]>
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 | ||
b8c5cec2 KS |
30 | static int __must_check bus_rescan_devices_helper(struct device *dev, |
31 | void *data); | |
32 | ||
1da177e4 LT |
33 | static ssize_t |
34 | drv_attr_show(struct kobject * kobj, struct attribute * attr, char * buf) | |
35 | { | |
36 | struct driver_attribute * drv_attr = to_drv_attr(attr); | |
37 | struct device_driver * drv = to_driver(kobj); | |
4a0c20bf | 38 | ssize_t ret = -EIO; |
1da177e4 LT |
39 | |
40 | if (drv_attr->show) | |
41 | ret = drv_attr->show(drv, buf); | |
42 | return ret; | |
43 | } | |
44 | ||
45 | static ssize_t | |
46 | drv_attr_store(struct kobject * kobj, struct attribute * attr, | |
47 | const char * buf, size_t count) | |
48 | { | |
49 | struct driver_attribute * drv_attr = to_drv_attr(attr); | |
50 | struct device_driver * drv = to_driver(kobj); | |
4a0c20bf | 51 | ssize_t ret = -EIO; |
1da177e4 LT |
52 | |
53 | if (drv_attr->store) | |
54 | ret = drv_attr->store(drv, buf, count); | |
55 | return ret; | |
56 | } | |
57 | ||
58 | static struct sysfs_ops driver_sysfs_ops = { | |
59 | .show = drv_attr_show, | |
60 | .store = drv_attr_store, | |
61 | }; | |
62 | ||
63 | ||
64 | static void driver_release(struct kobject * kobj) | |
65 | { | |
74e9f5fa GKH |
66 | /* |
67 | * Yes this is an empty release function, it is this way because struct | |
68 | * device is always a static object, not a dynamic one. Yes, this is | |
69 | * not nice and bad, but remember, drivers are code, reference counted | |
70 | * by the module count, not a device, which is really data. And yes, | |
71 | * in the future I do want to have all drivers be created dynamically, | |
72 | * and am working toward that goal, but it will take a bit longer... | |
73 | * | |
74 | * But do not let this example give _anyone_ the idea that they can | |
75 | * create a release function without any code in it at all, to do that | |
76 | * is almost always wrong. If you have any questions about this, | |
77 | * please send an email to <greg@kroah.com> | |
78 | */ | |
1da177e4 LT |
79 | } |
80 | ||
81 | static struct kobj_type ktype_driver = { | |
82 | .sysfs_ops = &driver_sysfs_ops, | |
83 | .release = driver_release, | |
84 | }; | |
85 | ||
86 | ||
87 | /* | |
88 | * sysfs bindings for buses | |
89 | */ | |
90 | ||
91 | ||
92 | static ssize_t | |
93 | bus_attr_show(struct kobject * kobj, struct attribute * attr, char * buf) | |
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->show) | |
100 | ret = bus_attr->show(bus, buf); | |
101 | return ret; | |
102 | } | |
103 | ||
104 | static ssize_t | |
105 | bus_attr_store(struct kobject * kobj, struct attribute * attr, | |
106 | const char * buf, size_t count) | |
107 | { | |
108 | struct bus_attribute * bus_attr = to_bus_attr(attr); | |
109 | struct bus_type * bus = to_bus(kobj); | |
110 | ssize_t ret = 0; | |
111 | ||
112 | if (bus_attr->store) | |
113 | ret = bus_attr->store(bus, buf, count); | |
114 | return ret; | |
115 | } | |
116 | ||
117 | static struct sysfs_ops bus_sysfs_ops = { | |
118 | .show = bus_attr_show, | |
119 | .store = bus_attr_store, | |
120 | }; | |
121 | ||
122 | int bus_create_file(struct bus_type * bus, struct bus_attribute * attr) | |
123 | { | |
124 | int error; | |
125 | if (get_bus(bus)) { | |
126 | error = sysfs_create_file(&bus->subsys.kset.kobj, &attr->attr); | |
127 | put_bus(bus); | |
128 | } else | |
129 | error = -EINVAL; | |
130 | return error; | |
131 | } | |
132 | ||
133 | void bus_remove_file(struct bus_type * bus, struct bus_attribute * attr) | |
134 | { | |
135 | if (get_bus(bus)) { | |
136 | sysfs_remove_file(&bus->subsys.kset.kobj, &attr->attr); | |
137 | put_bus(bus); | |
138 | } | |
139 | } | |
140 | ||
141 | static struct kobj_type ktype_bus = { | |
142 | .sysfs_ops = &bus_sysfs_ops, | |
143 | ||
144 | }; | |
145 | ||
7e4ef085 | 146 | static decl_subsys(bus, &ktype_bus, NULL); |
1da177e4 | 147 | |
1da177e4 | 148 | |
2139bdd5 | 149 | #ifdef CONFIG_HOTPLUG |
2b08c8d0 | 150 | /* Manually detach a device from its associated driver. */ |
151ef38f GKH |
151 | static int driver_helper(struct device *dev, void *data) |
152 | { | |
153 | const char *name = data; | |
154 | ||
155 | if (strcmp(name, dev->bus_id) == 0) | |
156 | return 1; | |
157 | return 0; | |
158 | } | |
159 | ||
160 | static ssize_t driver_unbind(struct device_driver *drv, | |
161 | const char *buf, size_t count) | |
162 | { | |
163 | struct bus_type *bus = get_bus(drv->bus); | |
164 | struct device *dev; | |
165 | int err = -ENODEV; | |
166 | ||
167 | dev = bus_find_device(bus, NULL, (void *)buf, driver_helper); | |
2b08c8d0 | 168 | if (dev && dev->driver == drv) { |
bf74ad5b AS |
169 | if (dev->parent) /* Needed for USB */ |
170 | down(&dev->parent->sem); | |
151ef38f | 171 | device_release_driver(dev); |
bf74ad5b AS |
172 | if (dev->parent) |
173 | up(&dev->parent->sem); | |
151ef38f GKH |
174 | err = count; |
175 | } | |
2b08c8d0 AS |
176 | put_device(dev); |
177 | put_bus(bus); | |
178 | return err; | |
151ef38f GKH |
179 | } |
180 | static DRIVER_ATTR(unbind, S_IWUSR, NULL, driver_unbind); | |
181 | ||
afdce75f GKH |
182 | /* |
183 | * Manually attach a device to a driver. | |
184 | * Note: the driver must want to bind to the device, | |
185 | * it is not possible to override the driver's id table. | |
186 | */ | |
187 | static ssize_t driver_bind(struct device_driver *drv, | |
188 | const char *buf, size_t count) | |
189 | { | |
190 | struct bus_type *bus = get_bus(drv->bus); | |
191 | struct device *dev; | |
192 | int err = -ENODEV; | |
193 | ||
194 | dev = bus_find_device(bus, NULL, (void *)buf, driver_helper); | |
2b08c8d0 | 195 | if (dev && dev->driver == NULL) { |
bf74ad5b AS |
196 | if (dev->parent) /* Needed for USB */ |
197 | down(&dev->parent->sem); | |
afdce75f GKH |
198 | down(&dev->sem); |
199 | err = driver_probe_device(drv, dev); | |
200 | up(&dev->sem); | |
bf74ad5b AS |
201 | if (dev->parent) |
202 | up(&dev->parent->sem); | |
37225401 RW |
203 | |
204 | if (err > 0) /* success */ | |
205 | err = count; | |
206 | else if (err == 0) /* driver didn't accept device */ | |
207 | err = -ENODEV; | |
afdce75f | 208 | } |
2b08c8d0 AS |
209 | put_device(dev); |
210 | put_bus(bus); | |
211 | return err; | |
afdce75f GKH |
212 | } |
213 | static DRIVER_ATTR(bind, S_IWUSR, NULL, driver_bind); | |
214 | ||
b8c5cec2 KS |
215 | static ssize_t show_drivers_autoprobe(struct bus_type *bus, char *buf) |
216 | { | |
217 | return sprintf(buf, "%d\n", bus->drivers_autoprobe); | |
218 | } | |
219 | ||
220 | static ssize_t store_drivers_autoprobe(struct bus_type *bus, | |
221 | const char *buf, size_t count) | |
222 | { | |
223 | if (buf[0] == '0') | |
224 | bus->drivers_autoprobe = 0; | |
225 | else | |
226 | bus->drivers_autoprobe = 1; | |
227 | return count; | |
228 | } | |
229 | ||
230 | static ssize_t store_drivers_probe(struct bus_type *bus, | |
231 | const char *buf, size_t count) | |
232 | { | |
233 | struct device *dev; | |
234 | ||
235 | dev = bus_find_device(bus, NULL, (void *)buf, driver_helper); | |
236 | if (!dev) | |
237 | return -ENODEV; | |
238 | if (bus_rescan_devices_helper(dev, NULL) != 0) | |
239 | return -EINVAL; | |
240 | return count; | |
241 | } | |
2139bdd5 | 242 | #endif |
151ef38f | 243 | |
465c7a3a PM |
244 | static struct device * next_device(struct klist_iter * i) |
245 | { | |
246 | struct klist_node * n = klist_next(i); | |
247 | return n ? container_of(n, struct device, knode_bus) : NULL; | |
248 | } | |
249 | ||
1da177e4 LT |
250 | /** |
251 | * bus_for_each_dev - device iterator. | |
252 | * @bus: bus type. | |
253 | * @start: device to start iterating from. | |
254 | * @data: data for the callback. | |
255 | * @fn: function to be called for each device. | |
256 | * | |
257 | * Iterate over @bus's list of devices, and call @fn for each, | |
258 | * passing it @data. If @start is not NULL, we use that device to | |
259 | * begin iterating from. | |
260 | * | |
261 | * We check the return of @fn each time. If it returns anything | |
262 | * other than 0, we break out and return that value. | |
263 | * | |
264 | * NOTE: The device that returns a non-zero value is not retained | |
265 | * in any way, nor is its refcount incremented. If the caller needs | |
266 | * to retain this data, it should do, and increment the reference | |
267 | * count in the supplied callback. | |
268 | */ | |
269 | ||
270 | int bus_for_each_dev(struct bus_type * bus, struct device * start, | |
271 | void * data, int (*fn)(struct device *, void *)) | |
272 | { | |
465c7a3a PM |
273 | struct klist_iter i; |
274 | struct device * dev; | |
275 | int error = 0; | |
1da177e4 | 276 | |
465c7a3a PM |
277 | if (!bus) |
278 | return -EINVAL; | |
279 | ||
280 | klist_iter_init_node(&bus->klist_devices, &i, | |
281 | (start ? &start->knode_bus : NULL)); | |
282 | while ((dev = next_device(&i)) && !error) | |
283 | error = fn(dev, data); | |
284 | klist_iter_exit(&i); | |
285 | return error; | |
1da177e4 LT |
286 | } |
287 | ||
0edb5860 CH |
288 | /** |
289 | * bus_find_device - device iterator for locating a particular device. | |
290 | * @bus: bus type | |
291 | * @start: Device to begin with | |
292 | * @data: Data to pass to match function | |
293 | * @match: Callback function to check device | |
294 | * | |
295 | * This is similar to the bus_for_each_dev() function above, but it | |
296 | * returns a reference to a device that is 'found' for later use, as | |
297 | * determined by the @match callback. | |
298 | * | |
299 | * The callback should return 0 if the device doesn't match and non-zero | |
300 | * if it does. If the callback returns non-zero, this function will | |
301 | * return to the caller and not iterate over any more devices. | |
302 | */ | |
303 | struct device * bus_find_device(struct bus_type *bus, | |
304 | struct device *start, void *data, | |
305 | int (*match)(struct device *, void *)) | |
306 | { | |
307 | struct klist_iter i; | |
308 | struct device *dev; | |
309 | ||
310 | if (!bus) | |
311 | return NULL; | |
312 | ||
313 | klist_iter_init_node(&bus->klist_devices, &i, | |
314 | (start ? &start->knode_bus : NULL)); | |
315 | while ((dev = next_device(&i))) | |
316 | if (match(dev, data) && get_device(dev)) | |
317 | break; | |
318 | klist_iter_exit(&i); | |
319 | return dev; | |
320 | } | |
38fdac3c PM |
321 | |
322 | ||
323 | static struct device_driver * next_driver(struct klist_iter * i) | |
324 | { | |
325 | struct klist_node * n = klist_next(i); | |
326 | return n ? container_of(n, struct device_driver, knode_bus) : NULL; | |
327 | } | |
328 | ||
1da177e4 LT |
329 | /** |
330 | * bus_for_each_drv - driver iterator | |
331 | * @bus: bus we're dealing with. | |
332 | * @start: driver to start iterating on. | |
333 | * @data: data to pass to the callback. | |
334 | * @fn: function to call for each driver. | |
335 | * | |
336 | * This is nearly identical to the device iterator above. | |
337 | * We iterate over each driver that belongs to @bus, and call | |
338 | * @fn for each. If @fn returns anything but 0, we break out | |
339 | * and return it. If @start is not NULL, we use it as the head | |
340 | * of the list. | |
341 | * | |
342 | * NOTE: we don't return the driver that returns a non-zero | |
343 | * value, nor do we leave the reference count incremented for that | |
344 | * driver. If the caller needs to know that info, it must set it | |
345 | * in the callback. It must also be sure to increment the refcount | |
346 | * so it doesn't disappear before returning to the caller. | |
347 | */ | |
348 | ||
349 | int bus_for_each_drv(struct bus_type * bus, struct device_driver * start, | |
350 | void * data, int (*fn)(struct device_driver *, void *)) | |
351 | { | |
38fdac3c PM |
352 | struct klist_iter i; |
353 | struct device_driver * drv; | |
354 | int error = 0; | |
1da177e4 | 355 | |
38fdac3c PM |
356 | if (!bus) |
357 | return -EINVAL; | |
358 | ||
359 | klist_iter_init_node(&bus->klist_drivers, &i, | |
360 | start ? &start->knode_bus : NULL); | |
361 | while ((drv = next_driver(&i)) && !error) | |
362 | error = fn(drv, data); | |
363 | klist_iter_exit(&i); | |
364 | return error; | |
1da177e4 LT |
365 | } |
366 | ||
4aca67e5 | 367 | static int device_add_attrs(struct bus_type *bus, struct device *dev) |
1da177e4 LT |
368 | { |
369 | int error = 0; | |
370 | int i; | |
371 | ||
4aca67e5 AM |
372 | if (!bus->dev_attrs) |
373 | return 0; | |
374 | ||
375 | for (i = 0; attr_name(bus->dev_attrs[i]); i++) { | |
376 | error = device_create_file(dev,&bus->dev_attrs[i]); | |
377 | if (error) { | |
378 | while (--i >= 0) | |
379 | device_remove_file(dev, &bus->dev_attrs[i]); | |
380 | break; | |
1da177e4 LT |
381 | } |
382 | } | |
1da177e4 | 383 | return error; |
1da177e4 LT |
384 | } |
385 | ||
1da177e4 LT |
386 | static void device_remove_attrs(struct bus_type * bus, struct device * dev) |
387 | { | |
388 | int i; | |
389 | ||
390 | if (bus->dev_attrs) { | |
391 | for (i = 0; attr_name(bus->dev_attrs[i]); i++) | |
392 | device_remove_file(dev,&bus->dev_attrs[i]); | |
393 | } | |
394 | } | |
395 | ||
b9cafc7d KS |
396 | #ifdef CONFIG_SYSFS_DEPRECATED |
397 | static int make_deprecated_bus_links(struct device *dev) | |
398 | { | |
399 | return sysfs_create_link(&dev->kobj, | |
400 | &dev->bus->subsys.kset.kobj, "bus"); | |
401 | } | |
402 | ||
403 | static void remove_deprecated_bus_links(struct device *dev) | |
404 | { | |
405 | sysfs_remove_link(&dev->kobj, "bus"); | |
406 | } | |
407 | #else | |
408 | static inline int make_deprecated_bus_links(struct device *dev) { return 0; } | |
409 | static inline void remove_deprecated_bus_links(struct device *dev) { } | |
410 | #endif | |
1da177e4 LT |
411 | |
412 | /** | |
413 | * bus_add_device - add device to bus | |
414 | * @dev: device being added | |
415 | * | |
416 | * - Add the device to its bus's list of devices. | |
53877d06 | 417 | * - Create link to device's bus. |
1da177e4 LT |
418 | */ |
419 | int bus_add_device(struct device * dev) | |
420 | { | |
421 | struct bus_type * bus = get_bus(dev->bus); | |
422 | int error = 0; | |
423 | ||
424 | if (bus) { | |
1da177e4 | 425 | pr_debug("bus %s: add device %s\n", bus->name, dev->bus_id); |
d377e85b | 426 | error = device_add_attrs(bus, dev); |
f86db396 | 427 | if (error) |
513e7337 | 428 | goto out_put; |
f86db396 AM |
429 | error = sysfs_create_link(&bus->devices.kobj, |
430 | &dev->kobj, dev->bus_id); | |
431 | if (error) | |
513e7337 | 432 | goto out_id; |
f86db396 AM |
433 | error = sysfs_create_link(&dev->kobj, |
434 | &dev->bus->subsys.kset.kobj, "subsystem"); | |
435 | if (error) | |
513e7337 | 436 | goto out_subsys; |
b9cafc7d | 437 | error = make_deprecated_bus_links(dev); |
513e7337 CH |
438 | if (error) |
439 | goto out_deprecated; | |
1da177e4 | 440 | } |
513e7337 CH |
441 | return 0; |
442 | ||
443 | out_deprecated: | |
444 | sysfs_remove_link(&dev->kobj, "subsystem"); | |
445 | out_subsys: | |
446 | sysfs_remove_link(&bus->devices.kobj, dev->bus_id); | |
447 | out_id: | |
448 | device_remove_attrs(bus, dev); | |
449 | out_put: | |
450 | put_bus(dev->bus); | |
1da177e4 LT |
451 | return error; |
452 | } | |
453 | ||
53877d06 KS |
454 | /** |
455 | * bus_attach_device - add device to bus | |
456 | * @dev: device tried to attach to a driver | |
457 | * | |
f2eaae19 | 458 | * - Add device to bus's list of devices. |
53877d06 KS |
459 | * - Try to attach to driver. |
460 | */ | |
c6a46696 | 461 | void bus_attach_device(struct device * dev) |
53877d06 | 462 | { |
f86db396 AM |
463 | struct bus_type *bus = dev->bus; |
464 | int ret = 0; | |
53877d06 KS |
465 | |
466 | if (bus) { | |
f2eaae19 | 467 | dev->is_registered = 1; |
b8c5cec2 KS |
468 | if (bus->drivers_autoprobe) |
469 | ret = device_attach(dev); | |
c6a46696 CH |
470 | WARN_ON(ret < 0); |
471 | if (ret >= 0) | |
f86db396 | 472 | klist_add_tail(&dev->knode_bus, &bus->klist_devices); |
c6a46696 | 473 | else |
f2eaae19 | 474 | dev->is_registered = 0; |
53877d06 KS |
475 | } |
476 | } | |
477 | ||
1da177e4 LT |
478 | /** |
479 | * bus_remove_device - remove device from bus | |
480 | * @dev: device to be removed | |
481 | * | |
482 | * - Remove symlink from bus's directory. | |
483 | * - Delete device from bus's list. | |
484 | * - Detach from its driver. | |
485 | * - Drop reference taken in bus_add_device(). | |
486 | */ | |
487 | void bus_remove_device(struct device * dev) | |
488 | { | |
489 | if (dev->bus) { | |
b9d9c82b | 490 | sysfs_remove_link(&dev->kobj, "subsystem"); |
b9cafc7d | 491 | remove_deprecated_bus_links(dev); |
1da177e4 LT |
492 | sysfs_remove_link(&dev->bus->devices.kobj, dev->bus_id); |
493 | device_remove_attrs(dev->bus, dev); | |
f70fa629 AS |
494 | if (dev->is_registered) { |
495 | dev->is_registered = 0; | |
496 | klist_del(&dev->knode_bus); | |
497 | } | |
1da177e4 LT |
498 | pr_debug("bus %s: remove device %s\n", dev->bus->name, dev->bus_id); |
499 | device_release_driver(dev); | |
1da177e4 LT |
500 | put_bus(dev->bus); |
501 | } | |
502 | } | |
503 | ||
504 | static int driver_add_attrs(struct bus_type * bus, struct device_driver * drv) | |
505 | { | |
506 | int error = 0; | |
507 | int i; | |
508 | ||
509 | if (bus->drv_attrs) { | |
510 | for (i = 0; attr_name(bus->drv_attrs[i]); i++) { | |
511 | error = driver_create_file(drv, &bus->drv_attrs[i]); | |
512 | if (error) | |
513 | goto Err; | |
514 | } | |
515 | } | |
516 | Done: | |
517 | return error; | |
518 | Err: | |
519 | while (--i >= 0) | |
520 | driver_remove_file(drv, &bus->drv_attrs[i]); | |
521 | goto Done; | |
522 | } | |
523 | ||
524 | ||
525 | static void driver_remove_attrs(struct bus_type * bus, struct device_driver * drv) | |
526 | { | |
527 | int i; | |
528 | ||
529 | if (bus->drv_attrs) { | |
530 | for (i = 0; attr_name(bus->drv_attrs[i]); i++) | |
531 | driver_remove_file(drv, &bus->drv_attrs[i]); | |
532 | } | |
533 | } | |
534 | ||
874c6241 GKH |
535 | #ifdef CONFIG_HOTPLUG |
536 | /* | |
537 | * Thanks to drivers making their tables __devinit, we can't allow manual | |
538 | * bind and unbind from userspace unless CONFIG_HOTPLUG is enabled. | |
539 | */ | |
f86db396 | 540 | static int __must_check add_bind_files(struct device_driver *drv) |
874c6241 | 541 | { |
f86db396 AM |
542 | int ret; |
543 | ||
544 | ret = driver_create_file(drv, &driver_attr_unbind); | |
545 | if (ret == 0) { | |
546 | ret = driver_create_file(drv, &driver_attr_bind); | |
547 | if (ret) | |
548 | driver_remove_file(drv, &driver_attr_unbind); | |
549 | } | |
550 | return ret; | |
874c6241 GKH |
551 | } |
552 | ||
553 | static void remove_bind_files(struct device_driver *drv) | |
554 | { | |
555 | driver_remove_file(drv, &driver_attr_bind); | |
556 | driver_remove_file(drv, &driver_attr_unbind); | |
557 | } | |
b8c5cec2 KS |
558 | |
559 | static int add_probe_files(struct bus_type *bus) | |
560 | { | |
561 | int retval; | |
562 | ||
563 | bus->drivers_probe_attr.attr.name = "drivers_probe"; | |
564 | bus->drivers_probe_attr.attr.mode = S_IWUSR; | |
565 | bus->drivers_probe_attr.attr.owner = bus->owner; | |
566 | bus->drivers_probe_attr.store = store_drivers_probe; | |
567 | retval = bus_create_file(bus, &bus->drivers_probe_attr); | |
568 | if (retval) | |
569 | goto out; | |
570 | ||
571 | bus->drivers_autoprobe_attr.attr.name = "drivers_autoprobe"; | |
572 | bus->drivers_autoprobe_attr.attr.mode = S_IWUSR | S_IRUGO; | |
573 | bus->drivers_autoprobe_attr.attr.owner = bus->owner; | |
574 | bus->drivers_autoprobe_attr.show = show_drivers_autoprobe; | |
575 | bus->drivers_autoprobe_attr.store = store_drivers_autoprobe; | |
576 | retval = bus_create_file(bus, &bus->drivers_autoprobe_attr); | |
577 | if (retval) | |
578 | bus_remove_file(bus, &bus->drivers_probe_attr); | |
579 | out: | |
580 | return retval; | |
581 | } | |
582 | ||
583 | static void remove_probe_files(struct bus_type *bus) | |
584 | { | |
585 | bus_remove_file(bus, &bus->drivers_autoprobe_attr); | |
586 | bus_remove_file(bus, &bus->drivers_probe_attr); | |
587 | } | |
874c6241 | 588 | #else |
35acfdd7 | 589 | static inline int add_bind_files(struct device_driver *drv) { return 0; } |
874c6241 | 590 | static inline void remove_bind_files(struct device_driver *drv) {} |
b8c5cec2 KS |
591 | static inline int add_probe_files(struct bus_type *bus) { return 0; } |
592 | static inline void remove_probe_files(struct bus_type *bus) {} | |
874c6241 | 593 | #endif |
1da177e4 LT |
594 | |
595 | /** | |
596 | * bus_add_driver - Add a driver to the bus. | |
597 | * @drv: driver. | |
598 | * | |
599 | */ | |
f86db396 | 600 | int bus_add_driver(struct device_driver *drv) |
1da177e4 LT |
601 | { |
602 | struct bus_type * bus = get_bus(drv->bus); | |
603 | int error = 0; | |
604 | ||
d9fd4d3b JG |
605 | if (!bus) |
606 | return 0; | |
607 | ||
608 | pr_debug("bus %s: add driver %s\n", bus->name, drv->name); | |
609 | error = kobject_set_name(&drv->kobj, "%s", drv->name); | |
610 | if (error) | |
611 | goto out_put_bus; | |
612 | drv->kobj.kset = &bus->drivers; | |
613 | if ((error = kobject_register(&drv->kobj))) | |
614 | goto out_put_bus; | |
615 | ||
b8c5cec2 KS |
616 | if (drv->bus->drivers_autoprobe) { |
617 | error = driver_attach(drv); | |
618 | if (error) | |
619 | goto out_unregister; | |
620 | } | |
d9fd4d3b JG |
621 | klist_add_tail(&drv->knode_bus, &bus->klist_drivers); |
622 | module_add_driver(drv->owner, drv); | |
623 | ||
624 | error = driver_add_attrs(bus, drv); | |
625 | if (error) { | |
626 | /* How the hell do we get out of this pickle? Give up */ | |
627 | printk(KERN_ERR "%s: driver_add_attrs(%s) failed\n", | |
628 | __FUNCTION__, drv->name); | |
629 | } | |
630 | error = add_bind_files(drv); | |
631 | if (error) { | |
632 | /* Ditto */ | |
633 | printk(KERN_ERR "%s: add_bind_files(%s) failed\n", | |
634 | __FUNCTION__, drv->name); | |
1da177e4 | 635 | } |
d9fd4d3b | 636 | |
1da177e4 | 637 | return error; |
f86db396 AM |
638 | out_unregister: |
639 | kobject_unregister(&drv->kobj); | |
640 | out_put_bus: | |
641 | put_bus(bus); | |
642 | return error; | |
1da177e4 LT |
643 | } |
644 | ||
1da177e4 LT |
645 | /** |
646 | * bus_remove_driver - delete driver from bus's knowledge. | |
647 | * @drv: driver. | |
648 | * | |
649 | * Detach the driver from the devices it controls, and remove | |
650 | * it from its bus's list of drivers. Finally, we drop the reference | |
651 | * to the bus we took in bus_add_driver(). | |
652 | */ | |
653 | ||
654 | void bus_remove_driver(struct device_driver * drv) | |
655 | { | |
d9fd4d3b JG |
656 | if (!drv->bus) |
657 | return; | |
658 | ||
659 | remove_bind_files(drv); | |
660 | driver_remove_attrs(drv->bus, drv); | |
661 | klist_remove(&drv->knode_bus); | |
662 | pr_debug("bus %s: remove driver %s\n", drv->bus->name, drv->name); | |
663 | driver_detach(drv); | |
664 | module_remove_driver(drv); | |
665 | kobject_unregister(&drv->kobj); | |
666 | put_bus(drv->bus); | |
1da177e4 LT |
667 | } |
668 | ||
669 | ||
670 | /* Helper for bus_rescan_devices's iter */ | |
f86db396 AM |
671 | static int __must_check bus_rescan_devices_helper(struct device *dev, |
672 | void *data) | |
1da177e4 | 673 | { |
f86db396 AM |
674 | int ret = 0; |
675 | ||
bf74ad5b AS |
676 | if (!dev->driver) { |
677 | if (dev->parent) /* Needed for USB */ | |
678 | down(&dev->parent->sem); | |
f86db396 | 679 | ret = device_attach(dev); |
bf74ad5b AS |
680 | if (dev->parent) |
681 | up(&dev->parent->sem); | |
682 | } | |
f86db396 | 683 | return ret < 0 ? ret : 0; |
1da177e4 LT |
684 | } |
685 | ||
1da177e4 | 686 | /** |
23d3d602 GKH |
687 | * bus_rescan_devices - rescan devices on the bus for possible drivers |
688 | * @bus: the bus to scan. | |
1da177e4 | 689 | * |
23d3d602 GKH |
690 | * This function will look for devices on the bus with no driver |
691 | * attached and rescan it against existing drivers to see if it matches | |
692 | * any by calling device_attach() for the unbound devices. | |
1da177e4 | 693 | */ |
f86db396 | 694 | int bus_rescan_devices(struct bus_type * bus) |
1da177e4 | 695 | { |
f86db396 | 696 | return bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper); |
1da177e4 LT |
697 | } |
698 | ||
e935d5da ME |
699 | /** |
700 | * device_reprobe - remove driver for a device and probe for a new driver | |
701 | * @dev: the device to reprobe | |
702 | * | |
703 | * This function detaches the attached driver (if any) for the given | |
704 | * device and restarts the driver probing process. It is intended | |
705 | * to use if probing criteria changed during a devices lifetime and | |
706 | * driver attachment should change accordingly. | |
707 | */ | |
f86db396 | 708 | int device_reprobe(struct device *dev) |
e935d5da ME |
709 | { |
710 | if (dev->driver) { | |
711 | if (dev->parent) /* Needed for USB */ | |
712 | down(&dev->parent->sem); | |
713 | device_release_driver(dev); | |
714 | if (dev->parent) | |
715 | up(&dev->parent->sem); | |
716 | } | |
f86db396 | 717 | return bus_rescan_devices_helper(dev, NULL); |
e935d5da ME |
718 | } |
719 | EXPORT_SYMBOL_GPL(device_reprobe); | |
1da177e4 | 720 | |
f86db396 | 721 | struct bus_type *get_bus(struct bus_type *bus) |
1da177e4 | 722 | { |
f86db396 AM |
723 | return bus ? container_of(subsys_get(&bus->subsys), |
724 | struct bus_type, subsys) : NULL; | |
1da177e4 LT |
725 | } |
726 | ||
727 | void put_bus(struct bus_type * bus) | |
728 | { | |
729 | subsys_put(&bus->subsys); | |
730 | } | |
731 | ||
732 | ||
733 | /** | |
734 | * find_bus - locate bus by name. | |
735 | * @name: name of bus. | |
736 | * | |
737 | * Call kset_find_obj() to iterate over list of buses to | |
738 | * find a bus by name. Return bus if found. | |
739 | * | |
740 | * Note that kset_find_obj increments bus' reference count. | |
741 | */ | |
7e4ef085 | 742 | #if 0 |
1da177e4 LT |
743 | struct bus_type * find_bus(char * name) |
744 | { | |
745 | struct kobject * k = kset_find_obj(&bus_subsys.kset, name); | |
746 | return k ? to_bus(k) : NULL; | |
747 | } | |
7e4ef085 | 748 | #endif /* 0 */ |
1da177e4 LT |
749 | |
750 | ||
751 | /** | |
752 | * bus_add_attrs - Add default attributes for this bus. | |
753 | * @bus: Bus that has just been registered. | |
754 | */ | |
755 | ||
756 | static int bus_add_attrs(struct bus_type * bus) | |
757 | { | |
758 | int error = 0; | |
759 | int i; | |
760 | ||
761 | if (bus->bus_attrs) { | |
762 | for (i = 0; attr_name(bus->bus_attrs[i]); i++) { | |
763 | if ((error = bus_create_file(bus,&bus->bus_attrs[i]))) | |
764 | goto Err; | |
765 | } | |
766 | } | |
767 | Done: | |
768 | return error; | |
769 | Err: | |
770 | while (--i >= 0) | |
771 | bus_remove_file(bus,&bus->bus_attrs[i]); | |
772 | goto Done; | |
773 | } | |
774 | ||
775 | static void bus_remove_attrs(struct bus_type * bus) | |
776 | { | |
777 | int i; | |
778 | ||
779 | if (bus->bus_attrs) { | |
780 | for (i = 0; attr_name(bus->bus_attrs[i]); i++) | |
781 | bus_remove_file(bus,&bus->bus_attrs[i]); | |
782 | } | |
783 | } | |
784 | ||
34bb61f9 JB |
785 | static void klist_devices_get(struct klist_node *n) |
786 | { | |
787 | struct device *dev = container_of(n, struct device, knode_bus); | |
788 | ||
789 | get_device(dev); | |
790 | } | |
791 | ||
792 | static void klist_devices_put(struct klist_node *n) | |
793 | { | |
794 | struct device *dev = container_of(n, struct device, knode_bus); | |
795 | ||
796 | put_device(dev); | |
797 | } | |
798 | ||
1da177e4 LT |
799 | /** |
800 | * bus_register - register a bus with the system. | |
801 | * @bus: bus. | |
802 | * | |
803 | * Once we have that, we registered the bus with the kobject | |
804 | * infrastructure, then register the children subsystems it has: | |
805 | * the devices and drivers that belong to the bus. | |
806 | */ | |
807 | int bus_register(struct bus_type * bus) | |
808 | { | |
809 | int retval; | |
810 | ||
116af378 BH |
811 | BLOCKING_INIT_NOTIFIER_HEAD(&bus->bus_notifier); |
812 | ||
1da177e4 LT |
813 | retval = kobject_set_name(&bus->subsys.kset.kobj, "%s", bus->name); |
814 | if (retval) | |
815 | goto out; | |
816 | ||
817 | subsys_set_kset(bus, bus_subsys); | |
818 | retval = subsystem_register(&bus->subsys); | |
819 | if (retval) | |
820 | goto out; | |
821 | ||
822 | kobject_set_name(&bus->devices.kobj, "devices"); | |
823 | bus->devices.subsys = &bus->subsys; | |
824 | retval = kset_register(&bus->devices); | |
825 | if (retval) | |
826 | goto bus_devices_fail; | |
827 | ||
828 | kobject_set_name(&bus->drivers.kobj, "drivers"); | |
829 | bus->drivers.subsys = &bus->subsys; | |
830 | bus->drivers.ktype = &ktype_driver; | |
831 | retval = kset_register(&bus->drivers); | |
832 | if (retval) | |
833 | goto bus_drivers_fail; | |
465c7a3a | 834 | |
34bb61f9 | 835 | klist_init(&bus->klist_devices, klist_devices_get, klist_devices_put); |
81107bf5 | 836 | klist_init(&bus->klist_drivers, NULL, NULL); |
b8c5cec2 KS |
837 | |
838 | bus->drivers_autoprobe = 1; | |
839 | retval = add_probe_files(bus); | |
840 | if (retval) | |
841 | goto bus_probe_files_fail; | |
842 | ||
1bb6881a CH |
843 | retval = bus_add_attrs(bus); |
844 | if (retval) | |
845 | goto bus_attrs_fail; | |
1da177e4 LT |
846 | |
847 | pr_debug("bus type '%s' registered\n", bus->name); | |
848 | return 0; | |
849 | ||
1bb6881a | 850 | bus_attrs_fail: |
b8c5cec2 KS |
851 | remove_probe_files(bus); |
852 | bus_probe_files_fail: | |
1bb6881a | 853 | kset_unregister(&bus->drivers); |
1da177e4 LT |
854 | bus_drivers_fail: |
855 | kset_unregister(&bus->devices); | |
856 | bus_devices_fail: | |
857 | subsystem_unregister(&bus->subsys); | |
858 | out: | |
859 | return retval; | |
860 | } | |
861 | ||
1da177e4 LT |
862 | /** |
863 | * bus_unregister - remove a bus from the system | |
864 | * @bus: bus. | |
865 | * | |
866 | * Unregister the child subsystems and the bus itself. | |
867 | * Finally, we call put_bus() to release the refcount | |
868 | */ | |
869 | void bus_unregister(struct bus_type * bus) | |
870 | { | |
871 | pr_debug("bus %s: unregistering\n", bus->name); | |
872 | bus_remove_attrs(bus); | |
b8c5cec2 | 873 | remove_probe_files(bus); |
1da177e4 LT |
874 | kset_unregister(&bus->drivers); |
875 | kset_unregister(&bus->devices); | |
876 | subsystem_unregister(&bus->subsys); | |
877 | } | |
878 | ||
116af378 BH |
879 | int bus_register_notifier(struct bus_type *bus, struct notifier_block *nb) |
880 | { | |
881 | return blocking_notifier_chain_register(&bus->bus_notifier, nb); | |
882 | } | |
883 | EXPORT_SYMBOL_GPL(bus_register_notifier); | |
884 | ||
885 | int bus_unregister_notifier(struct bus_type *bus, struct notifier_block *nb) | |
886 | { | |
887 | return blocking_notifier_chain_unregister(&bus->bus_notifier, nb); | |
888 | } | |
889 | EXPORT_SYMBOL_GPL(bus_unregister_notifier); | |
890 | ||
1da177e4 LT |
891 | int __init buses_init(void) |
892 | { | |
893 | return subsystem_register(&bus_subsys); | |
894 | } | |
895 | ||
896 | ||
897 | EXPORT_SYMBOL_GPL(bus_for_each_dev); | |
0edb5860 | 898 | EXPORT_SYMBOL_GPL(bus_find_device); |
1da177e4 LT |
899 | EXPORT_SYMBOL_GPL(bus_for_each_drv); |
900 | ||
1da177e4 LT |
901 | EXPORT_SYMBOL_GPL(bus_register); |
902 | EXPORT_SYMBOL_GPL(bus_unregister); | |
903 | EXPORT_SYMBOL_GPL(bus_rescan_devices); | |
1da177e4 LT |
904 | |
905 | EXPORT_SYMBOL_GPL(bus_create_file); | |
906 | EXPORT_SYMBOL_GPL(bus_remove_file); |