xref: /openbmc/u-boot/drivers/usb/host/usb-uclass.c (revision 395e2142)
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/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, DM_REMOVE_NORMAL);
158 		if (ret && !err)
159 			err = ret;
160 	}
161 #ifdef CONFIG_BLK
162 	ret = blk_unbind_all(IF_TYPE_USB);
163 	if (ret && !err)
164 		err = ret;
165 #endif
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 static void remove_inactive_children(struct uclass *uc, struct udevice *bus)
209 {
210 	uclass_foreach_dev(bus, uc) {
211 		struct udevice *dev, *next;
212 
213 		if (!device_active(bus))
214 			continue;
215 		device_foreach_child_safe(dev, next, bus) {
216 			if (!device_active(dev))
217 				device_unbind(dev);
218 		}
219 	}
220 }
221 
222 int usb_init(void)
223 {
224 	int controllers_initialized = 0;
225 	struct usb_uclass_priv *uc_priv;
226 	struct usb_bus_priv *priv;
227 	struct udevice *bus;
228 	struct uclass *uc;
229 	int count = 0;
230 	int ret;
231 
232 	asynch_allowed = 1;
233 	usb_hub_reset();
234 
235 	ret = uclass_get(UCLASS_USB, &uc);
236 	if (ret)
237 		return ret;
238 
239 	uc_priv = uc->priv;
240 
241 	uclass_foreach_dev(bus, uc) {
242 		/* init low_level USB */
243 		printf("USB%d:   ", count);
244 		count++;
245 		ret = device_probe(bus);
246 		if (ret == -ENODEV) {	/* No such device. */
247 			puts("Port not available.\n");
248 			controllers_initialized++;
249 			continue;
250 		}
251 
252 		if (ret) {		/* Other error. */
253 			printf("probe failed, error %d\n", ret);
254 			continue;
255 		}
256 		controllers_initialized++;
257 		usb_started = true;
258 	}
259 
260 	/*
261 	 * lowlevel init done, now scan the bus for devices i.e. search HUBs
262 	 * and configure them, first scan primary controllers.
263 	 */
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 	 * Now that the primary controllers have been scanned and have handed
275 	 * over any devices they do not understand to their companions, scan
276 	 * the companions if necessary.
277 	 */
278 	if (uc_priv->companion_device_count) {
279 		uclass_foreach_dev(bus, uc) {
280 			if (!device_active(bus))
281 				continue;
282 
283 			priv = dev_get_uclass_priv(bus);
284 			if (priv->companion)
285 				usb_scan_bus(bus, true);
286 		}
287 	}
288 
289 	debug("scan end\n");
290 
291 	/* Remove any devices that were not found on this scan */
292 	remove_inactive_children(uc, bus);
293 
294 	ret = uclass_get(UCLASS_USB_HUB, &uc);
295 	if (ret)
296 		return ret;
297 	remove_inactive_children(uc, bus);
298 
299 	/* if we were not able to find at least one working bus, bail out */
300 	if (!count)
301 		printf("No controllers found\n");
302 	else if (controllers_initialized == 0)
303 		printf("USB error: all controllers failed lowlevel init\n");
304 
305 	return usb_started ? 0 : -1;
306 }
307 
308 /*
309  * TODO(sjg@chromium.org): Remove this legacy function. At present it is needed
310  * to support boards which use driver model for USB but not Ethernet, and want
311  * to use USB Ethernet.
312  *
313  * The #if clause is here to ensure that remains the only case.
314  */
315 #if !defined(CONFIG_DM_ETH) && defined(CONFIG_USB_HOST_ETHER)
316 static struct usb_device *find_child_devnum(struct udevice *parent, int devnum)
317 {
318 	struct usb_device *udev;
319 	struct udevice *dev;
320 
321 	if (!device_active(parent))
322 		return NULL;
323 	udev = dev_get_parent_priv(parent);
324 	if (udev->devnum == devnum)
325 		return udev;
326 
327 	for (device_find_first_child(parent, &dev);
328 	     dev;
329 	     device_find_next_child(&dev)) {
330 		udev = find_child_devnum(dev, devnum);
331 		if (udev)
332 			return udev;
333 	}
334 
335 	return NULL;
336 }
337 
338 struct usb_device *usb_get_dev_index(struct udevice *bus, int index)
339 {
340 	struct udevice *dev;
341 	int devnum = index + 1; /* Addresses are allocated from 1 on USB */
342 
343 	device_find_first_child(bus, &dev);
344 	if (!dev)
345 		return NULL;
346 
347 	return find_child_devnum(dev, devnum);
348 }
349 #endif
350 
351 int usb_setup_ehci_gadget(struct ehci_ctrl **ctlrp)
352 {
353 	struct usb_platdata *plat;
354 	struct udevice *dev;
355 	int ret;
356 
357 	/* Find the old device and remove it */
358 	ret = uclass_find_device_by_seq(UCLASS_USB, 0, true, &dev);
359 	if (ret)
360 		return ret;
361 	ret = device_remove(dev, DM_REMOVE_NORMAL);
362 	if (ret)
363 		return ret;
364 
365 	plat = dev_get_platdata(dev);
366 	plat->init_type = USB_INIT_DEVICE;
367 	ret = device_probe(dev);
368 	if (ret)
369 		return ret;
370 	*ctlrp = dev_get_priv(dev);
371 
372 	return 0;
373 }
374 
375 /* returns 0 if no match, 1 if match */
376 int usb_match_device(const struct usb_device_descriptor *desc,
377 		     const struct usb_device_id *id)
378 {
379 	if ((id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
380 	    id->idVendor != le16_to_cpu(desc->idVendor))
381 		return 0;
382 
383 	if ((id->match_flags & USB_DEVICE_ID_MATCH_PRODUCT) &&
384 	    id->idProduct != le16_to_cpu(desc->idProduct))
385 		return 0;
386 
387 	/* No need to test id->bcdDevice_lo != 0, since 0 is never
388 	   greater than any unsigned number. */
389 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_LO) &&
390 	    (id->bcdDevice_lo > le16_to_cpu(desc->bcdDevice)))
391 		return 0;
392 
393 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_HI) &&
394 	    (id->bcdDevice_hi < le16_to_cpu(desc->bcdDevice)))
395 		return 0;
396 
397 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_CLASS) &&
398 	    (id->bDeviceClass != desc->bDeviceClass))
399 		return 0;
400 
401 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_SUBCLASS) &&
402 	    (id->bDeviceSubClass != desc->bDeviceSubClass))
403 		return 0;
404 
405 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_PROTOCOL) &&
406 	    (id->bDeviceProtocol != desc->bDeviceProtocol))
407 		return 0;
408 
409 	return 1;
410 }
411 
412 /* returns 0 if no match, 1 if match */
413 int usb_match_one_id_intf(const struct usb_device_descriptor *desc,
414 			  const struct usb_interface_descriptor *int_desc,
415 			  const struct usb_device_id *id)
416 {
417 	/* The interface class, subclass, protocol and number should never be
418 	 * checked for a match if the device class is Vendor Specific,
419 	 * unless the match record specifies the Vendor ID. */
420 	if (desc->bDeviceClass == USB_CLASS_VENDOR_SPEC &&
421 	    !(id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
422 	    (id->match_flags & (USB_DEVICE_ID_MATCH_INT_CLASS |
423 				USB_DEVICE_ID_MATCH_INT_SUBCLASS |
424 				USB_DEVICE_ID_MATCH_INT_PROTOCOL |
425 				USB_DEVICE_ID_MATCH_INT_NUMBER)))
426 		return 0;
427 
428 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_CLASS) &&
429 	    (id->bInterfaceClass != int_desc->bInterfaceClass))
430 		return 0;
431 
432 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_SUBCLASS) &&
433 	    (id->bInterfaceSubClass != int_desc->bInterfaceSubClass))
434 		return 0;
435 
436 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_PROTOCOL) &&
437 	    (id->bInterfaceProtocol != int_desc->bInterfaceProtocol))
438 		return 0;
439 
440 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_NUMBER) &&
441 	    (id->bInterfaceNumber != int_desc->bInterfaceNumber))
442 		return 0;
443 
444 	return 1;
445 }
446 
447 /* returns 0 if no match, 1 if match */
448 int usb_match_one_id(struct usb_device_descriptor *desc,
449 		     struct usb_interface_descriptor *int_desc,
450 		     const struct usb_device_id *id)
451 {
452 	if (!usb_match_device(desc, id))
453 		return 0;
454 
455 	return usb_match_one_id_intf(desc, int_desc, id);
456 }
457 
458 /**
459  * usb_find_and_bind_driver() - Find and bind the right USB driver
460  *
461  * This only looks at certain fields in the descriptor.
462  */
463 static int usb_find_and_bind_driver(struct udevice *parent,
464 				    struct usb_device_descriptor *desc,
465 				    struct usb_interface_descriptor *iface,
466 				    int bus_seq, int devnum,
467 				    struct udevice **devp)
468 {
469 	struct usb_driver_entry *start, *entry;
470 	int n_ents;
471 	int ret;
472 	char name[30], *str;
473 
474 	*devp = NULL;
475 	debug("%s: Searching for driver\n", __func__);
476 	start = ll_entry_start(struct usb_driver_entry, usb_driver_entry);
477 	n_ents = ll_entry_count(struct usb_driver_entry, usb_driver_entry);
478 	for (entry = start; entry != start + n_ents; entry++) {
479 		const struct usb_device_id *id;
480 		struct udevice *dev;
481 		const struct driver *drv;
482 		struct usb_dev_platdata *plat;
483 
484 		for (id = entry->match; id->match_flags; id++) {
485 			if (!usb_match_one_id(desc, iface, id))
486 				continue;
487 
488 			drv = entry->driver;
489 			/*
490 			 * We could pass the descriptor to the driver as
491 			 * platdata (instead of NULL) and allow its bind()
492 			 * method to return -ENOENT if it doesn't support this
493 			 * device. That way we could continue the search to
494 			 * find another driver. For now this doesn't seem
495 			 * necesssary, so just bind the first match.
496 			 */
497 			ret = device_bind(parent, drv, drv->name, NULL, -1,
498 					  &dev);
499 			if (ret)
500 				goto error;
501 			debug("%s: Match found: %s\n", __func__, drv->name);
502 			dev->driver_data = id->driver_info;
503 			plat = dev_get_parent_platdata(dev);
504 			plat->id = *id;
505 			*devp = dev;
506 			return 0;
507 		}
508 	}
509 
510 	/* Bind a generic driver so that the device can be used */
511 	snprintf(name, sizeof(name), "generic_bus_%x_dev_%x", bus_seq, devnum);
512 	str = strdup(name);
513 	if (!str)
514 		return -ENOMEM;
515 	ret = device_bind_driver(parent, "usb_dev_generic_drv", str, devp);
516 
517 error:
518 	debug("%s: No match found: %d\n", __func__, ret);
519 	return ret;
520 }
521 
522 /**
523  * usb_find_child() - Find an existing device which matches our needs
524  *
525  *
526  */
527 static int usb_find_child(struct udevice *parent,
528 			  struct usb_device_descriptor *desc,
529 			  struct usb_interface_descriptor *iface,
530 			  struct udevice **devp)
531 {
532 	struct udevice *dev;
533 
534 	*devp = NULL;
535 	for (device_find_first_child(parent, &dev);
536 	     dev;
537 	     device_find_next_child(&dev)) {
538 		struct usb_dev_platdata *plat = dev_get_parent_platdata(dev);
539 
540 		/* If this device is already in use, skip it */
541 		if (device_active(dev))
542 			continue;
543 		debug("   %s: name='%s', plat=%d, desc=%d\n", __func__,
544 		      dev->name, plat->id.bDeviceClass, desc->bDeviceClass);
545 		if (usb_match_one_id(desc, iface, &plat->id)) {
546 			*devp = dev;
547 			return 0;
548 		}
549 	}
550 
551 	return -ENOENT;
552 }
553 
554 int usb_scan_device(struct udevice *parent, int port,
555 		    enum usb_device_speed speed, struct udevice **devp)
556 {
557 	struct udevice *dev;
558 	bool created = false;
559 	struct usb_dev_platdata *plat;
560 	struct usb_bus_priv *priv;
561 	struct usb_device *parent_udev;
562 	int ret;
563 	ALLOC_CACHE_ALIGN_BUFFER(struct usb_device, udev, 1);
564 	struct usb_interface_descriptor *iface = &udev->config.if_desc[0].desc;
565 
566 	*devp = NULL;
567 	memset(udev, '\0', sizeof(*udev));
568 	udev->controller_dev = usb_get_bus(parent);
569 	priv = dev_get_uclass_priv(udev->controller_dev);
570 
571 	/*
572 	 * Somewhat nasty, this. We create a local device and use the normal
573 	 * USB stack to read its descriptor. Then we know what type of device
574 	 * to create for real.
575 	 *
576 	 * udev->dev is set to the parent, since we don't have a real device
577 	 * yet. The USB stack should not access udev.dev anyway, except perhaps
578 	 * to find the controller, and the controller will either be @parent,
579 	 * or some parent of @parent.
580 	 *
581 	 * Another option might be to create the device as a generic USB
582 	 * device, then morph it into the correct one when we know what it
583 	 * should be. This means that a generic USB device would morph into
584 	 * a network controller, or a USB flash stick, for example. However,
585 	 * we don't support such morphing and it isn't clear that it would
586 	 * be easy to do.
587 	 *
588 	 * Yet another option is to split out the USB stack parts of udev
589 	 * into something like a 'struct urb' (as Linux does) which can exist
590 	 * independently of any device. This feels cleaner, but calls for quite
591 	 * a big change to the USB stack.
592 	 *
593 	 * For now, the approach is to set up an empty udev, read its
594 	 * descriptor and assign it an address, then bind a real device and
595 	 * stash the resulting information into the device's parent
596 	 * platform data. Then when we probe it, usb_child_pre_probe() is called
597 	 * and it will pull the information out of the stash.
598 	 */
599 	udev->dev = parent;
600 	udev->speed = speed;
601 	udev->devnum = priv->next_addr + 1;
602 	udev->portnr = port;
603 	debug("Calling usb_setup_device(), portnr=%d\n", udev->portnr);
604 	parent_udev = device_get_uclass_id(parent) == UCLASS_USB_HUB ?
605 		dev_get_parent_priv(parent) : NULL;
606 	ret = usb_setup_device(udev, priv->desc_before_addr, parent_udev);
607 	debug("read_descriptor for '%s': ret=%d\n", parent->name, ret);
608 	if (ret)
609 		return ret;
610 	ret = usb_find_child(parent, &udev->descriptor, iface, &dev);
611 	debug("** usb_find_child returns %d\n", ret);
612 	if (ret) {
613 		if (ret != -ENOENT)
614 			return ret;
615 		ret = usb_find_and_bind_driver(parent, &udev->descriptor, iface,
616 					       udev->controller_dev->seq,
617 					       udev->devnum, &dev);
618 		if (ret)
619 			return ret;
620 		created = true;
621 	}
622 	plat = dev_get_parent_platdata(dev);
623 	debug("%s: Probing '%s', plat=%p\n", __func__, dev->name, plat);
624 	plat->devnum = udev->devnum;
625 	plat->udev = udev;
626 	priv->next_addr++;
627 	ret = device_probe(dev);
628 	if (ret) {
629 		debug("%s: Device '%s' probe failed\n", __func__, dev->name);
630 		priv->next_addr--;
631 		if (created)
632 			device_unbind(dev);
633 		return ret;
634 	}
635 	*devp = dev;
636 
637 	return 0;
638 }
639 
640 /*
641  * Detect if a USB device has been plugged or unplugged.
642  */
643 int usb_detect_change(void)
644 {
645 	struct udevice *hub;
646 	struct uclass *uc;
647 	int change = 0;
648 	int ret;
649 
650 	ret = uclass_get(UCLASS_USB_HUB, &uc);
651 	if (ret)
652 		return ret;
653 
654 	uclass_foreach_dev(hub, uc) {
655 		struct usb_device *udev;
656 		struct udevice *dev;
657 
658 		if (!device_active(hub))
659 			continue;
660 		for (device_find_first_child(hub, &dev);
661 		     dev;
662 		     device_find_next_child(&dev)) {
663 			struct usb_port_status status;
664 
665 			if (!device_active(dev))
666 				continue;
667 
668 			udev = dev_get_parent_priv(dev);
669 			if (usb_get_port_status(udev, udev->portnr, &status)
670 					< 0)
671 				/* USB request failed */
672 				continue;
673 
674 			if (le16_to_cpu(status.wPortChange) &
675 			    USB_PORT_STAT_C_CONNECTION)
676 				change++;
677 		}
678 	}
679 
680 	return change;
681 }
682 
683 int usb_child_post_bind(struct udevice *dev)
684 {
685 	struct usb_dev_platdata *plat = dev_get_parent_platdata(dev);
686 	const void *blob = gd->fdt_blob;
687 	int val;
688 
689 	if (dev_of_offset(dev) == -1)
690 		return 0;
691 
692 	/* We only support matching a few things */
693 	val = fdtdec_get_int(blob, dev_of_offset(dev), "usb,device-class", -1);
694 	if (val != -1) {
695 		plat->id.match_flags |= USB_DEVICE_ID_MATCH_DEV_CLASS;
696 		plat->id.bDeviceClass = val;
697 	}
698 	val = fdtdec_get_int(blob, dev_of_offset(dev), "usb,interface-class",
699 			     -1);
700 	if (val != -1) {
701 		plat->id.match_flags |= USB_DEVICE_ID_MATCH_INT_CLASS;
702 		plat->id.bInterfaceClass = val;
703 	}
704 
705 	return 0;
706 }
707 
708 struct udevice *usb_get_bus(struct udevice *dev)
709 {
710 	struct udevice *bus;
711 
712 	for (bus = dev; bus && device_get_uclass_id(bus) != UCLASS_USB; )
713 		bus = bus->parent;
714 	if (!bus) {
715 		/* By design this cannot happen */
716 		assert(bus);
717 		debug("USB HUB '%s' does not have a controller\n", dev->name);
718 	}
719 
720 	return bus;
721 }
722 
723 int usb_child_pre_probe(struct udevice *dev)
724 {
725 	struct usb_device *udev = dev_get_parent_priv(dev);
726 	struct usb_dev_platdata *plat = dev_get_parent_platdata(dev);
727 	int ret;
728 
729 	if (plat->udev) {
730 		/*
731 		 * Copy over all the values set in the on stack struct
732 		 * usb_device in usb_scan_device() to our final struct
733 		 * usb_device for this dev.
734 		 */
735 		*udev = *(plat->udev);
736 		/* And clear plat->udev as it will not be valid for long */
737 		plat->udev = NULL;
738 		udev->dev = dev;
739 	} else {
740 		/*
741 		 * This happens with devices which are explicitly bound
742 		 * instead of being discovered through usb_scan_device()
743 		 * such as sandbox emul devices.
744 		 */
745 		udev->dev = dev;
746 		udev->controller_dev = usb_get_bus(dev);
747 		udev->devnum = plat->devnum;
748 
749 		/*
750 		 * udev did not go through usb_scan_device(), so we need to
751 		 * select the config and read the config descriptors.
752 		 */
753 		ret = usb_select_config(udev);
754 		if (ret)
755 			return ret;
756 	}
757 
758 	return 0;
759 }
760 
761 UCLASS_DRIVER(usb) = {
762 	.id		= UCLASS_USB,
763 	.name		= "usb",
764 	.flags		= DM_UC_FLAG_SEQ_ALIAS,
765 	.post_bind	= dm_scan_fdt_dev,
766 	.priv_auto_alloc_size = sizeof(struct usb_uclass_priv),
767 	.per_child_auto_alloc_size = sizeof(struct usb_device),
768 	.per_device_auto_alloc_size = sizeof(struct usb_bus_priv),
769 	.child_post_bind = usb_child_post_bind,
770 	.child_pre_probe = usb_child_pre_probe,
771 	.per_child_platdata_auto_alloc_size = sizeof(struct usb_dev_platdata),
772 };
773 
774 UCLASS_DRIVER(usb_dev_generic) = {
775 	.id		= UCLASS_USB_DEV_GENERIC,
776 	.name		= "usb_dev_generic",
777 };
778 
779 U_BOOT_DRIVER(usb_dev_generic_drv) = {
780 	.id		= UCLASS_USB_DEV_GENERIC,
781 	.name		= "usb_dev_generic_drv",
782 };
783