xref: /openbmc/u-boot/drivers/usb/host/usb-uclass.c (revision 679f82c3)
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 };
755