1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * drivers/usb/core/driver.c - most of the driver model stuff for usb
   4 *
   5 * (C) Copyright 2005 Greg Kroah-Hartman <gregkh@suse.de>
   6 *
   7 * based on drivers/usb/usb.c which had the following copyrights:
   8 *	(C) Copyright Linus Torvalds 1999
   9 *	(C) Copyright Johannes Erdfelt 1999-2001
  10 *	(C) Copyright Andreas Gal 1999
  11 *	(C) Copyright Gregory P. Smith 1999
  12 *	(C) Copyright Deti Fliegl 1999 (new USB architecture)
  13 *	(C) Copyright Randy Dunlap 2000
  14 *	(C) Copyright David Brownell 2000-2004
  15 *	(C) Copyright Yggdrasil Computing, Inc. 2000
  16 *		(usb_device_id matching changes by Adam J. Richter)
  17 *	(C) Copyright Greg Kroah-Hartman 2002-2003
  18 *
  19 * Released under the GPLv2 only.
  20 *
  21 * NOTE! This is not actually a driver at all, rather this is
  22 * just a collection of helper routines that implement the
  23 * matching, probing, releasing, suspending and resuming for
  24 * real drivers.
  25 *
  26 */
  27
  28#include <linux/device.h>
  29#include <linux/slab.h>
  30#include <linux/export.h>
  31#include <linux/usb.h>
  32#include <linux/usb/quirks.h>
  33#include <linux/usb/hcd.h>
  34
  35#include "usb.h"
  36
  37
 
 
  38/*
  39 * Adds a new dynamic USBdevice ID to this driver,
  40 * and cause the driver to probe for all devices again.
  41 */
  42ssize_t usb_store_new_id(struct usb_dynids *dynids,
  43			 const struct usb_device_id *id_table,
  44			 struct device_driver *driver,
  45			 const char *buf, size_t count)
  46{
  47	struct usb_dynid *dynid;
  48	u32 idVendor = 0;
  49	u32 idProduct = 0;
  50	unsigned int bInterfaceClass = 0;
  51	u32 refVendor, refProduct;
  52	int fields = 0;
  53	int retval = 0;
  54
  55	fields = sscanf(buf, "%x %x %x %x %x", &idVendor, &idProduct,
  56			&bInterfaceClass, &refVendor, &refProduct);
  57	if (fields < 2)
  58		return -EINVAL;
  59
  60	dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
  61	if (!dynid)
  62		return -ENOMEM;
  63
  64	INIT_LIST_HEAD(&dynid->node);
  65	dynid->id.idVendor = idVendor;
  66	dynid->id.idProduct = idProduct;
  67	dynid->id.match_flags = USB_DEVICE_ID_MATCH_DEVICE;
  68	if (fields > 2 && bInterfaceClass) {
  69		if (bInterfaceClass > 255) {
  70			retval = -EINVAL;
  71			goto fail;
  72		}
  73
  74		dynid->id.bInterfaceClass = (u8)bInterfaceClass;
  75		dynid->id.match_flags |= USB_DEVICE_ID_MATCH_INT_CLASS;
  76	}
  77
  78	if (fields > 4) {
  79		const struct usb_device_id *id = id_table;
  80
  81		if (!id) {
  82			retval = -ENODEV;
  83			goto fail;
  84		}
  85
  86		for (; id->match_flags; id++)
  87			if (id->idVendor == refVendor && id->idProduct == refProduct)
  88				break;
  89
  90		if (id->match_flags) {
  91			dynid->id.driver_info = id->driver_info;
  92		} else {
  93			retval = -ENODEV;
  94			goto fail;
  95		}
  96	}
  97
  98	spin_lock(&dynids->lock);
  99	list_add_tail(&dynid->node, &dynids->list);
 100	spin_unlock(&dynids->lock);
 101
 102	retval = driver_attach(driver);
 103
 104	if (retval)
 105		return retval;
 106	return count;
 107
 108fail:
 109	kfree(dynid);
 110	return retval;
 111}
 112EXPORT_SYMBOL_GPL(usb_store_new_id);
 113
 114ssize_t usb_show_dynids(struct usb_dynids *dynids, char *buf)
 115{
 116	struct usb_dynid *dynid;
 117	size_t count = 0;
 118
 119	list_for_each_entry(dynid, &dynids->list, node)
 120		if (dynid->id.bInterfaceClass != 0)
 121			count += scnprintf(&buf[count], PAGE_SIZE - count, "%04x %04x %02x\n",
 122					   dynid->id.idVendor, dynid->id.idProduct,
 123					   dynid->id.bInterfaceClass);
 124		else
 125			count += scnprintf(&buf[count], PAGE_SIZE - count, "%04x %04x\n",
 126					   dynid->id.idVendor, dynid->id.idProduct);
 127	return count;
 128}
 129EXPORT_SYMBOL_GPL(usb_show_dynids);
 130
 131static ssize_t new_id_show(struct device_driver *driver, char *buf)
 132{
 133	struct usb_driver *usb_drv = to_usb_driver(driver);
 134
 135	return usb_show_dynids(&usb_drv->dynids, buf);
 136}
 137
 138static ssize_t new_id_store(struct device_driver *driver,
 139			    const char *buf, size_t count)
 140{
 141	struct usb_driver *usb_drv = to_usb_driver(driver);
 142
 143	return usb_store_new_id(&usb_drv->dynids, usb_drv->id_table, driver, buf, count);
 144}
 145static DRIVER_ATTR_RW(new_id);
 146
 147/*
 148 * Remove a USB device ID from this driver
 
 
 
 
 
 149 */
 150static ssize_t remove_id_store(struct device_driver *driver, const char *buf,
 151			       size_t count)
 152{
 153	struct usb_dynid *dynid, *n;
 154	struct usb_driver *usb_driver = to_usb_driver(driver);
 155	u32 idVendor;
 156	u32 idProduct;
 157	int fields;
 
 158
 159	fields = sscanf(buf, "%x %x", &idVendor, &idProduct);
 160	if (fields < 2)
 161		return -EINVAL;
 162
 163	spin_lock(&usb_driver->dynids.lock);
 164	list_for_each_entry_safe(dynid, n, &usb_driver->dynids.list, node) {
 165		struct usb_device_id *id = &dynid->id;
 166
 167		if ((id->idVendor == idVendor) &&
 168		    (id->idProduct == idProduct)) {
 169			list_del(&dynid->node);
 170			kfree(dynid);
 
 171			break;
 172		}
 173	}
 174	spin_unlock(&usb_driver->dynids.lock);
 175	return count;
 176}
 177
 178static ssize_t remove_id_show(struct device_driver *driver, char *buf)
 179{
 180	return new_id_show(driver, buf);
 181}
 182static DRIVER_ATTR_RW(remove_id);
 183
 184static int usb_create_newid_files(struct usb_driver *usb_drv)
 185{
 186	int error = 0;
 187
 188	if (usb_drv->no_dynamic_id)
 189		goto exit;
 190
 191	if (usb_drv->probe != NULL) {
 192		error = driver_create_file(&usb_drv->driver,
 193					   &driver_attr_new_id);
 194		if (error == 0) {
 195			error = driver_create_file(&usb_drv->driver,
 196					&driver_attr_remove_id);
 197			if (error)
 198				driver_remove_file(&usb_drv->driver,
 199						&driver_attr_new_id);
 200		}
 201	}
 202exit:
 203	return error;
 204}
 205
 206static void usb_remove_newid_files(struct usb_driver *usb_drv)
 207{
 208	if (usb_drv->no_dynamic_id)
 209		return;
 210
 211	if (usb_drv->probe != NULL) {
 212		driver_remove_file(&usb_drv->driver,
 213				&driver_attr_remove_id);
 214		driver_remove_file(&usb_drv->driver,
 215				   &driver_attr_new_id);
 216	}
 217}
 218
 219static void usb_free_dynids(struct usb_driver *usb_drv)
 220{
 221	struct usb_dynid *dynid, *n;
 222
 223	spin_lock(&usb_drv->dynids.lock);
 224	list_for_each_entry_safe(dynid, n, &usb_drv->dynids.list, node) {
 225		list_del(&dynid->node);
 226		kfree(dynid);
 227	}
 228	spin_unlock(&usb_drv->dynids.lock);
 229}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 230
 231static const struct usb_device_id *usb_match_dynamic_id(struct usb_interface *intf,
 232							struct usb_driver *drv)
 233{
 234	struct usb_dynid *dynid;
 235
 236	spin_lock(&drv->dynids.lock);
 237	list_for_each_entry(dynid, &drv->dynids.list, node) {
 238		if (usb_match_one_id(intf, &dynid->id)) {
 239			spin_unlock(&drv->dynids.lock);
 240			return &dynid->id;
 241		}
 242	}
 243	spin_unlock(&drv->dynids.lock);
 244	return NULL;
 245}
 246
 247
 248/* called from driver core with dev locked */
 249static int usb_probe_device(struct device *dev)
 250{
 251	struct usb_device_driver *udriver = to_usb_device_driver(dev->driver);
 252	struct usb_device *udev = to_usb_device(dev);
 253	int error = 0;
 254
 255	dev_dbg(dev, "%s\n", __func__);
 256
 257	/* TODO: Add real matching code */
 258
 259	/* The device should always appear to be in use
 260	 * unless the driver supports autosuspend.
 261	 */
 262	if (!udriver->supports_autosuspend)
 263		error = usb_autoresume_device(udev);
 264	if (error)
 265		return error;
 266
 267	if (udriver->generic_subclass)
 268		error = usb_generic_driver_probe(udev);
 269	if (error)
 270		return error;
 271
 272	/* Probe the USB device with the driver in hand, but only
 273	 * defer to a generic driver in case the current USB
 274	 * device driver has an id_table or a match function; i.e.,
 275	 * when the device driver was explicitly matched against
 276	 * a device.
 277	 *
 278	 * If the device driver does not have either of these,
 279	 * then we assume that it can bind to any device and is
 280	 * not truly a more specialized/non-generic driver, so a
 281	 * return value of -ENODEV should not force the device
 282	 * to be handled by the generic USB driver, as there
 283	 * can still be another, more specialized, device driver.
 284	 *
 285	 * This accommodates the usbip driver.
 286	 *
 287	 * TODO: What if, in the future, there are multiple
 288	 * specialized USB device drivers for a particular device?
 289	 * In such cases, there is a need to try all matching
 290	 * specialised device drivers prior to setting the
 291	 * use_generic_driver bit.
 292	 */
 293	if (udriver->probe)
 294		error = udriver->probe(udev);
 295	else if (!udriver->generic_subclass)
 296		error = -EINVAL;
 297	if (error == -ENODEV && udriver != &usb_generic_driver &&
 298	    (udriver->id_table || udriver->match)) {
 299		udev->use_generic_driver = 1;
 300		return -EPROBE_DEFER;
 301	}
 302	return error;
 303}
 304
 305/* called from driver core with dev locked */
 306static int usb_unbind_device(struct device *dev)
 307{
 308	struct usb_device *udev = to_usb_device(dev);
 309	struct usb_device_driver *udriver = to_usb_device_driver(dev->driver);
 310
 311	if (udriver->disconnect)
 312		udriver->disconnect(udev);
 313	if (udriver->generic_subclass)
 314		usb_generic_driver_disconnect(udev);
 315	if (!udriver->supports_autosuspend)
 316		usb_autosuspend_device(udev);
 317	return 0;
 318}
 319
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 320/* called from driver core with dev locked */
 321static int usb_probe_interface(struct device *dev)
 322{
 323	struct usb_driver *driver = to_usb_driver(dev->driver);
 324	struct usb_interface *intf = to_usb_interface(dev);
 325	struct usb_device *udev = interface_to_usbdev(intf);
 326	const struct usb_device_id *id;
 327	int error = -ENODEV;
 328	int lpm_disable_error = -ENODEV;
 329
 330	dev_dbg(dev, "%s\n", __func__);
 331
 332	intf->needs_binding = 0;
 333
 334	if (usb_device_is_owned(udev))
 335		return error;
 336
 337	if (udev->authorized == 0) {
 338		dev_err(&intf->dev, "Device is not authorized for usage\n");
 339		return error;
 340	} else if (intf->authorized == 0) {
 341		dev_err(&intf->dev, "Interface %d is not authorized for usage\n",
 342				intf->altsetting->desc.bInterfaceNumber);
 343		return error;
 344	}
 345
 346	id = usb_match_dynamic_id(intf, driver);
 347	if (!id)
 348		id = usb_match_id(intf, driver->id_table);
 349	if (!id)
 350		return error;
 351
 352	dev_dbg(dev, "%s - got id\n", __func__);
 353
 354	error = usb_autoresume_device(udev);
 355	if (error)
 356		return error;
 357
 358	intf->condition = USB_INTERFACE_BINDING;
 359
 360	/* Probed interfaces are initially active.  They are
 361	 * runtime-PM-enabled only if the driver has autosuspend support.
 362	 * They are sensitive to their children's power states.
 363	 */
 364	pm_runtime_set_active(dev);
 365	pm_suspend_ignore_children(dev, false);
 366	if (driver->supports_autosuspend)
 367		pm_runtime_enable(dev);
 368
 369	/* If the new driver doesn't allow hub-initiated LPM, and we can't
 370	 * disable hub-initiated LPM, then fail the probe.
 371	 *
 372	 * Otherwise, leaving LPM enabled should be harmless, because the
 373	 * endpoint intervals should remain the same, and the U1/U2 timeouts
 374	 * should remain the same.
 375	 *
 376	 * If we need to install alt setting 0 before probe, or another alt
 377	 * setting during probe, that should also be fine.  usb_set_interface()
 378	 * will attempt to disable LPM, and fail if it can't disable it.
 379	 */
 380	if (driver->disable_hub_initiated_lpm) {
 381		lpm_disable_error = usb_unlocked_disable_lpm(udev);
 382		if (lpm_disable_error) {
 383			dev_err(&intf->dev, "%s Failed to disable LPM for driver %s\n",
 384				__func__, driver->name);
 385			error = lpm_disable_error;
 386			goto err;
 387		}
 388	}
 389
 390	/* Carry out a deferred switch to altsetting 0 */
 391	if (intf->needs_altsetting0) {
 392		error = usb_set_interface(udev, intf->altsetting[0].
 393				desc.bInterfaceNumber, 0);
 394		if (error < 0)
 395			goto err;
 396		intf->needs_altsetting0 = 0;
 397	}
 398
 399	error = driver->probe(intf, id);
 400	if (error)
 401		goto err;
 402
 403	intf->condition = USB_INTERFACE_BOUND;
 404
 405	/* If the LPM disable succeeded, balance the ref counts. */
 406	if (!lpm_disable_error)
 407		usb_unlocked_enable_lpm(udev);
 408
 409	usb_autosuspend_device(udev);
 410	return error;
 411
 412 err:
 413	usb_set_intfdata(intf, NULL);
 414	intf->needs_remote_wakeup = 0;
 415	intf->condition = USB_INTERFACE_UNBOUND;
 416
 417	/* If the LPM disable succeeded, balance the ref counts. */
 418	if (!lpm_disable_error)
 419		usb_unlocked_enable_lpm(udev);
 420
 421	/* Unbound interfaces are always runtime-PM-disabled and -suspended */
 422	if (driver->supports_autosuspend)
 423		pm_runtime_disable(dev);
 424	pm_runtime_set_suspended(dev);
 425
 426	usb_autosuspend_device(udev);
 427	return error;
 428}
 429
 430/* called from driver core with dev locked */
 431static int usb_unbind_interface(struct device *dev)
 432{
 433	struct usb_driver *driver = to_usb_driver(dev->driver);
 434	struct usb_interface *intf = to_usb_interface(dev);
 435	struct usb_host_endpoint *ep, **eps = NULL;
 436	struct usb_device *udev;
 437	int i, j, error, r;
 438	int lpm_disable_error = -ENODEV;
 439
 440	intf->condition = USB_INTERFACE_UNBINDING;
 441
 442	/* Autoresume for set_interface call below */
 443	udev = interface_to_usbdev(intf);
 444	error = usb_autoresume_device(udev);
 445
 446	/* If hub-initiated LPM policy may change, attempt to disable LPM until
 447	 * the driver is unbound.  If LPM isn't disabled, that's fine because it
 448	 * wouldn't be enabled unless all the bound interfaces supported
 449	 * hub-initiated LPM.
 450	 */
 451	if (driver->disable_hub_initiated_lpm)
 452		lpm_disable_error = usb_unlocked_disable_lpm(udev);
 453
 454	/*
 455	 * Terminate all URBs for this interface unless the driver
 456	 * supports "soft" unbinding and the device is still present.
 457	 */
 458	if (!driver->soft_unbind || udev->state == USB_STATE_NOTATTACHED)
 459		usb_disable_interface(udev, intf, false);
 460
 461	driver->disconnect(intf);
 462
 463	/* Free streams */
 464	for (i = 0, j = 0; i < intf->cur_altsetting->desc.bNumEndpoints; i++) {
 465		ep = &intf->cur_altsetting->endpoint[i];
 466		if (ep->streams == 0)
 467			continue;
 468		if (j == 0) {
 469			eps = kmalloc_array(USB_MAXENDPOINTS, sizeof(void *),
 470				      GFP_KERNEL);
 471			if (!eps)
 472				break;
 473		}
 474		eps[j++] = ep;
 475	}
 476	if (j) {
 477		usb_free_streams(intf, eps, j, GFP_KERNEL);
 478		kfree(eps);
 479	}
 480
 481	/* Reset other interface state.
 482	 * We cannot do a Set-Interface if the device is suspended or
 483	 * if it is prepared for a system sleep (since installing a new
 484	 * altsetting means creating new endpoint device entries).
 485	 * When either of these happens, defer the Set-Interface.
 486	 */
 487	if (intf->cur_altsetting->desc.bAlternateSetting == 0) {
 488		/* Already in altsetting 0 so skip Set-Interface.
 489		 * Just re-enable it without affecting the endpoint toggles.
 490		 */
 491		usb_enable_interface(udev, intf, false);
 492	} else if (!error && !intf->dev.power.is_prepared) {
 493		r = usb_set_interface(udev, intf->altsetting[0].
 494				desc.bInterfaceNumber, 0);
 495		if (r < 0)
 496			intf->needs_altsetting0 = 1;
 497	} else {
 498		intf->needs_altsetting0 = 1;
 499	}
 500	usb_set_intfdata(intf, NULL);
 501
 502	intf->condition = USB_INTERFACE_UNBOUND;
 503	intf->needs_remote_wakeup = 0;
 504
 505	/* Attempt to re-enable USB3 LPM, if the disable succeeded. */
 506	if (!lpm_disable_error)
 507		usb_unlocked_enable_lpm(udev);
 508
 509	/* Unbound interfaces are always runtime-PM-disabled and -suspended */
 510	if (driver->supports_autosuspend)
 511		pm_runtime_disable(dev);
 512	pm_runtime_set_suspended(dev);
 513
 
 
 
 
 
 514	if (!error)
 515		usb_autosuspend_device(udev);
 516
 517	return 0;
 518}
 519
 520/**
 521 * usb_driver_claim_interface - bind a driver to an interface
 522 * @driver: the driver to be bound
 523 * @iface: the interface to which it will be bound; must be in the
 524 *	usb device's active configuration
 525 * @data: driver data associated with that interface
 526 *
 527 * This is used by usb device drivers that need to claim more than one
 528 * interface on a device when probing (audio and acm are current examples).
 529 * No device driver should directly modify internal usb_interface or
 530 * usb_device structure members.
 531 *
 
 
 
 
 532 * Callers must own the device lock, so driver probe() entries don't need
 533 * extra locking, but other call contexts may need to explicitly claim that
 534 * lock.
 535 *
 536 * Return: 0 on success.
 537 */
 538int usb_driver_claim_interface(struct usb_driver *driver,
 539				struct usb_interface *iface, void *data)
 540{
 541	struct device *dev;
 
 542	int retval = 0;
 
 543
 544	if (!iface)
 545		return -ENODEV;
 546
 547	dev = &iface->dev;
 548	if (dev->driver)
 549		return -EBUSY;
 550
 551	/* reject claim if interface is not authorized */
 552	if (!iface->authorized)
 553		return -ENODEV;
 554
 555	dev->driver = &driver->driver;
 556	usb_set_intfdata(iface, data);
 557	iface->needs_binding = 0;
 558
 559	iface->condition = USB_INTERFACE_BOUND;
 560
 
 
 
 
 
 
 
 
 561	/* Claimed interfaces are initially inactive (suspended) and
 562	 * runtime-PM-enabled, but only if the driver has autosuspend
 563	 * support.  Otherwise they are marked active, to prevent the
 564	 * device from being autosuspended, but left disabled.  In either
 565	 * case they are sensitive to their children's power states.
 566	 */
 567	pm_suspend_ignore_children(dev, false);
 568	if (driver->supports_autosuspend)
 569		pm_runtime_enable(dev);
 570	else
 571		pm_runtime_set_active(dev);
 572
 573	/* if interface was already added, bind now; else let
 574	 * the future device_add() bind it, bypassing probe()
 575	 */
 576	if (device_is_registered(dev))
 577		retval = device_bind_driver(dev);
 578
 579	if (retval) {
 580		dev->driver = NULL;
 581		usb_set_intfdata(iface, NULL);
 582		iface->needs_remote_wakeup = 0;
 583		iface->condition = USB_INTERFACE_UNBOUND;
 584
 585		/*
 586		 * Unbound interfaces are always runtime-PM-disabled
 587		 * and runtime-PM-suspended
 588		 */
 589		if (driver->supports_autosuspend)
 590			pm_runtime_disable(dev);
 591		pm_runtime_set_suspended(dev);
 592	}
 593
 594	return retval;
 595}
 596EXPORT_SYMBOL_GPL(usb_driver_claim_interface);
 597
 598/**
 599 * usb_driver_release_interface - unbind a driver from an interface
 600 * @driver: the driver to be unbound
 601 * @iface: the interface from which it will be unbound
 602 *
 603 * This can be used by drivers to release an interface without waiting
 604 * for their disconnect() methods to be called.  In typical cases this
 605 * also causes the driver disconnect() method to be called.
 606 *
 607 * This call is synchronous, and may not be used in an interrupt context.
 608 * Callers must own the device lock, so driver disconnect() entries don't
 609 * need extra locking, but other call contexts may need to explicitly claim
 610 * that lock.
 611 */
 612void usb_driver_release_interface(struct usb_driver *driver,
 613					struct usb_interface *iface)
 614{
 615	struct device *dev = &iface->dev;
 616
 617	/* this should never happen, don't release something that's not ours */
 618	if (!dev->driver || dev->driver != &driver->driver)
 619		return;
 620
 621	/* don't release from within disconnect() */
 622	if (iface->condition != USB_INTERFACE_BOUND)
 623		return;
 624	iface->condition = USB_INTERFACE_UNBINDING;
 625
 626	/* Release via the driver core only if the interface
 627	 * has already been registered
 628	 */
 629	if (device_is_registered(dev)) {
 630		device_release_driver(dev);
 631	} else {
 632		device_lock(dev);
 633		usb_unbind_interface(dev);
 634		dev->driver = NULL;
 635		device_unlock(dev);
 636	}
 637}
 638EXPORT_SYMBOL_GPL(usb_driver_release_interface);
 639
 640/* returns 0 if no match, 1 if match */
 641int usb_match_device(struct usb_device *dev, const struct usb_device_id *id)
 642{
 643	if ((id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
 644	    id->idVendor != le16_to_cpu(dev->descriptor.idVendor))
 645		return 0;
 646
 647	if ((id->match_flags & USB_DEVICE_ID_MATCH_PRODUCT) &&
 648	    id->idProduct != le16_to_cpu(dev->descriptor.idProduct))
 649		return 0;
 650
 651	/* No need to test id->bcdDevice_lo != 0, since 0 is never
 652	   greater than any unsigned number. */
 653	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_LO) &&
 654	    (id->bcdDevice_lo > le16_to_cpu(dev->descriptor.bcdDevice)))
 655		return 0;
 656
 657	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_HI) &&
 658	    (id->bcdDevice_hi < le16_to_cpu(dev->descriptor.bcdDevice)))
 659		return 0;
 660
 661	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_CLASS) &&
 662	    (id->bDeviceClass != dev->descriptor.bDeviceClass))
 663		return 0;
 664
 665	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_SUBCLASS) &&
 666	    (id->bDeviceSubClass != dev->descriptor.bDeviceSubClass))
 667		return 0;
 668
 669	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_PROTOCOL) &&
 670	    (id->bDeviceProtocol != dev->descriptor.bDeviceProtocol))
 671		return 0;
 672
 673	return 1;
 674}
 675
 676/* returns 0 if no match, 1 if match */
 677int usb_match_one_id_intf(struct usb_device *dev,
 678			  struct usb_host_interface *intf,
 679			  const struct usb_device_id *id)
 680{
 681	/* The interface class, subclass, protocol and number should never be
 
 
 
 
 
 
 
 
 
 
 
 
 
 682	 * checked for a match if the device class is Vendor Specific,
 683	 * unless the match record specifies the Vendor ID. */
 684	if (dev->descriptor.bDeviceClass == USB_CLASS_VENDOR_SPEC &&
 685			!(id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
 686			(id->match_flags & (USB_DEVICE_ID_MATCH_INT_CLASS |
 687				USB_DEVICE_ID_MATCH_INT_SUBCLASS |
 688				USB_DEVICE_ID_MATCH_INT_PROTOCOL |
 689				USB_DEVICE_ID_MATCH_INT_NUMBER)))
 690		return 0;
 691
 692	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_CLASS) &&
 693	    (id->bInterfaceClass != intf->desc.bInterfaceClass))
 694		return 0;
 695
 696	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_SUBCLASS) &&
 697	    (id->bInterfaceSubClass != intf->desc.bInterfaceSubClass))
 698		return 0;
 699
 700	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_PROTOCOL) &&
 701	    (id->bInterfaceProtocol != intf->desc.bInterfaceProtocol))
 702		return 0;
 703
 704	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_NUMBER) &&
 705	    (id->bInterfaceNumber != intf->desc.bInterfaceNumber))
 706		return 0;
 707
 708	return 1;
 709}
 710
 711/* returns 0 if no match, 1 if match */
 712int usb_match_one_id(struct usb_interface *interface,
 713		     const struct usb_device_id *id)
 714{
 715	struct usb_host_interface *intf;
 716	struct usb_device *dev;
 717
 718	/* proc_connectinfo in devio.c may call us with id == NULL. */
 719	if (id == NULL)
 720		return 0;
 721
 722	intf = interface->cur_altsetting;
 723	dev = interface_to_usbdev(interface);
 724
 725	if (!usb_match_device(dev, id))
 726		return 0;
 727
 728	return usb_match_one_id_intf(dev, intf, id);
 729}
 730EXPORT_SYMBOL_GPL(usb_match_one_id);
 731
 732/**
 733 * usb_match_id - find first usb_device_id matching device or interface
 734 * @interface: the interface of interest
 735 * @id: array of usb_device_id structures, terminated by zero entry
 736 *
 737 * usb_match_id searches an array of usb_device_id's and returns
 738 * the first one matching the device or interface, or null.
 739 * This is used when binding (or rebinding) a driver to an interface.
 740 * Most USB device drivers will use this indirectly, through the usb core,
 741 * but some layered driver frameworks use it directly.
 742 * These device tables are exported with MODULE_DEVICE_TABLE, through
 743 * modutils, to support the driver loading functionality of USB hotplugging.
 744 *
 745 * Return: The first matching usb_device_id, or %NULL.
 746 *
 747 * What Matches:
 748 *
 749 * The "match_flags" element in a usb_device_id controls which
 750 * members are used.  If the corresponding bit is set, the
 751 * value in the device_id must match its corresponding member
 752 * in the device or interface descriptor, or else the device_id
 753 * does not match.
 754 *
 755 * "driver_info" is normally used only by device drivers,
 756 * but you can create a wildcard "matches anything" usb_device_id
 757 * as a driver's "modules.usbmap" entry if you provide an id with
 758 * only a nonzero "driver_info" field.  If you do this, the USB device
 759 * driver's probe() routine should use additional intelligence to
 760 * decide whether to bind to the specified interface.
 761 *
 762 * What Makes Good usb_device_id Tables:
 763 *
 764 * The match algorithm is very simple, so that intelligence in
 765 * driver selection must come from smart driver id records.
 766 * Unless you have good reasons to use another selection policy,
 767 * provide match elements only in related groups, and order match
 768 * specifiers from specific to general.  Use the macros provided
 769 * for that purpose if you can.
 770 *
 771 * The most specific match specifiers use device descriptor
 772 * data.  These are commonly used with product-specific matches;
 773 * the USB_DEVICE macro lets you provide vendor and product IDs,
 774 * and you can also match against ranges of product revisions.
 775 * These are widely used for devices with application or vendor
 776 * specific bDeviceClass values.
 777 *
 778 * Matches based on device class/subclass/protocol specifications
 779 * are slightly more general; use the USB_DEVICE_INFO macro, or
 780 * its siblings.  These are used with single-function devices
 781 * where bDeviceClass doesn't specify that each interface has
 782 * its own class.
 783 *
 784 * Matches based on interface class/subclass/protocol are the
 785 * most general; they let drivers bind to any interface on a
 786 * multiple-function device.  Use the USB_INTERFACE_INFO
 787 * macro, or its siblings, to match class-per-interface style
 788 * devices (as recorded in bInterfaceClass).
 789 *
 790 * Note that an entry created by USB_INTERFACE_INFO won't match
 791 * any interface if the device class is set to Vendor-Specific.
 792 * This is deliberate; according to the USB spec the meanings of
 793 * the interface class/subclass/protocol for these devices are also
 794 * vendor-specific, and hence matching against a standard product
 795 * class wouldn't work anyway.  If you really want to use an
 796 * interface-based match for such a device, create a match record
 797 * that also specifies the vendor ID.  (Unforunately there isn't a
 798 * standard macro for creating records like this.)
 799 *
 800 * Within those groups, remember that not all combinations are
 801 * meaningful.  For example, don't give a product version range
 802 * without vendor and product IDs; or specify a protocol without
 803 * its associated class and subclass.
 804 */
 805const struct usb_device_id *usb_match_id(struct usb_interface *interface,
 806					 const struct usb_device_id *id)
 807{
 808	/* proc_connectinfo in devio.c may call us with id == NULL. */
 809	if (id == NULL)
 810		return NULL;
 811
 812	/* It is important to check that id->driver_info is nonzero,
 813	   since an entry that is all zeroes except for a nonzero
 814	   id->driver_info is the way to create an entry that
 815	   indicates that the driver want to examine every
 816	   device and interface. */
 817	for (; id->idVendor || id->idProduct || id->bDeviceClass ||
 818	       id->bInterfaceClass || id->driver_info; id++) {
 819		if (usb_match_one_id(interface, id))
 820			return id;
 821	}
 822
 823	return NULL;
 824}
 825EXPORT_SYMBOL_GPL(usb_match_id);
 826
 827const struct usb_device_id *usb_device_match_id(struct usb_device *udev,
 828				const struct usb_device_id *id)
 829{
 830	if (!id)
 831		return NULL;
 832
 833	for (; id->idVendor || id->idProduct ; id++) {
 834		if (usb_match_device(udev, id))
 835			return id;
 836	}
 837
 838	return NULL;
 839}
 840EXPORT_SYMBOL_GPL(usb_device_match_id);
 841
 842bool usb_driver_applicable(struct usb_device *udev,
 843			   struct usb_device_driver *udrv)
 844{
 845	if (udrv->id_table && udrv->match)
 846		return usb_device_match_id(udev, udrv->id_table) != NULL &&
 847		       udrv->match(udev);
 848
 849	if (udrv->id_table)
 850		return usb_device_match_id(udev, udrv->id_table) != NULL;
 851
 852	if (udrv->match)
 853		return udrv->match(udev);
 854
 855	return false;
 856}
 857
 858static int usb_device_match(struct device *dev, struct device_driver *drv)
 859{
 860	/* devices and interfaces are handled separately */
 861	if (is_usb_device(dev)) {
 862		struct usb_device *udev;
 863		struct usb_device_driver *udrv;
 864
 865		/* interface drivers never match devices */
 866		if (!is_usb_device_driver(drv))
 867			return 0;
 868
 869		udev = to_usb_device(dev);
 870		udrv = to_usb_device_driver(drv);
 871
 872		/* If the device driver under consideration does not have a
 873		 * id_table or a match function, then let the driver's probe
 874		 * function decide.
 875		 */
 876		if (!udrv->id_table && !udrv->match)
 877			return 1;
 878
 879		return usb_driver_applicable(udev, udrv);
 880
 881	} else if (is_usb_interface(dev)) {
 882		struct usb_interface *intf;
 883		struct usb_driver *usb_drv;
 884		const struct usb_device_id *id;
 885
 886		/* device drivers never match interfaces */
 887		if (is_usb_device_driver(drv))
 888			return 0;
 889
 890		intf = to_usb_interface(dev);
 891		usb_drv = to_usb_driver(drv);
 892
 893		id = usb_match_id(intf, usb_drv->id_table);
 894		if (id)
 895			return 1;
 896
 897		id = usb_match_dynamic_id(intf, usb_drv);
 898		if (id)
 899			return 1;
 900	}
 901
 902	return 0;
 903}
 904
 905static int usb_uevent(const struct device *dev, struct kobj_uevent_env *env)
 
 906{
 907	const struct usb_device *usb_dev;
 908
 909	if (is_usb_device(dev)) {
 910		usb_dev = to_usb_device(dev);
 911	} else if (is_usb_interface(dev)) {
 912		const struct usb_interface *intf = to_usb_interface(dev);
 913
 914		usb_dev = interface_to_usbdev(intf);
 915	} else {
 916		return 0;
 917	}
 918
 919	if (usb_dev->devnum < 0) {
 920		/* driver is often null here; dev_dbg() would oops */
 921		pr_debug("usb %s: already deleted?\n", dev_name(dev));
 922		return -ENODEV;
 923	}
 924	if (!usb_dev->bus) {
 925		pr_debug("usb %s: bus removed?\n", dev_name(dev));
 926		return -ENODEV;
 927	}
 928
 929	/* per-device configurations are common */
 930	if (add_uevent_var(env, "PRODUCT=%x/%x/%x",
 931			   le16_to_cpu(usb_dev->descriptor.idVendor),
 932			   le16_to_cpu(usb_dev->descriptor.idProduct),
 933			   le16_to_cpu(usb_dev->descriptor.bcdDevice)))
 934		return -ENOMEM;
 935
 936	/* class-based driver binding models */
 937	if (add_uevent_var(env, "TYPE=%d/%d/%d",
 938			   usb_dev->descriptor.bDeviceClass,
 939			   usb_dev->descriptor.bDeviceSubClass,
 940			   usb_dev->descriptor.bDeviceProtocol))
 941		return -ENOMEM;
 942
 943	return 0;
 944}
 945
 946static int __usb_bus_reprobe_drivers(struct device *dev, void *data)
 947{
 948	struct usb_device_driver *new_udriver = data;
 949	struct usb_device *udev;
 950	int ret;
 951
 952	/* Don't reprobe if current driver isn't usb_generic_driver */
 953	if (dev->driver != &usb_generic_driver.driver)
 954		return 0;
 955
 956	udev = to_usb_device(dev);
 957	if (!usb_driver_applicable(udev, new_udriver))
 958		return 0;
 959
 960	ret = device_reprobe(dev);
 961	if (ret && ret != -EPROBE_DEFER)
 962		dev_err(dev, "Failed to reprobe device (error %d)\n", ret);
 963
 964	return 0;
 965}
 966
 967bool is_usb_device_driver(const struct device_driver *drv)
 968{
 969	return drv->probe == usb_probe_device;
 970}
 
 971
 972/**
 973 * usb_register_device_driver - register a USB device (not interface) driver
 974 * @new_udriver: USB operations for the device driver
 975 * @owner: module owner of this driver.
 976 *
 977 * Registers a USB device driver with the USB core.  The list of
 978 * unattached devices will be rescanned whenever a new driver is
 979 * added, allowing the new driver to attach to any recognized devices.
 980 *
 981 * Return: A negative error code on failure and 0 on success.
 982 */
 983int usb_register_device_driver(struct usb_device_driver *new_udriver,
 984		struct module *owner)
 985{
 986	int retval = 0;
 987
 988	if (usb_disabled())
 989		return -ENODEV;
 990
 991	new_udriver->driver.name = new_udriver->name;
 992	new_udriver->driver.bus = &usb_bus_type;
 993	new_udriver->driver.probe = usb_probe_device;
 994	new_udriver->driver.remove = usb_unbind_device;
 995	new_udriver->driver.owner = owner;
 996	new_udriver->driver.dev_groups = new_udriver->dev_groups;
 997
 998	retval = driver_register(&new_udriver->driver);
 999
1000	if (!retval) {
1001		pr_info("%s: registered new device driver %s\n",
1002			usbcore_name, new_udriver->name);
1003		/*
1004		 * Check whether any device could be better served with
1005		 * this new driver
1006		 */
1007		bus_for_each_dev(&usb_bus_type, NULL, new_udriver,
1008				 __usb_bus_reprobe_drivers);
1009	} else {
1010		pr_err("%s: error %d registering device driver %s\n",
1011			usbcore_name, retval, new_udriver->name);
1012	}
1013
1014	return retval;
1015}
1016EXPORT_SYMBOL_GPL(usb_register_device_driver);
1017
1018/**
1019 * usb_deregister_device_driver - unregister a USB device (not interface) driver
1020 * @udriver: USB operations of the device driver to unregister
1021 * Context: must be able to sleep
1022 *
1023 * Unlinks the specified driver from the internal USB driver list.
1024 */
1025void usb_deregister_device_driver(struct usb_device_driver *udriver)
1026{
1027	pr_info("%s: deregistering device driver %s\n",
1028			usbcore_name, udriver->name);
1029
1030	driver_unregister(&udriver->driver);
1031}
1032EXPORT_SYMBOL_GPL(usb_deregister_device_driver);
1033
1034/**
1035 * usb_register_driver - register a USB interface driver
1036 * @new_driver: USB operations for the interface driver
1037 * @owner: module owner of this driver.
1038 * @mod_name: module name string
1039 *
1040 * Registers a USB interface driver with the USB core.  The list of
1041 * unattached interfaces will be rescanned whenever a new driver is
1042 * added, allowing the new driver to attach to any recognized interfaces.
1043 *
1044 * Return: A negative error code on failure and 0 on success.
1045 *
1046 * NOTE: if you want your driver to use the USB major number, you must call
1047 * usb_register_dev() to enable that functionality.  This function no longer
1048 * takes care of that.
1049 */
1050int usb_register_driver(struct usb_driver *new_driver, struct module *owner,
1051			const char *mod_name)
1052{
1053	int retval = 0;
1054
1055	if (usb_disabled())
1056		return -ENODEV;
1057
1058	new_driver->driver.name = new_driver->name;
1059	new_driver->driver.bus = &usb_bus_type;
1060	new_driver->driver.probe = usb_probe_interface;
1061	new_driver->driver.remove = usb_unbind_interface;
1062	new_driver->driver.owner = owner;
1063	new_driver->driver.mod_name = mod_name;
1064	new_driver->driver.dev_groups = new_driver->dev_groups;
1065	spin_lock_init(&new_driver->dynids.lock);
1066	INIT_LIST_HEAD(&new_driver->dynids.list);
1067
1068	retval = driver_register(&new_driver->driver);
1069	if (retval)
1070		goto out;
1071
1072	retval = usb_create_newid_files(new_driver);
1073	if (retval)
1074		goto out_newid;
1075
1076	pr_info("%s: registered new interface driver %s\n",
1077			usbcore_name, new_driver->name);
1078
1079out:
1080	return retval;
1081
1082out_newid:
1083	driver_unregister(&new_driver->driver);
1084
1085	pr_err("%s: error %d registering interface driver %s\n",
1086		usbcore_name, retval, new_driver->name);
 
1087	goto out;
1088}
1089EXPORT_SYMBOL_GPL(usb_register_driver);
1090
1091/**
1092 * usb_deregister - unregister a USB interface driver
1093 * @driver: USB operations of the interface driver to unregister
1094 * Context: must be able to sleep
1095 *
1096 * Unlinks the specified driver from the internal USB driver list.
1097 *
1098 * NOTE: If you called usb_register_dev(), you still need to call
1099 * usb_deregister_dev() to clean up your driver's allocated minor numbers,
1100 * this * call will no longer do it for you.
1101 */
1102void usb_deregister(struct usb_driver *driver)
1103{
1104	pr_info("%s: deregistering interface driver %s\n",
1105			usbcore_name, driver->name);
1106
1107	usb_remove_newid_files(driver);
1108	driver_unregister(&driver->driver);
1109	usb_free_dynids(driver);
1110}
1111EXPORT_SYMBOL_GPL(usb_deregister);
1112
1113/* Forced unbinding of a USB interface driver, either because
1114 * it doesn't support pre_reset/post_reset/reset_resume or
1115 * because it doesn't support suspend/resume.
1116 *
1117 * The caller must hold @intf's device's lock, but not @intf's lock.
 
1118 */
1119void usb_forced_unbind_intf(struct usb_interface *intf)
1120{
1121	struct usb_driver *driver = to_usb_driver(intf->dev.driver);
1122
1123	dev_dbg(&intf->dev, "forced unbind\n");
1124	usb_driver_release_interface(driver, intf);
1125
1126	/* Mark the interface for later rebinding */
1127	intf->needs_binding = 1;
1128}
1129
1130/*
1131 * Unbind drivers for @udev's marked interfaces.  These interfaces have
1132 * the needs_binding flag set, for example by usb_resume_interface().
1133 *
1134 * The caller must hold @udev's device lock.
1135 */
1136static void unbind_marked_interfaces(struct usb_device *udev)
1137{
1138	struct usb_host_config	*config;
1139	int			i;
1140	struct usb_interface	*intf;
1141
1142	config = udev->actconfig;
1143	if (config) {
1144		for (i = 0; i < config->desc.bNumInterfaces; ++i) {
1145			intf = config->interface[i];
1146			if (intf->dev.driver && intf->needs_binding)
1147				usb_forced_unbind_intf(intf);
1148		}
1149	}
1150}
1151
1152/* Delayed forced unbinding of a USB interface driver and scan
1153 * for rebinding.
1154 *
1155 * The caller must hold @intf's device's lock, but not @intf's lock.
 
1156 *
1157 * Note: Rebinds will be skipped if a system sleep transition is in
1158 * progress and the PM "complete" callback hasn't occurred yet.
1159 */
1160static void usb_rebind_intf(struct usb_interface *intf)
1161{
1162	int rc;
1163
1164	/* Delayed unbind of an existing driver */
1165	if (intf->dev.driver)
1166		usb_forced_unbind_intf(intf);
1167
1168	/* Try to rebind the interface */
1169	if (!intf->dev.power.is_prepared) {
1170		intf->needs_binding = 0;
1171		rc = device_attach(&intf->dev);
1172		if (rc < 0 && rc != -EPROBE_DEFER)
1173			dev_warn(&intf->dev, "rebind failed: %d\n", rc);
1174	}
1175}
1176
1177/*
1178 * Rebind drivers to @udev's marked interfaces.  These interfaces have
1179 * the needs_binding flag set.
 
 
1180 *
1181 * The caller must hold @udev's device lock.
1182 */
1183static void rebind_marked_interfaces(struct usb_device *udev)
1184{
1185	struct usb_host_config	*config;
1186	int			i;
1187	struct usb_interface	*intf;
 
1188
1189	config = udev->actconfig;
1190	if (config) {
1191		for (i = 0; i < config->desc.bNumInterfaces; ++i) {
1192			intf = config->interface[i];
1193			if (intf->needs_binding)
1194				usb_rebind_intf(intf);
 
 
 
 
1195		}
1196	}
1197}
1198
1199/*
1200 * Unbind all of @udev's marked interfaces and then rebind all of them.
1201 * This ordering is necessary because some drivers claim several interfaces
1202 * when they are first probed.
1203 *
1204 * The caller must hold @udev's device lock.
1205 */
1206void usb_unbind_and_rebind_marked_interfaces(struct usb_device *udev)
1207{
1208	unbind_marked_interfaces(udev);
1209	rebind_marked_interfaces(udev);
1210}
1211
1212#ifdef CONFIG_PM
 
 
 
 
 
 
 
 
1213
1214/* Unbind drivers for @udev's interfaces that don't support suspend/resume
1215 * There is no check for reset_resume here because it can be determined
1216 * only during resume whether reset_resume is needed.
1217 *
1218 * The caller must hold @udev's device lock.
1219 */
1220static void unbind_no_pm_drivers_interfaces(struct usb_device *udev)
1221{
1222	struct usb_host_config	*config;
1223	int			i;
1224	struct usb_interface	*intf;
1225	struct usb_driver	*drv;
1226
1227	config = udev->actconfig;
1228	if (config) {
1229		for (i = 0; i < config->desc.bNumInterfaces; ++i) {
1230			intf = config->interface[i];
1231
1232			if (intf->dev.driver) {
1233				drv = to_usb_driver(intf->dev.driver);
1234				if (!drv->suspend || !drv->resume)
1235					usb_forced_unbind_intf(intf);
1236			}
1237		}
1238	}
1239}
1240
1241static int usb_suspend_device(struct usb_device *udev, pm_message_t msg)
1242{
1243	struct usb_device_driver	*udriver;
1244	int				status = 0;
1245
1246	if (udev->state == USB_STATE_NOTATTACHED ||
1247			udev->state == USB_STATE_SUSPENDED)
1248		goto done;
1249
1250	/* For devices that don't have a driver, we do a generic suspend. */
1251	if (udev->dev.driver)
1252		udriver = to_usb_device_driver(udev->dev.driver);
1253	else {
1254		udev->do_remote_wakeup = 0;
1255		udriver = &usb_generic_driver;
1256	}
1257	if (udriver->suspend)
1258		status = udriver->suspend(udev, msg);
1259	if (status == 0 && udriver->generic_subclass)
1260		status = usb_generic_driver_suspend(udev, msg);
1261
1262 done:
1263	dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1264	return status;
1265}
1266
1267static int usb_resume_device(struct usb_device *udev, pm_message_t msg)
1268{
1269	struct usb_device_driver	*udriver;
1270	int				status = 0;
1271
1272	if (udev->state == USB_STATE_NOTATTACHED)
1273		goto done;
1274
1275	/* Can't resume it if it doesn't have a driver. */
1276	if (udev->dev.driver == NULL) {
1277		status = -ENOTCONN;
1278		goto done;
1279	}
1280
1281	/* Non-root devices on a full/low-speed bus must wait for their
1282	 * companion high-speed root hub, in case a handoff is needed.
1283	 */
1284	if (!PMSG_IS_AUTO(msg) && udev->parent && udev->bus->hs_companion)
1285		device_pm_wait_for_dev(&udev->dev,
1286				&udev->bus->hs_companion->root_hub->dev);
1287
1288	if (udev->quirks & USB_QUIRK_RESET_RESUME)
1289		udev->reset_resume = 1;
1290
1291	udriver = to_usb_device_driver(udev->dev.driver);
1292	if (udriver->generic_subclass)
1293		status = usb_generic_driver_resume(udev, msg);
1294	if (status == 0 && udriver->resume)
1295		status = udriver->resume(udev, msg);
1296
1297 done:
1298	dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1299	return status;
1300}
1301
1302static int usb_suspend_interface(struct usb_device *udev,
1303		struct usb_interface *intf, pm_message_t msg)
1304{
1305	struct usb_driver	*driver;
1306	int			status = 0;
1307
1308	if (udev->state == USB_STATE_NOTATTACHED ||
1309			intf->condition == USB_INTERFACE_UNBOUND)
1310		goto done;
1311	driver = to_usb_driver(intf->dev.driver);
1312
1313	/* at this time we know the driver supports suspend */
1314	status = driver->suspend(intf, msg);
1315	if (status && !PMSG_IS_AUTO(msg))
1316		dev_err(&intf->dev, "suspend error %d\n", status);
1317
1318 done:
1319	dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
1320	return status;
1321}
1322
1323static int usb_resume_interface(struct usb_device *udev,
1324		struct usb_interface *intf, pm_message_t msg, int reset_resume)
1325{
1326	struct usb_driver	*driver;
1327	int			status = 0;
1328
1329	if (udev->state == USB_STATE_NOTATTACHED)
1330		goto done;
1331
1332	/* Don't let autoresume interfere with unbinding */
1333	if (intf->condition == USB_INTERFACE_UNBINDING)
1334		goto done;
1335
1336	/* Can't resume it if it doesn't have a driver. */
1337	if (intf->condition == USB_INTERFACE_UNBOUND) {
1338
1339		/* Carry out a deferred switch to altsetting 0 */
1340		if (intf->needs_altsetting0 && !intf->dev.power.is_prepared) {
1341			usb_set_interface(udev, intf->altsetting[0].
1342					desc.bInterfaceNumber, 0);
1343			intf->needs_altsetting0 = 0;
1344		}
1345		goto done;
1346	}
1347
1348	/* Don't resume if the interface is marked for rebinding */
1349	if (intf->needs_binding)
1350		goto done;
1351	driver = to_usb_driver(intf->dev.driver);
1352
1353	if (reset_resume) {
1354		if (driver->reset_resume) {
1355			status = driver->reset_resume(intf);
1356			if (status)
1357				dev_err(&intf->dev, "%s error %d\n",
1358						"reset_resume", status);
1359		} else {
1360			intf->needs_binding = 1;
1361			dev_dbg(&intf->dev, "no reset_resume for driver %s?\n",
1362					driver->name);
1363		}
1364	} else {
1365		status = driver->resume(intf);
1366		if (status)
1367			dev_err(&intf->dev, "resume error %d\n", status);
1368	}
1369
1370done:
1371	dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
1372
1373	/* Later we will unbind the driver and/or reprobe, if necessary */
1374	return status;
1375}
1376
1377/**
1378 * usb_suspend_both - suspend a USB device and its interfaces
1379 * @udev: the usb_device to suspend
1380 * @msg: Power Management message describing this state transition
1381 *
1382 * This is the central routine for suspending USB devices.  It calls the
1383 * suspend methods for all the interface drivers in @udev and then calls
1384 * the suspend method for @udev itself.  When the routine is called in
1385 * autosuspend, if an error occurs at any stage, all the interfaces
1386 * which were suspended are resumed so that they remain in the same
1387 * state as the device, but when called from system sleep, all error
1388 * from suspend methods of interfaces and the non-root-hub device itself
1389 * are simply ignored, so all suspended interfaces are only resumed
1390 * to the device's state when @udev is root-hub and its suspend method
1391 * returns failure.
1392 *
1393 * Autosuspend requests originating from a child device or an interface
1394 * driver may be made without the protection of @udev's device lock, but
1395 * all other suspend calls will hold the lock.  Usbcore will insure that
1396 * method calls do not arrive during bind, unbind, or reset operations.
1397 * However drivers must be prepared to handle suspend calls arriving at
1398 * unpredictable times.
1399 *
1400 * This routine can run only in process context.
1401 *
1402 * Return: 0 if the suspend succeeded.
1403 */
1404static int usb_suspend_both(struct usb_device *udev, pm_message_t msg)
1405{
1406	int			status = 0;
1407	int			i = 0, n = 0;
1408	struct usb_interface	*intf;
1409
1410	if (udev->state == USB_STATE_NOTATTACHED ||
1411			udev->state == USB_STATE_SUSPENDED)
1412		goto done;
1413
1414	/* Suspend all the interfaces and then udev itself */
1415	if (udev->actconfig) {
1416		n = udev->actconfig->desc.bNumInterfaces;
1417		for (i = n - 1; i >= 0; --i) {
1418			intf = udev->actconfig->interface[i];
1419			status = usb_suspend_interface(udev, intf, msg);
1420
1421			/* Ignore errors during system sleep transitions */
1422			if (!PMSG_IS_AUTO(msg))
1423				status = 0;
1424			if (status != 0)
1425				break;
1426		}
1427	}
1428	if (status == 0) {
1429		status = usb_suspend_device(udev, msg);
1430
1431		/*
1432		 * Ignore errors from non-root-hub devices during
1433		 * system sleep transitions.  For the most part,
1434		 * these devices should go to low power anyway when
1435		 * the entire bus is suspended.
1436		 */
1437		if (udev->parent && !PMSG_IS_AUTO(msg))
1438			status = 0;
1439
1440		/*
1441		 * If the device is inaccessible, don't try to resume
1442		 * suspended interfaces and just return the error.
1443		 */
1444		if (status && status != -EBUSY) {
1445			int err;
1446			u16 devstat;
1447
1448			err = usb_get_std_status(udev, USB_RECIP_DEVICE, 0,
1449						 &devstat);
1450			if (err) {
1451				dev_err(&udev->dev,
1452					"Failed to suspend device, error %d\n",
1453					status);
1454				goto done;
1455			}
1456		}
1457	}
1458
1459	/* If the suspend failed, resume interfaces that did get suspended */
1460	if (status != 0) {
1461		if (udev->actconfig) {
1462			msg.event ^= (PM_EVENT_SUSPEND | PM_EVENT_RESUME);
1463			while (++i < n) {
1464				intf = udev->actconfig->interface[i];
1465				usb_resume_interface(udev, intf, msg, 0);
1466			}
1467		}
1468
1469	/* If the suspend succeeded then prevent any more URB submissions
1470	 * and flush any outstanding URBs.
1471	 */
1472	} else {
1473		udev->can_submit = 0;
1474		for (i = 0; i < 16; ++i) {
1475			usb_hcd_flush_endpoint(udev, udev->ep_out[i]);
1476			usb_hcd_flush_endpoint(udev, udev->ep_in[i]);
1477		}
1478	}
1479
1480 done:
1481	dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1482	return status;
1483}
1484
1485/**
1486 * usb_resume_both - resume a USB device and its interfaces
1487 * @udev: the usb_device to resume
1488 * @msg: Power Management message describing this state transition
1489 *
1490 * This is the central routine for resuming USB devices.  It calls the
1491 * resume method for @udev and then calls the resume methods for all
1492 * the interface drivers in @udev.
1493 *
1494 * Autoresume requests originating from a child device or an interface
1495 * driver may be made without the protection of @udev's device lock, but
1496 * all other resume calls will hold the lock.  Usbcore will insure that
1497 * method calls do not arrive during bind, unbind, or reset operations.
1498 * However drivers must be prepared to handle resume calls arriving at
1499 * unpredictable times.
1500 *
1501 * This routine can run only in process context.
1502 *
1503 * Return: 0 on success.
1504 */
1505static int usb_resume_both(struct usb_device *udev, pm_message_t msg)
1506{
1507	int			status = 0;
1508	int			i;
1509	struct usb_interface	*intf;
1510
1511	if (udev->state == USB_STATE_NOTATTACHED) {
1512		status = -ENODEV;
1513		goto done;
1514	}
1515	udev->can_submit = 1;
1516
1517	/* Resume the device */
1518	if (udev->state == USB_STATE_SUSPENDED || udev->reset_resume)
1519		status = usb_resume_device(udev, msg);
1520
1521	/* Resume the interfaces */
1522	if (status == 0 && udev->actconfig) {
1523		for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
1524			intf = udev->actconfig->interface[i];
1525			usb_resume_interface(udev, intf, msg,
1526					udev->reset_resume);
1527		}
1528	}
1529	usb_mark_last_busy(udev);
1530
1531 done:
1532	dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1533	if (!status)
1534		udev->reset_resume = 0;
1535	return status;
1536}
1537
1538static void choose_wakeup(struct usb_device *udev, pm_message_t msg)
1539{
1540	int	w;
1541
1542	/*
1543	 * For FREEZE/QUIESCE, disable remote wakeups so no interrupts get
1544	 * generated.
1545	 */
1546	if (msg.event == PM_EVENT_FREEZE || msg.event == PM_EVENT_QUIESCE) {
1547		w = 0;
1548
1549	} else {
1550		/*
1551		 * Enable remote wakeup if it is allowed, even if no interface
1552		 * drivers actually want it.
1553		 */
1554		w = device_may_wakeup(&udev->dev);
1555	}
1556
1557	/*
1558	 * If the device is autosuspended with the wrong wakeup setting,
 
 
 
 
1559	 * autoresume now so the setting can be changed.
1560	 */
1561	if (udev->state == USB_STATE_SUSPENDED && w != udev->do_remote_wakeup)
1562		pm_runtime_resume(&udev->dev);
1563	udev->do_remote_wakeup = w;
1564}
1565
1566/* The device lock is held by the PM core */
1567int usb_suspend(struct device *dev, pm_message_t msg)
1568{
1569	struct usb_device	*udev = to_usb_device(dev);
1570	int r;
1571
1572	unbind_no_pm_drivers_interfaces(udev);
1573
1574	/* From now on we are sure all drivers support suspend/resume
1575	 * but not necessarily reset_resume()
1576	 * so we may still need to unbind and rebind upon resume
1577	 */
1578	choose_wakeup(udev, msg);
1579	r = usb_suspend_both(udev, msg);
1580	if (r)
1581		return r;
1582
1583	if (udev->quirks & USB_QUIRK_DISCONNECT_SUSPEND)
1584		usb_port_disable(udev);
1585
1586	return 0;
1587}
1588
1589/* The device lock is held by the PM core */
1590int usb_resume_complete(struct device *dev)
1591{
1592	struct usb_device *udev = to_usb_device(dev);
1593
1594	/* For PM complete calls, all we do is rebind interfaces
1595	 * whose needs_binding flag is set
1596	 */
1597	if (udev->state != USB_STATE_NOTATTACHED)
1598		rebind_marked_interfaces(udev);
1599	return 0;
1600}
1601
1602/* The device lock is held by the PM core */
1603int usb_resume(struct device *dev, pm_message_t msg)
1604{
1605	struct usb_device	*udev = to_usb_device(dev);
1606	int			status;
1607
1608	/* For all calls, take the device back to full power and
1609	 * tell the PM core in case it was autosuspended previously.
1610	 * Unbind the interfaces that will need rebinding later,
1611	 * because they fail to support reset_resume.
1612	 * (This can't be done in usb_resume_interface()
1613	 * above because it doesn't own the right set of locks.)
1614	 */
1615	status = usb_resume_both(udev, msg);
1616	if (status == 0) {
1617		pm_runtime_disable(dev);
1618		pm_runtime_set_active(dev);
1619		pm_runtime_enable(dev);
1620		unbind_marked_interfaces(udev);
1621	}
1622
1623	/* Avoid PM error messages for devices disconnected while suspended
1624	 * as we'll display regular disconnect messages just a bit later.
1625	 */
1626	if (status == -ENODEV || status == -ESHUTDOWN)
1627		status = 0;
1628	return status;
1629}
1630
 
 
 
 
1631/**
1632 * usb_enable_autosuspend - allow a USB device to be autosuspended
1633 * @udev: the USB device which may be autosuspended
1634 *
1635 * This routine allows @udev to be autosuspended.  An autosuspend won't
1636 * take place until the autosuspend_delay has elapsed and all the other
1637 * necessary conditions are satisfied.
1638 *
1639 * The caller must hold @udev's device lock.
1640 */
1641void usb_enable_autosuspend(struct usb_device *udev)
1642{
1643	pm_runtime_allow(&udev->dev);
1644}
1645EXPORT_SYMBOL_GPL(usb_enable_autosuspend);
1646
1647/**
1648 * usb_disable_autosuspend - prevent a USB device from being autosuspended
1649 * @udev: the USB device which may not be autosuspended
1650 *
1651 * This routine prevents @udev from being autosuspended and wakes it up
1652 * if it is already autosuspended.
1653 *
1654 * The caller must hold @udev's device lock.
1655 */
1656void usb_disable_autosuspend(struct usb_device *udev)
1657{
1658	pm_runtime_forbid(&udev->dev);
1659}
1660EXPORT_SYMBOL_GPL(usb_disable_autosuspend);
1661
1662/**
1663 * usb_autosuspend_device - delayed autosuspend of a USB device and its interfaces
1664 * @udev: the usb_device to autosuspend
1665 *
1666 * This routine should be called when a core subsystem is finished using
1667 * @udev and wants to allow it to autosuspend.  Examples would be when
1668 * @udev's device file in usbfs is closed or after a configuration change.
1669 *
1670 * @udev's usage counter is decremented; if it drops to 0 and all the
1671 * interfaces are inactive then a delayed autosuspend will be attempted.
1672 * The attempt may fail (see autosuspend_check()).
1673 *
1674 * The caller must hold @udev's device lock.
1675 *
1676 * This routine can run only in process context.
1677 */
1678void usb_autosuspend_device(struct usb_device *udev)
1679{
1680	int	status;
1681
1682	usb_mark_last_busy(udev);
1683	status = pm_runtime_put_sync_autosuspend(&udev->dev);
1684	dev_vdbg(&udev->dev, "%s: cnt %d -> %d\n",
1685			__func__, atomic_read(&udev->dev.power.usage_count),
1686			status);
1687}
1688
1689/**
1690 * usb_autoresume_device - immediately autoresume a USB device and its interfaces
1691 * @udev: the usb_device to autoresume
1692 *
1693 * This routine should be called when a core subsystem wants to use @udev
1694 * and needs to guarantee that it is not suspended.  No autosuspend will
1695 * occur until usb_autosuspend_device() is called.  (Note that this will
1696 * not prevent suspend events originating in the PM core.)  Examples would
1697 * be when @udev's device file in usbfs is opened or when a remote-wakeup
1698 * request is received.
1699 *
1700 * @udev's usage counter is incremented to prevent subsequent autosuspends.
1701 * However if the autoresume fails then the usage counter is re-decremented.
1702 *
1703 * The caller must hold @udev's device lock.
1704 *
1705 * This routine can run only in process context.
1706 *
1707 * Return: 0 on success. A negative error code otherwise.
1708 */
1709int usb_autoresume_device(struct usb_device *udev)
1710{
1711	int	status;
1712
1713	status = pm_runtime_get_sync(&udev->dev);
1714	if (status < 0)
1715		pm_runtime_put_sync(&udev->dev);
1716	dev_vdbg(&udev->dev, "%s: cnt %d -> %d\n",
1717			__func__, atomic_read(&udev->dev.power.usage_count),
1718			status);
1719	if (status > 0)
1720		status = 0;
1721	return status;
1722}
1723
1724/**
1725 * usb_autopm_put_interface - decrement a USB interface's PM-usage counter
1726 * @intf: the usb_interface whose counter should be decremented
1727 *
1728 * This routine should be called by an interface driver when it is
1729 * finished using @intf and wants to allow it to autosuspend.  A typical
1730 * example would be a character-device driver when its device file is
1731 * closed.
1732 *
1733 * The routine decrements @intf's usage counter.  When the counter reaches
1734 * 0, a delayed autosuspend request for @intf's device is attempted.  The
1735 * attempt may fail (see autosuspend_check()).
1736 *
1737 * This routine can run only in process context.
1738 */
1739void usb_autopm_put_interface(struct usb_interface *intf)
1740{
1741	struct usb_device	*udev = interface_to_usbdev(intf);
1742	int			status;
1743
1744	usb_mark_last_busy(udev);
 
1745	status = pm_runtime_put_sync(&intf->dev);
1746	dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1747			__func__, atomic_read(&intf->dev.power.usage_count),
1748			status);
1749}
1750EXPORT_SYMBOL_GPL(usb_autopm_put_interface);
1751
1752/**
1753 * usb_autopm_put_interface_async - decrement a USB interface's PM-usage counter
1754 * @intf: the usb_interface whose counter should be decremented
1755 *
1756 * This routine does much the same thing as usb_autopm_put_interface():
1757 * It decrements @intf's usage counter and schedules a delayed
1758 * autosuspend request if the counter is <= 0.  The difference is that it
1759 * does not perform any synchronization; callers should hold a private
1760 * lock and handle all synchronization issues themselves.
1761 *
1762 * Typically a driver would call this routine during an URB's completion
1763 * handler, if no more URBs were pending.
1764 *
1765 * This routine can run in atomic context.
1766 */
1767void usb_autopm_put_interface_async(struct usb_interface *intf)
1768{
1769	struct usb_device	*udev = interface_to_usbdev(intf);
1770	int			status;
1771
1772	usb_mark_last_busy(udev);
 
1773	status = pm_runtime_put(&intf->dev);
1774	dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1775			__func__, atomic_read(&intf->dev.power.usage_count),
1776			status);
1777}
1778EXPORT_SYMBOL_GPL(usb_autopm_put_interface_async);
1779
1780/**
1781 * usb_autopm_put_interface_no_suspend - decrement a USB interface's PM-usage counter
1782 * @intf: the usb_interface whose counter should be decremented
1783 *
1784 * This routine decrements @intf's usage counter but does not carry out an
1785 * autosuspend.
1786 *
1787 * This routine can run in atomic context.
1788 */
1789void usb_autopm_put_interface_no_suspend(struct usb_interface *intf)
1790{
1791	struct usb_device	*udev = interface_to_usbdev(intf);
1792
1793	usb_mark_last_busy(udev);
 
1794	pm_runtime_put_noidle(&intf->dev);
1795}
1796EXPORT_SYMBOL_GPL(usb_autopm_put_interface_no_suspend);
1797
1798/**
1799 * usb_autopm_get_interface - increment a USB interface's PM-usage counter
1800 * @intf: the usb_interface whose counter should be incremented
1801 *
1802 * This routine should be called by an interface driver when it wants to
1803 * use @intf and needs to guarantee that it is not suspended.  In addition,
1804 * the routine prevents @intf from being autosuspended subsequently.  (Note
1805 * that this will not prevent suspend events originating in the PM core.)
1806 * This prevention will persist until usb_autopm_put_interface() is called
1807 * or @intf is unbound.  A typical example would be a character-device
1808 * driver when its device file is opened.
1809 *
1810 * @intf's usage counter is incremented to prevent subsequent autosuspends.
1811 * However if the autoresume fails then the counter is re-decremented.
1812 *
1813 * This routine can run only in process context.
1814 *
1815 * Return: 0 on success.
1816 */
1817int usb_autopm_get_interface(struct usb_interface *intf)
1818{
1819	int	status;
1820
1821	status = pm_runtime_get_sync(&intf->dev);
1822	if (status < 0)
1823		pm_runtime_put_sync(&intf->dev);
 
 
1824	dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1825			__func__, atomic_read(&intf->dev.power.usage_count),
1826			status);
1827	if (status > 0)
1828		status = 0;
1829	return status;
1830}
1831EXPORT_SYMBOL_GPL(usb_autopm_get_interface);
1832
1833/**
1834 * usb_autopm_get_interface_async - increment a USB interface's PM-usage counter
1835 * @intf: the usb_interface whose counter should be incremented
1836 *
1837 * This routine does much the same thing as
1838 * usb_autopm_get_interface(): It increments @intf's usage counter and
1839 * queues an autoresume request if the device is suspended.  The
1840 * differences are that it does not perform any synchronization (callers
1841 * should hold a private lock and handle all synchronization issues
1842 * themselves), and it does not autoresume the device directly (it only
1843 * queues a request).  After a successful call, the device may not yet be
1844 * resumed.
1845 *
1846 * This routine can run in atomic context.
1847 *
1848 * Return: 0 on success. A negative error code otherwise.
1849 */
1850int usb_autopm_get_interface_async(struct usb_interface *intf)
1851{
1852	int	status;
1853
1854	status = pm_runtime_get(&intf->dev);
1855	if (status < 0 && status != -EINPROGRESS)
1856		pm_runtime_put_noidle(&intf->dev);
 
 
1857	dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1858			__func__, atomic_read(&intf->dev.power.usage_count),
1859			status);
1860	if (status > 0 || status == -EINPROGRESS)
1861		status = 0;
1862	return status;
1863}
1864EXPORT_SYMBOL_GPL(usb_autopm_get_interface_async);
1865
1866/**
1867 * usb_autopm_get_interface_no_resume - increment a USB interface's PM-usage counter
1868 * @intf: the usb_interface whose counter should be incremented
1869 *
1870 * This routine increments @intf's usage counter but does not carry out an
1871 * autoresume.
1872 *
1873 * This routine can run in atomic context.
1874 */
1875void usb_autopm_get_interface_no_resume(struct usb_interface *intf)
1876{
1877	struct usb_device	*udev = interface_to_usbdev(intf);
1878
1879	usb_mark_last_busy(udev);
 
1880	pm_runtime_get_noresume(&intf->dev);
1881}
1882EXPORT_SYMBOL_GPL(usb_autopm_get_interface_no_resume);
1883
1884/* Internal routine to check whether we may autosuspend a device. */
1885static int autosuspend_check(struct usb_device *udev)
1886{
1887	int			w, i;
1888	struct usb_interface	*intf;
1889
1890	if (udev->state == USB_STATE_NOTATTACHED)
1891		return -ENODEV;
1892
1893	/* Fail if autosuspend is disabled, or any interfaces are in use, or
1894	 * any interface drivers require remote wakeup but it isn't available.
1895	 */
1896	w = 0;
1897	if (udev->actconfig) {
1898		for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
1899			intf = udev->actconfig->interface[i];
1900
1901			/* We don't need to check interfaces that are
1902			 * disabled for runtime PM.  Either they are unbound
1903			 * or else their drivers don't support autosuspend
1904			 * and so they are permanently active.
1905			 */
1906			if (intf->dev.power.disable_depth)
1907				continue;
1908			if (atomic_read(&intf->dev.power.usage_count) > 0)
1909				return -EBUSY;
1910			w |= intf->needs_remote_wakeup;
1911
1912			/* Don't allow autosuspend if the device will need
1913			 * a reset-resume and any of its interface drivers
1914			 * doesn't include support or needs remote wakeup.
1915			 */
1916			if (udev->quirks & USB_QUIRK_RESET_RESUME) {
1917				struct usb_driver *driver;
1918
1919				driver = to_usb_driver(intf->dev.driver);
1920				if (!driver->reset_resume ||
1921						intf->needs_remote_wakeup)
1922					return -EOPNOTSUPP;
1923			}
1924		}
1925	}
1926	if (w && !device_can_wakeup(&udev->dev)) {
1927		dev_dbg(&udev->dev, "remote wakeup needed for autosuspend\n");
1928		return -EOPNOTSUPP;
1929	}
1930
1931	/*
1932	 * If the device is a direct child of the root hub and the HCD
1933	 * doesn't handle wakeup requests, don't allow autosuspend when
1934	 * wakeup is needed.
1935	 */
1936	if (w && udev->parent == udev->bus->root_hub &&
1937			bus_to_hcd(udev->bus)->cant_recv_wakeups) {
1938		dev_dbg(&udev->dev, "HCD doesn't handle wakeup requests\n");
1939		return -EOPNOTSUPP;
1940	}
1941
1942	udev->do_remote_wakeup = w;
1943	return 0;
1944}
1945
1946int usb_runtime_suspend(struct device *dev)
1947{
1948	struct usb_device	*udev = to_usb_device(dev);
1949	int			status;
1950
1951	/* A USB device can be suspended if it passes the various autosuspend
1952	 * checks.  Runtime suspend for a USB device means suspending all the
1953	 * interfaces and then the device itself.
1954	 */
1955	if (autosuspend_check(udev) != 0)
1956		return -EAGAIN;
1957
1958	status = usb_suspend_both(udev, PMSG_AUTO_SUSPEND);
1959
1960	/* Allow a retry if autosuspend failed temporarily */
1961	if (status == -EAGAIN || status == -EBUSY)
1962		usb_mark_last_busy(udev);
1963
1964	/*
1965	 * The PM core reacts badly unless the return code is 0,
1966	 * -EAGAIN, or -EBUSY, so always return -EBUSY on an error
1967	 * (except for root hubs, because they don't suspend through
1968	 * an upstream port like other USB devices).
1969	 */
1970	if (status != 0 && udev->parent)
1971		return -EBUSY;
1972	return status;
1973}
1974
1975int usb_runtime_resume(struct device *dev)
1976{
1977	struct usb_device	*udev = to_usb_device(dev);
1978	int			status;
1979
1980	/* Runtime resume for a USB device means resuming both the device
1981	 * and all its interfaces.
1982	 */
1983	status = usb_resume_both(udev, PMSG_AUTO_RESUME);
1984	return status;
1985}
1986
1987int usb_runtime_idle(struct device *dev)
1988{
1989	struct usb_device	*udev = to_usb_device(dev);
1990
1991	/* An idle USB device can be suspended if it passes the various
1992	 * autosuspend checks.
1993	 */
1994	if (autosuspend_check(udev) == 0)
1995		pm_runtime_autosuspend(dev);
1996	/* Tell the core not to suspend it, though. */
1997	return -EBUSY;
1998}
1999
2000static int usb_set_usb2_hardware_lpm(struct usb_device *udev, int enable)
2001{
2002	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
2003	int ret = -EPERM;
2004
2005	if (hcd->driver->set_usb2_hw_lpm) {
2006		ret = hcd->driver->set_usb2_hw_lpm(hcd, udev, enable);
2007		if (!ret)
2008			udev->usb2_hw_lpm_enabled = enable;
2009	}
2010
2011	return ret;
2012}
2013
2014int usb_enable_usb2_hardware_lpm(struct usb_device *udev)
2015{
2016	if (!udev->usb2_hw_lpm_capable ||
2017	    !udev->usb2_hw_lpm_allowed ||
2018	    udev->usb2_hw_lpm_enabled)
2019		return 0;
2020
2021	return usb_set_usb2_hardware_lpm(udev, 1);
2022}
2023
2024int usb_disable_usb2_hardware_lpm(struct usb_device *udev)
2025{
2026	if (!udev->usb2_hw_lpm_enabled)
2027		return 0;
2028
2029	return usb_set_usb2_hardware_lpm(udev, 0);
2030}
2031
2032#endif /* CONFIG_PM */
2033
2034const struct bus_type usb_bus_type = {
2035	.name =		"usb",
2036	.match =	usb_device_match,
2037	.uevent =	usb_uevent,
2038	.need_parent_lock =	true,
2039};