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 | ||
5901d014 GKH |
33 | static struct bus_type *bus_get(struct bus_type *bus) |
34 | { | |
35 | return bus ? container_of(kset_get(&bus->subsys), | |
36 | struct bus_type, subsys) : NULL; | |
37 | } | |
38 | ||
fc1ede58 GKH |
39 | static void bus_put(struct bus_type *bus) |
40 | { | |
41 | kset_put(&bus->subsys); | |
42 | } | |
43 | ||
1da177e4 LT |
44 | static ssize_t |
45 | drv_attr_show(struct kobject * kobj, struct attribute * attr, char * buf) | |
46 | { | |
47 | struct driver_attribute * drv_attr = to_drv_attr(attr); | |
48 | struct device_driver * drv = to_driver(kobj); | |
4a0c20bf | 49 | ssize_t ret = -EIO; |
1da177e4 LT |
50 | |
51 | if (drv_attr->show) | |
52 | ret = drv_attr->show(drv, buf); | |
53 | return ret; | |
54 | } | |
55 | ||
56 | static ssize_t | |
57 | drv_attr_store(struct kobject * kobj, struct attribute * attr, | |
58 | const char * buf, size_t count) | |
59 | { | |
60 | struct driver_attribute * drv_attr = to_drv_attr(attr); | |
61 | struct device_driver * drv = to_driver(kobj); | |
4a0c20bf | 62 | ssize_t ret = -EIO; |
1da177e4 LT |
63 | |
64 | if (drv_attr->store) | |
65 | ret = drv_attr->store(drv, buf, count); | |
66 | return ret; | |
67 | } | |
68 | ||
69 | static struct sysfs_ops driver_sysfs_ops = { | |
70 | .show = drv_attr_show, | |
71 | .store = drv_attr_store, | |
72 | }; | |
73 | ||
74 | ||
75 | static void driver_release(struct kobject * kobj) | |
76 | { | |
74e9f5fa GKH |
77 | /* |
78 | * Yes this is an empty release function, it is this way because struct | |
79 | * device is always a static object, not a dynamic one. Yes, this is | |
80 | * not nice and bad, but remember, drivers are code, reference counted | |
81 | * by the module count, not a device, which is really data. And yes, | |
82 | * in the future I do want to have all drivers be created dynamically, | |
83 | * and am working toward that goal, but it will take a bit longer... | |
84 | * | |
85 | * But do not let this example give _anyone_ the idea that they can | |
86 | * create a release function without any code in it at all, to do that | |
87 | * is almost always wrong. If you have any questions about this, | |
88 | * please send an email to <greg@kroah.com> | |
89 | */ | |
1da177e4 LT |
90 | } |
91 | ||
a1148fb0 | 92 | static struct kobj_type driver_ktype = { |
1da177e4 LT |
93 | .sysfs_ops = &driver_sysfs_ops, |
94 | .release = driver_release, | |
95 | }; | |
96 | ||
97 | ||
98 | /* | |
99 | * sysfs bindings for buses | |
100 | */ | |
101 | ||
102 | ||
103 | static ssize_t | |
104 | bus_attr_show(struct kobject * kobj, struct attribute * attr, char * buf) | |
105 | { | |
106 | struct bus_attribute * bus_attr = to_bus_attr(attr); | |
107 | struct bus_type * bus = to_bus(kobj); | |
108 | ssize_t ret = 0; | |
109 | ||
110 | if (bus_attr->show) | |
111 | ret = bus_attr->show(bus, buf); | |
112 | return ret; | |
113 | } | |
114 | ||
115 | static ssize_t | |
116 | bus_attr_store(struct kobject * kobj, struct attribute * attr, | |
117 | const char * buf, size_t count) | |
118 | { | |
119 | struct bus_attribute * bus_attr = to_bus_attr(attr); | |
120 | struct bus_type * bus = to_bus(kobj); | |
121 | ssize_t ret = 0; | |
122 | ||
123 | if (bus_attr->store) | |
124 | ret = bus_attr->store(bus, buf, count); | |
125 | return ret; | |
126 | } | |
127 | ||
128 | static struct sysfs_ops bus_sysfs_ops = { | |
129 | .show = bus_attr_show, | |
130 | .store = bus_attr_store, | |
131 | }; | |
132 | ||
133 | int bus_create_file(struct bus_type * bus, struct bus_attribute * attr) | |
134 | { | |
135 | int error; | |
5901d014 | 136 | if (bus_get(bus)) { |
823bccfc | 137 | error = sysfs_create_file(&bus->subsys.kobj, &attr->attr); |
fc1ede58 | 138 | bus_put(bus); |
1da177e4 LT |
139 | } else |
140 | error = -EINVAL; | |
141 | return error; | |
142 | } | |
143 | ||
144 | void bus_remove_file(struct bus_type * bus, struct bus_attribute * attr) | |
145 | { | |
5901d014 | 146 | if (bus_get(bus)) { |
823bccfc | 147 | sysfs_remove_file(&bus->subsys.kobj, &attr->attr); |
fc1ede58 | 148 | bus_put(bus); |
1da177e4 LT |
149 | } |
150 | } | |
151 | ||
80f03e34 | 152 | static struct kobj_type bus_ktype = { |
1da177e4 | 153 | .sysfs_ops = &bus_sysfs_ops, |
80f03e34 KS |
154 | }; |
155 | ||
156 | static int bus_uevent_filter(struct kset *kset, struct kobject *kobj) | |
157 | { | |
158 | struct kobj_type *ktype = get_ktype(kobj); | |
159 | ||
160 | if (ktype == &bus_ktype) | |
161 | return 1; | |
162 | return 0; | |
163 | } | |
1da177e4 | 164 | |
80f03e34 KS |
165 | static struct kset_uevent_ops bus_uevent_ops = { |
166 | .filter = bus_uevent_filter, | |
1da177e4 LT |
167 | }; |
168 | ||
59a54833 | 169 | static struct kset *bus_kset; |
1da177e4 | 170 | |
1da177e4 | 171 | |
2139bdd5 | 172 | #ifdef CONFIG_HOTPLUG |
2b08c8d0 | 173 | /* Manually detach a device from its associated driver. */ |
151ef38f GKH |
174 | static int driver_helper(struct device *dev, void *data) |
175 | { | |
176 | const char *name = data; | |
177 | ||
178 | if (strcmp(name, dev->bus_id) == 0) | |
179 | return 1; | |
180 | return 0; | |
181 | } | |
182 | ||
183 | static ssize_t driver_unbind(struct device_driver *drv, | |
184 | const char *buf, size_t count) | |
185 | { | |
5901d014 | 186 | struct bus_type *bus = bus_get(drv->bus); |
151ef38f GKH |
187 | struct device *dev; |
188 | int err = -ENODEV; | |
189 | ||
190 | dev = bus_find_device(bus, NULL, (void *)buf, driver_helper); | |
2b08c8d0 | 191 | if (dev && dev->driver == drv) { |
bf74ad5b AS |
192 | if (dev->parent) /* Needed for USB */ |
193 | down(&dev->parent->sem); | |
151ef38f | 194 | device_release_driver(dev); |
bf74ad5b AS |
195 | if (dev->parent) |
196 | up(&dev->parent->sem); | |
151ef38f GKH |
197 | err = count; |
198 | } | |
2b08c8d0 | 199 | put_device(dev); |
fc1ede58 | 200 | bus_put(bus); |
2b08c8d0 | 201 | return err; |
151ef38f GKH |
202 | } |
203 | static DRIVER_ATTR(unbind, S_IWUSR, NULL, driver_unbind); | |
204 | ||
afdce75f GKH |
205 | /* |
206 | * Manually attach a device to a driver. | |
207 | * Note: the driver must want to bind to the device, | |
208 | * it is not possible to override the driver's id table. | |
209 | */ | |
210 | static ssize_t driver_bind(struct device_driver *drv, | |
211 | const char *buf, size_t count) | |
212 | { | |
5901d014 | 213 | struct bus_type *bus = bus_get(drv->bus); |
afdce75f GKH |
214 | struct device *dev; |
215 | int err = -ENODEV; | |
216 | ||
217 | dev = bus_find_device(bus, NULL, (void *)buf, driver_helper); | |
2b08c8d0 | 218 | if (dev && dev->driver == NULL) { |
bf74ad5b AS |
219 | if (dev->parent) /* Needed for USB */ |
220 | down(&dev->parent->sem); | |
afdce75f GKH |
221 | down(&dev->sem); |
222 | err = driver_probe_device(drv, dev); | |
223 | up(&dev->sem); | |
bf74ad5b AS |
224 | if (dev->parent) |
225 | up(&dev->parent->sem); | |
37225401 RW |
226 | |
227 | if (err > 0) /* success */ | |
228 | err = count; | |
229 | else if (err == 0) /* driver didn't accept device */ | |
230 | err = -ENODEV; | |
afdce75f | 231 | } |
2b08c8d0 | 232 | put_device(dev); |
fc1ede58 | 233 | bus_put(bus); |
2b08c8d0 | 234 | return err; |
afdce75f GKH |
235 | } |
236 | static DRIVER_ATTR(bind, S_IWUSR, NULL, driver_bind); | |
237 | ||
b8c5cec2 KS |
238 | static ssize_t show_drivers_autoprobe(struct bus_type *bus, char *buf) |
239 | { | |
240 | return sprintf(buf, "%d\n", bus->drivers_autoprobe); | |
241 | } | |
242 | ||
243 | static ssize_t store_drivers_autoprobe(struct bus_type *bus, | |
244 | const char *buf, size_t count) | |
245 | { | |
246 | if (buf[0] == '0') | |
247 | bus->drivers_autoprobe = 0; | |
248 | else | |
249 | bus->drivers_autoprobe = 1; | |
250 | return count; | |
251 | } | |
252 | ||
253 | static ssize_t store_drivers_probe(struct bus_type *bus, | |
254 | const char *buf, size_t count) | |
255 | { | |
256 | struct device *dev; | |
257 | ||
258 | dev = bus_find_device(bus, NULL, (void *)buf, driver_helper); | |
259 | if (!dev) | |
260 | return -ENODEV; | |
261 | if (bus_rescan_devices_helper(dev, NULL) != 0) | |
262 | return -EINVAL; | |
263 | return count; | |
264 | } | |
2139bdd5 | 265 | #endif |
151ef38f | 266 | |
465c7a3a | 267 | static struct device * next_device(struct klist_iter * i) |
268 | { | |
269 | struct klist_node * n = klist_next(i); | |
270 | return n ? container_of(n, struct device, knode_bus) : NULL; | |
271 | } | |
272 | ||
1da177e4 LT |
273 | /** |
274 | * bus_for_each_dev - device iterator. | |
275 | * @bus: bus type. | |
276 | * @start: device to start iterating from. | |
277 | * @data: data for the callback. | |
278 | * @fn: function to be called for each device. | |
279 | * | |
280 | * Iterate over @bus's list of devices, and call @fn for each, | |
281 | * passing it @data. If @start is not NULL, we use that device to | |
282 | * begin iterating from. | |
283 | * | |
284 | * We check the return of @fn each time. If it returns anything | |
285 | * other than 0, we break out and return that value. | |
286 | * | |
287 | * NOTE: The device that returns a non-zero value is not retained | |
288 | * in any way, nor is its refcount incremented. If the caller needs | |
289 | * to retain this data, it should do, and increment the reference | |
290 | * count in the supplied callback. | |
291 | */ | |
292 | ||
293 | int bus_for_each_dev(struct bus_type * bus, struct device * start, | |
294 | void * data, int (*fn)(struct device *, void *)) | |
295 | { | |
465c7a3a | 296 | struct klist_iter i; |
297 | struct device * dev; | |
298 | int error = 0; | |
1da177e4 | 299 | |
465c7a3a | 300 | if (!bus) |
301 | return -EINVAL; | |
302 | ||
303 | klist_iter_init_node(&bus->klist_devices, &i, | |
304 | (start ? &start->knode_bus : NULL)); | |
305 | while ((dev = next_device(&i)) && !error) | |
306 | error = fn(dev, data); | |
307 | klist_iter_exit(&i); | |
308 | return error; | |
1da177e4 LT |
309 | } |
310 | ||
0edb5860 CH |
311 | /** |
312 | * bus_find_device - device iterator for locating a particular device. | |
313 | * @bus: bus type | |
314 | * @start: Device to begin with | |
315 | * @data: Data to pass to match function | |
316 | * @match: Callback function to check device | |
317 | * | |
318 | * This is similar to the bus_for_each_dev() function above, but it | |
319 | * returns a reference to a device that is 'found' for later use, as | |
320 | * determined by the @match callback. | |
321 | * | |
322 | * The callback should return 0 if the device doesn't match and non-zero | |
323 | * if it does. If the callback returns non-zero, this function will | |
324 | * return to the caller and not iterate over any more devices. | |
325 | */ | |
326 | struct device * bus_find_device(struct bus_type *bus, | |
327 | struct device *start, void *data, | |
328 | int (*match)(struct device *, void *)) | |
329 | { | |
330 | struct klist_iter i; | |
331 | struct device *dev; | |
332 | ||
333 | if (!bus) | |
334 | return NULL; | |
335 | ||
336 | klist_iter_init_node(&bus->klist_devices, &i, | |
337 | (start ? &start->knode_bus : NULL)); | |
338 | while ((dev = next_device(&i))) | |
339 | if (match(dev, data) && get_device(dev)) | |
340 | break; | |
341 | klist_iter_exit(&i); | |
342 | return dev; | |
343 | } | |
38fdac3c | 344 | |
345 | ||
346 | static struct device_driver * next_driver(struct klist_iter * i) | |
347 | { | |
348 | struct klist_node * n = klist_next(i); | |
349 | return n ? container_of(n, struct device_driver, knode_bus) : NULL; | |
350 | } | |
351 | ||
1da177e4 LT |
352 | /** |
353 | * bus_for_each_drv - driver iterator | |
354 | * @bus: bus we're dealing with. | |
355 | * @start: driver to start iterating on. | |
356 | * @data: data to pass to the callback. | |
357 | * @fn: function to call for each driver. | |
358 | * | |
359 | * This is nearly identical to the device iterator above. | |
360 | * We iterate over each driver that belongs to @bus, and call | |
361 | * @fn for each. If @fn returns anything but 0, we break out | |
362 | * and return it. If @start is not NULL, we use it as the head | |
363 | * of the list. | |
364 | * | |
365 | * NOTE: we don't return the driver that returns a non-zero | |
366 | * value, nor do we leave the reference count incremented for that | |
367 | * driver. If the caller needs to know that info, it must set it | |
368 | * in the callback. It must also be sure to increment the refcount | |
369 | * so it doesn't disappear before returning to the caller. | |
370 | */ | |
371 | ||
372 | int bus_for_each_drv(struct bus_type * bus, struct device_driver * start, | |
373 | void * data, int (*fn)(struct device_driver *, void *)) | |
374 | { | |
38fdac3c | 375 | struct klist_iter i; |
376 | struct device_driver * drv; | |
377 | int error = 0; | |
1da177e4 | 378 | |
38fdac3c | 379 | if (!bus) |
380 | return -EINVAL; | |
381 | ||
382 | klist_iter_init_node(&bus->klist_drivers, &i, | |
383 | start ? &start->knode_bus : NULL); | |
384 | while ((drv = next_driver(&i)) && !error) | |
385 | error = fn(drv, data); | |
386 | klist_iter_exit(&i); | |
387 | return error; | |
1da177e4 LT |
388 | } |
389 | ||
4aca67e5 | 390 | static int device_add_attrs(struct bus_type *bus, struct device *dev) |
1da177e4 LT |
391 | { |
392 | int error = 0; | |
393 | int i; | |
394 | ||
4aca67e5 AM |
395 | if (!bus->dev_attrs) |
396 | return 0; | |
397 | ||
398 | for (i = 0; attr_name(bus->dev_attrs[i]); i++) { | |
399 | error = device_create_file(dev,&bus->dev_attrs[i]); | |
400 | if (error) { | |
401 | while (--i >= 0) | |
402 | device_remove_file(dev, &bus->dev_attrs[i]); | |
403 | break; | |
1da177e4 LT |
404 | } |
405 | } | |
1da177e4 | 406 | return error; |
1da177e4 LT |
407 | } |
408 | ||
1da177e4 LT |
409 | static void device_remove_attrs(struct bus_type * bus, struct device * dev) |
410 | { | |
411 | int i; | |
412 | ||
413 | if (bus->dev_attrs) { | |
414 | for (i = 0; attr_name(bus->dev_attrs[i]); i++) | |
415 | device_remove_file(dev,&bus->dev_attrs[i]); | |
416 | } | |
417 | } | |
418 | ||
b9cafc7d KS |
419 | #ifdef CONFIG_SYSFS_DEPRECATED |
420 | static int make_deprecated_bus_links(struct device *dev) | |
421 | { | |
422 | return sysfs_create_link(&dev->kobj, | |
823bccfc | 423 | &dev->bus->subsys.kobj, "bus"); |
b9cafc7d KS |
424 | } |
425 | ||
426 | static void remove_deprecated_bus_links(struct device *dev) | |
427 | { | |
428 | sysfs_remove_link(&dev->kobj, "bus"); | |
429 | } | |
430 | #else | |
431 | static inline int make_deprecated_bus_links(struct device *dev) { return 0; } | |
432 | static inline void remove_deprecated_bus_links(struct device *dev) { } | |
433 | #endif | |
1da177e4 LT |
434 | |
435 | /** | |
436 | * bus_add_device - add device to bus | |
437 | * @dev: device being added | |
438 | * | |
439 | * - Add the device to its bus's list of devices. | |
53877d06 | 440 | * - Create link to device's bus. |
1da177e4 LT |
441 | */ |
442 | int bus_add_device(struct device * dev) | |
443 | { | |
5901d014 | 444 | struct bus_type * bus = bus_get(dev->bus); |
1da177e4 LT |
445 | int error = 0; |
446 | ||
447 | if (bus) { | |
1da177e4 | 448 | pr_debug("bus %s: add device %s\n", bus->name, dev->bus_id); |
d377e85b | 449 | error = device_add_attrs(bus, dev); |
f86db396 | 450 | if (error) |
513e7337 | 451 | goto out_put; |
f86db396 AM |
452 | error = sysfs_create_link(&bus->devices.kobj, |
453 | &dev->kobj, dev->bus_id); | |
454 | if (error) | |
513e7337 | 455 | goto out_id; |
f86db396 | 456 | error = sysfs_create_link(&dev->kobj, |
823bccfc | 457 | &dev->bus->subsys.kobj, "subsystem"); |
f86db396 | 458 | if (error) |
513e7337 | 459 | goto out_subsys; |
b9cafc7d | 460 | error = make_deprecated_bus_links(dev); |
513e7337 CH |
461 | if (error) |
462 | goto out_deprecated; | |
1da177e4 | 463 | } |
513e7337 CH |
464 | return 0; |
465 | ||
466 | out_deprecated: | |
467 | sysfs_remove_link(&dev->kobj, "subsystem"); | |
468 | out_subsys: | |
469 | sysfs_remove_link(&bus->devices.kobj, dev->bus_id); | |
470 | out_id: | |
471 | device_remove_attrs(bus, dev); | |
472 | out_put: | |
fc1ede58 | 473 | bus_put(dev->bus); |
1da177e4 LT |
474 | return error; |
475 | } | |
476 | ||
53877d06 KS |
477 | /** |
478 | * bus_attach_device - add device to bus | |
479 | * @dev: device tried to attach to a driver | |
480 | * | |
f2eaae19 | 481 | * - Add device to bus's list of devices. |
53877d06 KS |
482 | * - Try to attach to driver. |
483 | */ | |
c6a46696 | 484 | void bus_attach_device(struct device * dev) |
53877d06 | 485 | { |
f86db396 AM |
486 | struct bus_type *bus = dev->bus; |
487 | int ret = 0; | |
53877d06 KS |
488 | |
489 | if (bus) { | |
f2eaae19 | 490 | dev->is_registered = 1; |
b8c5cec2 KS |
491 | if (bus->drivers_autoprobe) |
492 | ret = device_attach(dev); | |
c6a46696 CH |
493 | WARN_ON(ret < 0); |
494 | if (ret >= 0) | |
f86db396 | 495 | klist_add_tail(&dev->knode_bus, &bus->klist_devices); |
c6a46696 | 496 | else |
f2eaae19 | 497 | dev->is_registered = 0; |
53877d06 KS |
498 | } |
499 | } | |
500 | ||
1da177e4 LT |
501 | /** |
502 | * bus_remove_device - remove device from bus | |
503 | * @dev: device to be removed | |
504 | * | |
505 | * - Remove symlink from bus's directory. | |
506 | * - Delete device from bus's list. | |
507 | * - Detach from its driver. | |
508 | * - Drop reference taken in bus_add_device(). | |
509 | */ | |
510 | void bus_remove_device(struct device * dev) | |
511 | { | |
512 | if (dev->bus) { | |
b9d9c82b | 513 | sysfs_remove_link(&dev->kobj, "subsystem"); |
b9cafc7d | 514 | remove_deprecated_bus_links(dev); |
1da177e4 LT |
515 | sysfs_remove_link(&dev->bus->devices.kobj, dev->bus_id); |
516 | device_remove_attrs(dev->bus, dev); | |
f70fa629 AS |
517 | if (dev->is_registered) { |
518 | dev->is_registered = 0; | |
519 | klist_del(&dev->knode_bus); | |
520 | } | |
1da177e4 LT |
521 | pr_debug("bus %s: remove device %s\n", dev->bus->name, dev->bus_id); |
522 | device_release_driver(dev); | |
fc1ede58 | 523 | bus_put(dev->bus); |
1da177e4 LT |
524 | } |
525 | } | |
526 | ||
527 | static int driver_add_attrs(struct bus_type * bus, struct device_driver * drv) | |
528 | { | |
529 | int error = 0; | |
530 | int i; | |
531 | ||
532 | if (bus->drv_attrs) { | |
533 | for (i = 0; attr_name(bus->drv_attrs[i]); i++) { | |
534 | error = driver_create_file(drv, &bus->drv_attrs[i]); | |
535 | if (error) | |
536 | goto Err; | |
537 | } | |
538 | } | |
539 | Done: | |
540 | return error; | |
541 | Err: | |
542 | while (--i >= 0) | |
543 | driver_remove_file(drv, &bus->drv_attrs[i]); | |
544 | goto Done; | |
545 | } | |
546 | ||
547 | ||
548 | static void driver_remove_attrs(struct bus_type * bus, struct device_driver * drv) | |
549 | { | |
550 | int i; | |
551 | ||
552 | if (bus->drv_attrs) { | |
553 | for (i = 0; attr_name(bus->drv_attrs[i]); i++) | |
554 | driver_remove_file(drv, &bus->drv_attrs[i]); | |
555 | } | |
556 | } | |
557 | ||
874c6241 GKH |
558 | #ifdef CONFIG_HOTPLUG |
559 | /* | |
560 | * Thanks to drivers making their tables __devinit, we can't allow manual | |
561 | * bind and unbind from userspace unless CONFIG_HOTPLUG is enabled. | |
562 | */ | |
f86db396 | 563 | static int __must_check add_bind_files(struct device_driver *drv) |
874c6241 | 564 | { |
f86db396 AM |
565 | int ret; |
566 | ||
567 | ret = driver_create_file(drv, &driver_attr_unbind); | |
568 | if (ret == 0) { | |
569 | ret = driver_create_file(drv, &driver_attr_bind); | |
570 | if (ret) | |
571 | driver_remove_file(drv, &driver_attr_unbind); | |
572 | } | |
573 | return ret; | |
874c6241 GKH |
574 | } |
575 | ||
576 | static void remove_bind_files(struct device_driver *drv) | |
577 | { | |
578 | driver_remove_file(drv, &driver_attr_bind); | |
579 | driver_remove_file(drv, &driver_attr_unbind); | |
580 | } | |
b8c5cec2 | 581 | |
8380770c KS |
582 | static BUS_ATTR(drivers_probe, S_IWUSR, NULL, store_drivers_probe); |
583 | static BUS_ATTR(drivers_autoprobe, S_IWUSR | S_IRUGO, | |
584 | show_drivers_autoprobe, store_drivers_autoprobe); | |
585 | ||
b8c5cec2 KS |
586 | static int add_probe_files(struct bus_type *bus) |
587 | { | |
588 | int retval; | |
589 | ||
8380770c | 590 | retval = bus_create_file(bus, &bus_attr_drivers_probe); |
b8c5cec2 KS |
591 | if (retval) |
592 | goto out; | |
593 | ||
8380770c | 594 | retval = bus_create_file(bus, &bus_attr_drivers_autoprobe); |
b8c5cec2 | 595 | if (retval) |
8380770c | 596 | bus_remove_file(bus, &bus_attr_drivers_probe); |
b8c5cec2 KS |
597 | out: |
598 | return retval; | |
599 | } | |
600 | ||
601 | static void remove_probe_files(struct bus_type *bus) | |
602 | { | |
8380770c KS |
603 | bus_remove_file(bus, &bus_attr_drivers_autoprobe); |
604 | bus_remove_file(bus, &bus_attr_drivers_probe); | |
b8c5cec2 | 605 | } |
874c6241 | 606 | #else |
35acfdd7 | 607 | static inline int add_bind_files(struct device_driver *drv) { return 0; } |
874c6241 | 608 | static inline void remove_bind_files(struct device_driver *drv) {} |
b8c5cec2 KS |
609 | static inline int add_probe_files(struct bus_type *bus) { return 0; } |
610 | static inline void remove_probe_files(struct bus_type *bus) {} | |
874c6241 | 611 | #endif |
1da177e4 | 612 | |
7ac1cf4a KS |
613 | static ssize_t driver_uevent_store(struct device_driver *drv, |
614 | const char *buf, size_t count) | |
615 | { | |
616 | enum kobject_action action; | |
617 | ||
618 | if (kobject_action_type(buf, count, &action) == 0) | |
619 | kobject_uevent(&drv->kobj, action); | |
620 | return count; | |
621 | } | |
622 | static DRIVER_ATTR(uevent, S_IWUSR, NULL, driver_uevent_store); | |
623 | ||
1da177e4 LT |
624 | /** |
625 | * bus_add_driver - Add a driver to the bus. | |
626 | * @drv: driver. | |
627 | * | |
628 | */ | |
f86db396 | 629 | int bus_add_driver(struct device_driver *drv) |
1da177e4 | 630 | { |
5901d014 | 631 | struct bus_type * bus = bus_get(drv->bus); |
1da177e4 LT |
632 | int error = 0; |
633 | ||
d9fd4d3b | 634 | if (!bus) |
4f6e1945 | 635 | return -EINVAL; |
d9fd4d3b JG |
636 | |
637 | pr_debug("bus %s: add driver %s\n", bus->name, drv->name); | |
638 | error = kobject_set_name(&drv->kobj, "%s", drv->name); | |
639 | if (error) | |
640 | goto out_put_bus; | |
641 | drv->kobj.kset = &bus->drivers; | |
3514faca | 642 | drv->kobj.ktype = &driver_ktype; |
dc0afa83 CH |
643 | error = kobject_register(&drv->kobj); |
644 | if (error) | |
d9fd4d3b JG |
645 | goto out_put_bus; |
646 | ||
b8c5cec2 KS |
647 | if (drv->bus->drivers_autoprobe) { |
648 | error = driver_attach(drv); | |
649 | if (error) | |
650 | goto out_unregister; | |
651 | } | |
d9fd4d3b JG |
652 | klist_add_tail(&drv->knode_bus, &bus->klist_drivers); |
653 | module_add_driver(drv->owner, drv); | |
654 | ||
7ac1cf4a KS |
655 | error = driver_create_file(drv, &driver_attr_uevent); |
656 | if (error) { | |
657 | printk(KERN_ERR "%s: uevent attr (%s) failed\n", | |
658 | __FUNCTION__, drv->name); | |
659 | } | |
d9fd4d3b JG |
660 | error = driver_add_attrs(bus, drv); |
661 | if (error) { | |
662 | /* How the hell do we get out of this pickle? Give up */ | |
663 | printk(KERN_ERR "%s: driver_add_attrs(%s) failed\n", | |
664 | __FUNCTION__, drv->name); | |
665 | } | |
666 | error = add_bind_files(drv); | |
667 | if (error) { | |
668 | /* Ditto */ | |
669 | printk(KERN_ERR "%s: add_bind_files(%s) failed\n", | |
670 | __FUNCTION__, drv->name); | |
1da177e4 | 671 | } |
d9fd4d3b | 672 | |
1da177e4 | 673 | return error; |
f86db396 AM |
674 | out_unregister: |
675 | kobject_unregister(&drv->kobj); | |
676 | out_put_bus: | |
fc1ede58 | 677 | bus_put(bus); |
f86db396 | 678 | return error; |
1da177e4 LT |
679 | } |
680 | ||
1da177e4 LT |
681 | /** |
682 | * bus_remove_driver - delete driver from bus's knowledge. | |
683 | * @drv: driver. | |
684 | * | |
685 | * Detach the driver from the devices it controls, and remove | |
686 | * it from its bus's list of drivers. Finally, we drop the reference | |
687 | * to the bus we took in bus_add_driver(). | |
688 | */ | |
689 | ||
690 | void bus_remove_driver(struct device_driver * drv) | |
691 | { | |
d9fd4d3b JG |
692 | if (!drv->bus) |
693 | return; | |
694 | ||
695 | remove_bind_files(drv); | |
696 | driver_remove_attrs(drv->bus, drv); | |
7ac1cf4a | 697 | driver_remove_file(drv, &driver_attr_uevent); |
d9fd4d3b JG |
698 | klist_remove(&drv->knode_bus); |
699 | pr_debug("bus %s: remove driver %s\n", drv->bus->name, drv->name); | |
700 | driver_detach(drv); | |
701 | module_remove_driver(drv); | |
702 | kobject_unregister(&drv->kobj); | |
fc1ede58 | 703 | bus_put(drv->bus); |
1da177e4 LT |
704 | } |
705 | ||
706 | ||
707 | /* Helper for bus_rescan_devices's iter */ | |
f86db396 AM |
708 | static int __must_check bus_rescan_devices_helper(struct device *dev, |
709 | void *data) | |
1da177e4 | 710 | { |
f86db396 AM |
711 | int ret = 0; |
712 | ||
bf74ad5b AS |
713 | if (!dev->driver) { |
714 | if (dev->parent) /* Needed for USB */ | |
715 | down(&dev->parent->sem); | |
f86db396 | 716 | ret = device_attach(dev); |
bf74ad5b AS |
717 | if (dev->parent) |
718 | up(&dev->parent->sem); | |
719 | } | |
f86db396 | 720 | return ret < 0 ? ret : 0; |
1da177e4 LT |
721 | } |
722 | ||
1da177e4 | 723 | /** |
23d3d602 GKH |
724 | * bus_rescan_devices - rescan devices on the bus for possible drivers |
725 | * @bus: the bus to scan. | |
1da177e4 | 726 | * |
23d3d602 GKH |
727 | * This function will look for devices on the bus with no driver |
728 | * attached and rescan it against existing drivers to see if it matches | |
729 | * any by calling device_attach() for the unbound devices. | |
1da177e4 | 730 | */ |
f86db396 | 731 | int bus_rescan_devices(struct bus_type * bus) |
1da177e4 | 732 | { |
f86db396 | 733 | return bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper); |
1da177e4 LT |
734 | } |
735 | ||
e935d5da ME |
736 | /** |
737 | * device_reprobe - remove driver for a device and probe for a new driver | |
738 | * @dev: the device to reprobe | |
739 | * | |
740 | * This function detaches the attached driver (if any) for the given | |
741 | * device and restarts the driver probing process. It is intended | |
742 | * to use if probing criteria changed during a devices lifetime and | |
743 | * driver attachment should change accordingly. | |
744 | */ | |
f86db396 | 745 | int device_reprobe(struct device *dev) |
e935d5da ME |
746 | { |
747 | if (dev->driver) { | |
748 | if (dev->parent) /* Needed for USB */ | |
749 | down(&dev->parent->sem); | |
750 | device_release_driver(dev); | |
751 | if (dev->parent) | |
752 | up(&dev->parent->sem); | |
753 | } | |
f86db396 | 754 | return bus_rescan_devices_helper(dev, NULL); |
e935d5da ME |
755 | } |
756 | EXPORT_SYMBOL_GPL(device_reprobe); | |
1da177e4 | 757 | |
1da177e4 LT |
758 | /** |
759 | * find_bus - locate bus by name. | |
760 | * @name: name of bus. | |
761 | * | |
762 | * Call kset_find_obj() to iterate over list of buses to | |
763 | * find a bus by name. Return bus if found. | |
764 | * | |
765 | * Note that kset_find_obj increments bus' reference count. | |
766 | */ | |
7e4ef085 | 767 | #if 0 |
1da177e4 LT |
768 | struct bus_type * find_bus(char * name) |
769 | { | |
59a54833 | 770 | struct kobject * k = kset_find_obj(bus_kset, name); |
1da177e4 LT |
771 | return k ? to_bus(k) : NULL; |
772 | } | |
7e4ef085 | 773 | #endif /* 0 */ |
1da177e4 LT |
774 | |
775 | ||
776 | /** | |
777 | * bus_add_attrs - Add default attributes for this bus. | |
778 | * @bus: Bus that has just been registered. | |
779 | */ | |
780 | ||
781 | static int bus_add_attrs(struct bus_type * bus) | |
782 | { | |
783 | int error = 0; | |
784 | int i; | |
785 | ||
786 | if (bus->bus_attrs) { | |
787 | for (i = 0; attr_name(bus->bus_attrs[i]); i++) { | |
dc0afa83 CH |
788 | error = bus_create_file(bus,&bus->bus_attrs[i]); |
789 | if (error) | |
1da177e4 LT |
790 | goto Err; |
791 | } | |
792 | } | |
793 | Done: | |
794 | return error; | |
795 | Err: | |
796 | while (--i >= 0) | |
797 | bus_remove_file(bus,&bus->bus_attrs[i]); | |
798 | goto Done; | |
799 | } | |
800 | ||
801 | static void bus_remove_attrs(struct bus_type * bus) | |
802 | { | |
803 | int i; | |
804 | ||
805 | if (bus->bus_attrs) { | |
806 | for (i = 0; attr_name(bus->bus_attrs[i]); i++) | |
807 | bus_remove_file(bus,&bus->bus_attrs[i]); | |
808 | } | |
809 | } | |
810 | ||
34bb61f9 JB |
811 | static void klist_devices_get(struct klist_node *n) |
812 | { | |
813 | struct device *dev = container_of(n, struct device, knode_bus); | |
814 | ||
815 | get_device(dev); | |
816 | } | |
817 | ||
818 | static void klist_devices_put(struct klist_node *n) | |
819 | { | |
820 | struct device *dev = container_of(n, struct device, knode_bus); | |
821 | ||
822 | put_device(dev); | |
823 | } | |
824 | ||
7ac1cf4a KS |
825 | static ssize_t bus_uevent_store(struct bus_type *bus, |
826 | const char *buf, size_t count) | |
827 | { | |
828 | enum kobject_action action; | |
829 | ||
830 | if (kobject_action_type(buf, count, &action) == 0) | |
831 | kobject_uevent(&bus->subsys.kobj, action); | |
832 | return count; | |
833 | } | |
834 | static BUS_ATTR(uevent, S_IWUSR, NULL, bus_uevent_store); | |
835 | ||
1da177e4 LT |
836 | /** |
837 | * bus_register - register a bus with the system. | |
838 | * @bus: bus. | |
839 | * | |
840 | * Once we have that, we registered the bus with the kobject | |
841 | * infrastructure, then register the children subsystems it has: | |
842 | * the devices and drivers that belong to the bus. | |
843 | */ | |
844 | int bus_register(struct bus_type * bus) | |
845 | { | |
846 | int retval; | |
847 | ||
116af378 BH |
848 | BLOCKING_INIT_NOTIFIER_HEAD(&bus->bus_notifier); |
849 | ||
823bccfc | 850 | retval = kobject_set_name(&bus->subsys.kobj, "%s", bus->name); |
1da177e4 LT |
851 | if (retval) |
852 | goto out; | |
853 | ||
59a54833 | 854 | bus->subsys.kobj.kset = bus_kset; |
3514faca | 855 | bus->subsys.kobj.ktype = &bus_ktype; |
d6b05b84 | 856 | |
1da177e4 LT |
857 | retval = subsystem_register(&bus->subsys); |
858 | if (retval) | |
859 | goto out; | |
860 | ||
7ac1cf4a KS |
861 | retval = bus_create_file(bus, &bus_attr_uevent); |
862 | if (retval) | |
863 | goto bus_uevent_fail; | |
864 | ||
1da177e4 | 865 | kobject_set_name(&bus->devices.kobj, "devices"); |
823bccfc | 866 | bus->devices.kobj.parent = &bus->subsys.kobj; |
1da177e4 LT |
867 | retval = kset_register(&bus->devices); |
868 | if (retval) | |
869 | goto bus_devices_fail; | |
870 | ||
871 | kobject_set_name(&bus->drivers.kobj, "drivers"); | |
823bccfc | 872 | bus->drivers.kobj.parent = &bus->subsys.kobj; |
1da177e4 LT |
873 | retval = kset_register(&bus->drivers); |
874 | if (retval) | |
875 | goto bus_drivers_fail; | |
465c7a3a | 876 | |
34bb61f9 | 877 | klist_init(&bus->klist_devices, klist_devices_get, klist_devices_put); |
81107bf5 | 878 | klist_init(&bus->klist_drivers, NULL, NULL); |
b8c5cec2 KS |
879 | |
880 | bus->drivers_autoprobe = 1; | |
881 | retval = add_probe_files(bus); | |
882 | if (retval) | |
883 | goto bus_probe_files_fail; | |
884 | ||
1bb6881a CH |
885 | retval = bus_add_attrs(bus); |
886 | if (retval) | |
887 | goto bus_attrs_fail; | |
1da177e4 LT |
888 | |
889 | pr_debug("bus type '%s' registered\n", bus->name); | |
890 | return 0; | |
891 | ||
1bb6881a | 892 | bus_attrs_fail: |
b8c5cec2 KS |
893 | remove_probe_files(bus); |
894 | bus_probe_files_fail: | |
1bb6881a | 895 | kset_unregister(&bus->drivers); |
1da177e4 LT |
896 | bus_drivers_fail: |
897 | kset_unregister(&bus->devices); | |
898 | bus_devices_fail: | |
7ac1cf4a KS |
899 | bus_remove_file(bus, &bus_attr_uevent); |
900 | bus_uevent_fail: | |
1da177e4 LT |
901 | subsystem_unregister(&bus->subsys); |
902 | out: | |
903 | return retval; | |
904 | } | |
905 | ||
1da177e4 LT |
906 | /** |
907 | * bus_unregister - remove a bus from the system | |
908 | * @bus: bus. | |
909 | * | |
910 | * Unregister the child subsystems and the bus itself. | |
fc1ede58 | 911 | * Finally, we call bus_put() to release the refcount |
1da177e4 LT |
912 | */ |
913 | void bus_unregister(struct bus_type * bus) | |
914 | { | |
915 | pr_debug("bus %s: unregistering\n", bus->name); | |
916 | bus_remove_attrs(bus); | |
b8c5cec2 | 917 | remove_probe_files(bus); |
1da177e4 LT |
918 | kset_unregister(&bus->drivers); |
919 | kset_unregister(&bus->devices); | |
7ac1cf4a | 920 | bus_remove_file(bus, &bus_attr_uevent); |
1da177e4 LT |
921 | subsystem_unregister(&bus->subsys); |
922 | } | |
923 | ||
116af378 BH |
924 | int bus_register_notifier(struct bus_type *bus, struct notifier_block *nb) |
925 | { | |
926 | return blocking_notifier_chain_register(&bus->bus_notifier, nb); | |
927 | } | |
928 | EXPORT_SYMBOL_GPL(bus_register_notifier); | |
929 | ||
930 | int bus_unregister_notifier(struct bus_type *bus, struct notifier_block *nb) | |
931 | { | |
932 | return blocking_notifier_chain_unregister(&bus->bus_notifier, nb); | |
933 | } | |
934 | EXPORT_SYMBOL_GPL(bus_unregister_notifier); | |
935 | ||
1da177e4 LT |
936 | int __init buses_init(void) |
937 | { | |
59a54833 GKH |
938 | bus_kset = kset_create_and_add("bus", &bus_uevent_ops, NULL); |
939 | if (!bus_kset) | |
940 | return -ENOMEM; | |
941 | return 0; | |
1da177e4 LT |
942 | } |
943 | ||
944 | ||
945 | EXPORT_SYMBOL_GPL(bus_for_each_dev); | |
0edb5860 | 946 | EXPORT_SYMBOL_GPL(bus_find_device); |
1da177e4 LT |
947 | EXPORT_SYMBOL_GPL(bus_for_each_drv); |
948 | ||
1da177e4 LT |
949 | EXPORT_SYMBOL_GPL(bus_register); |
950 | EXPORT_SYMBOL_GPL(bus_unregister); | |
951 | EXPORT_SYMBOL_GPL(bus_rescan_devices); | |
1da177e4 LT |
952 | |
953 | EXPORT_SYMBOL_GPL(bus_create_file); | |
954 | EXPORT_SYMBOL_GPL(bus_remove_file); |