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