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