272 | * @drv: driver. | |
273 | * @dev: device. | |
274 | * | |
275 | * First, we call the bus's match function, if one present, which | |
276 | * should compare the device IDs the driver supports with the | |
277 | * device IDs of the device. Note we don't do this ourselves | |
278 | * because we don't know the format of the ID structures, nor what | |
279 | * is to be considered a match and what is not. | |
280 | * | |
281 | * If we find a match, we call @drv->probe(@dev) if it exists, and | |
282 | * call device_bind_driver() above. | |
283 | */ | |
284 | int driver_probe_device(struct device_driver * drv, struct device * dev) | |
285 | { | |
286 | if (drv->bus->match && !drv->bus->match(dev, drv)) | |
287 | return -ENODEV; | |
288 | ||
289 | dev->driver = drv; | |
290 | if (drv->probe) { | |
291 | int error = drv->probe(dev); | |
292 | if (error) { | |
293 | dev->driver = NULL; | |
294 | return error; | |
295 | } | |
296 | } | |
297 | ||
298 | device_bind_driver(dev); | |
299 | return 0; | |
300 | } | |
301 | ||
302 | ||
303 | /** | |
304 | * device_attach - try to attach device to a driver. | |
305 | * @dev: device. | |
306 | * | |
307 | * Walk the list of drivers that the bus has and call | |
308 | * driver_probe_device() for each pair. If a compatible | |
309 | * pair is found, break out and return. | |
310 | */ | |
311 | int device_attach(struct device * dev) | |
312 | { | |
313 | struct bus_type * bus = dev->bus; | |
314 | struct list_head * entry; | |
315 | int error; | |
316 | ||
317 | if (dev->driver) { | |
318 | device_bind_driver(dev); | |
319 | return 1; | |
320 | } | |
321 | ||
322 | if (bus->match) { | |
323 | list_for_each(entry, &bus->drivers.list) { | |
324 | struct device_driver * drv = to_drv(entry); | |
325 | error = driver_probe_device(drv, dev); | |
326 | if (!error) | |
327 | /* success, driver matched */ | |
328 | return 1; | |
329 | if (error != -ENODEV && error != -ENXIO) | |
330 | /* driver matched but the probe failed */ | |
331 | printk(KERN_WARNING | |
332 | "%s: probe of %s failed with error %d\n", | |
333 | drv->name, dev->bus_id, error); | |
334 | } | |
335 | } | |
336 | ||
337 | return 0; | |
338 | } | |
339 | ||
340 | ||
341 | /** | |
342 | * driver_attach - try to bind driver to devices. | |
343 | * @drv: driver. | |
344 | * | |
345 | * Walk the list of devices that the bus has on it and try to | |
346 | * match the driver with each one. If driver_probe_device() | |
347 | * returns 0 and the @dev->driver is set, we've found a | |
348 | * compatible pair. | |
349 | * | |
350 | * Note that we ignore the -ENODEV error from driver_probe_device(), | |
351 | * since it's perfectly valid for a driver not to bind to any devices. | |
352 | */ | |
353 | void driver_attach(struct device_driver * drv) | |
354 | { | |
355 | struct bus_type * bus = drv->bus; | |
356 | struct list_head * entry; | |
357 | int error; | |
358 | ||
359 | if (!bus->match) | |
360 | return; | |
361 | ||
362 | list_for_each(entry, &bus->devices.list) { | |
363 | struct device * dev = container_of(entry, struct device, bus_list); | |
364 | if (!dev->driver) { | |
365 | error = driver_probe_device(drv, dev); | |
366 | if (error && (error != -ENODEV)) | |
367 | /* driver matched but the probe failed */ | |
368 | printk(KERN_WARNING | |
369 | "%s: probe of %s failed with error %d\n", | |
370 | drv->name, dev->bus_id, error); | |
371 | } | |
372 | } | |
373 | } | |
374 | ||
375 | ||
376 | /** | |
377 | * device_release_driver - manually detach device from driver. | |
378 | * @dev: device. | |
379 | * | |
380 | * Manually detach device from driver. | |
381 | * Note that this is called without incrementing the bus | |
382 | * reference count nor taking the bus's rwsem. Be sure that | |
383 | * those are accounted for before calling this function. | |
384 | */ | |
385 | ||
386 | void device_release_driver(struct device * dev) | |
387 | { | |
388 | struct device_driver * drv = dev->driver; | |
389 | if (drv) { | |
390 | sysfs_remove_link(&drv->kobj, kobject_name(&dev->kobj)); | |
391 | sysfs_remove_link(&dev->kobj, "driver"); | |
392 | list_del_init(&dev->driver_list); | |
393 | device_detach_shutdown(dev); | |
394 | if (drv->remove) | |
395 | drv->remove(dev); | |
396 | dev->driver = NULL; | |
397 | } | |
398 | } | |
399 | ||
400 | ||
401 | /** | |
402 | * driver_detach - detach driver from all devices it controls. | |
403 | * @drv: driver. | |
404 | */ | |
405 | ||
406 | static void driver_detach(struct device_driver * drv) | |
407 | { | |
408 | struct list_head * entry, * next; | |
409 | list_for_each_safe(entry, next, &drv->devices) { | |
410 | struct device * dev = container_of(entry, struct device, driver_list); | |
411 | device_release_driver(dev); | |
412 | } | |
413 | } | |
414 | ||
415 | static int device_add_attrs(struct bus_type * bus, struct device * dev) | |
416 | { | |
417 | int error = 0; | |
418 | int i; | |
419 | ||
420 | if (bus->dev_attrs) { | |
421 | for (i = 0; attr_name(bus->dev_attrs[i]); i++) { | |
422 | error = device_create_file(dev,&bus->dev_attrs[i]); | |
423 | if (error) | |
424 | goto Err; | |
425 | } | |
426 | } | |
427 | Done: | |
428 | return error; | |
429 | Err: | |
430 | while (--i >= 0) | |
431 | device_remove_file(dev,&bus->dev_attrs[i]); | |
432 | goto Done; | |
433 | } | |
434 | ||
435 | ||
436 | static void device_remove_attrs(struct bus_type * bus, struct device * dev) | |
437 | { | |
438 | int i; | |
439 | ||
440 | if (bus->dev_attrs) { | |
441 | for (i = 0; attr_name(bus->dev_attrs[i]); i++) | |
442 | device_remove_file(dev,&bus->dev_attrs[i]); | |
443 | } | |
444 | } | |
445 | ||
446 | ||
447 | /** | |
448 | * bus_add_device - add device to bus | |
449 | * @dev: device being added | |
450 | * | |
451 | * - Add the device to its bus's list of devices. | |
452 | * - Try to attach to driver. | |
453 | * - Create link to device's physical location. | |
454 | */ | |
455 | int bus_add_device(struct device * dev) | |
456 | { | |
457 | struct bus_type * bus = get_bus(dev->bus); | |
458 | int error = 0; | |
459 | ||
460 | if (bus) { | |
461 | down_write(&dev->bus->subsys.rwsem); | |
462 | pr_debug("bus %s: add device %s\n", bus->name, dev->bus_id); | |
463 | list_add_tail(&dev->bus_list, &dev->bus->devices.list); | |
464 | device_attach(dev); | |
465 | up_write(&dev->bus->subsys.rwsem); | |
466 | device_add_attrs(bus, dev); | |
467 | sysfs_create_link(&bus->devices.kobj, &dev->kobj, dev->bus_id); | |
468 | sysfs_create_link(&dev->kobj, &dev->bus->subsys.kset.kobj, "bus"); | |
469 | } | |
470 | return error; | |
471 | } | |
472 | ||
473 | /** | |
474 | * bus_remove_device - remove device from bus | |
475 | * @dev: device to be removed | |
476 | * | |
477 | * - Remove symlink from bus's directory. | |
478 | * - Delete device from bus's list. | |
479 | * - Detach from its driver. | |
480 | * - Drop reference taken in bus_add_device(). | |
481 | */ | |
482 | void bus_remove_device(struct device * dev) | |
483 | { | |
484 | if (dev->bus) { | |
485 | sysfs_remove_link(&dev->kobj, "bus"); | |
486 | sysfs_remove_link(&dev->bus->devices.kobj, dev->bus_id); | |
487 | device_remove_attrs(dev->bus, dev); | |
488 | down_write(&dev->bus->subsys.rwsem); | |
489 | pr_debug("bus %s: remove device %s\n", dev->bus->name, dev->bus_id); | |
490 | device_release_driver(dev); | |
491 | list_del_init(&dev->bus_list); | |
492 | up_write(&dev->bus->subsys.rwsem); | |
493 | put_bus(dev->bus); | |
494 | } | |
495 | } | |
496 | ||
497 | static int driver_add_attrs(struct bus_type * bus, struct device_driver * drv) | |
498 | { | |
499 | int error = 0; | |
500 | int i; | |
501 | ||
502 | if (bus->drv_attrs) { | |
503 | for (i = 0; attr_name(bus->drv_attrs[i]); i++) { | |
504 | error = driver_create_file(drv, &bus->drv_attrs[i]); | |
505 | if (error) | |
506 | goto Err; | |
507 | } | |
508 | } | |
509 | Done: | |
510 | return error; | |
511 | Err: | |
512 | while (--i >= 0) | |
513 | driver_remove_file(drv, &bus->drv_attrs[i]); | |
514 | goto Done; | |
515 | } | |
516 | ||
517 | ||
518 | static void driver_remove_attrs(struct bus_type * bus, struct device_driver * drv) | |
519 | { | |
520 | int i; | |
521 | ||
522 | if (bus->drv_attrs) { | |
523 | for (i = 0; attr_name(bus->drv_attrs[i]); i++) | |
524 | driver_remove_file(drv, &bus->drv_attrs[i]); | |
525 | } | |
526 | } | |
527 | ||
528 | ||
529 | /** | |
530 | * bus_add_driver - Add a driver to the bus. | |
531 | * @drv: driver. | |
532 | * | |
533 | */ | |
534 | int bus_add_driver(struct device_driver * drv) | |
535 | { | |
536 | struct bus_type * bus = get_bus(drv->bus); | |
537 | int error = 0; | |
538 | ||
539 | if (bus) { | |
540 | pr_debug("bus %s: add driver %s\n", bus->name, drv->name); | |
541 | error = kobject_set_name(&drv->kobj, "%s", drv->name); | |
542 | if (error) { | |
543 | put_bus(bus); | |
544 | return error; | |
545 | } | |
546 | drv->kobj.kset = &bus->drivers; | |
547 | if ((error = kobject_register(&drv->kobj))) { | |
548 | put_bus(bus); | |
549 | return error; | |
550 | } | |
551 | ||
552 | down_write(&bus->subsys.rwsem); | |
553 | driver_attach(drv); | |
554 | up_write(&bus->subsys.rwsem); | |
555 | module_add_driver(drv->owner, drv); | |
556 | ||
557 | driver_add_attrs(bus, drv); | |
558 | } | |
559 | return error; | |
560 | } | |
561 | ||
562 | ||
563 | /** | |
564 | * bus_remove_driver - delete driver from bus's knowledge. | |
565 | * @drv: driver. | |
566 | * | |
567 | * Detach the driver from the devices it controls, and remove | |
568 | * it from its bus's list of drivers. Finally, we drop the reference | |
569 | * to the bus we took in bus_add_driver(). | |
570 | */ | |
571 | ||
572 | void bus_remove_driver(struct device_driver * drv) | |
573 | { | |
574 | if (drv->bus) { | |
575 | driver_remove_attrs(drv->bus, drv); | |
576 | down_write(&drv->bus->subsys.rwsem); | |
577 | pr_debug("bus %s: remove driver %s\n", drv->bus->name, drv->name); | |
578 | driver_detach(drv); | |
579 | up_write(&drv->bus->subsys.rwsem); | |
580 | module_remove_driver(drv); | |
581 | kobject_unregister(&drv->kobj); | |
582 | put_bus(drv->bus); | |
583 | } | |
584 | } | |
585 | ||
586 | ||
587 | /* Helper for bus_rescan_devices's iter */ | |
588 | static int bus_rescan_devices_helper(struct device *dev, void *data) | |
589 | { | |
590 | int *count = data; | |
591 | ||
592 | if (!dev->driver && device_attach(dev)) | |
593 | (*count)++; | |
594 | ||
595 | return 0; | |
596 | } | |
597 | ||
598 | ||
599 | /** | |
600 | * bus_rescan_devices - rescan devices on the bus for possible drivers | |
601 | * @bus: the bus to scan. | |
602 | * | |
603 | * This function will look for devices on the bus with no driver | |
604 | * attached and rescan it against existing drivers to see if it | |
605 | * matches any. Calls device_attach(). Returns the number of devices | |
606 | * that were sucessfully bound to a driver. | |
607 | */ | |
608 | int bus_rescan_devices(struct bus_type * bus) | |
609 | { | |
610 | int count = 0; | |
611 | ||
612 | down_write(&bus->subsys.rwsem); | |
613 | __bus_for_each_dev(bus, NULL, &count, bus_rescan_devices_helper); | |
614 | up_write(&bus->subsys.rwsem); | |
615 | ||
616 | return count; | |
617 | } | |
618 | ||
619 | ||
620 | struct bus_type * get_bus(struct bus_type * bus) | |
621 | { | |
622 | return bus ? container_of(subsys_get(&bus->subsys), struct bus_type, subsys) : NULL; | |
623 | } | |
624 | ||
625 | void put_bus(struct bus_type * bus) | |
626 | { | |
627 | subsys_put(&bus->subsys); | |
628 | } | |
629 | ||
630 | ||
631 | /** | |
632 | * find_bus - locate bus by name. | |
633 | * @name: name of bus. | |
634 | * | |
635 | * Call kset_find_obj() to iterate over list of buses to | |
636 | * find a bus by name. Return bus if found. | |
637 | * | |
638 | * Note that kset_find_obj increments bus' reference count. | |
639 | */ | |
640 | ||
641 | struct bus_type * find_bus(char * name) | |
642 | { | |
643 | struct kobject * k = kset_find_obj(&bus_subsys.kset, name); | |
644 | return k ? to_bus(k) : NULL; | |
645 | } | |
646 | ||
647 | ||
648 | /** | |
649 | * bus_add_attrs - Add default attributes for this bus. | |
650 | * @bus: Bus that has just been registered. | |
651 | */ | |
652 | ||
653 | static int bus_add_attrs(struct bus_type * bus) | |
654 | { | |
655 | int error = 0; | |
656 | int i; | |
657 | ||
658 | if (bus->bus_attrs) { | |
659 | for (i = 0; attr_name(bus->bus_attrs[i]); i++) { | |
660 | if ((error = bus_create_file(bus,&bus->bus_attrs[i]))) | |
661 | goto Err; | |
662 | } | |
663 | } | |
664 | Done: | |
665 | return error; | |
666 | Err: | |
667 | while (--i >= 0) | |
668 | bus_remove_file(bus,&bus->bus_attrs[i]); | |
669 | goto Done; | |
670 | } | |
671 | ||
672 | static void bus_remove_attrs(struct bus_type * bus) | |
673 | { | |
674 | int i; | |
675 | ||
676 | if (bus->bus_attrs) { | |
677 | for (i = 0; attr_name(bus->bus_attrs[i]); i++) | |
678 | bus_remove_file(bus,&bus->bus_attrs[i]); | |
679 | } | |
680 | } | |
681 | ||
682 | /** | |
683 | * bus_register - register a bus with the system. | |
684 | * @bus: bus. | |
685 | * | |
686 | * Once we have that, we registered the bus with the kobject | |
687 | * infrastructure, then register the children subsystems it has: | |
688 | * the devices and drivers that belong to the bus. | |
689 | */ | |
690 | int bus_register(struct bus_type * bus) | |
691 | { | |
692 | int retval; | |
693 | ||
694 | retval = kobject_set_name(&bus->subsys.kset.kobj, "%s", bus->name); | |
695 | if (retval) | |
696 | goto out; | |
697 | ||
698 | subsys_set_kset(bus, bus_subsys); | |
699 | retval = subsystem_register(&bus->subsys); | |
700 | if (retval) | |
701 | goto out; | |
702 | ||
703 | kobject_set_name(&bus->devices.kobj, "devices"); | |
704 | bus->devices.subsys = &bus->subsys; | |
705 | retval = kset_register(&bus->devices); | |
706 | if (retval) | |
707 | goto bus_devices_fail; | |
708 | ||
709 | kobject_set_name(&bus->drivers.kobj, "drivers"); | |
710 | bus->drivers.subsys = &bus->subsys; | |
711 | bus->drivers.ktype = &ktype_driver; | |
712 | retval = kset_register(&bus->drivers); | |
713 | if (retval) | |
714 | goto bus_drivers_fail; | |
715 | bus_add_attrs(bus); | |
716 | ||
717 | pr_debug("bus type '%s' registered\n", bus->name); | |
718 | return 0; | |
719 | ||
720 | bus_drivers_fail: | |
721 | kset_unregister(&bus->devices); | |
722 | bus_devices_fail: | |
723 | subsystem_unregister(&bus->subsys); | |
724 | out: | |
725 | return retval; | |
726 | } | |
727 | ||
728 | ||
729 | /** | |
730 | * bus_unregister - remove a bus from the system | |
731 | * @bus: bus. | |
732 | * | |
733 | * Unregister the child subsystems and the bus itself. | |
734 | * Finally, we call put_bus() to release the refcount | |
735 | */ | |
736 | void bus_unregister(struct bus_type * bus) | |
737 | { | |
738 | pr_debug("bus %s: unregistering\n", bus->name); | |
739 | bus_remove_attrs(bus); | |
740 | kset_unregister(&bus->drivers); | |
741 | kset_unregister(&bus->devices); | |
742 | subsystem_unregister(&bus->subsys); | |
743 | } | |
744 | ||
745 | int __init buses_init(void) | |
746 | { | |
747 | return subsystem_register(&bus_subsys); | |
748 | } | |
749 | ||
750 | ||
751 | EXPORT_SYMBOL_GPL(bus_for_each_dev); | |
752 | EXPORT_SYMBOL_GPL(bus_for_each_drv); | |
753 | ||
754 | EXPORT_SYMBOL_GPL(driver_probe_device); | |
755 | EXPORT_SYMBOL_GPL(device_bind_driver); | |
756 | EXPORT_SYMBOL_GPL(device_release_driver); | |
757 | EXPORT_SYMBOL_GPL(device_attach); | |
758 | EXPORT_SYMBOL_GPL(driver_attach); | |
759 | ||
760 | EXPORT_SYMBOL_GPL(bus_add_device); | |
761 | EXPORT_SYMBOL_GPL(bus_remove_device); | |
762 | EXPORT_SYMBOL_GPL(bus_register); | |
763 | EXPORT_SYMBOL_GPL(bus_unregister); | |
764 | EXPORT_SYMBOL_GPL(bus_rescan_devices); | |
765 | EXPORT_SYMBOL_GPL(get_bus); | |
766 | EXPORT_SYMBOL_GPL(put_bus); | |
767 | EXPORT_SYMBOL_GPL(find_bus); | |
768 | ||
769 | EXPORT_SYMBOL_GPL(bus_create_file); | |
770 | EXPORT_SYMBOL_GPL(bus_remove_file); |