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