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 | 19 | #define to_bus_attr(_attr) container_of(_attr, struct bus_attribute, attr) |
823bccfc | 20 | #define to_bus(obj) container_of(obj, struct bus_type, subsys.kobj) |
1da177e4 LT |
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 | ||
fc1ede58 GKH |
33 | static void bus_put(struct bus_type *bus) |
34 | { | |
35 | kset_put(&bus->subsys); | |
36 | } | |
37 | ||
1da177e4 LT |
38 | static ssize_t |
39 | drv_attr_show(struct kobject * kobj, struct attribute * attr, char * buf) | |
40 | { | |
41 | struct driver_attribute * drv_attr = to_drv_attr(attr); | |
42 | struct device_driver * drv = to_driver(kobj); | |
4a0c20bf | 43 | ssize_t ret = -EIO; |
1da177e4 LT |
44 | |
45 | if (drv_attr->show) | |
46 | ret = drv_attr->show(drv, buf); | |
47 | return ret; | |
48 | } | |
49 | ||
50 | static ssize_t | |
51 | drv_attr_store(struct kobject * kobj, struct attribute * attr, | |
52 | const char * buf, size_t count) | |
53 | { | |
54 | struct driver_attribute * drv_attr = to_drv_attr(attr); | |
55 | struct device_driver * drv = to_driver(kobj); | |
4a0c20bf | 56 | ssize_t ret = -EIO; |
1da177e4 LT |
57 | |
58 | if (drv_attr->store) | |
59 | ret = drv_attr->store(drv, buf, count); | |
60 | return ret; | |
61 | } | |
62 | ||
63 | static struct sysfs_ops driver_sysfs_ops = { | |
64 | .show = drv_attr_show, | |
65 | .store = drv_attr_store, | |
66 | }; | |
67 | ||
68 | ||
69 | static void driver_release(struct kobject * kobj) | |
70 | { | |
74e9f5fa GKH |
71 | /* |
72 | * Yes this is an empty release function, it is this way because struct | |
73 | * device is always a static object, not a dynamic one. Yes, this is | |
74 | * not nice and bad, but remember, drivers are code, reference counted | |
75 | * by the module count, not a device, which is really data. And yes, | |
76 | * in the future I do want to have all drivers be created dynamically, | |
77 | * and am working toward that goal, but it will take a bit longer... | |
78 | * | |
79 | * But do not let this example give _anyone_ the idea that they can | |
80 | * create a release function without any code in it at all, to do that | |
81 | * is almost always wrong. If you have any questions about this, | |
82 | * please send an email to <greg@kroah.com> | |
83 | */ | |
1da177e4 LT |
84 | } |
85 | ||
86 | static struct kobj_type ktype_driver = { | |
87 | .sysfs_ops = &driver_sysfs_ops, | |
88 | .release = driver_release, | |
89 | }; | |
90 | ||
91 | ||
92 | /* | |
93 | * sysfs bindings for buses | |
94 | */ | |
95 | ||
96 | ||
97 | static ssize_t | |
98 | bus_attr_show(struct kobject * kobj, struct attribute * attr, char * buf) | |
99 | { | |
100 | struct bus_attribute * bus_attr = to_bus_attr(attr); | |
101 | struct bus_type * bus = to_bus(kobj); | |
102 | ssize_t ret = 0; | |
103 | ||
104 | if (bus_attr->show) | |
105 | ret = bus_attr->show(bus, buf); | |
106 | return ret; | |
107 | } | |
108 | ||
109 | static ssize_t | |
110 | bus_attr_store(struct kobject * kobj, struct attribute * attr, | |
111 | const char * buf, size_t count) | |
112 | { | |
113 | struct bus_attribute * bus_attr = to_bus_attr(attr); | |
114 | struct bus_type * bus = to_bus(kobj); | |
115 | ssize_t ret = 0; | |
116 | ||
117 | if (bus_attr->store) | |
118 | ret = bus_attr->store(bus, buf, count); | |
119 | return ret; | |
120 | } | |
121 | ||
122 | static struct sysfs_ops bus_sysfs_ops = { | |
123 | .show = bus_attr_show, | |
124 | .store = bus_attr_store, | |
125 | }; | |
126 | ||
127 | int bus_create_file(struct bus_type * bus, struct bus_attribute * attr) | |
128 | { | |
129 | int error; | |
130 | if (get_bus(bus)) { | |
823bccfc | 131 | error = sysfs_create_file(&bus->subsys.kobj, &attr->attr); |
fc1ede58 | 132 | bus_put(bus); |
1da177e4 LT |
133 | } else |
134 | error = -EINVAL; | |
135 | return error; | |
136 | } | |
137 | ||
138 | void bus_remove_file(struct bus_type * bus, struct bus_attribute * attr) | |
139 | { | |
140 | if (get_bus(bus)) { | |
823bccfc | 141 | sysfs_remove_file(&bus->subsys.kobj, &attr->attr); |
fc1ede58 | 142 | bus_put(bus); |
1da177e4 LT |
143 | } |
144 | } | |
145 | ||
80f03e34 | 146 | static struct kobj_type bus_ktype = { |
1da177e4 | 147 | .sysfs_ops = &bus_sysfs_ops, |
80f03e34 KS |
148 | }; |
149 | ||
150 | static int bus_uevent_filter(struct kset *kset, struct kobject *kobj) | |
151 | { | |
152 | struct kobj_type *ktype = get_ktype(kobj); | |
153 | ||
154 | if (ktype == &bus_ktype) | |
155 | return 1; | |
156 | return 0; | |
157 | } | |
1da177e4 | 158 | |
80f03e34 KS |
159 | static struct kset_uevent_ops bus_uevent_ops = { |
160 | .filter = bus_uevent_filter, | |
1da177e4 LT |
161 | }; |
162 | ||
80f03e34 | 163 | static decl_subsys(bus, &bus_ktype, &bus_uevent_ops); |
1da177e4 | 164 | |
1da177e4 | 165 | |
2139bdd5 | 166 | #ifdef CONFIG_HOTPLUG |
2b08c8d0 | 167 | /* Manually detach a device from its associated driver. */ |
151ef38f GKH |
168 | static int driver_helper(struct device *dev, void *data) |
169 | { | |
170 | const char *name = data; | |
171 | ||
172 | if (strcmp(name, dev->bus_id) == 0) | |
173 | return 1; | |
174 | return 0; | |
175 | } | |
176 | ||
177 | static ssize_t driver_unbind(struct device_driver *drv, | |
178 | const char *buf, size_t count) | |
179 | { | |
180 | struct bus_type *bus = get_bus(drv->bus); | |
181 | struct device *dev; | |
182 | int err = -ENODEV; | |
183 | ||
184 | dev = bus_find_device(bus, NULL, (void *)buf, driver_helper); | |
2b08c8d0 | 185 | if (dev && dev->driver == drv) { |
bf74ad5b AS |
186 | if (dev->parent) /* Needed for USB */ |
187 | down(&dev->parent->sem); | |
151ef38f | 188 | device_release_driver(dev); |
bf74ad5b AS |
189 | if (dev->parent) |
190 | up(&dev->parent->sem); | |
151ef38f GKH |
191 | err = count; |
192 | } | |
2b08c8d0 | 193 | put_device(dev); |
fc1ede58 | 194 | bus_put(bus); |
2b08c8d0 | 195 | return err; |
151ef38f GKH |
196 | } |
197 | static DRIVER_ATTR(unbind, S_IWUSR, NULL, driver_unbind); | |
198 | ||
afdce75f GKH |
199 | /* |
200 | * Manually attach a device to a driver. | |
201 | * Note: the driver must want to bind to the device, | |
202 | * it is not possible to override the driver's id table. | |
203 | */ | |
204 | static ssize_t driver_bind(struct device_driver *drv, | |
205 | const char *buf, size_t count) | |
206 | { | |
207 | struct bus_type *bus = get_bus(drv->bus); | |
208 | struct device *dev; | |
209 | int err = -ENODEV; | |
210 | ||
211 | dev = bus_find_device(bus, NULL, (void *)buf, driver_helper); | |
2b08c8d0 | 212 | if (dev && dev->driver == NULL) { |
bf74ad5b AS |
213 | if (dev->parent) /* Needed for USB */ |
214 | down(&dev->parent->sem); | |
afdce75f GKH |
215 | down(&dev->sem); |
216 | err = driver_probe_device(drv, dev); | |
217 | up(&dev->sem); | |
bf74ad5b AS |
218 | if (dev->parent) |
219 | up(&dev->parent->sem); | |
37225401 RW |
220 | |
221 | if (err > 0) /* success */ | |
222 | err = count; | |
223 | else if (err == 0) /* driver didn't accept device */ | |
224 | err = -ENODEV; | |
afdce75f | 225 | } |
2b08c8d0 | 226 | put_device(dev); |
fc1ede58 | 227 | bus_put(bus); |
2b08c8d0 | 228 | return err; |
afdce75f GKH |
229 | } |
230 | static DRIVER_ATTR(bind, S_IWUSR, NULL, driver_bind); | |
231 | ||
b8c5cec2 KS |
232 | static ssize_t show_drivers_autoprobe(struct bus_type *bus, char *buf) |
233 | { | |
234 | return sprintf(buf, "%d\n", bus->drivers_autoprobe); | |
235 | } | |
236 | ||
237 | static ssize_t store_drivers_autoprobe(struct bus_type *bus, | |
238 | const char *buf, size_t count) | |
239 | { | |
240 | if (buf[0] == '0') | |
241 | bus->drivers_autoprobe = 0; | |
242 | else | |
243 | bus->drivers_autoprobe = 1; | |
244 | return count; | |
245 | } | |
246 | ||
247 | static ssize_t store_drivers_probe(struct bus_type *bus, | |
248 | const char *buf, size_t count) | |
249 | { | |
250 | struct device *dev; | |
251 | ||
252 | dev = bus_find_device(bus, NULL, (void *)buf, driver_helper); | |
253 | if (!dev) | |
254 | return -ENODEV; | |
255 | if (bus_rescan_devices_helper(dev, NULL) != 0) | |
256 | return -EINVAL; | |
257 | return count; | |
258 | } | |
2139bdd5 | 259 | #endif |
151ef38f | 260 | |
465c7a3a | 261 | static struct device * next_device(struct klist_iter * i) |
262 | { | |
263 | struct klist_node * n = klist_next(i); | |
264 | return n ? container_of(n, struct device, knode_bus) : NULL; | |
265 | } | |
266 | ||
1da177e4 LT |
267 | /** |
268 | * bus_for_each_dev - device iterator. | |
269 | * @bus: bus type. | |
270 | * @start: device to start iterating from. | |
271 | * @data: data for the callback. | |
272 | * @fn: function to be called for each device. | |
273 | * | |
274 | * Iterate over @bus's list of devices, and call @fn for each, | |
275 | * passing it @data. If @start is not NULL, we use that device to | |
276 | * begin iterating from. | |
277 | * | |
278 | * We check the return of @fn each time. If it returns anything | |
279 | * other than 0, we break out and return that value. | |
280 | * | |
281 | * NOTE: The device that returns a non-zero value is not retained | |
282 | * in any way, nor is its refcount incremented. If the caller needs | |
283 | * to retain this data, it should do, and increment the reference | |
284 | * count in the supplied callback. | |
285 | */ | |
286 | ||
287 | int bus_for_each_dev(struct bus_type * bus, struct device * start, | |
288 | void * data, int (*fn)(struct device *, void *)) | |
289 | { | |
465c7a3a | 290 | struct klist_iter i; |
291 | struct device * dev; | |
292 | int error = 0; | |
1da177e4 | 293 | |
465c7a3a | 294 | if (!bus) |
295 | return -EINVAL; | |
296 | ||
297 | klist_iter_init_node(&bus->klist_devices, &i, | |
298 | (start ? &start->knode_bus : NULL)); | |
299 | while ((dev = next_device(&i)) && !error) | |
300 | error = fn(dev, data); | |
301 | klist_iter_exit(&i); | |
302 | return error; | |
1da177e4 LT |
303 | } |
304 | ||
0edb5860 CH |
305 | /** |
306 | * bus_find_device - device iterator for locating a particular device. | |
307 | * @bus: bus type | |
308 | * @start: Device to begin with | |
309 | * @data: Data to pass to match function | |
310 | * @match: Callback function to check device | |
311 | * | |
312 | * This is similar to the bus_for_each_dev() function above, but it | |
313 | * returns a reference to a device that is 'found' for later use, as | |
314 | * determined by the @match callback. | |
315 | * | |
316 | * The callback should return 0 if the device doesn't match and non-zero | |
317 | * if it does. If the callback returns non-zero, this function will | |
318 | * return to the caller and not iterate over any more devices. | |
319 | */ | |
320 | struct device * bus_find_device(struct bus_type *bus, | |
321 | struct device *start, void *data, | |
322 | int (*match)(struct device *, void *)) | |
323 | { | |
324 | struct klist_iter i; | |
325 | struct device *dev; | |
326 | ||
327 | if (!bus) | |
328 | return NULL; | |
329 | ||
330 | klist_iter_init_node(&bus->klist_devices, &i, | |
331 | (start ? &start->knode_bus : NULL)); | |
332 | while ((dev = next_device(&i))) | |
333 | if (match(dev, data) && get_device(dev)) | |
334 | break; | |
335 | klist_iter_exit(&i); | |
336 | return dev; | |
337 | } | |
38fdac3c | 338 | |
339 | ||
340 | static struct device_driver * next_driver(struct klist_iter * i) | |
341 | { | |
342 | struct klist_node * n = klist_next(i); | |
343 | return n ? container_of(n, struct device_driver, knode_bus) : NULL; | |
344 | } | |
345 | ||
1da177e4 LT |
346 | /** |
347 | * bus_for_each_drv - driver iterator | |
348 | * @bus: bus we're dealing with. | |
349 | * @start: driver to start iterating on. | |
350 | * @data: data to pass to the callback. | |
351 | * @fn: function to call for each driver. | |
352 | * | |
353 | * This is nearly identical to the device iterator above. | |
354 | * We iterate over each driver that belongs to @bus, and call | |
355 | * @fn for each. If @fn returns anything but 0, we break out | |
356 | * and return it. If @start is not NULL, we use it as the head | |
357 | * of the list. | |
358 | * | |
359 | * NOTE: we don't return the driver that returns a non-zero | |
360 | * value, nor do we leave the reference count incremented for that | |
361 | * driver. If the caller needs to know that info, it must set it | |
362 | * in the callback. It must also be sure to increment the refcount | |
363 | * so it doesn't disappear before returning to the caller. | |
364 | */ | |
365 | ||
366 | int bus_for_each_drv(struct bus_type * bus, struct device_driver * start, | |
367 | void * data, int (*fn)(struct device_driver *, void *)) | |
368 | { | |
38fdac3c | 369 | struct klist_iter i; |
370 | struct device_driver * drv; | |
371 | int error = 0; | |
1da177e4 | 372 | |
38fdac3c | 373 | if (!bus) |
374 | return -EINVAL; | |
375 | ||
376 | klist_iter_init_node(&bus->klist_drivers, &i, | |
377 | start ? &start->knode_bus : NULL); | |
378 | while ((drv = next_driver(&i)) && !error) | |
379 | error = fn(drv, data); | |
380 | klist_iter_exit(&i); | |
381 | return error; | |
1da177e4 LT |
382 | } |
383 | ||
4aca67e5 | 384 | static int device_add_attrs(struct bus_type *bus, struct device *dev) |
1da177e4 LT |
385 | { |
386 | int error = 0; | |
387 | int i; | |
388 | ||
4aca67e5 AM |
389 | if (!bus->dev_attrs) |
390 | return 0; | |
391 | ||
392 | for (i = 0; attr_name(bus->dev_attrs[i]); i++) { | |
393 | error = device_create_file(dev,&bus->dev_attrs[i]); | |
394 | if (error) { | |
395 | while (--i >= 0) | |
396 | device_remove_file(dev, &bus->dev_attrs[i]); | |
397 | break; | |
1da177e4 LT |
398 | } |
399 | } | |
1da177e4 | 400 | return error; |
1da177e4 LT |
401 | } |
402 | ||
1da177e4 LT |
403 | static void device_remove_attrs(struct bus_type * bus, struct device * dev) |
404 | { | |
405 | int i; | |
406 | ||
407 | if (bus->dev_attrs) { | |
408 | for (i = 0; attr_name(bus->dev_attrs[i]); i++) | |
409 | device_remove_file(dev,&bus->dev_attrs[i]); | |
410 | } | |
411 | } | |
412 | ||
b9cafc7d KS |
413 | #ifdef CONFIG_SYSFS_DEPRECATED |
414 | static int make_deprecated_bus_links(struct device *dev) | |
415 | { | |
416 | return sysfs_create_link(&dev->kobj, | |
823bccfc | 417 | &dev->bus->subsys.kobj, "bus"); |
b9cafc7d KS |
418 | } |
419 | ||
420 | static void remove_deprecated_bus_links(struct device *dev) | |
421 | { | |
422 | sysfs_remove_link(&dev->kobj, "bus"); | |
423 | } | |
424 | #else | |
425 | static inline int make_deprecated_bus_links(struct device *dev) { return 0; } | |
426 | static inline void remove_deprecated_bus_links(struct device *dev) { } | |
427 | #endif | |
1da177e4 LT |
428 | |
429 | /** | |
430 | * bus_add_device - add device to bus | |
431 | * @dev: device being added | |
432 | * | |
433 | * - Add the device to its bus's list of devices. | |
53877d06 | 434 | * - Create link to device's bus. |
1da177e4 LT |
435 | */ |
436 | int bus_add_device(struct device * dev) | |
437 | { | |
438 | struct bus_type * bus = get_bus(dev->bus); | |
439 | int error = 0; | |
440 | ||
441 | if (bus) { | |
1da177e4 | 442 | pr_debug("bus %s: add device %s\n", bus->name, dev->bus_id); |
d377e85b | 443 | error = device_add_attrs(bus, dev); |
f86db396 | 444 | if (error) |
513e7337 | 445 | goto out_put; |
f86db396 AM |
446 | error = sysfs_create_link(&bus->devices.kobj, |
447 | &dev->kobj, dev->bus_id); | |
448 | if (error) | |
513e7337 | 449 | goto out_id; |
f86db396 | 450 | error = sysfs_create_link(&dev->kobj, |
823bccfc | 451 | &dev->bus->subsys.kobj, "subsystem"); |
f86db396 | 452 | if (error) |
513e7337 | 453 | goto out_subsys; |
b9cafc7d | 454 | error = make_deprecated_bus_links(dev); |
513e7337 CH |
455 | if (error) |
456 | goto out_deprecated; | |
1da177e4 | 457 | } |
513e7337 CH |
458 | return 0; |
459 | ||
460 | out_deprecated: | |
461 | sysfs_remove_link(&dev->kobj, "subsystem"); | |
462 | out_subsys: | |
463 | sysfs_remove_link(&bus->devices.kobj, dev->bus_id); | |
464 | out_id: | |
465 | device_remove_attrs(bus, dev); | |
466 | out_put: | |
fc1ede58 | 467 | bus_put(dev->bus); |
1da177e4 LT |
468 | return error; |
469 | } | |
470 | ||
53877d06 KS |
471 | /** |
472 | * bus_attach_device - add device to bus | |
473 | * @dev: device tried to attach to a driver | |
474 | * | |
f2eaae19 | 475 | * - Add device to bus's list of devices. |
53877d06 KS |
476 | * - Try to attach to driver. |
477 | */ | |
c6a46696 | 478 | void bus_attach_device(struct device * dev) |
53877d06 | 479 | { |
f86db396 AM |
480 | struct bus_type *bus = dev->bus; |
481 | int ret = 0; | |
53877d06 KS |
482 | |
483 | if (bus) { | |
f2eaae19 | 484 | dev->is_registered = 1; |
b8c5cec2 KS |
485 | if (bus->drivers_autoprobe) |
486 | ret = device_attach(dev); | |
c6a46696 CH |
487 | WARN_ON(ret < 0); |
488 | if (ret >= 0) | |
f86db396 | 489 | klist_add_tail(&dev->knode_bus, &bus->klist_devices); |
c6a46696 | 490 | else |
f2eaae19 | 491 | dev->is_registered = 0; |
53877d06 KS |
492 | } |
493 | } | |
494 | ||
1da177e4 LT |
495 | /** |
496 | * bus_remove_device - remove device from bus | |
497 | * @dev: device to be removed | |
498 | * | |
499 | * - Remove symlink from bus's directory. | |
500 | * - Delete device from bus's list. | |
501 | * - Detach from its driver. | |
502 | * - Drop reference taken in bus_add_device(). | |
503 | */ | |
504 | void bus_remove_device(struct device * dev) | |
505 | { | |
506 | if (dev->bus) { | |
b9d9c82b | 507 | sysfs_remove_link(&dev->kobj, "subsystem"); |
b9cafc7d | 508 | remove_deprecated_bus_links(dev); |
1da177e4 LT |
509 | sysfs_remove_link(&dev->bus->devices.kobj, dev->bus_id); |
510 | device_remove_attrs(dev->bus, dev); | |
f70fa629 AS |
511 | if (dev->is_registered) { |
512 | dev->is_registered = 0; | |
513 | klist_del(&dev->knode_bus); | |
514 | } | |
1da177e4 LT |
515 | pr_debug("bus %s: remove device %s\n", dev->bus->name, dev->bus_id); |
516 | device_release_driver(dev); | |
fc1ede58 | 517 | bus_put(dev->bus); |
1da177e4 LT |
518 | } |
519 | } | |
520 | ||
521 | static int driver_add_attrs(struct bus_type * bus, struct device_driver * drv) | |
522 | { | |
523 | int error = 0; | |
524 | int i; | |
525 | ||
526 | if (bus->drv_attrs) { | |
527 | for (i = 0; attr_name(bus->drv_attrs[i]); i++) { | |
528 | error = driver_create_file(drv, &bus->drv_attrs[i]); | |
529 | if (error) | |
530 | goto Err; | |
531 | } | |
532 | } | |
533 | Done: | |
534 | return error; | |
535 | Err: | |
536 | while (--i >= 0) | |
537 | driver_remove_file(drv, &bus->drv_attrs[i]); | |
538 | goto Done; | |
539 | } | |
540 | ||
541 | ||
542 | static void driver_remove_attrs(struct bus_type * bus, struct device_driver * drv) | |
543 | { | |
544 | int i; | |
545 | ||
546 | if (bus->drv_attrs) { | |
547 | for (i = 0; attr_name(bus->drv_attrs[i]); i++) | |
548 | driver_remove_file(drv, &bus->drv_attrs[i]); | |
549 | } | |
550 | } | |
551 | ||
874c6241 GKH |
552 | #ifdef CONFIG_HOTPLUG |
553 | /* | |
554 | * Thanks to drivers making their tables __devinit, we can't allow manual | |
555 | * bind and unbind from userspace unless CONFIG_HOTPLUG is enabled. | |
556 | */ | |
f86db396 | 557 | static int __must_check add_bind_files(struct device_driver *drv) |
874c6241 | 558 | { |
f86db396 AM |
559 | int ret; |
560 | ||
561 | ret = driver_create_file(drv, &driver_attr_unbind); | |
562 | if (ret == 0) { | |
563 | ret = driver_create_file(drv, &driver_attr_bind); | |
564 | if (ret) | |
565 | driver_remove_file(drv, &driver_attr_unbind); | |
566 | } | |
567 | return ret; | |
874c6241 GKH |
568 | } |
569 | ||
570 | static void remove_bind_files(struct device_driver *drv) | |
571 | { | |
572 | driver_remove_file(drv, &driver_attr_bind); | |
573 | driver_remove_file(drv, &driver_attr_unbind); | |
574 | } | |
b8c5cec2 | 575 | |
8380770c KS |
576 | static BUS_ATTR(drivers_probe, S_IWUSR, NULL, store_drivers_probe); |
577 | static BUS_ATTR(drivers_autoprobe, S_IWUSR | S_IRUGO, | |
578 | show_drivers_autoprobe, store_drivers_autoprobe); | |
579 | ||
b8c5cec2 KS |
580 | static int add_probe_files(struct bus_type *bus) |
581 | { | |
582 | int retval; | |
583 | ||
8380770c | 584 | retval = bus_create_file(bus, &bus_attr_drivers_probe); |
b8c5cec2 KS |
585 | if (retval) |
586 | goto out; | |
587 | ||
8380770c | 588 | retval = bus_create_file(bus, &bus_attr_drivers_autoprobe); |
b8c5cec2 | 589 | if (retval) |
8380770c | 590 | bus_remove_file(bus, &bus_attr_drivers_probe); |
b8c5cec2 KS |
591 | out: |
592 | return retval; | |
593 | } | |
594 | ||
595 | static void remove_probe_files(struct bus_type *bus) | |
596 | { | |
8380770c KS |
597 | bus_remove_file(bus, &bus_attr_drivers_autoprobe); |
598 | bus_remove_file(bus, &bus_attr_drivers_probe); | |
b8c5cec2 | 599 | } |
874c6241 | 600 | #else |
35acfdd7 | 601 | static inline int add_bind_files(struct device_driver *drv) { return 0; } |
874c6241 | 602 | static inline void remove_bind_files(struct device_driver *drv) {} |
b8c5cec2 KS |
603 | static inline int add_probe_files(struct bus_type *bus) { return 0; } |
604 | static inline void remove_probe_files(struct bus_type *bus) {} | |
874c6241 | 605 | #endif |
1da177e4 LT |
606 | |
607 | /** | |
608 | * bus_add_driver - Add a driver to the bus. | |
609 | * @drv: driver. | |
610 | * | |
611 | */ | |
f86db396 | 612 | int bus_add_driver(struct device_driver *drv) |
1da177e4 LT |
613 | { |
614 | struct bus_type * bus = get_bus(drv->bus); | |
615 | int error = 0; | |
616 | ||
d9fd4d3b | 617 | if (!bus) |
4f6e1945 | 618 | return -EINVAL; |
d9fd4d3b JG |
619 | |
620 | pr_debug("bus %s: add driver %s\n", bus->name, drv->name); | |
621 | error = kobject_set_name(&drv->kobj, "%s", drv->name); | |
622 | if (error) | |
623 | goto out_put_bus; | |
624 | drv->kobj.kset = &bus->drivers; | |
dc0afa83 CH |
625 | error = kobject_register(&drv->kobj); |
626 | if (error) | |
d9fd4d3b JG |
627 | goto out_put_bus; |
628 | ||
b8c5cec2 KS |
629 | if (drv->bus->drivers_autoprobe) { |
630 | error = driver_attach(drv); | |
631 | if (error) | |
632 | goto out_unregister; | |
633 | } | |
d9fd4d3b JG |
634 | klist_add_tail(&drv->knode_bus, &bus->klist_drivers); |
635 | module_add_driver(drv->owner, drv); | |
636 | ||
637 | error = driver_add_attrs(bus, drv); | |
638 | if (error) { | |
639 | /* How the hell do we get out of this pickle? Give up */ | |
640 | printk(KERN_ERR "%s: driver_add_attrs(%s) failed\n", | |
641 | __FUNCTION__, drv->name); | |
642 | } | |
643 | error = add_bind_files(drv); | |
644 | if (error) { | |
645 | /* Ditto */ | |
646 | printk(KERN_ERR "%s: add_bind_files(%s) failed\n", | |
647 | __FUNCTION__, drv->name); | |
1da177e4 | 648 | } |
d9fd4d3b | 649 | |
1da177e4 | 650 | return error; |
f86db396 AM |
651 | out_unregister: |
652 | kobject_unregister(&drv->kobj); | |
653 | out_put_bus: | |
fc1ede58 | 654 | bus_put(bus); |
f86db396 | 655 | return error; |
1da177e4 LT |
656 | } |
657 | ||
1da177e4 LT |
658 | /** |
659 | * bus_remove_driver - delete driver from bus's knowledge. | |
660 | * @drv: driver. | |
661 | * | |
662 | * Detach the driver from the devices it controls, and remove | |
663 | * it from its bus's list of drivers. Finally, we drop the reference | |
664 | * to the bus we took in bus_add_driver(). | |
665 | */ | |
666 | ||
667 | void bus_remove_driver(struct device_driver * drv) | |
668 | { | |
d9fd4d3b JG |
669 | if (!drv->bus) |
670 | return; | |
671 | ||
672 | remove_bind_files(drv); | |
673 | driver_remove_attrs(drv->bus, drv); | |
674 | klist_remove(&drv->knode_bus); | |
675 | pr_debug("bus %s: remove driver %s\n", drv->bus->name, drv->name); | |
676 | driver_detach(drv); | |
677 | module_remove_driver(drv); | |
678 | kobject_unregister(&drv->kobj); | |
fc1ede58 | 679 | bus_put(drv->bus); |
1da177e4 LT |
680 | } |
681 | ||
682 | ||
683 | /* Helper for bus_rescan_devices's iter */ | |
f86db396 AM |
684 | static int __must_check bus_rescan_devices_helper(struct device *dev, |
685 | void *data) | |
1da177e4 | 686 | { |
f86db396 AM |
687 | int ret = 0; |
688 | ||
bf74ad5b AS |
689 | if (!dev->driver) { |
690 | if (dev->parent) /* Needed for USB */ | |
691 | down(&dev->parent->sem); | |
f86db396 | 692 | ret = device_attach(dev); |
bf74ad5b AS |
693 | if (dev->parent) |
694 | up(&dev->parent->sem); | |
695 | } | |
f86db396 | 696 | return ret < 0 ? ret : 0; |
1da177e4 LT |
697 | } |
698 | ||
1da177e4 | 699 | /** |
23d3d602 GKH |
700 | * bus_rescan_devices - rescan devices on the bus for possible drivers |
701 | * @bus: the bus to scan. | |
1da177e4 | 702 | * |
23d3d602 GKH |
703 | * This function will look for devices on the bus with no driver |
704 | * attached and rescan it against existing drivers to see if it matches | |
705 | * any by calling device_attach() for the unbound devices. | |
1da177e4 | 706 | */ |
f86db396 | 707 | int bus_rescan_devices(struct bus_type * bus) |
1da177e4 | 708 | { |
f86db396 | 709 | return bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper); |
1da177e4 LT |
710 | } |
711 | ||
e935d5da ME |
712 | /** |
713 | * device_reprobe - remove driver for a device and probe for a new driver | |
714 | * @dev: the device to reprobe | |
715 | * | |
716 | * This function detaches the attached driver (if any) for the given | |
717 | * device and restarts the driver probing process. It is intended | |
718 | * to use if probing criteria changed during a devices lifetime and | |
719 | * driver attachment should change accordingly. | |
720 | */ | |
f86db396 | 721 | int device_reprobe(struct device *dev) |
e935d5da ME |
722 | { |
723 | if (dev->driver) { | |
724 | if (dev->parent) /* Needed for USB */ | |
725 | down(&dev->parent->sem); | |
726 | device_release_driver(dev); | |
727 | if (dev->parent) | |
728 | up(&dev->parent->sem); | |
729 | } | |
f86db396 | 730 | return bus_rescan_devices_helper(dev, NULL); |
e935d5da ME |
731 | } |
732 | EXPORT_SYMBOL_GPL(device_reprobe); | |
1da177e4 | 733 | |
f86db396 | 734 | struct bus_type *get_bus(struct bus_type *bus) |
1da177e4 | 735 | { |
1ef4cfac | 736 | return bus ? container_of(kset_get(&bus->subsys), |
f86db396 | 737 | struct bus_type, subsys) : NULL; |
1da177e4 LT |
738 | } |
739 | ||
1da177e4 LT |
740 | /** |
741 | * find_bus - locate bus by name. | |
742 | * @name: name of bus. | |
743 | * | |
744 | * Call kset_find_obj() to iterate over list of buses to | |
745 | * find a bus by name. Return bus if found. | |
746 | * | |
747 | * Note that kset_find_obj increments bus' reference count. | |
748 | */ | |
7e4ef085 | 749 | #if 0 |
1da177e4 LT |
750 | struct bus_type * find_bus(char * name) |
751 | { | |
752 | struct kobject * k = kset_find_obj(&bus_subsys.kset, name); | |
753 | return k ? to_bus(k) : NULL; | |
754 | } | |
7e4ef085 | 755 | #endif /* 0 */ |
1da177e4 LT |
756 | |
757 | ||
758 | /** | |
759 | * bus_add_attrs - Add default attributes for this bus. | |
760 | * @bus: Bus that has just been registered. | |
761 | */ | |
762 | ||
763 | static int bus_add_attrs(struct bus_type * bus) | |
764 | { | |
765 | int error = 0; | |
766 | int i; | |
767 | ||
768 | if (bus->bus_attrs) { | |
769 | for (i = 0; attr_name(bus->bus_attrs[i]); i++) { | |
dc0afa83 CH |
770 | error = bus_create_file(bus,&bus->bus_attrs[i]); |
771 | if (error) | |
1da177e4 LT |
772 | goto Err; |
773 | } | |
774 | } | |
775 | Done: | |
776 | return error; | |
777 | Err: | |
778 | while (--i >= 0) | |
779 | bus_remove_file(bus,&bus->bus_attrs[i]); | |
780 | goto Done; | |
781 | } | |
782 | ||
783 | static void bus_remove_attrs(struct bus_type * bus) | |
784 | { | |
785 | int i; | |
786 | ||
787 | if (bus->bus_attrs) { | |
788 | for (i = 0; attr_name(bus->bus_attrs[i]); i++) | |
789 | bus_remove_file(bus,&bus->bus_attrs[i]); | |
790 | } | |
791 | } | |
792 | ||
34bb61f9 JB |
793 | static void klist_devices_get(struct klist_node *n) |
794 | { | |
795 | struct device *dev = container_of(n, struct device, knode_bus); | |
796 | ||
797 | get_device(dev); | |
798 | } | |
799 | ||
800 | static void klist_devices_put(struct klist_node *n) | |
801 | { | |
802 | struct device *dev = container_of(n, struct device, knode_bus); | |
803 | ||
804 | put_device(dev); | |
805 | } | |
806 | ||
1da177e4 LT |
807 | /** |
808 | * bus_register - register a bus with the system. | |
809 | * @bus: bus. | |
810 | * | |
811 | * Once we have that, we registered the bus with the kobject | |
812 | * infrastructure, then register the children subsystems it has: | |
813 | * the devices and drivers that belong to the bus. | |
814 | */ | |
815 | int bus_register(struct bus_type * bus) | |
816 | { | |
817 | int retval; | |
818 | ||
116af378 BH |
819 | BLOCKING_INIT_NOTIFIER_HEAD(&bus->bus_notifier); |
820 | ||
823bccfc | 821 | retval = kobject_set_name(&bus->subsys.kobj, "%s", bus->name); |
1da177e4 LT |
822 | if (retval) |
823 | goto out; | |
824 | ||
d6b05b84 GKH |
825 | bus->subsys.kobj.kset = &bus_subsys; |
826 | ||
1da177e4 LT |
827 | retval = subsystem_register(&bus->subsys); |
828 | if (retval) | |
829 | goto out; | |
830 | ||
831 | kobject_set_name(&bus->devices.kobj, "devices"); | |
823bccfc | 832 | bus->devices.kobj.parent = &bus->subsys.kobj; |
1da177e4 LT |
833 | retval = kset_register(&bus->devices); |
834 | if (retval) | |
835 | goto bus_devices_fail; | |
836 | ||
837 | kobject_set_name(&bus->drivers.kobj, "drivers"); | |
823bccfc | 838 | bus->drivers.kobj.parent = &bus->subsys.kobj; |
1da177e4 LT |
839 | bus->drivers.ktype = &ktype_driver; |
840 | retval = kset_register(&bus->drivers); | |
841 | if (retval) | |
842 | goto bus_drivers_fail; | |
465c7a3a | 843 | |
34bb61f9 | 844 | klist_init(&bus->klist_devices, klist_devices_get, klist_devices_put); |
81107bf5 | 845 | klist_init(&bus->klist_drivers, NULL, NULL); |
b8c5cec2 KS |
846 | |
847 | bus->drivers_autoprobe = 1; | |
848 | retval = add_probe_files(bus); | |
849 | if (retval) | |
850 | goto bus_probe_files_fail; | |
851 | ||
1bb6881a CH |
852 | retval = bus_add_attrs(bus); |
853 | if (retval) | |
854 | goto bus_attrs_fail; | |
1da177e4 LT |
855 | |
856 | pr_debug("bus type '%s' registered\n", bus->name); | |
857 | return 0; | |
858 | ||
1bb6881a | 859 | bus_attrs_fail: |
b8c5cec2 KS |
860 | remove_probe_files(bus); |
861 | bus_probe_files_fail: | |
1bb6881a | 862 | kset_unregister(&bus->drivers); |
1da177e4 LT |
863 | bus_drivers_fail: |
864 | kset_unregister(&bus->devices); | |
865 | bus_devices_fail: | |
866 | subsystem_unregister(&bus->subsys); | |
867 | out: | |
868 | return retval; | |
869 | } | |
870 | ||
1da177e4 LT |
871 | /** |
872 | * bus_unregister - remove a bus from the system | |
873 | * @bus: bus. | |
874 | * | |
875 | * Unregister the child subsystems and the bus itself. | |
fc1ede58 | 876 | * Finally, we call bus_put() to release the refcount |
1da177e4 LT |
877 | */ |
878 | void bus_unregister(struct bus_type * bus) | |
879 | { | |
880 | pr_debug("bus %s: unregistering\n", bus->name); | |
881 | bus_remove_attrs(bus); | |
b8c5cec2 | 882 | remove_probe_files(bus); |
1da177e4 LT |
883 | kset_unregister(&bus->drivers); |
884 | kset_unregister(&bus->devices); | |
885 | subsystem_unregister(&bus->subsys); | |
886 | } | |
887 | ||
116af378 BH |
888 | int bus_register_notifier(struct bus_type *bus, struct notifier_block *nb) |
889 | { | |
890 | return blocking_notifier_chain_register(&bus->bus_notifier, nb); | |
891 | } | |
892 | EXPORT_SYMBOL_GPL(bus_register_notifier); | |
893 | ||
894 | int bus_unregister_notifier(struct bus_type *bus, struct notifier_block *nb) | |
895 | { | |
896 | return blocking_notifier_chain_unregister(&bus->bus_notifier, nb); | |
897 | } | |
898 | EXPORT_SYMBOL_GPL(bus_unregister_notifier); | |
899 | ||
1da177e4 LT |
900 | int __init buses_init(void) |
901 | { | |
902 | return subsystem_register(&bus_subsys); | |
903 | } | |
904 | ||
905 | ||
906 | EXPORT_SYMBOL_GPL(bus_for_each_dev); | |
0edb5860 | 907 | EXPORT_SYMBOL_GPL(bus_find_device); |
1da177e4 LT |
908 | EXPORT_SYMBOL_GPL(bus_for_each_drv); |
909 | ||
1da177e4 LT |
910 | EXPORT_SYMBOL_GPL(bus_register); |
911 | EXPORT_SYMBOL_GPL(bus_unregister); | |
912 | EXPORT_SYMBOL_GPL(bus_rescan_devices); | |
1da177e4 LT |
913 | |
914 | EXPORT_SYMBOL_GPL(bus_create_file); | |
915 | EXPORT_SYMBOL_GPL(bus_remove_file); |