diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/base/bus.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'drivers/base/bus.c')
-rw-r--r-- | drivers/base/bus.c | 770 |
1 files changed, 770 insertions, 0 deletions
diff --git a/drivers/base/bus.c b/drivers/base/bus.c new file mode 100644 index 000000000000..f4fa27315fb4 --- /dev/null +++ b/drivers/base/bus.c | |||
@@ -0,0 +1,770 @@ | |||
1 | /* | ||
2 | * bus.c - bus driver management | ||
3 | * | ||
4 | * Copyright (c) 2002-3 Patrick Mochel | ||
5 | * Copyright (c) 2002-3 Open Source Development Labs | ||
6 | * | ||
7 | * This file is released under the GPLv2 | ||
8 | * | ||
9 | */ | ||
10 | |||
11 | #include <linux/config.h> | ||
12 | #include <linux/device.h> | ||
13 | #include <linux/module.h> | ||
14 | #include <linux/errno.h> | ||
15 | #include <linux/init.h> | ||
16 | #include <linux/string.h> | ||
17 | #include "base.h" | ||
18 | #include "power/power.h" | ||
19 | |||
20 | #define to_dev(node) container_of(node, struct device, bus_list) | ||
21 | #define to_drv(node) container_of(node, struct device_driver, kobj.entry) | ||
22 | |||
23 | #define to_bus_attr(_attr) container_of(_attr, struct bus_attribute, attr) | ||
24 | #define to_bus(obj) container_of(obj, struct bus_type, subsys.kset.kobj) | ||
25 | |||
26 | /* | ||
27 | * sysfs bindings for drivers | ||
28 | */ | ||
29 | |||
30 | #define to_drv_attr(_attr) container_of(_attr, struct driver_attribute, attr) | ||
31 | #define to_driver(obj) container_of(obj, struct device_driver, kobj) | ||
32 | |||
33 | |||
34 | static ssize_t | ||
35 | drv_attr_show(struct kobject * kobj, struct attribute * attr, char * buf) | ||
36 | { | ||
37 | struct driver_attribute * drv_attr = to_drv_attr(attr); | ||
38 | struct device_driver * drv = to_driver(kobj); | ||
39 | ssize_t ret = 0; | ||
40 | |||
41 | if (drv_attr->show) | ||
42 | ret = drv_attr->show(drv, buf); | ||
43 | return ret; | ||
44 | } | ||
45 | |||
46 | static ssize_t | ||
47 | drv_attr_store(struct kobject * kobj, struct attribute * attr, | ||
48 | const char * buf, size_t count) | ||
49 | { | ||
50 | struct driver_attribute * drv_attr = to_drv_attr(attr); | ||
51 | struct device_driver * drv = to_driver(kobj); | ||
52 | ssize_t ret = 0; | ||
53 | |||
54 | if (drv_attr->store) | ||
55 | ret = drv_attr->store(drv, buf, count); | ||
56 | return ret; | ||
57 | } | ||
58 | |||
59 | static struct sysfs_ops driver_sysfs_ops = { | ||
60 | .show = drv_attr_show, | ||
61 | .store = drv_attr_store, | ||
62 | }; | ||
63 | |||
64 | |||
65 | static void driver_release(struct kobject * kobj) | ||
66 | { | ||
67 | struct device_driver * drv = to_driver(kobj); | ||
68 | complete(&drv->unloaded); | ||
69 | } | ||
70 | |||
71 | static struct kobj_type ktype_driver = { | ||
72 | .sysfs_ops = &driver_sysfs_ops, | ||
73 | .release = driver_release, | ||
74 | }; | ||
75 | |||
76 | |||
77 | /* | ||
78 | * sysfs bindings for buses | ||
79 | */ | ||
80 | |||
81 | |||
82 | static ssize_t | ||
83 | bus_attr_show(struct kobject * kobj, struct attribute * attr, char * buf) | ||
84 | { | ||
85 | struct bus_attribute * bus_attr = to_bus_attr(attr); | ||
86 | struct bus_type * bus = to_bus(kobj); | ||
87 | ssize_t ret = 0; | ||
88 | |||
89 | if (bus_attr->show) | ||
90 | ret = bus_attr->show(bus, buf); | ||
91 | return ret; | ||
92 | } | ||
93 | |||
94 | static ssize_t | ||
95 | bus_attr_store(struct kobject * kobj, struct attribute * attr, | ||
96 | const char * buf, size_t count) | ||
97 | { | ||
98 | struct bus_attribute * bus_attr = to_bus_attr(attr); | ||
99 | struct bus_type * bus = to_bus(kobj); | ||
100 | ssize_t ret = 0; | ||
101 | |||
102 | if (bus_attr->store) | ||
103 | ret = bus_attr->store(bus, buf, count); | ||
104 | return ret; | ||
105 | } | ||
106 | |||
107 | static struct sysfs_ops bus_sysfs_ops = { | ||
108 | .show = bus_attr_show, | ||
109 | .store = bus_attr_store, | ||
110 | }; | ||
111 | |||
112 | int bus_create_file(struct bus_type * bus, struct bus_attribute * attr) | ||
113 | { | ||
114 | int error; | ||
115 | if (get_bus(bus)) { | ||
116 | error = sysfs_create_file(&bus->subsys.kset.kobj, &attr->attr); | ||
117 | put_bus(bus); | ||
118 | } else | ||
119 | error = -EINVAL; | ||
120 | return error; | ||
121 | } | ||
122 | |||
123 | void bus_remove_file(struct bus_type * bus, struct bus_attribute * attr) | ||
124 | { | ||
125 | if (get_bus(bus)) { | ||
126 | sysfs_remove_file(&bus->subsys.kset.kobj, &attr->attr); | ||
127 | put_bus(bus); | ||
128 | } | ||
129 | } | ||
130 | |||
131 | static struct kobj_type ktype_bus = { | ||
132 | .sysfs_ops = &bus_sysfs_ops, | ||
133 | |||
134 | }; | ||
135 | |||
136 | decl_subsys(bus, &ktype_bus, NULL); | ||
137 | |||
138 | static int __bus_for_each_dev(struct bus_type *bus, struct device *start, | ||
139 | void *data, int (*fn)(struct device *, void *)) | ||
140 | { | ||
141 | struct list_head *head; | ||
142 | struct device *dev; | ||
143 | int error = 0; | ||
144 | |||
145 | if (!(bus = get_bus(bus))) | ||
146 | return -EINVAL; | ||
147 | |||
148 | head = &bus->devices.list; | ||
149 | dev = list_prepare_entry(start, head, bus_list); | ||
150 | list_for_each_entry_continue(dev, head, bus_list) { | ||
151 | get_device(dev); | ||
152 | error = fn(dev, data); | ||
153 | put_device(dev); | ||
154 | if (error) | ||
155 | break; | ||
156 | } | ||
157 | put_bus(bus); | ||
158 | return error; | ||
159 | } | ||
160 | |||
161 | static int __bus_for_each_drv(struct bus_type *bus, struct device_driver *start, | ||
162 | void * data, int (*fn)(struct device_driver *, void *)) | ||
163 | { | ||
164 | struct list_head *head; | ||
165 | struct device_driver *drv; | ||
166 | int error = 0; | ||
167 | |||
168 | if (!(bus = get_bus(bus))) | ||
169 | return -EINVAL; | ||
170 | |||
171 | head = &bus->drivers.list; | ||
172 | drv = list_prepare_entry(start, head, kobj.entry); | ||
173 | list_for_each_entry_continue(drv, head, kobj.entry) { | ||
174 | get_driver(drv); | ||
175 | error = fn(drv, data); | ||
176 | put_driver(drv); | ||
177 | if (error) | ||
178 | break; | ||
179 | } | ||
180 | put_bus(bus); | ||
181 | return error; | ||
182 | } | ||
183 | |||
184 | /** | ||
185 | * bus_for_each_dev - device iterator. | ||
186 | * @bus: bus type. | ||
187 | * @start: device to start iterating from. | ||
188 | * @data: data for the callback. | ||
189 | * @fn: function to be called for each device. | ||
190 | * | ||
191 | * Iterate over @bus's list of devices, and call @fn for each, | ||
192 | * passing it @data. If @start is not NULL, we use that device to | ||
193 | * begin iterating from. | ||
194 | * | ||
195 | * We check the return of @fn each time. If it returns anything | ||
196 | * other than 0, we break out and return that value. | ||
197 | * | ||
198 | * NOTE: The device that returns a non-zero value is not retained | ||
199 | * in any way, nor is its refcount incremented. If the caller needs | ||
200 | * to retain this data, it should do, and increment the reference | ||
201 | * count in the supplied callback. | ||
202 | */ | ||
203 | |||
204 | int bus_for_each_dev(struct bus_type * bus, struct device * start, | ||
205 | void * data, int (*fn)(struct device *, void *)) | ||
206 | { | ||
207 | int ret; | ||
208 | |||
209 | down_read(&bus->subsys.rwsem); | ||
210 | ret = __bus_for_each_dev(bus, start, data, fn); | ||
211 | up_read(&bus->subsys.rwsem); | ||
212 | return ret; | ||
213 | } | ||
214 | |||
215 | /** | ||
216 | * bus_for_each_drv - driver iterator | ||
217 | * @bus: bus we're dealing with. | ||
218 | * @start: driver to start iterating on. | ||
219 | * @data: data to pass to the callback. | ||
220 | * @fn: function to call for each driver. | ||
221 | * | ||
222 | * This is nearly identical to the device iterator above. | ||
223 | * We iterate over each driver that belongs to @bus, and call | ||
224 | * @fn for each. If @fn returns anything but 0, we break out | ||
225 | * and return it. If @start is not NULL, we use it as the head | ||
226 | * of the list. | ||
227 | * | ||
228 | * NOTE: we don't return the driver that returns a non-zero | ||
229 | * value, nor do we leave the reference count incremented for that | ||
230 | * driver. If the caller needs to know that info, it must set it | ||
231 | * in the callback. It must also be sure to increment the refcount | ||
232 | * so it doesn't disappear before returning to the caller. | ||
233 | */ | ||
234 | |||
235 | int bus_for_each_drv(struct bus_type * bus, struct device_driver * start, | ||
236 | void * data, int (*fn)(struct device_driver *, void *)) | ||
237 | { | ||
238 | int ret; | ||
239 | |||
240 | down_read(&bus->subsys.rwsem); | ||
241 | ret = __bus_for_each_drv(bus, start, data, fn); | ||
242 | up_read(&bus->subsys.rwsem); | ||
243 | return ret; | ||
244 | } | ||
245 | |||
246 | /** | ||
247 | * device_bind_driver - bind a driver to one device. | ||
248 | * @dev: device. | ||
249 | * | ||
250 | * Allow manual attachment of a driver to a device. | ||
251 | * Caller must have already set @dev->driver. | ||
252 | * | ||
253 | * Note that this does not modify the bus reference count | ||
254 | * nor take the bus's rwsem. Please verify those are accounted | ||
255 | * for before calling this. (It is ok to call with no other effort | ||
256 | * from a driver's probe() method.) | ||
257 | */ | ||
258 | |||
259 | void device_bind_driver(struct device * dev) | ||
260 | { | ||
261 | pr_debug("bound device '%s' to driver '%s'\n", | ||
262 | dev->bus_id, dev->driver->name); | ||
263 | list_add_tail(&dev->driver_list, &dev->driver->devices); | ||
264 | sysfs_create_link(&dev->driver->kobj, &dev->kobj, | ||
265 | kobject_name(&dev->kobj)); | ||
266 | sysfs_create_link(&dev->kobj, &dev->driver->kobj, "driver"); | ||
267 | } | ||
268 | |||
269 | |||
270 | /** | ||
271 | * driver_probe_device - attempt to bind device & driver. | ||
272 | * @drv: driver. | ||
273 | * @dev: device. | ||
274 | * | ||
275 | * First, we call the bus's match function, if one present, which | ||
276 | * should compare the device IDs the driver supports with the | ||
277 | * device IDs of the device. Note we don't do this ourselves | ||
278 | * because we don't know the format of the ID structures, nor what | ||
279 | * is to be considered a match and what is not. | ||
280 | * | ||
281 | * If we find a match, we call @drv->probe(@dev) if it exists, and | ||
282 | * call device_bind_driver() above. | ||
283 | */ | ||
284 | int driver_probe_device(struct device_driver * drv, struct device * dev) | ||
285 | { | ||
286 | if (drv->bus->match && !drv->bus->match(dev, drv)) | ||
287 | return -ENODEV; | ||
288 | |||
289 | dev->driver = drv; | ||
290 | if (drv->probe) { | ||
291 | int error = drv->probe(dev); | ||
292 | if (error) { | ||
293 | dev->driver = NULL; | ||
294 | return error; | ||
295 | } | ||
296 | } | ||
297 | |||
298 | device_bind_driver(dev); | ||
299 | return 0; | ||
300 | } | ||
301 | |||
302 | |||
303 | /** | ||
304 | * device_attach - try to attach device to a driver. | ||
305 | * @dev: device. | ||
306 | * | ||
307 | * Walk the list of drivers that the bus has and call | ||
308 | * driver_probe_device() for each pair. If a compatible | ||
309 | * pair is found, break out and return. | ||
310 | */ | ||
311 | int device_attach(struct device * dev) | ||
312 | { | ||
313 | struct bus_type * bus = dev->bus; | ||
314 | struct list_head * entry; | ||
315 | int error; | ||
316 | |||
317 | if (dev->driver) { | ||
318 | device_bind_driver(dev); | ||
319 | return 1; | ||
320 | } | ||
321 | |||
322 | if (bus->match) { | ||
323 | list_for_each(entry, &bus->drivers.list) { | ||
324 | struct device_driver * drv = to_drv(entry); | ||
325 | error = driver_probe_device(drv, dev); | ||
326 | if (!error) | ||
327 | /* success, driver matched */ | ||
328 | return 1; | ||
329 | if (error != -ENODEV && error != -ENXIO) | ||
330 | /* driver matched but the probe failed */ | ||
331 | printk(KERN_WARNING | ||
332 | "%s: probe of %s failed with error %d\n", | ||
333 | drv->name, dev->bus_id, error); | ||
334 | } | ||
335 | } | ||
336 | |||
337 | return 0; | ||
338 | } | ||
339 | |||
340 | |||
341 | /** | ||
342 | * driver_attach - try to bind driver to devices. | ||
343 | * @drv: driver. | ||
344 | * | ||
345 | * Walk the list of devices that the bus has on it and try to | ||
346 | * match the driver with each one. If driver_probe_device() | ||
347 | * returns 0 and the @dev->driver is set, we've found a | ||
348 | * compatible pair. | ||
349 | * | ||
350 | * Note that we ignore the -ENODEV error from driver_probe_device(), | ||
351 | * since it's perfectly valid for a driver not to bind to any devices. | ||
352 | */ | ||
353 | void driver_attach(struct device_driver * drv) | ||
354 | { | ||
355 | struct bus_type * bus = drv->bus; | ||
356 | struct list_head * entry; | ||
357 | int error; | ||
358 | |||
359 | if (!bus->match) | ||
360 | return; | ||
361 | |||
362 | list_for_each(entry, &bus->devices.list) { | ||
363 | struct device * dev = container_of(entry, struct device, bus_list); | ||
364 | if (!dev->driver) { | ||
365 | error = driver_probe_device(drv, dev); | ||
366 | if (error && (error != -ENODEV)) | ||
367 | /* driver matched but the probe failed */ | ||
368 | printk(KERN_WARNING | ||
369 | "%s: probe of %s failed with error %d\n", | ||
370 | drv->name, dev->bus_id, error); | ||
371 | } | ||
372 | } | ||
373 | } | ||
374 | |||
375 | |||
376 | /** | ||
377 | * device_release_driver - manually detach device from driver. | ||
378 | * @dev: device. | ||
379 | * | ||
380 | * Manually detach device from driver. | ||
381 | * Note that this is called without incrementing the bus | ||
382 | * reference count nor taking the bus's rwsem. Be sure that | ||
383 | * those are accounted for before calling this function. | ||
384 | */ | ||
385 | |||
386 | void device_release_driver(struct device * dev) | ||
387 | { | ||
388 | struct device_driver * drv = dev->driver; | ||
389 | if (drv) { | ||
390 | sysfs_remove_link(&drv->kobj, kobject_name(&dev->kobj)); | ||
391 | sysfs_remove_link(&dev->kobj, "driver"); | ||
392 | list_del_init(&dev->driver_list); | ||
393 | device_detach_shutdown(dev); | ||
394 | if (drv->remove) | ||
395 | drv->remove(dev); | ||
396 | dev->driver = NULL; | ||
397 | } | ||
398 | } | ||
399 | |||
400 | |||
401 | /** | ||
402 | * driver_detach - detach driver from all devices it controls. | ||
403 | * @drv: driver. | ||
404 | */ | ||
405 | |||
406 | static void driver_detach(struct device_driver * drv) | ||
407 | { | ||
408 | struct list_head * entry, * next; | ||
409 | list_for_each_safe(entry, next, &drv->devices) { | ||
410 | struct device * dev = container_of(entry, struct device, driver_list); | ||
411 | device_release_driver(dev); | ||
412 | } | ||
413 | } | ||
414 | |||
415 | static int device_add_attrs(struct bus_type * bus, struct device * dev) | ||
416 | { | ||
417 | int error = 0; | ||
418 | int i; | ||
419 | |||
420 | if (bus->dev_attrs) { | ||
421 | for (i = 0; attr_name(bus->dev_attrs[i]); i++) { | ||
422 | error = device_create_file(dev,&bus->dev_attrs[i]); | ||
423 | if (error) | ||
424 | goto Err; | ||
425 | } | ||
426 | } | ||
427 | Done: | ||
428 | return error; | ||
429 | Err: | ||
430 | while (--i >= 0) | ||
431 | device_remove_file(dev,&bus->dev_attrs[i]); | ||
432 | goto Done; | ||
433 | } | ||
434 | |||
435 | |||
436 | static void device_remove_attrs(struct bus_type * bus, struct device * dev) | ||
437 | { | ||
438 | int i; | ||
439 | |||
440 | if (bus->dev_attrs) { | ||
441 | for (i = 0; attr_name(bus->dev_attrs[i]); i++) | ||
442 | device_remove_file(dev,&bus->dev_attrs[i]); | ||
443 | } | ||
444 | } | ||
445 | |||
446 | |||
447 | /** | ||
448 | * bus_add_device - add device to bus | ||
449 | * @dev: device being added | ||
450 | * | ||
451 | * - Add the device to its bus's list of devices. | ||
452 | * - Try to attach to driver. | ||
453 | * - Create link to device's physical location. | ||
454 | */ | ||
455 | int bus_add_device(struct device * dev) | ||
456 | { | ||
457 | struct bus_type * bus = get_bus(dev->bus); | ||
458 | int error = 0; | ||
459 | |||
460 | if (bus) { | ||
461 | down_write(&dev->bus->subsys.rwsem); | ||
462 | pr_debug("bus %s: add device %s\n", bus->name, dev->bus_id); | ||
463 | list_add_tail(&dev->bus_list, &dev->bus->devices.list); | ||
464 | device_attach(dev); | ||
465 | up_write(&dev->bus->subsys.rwsem); | ||
466 | device_add_attrs(bus, dev); | ||
467 | sysfs_create_link(&bus->devices.kobj, &dev->kobj, dev->bus_id); | ||
468 | sysfs_create_link(&dev->kobj, &dev->bus->subsys.kset.kobj, "bus"); | ||
469 | } | ||
470 | return error; | ||
471 | } | ||
472 | |||
473 | /** | ||
474 | * bus_remove_device - remove device from bus | ||
475 | * @dev: device to be removed | ||
476 | * | ||
477 | * - Remove symlink from bus's directory. | ||
478 | * - Delete device from bus's list. | ||
479 | * - Detach from its driver. | ||
480 | * - Drop reference taken in bus_add_device(). | ||
481 | */ | ||
482 | void bus_remove_device(struct device * dev) | ||
483 | { | ||
484 | if (dev->bus) { | ||
485 | sysfs_remove_link(&dev->kobj, "bus"); | ||
486 | sysfs_remove_link(&dev->bus->devices.kobj, dev->bus_id); | ||
487 | device_remove_attrs(dev->bus, dev); | ||
488 | down_write(&dev->bus->subsys.rwsem); | ||
489 | pr_debug("bus %s: remove device %s\n", dev->bus->name, dev->bus_id); | ||
490 | device_release_driver(dev); | ||
491 | list_del_init(&dev->bus_list); | ||
492 | up_write(&dev->bus->subsys.rwsem); | ||
493 | put_bus(dev->bus); | ||
494 | } | ||
495 | } | ||
496 | |||
497 | static int driver_add_attrs(struct bus_type * bus, struct device_driver * drv) | ||
498 | { | ||
499 | int error = 0; | ||
500 | int i; | ||
501 | |||
502 | if (bus->drv_attrs) { | ||
503 | for (i = 0; attr_name(bus->drv_attrs[i]); i++) { | ||
504 | error = driver_create_file(drv, &bus->drv_attrs[i]); | ||
505 | if (error) | ||
506 | goto Err; | ||
507 | } | ||
508 | } | ||
509 | Done: | ||
510 | return error; | ||
511 | Err: | ||
512 | while (--i >= 0) | ||
513 | driver_remove_file(drv, &bus->drv_attrs[i]); | ||
514 | goto Done; | ||
515 | } | ||
516 | |||
517 | |||
518 | static void driver_remove_attrs(struct bus_type * bus, struct device_driver * drv) | ||
519 | { | ||
520 | int i; | ||
521 | |||
522 | if (bus->drv_attrs) { | ||
523 | for (i = 0; attr_name(bus->drv_attrs[i]); i++) | ||
524 | driver_remove_file(drv, &bus->drv_attrs[i]); | ||
525 | } | ||
526 | } | ||
527 | |||
528 | |||
529 | /** | ||
530 | * bus_add_driver - Add a driver to the bus. | ||
531 | * @drv: driver. | ||
532 | * | ||
533 | */ | ||
534 | int bus_add_driver(struct device_driver * drv) | ||
535 | { | ||
536 | struct bus_type * bus = get_bus(drv->bus); | ||
537 | int error = 0; | ||
538 | |||
539 | if (bus) { | ||
540 | pr_debug("bus %s: add driver %s\n", bus->name, drv->name); | ||
541 | error = kobject_set_name(&drv->kobj, "%s", drv->name); | ||
542 | if (error) { | ||
543 | put_bus(bus); | ||
544 | return error; | ||
545 | } | ||
546 | drv->kobj.kset = &bus->drivers; | ||
547 | if ((error = kobject_register(&drv->kobj))) { | ||
548 | put_bus(bus); | ||
549 | return error; | ||
550 | } | ||
551 | |||
552 | down_write(&bus->subsys.rwsem); | ||
553 | driver_attach(drv); | ||
554 | up_write(&bus->subsys.rwsem); | ||
555 | module_add_driver(drv->owner, drv); | ||
556 | |||
557 | driver_add_attrs(bus, drv); | ||
558 | } | ||
559 | return error; | ||
560 | } | ||
561 | |||
562 | |||
563 | /** | ||
564 | * bus_remove_driver - delete driver from bus's knowledge. | ||
565 | * @drv: driver. | ||
566 | * | ||
567 | * Detach the driver from the devices it controls, and remove | ||
568 | * it from its bus's list of drivers. Finally, we drop the reference | ||
569 | * to the bus we took in bus_add_driver(). | ||
570 | */ | ||
571 | |||
572 | void bus_remove_driver(struct device_driver * drv) | ||
573 | { | ||
574 | if (drv->bus) { | ||
575 | driver_remove_attrs(drv->bus, drv); | ||
576 | down_write(&drv->bus->subsys.rwsem); | ||
577 | pr_debug("bus %s: remove driver %s\n", drv->bus->name, drv->name); | ||
578 | driver_detach(drv); | ||
579 | up_write(&drv->bus->subsys.rwsem); | ||
580 | module_remove_driver(drv); | ||
581 | kobject_unregister(&drv->kobj); | ||
582 | put_bus(drv->bus); | ||
583 | } | ||
584 | } | ||
585 | |||
586 | |||
587 | /* Helper for bus_rescan_devices's iter */ | ||
588 | static int bus_rescan_devices_helper(struct device *dev, void *data) | ||
589 | { | ||
590 | int *count = data; | ||
591 | |||
592 | if (!dev->driver && device_attach(dev)) | ||
593 | (*count)++; | ||
594 | |||
595 | return 0; | ||
596 | } | ||
597 | |||
598 | |||
599 | /** | ||
600 | * bus_rescan_devices - rescan devices on the bus for possible drivers | ||
601 | * @bus: the bus to scan. | ||
602 | * | ||
603 | * This function will look for devices on the bus with no driver | ||
604 | * attached and rescan it against existing drivers to see if it | ||
605 | * matches any. Calls device_attach(). Returns the number of devices | ||
606 | * that were sucessfully bound to a driver. | ||
607 | */ | ||
608 | int bus_rescan_devices(struct bus_type * bus) | ||
609 | { | ||
610 | int count = 0; | ||
611 | |||
612 | down_write(&bus->subsys.rwsem); | ||
613 | __bus_for_each_dev(bus, NULL, &count, bus_rescan_devices_helper); | ||
614 | up_write(&bus->subsys.rwsem); | ||
615 | |||
616 | return count; | ||
617 | } | ||
618 | |||
619 | |||
620 | struct bus_type * get_bus(struct bus_type * bus) | ||
621 | { | ||
622 | return bus ? container_of(subsys_get(&bus->subsys), struct bus_type, subsys) : NULL; | ||
623 | } | ||
624 | |||
625 | void put_bus(struct bus_type * bus) | ||
626 | { | ||
627 | subsys_put(&bus->subsys); | ||
628 | } | ||
629 | |||
630 | |||
631 | /** | ||
632 | * find_bus - locate bus by name. | ||
633 | * @name: name of bus. | ||
634 | * | ||
635 | * Call kset_find_obj() to iterate over list of buses to | ||
636 | * find a bus by name. Return bus if found. | ||
637 | * | ||
638 | * Note that kset_find_obj increments bus' reference count. | ||
639 | */ | ||
640 | |||
641 | struct bus_type * find_bus(char * name) | ||
642 | { | ||
643 | struct kobject * k = kset_find_obj(&bus_subsys.kset, name); | ||
644 | return k ? to_bus(k) : NULL; | ||
645 | } | ||
646 | |||
647 | |||
648 | /** | ||
649 | * bus_add_attrs - Add default attributes for this bus. | ||
650 | * @bus: Bus that has just been registered. | ||
651 | */ | ||
652 | |||
653 | static int bus_add_attrs(struct bus_type * bus) | ||
654 | { | ||
655 | int error = 0; | ||
656 | int i; | ||
657 | |||
658 | if (bus->bus_attrs) { | ||
659 | for (i = 0; attr_name(bus->bus_attrs[i]); i++) { | ||
660 | if ((error = bus_create_file(bus,&bus->bus_attrs[i]))) | ||
661 | goto Err; | ||
662 | } | ||
663 | } | ||
664 | Done: | ||
665 | return error; | ||
666 | Err: | ||
667 | while (--i >= 0) | ||
668 | bus_remove_file(bus,&bus->bus_attrs[i]); | ||
669 | goto Done; | ||
670 | } | ||
671 | |||
672 | static void bus_remove_attrs(struct bus_type * bus) | ||
673 | { | ||
674 | int i; | ||
675 | |||
676 | if (bus->bus_attrs) { | ||
677 | for (i = 0; attr_name(bus->bus_attrs[i]); i++) | ||
678 | bus_remove_file(bus,&bus->bus_attrs[i]); | ||
679 | } | ||
680 | } | ||
681 | |||
682 | /** | ||
683 | * bus_register - register a bus with the system. | ||
684 | * @bus: bus. | ||
685 | * | ||
686 | * Once we have that, we registered the bus with the kobject | ||
687 | * infrastructure, then register the children subsystems it has: | ||
688 | * the devices and drivers that belong to the bus. | ||
689 | */ | ||
690 | int bus_register(struct bus_type * bus) | ||
691 | { | ||
692 | int retval; | ||
693 | |||
694 | retval = kobject_set_name(&bus->subsys.kset.kobj, "%s", bus->name); | ||
695 | if (retval) | ||
696 | goto out; | ||
697 | |||
698 | subsys_set_kset(bus, bus_subsys); | ||
699 | retval = subsystem_register(&bus->subsys); | ||
700 | if (retval) | ||
701 | goto out; | ||
702 | |||
703 | kobject_set_name(&bus->devices.kobj, "devices"); | ||
704 | bus->devices.subsys = &bus->subsys; | ||
705 | retval = kset_register(&bus->devices); | ||
706 | if (retval) | ||
707 | goto bus_devices_fail; | ||
708 | |||
709 | kobject_set_name(&bus->drivers.kobj, "drivers"); | ||
710 | bus->drivers.subsys = &bus->subsys; | ||
711 | bus->drivers.ktype = &ktype_driver; | ||
712 | retval = kset_register(&bus->drivers); | ||
713 | if (retval) | ||
714 | goto bus_drivers_fail; | ||
715 | bus_add_attrs(bus); | ||
716 | |||
717 | pr_debug("bus type '%s' registered\n", bus->name); | ||
718 | return 0; | ||
719 | |||
720 | bus_drivers_fail: | ||
721 | kset_unregister(&bus->devices); | ||
722 | bus_devices_fail: | ||
723 | subsystem_unregister(&bus->subsys); | ||
724 | out: | ||
725 | return retval; | ||
726 | } | ||
727 | |||
728 | |||
729 | /** | ||
730 | * bus_unregister - remove a bus from the system | ||
731 | * @bus: bus. | ||
732 | * | ||
733 | * Unregister the child subsystems and the bus itself. | ||
734 | * Finally, we call put_bus() to release the refcount | ||
735 | */ | ||
736 | void bus_unregister(struct bus_type * bus) | ||
737 | { | ||
738 | pr_debug("bus %s: unregistering\n", bus->name); | ||
739 | bus_remove_attrs(bus); | ||
740 | kset_unregister(&bus->drivers); | ||
741 | kset_unregister(&bus->devices); | ||
742 | subsystem_unregister(&bus->subsys); | ||
743 | } | ||
744 | |||
745 | int __init buses_init(void) | ||
746 | { | ||
747 | return subsystem_register(&bus_subsys); | ||
748 | } | ||
749 | |||
750 | |||
751 | EXPORT_SYMBOL_GPL(bus_for_each_dev); | ||
752 | EXPORT_SYMBOL_GPL(bus_for_each_drv); | ||
753 | |||
754 | EXPORT_SYMBOL_GPL(driver_probe_device); | ||
755 | EXPORT_SYMBOL_GPL(device_bind_driver); | ||
756 | EXPORT_SYMBOL_GPL(device_release_driver); | ||
757 | EXPORT_SYMBOL_GPL(device_attach); | ||
758 | EXPORT_SYMBOL_GPL(driver_attach); | ||
759 | |||
760 | EXPORT_SYMBOL_GPL(bus_add_device); | ||
761 | EXPORT_SYMBOL_GPL(bus_remove_device); | ||
762 | EXPORT_SYMBOL_GPL(bus_register); | ||
763 | EXPORT_SYMBOL_GPL(bus_unregister); | ||
764 | EXPORT_SYMBOL_GPL(bus_rescan_devices); | ||
765 | EXPORT_SYMBOL_GPL(get_bus); | ||
766 | EXPORT_SYMBOL_GPL(put_bus); | ||
767 | EXPORT_SYMBOL_GPL(find_bus); | ||
768 | |||
769 | EXPORT_SYMBOL_GPL(bus_create_file); | ||
770 | EXPORT_SYMBOL_GPL(bus_remove_file); | ||