xref: /openbmc/u-boot/drivers/usb/host/usb-uclass.c (revision 0edd82e2)
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 
163 #ifdef CONFIG_SANDBOX
164 	struct udevice *dev;
165 
166 	/* Reset all enulation devices */
167 	ret = uclass_get(UCLASS_USB_EMUL, &uc);
168 	if (ret)
169 		return ret;
170 
171 	uclass_foreach_dev(dev, uc)
172 		usb_emul_reset(dev);
173 #endif
174 #ifdef CONFIG_USB_STORAGE
175 	usb_stor_reset();
176 #endif
177 	usb_hub_reset();
178 	uc_priv->companion_device_count = 0;
179 	usb_started = 0;
180 
181 	return err;
182 }
183 
184 static void usb_scan_bus(struct udevice *bus, bool recurse)
185 {
186 	struct usb_bus_priv *priv;
187 	struct udevice *dev;
188 	int ret;
189 
190 	priv = dev_get_uclass_priv(bus);
191 
192 	assert(recurse);	/* TODO: Support non-recusive */
193 
194 	printf("scanning bus %d for devices... ", bus->seq);
195 	debug("\n");
196 	ret = usb_scan_device(bus, 0, USB_SPEED_FULL, &dev);
197 	if (ret)
198 		printf("failed, error %d\n", ret);
199 	else if (priv->next_addr == 0)
200 		printf("No USB Device found\n");
201 	else
202 		printf("%d USB Device(s) found\n", priv->next_addr);
203 }
204 
205 static void remove_inactive_children(struct uclass *uc, struct udevice *bus)
206 {
207 	uclass_foreach_dev(bus, uc) {
208 		struct udevice *dev, *next;
209 
210 		if (!device_active(bus))
211 			continue;
212 		device_foreach_child_safe(dev, next, bus) {
213 			if (!device_active(dev))
214 				device_unbind(dev);
215 		}
216 	}
217 }
218 
219 int usb_init(void)
220 {
221 	int controllers_initialized = 0;
222 	struct usb_uclass_priv *uc_priv;
223 	struct usb_bus_priv *priv;
224 	struct udevice *bus;
225 	struct uclass *uc;
226 	int count = 0;
227 	int ret;
228 
229 	asynch_allowed = 1;
230 	usb_hub_reset();
231 
232 	ret = uclass_get(UCLASS_USB, &uc);
233 	if (ret)
234 		return ret;
235 
236 	uc_priv = uc->priv;
237 
238 	uclass_foreach_dev(bus, uc) {
239 		/* init low_level USB */
240 		printf("USB%d:   ", count);
241 		count++;
242 		ret = device_probe(bus);
243 		if (ret == -ENODEV) {	/* No such device. */
244 			puts("Port not available.\n");
245 			controllers_initialized++;
246 			continue;
247 		}
248 
249 		if (ret) {		/* Other error. */
250 			printf("probe failed, error %d\n", ret);
251 			continue;
252 		}
253 		controllers_initialized++;
254 		usb_started = true;
255 	}
256 
257 	/*
258 	 * lowlevel init done, now scan the bus for devices i.e. search HUBs
259 	 * and configure them, first scan primary controllers.
260 	 */
261 	uclass_foreach_dev(bus, uc) {
262 		if (!device_active(bus))
263 			continue;
264 
265 		priv = dev_get_uclass_priv(bus);
266 		if (!priv->companion)
267 			usb_scan_bus(bus, true);
268 	}
269 
270 	/*
271 	 * Now that the primary controllers have been scanned and have handed
272 	 * over any devices they do not understand to their companions, scan
273 	 * the companions if necessary.
274 	 */
275 	if (uc_priv->companion_device_count) {
276 		uclass_foreach_dev(bus, uc) {
277 			if (!device_active(bus))
278 				continue;
279 
280 			priv = dev_get_uclass_priv(bus);
281 			if (priv->companion)
282 				usb_scan_bus(bus, true);
283 		}
284 	}
285 
286 	debug("scan end\n");
287 
288 	/* Remove any devices that were not found on this scan */
289 	remove_inactive_children(uc, bus);
290 
291 	ret = uclass_get(UCLASS_USB_HUB, &uc);
292 	if (ret)
293 		return ret;
294 	remove_inactive_children(uc, bus);
295 
296 	/* if we were not able to find at least one working bus, bail out */
297 	if (!count)
298 		printf("No controllers found\n");
299 	else if (controllers_initialized == 0)
300 		printf("USB error: all controllers failed lowlevel init\n");
301 
302 	return usb_started ? 0 : -1;
303 }
304 
305 /*
306  * TODO(sjg@chromium.org): Remove this legacy function. At present it is needed
307  * to support boards which use driver model for USB but not Ethernet, and want
308  * to use USB Ethernet.
309  *
310  * The #if clause is here to ensure that remains the only case.
311  */
312 #if !defined(CONFIG_DM_ETH) && defined(CONFIG_USB_HOST_ETHER)
313 static struct usb_device *find_child_devnum(struct udevice *parent, int devnum)
314 {
315 	struct usb_device *udev;
316 	struct udevice *dev;
317 
318 	if (!device_active(parent))
319 		return NULL;
320 	udev = dev_get_parent_priv(parent);
321 	if (udev->devnum == devnum)
322 		return udev;
323 
324 	for (device_find_first_child(parent, &dev);
325 	     dev;
326 	     device_find_next_child(&dev)) {
327 		udev = find_child_devnum(dev, devnum);
328 		if (udev)
329 			return udev;
330 	}
331 
332 	return NULL;
333 }
334 
335 struct usb_device *usb_get_dev_index(struct udevice *bus, int index)
336 {
337 	struct udevice *dev;
338 	int devnum = index + 1; /* Addresses are allocated from 1 on USB */
339 
340 	device_find_first_child(bus, &dev);
341 	if (!dev)
342 		return NULL;
343 
344 	return find_child_devnum(dev, devnum);
345 }
346 #endif
347 
348 int usb_post_bind(struct udevice *dev)
349 {
350 	/* Scan the bus for devices */
351 	return dm_scan_fdt_node(dev, gd->fdt_blob, dev->of_offset, false);
352 }
353 
354 int usb_setup_ehci_gadget(struct ehci_ctrl **ctlrp)
355 {
356 	struct usb_platdata *plat;
357 	struct udevice *dev;
358 	int ret;
359 
360 	/* Find the old device and remove it */
361 	ret = uclass_find_device_by_seq(UCLASS_USB, 0, true, &dev);
362 	if (ret)
363 		return ret;
364 	ret = device_remove(dev);
365 	if (ret)
366 		return ret;
367 
368 	plat = dev_get_platdata(dev);
369 	plat->init_type = USB_INIT_DEVICE;
370 	ret = device_probe(dev);
371 	if (ret)
372 		return ret;
373 	*ctlrp = dev_get_priv(dev);
374 
375 	return 0;
376 }
377 
378 /* returns 0 if no match, 1 if match */
379 int usb_match_device(const struct usb_device_descriptor *desc,
380 		     const struct usb_device_id *id)
381 {
382 	if ((id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
383 	    id->idVendor != le16_to_cpu(desc->idVendor))
384 		return 0;
385 
386 	if ((id->match_flags & USB_DEVICE_ID_MATCH_PRODUCT) &&
387 	    id->idProduct != le16_to_cpu(desc->idProduct))
388 		return 0;
389 
390 	/* No need to test id->bcdDevice_lo != 0, since 0 is never
391 	   greater than any unsigned number. */
392 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_LO) &&
393 	    (id->bcdDevice_lo > le16_to_cpu(desc->bcdDevice)))
394 		return 0;
395 
396 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_HI) &&
397 	    (id->bcdDevice_hi < le16_to_cpu(desc->bcdDevice)))
398 		return 0;
399 
400 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_CLASS) &&
401 	    (id->bDeviceClass != desc->bDeviceClass))
402 		return 0;
403 
404 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_SUBCLASS) &&
405 	    (id->bDeviceSubClass != desc->bDeviceSubClass))
406 		return 0;
407 
408 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_PROTOCOL) &&
409 	    (id->bDeviceProtocol != desc->bDeviceProtocol))
410 		return 0;
411 
412 	return 1;
413 }
414 
415 /* returns 0 if no match, 1 if match */
416 int usb_match_one_id_intf(const struct usb_device_descriptor *desc,
417 			  const struct usb_interface_descriptor *int_desc,
418 			  const struct usb_device_id *id)
419 {
420 	/* The interface class, subclass, protocol and number should never be
421 	 * checked for a match if the device class is Vendor Specific,
422 	 * unless the match record specifies the Vendor ID. */
423 	if (desc->bDeviceClass == USB_CLASS_VENDOR_SPEC &&
424 	    !(id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
425 	    (id->match_flags & (USB_DEVICE_ID_MATCH_INT_CLASS |
426 				USB_DEVICE_ID_MATCH_INT_SUBCLASS |
427 				USB_DEVICE_ID_MATCH_INT_PROTOCOL |
428 				USB_DEVICE_ID_MATCH_INT_NUMBER)))
429 		return 0;
430 
431 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_CLASS) &&
432 	    (id->bInterfaceClass != int_desc->bInterfaceClass))
433 		return 0;
434 
435 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_SUBCLASS) &&
436 	    (id->bInterfaceSubClass != int_desc->bInterfaceSubClass))
437 		return 0;
438 
439 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_PROTOCOL) &&
440 	    (id->bInterfaceProtocol != int_desc->bInterfaceProtocol))
441 		return 0;
442 
443 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_NUMBER) &&
444 	    (id->bInterfaceNumber != int_desc->bInterfaceNumber))
445 		return 0;
446 
447 	return 1;
448 }
449 
450 /* returns 0 if no match, 1 if match */
451 int usb_match_one_id(struct usb_device_descriptor *desc,
452 		     struct usb_interface_descriptor *int_desc,
453 		     const struct usb_device_id *id)
454 {
455 	if (!usb_match_device(desc, id))
456 		return 0;
457 
458 	return usb_match_one_id_intf(desc, int_desc, id);
459 }
460 
461 /**
462  * usb_find_and_bind_driver() - Find and bind the right USB driver
463  *
464  * This only looks at certain fields in the descriptor.
465  */
466 static int usb_find_and_bind_driver(struct udevice *parent,
467 				    struct usb_device_descriptor *desc,
468 				    struct usb_interface_descriptor *iface,
469 				    int bus_seq, int devnum,
470 				    struct udevice **devp)
471 {
472 	struct usb_driver_entry *start, *entry;
473 	int n_ents;
474 	int ret;
475 	char name[30], *str;
476 
477 	*devp = NULL;
478 	debug("%s: Searching for driver\n", __func__);
479 	start = ll_entry_start(struct usb_driver_entry, usb_driver_entry);
480 	n_ents = ll_entry_count(struct usb_driver_entry, usb_driver_entry);
481 	for (entry = start; entry != start + n_ents; entry++) {
482 		const struct usb_device_id *id;
483 		struct udevice *dev;
484 		const struct driver *drv;
485 		struct usb_dev_platdata *plat;
486 
487 		for (id = entry->match; id->match_flags; id++) {
488 			if (!usb_match_one_id(desc, iface, id))
489 				continue;
490 
491 			drv = entry->driver;
492 			/*
493 			 * We could pass the descriptor to the driver as
494 			 * platdata (instead of NULL) and allow its bind()
495 			 * method to return -ENOENT if it doesn't support this
496 			 * device. That way we could continue the search to
497 			 * find another driver. For now this doesn't seem
498 			 * necesssary, so just bind the first match.
499 			 */
500 			ret = device_bind(parent, drv, drv->name, NULL, -1,
501 					  &dev);
502 			if (ret)
503 				goto error;
504 			debug("%s: Match found: %s\n", __func__, drv->name);
505 			dev->driver_data = id->driver_info;
506 			plat = dev_get_parent_platdata(dev);
507 			plat->id = *id;
508 			*devp = dev;
509 			return 0;
510 		}
511 	}
512 
513 	/* Bind a generic driver so that the device can be used */
514 	snprintf(name, sizeof(name), "generic_bus_%x_dev_%x", bus_seq, devnum);
515 	str = strdup(name);
516 	if (!str)
517 		return -ENOMEM;
518 	ret = device_bind_driver(parent, "usb_dev_generic_drv", str, devp);
519 
520 error:
521 	debug("%s: No match found: %d\n", __func__, ret);
522 	return ret;
523 }
524 
525 /**
526  * usb_find_child() - Find an existing device which matches our needs
527  *
528  *
529  */
530 static int usb_find_child(struct udevice *parent,
531 			  struct usb_device_descriptor *desc,
532 			  struct usb_interface_descriptor *iface,
533 			  struct udevice **devp)
534 {
535 	struct udevice *dev;
536 
537 	*devp = NULL;
538 	for (device_find_first_child(parent, &dev);
539 	     dev;
540 	     device_find_next_child(&dev)) {
541 		struct usb_dev_platdata *plat = dev_get_parent_platdata(dev);
542 
543 		/* If this device is already in use, skip it */
544 		if (device_active(dev))
545 			continue;
546 		debug("   %s: name='%s', plat=%d, desc=%d\n", __func__,
547 		      dev->name, plat->id.bDeviceClass, desc->bDeviceClass);
548 		if (usb_match_one_id(desc, iface, &plat->id)) {
549 			*devp = dev;
550 			return 0;
551 		}
552 	}
553 
554 	return -ENOENT;
555 }
556 
557 int usb_scan_device(struct udevice *parent, int port,
558 		    enum usb_device_speed speed, struct udevice **devp)
559 {
560 	struct udevice *dev;
561 	bool created = false;
562 	struct usb_dev_platdata *plat;
563 	struct usb_bus_priv *priv;
564 	struct usb_device *parent_udev;
565 	int ret;
566 	ALLOC_CACHE_ALIGN_BUFFER(struct usb_device, udev, 1);
567 	struct usb_interface_descriptor *iface = &udev->config.if_desc[0].desc;
568 
569 	*devp = NULL;
570 	memset(udev, '\0', sizeof(*udev));
571 	udev->controller_dev = usb_get_bus(parent);
572 	priv = dev_get_uclass_priv(udev->controller_dev);
573 
574 	/*
575 	 * Somewhat nasty, this. We create a local device and use the normal
576 	 * USB stack to read its descriptor. Then we know what type of device
577 	 * to create for real.
578 	 *
579 	 * udev->dev is set to the parent, since we don't have a real device
580 	 * yet. The USB stack should not access udev.dev anyway, except perhaps
581 	 * to find the controller, and the controller will either be @parent,
582 	 * or some parent of @parent.
583 	 *
584 	 * Another option might be to create the device as a generic USB
585 	 * device, then morph it into the correct one when we know what it
586 	 * should be. This means that a generic USB device would morph into
587 	 * a network controller, or a USB flash stick, for example. However,
588 	 * we don't support such morphing and it isn't clear that it would
589 	 * be easy to do.
590 	 *
591 	 * Yet another option is to split out the USB stack parts of udev
592 	 * into something like a 'struct urb' (as Linux does) which can exist
593 	 * independently of any device. This feels cleaner, but calls for quite
594 	 * a big change to the USB stack.
595 	 *
596 	 * For now, the approach is to set up an empty udev, read its
597 	 * descriptor and assign it an address, then bind a real device and
598 	 * stash the resulting information into the device's parent
599 	 * platform data. Then when we probe it, usb_child_pre_probe() is called
600 	 * and it will pull the information out of the stash.
601 	 */
602 	udev->dev = parent;
603 	udev->speed = speed;
604 	udev->devnum = priv->next_addr + 1;
605 	udev->portnr = port;
606 	debug("Calling usb_setup_device(), portnr=%d\n", udev->portnr);
607 	parent_udev = device_get_uclass_id(parent) == UCLASS_USB_HUB ?
608 		dev_get_parent_priv(parent) : NULL;
609 	ret = usb_setup_device(udev, priv->desc_before_addr, parent_udev);
610 	debug("read_descriptor for '%s': ret=%d\n", parent->name, ret);
611 	if (ret)
612 		return ret;
613 	ret = usb_find_child(parent, &udev->descriptor, iface, &dev);
614 	debug("** usb_find_child returns %d\n", ret);
615 	if (ret) {
616 		if (ret != -ENOENT)
617 			return ret;
618 		ret = usb_find_and_bind_driver(parent, &udev->descriptor, iface,
619 					       udev->controller_dev->seq,
620 					       udev->devnum, &dev);
621 		if (ret)
622 			return ret;
623 		created = true;
624 	}
625 	plat = dev_get_parent_platdata(dev);
626 	debug("%s: Probing '%s', plat=%p\n", __func__, dev->name, plat);
627 	plat->devnum = udev->devnum;
628 	plat->udev = udev;
629 	priv->next_addr++;
630 	ret = device_probe(dev);
631 	if (ret) {
632 		debug("%s: Device '%s' probe failed\n", __func__, dev->name);
633 		priv->next_addr--;
634 		if (created)
635 			device_unbind(dev);
636 		return ret;
637 	}
638 	*devp = dev;
639 
640 	return 0;
641 }
642 
643 /*
644  * Detect if a USB device has been plugged or unplugged.
645  */
646 int usb_detect_change(void)
647 {
648 	struct udevice *hub;
649 	struct uclass *uc;
650 	int change = 0;
651 	int ret;
652 
653 	ret = uclass_get(UCLASS_USB_HUB, &uc);
654 	if (ret)
655 		return ret;
656 
657 	uclass_foreach_dev(hub, uc) {
658 		struct usb_device *udev;
659 		struct udevice *dev;
660 
661 		if (!device_active(hub))
662 			continue;
663 		for (device_find_first_child(hub, &dev);
664 		     dev;
665 		     device_find_next_child(&dev)) {
666 			struct usb_port_status status;
667 
668 			if (!device_active(dev))
669 				continue;
670 
671 			udev = dev_get_parent_priv(dev);
672 			if (usb_get_port_status(udev, udev->portnr, &status)
673 					< 0)
674 				/* USB request failed */
675 				continue;
676 
677 			if (le16_to_cpu(status.wPortChange) &
678 			    USB_PORT_STAT_C_CONNECTION)
679 				change++;
680 		}
681 	}
682 
683 	return change;
684 }
685 
686 int usb_child_post_bind(struct udevice *dev)
687 {
688 	struct usb_dev_platdata *plat = dev_get_parent_platdata(dev);
689 	const void *blob = gd->fdt_blob;
690 	int val;
691 
692 	if (dev->of_offset == -1)
693 		return 0;
694 
695 	/* We only support matching a few things */
696 	val = fdtdec_get_int(blob, dev->of_offset, "usb,device-class", -1);
697 	if (val != -1) {
698 		plat->id.match_flags |= USB_DEVICE_ID_MATCH_DEV_CLASS;
699 		plat->id.bDeviceClass = val;
700 	}
701 	val = fdtdec_get_int(blob, dev->of_offset, "usb,interface-class", -1);
702 	if (val != -1) {
703 		plat->id.match_flags |= USB_DEVICE_ID_MATCH_INT_CLASS;
704 		plat->id.bInterfaceClass = val;
705 	}
706 
707 	return 0;
708 }
709 
710 struct udevice *usb_get_bus(struct udevice *dev)
711 {
712 	struct udevice *bus;
713 
714 	for (bus = dev; bus && device_get_uclass_id(bus) != UCLASS_USB; )
715 		bus = bus->parent;
716 	if (!bus) {
717 		/* By design this cannot happen */
718 		assert(bus);
719 		debug("USB HUB '%s' does not have a controller\n", dev->name);
720 	}
721 
722 	return bus;
723 }
724 
725 int usb_child_pre_probe(struct udevice *dev)
726 {
727 	struct usb_device *udev = dev_get_parent_priv(dev);
728 	struct usb_dev_platdata *plat = dev_get_parent_platdata(dev);
729 	int ret;
730 
731 	if (plat->udev) {
732 		/*
733 		 * Copy over all the values set in the on stack struct
734 		 * usb_device in usb_scan_device() to our final struct
735 		 * usb_device for this dev.
736 		 */
737 		*udev = *(plat->udev);
738 		/* And clear plat->udev as it will not be valid for long */
739 		plat->udev = NULL;
740 		udev->dev = dev;
741 	} else {
742 		/*
743 		 * This happens with devices which are explicitly bound
744 		 * instead of being discovered through usb_scan_device()
745 		 * such as sandbox emul devices.
746 		 */
747 		udev->dev = dev;
748 		udev->controller_dev = usb_get_bus(dev);
749 		udev->devnum = plat->devnum;
750 
751 		/*
752 		 * udev did not go through usb_scan_device(), so we need to
753 		 * select the config and read the config descriptors.
754 		 */
755 		ret = usb_select_config(udev);
756 		if (ret)
757 			return ret;
758 	}
759 
760 	return 0;
761 }
762 
763 UCLASS_DRIVER(usb) = {
764 	.id		= UCLASS_USB,
765 	.name		= "usb",
766 	.flags		= DM_UC_FLAG_SEQ_ALIAS,
767 	.post_bind	= usb_post_bind,
768 	.priv_auto_alloc_size = sizeof(struct usb_uclass_priv),
769 	.per_child_auto_alloc_size = sizeof(struct usb_device),
770 	.per_device_auto_alloc_size = sizeof(struct usb_bus_priv),
771 	.child_post_bind = usb_child_post_bind,
772 	.child_pre_probe = usb_child_pre_probe,
773 	.per_child_platdata_auto_alloc_size = sizeof(struct usb_dev_platdata),
774 };
775 
776 UCLASS_DRIVER(usb_dev_generic) = {
777 	.id		= UCLASS_USB_DEV_GENERIC,
778 	.name		= "usb_dev_generic",
779 };
780 
781 U_BOOT_DRIVER(usb_dev_generic_drv) = {
782 	.id		= UCLASS_USB_DEV_GENERIC,
783 	.name		= "usb_dev_generic_drv",
784 };
785