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	mutex_lock(&usb_dynids_lock);
  99	list_add_tail(&dynid->node, &dynids->list);
 100	mutex_unlock(&usb_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	guard(mutex)(&usb_dynids_lock);
 120	list_for_each_entry(dynid, &dynids->list, node)
 121		if (dynid->id.bInterfaceClass != 0)
 122			count += scnprintf(&buf[count], PAGE_SIZE - count, "%04x %04x %02x\n",
 123					   dynid->id.idVendor, dynid->id.idProduct,
 124					   dynid->id.bInterfaceClass);
 125		else
 126			count += scnprintf(&buf[count], PAGE_SIZE - count, "%04x %04x\n",
 127					   dynid->id.idVendor, dynid->id.idProduct);
 128	return count;
 129}
 130EXPORT_SYMBOL_GPL(usb_show_dynids);
 131
 132static ssize_t new_id_show(struct device_driver *driver, char *buf)
 133{
 134	struct usb_driver *usb_drv = to_usb_driver(driver);
 135
 136	return usb_show_dynids(&usb_drv->dynids, buf);
 137}
 138
 139static ssize_t new_id_store(struct device_driver *driver,
 140			    const char *buf, size_t count)
 141{
 142	struct usb_driver *usb_drv = to_usb_driver(driver);
 143
 144	return usb_store_new_id(&usb_drv->dynids, usb_drv->id_table, driver, buf, count);
 145}
 146static DRIVER_ATTR_RW(new_id);
 147
 148/*
 149 * Remove a USB device ID from this driver
 
 
 
 
 
 150 */
 151static ssize_t remove_id_store(struct device_driver *driver, const char *buf,
 152			       size_t count)
 153{
 154	struct usb_dynid *dynid, *n;
 155	struct usb_driver *usb_driver = to_usb_driver(driver);
 156	u32 idVendor;
 157	u32 idProduct;
 158	int fields;
 
 159
 160	fields = sscanf(buf, "%x %x", &idVendor, &idProduct);
 161	if (fields < 2)
 162		return -EINVAL;
 163
 164	guard(mutex)(&usb_dynids_lock);
 165	list_for_each_entry_safe(dynid, n, &usb_driver->dynids.list, node) {
 166		struct usb_device_id *id = &dynid->id;
 167
 168		if ((id->idVendor == idVendor) &&
 169		    (id->idProduct == idProduct)) {
 170			list_del(&dynid->node);
 171			kfree(dynid);
 
 172			break;
 173		}
 174	}
 175	return count;
 176}
 177
 178static ssize_t remove_id_show(struct device_driver *driver, char *buf)
 179{
 180	return new_id_show(driver, buf);
 181}
 182static DRIVER_ATTR_RW(remove_id);
 183
 184static int usb_create_newid_files(struct usb_driver *usb_drv)
 185{
 186	int error = 0;
 187
 188	if (usb_drv->no_dynamic_id)
 189		goto exit;
 190
 191	if (usb_drv->probe != NULL) {
 192		error = driver_create_file(&usb_drv->driver,
 193					   &driver_attr_new_id);
 194		if (error == 0) {
 195			error = driver_create_file(&usb_drv->driver,
 196					&driver_attr_remove_id);
 197			if (error)
 198				driver_remove_file(&usb_drv->driver,
 199						&driver_attr_new_id);
 200		}
 201	}
 202exit:
 203	return error;
 204}
 205
 206static void usb_remove_newid_files(struct usb_driver *usb_drv)
 207{
 208	if (usb_drv->no_dynamic_id)
 209		return;
 210
 211	if (usb_drv->probe != NULL) {
 212		driver_remove_file(&usb_drv->driver,
 213				&driver_attr_remove_id);
 214		driver_remove_file(&usb_drv->driver,
 215				   &driver_attr_new_id);
 216	}
 217}
 218
 219static void usb_free_dynids(struct usb_driver *usb_drv)
 220{
 221	struct usb_dynid *dynid, *n;
 222
 223	guard(mutex)(&usb_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}
 229
 
 
 
 
 
 230static const struct usb_device_id *usb_match_dynamic_id(struct usb_interface *intf,
 231							const struct usb_driver *drv)
 232{
 233	struct usb_dynid *dynid;
 234
 235	guard(mutex)(&usb_dynids_lock);
 236	list_for_each_entry(dynid, &drv->dynids.list, node) {
 237		if (usb_match_one_id(intf, &dynid->id)) {
 
 238			return &dynid->id;
 239		}
 240	}
 
 241	return NULL;
 242}
 243
 244
 245/* called from driver core with dev locked */
 246static int usb_probe_device(struct device *dev)
 247{
 248	struct usb_device_driver *udriver = to_usb_device_driver(dev->driver);
 249	struct usb_device *udev = to_usb_device(dev);
 250	int error = 0;
 251
 252	dev_dbg(dev, "%s\n", __func__);
 253
 254	/* TODO: Add real matching code */
 255
 256	/* The device should always appear to be in use
 257	 * unless the driver supports autosuspend.
 258	 */
 259	if (!udriver->supports_autosuspend)
 260		error = usb_autoresume_device(udev);
 261	if (error)
 262		return error;
 263
 264	if (udriver->generic_subclass)
 265		error = usb_generic_driver_probe(udev);
 266	if (error)
 267		return error;
 268
 269	/* Probe the USB device with the driver in hand, but only
 270	 * defer to a generic driver in case the current USB
 271	 * device driver has an id_table or a match function; i.e.,
 272	 * when the device driver was explicitly matched against
 273	 * a device.
 274	 *
 275	 * If the device driver does not have either of these,
 276	 * then we assume that it can bind to any device and is
 277	 * not truly a more specialized/non-generic driver, so a
 278	 * return value of -ENODEV should not force the device
 279	 * to be handled by the generic USB driver, as there
 280	 * can still be another, more specialized, device driver.
 281	 *
 282	 * This accommodates the usbip driver.
 283	 *
 284	 * TODO: What if, in the future, there are multiple
 285	 * specialized USB device drivers for a particular device?
 286	 * In such cases, there is a need to try all matching
 287	 * specialised device drivers prior to setting the
 288	 * use_generic_driver bit.
 289	 */
 290	if (udriver->probe)
 291		error = udriver->probe(udev);
 292	else if (!udriver->generic_subclass)
 293		error = -EINVAL;
 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
 517static void usb_shutdown_interface(struct device *dev)
 518{
 519	struct usb_interface *intf = to_usb_interface(dev);
 520	struct usb_driver *driver;
 521
 522	if (!dev->driver)
 523		return;
 524
 525	driver = to_usb_driver(dev->driver);
 526	if (driver->shutdown)
 527		driver->shutdown(intf);
 528}
 529
 530/**
 531 * usb_driver_claim_interface - bind a driver to an interface
 532 * @driver: the driver to be bound
 533 * @iface: the interface to which it will be bound; must be in the
 534 *	usb device's active configuration
 535 * @data: driver data associated with that interface
 536 *
 537 * This is used by usb device drivers that need to claim more than one
 538 * interface on a device when probing (audio and acm are current examples).
 539 * No device driver should directly modify internal usb_interface or
 540 * usb_device structure members.
 541 *
 
 
 
 
 542 * Callers must own the device lock, so driver probe() entries don't need
 543 * extra locking, but other call contexts may need to explicitly claim that
 544 * lock.
 545 *
 546 * Return: 0 on success.
 547 */
 548int usb_driver_claim_interface(struct usb_driver *driver,
 549				struct usb_interface *iface, void *data)
 550{
 551	struct device *dev;
 
 552	int retval = 0;
 
 553
 554	if (!iface)
 555		return -ENODEV;
 556
 557	dev = &iface->dev;
 558	if (dev->driver)
 559		return -EBUSY;
 560
 561	/* reject claim if interface is not authorized */
 562	if (!iface->authorized)
 563		return -ENODEV;
 564
 565	dev->driver = &driver->driver;
 566	usb_set_intfdata(iface, data);
 567	iface->needs_binding = 0;
 568
 569	iface->condition = USB_INTERFACE_BOUND;
 570
 
 
 
 
 
 
 
 
 571	/* Claimed interfaces are initially inactive (suspended) and
 572	 * runtime-PM-enabled, but only if the driver has autosuspend
 573	 * support.  Otherwise they are marked active, to prevent the
 574	 * device from being autosuspended, but left disabled.  In either
 575	 * case they are sensitive to their children's power states.
 576	 */
 577	pm_suspend_ignore_children(dev, false);
 578	if (driver->supports_autosuspend)
 579		pm_runtime_enable(dev);
 580	else
 581		pm_runtime_set_active(dev);
 582
 583	/* if interface was already added, bind now; else let
 584	 * the future device_add() bind it, bypassing probe()
 585	 */
 586	if (device_is_registered(dev))
 587		retval = device_bind_driver(dev);
 588
 589	if (retval) {
 590		dev->driver = NULL;
 591		usb_set_intfdata(iface, NULL);
 592		iface->needs_remote_wakeup = 0;
 593		iface->condition = USB_INTERFACE_UNBOUND;
 594
 595		/*
 596		 * Unbound interfaces are always runtime-PM-disabled
 597		 * and runtime-PM-suspended
 598		 */
 599		if (driver->supports_autosuspend)
 600			pm_runtime_disable(dev);
 601		pm_runtime_set_suspended(dev);
 602	}
 603
 604	return retval;
 605}
 606EXPORT_SYMBOL_GPL(usb_driver_claim_interface);
 607
 608/**
 609 * usb_driver_release_interface - unbind a driver from an interface
 610 * @driver: the driver to be unbound
 611 * @iface: the interface from which it will be unbound
 612 *
 613 * This can be used by drivers to release an interface without waiting
 614 * for their disconnect() methods to be called.  In typical cases this
 615 * also causes the driver disconnect() method to be called.
 616 *
 617 * This call is synchronous, and may not be used in an interrupt context.
 618 * Callers must own the device lock, so driver disconnect() entries don't
 619 * need extra locking, but other call contexts may need to explicitly claim
 620 * that lock.
 621 */
 622void usb_driver_release_interface(struct usb_driver *driver,
 623					struct usb_interface *iface)
 624{
 625	struct device *dev = &iface->dev;
 626
 627	/* this should never happen, don't release something that's not ours */
 628	if (!dev->driver || dev->driver != &driver->driver)
 629		return;
 630
 631	/* don't release from within disconnect() */
 632	if (iface->condition != USB_INTERFACE_BOUND)
 633		return;
 634	iface->condition = USB_INTERFACE_UNBINDING;
 635
 636	/* Release via the driver core only if the interface
 637	 * has already been registered
 638	 */
 639	if (device_is_registered(dev)) {
 640		device_release_driver(dev);
 641	} else {
 642		device_lock(dev);
 643		usb_unbind_interface(dev);
 644		dev->driver = NULL;
 645		device_unlock(dev);
 646	}
 647}
 648EXPORT_SYMBOL_GPL(usb_driver_release_interface);
 649
 650/* returns 0 if no match, 1 if match */
 651int usb_match_device(struct usb_device *dev, const struct usb_device_id *id)
 652{
 653	if ((id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
 654	    id->idVendor != le16_to_cpu(dev->descriptor.idVendor))
 655		return 0;
 656
 657	if ((id->match_flags & USB_DEVICE_ID_MATCH_PRODUCT) &&
 658	    id->idProduct != le16_to_cpu(dev->descriptor.idProduct))
 659		return 0;
 660
 661	/* No need to test id->bcdDevice_lo != 0, since 0 is never
 662	   greater than any unsigned number. */
 663	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_LO) &&
 664	    (id->bcdDevice_lo > le16_to_cpu(dev->descriptor.bcdDevice)))
 665		return 0;
 666
 667	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_HI) &&
 668	    (id->bcdDevice_hi < le16_to_cpu(dev->descriptor.bcdDevice)))
 669		return 0;
 670
 671	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_CLASS) &&
 672	    (id->bDeviceClass != dev->descriptor.bDeviceClass))
 673		return 0;
 674
 675	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_SUBCLASS) &&
 676	    (id->bDeviceSubClass != dev->descriptor.bDeviceSubClass))
 677		return 0;
 678
 679	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_PROTOCOL) &&
 680	    (id->bDeviceProtocol != dev->descriptor.bDeviceProtocol))
 681		return 0;
 682
 683	return 1;
 684}
 685
 686/* returns 0 if no match, 1 if match */
 687int usb_match_one_id_intf(struct usb_device *dev,
 688			  struct usb_host_interface *intf,
 689			  const struct usb_device_id *id)
 690{
 691	/* The interface class, subclass, protocol and number should never be
 
 
 
 
 
 
 
 
 
 
 
 
 
 692	 * checked for a match if the device class is Vendor Specific,
 693	 * unless the match record specifies the Vendor ID. */
 694	if (dev->descriptor.bDeviceClass == USB_CLASS_VENDOR_SPEC &&
 695			!(id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
 696			(id->match_flags & (USB_DEVICE_ID_MATCH_INT_CLASS |
 697				USB_DEVICE_ID_MATCH_INT_SUBCLASS |
 698				USB_DEVICE_ID_MATCH_INT_PROTOCOL |
 699				USB_DEVICE_ID_MATCH_INT_NUMBER)))
 700		return 0;
 701
 702	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_CLASS) &&
 703	    (id->bInterfaceClass != intf->desc.bInterfaceClass))
 704		return 0;
 705
 706	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_SUBCLASS) &&
 707	    (id->bInterfaceSubClass != intf->desc.bInterfaceSubClass))
 708		return 0;
 709
 710	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_PROTOCOL) &&
 711	    (id->bInterfaceProtocol != intf->desc.bInterfaceProtocol))
 712		return 0;
 713
 714	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_NUMBER) &&
 715	    (id->bInterfaceNumber != intf->desc.bInterfaceNumber))
 716		return 0;
 717
 718	return 1;
 719}
 720
 721/* returns 0 if no match, 1 if match */
 722int usb_match_one_id(struct usb_interface *interface,
 723		     const struct usb_device_id *id)
 724{
 725	struct usb_host_interface *intf;
 726	struct usb_device *dev;
 727
 728	/* proc_connectinfo in devio.c may call us with id == NULL. */
 729	if (id == NULL)
 730		return 0;
 731
 732	intf = interface->cur_altsetting;
 733	dev = interface_to_usbdev(interface);
 734
 735	if (!usb_match_device(dev, id))
 736		return 0;
 737
 738	return usb_match_one_id_intf(dev, intf, id);
 739}
 740EXPORT_SYMBOL_GPL(usb_match_one_id);
 741
 742/**
 743 * usb_match_id - find first usb_device_id matching device or interface
 744 * @interface: the interface of interest
 745 * @id: array of usb_device_id structures, terminated by zero entry
 746 *
 747 * usb_match_id searches an array of usb_device_id's and returns
 748 * the first one matching the device or interface, or null.
 749 * This is used when binding (or rebinding) a driver to an interface.
 750 * Most USB device drivers will use this indirectly, through the usb core,
 751 * but some layered driver frameworks use it directly.
 752 * These device tables are exported with MODULE_DEVICE_TABLE, through
 753 * modutils, to support the driver loading functionality of USB hotplugging.
 754 *
 755 * Return: The first matching usb_device_id, or %NULL.
 756 *
 757 * What Matches:
 758 *
 759 * The "match_flags" element in a usb_device_id controls which
 760 * members are used.  If the corresponding bit is set, the
 761 * value in the device_id must match its corresponding member
 762 * in the device or interface descriptor, or else the device_id
 763 * does not match.
 764 *
 765 * "driver_info" is normally used only by device drivers,
 766 * but you can create a wildcard "matches anything" usb_device_id
 767 * as a driver's "modules.usbmap" entry if you provide an id with
 768 * only a nonzero "driver_info" field.  If you do this, the USB device
 769 * driver's probe() routine should use additional intelligence to
 770 * decide whether to bind to the specified interface.
 771 *
 772 * What Makes Good usb_device_id Tables:
 773 *
 774 * The match algorithm is very simple, so that intelligence in
 775 * driver selection must come from smart driver id records.
 776 * Unless you have good reasons to use another selection policy,
 777 * provide match elements only in related groups, and order match
 778 * specifiers from specific to general.  Use the macros provided
 779 * for that purpose if you can.
 780 *
 781 * The most specific match specifiers use device descriptor
 782 * data.  These are commonly used with product-specific matches;
 783 * the USB_DEVICE macro lets you provide vendor and product IDs,
 784 * and you can also match against ranges of product revisions.
 785 * These are widely used for devices with application or vendor
 786 * specific bDeviceClass values.
 787 *
 788 * Matches based on device class/subclass/protocol specifications
 789 * are slightly more general; use the USB_DEVICE_INFO macro, or
 790 * its siblings.  These are used with single-function devices
 791 * where bDeviceClass doesn't specify that each interface has
 792 * its own class.
 793 *
 794 * Matches based on interface class/subclass/protocol are the
 795 * most general; they let drivers bind to any interface on a
 796 * multiple-function device.  Use the USB_INTERFACE_INFO
 797 * macro, or its siblings, to match class-per-interface style
 798 * devices (as recorded in bInterfaceClass).
 799 *
 800 * Note that an entry created by USB_INTERFACE_INFO won't match
 801 * any interface if the device class is set to Vendor-Specific.
 802 * This is deliberate; according to the USB spec the meanings of
 803 * the interface class/subclass/protocol for these devices are also
 804 * vendor-specific, and hence matching against a standard product
 805 * class wouldn't work anyway.  If you really want to use an
 806 * interface-based match for such a device, create a match record
 807 * that also specifies the vendor ID.  (Unforunately there isn't a
 808 * standard macro for creating records like this.)
 809 *
 810 * Within those groups, remember that not all combinations are
 811 * meaningful.  For example, don't give a product version range
 812 * without vendor and product IDs; or specify a protocol without
 813 * its associated class and subclass.
 814 */
 815const struct usb_device_id *usb_match_id(struct usb_interface *interface,
 816					 const struct usb_device_id *id)
 817{
 818	/* proc_connectinfo in devio.c may call us with id == NULL. */
 819	if (id == NULL)
 820		return NULL;
 821
 822	/* It is important to check that id->driver_info is nonzero,
 823	   since an entry that is all zeroes except for a nonzero
 824	   id->driver_info is the way to create an entry that
 825	   indicates that the driver want to examine every
 826	   device and interface. */
 827	for (; id->idVendor || id->idProduct || id->bDeviceClass ||
 828	       id->bInterfaceClass || id->driver_info; id++) {
 829		if (usb_match_one_id(interface, id))
 830			return id;
 831	}
 832
 833	return NULL;
 834}
 835EXPORT_SYMBOL_GPL(usb_match_id);
 836
 837const struct usb_device_id *usb_device_match_id(struct usb_device *udev,
 838				const struct usb_device_id *id)
 839{
 840	if (!id)
 841		return NULL;
 842
 843	for (; id->idVendor || id->idProduct ; id++) {
 844		if (usb_match_device(udev, id))
 845			return id;
 846	}
 847
 848	return NULL;
 849}
 850EXPORT_SYMBOL_GPL(usb_device_match_id);
 851
 852bool usb_driver_applicable(struct usb_device *udev,
 853			   const struct usb_device_driver *udrv)
 854{
 855	if (udrv->id_table && udrv->match)
 856		return usb_device_match_id(udev, udrv->id_table) != NULL &&
 857		       udrv->match(udev);
 858
 859	if (udrv->id_table)
 860		return usb_device_match_id(udev, udrv->id_table) != NULL;
 861
 862	if (udrv->match)
 863		return udrv->match(udev);
 864
 865	return false;
 866}
 867
 868static int usb_device_match(struct device *dev, const struct device_driver *drv)
 869{
 870	/* devices and interfaces are handled separately */
 871	if (is_usb_device(dev)) {
 872		struct usb_device *udev;
 873		const struct usb_device_driver *udrv;
 874
 875		/* interface drivers never match devices */
 876		if (!is_usb_device_driver(drv))
 877			return 0;
 878
 879		udev = to_usb_device(dev);
 880		udrv = to_usb_device_driver(drv);
 881
 882		/* If the device driver under consideration does not have a
 883		 * id_table or a match function, then let the driver's probe
 884		 * function decide.
 885		 */
 886		if (!udrv->id_table && !udrv->match)
 887			return 1;
 888
 889		return usb_driver_applicable(udev, udrv);
 890
 891	} else if (is_usb_interface(dev)) {
 892		struct usb_interface *intf;
 893		const struct usb_driver *usb_drv;
 894		const struct usb_device_id *id;
 895
 896		/* device drivers never match interfaces */
 897		if (is_usb_device_driver(drv))
 898			return 0;
 899
 900		intf = to_usb_interface(dev);
 901		usb_drv = to_usb_driver(drv);
 902
 903		id = usb_match_id(intf, usb_drv->id_table);
 904		if (id)
 905			return 1;
 906
 907		id = usb_match_dynamic_id(intf, usb_drv);
 908		if (id)
 909			return 1;
 910	}
 911
 912	return 0;
 913}
 914
 915static int usb_uevent(const struct device *dev, struct kobj_uevent_env *env)
 
 916{
 917	const struct usb_device *usb_dev;
 918
 919	if (is_usb_device(dev)) {
 920		usb_dev = to_usb_device(dev);
 921	} else if (is_usb_interface(dev)) {
 922		const struct usb_interface *intf = to_usb_interface(dev);
 923
 924		usb_dev = interface_to_usbdev(intf);
 925	} else {
 926		return 0;
 927	}
 928
 929	if (usb_dev->devnum < 0) {
 930		/* driver is often null here; dev_dbg() would oops */
 931		pr_debug("usb %s: already deleted?\n", dev_name(dev));
 932		return -ENODEV;
 933	}
 934	if (!usb_dev->bus) {
 935		pr_debug("usb %s: bus removed?\n", dev_name(dev));
 936		return -ENODEV;
 937	}
 938
 939	/* per-device configurations are common */
 940	if (add_uevent_var(env, "PRODUCT=%x/%x/%x",
 941			   le16_to_cpu(usb_dev->descriptor.idVendor),
 942			   le16_to_cpu(usb_dev->descriptor.idProduct),
 943			   le16_to_cpu(usb_dev->descriptor.bcdDevice)))
 944		return -ENOMEM;
 945
 946	/* class-based driver binding models */
 947	if (add_uevent_var(env, "TYPE=%d/%d/%d",
 948			   usb_dev->descriptor.bDeviceClass,
 949			   usb_dev->descriptor.bDeviceSubClass,
 950			   usb_dev->descriptor.bDeviceProtocol))
 951		return -ENOMEM;
 952
 953	return 0;
 954}
 955
 956static int __usb_bus_reprobe_drivers(struct device *dev, void *data)
 957{
 958	struct usb_device_driver *new_udriver = data;
 959	struct usb_device *udev;
 960	int ret;
 961
 962	/* Don't reprobe if current driver isn't usb_generic_driver */
 963	if (dev->driver != &usb_generic_driver.driver)
 964		return 0;
 965
 966	udev = to_usb_device(dev);
 967	if (!usb_driver_applicable(udev, new_udriver))
 968		return 0;
 969
 970	ret = device_reprobe(dev);
 971	if (ret && ret != -EPROBE_DEFER)
 972		dev_err(dev, "Failed to reprobe device (error %d)\n", ret);
 973
 974	return 0;
 975}
 976
 977bool is_usb_device_driver(const struct device_driver *drv)
 978{
 979	return drv->probe == usb_probe_device;
 980}
 
 981
 982/**
 983 * usb_register_device_driver - register a USB device (not interface) driver
 984 * @new_udriver: USB operations for the device driver
 985 * @owner: module owner of this driver.
 986 *
 987 * Registers a USB device driver with the USB core.  The list of
 988 * unattached devices will be rescanned whenever a new driver is
 989 * added, allowing the new driver to attach to any recognized devices.
 990 *
 991 * Return: A negative error code on failure and 0 on success.
 992 */
 993int usb_register_device_driver(struct usb_device_driver *new_udriver,
 994		struct module *owner)
 995{
 996	int retval = 0;
 997
 998	if (usb_disabled())
 999		return -ENODEV;
1000
1001	new_udriver->driver.name = new_udriver->name;
1002	new_udriver->driver.bus = &usb_bus_type;
1003	new_udriver->driver.probe = usb_probe_device;
1004	new_udriver->driver.remove = usb_unbind_device;
1005	new_udriver->driver.owner = owner;
1006	new_udriver->driver.dev_groups = new_udriver->dev_groups;
1007
1008	retval = driver_register(&new_udriver->driver);
1009
1010	if (!retval) {
1011		pr_info("%s: registered new device driver %s\n",
1012			usbcore_name, new_udriver->name);
1013		/*
1014		 * Check whether any device could be better served with
1015		 * this new driver
1016		 */
1017		bus_for_each_dev(&usb_bus_type, NULL, new_udriver,
1018				 __usb_bus_reprobe_drivers);
1019	} else {
1020		pr_err("%s: error %d registering device driver %s\n",
1021			usbcore_name, retval, new_udriver->name);
1022	}
1023
1024	return retval;
1025}
1026EXPORT_SYMBOL_GPL(usb_register_device_driver);
1027
1028/**
1029 * usb_deregister_device_driver - unregister a USB device (not interface) driver
1030 * @udriver: USB operations of the device driver to unregister
1031 * Context: must be able to sleep
1032 *
1033 * Unlinks the specified driver from the internal USB driver list.
1034 */
1035void usb_deregister_device_driver(struct usb_device_driver *udriver)
1036{
1037	pr_info("%s: deregistering device driver %s\n",
1038			usbcore_name, udriver->name);
1039
1040	driver_unregister(&udriver->driver);
1041}
1042EXPORT_SYMBOL_GPL(usb_deregister_device_driver);
1043
1044/**
1045 * usb_register_driver - register a USB interface driver
1046 * @new_driver: USB operations for the interface driver
1047 * @owner: module owner of this driver.
1048 * @mod_name: module name string
1049 *
1050 * Registers a USB interface driver with the USB core.  The list of
1051 * unattached interfaces will be rescanned whenever a new driver is
1052 * added, allowing the new driver to attach to any recognized interfaces.
1053 *
1054 * Return: A negative error code on failure and 0 on success.
1055 *
1056 * NOTE: if you want your driver to use the USB major number, you must call
1057 * usb_register_dev() to enable that functionality.  This function no longer
1058 * takes care of that.
1059 */
1060int usb_register_driver(struct usb_driver *new_driver, struct module *owner,
1061			const char *mod_name)
1062{
1063	int retval = 0;
1064
1065	if (usb_disabled())
1066		return -ENODEV;
1067
1068	new_driver->driver.name = new_driver->name;
1069	new_driver->driver.bus = &usb_bus_type;
1070	new_driver->driver.probe = usb_probe_interface;
1071	new_driver->driver.remove = usb_unbind_interface;
1072	new_driver->driver.shutdown = usb_shutdown_interface;
1073	new_driver->driver.owner = owner;
1074	new_driver->driver.mod_name = mod_name;
1075	new_driver->driver.dev_groups = new_driver->dev_groups;
1076	INIT_LIST_HEAD(&new_driver->dynids.list);
1077
1078	retval = driver_register(&new_driver->driver);
1079	if (retval)
1080		goto out;
1081
1082	retval = usb_create_newid_files(new_driver);
1083	if (retval)
1084		goto out_newid;
1085
1086	pr_info("%s: registered new interface driver %s\n",
1087			usbcore_name, new_driver->name);
1088
1089out:
1090	return retval;
1091
1092out_newid:
1093	driver_unregister(&new_driver->driver);
1094
1095	pr_err("%s: error %d registering interface driver %s\n",
1096		usbcore_name, retval, new_driver->name);
 
1097	goto out;
1098}
1099EXPORT_SYMBOL_GPL(usb_register_driver);
1100
1101/**
1102 * usb_deregister - unregister a USB interface driver
1103 * @driver: USB operations of the interface driver to unregister
1104 * Context: must be able to sleep
1105 *
1106 * Unlinks the specified driver from the internal USB driver list.
1107 *
1108 * NOTE: If you called usb_register_dev(), you still need to call
1109 * usb_deregister_dev() to clean up your driver's allocated minor numbers,
1110 * this * call will no longer do it for you.
1111 */
1112void usb_deregister(struct usb_driver *driver)
1113{
1114	pr_info("%s: deregistering interface driver %s\n",
1115			usbcore_name, driver->name);
1116
1117	usb_remove_newid_files(driver);
1118	driver_unregister(&driver->driver);
1119	usb_free_dynids(driver);
1120}
1121EXPORT_SYMBOL_GPL(usb_deregister);
1122
1123/* Forced unbinding of a USB interface driver, either because
1124 * it doesn't support pre_reset/post_reset/reset_resume or
1125 * because it doesn't support suspend/resume.
1126 *
1127 * The caller must hold @intf's device's lock, but not @intf's lock.
 
1128 */
1129void usb_forced_unbind_intf(struct usb_interface *intf)
1130{
1131	struct usb_driver *driver = to_usb_driver(intf->dev.driver);
1132
1133	dev_dbg(&intf->dev, "forced unbind\n");
1134	usb_driver_release_interface(driver, intf);
1135
1136	/* Mark the interface for later rebinding */
1137	intf->needs_binding = 1;
1138}
1139
1140/*
1141 * Unbind drivers for @udev's marked interfaces.  These interfaces have
1142 * the needs_binding flag set, for example by usb_resume_interface().
1143 *
1144 * The caller must hold @udev's device lock.
1145 */
1146static void unbind_marked_interfaces(struct usb_device *udev)
1147{
1148	struct usb_host_config	*config;
1149	int			i;
1150	struct usb_interface	*intf;
1151
1152	config = udev->actconfig;
1153	if (config) {
1154		for (i = 0; i < config->desc.bNumInterfaces; ++i) {
1155			intf = config->interface[i];
1156			if (intf->dev.driver && intf->needs_binding)
1157				usb_forced_unbind_intf(intf);
1158		}
1159	}
1160}
1161
1162/* Delayed forced unbinding of a USB interface driver and scan
1163 * for rebinding.
1164 *
1165 * The caller must hold @intf's device's lock, but not @intf's lock.
 
1166 *
1167 * Note: Rebinds will be skipped if a system sleep transition is in
1168 * progress and the PM "complete" callback hasn't occurred yet.
1169 */
1170static void usb_rebind_intf(struct usb_interface *intf)
1171{
1172	int rc;
1173
1174	/* Delayed unbind of an existing driver */
1175	if (intf->dev.driver)
1176		usb_forced_unbind_intf(intf);
1177
1178	/* Try to rebind the interface */
1179	if (!intf->dev.power.is_prepared) {
1180		intf->needs_binding = 0;
1181		rc = device_attach(&intf->dev);
1182		if (rc < 0 && rc != -EPROBE_DEFER)
1183			dev_warn(&intf->dev, "rebind failed: %d\n", rc);
1184	}
1185}
1186
1187/*
1188 * Rebind drivers to @udev's marked interfaces.  These interfaces have
1189 * the needs_binding flag set.
 
 
1190 *
1191 * The caller must hold @udev's device lock.
1192 */
1193static void rebind_marked_interfaces(struct usb_device *udev)
1194{
1195	struct usb_host_config	*config;
1196	int			i;
1197	struct usb_interface	*intf;
 
1198
1199	config = udev->actconfig;
1200	if (config) {
1201		for (i = 0; i < config->desc.bNumInterfaces; ++i) {
1202			intf = config->interface[i];
1203			if (intf->needs_binding)
1204				usb_rebind_intf(intf);
 
 
 
 
1205		}
1206	}
1207}
1208
1209/*
1210 * Unbind all of @udev's marked interfaces and then rebind all of them.
1211 * This ordering is necessary because some drivers claim several interfaces
1212 * when they are first probed.
1213 *
1214 * The caller must hold @udev's device lock.
1215 */
1216void usb_unbind_and_rebind_marked_interfaces(struct usb_device *udev)
1217{
1218	unbind_marked_interfaces(udev);
1219	rebind_marked_interfaces(udev);
1220}
1221
1222#ifdef CONFIG_PM
 
 
 
 
 
 
 
 
1223
1224/* Unbind drivers for @udev's interfaces that don't support suspend/resume
1225 * There is no check for reset_resume here because it can be determined
1226 * only during resume whether reset_resume is needed.
1227 *
1228 * The caller must hold @udev's device lock.
1229 */
1230static void unbind_no_pm_drivers_interfaces(struct usb_device *udev)
1231{
1232	struct usb_host_config	*config;
1233	int			i;
1234	struct usb_interface	*intf;
1235	struct usb_driver	*drv;
1236
1237	config = udev->actconfig;
1238	if (config) {
1239		for (i = 0; i < config->desc.bNumInterfaces; ++i) {
1240			intf = config->interface[i];
1241
1242			if (intf->dev.driver) {
1243				drv = to_usb_driver(intf->dev.driver);
1244				if (!drv->suspend || !drv->resume)
1245					usb_forced_unbind_intf(intf);
1246			}
1247		}
1248	}
1249}
1250
1251static int usb_suspend_device(struct usb_device *udev, pm_message_t msg)
1252{
1253	struct usb_device_driver	*udriver;
1254	int				status = 0;
1255
1256	if (udev->state == USB_STATE_NOTATTACHED ||
1257			udev->state == USB_STATE_SUSPENDED)
1258		goto done;
1259
1260	/* For devices that don't have a driver, we do a generic suspend. */
1261	if (udev->dev.driver)
1262		udriver = to_usb_device_driver(udev->dev.driver);
1263	else {
1264		udev->do_remote_wakeup = 0;
1265		udriver = &usb_generic_driver;
1266	}
1267	if (udriver->suspend)
1268		status = udriver->suspend(udev, msg);
1269	if (status == 0 && udriver->generic_subclass)
1270		status = usb_generic_driver_suspend(udev, msg);
1271
1272 done:
1273	dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1274	return status;
1275}
1276
1277static int usb_resume_device(struct usb_device *udev, pm_message_t msg)
1278{
1279	struct usb_device_driver	*udriver;
1280	int				status = 0;
1281
1282	if (udev->state == USB_STATE_NOTATTACHED)
1283		goto done;
1284
1285	/* Can't resume it if it doesn't have a driver. */
1286	if (udev->dev.driver == NULL) {
1287		status = -ENOTCONN;
1288		goto done;
1289	}
1290
1291	/* Non-root devices on a full/low-speed bus must wait for their
1292	 * companion high-speed root hub, in case a handoff is needed.
1293	 */
1294	if (!PMSG_IS_AUTO(msg) && udev->parent && udev->bus->hs_companion)
1295		device_pm_wait_for_dev(&udev->dev,
1296				&udev->bus->hs_companion->root_hub->dev);
1297
1298	if (udev->quirks & USB_QUIRK_RESET_RESUME)
1299		udev->reset_resume = 1;
1300
1301	udriver = to_usb_device_driver(udev->dev.driver);
1302	if (udriver->generic_subclass)
1303		status = usb_generic_driver_resume(udev, msg);
1304	if (status == 0 && udriver->resume)
1305		status = udriver->resume(udev, msg);
1306
1307 done:
1308	dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1309	return status;
1310}
1311
1312static int usb_suspend_interface(struct usb_device *udev,
1313		struct usb_interface *intf, pm_message_t msg)
1314{
1315	struct usb_driver	*driver;
1316	int			status = 0;
1317
1318	if (udev->state == USB_STATE_NOTATTACHED ||
1319			intf->condition == USB_INTERFACE_UNBOUND)
1320		goto done;
1321	driver = to_usb_driver(intf->dev.driver);
1322
1323	/* at this time we know the driver supports suspend */
1324	status = driver->suspend(intf, msg);
1325	if (status && !PMSG_IS_AUTO(msg))
1326		dev_err(&intf->dev, "suspend error %d\n", status);
1327
1328 done:
1329	dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
1330	return status;
1331}
1332
1333static int usb_resume_interface(struct usb_device *udev,
1334		struct usb_interface *intf, pm_message_t msg, int reset_resume)
1335{
1336	struct usb_driver	*driver;
1337	int			status = 0;
1338
1339	if (udev->state == USB_STATE_NOTATTACHED)
1340		goto done;
1341
1342	/* Don't let autoresume interfere with unbinding */
1343	if (intf->condition == USB_INTERFACE_UNBINDING)
1344		goto done;
1345
1346	/* Can't resume it if it doesn't have a driver. */
1347	if (intf->condition == USB_INTERFACE_UNBOUND) {
1348
1349		/* Carry out a deferred switch to altsetting 0 */
1350		if (intf->needs_altsetting0 && !intf->dev.power.is_prepared) {
1351			usb_set_interface(udev, intf->altsetting[0].
1352					desc.bInterfaceNumber, 0);
1353			intf->needs_altsetting0 = 0;
1354		}
1355		goto done;
1356	}
1357
1358	/* Don't resume if the interface is marked for rebinding */
1359	if (intf->needs_binding)
1360		goto done;
1361	driver = to_usb_driver(intf->dev.driver);
1362
1363	if (reset_resume) {
1364		if (driver->reset_resume) {
1365			status = driver->reset_resume(intf);
1366			if (status)
1367				dev_err(&intf->dev, "%s error %d\n",
1368						"reset_resume", status);
1369		} else {
1370			intf->needs_binding = 1;
1371			dev_dbg(&intf->dev, "no reset_resume for driver %s?\n",
1372					driver->name);
1373		}
1374	} else {
1375		status = driver->resume(intf);
1376		if (status)
1377			dev_err(&intf->dev, "resume error %d\n", status);
1378	}
1379
1380done:
1381	dev_vdbg(&intf->dev, "%s: status %d\n", __func__, status);
1382
1383	/* Later we will unbind the driver and/or reprobe, if necessary */
1384	return status;
1385}
1386
1387/**
1388 * usb_suspend_both - suspend a USB device and its interfaces
1389 * @udev: the usb_device to suspend
1390 * @msg: Power Management message describing this state transition
1391 *
1392 * This is the central routine for suspending USB devices.  It calls the
1393 * suspend methods for all the interface drivers in @udev and then calls
1394 * the suspend method for @udev itself.  When the routine is called in
1395 * autosuspend, if an error occurs at any stage, all the interfaces
1396 * which were suspended are resumed so that they remain in the same
1397 * state as the device, but when called from system sleep, all error
1398 * from suspend methods of interfaces and the non-root-hub device itself
1399 * are simply ignored, so all suspended interfaces are only resumed
1400 * to the device's state when @udev is root-hub and its suspend method
1401 * returns failure.
1402 *
1403 * Autosuspend requests originating from a child device or an interface
1404 * driver may be made without the protection of @udev's device lock, but
1405 * all other suspend calls will hold the lock.  Usbcore will insure that
1406 * method calls do not arrive during bind, unbind, or reset operations.
1407 * However drivers must be prepared to handle suspend calls arriving at
1408 * unpredictable times.
1409 *
1410 * This routine can run only in process context.
1411 *
1412 * Return: 0 if the suspend succeeded.
1413 */
1414static int usb_suspend_both(struct usb_device *udev, pm_message_t msg)
1415{
1416	int			status = 0;
1417	int			i = 0, n = 0;
1418	struct usb_interface	*intf;
1419
1420	if (udev->state == USB_STATE_NOTATTACHED ||
1421			udev->state == USB_STATE_SUSPENDED)
1422		goto done;
1423
1424	/* Suspend all the interfaces and then udev itself */
1425	if (udev->actconfig) {
1426		n = udev->actconfig->desc.bNumInterfaces;
1427		for (i = n - 1; i >= 0; --i) {
1428			intf = udev->actconfig->interface[i];
1429			status = usb_suspend_interface(udev, intf, msg);
1430
1431			/* Ignore errors during system sleep transitions */
1432			if (!PMSG_IS_AUTO(msg))
1433				status = 0;
1434			if (status != 0)
1435				break;
1436		}
1437	}
1438	if (status == 0) {
1439		status = usb_suspend_device(udev, msg);
1440
1441		/*
1442		 * Ignore errors from non-root-hub devices during
1443		 * system sleep transitions.  For the most part,
1444		 * these devices should go to low power anyway when
1445		 * the entire bus is suspended.
1446		 */
1447		if (udev->parent && !PMSG_IS_AUTO(msg))
1448			status = 0;
1449
1450		/*
1451		 * If the device is inaccessible, don't try to resume
1452		 * suspended interfaces and just return the error.
1453		 */
1454		if (status && status != -EBUSY) {
1455			int err;
1456			u16 devstat;
1457
1458			err = usb_get_std_status(udev, USB_RECIP_DEVICE, 0,
1459						 &devstat);
1460			if (err) {
1461				dev_err(&udev->dev,
1462					"Failed to suspend device, error %d\n",
1463					status);
1464				goto done;
1465			}
1466		}
1467	}
1468
1469	/* If the suspend failed, resume interfaces that did get suspended */
1470	if (status != 0) {
1471		if (udev->actconfig) {
1472			msg.event ^= (PM_EVENT_SUSPEND | PM_EVENT_RESUME);
1473			while (++i < n) {
1474				intf = udev->actconfig->interface[i];
1475				usb_resume_interface(udev, intf, msg, 0);
1476			}
1477		}
1478
1479	/* If the suspend succeeded then prevent any more URB submissions
1480	 * and flush any outstanding URBs.
1481	 */
1482	} else {
1483		udev->can_submit = 0;
1484		for (i = 0; i < 16; ++i) {
1485			usb_hcd_flush_endpoint(udev, udev->ep_out[i]);
1486			usb_hcd_flush_endpoint(udev, udev->ep_in[i]);
1487		}
1488	}
1489
1490 done:
1491	dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1492	return status;
1493}
1494
1495/**
1496 * usb_resume_both - resume a USB device and its interfaces
1497 * @udev: the usb_device to resume
1498 * @msg: Power Management message describing this state transition
1499 *
1500 * This is the central routine for resuming USB devices.  It calls the
1501 * resume method for @udev and then calls the resume methods for all
1502 * the interface drivers in @udev.
1503 *
1504 * Autoresume requests originating from a child device or an interface
1505 * driver may be made without the protection of @udev's device lock, but
1506 * all other resume calls will hold the lock.  Usbcore will insure that
1507 * method calls do not arrive during bind, unbind, or reset operations.
1508 * However drivers must be prepared to handle resume calls arriving at
1509 * unpredictable times.
1510 *
1511 * This routine can run only in process context.
1512 *
1513 * Return: 0 on success.
1514 */
1515static int usb_resume_both(struct usb_device *udev, pm_message_t msg)
1516{
1517	int			status = 0;
1518	int			i;
1519	struct usb_interface	*intf;
1520
1521	if (udev->state == USB_STATE_NOTATTACHED) {
1522		status = -ENODEV;
1523		goto done;
1524	}
1525	udev->can_submit = 1;
1526
1527	/* Resume the device */
1528	if (udev->state == USB_STATE_SUSPENDED || udev->reset_resume)
1529		status = usb_resume_device(udev, msg);
1530
1531	/* Resume the interfaces */
1532	if (status == 0 && udev->actconfig) {
1533		for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
1534			intf = udev->actconfig->interface[i];
1535			usb_resume_interface(udev, intf, msg,
1536					udev->reset_resume);
1537		}
1538	}
1539	usb_mark_last_busy(udev);
1540
1541 done:
1542	dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
1543	if (!status)
1544		udev->reset_resume = 0;
1545	return status;
1546}
1547
1548static void choose_wakeup(struct usb_device *udev, pm_message_t msg)
1549{
1550	int	w;
1551
1552	/*
1553	 * For FREEZE/QUIESCE, disable remote wakeups so no interrupts get
1554	 * generated.
1555	 */
1556	if (msg.event == PM_EVENT_FREEZE || msg.event == PM_EVENT_QUIESCE) {
1557		w = 0;
1558
1559	} else {
1560		/*
1561		 * Enable remote wakeup if it is allowed, even if no interface
1562		 * drivers actually want it.
1563		 */
1564		w = device_may_wakeup(&udev->dev);
1565	}
1566
1567	/*
1568	 * If the device is autosuspended with the wrong wakeup setting,
 
 
 
 
1569	 * autoresume now so the setting can be changed.
1570	 */
1571	if (udev->state == USB_STATE_SUSPENDED && w != udev->do_remote_wakeup)
1572		pm_runtime_resume(&udev->dev);
1573	udev->do_remote_wakeup = w;
1574}
1575
1576/* The device lock is held by the PM core */
1577int usb_suspend(struct device *dev, pm_message_t msg)
1578{
1579	struct usb_device	*udev = to_usb_device(dev);
1580	int r;
1581
1582	unbind_no_pm_drivers_interfaces(udev);
1583
1584	/* From now on we are sure all drivers support suspend/resume
1585	 * but not necessarily reset_resume()
1586	 * so we may still need to unbind and rebind upon resume
1587	 */
1588	choose_wakeup(udev, msg);
1589	r = usb_suspend_both(udev, msg);
1590	if (r)
1591		return r;
1592
1593	if (udev->quirks & USB_QUIRK_DISCONNECT_SUSPEND)
1594		usb_port_disable(udev);
1595
1596	return 0;
1597}
1598
1599/* The device lock is held by the PM core */
1600int usb_resume_complete(struct device *dev)
1601{
1602	struct usb_device *udev = to_usb_device(dev);
1603
1604	/* For PM complete calls, all we do is rebind interfaces
1605	 * whose needs_binding flag is set
1606	 */
1607	if (udev->state != USB_STATE_NOTATTACHED)
1608		rebind_marked_interfaces(udev);
1609	return 0;
1610}
1611
1612/* The device lock is held by the PM core */
1613int usb_resume(struct device *dev, pm_message_t msg)
1614{
1615	struct usb_device	*udev = to_usb_device(dev);
1616	int			status;
1617
1618	/* For all calls, take the device back to full power and
1619	 * tell the PM core in case it was autosuspended previously.
1620	 * Unbind the interfaces that will need rebinding later,
1621	 * because they fail to support reset_resume.
1622	 * (This can't be done in usb_resume_interface()
1623	 * above because it doesn't own the right set of locks.)
1624	 */
1625	status = usb_resume_both(udev, msg);
1626	if (status == 0) {
1627		pm_runtime_disable(dev);
1628		pm_runtime_set_active(dev);
1629		pm_runtime_enable(dev);
1630		unbind_marked_interfaces(udev);
1631	}
1632
1633	/* Avoid PM error messages for devices disconnected while suspended
1634	 * as we'll display regular disconnect messages just a bit later.
1635	 */
1636	if (status == -ENODEV || status == -ESHUTDOWN)
1637		status = 0;
1638	return status;
1639}
1640
 
 
 
 
1641/**
1642 * usb_enable_autosuspend - allow a USB device to be autosuspended
1643 * @udev: the USB device which may be autosuspended
1644 *
1645 * This routine allows @udev to be autosuspended.  An autosuspend won't
1646 * take place until the autosuspend_delay has elapsed and all the other
1647 * necessary conditions are satisfied.
1648 *
1649 * The caller must hold @udev's device lock.
1650 */
1651void usb_enable_autosuspend(struct usb_device *udev)
1652{
1653	pm_runtime_allow(&udev->dev);
1654}
1655EXPORT_SYMBOL_GPL(usb_enable_autosuspend);
1656
1657/**
1658 * usb_disable_autosuspend - prevent a USB device from being autosuspended
1659 * @udev: the USB device which may not be autosuspended
1660 *
1661 * This routine prevents @udev from being autosuspended and wakes it up
1662 * if it is already autosuspended.
1663 *
1664 * The caller must hold @udev's device lock.
1665 */
1666void usb_disable_autosuspend(struct usb_device *udev)
1667{
1668	pm_runtime_forbid(&udev->dev);
1669}
1670EXPORT_SYMBOL_GPL(usb_disable_autosuspend);
1671
1672/**
1673 * usb_autosuspend_device - delayed autosuspend of a USB device and its interfaces
1674 * @udev: the usb_device to autosuspend
1675 *
1676 * This routine should be called when a core subsystem is finished using
1677 * @udev and wants to allow it to autosuspend.  Examples would be when
1678 * @udev's device file in usbfs is closed or after a configuration change.
1679 *
1680 * @udev's usage counter is decremented; if it drops to 0 and all the
1681 * interfaces are inactive then a delayed autosuspend will be attempted.
1682 * The attempt may fail (see autosuspend_check()).
1683 *
1684 * The caller must hold @udev's device lock.
1685 *
1686 * This routine can run only in process context.
1687 */
1688void usb_autosuspend_device(struct usb_device *udev)
1689{
1690	int	status;
1691
1692	usb_mark_last_busy(udev);
1693	status = pm_runtime_put_sync_autosuspend(&udev->dev);
1694	dev_vdbg(&udev->dev, "%s: cnt %d -> %d\n",
1695			__func__, atomic_read(&udev->dev.power.usage_count),
1696			status);
1697}
1698
1699/**
1700 * usb_autoresume_device - immediately autoresume a USB device and its interfaces
1701 * @udev: the usb_device to autoresume
1702 *
1703 * This routine should be called when a core subsystem wants to use @udev
1704 * and needs to guarantee that it is not suspended.  No autosuspend will
1705 * occur until usb_autosuspend_device() is called.  (Note that this will
1706 * not prevent suspend events originating in the PM core.)  Examples would
1707 * be when @udev's device file in usbfs is opened or when a remote-wakeup
1708 * request is received.
1709 *
1710 * @udev's usage counter is incremented to prevent subsequent autosuspends.
1711 * However if the autoresume fails then the usage counter is re-decremented.
1712 *
1713 * The caller must hold @udev's device lock.
1714 *
1715 * This routine can run only in process context.
1716 *
1717 * Return: 0 on success. A negative error code otherwise.
1718 */
1719int usb_autoresume_device(struct usb_device *udev)
1720{
1721	int	status;
1722
1723	status = pm_runtime_resume_and_get(&udev->dev);
 
 
1724	dev_vdbg(&udev->dev, "%s: cnt %d -> %d\n",
1725			__func__, atomic_read(&udev->dev.power.usage_count),
1726			status);
1727	if (status > 0)
1728		status = 0;
1729	return status;
1730}
1731
1732/**
1733 * usb_autopm_put_interface - decrement a USB interface's PM-usage counter
1734 * @intf: the usb_interface whose counter should be decremented
1735 *
1736 * This routine should be called by an interface driver when it is
1737 * finished using @intf and wants to allow it to autosuspend.  A typical
1738 * example would be a character-device driver when its device file is
1739 * closed.
1740 *
1741 * The routine decrements @intf's usage counter.  When the counter reaches
1742 * 0, a delayed autosuspend request for @intf's device is attempted.  The
1743 * attempt may fail (see autosuspend_check()).
1744 *
1745 * This routine can run only in process context.
1746 */
1747void usb_autopm_put_interface(struct usb_interface *intf)
1748{
1749	struct usb_device	*udev = interface_to_usbdev(intf);
1750	int			status;
1751
1752	usb_mark_last_busy(udev);
 
1753	status = pm_runtime_put_sync(&intf->dev);
1754	dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1755			__func__, atomic_read(&intf->dev.power.usage_count),
1756			status);
1757}
1758EXPORT_SYMBOL_GPL(usb_autopm_put_interface);
1759
1760/**
1761 * usb_autopm_put_interface_async - decrement a USB interface's PM-usage counter
1762 * @intf: the usb_interface whose counter should be decremented
1763 *
1764 * This routine does much the same thing as usb_autopm_put_interface():
1765 * It decrements @intf's usage counter and schedules a delayed
1766 * autosuspend request if the counter is <= 0.  The difference is that it
1767 * does not perform any synchronization; callers should hold a private
1768 * lock and handle all synchronization issues themselves.
1769 *
1770 * Typically a driver would call this routine during an URB's completion
1771 * handler, if no more URBs were pending.
1772 *
1773 * This routine can run in atomic context.
1774 */
1775void usb_autopm_put_interface_async(struct usb_interface *intf)
1776{
1777	struct usb_device	*udev = interface_to_usbdev(intf);
1778	int			status;
1779
1780	usb_mark_last_busy(udev);
 
1781	status = pm_runtime_put(&intf->dev);
1782	dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1783			__func__, atomic_read(&intf->dev.power.usage_count),
1784			status);
1785}
1786EXPORT_SYMBOL_GPL(usb_autopm_put_interface_async);
1787
1788/**
1789 * usb_autopm_put_interface_no_suspend - decrement a USB interface's PM-usage counter
1790 * @intf: the usb_interface whose counter should be decremented
1791 *
1792 * This routine decrements @intf's usage counter but does not carry out an
1793 * autosuspend.
1794 *
1795 * This routine can run in atomic context.
1796 */
1797void usb_autopm_put_interface_no_suspend(struct usb_interface *intf)
1798{
1799	struct usb_device	*udev = interface_to_usbdev(intf);
1800
1801	usb_mark_last_busy(udev);
 
1802	pm_runtime_put_noidle(&intf->dev);
1803}
1804EXPORT_SYMBOL_GPL(usb_autopm_put_interface_no_suspend);
1805
1806/**
1807 * usb_autopm_get_interface - increment a USB interface's PM-usage counter
1808 * @intf: the usb_interface whose counter should be incremented
1809 *
1810 * This routine should be called by an interface driver when it wants to
1811 * use @intf and needs to guarantee that it is not suspended.  In addition,
1812 * the routine prevents @intf from being autosuspended subsequently.  (Note
1813 * that this will not prevent suspend events originating in the PM core.)
1814 * This prevention will persist until usb_autopm_put_interface() is called
1815 * or @intf is unbound.  A typical example would be a character-device
1816 * driver when its device file is opened.
1817 *
1818 * @intf's usage counter is incremented to prevent subsequent autosuspends.
1819 * However if the autoresume fails then the counter is re-decremented.
1820 *
1821 * This routine can run only in process context.
1822 *
1823 * Return: 0 on success.
1824 */
1825int usb_autopm_get_interface(struct usb_interface *intf)
1826{
1827	int	status;
1828
1829	status = pm_runtime_resume_and_get(&intf->dev);
 
 
 
 
1830	dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1831			__func__, atomic_read(&intf->dev.power.usage_count),
1832			status);
1833	if (status > 0)
1834		status = 0;
1835	return status;
1836}
1837EXPORT_SYMBOL_GPL(usb_autopm_get_interface);
1838
1839/**
1840 * usb_autopm_get_interface_async - increment a USB interface's PM-usage counter
1841 * @intf: the usb_interface whose counter should be incremented
1842 *
1843 * This routine does much the same thing as
1844 * usb_autopm_get_interface(): It increments @intf's usage counter and
1845 * queues an autoresume request if the device is suspended.  The
1846 * differences are that it does not perform any synchronization (callers
1847 * should hold a private lock and handle all synchronization issues
1848 * themselves), and it does not autoresume the device directly (it only
1849 * queues a request).  After a successful call, the device may not yet be
1850 * resumed.
1851 *
1852 * This routine can run in atomic context.
1853 *
1854 * Return: 0 on success. A negative error code otherwise.
1855 */
1856int usb_autopm_get_interface_async(struct usb_interface *intf)
1857{
1858	int	status;
1859
1860	status = pm_runtime_get(&intf->dev);
1861	if (status < 0 && status != -EINPROGRESS)
1862		pm_runtime_put_noidle(&intf->dev);
 
 
1863	dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
1864			__func__, atomic_read(&intf->dev.power.usage_count),
1865			status);
1866	if (status > 0 || status == -EINPROGRESS)
1867		status = 0;
1868	return status;
1869}
1870EXPORT_SYMBOL_GPL(usb_autopm_get_interface_async);
1871
1872/**
1873 * usb_autopm_get_interface_no_resume - increment a USB interface's PM-usage counter
1874 * @intf: the usb_interface whose counter should be incremented
1875 *
1876 * This routine increments @intf's usage counter but does not carry out an
1877 * autoresume.
1878 *
1879 * This routine can run in atomic context.
1880 */
1881void usb_autopm_get_interface_no_resume(struct usb_interface *intf)
1882{
1883	struct usb_device	*udev = interface_to_usbdev(intf);
1884
1885	usb_mark_last_busy(udev);
 
1886	pm_runtime_get_noresume(&intf->dev);
1887}
1888EXPORT_SYMBOL_GPL(usb_autopm_get_interface_no_resume);
1889
1890/* Internal routine to check whether we may autosuspend a device. */
1891static int autosuspend_check(struct usb_device *udev)
1892{
1893	int			w, i;
1894	struct usb_interface	*intf;
1895
1896	if (udev->state == USB_STATE_NOTATTACHED)
1897		return -ENODEV;
1898
1899	/* Fail if autosuspend is disabled, or any interfaces are in use, or
1900	 * any interface drivers require remote wakeup but it isn't available.
1901	 */
1902	w = 0;
1903	if (udev->actconfig) {
1904		for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
1905			intf = udev->actconfig->interface[i];
1906
1907			/* We don't need to check interfaces that are
1908			 * disabled for runtime PM.  Either they are unbound
1909			 * or else their drivers don't support autosuspend
1910			 * and so they are permanently active.
1911			 */
1912			if (intf->dev.power.disable_depth)
1913				continue;
1914			if (atomic_read(&intf->dev.power.usage_count) > 0)
1915				return -EBUSY;
1916			w |= intf->needs_remote_wakeup;
1917
1918			/* Don't allow autosuspend if the device will need
1919			 * a reset-resume and any of its interface drivers
1920			 * doesn't include support or needs remote wakeup.
1921			 */
1922			if (udev->quirks & USB_QUIRK_RESET_RESUME) {
1923				struct usb_driver *driver;
1924
1925				driver = to_usb_driver(intf->dev.driver);
1926				if (!driver->reset_resume ||
1927						intf->needs_remote_wakeup)
1928					return -EOPNOTSUPP;
1929			}
1930		}
1931	}
1932	if (w && !device_can_wakeup(&udev->dev)) {
1933		dev_dbg(&udev->dev, "remote wakeup needed for autosuspend\n");
1934		return -EOPNOTSUPP;
1935	}
1936
1937	/*
1938	 * If the device is a direct child of the root hub and the HCD
1939	 * doesn't handle wakeup requests, don't allow autosuspend when
1940	 * wakeup is needed.
1941	 */
1942	if (w && udev->parent == udev->bus->root_hub &&
1943			bus_to_hcd(udev->bus)->cant_recv_wakeups) {
1944		dev_dbg(&udev->dev, "HCD doesn't handle wakeup requests\n");
1945		return -EOPNOTSUPP;
1946	}
1947
1948	udev->do_remote_wakeup = w;
1949	return 0;
1950}
1951
1952int usb_runtime_suspend(struct device *dev)
1953{
1954	struct usb_device	*udev = to_usb_device(dev);
1955	int			status;
1956
1957	/* A USB device can be suspended if it passes the various autosuspend
1958	 * checks.  Runtime suspend for a USB device means suspending all the
1959	 * interfaces and then the device itself.
1960	 */
1961	if (autosuspend_check(udev) != 0)
1962		return -EAGAIN;
1963
1964	status = usb_suspend_both(udev, PMSG_AUTO_SUSPEND);
1965
1966	/* Allow a retry if autosuspend failed temporarily */
1967	if (status == -EAGAIN || status == -EBUSY)
1968		usb_mark_last_busy(udev);
1969
1970	/*
1971	 * The PM core reacts badly unless the return code is 0,
1972	 * -EAGAIN, or -EBUSY, so always return -EBUSY on an error
1973	 * (except for root hubs, because they don't suspend through
1974	 * an upstream port like other USB devices).
1975	 */
1976	if (status != 0 && udev->parent)
1977		return -EBUSY;
1978	return status;
1979}
1980
1981int usb_runtime_resume(struct device *dev)
1982{
1983	struct usb_device	*udev = to_usb_device(dev);
1984	int			status;
1985
1986	/* Runtime resume for a USB device means resuming both the device
1987	 * and all its interfaces.
1988	 */
1989	status = usb_resume_both(udev, PMSG_AUTO_RESUME);
1990	return status;
1991}
1992
1993int usb_runtime_idle(struct device *dev)
1994{
1995	struct usb_device	*udev = to_usb_device(dev);
1996
1997	/* An idle USB device can be suspended if it passes the various
1998	 * autosuspend checks.
1999	 */
2000	if (autosuspend_check(udev) == 0)
2001		pm_runtime_autosuspend(dev);
2002	/* Tell the core not to suspend it, though. */
2003	return -EBUSY;
2004}
2005
2006static int usb_set_usb2_hardware_lpm(struct usb_device *udev, int enable)
2007{
2008	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
2009	int ret = -EPERM;
2010
2011	if (hcd->driver->set_usb2_hw_lpm) {
2012		ret = hcd->driver->set_usb2_hw_lpm(hcd, udev, enable);
2013		if (!ret)
2014			udev->usb2_hw_lpm_enabled = enable;
2015	}
2016
2017	return ret;
2018}
2019
2020int usb_enable_usb2_hardware_lpm(struct usb_device *udev)
2021{
2022	if (!udev->usb2_hw_lpm_capable ||
2023	    !udev->usb2_hw_lpm_allowed ||
2024	    udev->usb2_hw_lpm_enabled)
2025		return 0;
2026
2027	return usb_set_usb2_hardware_lpm(udev, 1);
2028}
2029
2030int usb_disable_usb2_hardware_lpm(struct usb_device *udev)
2031{
2032	if (!udev->usb2_hw_lpm_enabled)
2033		return 0;
2034
2035	return usb_set_usb2_hardware_lpm(udev, 0);
2036}
2037
2038#endif /* CONFIG_PM */
2039
2040const struct bus_type usb_bus_type = {
2041	.name =		"usb",
2042	.match =	usb_device_match,
2043	.uevent =	usb_uevent,
2044	.need_parent_lock =	true,
2045};