core.c 35.1 KB
Newer Older
L
Linus Torvalds 已提交
1 2 3 4 5
/*
 * drivers/base/core.c - core driver model code (device registration, etc)
 *
 * Copyright (c) 2002-3 Patrick Mochel
 * Copyright (c) 2002-3 Open Source Development Labs
6 7
 * Copyright (c) 2006 Greg Kroah-Hartman <gregkh@suse.de>
 * Copyright (c) 2006 Novell, Inc.
L
Linus Torvalds 已提交
8 9 10 11 12 13 14 15 16 17 18
 *
 * This file is released under the GPLv2
 *
 */

#include <linux/device.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/string.h>
19
#include <linux/kdev_t.h>
20
#include <linux/notifier.h>
L
Linus Torvalds 已提交
21 22 23 24 25 26 27 28 29 30 31 32 33

#include <asm/semaphore.h>

#include "base.h"
#include "power/power.h"

int (*platform_notify)(struct device * dev) = NULL;
int (*platform_notify_remove)(struct device * dev) = NULL;

/*
 * sysfs bindings for devices.
 */

34 35 36 37 38 39 40 41 42 43 44 45
/**
 * dev_driver_string - Return a device's driver name, if at all possible
 * @dev: struct device to get the name of
 *
 * Will return the device's driver's name if it is bound to a device.  If
 * the device is not bound to a device, it will return the name of the bus
 * it is attached to.  If it is not attached to a bus either, an empty
 * string will be returned.
 */
const char *dev_driver_string(struct device *dev)
{
	return dev->driver ? dev->driver->name :
46 47
			(dev->bus ? dev->bus->name :
			(dev->class ? dev->class->name : ""));
48
}
M
Matthew Wilcox 已提交
49
EXPORT_SYMBOL(dev_driver_string);
50

L
Linus Torvalds 已提交
51 52 53 54 55 56 57 58
#define to_dev(obj) container_of(obj, struct device, kobj)
#define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)

static ssize_t
dev_attr_show(struct kobject * kobj, struct attribute * attr, char * buf)
{
	struct device_attribute * dev_attr = to_dev_attr(attr);
	struct device * dev = to_dev(kobj);
59
	ssize_t ret = -EIO;
L
Linus Torvalds 已提交
60 61

	if (dev_attr->show)
62
		ret = dev_attr->show(dev, dev_attr, buf);
L
Linus Torvalds 已提交
63 64 65 66 67 68 69 70 71
	return ret;
}

static ssize_t
dev_attr_store(struct kobject * kobj, struct attribute * attr,
	       const char * buf, size_t count)
{
	struct device_attribute * dev_attr = to_dev_attr(attr);
	struct device * dev = to_dev(kobj);
72
	ssize_t ret = -EIO;
L
Linus Torvalds 已提交
73 74

	if (dev_attr->store)
75
		ret = dev_attr->store(dev, dev_attr, buf, count);
L
Linus Torvalds 已提交
76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98
	return ret;
}

static struct sysfs_ops dev_sysfs_ops = {
	.show	= dev_attr_show,
	.store	= dev_attr_store,
};


/**
 *	device_release - free device structure.
 *	@kobj:	device's kobject.
 *
 *	This is called once the reference count for the object
 *	reaches 0. We forward the call to the device's release
 *	method, which should handle actually freeing the structure.
 */
static void device_release(struct kobject * kobj)
{
	struct device * dev = to_dev(kobj);

	if (dev->release)
		dev->release(dev);
99 100
	else if (dev->type && dev->type->release)
		dev->type->release(dev);
101 102
	else if (dev->class && dev->class->dev_release)
		dev->class->dev_release(dev);
L
Linus Torvalds 已提交
103 104 105 106 107 108 109 110
	else {
		printk(KERN_ERR "Device '%s' does not have a release() function, "
			"it is broken and must be fixed.\n",
			dev->bus_id);
		WARN_ON(1);
	}
}

111
static struct kobj_type device_ktype = {
L
Linus Torvalds 已提交
112 113 114 115 116
	.release	= device_release,
	.sysfs_ops	= &dev_sysfs_ops,
};


117
static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
L
Linus Torvalds 已提交
118 119 120
{
	struct kobj_type *ktype = get_ktype(kobj);

121
	if (ktype == &device_ktype) {
L
Linus Torvalds 已提交
122
		struct device *dev = to_dev(kobj);
123 124
		if (dev->uevent_suppress)
			return 0;
L
Linus Torvalds 已提交
125 126
		if (dev->bus)
			return 1;
127 128
		if (dev->class)
			return 1;
L
Linus Torvalds 已提交
129 130 131 132
	}
	return 0;
}

133
static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
L
Linus Torvalds 已提交
134 135 136
{
	struct device *dev = to_dev(kobj);

137 138 139 140 141
	if (dev->bus)
		return dev->bus->name;
	if (dev->class)
		return dev->class->name;
	return NULL;
L
Linus Torvalds 已提交
142 143
}

144 145
static int dev_uevent(struct kset *kset, struct kobject *kobj,
		      struct kobj_uevent_env *env)
L
Linus Torvalds 已提交
146 147 148 149
{
	struct device *dev = to_dev(kobj);
	int retval = 0;

150 151
	/* add the major/minor if present */
	if (MAJOR(dev->devt)) {
152 153
		add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
		add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
154 155
	}

156
	if (dev->type && dev->type->name)
157
		add_uevent_var(env, "DEVTYPE=%s", dev->type->name);
158

159
	if (dev->driver)
160
		add_uevent_var(env, "DRIVER=%s", dev->driver->name);
161

162
#ifdef CONFIG_SYSFS_DEPRECATED
163 164 165 166 167 168 169 170 171 172
	if (dev->class) {
		struct device *parent = dev->parent;

		/* find first bus device in parent chain */
		while (parent && !parent->bus)
			parent = parent->parent;
		if (parent && parent->bus) {
			const char *path;

			path = kobject_get_path(&parent->kobj, GFP_KERNEL);
173
			if (path) {
174
				add_uevent_var(env, "PHYSDEVPATH=%s", path);
175 176
				kfree(path);
			}
177

178
			add_uevent_var(env, "PHYSDEVBUS=%s", parent->bus->name);
179 180

			if (parent->driver)
181 182
				add_uevent_var(env, "PHYSDEVDRIVER=%s",
					       parent->driver->name);
183 184
		}
	} else if (dev->bus) {
185
		add_uevent_var(env, "PHYSDEVBUS=%s", dev->bus->name);
186 187

		if (dev->driver)
188
			add_uevent_var(env, "PHYSDEVDRIVER=%s", dev->driver->name);
K
Kay Sievers 已提交
189
	}
190
#endif
L
Linus Torvalds 已提交
191

192
	/* have the bus specific function add its stuff */
193
	if (dev->bus && dev->bus->uevent) {
194
		retval = dev->bus->uevent(dev, env);
195 196
		if (retval)
			pr_debug ("%s: bus uevent() returned %d\n",
L
Linus Torvalds 已提交
197 198 199
				  __FUNCTION__, retval);
	}

200
	/* have the class specific function add its stuff */
201
	if (dev->class && dev->class->dev_uevent) {
202
		retval = dev->class->dev_uevent(dev, env);
203 204 205 206 207
		if (retval)
			pr_debug("%s: class uevent() returned %d\n",
				 __FUNCTION__, retval);
	}

208
	/* have the device type specific fuction add its stuff */
209
	if (dev->type && dev->type->uevent) {
210
		retval = dev->type->uevent(dev, env);
211 212 213
		if (retval)
			pr_debug("%s: dev_type uevent() returned %d\n",
				 __FUNCTION__, retval);
214 215
	}

L
Linus Torvalds 已提交
216 217 218
	return retval;
}

219 220 221 222
static struct kset_uevent_ops device_uevent_ops = {
	.filter =	dev_uevent_filter,
	.name =		dev_uevent_name,
	.uevent =	dev_uevent,
L
Linus Torvalds 已提交
223 224
};

225 226 227 228 229
static ssize_t show_uevent(struct device *dev, struct device_attribute *attr,
			   char *buf)
{
	struct kobject *top_kobj;
	struct kset *kset;
230
	struct kobj_uevent_env *env = NULL;
231 232 233 234 235 236
	int i;
	size_t count = 0;
	int retval;

	/* search the kset, the device belongs to */
	top_kobj = &dev->kobj;
237 238
	while (!top_kobj->kset && top_kobj->parent)
		top_kobj = top_kobj->parent;
239 240
	if (!top_kobj->kset)
		goto out;
241

242 243 244 245 246 247 248 249 250
	kset = top_kobj->kset;
	if (!kset->uevent_ops || !kset->uevent_ops->uevent)
		goto out;

	/* respect filter */
	if (kset->uevent_ops && kset->uevent_ops->filter)
		if (!kset->uevent_ops->filter(kset, &dev->kobj))
			goto out;

251 252
	env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
	if (!env)
253 254
		return -ENOMEM;

255
	/* let the kset specific function add its keys */
256
	retval = kset->uevent_ops->uevent(kset, &dev->kobj, env);
257 258 259 260
	if (retval)
		goto out;

	/* copy keys to file */
261 262
	for (i = 0; i < env->envp_idx; i++)
		count += sprintf(&buf[count], "%s\n", env->envp[i]);
263
out:
264
	kfree(env);
265 266 267
	return count;
}

268 269 270
static ssize_t store_uevent(struct device *dev, struct device_attribute *attr,
			    const char *buf, size_t count)
{
271 272
	enum kobject_action action;

273
	if (kobject_action_type(buf, count, &action) == 0) {
274 275 276 277 278 279
		kobject_uevent(&dev->kobj, action);
		goto out;
	}

	dev_err(dev, "uevent: unsupported action-string; this will "
		     "be ignored in a future kernel version\n");
280
	kobject_uevent(&dev->kobj, KOBJ_ADD);
281
out:
282 283 284
	return count;
}

285 286 287
static struct device_attribute uevent_attr =
	__ATTR(uevent, S_IRUGO | S_IWUSR, show_uevent, store_uevent);

288 289
static int device_add_attributes(struct device *dev,
				 struct device_attribute *attrs)
290
{
291
	int error = 0;
292
	int i;
293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319

	if (attrs) {
		for (i = 0; attr_name(attrs[i]); i++) {
			error = device_create_file(dev, &attrs[i]);
			if (error)
				break;
		}
		if (error)
			while (--i >= 0)
				device_remove_file(dev, &attrs[i]);
	}
	return error;
}

static void device_remove_attributes(struct device *dev,
				     struct device_attribute *attrs)
{
	int i;

	if (attrs)
		for (i = 0; attr_name(attrs[i]); i++)
			device_remove_file(dev, &attrs[i]);
}

static int device_add_groups(struct device *dev,
			     struct attribute_group **groups)
{
320
	int error = 0;
321
	int i;
322

323 324 325
	if (groups) {
		for (i = 0; groups[i]; i++) {
			error = sysfs_create_group(&dev->kobj, groups[i]);
326 327
			if (error) {
				while (--i >= 0)
328 329
					sysfs_remove_group(&dev->kobj, groups[i]);
				break;
330 331 332 333 334 335
			}
		}
	}
	return error;
}

336 337
static void device_remove_groups(struct device *dev,
				 struct attribute_group **groups)
338 339
{
	int i;
340 341 342 343

	if (groups)
		for (i = 0; groups[i]; i++)
			sysfs_remove_group(&dev->kobj, groups[i]);
344 345
}

346 347 348
static int device_add_attrs(struct device *dev)
{
	struct class *class = dev->class;
349
	struct device_type *type = dev->type;
350
	int error;
351

352 353
	if (class) {
		error = device_add_attributes(dev, class->dev_attrs);
354
		if (error)
355
			return error;
356
	}
357

358 359
	if (type) {
		error = device_add_groups(dev, type->groups);
360
		if (error)
361
			goto err_remove_class_attrs;
362 363
	}

364 365 366 367 368 369 370 371 372 373 374 375 376
	error = device_add_groups(dev, dev->groups);
	if (error)
		goto err_remove_type_groups;

	return 0;

 err_remove_type_groups:
	if (type)
		device_remove_groups(dev, type->groups);
 err_remove_class_attrs:
	if (class)
		device_remove_attributes(dev, class->dev_attrs);

377 378 379 380 381 382
	return error;
}

static void device_remove_attrs(struct device *dev)
{
	struct class *class = dev->class;
383
	struct device_type *type = dev->type;
384

385
	device_remove_groups(dev, dev->groups);
386

387 388 389 390 391
	if (type)
		device_remove_groups(dev, type->groups);

	if (class)
		device_remove_attributes(dev, class->dev_attrs);
392 393 394
}


395 396 397 398 399 400
static ssize_t show_dev(struct device *dev, struct device_attribute *attr,
			char *buf)
{
	return print_dev_t(buf, dev->devt);
}

401 402 403
static struct device_attribute devt_attr =
	__ATTR(dev, S_IRUGO, show_dev, NULL);

404 405
/*
 *	devices_subsys - structure to be registered with kobject core.
L
Linus Torvalds 已提交
406 407
 */

408
decl_subsys(devices, &device_uevent_ops);
L
Linus Torvalds 已提交
409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440


/**
 *	device_create_file - create sysfs attribute file for device.
 *	@dev:	device.
 *	@attr:	device attribute descriptor.
 */

int device_create_file(struct device * dev, struct device_attribute * attr)
{
	int error = 0;
	if (get_device(dev)) {
		error = sysfs_create_file(&dev->kobj, &attr->attr);
		put_device(dev);
	}
	return error;
}

/**
 *	device_remove_file - remove sysfs attribute file.
 *	@dev:	device.
 *	@attr:	device attribute descriptor.
 */

void device_remove_file(struct device * dev, struct device_attribute * attr)
{
	if (get_device(dev)) {
		sysfs_remove_file(&dev->kobj, &attr->attr);
		put_device(dev);
	}
}

441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466
/**
 * device_create_bin_file - create sysfs binary attribute file for device.
 * @dev: device.
 * @attr: device binary attribute descriptor.
 */
int device_create_bin_file(struct device *dev, struct bin_attribute *attr)
{
	int error = -EINVAL;
	if (dev)
		error = sysfs_create_bin_file(&dev->kobj, attr);
	return error;
}
EXPORT_SYMBOL_GPL(device_create_bin_file);

/**
 * device_remove_bin_file - remove sysfs binary attribute file
 * @dev: device.
 * @attr: device binary attribute descriptor.
 */
void device_remove_bin_file(struct device *dev, struct bin_attribute *attr)
{
	if (dev)
		sysfs_remove_bin_file(&dev->kobj, attr);
}
EXPORT_SYMBOL_GPL(device_remove_bin_file);

467
/**
468
 * device_schedule_callback_owner - helper to schedule a callback for a device
469 470
 * @dev: device.
 * @func: callback function to invoke later.
471
 * @owner: module owning the callback routine
472 473 474 475 476 477 478 479 480 481
 *
 * Attribute methods must not unregister themselves or their parent device
 * (which would amount to the same thing).  Attempts to do so will deadlock,
 * since unregistration is mutually exclusive with driver callbacks.
 *
 * Instead methods can call this routine, which will attempt to allocate
 * and schedule a workqueue request to call back @func with @dev as its
 * argument in the workqueue's process context.  @dev will be pinned until
 * @func returns.
 *
482 483 484
 * This routine is usually called via the inline device_schedule_callback(),
 * which automatically sets @owner to THIS_MODULE.
 *
485
 * Returns 0 if the request was submitted, -ENOMEM if storage could not
486
 * be allocated, -ENODEV if a reference to @owner isn't available.
487 488 489 490 491
 *
 * NOTE: This routine won't work if CONFIG_SYSFS isn't set!  It uses an
 * underlying sysfs routine (since it is intended for use by attribute
 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
 */
492 493
int device_schedule_callback_owner(struct device *dev,
		void (*func)(struct device *), struct module *owner)
494 495
{
	return sysfs_schedule_callback(&dev->kobj,
496
			(void (*)(void *)) func, dev, owner);
497
}
498
EXPORT_SYMBOL_GPL(device_schedule_callback_owner);
499

500 501 502 503 504 505 506 507 508 509 510 511 512 513
static void klist_children_get(struct klist_node *n)
{
	struct device *dev = container_of(n, struct device, knode_parent);

	get_device(dev);
}

static void klist_children_put(struct klist_node *n)
{
	struct device *dev = container_of(n, struct device, knode_parent);

	put_device(dev);
}

L
Linus Torvalds 已提交
514 515 516 517 518 519 520 521 522 523 524 525 526 527

/**
 *	device_initialize - init device structure.
 *	@dev:	device.
 *
 *	This prepares the device for use by other layers,
 *	including adding it to the device hierarchy.
 *	It is the first half of device_register(), if called by
 *	that, though it can also be called separately, so one
 *	may use @dev's fields (e.g. the refcount).
 */

void device_initialize(struct device *dev)
{
528 529
	dev->kobj.kset = &devices_subsys;
	dev->kobj.ktype = &device_ktype;
L
Linus Torvalds 已提交
530
	kobject_init(&dev->kobj);
531 532
	klist_init(&dev->klist_children, klist_children_get,
		   klist_children_put);
L
Linus Torvalds 已提交
533
	INIT_LIST_HEAD(&dev->dma_pools);
534
	INIT_LIST_HEAD(&dev->node);
535
	init_MUTEX(&dev->sem);
T
Tejun Heo 已提交
536 537
	spin_lock_init(&dev->devres_lock);
	INIT_LIST_HEAD(&dev->devres_head);
D
David Brownell 已提交
538
	device_init_wakeup(dev, 0);
539
	set_dev_node(dev, -1);
L
Linus Torvalds 已提交
540 541
}

542
#ifdef CONFIG_SYSFS_DEPRECATED
543 544
static struct kobject * get_device_parent(struct device *dev,
					  struct device *parent)
545
{
546 547 548 549 550 551 552
	/*
	 * Set the parent to the class, not the parent device
	 * for topmost devices in class hierarchy.
	 * This keeps sysfs from having a symlink to make old
	 * udevs happy
	 */
	if (dev->class && (!parent || parent->class != dev->class))
553
		return &dev->class->subsys.kobj;
554
	else if (parent)
555
		return &parent->kobj;
556

557
	return NULL;
558 559
}
#else
560
static struct kobject *virtual_device_parent(struct device *dev)
561
{
562
	static struct kobject *virtual_dir = NULL;
563

564
	if (!virtual_dir)
565 566
		virtual_dir = kobject_create_and_add("virtual",
						     &devices_subsys.kobj);
567

568
	return virtual_dir;
569 570
}

571 572
static struct kobject * get_device_parent(struct device *dev,
					  struct device *parent)
573
{
574 575
	int retval;

576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604
	if (dev->class) {
		struct kobject *kobj = NULL;
		struct kobject *parent_kobj;
		struct kobject *k;

		/*
		 * If we have no parent, we live in "virtual".
		 * Class-devices with a bus-device as parent, live
		 * in a class-directory to prevent namespace collisions.
		 */
		if (parent == NULL)
			parent_kobj = virtual_device_parent(dev);
		else if (parent->class)
			return &parent->kobj;
		else
			parent_kobj = &parent->kobj;

		/* find our class-directory at the parent and reference it */
		spin_lock(&dev->class->class_dirs.list_lock);
		list_for_each_entry(k, &dev->class->class_dirs.list, entry)
			if (k->parent == parent_kobj) {
				kobj = kobject_get(k);
				break;
			}
		spin_unlock(&dev->class->class_dirs.list_lock);
		if (kobj)
			return kobj;

		/* or create a new class-directory at the parent device */
605 606 607 608 609 610 611 612 613 614 615 616
		k = kobject_create();
		if (!k)
			return NULL;
		k->kset = &dev->class->class_dirs;
		retval = kobject_add_ng(k, parent_kobj, "%s", dev->class->name);
		if (retval < 0) {
			kobject_put(k);
			return NULL;
		}
		/* Do not emit a uevent, as it's not needed for this
		 * "class glue" directory. */
		return k;
617 618 619
	}

	if (parent)
620 621 622 623
		return &parent->kobj;
	return NULL;
}
#endif
624

625 626 627 628 629 630 631 632
static int setup_parent(struct device *dev, struct device *parent)
{
	struct kobject *kobj;
	kobj = get_device_parent(dev, parent);
	if (IS_ERR(kobj))
		return PTR_ERR(kobj);
	if (kobj)
		dev->kobj.parent = kobj;
633 634 635
	return 0;
}

636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655
static int device_add_class_symlinks(struct device *dev)
{
	int error;

	if (!dev->class)
		return 0;
	error = sysfs_create_link(&dev->kobj, &dev->class->subsys.kobj,
				  "subsystem");
	if (error)
		goto out;
	/*
	 * If this is not a "fake" compatible device, then create the
	 * symlink from the class to the device.
	 */
	if (dev->kobj.parent != &dev->class->subsys.kobj) {
		error = sysfs_create_link(&dev->class->subsys.kobj, &dev->kobj,
					  dev->bus_id);
		if (error)
			goto out_subsys;
	}
656
	if (dev->parent) {
657 658
#ifdef CONFIG_SYSFS_DEPRECATED
		{
659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676
			struct device *parent = dev->parent;
			char *class_name;

			/*
			 * In old sysfs stacked class devices had 'device'
			 * link pointing to real device instead of parent
			 */
			while (parent->class && !parent->bus && parent->parent)
				parent = parent->parent;

			error = sysfs_create_link(&dev->kobj,
						  &parent->kobj,
						  "device");
			if (error)
				goto out_busid;

			class_name = make_class_name(dev->class->name,
							&dev->kobj);
677 678 679 680 681 682 683
			if (class_name)
				error = sysfs_create_link(&dev->parent->kobj,
							&dev->kobj, class_name);
			kfree(class_name);
			if (error)
				goto out_device;
		}
684 685 686 687 688
#else
		error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
					  "device");
		if (error)
			goto out_busid;
689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727
#endif
	}
	return 0;

#ifdef CONFIG_SYSFS_DEPRECATED
out_device:
	if (dev->parent)
		sysfs_remove_link(&dev->kobj, "device");
#endif
out_busid:
	if (dev->kobj.parent != &dev->class->subsys.kobj)
		sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
out_subsys:
	sysfs_remove_link(&dev->kobj, "subsystem");
out:
	return error;
}

static void device_remove_class_symlinks(struct device *dev)
{
	if (!dev->class)
		return;
	if (dev->parent) {
#ifdef CONFIG_SYSFS_DEPRECATED
		char *class_name;

		class_name = make_class_name(dev->class->name, &dev->kobj);
		if (class_name) {
			sysfs_remove_link(&dev->parent->kobj, class_name);
			kfree(class_name);
		}
#endif
		sysfs_remove_link(&dev->kobj, "device");
	}
	if (dev->kobj.parent != &dev->class->subsys.kobj)
		sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
	sysfs_remove_link(&dev->kobj, "subsystem");
}

L
Linus Torvalds 已提交
728 729 730 731 732 733 734 735 736 737 738 739 740 741
/**
 *	device_add - add device to device hierarchy.
 *	@dev:	device.
 *
 *	This is part 2 of device_register(), though may be called
 *	separately _iff_ device_initialize() has been called separately.
 *
 *	This adds it to the kobject hierarchy via kobject_add(), adds it
 *	to the global and sibling lists for the device, then
 *	adds it to the other relevant subsystems of the driver model.
 */
int device_add(struct device *dev)
{
	struct device *parent = NULL;
742
	struct class_interface *class_intf;
743 744 745 746 747 748 749 750
	int error;

	error = pm_sleep_lock();
	if (error) {
		dev_warn(dev, "Suspicious %s during suspend\n", __FUNCTION__);
		dump_stack();
		return error;
	}
L
Linus Torvalds 已提交
751 752

	dev = get_device(dev);
753 754
	if (!dev || !strlen(dev->bus_id)) {
		error = -EINVAL;
L
Linus Torvalds 已提交
755
		goto Error;
756
	}
L
Linus Torvalds 已提交
757

758
	pr_debug("DEV: registering device: ID = '%s'\n", dev->bus_id);
759

L
Linus Torvalds 已提交
760
	parent = get_device(dev->parent);
761 762 763
	error = setup_parent(dev, parent);
	if (error)
		goto Error;
L
Linus Torvalds 已提交
764 765 766

	/* first, register with generic layer. */
	kobject_set_name(&dev->kobj, "%s", dev->bus_id);
767 768
	error = kobject_add(&dev->kobj);
	if (error)
L
Linus Torvalds 已提交
769
		goto Error;
770

771 772 773 774
	/* notify platform of device entry */
	if (platform_notify)
		platform_notify(dev);

775 776 777 778 779
	/* notify clients of device entry (new way) */
	if (dev->bus)
		blocking_notifier_call_chain(&dev->bus->bus_notifier,
					     BUS_NOTIFY_ADD_DEVICE, dev);

780
	error = device_create_file(dev, &uevent_attr);
781 782
	if (error)
		goto attrError;
783

784
	if (MAJOR(dev->devt)) {
785 786
		error = device_create_file(dev, &devt_attr);
		if (error)
787
			goto ueventattrError;
788 789
	}

790 791 792
	error = device_add_class_symlinks(dev);
	if (error)
		goto SymlinkError;
793 794
	error = device_add_attrs(dev);
	if (error)
795
		goto AttrsError;
796
	error = dpm_sysfs_add(dev);
797
	if (error)
L
Linus Torvalds 已提交
798
		goto PMError;
799
	device_pm_add(dev);
800 801
	error = bus_add_device(dev);
	if (error)
L
Linus Torvalds 已提交
802
		goto BusError;
803
	kobject_uevent(&dev->kobj, KOBJ_ADD);
804
	bus_attach_device(dev);
L
Linus Torvalds 已提交
805
	if (parent)
806
		klist_add_tail(&dev->knode_parent, &parent->klist_children);
L
Linus Torvalds 已提交
807

808 809
	if (dev->class) {
		down(&dev->class->sem);
810
		/* tie the class to the device */
811
		list_add_tail(&dev->node, &dev->class->devices);
812 813 814 815 816

		/* notify any interfaces that the device is here */
		list_for_each_entry(class_intf, &dev->class->interfaces, node)
			if (class_intf->add_dev)
				class_intf->add_dev(dev, class_intf);
817 818
		up(&dev->class->sem);
	}
L
Linus Torvalds 已提交
819 820
 Done:
	put_device(dev);
821
	pm_sleep_unlock();
L
Linus Torvalds 已提交
822 823 824
	return error;
 BusError:
	device_pm_remove(dev);
825
	dpm_sysfs_remove(dev);
L
Linus Torvalds 已提交
826
 PMError:
827 828 829
	if (dev->bus)
		blocking_notifier_call_chain(&dev->bus->bus_notifier,
					     BUS_NOTIFY_DEL_DEVICE, dev);
830
	device_remove_attrs(dev);
831
 AttrsError:
832 833
	device_remove_class_symlinks(dev);
 SymlinkError:
834 835
	if (MAJOR(dev->devt))
		device_remove_file(dev, &devt_attr);
836 837 838 839 840

	if (dev->class) {
		sysfs_remove_link(&dev->kobj, "subsystem");
		/* If this is not a "fake" compatible device, remove the
		 * symlink from the class to the device. */
841 842
		if (dev->kobj.parent != &dev->class->subsys.kobj)
			sysfs_remove_link(&dev->class->subsys.kobj,
843 844
					  dev->bus_id);
		if (parent) {
845
#ifdef CONFIG_SYSFS_DEPRECATED
846 847 848 849 850 851
			char *class_name = make_class_name(dev->class->name,
							   &dev->kobj);
			if (class_name)
				sysfs_remove_link(&dev->parent->kobj,
						  class_name);
			kfree(class_name);
852
#endif
853 854 855
			sysfs_remove_link(&dev->kobj, "device");
		}
	}
856
 ueventattrError:
857
	device_remove_file(dev, &uevent_attr);
858
 attrError:
859
	kobject_uevent(&dev->kobj, KOBJ_REMOVE);
L
Linus Torvalds 已提交
860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929
	kobject_del(&dev->kobj);
 Error:
	if (parent)
		put_device(parent);
	goto Done;
}


/**
 *	device_register - register a device with the system.
 *	@dev:	pointer to the device structure
 *
 *	This happens in two clean steps - initialize the device
 *	and add it to the system. The two steps can be called
 *	separately, but this is the easiest and most common.
 *	I.e. you should only call the two helpers separately if
 *	have a clearly defined need to use and refcount the device
 *	before it is added to the hierarchy.
 */

int device_register(struct device *dev)
{
	device_initialize(dev);
	return device_add(dev);
}


/**
 *	get_device - increment reference count for device.
 *	@dev:	device.
 *
 *	This simply forwards the call to kobject_get(), though
 *	we do take care to provide for the case that we get a NULL
 *	pointer passed in.
 */

struct device * get_device(struct device * dev)
{
	return dev ? to_dev(kobject_get(&dev->kobj)) : NULL;
}


/**
 *	put_device - decrement reference count.
 *	@dev:	device in question.
 */
void put_device(struct device * dev)
{
	if (dev)
		kobject_put(&dev->kobj);
}


/**
 *	device_del - delete device from system.
 *	@dev:	device.
 *
 *	This is the first part of the device unregistration
 *	sequence. This removes the device from the lists we control
 *	from here, has it removed from the other driver model
 *	subsystems it was added to in device_add(), and removes it
 *	from the kobject hierarchy.
 *
 *	NOTE: this should be called manually _iff_ device_add() was
 *	also called manually.
 */

void device_del(struct device * dev)
{
	struct device * parent = dev->parent;
930
	struct class_interface *class_intf;
L
Linus Torvalds 已提交
931

932
	device_pm_remove(dev);
L
Linus Torvalds 已提交
933
	if (parent)
934
		klist_del(&dev->knode_parent);
935 936
	if (MAJOR(dev->devt))
		device_remove_file(dev, &devt_attr);
937 938
	if (dev->class) {
		sysfs_remove_link(&dev->kobj, "subsystem");
939 940
		/* If this is not a "fake" compatible device, remove the
		 * symlink from the class to the device. */
941 942
		if (dev->kobj.parent != &dev->class->subsys.kobj)
			sysfs_remove_link(&dev->class->subsys.kobj,
943
					  dev->bus_id);
944
		if (parent) {
945
#ifdef CONFIG_SYSFS_DEPRECATED
946 947
			char *class_name = make_class_name(dev->class->name,
							   &dev->kobj);
948 949 950
			if (class_name)
				sysfs_remove_link(&dev->parent->kobj,
						  class_name);
951
			kfree(class_name);
952
#endif
953
			sysfs_remove_link(&dev->kobj, "device");
954
		}
955

956
		down(&dev->class->sem);
957 958 959 960 961
		/* notify any interfaces that the device is now gone */
		list_for_each_entry(class_intf, &dev->class->interfaces, node)
			if (class_intf->remove_dev)
				class_intf->remove_dev(dev, class_intf);
		/* remove the device from the class list */
962 963
		list_del_init(&dev->node);
		up(&dev->class->sem);
964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988

		/* If we live in a parent class-directory, unreference it */
		if (dev->kobj.parent->kset == &dev->class->class_dirs) {
			struct device *d;
			int other = 0;

			/*
			 * if we are the last child of our class, delete
			 * our class-directory at this parent
			 */
			down(&dev->class->sem);
			list_for_each_entry(d, &dev->class->devices, node) {
				if (d == dev)
					continue;
				if (d->kobj.parent == dev->kobj.parent) {
					other = 1;
					break;
				}
			}
			if (!other)
				kobject_del(dev->kobj.parent);

			kobject_put(dev->kobj.parent);
			up(&dev->class->sem);
		}
989
	}
990
	device_remove_file(dev, &uevent_attr);
991
	device_remove_attrs(dev);
992
	bus_remove_device(dev);
L
Linus Torvalds 已提交
993

994 995 996 997 998 999 1000
	/*
	 * Some platform devices are driven without driver attached
	 * and managed resources may have been acquired.  Make sure
	 * all resources are released.
	 */
	devres_release_all(dev);

L
Linus Torvalds 已提交
1001 1002 1003 1004 1005
	/* Notify the platform of the removal, in case they
	 * need to do anything...
	 */
	if (platform_notify_remove)
		platform_notify_remove(dev);
1006 1007 1008
	if (dev->bus)
		blocking_notifier_call_chain(&dev->bus->bus_notifier,
					     BUS_NOTIFY_DEL_DEVICE, dev);
1009
	kobject_uevent(&dev->kobj, KOBJ_REMOVE);
L
Linus Torvalds 已提交
1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033
	kobject_del(&dev->kobj);
	if (parent)
		put_device(parent);
}

/**
 *	device_unregister - unregister device from system.
 *	@dev:	device going away.
 *
 *	We do this in two parts, like we do device_register(). First,
 *	we remove it from all the subsystems with device_del(), then
 *	we decrement the reference count via put_device(). If that
 *	is the final reference count, the device will be cleaned up
 *	via device_release() above. Otherwise, the structure will
 *	stick around until the final reference to the device is dropped.
 */
void device_unregister(struct device * dev)
{
	pr_debug("DEV: Unregistering device. ID = '%s'\n", dev->bus_id);
	device_del(dev);
	put_device(dev);
}


1034 1035 1036 1037 1038 1039
static struct device * next_device(struct klist_iter * i)
{
	struct klist_node * n = klist_next(i);
	return n ? container_of(n, struct device, knode_parent) : NULL;
}

L
Linus Torvalds 已提交
1040 1041
/**
 *	device_for_each_child - device child iterator.
1042
 *	@parent: parent struct device.
L
Linus Torvalds 已提交
1043 1044 1045
 *	@data:	data for the callback.
 *	@fn:	function to be called for each device.
 *
1046
 *	Iterate over @parent's child devices, and call @fn for each,
L
Linus Torvalds 已提交
1047 1048 1049 1050 1051
 *	passing it @data.
 *
 *	We check the return of @fn each time. If it returns anything
 *	other than 0, we break out and return that value.
 */
1052
int device_for_each_child(struct device * parent, void * data,
L
Linus Torvalds 已提交
1053 1054
		     int (*fn)(struct device *, void *))
{
1055
	struct klist_iter i;
L
Linus Torvalds 已提交
1056 1057 1058
	struct device * child;
	int error = 0;

1059 1060 1061 1062
	klist_iter_init(&parent->klist_children, &i);
	while ((child = next_device(&i)) && !error)
		error = fn(child, data);
	klist_iter_exit(&i);
L
Linus Torvalds 已提交
1063 1064 1065
	return error;
}

1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097
/**
 * device_find_child - device iterator for locating a particular device.
 * @parent: parent struct device
 * @data: Data to pass to match function
 * @match: Callback function to check device
 *
 * This is similar to the device_for_each_child() function above, but it
 * returns a reference to a device that is 'found' for later use, as
 * determined by the @match callback.
 *
 * The callback should return 0 if the device doesn't match and non-zero
 * if it does.  If the callback returns non-zero and a reference to the
 * current device can be obtained, this function will return to the caller
 * and not iterate over any more devices.
 */
struct device * device_find_child(struct device *parent, void *data,
				  int (*match)(struct device *, void *))
{
	struct klist_iter i;
	struct device *child;

	if (!parent)
		return NULL;

	klist_iter_init(&parent->klist_children, &i);
	while ((child = next_device(&i)))
		if (match(child, data) && get_device(child))
			break;
	klist_iter_exit(&i);
	return child;
}

L
Linus Torvalds 已提交
1098 1099 1100 1101 1102 1103
int __init devices_init(void)
{
	return subsystem_register(&devices_subsys);
}

EXPORT_SYMBOL_GPL(device_for_each_child);
1104
EXPORT_SYMBOL_GPL(device_find_child);
L
Linus Torvalds 已提交
1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116

EXPORT_SYMBOL_GPL(device_initialize);
EXPORT_SYMBOL_GPL(device_add);
EXPORT_SYMBOL_GPL(device_register);

EXPORT_SYMBOL_GPL(device_del);
EXPORT_SYMBOL_GPL(device_unregister);
EXPORT_SYMBOL_GPL(get_device);
EXPORT_SYMBOL_GPL(put_device);

EXPORT_SYMBOL_GPL(device_create_file);
EXPORT_SYMBOL_GPL(device_remove_file);
1117 1118 1119 1120 1121 1122 1123 1124 1125 1126


static void device_create_release(struct device *dev)
{
	pr_debug("%s called for %s\n", __FUNCTION__, dev->bus_id);
	kfree(dev);
}

/**
 * device_create - creates a device and registers it with sysfs
1127 1128 1129 1130 1131 1132 1133
 * @class: pointer to the struct class that this device should be registered to
 * @parent: pointer to the parent struct device of this new device, if any
 * @devt: the dev_t for the char device to be added
 * @fmt: string for the device's name
 *
 * This function can be used by char device classes.  A struct device
 * will be created in sysfs, registered to the specified class.
1134 1135 1136
 *
 * A "dev" file will be created, showing the dev_t for the device, if
 * the dev_t is not 0,0.
1137 1138 1139 1140
 * If a pointer to a parent struct device is passed in, the newly created
 * struct device will be a child of that device in sysfs.
 * The pointer to the struct device will be returned from the call.
 * Any further sysfs files that might be required can be created using this
1141 1142 1143 1144 1145 1146
 * pointer.
 *
 * Note: the struct class passed to this function must have previously
 * been created with a call to class_create().
 */
struct device *device_create(struct class *class, struct device *parent,
1147
			     dev_t devt, const char *fmt, ...)
1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182
{
	va_list args;
	struct device *dev = NULL;
	int retval = -ENODEV;

	if (class == NULL || IS_ERR(class))
		goto error;

	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
	if (!dev) {
		retval = -ENOMEM;
		goto error;
	}

	dev->devt = devt;
	dev->class = class;
	dev->parent = parent;
	dev->release = device_create_release;

	va_start(args, fmt);
	vsnprintf(dev->bus_id, BUS_ID_SIZE, fmt, args);
	va_end(args);
	retval = device_register(dev);
	if (retval)
		goto error;

	return dev;

error:
	kfree(dev);
	return ERR_PTR(retval);
}
EXPORT_SYMBOL_GPL(device_create);

/**
1183
 * find_device - finds a device that was created with device_create()
1184 1185
 * @class: pointer to the struct class that this device was registered with
 * @devt: the dev_t of the device that was previously registered
1186
 */
1187
static struct device *find_device(struct class *class, dev_t devt)
1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199
{
	struct device *dev = NULL;
	struct device *dev_tmp;

	down(&class->sem);
	list_for_each_entry(dev_tmp, &class->devices, node) {
		if (dev_tmp->devt == devt) {
			dev = dev_tmp;
			break;
		}
	}
	up(&class->sem);
1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213
	return dev;
}

/**
 * device_destroy - removes a device that was created with device_create()
 * @class: pointer to the struct class that this device was registered with
 * @devt: the dev_t of the device that was previously registered
 *
 * This call unregisters and cleans up a device that was created with a
 * call to device_create().
 */
void device_destroy(struct class *class, dev_t devt)
{
	struct device *dev;
1214

1215
	dev = find_device(class, devt);
1216
	if (dev)
1217 1218 1219
		device_unregister(dev);
}
EXPORT_SYMBOL_GPL(device_destroy);
1220

1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247
#ifdef CONFIG_PM_SLEEP
/**
 * destroy_suspended_device - asks the PM core to remove a suspended device
 * @class: pointer to the struct class that this device was registered with
 * @devt: the dev_t of the device that was previously registered
 *
 * This call notifies the PM core of the necessity to unregister a suspended
 * device created with a call to device_create() (devices cannot be
 * unregistered directly while suspended, since the PM core holds their
 * semaphores at that time).
 *
 * It can only be called within the scope of a system sleep transition.  In
 * practice this means it has to be directly or indirectly invoked either by
 * a suspend or resume method, or by the PM core (e.g. via
 * disable_nonboot_cpus() or enable_nonboot_cpus()).
 */
void destroy_suspended_device(struct class *class, dev_t devt)
{
	struct device *dev;

	dev = find_device(class, devt);
	if (dev)
		device_pm_schedule_removal(dev);
}
EXPORT_SYMBOL_GPL(destroy_suspended_device);
#endif /* CONFIG_PM_SLEEP */

1248 1249 1250 1251 1252 1253 1254 1255 1256
/**
 * device_rename - renames a device
 * @dev: the pointer to the struct device to be renamed
 * @new_name: the new name of the device
 */
int device_rename(struct device *dev, char *new_name)
{
	char *old_class_name = NULL;
	char *new_class_name = NULL;
1257
	char *old_device_name = NULL;
1258 1259 1260 1261 1262 1263 1264 1265
	int error;

	dev = get_device(dev);
	if (!dev)
		return -EINVAL;

	pr_debug("DEVICE: renaming '%s' to '%s'\n", dev->bus_id, new_name);

1266
#ifdef CONFIG_SYSFS_DEPRECATED
1267 1268
	if ((dev->class) && (dev->parent))
		old_class_name = make_class_name(dev->class->name, &dev->kobj);
1269
#endif
1270

1271 1272 1273 1274
	old_device_name = kmalloc(BUS_ID_SIZE, GFP_KERNEL);
	if (!old_device_name) {
		error = -ENOMEM;
		goto out;
1275
	}
1276
	strlcpy(old_device_name, dev->bus_id, BUS_ID_SIZE);
1277 1278 1279
	strlcpy(dev->bus_id, new_name, BUS_ID_SIZE);

	error = kobject_rename(&dev->kobj, new_name);
1280 1281 1282 1283
	if (error) {
		strlcpy(dev->bus_id, old_device_name, BUS_ID_SIZE);
		goto out;
	}
1284

1285
#ifdef CONFIG_SYSFS_DEPRECATED
1286 1287 1288
	if (old_class_name) {
		new_class_name = make_class_name(dev->class->name, &dev->kobj);
		if (new_class_name) {
1289 1290 1291 1292
			error = sysfs_create_link(&dev->parent->kobj,
						  &dev->kobj, new_class_name);
			if (error)
				goto out;
1293 1294 1295
			sysfs_remove_link(&dev->parent->kobj, old_class_name);
		}
	}
1296
#else
1297
	if (dev->class) {
1298 1299 1300 1301 1302 1303 1304
		sysfs_remove_link(&dev->class->subsys.kobj, old_device_name);
		error = sysfs_create_link(&dev->class->subsys.kobj, &dev->kobj,
					  dev->bus_id);
		if (error) {
			dev_err(dev, "%s: sysfs_create_symlink failed (%d)\n",
				__FUNCTION__, error);
		}
1305
	}
1306 1307
#endif

1308
out:
1309 1310 1311
	put_device(dev);

	kfree(new_class_name);
1312
	kfree(old_class_name);
1313
	kfree(old_device_name);
1314 1315 1316

	return error;
}
1317
EXPORT_SYMBOL_GPL(device_rename);
1318 1319 1320 1321 1322

static int device_move_class_links(struct device *dev,
				   struct device *old_parent,
				   struct device *new_parent)
{
1323
	int error = 0;
1324 1325 1326 1327 1328
#ifdef CONFIG_SYSFS_DEPRECATED
	char *class_name;

	class_name = make_class_name(dev->class->name, &dev->kobj);
	if (!class_name) {
1329
		error = -ENOMEM;
1330 1331 1332 1333 1334 1335
		goto out;
	}
	if (old_parent) {
		sysfs_remove_link(&dev->kobj, "device");
		sysfs_remove_link(&old_parent->kobj, class_name);
	}
1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347
	if (new_parent) {
		error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
					  "device");
		if (error)
			goto out;
		error = sysfs_create_link(&new_parent->kobj, &dev->kobj,
					  class_name);
		if (error)
			sysfs_remove_link(&dev->kobj, "device");
	}
	else
		error = 0;
1348 1349 1350 1351
out:
	kfree(class_name);
	return error;
#else
1352 1353 1354 1355 1356 1357
	if (old_parent)
		sysfs_remove_link(&dev->kobj, "device");
	if (new_parent)
		error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
					  "device");
	return error;
1358 1359 1360 1361 1362 1363
#endif
}

/**
 * device_move - moves a device to a new parent
 * @dev: the pointer to the struct device to be moved
1364
 * @new_parent: the new parent of the device (can by NULL)
1365 1366 1367 1368 1369
 */
int device_move(struct device *dev, struct device *new_parent)
{
	int error;
	struct device *old_parent;
1370
	struct kobject *new_parent_kobj;
1371 1372 1373 1374 1375 1376

	dev = get_device(dev);
	if (!dev)
		return -EINVAL;

	new_parent = get_device(new_parent);
1377 1378 1379 1380
	new_parent_kobj = get_device_parent (dev, new_parent);
	if (IS_ERR(new_parent_kobj)) {
		error = PTR_ERR(new_parent_kobj);
		put_device(new_parent);
1381 1382 1383
		goto out;
	}
	pr_debug("DEVICE: moving '%s' to '%s'\n", dev->bus_id,
1384 1385
		 new_parent ? new_parent->bus_id : "<NULL>");
	error = kobject_move(&dev->kobj, new_parent_kobj);
1386 1387 1388 1389 1390 1391 1392
	if (error) {
		put_device(new_parent);
		goto out;
	}
	old_parent = dev->parent;
	dev->parent = new_parent;
	if (old_parent)
1393
		klist_remove(&dev->knode_parent);
1394 1395
	if (new_parent)
		klist_add_tail(&dev->knode_parent, &new_parent->klist_children);
1396 1397 1398 1399 1400 1401 1402
	if (!dev->class)
		goto out_put;
	error = device_move_class_links(dev, old_parent, new_parent);
	if (error) {
		/* We ignore errors on cleanup since we're hosed anyway... */
		device_move_class_links(dev, new_parent, old_parent);
		if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
1403 1404
			if (new_parent)
				klist_remove(&dev->knode_parent);
1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419
			if (old_parent)
				klist_add_tail(&dev->knode_parent,
					       &old_parent->klist_children);
		}
		put_device(new_parent);
		goto out;
	}
out_put:
	put_device(old_parent);
out:
	put_device(dev);
	return error;
}

EXPORT_SYMBOL_GPL(device_move);