xref: /openbmc/u-boot/drivers/usb/host/usb-uclass.c (revision 2e3f1ff63f50f36e74d46f939823241856ebf1bd)
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);
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_post_bind(struct udevice *dev)
352 {
353 	return dm_scan_fdt_dev(dev);
354 }
355 
356 int usb_setup_ehci_gadget(struct ehci_ctrl **ctlrp)
357 {
358 	struct usb_platdata *plat;
359 	struct udevice *dev;
360 	int ret;
361 
362 	/* Find the old device and remove it */
363 	ret = uclass_find_device_by_seq(UCLASS_USB, 0, true, &dev);
364 	if (ret)
365 		return ret;
366 	ret = device_remove(dev);
367 	if (ret)
368 		return ret;
369 
370 	plat = dev_get_platdata(dev);
371 	plat->init_type = USB_INIT_DEVICE;
372 	ret = device_probe(dev);
373 	if (ret)
374 		return ret;
375 	*ctlrp = dev_get_priv(dev);
376 
377 	return 0;
378 }
379 
380 /* returns 0 if no match, 1 if match */
381 int usb_match_device(const struct usb_device_descriptor *desc,
382 		     const struct usb_device_id *id)
383 {
384 	if ((id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
385 	    id->idVendor != le16_to_cpu(desc->idVendor))
386 		return 0;
387 
388 	if ((id->match_flags & USB_DEVICE_ID_MATCH_PRODUCT) &&
389 	    id->idProduct != le16_to_cpu(desc->idProduct))
390 		return 0;
391 
392 	/* No need to test id->bcdDevice_lo != 0, since 0 is never
393 	   greater than any unsigned number. */
394 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_LO) &&
395 	    (id->bcdDevice_lo > le16_to_cpu(desc->bcdDevice)))
396 		return 0;
397 
398 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_HI) &&
399 	    (id->bcdDevice_hi < le16_to_cpu(desc->bcdDevice)))
400 		return 0;
401 
402 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_CLASS) &&
403 	    (id->bDeviceClass != desc->bDeviceClass))
404 		return 0;
405 
406 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_SUBCLASS) &&
407 	    (id->bDeviceSubClass != desc->bDeviceSubClass))
408 		return 0;
409 
410 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_PROTOCOL) &&
411 	    (id->bDeviceProtocol != desc->bDeviceProtocol))
412 		return 0;
413 
414 	return 1;
415 }
416 
417 /* returns 0 if no match, 1 if match */
418 int usb_match_one_id_intf(const struct usb_device_descriptor *desc,
419 			  const struct usb_interface_descriptor *int_desc,
420 			  const struct usb_device_id *id)
421 {
422 	/* The interface class, subclass, protocol and number should never be
423 	 * checked for a match if the device class is Vendor Specific,
424 	 * unless the match record specifies the Vendor ID. */
425 	if (desc->bDeviceClass == USB_CLASS_VENDOR_SPEC &&
426 	    !(id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
427 	    (id->match_flags & (USB_DEVICE_ID_MATCH_INT_CLASS |
428 				USB_DEVICE_ID_MATCH_INT_SUBCLASS |
429 				USB_DEVICE_ID_MATCH_INT_PROTOCOL |
430 				USB_DEVICE_ID_MATCH_INT_NUMBER)))
431 		return 0;
432 
433 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_CLASS) &&
434 	    (id->bInterfaceClass != int_desc->bInterfaceClass))
435 		return 0;
436 
437 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_SUBCLASS) &&
438 	    (id->bInterfaceSubClass != int_desc->bInterfaceSubClass))
439 		return 0;
440 
441 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_PROTOCOL) &&
442 	    (id->bInterfaceProtocol != int_desc->bInterfaceProtocol))
443 		return 0;
444 
445 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_NUMBER) &&
446 	    (id->bInterfaceNumber != int_desc->bInterfaceNumber))
447 		return 0;
448 
449 	return 1;
450 }
451 
452 /* returns 0 if no match, 1 if match */
453 int usb_match_one_id(struct usb_device_descriptor *desc,
454 		     struct usb_interface_descriptor *int_desc,
455 		     const struct usb_device_id *id)
456 {
457 	if (!usb_match_device(desc, id))
458 		return 0;
459 
460 	return usb_match_one_id_intf(desc, int_desc, id);
461 }
462 
463 /**
464  * usb_find_and_bind_driver() - Find and bind the right USB driver
465  *
466  * This only looks at certain fields in the descriptor.
467  */
468 static int usb_find_and_bind_driver(struct udevice *parent,
469 				    struct usb_device_descriptor *desc,
470 				    struct usb_interface_descriptor *iface,
471 				    int bus_seq, int devnum,
472 				    struct udevice **devp)
473 {
474 	struct usb_driver_entry *start, *entry;
475 	int n_ents;
476 	int ret;
477 	char name[30], *str;
478 
479 	*devp = NULL;
480 	debug("%s: Searching for driver\n", __func__);
481 	start = ll_entry_start(struct usb_driver_entry, usb_driver_entry);
482 	n_ents = ll_entry_count(struct usb_driver_entry, usb_driver_entry);
483 	for (entry = start; entry != start + n_ents; entry++) {
484 		const struct usb_device_id *id;
485 		struct udevice *dev;
486 		const struct driver *drv;
487 		struct usb_dev_platdata *plat;
488 
489 		for (id = entry->match; id->match_flags; id++) {
490 			if (!usb_match_one_id(desc, iface, id))
491 				continue;
492 
493 			drv = entry->driver;
494 			/*
495 			 * We could pass the descriptor to the driver as
496 			 * platdata (instead of NULL) and allow its bind()
497 			 * method to return -ENOENT if it doesn't support this
498 			 * device. That way we could continue the search to
499 			 * find another driver. For now this doesn't seem
500 			 * necesssary, so just bind the first match.
501 			 */
502 			ret = device_bind(parent, drv, drv->name, NULL, -1,
503 					  &dev);
504 			if (ret)
505 				goto error;
506 			debug("%s: Match found: %s\n", __func__, drv->name);
507 			dev->driver_data = id->driver_info;
508 			plat = dev_get_parent_platdata(dev);
509 			plat->id = *id;
510 			*devp = dev;
511 			return 0;
512 		}
513 	}
514 
515 	/* Bind a generic driver so that the device can be used */
516 	snprintf(name, sizeof(name), "generic_bus_%x_dev_%x", bus_seq, devnum);
517 	str = strdup(name);
518 	if (!str)
519 		return -ENOMEM;
520 	ret = device_bind_driver(parent, "usb_dev_generic_drv", str, devp);
521 
522 error:
523 	debug("%s: No match found: %d\n", __func__, ret);
524 	return ret;
525 }
526 
527 /**
528  * usb_find_child() - Find an existing device which matches our needs
529  *
530  *
531  */
532 static int usb_find_child(struct udevice *parent,
533 			  struct usb_device_descriptor *desc,
534 			  struct usb_interface_descriptor *iface,
535 			  struct udevice **devp)
536 {
537 	struct udevice *dev;
538 
539 	*devp = NULL;
540 	for (device_find_first_child(parent, &dev);
541 	     dev;
542 	     device_find_next_child(&dev)) {
543 		struct usb_dev_platdata *plat = dev_get_parent_platdata(dev);
544 
545 		/* If this device is already in use, skip it */
546 		if (device_active(dev))
547 			continue;
548 		debug("   %s: name='%s', plat=%d, desc=%d\n", __func__,
549 		      dev->name, plat->id.bDeviceClass, desc->bDeviceClass);
550 		if (usb_match_one_id(desc, iface, &plat->id)) {
551 			*devp = dev;
552 			return 0;
553 		}
554 	}
555 
556 	return -ENOENT;
557 }
558 
559 int usb_scan_device(struct udevice *parent, int port,
560 		    enum usb_device_speed speed, struct udevice **devp)
561 {
562 	struct udevice *dev;
563 	bool created = false;
564 	struct usb_dev_platdata *plat;
565 	struct usb_bus_priv *priv;
566 	struct usb_device *parent_udev;
567 	int ret;
568 	ALLOC_CACHE_ALIGN_BUFFER(struct usb_device, udev, 1);
569 	struct usb_interface_descriptor *iface = &udev->config.if_desc[0].desc;
570 
571 	*devp = NULL;
572 	memset(udev, '\0', sizeof(*udev));
573 	udev->controller_dev = usb_get_bus(parent);
574 	priv = dev_get_uclass_priv(udev->controller_dev);
575 
576 	/*
577 	 * Somewhat nasty, this. We create a local device and use the normal
578 	 * USB stack to read its descriptor. Then we know what type of device
579 	 * to create for real.
580 	 *
581 	 * udev->dev is set to the parent, since we don't have a real device
582 	 * yet. The USB stack should not access udev.dev anyway, except perhaps
583 	 * to find the controller, and the controller will either be @parent,
584 	 * or some parent of @parent.
585 	 *
586 	 * Another option might be to create the device as a generic USB
587 	 * device, then morph it into the correct one when we know what it
588 	 * should be. This means that a generic USB device would morph into
589 	 * a network controller, or a USB flash stick, for example. However,
590 	 * we don't support such morphing and it isn't clear that it would
591 	 * be easy to do.
592 	 *
593 	 * Yet another option is to split out the USB stack parts of udev
594 	 * into something like a 'struct urb' (as Linux does) which can exist
595 	 * independently of any device. This feels cleaner, but calls for quite
596 	 * a big change to the USB stack.
597 	 *
598 	 * For now, the approach is to set up an empty udev, read its
599 	 * descriptor and assign it an address, then bind a real device and
600 	 * stash the resulting information into the device's parent
601 	 * platform data. Then when we probe it, usb_child_pre_probe() is called
602 	 * and it will pull the information out of the stash.
603 	 */
604 	udev->dev = parent;
605 	udev->speed = speed;
606 	udev->devnum = priv->next_addr + 1;
607 	udev->portnr = port;
608 	debug("Calling usb_setup_device(), portnr=%d\n", udev->portnr);
609 	parent_udev = device_get_uclass_id(parent) == UCLASS_USB_HUB ?
610 		dev_get_parent_priv(parent) : NULL;
611 	ret = usb_setup_device(udev, priv->desc_before_addr, parent_udev);
612 	debug("read_descriptor for '%s': ret=%d\n", parent->name, ret);
613 	if (ret)
614 		return ret;
615 	ret = usb_find_child(parent, &udev->descriptor, iface, &dev);
616 	debug("** usb_find_child returns %d\n", ret);
617 	if (ret) {
618 		if (ret != -ENOENT)
619 			return ret;
620 		ret = usb_find_and_bind_driver(parent, &udev->descriptor, iface,
621 					       udev->controller_dev->seq,
622 					       udev->devnum, &dev);
623 		if (ret)
624 			return ret;
625 		created = true;
626 	}
627 	plat = dev_get_parent_platdata(dev);
628 	debug("%s: Probing '%s', plat=%p\n", __func__, dev->name, plat);
629 	plat->devnum = udev->devnum;
630 	plat->udev = udev;
631 	priv->next_addr++;
632 	ret = device_probe(dev);
633 	if (ret) {
634 		debug("%s: Device '%s' probe failed\n", __func__, dev->name);
635 		priv->next_addr--;
636 		if (created)
637 			device_unbind(dev);
638 		return ret;
639 	}
640 	*devp = dev;
641 
642 	return 0;
643 }
644 
645 /*
646  * Detect if a USB device has been plugged or unplugged.
647  */
648 int usb_detect_change(void)
649 {
650 	struct udevice *hub;
651 	struct uclass *uc;
652 	int change = 0;
653 	int ret;
654 
655 	ret = uclass_get(UCLASS_USB_HUB, &uc);
656 	if (ret)
657 		return ret;
658 
659 	uclass_foreach_dev(hub, uc) {
660 		struct usb_device *udev;
661 		struct udevice *dev;
662 
663 		if (!device_active(hub))
664 			continue;
665 		for (device_find_first_child(hub, &dev);
666 		     dev;
667 		     device_find_next_child(&dev)) {
668 			struct usb_port_status status;
669 
670 			if (!device_active(dev))
671 				continue;
672 
673 			udev = dev_get_parent_priv(dev);
674 			if (usb_get_port_status(udev, udev->portnr, &status)
675 					< 0)
676 				/* USB request failed */
677 				continue;
678 
679 			if (le16_to_cpu(status.wPortChange) &
680 			    USB_PORT_STAT_C_CONNECTION)
681 				change++;
682 		}
683 	}
684 
685 	return change;
686 }
687 
688 int usb_child_post_bind(struct udevice *dev)
689 {
690 	struct usb_dev_platdata *plat = dev_get_parent_platdata(dev);
691 	const void *blob = gd->fdt_blob;
692 	int val;
693 
694 	if (dev->of_offset == -1)
695 		return 0;
696 
697 	/* We only support matching a few things */
698 	val = fdtdec_get_int(blob, dev->of_offset, "usb,device-class", -1);
699 	if (val != -1) {
700 		plat->id.match_flags |= USB_DEVICE_ID_MATCH_DEV_CLASS;
701 		plat->id.bDeviceClass = val;
702 	}
703 	val = fdtdec_get_int(blob, dev->of_offset, "usb,interface-class", -1);
704 	if (val != -1) {
705 		plat->id.match_flags |= USB_DEVICE_ID_MATCH_INT_CLASS;
706 		plat->id.bInterfaceClass = val;
707 	}
708 
709 	return 0;
710 }
711 
712 struct udevice *usb_get_bus(struct udevice *dev)
713 {
714 	struct udevice *bus;
715 
716 	for (bus = dev; bus && device_get_uclass_id(bus) != UCLASS_USB; )
717 		bus = bus->parent;
718 	if (!bus) {
719 		/* By design this cannot happen */
720 		assert(bus);
721 		debug("USB HUB '%s' does not have a controller\n", dev->name);
722 	}
723 
724 	return bus;
725 }
726 
727 int usb_child_pre_probe(struct udevice *dev)
728 {
729 	struct usb_device *udev = dev_get_parent_priv(dev);
730 	struct usb_dev_platdata *plat = dev_get_parent_platdata(dev);
731 	int ret;
732 
733 	if (plat->udev) {
734 		/*
735 		 * Copy over all the values set in the on stack struct
736 		 * usb_device in usb_scan_device() to our final struct
737 		 * usb_device for this dev.
738 		 */
739 		*udev = *(plat->udev);
740 		/* And clear plat->udev as it will not be valid for long */
741 		plat->udev = NULL;
742 		udev->dev = dev;
743 	} else {
744 		/*
745 		 * This happens with devices which are explicitly bound
746 		 * instead of being discovered through usb_scan_device()
747 		 * such as sandbox emul devices.
748 		 */
749 		udev->dev = dev;
750 		udev->controller_dev = usb_get_bus(dev);
751 		udev->devnum = plat->devnum;
752 
753 		/*
754 		 * udev did not go through usb_scan_device(), so we need to
755 		 * select the config and read the config descriptors.
756 		 */
757 		ret = usb_select_config(udev);
758 		if (ret)
759 			return ret;
760 	}
761 
762 	return 0;
763 }
764 
765 UCLASS_DRIVER(usb) = {
766 	.id		= UCLASS_USB,
767 	.name		= "usb",
768 	.flags		= DM_UC_FLAG_SEQ_ALIAS,
769 	.post_bind	= usb_post_bind,
770 	.priv_auto_alloc_size = sizeof(struct usb_uclass_priv),
771 	.per_child_auto_alloc_size = sizeof(struct usb_device),
772 	.per_device_auto_alloc_size = sizeof(struct usb_bus_priv),
773 	.child_post_bind = usb_child_post_bind,
774 	.child_pre_probe = usb_child_pre_probe,
775 	.per_child_platdata_auto_alloc_size = sizeof(struct usb_dev_platdata),
776 };
777 
778 UCLASS_DRIVER(usb_dev_generic) = {
779 	.id		= UCLASS_USB_DEV_GENERIC,
780 	.name		= "usb_dev_generic",
781 };
782 
783 U_BOOT_DRIVER(usb_dev_generic_drv) = {
784 	.id		= UCLASS_USB_DEV_GENERIC,
785 	.name		= "usb_dev_generic_drv",
786 };
787