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CommitLineData
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>
5a0e3ad6 16#include <linux/slab.h>
1da177e4
LT
17#include <linux/init.h>
18#include <linux/string.h>
ca22e56d 19#include <linux/mutex.h>
63967685 20#include <linux/sysfs.h>
1da177e4
LT
21#include "base.h"
22#include "power/power.h"
23
ca22e56d 24/* /sys/devices/system */
97ec448a 25static struct kset *system_kset;
ca22e56d 26
1da177e4 27#define to_bus_attr(_attr) container_of(_attr, struct bus_attribute, attr)
1da177e4
LT
28
29/*
30 * sysfs bindings for drivers
31 */
32
33#define to_drv_attr(_attr) container_of(_attr, struct driver_attribute, attr)
1da177e4
LT
34
35
b8c5cec2
KS
36static int __must_check bus_rescan_devices_helper(struct device *dev,
37 void *data);
38
5901d014
GKH
39static struct bus_type *bus_get(struct bus_type *bus)
40{
c6f7e72a
GKH
41 if (bus) {
42 kset_get(&bus->p->subsys);
43 return bus;
44 }
45 return NULL;
5901d014
GKH
46}
47
fc1ede58
GKH
48static void bus_put(struct bus_type *bus)
49{
c6f7e72a
GKH
50 if (bus)
51 kset_put(&bus->p->subsys);
fc1ede58
GKH
52}
53
4a3ad20c
GKH
54static ssize_t drv_attr_show(struct kobject *kobj, struct attribute *attr,
55 char *buf)
1da177e4 56{
4a3ad20c 57 struct driver_attribute *drv_attr = to_drv_attr(attr);
e5dd1278 58 struct driver_private *drv_priv = to_driver(kobj);
4a0c20bf 59 ssize_t ret = -EIO;
1da177e4
LT
60
61 if (drv_attr->show)
e5dd1278 62 ret = drv_attr->show(drv_priv->driver, buf);
1da177e4
LT
63 return ret;
64}
65
4a3ad20c
GKH
66static ssize_t drv_attr_store(struct kobject *kobj, struct attribute *attr,
67 const char *buf, size_t count)
1da177e4 68{
4a3ad20c 69 struct driver_attribute *drv_attr = to_drv_attr(attr);
e5dd1278 70 struct driver_private *drv_priv = to_driver(kobj);
4a0c20bf 71 ssize_t ret = -EIO;
1da177e4
LT
72
73 if (drv_attr->store)
e5dd1278 74 ret = drv_attr->store(drv_priv->driver, buf, count);
1da177e4
LT
75 return ret;
76}
77
52cf25d0 78static const struct sysfs_ops driver_sysfs_ops = {
1da177e4
LT
79 .show = drv_attr_show,
80 .store = drv_attr_store,
81};
82
e5dd1278 83static void driver_release(struct kobject *kobj)
1da177e4 84{
e5dd1278
GKH
85 struct driver_private *drv_priv = to_driver(kobj);
86
2b3a302a 87 pr_debug("driver: '%s': %s\n", kobject_name(kobj), __func__);
e5dd1278 88 kfree(drv_priv);
1da177e4
LT
89}
90
a1148fb0 91static struct kobj_type driver_ktype = {
1da177e4
LT
92 .sysfs_ops = &driver_sysfs_ops,
93 .release = driver_release,
94};
95
1da177e4
LT
96/*
97 * sysfs bindings for buses
98 */
4a3ad20c
GKH
99static ssize_t bus_attr_show(struct kobject *kobj, struct attribute *attr,
100 char *buf)
1da177e4 101{
4a3ad20c 102 struct bus_attribute *bus_attr = to_bus_attr(attr);
6b6e39a6 103 struct subsys_private *subsys_priv = to_subsys_private(kobj);
1da177e4
LT
104 ssize_t ret = 0;
105
106 if (bus_attr->show)
6b6e39a6 107 ret = bus_attr->show(subsys_priv->bus, buf);
1da177e4
LT
108 return ret;
109}
110
4a3ad20c
GKH
111static ssize_t bus_attr_store(struct kobject *kobj, struct attribute *attr,
112 const char *buf, size_t count)
1da177e4 113{
4a3ad20c 114 struct bus_attribute *bus_attr = to_bus_attr(attr);
6b6e39a6 115 struct subsys_private *subsys_priv = to_subsys_private(kobj);
1da177e4
LT
116 ssize_t ret = 0;
117
118 if (bus_attr->store)
6b6e39a6 119 ret = bus_attr->store(subsys_priv->bus, buf, count);
1da177e4
LT
120 return ret;
121}
122
52cf25d0 123static const struct sysfs_ops bus_sysfs_ops = {
1da177e4
LT
124 .show = bus_attr_show,
125 .store = bus_attr_store,
126};
127
4a3ad20c 128int bus_create_file(struct bus_type *bus, struct bus_attribute *attr)
1da177e4
LT
129{
130 int error;
5901d014 131 if (bus_get(bus)) {
c6f7e72a 132 error = sysfs_create_file(&bus->p->subsys.kobj, &attr->attr);
fc1ede58 133 bus_put(bus);
1da177e4
LT
134 } else
135 error = -EINVAL;
136 return error;
137}
4a3ad20c 138EXPORT_SYMBOL_GPL(bus_create_file);
1da177e4 139
4a3ad20c 140void bus_remove_file(struct bus_type *bus, struct bus_attribute *attr)
1da177e4 141{
5901d014 142 if (bus_get(bus)) {
c6f7e72a 143 sysfs_remove_file(&bus->p->subsys.kobj, &attr->attr);
fc1ede58 144 bus_put(bus);
1da177e4
LT
145 }
146}
4a3ad20c 147EXPORT_SYMBOL_GPL(bus_remove_file);
1da177e4 148
80f03e34 149static struct kobj_type bus_ktype = {
1da177e4 150 .sysfs_ops = &bus_sysfs_ops,
80f03e34
KS
151};
152
153static int bus_uevent_filter(struct kset *kset, struct kobject *kobj)
154{
155 struct kobj_type *ktype = get_ktype(kobj);
156
157 if (ktype == &bus_ktype)
158 return 1;
159 return 0;
160}
1da177e4 161
9cd43611 162static const struct kset_uevent_ops bus_uevent_ops = {
80f03e34 163 .filter = bus_uevent_filter,
1da177e4
LT
164};
165
59a54833 166static struct kset *bus_kset;
1da177e4 167
2b08c8d0 168/* Manually detach a device from its associated driver. */
2581c9cc
GKH
169static ssize_t unbind_store(struct device_driver *drv, const char *buf,
170 size_t count)
151ef38f 171{
5901d014 172 struct bus_type *bus = bus_get(drv->bus);
151ef38f
GKH
173 struct device *dev;
174 int err = -ENODEV;
175
1f9ffc04 176 dev = bus_find_device_by_name(bus, NULL, buf);
2b08c8d0 177 if (dev && dev->driver == drv) {
bf74ad5b 178 if (dev->parent) /* Needed for USB */
8e9394ce 179 device_lock(dev->parent);
151ef38f 180 device_release_driver(dev);
bf74ad5b 181 if (dev->parent)
8e9394ce 182 device_unlock(dev->parent);
151ef38f
GKH
183 err = count;
184 }
2b08c8d0 185 put_device(dev);
fc1ede58 186 bus_put(bus);
2b08c8d0 187 return err;
151ef38f 188}
2581c9cc 189static DRIVER_ATTR_WO(unbind);
151ef38f 190
afdce75f
GKH
191/*
192 * Manually attach a device to a driver.
193 * Note: the driver must want to bind to the device,
194 * it is not possible to override the driver's id table.
195 */
2581c9cc
GKH
196static ssize_t bind_store(struct device_driver *drv, const char *buf,
197 size_t count)
afdce75f 198{
5901d014 199 struct bus_type *bus = bus_get(drv->bus);
afdce75f
GKH
200 struct device *dev;
201 int err = -ENODEV;
202
1f9ffc04 203 dev = bus_find_device_by_name(bus, NULL, buf);
49b420a1 204 if (dev && dev->driver == NULL && driver_match_device(drv, dev)) {
bf74ad5b 205 if (dev->parent) /* Needed for USB */
8e9394ce
GKH
206 device_lock(dev->parent);
207 device_lock(dev);
afdce75f 208 err = driver_probe_device(drv, dev);
8e9394ce 209 device_unlock(dev);
bf74ad5b 210 if (dev->parent)
8e9394ce 211 device_unlock(dev->parent);
37225401 212
4a3ad20c
GKH
213 if (err > 0) {
214 /* success */
37225401 215 err = count;
4a3ad20c
GKH
216 } else if (err == 0) {
217 /* driver didn't accept device */
37225401 218 err = -ENODEV;
4a3ad20c 219 }
afdce75f 220 }
2b08c8d0 221 put_device(dev);
fc1ede58 222 bus_put(bus);
2b08c8d0 223 return err;
afdce75f 224}
2581c9cc 225static DRIVER_ATTR_WO(bind);
afdce75f 226
b8c5cec2
KS
227static ssize_t show_drivers_autoprobe(struct bus_type *bus, char *buf)
228{
c6f7e72a 229 return sprintf(buf, "%d\n", bus->p->drivers_autoprobe);
b8c5cec2
KS
230}
231
232static ssize_t store_drivers_autoprobe(struct bus_type *bus,
233 const char *buf, size_t count)
234{
235 if (buf[0] == '0')
c6f7e72a 236 bus->p->drivers_autoprobe = 0;
b8c5cec2 237 else
c6f7e72a 238 bus->p->drivers_autoprobe = 1;
b8c5cec2
KS
239 return count;
240}
241
242static ssize_t store_drivers_probe(struct bus_type *bus,
243 const char *buf, size_t count)
244{
245 struct device *dev;
246
1f9ffc04 247 dev = bus_find_device_by_name(bus, NULL, buf);
b8c5cec2
KS
248 if (!dev)
249 return -ENODEV;
250 if (bus_rescan_devices_helper(dev, NULL) != 0)
251 return -EINVAL;
252 return count;
253}
151ef38f 254
4a3ad20c 255static struct device *next_device(struct klist_iter *i)
465c7a3a 256{
4a3ad20c 257 struct klist_node *n = klist_next(i);
ae1b4171
GKH
258 struct device *dev = NULL;
259 struct device_private *dev_prv;
260
261 if (n) {
262 dev_prv = to_device_private_bus(n);
263 dev = dev_prv->device;
264 }
265 return dev;
465c7a3a
PM
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
0fa1b0a1 284 * to retain this data, it should do so, and increment the reference
4a3ad20c 285 * count in the supplied callback.
1da177e4 286 */
4a3ad20c
GKH
287int 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
4fa3e78b 294 if (!bus || !bus->p)
465c7a3a
PM
295 return -EINVAL;
296
7cd9c9bb
GKH
297 klist_iter_init_node(&bus->p->klist_devices, &i,
298 (start ? &start->p->knode_bus : NULL));
299 while ((dev = next_device(&i)) && !error)
300 error = fn(dev, data);
301 klist_iter_exit(&i);
465c7a3a 302 return error;
1da177e4 303}
4a3ad20c 304EXPORT_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
321struct 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
4fa3e78b 328 if (!bus || !bus->p)
0edb5860
CH
329 return NULL;
330
7cd9c9bb
GKH
331 klist_iter_init_node(&bus->p->klist_devices, &i,
332 (start ? &start->p->knode_bus : NULL));
0edb5860
CH
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 339EXPORT_SYMBOL_GPL(bus_find_device);
38fdac3c 340
1f9ffc04
GKH
341static int match_name(struct device *dev, void *data)
342{
343 const char *name = data;
344
1e0b2cf9 345 return sysfs_streq(name, dev_name(dev));
1f9ffc04
GKH
346}
347
348/**
349 * bus_find_device_by_name - device iterator for locating a particular device of a specific name
350 * @bus: bus type
351 * @start: Device to begin with
352 * @name: name of the device to match
353 *
354 * This is similar to the bus_find_device() function above, but it handles
355 * searching by a name automatically, no need to write another strcmp matching
356 * function.
357 */
358struct device *bus_find_device_by_name(struct bus_type *bus,
359 struct device *start, const char *name)
360{
361 return bus_find_device(bus, start, (void *)name, match_name);
362}
363EXPORT_SYMBOL_GPL(bus_find_device_by_name);
364
ca22e56d
KS
365/**
366 * subsys_find_device_by_id - find a device with a specific enumeration number
367 * @subsys: subsystem
368 * @id: index 'id' in struct device
369 * @hint: device to check first
370 *
371 * Check the hint's next object and if it is a match return it directly,
372 * otherwise, fall back to a full list search. Either way a reference for
373 * the returned object is taken.
374 */
375struct device *subsys_find_device_by_id(struct bus_type *subsys, unsigned int id,
376 struct device *hint)
377{
378 struct klist_iter i;
379 struct device *dev;
380
381 if (!subsys)
382 return NULL;
383
384 if (hint) {
7cd9c9bb 385 klist_iter_init_node(&subsys->p->klist_devices, &i, &hint->p->knode_bus);
ca22e56d
KS
386 dev = next_device(&i);
387 if (dev && dev->id == id && get_device(dev)) {
388 klist_iter_exit(&i);
389 return dev;
390 }
391 klist_iter_exit(&i);
392 }
393
394 klist_iter_init_node(&subsys->p->klist_devices, &i, NULL);
395 while ((dev = next_device(&i))) {
396 if (dev->id == id && get_device(dev)) {
397 klist_iter_exit(&i);
398 return dev;
399 }
400 }
401 klist_iter_exit(&i);
402 return NULL;
403}
404EXPORT_SYMBOL_GPL(subsys_find_device_by_id);
405
4a3ad20c 406static struct device_driver *next_driver(struct klist_iter *i)
38fdac3c 407{
4a3ad20c 408 struct klist_node *n = klist_next(i);
e5dd1278
GKH
409 struct driver_private *drv_priv;
410
411 if (n) {
412 drv_priv = container_of(n, struct driver_private, knode_bus);
413 return drv_priv->driver;
414 }
415 return NULL;
38fdac3c
PM
416}
417
1da177e4 418/**
4a3ad20c
GKH
419 * bus_for_each_drv - driver iterator
420 * @bus: bus we're dealing with.
421 * @start: driver to start iterating on.
422 * @data: data to pass to the callback.
423 * @fn: function to call for each driver.
1da177e4 424 *
4a3ad20c
GKH
425 * This is nearly identical to the device iterator above.
426 * We iterate over each driver that belongs to @bus, and call
427 * @fn for each. If @fn returns anything but 0, we break out
428 * and return it. If @start is not NULL, we use it as the head
429 * of the list.
1da177e4 430 *
4a3ad20c
GKH
431 * NOTE: we don't return the driver that returns a non-zero
432 * value, nor do we leave the reference count incremented for that
433 * driver. If the caller needs to know that info, it must set it
434 * in the callback. It must also be sure to increment the refcount
435 * so it doesn't disappear before returning to the caller.
1da177e4 436 */
4a3ad20c
GKH
437int bus_for_each_drv(struct bus_type *bus, struct device_driver *start,
438 void *data, int (*fn)(struct device_driver *, void *))
1da177e4 439{
38fdac3c 440 struct klist_iter i;
4a3ad20c 441 struct device_driver *drv;
38fdac3c 442 int error = 0;
1da177e4 443
38fdac3c
PM
444 if (!bus)
445 return -EINVAL;
446
7cd9c9bb
GKH
447 klist_iter_init_node(&bus->p->klist_drivers, &i,
448 start ? &start->p->knode_bus : NULL);
449 while ((drv = next_driver(&i)) && !error)
450 error = fn(drv, data);
451 klist_iter_exit(&i);
38fdac3c 452 return error;
1da177e4 453}
4a3ad20c 454EXPORT_SYMBOL_GPL(bus_for_each_drv);
1da177e4 455
4aca67e5 456static int device_add_attrs(struct bus_type *bus, struct device *dev)
1da177e4
LT
457{
458 int error = 0;
459 int i;
460
4aca67e5
AM
461 if (!bus->dev_attrs)
462 return 0;
463
3e1026b3 464 for (i = 0; bus->dev_attrs[i].attr.name; i++) {
4a3ad20c 465 error = device_create_file(dev, &bus->dev_attrs[i]);
4aca67e5
AM
466 if (error) {
467 while (--i >= 0)
468 device_remove_file(dev, &bus->dev_attrs[i]);
469 break;
1da177e4
LT
470 }
471 }
1da177e4 472 return error;
1da177e4
LT
473}
474
4a3ad20c 475static void device_remove_attrs(struct bus_type *bus, struct device *dev)
1da177e4
LT
476{
477 int i;
478
479 if (bus->dev_attrs) {
3e1026b3 480 for (i = 0; bus->dev_attrs[i].attr.name; i++)
4a3ad20c 481 device_remove_file(dev, &bus->dev_attrs[i]);
1da177e4
LT
482 }
483}
484
1da177e4 485/**
4a3ad20c
GKH
486 * bus_add_device - add device to bus
487 * @dev: device being added
1da177e4 488 *
2023c610
AS
489 * - Add device's bus attributes.
490 * - Create links to device's bus.
4a3ad20c 491 * - Add the device to its bus's list of devices.
1da177e4 492 */
4a3ad20c 493int bus_add_device(struct device *dev)
1da177e4 494{
4a3ad20c 495 struct bus_type *bus = bus_get(dev->bus);
1da177e4
LT
496 int error = 0;
497
498 if (bus) {
1e0b2cf9 499 pr_debug("bus: '%s': add device %s\n", bus->name, dev_name(dev));
d377e85b 500 error = device_add_attrs(bus, dev);
f86db396 501 if (error)
513e7337 502 goto out_put;
fa6fdb33
GKH
503 error = device_add_groups(dev, bus->dev_groups);
504 if (error)
505 goto out_groups;
c6f7e72a 506 error = sysfs_create_link(&bus->p->devices_kset->kobj,
1e0b2cf9 507 &dev->kobj, dev_name(dev));
f86db396 508 if (error)
513e7337 509 goto out_id;
f86db396 510 error = sysfs_create_link(&dev->kobj,
c6f7e72a 511 &dev->bus->p->subsys.kobj, "subsystem");
f86db396 512 if (error)
513e7337 513 goto out_subsys;
2023c610 514 klist_add_tail(&dev->p->knode_bus, &bus->p->klist_devices);
1da177e4 515 }
513e7337
CH
516 return 0;
517
513e7337 518out_subsys:
1e0b2cf9 519 sysfs_remove_link(&bus->p->devices_kset->kobj, dev_name(dev));
fa6fdb33
GKH
520out_groups:
521 device_remove_groups(dev, bus->dev_groups);
513e7337
CH
522out_id:
523 device_remove_attrs(bus, dev);
524out_put:
fc1ede58 525 bus_put(dev->bus);
1da177e4
LT
526 return error;
527}
528
53877d06 529/**
2023c610
AS
530 * bus_probe_device - probe drivers for a new device
531 * @dev: device to probe
53877d06 532 *
2023c610 533 * - Automatically probe for a driver if the bus allows it.
53877d06 534 */
2023c610 535void bus_probe_device(struct device *dev)
53877d06 536{
f86db396 537 struct bus_type *bus = dev->bus;
ca22e56d 538 struct subsys_interface *sif;
2023c610 539 int ret;
53877d06 540
ca22e56d
KS
541 if (!bus)
542 return;
543
544 if (bus->p->drivers_autoprobe) {
2023c610 545 ret = device_attach(dev);
c6a46696 546 WARN_ON(ret < 0);
53877d06 547 }
ca22e56d
KS
548
549 mutex_lock(&bus->p->mutex);
550 list_for_each_entry(sif, &bus->p->interfaces, node)
551 if (sif->add_dev)
552 sif->add_dev(dev, sif);
553 mutex_unlock(&bus->p->mutex);
53877d06
KS
554}
555
1da177e4 556/**
4a3ad20c
GKH
557 * bus_remove_device - remove device from bus
558 * @dev: device to be removed
1da177e4 559 *
ca22e56d
KS
560 * - Remove device from all interfaces.
561 * - Remove symlink from bus' directory.
4a3ad20c
GKH
562 * - Delete device from bus's list.
563 * - Detach from its driver.
564 * - Drop reference taken in bus_add_device().
1da177e4 565 */
4a3ad20c 566void bus_remove_device(struct device *dev)
1da177e4 567{
ca22e56d
KS
568 struct bus_type *bus = dev->bus;
569 struct subsys_interface *sif;
570
571 if (!bus)
572 return;
573
574 mutex_lock(&bus->p->mutex);
575 list_for_each_entry(sif, &bus->p->interfaces, node)
576 if (sif->remove_dev)
577 sif->remove_dev(dev, sif);
578 mutex_unlock(&bus->p->mutex);
579
580 sysfs_remove_link(&dev->kobj, "subsystem");
581 sysfs_remove_link(&dev->bus->p->devices_kset->kobj,
582 dev_name(dev));
583 device_remove_attrs(dev->bus, dev);
fa6fdb33 584 device_remove_groups(dev, dev->bus->dev_groups);
ca22e56d
KS
585 if (klist_node_attached(&dev->p->knode_bus))
586 klist_del(&dev->p->knode_bus);
587
588 pr_debug("bus: '%s': remove device %s\n",
589 dev->bus->name, dev_name(dev));
590 device_release_driver(dev);
591 bus_put(dev->bus);
1da177e4
LT
592}
593
4a3ad20c 594static int driver_add_attrs(struct bus_type *bus, struct device_driver *drv)
1da177e4
LT
595{
596 int error = 0;
597 int i;
598
599 if (bus->drv_attrs) {
3e1026b3 600 for (i = 0; bus->drv_attrs[i].attr.name; i++) {
1da177e4
LT
601 error = driver_create_file(drv, &bus->drv_attrs[i]);
602 if (error)
4a3ad20c 603 goto err;
1da177e4
LT
604 }
605 }
4a3ad20c 606done:
1da177e4 607 return error;
4a3ad20c 608err:
1da177e4
LT
609 while (--i >= 0)
610 driver_remove_file(drv, &bus->drv_attrs[i]);
4a3ad20c 611 goto done;
1da177e4
LT
612}
613
4a3ad20c
GKH
614static void driver_remove_attrs(struct bus_type *bus,
615 struct device_driver *drv)
1da177e4
LT
616{
617 int i;
618
619 if (bus->drv_attrs) {
3e1026b3 620 for (i = 0; bus->drv_attrs[i].attr.name; i++)
1da177e4
LT
621 driver_remove_file(drv, &bus->drv_attrs[i]);
622 }
623}
624
f86db396 625static int __must_check add_bind_files(struct device_driver *drv)
874c6241 626{
f86db396
AM
627 int ret;
628
629 ret = driver_create_file(drv, &driver_attr_unbind);
630 if (ret == 0) {
631 ret = driver_create_file(drv, &driver_attr_bind);
632 if (ret)
633 driver_remove_file(drv, &driver_attr_unbind);
634 }
635 return ret;
874c6241
GKH
636}
637
638static void remove_bind_files(struct device_driver *drv)
639{
640 driver_remove_file(drv, &driver_attr_bind);
641 driver_remove_file(drv, &driver_attr_unbind);
642}
b8c5cec2 643
8380770c
KS
644static BUS_ATTR(drivers_probe, S_IWUSR, NULL, store_drivers_probe);
645static BUS_ATTR(drivers_autoprobe, S_IWUSR | S_IRUGO,
646 show_drivers_autoprobe, store_drivers_autoprobe);
647
b8c5cec2
KS
648static int add_probe_files(struct bus_type *bus)
649{
650 int retval;
651
8380770c 652 retval = bus_create_file(bus, &bus_attr_drivers_probe);
b8c5cec2
KS
653 if (retval)
654 goto out;
655
8380770c 656 retval = bus_create_file(bus, &bus_attr_drivers_autoprobe);
b8c5cec2 657 if (retval)
8380770c 658 bus_remove_file(bus, &bus_attr_drivers_probe);
b8c5cec2
KS
659out:
660 return retval;
661}
662
663static void remove_probe_files(struct bus_type *bus)
664{
8380770c
KS
665 bus_remove_file(bus, &bus_attr_drivers_autoprobe);
666 bus_remove_file(bus, &bus_attr_drivers_probe);
b8c5cec2 667}
1da177e4 668
2581c9cc
GKH
669static ssize_t uevent_store(struct device_driver *drv, const char *buf,
670 size_t count)
7ac1cf4a
KS
671{
672 enum kobject_action action;
673
674 if (kobject_action_type(buf, count, &action) == 0)
e5dd1278 675 kobject_uevent(&drv->p->kobj, action);
7ac1cf4a
KS
676 return count;
677}
2581c9cc 678static DRIVER_ATTR_WO(uevent);
7ac1cf4a 679
1da177e4 680/**
4a3ad20c
GKH
681 * bus_add_driver - Add a driver to the bus.
682 * @drv: driver.
1da177e4 683 */
f86db396 684int bus_add_driver(struct device_driver *drv)
1da177e4 685{
e5dd1278
GKH
686 struct bus_type *bus;
687 struct driver_private *priv;
1da177e4
LT
688 int error = 0;
689
e5dd1278 690 bus = bus_get(drv->bus);
d9fd4d3b 691 if (!bus)
4f6e1945 692 return -EINVAL;
d9fd4d3b 693
7dc72b28 694 pr_debug("bus: '%s': add driver %s\n", bus->name, drv->name);
e5dd1278
GKH
695
696 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
07634464
CH
697 if (!priv) {
698 error = -ENOMEM;
699 goto out_put_bus;
700 }
e5dd1278
GKH
701 klist_init(&priv->klist_devices, NULL, NULL);
702 priv->driver = drv;
703 drv->p = priv;
c8e90d82
GKH
704 priv->kobj.kset = bus->p->drivers_kset;
705 error = kobject_init_and_add(&priv->kobj, &driver_ktype, NULL,
706 "%s", drv->name);
dc0afa83 707 if (error)
07634464 708 goto out_unregister;
d9fd4d3b 709
190888ac 710 klist_add_tail(&priv->knode_bus, &bus->p->klist_drivers);
c6f7e72a 711 if (drv->bus->p->drivers_autoprobe) {
b8c5cec2
KS
712 error = driver_attach(drv);
713 if (error)
714 goto out_unregister;
715 }
d9fd4d3b
JG
716 module_add_driver(drv->owner, drv);
717
7ac1cf4a
KS
718 error = driver_create_file(drv, &driver_attr_uevent);
719 if (error) {
720 printk(KERN_ERR "%s: uevent attr (%s) failed\n",
2b3a302a 721 __func__, drv->name);
7ac1cf4a 722 }
d9fd4d3b
JG
723 error = driver_add_attrs(bus, drv);
724 if (error) {
725 /* How the hell do we get out of this pickle? Give up */
726 printk(KERN_ERR "%s: driver_add_attrs(%s) failed\n",
2b3a302a 727 __func__, drv->name);
d9fd4d3b 728 }
ed0617b5
GKH
729 error = driver_add_groups(drv, bus->drv_groups);
730 if (error)
731 printk(KERN_ERR "%s: driver_create_groups(%s) failed\n",
732 __func__, drv->name);
1a6f2a75
DT
733
734 if (!drv->suppress_bind_attrs) {
735 error = add_bind_files(drv);
736 if (error) {
737 /* Ditto */
738 printk(KERN_ERR "%s: add_bind_files(%s) failed\n",
739 __func__, drv->name);
740 }
1da177e4 741 }
d9fd4d3b 742
5c8563d7 743 return 0;
1a6f2a75 744
f86db396 745out_unregister:
99b28f1b 746 kobject_put(&priv->kobj);
5c8563d7
KS
747 kfree(drv->p);
748 drv->p = NULL;
f86db396 749out_put_bus:
fc1ede58 750 bus_put(bus);
f86db396 751 return error;
1da177e4
LT
752}
753
1da177e4 754/**
4a3ad20c
GKH
755 * bus_remove_driver - delete driver from bus's knowledge.
756 * @drv: driver.
1da177e4 757 *
4a3ad20c
GKH
758 * Detach the driver from the devices it controls, and remove
759 * it from its bus's list of drivers. Finally, we drop the reference
760 * to the bus we took in bus_add_driver().
1da177e4 761 */
4a3ad20c 762void bus_remove_driver(struct device_driver *drv)
1da177e4 763{
d9fd4d3b
JG
764 if (!drv->bus)
765 return;
766
1a6f2a75
DT
767 if (!drv->suppress_bind_attrs)
768 remove_bind_files(drv);
d9fd4d3b 769 driver_remove_attrs(drv->bus, drv);
ed0617b5 770 driver_remove_groups(drv, drv->bus->drv_groups);
7ac1cf4a 771 driver_remove_file(drv, &driver_attr_uevent);
e5dd1278 772 klist_remove(&drv->p->knode_bus);
7dc72b28 773 pr_debug("bus: '%s': remove driver %s\n", drv->bus->name, drv->name);
d9fd4d3b
JG
774 driver_detach(drv);
775 module_remove_driver(drv);
c10997f6 776 kobject_put(&drv->p->kobj);
fc1ede58 777 bus_put(drv->bus);
1da177e4
LT
778}
779
1da177e4 780/* Helper for bus_rescan_devices's iter */
f86db396 781static int __must_check bus_rescan_devices_helper(struct device *dev,
4a3ad20c 782 void *data)
1da177e4 783{
f86db396
AM
784 int ret = 0;
785
bf74ad5b
AS
786 if (!dev->driver) {
787 if (dev->parent) /* Needed for USB */
8e9394ce 788 device_lock(dev->parent);
f86db396 789 ret = device_attach(dev);
bf74ad5b 790 if (dev->parent)
8e9394ce 791 device_unlock(dev->parent);
bf74ad5b 792 }
f86db396 793 return ret < 0 ? ret : 0;
1da177e4
LT
794}
795
1da177e4 796/**
23d3d602
GKH
797 * bus_rescan_devices - rescan devices on the bus for possible drivers
798 * @bus: the bus to scan.
1da177e4 799 *
23d3d602
GKH
800 * This function will look for devices on the bus with no driver
801 * attached and rescan it against existing drivers to see if it matches
802 * any by calling device_attach() for the unbound devices.
1da177e4 803 */
4a3ad20c 804int bus_rescan_devices(struct bus_type *bus)
1da177e4 805{
f86db396 806 return bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper);
1da177e4 807}
4a3ad20c 808EXPORT_SYMBOL_GPL(bus_rescan_devices);
1da177e4 809
e935d5da
ME
810/**
811 * device_reprobe - remove driver for a device and probe for a new driver
812 * @dev: the device to reprobe
813 *
814 * This function detaches the attached driver (if any) for the given
815 * device and restarts the driver probing process. It is intended
816 * to use if probing criteria changed during a devices lifetime and
817 * driver attachment should change accordingly.
818 */
f86db396 819int device_reprobe(struct device *dev)
e935d5da
ME
820{
821 if (dev->driver) {
822 if (dev->parent) /* Needed for USB */
8e9394ce 823 device_lock(dev->parent);
e935d5da
ME
824 device_release_driver(dev);
825 if (dev->parent)
8e9394ce 826 device_unlock(dev->parent);
e935d5da 827 }
f86db396 828 return bus_rescan_devices_helper(dev, NULL);
e935d5da
ME
829}
830EXPORT_SYMBOL_GPL(device_reprobe);
1da177e4 831
1da177e4 832/**
4a3ad20c
GKH
833 * find_bus - locate bus by name.
834 * @name: name of bus.
1da177e4 835 *
4a3ad20c
GKH
836 * Call kset_find_obj() to iterate over list of buses to
837 * find a bus by name. Return bus if found.
1da177e4 838 *
4a3ad20c 839 * Note that kset_find_obj increments bus' reference count.
1da177e4 840 */
7e4ef085 841#if 0
4a3ad20c 842struct bus_type *find_bus(char *name)
1da177e4 843{
4a3ad20c 844 struct kobject *k = kset_find_obj(bus_kset, name);
1da177e4
LT
845 return k ? to_bus(k) : NULL;
846}
7e4ef085 847#endif /* 0 */
1da177e4
LT
848
849
850/**
4a3ad20c
GKH
851 * bus_add_attrs - Add default attributes for this bus.
852 * @bus: Bus that has just been registered.
1da177e4
LT
853 */
854
4a3ad20c 855static int bus_add_attrs(struct bus_type *bus)
1da177e4
LT
856{
857 int error = 0;
858 int i;
859
860 if (bus->bus_attrs) {
3e1026b3 861 for (i = 0; bus->bus_attrs[i].attr.name; i++) {
4a3ad20c 862 error = bus_create_file(bus, &bus->bus_attrs[i]);
dc0afa83 863 if (error)
4a3ad20c 864 goto err;
1da177e4
LT
865 }
866 }
4a3ad20c 867done:
1da177e4 868 return error;
4a3ad20c 869err:
1da177e4 870 while (--i >= 0)
4a3ad20c
GKH
871 bus_remove_file(bus, &bus->bus_attrs[i]);
872 goto done;
1da177e4
LT
873}
874
4a3ad20c 875static void bus_remove_attrs(struct bus_type *bus)
1da177e4
LT
876{
877 int i;
878
879 if (bus->bus_attrs) {
3e1026b3 880 for (i = 0; bus->bus_attrs[i].attr.name; i++)
4a3ad20c 881 bus_remove_file(bus, &bus->bus_attrs[i]);
1da177e4
LT
882 }
883}
884
12478ba0
GKH
885static int bus_add_groups(struct bus_type *bus,
886 const struct attribute_group **groups)
887{
3e9b2bae 888 return sysfs_create_groups(&bus->p->subsys.kobj, groups);
12478ba0
GKH
889}
890
891static void bus_remove_groups(struct bus_type *bus,
892 const struct attribute_group **groups)
893{
3e9b2bae 894 sysfs_remove_groups(&bus->p->subsys.kobj, groups);
12478ba0
GKH
895}
896
34bb61f9
JB
897static void klist_devices_get(struct klist_node *n)
898{
ae1b4171
GKH
899 struct device_private *dev_prv = to_device_private_bus(n);
900 struct device *dev = dev_prv->device;
34bb61f9
JB
901
902 get_device(dev);
903}
904
905static void klist_devices_put(struct klist_node *n)
906{
ae1b4171
GKH
907 struct device_private *dev_prv = to_device_private_bus(n);
908 struct device *dev = dev_prv->device;
34bb61f9
JB
909
910 put_device(dev);
911}
912
7ac1cf4a
KS
913static ssize_t bus_uevent_store(struct bus_type *bus,
914 const char *buf, size_t count)
915{
916 enum kobject_action action;
917
918 if (kobject_action_type(buf, count, &action) == 0)
c6f7e72a 919 kobject_uevent(&bus->p->subsys.kobj, action);
7ac1cf4a
KS
920 return count;
921}
922static BUS_ATTR(uevent, S_IWUSR, NULL, bus_uevent_store);
923
1da177e4 924/**
be871b7e 925 * bus_register - register a driver-core subsystem
78d79559 926 * @bus: bus to register
1da177e4 927 *
78d79559 928 * Once we have that, we register the bus with the kobject
4a3ad20c 929 * infrastructure, then register the children subsystems it has:
ca22e56d 930 * the devices and drivers that belong to the subsystem.
1da177e4 931 */
be871b7e 932int bus_register(struct bus_type *bus)
1da177e4
LT
933{
934 int retval;
6b6e39a6 935 struct subsys_private *priv;
be871b7e 936 struct lock_class_key *key = &bus->lock_key;
c6f7e72a 937
6b6e39a6 938 priv = kzalloc(sizeof(struct subsys_private), GFP_KERNEL);
c6f7e72a
GKH
939 if (!priv)
940 return -ENOMEM;
941
942 priv->bus = bus;
943 bus->p = priv;
1da177e4 944
c6f7e72a 945 BLOCKING_INIT_NOTIFIER_HEAD(&priv->bus_notifier);
116af378 946
c6f7e72a 947 retval = kobject_set_name(&priv->subsys.kobj, "%s", bus->name);
1da177e4
LT
948 if (retval)
949 goto out;
950
c6f7e72a
GKH
951 priv->subsys.kobj.kset = bus_kset;
952 priv->subsys.kobj.ktype = &bus_ktype;
953 priv->drivers_autoprobe = 1;
d6b05b84 954
c6f7e72a 955 retval = kset_register(&priv->subsys);
1da177e4
LT
956 if (retval)
957 goto out;
958
7ac1cf4a
KS
959 retval = bus_create_file(bus, &bus_attr_uevent);
960 if (retval)
961 goto bus_uevent_fail;
962
c6f7e72a
GKH
963 priv->devices_kset = kset_create_and_add("devices", NULL,
964 &priv->subsys.kobj);
965 if (!priv->devices_kset) {
3d899596 966 retval = -ENOMEM;
1da177e4 967 goto bus_devices_fail;
3d899596 968 }
1da177e4 969
c6f7e72a
GKH
970 priv->drivers_kset = kset_create_and_add("drivers", NULL,
971 &priv->subsys.kobj);
972 if (!priv->drivers_kset) {
6dcec251 973 retval = -ENOMEM;
1da177e4 974 goto bus_drivers_fail;
6dcec251 975 }
465c7a3a 976
ca22e56d
KS
977 INIT_LIST_HEAD(&priv->interfaces);
978 __mutex_init(&priv->mutex, "subsys mutex", key);
c6f7e72a
GKH
979 klist_init(&priv->klist_devices, klist_devices_get, klist_devices_put);
980 klist_init(&priv->klist_drivers, NULL, NULL);
b8c5cec2 981
b8c5cec2
KS
982 retval = add_probe_files(bus);
983 if (retval)
984 goto bus_probe_files_fail;
985
1bb6881a
CH
986 retval = bus_add_attrs(bus);
987 if (retval)
988 goto bus_attrs_fail;
12478ba0
GKH
989 retval = bus_add_groups(bus, bus->bus_groups);
990 if (retval)
991 goto bus_groups_fail;
1da177e4 992
7dc72b28 993 pr_debug("bus: '%s': registered\n", bus->name);
1da177e4
LT
994 return 0;
995
12478ba0
GKH
996bus_groups_fail:
997 bus_remove_attrs(bus);
1bb6881a 998bus_attrs_fail:
b8c5cec2
KS
999 remove_probe_files(bus);
1000bus_probe_files_fail:
c6f7e72a 1001 kset_unregister(bus->p->drivers_kset);
1da177e4 1002bus_drivers_fail:
c6f7e72a 1003 kset_unregister(bus->p->devices_kset);
1da177e4 1004bus_devices_fail:
7ac1cf4a
KS
1005 bus_remove_file(bus, &bus_attr_uevent);
1006bus_uevent_fail:
c6f7e72a 1007 kset_unregister(&bus->p->subsys);
1da177e4 1008out:
600c20f3 1009 kfree(bus->p);
f48f3feb 1010 bus->p = NULL;
1da177e4
LT
1011 return retval;
1012}
be871b7e 1013EXPORT_SYMBOL_GPL(bus_register);
1da177e4 1014
1da177e4 1015/**
4a3ad20c
GKH
1016 * bus_unregister - remove a bus from the system
1017 * @bus: bus.
1da177e4 1018 *
4a3ad20c
GKH
1019 * Unregister the child subsystems and the bus itself.
1020 * Finally, we call bus_put() to release the refcount
1da177e4 1021 */
4a3ad20c 1022void bus_unregister(struct bus_type *bus)
1da177e4 1023{
7dc72b28 1024 pr_debug("bus: '%s': unregistering\n", bus->name);
ca22e56d
KS
1025 if (bus->dev_root)
1026 device_unregister(bus->dev_root);
1da177e4 1027 bus_remove_attrs(bus);
12478ba0 1028 bus_remove_groups(bus, bus->bus_groups);
b8c5cec2 1029 remove_probe_files(bus);
c6f7e72a
GKH
1030 kset_unregister(bus->p->drivers_kset);
1031 kset_unregister(bus->p->devices_kset);
7ac1cf4a 1032 bus_remove_file(bus, &bus_attr_uevent);
c6f7e72a
GKH
1033 kset_unregister(&bus->p->subsys);
1034 kfree(bus->p);
f48f3feb 1035 bus->p = NULL;
1da177e4 1036}
4a3ad20c 1037EXPORT_SYMBOL_GPL(bus_unregister);
1da177e4 1038
116af378
BH
1039int bus_register_notifier(struct bus_type *bus, struct notifier_block *nb)
1040{
c6f7e72a 1041 return blocking_notifier_chain_register(&bus->p->bus_notifier, nb);
116af378
BH
1042}
1043EXPORT_SYMBOL_GPL(bus_register_notifier);
1044
1045int bus_unregister_notifier(struct bus_type *bus, struct notifier_block *nb)
1046{
c6f7e72a 1047 return blocking_notifier_chain_unregister(&bus->p->bus_notifier, nb);
116af378
BH
1048}
1049EXPORT_SYMBOL_GPL(bus_unregister_notifier);
1050
0fed80f7
GKH
1051struct kset *bus_get_kset(struct bus_type *bus)
1052{
c6f7e72a 1053 return &bus->p->subsys;
0fed80f7
GKH
1054}
1055EXPORT_SYMBOL_GPL(bus_get_kset);
1056
b249072e
GKH
1057struct klist *bus_get_device_klist(struct bus_type *bus)
1058{
c6f7e72a 1059 return &bus->p->klist_devices;
b249072e
GKH
1060}
1061EXPORT_SYMBOL_GPL(bus_get_device_klist);
1062
99178b03 1063/*
dca25ebd 1064 * Yes, this forcibly breaks the klist abstraction temporarily. It
99178b03
GKH
1065 * just wants to sort the klist, not change reference counts and
1066 * take/drop locks rapidly in the process. It does all this while
1067 * holding the lock for the list, so objects can't otherwise be
1068 * added/removed while we're swizzling.
1069 */
1070static void device_insertion_sort_klist(struct device *a, struct list_head *list,
1071 int (*compare)(const struct device *a,
1072 const struct device *b))
1073{
1074 struct list_head *pos;
1075 struct klist_node *n;
ae1b4171 1076 struct device_private *dev_prv;
99178b03
GKH
1077 struct device *b;
1078
1079 list_for_each(pos, list) {
1080 n = container_of(pos, struct klist_node, n_node);
ae1b4171
GKH
1081 dev_prv = to_device_private_bus(n);
1082 b = dev_prv->device;
99178b03 1083 if (compare(a, b) <= 0) {
ae1b4171
GKH
1084 list_move_tail(&a->p->knode_bus.n_node,
1085 &b->p->knode_bus.n_node);
99178b03
GKH
1086 return;
1087 }
1088 }
ae1b4171 1089 list_move_tail(&a->p->knode_bus.n_node, list);
99178b03
GKH
1090}
1091
1092void bus_sort_breadthfirst(struct bus_type *bus,
1093 int (*compare)(const struct device *a,
1094 const struct device *b))
1095{
1096 LIST_HEAD(sorted_devices);
1097 struct list_head *pos, *tmp;
1098 struct klist_node *n;
ae1b4171 1099 struct device_private *dev_prv;
99178b03
GKH
1100 struct device *dev;
1101 struct klist *device_klist;
1102
1103 device_klist = bus_get_device_klist(bus);
1104
1105 spin_lock(&device_klist->k_lock);
1106 list_for_each_safe(pos, tmp, &device_klist->k_list) {
1107 n = container_of(pos, struct klist_node, n_node);
ae1b4171
GKH
1108 dev_prv = to_device_private_bus(n);
1109 dev = dev_prv->device;
99178b03
GKH
1110 device_insertion_sort_klist(dev, &sorted_devices, compare);
1111 }
1112 list_splice(&sorted_devices, &device_klist->k_list);
1113 spin_unlock(&device_klist->k_lock);
1114}
1115EXPORT_SYMBOL_GPL(bus_sort_breadthfirst);
1116
ca22e56d
KS
1117/**
1118 * subsys_dev_iter_init - initialize subsys device iterator
1119 * @iter: subsys iterator to initialize
1120 * @subsys: the subsys we wanna iterate over
1121 * @start: the device to start iterating from, if any
1122 * @type: device_type of the devices to iterate over, NULL for all
1123 *
1124 * Initialize subsys iterator @iter such that it iterates over devices
1125 * of @subsys. If @start is set, the list iteration will start there,
1126 * otherwise if it is NULL, the iteration starts at the beginning of
1127 * the list.
1128 */
7cd9c9bb
GKH
1129void subsys_dev_iter_init(struct subsys_dev_iter *iter, struct bus_type *subsys,
1130 struct device *start, const struct device_type *type)
ca22e56d
KS
1131{
1132 struct klist_node *start_knode = NULL;
1133
1134 if (start)
1135 start_knode = &start->p->knode_bus;
7cd9c9bb
GKH
1136 klist_iter_init_node(&subsys->p->klist_devices, &iter->ki, start_knode);
1137 iter->type = type;
ca22e56d
KS
1138}
1139EXPORT_SYMBOL_GPL(subsys_dev_iter_init);
1140
1141/**
1142 * subsys_dev_iter_next - iterate to the next device
1143 * @iter: subsys iterator to proceed
1144 *
1145 * Proceed @iter to the next device and return it. Returns NULL if
1146 * iteration is complete.
1147 *
1148 * The returned device is referenced and won't be released till
1149 * iterator is proceed to the next device or exited. The caller is
1150 * free to do whatever it wants to do with the device including
1151 * calling back into subsys code.
1152 */
1153struct device *subsys_dev_iter_next(struct subsys_dev_iter *iter)
1154{
1155 struct klist_node *knode;
1156 struct device *dev;
1157
1158 for (;;) {
1159 knode = klist_next(&iter->ki);
1160 if (!knode)
1161 return NULL;
1162 dev = container_of(knode, struct device_private, knode_bus)->device;
1163 if (!iter->type || iter->type == dev->type)
1164 return dev;
1165 }
1166}
1167EXPORT_SYMBOL_GPL(subsys_dev_iter_next);
1168
1169/**
1170 * subsys_dev_iter_exit - finish iteration
1171 * @iter: subsys iterator to finish
1172 *
1173 * Finish an iteration. Always call this function after iteration is
1174 * complete whether the iteration ran till the end or not.
1175 */
1176void subsys_dev_iter_exit(struct subsys_dev_iter *iter)
1177{
1178 klist_iter_exit(&iter->ki);
1179}
1180EXPORT_SYMBOL_GPL(subsys_dev_iter_exit);
1181
1182int subsys_interface_register(struct subsys_interface *sif)
1183{
1184 struct bus_type *subsys;
1185 struct subsys_dev_iter iter;
1186 struct device *dev;
1187
1188 if (!sif || !sif->subsys)
1189 return -ENODEV;
1190
1191 subsys = bus_get(sif->subsys);
1192 if (!subsys)
1193 return -EINVAL;
1194
1195 mutex_lock(&subsys->p->mutex);
1196 list_add_tail(&sif->node, &subsys->p->interfaces);
1197 if (sif->add_dev) {
1198 subsys_dev_iter_init(&iter, subsys, NULL, NULL);
1199 while ((dev = subsys_dev_iter_next(&iter)))
1200 sif->add_dev(dev, sif);
1201 subsys_dev_iter_exit(&iter);
1202 }
1203 mutex_unlock(&subsys->p->mutex);
1204
1205 return 0;
1206}
1207EXPORT_SYMBOL_GPL(subsys_interface_register);
1208
1209void subsys_interface_unregister(struct subsys_interface *sif)
1210{
2b31594a 1211 struct bus_type *subsys;
ca22e56d
KS
1212 struct subsys_dev_iter iter;
1213 struct device *dev;
1214
2b31594a 1215 if (!sif || !sif->subsys)
ca22e56d
KS
1216 return;
1217
2b31594a
JC
1218 subsys = sif->subsys;
1219
ca22e56d
KS
1220 mutex_lock(&subsys->p->mutex);
1221 list_del_init(&sif->node);
1222 if (sif->remove_dev) {
1223 subsys_dev_iter_init(&iter, subsys, NULL, NULL);
1224 while ((dev = subsys_dev_iter_next(&iter)))
1225 sif->remove_dev(dev, sif);
1226 subsys_dev_iter_exit(&iter);
1227 }
1228 mutex_unlock(&subsys->p->mutex);
1229
1230 bus_put(subsys);
1231}
1232EXPORT_SYMBOL_GPL(subsys_interface_unregister);
1233
1234static void system_root_device_release(struct device *dev)
1235{
1236 kfree(dev);
1237}
d73ce004
TH
1238
1239static int subsys_register(struct bus_type *subsys,
1240 const struct attribute_group **groups,
1241 struct kobject *parent_of_root)
ca22e56d
KS
1242{
1243 struct device *dev;
1244 int err;
1245
1246 err = bus_register(subsys);
1247 if (err < 0)
1248 return err;
1249
1250 dev = kzalloc(sizeof(struct device), GFP_KERNEL);
1251 if (!dev) {
1252 err = -ENOMEM;
1253 goto err_dev;
1254 }
1255
1256 err = dev_set_name(dev, "%s", subsys->name);
1257 if (err < 0)
1258 goto err_name;
1259
d73ce004 1260 dev->kobj.parent = parent_of_root;
ca22e56d
KS
1261 dev->groups = groups;
1262 dev->release = system_root_device_release;
1263
1264 err = device_register(dev);
1265 if (err < 0)
1266 goto err_dev_reg;
1267
1268 subsys->dev_root = dev;
1269 return 0;
1270
1271err_dev_reg:
1272 put_device(dev);
1273 dev = NULL;
1274err_name:
1275 kfree(dev);
1276err_dev:
1277 bus_unregister(subsys);
1278 return err;
1279}
d73ce004
TH
1280
1281/**
1282 * subsys_system_register - register a subsystem at /sys/devices/system/
1283 * @subsys: system subsystem
1284 * @groups: default attributes for the root device
1285 *
1286 * All 'system' subsystems have a /sys/devices/system/<name> root device
1287 * with the name of the subsystem. The root device can carry subsystem-
1288 * wide attributes. All registered devices are below this single root
1289 * device and are named after the subsystem with a simple enumeration
1290 * number appended. The registered devices are not explicitely named;
1291 * only 'id' in the device needs to be set.
1292 *
1293 * Do not use this interface for anything new, it exists for compatibility
1294 * with bad ideas only. New subsystems should use plain subsystems; and
1295 * add the subsystem-wide attributes should be added to the subsystem
1296 * directory itself and not some create fake root-device placed in
1297 * /sys/devices/system/<name>.
1298 */
1299int subsys_system_register(struct bus_type *subsys,
1300 const struct attribute_group **groups)
1301{
1302 return subsys_register(subsys, groups, &system_kset->kobj);
1303}
ca22e56d
KS
1304EXPORT_SYMBOL_GPL(subsys_system_register);
1305
d73ce004
TH
1306/**
1307 * subsys_virtual_register - register a subsystem at /sys/devices/virtual/
1308 * @subsys: virtual subsystem
1309 * @groups: default attributes for the root device
1310 *
1311 * All 'virtual' subsystems have a /sys/devices/system/<name> root device
1312 * with the name of the subystem. The root device can carry subsystem-wide
1313 * attributes. All registered devices are below this single root device.
1314 * There's no restriction on device naming. This is for kernel software
1315 * constructs which need sysfs interface.
1316 */
1317int subsys_virtual_register(struct bus_type *subsys,
1318 const struct attribute_group **groups)
1319{
1320 struct kobject *virtual_dir;
1321
1322 virtual_dir = virtual_device_parent(NULL);
1323 if (!virtual_dir)
1324 return -ENOMEM;
1325
1326 return subsys_register(subsys, groups, virtual_dir);
1327}
1c04fc35 1328EXPORT_SYMBOL_GPL(subsys_virtual_register);
d73ce004 1329
1da177e4
LT
1330int __init buses_init(void)
1331{
59a54833
GKH
1332 bus_kset = kset_create_and_add("bus", &bus_uevent_ops, NULL);
1333 if (!bus_kset)
1334 return -ENOMEM;
ca22e56d
KS
1335
1336 system_kset = kset_create_and_add("system", NULL, &devices_kset->kobj);
1337 if (!system_kset)
1338 return -ENOMEM;
1339
59a54833 1340 return 0;
1da177e4 1341}