driver.c 53.3 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
/*
 * drivers/usb/driver.c - most of the driver model stuff for usb
 *
 * (C) Copyright 2005 Greg Kroah-Hartman <gregkh@suse.de>
 *
 * based on drivers/usb/usb.c which had the following copyrights:
 *	(C) Copyright Linus Torvalds 1999
 *	(C) Copyright Johannes Erdfelt 1999-2001
 *	(C) Copyright Andreas Gal 1999
 *	(C) Copyright Gregory P. Smith 1999
 *	(C) Copyright Deti Fliegl 1999 (new USB architecture)
 *	(C) Copyright Randy Dunlap 2000
 *	(C) Copyright David Brownell 2000-2004
 *	(C) Copyright Yggdrasil Computing, Inc. 2000
 *		(usb_device_id matching changes by Adam J. Richter)
 *	(C) Copyright Greg Kroah-Hartman 2002-2003
 *
 * NOTE! This is not actually a driver at all, rather this is
 * just a collection of helper routines that implement the
20 21
 * matching, probing, releasing, suspending and resuming for
 * real drivers.
22 23 24 25 26
 *
 */

#include <linux/device.h>
#include <linux/usb.h>
A
Alan Stern 已提交
27
#include <linux/usb/quirks.h>
28
#include <linux/workqueue.h>
29 30 31
#include "hcd.h"
#include "usb.h"

A
Alan Stern 已提交
32

33 34 35 36 37 38
#ifdef CONFIG_HOTPLUG

/*
 * Adds a new dynamic USBdevice ID to this driver,
 * and cause the driver to probe for all devices again.
 */
39 40 41
ssize_t usb_store_new_id(struct usb_dynids *dynids,
			 struct device_driver *driver,
			 const char *buf, size_t count)
42 43 44 45 46
{
	struct usb_dynid *dynid;
	u32 idVendor = 0;
	u32 idProduct = 0;
	int fields = 0;
47
	int retval = 0;
48 49 50 51 52 53 54 55 56 57 58 59 60 61

	fields = sscanf(buf, "%x %x", &idVendor, &idProduct);
	if (fields < 2)
		return -EINVAL;

	dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
	if (!dynid)
		return -ENOMEM;

	INIT_LIST_HEAD(&dynid->node);
	dynid->id.idVendor = idVendor;
	dynid->id.idProduct = idProduct;
	dynid->id.match_flags = USB_DEVICE_ID_MATCH_DEVICE;

62
	spin_lock(&dynids->lock);
63
	list_add_tail(&dynid->node, &dynids->list);
64
	spin_unlock(&dynids->lock);
65 66

	if (get_driver(driver)) {
67
		retval = driver_attach(driver);
68 69 70
		put_driver(driver);
	}

71 72
	if (retval)
		return retval;
73 74
	return count;
}
75 76 77 78 79 80 81 82 83
EXPORT_SYMBOL_GPL(usb_store_new_id);

static ssize_t store_new_id(struct device_driver *driver,
			    const char *buf, size_t count)
{
	struct usb_driver *usb_drv = to_usb_driver(driver);

	return usb_store_new_id(&usb_drv->dynids, driver, buf, count);
}
84 85 86 87 88 89
static DRIVER_ATTR(new_id, S_IWUSR, NULL, store_new_id);

static int usb_create_newid_file(struct usb_driver *usb_drv)
{
	int error = 0;

90 91 92
	if (usb_drv->no_dynamic_id)
		goto exit;

93
	if (usb_drv->probe != NULL)
94 95
		error = driver_create_file(&usb_drv->drvwrap.driver,
					   &driver_attr_new_id);
96
exit:
97 98 99
	return error;
}

100 101 102 103 104 105
static void usb_remove_newid_file(struct usb_driver *usb_drv)
{
	if (usb_drv->no_dynamic_id)
		return;

	if (usb_drv->probe != NULL)
106 107
		driver_remove_file(&usb_drv->drvwrap.driver,
				   &driver_attr_new_id);
108 109
}

110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126
static void usb_free_dynids(struct usb_driver *usb_drv)
{
	struct usb_dynid *dynid, *n;

	spin_lock(&usb_drv->dynids.lock);
	list_for_each_entry_safe(dynid, n, &usb_drv->dynids.list, node) {
		list_del(&dynid->node);
		kfree(dynid);
	}
	spin_unlock(&usb_drv->dynids.lock);
}
#else
static inline int usb_create_newid_file(struct usb_driver *usb_drv)
{
	return 0;
}

127 128 129 130
static void usb_remove_newid_file(struct usb_driver *usb_drv)
{
}

131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152
static inline void usb_free_dynids(struct usb_driver *usb_drv)
{
}
#endif

static const struct usb_device_id *usb_match_dynamic_id(struct usb_interface *intf,
							struct usb_driver *drv)
{
	struct usb_dynid *dynid;

	spin_lock(&drv->dynids.lock);
	list_for_each_entry(dynid, &drv->dynids.list, node) {
		if (usb_match_one_id(intf, &dynid->id)) {
			spin_unlock(&drv->dynids.lock);
			return &dynid->id;
		}
	}
	spin_unlock(&drv->dynids.lock);
	return NULL;
}


153 154 155 156 157 158 159
/* called from driver core with dev locked */
static int usb_probe_device(struct device *dev)
{
	struct usb_device_driver *udriver = to_usb_device_driver(dev->driver);
	struct usb_device *udev;
	int error = -ENODEV;

160
	dev_dbg(dev, "%s\n", __func__);
161 162 163 164 165 166 167 168

	if (!is_usb_device(dev))	/* Sanity check */
		return error;

	udev = to_usb_device(dev);

	/* TODO: Add real matching code */

169 170 171 172 173
	/* The device should always appear to be in use
	 * unless the driver suports autosuspend.
	 */
	udev->pm_usage_cnt = !(udriver->supports_autosuspend);

174 175 176 177 178 179 180 181 182 183 184 185 186
	error = udriver->probe(udev);
	return error;
}

/* called from driver core with dev locked */
static int usb_unbind_device(struct device *dev)
{
	struct usb_device_driver *udriver = to_usb_device_driver(dev->driver);

	udriver->disconnect(to_usb_device(dev));
	return 0;
}

187 188 189 190 191 192 193 194 195 196 197 198 199 200
/*
 * Cancel any pending scheduled resets
 *
 * [see usb_queue_reset_device()]
 *
 * Called after unconfiguring / when releasing interfaces. See
 * comments in __usb_queue_reset_device() regarding
 * udev->reset_running.
 */
static void usb_cancel_queued_reset(struct usb_interface *iface)
{
	if (iface->reset_running == 0)
		cancel_work_sync(&iface->reset_ws);
}
201 202

/* called from driver core with dev locked */
203 204
static int usb_probe_interface(struct device *dev)
{
205 206
	struct usb_driver *driver = to_usb_driver(dev->driver);
	struct usb_interface *intf;
207
	struct usb_device *udev;
208 209 210
	const struct usb_device_id *id;
	int error = -ENODEV;

211
	dev_dbg(dev, "%s\n", __func__);
212

213
	if (is_usb_device(dev))		/* Sanity check */
214
		return error;
215 216

	intf = to_usb_interface(dev);
217
	udev = interface_to_usbdev(intf);
218
	intf->needs_binding = 0;
219

220 221 222 223
	if (udev->authorized == 0) {
		dev_err(&intf->dev, "Device is not authorized for usage\n");
		return -ENODEV;
	}
224

225
	id = usb_match_id(intf, driver->id_table);
226 227
	if (!id)
		id = usb_match_dynamic_id(intf, driver);
228
	if (id) {
229
		dev_dbg(dev, "%s - got id\n", __func__);
230

231
		error = usb_autoresume_device(udev);
232 233 234
		if (error)
			return error;

235 236 237 238 239 240
		/* Interface "power state" doesn't correspond to any hardware
		 * state whatsoever.  We use it to record when it's bound to
		 * a driver that may start I/0:  it's not frozen/quiesced.
		 */
		mark_active(intf);
		intf->condition = USB_INTERFACE_BINDING;
241 242 243 244 245 246

		/* The interface should always appear to be in use
		 * unless the driver suports autosuspend.
		 */
		intf->pm_usage_cnt = !(driver->supports_autosuspend);

247 248 249 250 251 252 253
		/* Carry out a deferred switch to altsetting 0 */
		if (intf->needs_altsetting0) {
			usb_set_interface(udev, intf->altsetting[0].
					desc.bInterfaceNumber, 0);
			intf->needs_altsetting0 = 0;
		}

254 255 256
		error = driver->probe(intf, id);
		if (error) {
			mark_quiesced(intf);
257
			intf->needs_remote_wakeup = 0;
258
			intf->condition = USB_INTERFACE_UNBOUND;
259
			usb_cancel_queued_reset(intf);
260 261
		} else
			intf->condition = USB_INTERFACE_BOUND;
262

263
		usb_autosuspend_device(udev);
264 265 266 267 268
	}

	return error;
}

269
/* called from driver core with dev locked */
270 271
static int usb_unbind_interface(struct device *dev)
{
272
	struct usb_driver *driver = to_usb_driver(dev->driver);
273
	struct usb_interface *intf = to_usb_interface(dev);
274 275
	struct usb_device *udev;
	int error;
276 277 278

	intf->condition = USB_INTERFACE_UNBINDING;

279 280
	/* Autoresume for set_interface call below */
	udev = interface_to_usbdev(intf);
281
	error = usb_autoresume_device(udev);
282

A
Alan Stern 已提交
283 284 285 286
	/* Terminate all URBs for this interface unless the driver
	 * supports "soft" unbinding.
	 */
	if (!driver->soft_unbind)
287
		usb_disable_interface(udev, intf, false);
288

289
	driver->disconnect(intf);
290
	usb_cancel_queued_reset(intf);
291

292 293 294 295 296 297
	/* Reset other interface state.
	 * We cannot do a Set-Interface if the device is suspended or
	 * if it is prepared for a system sleep (since installing a new
	 * altsetting means creating new endpoint device entries).
	 * When either of these happens, defer the Set-Interface.
	 */
298 299 300 301 302 303
	if (intf->cur_altsetting->desc.bAlternateSetting == 0) {
		/* Already in altsetting 0 so skip Set-Interface.
		 * Just re-enable it without affecting the endpoint toggles.
		 */
		usb_enable_interface(udev, intf, false);
	} else if (!error && intf->dev.power.status == DPM_ON)
304 305 306 307
		usb_set_interface(udev, intf->altsetting[0].
				desc.bInterfaceNumber, 0);
	else
		intf->needs_altsetting0 = 1;
308
	usb_set_intfdata(intf, NULL);
309

310 311
	intf->condition = USB_INTERFACE_UNBOUND;
	mark_quiesced(intf);
312 313 314
	intf->needs_remote_wakeup = 0;

	if (!error)
315
		usb_autosuspend_device(udev);
316 317 318 319

	return 0;
}

320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335
/**
 * usb_driver_claim_interface - bind a driver to an interface
 * @driver: the driver to be bound
 * @iface: the interface to which it will be bound; must be in the
 *	usb device's active configuration
 * @priv: driver data associated with that interface
 *
 * This is used by usb device drivers that need to claim more than one
 * interface on a device when probing (audio and acm are current examples).
 * No device driver should directly modify internal usb_interface or
 * usb_device structure members.
 *
 * Few drivers should need to use this routine, since the most natural
 * way to bind to an interface is to return the private data from
 * the driver's probe() method.
 *
336 337 338
 * Callers must own the device lock, so driver probe() entries don't need
 * extra locking, but other call contexts may need to explicitly claim that
 * lock.
339 340
 */
int usb_driver_claim_interface(struct usb_driver *driver,
341
				struct usb_interface *iface, void *priv)
342 343
{
	struct device *dev = &iface->dev;
344
	struct usb_device *udev = interface_to_usbdev(iface);
345
	int retval = 0;
346 347 348 349

	if (dev->driver)
		return -EBUSY;

350
	dev->driver = &driver->drvwrap.driver;
351
	usb_set_intfdata(iface, priv);
352
	iface->needs_binding = 0;
353

354
	usb_pm_lock(udev);
355 356
	iface->condition = USB_INTERFACE_BOUND;
	mark_active(iface);
357
	iface->pm_usage_cnt = !(driver->supports_autosuspend);
358
	usb_pm_unlock(udev);
359 360 361 362 363

	/* if interface was already added, bind now; else let
	 * the future device_add() bind it, bypassing probe()
	 */
	if (device_is_registered(dev))
364
		retval = device_bind_driver(dev);
365

366
	return retval;
367
}
368
EXPORT_SYMBOL_GPL(usb_driver_claim_interface);
369 370 371 372 373 374 375 376 377 378 379

/**
 * usb_driver_release_interface - unbind a driver from an interface
 * @driver: the driver to be unbound
 * @iface: the interface from which it will be unbound
 *
 * This can be used by drivers to release an interface without waiting
 * for their disconnect() methods to be called.  In typical cases this
 * also causes the driver disconnect() method to be called.
 *
 * This call is synchronous, and may not be used in an interrupt context.
380 381 382
 * Callers must own the device lock, so driver disconnect() entries don't
 * need extra locking, but other call contexts may need to explicitly claim
 * that lock.
383 384 385 386 387 388 389
 */
void usb_driver_release_interface(struct usb_driver *driver,
					struct usb_interface *iface)
{
	struct device *dev = &iface->dev;

	/* this should never happen, don't release something that's not ours */
390
	if (!dev->driver || dev->driver != &driver->drvwrap.driver)
391 392 393 394 395
		return;

	/* don't release from within disconnect() */
	if (iface->condition != USB_INTERFACE_BOUND)
		return;
396
	iface->condition = USB_INTERFACE_UNBINDING;
397

398 399 400
	/* Release via the driver core only if the interface
	 * has already been registered
	 */
401 402
	if (device_is_registered(dev)) {
		device_release_driver(dev);
403
	} else {
404 405 406 407
		down(&dev->sem);
		usb_unbind_interface(dev);
		dev->driver = NULL;
		up(&dev->sem);
408 409
	}
}
410
EXPORT_SYMBOL_GPL(usb_driver_release_interface);
411

412
/* returns 0 if no match, 1 if match */
413
int usb_match_device(struct usb_device *dev, const struct usb_device_id *id)
414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437
{
	if ((id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
	    id->idVendor != le16_to_cpu(dev->descriptor.idVendor))
		return 0;

	if ((id->match_flags & USB_DEVICE_ID_MATCH_PRODUCT) &&
	    id->idProduct != le16_to_cpu(dev->descriptor.idProduct))
		return 0;

	/* No need to test id->bcdDevice_lo != 0, since 0 is never
	   greater than any unsigned number. */
	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_LO) &&
	    (id->bcdDevice_lo > le16_to_cpu(dev->descriptor.bcdDevice)))
		return 0;

	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_HI) &&
	    (id->bcdDevice_hi < le16_to_cpu(dev->descriptor.bcdDevice)))
		return 0;

	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_CLASS) &&
	    (id->bDeviceClass != dev->descriptor.bDeviceClass))
		return 0;

	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_SUBCLASS) &&
438
	    (id->bDeviceSubClass != dev->descriptor.bDeviceSubClass))
439 440 441 442 443 444
		return 0;

	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_PROTOCOL) &&
	    (id->bDeviceProtocol != dev->descriptor.bDeviceProtocol))
		return 0;

445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464
	return 1;
}

/* returns 0 if no match, 1 if match */
int usb_match_one_id(struct usb_interface *interface,
		     const struct usb_device_id *id)
{
	struct usb_host_interface *intf;
	struct usb_device *dev;

	/* proc_connectinfo in devio.c may call us with id == NULL. */
	if (id == NULL)
		return 0;

	intf = interface->cur_altsetting;
	dev = interface_to_usbdev(interface);

	if (!usb_match_device(dev, id))
		return 0;

465 466 467 468 469 470 471 472 473 474
	/* The interface class, subclass, and protocol should never be
	 * checked for a match if the device class is Vendor Specific,
	 * unless the match record specifies the Vendor ID. */
	if (dev->descriptor.bDeviceClass == USB_CLASS_VENDOR_SPEC &&
			!(id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
			(id->match_flags & (USB_DEVICE_ID_MATCH_INT_CLASS |
				USB_DEVICE_ID_MATCH_INT_SUBCLASS |
				USB_DEVICE_ID_MATCH_INT_PROTOCOL)))
		return 0;

475 476 477 478 479 480 481 482 483 484 485 486 487 488
	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_CLASS) &&
	    (id->bInterfaceClass != intf->desc.bInterfaceClass))
		return 0;

	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_SUBCLASS) &&
	    (id->bInterfaceSubClass != intf->desc.bInterfaceSubClass))
		return 0;

	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_PROTOCOL) &&
	    (id->bInterfaceProtocol != intf->desc.bInterfaceProtocol))
		return 0;

	return 1;
}
489 490
EXPORT_SYMBOL_GPL(usb_match_one_id);

491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544
/**
 * usb_match_id - find first usb_device_id matching device or interface
 * @interface: the interface of interest
 * @id: array of usb_device_id structures, terminated by zero entry
 *
 * usb_match_id searches an array of usb_device_id's and returns
 * the first one matching the device or interface, or null.
 * This is used when binding (or rebinding) a driver to an interface.
 * Most USB device drivers will use this indirectly, through the usb core,
 * but some layered driver frameworks use it directly.
 * These device tables are exported with MODULE_DEVICE_TABLE, through
 * modutils, to support the driver loading functionality of USB hotplugging.
 *
 * What Matches:
 *
 * The "match_flags" element in a usb_device_id controls which
 * members are used.  If the corresponding bit is set, the
 * value in the device_id must match its corresponding member
 * in the device or interface descriptor, or else the device_id
 * does not match.
 *
 * "driver_info" is normally used only by device drivers,
 * but you can create a wildcard "matches anything" usb_device_id
 * as a driver's "modules.usbmap" entry if you provide an id with
 * only a nonzero "driver_info" field.  If you do this, the USB device
 * driver's probe() routine should use additional intelligence to
 * decide whether to bind to the specified interface.
 *
 * What Makes Good usb_device_id Tables:
 *
 * The match algorithm is very simple, so that intelligence in
 * driver selection must come from smart driver id records.
 * Unless you have good reasons to use another selection policy,
 * provide match elements only in related groups, and order match
 * specifiers from specific to general.  Use the macros provided
 * for that purpose if you can.
 *
 * The most specific match specifiers use device descriptor
 * data.  These are commonly used with product-specific matches;
 * the USB_DEVICE macro lets you provide vendor and product IDs,
 * and you can also match against ranges of product revisions.
 * These are widely used for devices with application or vendor
 * specific bDeviceClass values.
 *
 * Matches based on device class/subclass/protocol specifications
 * are slightly more general; use the USB_DEVICE_INFO macro, or
 * its siblings.  These are used with single-function devices
 * where bDeviceClass doesn't specify that each interface has
 * its own class.
 *
 * Matches based on interface class/subclass/protocol are the
 * most general; they let drivers bind to any interface on a
 * multiple-function device.  Use the USB_INTERFACE_INFO
 * macro, or its siblings, to match class-per-interface style
545 546 547 548 549 550 551 552 553 554 555
 * devices (as recorded in bInterfaceClass).
 *
 * Note that an entry created by USB_INTERFACE_INFO won't match
 * any interface if the device class is set to Vendor-Specific.
 * This is deliberate; according to the USB spec the meanings of
 * the interface class/subclass/protocol for these devices are also
 * vendor-specific, and hence matching against a standard product
 * class wouldn't work anyway.  If you really want to use an
 * interface-based match for such a device, create a match record
 * that also specifies the vendor ID.  (Unforunately there isn't a
 * standard macro for creating records like this.)
556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573
 *
 * Within those groups, remember that not all combinations are
 * meaningful.  For example, don't give a product version range
 * without vendor and product IDs; or specify a protocol without
 * its associated class and subclass.
 */
const struct usb_device_id *usb_match_id(struct usb_interface *interface,
					 const struct usb_device_id *id)
{
	/* proc_connectinfo in devio.c may call us with id == NULL. */
	if (id == NULL)
		return NULL;

	/* It is important to check that id->driver_info is nonzero,
	   since an entry that is all zeroes except for a nonzero
	   id->driver_info is the way to create an entry that
	   indicates that the driver want to examine every
	   device and interface. */
574 575
	for (; id->idVendor || id->idProduct || id->bDeviceClass ||
	       id->bInterfaceClass || id->driver_info; id++) {
576 577
		if (usb_match_one_id(interface, id))
			return id;
578 579 580 581
	}

	return NULL;
}
582
EXPORT_SYMBOL_GPL(usb_match_id);
583

584
static int usb_device_match(struct device *dev, struct device_driver *drv)
585
{
586 587
	/* devices and interfaces are handled separately */
	if (is_usb_device(dev)) {
588

589 590 591
		/* interface drivers never match devices */
		if (!is_usb_device_driver(drv))
			return 0;
592

593
		/* TODO: Add real matching code */
594 595
		return 1;

596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616
	} else {
		struct usb_interface *intf;
		struct usb_driver *usb_drv;
		const struct usb_device_id *id;

		/* device drivers never match interfaces */
		if (is_usb_device_driver(drv))
			return 0;

		intf = to_usb_interface(dev);
		usb_drv = to_usb_driver(drv);

		id = usb_match_id(intf, usb_drv->id_table);
		if (id)
			return 1;

		id = usb_match_dynamic_id(intf, usb_drv);
		if (id)
			return 1;
	}

617 618 619
	return 0;
}

620
#ifdef	CONFIG_HOTPLUG
621
static int usb_uevent(struct device *dev, struct kobj_uevent_env *env)
622 623 624 625
{
	struct usb_device *usb_dev;

	/* driver is often null here; dev_dbg() would oops */
626
	pr_debug("usb %s: uevent\n", dev_name(dev));
627

628
	if (is_usb_device(dev))
629
		usb_dev = to_usb_device(dev);
630 631
	else {
		struct usb_interface *intf = to_usb_interface(dev);
632 633
		usb_dev = interface_to_usbdev(intf);
	}
634 635

	if (usb_dev->devnum < 0) {
636
		pr_debug("usb %s: already deleted?\n", dev_name(dev));
637 638 639
		return -ENODEV;
	}
	if (!usb_dev->bus) {
640
		pr_debug("usb %s: bus removed?\n", dev_name(dev));
641 642 643 644 645 646
		return -ENODEV;
	}

#ifdef	CONFIG_USB_DEVICEFS
	/* If this is available, userspace programs can directly read
	 * all the device descriptors we don't tell them about.  Or
647
	 * act as usermode drivers.
648
	 */
649
	if (add_uevent_var(env, "DEVICE=/proc/bus/usb/%03d/%03d",
650 651 652 653 654
			   usb_dev->bus->busnum, usb_dev->devnum))
		return -ENOMEM;
#endif

	/* per-device configurations are common */
655
	if (add_uevent_var(env, "PRODUCT=%x/%x/%x",
656 657 658 659 660 661
			   le16_to_cpu(usb_dev->descriptor.idVendor),
			   le16_to_cpu(usb_dev->descriptor.idProduct),
			   le16_to_cpu(usb_dev->descriptor.bcdDevice)))
		return -ENOMEM;

	/* class-based driver binding models */
662
	if (add_uevent_var(env, "TYPE=%d/%d/%d",
663 664 665 666 667 668 669 670 671 672
			   usb_dev->descriptor.bDeviceClass,
			   usb_dev->descriptor.bDeviceSubClass,
			   usb_dev->descriptor.bDeviceProtocol))
		return -ENOMEM;

	return 0;
}

#else

673
static int usb_uevent(struct device *dev, struct kobj_uevent_env *env)
674 675 676 677 678
{
	return -ENODEV;
}
#endif	/* CONFIG_HOTPLUG */

679
/**
680 681
 * usb_register_device_driver - register a USB device (not interface) driver
 * @new_udriver: USB operations for the device driver
682
 * @owner: module owner of this driver.
683
 *
684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740
 * Registers a USB device driver with the USB core.  The list of
 * unattached devices will be rescanned whenever a new driver is
 * added, allowing the new driver to attach to any recognized devices.
 * Returns a negative error code on failure and 0 on success.
 */
int usb_register_device_driver(struct usb_device_driver *new_udriver,
		struct module *owner)
{
	int retval = 0;

	if (usb_disabled())
		return -ENODEV;

	new_udriver->drvwrap.for_devices = 1;
	new_udriver->drvwrap.driver.name = (char *) new_udriver->name;
	new_udriver->drvwrap.driver.bus = &usb_bus_type;
	new_udriver->drvwrap.driver.probe = usb_probe_device;
	new_udriver->drvwrap.driver.remove = usb_unbind_device;
	new_udriver->drvwrap.driver.owner = owner;

	retval = driver_register(&new_udriver->drvwrap.driver);

	if (!retval) {
		pr_info("%s: registered new device driver %s\n",
			usbcore_name, new_udriver->name);
		usbfs_update_special();
	} else {
		printk(KERN_ERR "%s: error %d registering device "
			"	driver %s\n",
			usbcore_name, retval, new_udriver->name);
	}

	return retval;
}
EXPORT_SYMBOL_GPL(usb_register_device_driver);

/**
 * usb_deregister_device_driver - unregister a USB device (not interface) driver
 * @udriver: USB operations of the device driver to unregister
 * Context: must be able to sleep
 *
 * Unlinks the specified driver from the internal USB driver list.
 */
void usb_deregister_device_driver(struct usb_device_driver *udriver)
{
	pr_info("%s: deregistering device driver %s\n",
			usbcore_name, udriver->name);

	driver_unregister(&udriver->drvwrap.driver);
	usbfs_update_special();
}
EXPORT_SYMBOL_GPL(usb_deregister_device_driver);

/**
 * usb_register_driver - register a USB interface driver
 * @new_driver: USB operations for the interface driver
 * @owner: module owner of this driver.
R
Randy Dunlap 已提交
741
 * @mod_name: module name string
742 743 744 745
 *
 * Registers a USB interface driver with the USB core.  The list of
 * unattached interfaces will be rescanned whenever a new driver is
 * added, allowing the new driver to attach to any recognized interfaces.
746 747 748 749 750 751
 * Returns a negative error code on failure and 0 on success.
 *
 * NOTE: if you want your driver to use the USB major number, you must call
 * usb_register_dev() to enable that functionality.  This function no longer
 * takes care of that.
 */
752 753
int usb_register_driver(struct usb_driver *new_driver, struct module *owner,
			const char *mod_name)
754 755 756 757 758 759
{
	int retval = 0;

	if (usb_disabled())
		return -ENODEV;

760 761 762 763 764 765
	new_driver->drvwrap.for_devices = 0;
	new_driver->drvwrap.driver.name = (char *) new_driver->name;
	new_driver->drvwrap.driver.bus = &usb_bus_type;
	new_driver->drvwrap.driver.probe = usb_probe_interface;
	new_driver->drvwrap.driver.remove = usb_unbind_interface;
	new_driver->drvwrap.driver.owner = owner;
766
	new_driver->drvwrap.driver.mod_name = mod_name;
767 768
	spin_lock_init(&new_driver->dynids.lock);
	INIT_LIST_HEAD(&new_driver->dynids.list);
769

770
	retval = driver_register(&new_driver->drvwrap.driver);
771 772

	if (!retval) {
773
		pr_info("%s: registered new interface driver %s\n",
774 775
			usbcore_name, new_driver->name);
		usbfs_update_special();
776
		usb_create_newid_file(new_driver);
777
	} else {
778 779
		printk(KERN_ERR "%s: error %d registering interface "
			"	driver %s\n",
780 781 782 783 784
			usbcore_name, retval, new_driver->name);
	}

	return retval;
}
785
EXPORT_SYMBOL_GPL(usb_register_driver);
786 787

/**
788 789
 * usb_deregister - unregister a USB interface driver
 * @driver: USB operations of the interface driver to unregister
790 791 792 793 794 795 796 797 798 799
 * Context: must be able to sleep
 *
 * Unlinks the specified driver from the internal USB driver list.
 *
 * NOTE: If you called usb_register_dev(), you still need to call
 * usb_deregister_dev() to clean up your driver's allocated minor numbers,
 * this * call will no longer do it for you.
 */
void usb_deregister(struct usb_driver *driver)
{
800 801
	pr_info("%s: deregistering interface driver %s\n",
			usbcore_name, driver->name);
802

803
	usb_remove_newid_file(driver);
804
	usb_free_dynids(driver);
805
	driver_unregister(&driver->drvwrap.driver);
806 807 808

	usbfs_update_special();
}
809
EXPORT_SYMBOL_GPL(usb_deregister);
810

811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834
/* Forced unbinding of a USB interface driver, either because
 * it doesn't support pre_reset/post_reset/reset_resume or
 * because it doesn't support suspend/resume.
 *
 * The caller must hold @intf's device's lock, but not its pm_mutex
 * and not @intf->dev.sem.
 */
void usb_forced_unbind_intf(struct usb_interface *intf)
{
	struct usb_driver *driver = to_usb_driver(intf->dev.driver);

	dev_dbg(&intf->dev, "forced unbind\n");
	usb_driver_release_interface(driver, intf);

	/* Mark the interface for later rebinding */
	intf->needs_binding = 1;
}

/* Delayed forced unbinding of a USB interface driver and scan
 * for rebinding.
 *
 * The caller must hold @intf's device's lock, but not its pm_mutex
 * and not @intf->dev.sem.
 *
835 836
 * Note: Rebinds will be skipped if a system sleep transition is in
 * progress and the PM "complete" callback hasn't occurred yet.
837 838 839 840 841 842 843 844 845 846 847 848 849 850 851
 */
void usb_rebind_intf(struct usb_interface *intf)
{
	int rc;

	/* Delayed unbind of an existing driver */
	if (intf->dev.driver) {
		struct usb_driver *driver =
				to_usb_driver(intf->dev.driver);

		dev_dbg(&intf->dev, "forced unbind\n");
		usb_driver_release_interface(driver, intf);
	}

	/* Try to rebind the interface */
852 853 854 855 856 857
	if (intf->dev.power.status == DPM_ON) {
		intf->needs_binding = 0;
		rc = device_attach(&intf->dev);
		if (rc < 0)
			dev_warn(&intf->dev, "rebind failed: %d\n", rc);
	}
858 859
}

A
Alan Stern 已提交
860 861
#ifdef CONFIG_PM

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
#define DO_UNBIND	0
#define DO_REBIND	1

/* Unbind drivers for @udev's interfaces that don't support suspend/resume,
 * or rebind interfaces that have been unbound, according to @action.
 *
 * The caller must hold @udev's device lock.
 */
static void do_unbind_rebind(struct usb_device *udev, int action)
{
	struct usb_host_config	*config;
	int			i;
	struct usb_interface	*intf;
	struct usb_driver	*drv;

	config = udev->actconfig;
	if (config) {
		for (i = 0; i < config->desc.bNumInterfaces; ++i) {
			intf = config->interface[i];
			switch (action) {
			case DO_UNBIND:
				if (intf->dev.driver) {
					drv = to_usb_driver(intf->dev.driver);
					if (!drv->suspend || !drv->resume)
						usb_forced_unbind_intf(intf);
				}
				break;
			case DO_REBIND:
890
				if (intf->needs_binding)
891 892 893 894 895 896 897
					usb_rebind_intf(intf);
				break;
			}
		}
	}
}

898
/* Caller has locked udev's pm_mutex */
899
static int usb_suspend_device(struct usb_device *udev, pm_message_t msg)
900
{
901
	struct usb_device_driver	*udriver;
902
	int				status = 0;
903

904 905 906 907
	if (udev->state == USB_STATE_NOTATTACHED ||
			udev->state == USB_STATE_SUSPENDED)
		goto done;

908 909 910 911
	/* For devices that don't have a driver, we do a generic suspend. */
	if (udev->dev.driver)
		udriver = to_usb_device_driver(udev->dev.driver);
	else {
912
		udev->do_remote_wakeup = 0;
913
		udriver = &usb_generic_driver;
914
	}
915 916
	status = udriver->suspend(udev, msg);

A
Alan Stern 已提交
917
 done:
918
	dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
919
	return status;
920 921
}

922
/* Caller has locked udev's pm_mutex */
A
Alan Stern 已提交
923
static int usb_resume_device(struct usb_device *udev, pm_message_t msg)
924 925
{
	struct usb_device_driver	*udriver;
926
	int				status = 0;
927

A
Alan Stern 已提交
928 929
	if (udev->state == USB_STATE_NOTATTACHED)
		goto done;
930

931 932 933
	/* Can't resume it if it doesn't have a driver. */
	if (udev->dev.driver == NULL) {
		status = -ENOTCONN;
934
		goto done;
935 936
	}

A
Alan Stern 已提交
937 938 939
	if (udev->quirks & USB_QUIRK_RESET_RESUME)
		udev->reset_resume = 1;

940
	udriver = to_usb_device_driver(udev->dev.driver);
A
Alan Stern 已提交
941
	status = udriver->resume(udev, msg);
942

A
Alan Stern 已提交
943
 done:
944
	dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
A
Alan Stern 已提交
945
	if (status == 0)
946
		udev->autoresume_disabled = 0;
947
	return status;
948 949
}

950
/* Caller has locked intf's usb_device's pm mutex */
951 952
static int usb_suspend_interface(struct usb_device *udev,
		struct usb_interface *intf, pm_message_t msg)
953 954
{
	struct usb_driver	*driver;
955
	int			status = 0;
956

957
	/* with no hardware, USB interfaces only use FREEZE and ON states */
958
	if (udev->state == USB_STATE_NOTATTACHED || !is_active(intf))
959
		goto done;
960

961 962
	/* This can happen; see usb_driver_release_interface() */
	if (intf->condition == USB_INTERFACE_UNBOUND)
963
		goto done;
964
	driver = to_usb_driver(intf->dev.driver);
965

966
	if (driver->suspend) {
967
		status = driver->suspend(intf, msg);
968 969
		if (status == 0)
			mark_quiesced(intf);
A
Alan Stern 已提交
970
		else if (!(msg.event & PM_EVENT_AUTO))
971 972
			dev_err(&intf->dev, "%s error %d\n",
					"suspend", status);
973
	} else {
974 975 976 977
		/* Later we will unbind the driver and reprobe */
		intf->needs_binding = 1;
		dev_warn(&intf->dev, "no %s for driver %s?\n",
				"suspend", driver->name);
978 979
		mark_quiesced(intf);
	}
980

A
Alan Stern 已提交
981
 done:
982
	dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
983 984 985
	return status;
}

986
/* Caller has locked intf's usb_device's pm_mutex */
987
static int usb_resume_interface(struct usb_device *udev,
A
Alan Stern 已提交
988
		struct usb_interface *intf, pm_message_t msg, int reset_resume)
989
{
990
	struct usb_driver	*driver;
991
	int			status = 0;
992

993
	if (udev->state == USB_STATE_NOTATTACHED || is_active(intf))
994
		goto done;
995

996 997 998 999
	/* Don't let autoresume interfere with unbinding */
	if (intf->condition == USB_INTERFACE_UNBINDING)
		goto done;

1000
	/* Can't resume it if it doesn't have a driver. */
1001 1002 1003 1004 1005 1006 1007 1008 1009
	if (intf->condition == USB_INTERFACE_UNBOUND) {

		/* Carry out a deferred switch to altsetting 0 */
		if (intf->needs_altsetting0 &&
				intf->dev.power.status == DPM_ON) {
			usb_set_interface(udev, intf->altsetting[0].
					desc.bInterfaceNumber, 0);
			intf->needs_altsetting0 = 0;
		}
1010
		goto done;
1011
	}
1012 1013 1014

	/* Don't resume if the interface is marked for rebinding */
	if (intf->needs_binding)
1015
		goto done;
1016
	driver = to_usb_driver(intf->dev.driver);
1017

A
Alan Stern 已提交
1018 1019 1020 1021 1022 1023 1024
	if (reset_resume) {
		if (driver->reset_resume) {
			status = driver->reset_resume(intf);
			if (status)
				dev_err(&intf->dev, "%s error %d\n",
						"reset_resume", status);
		} else {
1025
			intf->needs_binding = 1;
A
Alan Stern 已提交
1026 1027 1028 1029 1030 1031 1032 1033 1034 1035
			dev_warn(&intf->dev, "no %s for driver %s?\n",
					"reset_resume", driver->name);
		}
	} else {
		if (driver->resume) {
			status = driver->resume(intf);
			if (status)
				dev_err(&intf->dev, "%s error %d\n",
						"resume", status);
		} else {
1036
			intf->needs_binding = 1;
A
Alan Stern 已提交
1037 1038 1039 1040
			dev_warn(&intf->dev, "no %s for driver %s?\n",
					"resume", driver->name);
		}
	}
1041 1042

done:
1043
	dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
1044
	if (status == 0 && intf->condition == USB_INTERFACE_BOUND)
A
Alan Stern 已提交
1045
		mark_active(intf);
A
Alan Stern 已提交
1046

1047
	/* Later we will unbind the driver and/or reprobe, if necessary */
1048
	return status;
1049 1050
}

1051 1052
#ifdef	CONFIG_USB_SUSPEND

A
Alan Stern 已提交
1053
/* Internal routine to check whether we may autosuspend a device. */
1054
static int autosuspend_check(struct usb_device *udev, int reschedule)
A
Alan Stern 已提交
1055 1056 1057
{
	int			i;
	struct usb_interface	*intf;
1058
	unsigned long		suspend_time, j;
A
Alan Stern 已提交
1059

1060 1061 1062 1063
	/* For autosuspend, fail fast if anything is in use or autosuspend
	 * is disabled.  Also fail if any interfaces require remote wakeup
	 * but it isn't available.
	 */
A
Alan Stern 已提交
1064 1065
	if (udev->pm_usage_cnt > 0)
		return -EBUSY;
1066
	if (udev->autosuspend_delay < 0 || udev->autosuspend_disabled)
1067 1068
		return -EPERM;

1069
	suspend_time = udev->last_busy + udev->autosuspend_delay;
A
Alan Stern 已提交
1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082
	if (udev->actconfig) {
		for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
			intf = udev->actconfig->interface[i];
			if (!is_active(intf))
				continue;
			if (intf->pm_usage_cnt > 0)
				return -EBUSY;
			if (intf->needs_remote_wakeup &&
					!udev->do_remote_wakeup) {
				dev_dbg(&udev->dev, "remote wakeup needed "
						"for autosuspend\n");
				return -EOPNOTSUPP;
			}
A
Alan Stern 已提交
1083 1084 1085 1086 1087 1088 1089 1090 1091

			/* Don't allow autosuspend if the device will need
			 * a reset-resume and any of its interface drivers
			 * doesn't include support.
			 */
			if (udev->quirks & USB_QUIRK_RESET_RESUME) {
				struct usb_driver *driver;

				driver = to_usb_driver(intf->dev.driver);
1092 1093
				if (!driver->reset_resume ||
				    intf->needs_remote_wakeup)
A
Alan Stern 已提交
1094 1095
					return -EOPNOTSUPP;
			}
A
Alan Stern 已提交
1096 1097
		}
	}
1098 1099

	/* If everything is okay but the device hasn't been idle for long
1100 1101 1102
	 * enough, queue a delayed autosuspend request.  If the device
	 * _has_ been idle for long enough and the reschedule flag is set,
	 * likewise queue a delayed (1 second) autosuspend request.
1103
	 */
1104 1105 1106 1107 1108 1109
	j = jiffies;
	if (time_before(j, suspend_time))
		reschedule = 1;
	else
		suspend_time = j + HZ;
	if (reschedule) {
1110
		if (!timer_pending(&udev->autosuspend.timer)) {
1111
			queue_delayed_work(ksuspend_usb_wq, &udev->autosuspend,
1112
				round_jiffies_up_relative(suspend_time - j));
1113
		}
1114 1115
		return -EAGAIN;
	}
A
Alan Stern 已提交
1116 1117 1118
	return 0;
}

1119 1120
#else

1121
static inline int autosuspend_check(struct usb_device *udev, int reschedule)
A
Alan Stern 已提交
1122 1123 1124
{
	return 0;
}
1125

1126
#endif	/* CONFIG_USB_SUSPEND */
1127

1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138
/**
 * usb_suspend_both - suspend a USB device and its interfaces
 * @udev: the usb_device to suspend
 * @msg: Power Management message describing this state transition
 *
 * This is the central routine for suspending USB devices.  It calls the
 * suspend methods for all the interface drivers in @udev and then calls
 * the suspend method for @udev itself.  If an error occurs at any stage,
 * all the interfaces which were suspended are resumed so that they remain
 * in the same state as the device.
 *
A
Alan Stern 已提交
1139 1140 1141
 * If an autosuspend is in progress the routine checks first to make sure
 * that neither the device itself or any of its active interfaces is in use
 * (pm_usage_cnt is greater than 0).  If they are, the autosuspend fails.
1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162
 *
 * If the suspend succeeds, the routine recursively queues an autosuspend
 * request for @udev's parent device, thereby propagating the change up
 * the device tree.  If all of the parent's children are now suspended,
 * the parent will autosuspend in turn.
 *
 * The suspend method calls are subject to mutual exclusion under control
 * of @udev's pm_mutex.  Many of these calls are also under the protection
 * of @udev's device lock (including all requests originating outside the
 * USB subsystem), but autosuspend requests generated by a child device or
 * interface driver may not be.  Usbcore will insure that the method calls
 * do not arrive during bind, unbind, or reset operations.  However, drivers
 * must be prepared to handle suspend calls arriving at unpredictable times.
 * The only way to block such calls is to do an autoresume (preventing
 * autosuspends) while holding @udev's device lock (preventing outside
 * suspends).
 *
 * The caller must hold @udev->pm_mutex.
 *
 * This routine can run only in process context.
 */
A
Alan Stern 已提交
1163
static int usb_suspend_both(struct usb_device *udev, pm_message_t msg)
1164 1165 1166 1167
{
	int			status = 0;
	int			i = 0;
	struct usb_interface	*intf;
1168 1169
	struct usb_device	*parent = udev->parent;

1170 1171 1172
	if (udev->state == USB_STATE_NOTATTACHED ||
			udev->state == USB_STATE_SUSPENDED)
		goto done;
1173

1174 1175
	udev->do_remote_wakeup = device_may_wakeup(&udev->dev);

A
Alan Stern 已提交
1176
	if (msg.event & PM_EVENT_AUTO) {
1177
		status = autosuspend_check(udev, 0);
A
Alan Stern 已提交
1178
		if (status < 0)
1179
			goto done;
1180 1181 1182
	}

	/* Suspend all the interfaces and then udev itself */
1183 1184 1185
	if (udev->actconfig) {
		for (; i < udev->actconfig->desc.bNumInterfaces; i++) {
			intf = udev->actconfig->interface[i];
1186
			status = usb_suspend_interface(udev, intf, msg);
1187 1188 1189 1190
			if (status != 0)
				break;
		}
	}
1191
	if (status == 0)
1192
		status = usb_suspend_device(udev, msg);
1193 1194 1195

	/* If the suspend failed, resume interfaces that did get suspended */
	if (status != 0) {
A
Alan Stern 已提交
1196 1197 1198
		pm_message_t msg2;

		msg2.event = msg.event ^ (PM_EVENT_SUSPEND | PM_EVENT_RESUME);
1199 1200
		while (--i >= 0) {
			intf = udev->actconfig->interface[i];
A
Alan Stern 已提交
1201
			usb_resume_interface(udev, intf, msg2, 0);
1202
		}
1203

A
Alan Stern 已提交
1204
		/* Try another autosuspend when the interfaces aren't busy */
A
Alan Stern 已提交
1205
		if (msg.event & PM_EVENT_AUTO)
1206
			autosuspend_check(udev, status == -EBUSY);
A
Alan Stern 已提交
1207

1208 1209 1210
	/* If the suspend succeeded then prevent any more URB submissions,
	 * flush any outstanding URBs, and propagate the suspend up the tree.
	 */
A
Alan Stern 已提交
1211 1212
	} else {
		cancel_delayed_work(&udev->autosuspend);
1213 1214 1215 1216 1217
		udev->can_submit = 0;
		for (i = 0; i < 16; ++i) {
			usb_hcd_flush_endpoint(udev, udev->ep_out[i]);
			usb_hcd_flush_endpoint(udev, udev->ep_in[i]);
		}
1218 1219 1220 1221 1222 1223

		/* If this is just a FREEZE or a PRETHAW, udev might
		 * not really be suspended.  Only true suspends get
		 * propagated up the device tree.
		 */
		if (parent && udev->state == USB_STATE_SUSPENDED)
A
Alan Stern 已提交
1224 1225
			usb_autosuspend_device(parent);
	}
1226

1227
 done:
1228
	dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1229 1230 1231
	return status;
}

1232 1233 1234
/**
 * usb_resume_both - resume a USB device and its interfaces
 * @udev: the usb_device to resume
A
Alan Stern 已提交
1235
 * @msg: Power Management message describing this state transition
1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260
 *
 * This is the central routine for resuming USB devices.  It calls the
 * the resume method for @udev and then calls the resume methods for all
 * the interface drivers in @udev.
 *
 * Before starting the resume, the routine calls itself recursively for
 * the parent device of @udev, thereby propagating the change up the device
 * tree and assuring that @udev will be able to resume.  If the parent is
 * unable to resume successfully, the routine fails.
 *
 * The resume method calls are subject to mutual exclusion under control
 * of @udev's pm_mutex.  Many of these calls are also under the protection
 * of @udev's device lock (including all requests originating outside the
 * USB subsystem), but autoresume requests generated by a child device or
 * interface driver may not be.  Usbcore will insure that the method calls
 * do not arrive during bind, unbind, or reset operations.  However, drivers
 * must be prepared to handle resume calls arriving at unpredictable times.
 * The only way to block such calls is to do an autoresume (preventing
 * other autoresumes) while holding @udev's device lock (preventing outside
 * resumes).
 *
 * The caller must hold @udev->pm_mutex.
 *
 * This routine can run only in process context.
 */
A
Alan Stern 已提交
1261
static int usb_resume_both(struct usb_device *udev, pm_message_t msg)
1262
{
1263
	int			status = 0;
1264 1265
	int			i;
	struct usb_interface	*intf;
1266 1267 1268
	struct usb_device	*parent = udev->parent;

	cancel_delayed_work(&udev->autosuspend);
1269 1270 1271 1272
	if (udev->state == USB_STATE_NOTATTACHED) {
		status = -ENODEV;
		goto done;
	}
1273
	udev->can_submit = 1;
1274

1275 1276
	/* Propagate the resume up the tree, if necessary */
	if (udev->state == USB_STATE_SUSPENDED) {
A
Alan Stern 已提交
1277 1278
		if ((msg.event & PM_EVENT_AUTO) &&
				udev->autoresume_disabled) {
1279 1280 1281
			status = -EPERM;
			goto done;
		}
1282
		if (parent) {
1283
			status = usb_autoresume_device(parent);
1284
			if (status == 0) {
A
Alan Stern 已提交
1285
				status = usb_resume_device(udev, msg);
A
Alan Stern 已提交
1286 1287
				if (status || udev->state ==
						USB_STATE_NOTATTACHED) {
1288
					usb_autosuspend_device(parent);
1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302

					/* It's possible usb_resume_device()
					 * failed after the port was
					 * unsuspended, causing udev to be
					 * logically disconnected.  We don't
					 * want usb_disconnect() to autosuspend
					 * the parent again, so tell it that
					 * udev disconnected while still
					 * suspended. */
					if (udev->state ==
							USB_STATE_NOTATTACHED)
						udev->discon_suspended = 1;
				}
			}
1303 1304 1305 1306 1307
		} else {

			/* We can't progagate beyond the USB subsystem,
			 * so if a root hub's controller is suspended
			 * then we're stuck. */
A
Alan Stern 已提交
1308
			status = usb_resume_device(udev, msg);
1309
		}
A
Alan Stern 已提交
1310
	} else if (udev->reset_resume)
A
Alan Stern 已提交
1311
		status = usb_resume_device(udev, msg);
1312

1313 1314 1315
	if (status == 0 && udev->actconfig) {
		for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
			intf = udev->actconfig->interface[i];
A
Alan Stern 已提交
1316 1317
			usb_resume_interface(udev, intf, msg,
					udev->reset_resume);
1318 1319
		}
	}
1320

1321
 done:
1322
	dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
A
Alan Stern 已提交
1323 1324
	if (!status)
		udev->reset_resume = 0;
1325 1326 1327 1328 1329
	return status;
}

#ifdef CONFIG_USB_SUSPEND

1330 1331 1332 1333 1334 1335 1336 1337
/* Internal routine to adjust a device's usage counter and change
 * its autosuspend state.
 */
static int usb_autopm_do_device(struct usb_device *udev, int inc_usage_cnt)
{
	int	status = 0;

	usb_pm_lock(udev);
1338
	udev->auto_pm = 1;
1339 1340
	udev->pm_usage_cnt += inc_usage_cnt;
	WARN_ON(udev->pm_usage_cnt < 0);
1341 1342
	if (inc_usage_cnt)
		udev->last_busy = jiffies;
1343
	if (inc_usage_cnt >= 0 && udev->pm_usage_cnt > 0) {
1344
		if (udev->state == USB_STATE_SUSPENDED)
A
Alan Stern 已提交
1345
			status = usb_resume_both(udev, PMSG_AUTO_RESUME);
1346 1347
		if (status != 0)
			udev->pm_usage_cnt -= inc_usage_cnt;
1348 1349 1350
		else if (inc_usage_cnt)
			udev->last_busy = jiffies;
	} else if (inc_usage_cnt <= 0 && udev->pm_usage_cnt <= 0) {
A
Alan Stern 已提交
1351
		status = usb_suspend_both(udev, PMSG_AUTO_SUSPEND);
1352
	}
1353 1354 1355 1356
	usb_pm_unlock(udev);
	return status;
}

1357 1358 1359 1360 1361 1362 1363 1364 1365
/* usb_autosuspend_work - callback routine to autosuspend a USB device */
void usb_autosuspend_work(struct work_struct *work)
{
	struct usb_device *udev =
		container_of(work, struct usb_device, autosuspend.work);

	usb_autopm_do_device(udev, 0);
}

1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378
/* usb_autoresume_work - callback routine to autoresume a USB device */
void usb_autoresume_work(struct work_struct *work)
{
	struct usb_device *udev =
		container_of(work, struct usb_device, autoresume);

	/* Wake it up, let the drivers do their thing, and then put it
	 * back to sleep.
	 */
	if (usb_autopm_do_device(udev, 1) == 0)
		usb_autopm_do_device(udev, -1);
}

1379 1380
/**
 * usb_autosuspend_device - delayed autosuspend of a USB device and its interfaces
1381
 * @udev: the usb_device to autosuspend
1382 1383 1384 1385 1386
 *
 * This routine should be called when a core subsystem is finished using
 * @udev and wants to allow it to autosuspend.  Examples would be when
 * @udev's device file in usbfs is closed or after a configuration change.
 *
1387 1388 1389 1390 1391 1392
 * @udev's usage counter is decremented.  If it or any of the usage counters
 * for an active interface is greater than 0, no autosuspend request will be
 * queued.  (If an interface driver does not support autosuspend then its
 * usage counter is permanently positive.)  Furthermore, if an interface
 * driver requires remote-wakeup capability during autosuspend but remote
 * wakeup is disabled, the autosuspend will fail.
1393 1394 1395 1396 1397 1398
 *
 * Often the caller will hold @udev's device lock, but this is not
 * necessary.
 *
 * This routine can run only in process context.
 */
1399
void usb_autosuspend_device(struct usb_device *udev)
1400
{
1401 1402 1403
	int	status;

	status = usb_autopm_do_device(udev, -1);
A
Alan Stern 已提交
1404
	dev_vdbg(&udev->dev, "%s: cnt %d\n",
1405
			__func__, udev->pm_usage_cnt);
1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423
}

/**
 * usb_try_autosuspend_device - attempt an autosuspend of a USB device and its interfaces
 * @udev: the usb_device to autosuspend
 *
 * This routine should be called when a core subsystem thinks @udev may
 * be ready to autosuspend.
 *
 * @udev's usage counter left unchanged.  If it or any of the usage counters
 * for an active interface is greater than 0, or autosuspend is not allowed
 * for any other reason, no autosuspend request will be queued.
 *
 * This routine can run only in process context.
 */
void usb_try_autosuspend_device(struct usb_device *udev)
{
	usb_autopm_do_device(udev, 0);
A
Alan Stern 已提交
1424
	dev_vdbg(&udev->dev, "%s: cnt %d\n",
1425
			__func__, udev->pm_usage_cnt);
1426 1427 1428 1429
}

/**
 * usb_autoresume_device - immediately autoresume a USB device and its interfaces
1430
 * @udev: the usb_device to autoresume
1431 1432
 *
 * This routine should be called when a core subsystem wants to use @udev
1433 1434 1435 1436 1437
 * and needs to guarantee that it is not suspended.  No autosuspend will
 * occur until usb_autosuspend_device is called.  (Note that this will not
 * prevent suspend events originating in the PM core.)  Examples would be
 * when @udev's device file in usbfs is opened or when a remote-wakeup
 * request is received.
1438
 *
1439 1440
 * @udev's usage counter is incremented to prevent subsequent autosuspends.
 * However if the autoresume fails then the usage counter is re-decremented.
1441 1442 1443 1444 1445 1446
 *
 * Often the caller will hold @udev's device lock, but this is not
 * necessary (and attempting it might cause deadlock).
 *
 * This routine can run only in process context.
 */
1447
int usb_autoresume_device(struct usb_device *udev)
1448 1449 1450
{
	int	status;

1451
	status = usb_autopm_do_device(udev, 1);
A
Alan Stern 已提交
1452
	dev_vdbg(&udev->dev, "%s: status %d cnt %d\n",
1453
			__func__, status, udev->pm_usage_cnt);
1454 1455 1456
	return status;
}

A
Alan Stern 已提交
1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469
/* Internal routine to adjust an interface's usage counter and change
 * its device's autosuspend state.
 */
static int usb_autopm_do_interface(struct usb_interface *intf,
		int inc_usage_cnt)
{
	struct usb_device	*udev = interface_to_usbdev(intf);
	int			status = 0;

	usb_pm_lock(udev);
	if (intf->condition == USB_INTERFACE_UNBOUND)
		status = -ENODEV;
	else {
1470
		udev->auto_pm = 1;
A
Alan Stern 已提交
1471
		intf->pm_usage_cnt += inc_usage_cnt;
1472
		udev->last_busy = jiffies;
A
Alan Stern 已提交
1473
		if (inc_usage_cnt >= 0 && intf->pm_usage_cnt > 0) {
1474
			if (udev->state == USB_STATE_SUSPENDED)
A
Alan Stern 已提交
1475 1476
				status = usb_resume_both(udev,
						PMSG_AUTO_RESUME);
A
Alan Stern 已提交
1477 1478
			if (status != 0)
				intf->pm_usage_cnt -= inc_usage_cnt;
1479
			else
1480 1481
				udev->last_busy = jiffies;
		} else if (inc_usage_cnt <= 0 && intf->pm_usage_cnt <= 0) {
A
Alan Stern 已提交
1482
			status = usb_suspend_both(udev, PMSG_AUTO_SUSPEND);
1483
		}
A
Alan Stern 已提交
1484 1485 1486 1487 1488
	}
	usb_pm_unlock(udev);
	return status;
}

1489 1490
/**
 * usb_autopm_put_interface - decrement a USB interface's PM-usage counter
1491
 * @intf: the usb_interface whose counter should be decremented
1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521
 *
 * This routine should be called by an interface driver when it is
 * finished using @intf and wants to allow it to autosuspend.  A typical
 * example would be a character-device driver when its device file is
 * closed.
 *
 * The routine decrements @intf's usage counter.  When the counter reaches
 * 0, a delayed autosuspend request for @intf's device is queued.  When
 * the delay expires, if @intf->pm_usage_cnt is still <= 0 along with all
 * the other usage counters for the sibling interfaces and @intf's
 * usb_device, the device and all its interfaces will be autosuspended.
 *
 * Note that @intf->pm_usage_cnt is owned by the interface driver.  The
 * core will not change its value other than the increment and decrement
 * in usb_autopm_get_interface and usb_autopm_put_interface.  The driver
 * may use this simple counter-oriented discipline or may set the value
 * any way it likes.
 *
 * If the driver has set @intf->needs_remote_wakeup then autosuspend will
 * take place only if the device's remote-wakeup facility is enabled.
 *
 * Suspend method calls queued by this routine can arrive at any time
 * while @intf is resumed and its usage counter is equal to 0.  They are
 * not protected by the usb_device's lock but only by its pm_mutex.
 * Drivers must provide their own synchronization.
 *
 * This routine can run only in process context.
 */
void usb_autopm_put_interface(struct usb_interface *intf)
{
A
Alan Stern 已提交
1522
	int	status;
1523

A
Alan Stern 已提交
1524
	status = usb_autopm_do_interface(intf, -1);
A
Alan Stern 已提交
1525
	dev_vdbg(&intf->dev, "%s: status %d cnt %d\n",
1526
			__func__, status, intf->pm_usage_cnt);
1527 1528 1529
}
EXPORT_SYMBOL_GPL(usb_autopm_put_interface);

1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559
/**
 * usb_autopm_put_interface_async - decrement a USB interface's PM-usage counter
 * @intf: the usb_interface whose counter should be decremented
 *
 * This routine does essentially the same thing as
 * usb_autopm_put_interface(): it decrements @intf's usage counter and
 * queues a delayed autosuspend request if the counter is <= 0.  The
 * difference is that it does not acquire the device's pm_mutex;
 * callers must handle all synchronization issues themselves.
 *
 * Typically a driver would call this routine during an URB's completion
 * handler, if no more URBs were pending.
 *
 * This routine can run in atomic context.
 */
void usb_autopm_put_interface_async(struct usb_interface *intf)
{
	struct usb_device	*udev = interface_to_usbdev(intf);
	int			status = 0;

	if (intf->condition == USB_INTERFACE_UNBOUND) {
		status = -ENODEV;
	} else {
		udev->last_busy = jiffies;
		--intf->pm_usage_cnt;
		if (udev->autosuspend_disabled || udev->autosuspend_delay < 0)
			status = -EPERM;
		else if (intf->pm_usage_cnt <= 0 &&
				!timer_pending(&udev->autosuspend.timer)) {
			queue_delayed_work(ksuspend_usb_wq, &udev->autosuspend,
1560
					round_jiffies_up_relative(
1561 1562 1563 1564 1565 1566 1567 1568
						udev->autosuspend_delay));
		}
	}
	dev_vdbg(&intf->dev, "%s: status %d cnt %d\n",
			__func__, status, intf->pm_usage_cnt);
}
EXPORT_SYMBOL_GPL(usb_autopm_put_interface_async);

1569 1570
/**
 * usb_autopm_get_interface - increment a USB interface's PM-usage counter
1571
 * @intf: the usb_interface whose counter should be incremented
1572 1573 1574 1575 1576 1577 1578 1579 1580
 *
 * This routine should be called by an interface driver when it wants to
 * use @intf and needs to guarantee that it is not suspended.  In addition,
 * the routine prevents @intf from being autosuspended subsequently.  (Note
 * that this will not prevent suspend events originating in the PM core.)
 * This prevention will persist until usb_autopm_put_interface() is called
 * or @intf is unbound.  A typical example would be a character-device
 * driver when its device file is opened.
 *
1581 1582 1583 1584 1585 1586 1587 1588
 *
 * The routine increments @intf's usage counter.  (However if the
 * autoresume fails then the counter is re-decremented.)  So long as the
 * counter is greater than 0, autosuspend will not be allowed for @intf
 * or its usb_device.  When the driver is finished using @intf it should
 * call usb_autopm_put_interface() to decrement the usage counter and
 * queue a delayed autosuspend request (if the counter is <= 0).
 *
1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604
 *
 * Note that @intf->pm_usage_cnt is owned by the interface driver.  The
 * core will not change its value other than the increment and decrement
 * in usb_autopm_get_interface and usb_autopm_put_interface.  The driver
 * may use this simple counter-oriented discipline or may set the value
 * any way it likes.
 *
 * Resume method calls generated by this routine can arrive at any time
 * while @intf is suspended.  They are not protected by the usb_device's
 * lock but only by its pm_mutex.  Drivers must provide their own
 * synchronization.
 *
 * This routine can run only in process context.
 */
int usb_autopm_get_interface(struct usb_interface *intf)
{
A
Alan Stern 已提交
1605
	int	status;
1606

A
Alan Stern 已提交
1607
	status = usb_autopm_do_interface(intf, 1);
A
Alan Stern 已提交
1608
	dev_vdbg(&intf->dev, "%s: status %d cnt %d\n",
1609
			__func__, status, intf->pm_usage_cnt);
1610 1611
	return status;
}
1612 1613
EXPORT_SYMBOL_GPL(usb_autopm_get_interface);

1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644
/**
 * usb_autopm_get_interface_async - increment a USB interface's PM-usage counter
 * @intf: the usb_interface whose counter should be incremented
 *
 * This routine does much the same thing as
 * usb_autopm_get_interface(): it increments @intf's usage counter and
 * queues an autoresume request if the result is > 0.  The differences
 * are that it does not acquire the device's pm_mutex (callers must
 * handle all synchronization issues themselves), and it does not
 * autoresume the device directly (it only queues a request).  After a
 * successful call, the device will generally not yet be resumed.
 *
 * This routine can run in atomic context.
 */
int usb_autopm_get_interface_async(struct usb_interface *intf)
{
	struct usb_device	*udev = interface_to_usbdev(intf);
	int			status = 0;

	if (intf->condition == USB_INTERFACE_UNBOUND)
		status = -ENODEV;
	else if (udev->autoresume_disabled)
		status = -EPERM;
	else if (++intf->pm_usage_cnt > 0 && udev->state == USB_STATE_SUSPENDED)
		queue_work(ksuspend_usb_wq, &udev->autoresume);
	dev_vdbg(&intf->dev, "%s: status %d cnt %d\n",
			__func__, status, intf->pm_usage_cnt);
	return status;
}
EXPORT_SYMBOL_GPL(usb_autopm_get_interface_async);

1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660
/**
 * usb_autopm_set_interface - set a USB interface's autosuspend state
 * @intf: the usb_interface whose state should be set
 *
 * This routine sets the autosuspend state of @intf's device according
 * to @intf's usage counter, which the caller must have set previously.
 * If the counter is <= 0, the device is autosuspended (if it isn't
 * already suspended and if nothing else prevents the autosuspend).  If
 * the counter is > 0, the device is autoresumed (if it isn't already
 * awake).
 */
int usb_autopm_set_interface(struct usb_interface *intf)
{
	int	status;

	status = usb_autopm_do_interface(intf, 0);
A
Alan Stern 已提交
1661
	dev_vdbg(&intf->dev, "%s: status %d cnt %d\n",
1662
			__func__, status, intf->pm_usage_cnt);
1663 1664 1665 1666
	return status;
}
EXPORT_SYMBOL_GPL(usb_autopm_set_interface);

A
Alan Stern 已提交
1667 1668 1669 1670 1671
#else

void usb_autosuspend_work(struct work_struct *work)
{}

1672 1673 1674
void usb_autoresume_work(struct work_struct *work)
{}

1675
#endif /* CONFIG_USB_SUSPEND */
1676

1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692
/**
 * usb_external_suspend_device - external suspend of a USB device and its interfaces
 * @udev: the usb_device to suspend
 * @msg: Power Management message describing this state transition
 *
 * This routine handles external suspend requests: ones not generated
 * internally by a USB driver (autosuspend) but rather coming from the user
 * (via sysfs) or the PM core (system sleep).  The suspend will be carried
 * out regardless of @udev's usage counter or those of its interfaces,
 * and regardless of whether or not remote wakeup is enabled.  Of course,
 * interface drivers still have the option of failing the suspend (if
 * there are unsuspended children, for example).
 *
 * The caller must hold @udev's device lock.
 */
int usb_external_suspend_device(struct usb_device *udev, pm_message_t msg)
1693 1694 1695
{
	int	status;

1696
	do_unbind_rebind(udev, DO_UNBIND);
1697 1698 1699 1700
	usb_pm_lock(udev);
	udev->auto_pm = 0;
	status = usb_suspend_both(udev, msg);
	usb_pm_unlock(udev);
1701 1702 1703
	return status;
}

1704 1705 1706
/**
 * usb_external_resume_device - external resume of a USB device and its interfaces
 * @udev: the usb_device to resume
A
Alan Stern 已提交
1707
 * @msg: Power Management message describing this state transition
1708 1709 1710 1711 1712 1713 1714 1715
 *
 * This routine handles external resume requests: ones not generated
 * internally by a USB driver (autoresume) but rather coming from the user
 * (via sysfs), the PM core (system resume), or the device itself (remote
 * wakeup).  @udev's usage counter is unaffected.
 *
 * The caller must hold @udev's device lock.
 */
A
Alan Stern 已提交
1716
int usb_external_resume_device(struct usb_device *udev, pm_message_t msg)
1717 1718 1719
{
	int	status;

1720 1721
	usb_pm_lock(udev);
	udev->auto_pm = 0;
A
Alan Stern 已提交
1722
	status = usb_resume_both(udev, msg);
A
Alan Stern 已提交
1723
	udev->last_busy = jiffies;
1724
	usb_pm_unlock(udev);
1725 1726
	if (status == 0)
		do_unbind_rebind(udev, DO_REBIND);
1727

1728 1729 1730 1731
	/* Now that the device is awake, we can start trying to autosuspend
	 * it again. */
	if (status == 0)
		usb_try_autosuspend_device(udev);
1732 1733 1734
	return status;
}

A
Alan Stern 已提交
1735
int usb_suspend(struct device *dev, pm_message_t msg)
1736
{
1737 1738 1739 1740 1741
	struct usb_device	*udev;

	udev = to_usb_device(dev);

	/* If udev is already suspended, we can skip this suspend and
1742 1743 1744 1745 1746
	 * we should also skip the upcoming system resume.  High-speed
	 * root hubs are an exception; they need to resume whenever the
	 * system wakes up in order for USB-PERSIST port handover to work
	 * properly.
	 */
1747
	if (udev->state == USB_STATE_SUSPENDED) {
1748 1749
		if (udev->parent || udev->speed != USB_SPEED_HIGH)
			udev->skip_sys_resume = 1;
1750 1751 1752 1753
		return 0;
	}

	udev->skip_sys_resume = 0;
A
Alan Stern 已提交
1754
	return usb_external_suspend_device(udev, msg);
1755 1756
}

A
Alan Stern 已提交
1757
int usb_resume(struct device *dev, pm_message_t msg)
1758
{
1759 1760 1761
	struct usb_device	*udev;

	udev = to_usb_device(dev);
A
Alan Stern 已提交
1762

1763
	/* If udev->skip_sys_resume is set then udev was already suspended
1764 1765 1766 1767 1768
	 * when the system sleep started, so we don't want to resume it
	 * during this system wakeup.
	 */
	if (udev->skip_sys_resume)
		return 0;
A
Alan Stern 已提交
1769
	return usb_external_resume_device(udev, msg);
1770 1771
}

1772 1773 1774 1775 1776 1777 1778
#endif /* CONFIG_PM */

struct bus_type usb_bus_type = {
	.name =		"usb",
	.match =	usb_device_match,
	.uevent =	usb_uevent,
};