1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * drivers/usb/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 * @priv: 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 * Few drivers should need to use this routine, since the most natural
 530 * way to bind to an interface is to return the private data from
 531 * the driver's probe() method.
 532 *
 533 * Callers must own the device lock, so driver probe() entries don't need
 534 * extra locking, but other call contexts may need to explicitly claim that
 535 * lock.
 536 *
 537 * Return: 0 on success.
 538 */
 539int usb_driver_claim_interface(struct usb_driver *driver,
 540				struct usb_interface *iface, void *priv)
 541{
 542	struct device *dev;
 
 543	int retval = 0;
 
 544
 545	if (!iface)
 546		return -ENODEV;
 547
 548	dev = &iface->dev;
 549	if (dev->driver)
 550		return -EBUSY;
 551
 552	/* reject claim if interface is not authorized */
 553	if (!iface->authorized)
 554		return -ENODEV;
 555
 556	dev->driver = &driver->drvwrap.driver;
 557	usb_set_intfdata(iface, priv);
 558	iface->needs_binding = 0;
 559
 560	iface->condition = USB_INTERFACE_BOUND;
 561
 
 
 
 
 
 
 
 
 562	/* Claimed interfaces are initially inactive (suspended) and
 563	 * runtime-PM-enabled, but only if the driver has autosuspend
 564	 * support.  Otherwise they are marked active, to prevent the
 565	 * device from being autosuspended, but left disabled.  In either
 566	 * case they are sensitive to their children's power states.
 567	 */
 568	pm_suspend_ignore_children(dev, false);
 569	if (driver->supports_autosuspend)
 570		pm_runtime_enable(dev);
 571	else
 572		pm_runtime_set_active(dev);
 573
 574	/* if interface was already added, bind now; else let
 575	 * the future device_add() bind it, bypassing probe()
 576	 */
 577	if (device_is_registered(dev))
 578		retval = device_bind_driver(dev);
 579
 580	if (retval) {
 581		dev->driver = NULL;
 582		usb_set_intfdata(iface, NULL);
 583		iface->needs_remote_wakeup = 0;
 584		iface->condition = USB_INTERFACE_UNBOUND;
 585
 586		/*
 587		 * Unbound interfaces are always runtime-PM-disabled
 588		 * and runtime-PM-suspended
 589		 */
 590		if (driver->supports_autosuspend)
 591			pm_runtime_disable(dev);
 592		pm_runtime_set_suspended(dev);
 593	}
 594
 595	return retval;
 596}
 597EXPORT_SYMBOL_GPL(usb_driver_claim_interface);
 598
 599/**
 600 * usb_driver_release_interface - unbind a driver from an interface
 601 * @driver: the driver to be unbound
 602 * @iface: the interface from which it will be unbound
 603 *
 604 * This can be used by drivers to release an interface without waiting
 605 * for their disconnect() methods to be called.  In typical cases this
 606 * also causes the driver disconnect() method to be called.
 607 *
 608 * This call is synchronous, and may not be used in an interrupt context.
 609 * Callers must own the device lock, so driver disconnect() entries don't
 610 * need extra locking, but other call contexts may need to explicitly claim
 611 * that lock.
 612 */
 613void usb_driver_release_interface(struct usb_driver *driver,
 614					struct usb_interface *iface)
 615{
 616	struct device *dev = &iface->dev;
 617
 618	/* this should never happen, don't release something that's not ours */
 619	if (!dev->driver || dev->driver != &driver->drvwrap.driver)
 620		return;
 621
 622	/* don't release from within disconnect() */
 623	if (iface->condition != USB_INTERFACE_BOUND)
 624		return;
 625	iface->condition = USB_INTERFACE_UNBINDING;
 626
 627	/* Release via the driver core only if the interface
 628	 * has already been registered
 629	 */
 630	if (device_is_registered(dev)) {
 631		device_release_driver(dev);
 632	} else {
 633		device_lock(dev);
 634		usb_unbind_interface(dev);
 635		dev->driver = NULL;
 636		device_unlock(dev);
 637	}
 638}
 639EXPORT_SYMBOL_GPL(usb_driver_release_interface);
 640
 641/* returns 0 if no match, 1 if match */
 642int usb_match_device(struct usb_device *dev, const struct usb_device_id *id)
 643{
 644	if ((id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
 645	    id->idVendor != le16_to_cpu(dev->descriptor.idVendor))
 646		return 0;
 647
 648	if ((id->match_flags & USB_DEVICE_ID_MATCH_PRODUCT) &&
 649	    id->idProduct != le16_to_cpu(dev->descriptor.idProduct))
 650		return 0;
 651
 652	/* No need to test id->bcdDevice_lo != 0, since 0 is never
 653	   greater than any unsigned number. */
 654	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_LO) &&
 655	    (id->bcdDevice_lo > le16_to_cpu(dev->descriptor.bcdDevice)))
 656		return 0;
 657
 658	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_HI) &&
 659	    (id->bcdDevice_hi < le16_to_cpu(dev->descriptor.bcdDevice)))
 660		return 0;
 661
 662	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_CLASS) &&
 663	    (id->bDeviceClass != dev->descriptor.bDeviceClass))
 664		return 0;
 665
 666	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_SUBCLASS) &&
 667	    (id->bDeviceSubClass != dev->descriptor.bDeviceSubClass))
 668		return 0;
 669
 670	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_PROTOCOL) &&
 671	    (id->bDeviceProtocol != dev->descriptor.bDeviceProtocol))
 672		return 0;
 673
 674	return 1;
 675}
 676
 677/* returns 0 if no match, 1 if match */
 678int usb_match_one_id_intf(struct usb_device *dev,
 679			  struct usb_host_interface *intf,
 680			  const struct usb_device_id *id)
 681{
 682	/* The interface class, subclass, protocol and number should never be
 
 
 
 
 
 
 
 
 
 
 
 
 
 683	 * checked for a match if the device class is Vendor Specific,
 684	 * unless the match record specifies the Vendor ID. */
 685	if (dev->descriptor.bDeviceClass == USB_CLASS_VENDOR_SPEC &&
 686			!(id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
 687			(id->match_flags & (USB_DEVICE_ID_MATCH_INT_CLASS |
 688				USB_DEVICE_ID_MATCH_INT_SUBCLASS |
 689				USB_DEVICE_ID_MATCH_INT_PROTOCOL |
 690				USB_DEVICE_ID_MATCH_INT_NUMBER)))
 691		return 0;
 692
 693	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_CLASS) &&
 694	    (id->bInterfaceClass != intf->desc.bInterfaceClass))
 695		return 0;
 696
 697	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_SUBCLASS) &&
 698	    (id->bInterfaceSubClass != intf->desc.bInterfaceSubClass))
 699		return 0;
 700
 701	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_PROTOCOL) &&
 702	    (id->bInterfaceProtocol != intf->desc.bInterfaceProtocol))
 703		return 0;
 704
 705	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_NUMBER) &&
 706	    (id->bInterfaceNumber != intf->desc.bInterfaceNumber))
 707		return 0;
 708
 709	return 1;
 710}
 711
 712/* returns 0 if no match, 1 if match */
 713int usb_match_one_id(struct usb_interface *interface,
 714		     const struct usb_device_id *id)
 715{
 716	struct usb_host_interface *intf;
 717	struct usb_device *dev;
 718
 719	/* proc_connectinfo in devio.c may call us with id == NULL. */
 720	if (id == NULL)
 721		return 0;
 722
 723	intf = interface->cur_altsetting;
 724	dev = interface_to_usbdev(interface);
 725
 726	if (!usb_match_device(dev, id))
 727		return 0;
 728
 729	return usb_match_one_id_intf(dev, intf, id);
 730}
 731EXPORT_SYMBOL_GPL(usb_match_one_id);
 732
 733/**
 734 * usb_match_id - find first usb_device_id matching device or interface
 735 * @interface: the interface of interest
 736 * @id: array of usb_device_id structures, terminated by zero entry
 737 *
 738 * usb_match_id searches an array of usb_device_id's and returns
 739 * the first one matching the device or interface, or null.
 740 * This is used when binding (or rebinding) a driver to an interface.
 741 * Most USB device drivers will use this indirectly, through the usb core,
 742 * but some layered driver frameworks use it directly.
 743 * These device tables are exported with MODULE_DEVICE_TABLE, through
 744 * modutils, to support the driver loading functionality of USB hotplugging.
 745 *
 746 * Return: The first matching usb_device_id, or %NULL.
 747 *
 748 * What Matches:
 749 *
 750 * The "match_flags" element in a usb_device_id controls which
 751 * members are used.  If the corresponding bit is set, the
 752 * value in the device_id must match its corresponding member
 753 * in the device or interface descriptor, or else the device_id
 754 * does not match.
 755 *
 756 * "driver_info" is normally used only by device drivers,
 757 * but you can create a wildcard "matches anything" usb_device_id
 758 * as a driver's "modules.usbmap" entry if you provide an id with
 759 * only a nonzero "driver_info" field.  If you do this, the USB device
 760 * driver's probe() routine should use additional intelligence to
 761 * decide whether to bind to the specified interface.
 762 *
 763 * What Makes Good usb_device_id Tables:
 764 *
 765 * The match algorithm is very simple, so that intelligence in
 766 * driver selection must come from smart driver id records.
 767 * Unless you have good reasons to use another selection policy,
 768 * provide match elements only in related groups, and order match
 769 * specifiers from specific to general.  Use the macros provided
 770 * for that purpose if you can.
 771 *
 772 * The most specific match specifiers use device descriptor
 773 * data.  These are commonly used with product-specific matches;
 774 * the USB_DEVICE macro lets you provide vendor and product IDs,
 775 * and you can also match against ranges of product revisions.
 776 * These are widely used for devices with application or vendor
 777 * specific bDeviceClass values.
 778 *
 779 * Matches based on device class/subclass/protocol specifications
 780 * are slightly more general; use the USB_DEVICE_INFO macro, or
 781 * its siblings.  These are used with single-function devices
 782 * where bDeviceClass doesn't specify that each interface has
 783 * its own class.
 784 *
 785 * Matches based on interface class/subclass/protocol are the
 786 * most general; they let drivers bind to any interface on a
 787 * multiple-function device.  Use the USB_INTERFACE_INFO
 788 * macro, or its siblings, to match class-per-interface style
 789 * devices (as recorded in bInterfaceClass).
 790 *
 791 * Note that an entry created by USB_INTERFACE_INFO won't match
 792 * any interface if the device class is set to Vendor-Specific.
 793 * This is deliberate; according to the USB spec the meanings of
 794 * the interface class/subclass/protocol for these devices are also
 795 * vendor-specific, and hence matching against a standard product
 796 * class wouldn't work anyway.  If you really want to use an
 797 * interface-based match for such a device, create a match record
 798 * that also specifies the vendor ID.  (Unforunately there isn't a
 799 * standard macro for creating records like this.)
 800 *
 801 * Within those groups, remember that not all combinations are
 802 * meaningful.  For example, don't give a product version range
 803 * without vendor and product IDs; or specify a protocol without
 804 * its associated class and subclass.
 805 */
 806const struct usb_device_id *usb_match_id(struct usb_interface *interface,
 807					 const struct usb_device_id *id)
 808{
 809	/* proc_connectinfo in devio.c may call us with id == NULL. */
 810	if (id == NULL)
 811		return NULL;
 812
 813	/* It is important to check that id->driver_info is nonzero,
 814	   since an entry that is all zeroes except for a nonzero
 815	   id->driver_info is the way to create an entry that
 816	   indicates that the driver want to examine every
 817	   device and interface. */
 818	for (; id->idVendor || id->idProduct || id->bDeviceClass ||
 819	       id->bInterfaceClass || id->driver_info; id++) {
 820		if (usb_match_one_id(interface, id))
 821			return id;
 822	}
 823
 824	return NULL;
 825}
 826EXPORT_SYMBOL_GPL(usb_match_id);
 827
 828const struct usb_device_id *usb_device_match_id(struct usb_device *udev,
 829				const struct usb_device_id *id)
 830{
 831	if (!id)
 832		return NULL;
 833
 834	for (; id->idVendor || id->idProduct ; id++) {
 835		if (usb_match_device(udev, id))
 836			return id;
 837	}
 838
 839	return NULL;
 840}
 841
 842static int usb_device_match(struct device *dev, struct device_driver *drv)
 843{
 844	/* devices and interfaces are handled separately */
 845	if (is_usb_device(dev)) {
 846		struct usb_device *udev;
 847		struct usb_device_driver *udrv;
 848
 849		/* interface drivers never match devices */
 850		if (!is_usb_device_driver(drv))
 851			return 0;
 852
 853		udev = to_usb_device(dev);
 854		udrv = to_usb_device_driver(drv);
 855
 856		if (udrv->id_table)
 857			return usb_device_match_id(udev, udrv->id_table) != NULL;
 858
 859		if (udrv->match)
 860			return udrv->match(udev);
 861
 862		/* If the device driver under consideration does not have a
 863		 * id_table or a match function, then let the driver's probe
 864		 * function decide.
 865		 */
 866		return 1;
 867
 868	} else if (is_usb_interface(dev)) {
 869		struct usb_interface *intf;
 870		struct usb_driver *usb_drv;
 871		const struct usb_device_id *id;
 872
 873		/* device drivers never match interfaces */
 874		if (is_usb_device_driver(drv))
 875			return 0;
 876
 877		intf = to_usb_interface(dev);
 878		usb_drv = to_usb_driver(drv);
 879
 880		id = usb_match_id(intf, usb_drv->id_table);
 881		if (id)
 882			return 1;
 883
 884		id = usb_match_dynamic_id(intf, usb_drv);
 885		if (id)
 886			return 1;
 887	}
 888
 889	return 0;
 890}
 891
 
 892static int usb_uevent(struct device *dev, struct kobj_uevent_env *env)
 893{
 894	struct usb_device *usb_dev;
 895
 896	if (is_usb_device(dev)) {
 897		usb_dev = to_usb_device(dev);
 898	} else if (is_usb_interface(dev)) {
 899		struct usb_interface *intf = to_usb_interface(dev);
 900
 901		usb_dev = interface_to_usbdev(intf);
 902	} else {
 903		return 0;
 904	}
 905
 906	if (usb_dev->devnum < 0) {
 907		/* driver is often null here; dev_dbg() would oops */
 908		pr_debug("usb %s: already deleted?\n", dev_name(dev));
 909		return -ENODEV;
 910	}
 911	if (!usb_dev->bus) {
 912		pr_debug("usb %s: bus removed?\n", dev_name(dev));
 913		return -ENODEV;
 914	}
 915
 916	/* per-device configurations are common */
 917	if (add_uevent_var(env, "PRODUCT=%x/%x/%x",
 918			   le16_to_cpu(usb_dev->descriptor.idVendor),
 919			   le16_to_cpu(usb_dev->descriptor.idProduct),
 920			   le16_to_cpu(usb_dev->descriptor.bcdDevice)))
 921		return -ENOMEM;
 922
 923	/* class-based driver binding models */
 924	if (add_uevent_var(env, "TYPE=%d/%d/%d",
 925			   usb_dev->descriptor.bDeviceClass,
 926			   usb_dev->descriptor.bDeviceSubClass,
 927			   usb_dev->descriptor.bDeviceProtocol))
 928		return -ENOMEM;
 929
 930	return 0;
 931}
 932
 933static int __usb_bus_reprobe_drivers(struct device *dev, void *data)
 934{
 935	struct usb_device_driver *new_udriver = data;
 936	struct usb_device *udev;
 937	int ret;
 938
 939	/* Don't reprobe if current driver isn't usb_generic_driver */
 940	if (dev->driver != &usb_generic_driver.drvwrap.driver)
 941		return 0;
 942
 943	udev = to_usb_device(dev);
 944	if (usb_device_match_id(udev, new_udriver->id_table) == NULL &&
 945	    (!new_udriver->match || new_udriver->match(udev) == 0))
 946		return 0;
 947
 948	ret = device_reprobe(dev);
 949	if (ret && ret != -EPROBE_DEFER)
 950		dev_err(dev, "Failed to reprobe device (error %d)\n", ret);
 951
 952	return 0;
 
 
 953}
 
 954
 955/**
 956 * usb_register_device_driver - register a USB device (not interface) driver
 957 * @new_udriver: USB operations for the device driver
 958 * @owner: module owner of this driver.
 959 *
 960 * Registers a USB device driver with the USB core.  The list of
 961 * unattached devices will be rescanned whenever a new driver is
 962 * added, allowing the new driver to attach to any recognized devices.
 963 *
 964 * Return: A negative error code on failure and 0 on success.
 965 */
 966int usb_register_device_driver(struct usb_device_driver *new_udriver,
 967		struct module *owner)
 968{
 969	int retval = 0;
 970
 971	if (usb_disabled())
 972		return -ENODEV;
 973
 974	new_udriver->drvwrap.for_devices = 1;
 975	new_udriver->drvwrap.driver.name = new_udriver->name;
 976	new_udriver->drvwrap.driver.bus = &usb_bus_type;
 977	new_udriver->drvwrap.driver.probe = usb_probe_device;
 978	new_udriver->drvwrap.driver.remove = usb_unbind_device;
 979	new_udriver->drvwrap.driver.owner = owner;
 980	new_udriver->drvwrap.driver.dev_groups = new_udriver->dev_groups;
 981
 982	retval = driver_register(&new_udriver->drvwrap.driver);
 983
 984	if (!retval) {
 985		pr_info("%s: registered new device driver %s\n",
 986			usbcore_name, new_udriver->name);
 987		/*
 988		 * Check whether any device could be better served with
 989		 * this new driver
 990		 */
 991		bus_for_each_dev(&usb_bus_type, NULL, new_udriver,
 992				 __usb_bus_reprobe_drivers);
 993	} else {
 994		printk(KERN_ERR "%s: error %d registering device "
 995			"	driver %s\n",
 996			usbcore_name, retval, new_udriver->name);
 997	}
 998
 999	return retval;
1000}
1001EXPORT_SYMBOL_GPL(usb_register_device_driver);
1002
1003/**
1004 * usb_deregister_device_driver - unregister a USB device (not interface) driver
1005 * @udriver: USB operations of the device driver to unregister
1006 * Context: must be able to sleep
1007 *
1008 * Unlinks the specified driver from the internal USB driver list.
1009 */
1010void usb_deregister_device_driver(struct usb_device_driver *udriver)
1011{
1012	pr_info("%s: deregistering device driver %s\n",
1013			usbcore_name, udriver->name);
1014
1015	driver_unregister(&udriver->drvwrap.driver);
1016}
1017EXPORT_SYMBOL_GPL(usb_deregister_device_driver);
1018
1019/**
1020 * usb_register_driver - register a USB interface driver
1021 * @new_driver: USB operations for the interface driver
1022 * @owner: module owner of this driver.
1023 * @mod_name: module name string
1024 *
1025 * Registers a USB interface driver with the USB core.  The list of
1026 * unattached interfaces will be rescanned whenever a new driver is
1027 * added, allowing the new driver to attach to any recognized interfaces.
1028 *
1029 * Return: A negative error code on failure and 0 on success.
1030 *
1031 * NOTE: if you want your driver to use the USB major number, you must call
1032 * usb_register_dev() to enable that functionality.  This function no longer
1033 * takes care of that.
1034 */
1035int usb_register_driver(struct usb_driver *new_driver, struct module *owner,
1036			const char *mod_name)
1037{
1038	int retval = 0;
1039
1040	if (usb_disabled())
1041		return -ENODEV;
1042
1043	new_driver->drvwrap.for_devices = 0;
1044	new_driver->drvwrap.driver.name = new_driver->name;
1045	new_driver->drvwrap.driver.bus = &usb_bus_type;
1046	new_driver->drvwrap.driver.probe = usb_probe_interface;
1047	new_driver->drvwrap.driver.remove = usb_unbind_interface;
1048	new_driver->drvwrap.driver.owner = owner;
1049	new_driver->drvwrap.driver.mod_name = mod_name;
1050	new_driver->drvwrap.driver.dev_groups = new_driver->dev_groups;
1051	spin_lock_init(&new_driver->dynids.lock);
1052	INIT_LIST_HEAD(&new_driver->dynids.list);
1053
1054	retval = driver_register(&new_driver->drvwrap.driver);
1055	if (retval)
1056		goto out;
1057
1058	retval = usb_create_newid_files(new_driver);
1059	if (retval)
1060		goto out_newid;
1061
1062	pr_info("%s: registered new interface driver %s\n",
1063			usbcore_name, new_driver->name);
1064
1065out:
1066	return retval;
1067
1068out_newid:
1069	driver_unregister(&new_driver->drvwrap.driver);
1070
1071	printk(KERN_ERR "%s: error %d registering interface "
1072			"	driver %s\n",
1073			usbcore_name, retval, new_driver->name);
1074	goto out;
1075}
1076EXPORT_SYMBOL_GPL(usb_register_driver);
1077
1078/**
1079 * usb_deregister - unregister a USB interface driver
1080 * @driver: USB operations of the interface driver to unregister
1081 * Context: must be able to sleep
1082 *
1083 * Unlinks the specified driver from the internal USB driver list.
1084 *
1085 * NOTE: If you called usb_register_dev(), you still need to call
1086 * usb_deregister_dev() to clean up your driver's allocated minor numbers,
1087 * this * call will no longer do it for you.
1088 */
1089void usb_deregister(struct usb_driver *driver)
1090{
1091	pr_info("%s: deregistering interface driver %s\n",
1092			usbcore_name, driver->name);
1093
1094	usb_remove_newid_files(driver);
1095	driver_unregister(&driver->drvwrap.driver);
1096	usb_free_dynids(driver);
1097}
1098EXPORT_SYMBOL_GPL(usb_deregister);
1099
1100/* Forced unbinding of a USB interface driver, either because
1101 * it doesn't support pre_reset/post_reset/reset_resume or
1102 * because it doesn't support suspend/resume.
1103 *
1104 * The caller must hold @intf's device's lock, but not @intf's lock.
 
1105 */
1106void usb_forced_unbind_intf(struct usb_interface *intf)
1107{
1108	struct usb_driver *driver = to_usb_driver(intf->dev.driver);
1109
1110	dev_dbg(&intf->dev, "forced unbind\n");
1111	usb_driver_release_interface(driver, intf);
1112
1113	/* Mark the interface for later rebinding */
1114	intf->needs_binding = 1;
1115}
1116
1117/*
1118 * Unbind drivers for @udev's marked interfaces.  These interfaces have
1119 * the needs_binding flag set, for example by usb_resume_interface().
1120 *
1121 * The caller must hold @udev's device lock.
1122 */
1123static void unbind_marked_interfaces(struct usb_device *udev)
1124{
1125	struct usb_host_config	*config;
1126	int			i;
1127	struct usb_interface	*intf;
1128
1129	config = udev->actconfig;
1130	if (config) {
1131		for (i = 0; i < config->desc.bNumInterfaces; ++i) {
1132			intf = config->interface[i];
1133			if (intf->dev.driver && intf->needs_binding)
1134				usb_forced_unbind_intf(intf);
1135		}
1136	}
1137}
1138
1139/* Delayed forced unbinding of a USB interface driver and scan
1140 * for rebinding.
1141 *
1142 * The caller must hold @intf's device's lock, but not @intf's lock.
 
1143 *
1144 * Note: Rebinds will be skipped if a system sleep transition is in
1145 * progress and the PM "complete" callback hasn't occurred yet.
1146 */
1147static void usb_rebind_intf(struct usb_interface *intf)
1148{
1149	int rc;
1150
1151	/* Delayed unbind of an existing driver */
1152	if (intf->dev.driver)
1153		usb_forced_unbind_intf(intf);
1154
1155	/* Try to rebind the interface */
1156	if (!intf->dev.power.is_prepared) {
1157		intf->needs_binding = 0;
1158		rc = device_attach(&intf->dev);
1159		if (rc < 0 && rc != -EPROBE_DEFER)
1160			dev_warn(&intf->dev, "rebind failed: %d\n", rc);
1161	}
1162}
1163
1164/*
1165 * Rebind drivers to @udev's marked interfaces.  These interfaces have
1166 * the needs_binding flag set.
 
 
1167 *
1168 * The caller must hold @udev's device lock.
1169 */
1170static void rebind_marked_interfaces(struct usb_device *udev)
1171{
1172	struct usb_host_config	*config;
1173	int			i;
1174	struct usb_interface	*intf;
 
1175
1176	config = udev->actconfig;
1177	if (config) {
1178		for (i = 0; i < config->desc.bNumInterfaces; ++i) {
1179			intf = config->interface[i];
1180			if (intf->needs_binding)
1181				usb_rebind_intf(intf);
 
 
 
 
1182		}
1183	}
1184}
1185
1186/*
1187 * Unbind all of @udev's marked interfaces and then rebind all of them.
1188 * This ordering is necessary because some drivers claim several interfaces
1189 * when they are first probed.
1190 *
1191 * The caller must hold @udev's device lock.
1192 */
1193void usb_unbind_and_rebind_marked_interfaces(struct usb_device *udev)
1194{
1195	unbind_marked_interfaces(udev);
1196	rebind_marked_interfaces(udev);
1197}
1198
1199#ifdef CONFIG_PM
 
 
 
 
 
 
 
 
1200
1201/* Unbind drivers for @udev's interfaces that don't support suspend/resume
1202 * There is no check for reset_resume here because it can be determined
1203 * only during resume whether reset_resume is needed.
1204 *
1205 * The caller must hold @udev's device lock.
1206 */
1207static void unbind_no_pm_drivers_interfaces(struct usb_device *udev)
1208{
1209	struct usb_host_config	*config;
1210	int			i;
1211	struct usb_interface	*intf;
1212	struct usb_driver	*drv;
1213
1214	config = udev->actconfig;
1215	if (config) {
1216		for (i = 0; i < config->desc.bNumInterfaces; ++i) {
1217			intf = config->interface[i];
1218
1219			if (intf->dev.driver) {
1220				drv = to_usb_driver(intf->dev.driver);
1221				if (!drv->suspend || !drv->resume)
1222					usb_forced_unbind_intf(intf);
1223			}
1224		}
1225	}
1226}
1227
1228static int usb_suspend_device(struct usb_device *udev, pm_message_t msg)
1229{
1230	struct usb_device_driver	*udriver;
1231	int				status = 0;
1232
1233	if (udev->state == USB_STATE_NOTATTACHED ||
1234			udev->state == USB_STATE_SUSPENDED)
1235		goto done;
1236
1237	/* For devices that don't have a driver, we do a generic suspend. */
1238	if (udev->dev.driver)
1239		udriver = to_usb_device_driver(udev->dev.driver);
1240	else {
1241		udev->do_remote_wakeup = 0;
1242		udriver = &usb_generic_driver;
1243	}
1244	if (udriver->suspend)
1245		status = udriver->suspend(udev, msg);
1246	if (status == 0 && udriver->generic_subclass)
1247		status = usb_generic_driver_suspend(udev, msg);
1248
1249 done:
1250	dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1251	return status;
1252}
1253
1254static int usb_resume_device(struct usb_device *udev, pm_message_t msg)
1255{
1256	struct usb_device_driver	*udriver;
1257	int				status = 0;
1258
1259	if (udev->state == USB_STATE_NOTATTACHED)
1260		goto done;
1261
1262	/* Can't resume it if it doesn't have a driver. */
1263	if (udev->dev.driver == NULL) {
1264		status = -ENOTCONN;
1265		goto done;
1266	}
1267
1268	/* Non-root devices on a full/low-speed bus must wait for their
1269	 * companion high-speed root hub, in case a handoff is needed.
1270	 */
1271	if (!PMSG_IS_AUTO(msg) && udev->parent && udev->bus->hs_companion)
1272		device_pm_wait_for_dev(&udev->dev,
1273				&udev->bus->hs_companion->root_hub->dev);
1274
1275	if (udev->quirks & USB_QUIRK_RESET_RESUME)
1276		udev->reset_resume = 1;
1277
1278	udriver = to_usb_device_driver(udev->dev.driver);
1279	if (udriver->generic_subclass)
1280		status = usb_generic_driver_resume(udev, msg);
1281	if (status == 0 && udriver->resume)
1282		status = udriver->resume(udev, msg);
1283
1284 done:
1285	dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1286	return status;
1287}
1288
1289static int usb_suspend_interface(struct usb_device *udev,
1290		struct usb_interface *intf, pm_message_t msg)
1291{
1292	struct usb_driver	*driver;
1293	int			status = 0;
1294
1295	if (udev->state == USB_STATE_NOTATTACHED ||
1296			intf->condition == USB_INTERFACE_UNBOUND)
1297		goto done;
1298	driver = to_usb_driver(intf->dev.driver);
1299
1300	/* at this time we know the driver supports suspend */
1301	status = driver->suspend(intf, msg);
1302	if (status && !PMSG_IS_AUTO(msg))
1303		dev_err(&intf->dev, "suspend error %d\n", status);
1304
1305 done:
1306	dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
1307	return status;
1308}
1309
1310static int usb_resume_interface(struct usb_device *udev,
1311		struct usb_interface *intf, pm_message_t msg, int reset_resume)
1312{
1313	struct usb_driver	*driver;
1314	int			status = 0;
1315
1316	if (udev->state == USB_STATE_NOTATTACHED)
1317		goto done;
1318
1319	/* Don't let autoresume interfere with unbinding */
1320	if (intf->condition == USB_INTERFACE_UNBINDING)
1321		goto done;
1322
1323	/* Can't resume it if it doesn't have a driver. */
1324	if (intf->condition == USB_INTERFACE_UNBOUND) {
1325
1326		/* Carry out a deferred switch to altsetting 0 */
1327		if (intf->needs_altsetting0 && !intf->dev.power.is_prepared) {
1328			usb_set_interface(udev, intf->altsetting[0].
1329					desc.bInterfaceNumber, 0);
1330			intf->needs_altsetting0 = 0;
1331		}
1332		goto done;
1333	}
1334
1335	/* Don't resume if the interface is marked for rebinding */
1336	if (intf->needs_binding)
1337		goto done;
1338	driver = to_usb_driver(intf->dev.driver);
1339
1340	if (reset_resume) {
1341		if (driver->reset_resume) {
1342			status = driver->reset_resume(intf);
1343			if (status)
1344				dev_err(&intf->dev, "%s error %d\n",
1345						"reset_resume", status);
1346		} else {
1347			intf->needs_binding = 1;
1348			dev_dbg(&intf->dev, "no reset_resume for driver %s?\n",
1349					driver->name);
1350		}
1351	} else {
1352		status = driver->resume(intf);
1353		if (status)
1354			dev_err(&intf->dev, "resume error %d\n", status);
1355	}
1356
1357done:
1358	dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
1359
1360	/* Later we will unbind the driver and/or reprobe, if necessary */
1361	return status;
1362}
1363
1364/**
1365 * usb_suspend_both - suspend a USB device and its interfaces
1366 * @udev: the usb_device to suspend
1367 * @msg: Power Management message describing this state transition
1368 *
1369 * This is the central routine for suspending USB devices.  It calls the
1370 * suspend methods for all the interface drivers in @udev and then calls
1371 * the suspend method for @udev itself.  When the routine is called in
1372 * autosuspend, if an error occurs at any stage, all the interfaces
1373 * which were suspended are resumed so that they remain in the same
1374 * state as the device, but when called from system sleep, all error
1375 * from suspend methods of interfaces and the non-root-hub device itself
1376 * are simply ignored, so all suspended interfaces are only resumed
1377 * to the device's state when @udev is root-hub and its suspend method
1378 * returns failure.
1379 *
1380 * Autosuspend requests originating from a child device or an interface
1381 * driver may be made without the protection of @udev's device lock, but
1382 * all other suspend calls will hold the lock.  Usbcore will insure that
1383 * method calls do not arrive during bind, unbind, or reset operations.
1384 * However drivers must be prepared to handle suspend calls arriving at
1385 * unpredictable times.
1386 *
1387 * This routine can run only in process context.
1388 *
1389 * Return: 0 if the suspend succeeded.
1390 */
1391static int usb_suspend_both(struct usb_device *udev, pm_message_t msg)
1392{
1393	int			status = 0;
1394	int			i = 0, n = 0;
1395	struct usb_interface	*intf;
1396
1397	if (udev->state == USB_STATE_NOTATTACHED ||
1398			udev->state == USB_STATE_SUSPENDED)
1399		goto done;
1400
1401	/* Suspend all the interfaces and then udev itself */
1402	if (udev->actconfig) {
1403		n = udev->actconfig->desc.bNumInterfaces;
1404		for (i = n - 1; i >= 0; --i) {
1405			intf = udev->actconfig->interface[i];
1406			status = usb_suspend_interface(udev, intf, msg);
1407
1408			/* Ignore errors during system sleep transitions */
1409			if (!PMSG_IS_AUTO(msg))
1410				status = 0;
1411			if (status != 0)
1412				break;
1413		}
1414	}
1415	if (status == 0) {
1416		status = usb_suspend_device(udev, msg);
1417
1418		/*
1419		 * Ignore errors from non-root-hub devices during
1420		 * system sleep transitions.  For the most part,
1421		 * these devices should go to low power anyway when
1422		 * the entire bus is suspended.
1423		 */
1424		if (udev->parent && !PMSG_IS_AUTO(msg))
1425			status = 0;
1426
1427		/*
1428		 * If the device is inaccessible, don't try to resume
1429		 * suspended interfaces and just return the error.
1430		 */
1431		if (status && status != -EBUSY) {
1432			int err;
1433			u16 devstat;
1434
1435			err = usb_get_std_status(udev, USB_RECIP_DEVICE, 0,
1436						 &devstat);
1437			if (err) {
1438				dev_err(&udev->dev,
1439					"Failed to suspend device, error %d\n",
1440					status);
1441				goto done;
1442			}
1443		}
1444	}
1445
1446	/* If the suspend failed, resume interfaces that did get suspended */
1447	if (status != 0) {
1448		if (udev->actconfig) {
1449			msg.event ^= (PM_EVENT_SUSPEND | PM_EVENT_RESUME);
1450			while (++i < n) {
1451				intf = udev->actconfig->interface[i];
1452				usb_resume_interface(udev, intf, msg, 0);
1453			}
1454		}
1455
1456	/* If the suspend succeeded then prevent any more URB submissions
1457	 * and flush any outstanding URBs.
1458	 */
1459	} else {
1460		udev->can_submit = 0;
1461		for (i = 0; i < 16; ++i) {
1462			usb_hcd_flush_endpoint(udev, udev->ep_out[i]);
1463			usb_hcd_flush_endpoint(udev, udev->ep_in[i]);
1464		}
1465	}
1466
1467 done:
1468	dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1469	return status;
1470}
1471
1472/**
1473 * usb_resume_both - resume a USB device and its interfaces
1474 * @udev: the usb_device to resume
1475 * @msg: Power Management message describing this state transition
1476 *
1477 * This is the central routine for resuming USB devices.  It calls the
1478 * the resume method for @udev and then calls the resume methods for all
1479 * the interface drivers in @udev.
1480 *
1481 * Autoresume requests originating from a child device or an interface
1482 * driver may be made without the protection of @udev's device lock, but
1483 * all other resume calls will hold the lock.  Usbcore will insure that
1484 * method calls do not arrive during bind, unbind, or reset operations.
1485 * However drivers must be prepared to handle resume calls arriving at
1486 * unpredictable times.
1487 *
1488 * This routine can run only in process context.
1489 *
1490 * Return: 0 on success.
1491 */
1492static int usb_resume_both(struct usb_device *udev, pm_message_t msg)
1493{
1494	int			status = 0;
1495	int			i;
1496	struct usb_interface	*intf;
1497
1498	if (udev->state == USB_STATE_NOTATTACHED) {
1499		status = -ENODEV;
1500		goto done;
1501	}
1502	udev->can_submit = 1;
1503
1504	/* Resume the device */
1505	if (udev->state == USB_STATE_SUSPENDED || udev->reset_resume)
1506		status = usb_resume_device(udev, msg);
1507
1508	/* Resume the interfaces */
1509	if (status == 0 && udev->actconfig) {
1510		for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
1511			intf = udev->actconfig->interface[i];
1512			usb_resume_interface(udev, intf, msg,
1513					udev->reset_resume);
1514		}
1515	}
1516	usb_mark_last_busy(udev);
1517
1518 done:
1519	dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1520	if (!status)
1521		udev->reset_resume = 0;
1522	return status;
1523}
1524
1525static void choose_wakeup(struct usb_device *udev, pm_message_t msg)
1526{
1527	int	w;
1528
1529	/* Remote wakeup is needed only when we actually go to sleep.
1530	 * For things like FREEZE and QUIESCE, if the device is already
1531	 * autosuspended then its current wakeup setting is okay.
1532	 */
1533	if (msg.event == PM_EVENT_FREEZE || msg.event == PM_EVENT_QUIESCE) {
1534		if (udev->state != USB_STATE_SUSPENDED)
1535			udev->do_remote_wakeup = 0;
1536		return;
1537	}
1538
1539	/* Enable remote wakeup if it is allowed, even if no interface drivers
1540	 * actually want it.
1541	 */
1542	w = device_may_wakeup(&udev->dev);
1543
1544	/* If the device is autosuspended with the wrong wakeup setting,
1545	 * autoresume now so the setting can be changed.
1546	 */
1547	if (udev->state == USB_STATE_SUSPENDED && w != udev->do_remote_wakeup)
1548		pm_runtime_resume(&udev->dev);
1549	udev->do_remote_wakeup = w;
1550}
1551
1552/* The device lock is held by the PM core */
1553int usb_suspend(struct device *dev, pm_message_t msg)
1554{
1555	struct usb_device	*udev = to_usb_device(dev);
1556	int r;
1557
1558	unbind_no_pm_drivers_interfaces(udev);
1559
1560	/* From now on we are sure all drivers support suspend/resume
1561	 * but not necessarily reset_resume()
1562	 * so we may still need to unbind and rebind upon resume
1563	 */
1564	choose_wakeup(udev, msg);
1565	r = usb_suspend_both(udev, msg);
1566	if (r)
1567		return r;
1568
1569	if (udev->quirks & USB_QUIRK_DISCONNECT_SUSPEND)
1570		usb_port_disable(udev);
1571
1572	return 0;
1573}
1574
1575/* The device lock is held by the PM core */
1576int usb_resume_complete(struct device *dev)
1577{
1578	struct usb_device *udev = to_usb_device(dev);
1579
1580	/* For PM complete calls, all we do is rebind interfaces
1581	 * whose needs_binding flag is set
1582	 */
1583	if (udev->state != USB_STATE_NOTATTACHED)
1584		rebind_marked_interfaces(udev);
1585	return 0;
1586}
1587
1588/* The device lock is held by the PM core */
1589int usb_resume(struct device *dev, pm_message_t msg)
1590{
1591	struct usb_device	*udev = to_usb_device(dev);
1592	int			status;
1593
1594	/* For all calls, take the device back to full power and
1595	 * tell the PM core in case it was autosuspended previously.
1596	 * Unbind the interfaces that will need rebinding later,
1597	 * because they fail to support reset_resume.
1598	 * (This can't be done in usb_resume_interface()
1599	 * above because it doesn't own the right set of locks.)
1600	 */
1601	status = usb_resume_both(udev, msg);
1602	if (status == 0) {
1603		pm_runtime_disable(dev);
1604		pm_runtime_set_active(dev);
1605		pm_runtime_enable(dev);
1606		unbind_marked_interfaces(udev);
1607	}
1608
1609	/* Avoid PM error messages for devices disconnected while suspended
1610	 * as we'll display regular disconnect messages just a bit later.
1611	 */
1612	if (status == -ENODEV || status == -ESHUTDOWN)
1613		status = 0;
1614	return status;
1615}
1616
 
 
 
 
1617/**
1618 * usb_enable_autosuspend - allow a USB device to be autosuspended
1619 * @udev: the USB device which may be autosuspended
1620 *
1621 * This routine allows @udev to be autosuspended.  An autosuspend won't
1622 * take place until the autosuspend_delay has elapsed and all the other
1623 * necessary conditions are satisfied.
1624 *
1625 * The caller must hold @udev's device lock.
1626 */
1627void usb_enable_autosuspend(struct usb_device *udev)
1628{
1629	pm_runtime_allow(&udev->dev);
1630}
1631EXPORT_SYMBOL_GPL(usb_enable_autosuspend);
1632
1633/**
1634 * usb_disable_autosuspend - prevent a USB device from being autosuspended
1635 * @udev: the USB device which may not be autosuspended
1636 *
1637 * This routine prevents @udev from being autosuspended and wakes it up
1638 * if it is already autosuspended.
1639 *
1640 * The caller must hold @udev's device lock.
1641 */
1642void usb_disable_autosuspend(struct usb_device *udev)
1643{
1644	pm_runtime_forbid(&udev->dev);
1645}
1646EXPORT_SYMBOL_GPL(usb_disable_autosuspend);
1647
1648/**
1649 * usb_autosuspend_device - delayed autosuspend of a USB device and its interfaces
1650 * @udev: the usb_device to autosuspend
1651 *
1652 * This routine should be called when a core subsystem is finished using
1653 * @udev and wants to allow it to autosuspend.  Examples would be when
1654 * @udev's device file in usbfs is closed or after a configuration change.
1655 *
1656 * @udev's usage counter is decremented; if it drops to 0 and all the
1657 * interfaces are inactive then a delayed autosuspend will be attempted.
1658 * The attempt may fail (see autosuspend_check()).
1659 *
1660 * The caller must hold @udev's device lock.
1661 *
1662 * This routine can run only in process context.
1663 */
1664void usb_autosuspend_device(struct usb_device *udev)
1665{
1666	int	status;
1667
1668	usb_mark_last_busy(udev);
1669	status = pm_runtime_put_sync_autosuspend(&udev->dev);
1670	dev_vdbg(&udev->dev, "%s: cnt %d -> %d\n",
1671			__func__, atomic_read(&udev->dev.power.usage_count),
1672			status);
1673}
1674
1675/**
1676 * usb_autoresume_device - immediately autoresume a USB device and its interfaces
1677 * @udev: the usb_device to autoresume
1678 *
1679 * This routine should be called when a core subsystem wants to use @udev
1680 * and needs to guarantee that it is not suspended.  No autosuspend will
1681 * occur until usb_autosuspend_device() is called.  (Note that this will
1682 * not prevent suspend events originating in the PM core.)  Examples would
1683 * be when @udev's device file in usbfs is opened or when a remote-wakeup
1684 * request is received.
1685 *
1686 * @udev's usage counter is incremented to prevent subsequent autosuspends.
1687 * However if the autoresume fails then the usage counter is re-decremented.
1688 *
1689 * The caller must hold @udev's device lock.
1690 *
1691 * This routine can run only in process context.
1692 *
1693 * Return: 0 on success. A negative error code otherwise.
1694 */
1695int usb_autoresume_device(struct usb_device *udev)
1696{
1697	int	status;
1698
1699	status = pm_runtime_get_sync(&udev->dev);
1700	if (status < 0)
1701		pm_runtime_put_sync(&udev->dev);
1702	dev_vdbg(&udev->dev, "%s: cnt %d -> %d\n",
1703			__func__, atomic_read(&udev->dev.power.usage_count),
1704			status);
1705	if (status > 0)
1706		status = 0;
1707	return status;
1708}
1709
1710/**
1711 * usb_autopm_put_interface - decrement a USB interface's PM-usage counter
1712 * @intf: the usb_interface whose counter should be decremented
1713 *
1714 * This routine should be called by an interface driver when it is
1715 * finished using @intf and wants to allow it to autosuspend.  A typical
1716 * example would be a character-device driver when its device file is
1717 * closed.
1718 *
1719 * The routine decrements @intf's usage counter.  When the counter reaches
1720 * 0, a delayed autosuspend request for @intf's device is attempted.  The
1721 * attempt may fail (see autosuspend_check()).
1722 *
1723 * This routine can run only in process context.
1724 */
1725void usb_autopm_put_interface(struct usb_interface *intf)
1726{
1727	struct usb_device	*udev = interface_to_usbdev(intf);
1728	int			status;
1729
1730	usb_mark_last_busy(udev);
 
1731	status = pm_runtime_put_sync(&intf->dev);
1732	dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1733			__func__, atomic_read(&intf->dev.power.usage_count),
1734			status);
1735}
1736EXPORT_SYMBOL_GPL(usb_autopm_put_interface);
1737
1738/**
1739 * usb_autopm_put_interface_async - decrement a USB interface's PM-usage counter
1740 * @intf: the usb_interface whose counter should be decremented
1741 *
1742 * This routine does much the same thing as usb_autopm_put_interface():
1743 * It decrements @intf's usage counter and schedules a delayed
1744 * autosuspend request if the counter is <= 0.  The difference is that it
1745 * does not perform any synchronization; callers should hold a private
1746 * lock and handle all synchronization issues themselves.
1747 *
1748 * Typically a driver would call this routine during an URB's completion
1749 * handler, if no more URBs were pending.
1750 *
1751 * This routine can run in atomic context.
1752 */
1753void usb_autopm_put_interface_async(struct usb_interface *intf)
1754{
1755	struct usb_device	*udev = interface_to_usbdev(intf);
1756	int			status;
1757
1758	usb_mark_last_busy(udev);
 
1759	status = pm_runtime_put(&intf->dev);
1760	dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1761			__func__, atomic_read(&intf->dev.power.usage_count),
1762			status);
1763}
1764EXPORT_SYMBOL_GPL(usb_autopm_put_interface_async);
1765
1766/**
1767 * usb_autopm_put_interface_no_suspend - decrement a USB interface's PM-usage counter
1768 * @intf: the usb_interface whose counter should be decremented
1769 *
1770 * This routine decrements @intf's usage counter but does not carry out an
1771 * autosuspend.
1772 *
1773 * This routine can run in atomic context.
1774 */
1775void usb_autopm_put_interface_no_suspend(struct usb_interface *intf)
1776{
1777	struct usb_device	*udev = interface_to_usbdev(intf);
1778
1779	usb_mark_last_busy(udev);
 
1780	pm_runtime_put_noidle(&intf->dev);
1781}
1782EXPORT_SYMBOL_GPL(usb_autopm_put_interface_no_suspend);
1783
1784/**
1785 * usb_autopm_get_interface - increment a USB interface's PM-usage counter
1786 * @intf: the usb_interface whose counter should be incremented
1787 *
1788 * This routine should be called by an interface driver when it wants to
1789 * use @intf and needs to guarantee that it is not suspended.  In addition,
1790 * the routine prevents @intf from being autosuspended subsequently.  (Note
1791 * that this will not prevent suspend events originating in the PM core.)
1792 * This prevention will persist until usb_autopm_put_interface() is called
1793 * or @intf is unbound.  A typical example would be a character-device
1794 * driver when its device file is opened.
1795 *
1796 * @intf's usage counter is incremented to prevent subsequent autosuspends.
1797 * However if the autoresume fails then the counter is re-decremented.
1798 *
1799 * This routine can run only in process context.
1800 *
1801 * Return: 0 on success.
1802 */
1803int usb_autopm_get_interface(struct usb_interface *intf)
1804{
1805	int	status;
1806
1807	status = pm_runtime_get_sync(&intf->dev);
1808	if (status < 0)
1809		pm_runtime_put_sync(&intf->dev);
 
 
1810	dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1811			__func__, atomic_read(&intf->dev.power.usage_count),
1812			status);
1813	if (status > 0)
1814		status = 0;
1815	return status;
1816}
1817EXPORT_SYMBOL_GPL(usb_autopm_get_interface);
1818
1819/**
1820 * usb_autopm_get_interface_async - increment a USB interface's PM-usage counter
1821 * @intf: the usb_interface whose counter should be incremented
1822 *
1823 * This routine does much the same thing as
1824 * usb_autopm_get_interface(): It increments @intf's usage counter and
1825 * queues an autoresume request if the device is suspended.  The
1826 * differences are that it does not perform any synchronization (callers
1827 * should hold a private lock and handle all synchronization issues
1828 * themselves), and it does not autoresume the device directly (it only
1829 * queues a request).  After a successful call, the device may not yet be
1830 * resumed.
1831 *
1832 * This routine can run in atomic context.
1833 *
1834 * Return: 0 on success. A negative error code otherwise.
1835 */
1836int usb_autopm_get_interface_async(struct usb_interface *intf)
1837{
1838	int	status;
1839
1840	status = pm_runtime_get(&intf->dev);
1841	if (status < 0 && status != -EINPROGRESS)
1842		pm_runtime_put_noidle(&intf->dev);
 
 
1843	dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1844			__func__, atomic_read(&intf->dev.power.usage_count),
1845			status);
1846	if (status > 0 || status == -EINPROGRESS)
1847		status = 0;
1848	return status;
1849}
1850EXPORT_SYMBOL_GPL(usb_autopm_get_interface_async);
1851
1852/**
1853 * usb_autopm_get_interface_no_resume - increment a USB interface's PM-usage counter
1854 * @intf: the usb_interface whose counter should be incremented
1855 *
1856 * This routine increments @intf's usage counter but does not carry out an
1857 * autoresume.
1858 *
1859 * This routine can run in atomic context.
1860 */
1861void usb_autopm_get_interface_no_resume(struct usb_interface *intf)
1862{
1863	struct usb_device	*udev = interface_to_usbdev(intf);
1864
1865	usb_mark_last_busy(udev);
 
1866	pm_runtime_get_noresume(&intf->dev);
1867}
1868EXPORT_SYMBOL_GPL(usb_autopm_get_interface_no_resume);
1869
1870/* Internal routine to check whether we may autosuspend a device. */
1871static int autosuspend_check(struct usb_device *udev)
1872{
1873	int			w, i;
1874	struct usb_interface	*intf;
1875
1876	if (udev->state == USB_STATE_NOTATTACHED)
1877		return -ENODEV;
1878
1879	/* Fail if autosuspend is disabled, or any interfaces are in use, or
1880	 * any interface drivers require remote wakeup but it isn't available.
1881	 */
1882	w = 0;
1883	if (udev->actconfig) {
1884		for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
1885			intf = udev->actconfig->interface[i];
1886
1887			/* We don't need to check interfaces that are
1888			 * disabled for runtime PM.  Either they are unbound
1889			 * or else their drivers don't support autosuspend
1890			 * and so they are permanently active.
1891			 */
1892			if (intf->dev.power.disable_depth)
1893				continue;
1894			if (atomic_read(&intf->dev.power.usage_count) > 0)
1895				return -EBUSY;
1896			w |= intf->needs_remote_wakeup;
1897
1898			/* Don't allow autosuspend if the device will need
1899			 * a reset-resume and any of its interface drivers
1900			 * doesn't include support or needs remote wakeup.
1901			 */
1902			if (udev->quirks & USB_QUIRK_RESET_RESUME) {
1903				struct usb_driver *driver;
1904
1905				driver = to_usb_driver(intf->dev.driver);
1906				if (!driver->reset_resume ||
1907						intf->needs_remote_wakeup)
1908					return -EOPNOTSUPP;
1909			}
1910		}
1911	}
1912	if (w && !device_can_wakeup(&udev->dev)) {
1913		dev_dbg(&udev->dev, "remote wakeup needed for autosuspend\n");
1914		return -EOPNOTSUPP;
1915	}
1916
1917	/*
1918	 * If the device is a direct child of the root hub and the HCD
1919	 * doesn't handle wakeup requests, don't allow autosuspend when
1920	 * wakeup is needed.
1921	 */
1922	if (w && udev->parent == udev->bus->root_hub &&
1923			bus_to_hcd(udev->bus)->cant_recv_wakeups) {
1924		dev_dbg(&udev->dev, "HCD doesn't handle wakeup requests\n");
1925		return -EOPNOTSUPP;
1926	}
1927
1928	udev->do_remote_wakeup = w;
1929	return 0;
1930}
1931
1932int usb_runtime_suspend(struct device *dev)
1933{
1934	struct usb_device	*udev = to_usb_device(dev);
1935	int			status;
1936
1937	/* A USB device can be suspended if it passes the various autosuspend
1938	 * checks.  Runtime suspend for a USB device means suspending all the
1939	 * interfaces and then the device itself.
1940	 */
1941	if (autosuspend_check(udev) != 0)
1942		return -EAGAIN;
1943
1944	status = usb_suspend_both(udev, PMSG_AUTO_SUSPEND);
1945
1946	/* Allow a retry if autosuspend failed temporarily */
1947	if (status == -EAGAIN || status == -EBUSY)
1948		usb_mark_last_busy(udev);
1949
1950	/*
1951	 * The PM core reacts badly unless the return code is 0,
1952	 * -EAGAIN, or -EBUSY, so always return -EBUSY on an error
1953	 * (except for root hubs, because they don't suspend through
1954	 * an upstream port like other USB devices).
1955	 */
1956	if (status != 0 && udev->parent)
1957		return -EBUSY;
1958	return status;
1959}
1960
1961int usb_runtime_resume(struct device *dev)
1962{
1963	struct usb_device	*udev = to_usb_device(dev);
1964	int			status;
1965
1966	/* Runtime resume for a USB device means resuming both the device
1967	 * and all its interfaces.
1968	 */
1969	status = usb_resume_both(udev, PMSG_AUTO_RESUME);
1970	return status;
1971}
1972
1973int usb_runtime_idle(struct device *dev)
1974{
1975	struct usb_device	*udev = to_usb_device(dev);
1976
1977	/* An idle USB device can be suspended if it passes the various
1978	 * autosuspend checks.
1979	 */
1980	if (autosuspend_check(udev) == 0)
1981		pm_runtime_autosuspend(dev);
1982	/* Tell the core not to suspend it, though. */
1983	return -EBUSY;
1984}
1985
1986static int usb_set_usb2_hardware_lpm(struct usb_device *udev, int enable)
1987{
1988	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
1989	int ret = -EPERM;
1990
1991	if (hcd->driver->set_usb2_hw_lpm) {
1992		ret = hcd->driver->set_usb2_hw_lpm(hcd, udev, enable);
1993		if (!ret)
1994			udev->usb2_hw_lpm_enabled = enable;
1995	}
1996
1997	return ret;
1998}
1999
2000int usb_enable_usb2_hardware_lpm(struct usb_device *udev)
2001{
2002	if (!udev->usb2_hw_lpm_capable ||
2003	    !udev->usb2_hw_lpm_allowed ||
2004	    udev->usb2_hw_lpm_enabled)
2005		return 0;
2006
2007	return usb_set_usb2_hardware_lpm(udev, 1);
2008}
2009
2010int usb_disable_usb2_hardware_lpm(struct usb_device *udev)
2011{
2012	if (!udev->usb2_hw_lpm_enabled)
2013		return 0;
2014
2015	return usb_set_usb2_hardware_lpm(udev, 0);
2016}
2017
2018#endif /* CONFIG_PM */
2019
2020struct bus_type usb_bus_type = {
2021	.name =		"usb",
2022	.match =	usb_device_match,
2023	.uevent =	usb_uevent,
2024	.need_parent_lock =	true,
2025};