core.c 33.3 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_ktype, &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
514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529

/**
 *	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)
{
	kobj_set_kset_s(dev, devices_subsys);
	kobject_init(&dev->kobj);
530 531
	klist_init(&dev->klist_children, klist_children_get,
		   klist_children_put);
L
Linus Torvalds 已提交
532
	INIT_LIST_HEAD(&dev->dma_pools);
533
	INIT_LIST_HEAD(&dev->node);
534
	init_MUTEX(&dev->sem);
T
Tejun Heo 已提交
535 536
	spin_lock_init(&dev->devres_lock);
	INIT_LIST_HEAD(&dev->devres_head);
D
David Brownell 已提交
537
	device_init_wakeup(dev, 0);
538
	set_dev_node(dev, -1);
L
Linus Torvalds 已提交
539 540
}

541
#ifdef CONFIG_SYSFS_DEPRECATED
542 543
static struct kobject * get_device_parent(struct device *dev,
					  struct device *parent)
544
{
545 546 547 548 549 550 551
	/*
	 * 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))
552
		return &dev->class->subsys.kobj;
553
	else if (parent)
554
		return &parent->kobj;
555

556
	return NULL;
557 558
}
#else
559
static struct kobject *virtual_device_parent(struct device *dev)
560
{
561
	static struct kobject *virtual_dir = NULL;
562

563
	if (!virtual_dir)
564
		virtual_dir = kobject_add_dir(&devices_subsys.kobj, "virtual");
565

566
	return virtual_dir;
567 568
}

569 570
static struct kobject * get_device_parent(struct device *dev,
					  struct device *parent)
571
{
572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605
	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 */
		return kobject_kset_add_dir(&dev->class->class_dirs,
					    parent_kobj, dev->class->name);
	}

	if (parent)
606 607 608 609
		return &parent->kobj;
	return NULL;
}
#endif
610

611 612 613 614 615 616 617 618
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;
619 620 621
	return 0;
}

622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641
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;
	}
642
	if (dev->parent) {
643 644
#ifdef CONFIG_SYSFS_DEPRECATED
		{
645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662
			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);
663 664 665 666 667 668 669
			if (class_name)
				error = sysfs_create_link(&dev->parent->kobj,
							&dev->kobj, class_name);
			kfree(class_name);
			if (error)
				goto out_device;
		}
670 671 672 673 674
#else
		error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
					  "device");
		if (error)
			goto out_busid;
675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713
#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
714 715 716 717 718 719 720 721 722 723 724 725 726 727
/**
 *	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;
728
	struct class_interface *class_intf;
L
Linus Torvalds 已提交
729 730 731 732 733 734
	int error = -EINVAL;

	dev = get_device(dev);
	if (!dev || !strlen(dev->bus_id))
		goto Error;

735
	pr_debug("DEV: registering device: ID = '%s'\n", dev->bus_id);
736

L
Linus Torvalds 已提交
737
	parent = get_device(dev->parent);
738 739 740
	error = setup_parent(dev, parent);
	if (error)
		goto Error;
L
Linus Torvalds 已提交
741 742 743

	/* first, register with generic layer. */
	kobject_set_name(&dev->kobj, "%s", dev->bus_id);
744 745
	error = kobject_add(&dev->kobj);
	if (error)
L
Linus Torvalds 已提交
746
		goto Error;
747

748 749 750 751
	/* notify platform of device entry */
	if (platform_notify)
		platform_notify(dev);

752 753 754 755 756
	/* notify clients of device entry (new way) */
	if (dev->bus)
		blocking_notifier_call_chain(&dev->bus->bus_notifier,
					     BUS_NOTIFY_ADD_DEVICE, dev);

757
	error = device_create_file(dev, &uevent_attr);
758 759
	if (error)
		goto attrError;
760

761
	if (MAJOR(dev->devt)) {
762 763
		error = device_create_file(dev, &devt_attr);
		if (error)
764
			goto ueventattrError;
765 766
	}

767 768 769
	error = device_add_class_symlinks(dev);
	if (error)
		goto SymlinkError;
770 771
	error = device_add_attrs(dev);
	if (error)
772
		goto AttrsError;
773
	error = dpm_sysfs_add(dev);
774
	if (error)
L
Linus Torvalds 已提交
775
		goto PMError;
776
	device_pm_add(dev);
777 778
	error = bus_add_device(dev);
	if (error)
L
Linus Torvalds 已提交
779
		goto BusError;
780
	kobject_uevent(&dev->kobj, KOBJ_ADD);
781
	bus_attach_device(dev);
L
Linus Torvalds 已提交
782
	if (parent)
783
		klist_add_tail(&dev->knode_parent, &parent->klist_children);
L
Linus Torvalds 已提交
784

785 786
	if (dev->class) {
		down(&dev->class->sem);
787
		/* tie the class to the device */
788
		list_add_tail(&dev->node, &dev->class->devices);
789 790 791 792 793

		/* 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);
794 795
		up(&dev->class->sem);
	}
L
Linus Torvalds 已提交
796 797 798 799 800
 Done:
	put_device(dev);
	return error;
 BusError:
	device_pm_remove(dev);
801
	dpm_sysfs_remove(dev);
L
Linus Torvalds 已提交
802
 PMError:
803 804 805
	if (dev->bus)
		blocking_notifier_call_chain(&dev->bus->bus_notifier,
					     BUS_NOTIFY_DEL_DEVICE, dev);
806
	device_remove_attrs(dev);
807
 AttrsError:
808 809
	device_remove_class_symlinks(dev);
 SymlinkError:
810 811
	if (MAJOR(dev->devt))
		device_remove_file(dev, &devt_attr);
812 813 814 815 816

	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. */
817 818
		if (dev->kobj.parent != &dev->class->subsys.kobj)
			sysfs_remove_link(&dev->class->subsys.kobj,
819 820
					  dev->bus_id);
		if (parent) {
821
#ifdef CONFIG_SYSFS_DEPRECATED
822 823 824 825 826 827
			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);
828
#endif
829 830 831
			sysfs_remove_link(&dev->kobj, "device");
		}
	}
832
 ueventattrError:
833
	device_remove_file(dev, &uevent_attr);
834
 attrError:
835
	kobject_uevent(&dev->kobj, KOBJ_REMOVE);
L
Linus Torvalds 已提交
836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905
	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;
906
	struct class_interface *class_intf;
L
Linus Torvalds 已提交
907 908

	if (parent)
909
		klist_del(&dev->knode_parent);
910 911
	if (MAJOR(dev->devt))
		device_remove_file(dev, &devt_attr);
912 913
	if (dev->class) {
		sysfs_remove_link(&dev->kobj, "subsystem");
914 915
		/* If this is not a "fake" compatible device, remove the
		 * symlink from the class to the device. */
916 917
		if (dev->kobj.parent != &dev->class->subsys.kobj)
			sysfs_remove_link(&dev->class->subsys.kobj,
918
					  dev->bus_id);
919
		if (parent) {
920
#ifdef CONFIG_SYSFS_DEPRECATED
921 922
			char *class_name = make_class_name(dev->class->name,
							   &dev->kobj);
923 924 925
			if (class_name)
				sysfs_remove_link(&dev->parent->kobj,
						  class_name);
926
			kfree(class_name);
927
#endif
928
			sysfs_remove_link(&dev->kobj, "device");
929
		}
930

931
		down(&dev->class->sem);
932 933 934 935 936
		/* 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 */
937 938
		list_del_init(&dev->node);
		up(&dev->class->sem);
939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963

		/* 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);
		}
964
	}
965
	device_remove_file(dev, &uevent_attr);
966
	device_remove_attrs(dev);
967
	bus_remove_device(dev);
L
Linus Torvalds 已提交
968

969 970 971 972 973 974 975
	/*
	 * 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
976 977 978 979 980
	/* Notify the platform of the removal, in case they
	 * need to do anything...
	 */
	if (platform_notify_remove)
		platform_notify_remove(dev);
981 982 983
	if (dev->bus)
		blocking_notifier_call_chain(&dev->bus->bus_notifier,
					     BUS_NOTIFY_DEL_DEVICE, dev);
L
Linus Torvalds 已提交
984
	device_pm_remove(dev);
985
	kobject_uevent(&dev->kobj, KOBJ_REMOVE);
L
Linus Torvalds 已提交
986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009
	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);
}


1010 1011 1012 1013 1014 1015
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
1016 1017
/**
 *	device_for_each_child - device child iterator.
1018
 *	@parent: parent struct device.
L
Linus Torvalds 已提交
1019 1020 1021
 *	@data:	data for the callback.
 *	@fn:	function to be called for each device.
 *
1022
 *	Iterate over @parent's child devices, and call @fn for each,
L
Linus Torvalds 已提交
1023 1024 1025 1026 1027
 *	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.
 */
1028
int device_for_each_child(struct device * parent, void * data,
L
Linus Torvalds 已提交
1029 1030
		     int (*fn)(struct device *, void *))
{
1031
	struct klist_iter i;
L
Linus Torvalds 已提交
1032 1033 1034
	struct device * child;
	int error = 0;

1035 1036 1037 1038
	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
1039 1040 1041
	return error;
}

1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073
/**
 * 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
1074 1075 1076 1077 1078 1079
int __init devices_init(void)
{
	return subsystem_register(&devices_subsys);
}

EXPORT_SYMBOL_GPL(device_for_each_child);
1080
EXPORT_SYMBOL_GPL(device_find_child);
L
Linus Torvalds 已提交
1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092

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);
1093 1094 1095 1096 1097 1098 1099 1100 1101 1102


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
1103 1104 1105 1106 1107 1108 1109
 * @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.
1110 1111 1112
 *
 * A "dev" file will be created, showing the dev_t for the device, if
 * the dev_t is not 0,0.
1113 1114 1115 1116
 * 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
1117 1118 1119 1120 1121 1122
 * 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,
1123
			     dev_t devt, const char *fmt, ...)
1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159
{
	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);

/**
 * device_destroy - removes a device that was created with device_create()
1160 1161
 * @class: pointer to the struct class that this device was registered with
 * @devt: the dev_t of the device that was previously registered
1162
 *
1163 1164
 * This call unregisters and cleans up a device that was created with a
 * call to device_create().
1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179
 */
void device_destroy(struct class *class, dev_t devt)
{
	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);

1180
	if (dev)
1181 1182 1183
		device_unregister(dev);
}
EXPORT_SYMBOL_GPL(device_destroy);
1184 1185 1186 1187 1188 1189 1190 1191 1192 1193

/**
 * 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;
1194
	char *old_device_name = NULL;
1195 1196 1197 1198 1199 1200 1201 1202
	int error;

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

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

1203
#ifdef CONFIG_SYSFS_DEPRECATED
1204 1205
	if ((dev->class) && (dev->parent))
		old_class_name = make_class_name(dev->class->name, &dev->kobj);
1206
#endif
1207

1208 1209 1210 1211
	old_device_name = kmalloc(BUS_ID_SIZE, GFP_KERNEL);
	if (!old_device_name) {
		error = -ENOMEM;
		goto out;
1212
	}
1213
	strlcpy(old_device_name, dev->bus_id, BUS_ID_SIZE);
1214 1215 1216
	strlcpy(dev->bus_id, new_name, BUS_ID_SIZE);

	error = kobject_rename(&dev->kobj, new_name);
1217 1218 1219 1220
	if (error) {
		strlcpy(dev->bus_id, old_device_name, BUS_ID_SIZE);
		goto out;
	}
1221

1222
#ifdef CONFIG_SYSFS_DEPRECATED
1223 1224 1225
	if (old_class_name) {
		new_class_name = make_class_name(dev->class->name, &dev->kobj);
		if (new_class_name) {
1226 1227 1228 1229
			error = sysfs_create_link(&dev->parent->kobj,
						  &dev->kobj, new_class_name);
			if (error)
				goto out;
1230 1231 1232
			sysfs_remove_link(&dev->parent->kobj, old_class_name);
		}
	}
1233
#else
1234
	if (dev->class) {
1235 1236 1237 1238 1239 1240 1241
		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);
		}
1242
	}
1243 1244
#endif

1245
out:
1246 1247 1248
	put_device(dev);

	kfree(new_class_name);
1249
	kfree(old_class_name);
1250
	kfree(old_device_name);
1251 1252 1253

	return error;
}
1254
EXPORT_SYMBOL_GPL(device_rename);
1255 1256 1257 1258 1259

static int device_move_class_links(struct device *dev,
				   struct device *old_parent,
				   struct device *new_parent)
{
1260
	int error = 0;
1261 1262 1263 1264 1265
#ifdef CONFIG_SYSFS_DEPRECATED
	char *class_name;

	class_name = make_class_name(dev->class->name, &dev->kobj);
	if (!class_name) {
1266
		error = -ENOMEM;
1267 1268 1269 1270 1271 1272
		goto out;
	}
	if (old_parent) {
		sysfs_remove_link(&dev->kobj, "device");
		sysfs_remove_link(&old_parent->kobj, class_name);
	}
1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284
	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;
1285 1286 1287 1288
out:
	kfree(class_name);
	return error;
#else
1289 1290 1291 1292 1293 1294
	if (old_parent)
		sysfs_remove_link(&dev->kobj, "device");
	if (new_parent)
		error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
					  "device");
	return error;
1295 1296 1297 1298 1299 1300
#endif
}

/**
 * device_move - moves a device to a new parent
 * @dev: the pointer to the struct device to be moved
1301
 * @new_parent: the new parent of the device (can by NULL)
1302 1303 1304 1305 1306
 */
int device_move(struct device *dev, struct device *new_parent)
{
	int error;
	struct device *old_parent;
1307
	struct kobject *new_parent_kobj;
1308 1309 1310 1311 1312 1313

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

	new_parent = get_device(new_parent);
1314 1315 1316 1317
	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);
1318 1319 1320
		goto out;
	}
	pr_debug("DEVICE: moving '%s' to '%s'\n", dev->bus_id,
1321 1322
		 new_parent ? new_parent->bus_id : "<NULL>");
	error = kobject_move(&dev->kobj, new_parent_kobj);
1323 1324 1325 1326 1327 1328 1329
	if (error) {
		put_device(new_parent);
		goto out;
	}
	old_parent = dev->parent;
	dev->parent = new_parent;
	if (old_parent)
1330
		klist_remove(&dev->knode_parent);
1331 1332
	if (new_parent)
		klist_add_tail(&dev->knode_parent, &new_parent->klist_children);
1333 1334 1335 1336 1337 1338 1339
	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)) {
1340 1341
			if (new_parent)
				klist_remove(&dev->knode_parent);
1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356
			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);