xref: /openbmc/u-boot/drivers/usb/host/usb-uclass.c (revision e04f9d0c)
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 	}
162 #ifdef CONFIG_BLK
163 	ret = blk_unbind_all(IF_TYPE_USB);
164 	if (ret && !err)
165 		err = ret;
166 #endif
167 #ifdef CONFIG_SANDBOX
168 	struct udevice *dev;
169 
170 	/* Reset all enulation devices */
171 	ret = uclass_get(UCLASS_USB_EMUL, &uc);
172 	if (ret)
173 		return ret;
174 
175 	uclass_foreach_dev(dev, uc)
176 		usb_emul_reset(dev);
177 #endif
178 #ifdef CONFIG_USB_STORAGE
179 	usb_stor_reset();
180 #endif
181 	usb_hub_reset();
182 	uc_priv->companion_device_count = 0;
183 	usb_started = 0;
184 
185 	return err;
186 }
187 
188 static void usb_scan_bus(struct udevice *bus, bool recurse)
189 {
190 	struct usb_bus_priv *priv;
191 	struct udevice *dev;
192 	int ret;
193 
194 	priv = dev_get_uclass_priv(bus);
195 
196 	assert(recurse);	/* TODO: Support non-recusive */
197 
198 	printf("scanning bus %d for devices... ", bus->seq);
199 	debug("\n");
200 	ret = usb_scan_device(bus, 0, USB_SPEED_FULL, &dev);
201 	if (ret)
202 		printf("failed, error %d\n", ret);
203 	else if (priv->next_addr == 0)
204 		printf("No USB Device found\n");
205 	else
206 		printf("%d USB Device(s) found\n", priv->next_addr);
207 }
208 
209 static void remove_inactive_children(struct uclass *uc, struct udevice *bus)
210 {
211 	uclass_foreach_dev(bus, uc) {
212 		struct udevice *dev, *next;
213 
214 		if (!device_active(bus))
215 			continue;
216 		device_foreach_child_safe(dev, next, bus) {
217 			if (!device_active(dev))
218 				device_unbind(dev);
219 		}
220 	}
221 }
222 
223 int usb_init(void)
224 {
225 	int controllers_initialized = 0;
226 	struct usb_uclass_priv *uc_priv;
227 	struct usb_bus_priv *priv;
228 	struct udevice *bus;
229 	struct uclass *uc;
230 	int count = 0;
231 	int ret;
232 
233 	asynch_allowed = 1;
234 	usb_hub_reset();
235 
236 	ret = uclass_get(UCLASS_USB, &uc);
237 	if (ret)
238 		return ret;
239 
240 	uc_priv = uc->priv;
241 
242 	uclass_foreach_dev(bus, uc) {
243 		/* init low_level USB */
244 		printf("USB%d:   ", count);
245 		count++;
246 		ret = device_probe(bus);
247 		if (ret == -ENODEV) {	/* No such device. */
248 			puts("Port not available.\n");
249 			controllers_initialized++;
250 			continue;
251 		}
252 
253 		if (ret) {		/* Other error. */
254 			printf("probe failed, error %d\n", ret);
255 			continue;
256 		}
257 		controllers_initialized++;
258 		usb_started = true;
259 	}
260 
261 	/*
262 	 * lowlevel init done, now scan the bus for devices i.e. search HUBs
263 	 * and configure them, first scan primary controllers.
264 	 */
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 	 * Now that the primary controllers have been scanned and have handed
276 	 * over any devices they do not understand to their companions, scan
277 	 * the companions if necessary.
278 	 */
279 	if (uc_priv->companion_device_count) {
280 		uclass_foreach_dev(bus, uc) {
281 			if (!device_active(bus))
282 				continue;
283 
284 			priv = dev_get_uclass_priv(bus);
285 			if (priv->companion)
286 				usb_scan_bus(bus, true);
287 		}
288 	}
289 
290 	debug("scan end\n");
291 
292 	/* Remove any devices that were not found on this scan */
293 	remove_inactive_children(uc, bus);
294 
295 	ret = uclass_get(UCLASS_USB_HUB, &uc);
296 	if (ret)
297 		return ret;
298 	remove_inactive_children(uc, bus);
299 
300 	/* if we were not able to find at least one working bus, bail out */
301 	if (!count)
302 		printf("No controllers found\n");
303 	else if (controllers_initialized == 0)
304 		printf("USB error: all controllers failed lowlevel init\n");
305 
306 	return usb_started ? 0 : -1;
307 }
308 
309 /*
310  * TODO(sjg@chromium.org): Remove this legacy function. At present it is needed
311  * to support boards which use driver model for USB but not Ethernet, and want
312  * to use USB Ethernet.
313  *
314  * The #if clause is here to ensure that remains the only case.
315  */
316 #if !defined(CONFIG_DM_ETH) && defined(CONFIG_USB_HOST_ETHER)
317 static struct usb_device *find_child_devnum(struct udevice *parent, int devnum)
318 {
319 	struct usb_device *udev;
320 	struct udevice *dev;
321 
322 	if (!device_active(parent))
323 		return NULL;
324 	udev = dev_get_parent_priv(parent);
325 	if (udev->devnum == devnum)
326 		return udev;
327 
328 	for (device_find_first_child(parent, &dev);
329 	     dev;
330 	     device_find_next_child(&dev)) {
331 		udev = find_child_devnum(dev, devnum);
332 		if (udev)
333 			return udev;
334 	}
335 
336 	return NULL;
337 }
338 
339 struct usb_device *usb_get_dev_index(struct udevice *bus, int index)
340 {
341 	struct udevice *dev;
342 	int devnum = index + 1; /* Addresses are allocated from 1 on USB */
343 
344 	device_find_first_child(bus, &dev);
345 	if (!dev)
346 		return NULL;
347 
348 	return find_child_devnum(dev, devnum);
349 }
350 #endif
351 
352 int usb_post_bind(struct udevice *dev)
353 {
354 	/* Scan the bus for devices */
355 	return dm_scan_fdt_node(dev, gd->fdt_blob, dev->of_offset, false);
356 }
357 
358 int usb_setup_ehci_gadget(struct ehci_ctrl **ctlrp)
359 {
360 	struct usb_platdata *plat;
361 	struct udevice *dev;
362 	int ret;
363 
364 	/* Find the old device and remove it */
365 	ret = uclass_find_device_by_seq(UCLASS_USB, 0, true, &dev);
366 	if (ret)
367 		return ret;
368 	ret = device_remove(dev);
369 	if (ret)
370 		return ret;
371 
372 	plat = dev_get_platdata(dev);
373 	plat->init_type = USB_INIT_DEVICE;
374 	ret = device_probe(dev);
375 	if (ret)
376 		return ret;
377 	*ctlrp = dev_get_priv(dev);
378 
379 	return 0;
380 }
381 
382 /* returns 0 if no match, 1 if match */
383 int usb_match_device(const struct usb_device_descriptor *desc,
384 		     const struct usb_device_id *id)
385 {
386 	if ((id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
387 	    id->idVendor != le16_to_cpu(desc->idVendor))
388 		return 0;
389 
390 	if ((id->match_flags & USB_DEVICE_ID_MATCH_PRODUCT) &&
391 	    id->idProduct != le16_to_cpu(desc->idProduct))
392 		return 0;
393 
394 	/* No need to test id->bcdDevice_lo != 0, since 0 is never
395 	   greater than any unsigned number. */
396 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_LO) &&
397 	    (id->bcdDevice_lo > le16_to_cpu(desc->bcdDevice)))
398 		return 0;
399 
400 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_HI) &&
401 	    (id->bcdDevice_hi < le16_to_cpu(desc->bcdDevice)))
402 		return 0;
403 
404 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_CLASS) &&
405 	    (id->bDeviceClass != desc->bDeviceClass))
406 		return 0;
407 
408 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_SUBCLASS) &&
409 	    (id->bDeviceSubClass != desc->bDeviceSubClass))
410 		return 0;
411 
412 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_PROTOCOL) &&
413 	    (id->bDeviceProtocol != desc->bDeviceProtocol))
414 		return 0;
415 
416 	return 1;
417 }
418 
419 /* returns 0 if no match, 1 if match */
420 int usb_match_one_id_intf(const struct usb_device_descriptor *desc,
421 			  const struct usb_interface_descriptor *int_desc,
422 			  const struct usb_device_id *id)
423 {
424 	/* The interface class, subclass, protocol and number should never be
425 	 * checked for a match if the device class is Vendor Specific,
426 	 * unless the match record specifies the Vendor ID. */
427 	if (desc->bDeviceClass == USB_CLASS_VENDOR_SPEC &&
428 	    !(id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
429 	    (id->match_flags & (USB_DEVICE_ID_MATCH_INT_CLASS |
430 				USB_DEVICE_ID_MATCH_INT_SUBCLASS |
431 				USB_DEVICE_ID_MATCH_INT_PROTOCOL |
432 				USB_DEVICE_ID_MATCH_INT_NUMBER)))
433 		return 0;
434 
435 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_CLASS) &&
436 	    (id->bInterfaceClass != int_desc->bInterfaceClass))
437 		return 0;
438 
439 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_SUBCLASS) &&
440 	    (id->bInterfaceSubClass != int_desc->bInterfaceSubClass))
441 		return 0;
442 
443 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_PROTOCOL) &&
444 	    (id->bInterfaceProtocol != int_desc->bInterfaceProtocol))
445 		return 0;
446 
447 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_NUMBER) &&
448 	    (id->bInterfaceNumber != int_desc->bInterfaceNumber))
449 		return 0;
450 
451 	return 1;
452 }
453 
454 /* returns 0 if no match, 1 if match */
455 int usb_match_one_id(struct usb_device_descriptor *desc,
456 		     struct usb_interface_descriptor *int_desc,
457 		     const struct usb_device_id *id)
458 {
459 	if (!usb_match_device(desc, id))
460 		return 0;
461 
462 	return usb_match_one_id_intf(desc, int_desc, id);
463 }
464 
465 /**
466  * usb_find_and_bind_driver() - Find and bind the right USB driver
467  *
468  * This only looks at certain fields in the descriptor.
469  */
470 static int usb_find_and_bind_driver(struct udevice *parent,
471 				    struct usb_device_descriptor *desc,
472 				    struct usb_interface_descriptor *iface,
473 				    int bus_seq, int devnum,
474 				    struct udevice **devp)
475 {
476 	struct usb_driver_entry *start, *entry;
477 	int n_ents;
478 	int ret;
479 	char name[30], *str;
480 
481 	*devp = NULL;
482 	debug("%s: Searching for driver\n", __func__);
483 	start = ll_entry_start(struct usb_driver_entry, usb_driver_entry);
484 	n_ents = ll_entry_count(struct usb_driver_entry, usb_driver_entry);
485 	for (entry = start; entry != start + n_ents; entry++) {
486 		const struct usb_device_id *id;
487 		struct udevice *dev;
488 		const struct driver *drv;
489 		struct usb_dev_platdata *plat;
490 
491 		for (id = entry->match; id->match_flags; id++) {
492 			if (!usb_match_one_id(desc, iface, id))
493 				continue;
494 
495 			drv = entry->driver;
496 			/*
497 			 * We could pass the descriptor to the driver as
498 			 * platdata (instead of NULL) and allow its bind()
499 			 * method to return -ENOENT if it doesn't support this
500 			 * device. That way we could continue the search to
501 			 * find another driver. For now this doesn't seem
502 			 * necesssary, so just bind the first match.
503 			 */
504 			ret = device_bind(parent, drv, drv->name, NULL, -1,
505 					  &dev);
506 			if (ret)
507 				goto error;
508 			debug("%s: Match found: %s\n", __func__, drv->name);
509 			dev->driver_data = id->driver_info;
510 			plat = dev_get_parent_platdata(dev);
511 			plat->id = *id;
512 			*devp = dev;
513 			return 0;
514 		}
515 	}
516 
517 	/* Bind a generic driver so that the device can be used */
518 	snprintf(name, sizeof(name), "generic_bus_%x_dev_%x", bus_seq, devnum);
519 	str = strdup(name);
520 	if (!str)
521 		return -ENOMEM;
522 	ret = device_bind_driver(parent, "usb_dev_generic_drv", str, devp);
523 
524 error:
525 	debug("%s: No match found: %d\n", __func__, ret);
526 	return ret;
527 }
528 
529 /**
530  * usb_find_child() - Find an existing device which matches our needs
531  *
532  *
533  */
534 static int usb_find_child(struct udevice *parent,
535 			  struct usb_device_descriptor *desc,
536 			  struct usb_interface_descriptor *iface,
537 			  struct udevice **devp)
538 {
539 	struct udevice *dev;
540 
541 	*devp = NULL;
542 	for (device_find_first_child(parent, &dev);
543 	     dev;
544 	     device_find_next_child(&dev)) {
545 		struct usb_dev_platdata *plat = dev_get_parent_platdata(dev);
546 
547 		/* If this device is already in use, skip it */
548 		if (device_active(dev))
549 			continue;
550 		debug("   %s: name='%s', plat=%d, desc=%d\n", __func__,
551 		      dev->name, plat->id.bDeviceClass, desc->bDeviceClass);
552 		if (usb_match_one_id(desc, iface, &plat->id)) {
553 			*devp = dev;
554 			return 0;
555 		}
556 	}
557 
558 	return -ENOENT;
559 }
560 
561 int usb_scan_device(struct udevice *parent, int port,
562 		    enum usb_device_speed speed, struct udevice **devp)
563 {
564 	struct udevice *dev;
565 	bool created = false;
566 	struct usb_dev_platdata *plat;
567 	struct usb_bus_priv *priv;
568 	struct usb_device *parent_udev;
569 	int ret;
570 	ALLOC_CACHE_ALIGN_BUFFER(struct usb_device, udev, 1);
571 	struct usb_interface_descriptor *iface = &udev->config.if_desc[0].desc;
572 
573 	*devp = NULL;
574 	memset(udev, '\0', sizeof(*udev));
575 	udev->controller_dev = usb_get_bus(parent);
576 	priv = dev_get_uclass_priv(udev->controller_dev);
577 
578 	/*
579 	 * Somewhat nasty, this. We create a local device and use the normal
580 	 * USB stack to read its descriptor. Then we know what type of device
581 	 * to create for real.
582 	 *
583 	 * udev->dev is set to the parent, since we don't have a real device
584 	 * yet. The USB stack should not access udev.dev anyway, except perhaps
585 	 * to find the controller, and the controller will either be @parent,
586 	 * or some parent of @parent.
587 	 *
588 	 * Another option might be to create the device as a generic USB
589 	 * device, then morph it into the correct one when we know what it
590 	 * should be. This means that a generic USB device would morph into
591 	 * a network controller, or a USB flash stick, for example. However,
592 	 * we don't support such morphing and it isn't clear that it would
593 	 * be easy to do.
594 	 *
595 	 * Yet another option is to split out the USB stack parts of udev
596 	 * into something like a 'struct urb' (as Linux does) which can exist
597 	 * independently of any device. This feels cleaner, but calls for quite
598 	 * a big change to the USB stack.
599 	 *
600 	 * For now, the approach is to set up an empty udev, read its
601 	 * descriptor and assign it an address, then bind a real device and
602 	 * stash the resulting information into the device's parent
603 	 * platform data. Then when we probe it, usb_child_pre_probe() is called
604 	 * and it will pull the information out of the stash.
605 	 */
606 	udev->dev = parent;
607 	udev->speed = speed;
608 	udev->devnum = priv->next_addr + 1;
609 	udev->portnr = port;
610 	debug("Calling usb_setup_device(), portnr=%d\n", udev->portnr);
611 	parent_udev = device_get_uclass_id(parent) == UCLASS_USB_HUB ?
612 		dev_get_parent_priv(parent) : NULL;
613 	ret = usb_setup_device(udev, priv->desc_before_addr, parent_udev);
614 	debug("read_descriptor for '%s': ret=%d\n", parent->name, ret);
615 	if (ret)
616 		return ret;
617 	ret = usb_find_child(parent, &udev->descriptor, iface, &dev);
618 	debug("** usb_find_child returns %d\n", ret);
619 	if (ret) {
620 		if (ret != -ENOENT)
621 			return ret;
622 		ret = usb_find_and_bind_driver(parent, &udev->descriptor, iface,
623 					       udev->controller_dev->seq,
624 					       udev->devnum, &dev);
625 		if (ret)
626 			return ret;
627 		created = true;
628 	}
629 	plat = dev_get_parent_platdata(dev);
630 	debug("%s: Probing '%s', plat=%p\n", __func__, dev->name, plat);
631 	plat->devnum = udev->devnum;
632 	plat->udev = udev;
633 	priv->next_addr++;
634 	ret = device_probe(dev);
635 	if (ret) {
636 		debug("%s: Device '%s' probe failed\n", __func__, dev->name);
637 		priv->next_addr--;
638 		if (created)
639 			device_unbind(dev);
640 		return ret;
641 	}
642 	*devp = dev;
643 
644 	return 0;
645 }
646 
647 /*
648  * Detect if a USB device has been plugged or unplugged.
649  */
650 int usb_detect_change(void)
651 {
652 	struct udevice *hub;
653 	struct uclass *uc;
654 	int change = 0;
655 	int ret;
656 
657 	ret = uclass_get(UCLASS_USB_HUB, &uc);
658 	if (ret)
659 		return ret;
660 
661 	uclass_foreach_dev(hub, uc) {
662 		struct usb_device *udev;
663 		struct udevice *dev;
664 
665 		if (!device_active(hub))
666 			continue;
667 		for (device_find_first_child(hub, &dev);
668 		     dev;
669 		     device_find_next_child(&dev)) {
670 			struct usb_port_status status;
671 
672 			if (!device_active(dev))
673 				continue;
674 
675 			udev = dev_get_parent_priv(dev);
676 			if (usb_get_port_status(udev, udev->portnr, &status)
677 					< 0)
678 				/* USB request failed */
679 				continue;
680 
681 			if (le16_to_cpu(status.wPortChange) &
682 			    USB_PORT_STAT_C_CONNECTION)
683 				change++;
684 		}
685 	}
686 
687 	return change;
688 }
689 
690 int usb_child_post_bind(struct udevice *dev)
691 {
692 	struct usb_dev_platdata *plat = dev_get_parent_platdata(dev);
693 	const void *blob = gd->fdt_blob;
694 	int val;
695 
696 	if (dev->of_offset == -1)
697 		return 0;
698 
699 	/* We only support matching a few things */
700 	val = fdtdec_get_int(blob, dev->of_offset, "usb,device-class", -1);
701 	if (val != -1) {
702 		plat->id.match_flags |= USB_DEVICE_ID_MATCH_DEV_CLASS;
703 		plat->id.bDeviceClass = val;
704 	}
705 	val = fdtdec_get_int(blob, dev->of_offset, "usb,interface-class", -1);
706 	if (val != -1) {
707 		plat->id.match_flags |= USB_DEVICE_ID_MATCH_INT_CLASS;
708 		plat->id.bInterfaceClass = val;
709 	}
710 
711 	return 0;
712 }
713 
714 struct udevice *usb_get_bus(struct udevice *dev)
715 {
716 	struct udevice *bus;
717 
718 	for (bus = dev; bus && device_get_uclass_id(bus) != UCLASS_USB; )
719 		bus = bus->parent;
720 	if (!bus) {
721 		/* By design this cannot happen */
722 		assert(bus);
723 		debug("USB HUB '%s' does not have a controller\n", dev->name);
724 	}
725 
726 	return bus;
727 }
728 
729 int usb_child_pre_probe(struct udevice *dev)
730 {
731 	struct usb_device *udev = dev_get_parent_priv(dev);
732 	struct usb_dev_platdata *plat = dev_get_parent_platdata(dev);
733 	int ret;
734 
735 	if (plat->udev) {
736 		/*
737 		 * Copy over all the values set in the on stack struct
738 		 * usb_device in usb_scan_device() to our final struct
739 		 * usb_device for this dev.
740 		 */
741 		*udev = *(plat->udev);
742 		/* And clear plat->udev as it will not be valid for long */
743 		plat->udev = NULL;
744 		udev->dev = dev;
745 	} else {
746 		/*
747 		 * This happens with devices which are explicitly bound
748 		 * instead of being discovered through usb_scan_device()
749 		 * such as sandbox emul devices.
750 		 */
751 		udev->dev = dev;
752 		udev->controller_dev = usb_get_bus(dev);
753 		udev->devnum = plat->devnum;
754 
755 		/*
756 		 * udev did not go through usb_scan_device(), so we need to
757 		 * select the config and read the config descriptors.
758 		 */
759 		ret = usb_select_config(udev);
760 		if (ret)
761 			return ret;
762 	}
763 
764 	return 0;
765 }
766 
767 UCLASS_DRIVER(usb) = {
768 	.id		= UCLASS_USB,
769 	.name		= "usb",
770 	.flags		= DM_UC_FLAG_SEQ_ALIAS,
771 	.post_bind	= usb_post_bind,
772 	.priv_auto_alloc_size = sizeof(struct usb_uclass_priv),
773 	.per_child_auto_alloc_size = sizeof(struct usb_device),
774 	.per_device_auto_alloc_size = sizeof(struct usb_bus_priv),
775 	.child_post_bind = usb_child_post_bind,
776 	.child_pre_probe = usb_child_pre_probe,
777 	.per_child_platdata_auto_alloc_size = sizeof(struct usb_dev_platdata),
778 };
779 
780 UCLASS_DRIVER(usb_dev_generic) = {
781 	.id		= UCLASS_USB_DEV_GENERIC,
782 	.name		= "usb_dev_generic",
783 };
784 
785 U_BOOT_DRIVER(usb_dev_generic_drv) = {
786 	.id		= UCLASS_USB_DEV_GENERIC,
787 	.name		= "usb_dev_generic_drv",
788 };
789