drivers/usb/host/usb-uclass.c

   1 /*
   2  * (C) Copyright 2015 Google, Inc
   3  * Written by Simon Glass <sjg@chromium.org>
   4  *
   5  * usb_match_device() modified from Linux kernel v4.0.
   6  *
   7  * SPDX-License-Identifier:     GPL-2.0+
   8  */
   9
  10 #include <common.h>
  11 #include <dm.h>
  12 #include <errno.h>
  13 #include <usb.h>
  14 #include <dm/device-internal.h>
  15 #include <dm/lists.h>
  16 #include <dm/root.h>
  17 #include <dm/uclass-internal.h>
  18
  19 DECLARE_GLOBAL_DATA_PTR;
  20
  21 extern bool usb_started; /* flag for the started/stopped USB status */
  22 static bool asynch_allowed;
  23
  24 struct usb_uclass_priv {
  25         int companion_device_count;
  26 };
  27
  28 int usb_disable_asynch(int disable)
  29 {
  30         int old_value = asynch_allowed;
  31
  32         asynch_allowed = !disable;
  33         return old_value;
  34 }
  35
  36 int submit_int_msg(struct usb_device *udev, unsigned long pipe, void *buffer,
  37                    int length, int interval)
  38 {
  39         struct udevice *bus = udev->controller_dev;
  40         struct dm_usb_ops *ops = usb_get_ops(bus);
  41
  42         if (!ops->interrupt)
  43                 return -ENOSYS;
  44
  45         return ops->interrupt(bus, udev, pipe, buffer, length, interval);
  46 }
  47
  48 int submit_control_msg(struct usb_device *udev, unsigned long pipe,
  49                        void *buffer, int length, struct devrequest *setup)
  50 {
  51         struct udevice *bus = udev->controller_dev;
  52         struct dm_usb_ops *ops = usb_get_ops(bus);
  53         struct usb_uclass_priv *uc_priv = bus->uclass->priv;
  54         int err;
  55
  56         if (!ops->control)
  57                 return -ENOSYS;
  58
  59         err = ops->control(bus, udev, pipe, buffer, length, setup);
  60         if (setup->request == USB_REQ_SET_FEATURE &&
  61             setup->requesttype == USB_RT_PORT &&
  62             setup->value == cpu_to_le16(USB_PORT_FEAT_RESET) &&
  63             err == -ENXIO) {
  64                 /* Device handed over to companion after port reset */
  65                 uc_priv->companion_device_count++;
  66         }
  67
  68         return err;
  69 }
  70
  71 int submit_bulk_msg(struct usb_device *udev, unsigned long pipe, void *buffer,
  72                     int length)
  73 {
  74         struct udevice *bus = udev->controller_dev;
  75         struct dm_usb_ops *ops = usb_get_ops(bus);
  76
  77         if (!ops->bulk)
  78                 return -ENOSYS;
  79
  80         return ops->bulk(bus, udev, pipe, buffer, length);
  81 }
  82
  83 struct int_queue *create_int_queue(struct usb_device *udev,
  84                 unsigned long pipe, int queuesize, int elementsize,
  85                 void *buffer, int interval)
  86 {
  87         struct udevice *bus = udev->controller_dev;
  88         struct dm_usb_ops *ops = usb_get_ops(bus);
  89
  90         if (!ops->create_int_queue)
  91                 return NULL;
  92
  93         return ops->create_int_queue(bus, udev, pipe, queuesize, elementsize,
  94                                      buffer, interval);
  95 }
  96
  97 void *poll_int_queue(struct usb_device *udev, struct int_queue *queue)
  98 {
  99         struct udevice *bus = udev->controller_dev;
 100         struct dm_usb_ops *ops = usb_get_ops(bus);
 101
 102         if (!ops->poll_int_queue)
 103                 return NULL;
 104
 105         return ops->poll_int_queue(bus, udev, queue);
 106 }
 107
 108 int destroy_int_queue(struct usb_device *udev, struct int_queue *queue)
 109 {
 110         struct udevice *bus = udev->controller_dev;
 111         struct dm_usb_ops *ops = usb_get_ops(bus);
 112
 113         if (!ops->destroy_int_queue)
 114                 return -ENOSYS;
 115
 116         return ops->destroy_int_queue(bus, udev, queue);
 117 }
 118
 119 int usb_alloc_device(struct usb_device *udev)
 120 {
 121         struct udevice *bus = udev->controller_dev;
 122         struct dm_usb_ops *ops = usb_get_ops(bus);
 123
 124         /* This is only requird by some controllers - current XHCI */
 125         if (!ops->alloc_device)
 126                 return 0;
 127
 128         return ops->alloc_device(bus, udev);
 129 }
 130
 131 int usb_stop(void)
 132 {
 133         struct udevice *bus;
 134         struct uclass *uc;
 135         struct usb_uclass_priv *uc_priv;
 136         int err = 0, ret;
 137
 138         /* De-activate any devices that have been activated */
 139         ret = uclass_get(UCLASS_USB, &uc);
 140         if (ret)
 141                 return ret;
 142
 143         uc_priv = uc->priv;
 144
 145         uclass_foreach_dev(bus, uc) {
 146                 ret = device_remove(bus);
 147                 if (ret && !err)
 148                         err = ret;
 149                 ret = device_unbind_children(bus);
 150                 if (ret && !err)
 151                         err = ret;
 152         }
 153
 154 #ifdef CONFIG_SANDBOX
 155         struct udevice *dev;
 156
 157         /* Reset all enulation devices */
 158         ret = uclass_get(UCLASS_USB_EMUL, &uc);
 159         if (ret)
 160                 return ret;
 161
 162         uclass_foreach_dev(dev, uc)
 163                 usb_emul_reset(dev);
 164 #endif
 165         usb_stor_reset();
 166         usb_hub_reset();
 167         uc_priv->companion_device_count = 0;
 168         usb_started = 0;
 169
 170         return err;
 171 }
 172
 173 static void usb_scan_bus(struct udevice *bus, bool recurse)
 174 {
 175         struct usb_bus_priv *priv;
 176         struct udevice *dev;
 177         int ret;
 178
 179         priv = dev_get_uclass_priv(bus);
 180
 181         assert(recurse);        /* TODO: Support non-recusive */
 182
 183         printf("scanning bus %d for devices... ", bus->seq);
 184         debug("\n");
 185         ret = usb_scan_device(bus, 0, USB_SPEED_FULL, &dev);
 186         if (ret)
 187                 printf("failed, error %d\n", ret);
 188         else if (priv->next_addr == 0)
 189                 printf("No USB Device found\n");
 190         else
 191                 printf("%d USB Device(s) found\n", priv->next_addr);
 192 }
 193
 194 int usb_init(void)
 195 {
 196         int controllers_initialized = 0;
 197         struct usb_uclass_priv *uc_priv;
 198         struct usb_bus_priv *priv;
 199         struct udevice *bus;
 200         struct uclass *uc;
 201         int count = 0;
 202         int ret;
 203
 204         asynch_allowed = 1;
 205         usb_hub_reset();
 206
 207         ret = uclass_get(UCLASS_USB, &uc);
 208         if (ret)
 209                 return ret;
 210
 211         uc_priv = uc->priv;
 212
 213         uclass_foreach_dev(bus, uc) {
 214                 /* init low_level USB */
 215                 printf("USB%d:   ", count);
 216                 count++;
 217                 ret = device_probe(bus);
 218                 if (ret == -ENODEV) {   /* No such device. */
 219                         puts("Port not available.\n");
 220                         controllers_initialized++;
 221                         continue;
 222                 }
 223
 224                 if (ret) {              /* Other error. */
 225                         printf("probe failed, error %d\n", ret);
 226                         continue;
 227                 }
 228                 controllers_initialized++;
 229                 usb_started = true;
 230         }
 231
 232         /*
 233          * lowlevel init done, now scan the bus for devices i.e. search HUBs
 234          * and configure them, first scan primary controllers.
 235          */
 236         uclass_foreach_dev(bus, uc) {
 237                 if (!device_active(bus))
 238                         continue;
 239
 240                 priv = dev_get_uclass_priv(bus);
 241                 if (!priv->companion)
 242                         usb_scan_bus(bus, true);
 243         }
 244
 245         /*
 246          * Now that the primary controllers have been scanned and have handed
 247          * over any devices they do not understand to their companions, scan
 248          * the companions if necessary.
 249          */
 250         if (uc_priv->companion_device_count) {
 251                 uclass_foreach_dev(bus, uc) {
 252                         if (!device_active(bus))
 253                                 continue;
 254
 255                         priv = dev_get_uclass_priv(bus);
 256                         if (priv->companion)
 257                                 usb_scan_bus(bus, true);
 258                 }
 259         }
 260
 261         debug("scan end\n");
 262         /* if we were not able to find at least one working bus, bail out */
 263         if (!count)
 264                 printf("No controllers found\n");
 265         else if (controllers_initialized == 0)
 266                 printf("USB error: all controllers failed lowlevel init\n");
 267
 268         return usb_started ? 0 : -1;
 269 }
 270
 271 int usb_reset_root_port(struct usb_device *udev)
 272 {
 273         return -ENOSYS;
 274 }
 275
 276 static struct usb_device *find_child_devnum(struct udevice *parent, int devnum)
 277 {
 278         struct usb_device *udev;
 279         struct udevice *dev;
 280
 281         if (!device_active(parent))
 282                 return NULL;
 283         udev = dev_get_parentdata(parent);
 284         if (udev->devnum == devnum)
 285                 return udev;
 286
 287         for (device_find_first_child(parent, &dev);
 288              dev;
 289              device_find_next_child(&dev)) {
 290                 udev = find_child_devnum(dev, devnum);
 291                 if (udev)
 292                         return udev;
 293         }
 294
 295         return NULL;
 296 }
 297
 298 struct usb_device *usb_get_dev_index(struct udevice *bus, int index)
 299 {
 300         struct udevice *hub;
 301         int devnum = index + 1; /* Addresses are allocated from 1 on USB */
 302
 303         device_find_first_child(bus, &hub);
 304         if (device_get_uclass_id(hub) == UCLASS_USB_HUB)
 305                 return find_child_devnum(hub, devnum);
 306
 307         return NULL;
 308 }
 309
 310 int usb_post_bind(struct udevice *dev)
 311 {
 312         /* Scan the bus for devices */
 313         return dm_scan_fdt_node(dev, gd->fdt_blob, dev->of_offset, false);
 314 }
 315
 316 int usb_setup_ehci_gadget(struct ehci_ctrl **ctlrp)
 317 {
 318         struct usb_platdata *plat;
 319         struct udevice *dev;
 320         int ret;
 321
 322         /* Find the old device and remove it */
 323         ret = uclass_find_device_by_seq(UCLASS_USB, 0, true, &dev);
 324         if (ret)
 325                 return ret;
 326         ret = device_remove(dev);
 327         if (ret)
 328                 return ret;
 329
 330         plat = dev_get_platdata(dev);
 331         plat->init_type = USB_INIT_DEVICE;
 332         ret = device_probe(dev);
 333         if (ret)
 334                 return ret;
 335         *ctlrp = dev_get_priv(dev);
 336
 337         return 0;
 338 }
 339
 340 /* returns 0 if no match, 1 if match */
 341 int usb_match_device(const struct usb_device_descriptor *desc,
 342                      const struct usb_device_id *id)
 343 {
 344         if ((id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
 345             id->idVendor != le16_to_cpu(desc->idVendor))
 346                 return 0;
 347
 348         if ((id->match_flags & USB_DEVICE_ID_MATCH_PRODUCT) &&
 349             id->idProduct != le16_to_cpu(desc->idProduct))
 350                 return 0;
 351
 352         /* No need to test id->bcdDevice_lo != 0, since 0 is never
 353            greater than any unsigned number. */
 354         if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_LO) &&
 355             (id->bcdDevice_lo > le16_to_cpu(desc->bcdDevice)))
 356                 return 0;
 357
 358         if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_HI) &&
 359             (id->bcdDevice_hi < le16_to_cpu(desc->bcdDevice)))
 360                 return 0;
 361
 362         if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_CLASS) &&
 363             (id->bDeviceClass != desc->bDeviceClass))
 364                 return 0;
 365
 366         if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_SUBCLASS) &&
 367             (id->bDeviceSubClass != desc->bDeviceSubClass))
 368                 return 0;
 369
 370         if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_PROTOCOL) &&
 371             (id->bDeviceProtocol != desc->bDeviceProtocol))
 372                 return 0;
 373
 374         return 1;
 375 }
 376
 377 /* returns 0 if no match, 1 if match */
 378 int usb_match_one_id_intf(const struct usb_device_descriptor *desc,
 379                           const struct usb_interface_descriptor *int_desc,
 380                           const struct usb_device_id *id)
 381 {
 382         /* The interface class, subclass, protocol and number should never be
 383          * checked for a match if the device class is Vendor Specific,
 384          * unless the match record specifies the Vendor ID. */
 385         if (desc->bDeviceClass == USB_CLASS_VENDOR_SPEC &&
 386             !(id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
 387             (id->match_flags & (USB_DEVICE_ID_MATCH_INT_CLASS |
 388                                 USB_DEVICE_ID_MATCH_INT_SUBCLASS |
 389                                 USB_DEVICE_ID_MATCH_INT_PROTOCOL |
 390                                 USB_DEVICE_ID_MATCH_INT_NUMBER)))
 391                 return 0;
 392
 393         if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_CLASS) &&
 394             (id->bInterfaceClass != int_desc->bInterfaceClass))
 395                 return 0;
 396
 397         if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_SUBCLASS) &&
 398             (id->bInterfaceSubClass != int_desc->bInterfaceSubClass))
 399                 return 0;
 400
 401         if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_PROTOCOL) &&
 402             (id->bInterfaceProtocol != int_desc->bInterfaceProtocol))
 403                 return 0;
 404
 405         if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_NUMBER) &&
 406             (id->bInterfaceNumber != int_desc->bInterfaceNumber))
 407                 return 0;
 408
 409         return 1;
 410 }
 411
 412 /* returns 0 if no match, 1 if match */
 413 int usb_match_one_id(struct usb_device_descriptor *desc,
 414                      struct usb_interface_descriptor *int_desc,
 415                      const struct usb_device_id *id)
 416 {
 417         if (!usb_match_device(desc, id))
 418                 return 0;
 419
 420         return usb_match_one_id_intf(desc, int_desc, id);
 421 }
 422
 423 /**
 424  * usb_find_and_bind_driver() - Find and bind the right USB driver
 425  *
 426  * This only looks at certain fields in the descriptor.
 427  */
 428 static int usb_find_and_bind_driver(struct udevice *parent,
 429                                     struct usb_device_descriptor *desc,
 430                                     struct usb_interface_descriptor *iface,
 431                                     int bus_seq, int devnum,
 432                                     struct udevice **devp)
 433 {
 434         struct usb_driver_entry *start, *entry;
 435         int n_ents;
 436         int ret;
 437         char name[30], *str;
 438
 439         *devp = NULL;
 440         debug("%s: Searching for driver\n", __func__);
 441         start = ll_entry_start(struct usb_driver_entry, usb_driver_entry);
 442         n_ents = ll_entry_count(struct usb_driver_entry, usb_driver_entry);
 443         for (entry = start; entry != start + n_ents; entry++) {
 444                 const struct usb_device_id *id;
 445                 struct udevice *dev;
 446                 const struct driver *drv;
 447                 struct usb_dev_platdata *plat;
 448
 449                 for (id = entry->match; id->match_flags; id++) {
 450                         if (!usb_match_one_id(desc, iface, id))
 451                                 continue;
 452
 453                         drv = entry->driver;
 454                         /*
 455                          * We could pass the descriptor to the driver as
 456                          * platdata (instead of NULL) and allow its bind()
 457                          * method to return -ENOENT if it doesn't support this
 458                          * device. That way we could continue the search to
 459                          * find another driver. For now this doesn't seem
 460                          * necesssary, so just bind the first match.
 461                          */
 462                         ret = device_bind(parent, drv, drv->name, NULL, -1,
 463                                           &dev);
 464                         if (ret)
 465                                 goto error;
 466                         debug("%s: Match found: %s\n", __func__, drv->name);
 467                         dev->driver_data = id->driver_info;
 468                         plat = dev_get_parent_platdata(dev);
 469                         plat->id = *id;
 470                         *devp = dev;
 471                         return 0;
 472                 }
 473         }
 474
 475         /* Bind a generic driver so that the device can be used */
 476         snprintf(name, sizeof(name), "generic_bus_%x_dev_%x", bus_seq, devnum);
 477         str = strdup(name);
 478         if (!str)
 479                 return -ENOMEM;
 480         ret = device_bind_driver(parent, "usb_dev_generic_drv", str, devp);
 481
 482 error:
 483         debug("%s: No match found: %d\n", __func__, ret);
 484         return ret;
 485 }
 486
 487 /**
 488  * usb_find_emul_child() - Find an existing device for emulated devices
 489  */
 490 static int usb_find_emul_child(struct udevice *parent,
 491                                struct usb_device_descriptor *desc,
 492                                struct usb_interface_descriptor *iface,
 493                                struct udevice **devp)
 494 {
 495 #ifdef CONFIG_SANDBOX
 496         struct udevice *dev;
 497
 498         *devp = NULL;
 499         for (device_find_first_child(parent, &dev);
 500              dev;
 501              device_find_next_child(&dev)) {
 502                 struct usb_dev_platdata *plat = dev_get_parent_platdata(dev);
 503
 504                 /* If this device is already in use, skip it */
 505                 if (device_active(dev))
 506                         continue;
 507                 debug("   %s: name='%s', plat=%d, desc=%d\n", __func__,
 508                       dev->name, plat->id.bDeviceClass, desc->bDeviceClass);
 509                 if (usb_match_one_id(desc, iface, &plat->id)) {
 510                         *devp = dev;
 511                         return 0;
 512                 }
 513         }
 514 #endif
 515         return -ENOENT;
 516 }
 517
 518 int usb_scan_device(struct udevice *parent, int port,
 519                     enum usb_device_speed speed, struct udevice **devp)
 520 {
 521         struct udevice *dev;
 522         bool created = false;
 523         struct usb_dev_platdata *plat;
 524         struct usb_bus_priv *priv;
 525         struct usb_device *parent_udev;
 526         int ret;
 527         ALLOC_CACHE_ALIGN_BUFFER(struct usb_device, udev, 1);
 528         struct usb_interface_descriptor *iface = &udev->config.if_desc[0].desc;
 529
 530         *devp = NULL;
 531         memset(udev, '\0', sizeof(*udev));
 532         udev->controller_dev = usb_get_bus(parent);
 533         priv = dev_get_uclass_priv(udev->controller_dev);
 534
 535         /*
 536          * Somewhat nasty, this. We create a local device and use the normal
 537          * USB stack to read its descriptor. Then we know what type of device
 538          * to create for real.
 539          *
 540          * udev->dev is set to the parent, since we don't have a real device
 541          * yet. The USB stack should not access udev.dev anyway, except perhaps
 542          * to find the controller, and the controller will either be @parent,
 543          * or some parent of @parent.
 544          *
 545          * Another option might be to create the device as a generic USB
 546          * device, then morph it into the correct one when we know what it
 547          * should be. This means that a generic USB device would morph into
 548          * a network controller, or a USB flash stick, for example. However,
 549          * we don't support such morphing and it isn't clear that it would
 550          * be easy to do.
 551          *
 552          * Yet another option is to split out the USB stack parts of udev
 553          * into something like a 'struct urb' (as Linux does) which can exist
 554          * independently of any device. This feels cleaner, but calls for quite
 555          * a big change to the USB stack.
 556          *
 557          * For now, the approach is to set up an empty udev, read its
 558          * descriptor and assign it an address, then bind a real device and
 559          * stash the resulting information into the device's parent
 560          * platform data. Then when we probe it, usb_child_pre_probe() is called
 561          * and it will pull the information out of the stash.
 562          */
 563         udev->dev = parent;
 564         udev->speed = speed;
 565         udev->devnum = priv->next_addr + 1;
 566         udev->portnr = port;
 567         debug("Calling usb_setup_device(), portnr=%d\n", udev->portnr);
 568         parent_udev = device_get_uclass_id(parent) == UCLASS_USB_HUB ?
 569                 dev_get_parentdata(parent) : NULL;
 570         ret = usb_setup_device(udev, priv->desc_before_addr, parent_udev);
 571         debug("read_descriptor for '%s': ret=%d\n", parent->name, ret);
 572         if (ret)
 573                 return ret;
 574         ret = usb_find_emul_child(parent, &udev->descriptor, iface, &dev);
 575         debug("** usb_find_emul_child returns %d\n", ret);
 576         if (ret) {
 577                 if (ret != -ENOENT)
 578                         return ret;
 579                 ret = usb_find_and_bind_driver(parent, &udev->descriptor, iface,
 580                                                udev->controller_dev->seq,
 581                                                udev->devnum, &dev);
 582                 if (ret)
 583                         return ret;
 584                 created = true;
 585         }
 586         plat = dev_get_parent_platdata(dev);
 587         debug("%s: Probing '%s', plat=%p\n", __func__, dev->name, plat);
 588         plat->devnum = udev->devnum;
 589         plat->udev = udev;
 590         priv->next_addr++;
 591         ret = device_probe(dev);
 592         if (ret) {
 593                 debug("%s: Device '%s' probe failed\n", __func__, dev->name);
 594                 priv->next_addr--;
 595                 if (created)
 596                         device_unbind(dev);
 597                 return ret;
 598         }
 599         *devp = dev;
 600
 601         return 0;
 602 }
 603
 604 /*
 605  * Detect if a USB device has been plugged or unplugged.
 606  */
 607 int usb_detect_change(void)
 608 {
 609         struct udevice *hub;
 610         struct uclass *uc;
 611         int change = 0;
 612         int ret;
 613
 614         ret = uclass_get(UCLASS_USB_HUB, &uc);
 615         if (ret)
 616                 return ret;
 617
 618         uclass_foreach_dev(hub, uc) {
 619                 struct usb_device *udev;
 620                 struct udevice *dev;
 621
 622                 if (!device_active(hub))
 623                         continue;
 624                 for (device_find_first_child(hub, &dev);
 625                      dev;
 626                      device_find_next_child(&dev)) {
 627                         struct usb_port_status status;
 628
 629                         if (!device_active(dev))
 630                                 continue;
 631
 632                         udev = dev_get_parentdata(dev);
 633                         if (usb_get_port_status(udev, udev->portnr, &status)
 634                                         < 0)
 635                                 /* USB request failed */
 636                                 continue;
 637
 638                         if (le16_to_cpu(status.wPortChange) &
 639                             USB_PORT_STAT_C_CONNECTION)
 640                                 change++;
 641                 }
 642         }
 643
 644         return change;
 645 }
 646
 647 int usb_child_post_bind(struct udevice *dev)
 648 {
 649         struct usb_dev_platdata *plat = dev_get_parent_platdata(dev);
 650         const void *blob = gd->fdt_blob;
 651         int val;
 652
 653         if (dev->of_offset == -1)
 654                 return 0;
 655
 656         /* We only support matching a few things */
 657         val = fdtdec_get_int(blob, dev->of_offset, "usb,device-class", -1);
 658         if (val != -1) {
 659                 plat->id.match_flags |= USB_DEVICE_ID_MATCH_DEV_CLASS;
 660                 plat->id.bDeviceClass = val;
 661         }
 662         val = fdtdec_get_int(blob, dev->of_offset, "usb,interface-class", -1);
 663         if (val != -1) {
 664                 plat->id.match_flags |= USB_DEVICE_ID_MATCH_INT_CLASS;
 665                 plat->id.bInterfaceClass = val;
 666         }
 667
 668         return 0;
 669 }
 670
 671 struct udevice *usb_get_bus(struct udevice *dev)
 672 {
 673         struct udevice *bus;
 674
 675         for (bus = dev; bus && device_get_uclass_id(bus) != UCLASS_USB; )
 676                 bus = bus->parent;
 677         if (!bus) {
 678                 /* By design this cannot happen */
 679                 assert(bus);
 680                 debug("USB HUB '%s' does not have a controller\n", dev->name);
 681         }
 682
 683         return bus;
 684 }
 685
 686 int usb_child_pre_probe(struct udevice *dev)
 687 {
 688         struct usb_device *udev = dev_get_parentdata(dev);
 689         struct usb_dev_platdata *plat = dev_get_parent_platdata(dev);
 690         int ret;
 691
 692         if (plat->udev) {
 693                 /*
 694                  * Copy over all the values set in the on stack struct
 695                  * usb_device in usb_scan_device() to our final struct
 696                  * usb_device for this dev.
 697                  */
 698                 *udev = *(plat->udev);
 699                 /* And clear plat->udev as it will not be valid for long */
 700                 plat->udev = NULL;
 701                 udev->dev = dev;
 702         } else {
 703                 /*
 704                  * This happens with devices which are explicitly bound
 705                  * instead of being discovered through usb_scan_device()
 706                  * such as sandbox emul devices.
 707                  */
 708                 udev->dev = dev;
 709                 udev->controller_dev = usb_get_bus(dev);
 710                 udev->devnum = plat->devnum;
 711
 712                 /*
 713                  * udev did not go through usb_scan_device(), so we need to
 714                  * select the config and read the config descriptors.
 715                  */
 716                 ret = usb_select_config(udev);
 717                 if (ret)
 718                         return ret;
 719         }
 720
 721         return 0;
 722 }
 723
 724 UCLASS_DRIVER(usb) = {
 725         .id             = UCLASS_USB,
 726         .name           = "usb",
 727         .flags          = DM_UC_FLAG_SEQ_ALIAS,
 728         .post_bind      = usb_post_bind,
 729         .priv_auto_alloc_size = sizeof(struct usb_uclass_priv),
 730         .per_child_auto_alloc_size = sizeof(struct usb_device),
 731         .per_device_auto_alloc_size = sizeof(struct usb_bus_priv),
 732         .child_post_bind = usb_child_post_bind,
 733         .child_pre_probe = usb_child_pre_probe,
 734         .per_child_platdata_auto_alloc_size = sizeof(struct usb_dev_platdata),
 735 };
 736
 737 UCLASS_DRIVER(usb_dev_generic) = {
 738         .id             = UCLASS_USB_DEV_GENERIC,
 739         .name           = "usb_dev_generic",
 740 };
 741
 742 U_BOOT_DRIVER(usb_dev_generic_drv) = {
 743         .id             = UCLASS_USB_DEV_GENERIC,
 744         .name           = "usb_dev_generic_drv",
 745 };