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