xref: /openbmc/u-boot/drivers/usb/host/usb-uclass.c (revision 9ee16897)
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 };
754