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v6.8
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * drivers/usb/core/usb.c
   4 *
   5 * (C) Copyright Linus Torvalds 1999
   6 * (C) Copyright Johannes Erdfelt 1999-2001
   7 * (C) Copyright Andreas Gal 1999
   8 * (C) Copyright Gregory P. Smith 1999
   9 * (C) Copyright Deti Fliegl 1999 (new USB architecture)
  10 * (C) Copyright Randy Dunlap 2000
  11 * (C) Copyright David Brownell 2000-2004
  12 * (C) Copyright Yggdrasil Computing, Inc. 2000
  13 *     (usb_device_id matching changes by Adam J. Richter)
  14 * (C) Copyright Greg Kroah-Hartman 2002-2003
  15 *
  16 * Released under the GPLv2 only.
 
  17 *
  18 * NOTE! This is not actually a driver at all, rather this is
  19 * just a collection of helper routines that implement the
  20 * generic USB things that the real drivers can use..
  21 *
  22 * Think of this as a "USB library" rather than anything else,
  23 * with no callbacks.  Callbacks are evil.
 
  24 */
  25
  26#include <linux/module.h>
  27#include <linux/moduleparam.h>
  28#include <linux/of.h>
  29#include <linux/string.h>
  30#include <linux/bitops.h>
  31#include <linux/slab.h>
 
  32#include <linux/kmod.h>
  33#include <linux/init.h>
  34#include <linux/spinlock.h>
  35#include <linux/errno.h>
  36#include <linux/usb.h>
  37#include <linux/usb/hcd.h>
  38#include <linux/mutex.h>
  39#include <linux/workqueue.h>
  40#include <linux/debugfs.h>
  41#include <linux/usb/of.h>
  42
  43#include <asm/io.h>
  44#include <linux/scatterlist.h>
  45#include <linux/mm.h>
  46#include <linux/dma-mapping.h>
  47
  48#include "hub.h"
 
  49
  50const char *usbcore_name = "usbcore";
  51
  52static bool nousb;	/* Disable USB when built into kernel image */
  53
  54module_param(nousb, bool, 0444);
  55
  56/*
  57 * for external read access to <nousb>
  58 */
  59int usb_disabled(void)
  60{
  61	return nousb;
  62}
  63EXPORT_SYMBOL_GPL(usb_disabled);
  64
  65#ifdef	CONFIG_PM
  66/* Default delay value, in seconds */
  67static int usb_autosuspend_delay = CONFIG_USB_AUTOSUSPEND_DELAY;
  68module_param_named(autosuspend, usb_autosuspend_delay, int, 0644);
  69MODULE_PARM_DESC(autosuspend, "default autosuspend delay");
  70
  71#else
  72#define usb_autosuspend_delay		0
  73#endif
  74
  75static bool match_endpoint(struct usb_endpoint_descriptor *epd,
  76		struct usb_endpoint_descriptor **bulk_in,
  77		struct usb_endpoint_descriptor **bulk_out,
  78		struct usb_endpoint_descriptor **int_in,
  79		struct usb_endpoint_descriptor **int_out)
  80{
  81	switch (usb_endpoint_type(epd)) {
  82	case USB_ENDPOINT_XFER_BULK:
  83		if (usb_endpoint_dir_in(epd)) {
  84			if (bulk_in && !*bulk_in) {
  85				*bulk_in = epd;
  86				break;
  87			}
  88		} else {
  89			if (bulk_out && !*bulk_out) {
  90				*bulk_out = epd;
  91				break;
  92			}
  93		}
  94
  95		return false;
  96	case USB_ENDPOINT_XFER_INT:
  97		if (usb_endpoint_dir_in(epd)) {
  98			if (int_in && !*int_in) {
  99				*int_in = epd;
 100				break;
 101			}
 102		} else {
 103			if (int_out && !*int_out) {
 104				*int_out = epd;
 105				break;
 106			}
 107		}
 108
 109		return false;
 110	default:
 111		return false;
 112	}
 113
 114	return (!bulk_in || *bulk_in) && (!bulk_out || *bulk_out) &&
 115			(!int_in || *int_in) && (!int_out || *int_out);
 116}
 117
 118/**
 119 * usb_find_common_endpoints() -- look up common endpoint descriptors
 120 * @alt:	alternate setting to search
 121 * @bulk_in:	pointer to descriptor pointer, or NULL
 122 * @bulk_out:	pointer to descriptor pointer, or NULL
 123 * @int_in:	pointer to descriptor pointer, or NULL
 124 * @int_out:	pointer to descriptor pointer, or NULL
 125 *
 126 * Search the alternate setting's endpoint descriptors for the first bulk-in,
 127 * bulk-out, interrupt-in and interrupt-out endpoints and return them in the
 128 * provided pointers (unless they are NULL).
 129 *
 130 * If a requested endpoint is not found, the corresponding pointer is set to
 131 * NULL.
 132 *
 133 * Return: Zero if all requested descriptors were found, or -ENXIO otherwise.
 134 */
 135int usb_find_common_endpoints(struct usb_host_interface *alt,
 136		struct usb_endpoint_descriptor **bulk_in,
 137		struct usb_endpoint_descriptor **bulk_out,
 138		struct usb_endpoint_descriptor **int_in,
 139		struct usb_endpoint_descriptor **int_out)
 140{
 141	struct usb_endpoint_descriptor *epd;
 142	int i;
 143
 144	if (bulk_in)
 145		*bulk_in = NULL;
 146	if (bulk_out)
 147		*bulk_out = NULL;
 148	if (int_in)
 149		*int_in = NULL;
 150	if (int_out)
 151		*int_out = NULL;
 152
 153	for (i = 0; i < alt->desc.bNumEndpoints; ++i) {
 154		epd = &alt->endpoint[i].desc;
 155
 156		if (match_endpoint(epd, bulk_in, bulk_out, int_in, int_out))
 157			return 0;
 158	}
 159
 160	return -ENXIO;
 161}
 162EXPORT_SYMBOL_GPL(usb_find_common_endpoints);
 163
 164/**
 165 * usb_find_common_endpoints_reverse() -- look up common endpoint descriptors
 166 * @alt:	alternate setting to search
 167 * @bulk_in:	pointer to descriptor pointer, or NULL
 168 * @bulk_out:	pointer to descriptor pointer, or NULL
 169 * @int_in:	pointer to descriptor pointer, or NULL
 170 * @int_out:	pointer to descriptor pointer, or NULL
 171 *
 172 * Search the alternate setting's endpoint descriptors for the last bulk-in,
 173 * bulk-out, interrupt-in and interrupt-out endpoints and return them in the
 174 * provided pointers (unless they are NULL).
 175 *
 176 * If a requested endpoint is not found, the corresponding pointer is set to
 177 * NULL.
 178 *
 179 * Return: Zero if all requested descriptors were found, or -ENXIO otherwise.
 180 */
 181int usb_find_common_endpoints_reverse(struct usb_host_interface *alt,
 182		struct usb_endpoint_descriptor **bulk_in,
 183		struct usb_endpoint_descriptor **bulk_out,
 184		struct usb_endpoint_descriptor **int_in,
 185		struct usb_endpoint_descriptor **int_out)
 186{
 187	struct usb_endpoint_descriptor *epd;
 188	int i;
 189
 190	if (bulk_in)
 191		*bulk_in = NULL;
 192	if (bulk_out)
 193		*bulk_out = NULL;
 194	if (int_in)
 195		*int_in = NULL;
 196	if (int_out)
 197		*int_out = NULL;
 198
 199	for (i = alt->desc.bNumEndpoints - 1; i >= 0; --i) {
 200		epd = &alt->endpoint[i].desc;
 201
 202		if (match_endpoint(epd, bulk_in, bulk_out, int_in, int_out))
 203			return 0;
 204	}
 205
 206	return -ENXIO;
 207}
 208EXPORT_SYMBOL_GPL(usb_find_common_endpoints_reverse);
 209
 210/**
 211 * usb_find_endpoint() - Given an endpoint address, search for the endpoint's
 212 * usb_host_endpoint structure in an interface's current altsetting.
 213 * @intf: the interface whose current altsetting should be searched
 214 * @ep_addr: the endpoint address (number and direction) to find
 215 *
 216 * Search the altsetting's list of endpoints for one with the specified address.
 217 *
 218 * Return: Pointer to the usb_host_endpoint if found, %NULL otherwise.
 219 */
 220static const struct usb_host_endpoint *usb_find_endpoint(
 221		const struct usb_interface *intf, unsigned int ep_addr)
 222{
 223	int n;
 224	const struct usb_host_endpoint *ep;
 225
 226	n = intf->cur_altsetting->desc.bNumEndpoints;
 227	ep = intf->cur_altsetting->endpoint;
 228	for (; n > 0; (--n, ++ep)) {
 229		if (ep->desc.bEndpointAddress == ep_addr)
 230			return ep;
 231	}
 232	return NULL;
 233}
 234
 235/**
 236 * usb_check_bulk_endpoints - Check whether an interface's current altsetting
 237 * contains a set of bulk endpoints with the given addresses.
 238 * @intf: the interface whose current altsetting should be searched
 239 * @ep_addrs: 0-terminated array of the endpoint addresses (number and
 240 * direction) to look for
 241 *
 242 * Search for endpoints with the specified addresses and check their types.
 243 *
 244 * Return: %true if all the endpoints are found and are bulk, %false otherwise.
 245 */
 246bool usb_check_bulk_endpoints(
 247		const struct usb_interface *intf, const u8 *ep_addrs)
 248{
 249	const struct usb_host_endpoint *ep;
 250
 251	for (; *ep_addrs; ++ep_addrs) {
 252		ep = usb_find_endpoint(intf, *ep_addrs);
 253		if (!ep || !usb_endpoint_xfer_bulk(&ep->desc))
 254			return false;
 255	}
 256	return true;
 257}
 258EXPORT_SYMBOL_GPL(usb_check_bulk_endpoints);
 259
 260/**
 261 * usb_check_int_endpoints - Check whether an interface's current altsetting
 262 * contains a set of interrupt endpoints with the given addresses.
 263 * @intf: the interface whose current altsetting should be searched
 264 * @ep_addrs: 0-terminated array of the endpoint addresses (number and
 265 * direction) to look for
 266 *
 267 * Search for endpoints with the specified addresses and check their types.
 268 *
 269 * Return: %true if all the endpoints are found and are interrupt,
 270 * %false otherwise.
 271 */
 272bool usb_check_int_endpoints(
 273		const struct usb_interface *intf, const u8 *ep_addrs)
 274{
 275	const struct usb_host_endpoint *ep;
 276
 277	for (; *ep_addrs; ++ep_addrs) {
 278		ep = usb_find_endpoint(intf, *ep_addrs);
 279		if (!ep || !usb_endpoint_xfer_int(&ep->desc))
 280			return false;
 281	}
 282	return true;
 283}
 284EXPORT_SYMBOL_GPL(usb_check_int_endpoints);
 285
 286/**
 287 * usb_find_alt_setting() - Given a configuration, find the alternate setting
 288 * for the given interface.
 289 * @config: the configuration to search (not necessarily the current config).
 290 * @iface_num: interface number to search in
 291 * @alt_num: alternate interface setting number to search for.
 292 *
 293 * Search the configuration's interface cache for the given alt setting.
 294 *
 295 * Return: The alternate setting, if found. %NULL otherwise.
 296 */
 297struct usb_host_interface *usb_find_alt_setting(
 298		struct usb_host_config *config,
 299		unsigned int iface_num,
 300		unsigned int alt_num)
 301{
 302	struct usb_interface_cache *intf_cache = NULL;
 303	int i;
 304
 305	if (!config)
 306		return NULL;
 307	for (i = 0; i < config->desc.bNumInterfaces; i++) {
 308		if (config->intf_cache[i]->altsetting[0].desc.bInterfaceNumber
 309				== iface_num) {
 310			intf_cache = config->intf_cache[i];
 311			break;
 312		}
 313	}
 314	if (!intf_cache)
 315		return NULL;
 316	for (i = 0; i < intf_cache->num_altsetting; i++)
 317		if (intf_cache->altsetting[i].desc.bAlternateSetting == alt_num)
 318			return &intf_cache->altsetting[i];
 319
 320	printk(KERN_DEBUG "Did not find alt setting %u for intf %u, "
 321			"config %u\n", alt_num, iface_num,
 322			config->desc.bConfigurationValue);
 323	return NULL;
 324}
 325EXPORT_SYMBOL_GPL(usb_find_alt_setting);
 326
 327/**
 328 * usb_ifnum_to_if - get the interface object with a given interface number
 329 * @dev: the device whose current configuration is considered
 330 * @ifnum: the desired interface
 331 *
 332 * This walks the device descriptor for the currently active configuration
 333 * to find the interface object with the particular interface number.
 334 *
 335 * Note that configuration descriptors are not required to assign interface
 336 * numbers sequentially, so that it would be incorrect to assume that
 337 * the first interface in that descriptor corresponds to interface zero.
 338 * This routine helps device drivers avoid such mistakes.
 339 * However, you should make sure that you do the right thing with any
 340 * alternate settings available for this interfaces.
 341 *
 342 * Don't call this function unless you are bound to one of the interfaces
 343 * on this device or you have locked the device!
 344 *
 345 * Return: A pointer to the interface that has @ifnum as interface number,
 346 * if found. %NULL otherwise.
 347 */
 348struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev,
 349				      unsigned ifnum)
 350{
 351	struct usb_host_config *config = dev->actconfig;
 352	int i;
 353
 354	if (!config)
 355		return NULL;
 356	for (i = 0; i < config->desc.bNumInterfaces; i++)
 357		if (config->interface[i]->altsetting[0]
 358				.desc.bInterfaceNumber == ifnum)
 359			return config->interface[i];
 360
 361	return NULL;
 362}
 363EXPORT_SYMBOL_GPL(usb_ifnum_to_if);
 364
 365/**
 366 * usb_altnum_to_altsetting - get the altsetting structure with a given alternate setting number.
 367 * @intf: the interface containing the altsetting in question
 368 * @altnum: the desired alternate setting number
 369 *
 370 * This searches the altsetting array of the specified interface for
 371 * an entry with the correct bAlternateSetting value.
 372 *
 373 * Note that altsettings need not be stored sequentially by number, so
 374 * it would be incorrect to assume that the first altsetting entry in
 375 * the array corresponds to altsetting zero.  This routine helps device
 376 * drivers avoid such mistakes.
 377 *
 378 * Don't call this function unless you are bound to the intf interface
 379 * or you have locked the device!
 380 *
 381 * Return: A pointer to the entry of the altsetting array of @intf that
 382 * has @altnum as the alternate setting number. %NULL if not found.
 383 */
 384struct usb_host_interface *usb_altnum_to_altsetting(
 385					const struct usb_interface *intf,
 386					unsigned int altnum)
 387{
 388	int i;
 389
 390	for (i = 0; i < intf->num_altsetting; i++) {
 391		if (intf->altsetting[i].desc.bAlternateSetting == altnum)
 392			return &intf->altsetting[i];
 393	}
 394	return NULL;
 395}
 396EXPORT_SYMBOL_GPL(usb_altnum_to_altsetting);
 397
 398struct find_interface_arg {
 399	int minor;
 400	struct device_driver *drv;
 401};
 402
 403static int __find_interface(struct device *dev, const void *data)
 404{
 405	const struct find_interface_arg *arg = data;
 406	struct usb_interface *intf;
 407
 408	if (!is_usb_interface(dev))
 409		return 0;
 410
 411	if (dev->driver != arg->drv)
 412		return 0;
 413	intf = to_usb_interface(dev);
 414	return intf->minor == arg->minor;
 415}
 416
 417/**
 418 * usb_find_interface - find usb_interface pointer for driver and device
 419 * @drv: the driver whose current configuration is considered
 420 * @minor: the minor number of the desired device
 421 *
 422 * This walks the bus device list and returns a pointer to the interface
 423 * with the matching minor and driver.  Note, this only works for devices
 424 * that share the USB major number.
 425 *
 426 * Return: A pointer to the interface with the matching major and @minor.
 427 */
 428struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor)
 429{
 430	struct find_interface_arg argb;
 431	struct device *dev;
 432
 433	argb.minor = minor;
 434	argb.drv = &drv->driver;
 435
 436	dev = bus_find_device(&usb_bus_type, NULL, &argb, __find_interface);
 437
 438	/* Drop reference count from bus_find_device */
 439	put_device(dev);
 440
 441	return dev ? to_usb_interface(dev) : NULL;
 442}
 443EXPORT_SYMBOL_GPL(usb_find_interface);
 444
 445struct each_dev_arg {
 446	void *data;
 447	int (*fn)(struct usb_device *, void *);
 448};
 449
 450static int __each_dev(struct device *dev, void *data)
 451{
 452	struct each_dev_arg *arg = (struct each_dev_arg *)data;
 453
 454	/* There are struct usb_interface on the same bus, filter them out */
 455	if (!is_usb_device(dev))
 456		return 0;
 457
 458	return arg->fn(to_usb_device(dev), arg->data);
 459}
 460
 461/**
 462 * usb_for_each_dev - iterate over all USB devices in the system
 463 * @data: data pointer that will be handed to the callback function
 464 * @fn: callback function to be called for each USB device
 465 *
 466 * Iterate over all USB devices and call @fn for each, passing it @data. If it
 467 * returns anything other than 0, we break the iteration prematurely and return
 468 * that value.
 469 */
 470int usb_for_each_dev(void *data, int (*fn)(struct usb_device *, void *))
 471{
 472	struct each_dev_arg arg = {data, fn};
 473
 474	return bus_for_each_dev(&usb_bus_type, NULL, &arg, __each_dev);
 475}
 476EXPORT_SYMBOL_GPL(usb_for_each_dev);
 477
 478/**
 479 * usb_release_dev - free a usb device structure when all users of it are finished.
 480 * @dev: device that's been disconnected
 481 *
 482 * Will be called only by the device core when all users of this usb device are
 483 * done.
 484 */
 485static void usb_release_dev(struct device *dev)
 486{
 487	struct usb_device *udev;
 488	struct usb_hcd *hcd;
 489
 490	udev = to_usb_device(dev);
 491	hcd = bus_to_hcd(udev->bus);
 492
 493	usb_destroy_configuration(udev);
 494	usb_release_bos_descriptor(udev);
 495	of_node_put(dev->of_node);
 496	usb_put_hcd(hcd);
 497	kfree(udev->product);
 498	kfree(udev->manufacturer);
 499	kfree(udev->serial);
 500	kfree(udev);
 501}
 502
 503static int usb_dev_uevent(const struct device *dev, struct kobj_uevent_env *env)
 504{
 505	const struct usb_device *usb_dev;
 506
 507	usb_dev = to_usb_device(dev);
 508
 509	if (add_uevent_var(env, "BUSNUM=%03d", usb_dev->bus->busnum))
 510		return -ENOMEM;
 511
 512	if (add_uevent_var(env, "DEVNUM=%03d", usb_dev->devnum))
 513		return -ENOMEM;
 514
 515	return 0;
 516}
 517
 518#ifdef	CONFIG_PM
 519
 520/* USB device Power-Management thunks.
 521 * There's no need to distinguish here between quiescing a USB device
 522 * and powering it down; the generic_suspend() routine takes care of
 523 * it by skipping the usb_port_suspend() call for a quiesce.  And for
 524 * USB interfaces there's no difference at all.
 525 */
 526
 527static int usb_dev_prepare(struct device *dev)
 528{
 529	return 0;		/* Implement eventually? */
 530}
 531
 532static void usb_dev_complete(struct device *dev)
 533{
 534	/* Currently used only for rebinding interfaces */
 535	usb_resume_complete(dev);
 536}
 537
 538static int usb_dev_suspend(struct device *dev)
 539{
 540	return usb_suspend(dev, PMSG_SUSPEND);
 541}
 542
 543static int usb_dev_resume(struct device *dev)
 544{
 545	return usb_resume(dev, PMSG_RESUME);
 546}
 547
 548static int usb_dev_freeze(struct device *dev)
 549{
 550	return usb_suspend(dev, PMSG_FREEZE);
 551}
 552
 553static int usb_dev_thaw(struct device *dev)
 554{
 555	return usb_resume(dev, PMSG_THAW);
 556}
 557
 558static int usb_dev_poweroff(struct device *dev)
 559{
 560	return usb_suspend(dev, PMSG_HIBERNATE);
 561}
 562
 563static int usb_dev_restore(struct device *dev)
 564{
 565	return usb_resume(dev, PMSG_RESTORE);
 566}
 567
 568static const struct dev_pm_ops usb_device_pm_ops = {
 569	.prepare =	usb_dev_prepare,
 570	.complete =	usb_dev_complete,
 571	.suspend =	usb_dev_suspend,
 572	.resume =	usb_dev_resume,
 573	.freeze =	usb_dev_freeze,
 574	.thaw =		usb_dev_thaw,
 575	.poweroff =	usb_dev_poweroff,
 576	.restore =	usb_dev_restore,
 577	.runtime_suspend =	usb_runtime_suspend,
 578	.runtime_resume =	usb_runtime_resume,
 579	.runtime_idle =		usb_runtime_idle,
 580};
 581
 582#endif	/* CONFIG_PM */
 583
 584
 585static char *usb_devnode(const struct device *dev,
 586			 umode_t *mode, kuid_t *uid, kgid_t *gid)
 587{
 588	const struct usb_device *usb_dev;
 589
 590	usb_dev = to_usb_device(dev);
 591	return kasprintf(GFP_KERNEL, "bus/usb/%03d/%03d",
 592			 usb_dev->bus->busnum, usb_dev->devnum);
 593}
 594
 595struct device_type usb_device_type = {
 596	.name =		"usb_device",
 597	.release =	usb_release_dev,
 598	.uevent =	usb_dev_uevent,
 599	.devnode = 	usb_devnode,
 600#ifdef CONFIG_PM
 601	.pm =		&usb_device_pm_ops,
 602#endif
 603};
 604
 605static bool usb_dev_authorized(struct usb_device *dev, struct usb_hcd *hcd)
 606{
 607	struct usb_hub *hub;
 608
 609	if (!dev->parent)
 610		return true; /* Root hub always ok [and always wired] */
 611
 612	switch (hcd->dev_policy) {
 613	case USB_DEVICE_AUTHORIZE_NONE:
 614	default:
 615		return false;
 616
 617	case USB_DEVICE_AUTHORIZE_ALL:
 618		return true;
 619
 620	case USB_DEVICE_AUTHORIZE_INTERNAL:
 621		hub = usb_hub_to_struct_hub(dev->parent);
 622		return hub->ports[dev->portnum - 1]->connect_type ==
 623				USB_PORT_CONNECT_TYPE_HARD_WIRED;
 624	}
 625}
 626
 
 627/**
 628 * usb_alloc_dev - usb device constructor (usbcore-internal)
 629 * @parent: hub to which device is connected; null to allocate a root hub
 630 * @bus: bus used to access the device
 631 * @port1: one-based index of port; ignored for root hubs
 632 *
 633 * Context: task context, might sleep.
 634 *
 635 * Only hub drivers (including virtual root hub drivers for host
 636 * controllers) should ever call this.
 637 *
 638 * This call may not be used in a non-sleeping context.
 639 *
 640 * Return: On success, a pointer to the allocated usb device. %NULL on
 641 * failure.
 642 */
 643struct usb_device *usb_alloc_dev(struct usb_device *parent,
 644				 struct usb_bus *bus, unsigned port1)
 645{
 646	struct usb_device *dev;
 647	struct usb_hcd *usb_hcd = bus_to_hcd(bus);
 
 648	unsigned raw_port = port1;
 649
 650	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 651	if (!dev)
 652		return NULL;
 653
 654	if (!usb_get_hcd(usb_hcd)) {
 655		kfree(dev);
 656		return NULL;
 657	}
 658	/* Root hubs aren't true devices, so don't allocate HCD resources */
 659	if (usb_hcd->driver->alloc_dev && parent &&
 660		!usb_hcd->driver->alloc_dev(usb_hcd, dev)) {
 661		usb_put_hcd(bus_to_hcd(bus));
 662		kfree(dev);
 663		return NULL;
 664	}
 665
 666	device_initialize(&dev->dev);
 667	dev->dev.bus = &usb_bus_type;
 668	dev->dev.type = &usb_device_type;
 669	dev->dev.groups = usb_device_groups;
 670	set_dev_node(&dev->dev, dev_to_node(bus->sysdev));
 
 
 
 
 
 
 
 
 
 
 
 
 671	dev->state = USB_STATE_ATTACHED;
 672	dev->lpm_disable_count = 1;
 673	atomic_set(&dev->urbnum, 0);
 674
 675	INIT_LIST_HEAD(&dev->ep0.urb_list);
 676	dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE;
 677	dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT;
 678	/* ep0 maxpacket comes later, from device descriptor */
 679	usb_enable_endpoint(dev, &dev->ep0, false);
 680	dev->can_submit = 1;
 681
 682	/* Save readable and stable topology id, distinguishing devices
 683	 * by location for diagnostics, tools, driver model, etc.  The
 684	 * string is a path along hub ports, from the root.  Each device's
 685	 * dev->devpath will be stable until USB is re-cabled, and hubs
 686	 * are often labeled with these port numbers.  The name isn't
 687	 * as stable:  bus->busnum changes easily from modprobe order,
 688	 * cardbus or pci hotplugging, and so on.
 689	 */
 690	if (unlikely(!parent)) {
 691		dev->devpath[0] = '0';
 692		dev->route = 0;
 693
 694		dev->dev.parent = bus->controller;
 695		device_set_of_node_from_dev(&dev->dev, bus->sysdev);
 696		dev_set_name(&dev->dev, "usb%d", bus->busnum);
 
 697	} else {
 698		/* match any labeling on the hubs; it's one-based */
 699		if (parent->devpath[0] == '0') {
 700			snprintf(dev->devpath, sizeof dev->devpath,
 701				"%d", port1);
 702			/* Root ports are not counted in route string */
 703			dev->route = 0;
 704		} else {
 705			snprintf(dev->devpath, sizeof dev->devpath,
 706				"%s.%d", parent->devpath, port1);
 707			/* Route string assumes hubs have less than 16 ports */
 708			if (port1 < 15)
 709				dev->route = parent->route +
 710					(port1 << ((parent->level - 1)*4));
 711			else
 712				dev->route = parent->route +
 713					(15 << ((parent->level - 1)*4));
 714		}
 715
 716		dev->dev.parent = &parent->dev;
 717		dev_set_name(&dev->dev, "%d-%s", bus->busnum, dev->devpath);
 718
 719		if (!parent->parent) {
 720			/* device under root hub's port */
 721			raw_port = usb_hcd_find_raw_port_number(usb_hcd,
 722				port1);
 723		}
 724		dev->dev.of_node = usb_of_get_device_node(parent, raw_port);
 
 725
 726		/* hub driver sets up TT records */
 727	}
 728
 729	dev->portnum = port1;
 730	dev->bus = bus;
 731	dev->parent = parent;
 732	INIT_LIST_HEAD(&dev->filelist);
 733
 734#ifdef	CONFIG_PM
 735	pm_runtime_set_autosuspend_delay(&dev->dev,
 736			usb_autosuspend_delay * 1000);
 737	dev->connect_time = jiffies;
 738	dev->active_duration = -jiffies;
 739#endif
 740
 741	dev->authorized = usb_dev_authorized(dev, usb_hcd);
 
 
 
 
 742	return dev;
 743}
 744EXPORT_SYMBOL_GPL(usb_alloc_dev);
 745
 746/**
 747 * usb_get_dev - increments the reference count of the usb device structure
 748 * @dev: the device being referenced
 749 *
 750 * Each live reference to a device should be refcounted.
 751 *
 752 * Drivers for USB interfaces should normally record such references in
 753 * their probe() methods, when they bind to an interface, and release
 754 * them by calling usb_put_dev(), in their disconnect() methods.
 755 * However, if a driver does not access the usb_device structure after
 756 * its disconnect() method returns then refcounting is not necessary,
 757 * because the USB core guarantees that a usb_device will not be
 758 * deallocated until after all of its interface drivers have been unbound.
 759 *
 760 * Return: A pointer to the device with the incremented reference counter.
 761 */
 762struct usb_device *usb_get_dev(struct usb_device *dev)
 763{
 764	if (dev)
 765		get_device(&dev->dev);
 766	return dev;
 767}
 768EXPORT_SYMBOL_GPL(usb_get_dev);
 769
 770/**
 771 * usb_put_dev - release a use of the usb device structure
 772 * @dev: device that's been disconnected
 773 *
 774 * Must be called when a user of a device is finished with it.  When the last
 775 * user of the device calls this function, the memory of the device is freed.
 776 */
 777void usb_put_dev(struct usb_device *dev)
 778{
 779	if (dev)
 780		put_device(&dev->dev);
 781}
 782EXPORT_SYMBOL_GPL(usb_put_dev);
 783
 784/**
 785 * usb_get_intf - increments the reference count of the usb interface structure
 786 * @intf: the interface being referenced
 787 *
 788 * Each live reference to a interface must be refcounted.
 789 *
 790 * Drivers for USB interfaces should normally record such references in
 791 * their probe() methods, when they bind to an interface, and release
 792 * them by calling usb_put_intf(), in their disconnect() methods.
 793 * However, if a driver does not access the usb_interface structure after
 794 * its disconnect() method returns then refcounting is not necessary,
 795 * because the USB core guarantees that a usb_interface will not be
 796 * deallocated until after its driver has been unbound.
 797 *
 798 * Return: A pointer to the interface with the incremented reference counter.
 799 */
 800struct usb_interface *usb_get_intf(struct usb_interface *intf)
 801{
 802	if (intf)
 803		get_device(&intf->dev);
 804	return intf;
 805}
 806EXPORT_SYMBOL_GPL(usb_get_intf);
 807
 808/**
 809 * usb_put_intf - release a use of the usb interface structure
 810 * @intf: interface that's been decremented
 811 *
 812 * Must be called when a user of an interface is finished with it.  When the
 813 * last user of the interface calls this function, the memory of the interface
 814 * is freed.
 815 */
 816void usb_put_intf(struct usb_interface *intf)
 817{
 818	if (intf)
 819		put_device(&intf->dev);
 820}
 821EXPORT_SYMBOL_GPL(usb_put_intf);
 822
 823/**
 824 * usb_intf_get_dma_device - acquire a reference on the usb interface's DMA endpoint
 825 * @intf: the usb interface
 826 *
 827 * While a USB device cannot perform DMA operations by itself, many USB
 828 * controllers can. A call to usb_intf_get_dma_device() returns the DMA endpoint
 829 * for the given USB interface, if any. The returned device structure must be
 830 * released with put_device().
 831 *
 832 * See also usb_get_dma_device().
 833 *
 834 * Returns: A reference to the usb interface's DMA endpoint; or NULL if none
 835 *          exists.
 836 */
 837struct device *usb_intf_get_dma_device(struct usb_interface *intf)
 838{
 839	struct usb_device *udev = interface_to_usbdev(intf);
 840	struct device *dmadev;
 841
 842	if (!udev->bus)
 843		return NULL;
 844
 845	dmadev = get_device(udev->bus->sysdev);
 846	if (!dmadev || !dmadev->dma_mask) {
 847		put_device(dmadev);
 848		return NULL;
 849	}
 850
 851	return dmadev;
 852}
 853EXPORT_SYMBOL_GPL(usb_intf_get_dma_device);
 854
 855/*			USB device locking
 856 *
 857 * USB devices and interfaces are locked using the semaphore in their
 858 * embedded struct device.  The hub driver guarantees that whenever a
 859 * device is connected or disconnected, drivers are called with the
 860 * USB device locked as well as their particular interface.
 861 *
 862 * Complications arise when several devices are to be locked at the same
 863 * time.  Only hub-aware drivers that are part of usbcore ever have to
 864 * do this; nobody else needs to worry about it.  The rule for locking
 865 * is simple:
 866 *
 867 *	When locking both a device and its parent, always lock the
 868 *	parent first.
 869 */
 870
 871/**
 872 * usb_lock_device_for_reset - cautiously acquire the lock for a usb device structure
 873 * @udev: device that's being locked
 874 * @iface: interface bound to the driver making the request (optional)
 875 *
 876 * Attempts to acquire the device lock, but fails if the device is
 877 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface
 878 * is neither BINDING nor BOUND.  Rather than sleeping to wait for the
 879 * lock, the routine polls repeatedly.  This is to prevent deadlock with
 880 * disconnect; in some drivers (such as usb-storage) the disconnect()
 881 * or suspend() method will block waiting for a device reset to complete.
 882 *
 883 * Return: A negative error code for failure, otherwise 0.
 884 */
 885int usb_lock_device_for_reset(struct usb_device *udev,
 886			      const struct usb_interface *iface)
 887{
 888	unsigned long jiffies_expire = jiffies + HZ;
 889
 890	if (udev->state == USB_STATE_NOTATTACHED)
 891		return -ENODEV;
 892	if (udev->state == USB_STATE_SUSPENDED)
 893		return -EHOSTUNREACH;
 894	if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
 895			iface->condition == USB_INTERFACE_UNBOUND))
 896		return -EINTR;
 897
 898	while (!usb_trylock_device(udev)) {
 899
 900		/* If we can't acquire the lock after waiting one second,
 901		 * we're probably deadlocked */
 902		if (time_after(jiffies, jiffies_expire))
 903			return -EBUSY;
 904
 905		msleep(15);
 906		if (udev->state == USB_STATE_NOTATTACHED)
 907			return -ENODEV;
 908		if (udev->state == USB_STATE_SUSPENDED)
 909			return -EHOSTUNREACH;
 910		if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
 911				iface->condition == USB_INTERFACE_UNBOUND))
 912			return -EINTR;
 913	}
 914	return 0;
 915}
 916EXPORT_SYMBOL_GPL(usb_lock_device_for_reset);
 917
 918/**
 919 * usb_get_current_frame_number - return current bus frame number
 920 * @dev: the device whose bus is being queried
 921 *
 922 * Return: The current frame number for the USB host controller used
 923 * with the given USB device. This can be used when scheduling
 924 * isochronous requests.
 925 *
 926 * Note: Different kinds of host controller have different "scheduling
 927 * horizons". While one type might support scheduling only 32 frames
 928 * into the future, others could support scheduling up to 1024 frames
 929 * into the future.
 930 *
 931 */
 932int usb_get_current_frame_number(struct usb_device *dev)
 933{
 934	return usb_hcd_get_frame_number(dev);
 935}
 936EXPORT_SYMBOL_GPL(usb_get_current_frame_number);
 937
 938/*-------------------------------------------------------------------*/
 939/*
 940 * __usb_get_extra_descriptor() finds a descriptor of specific type in the
 941 * extra field of the interface and endpoint descriptor structs.
 942 */
 943
 944int __usb_get_extra_descriptor(char *buffer, unsigned size,
 945			       unsigned char type, void **ptr, size_t minsize)
 946{
 947	struct usb_descriptor_header *header;
 948
 949	while (size >= sizeof(struct usb_descriptor_header)) {
 950		header = (struct usb_descriptor_header *)buffer;
 951
 952		if (header->bLength < 2 || header->bLength > size) {
 953			printk(KERN_ERR
 954				"%s: bogus descriptor, type %d length %d\n",
 955				usbcore_name,
 956				header->bDescriptorType,
 957				header->bLength);
 958			return -1;
 959		}
 960
 961		if (header->bDescriptorType == type && header->bLength >= minsize) {
 962			*ptr = header;
 963			return 0;
 964		}
 965
 966		buffer += header->bLength;
 967		size -= header->bLength;
 968	}
 969	return -1;
 970}
 971EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor);
 972
 973/**
 974 * usb_alloc_coherent - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
 975 * @dev: device the buffer will be used with
 976 * @size: requested buffer size
 977 * @mem_flags: affect whether allocation may block
 978 * @dma: used to return DMA address of buffer
 979 *
 980 * Return: Either null (indicating no buffer could be allocated), or the
 981 * cpu-space pointer to a buffer that may be used to perform DMA to the
 982 * specified device.  Such cpu-space buffers are returned along with the DMA
 983 * address (through the pointer provided).
 984 *
 985 * Note:
 986 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
 987 * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU
 988 * hardware during URB completion/resubmit.  The implementation varies between
 989 * platforms, depending on details of how DMA will work to this device.
 990 * Using these buffers also eliminates cacheline sharing problems on
 991 * architectures where CPU caches are not DMA-coherent.  On systems without
 992 * bus-snooping caches, these buffers are uncached.
 993 *
 994 * When the buffer is no longer used, free it with usb_free_coherent().
 995 */
 996void *usb_alloc_coherent(struct usb_device *dev, size_t size, gfp_t mem_flags,
 997			 dma_addr_t *dma)
 998{
 999	if (!dev || !dev->bus)
1000		return NULL;
1001	return hcd_buffer_alloc(dev->bus, size, mem_flags, dma);
1002}
1003EXPORT_SYMBOL_GPL(usb_alloc_coherent);
1004
1005/**
1006 * usb_free_coherent - free memory allocated with usb_alloc_coherent()
1007 * @dev: device the buffer was used with
1008 * @size: requested buffer size
1009 * @addr: CPU address of buffer
1010 * @dma: DMA address of buffer
1011 *
1012 * This reclaims an I/O buffer, letting it be reused.  The memory must have
1013 * been allocated using usb_alloc_coherent(), and the parameters must match
1014 * those provided in that allocation request.
1015 */
1016void usb_free_coherent(struct usb_device *dev, size_t size, void *addr,
1017		       dma_addr_t dma)
1018{
1019	if (!dev || !dev->bus)
1020		return;
1021	if (!addr)
1022		return;
1023	hcd_buffer_free(dev->bus, size, addr, dma);
1024}
1025EXPORT_SYMBOL_GPL(usb_free_coherent);
1026
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1027/*
1028 * Notifications of device and interface registration
1029 */
1030static int usb_bus_notify(struct notifier_block *nb, unsigned long action,
1031		void *data)
1032{
1033	struct device *dev = data;
1034
1035	switch (action) {
1036	case BUS_NOTIFY_ADD_DEVICE:
1037		if (dev->type == &usb_device_type)
1038			(void) usb_create_sysfs_dev_files(to_usb_device(dev));
1039		else if (dev->type == &usb_if_device_type)
1040			usb_create_sysfs_intf_files(to_usb_interface(dev));
1041		break;
1042
1043	case BUS_NOTIFY_DEL_DEVICE:
1044		if (dev->type == &usb_device_type)
1045			usb_remove_sysfs_dev_files(to_usb_device(dev));
1046		else if (dev->type == &usb_if_device_type)
1047			usb_remove_sysfs_intf_files(to_usb_interface(dev));
1048		break;
1049	}
1050	return 0;
1051}
1052
1053static struct notifier_block usb_bus_nb = {
1054	.notifier_call = usb_bus_notify,
1055};
1056
1057static void usb_debugfs_init(void)
 
 
 
 
 
1058{
1059	debugfs_create_file("devices", 0444, usb_debug_root, NULL,
1060			    &usbfs_devices_fops);
 
 
 
 
 
 
 
 
 
 
 
 
1061}
1062
1063static void usb_debugfs_cleanup(void)
1064{
1065	debugfs_lookup_and_remove("devices", usb_debug_root);
 
1066}
1067
1068/*
1069 * Init
1070 */
1071static int __init usb_init(void)
1072{
1073	int retval;
1074	if (usb_disabled()) {
1075		pr_info("%s: USB support disabled\n", usbcore_name);
1076		return 0;
1077	}
1078	usb_init_pool_max();
1079
1080	usb_debugfs_init();
 
 
1081
1082	usb_acpi_register();
1083	retval = bus_register(&usb_bus_type);
1084	if (retval)
1085		goto bus_register_failed;
1086	retval = bus_register_notifier(&usb_bus_type, &usb_bus_nb);
1087	if (retval)
1088		goto bus_notifier_failed;
1089	retval = usb_major_init();
1090	if (retval)
1091		goto major_init_failed;
1092	retval = class_register(&usbmisc_class);
1093	if (retval)
1094		goto class_register_failed;
1095	retval = usb_register(&usbfs_driver);
1096	if (retval)
1097		goto driver_register_failed;
1098	retval = usb_devio_init();
1099	if (retval)
1100		goto usb_devio_init_failed;
1101	retval = usb_hub_init();
1102	if (retval)
1103		goto hub_init_failed;
1104	retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE);
1105	if (!retval)
1106		goto out;
1107
1108	usb_hub_cleanup();
1109hub_init_failed:
1110	usb_devio_cleanup();
1111usb_devio_init_failed:
1112	usb_deregister(&usbfs_driver);
1113driver_register_failed:
1114	class_unregister(&usbmisc_class);
1115class_register_failed:
1116	usb_major_cleanup();
1117major_init_failed:
1118	bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1119bus_notifier_failed:
1120	bus_unregister(&usb_bus_type);
1121bus_register_failed:
1122	usb_acpi_unregister();
1123	usb_debugfs_cleanup();
1124out:
1125	return retval;
1126}
1127
1128/*
1129 * Cleanup
1130 */
1131static void __exit usb_exit(void)
1132{
1133	/* This will matter if shutdown/reboot does exitcalls. */
1134	if (usb_disabled())
1135		return;
1136
1137	usb_release_quirk_list();
1138	usb_deregister_device_driver(&usb_generic_driver);
1139	usb_major_cleanup();
1140	usb_deregister(&usbfs_driver);
1141	usb_devio_cleanup();
1142	usb_hub_cleanup();
1143	class_unregister(&usbmisc_class);
1144	bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1145	bus_unregister(&usb_bus_type);
1146	usb_acpi_unregister();
1147	usb_debugfs_cleanup();
1148	idr_destroy(&usb_bus_idr);
1149}
1150
1151subsys_initcall(usb_init);
1152module_exit(usb_exit);
1153MODULE_LICENSE("GPL");
v4.10.11
 
   1/*
   2 * drivers/usb/core/usb.c
   3 *
   4 * (C) Copyright Linus Torvalds 1999
   5 * (C) Copyright Johannes Erdfelt 1999-2001
   6 * (C) Copyright Andreas Gal 1999
   7 * (C) Copyright Gregory P. Smith 1999
   8 * (C) Copyright Deti Fliegl 1999 (new USB architecture)
   9 * (C) Copyright Randy Dunlap 2000
  10 * (C) Copyright David Brownell 2000-2004
  11 * (C) Copyright Yggdrasil Computing, Inc. 2000
  12 *     (usb_device_id matching changes by Adam J. Richter)
  13 * (C) Copyright Greg Kroah-Hartman 2002-2003
  14 *
  15 * Released under the GPLv2 only.
  16 * SPDX-License-Identifier: GPL-2.0
  17 *
  18 * NOTE! This is not actually a driver at all, rather this is
  19 * just a collection of helper routines that implement the
  20 * generic USB things that the real drivers can use..
  21 *
  22 * Think of this as a "USB library" rather than anything else.
  23 * It should be considered a slave, with no callbacks. Callbacks
  24 * are evil.
  25 */
  26
  27#include <linux/module.h>
  28#include <linux/moduleparam.h>
 
  29#include <linux/string.h>
  30#include <linux/bitops.h>
  31#include <linux/slab.h>
  32#include <linux/interrupt.h>  /* for in_interrupt() */
  33#include <linux/kmod.h>
  34#include <linux/init.h>
  35#include <linux/spinlock.h>
  36#include <linux/errno.h>
  37#include <linux/usb.h>
  38#include <linux/usb/hcd.h>
  39#include <linux/mutex.h>
  40#include <linux/workqueue.h>
  41#include <linux/debugfs.h>
  42#include <linux/usb/of.h>
  43
  44#include <asm/io.h>
  45#include <linux/scatterlist.h>
  46#include <linux/mm.h>
  47#include <linux/dma-mapping.h>
  48
  49#include "usb.h"
  50
  51
  52const char *usbcore_name = "usbcore";
  53
  54static bool nousb;	/* Disable USB when built into kernel image */
  55
  56module_param(nousb, bool, 0444);
  57
  58/*
  59 * for external read access to <nousb>
  60 */
  61int usb_disabled(void)
  62{
  63	return nousb;
  64}
  65EXPORT_SYMBOL_GPL(usb_disabled);
  66
  67#ifdef	CONFIG_PM
  68static int usb_autosuspend_delay = 2;		/* Default delay value,
  69						 * in seconds */
  70module_param_named(autosuspend, usb_autosuspend_delay, int, 0644);
  71MODULE_PARM_DESC(autosuspend, "default autosuspend delay");
  72
  73#else
  74#define usb_autosuspend_delay		0
  75#endif
  76
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  77
  78/**
  79 * usb_find_alt_setting() - Given a configuration, find the alternate setting
  80 * for the given interface.
  81 * @config: the configuration to search (not necessarily the current config).
  82 * @iface_num: interface number to search in
  83 * @alt_num: alternate interface setting number to search for.
  84 *
  85 * Search the configuration's interface cache for the given alt setting.
  86 *
  87 * Return: The alternate setting, if found. %NULL otherwise.
  88 */
  89struct usb_host_interface *usb_find_alt_setting(
  90		struct usb_host_config *config,
  91		unsigned int iface_num,
  92		unsigned int alt_num)
  93{
  94	struct usb_interface_cache *intf_cache = NULL;
  95	int i;
  96
 
 
  97	for (i = 0; i < config->desc.bNumInterfaces; i++) {
  98		if (config->intf_cache[i]->altsetting[0].desc.bInterfaceNumber
  99				== iface_num) {
 100			intf_cache = config->intf_cache[i];
 101			break;
 102		}
 103	}
 104	if (!intf_cache)
 105		return NULL;
 106	for (i = 0; i < intf_cache->num_altsetting; i++)
 107		if (intf_cache->altsetting[i].desc.bAlternateSetting == alt_num)
 108			return &intf_cache->altsetting[i];
 109
 110	printk(KERN_DEBUG "Did not find alt setting %u for intf %u, "
 111			"config %u\n", alt_num, iface_num,
 112			config->desc.bConfigurationValue);
 113	return NULL;
 114}
 115EXPORT_SYMBOL_GPL(usb_find_alt_setting);
 116
 117/**
 118 * usb_ifnum_to_if - get the interface object with a given interface number
 119 * @dev: the device whose current configuration is considered
 120 * @ifnum: the desired interface
 121 *
 122 * This walks the device descriptor for the currently active configuration
 123 * to find the interface object with the particular interface number.
 124 *
 125 * Note that configuration descriptors are not required to assign interface
 126 * numbers sequentially, so that it would be incorrect to assume that
 127 * the first interface in that descriptor corresponds to interface zero.
 128 * This routine helps device drivers avoid such mistakes.
 129 * However, you should make sure that you do the right thing with any
 130 * alternate settings available for this interfaces.
 131 *
 132 * Don't call this function unless you are bound to one of the interfaces
 133 * on this device or you have locked the device!
 134 *
 135 * Return: A pointer to the interface that has @ifnum as interface number,
 136 * if found. %NULL otherwise.
 137 */
 138struct usb_interface *usb_ifnum_to_if(const struct usb_device *dev,
 139				      unsigned ifnum)
 140{
 141	struct usb_host_config *config = dev->actconfig;
 142	int i;
 143
 144	if (!config)
 145		return NULL;
 146	for (i = 0; i < config->desc.bNumInterfaces; i++)
 147		if (config->interface[i]->altsetting[0]
 148				.desc.bInterfaceNumber == ifnum)
 149			return config->interface[i];
 150
 151	return NULL;
 152}
 153EXPORT_SYMBOL_GPL(usb_ifnum_to_if);
 154
 155/**
 156 * usb_altnum_to_altsetting - get the altsetting structure with a given alternate setting number.
 157 * @intf: the interface containing the altsetting in question
 158 * @altnum: the desired alternate setting number
 159 *
 160 * This searches the altsetting array of the specified interface for
 161 * an entry with the correct bAlternateSetting value.
 162 *
 163 * Note that altsettings need not be stored sequentially by number, so
 164 * it would be incorrect to assume that the first altsetting entry in
 165 * the array corresponds to altsetting zero.  This routine helps device
 166 * drivers avoid such mistakes.
 167 *
 168 * Don't call this function unless you are bound to the intf interface
 169 * or you have locked the device!
 170 *
 171 * Return: A pointer to the entry of the altsetting array of @intf that
 172 * has @altnum as the alternate setting number. %NULL if not found.
 173 */
 174struct usb_host_interface *usb_altnum_to_altsetting(
 175					const struct usb_interface *intf,
 176					unsigned int altnum)
 177{
 178	int i;
 179
 180	for (i = 0; i < intf->num_altsetting; i++) {
 181		if (intf->altsetting[i].desc.bAlternateSetting == altnum)
 182			return &intf->altsetting[i];
 183	}
 184	return NULL;
 185}
 186EXPORT_SYMBOL_GPL(usb_altnum_to_altsetting);
 187
 188struct find_interface_arg {
 189	int minor;
 190	struct device_driver *drv;
 191};
 192
 193static int __find_interface(struct device *dev, void *data)
 194{
 195	struct find_interface_arg *arg = data;
 196	struct usb_interface *intf;
 197
 198	if (!is_usb_interface(dev))
 199		return 0;
 200
 201	if (dev->driver != arg->drv)
 202		return 0;
 203	intf = to_usb_interface(dev);
 204	return intf->minor == arg->minor;
 205}
 206
 207/**
 208 * usb_find_interface - find usb_interface pointer for driver and device
 209 * @drv: the driver whose current configuration is considered
 210 * @minor: the minor number of the desired device
 211 *
 212 * This walks the bus device list and returns a pointer to the interface
 213 * with the matching minor and driver.  Note, this only works for devices
 214 * that share the USB major number.
 215 *
 216 * Return: A pointer to the interface with the matching major and @minor.
 217 */
 218struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor)
 219{
 220	struct find_interface_arg argb;
 221	struct device *dev;
 222
 223	argb.minor = minor;
 224	argb.drv = &drv->drvwrap.driver;
 225
 226	dev = bus_find_device(&usb_bus_type, NULL, &argb, __find_interface);
 227
 228	/* Drop reference count from bus_find_device */
 229	put_device(dev);
 230
 231	return dev ? to_usb_interface(dev) : NULL;
 232}
 233EXPORT_SYMBOL_GPL(usb_find_interface);
 234
 235struct each_dev_arg {
 236	void *data;
 237	int (*fn)(struct usb_device *, void *);
 238};
 239
 240static int __each_dev(struct device *dev, void *data)
 241{
 242	struct each_dev_arg *arg = (struct each_dev_arg *)data;
 243
 244	/* There are struct usb_interface on the same bus, filter them out */
 245	if (!is_usb_device(dev))
 246		return 0;
 247
 248	return arg->fn(to_usb_device(dev), arg->data);
 249}
 250
 251/**
 252 * usb_for_each_dev - iterate over all USB devices in the system
 253 * @data: data pointer that will be handed to the callback function
 254 * @fn: callback function to be called for each USB device
 255 *
 256 * Iterate over all USB devices and call @fn for each, passing it @data. If it
 257 * returns anything other than 0, we break the iteration prematurely and return
 258 * that value.
 259 */
 260int usb_for_each_dev(void *data, int (*fn)(struct usb_device *, void *))
 261{
 262	struct each_dev_arg arg = {data, fn};
 263
 264	return bus_for_each_dev(&usb_bus_type, NULL, &arg, __each_dev);
 265}
 266EXPORT_SYMBOL_GPL(usb_for_each_dev);
 267
 268/**
 269 * usb_release_dev - free a usb device structure when all users of it are finished.
 270 * @dev: device that's been disconnected
 271 *
 272 * Will be called only by the device core when all users of this usb device are
 273 * done.
 274 */
 275static void usb_release_dev(struct device *dev)
 276{
 277	struct usb_device *udev;
 278	struct usb_hcd *hcd;
 279
 280	udev = to_usb_device(dev);
 281	hcd = bus_to_hcd(udev->bus);
 282
 283	usb_destroy_configuration(udev);
 284	usb_release_bos_descriptor(udev);
 
 285	usb_put_hcd(hcd);
 286	kfree(udev->product);
 287	kfree(udev->manufacturer);
 288	kfree(udev->serial);
 289	kfree(udev);
 290}
 291
 292static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
 293{
 294	struct usb_device *usb_dev;
 295
 296	usb_dev = to_usb_device(dev);
 297
 298	if (add_uevent_var(env, "BUSNUM=%03d", usb_dev->bus->busnum))
 299		return -ENOMEM;
 300
 301	if (add_uevent_var(env, "DEVNUM=%03d", usb_dev->devnum))
 302		return -ENOMEM;
 303
 304	return 0;
 305}
 306
 307#ifdef	CONFIG_PM
 308
 309/* USB device Power-Management thunks.
 310 * There's no need to distinguish here between quiescing a USB device
 311 * and powering it down; the generic_suspend() routine takes care of
 312 * it by skipping the usb_port_suspend() call for a quiesce.  And for
 313 * USB interfaces there's no difference at all.
 314 */
 315
 316static int usb_dev_prepare(struct device *dev)
 317{
 318	return 0;		/* Implement eventually? */
 319}
 320
 321static void usb_dev_complete(struct device *dev)
 322{
 323	/* Currently used only for rebinding interfaces */
 324	usb_resume_complete(dev);
 325}
 326
 327static int usb_dev_suspend(struct device *dev)
 328{
 329	return usb_suspend(dev, PMSG_SUSPEND);
 330}
 331
 332static int usb_dev_resume(struct device *dev)
 333{
 334	return usb_resume(dev, PMSG_RESUME);
 335}
 336
 337static int usb_dev_freeze(struct device *dev)
 338{
 339	return usb_suspend(dev, PMSG_FREEZE);
 340}
 341
 342static int usb_dev_thaw(struct device *dev)
 343{
 344	return usb_resume(dev, PMSG_THAW);
 345}
 346
 347static int usb_dev_poweroff(struct device *dev)
 348{
 349	return usb_suspend(dev, PMSG_HIBERNATE);
 350}
 351
 352static int usb_dev_restore(struct device *dev)
 353{
 354	return usb_resume(dev, PMSG_RESTORE);
 355}
 356
 357static const struct dev_pm_ops usb_device_pm_ops = {
 358	.prepare =	usb_dev_prepare,
 359	.complete =	usb_dev_complete,
 360	.suspend =	usb_dev_suspend,
 361	.resume =	usb_dev_resume,
 362	.freeze =	usb_dev_freeze,
 363	.thaw =		usb_dev_thaw,
 364	.poweroff =	usb_dev_poweroff,
 365	.restore =	usb_dev_restore,
 366	.runtime_suspend =	usb_runtime_suspend,
 367	.runtime_resume =	usb_runtime_resume,
 368	.runtime_idle =		usb_runtime_idle,
 369};
 370
 371#endif	/* CONFIG_PM */
 372
 373
 374static char *usb_devnode(struct device *dev,
 375			 umode_t *mode, kuid_t *uid, kgid_t *gid)
 376{
 377	struct usb_device *usb_dev;
 378
 379	usb_dev = to_usb_device(dev);
 380	return kasprintf(GFP_KERNEL, "bus/usb/%03d/%03d",
 381			 usb_dev->bus->busnum, usb_dev->devnum);
 382}
 383
 384struct device_type usb_device_type = {
 385	.name =		"usb_device",
 386	.release =	usb_release_dev,
 387	.uevent =	usb_dev_uevent,
 388	.devnode = 	usb_devnode,
 389#ifdef CONFIG_PM
 390	.pm =		&usb_device_pm_ops,
 391#endif
 392};
 393
 
 
 
 
 
 
 
 
 
 
 
 394
 395/* Returns 1 if @usb_bus is WUSB, 0 otherwise */
 396static unsigned usb_bus_is_wusb(struct usb_bus *bus)
 397{
 398	struct usb_hcd *hcd = bus_to_hcd(bus);
 399	return hcd->wireless;
 
 
 
 400}
 401
 402
 403/**
 404 * usb_alloc_dev - usb device constructor (usbcore-internal)
 405 * @parent: hub to which device is connected; null to allocate a root hub
 406 * @bus: bus used to access the device
 407 * @port1: one-based index of port; ignored for root hubs
 408 * Context: !in_interrupt()
 
 409 *
 410 * Only hub drivers (including virtual root hub drivers for host
 411 * controllers) should ever call this.
 412 *
 413 * This call may not be used in a non-sleeping context.
 414 *
 415 * Return: On success, a pointer to the allocated usb device. %NULL on
 416 * failure.
 417 */
 418struct usb_device *usb_alloc_dev(struct usb_device *parent,
 419				 struct usb_bus *bus, unsigned port1)
 420{
 421	struct usb_device *dev;
 422	struct usb_hcd *usb_hcd = bus_to_hcd(bus);
 423	unsigned root_hub = 0;
 424	unsigned raw_port = port1;
 425
 426	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 427	if (!dev)
 428		return NULL;
 429
 430	if (!usb_get_hcd(usb_hcd)) {
 431		kfree(dev);
 432		return NULL;
 433	}
 434	/* Root hubs aren't true devices, so don't allocate HCD resources */
 435	if (usb_hcd->driver->alloc_dev && parent &&
 436		!usb_hcd->driver->alloc_dev(usb_hcd, dev)) {
 437		usb_put_hcd(bus_to_hcd(bus));
 438		kfree(dev);
 439		return NULL;
 440	}
 441
 442	device_initialize(&dev->dev);
 443	dev->dev.bus = &usb_bus_type;
 444	dev->dev.type = &usb_device_type;
 445	dev->dev.groups = usb_device_groups;
 446	/*
 447	 * Fake a dma_mask/offset for the USB device:
 448	 * We cannot really use the dma-mapping API (dma_alloc_* and
 449	 * dma_map_*) for USB devices but instead need to use
 450	 * usb_alloc_coherent and pass data in 'urb's, but some subsystems
 451	 * manually look into the mask/offset pair to determine whether
 452	 * they need bounce buffers.
 453	 * Note: calling dma_set_mask() on a USB device would set the
 454	 * mask for the entire HCD, so don't do that.
 455	 */
 456	dev->dev.dma_mask = bus->controller->dma_mask;
 457	dev->dev.dma_pfn_offset = bus->controller->dma_pfn_offset;
 458	set_dev_node(&dev->dev, dev_to_node(bus->controller));
 459	dev->state = USB_STATE_ATTACHED;
 460	dev->lpm_disable_count = 1;
 461	atomic_set(&dev->urbnum, 0);
 462
 463	INIT_LIST_HEAD(&dev->ep0.urb_list);
 464	dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE;
 465	dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT;
 466	/* ep0 maxpacket comes later, from device descriptor */
 467	usb_enable_endpoint(dev, &dev->ep0, false);
 468	dev->can_submit = 1;
 469
 470	/* Save readable and stable topology id, distinguishing devices
 471	 * by location for diagnostics, tools, driver model, etc.  The
 472	 * string is a path along hub ports, from the root.  Each device's
 473	 * dev->devpath will be stable until USB is re-cabled, and hubs
 474	 * are often labeled with these port numbers.  The name isn't
 475	 * as stable:  bus->busnum changes easily from modprobe order,
 476	 * cardbus or pci hotplugging, and so on.
 477	 */
 478	if (unlikely(!parent)) {
 479		dev->devpath[0] = '0';
 480		dev->route = 0;
 481
 482		dev->dev.parent = bus->controller;
 
 483		dev_set_name(&dev->dev, "usb%d", bus->busnum);
 484		root_hub = 1;
 485	} else {
 486		/* match any labeling on the hubs; it's one-based */
 487		if (parent->devpath[0] == '0') {
 488			snprintf(dev->devpath, sizeof dev->devpath,
 489				"%d", port1);
 490			/* Root ports are not counted in route string */
 491			dev->route = 0;
 492		} else {
 493			snprintf(dev->devpath, sizeof dev->devpath,
 494				"%s.%d", parent->devpath, port1);
 495			/* Route string assumes hubs have less than 16 ports */
 496			if (port1 < 15)
 497				dev->route = parent->route +
 498					(port1 << ((parent->level - 1)*4));
 499			else
 500				dev->route = parent->route +
 501					(15 << ((parent->level - 1)*4));
 502		}
 503
 504		dev->dev.parent = &parent->dev;
 505		dev_set_name(&dev->dev, "%d-%s", bus->busnum, dev->devpath);
 506
 507		if (!parent->parent) {
 508			/* device under root hub's port */
 509			raw_port = usb_hcd_find_raw_port_number(usb_hcd,
 510				port1);
 511		}
 512		dev->dev.of_node = usb_of_get_child_node(parent->dev.of_node,
 513				raw_port);
 514
 515		/* hub driver sets up TT records */
 516	}
 517
 518	dev->portnum = port1;
 519	dev->bus = bus;
 520	dev->parent = parent;
 521	INIT_LIST_HEAD(&dev->filelist);
 522
 523#ifdef	CONFIG_PM
 524	pm_runtime_set_autosuspend_delay(&dev->dev,
 525			usb_autosuspend_delay * 1000);
 526	dev->connect_time = jiffies;
 527	dev->active_duration = -jiffies;
 528#endif
 529	if (root_hub)	/* Root hub always ok [and always wired] */
 530		dev->authorized = 1;
 531	else {
 532		dev->authorized = !!HCD_DEV_AUTHORIZED(usb_hcd);
 533		dev->wusb = usb_bus_is_wusb(bus) ? 1 : 0;
 534	}
 535	return dev;
 536}
 537EXPORT_SYMBOL_GPL(usb_alloc_dev);
 538
 539/**
 540 * usb_get_dev - increments the reference count of the usb device structure
 541 * @dev: the device being referenced
 542 *
 543 * Each live reference to a device should be refcounted.
 544 *
 545 * Drivers for USB interfaces should normally record such references in
 546 * their probe() methods, when they bind to an interface, and release
 547 * them by calling usb_put_dev(), in their disconnect() methods.
 
 
 
 
 548 *
 549 * Return: A pointer to the device with the incremented reference counter.
 550 */
 551struct usb_device *usb_get_dev(struct usb_device *dev)
 552{
 553	if (dev)
 554		get_device(&dev->dev);
 555	return dev;
 556}
 557EXPORT_SYMBOL_GPL(usb_get_dev);
 558
 559/**
 560 * usb_put_dev - release a use of the usb device structure
 561 * @dev: device that's been disconnected
 562 *
 563 * Must be called when a user of a device is finished with it.  When the last
 564 * user of the device calls this function, the memory of the device is freed.
 565 */
 566void usb_put_dev(struct usb_device *dev)
 567{
 568	if (dev)
 569		put_device(&dev->dev);
 570}
 571EXPORT_SYMBOL_GPL(usb_put_dev);
 572
 573/**
 574 * usb_get_intf - increments the reference count of the usb interface structure
 575 * @intf: the interface being referenced
 576 *
 577 * Each live reference to a interface must be refcounted.
 578 *
 579 * Drivers for USB interfaces should normally record such references in
 580 * their probe() methods, when they bind to an interface, and release
 581 * them by calling usb_put_intf(), in their disconnect() methods.
 
 
 
 
 582 *
 583 * Return: A pointer to the interface with the incremented reference counter.
 584 */
 585struct usb_interface *usb_get_intf(struct usb_interface *intf)
 586{
 587	if (intf)
 588		get_device(&intf->dev);
 589	return intf;
 590}
 591EXPORT_SYMBOL_GPL(usb_get_intf);
 592
 593/**
 594 * usb_put_intf - release a use of the usb interface structure
 595 * @intf: interface that's been decremented
 596 *
 597 * Must be called when a user of an interface is finished with it.  When the
 598 * last user of the interface calls this function, the memory of the interface
 599 * is freed.
 600 */
 601void usb_put_intf(struct usb_interface *intf)
 602{
 603	if (intf)
 604		put_device(&intf->dev);
 605}
 606EXPORT_SYMBOL_GPL(usb_put_intf);
 607
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 608/*			USB device locking
 609 *
 610 * USB devices and interfaces are locked using the semaphore in their
 611 * embedded struct device.  The hub driver guarantees that whenever a
 612 * device is connected or disconnected, drivers are called with the
 613 * USB device locked as well as their particular interface.
 614 *
 615 * Complications arise when several devices are to be locked at the same
 616 * time.  Only hub-aware drivers that are part of usbcore ever have to
 617 * do this; nobody else needs to worry about it.  The rule for locking
 618 * is simple:
 619 *
 620 *	When locking both a device and its parent, always lock the
 621 *	the parent first.
 622 */
 623
 624/**
 625 * usb_lock_device_for_reset - cautiously acquire the lock for a usb device structure
 626 * @udev: device that's being locked
 627 * @iface: interface bound to the driver making the request (optional)
 628 *
 629 * Attempts to acquire the device lock, but fails if the device is
 630 * NOTATTACHED or SUSPENDED, or if iface is specified and the interface
 631 * is neither BINDING nor BOUND.  Rather than sleeping to wait for the
 632 * lock, the routine polls repeatedly.  This is to prevent deadlock with
 633 * disconnect; in some drivers (such as usb-storage) the disconnect()
 634 * or suspend() method will block waiting for a device reset to complete.
 635 *
 636 * Return: A negative error code for failure, otherwise 0.
 637 */
 638int usb_lock_device_for_reset(struct usb_device *udev,
 639			      const struct usb_interface *iface)
 640{
 641	unsigned long jiffies_expire = jiffies + HZ;
 642
 643	if (udev->state == USB_STATE_NOTATTACHED)
 644		return -ENODEV;
 645	if (udev->state == USB_STATE_SUSPENDED)
 646		return -EHOSTUNREACH;
 647	if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
 648			iface->condition == USB_INTERFACE_UNBOUND))
 649		return -EINTR;
 650
 651	while (!usb_trylock_device(udev)) {
 652
 653		/* If we can't acquire the lock after waiting one second,
 654		 * we're probably deadlocked */
 655		if (time_after(jiffies, jiffies_expire))
 656			return -EBUSY;
 657
 658		msleep(15);
 659		if (udev->state == USB_STATE_NOTATTACHED)
 660			return -ENODEV;
 661		if (udev->state == USB_STATE_SUSPENDED)
 662			return -EHOSTUNREACH;
 663		if (iface && (iface->condition == USB_INTERFACE_UNBINDING ||
 664				iface->condition == USB_INTERFACE_UNBOUND))
 665			return -EINTR;
 666	}
 667	return 0;
 668}
 669EXPORT_SYMBOL_GPL(usb_lock_device_for_reset);
 670
 671/**
 672 * usb_get_current_frame_number - return current bus frame number
 673 * @dev: the device whose bus is being queried
 674 *
 675 * Return: The current frame number for the USB host controller used
 676 * with the given USB device. This can be used when scheduling
 677 * isochronous requests.
 678 *
 679 * Note: Different kinds of host controller have different "scheduling
 680 * horizons". While one type might support scheduling only 32 frames
 681 * into the future, others could support scheduling up to 1024 frames
 682 * into the future.
 683 *
 684 */
 685int usb_get_current_frame_number(struct usb_device *dev)
 686{
 687	return usb_hcd_get_frame_number(dev);
 688}
 689EXPORT_SYMBOL_GPL(usb_get_current_frame_number);
 690
 691/*-------------------------------------------------------------------*/
 692/*
 693 * __usb_get_extra_descriptor() finds a descriptor of specific type in the
 694 * extra field of the interface and endpoint descriptor structs.
 695 */
 696
 697int __usb_get_extra_descriptor(char *buffer, unsigned size,
 698			       unsigned char type, void **ptr)
 699{
 700	struct usb_descriptor_header *header;
 701
 702	while (size >= sizeof(struct usb_descriptor_header)) {
 703		header = (struct usb_descriptor_header *)buffer;
 704
 705		if (header->bLength < 2) {
 706			printk(KERN_ERR
 707				"%s: bogus descriptor, type %d length %d\n",
 708				usbcore_name,
 709				header->bDescriptorType,
 710				header->bLength);
 711			return -1;
 712		}
 713
 714		if (header->bDescriptorType == type) {
 715			*ptr = header;
 716			return 0;
 717		}
 718
 719		buffer += header->bLength;
 720		size -= header->bLength;
 721	}
 722	return -1;
 723}
 724EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor);
 725
 726/**
 727 * usb_alloc_coherent - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
 728 * @dev: device the buffer will be used with
 729 * @size: requested buffer size
 730 * @mem_flags: affect whether allocation may block
 731 * @dma: used to return DMA address of buffer
 732 *
 733 * Return: Either null (indicating no buffer could be allocated), or the
 734 * cpu-space pointer to a buffer that may be used to perform DMA to the
 735 * specified device.  Such cpu-space buffers are returned along with the DMA
 736 * address (through the pointer provided).
 737 *
 738 * Note:
 739 * These buffers are used with URB_NO_xxx_DMA_MAP set in urb->transfer_flags
 740 * to avoid behaviors like using "DMA bounce buffers", or thrashing IOMMU
 741 * hardware during URB completion/resubmit.  The implementation varies between
 742 * platforms, depending on details of how DMA will work to this device.
 743 * Using these buffers also eliminates cacheline sharing problems on
 744 * architectures where CPU caches are not DMA-coherent.  On systems without
 745 * bus-snooping caches, these buffers are uncached.
 746 *
 747 * When the buffer is no longer used, free it with usb_free_coherent().
 748 */
 749void *usb_alloc_coherent(struct usb_device *dev, size_t size, gfp_t mem_flags,
 750			 dma_addr_t *dma)
 751{
 752	if (!dev || !dev->bus)
 753		return NULL;
 754	return hcd_buffer_alloc(dev->bus, size, mem_flags, dma);
 755}
 756EXPORT_SYMBOL_GPL(usb_alloc_coherent);
 757
 758/**
 759 * usb_free_coherent - free memory allocated with usb_alloc_coherent()
 760 * @dev: device the buffer was used with
 761 * @size: requested buffer size
 762 * @addr: CPU address of buffer
 763 * @dma: DMA address of buffer
 764 *
 765 * This reclaims an I/O buffer, letting it be reused.  The memory must have
 766 * been allocated using usb_alloc_coherent(), and the parameters must match
 767 * those provided in that allocation request.
 768 */
 769void usb_free_coherent(struct usb_device *dev, size_t size, void *addr,
 770		       dma_addr_t dma)
 771{
 772	if (!dev || !dev->bus)
 773		return;
 774	if (!addr)
 775		return;
 776	hcd_buffer_free(dev->bus, size, addr, dma);
 777}
 778EXPORT_SYMBOL_GPL(usb_free_coherent);
 779
 780/**
 781 * usb_buffer_map - create DMA mapping(s) for an urb
 782 * @urb: urb whose transfer_buffer/setup_packet will be mapped
 783 *
 784 * URB_NO_TRANSFER_DMA_MAP is added to urb->transfer_flags if the operation
 785 * succeeds. If the device is connected to this system through a non-DMA
 786 * controller, this operation always succeeds.
 787 *
 788 * This call would normally be used for an urb which is reused, perhaps
 789 * as the target of a large periodic transfer, with usb_buffer_dmasync()
 790 * calls to synchronize memory and dma state.
 791 *
 792 * Reverse the effect of this call with usb_buffer_unmap().
 793 *
 794 * Return: Either %NULL (indicating no buffer could be mapped), or @urb.
 795 *
 796 */
 797#if 0
 798struct urb *usb_buffer_map(struct urb *urb)
 799{
 800	struct usb_bus		*bus;
 801	struct device		*controller;
 802
 803	if (!urb
 804			|| !urb->dev
 805			|| !(bus = urb->dev->bus)
 806			|| !(controller = bus->controller))
 807		return NULL;
 808
 809	if (controller->dma_mask) {
 810		urb->transfer_dma = dma_map_single(controller,
 811			urb->transfer_buffer, urb->transfer_buffer_length,
 812			usb_pipein(urb->pipe)
 813				? DMA_FROM_DEVICE : DMA_TO_DEVICE);
 814	/* FIXME generic api broken like pci, can't report errors */
 815	/* if (urb->transfer_dma == DMA_ADDR_INVALID) return 0; */
 816	} else
 817		urb->transfer_dma = ~0;
 818	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 819	return urb;
 820}
 821EXPORT_SYMBOL_GPL(usb_buffer_map);
 822#endif  /*  0  */
 823
 824/* XXX DISABLED, no users currently.  If you wish to re-enable this
 825 * XXX please determine whether the sync is to transfer ownership of
 826 * XXX the buffer from device to cpu or vice verse, and thusly use the
 827 * XXX appropriate _for_{cpu,device}() method.  -DaveM
 828 */
 829#if 0
 830
 831/**
 832 * usb_buffer_dmasync - synchronize DMA and CPU view of buffer(s)
 833 * @urb: urb whose transfer_buffer/setup_packet will be synchronized
 834 */
 835void usb_buffer_dmasync(struct urb *urb)
 836{
 837	struct usb_bus		*bus;
 838	struct device		*controller;
 839
 840	if (!urb
 841			|| !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
 842			|| !urb->dev
 843			|| !(bus = urb->dev->bus)
 844			|| !(controller = bus->controller))
 845		return;
 846
 847	if (controller->dma_mask) {
 848		dma_sync_single_for_cpu(controller,
 849			urb->transfer_dma, urb->transfer_buffer_length,
 850			usb_pipein(urb->pipe)
 851				? DMA_FROM_DEVICE : DMA_TO_DEVICE);
 852		if (usb_pipecontrol(urb->pipe))
 853			dma_sync_single_for_cpu(controller,
 854					urb->setup_dma,
 855					sizeof(struct usb_ctrlrequest),
 856					DMA_TO_DEVICE);
 857	}
 858}
 859EXPORT_SYMBOL_GPL(usb_buffer_dmasync);
 860#endif
 861
 862/**
 863 * usb_buffer_unmap - free DMA mapping(s) for an urb
 864 * @urb: urb whose transfer_buffer will be unmapped
 865 *
 866 * Reverses the effect of usb_buffer_map().
 867 */
 868#if 0
 869void usb_buffer_unmap(struct urb *urb)
 870{
 871	struct usb_bus		*bus;
 872	struct device		*controller;
 873
 874	if (!urb
 875			|| !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
 876			|| !urb->dev
 877			|| !(bus = urb->dev->bus)
 878			|| !(controller = bus->controller))
 879		return;
 880
 881	if (controller->dma_mask) {
 882		dma_unmap_single(controller,
 883			urb->transfer_dma, urb->transfer_buffer_length,
 884			usb_pipein(urb->pipe)
 885				? DMA_FROM_DEVICE : DMA_TO_DEVICE);
 886	}
 887	urb->transfer_flags &= ~URB_NO_TRANSFER_DMA_MAP;
 888}
 889EXPORT_SYMBOL_GPL(usb_buffer_unmap);
 890#endif  /*  0  */
 891
 892#if 0
 893/**
 894 * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint
 895 * @dev: device to which the scatterlist will be mapped
 896 * @is_in: mapping transfer direction
 897 * @sg: the scatterlist to map
 898 * @nents: the number of entries in the scatterlist
 899 *
 900 * Return: Either < 0 (indicating no buffers could be mapped), or the
 901 * number of DMA mapping array entries in the scatterlist.
 902 *
 903 * Note:
 904 * The caller is responsible for placing the resulting DMA addresses from
 905 * the scatterlist into URB transfer buffer pointers, and for setting the
 906 * URB_NO_TRANSFER_DMA_MAP transfer flag in each of those URBs.
 907 *
 908 * Top I/O rates come from queuing URBs, instead of waiting for each one
 909 * to complete before starting the next I/O.   This is particularly easy
 910 * to do with scatterlists.  Just allocate and submit one URB for each DMA
 911 * mapping entry returned, stopping on the first error or when all succeed.
 912 * Better yet, use the usb_sg_*() calls, which do that (and more) for you.
 913 *
 914 * This call would normally be used when translating scatterlist requests,
 915 * rather than usb_buffer_map(), since on some hardware (with IOMMUs) it
 916 * may be able to coalesce mappings for improved I/O efficiency.
 917 *
 918 * Reverse the effect of this call with usb_buffer_unmap_sg().
 919 */
 920int usb_buffer_map_sg(const struct usb_device *dev, int is_in,
 921		      struct scatterlist *sg, int nents)
 922{
 923	struct usb_bus		*bus;
 924	struct device		*controller;
 925
 926	if (!dev
 927			|| !(bus = dev->bus)
 928			|| !(controller = bus->controller)
 929			|| !controller->dma_mask)
 930		return -EINVAL;
 931
 932	/* FIXME generic api broken like pci, can't report errors */
 933	return dma_map_sg(controller, sg, nents,
 934			is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE) ? : -ENOMEM;
 935}
 936EXPORT_SYMBOL_GPL(usb_buffer_map_sg);
 937#endif
 938
 939/* XXX DISABLED, no users currently.  If you wish to re-enable this
 940 * XXX please determine whether the sync is to transfer ownership of
 941 * XXX the buffer from device to cpu or vice verse, and thusly use the
 942 * XXX appropriate _for_{cpu,device}() method.  -DaveM
 943 */
 944#if 0
 945
 946/**
 947 * usb_buffer_dmasync_sg - synchronize DMA and CPU view of scatterlist buffer(s)
 948 * @dev: device to which the scatterlist will be mapped
 949 * @is_in: mapping transfer direction
 950 * @sg: the scatterlist to synchronize
 951 * @n_hw_ents: the positive return value from usb_buffer_map_sg
 952 *
 953 * Use this when you are re-using a scatterlist's data buffers for
 954 * another USB request.
 955 */
 956void usb_buffer_dmasync_sg(const struct usb_device *dev, int is_in,
 957			   struct scatterlist *sg, int n_hw_ents)
 958{
 959	struct usb_bus		*bus;
 960	struct device		*controller;
 961
 962	if (!dev
 963			|| !(bus = dev->bus)
 964			|| !(controller = bus->controller)
 965			|| !controller->dma_mask)
 966		return;
 967
 968	dma_sync_sg_for_cpu(controller, sg, n_hw_ents,
 969			    is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
 970}
 971EXPORT_SYMBOL_GPL(usb_buffer_dmasync_sg);
 972#endif
 973
 974#if 0
 975/**
 976 * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist
 977 * @dev: device to which the scatterlist will be mapped
 978 * @is_in: mapping transfer direction
 979 * @sg: the scatterlist to unmap
 980 * @n_hw_ents: the positive return value from usb_buffer_map_sg
 981 *
 982 * Reverses the effect of usb_buffer_map_sg().
 983 */
 984void usb_buffer_unmap_sg(const struct usb_device *dev, int is_in,
 985			 struct scatterlist *sg, int n_hw_ents)
 986{
 987	struct usb_bus		*bus;
 988	struct device		*controller;
 989
 990	if (!dev
 991			|| !(bus = dev->bus)
 992			|| !(controller = bus->controller)
 993			|| !controller->dma_mask)
 994		return;
 995
 996	dma_unmap_sg(controller, sg, n_hw_ents,
 997			is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
 998}
 999EXPORT_SYMBOL_GPL(usb_buffer_unmap_sg);
1000#endif
1001
1002/*
1003 * Notifications of device and interface registration
1004 */
1005static int usb_bus_notify(struct notifier_block *nb, unsigned long action,
1006		void *data)
1007{
1008	struct device *dev = data;
1009
1010	switch (action) {
1011	case BUS_NOTIFY_ADD_DEVICE:
1012		if (dev->type == &usb_device_type)
1013			(void) usb_create_sysfs_dev_files(to_usb_device(dev));
1014		else if (dev->type == &usb_if_device_type)
1015			usb_create_sysfs_intf_files(to_usb_interface(dev));
1016		break;
1017
1018	case BUS_NOTIFY_DEL_DEVICE:
1019		if (dev->type == &usb_device_type)
1020			usb_remove_sysfs_dev_files(to_usb_device(dev));
1021		else if (dev->type == &usb_if_device_type)
1022			usb_remove_sysfs_intf_files(to_usb_interface(dev));
1023		break;
1024	}
1025	return 0;
1026}
1027
1028static struct notifier_block usb_bus_nb = {
1029	.notifier_call = usb_bus_notify,
1030};
1031
1032struct dentry *usb_debug_root;
1033EXPORT_SYMBOL_GPL(usb_debug_root);
1034
1035static struct dentry *usb_debug_devices;
1036
1037static int usb_debugfs_init(void)
1038{
1039	usb_debug_root = debugfs_create_dir("usb", NULL);
1040	if (!usb_debug_root)
1041		return -ENOENT;
1042
1043	usb_debug_devices = debugfs_create_file("devices", 0444,
1044						usb_debug_root, NULL,
1045						&usbfs_devices_fops);
1046	if (!usb_debug_devices) {
1047		debugfs_remove(usb_debug_root);
1048		usb_debug_root = NULL;
1049		return -ENOENT;
1050	}
1051
1052	return 0;
1053}
1054
1055static void usb_debugfs_cleanup(void)
1056{
1057	debugfs_remove(usb_debug_devices);
1058	debugfs_remove(usb_debug_root);
1059}
1060
1061/*
1062 * Init
1063 */
1064static int __init usb_init(void)
1065{
1066	int retval;
1067	if (usb_disabled()) {
1068		pr_info("%s: USB support disabled\n", usbcore_name);
1069		return 0;
1070	}
1071	usb_init_pool_max();
1072
1073	retval = usb_debugfs_init();
1074	if (retval)
1075		goto out;
1076
1077	usb_acpi_register();
1078	retval = bus_register(&usb_bus_type);
1079	if (retval)
1080		goto bus_register_failed;
1081	retval = bus_register_notifier(&usb_bus_type, &usb_bus_nb);
1082	if (retval)
1083		goto bus_notifier_failed;
1084	retval = usb_major_init();
1085	if (retval)
1086		goto major_init_failed;
 
 
 
1087	retval = usb_register(&usbfs_driver);
1088	if (retval)
1089		goto driver_register_failed;
1090	retval = usb_devio_init();
1091	if (retval)
1092		goto usb_devio_init_failed;
1093	retval = usb_hub_init();
1094	if (retval)
1095		goto hub_init_failed;
1096	retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE);
1097	if (!retval)
1098		goto out;
1099
1100	usb_hub_cleanup();
1101hub_init_failed:
1102	usb_devio_cleanup();
1103usb_devio_init_failed:
1104	usb_deregister(&usbfs_driver);
1105driver_register_failed:
 
 
1106	usb_major_cleanup();
1107major_init_failed:
1108	bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1109bus_notifier_failed:
1110	bus_unregister(&usb_bus_type);
1111bus_register_failed:
1112	usb_acpi_unregister();
1113	usb_debugfs_cleanup();
1114out:
1115	return retval;
1116}
1117
1118/*
1119 * Cleanup
1120 */
1121static void __exit usb_exit(void)
1122{
1123	/* This will matter if shutdown/reboot does exitcalls. */
1124	if (usb_disabled())
1125		return;
1126
 
1127	usb_deregister_device_driver(&usb_generic_driver);
1128	usb_major_cleanup();
1129	usb_deregister(&usbfs_driver);
1130	usb_devio_cleanup();
1131	usb_hub_cleanup();
 
1132	bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
1133	bus_unregister(&usb_bus_type);
1134	usb_acpi_unregister();
1135	usb_debugfs_cleanup();
1136	idr_destroy(&usb_bus_idr);
1137}
1138
1139subsys_initcall(usb_init);
1140module_exit(usb_exit);
1141MODULE_LICENSE("GPL");