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