git.sur5r.net Git - u-boot/blob - 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 <memalign.h>
  14 #include <usb.h>
  15 #include <dm/device-internal.h>
  16 #include <dm/lists.h>
  17 #include <dm/root.h>
  18 #include <dm/uclass-internal.h>
  19
  20 DECLARE_GLOBAL_DATA_PTR;
  21
  22 extern bool usb_started; /* flag for the started/stopped USB status */
  23 static bool asynch_allowed;
  24
  25 struct usb_uclass_priv {
  26         int companion_device_count;
  27 };
  28
  29 int usb_disable_asynch(int disable)
  30 {
  31         int old_value = asynch_allowed;
  32
  33         asynch_allowed = !disable;
  34         return old_value;
  35 }
  36
  37 int submit_int_msg(struct usb_device *udev, unsigned long pipe, void *buffer,
  38                    int length, int interval)
  39 {
  40         struct udevice *bus = udev->controller_dev;
  41         struct dm_usb_ops *ops = usb_get_ops(bus);
  42
  43         if (!ops->interrupt)
  44                 return -ENOSYS;
  45
  46         return ops->interrupt(bus, udev, pipe, buffer, length, interval);
  47 }
  48
  49 int submit_control_msg(struct usb_device *udev, unsigned long pipe,
  50                        void *buffer, int length, struct devrequest *setup)
  51 {
  52         struct udevice *bus = udev->controller_dev;
  53         struct dm_usb_ops *ops = usb_get_ops(bus);
  54         struct usb_uclass_priv *uc_priv = bus->uclass->priv;
  55         int err;
  56
  57         if (!ops->control)
  58                 return -ENOSYS;
  59
  60         err = ops->control(bus, udev, pipe, buffer, length, setup);
  61         if (setup->request == USB_REQ_SET_FEATURE &&
  62             setup->requesttype == USB_RT_PORT &&
  63             setup->value == cpu_to_le16(USB_PORT_FEAT_RESET) &&
  64             err == -ENXIO) {
  65                 /* Device handed over to companion after port reset */
  66                 uc_priv->companion_device_count++;
  67         }
  68
  69         return err;
  70 }
  71
  72 int submit_bulk_msg(struct usb_device *udev, unsigned long pipe, void *buffer,
  73                     int length)
  74 {
  75         struct udevice *bus = udev->controller_dev;
  76         struct dm_usb_ops *ops = usb_get_ops(bus);
  77
  78         if (!ops->bulk)
  79                 return -ENOSYS;
  80
  81         return ops->bulk(bus, udev, pipe, buffer, length);
  82 }
  83
  84 struct int_queue *create_int_queue(struct usb_device *udev,
  85                 unsigned long pipe, int queuesize, int elementsize,
  86                 void *buffer, int interval)
  87 {
  88         struct udevice *bus = udev->controller_dev;
  89         struct dm_usb_ops *ops = usb_get_ops(bus);
  90
  91         if (!ops->create_int_queue)
  92                 return NULL;
  93
  94         return ops->create_int_queue(bus, udev, pipe, queuesize, elementsize,
  95                                      buffer, interval);
  96 }
  97
  98 void *poll_int_queue(struct usb_device *udev, struct int_queue *queue)
  99 {
 100         struct udevice *bus = udev->controller_dev;
 101         struct dm_usb_ops *ops = usb_get_ops(bus);
 102
 103         if (!ops->poll_int_queue)
 104                 return NULL;
 105
 106         return ops->poll_int_queue(bus, udev, queue);
 107 }
 108
 109 int destroy_int_queue(struct usb_device *udev, struct int_queue *queue)
 110 {
 111         struct udevice *bus = udev->controller_dev;
 112         struct dm_usb_ops *ops = usb_get_ops(bus);
 113
 114         if (!ops->destroy_int_queue)
 115                 return -ENOSYS;
 116
 117         return ops->destroy_int_queue(bus, udev, queue);
 118 }
 119
 120 int usb_alloc_device(struct usb_device *udev)
 121 {
 122         struct udevice *bus = udev->controller_dev;
 123         struct dm_usb_ops *ops = usb_get_ops(bus);
 124
 125         /* This is only requird by some controllers - current XHCI */
 126         if (!ops->alloc_device)
 127                 return 0;
 128
 129         return ops->alloc_device(bus, udev);
 130 }
 131
 132 int usb_reset_root_port(struct usb_device *udev)
 133 {
 134         struct udevice *bus = udev->controller_dev;
 135         struct dm_usb_ops *ops = usb_get_ops(bus);
 136
 137         if (!ops->reset_root_port)
 138                 return -ENOSYS;
 139
 140         return ops->reset_root_port(bus, udev);
 141 }
 142
 143 int usb_stop(void)
 144 {
 145         struct udevice *bus;
 146         struct uclass *uc;
 147         struct usb_uclass_priv *uc_priv;
 148         int err = 0, ret;
 149
 150         /* De-activate any devices that have been activated */
 151         ret = uclass_get(UCLASS_USB, &uc);
 152         if (ret)
 153                 return ret;
 154
 155         uc_priv = uc->priv;
 156
 157         uclass_foreach_dev(bus, uc) {
 158                 ret = device_remove(bus);
 159                 if (ret && !err)
 160                         err = ret;
 161                 ret = device_unbind_children(bus);
 162                 if (ret && !err)
 163                         err = ret;
 164         }
 165
 166 #ifdef CONFIG_SANDBOX
 167         struct udevice *dev;
 168
 169         /* Reset all enulation devices */
 170         ret = uclass_get(UCLASS_USB_EMUL, &uc);
 171         if (ret)
 172                 return ret;
 173
 174         uclass_foreach_dev(dev, uc)
 175                 usb_emul_reset(dev);
 176 #endif
 177 #ifdef CONFIG_USB_STORAGE
 178         usb_stor_reset();
 179 #endif
 180         usb_hub_reset();
 181         uc_priv->companion_device_count = 0;
 182         usb_started = 0;
 183
 184         return err;
 185 }
 186
 187 static void usb_scan_bus(struct udevice *bus, bool recurse)
 188 {
 189         struct usb_bus_priv *priv;
 190         struct udevice *dev;
 191         int ret;
 192
 193         priv = dev_get_uclass_priv(bus);
 194
 195         assert(recurse);        /* TODO: Support non-recusive */
 196
 197         printf("scanning bus %d for devices... ", bus->seq);
 198         debug("\n");
 199         ret = usb_scan_device(bus, 0, USB_SPEED_FULL, &dev);
 200         if (ret)
 201                 printf("failed, error %d\n", ret);
 202         else if (priv->next_addr == 0)
 203                 printf("No USB Device found\n");
 204         else
 205                 printf("%d USB Device(s) found\n", priv->next_addr);
 206 }
 207
 208 int usb_init(void)
 209 {
 210         int controllers_initialized = 0;
 211         struct usb_uclass_priv *uc_priv;
 212         struct usb_bus_priv *priv;
 213         struct udevice *bus;
 214         struct uclass *uc;
 215         int count = 0;
 216         int ret;
 217
 218         asynch_allowed = 1;
 219         usb_hub_reset();
 220
 221         ret = uclass_get(UCLASS_USB, &uc);
 222         if (ret)
 223                 return ret;
 224
 225         uc_priv = uc->priv;
 226
 227         uclass_foreach_dev(bus, uc) {
 228                 /* init low_level USB */
 229                 printf("USB%d:   ", count);
 230                 count++;
 231                 ret = device_probe(bus);
 232                 if (ret == -ENODEV) {   /* No such device. */
 233                         puts("Port not available.\n");
 234                         controllers_initialized++;
 235                         continue;
 236                 }
 237
 238                 if (ret) {              /* Other error. */
 239                         printf("probe failed, error %d\n", ret);
 240                         continue;
 241                 }
 242                 controllers_initialized++;
 243                 usb_started = true;
 244         }
 245
 246         /*
 247          * lowlevel init done, now scan the bus for devices i.e. search HUBs
 248          * and configure them, first scan primary controllers.
 249          */
 250         uclass_foreach_dev(bus, uc) {
 251                 if (!device_active(bus))
 252                         continue;
 253
 254                 priv = dev_get_uclass_priv(bus);
 255                 if (!priv->companion)
 256                         usb_scan_bus(bus, true);
 257         }
 258
 259         /*
 260          * Now that the primary controllers have been scanned and have handed
 261          * over any devices they do not understand to their companions, scan
 262          * the companions if necessary.
 263          */
 264         if (uc_priv->companion_device_count) {
 265                 uclass_foreach_dev(bus, uc) {
 266                         if (!device_active(bus))
 267                                 continue;
 268
 269                         priv = dev_get_uclass_priv(bus);
 270                         if (priv->companion)
 271                                 usb_scan_bus(bus, true);
 272                 }
 273         }
 274
 275         debug("scan end\n");
 276         /* if we were not able to find at least one working bus, bail out */
 277         if (!count)
 278                 printf("No controllers found\n");
 279         else if (controllers_initialized == 0)
 280                 printf("USB error: all controllers failed lowlevel init\n");
 281
 282         return usb_started ? 0 : -1;
 283 }
 284
 285 static struct usb_device *find_child_devnum(struct udevice *parent, int devnum)
 286 {
 287         struct usb_device *udev;
 288         struct udevice *dev;
 289
 290         if (!device_active(parent))
 291                 return NULL;
 292         udev = dev_get_parentdata(parent);
 293         if (udev->devnum == devnum)
 294                 return udev;
 295
 296         for (device_find_first_child(parent, &dev);
 297              dev;
 298              device_find_next_child(&dev)) {
 299                 udev = find_child_devnum(dev, devnum);
 300                 if (udev)
 301                         return udev;
 302         }
 303
 304         return NULL;
 305 }
 306
 307 struct usb_device *usb_get_dev_index(struct udevice *bus, int index)
 308 {
 309         struct udevice *dev;
 310         int devnum = index + 1; /* Addresses are allocated from 1 on USB */
 311
 312         device_find_first_child(bus, &dev);
 313         if (!dev)
 314                 return NULL;
 315
 316         return find_child_devnum(dev, devnum);
 317 }
 318
 319 int usb_post_bind(struct udevice *dev)
 320 {
 321         /* Scan the bus for devices */
 322         return dm_scan_fdt_node(dev, gd->fdt_blob, dev->of_offset, false);
 323 }
 324
 325 int usb_setup_ehci_gadget(struct ehci_ctrl **ctlrp)
 326 {
 327         struct usb_platdata *plat;
 328         struct udevice *dev;
 329         int ret;
 330
 331         /* Find the old device and remove it */
 332         ret = uclass_find_device_by_seq(UCLASS_USB, 0, true, &dev);
 333         if (ret)
 334                 return ret;
 335         ret = device_remove(dev);
 336         if (ret)
 337                 return ret;
 338
 339         plat = dev_get_platdata(dev);
 340         plat->init_type = USB_INIT_DEVICE;
 341         ret = device_probe(dev);
 342         if (ret)
 343                 return ret;
 344         *ctlrp = dev_get_priv(dev);
 345
 346         return 0;
 347 }
 348
 349 /* returns 0 if no match, 1 if match */
 350 int usb_match_device(const struct usb_device_descriptor *desc,
 351                      const struct usb_device_id *id)
 352 {
 353         if ((id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
 354             id->idVendor != le16_to_cpu(desc->idVendor))
 355                 return 0;
 356
 357         if ((id->match_flags & USB_DEVICE_ID_MATCH_PRODUCT) &&
 358             id->idProduct != le16_to_cpu(desc->idProduct))
 359                 return 0;
 360
 361         /* No need to test id->bcdDevice_lo != 0, since 0 is never
 362            greater than any unsigned number. */
 363         if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_LO) &&
 364             (id->bcdDevice_lo > le16_to_cpu(desc->bcdDevice)))
 365                 return 0;
 366
 367         if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_HI) &&
 368             (id->bcdDevice_hi < le16_to_cpu(desc->bcdDevice)))
 369                 return 0;
 370
 371         if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_CLASS) &&
 372             (id->bDeviceClass != desc->bDeviceClass))
 373                 return 0;
 374
 375         if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_SUBCLASS) &&
 376             (id->bDeviceSubClass != desc->bDeviceSubClass))
 377                 return 0;
 378
 379         if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_PROTOCOL) &&
 380             (id->bDeviceProtocol != desc->bDeviceProtocol))
 381                 return 0;
 382
 383         return 1;
 384 }
 385
 386 /* returns 0 if no match, 1 if match */
 387 int usb_match_one_id_intf(const struct usb_device_descriptor *desc,
 388                           const struct usb_interface_descriptor *int_desc,
 389                           const struct usb_device_id *id)
 390 {
 391         /* The interface class, subclass, protocol and number should never be
 392          * checked for a match if the device class is Vendor Specific,
 393          * unless the match record specifies the Vendor ID. */
 394         if (desc->bDeviceClass == USB_CLASS_VENDOR_SPEC &&
 395             !(id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
 396             (id->match_flags & (USB_DEVICE_ID_MATCH_INT_CLASS |
 397                                 USB_DEVICE_ID_MATCH_INT_SUBCLASS |
 398                                 USB_DEVICE_ID_MATCH_INT_PROTOCOL |
 399                                 USB_DEVICE_ID_MATCH_INT_NUMBER)))
 400                 return 0;
 401
 402         if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_CLASS) &&
 403             (id->bInterfaceClass != int_desc->bInterfaceClass))
 404                 return 0;
 405
 406         if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_SUBCLASS) &&
 407             (id->bInterfaceSubClass != int_desc->bInterfaceSubClass))
 408                 return 0;
 409
 410         if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_PROTOCOL) &&
 411             (id->bInterfaceProtocol != int_desc->bInterfaceProtocol))
 412                 return 0;
 413
 414         if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_NUMBER) &&
 415             (id->bInterfaceNumber != int_desc->bInterfaceNumber))
 416                 return 0;
 417
 418         return 1;
 419 }
 420
 421 /* returns 0 if no match, 1 if match */
 422 int usb_match_one_id(struct usb_device_descriptor *desc,
 423                      struct usb_interface_descriptor *int_desc,
 424                      const struct usb_device_id *id)
 425 {
 426         if (!usb_match_device(desc, id))
 427                 return 0;
 428
 429         return usb_match_one_id_intf(desc, int_desc, id);
 430 }
 431
 432 /**
 433  * usb_find_and_bind_driver() - Find and bind the right USB driver
 434  *
 435  * This only looks at certain fields in the descriptor.
 436  */
 437 static int usb_find_and_bind_driver(struct udevice *parent,
 438                                     struct usb_device_descriptor *desc,
 439                                     struct usb_interface_descriptor *iface,
 440                                     int bus_seq, int devnum,
 441                                     struct udevice **devp)
 442 {
 443         struct usb_driver_entry *start, *entry;
 444         int n_ents;
 445         int ret;
 446         char name[30], *str;
 447
 448         *devp = NULL;
 449         debug("%s: Searching for driver\n", __func__);
 450         start = ll_entry_start(struct usb_driver_entry, usb_driver_entry);
 451         n_ents = ll_entry_count(struct usb_driver_entry, usb_driver_entry);
 452         for (entry = start; entry != start + n_ents; entry++) {
 453                 const struct usb_device_id *id;
 454                 struct udevice *dev;
 455                 const struct driver *drv;
 456                 struct usb_dev_platdata *plat;
 457
 458                 for (id = entry->match; id->match_flags; id++) {
 459                         if (!usb_match_one_id(desc, iface, id))
 460                                 continue;
 461
 462                         drv = entry->driver;
 463                         /*
 464                          * We could pass the descriptor to the driver as
 465                          * platdata (instead of NULL) and allow its bind()
 466                          * method to return -ENOENT if it doesn't support this
 467                          * device. That way we could continue the search to
 468                          * find another driver. For now this doesn't seem
 469                          * necesssary, so just bind the first match.
 470                          */
 471                         ret = device_bind(parent, drv, drv->name, NULL, -1,
 472                                           &dev);
 473                         if (ret)
 474                                 goto error;
 475                         debug("%s: Match found: %s\n", __func__, drv->name);
 476                         dev->driver_data = id->driver_info;
 477                         plat = dev_get_parent_platdata(dev);
 478                         plat->id = *id;
 479                         *devp = dev;
 480                         return 0;
 481                 }
 482         }
 483
 484         /* Bind a generic driver so that the device can be used */
 485         snprintf(name, sizeof(name), "generic_bus_%x_dev_%x", bus_seq, devnum);
 486         str = strdup(name);
 487         if (!str)
 488                 return -ENOMEM;
 489         ret = device_bind_driver(parent, "usb_dev_generic_drv", str, devp);
 490
 491 error:
 492         debug("%s: No match found: %d\n", __func__, ret);
 493         return ret;
 494 }
 495
 496 /**
 497  * usb_find_emul_child() - Find an existing device for emulated devices
 498  */
 499 static int usb_find_emul_child(struct udevice *parent,
 500                                struct usb_device_descriptor *desc,
 501                                struct usb_interface_descriptor *iface,
 502                                struct udevice **devp)
 503 {
 504 #ifdef CONFIG_SANDBOX
 505         struct udevice *dev;
 506
 507         *devp = NULL;
 508         for (device_find_first_child(parent, &dev);
 509              dev;
 510              device_find_next_child(&dev)) {
 511                 struct usb_dev_platdata *plat = dev_get_parent_platdata(dev);
 512
 513                 /* If this device is already in use, skip it */
 514                 if (device_active(dev))
 515                         continue;
 516                 debug("   %s: name='%s', plat=%d, desc=%d\n", __func__,
 517                       dev->name, plat->id.bDeviceClass, desc->bDeviceClass);
 518                 if (usb_match_one_id(desc, iface, &plat->id)) {
 519                         *devp = dev;
 520                         return 0;
 521                 }
 522         }
 523 #endif
 524         return -ENOENT;
 525 }
 526
 527 int usb_scan_device(struct udevice *parent, int port,
 528                     enum usb_device_speed speed, struct udevice **devp)
 529 {
 530         struct udevice *dev;
 531         bool created = false;
 532         struct usb_dev_platdata *plat;
 533         struct usb_bus_priv *priv;
 534         struct usb_device *parent_udev;
 535         int ret;
 536         ALLOC_CACHE_ALIGN_BUFFER(struct usb_device, udev, 1);
 537         struct usb_interface_descriptor *iface = &udev->config.if_desc[0].desc;
 538
 539         *devp = NULL;
 540         memset(udev, '\0', sizeof(*udev));
 541         udev->controller_dev = usb_get_bus(parent);
 542         priv = dev_get_uclass_priv(udev->controller_dev);
 543
 544         /*
 545          * Somewhat nasty, this. We create a local device and use the normal
 546          * USB stack to read its descriptor. Then we know what type of device
 547          * to create for real.
 548          *
 549          * udev->dev is set to the parent, since we don't have a real device
 550          * yet. The USB stack should not access udev.dev anyway, except perhaps
 551          * to find the controller, and the controller will either be @parent,
 552          * or some parent of @parent.
 553          *
 554          * Another option might be to create the device as a generic USB
 555          * device, then morph it into the correct one when we know what it
 556          * should be. This means that a generic USB device would morph into
 557          * a network controller, or a USB flash stick, for example. However,
 558          * we don't support such morphing and it isn't clear that it would
 559          * be easy to do.
 560          *
 561          * Yet another option is to split out the USB stack parts of udev
 562          * into something like a 'struct urb' (as Linux does) which can exist
 563          * independently of any device. This feels cleaner, but calls for quite
 564          * a big change to the USB stack.
 565          *
 566          * For now, the approach is to set up an empty udev, read its
 567          * descriptor and assign it an address, then bind a real device and
 568          * stash the resulting information into the device's parent
 569          * platform data. Then when we probe it, usb_child_pre_probe() is called
 570          * and it will pull the information out of the stash.
 571          */
 572         udev->dev = parent;
 573         udev->speed = speed;
 574         udev->devnum = priv->next_addr + 1;
 575         udev->portnr = port;
 576         debug("Calling usb_setup_device(), portnr=%d\n", udev->portnr);
 577         parent_udev = device_get_uclass_id(parent) == UCLASS_USB_HUB ?
 578                 dev_get_parentdata(parent) : NULL;
 579         ret = usb_setup_device(udev, priv->desc_before_addr, parent_udev);
 580         debug("read_descriptor for '%s': ret=%d\n", parent->name, ret);
 581         if (ret)
 582                 return ret;
 583         ret = usb_find_emul_child(parent, &udev->descriptor, iface, &dev);
 584         debug("** usb_find_emul_child returns %d\n", ret);
 585         if (ret) {
 586                 if (ret != -ENOENT)
 587                         return ret;
 588                 ret = usb_find_and_bind_driver(parent, &udev->descriptor, iface,
 589                                                udev->controller_dev->seq,
 590                                                udev->devnum, &dev);
 591                 if (ret)
 592                         return ret;
 593                 created = true;
 594         }
 595         plat = dev_get_parent_platdata(dev);
 596         debug("%s: Probing '%s', plat=%p\n", __func__, dev->name, plat);
 597         plat->devnum = udev->devnum;
 598         plat->udev = udev;
 599         priv->next_addr++;
 600         ret = device_probe(dev);
 601         if (ret) {
 602                 debug("%s: Device '%s' probe failed\n", __func__, dev->name);
 603                 priv->next_addr--;
 604                 if (created)
 605                         device_unbind(dev);
 606                 return ret;
 607         }
 608         *devp = dev;
 609
 610         return 0;
 611 }
 612
 613 /*
 614  * Detect if a USB device has been plugged or unplugged.
 615  */
 616 int usb_detect_change(void)
 617 {
 618         struct udevice *hub;
 619         struct uclass *uc;
 620         int change = 0;
 621         int ret;
 622
 623         ret = uclass_get(UCLASS_USB_HUB, &uc);
 624         if (ret)
 625                 return ret;
 626
 627         uclass_foreach_dev(hub, uc) {
 628                 struct usb_device *udev;
 629                 struct udevice *dev;
 630
 631                 if (!device_active(hub))
 632                         continue;
 633                 for (device_find_first_child(hub, &dev);
 634                      dev;
 635                      device_find_next_child(&dev)) {
 636                         struct usb_port_status status;
 637
 638                         if (!device_active(dev))
 639                                 continue;
 640
 641                         udev = dev_get_parentdata(dev);
 642                         if (usb_get_port_status(udev, udev->portnr, &status)
 643                                         < 0)
 644                                 /* USB request failed */
 645                                 continue;
 646
 647                         if (le16_to_cpu(status.wPortChange) &
 648                             USB_PORT_STAT_C_CONNECTION)
 649                                 change++;
 650                 }
 651         }
 652
 653         return change;
 654 }
 655
 656 int usb_child_post_bind(struct udevice *dev)
 657 {
 658         struct usb_dev_platdata *plat = dev_get_parent_platdata(dev);
 659         const void *blob = gd->fdt_blob;
 660         int val;
 661
 662         if (dev->of_offset == -1)
 663                 return 0;
 664
 665         /* We only support matching a few things */
 666         val = fdtdec_get_int(blob, dev->of_offset, "usb,device-class", -1);
 667         if (val != -1) {
 668                 plat->id.match_flags |= USB_DEVICE_ID_MATCH_DEV_CLASS;
 669                 plat->id.bDeviceClass = val;
 670         }
 671         val = fdtdec_get_int(blob, dev->of_offset, "usb,interface-class", -1);
 672         if (val != -1) {
 673                 plat->id.match_flags |= USB_DEVICE_ID_MATCH_INT_CLASS;
 674                 plat->id.bInterfaceClass = val;
 675         }
 676
 677         return 0;
 678 }
 679
 680 struct udevice *usb_get_bus(struct udevice *dev)
 681 {
 682         struct udevice *bus;
 683
 684         for (bus = dev; bus && device_get_uclass_id(bus) != UCLASS_USB; )
 685                 bus = bus->parent;
 686         if (!bus) {
 687                 /* By design this cannot happen */
 688                 assert(bus);
 689                 debug("USB HUB '%s' does not have a controller\n", dev->name);
 690         }
 691
 692         return bus;
 693 }
 694
 695 int usb_child_pre_probe(struct udevice *dev)
 696 {
 697         struct usb_device *udev = dev_get_parentdata(dev);
 698         struct usb_dev_platdata *plat = dev_get_parent_platdata(dev);
 699         int ret;
 700
 701         if (plat->udev) {
 702                 /*
 703                  * Copy over all the values set in the on stack struct
 704                  * usb_device in usb_scan_device() to our final struct
 705                  * usb_device for this dev.
 706                  */
 707                 *udev = *(plat->udev);
 708                 /* And clear plat->udev as it will not be valid for long */
 709                 plat->udev = NULL;
 710                 udev->dev = dev;
 711         } else {
 712                 /*
 713                  * This happens with devices which are explicitly bound
 714                  * instead of being discovered through usb_scan_device()
 715                  * such as sandbox emul devices.
 716                  */
 717                 udev->dev = dev;
 718                 udev->controller_dev = usb_get_bus(dev);
 719                 udev->devnum = plat->devnum;
 720
 721                 /*
 722                  * udev did not go through usb_scan_device(), so we need to
 723                  * select the config and read the config descriptors.
 724                  */
 725                 ret = usb_select_config(udev);
 726                 if (ret)
 727                         return ret;
 728         }
 729
 730         return 0;
 731 }
 732
 733 UCLASS_DRIVER(usb) = {
 734         .id             = UCLASS_USB,
 735         .name           = "usb",
 736         .flags          = DM_UC_FLAG_SEQ_ALIAS,
 737         .post_bind      = usb_post_bind,
 738         .priv_auto_alloc_size = sizeof(struct usb_uclass_priv),
 739         .per_child_auto_alloc_size = sizeof(struct usb_device),
 740         .per_device_auto_alloc_size = sizeof(struct usb_bus_priv),
 741         .child_post_bind = usb_child_post_bind,
 742         .child_pre_probe = usb_child_pre_probe,
 743         .per_child_platdata_auto_alloc_size = sizeof(struct usb_dev_platdata),
 744 };
 745
 746 UCLASS_DRIVER(usb_dev_generic) = {
 747         .id             = UCLASS_USB_DEV_GENERIC,
 748         .name           = "usb_dev_generic",
 749 };
 750
 751 U_BOOT_DRIVER(usb_dev_generic_drv) = {
 752         .id             = UCLASS_USB_DEV_GENERIC,
 753         .name           = "usb_dev_generic_drv",
 754 };