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 | |
e5dd1278 GKH |
6 | * Copyright (c) 2007 Greg Kroah-Hartman <gregkh@suse.de> |
7 | * Copyright (c) 2007 Novell Inc. | |
1da177e4 LT |
8 | * |
9 | * This file is released under the GPLv2 | |
10 | * | |
11 | */ | |
12 | ||
1da177e4 LT |
13 | #include <linux/device.h> |
14 | #include <linux/module.h> | |
15 | #include <linux/errno.h> | |
16 | #include <linux/init.h> | |
17 | #include <linux/string.h> | |
18 | #include "base.h" | |
19 | #include "power/power.h" | |
20 | ||
1da177e4 | 21 | #define to_bus_attr(_attr) container_of(_attr, struct bus_attribute, attr) |
c6f7e72a | 22 | #define to_bus(obj) container_of(obj, struct bus_type_private, subsys.kobj) |
1da177e4 LT |
23 | |
24 | /* | |
25 | * sysfs bindings for drivers | |
26 | */ | |
27 | ||
28 | #define to_drv_attr(_attr) container_of(_attr, struct driver_attribute, attr) | |
1da177e4 LT |
29 | |
30 | ||
b8c5cec2 KS |
31 | static int __must_check bus_rescan_devices_helper(struct device *dev, |
32 | void *data); | |
33 | ||
5901d014 GKH |
34 | static struct bus_type *bus_get(struct bus_type *bus) |
35 | { | |
c6f7e72a GKH |
36 | if (bus) { |
37 | kset_get(&bus->p->subsys); | |
38 | return bus; | |
39 | } | |
40 | return NULL; | |
5901d014 GKH |
41 | } |
42 | ||
fc1ede58 GKH |
43 | static void bus_put(struct bus_type *bus) |
44 | { | |
c6f7e72a GKH |
45 | if (bus) |
46 | kset_put(&bus->p->subsys); | |
fc1ede58 GKH |
47 | } |
48 | ||
4a3ad20c GKH |
49 | static ssize_t drv_attr_show(struct kobject *kobj, struct attribute *attr, |
50 | char *buf) | |
1da177e4 | 51 | { |
4a3ad20c | 52 | struct driver_attribute *drv_attr = to_drv_attr(attr); |
e5dd1278 | 53 | struct driver_private *drv_priv = to_driver(kobj); |
4a0c20bf | 54 | ssize_t ret = -EIO; |
1da177e4 LT |
55 | |
56 | if (drv_attr->show) | |
e5dd1278 | 57 | ret = drv_attr->show(drv_priv->driver, buf); |
1da177e4 LT |
58 | return ret; |
59 | } | |
60 | ||
4a3ad20c GKH |
61 | static ssize_t drv_attr_store(struct kobject *kobj, struct attribute *attr, |
62 | const char *buf, size_t count) | |
1da177e4 | 63 | { |
4a3ad20c | 64 | struct driver_attribute *drv_attr = to_drv_attr(attr); |
e5dd1278 | 65 | struct driver_private *drv_priv = to_driver(kobj); |
4a0c20bf | 66 | ssize_t ret = -EIO; |
1da177e4 LT |
67 | |
68 | if (drv_attr->store) | |
e5dd1278 | 69 | ret = drv_attr->store(drv_priv->driver, buf, count); |
1da177e4 LT |
70 | return ret; |
71 | } | |
72 | ||
73 | static struct sysfs_ops driver_sysfs_ops = { | |
74 | .show = drv_attr_show, | |
75 | .store = drv_attr_store, | |
76 | }; | |
77 | ||
e5dd1278 | 78 | static void driver_release(struct kobject *kobj) |
1da177e4 | 79 | { |
e5dd1278 GKH |
80 | struct driver_private *drv_priv = to_driver(kobj); |
81 | ||
7dc72b28 | 82 | pr_debug("driver: '%s': %s\n", kobject_name(kobj), __FUNCTION__); |
e5dd1278 | 83 | kfree(drv_priv); |
1da177e4 LT |
84 | } |
85 | ||
a1148fb0 | 86 | static struct kobj_type driver_ktype = { |
1da177e4 LT |
87 | .sysfs_ops = &driver_sysfs_ops, |
88 | .release = driver_release, | |
89 | }; | |
90 | ||
1da177e4 LT |
91 | /* |
92 | * sysfs bindings for buses | |
93 | */ | |
4a3ad20c GKH |
94 | static ssize_t bus_attr_show(struct kobject *kobj, struct attribute *attr, |
95 | char *buf) | |
1da177e4 | 96 | { |
4a3ad20c | 97 | struct bus_attribute *bus_attr = to_bus_attr(attr); |
c6f7e72a | 98 | struct bus_type_private *bus_priv = to_bus(kobj); |
1da177e4 LT |
99 | ssize_t ret = 0; |
100 | ||
101 | if (bus_attr->show) | |
c6f7e72a | 102 | ret = bus_attr->show(bus_priv->bus, buf); |
1da177e4 LT |
103 | return ret; |
104 | } | |
105 | ||
4a3ad20c GKH |
106 | static ssize_t bus_attr_store(struct kobject *kobj, struct attribute *attr, |
107 | const char *buf, size_t count) | |
1da177e4 | 108 | { |
4a3ad20c | 109 | struct bus_attribute *bus_attr = to_bus_attr(attr); |
c6f7e72a | 110 | struct bus_type_private *bus_priv = to_bus(kobj); |
1da177e4 LT |
111 | ssize_t ret = 0; |
112 | ||
113 | if (bus_attr->store) | |
c6f7e72a | 114 | ret = bus_attr->store(bus_priv->bus, buf, count); |
1da177e4 LT |
115 | return ret; |
116 | } | |
117 | ||
118 | static struct sysfs_ops bus_sysfs_ops = { | |
119 | .show = bus_attr_show, | |
120 | .store = bus_attr_store, | |
121 | }; | |
122 | ||
4a3ad20c | 123 | int bus_create_file(struct bus_type *bus, struct bus_attribute *attr) |
1da177e4 LT |
124 | { |
125 | int error; | |
5901d014 | 126 | if (bus_get(bus)) { |
c6f7e72a | 127 | error = sysfs_create_file(&bus->p->subsys.kobj, &attr->attr); |
fc1ede58 | 128 | bus_put(bus); |
1da177e4 LT |
129 | } else |
130 | error = -EINVAL; | |
131 | return error; | |
132 | } | |
4a3ad20c | 133 | EXPORT_SYMBOL_GPL(bus_create_file); |
1da177e4 | 134 | |
4a3ad20c | 135 | void bus_remove_file(struct bus_type *bus, struct bus_attribute *attr) |
1da177e4 | 136 | { |
5901d014 | 137 | if (bus_get(bus)) { |
c6f7e72a | 138 | sysfs_remove_file(&bus->p->subsys.kobj, &attr->attr); |
fc1ede58 | 139 | bus_put(bus); |
1da177e4 LT |
140 | } |
141 | } | |
4a3ad20c | 142 | EXPORT_SYMBOL_GPL(bus_remove_file); |
1da177e4 | 143 | |
80f03e34 | 144 | static struct kobj_type bus_ktype = { |
1da177e4 | 145 | .sysfs_ops = &bus_sysfs_ops, |
80f03e34 KS |
146 | }; |
147 | ||
148 | static int bus_uevent_filter(struct kset *kset, struct kobject *kobj) | |
149 | { | |
150 | struct kobj_type *ktype = get_ktype(kobj); | |
151 | ||
152 | if (ktype == &bus_ktype) | |
153 | return 1; | |
154 | return 0; | |
155 | } | |
1da177e4 | 156 | |
80f03e34 KS |
157 | static struct kset_uevent_ops bus_uevent_ops = { |
158 | .filter = bus_uevent_filter, | |
1da177e4 LT |
159 | }; |
160 | ||
59a54833 | 161 | static struct kset *bus_kset; |
1da177e4 | 162 | |
1da177e4 | 163 | |
2139bdd5 | 164 | #ifdef CONFIG_HOTPLUG |
2b08c8d0 | 165 | /* Manually detach a device from its associated driver. */ |
151ef38f GKH |
166 | static int driver_helper(struct device *dev, void *data) |
167 | { | |
168 | const char *name = data; | |
169 | ||
170 | if (strcmp(name, dev->bus_id) == 0) | |
171 | return 1; | |
172 | return 0; | |
173 | } | |
174 | ||
175 | static ssize_t driver_unbind(struct device_driver *drv, | |
176 | const char *buf, size_t count) | |
177 | { | |
5901d014 | 178 | struct bus_type *bus = bus_get(drv->bus); |
151ef38f GKH |
179 | struct device *dev; |
180 | int err = -ENODEV; | |
181 | ||
182 | dev = bus_find_device(bus, NULL, (void *)buf, driver_helper); | |
2b08c8d0 | 183 | if (dev && dev->driver == drv) { |
bf74ad5b AS |
184 | if (dev->parent) /* Needed for USB */ |
185 | down(&dev->parent->sem); | |
151ef38f | 186 | device_release_driver(dev); |
bf74ad5b AS |
187 | if (dev->parent) |
188 | up(&dev->parent->sem); | |
151ef38f GKH |
189 | err = count; |
190 | } | |
2b08c8d0 | 191 | put_device(dev); |
fc1ede58 | 192 | bus_put(bus); |
2b08c8d0 | 193 | return err; |
151ef38f GKH |
194 | } |
195 | static DRIVER_ATTR(unbind, S_IWUSR, NULL, driver_unbind); | |
196 | ||
afdce75f GKH |
197 | /* |
198 | * Manually attach a device to a driver. | |
199 | * Note: the driver must want to bind to the device, | |
200 | * it is not possible to override the driver's id table. | |
201 | */ | |
202 | static ssize_t driver_bind(struct device_driver *drv, | |
203 | const char *buf, size_t count) | |
204 | { | |
5901d014 | 205 | struct bus_type *bus = bus_get(drv->bus); |
afdce75f GKH |
206 | struct device *dev; |
207 | int err = -ENODEV; | |
208 | ||
209 | dev = bus_find_device(bus, NULL, (void *)buf, driver_helper); | |
2b08c8d0 | 210 | if (dev && dev->driver == NULL) { |
bf74ad5b AS |
211 | if (dev->parent) /* Needed for USB */ |
212 | down(&dev->parent->sem); | |
afdce75f GKH |
213 | down(&dev->sem); |
214 | err = driver_probe_device(drv, dev); | |
215 | up(&dev->sem); | |
bf74ad5b AS |
216 | if (dev->parent) |
217 | up(&dev->parent->sem); | |
37225401 | 218 | |
4a3ad20c GKH |
219 | if (err > 0) { |
220 | /* success */ | |
37225401 | 221 | err = count; |
4a3ad20c GKH |
222 | } else if (err == 0) { |
223 | /* driver didn't accept device */ | |
37225401 | 224 | err = -ENODEV; |
4a3ad20c | 225 | } |
afdce75f | 226 | } |
2b08c8d0 | 227 | put_device(dev); |
fc1ede58 | 228 | bus_put(bus); |
2b08c8d0 | 229 | return err; |
afdce75f GKH |
230 | } |
231 | static DRIVER_ATTR(bind, S_IWUSR, NULL, driver_bind); | |
232 | ||
b8c5cec2 KS |
233 | static ssize_t show_drivers_autoprobe(struct bus_type *bus, char *buf) |
234 | { | |
c6f7e72a | 235 | return sprintf(buf, "%d\n", bus->p->drivers_autoprobe); |
b8c5cec2 KS |
236 | } |
237 | ||
238 | static ssize_t store_drivers_autoprobe(struct bus_type *bus, | |
239 | const char *buf, size_t count) | |
240 | { | |
241 | if (buf[0] == '0') | |
c6f7e72a | 242 | bus->p->drivers_autoprobe = 0; |
b8c5cec2 | 243 | else |
c6f7e72a | 244 | bus->p->drivers_autoprobe = 1; |
b8c5cec2 KS |
245 | return count; |
246 | } | |
247 | ||
248 | static ssize_t store_drivers_probe(struct bus_type *bus, | |
249 | const char *buf, size_t count) | |
250 | { | |
251 | struct device *dev; | |
252 | ||
253 | dev = bus_find_device(bus, NULL, (void *)buf, driver_helper); | |
254 | if (!dev) | |
255 | return -ENODEV; | |
256 | if (bus_rescan_devices_helper(dev, NULL) != 0) | |
257 | return -EINVAL; | |
258 | return count; | |
259 | } | |
2139bdd5 | 260 | #endif |
151ef38f | 261 | |
4a3ad20c | 262 | static struct device *next_device(struct klist_iter *i) |
465c7a3a | 263 | { |
4a3ad20c | 264 | struct klist_node *n = klist_next(i); |
465c7a3a | 265 | return n ? container_of(n, struct device, knode_bus) : NULL; |
266 | } | |
267 | ||
1da177e4 | 268 | /** |
4a3ad20c GKH |
269 | * bus_for_each_dev - device iterator. |
270 | * @bus: bus type. | |
271 | * @start: device to start iterating from. | |
272 | * @data: data for the callback. | |
273 | * @fn: function to be called for each device. | |
1da177e4 | 274 | * |
4a3ad20c GKH |
275 | * Iterate over @bus's list of devices, and call @fn for each, |
276 | * passing it @data. If @start is not NULL, we use that device to | |
277 | * begin iterating from. | |
1da177e4 | 278 | * |
4a3ad20c GKH |
279 | * We check the return of @fn each time. If it returns anything |
280 | * other than 0, we break out and return that value. | |
1da177e4 | 281 | * |
4a3ad20c GKH |
282 | * NOTE: The device that returns a non-zero value is not retained |
283 | * in any way, nor is its refcount incremented. If the caller needs | |
284 | * to retain this data, it should do, and increment the reference | |
285 | * count in the supplied callback. | |
1da177e4 | 286 | */ |
4a3ad20c GKH |
287 | int bus_for_each_dev(struct bus_type *bus, struct device *start, |
288 | void *data, int (*fn)(struct device *, void *)) | |
1da177e4 | 289 | { |
465c7a3a | 290 | struct klist_iter i; |
4a3ad20c | 291 | struct device *dev; |
465c7a3a | 292 | int error = 0; |
1da177e4 | 293 | |
465c7a3a | 294 | if (!bus) |
295 | return -EINVAL; | |
296 | ||
c6f7e72a | 297 | klist_iter_init_node(&bus->p->klist_devices, &i, |
465c7a3a | 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 | 303 | } |
4a3ad20c | 304 | EXPORT_SYMBOL_GPL(bus_for_each_dev); |
1da177e4 | 305 | |
0edb5860 CH |
306 | /** |
307 | * bus_find_device - device iterator for locating a particular device. | |
308 | * @bus: bus type | |
309 | * @start: Device to begin with | |
310 | * @data: Data to pass to match function | |
311 | * @match: Callback function to check device | |
312 | * | |
313 | * This is similar to the bus_for_each_dev() function above, but it | |
314 | * returns a reference to a device that is 'found' for later use, as | |
315 | * determined by the @match callback. | |
316 | * | |
317 | * The callback should return 0 if the device doesn't match and non-zero | |
318 | * if it does. If the callback returns non-zero, this function will | |
319 | * return to the caller and not iterate over any more devices. | |
320 | */ | |
4a3ad20c GKH |
321 | struct device *bus_find_device(struct bus_type *bus, |
322 | struct device *start, void *data, | |
323 | int (*match)(struct device *dev, void *data)) | |
0edb5860 CH |
324 | { |
325 | struct klist_iter i; | |
326 | struct device *dev; | |
327 | ||
328 | if (!bus) | |
329 | return NULL; | |
330 | ||
c6f7e72a | 331 | klist_iter_init_node(&bus->p->klist_devices, &i, |
0edb5860 CH |
332 | (start ? &start->knode_bus : NULL)); |
333 | while ((dev = next_device(&i))) | |
334 | if (match(dev, data) && get_device(dev)) | |
335 | break; | |
336 | klist_iter_exit(&i); | |
337 | return dev; | |
338 | } | |
4a3ad20c | 339 | EXPORT_SYMBOL_GPL(bus_find_device); |
38fdac3c | 340 | |
4a3ad20c | 341 | static struct device_driver *next_driver(struct klist_iter *i) |
38fdac3c | 342 | { |
4a3ad20c | 343 | struct klist_node *n = klist_next(i); |
e5dd1278 GKH |
344 | struct driver_private *drv_priv; |
345 | ||
346 | if (n) { | |
347 | drv_priv = container_of(n, struct driver_private, knode_bus); | |
348 | return drv_priv->driver; | |
349 | } | |
350 | return NULL; | |
38fdac3c | 351 | } |
352 | ||
1da177e4 | 353 | /** |
4a3ad20c GKH |
354 | * bus_for_each_drv - driver iterator |
355 | * @bus: bus we're dealing with. | |
356 | * @start: driver to start iterating on. | |
357 | * @data: data to pass to the callback. | |
358 | * @fn: function to call for each driver. | |
1da177e4 | 359 | * |
4a3ad20c GKH |
360 | * This is nearly identical to the device iterator above. |
361 | * We iterate over each driver that belongs to @bus, and call | |
362 | * @fn for each. If @fn returns anything but 0, we break out | |
363 | * and return it. If @start is not NULL, we use it as the head | |
364 | * of the list. | |
1da177e4 | 365 | * |
4a3ad20c GKH |
366 | * NOTE: we don't return the driver that returns a non-zero |
367 | * value, nor do we leave the reference count incremented for that | |
368 | * driver. If the caller needs to know that info, it must set it | |
369 | * in the callback. It must also be sure to increment the refcount | |
370 | * so it doesn't disappear before returning to the caller. | |
1da177e4 | 371 | */ |
4a3ad20c GKH |
372 | int bus_for_each_drv(struct bus_type *bus, struct device_driver *start, |
373 | void *data, int (*fn)(struct device_driver *, void *)) | |
1da177e4 | 374 | { |
38fdac3c | 375 | struct klist_iter i; |
4a3ad20c | 376 | struct device_driver *drv; |
38fdac3c | 377 | int error = 0; |
1da177e4 | 378 | |
38fdac3c | 379 | if (!bus) |
380 | return -EINVAL; | |
381 | ||
c6f7e72a | 382 | klist_iter_init_node(&bus->p->klist_drivers, &i, |
e5dd1278 | 383 | start ? &start->p->knode_bus : NULL); |
38fdac3c | 384 | while ((drv = next_driver(&i)) && !error) |
385 | error = fn(drv, data); | |
386 | klist_iter_exit(&i); | |
387 | return error; | |
1da177e4 | 388 | } |
4a3ad20c | 389 | EXPORT_SYMBOL_GPL(bus_for_each_drv); |
1da177e4 | 390 | |
4aca67e5 | 391 | static int device_add_attrs(struct bus_type *bus, struct device *dev) |
1da177e4 LT |
392 | { |
393 | int error = 0; | |
394 | int i; | |
395 | ||
4aca67e5 AM |
396 | if (!bus->dev_attrs) |
397 | return 0; | |
398 | ||
399 | for (i = 0; attr_name(bus->dev_attrs[i]); i++) { | |
4a3ad20c | 400 | error = device_create_file(dev, &bus->dev_attrs[i]); |
4aca67e5 AM |
401 | if (error) { |
402 | while (--i >= 0) | |
403 | device_remove_file(dev, &bus->dev_attrs[i]); | |
404 | break; | |
1da177e4 LT |
405 | } |
406 | } | |
1da177e4 | 407 | return error; |
1da177e4 LT |
408 | } |
409 | ||
4a3ad20c | 410 | static void device_remove_attrs(struct bus_type *bus, struct device *dev) |
1da177e4 LT |
411 | { |
412 | int i; | |
413 | ||
414 | if (bus->dev_attrs) { | |
415 | for (i = 0; attr_name(bus->dev_attrs[i]); i++) | |
4a3ad20c | 416 | device_remove_file(dev, &bus->dev_attrs[i]); |
1da177e4 LT |
417 | } |
418 | } | |
419 | ||
b9cafc7d KS |
420 | #ifdef CONFIG_SYSFS_DEPRECATED |
421 | static int make_deprecated_bus_links(struct device *dev) | |
422 | { | |
423 | return sysfs_create_link(&dev->kobj, | |
c6f7e72a | 424 | &dev->bus->p->subsys.kobj, "bus"); |
b9cafc7d KS |
425 | } |
426 | ||
427 | static void remove_deprecated_bus_links(struct device *dev) | |
428 | { | |
429 | sysfs_remove_link(&dev->kobj, "bus"); | |
430 | } | |
431 | #else | |
432 | static inline int make_deprecated_bus_links(struct device *dev) { return 0; } | |
433 | static inline void remove_deprecated_bus_links(struct device *dev) { } | |
434 | #endif | |
1da177e4 LT |
435 | |
436 | /** | |
4a3ad20c GKH |
437 | * bus_add_device - add device to bus |
438 | * @dev: device being added | |
1da177e4 | 439 | * |
4a3ad20c GKH |
440 | * - Add the device to its bus's list of devices. |
441 | * - Create link to device's bus. | |
1da177e4 | 442 | */ |
4a3ad20c | 443 | int bus_add_device(struct device *dev) |
1da177e4 | 444 | { |
4a3ad20c | 445 | struct bus_type *bus = bus_get(dev->bus); |
1da177e4 LT |
446 | int error = 0; |
447 | ||
448 | if (bus) { | |
7dc72b28 | 449 | pr_debug("bus: '%s': add device %s\n", bus->name, dev->bus_id); |
d377e85b | 450 | error = device_add_attrs(bus, dev); |
f86db396 | 451 | if (error) |
513e7337 | 452 | goto out_put; |
c6f7e72a | 453 | error = sysfs_create_link(&bus->p->devices_kset->kobj, |
f86db396 AM |
454 | &dev->kobj, dev->bus_id); |
455 | if (error) | |
513e7337 | 456 | goto out_id; |
f86db396 | 457 | error = sysfs_create_link(&dev->kobj, |
c6f7e72a | 458 | &dev->bus->p->subsys.kobj, "subsystem"); |
f86db396 | 459 | if (error) |
513e7337 | 460 | goto out_subsys; |
b9cafc7d | 461 | error = make_deprecated_bus_links(dev); |
513e7337 CH |
462 | if (error) |
463 | goto out_deprecated; | |
1da177e4 | 464 | } |
513e7337 CH |
465 | return 0; |
466 | ||
467 | out_deprecated: | |
468 | sysfs_remove_link(&dev->kobj, "subsystem"); | |
469 | out_subsys: | |
c6f7e72a | 470 | sysfs_remove_link(&bus->p->devices_kset->kobj, dev->bus_id); |
513e7337 CH |
471 | out_id: |
472 | device_remove_attrs(bus, dev); | |
473 | out_put: | |
fc1ede58 | 474 | bus_put(dev->bus); |
1da177e4 LT |
475 | return error; |
476 | } | |
477 | ||
53877d06 | 478 | /** |
4a3ad20c GKH |
479 | * bus_attach_device - add device to bus |
480 | * @dev: device tried to attach to a driver | |
53877d06 | 481 | * |
4a3ad20c GKH |
482 | * - Add device to bus's list of devices. |
483 | * - Try to attach to driver. | |
53877d06 | 484 | */ |
4a3ad20c | 485 | void bus_attach_device(struct device *dev) |
53877d06 | 486 | { |
f86db396 AM |
487 | struct bus_type *bus = dev->bus; |
488 | int ret = 0; | |
53877d06 KS |
489 | |
490 | if (bus) { | |
f2eaae19 | 491 | dev->is_registered = 1; |
c6f7e72a | 492 | if (bus->p->drivers_autoprobe) |
b8c5cec2 | 493 | ret = device_attach(dev); |
c6a46696 CH |
494 | WARN_ON(ret < 0); |
495 | if (ret >= 0) | |
c6f7e72a | 496 | klist_add_tail(&dev->knode_bus, &bus->p->klist_devices); |
c6a46696 | 497 | else |
f2eaae19 | 498 | dev->is_registered = 0; |
53877d06 KS |
499 | } |
500 | } | |
501 | ||
1da177e4 | 502 | /** |
4a3ad20c GKH |
503 | * bus_remove_device - remove device from bus |
504 | * @dev: device to be removed | |
1da177e4 | 505 | * |
4a3ad20c GKH |
506 | * - Remove symlink from bus's directory. |
507 | * - Delete device from bus's list. | |
508 | * - Detach from its driver. | |
509 | * - Drop reference taken in bus_add_device(). | |
1da177e4 | 510 | */ |
4a3ad20c | 511 | void bus_remove_device(struct device *dev) |
1da177e4 LT |
512 | { |
513 | if (dev->bus) { | |
b9d9c82b | 514 | sysfs_remove_link(&dev->kobj, "subsystem"); |
b9cafc7d | 515 | remove_deprecated_bus_links(dev); |
4a3ad20c GKH |
516 | sysfs_remove_link(&dev->bus->p->devices_kset->kobj, |
517 | dev->bus_id); | |
1da177e4 | 518 | device_remove_attrs(dev->bus, dev); |
f70fa629 AS |
519 | if (dev->is_registered) { |
520 | dev->is_registered = 0; | |
521 | klist_del(&dev->knode_bus); | |
522 | } | |
4a3ad20c GKH |
523 | pr_debug("bus: '%s': remove device %s\n", |
524 | dev->bus->name, dev->bus_id); | |
1da177e4 | 525 | device_release_driver(dev); |
fc1ede58 | 526 | bus_put(dev->bus); |
1da177e4 LT |
527 | } |
528 | } | |
529 | ||
4a3ad20c | 530 | static int driver_add_attrs(struct bus_type *bus, struct device_driver *drv) |
1da177e4 LT |
531 | { |
532 | int error = 0; | |
533 | int i; | |
534 | ||
535 | if (bus->drv_attrs) { | |
536 | for (i = 0; attr_name(bus->drv_attrs[i]); i++) { | |
537 | error = driver_create_file(drv, &bus->drv_attrs[i]); | |
538 | if (error) | |
4a3ad20c | 539 | goto err; |
1da177e4 LT |
540 | } |
541 | } | |
4a3ad20c | 542 | done: |
1da177e4 | 543 | return error; |
4a3ad20c | 544 | err: |
1da177e4 LT |
545 | while (--i >= 0) |
546 | driver_remove_file(drv, &bus->drv_attrs[i]); | |
4a3ad20c | 547 | goto done; |
1da177e4 LT |
548 | } |
549 | ||
4a3ad20c GKH |
550 | static void driver_remove_attrs(struct bus_type *bus, |
551 | struct device_driver *drv) | |
1da177e4 LT |
552 | { |
553 | int i; | |
554 | ||
555 | if (bus->drv_attrs) { | |
556 | for (i = 0; attr_name(bus->drv_attrs[i]); i++) | |
557 | driver_remove_file(drv, &bus->drv_attrs[i]); | |
558 | } | |
559 | } | |
560 | ||
874c6241 GKH |
561 | #ifdef CONFIG_HOTPLUG |
562 | /* | |
563 | * Thanks to drivers making their tables __devinit, we can't allow manual | |
564 | * bind and unbind from userspace unless CONFIG_HOTPLUG is enabled. | |
565 | */ | |
f86db396 | 566 | static int __must_check add_bind_files(struct device_driver *drv) |
874c6241 | 567 | { |
f86db396 AM |
568 | int ret; |
569 | ||
570 | ret = driver_create_file(drv, &driver_attr_unbind); | |
571 | if (ret == 0) { | |
572 | ret = driver_create_file(drv, &driver_attr_bind); | |
573 | if (ret) | |
574 | driver_remove_file(drv, &driver_attr_unbind); | |
575 | } | |
576 | return ret; | |
874c6241 GKH |
577 | } |
578 | ||
579 | static void remove_bind_files(struct device_driver *drv) | |
580 | { | |
581 | driver_remove_file(drv, &driver_attr_bind); | |
582 | driver_remove_file(drv, &driver_attr_unbind); | |
583 | } | |
b8c5cec2 | 584 | |
8380770c KS |
585 | static BUS_ATTR(drivers_probe, S_IWUSR, NULL, store_drivers_probe); |
586 | static BUS_ATTR(drivers_autoprobe, S_IWUSR | S_IRUGO, | |
587 | show_drivers_autoprobe, store_drivers_autoprobe); | |
588 | ||
b8c5cec2 KS |
589 | static int add_probe_files(struct bus_type *bus) |
590 | { | |
591 | int retval; | |
592 | ||
8380770c | 593 | retval = bus_create_file(bus, &bus_attr_drivers_probe); |
b8c5cec2 KS |
594 | if (retval) |
595 | goto out; | |
596 | ||
8380770c | 597 | retval = bus_create_file(bus, &bus_attr_drivers_autoprobe); |
b8c5cec2 | 598 | if (retval) |
8380770c | 599 | bus_remove_file(bus, &bus_attr_drivers_probe); |
b8c5cec2 KS |
600 | out: |
601 | return retval; | |
602 | } | |
603 | ||
604 | static void remove_probe_files(struct bus_type *bus) | |
605 | { | |
8380770c KS |
606 | bus_remove_file(bus, &bus_attr_drivers_autoprobe); |
607 | bus_remove_file(bus, &bus_attr_drivers_probe); | |
b8c5cec2 | 608 | } |
874c6241 | 609 | #else |
35acfdd7 | 610 | static inline int add_bind_files(struct device_driver *drv) { return 0; } |
874c6241 | 611 | static inline void remove_bind_files(struct device_driver *drv) {} |
b8c5cec2 KS |
612 | static inline int add_probe_files(struct bus_type *bus) { return 0; } |
613 | static inline void remove_probe_files(struct bus_type *bus) {} | |
874c6241 | 614 | #endif |
1da177e4 | 615 | |
7ac1cf4a KS |
616 | static ssize_t driver_uevent_store(struct device_driver *drv, |
617 | const char *buf, size_t count) | |
618 | { | |
619 | enum kobject_action action; | |
620 | ||
621 | if (kobject_action_type(buf, count, &action) == 0) | |
e5dd1278 | 622 | kobject_uevent(&drv->p->kobj, action); |
7ac1cf4a KS |
623 | return count; |
624 | } | |
625 | static DRIVER_ATTR(uevent, S_IWUSR, NULL, driver_uevent_store); | |
626 | ||
1da177e4 | 627 | /** |
4a3ad20c GKH |
628 | * bus_add_driver - Add a driver to the bus. |
629 | * @drv: driver. | |
1da177e4 | 630 | */ |
f86db396 | 631 | int bus_add_driver(struct device_driver *drv) |
1da177e4 | 632 | { |
e5dd1278 GKH |
633 | struct bus_type *bus; |
634 | struct driver_private *priv; | |
1da177e4 LT |
635 | int error = 0; |
636 | ||
e5dd1278 | 637 | bus = bus_get(drv->bus); |
d9fd4d3b | 638 | if (!bus) |
4f6e1945 | 639 | return -EINVAL; |
d9fd4d3b | 640 | |
7dc72b28 | 641 | pr_debug("bus: '%s': add driver %s\n", bus->name, drv->name); |
e5dd1278 GKH |
642 | |
643 | priv = kzalloc(sizeof(*priv), GFP_KERNEL); | |
644 | if (!priv) | |
645 | return -ENOMEM; | |
646 | ||
e5dd1278 GKH |
647 | klist_init(&priv->klist_devices, NULL, NULL); |
648 | priv->driver = drv; | |
649 | drv->p = priv; | |
c8e90d82 GKH |
650 | priv->kobj.kset = bus->p->drivers_kset; |
651 | error = kobject_init_and_add(&priv->kobj, &driver_ktype, NULL, | |
652 | "%s", drv->name); | |
dc0afa83 | 653 | if (error) |
d9fd4d3b JG |
654 | goto out_put_bus; |
655 | ||
c6f7e72a | 656 | if (drv->bus->p->drivers_autoprobe) { |
b8c5cec2 KS |
657 | error = driver_attach(drv); |
658 | if (error) | |
659 | goto out_unregister; | |
660 | } | |
e5dd1278 | 661 | klist_add_tail(&priv->knode_bus, &bus->p->klist_drivers); |
d9fd4d3b JG |
662 | module_add_driver(drv->owner, drv); |
663 | ||
7ac1cf4a KS |
664 | error = driver_create_file(drv, &driver_attr_uevent); |
665 | if (error) { | |
666 | printk(KERN_ERR "%s: uevent attr (%s) failed\n", | |
667 | __FUNCTION__, drv->name); | |
668 | } | |
d9fd4d3b JG |
669 | error = driver_add_attrs(bus, drv); |
670 | if (error) { | |
671 | /* How the hell do we get out of this pickle? Give up */ | |
672 | printk(KERN_ERR "%s: driver_add_attrs(%s) failed\n", | |
673 | __FUNCTION__, drv->name); | |
674 | } | |
675 | error = add_bind_files(drv); | |
676 | if (error) { | |
677 | /* Ditto */ | |
678 | printk(KERN_ERR "%s: add_bind_files(%s) failed\n", | |
679 | __FUNCTION__, drv->name); | |
1da177e4 | 680 | } |
d9fd4d3b | 681 | |
c8e90d82 | 682 | kobject_uevent(&priv->kobj, KOBJ_ADD); |
1da177e4 | 683 | return error; |
f86db396 | 684 | out_unregister: |
c10997f6 | 685 | kobject_put(&priv->kobj); |
f86db396 | 686 | out_put_bus: |
fc1ede58 | 687 | bus_put(bus); |
f86db396 | 688 | return error; |
1da177e4 LT |
689 | } |
690 | ||
1da177e4 | 691 | /** |
4a3ad20c GKH |
692 | * bus_remove_driver - delete driver from bus's knowledge. |
693 | * @drv: driver. | |
1da177e4 | 694 | * |
4a3ad20c GKH |
695 | * Detach the driver from the devices it controls, and remove |
696 | * it from its bus's list of drivers. Finally, we drop the reference | |
697 | * to the bus we took in bus_add_driver(). | |
1da177e4 | 698 | */ |
4a3ad20c | 699 | void bus_remove_driver(struct device_driver *drv) |
1da177e4 | 700 | { |
d9fd4d3b JG |
701 | if (!drv->bus) |
702 | return; | |
703 | ||
704 | remove_bind_files(drv); | |
705 | driver_remove_attrs(drv->bus, drv); | |
7ac1cf4a | 706 | driver_remove_file(drv, &driver_attr_uevent); |
e5dd1278 | 707 | klist_remove(&drv->p->knode_bus); |
7dc72b28 | 708 | pr_debug("bus: '%s': remove driver %s\n", drv->bus->name, drv->name); |
d9fd4d3b JG |
709 | driver_detach(drv); |
710 | module_remove_driver(drv); | |
c10997f6 | 711 | kobject_put(&drv->p->kobj); |
fc1ede58 | 712 | bus_put(drv->bus); |
1da177e4 LT |
713 | } |
714 | ||
1da177e4 | 715 | /* Helper for bus_rescan_devices's iter */ |
f86db396 | 716 | static int __must_check bus_rescan_devices_helper(struct device *dev, |
4a3ad20c | 717 | void *data) |
1da177e4 | 718 | { |
f86db396 AM |
719 | int ret = 0; |
720 | ||
bf74ad5b AS |
721 | if (!dev->driver) { |
722 | if (dev->parent) /* Needed for USB */ | |
723 | down(&dev->parent->sem); | |
f86db396 | 724 | ret = device_attach(dev); |
bf74ad5b AS |
725 | if (dev->parent) |
726 | up(&dev->parent->sem); | |
727 | } | |
f86db396 | 728 | return ret < 0 ? ret : 0; |
1da177e4 LT |
729 | } |
730 | ||
1da177e4 | 731 | /** |
23d3d602 GKH |
732 | * bus_rescan_devices - rescan devices on the bus for possible drivers |
733 | * @bus: the bus to scan. | |
1da177e4 | 734 | * |
23d3d602 GKH |
735 | * This function will look for devices on the bus with no driver |
736 | * attached and rescan it against existing drivers to see if it matches | |
737 | * any by calling device_attach() for the unbound devices. | |
1da177e4 | 738 | */ |
4a3ad20c | 739 | int bus_rescan_devices(struct bus_type *bus) |
1da177e4 | 740 | { |
f86db396 | 741 | return bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper); |
1da177e4 | 742 | } |
4a3ad20c | 743 | EXPORT_SYMBOL_GPL(bus_rescan_devices); |
1da177e4 | 744 | |
e935d5da ME |
745 | /** |
746 | * device_reprobe - remove driver for a device and probe for a new driver | |
747 | * @dev: the device to reprobe | |
748 | * | |
749 | * This function detaches the attached driver (if any) for the given | |
750 | * device and restarts the driver probing process. It is intended | |
751 | * to use if probing criteria changed during a devices lifetime and | |
752 | * driver attachment should change accordingly. | |
753 | */ | |
f86db396 | 754 | int device_reprobe(struct device *dev) |
e935d5da ME |
755 | { |
756 | if (dev->driver) { | |
757 | if (dev->parent) /* Needed for USB */ | |
758 | down(&dev->parent->sem); | |
759 | device_release_driver(dev); | |
760 | if (dev->parent) | |
761 | up(&dev->parent->sem); | |
762 | } | |
f86db396 | 763 | return bus_rescan_devices_helper(dev, NULL); |
e935d5da ME |
764 | } |
765 | EXPORT_SYMBOL_GPL(device_reprobe); | |
1da177e4 | 766 | |
1da177e4 | 767 | /** |
4a3ad20c GKH |
768 | * find_bus - locate bus by name. |
769 | * @name: name of bus. | |
1da177e4 | 770 | * |
4a3ad20c GKH |
771 | * Call kset_find_obj() to iterate over list of buses to |
772 | * find a bus by name. Return bus if found. | |
1da177e4 | 773 | * |
4a3ad20c | 774 | * Note that kset_find_obj increments bus' reference count. |
1da177e4 | 775 | */ |
7e4ef085 | 776 | #if 0 |
4a3ad20c | 777 | struct bus_type *find_bus(char *name) |
1da177e4 | 778 | { |
4a3ad20c | 779 | struct kobject *k = kset_find_obj(bus_kset, name); |
1da177e4 LT |
780 | return k ? to_bus(k) : NULL; |
781 | } | |
7e4ef085 | 782 | #endif /* 0 */ |
1da177e4 LT |
783 | |
784 | ||
785 | /** | |
4a3ad20c GKH |
786 | * bus_add_attrs - Add default attributes for this bus. |
787 | * @bus: Bus that has just been registered. | |
1da177e4 LT |
788 | */ |
789 | ||
4a3ad20c | 790 | static int bus_add_attrs(struct bus_type *bus) |
1da177e4 LT |
791 | { |
792 | int error = 0; | |
793 | int i; | |
794 | ||
795 | if (bus->bus_attrs) { | |
796 | for (i = 0; attr_name(bus->bus_attrs[i]); i++) { | |
4a3ad20c | 797 | error = bus_create_file(bus, &bus->bus_attrs[i]); |
dc0afa83 | 798 | if (error) |
4a3ad20c | 799 | goto err; |
1da177e4 LT |
800 | } |
801 | } | |
4a3ad20c | 802 | done: |
1da177e4 | 803 | return error; |
4a3ad20c | 804 | err: |
1da177e4 | 805 | while (--i >= 0) |
4a3ad20c GKH |
806 | bus_remove_file(bus, &bus->bus_attrs[i]); |
807 | goto done; | |
1da177e4 LT |
808 | } |
809 | ||
4a3ad20c | 810 | static void bus_remove_attrs(struct bus_type *bus) |
1da177e4 LT |
811 | { |
812 | int i; | |
813 | ||
814 | if (bus->bus_attrs) { | |
815 | for (i = 0; attr_name(bus->bus_attrs[i]); i++) | |
4a3ad20c | 816 | bus_remove_file(bus, &bus->bus_attrs[i]); |
1da177e4 LT |
817 | } |
818 | } | |
819 | ||
34bb61f9 JB |
820 | static void klist_devices_get(struct klist_node *n) |
821 | { | |
822 | struct device *dev = container_of(n, struct device, knode_bus); | |
823 | ||
824 | get_device(dev); | |
825 | } | |
826 | ||
827 | static void klist_devices_put(struct klist_node *n) | |
828 | { | |
829 | struct device *dev = container_of(n, struct device, knode_bus); | |
830 | ||
831 | put_device(dev); | |
832 | } | |
833 | ||
7ac1cf4a KS |
834 | static ssize_t bus_uevent_store(struct bus_type *bus, |
835 | const char *buf, size_t count) | |
836 | { | |
837 | enum kobject_action action; | |
838 | ||
839 | if (kobject_action_type(buf, count, &action) == 0) | |
c6f7e72a | 840 | kobject_uevent(&bus->p->subsys.kobj, action); |
7ac1cf4a KS |
841 | return count; |
842 | } | |
843 | static BUS_ATTR(uevent, S_IWUSR, NULL, bus_uevent_store); | |
844 | ||
1da177e4 | 845 | /** |
4a3ad20c GKH |
846 | * bus_register - register a bus with the system. |
847 | * @bus: bus. | |
1da177e4 | 848 | * |
4a3ad20c GKH |
849 | * Once we have that, we registered the bus with the kobject |
850 | * infrastructure, then register the children subsystems it has: | |
851 | * the devices and drivers that belong to the bus. | |
1da177e4 | 852 | */ |
4a3ad20c | 853 | int bus_register(struct bus_type *bus) |
1da177e4 LT |
854 | { |
855 | int retval; | |
c6f7e72a GKH |
856 | struct bus_type_private *priv; |
857 | ||
858 | priv = kzalloc(sizeof(struct bus_type_private), GFP_KERNEL); | |
859 | if (!priv) | |
860 | return -ENOMEM; | |
861 | ||
862 | priv->bus = bus; | |
863 | bus->p = priv; | |
1da177e4 | 864 | |
c6f7e72a | 865 | BLOCKING_INIT_NOTIFIER_HEAD(&priv->bus_notifier); |
116af378 | 866 | |
c6f7e72a | 867 | retval = kobject_set_name(&priv->subsys.kobj, "%s", bus->name); |
1da177e4 LT |
868 | if (retval) |
869 | goto out; | |
870 | ||
c6f7e72a GKH |
871 | priv->subsys.kobj.kset = bus_kset; |
872 | priv->subsys.kobj.ktype = &bus_ktype; | |
873 | priv->drivers_autoprobe = 1; | |
d6b05b84 | 874 | |
c6f7e72a | 875 | retval = kset_register(&priv->subsys); |
1da177e4 LT |
876 | if (retval) |
877 | goto out; | |
878 | ||
7ac1cf4a KS |
879 | retval = bus_create_file(bus, &bus_attr_uevent); |
880 | if (retval) | |
881 | goto bus_uevent_fail; | |
882 | ||
c6f7e72a GKH |
883 | priv->devices_kset = kset_create_and_add("devices", NULL, |
884 | &priv->subsys.kobj); | |
885 | if (!priv->devices_kset) { | |
3d899596 | 886 | retval = -ENOMEM; |
1da177e4 | 887 | goto bus_devices_fail; |
3d899596 | 888 | } |
1da177e4 | 889 | |
c6f7e72a GKH |
890 | priv->drivers_kset = kset_create_and_add("drivers", NULL, |
891 | &priv->subsys.kobj); | |
892 | if (!priv->drivers_kset) { | |
6dcec251 | 893 | retval = -ENOMEM; |
1da177e4 | 894 | goto bus_drivers_fail; |
6dcec251 | 895 | } |
465c7a3a | 896 | |
c6f7e72a GKH |
897 | klist_init(&priv->klist_devices, klist_devices_get, klist_devices_put); |
898 | klist_init(&priv->klist_drivers, NULL, NULL); | |
b8c5cec2 | 899 | |
b8c5cec2 KS |
900 | retval = add_probe_files(bus); |
901 | if (retval) | |
902 | goto bus_probe_files_fail; | |
903 | ||
1bb6881a CH |
904 | retval = bus_add_attrs(bus); |
905 | if (retval) | |
906 | goto bus_attrs_fail; | |
1da177e4 | 907 | |
7dc72b28 | 908 | pr_debug("bus: '%s': registered\n", bus->name); |
1da177e4 LT |
909 | return 0; |
910 | ||
1bb6881a | 911 | bus_attrs_fail: |
b8c5cec2 KS |
912 | remove_probe_files(bus); |
913 | bus_probe_files_fail: | |
c6f7e72a | 914 | kset_unregister(bus->p->drivers_kset); |
1da177e4 | 915 | bus_drivers_fail: |
c6f7e72a | 916 | kset_unregister(bus->p->devices_kset); |
1da177e4 | 917 | bus_devices_fail: |
7ac1cf4a KS |
918 | bus_remove_file(bus, &bus_attr_uevent); |
919 | bus_uevent_fail: | |
c6f7e72a GKH |
920 | kset_unregister(&bus->p->subsys); |
921 | kfree(bus->p); | |
1da177e4 LT |
922 | out: |
923 | return retval; | |
924 | } | |
4a3ad20c | 925 | EXPORT_SYMBOL_GPL(bus_register); |
1da177e4 | 926 | |
1da177e4 | 927 | /** |
4a3ad20c GKH |
928 | * bus_unregister - remove a bus from the system |
929 | * @bus: bus. | |
1da177e4 | 930 | * |
4a3ad20c GKH |
931 | * Unregister the child subsystems and the bus itself. |
932 | * Finally, we call bus_put() to release the refcount | |
1da177e4 | 933 | */ |
4a3ad20c | 934 | void bus_unregister(struct bus_type *bus) |
1da177e4 | 935 | { |
7dc72b28 | 936 | pr_debug("bus: '%s': unregistering\n", bus->name); |
1da177e4 | 937 | bus_remove_attrs(bus); |
b8c5cec2 | 938 | remove_probe_files(bus); |
c6f7e72a GKH |
939 | kset_unregister(bus->p->drivers_kset); |
940 | kset_unregister(bus->p->devices_kset); | |
7ac1cf4a | 941 | bus_remove_file(bus, &bus_attr_uevent); |
c6f7e72a GKH |
942 | kset_unregister(&bus->p->subsys); |
943 | kfree(bus->p); | |
1da177e4 | 944 | } |
4a3ad20c | 945 | EXPORT_SYMBOL_GPL(bus_unregister); |
1da177e4 | 946 | |
116af378 BH |
947 | int bus_register_notifier(struct bus_type *bus, struct notifier_block *nb) |
948 | { | |
c6f7e72a | 949 | return blocking_notifier_chain_register(&bus->p->bus_notifier, nb); |
116af378 BH |
950 | } |
951 | EXPORT_SYMBOL_GPL(bus_register_notifier); | |
952 | ||
953 | int bus_unregister_notifier(struct bus_type *bus, struct notifier_block *nb) | |
954 | { | |
c6f7e72a | 955 | return blocking_notifier_chain_unregister(&bus->p->bus_notifier, nb); |
116af378 BH |
956 | } |
957 | EXPORT_SYMBOL_GPL(bus_unregister_notifier); | |
958 | ||
0fed80f7 GKH |
959 | struct kset *bus_get_kset(struct bus_type *bus) |
960 | { | |
c6f7e72a | 961 | return &bus->p->subsys; |
0fed80f7 GKH |
962 | } |
963 | EXPORT_SYMBOL_GPL(bus_get_kset); | |
964 | ||
b249072e GKH |
965 | struct klist *bus_get_device_klist(struct bus_type *bus) |
966 | { | |
c6f7e72a | 967 | return &bus->p->klist_devices; |
b249072e GKH |
968 | } |
969 | EXPORT_SYMBOL_GPL(bus_get_device_klist); | |
970 | ||
1da177e4 LT |
971 | int __init buses_init(void) |
972 | { | |
59a54833 GKH |
973 | bus_kset = kset_create_and_add("bus", &bus_uevent_ops, NULL); |
974 | if (!bus_kset) | |
975 | return -ENOMEM; | |
976 | return 0; | |
1da177e4 | 977 | } |