xref: /openbmc/u-boot/drivers/usb/host/usb-uclass.c (revision 48263504)
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_update_hub_device(struct usb_device *udev)
143 {
144 	struct udevice *bus = udev->controller_dev;
145 	struct dm_usb_ops *ops = usb_get_ops(bus);
146 
147 	if (!ops->update_hub_device)
148 		return -ENOSYS;
149 
150 	return ops->update_hub_device(bus, udev);
151 }
152 
153 int usb_get_max_xfer_size(struct usb_device *udev, size_t *size)
154 {
155 	struct udevice *bus = udev->controller_dev;
156 	struct dm_usb_ops *ops = usb_get_ops(bus);
157 
158 	if (!ops->get_max_xfer_size)
159 		return -ENOSYS;
160 
161 	return ops->get_max_xfer_size(bus, size);
162 }
163 
164 int usb_stop(void)
165 {
166 	struct udevice *bus;
167 	struct udevice *rh;
168 	struct uclass *uc;
169 	struct usb_uclass_priv *uc_priv;
170 	int err = 0, ret;
171 
172 	/* De-activate any devices that have been activated */
173 	ret = uclass_get(UCLASS_USB, &uc);
174 	if (ret)
175 		return ret;
176 
177 	uc_priv = uc->priv;
178 
179 	uclass_foreach_dev(bus, uc) {
180 		ret = device_remove(bus, DM_REMOVE_NORMAL);
181 		if (ret && !err)
182 			err = ret;
183 
184 		/* Locate root hub device */
185 		device_find_first_child(bus, &rh);
186 		if (rh) {
187 			/*
188 			 * All USB devices are children of root hub.
189 			 * Unbinding root hub will unbind all of its children.
190 			 */
191 			ret = device_unbind(rh);
192 			if (ret && !err)
193 				err = ret;
194 		}
195 	}
196 
197 #ifdef CONFIG_USB_STORAGE
198 	usb_stor_reset();
199 #endif
200 	uc_priv->companion_device_count = 0;
201 	usb_started = 0;
202 
203 	return err;
204 }
205 
206 static void usb_scan_bus(struct udevice *bus, bool recurse)
207 {
208 	struct usb_bus_priv *priv;
209 	struct udevice *dev;
210 	int ret;
211 
212 	priv = dev_get_uclass_priv(bus);
213 
214 	assert(recurse);	/* TODO: Support non-recusive */
215 
216 	printf("scanning bus %d for devices... ", bus->seq);
217 	debug("\n");
218 	ret = usb_scan_device(bus, 0, USB_SPEED_FULL, &dev);
219 	if (ret)
220 		printf("failed, error %d\n", ret);
221 	else if (priv->next_addr == 0)
222 		printf("No USB Device found\n");
223 	else
224 		printf("%d USB Device(s) found\n", priv->next_addr);
225 }
226 
227 static void remove_inactive_children(struct uclass *uc, struct udevice *bus)
228 {
229 	uclass_foreach_dev(bus, uc) {
230 		struct udevice *dev, *next;
231 
232 		if (!device_active(bus))
233 			continue;
234 		device_foreach_child_safe(dev, next, bus) {
235 			if (!device_active(dev))
236 				device_unbind(dev);
237 		}
238 	}
239 }
240 
241 int usb_init(void)
242 {
243 	int controllers_initialized = 0;
244 	struct usb_uclass_priv *uc_priv;
245 	struct usb_bus_priv *priv;
246 	struct udevice *bus;
247 	struct uclass *uc;
248 	int count = 0;
249 	int ret;
250 
251 	asynch_allowed = 1;
252 
253 	ret = uclass_get(UCLASS_USB, &uc);
254 	if (ret)
255 		return ret;
256 
257 	uc_priv = uc->priv;
258 
259 	uclass_foreach_dev(bus, uc) {
260 		/* init low_level USB */
261 		printf("USB%d:   ", count);
262 		count++;
263 
264 #ifdef CONFIG_SANDBOX
265 		/*
266 		 * For Sandbox, we need scan the device tree each time when we
267 		 * start the USB stack, in order to re-create the emulated USB
268 		 * devices and bind drivers for them before we actually do the
269 		 * driver probe.
270 		 */
271 		ret = dm_scan_fdt_dev(bus);
272 		if (ret) {
273 			printf("Sandbox USB device scan failed (%d)\n", ret);
274 			continue;
275 		}
276 #endif
277 
278 		ret = device_probe(bus);
279 		if (ret == -ENODEV) {	/* No such device. */
280 			puts("Port not available.\n");
281 			controllers_initialized++;
282 			continue;
283 		}
284 
285 		if (ret) {		/* Other error. */
286 			printf("probe failed, error %d\n", ret);
287 			continue;
288 		}
289 		controllers_initialized++;
290 		usb_started = true;
291 	}
292 
293 	/*
294 	 * lowlevel init done, now scan the bus for devices i.e. search HUBs
295 	 * and configure them, first scan primary controllers.
296 	 */
297 	uclass_foreach_dev(bus, uc) {
298 		if (!device_active(bus))
299 			continue;
300 
301 		priv = dev_get_uclass_priv(bus);
302 		if (!priv->companion)
303 			usb_scan_bus(bus, true);
304 	}
305 
306 	/*
307 	 * Now that the primary controllers have been scanned and have handed
308 	 * over any devices they do not understand to their companions, scan
309 	 * the companions if necessary.
310 	 */
311 	if (uc_priv->companion_device_count) {
312 		uclass_foreach_dev(bus, uc) {
313 			if (!device_active(bus))
314 				continue;
315 
316 			priv = dev_get_uclass_priv(bus);
317 			if (priv->companion)
318 				usb_scan_bus(bus, true);
319 		}
320 	}
321 
322 	debug("scan end\n");
323 
324 	/* Remove any devices that were not found on this scan */
325 	remove_inactive_children(uc, bus);
326 
327 	ret = uclass_get(UCLASS_USB_HUB, &uc);
328 	if (ret)
329 		return ret;
330 	remove_inactive_children(uc, bus);
331 
332 	/* if we were not able to find at least one working bus, bail out */
333 	if (!count)
334 		printf("No controllers found\n");
335 	else if (controllers_initialized == 0)
336 		printf("USB error: all controllers failed lowlevel init\n");
337 
338 	return usb_started ? 0 : -1;
339 }
340 
341 /*
342  * TODO(sjg@chromium.org): Remove this legacy function. At present it is needed
343  * to support boards which use driver model for USB but not Ethernet, and want
344  * to use USB Ethernet.
345  *
346  * The #if clause is here to ensure that remains the only case.
347  */
348 #if !defined(CONFIG_DM_ETH) && defined(CONFIG_USB_HOST_ETHER)
349 static struct usb_device *find_child_devnum(struct udevice *parent, int devnum)
350 {
351 	struct usb_device *udev;
352 	struct udevice *dev;
353 
354 	if (!device_active(parent))
355 		return NULL;
356 	udev = dev_get_parent_priv(parent);
357 	if (udev->devnum == devnum)
358 		return udev;
359 
360 	for (device_find_first_child(parent, &dev);
361 	     dev;
362 	     device_find_next_child(&dev)) {
363 		udev = find_child_devnum(dev, devnum);
364 		if (udev)
365 			return udev;
366 	}
367 
368 	return NULL;
369 }
370 
371 struct usb_device *usb_get_dev_index(struct udevice *bus, int index)
372 {
373 	struct udevice *dev;
374 	int devnum = index + 1; /* Addresses are allocated from 1 on USB */
375 
376 	device_find_first_child(bus, &dev);
377 	if (!dev)
378 		return NULL;
379 
380 	return find_child_devnum(dev, devnum);
381 }
382 #endif
383 
384 int usb_setup_ehci_gadget(struct ehci_ctrl **ctlrp)
385 {
386 	struct usb_platdata *plat;
387 	struct udevice *dev;
388 	int ret;
389 
390 	/* Find the old device and remove it */
391 	ret = uclass_find_device_by_seq(UCLASS_USB, 0, true, &dev);
392 	if (ret)
393 		return ret;
394 	ret = device_remove(dev, DM_REMOVE_NORMAL);
395 	if (ret)
396 		return ret;
397 
398 	plat = dev_get_platdata(dev);
399 	plat->init_type = USB_INIT_DEVICE;
400 	ret = device_probe(dev);
401 	if (ret)
402 		return ret;
403 	*ctlrp = dev_get_priv(dev);
404 
405 	return 0;
406 }
407 
408 /* returns 0 if no match, 1 if match */
409 static int usb_match_device(const struct usb_device_descriptor *desc,
410 			    const struct usb_device_id *id)
411 {
412 	if ((id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
413 	    id->idVendor != le16_to_cpu(desc->idVendor))
414 		return 0;
415 
416 	if ((id->match_flags & USB_DEVICE_ID_MATCH_PRODUCT) &&
417 	    id->idProduct != le16_to_cpu(desc->idProduct))
418 		return 0;
419 
420 	/* No need to test id->bcdDevice_lo != 0, since 0 is never
421 	   greater than any unsigned number. */
422 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_LO) &&
423 	    (id->bcdDevice_lo > le16_to_cpu(desc->bcdDevice)))
424 		return 0;
425 
426 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_HI) &&
427 	    (id->bcdDevice_hi < le16_to_cpu(desc->bcdDevice)))
428 		return 0;
429 
430 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_CLASS) &&
431 	    (id->bDeviceClass != desc->bDeviceClass))
432 		return 0;
433 
434 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_SUBCLASS) &&
435 	    (id->bDeviceSubClass != desc->bDeviceSubClass))
436 		return 0;
437 
438 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_PROTOCOL) &&
439 	    (id->bDeviceProtocol != desc->bDeviceProtocol))
440 		return 0;
441 
442 	return 1;
443 }
444 
445 /* returns 0 if no match, 1 if match */
446 static int usb_match_one_id_intf(const struct usb_device_descriptor *desc,
447 			const struct usb_interface_descriptor *int_desc,
448 			const struct usb_device_id *id)
449 {
450 	/* The interface class, subclass, protocol and number should never be
451 	 * checked for a match if the device class is Vendor Specific,
452 	 * unless the match record specifies the Vendor ID. */
453 	if (desc->bDeviceClass == USB_CLASS_VENDOR_SPEC &&
454 	    !(id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
455 	    (id->match_flags & (USB_DEVICE_ID_MATCH_INT_CLASS |
456 				USB_DEVICE_ID_MATCH_INT_SUBCLASS |
457 				USB_DEVICE_ID_MATCH_INT_PROTOCOL |
458 				USB_DEVICE_ID_MATCH_INT_NUMBER)))
459 		return 0;
460 
461 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_CLASS) &&
462 	    (id->bInterfaceClass != int_desc->bInterfaceClass))
463 		return 0;
464 
465 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_SUBCLASS) &&
466 	    (id->bInterfaceSubClass != int_desc->bInterfaceSubClass))
467 		return 0;
468 
469 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_PROTOCOL) &&
470 	    (id->bInterfaceProtocol != int_desc->bInterfaceProtocol))
471 		return 0;
472 
473 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_NUMBER) &&
474 	    (id->bInterfaceNumber != int_desc->bInterfaceNumber))
475 		return 0;
476 
477 	return 1;
478 }
479 
480 /* returns 0 if no match, 1 if match */
481 static int usb_match_one_id(struct usb_device_descriptor *desc,
482 			    struct usb_interface_descriptor *int_desc,
483 			    const struct usb_device_id *id)
484 {
485 	if (!usb_match_device(desc, id))
486 		return 0;
487 
488 	return usb_match_one_id_intf(desc, int_desc, id);
489 }
490 
491 /**
492  * usb_find_and_bind_driver() - Find and bind the right USB driver
493  *
494  * This only looks at certain fields in the descriptor.
495  */
496 static int usb_find_and_bind_driver(struct udevice *parent,
497 				    struct usb_device_descriptor *desc,
498 				    struct usb_interface_descriptor *iface,
499 				    int bus_seq, int devnum,
500 				    struct udevice **devp)
501 {
502 	struct usb_driver_entry *start, *entry;
503 	int n_ents;
504 	int ret;
505 	char name[30], *str;
506 
507 	*devp = NULL;
508 	debug("%s: Searching for driver\n", __func__);
509 	start = ll_entry_start(struct usb_driver_entry, usb_driver_entry);
510 	n_ents = ll_entry_count(struct usb_driver_entry, usb_driver_entry);
511 	for (entry = start; entry != start + n_ents; entry++) {
512 		const struct usb_device_id *id;
513 		struct udevice *dev;
514 		const struct driver *drv;
515 		struct usb_dev_platdata *plat;
516 
517 		for (id = entry->match; id->match_flags; id++) {
518 			if (!usb_match_one_id(desc, iface, id))
519 				continue;
520 
521 			drv = entry->driver;
522 			/*
523 			 * We could pass the descriptor to the driver as
524 			 * platdata (instead of NULL) and allow its bind()
525 			 * method to return -ENOENT if it doesn't support this
526 			 * device. That way we could continue the search to
527 			 * find another driver. For now this doesn't seem
528 			 * necesssary, so just bind the first match.
529 			 */
530 			ret = device_bind(parent, drv, drv->name, NULL, -1,
531 					  &dev);
532 			if (ret)
533 				goto error;
534 			debug("%s: Match found: %s\n", __func__, drv->name);
535 			dev->driver_data = id->driver_info;
536 			plat = dev_get_parent_platdata(dev);
537 			plat->id = *id;
538 			*devp = dev;
539 			return 0;
540 		}
541 	}
542 
543 	/* Bind a generic driver so that the device can be used */
544 	snprintf(name, sizeof(name), "generic_bus_%x_dev_%x", bus_seq, devnum);
545 	str = strdup(name);
546 	if (!str)
547 		return -ENOMEM;
548 	ret = device_bind_driver(parent, "usb_dev_generic_drv", str, devp);
549 
550 error:
551 	debug("%s: No match found: %d\n", __func__, ret);
552 	return ret;
553 }
554 
555 /**
556  * usb_find_child() - Find an existing device which matches our needs
557  *
558  *
559  */
560 static int usb_find_child(struct udevice *parent,
561 			  struct usb_device_descriptor *desc,
562 			  struct usb_interface_descriptor *iface,
563 			  struct udevice **devp)
564 {
565 	struct udevice *dev;
566 
567 	*devp = NULL;
568 	for (device_find_first_child(parent, &dev);
569 	     dev;
570 	     device_find_next_child(&dev)) {
571 		struct usb_dev_platdata *plat = dev_get_parent_platdata(dev);
572 
573 		/* If this device is already in use, skip it */
574 		if (device_active(dev))
575 			continue;
576 		debug("   %s: name='%s', plat=%d, desc=%d\n", __func__,
577 		      dev->name, plat->id.bDeviceClass, desc->bDeviceClass);
578 		if (usb_match_one_id(desc, iface, &plat->id)) {
579 			*devp = dev;
580 			return 0;
581 		}
582 	}
583 
584 	return -ENOENT;
585 }
586 
587 int usb_scan_device(struct udevice *parent, int port,
588 		    enum usb_device_speed speed, struct udevice **devp)
589 {
590 	struct udevice *dev;
591 	bool created = false;
592 	struct usb_dev_platdata *plat;
593 	struct usb_bus_priv *priv;
594 	struct usb_device *parent_udev;
595 	int ret;
596 	ALLOC_CACHE_ALIGN_BUFFER(struct usb_device, udev, 1);
597 	struct usb_interface_descriptor *iface = &udev->config.if_desc[0].desc;
598 
599 	*devp = NULL;
600 	memset(udev, '\0', sizeof(*udev));
601 	udev->controller_dev = usb_get_bus(parent);
602 	priv = dev_get_uclass_priv(udev->controller_dev);
603 
604 	/*
605 	 * Somewhat nasty, this. We create a local device and use the normal
606 	 * USB stack to read its descriptor. Then we know what type of device
607 	 * to create for real.
608 	 *
609 	 * udev->dev is set to the parent, since we don't have a real device
610 	 * yet. The USB stack should not access udev.dev anyway, except perhaps
611 	 * to find the controller, and the controller will either be @parent,
612 	 * or some parent of @parent.
613 	 *
614 	 * Another option might be to create the device as a generic USB
615 	 * device, then morph it into the correct one when we know what it
616 	 * should be. This means that a generic USB device would morph into
617 	 * a network controller, or a USB flash stick, for example. However,
618 	 * we don't support such morphing and it isn't clear that it would
619 	 * be easy to do.
620 	 *
621 	 * Yet another option is to split out the USB stack parts of udev
622 	 * into something like a 'struct urb' (as Linux does) which can exist
623 	 * independently of any device. This feels cleaner, but calls for quite
624 	 * a big change to the USB stack.
625 	 *
626 	 * For now, the approach is to set up an empty udev, read its
627 	 * descriptor and assign it an address, then bind a real device and
628 	 * stash the resulting information into the device's parent
629 	 * platform data. Then when we probe it, usb_child_pre_probe() is called
630 	 * and it will pull the information out of the stash.
631 	 */
632 	udev->dev = parent;
633 	udev->speed = speed;
634 	udev->devnum = priv->next_addr + 1;
635 	udev->portnr = port;
636 	debug("Calling usb_setup_device(), portnr=%d\n", udev->portnr);
637 	parent_udev = device_get_uclass_id(parent) == UCLASS_USB_HUB ?
638 		dev_get_parent_priv(parent) : NULL;
639 	ret = usb_setup_device(udev, priv->desc_before_addr, parent_udev);
640 	debug("read_descriptor for '%s': ret=%d\n", parent->name, ret);
641 	if (ret)
642 		return ret;
643 	ret = usb_find_child(parent, &udev->descriptor, iface, &dev);
644 	debug("** usb_find_child returns %d\n", ret);
645 	if (ret) {
646 		if (ret != -ENOENT)
647 			return ret;
648 		ret = usb_find_and_bind_driver(parent, &udev->descriptor, iface,
649 					       udev->controller_dev->seq,
650 					       udev->devnum, &dev);
651 		if (ret)
652 			return ret;
653 		created = true;
654 	}
655 	plat = dev_get_parent_platdata(dev);
656 	debug("%s: Probing '%s', plat=%p\n", __func__, dev->name, plat);
657 	plat->devnum = udev->devnum;
658 	plat->udev = udev;
659 	priv->next_addr++;
660 	ret = device_probe(dev);
661 	if (ret) {
662 		debug("%s: Device '%s' probe failed\n", __func__, dev->name);
663 		priv->next_addr--;
664 		if (created)
665 			device_unbind(dev);
666 		return ret;
667 	}
668 	*devp = dev;
669 
670 	return 0;
671 }
672 
673 /*
674  * Detect if a USB device has been plugged or unplugged.
675  */
676 int usb_detect_change(void)
677 {
678 	struct udevice *hub;
679 	struct uclass *uc;
680 	int change = 0;
681 	int ret;
682 
683 	ret = uclass_get(UCLASS_USB_HUB, &uc);
684 	if (ret)
685 		return ret;
686 
687 	uclass_foreach_dev(hub, uc) {
688 		struct usb_device *udev;
689 		struct udevice *dev;
690 
691 		if (!device_active(hub))
692 			continue;
693 		for (device_find_first_child(hub, &dev);
694 		     dev;
695 		     device_find_next_child(&dev)) {
696 			struct usb_port_status status;
697 
698 			if (!device_active(dev))
699 				continue;
700 
701 			udev = dev_get_parent_priv(dev);
702 			if (usb_get_port_status(udev, udev->portnr, &status)
703 					< 0)
704 				/* USB request failed */
705 				continue;
706 
707 			if (le16_to_cpu(status.wPortChange) &
708 			    USB_PORT_STAT_C_CONNECTION)
709 				change++;
710 		}
711 	}
712 
713 	return change;
714 }
715 
716 static int usb_child_post_bind(struct udevice *dev)
717 {
718 	struct usb_dev_platdata *plat = dev_get_parent_platdata(dev);
719 	int val;
720 
721 	if (!dev_of_valid(dev))
722 		return 0;
723 
724 	/* We only support matching a few things */
725 	val = dev_read_u32_default(dev, "usb,device-class", -1);
726 	if (val != -1) {
727 		plat->id.match_flags |= USB_DEVICE_ID_MATCH_DEV_CLASS;
728 		plat->id.bDeviceClass = val;
729 	}
730 	val = dev_read_u32_default(dev, "usb,interface-class", -1);
731 	if (val != -1) {
732 		plat->id.match_flags |= USB_DEVICE_ID_MATCH_INT_CLASS;
733 		plat->id.bInterfaceClass = val;
734 	}
735 
736 	return 0;
737 }
738 
739 struct udevice *usb_get_bus(struct udevice *dev)
740 {
741 	struct udevice *bus;
742 
743 	for (bus = dev; bus && device_get_uclass_id(bus) != UCLASS_USB; )
744 		bus = bus->parent;
745 	if (!bus) {
746 		/* By design this cannot happen */
747 		assert(bus);
748 		debug("USB HUB '%s' does not have a controller\n", dev->name);
749 	}
750 
751 	return bus;
752 }
753 
754 int usb_child_pre_probe(struct udevice *dev)
755 {
756 	struct usb_device *udev = dev_get_parent_priv(dev);
757 	struct usb_dev_platdata *plat = dev_get_parent_platdata(dev);
758 	int ret;
759 
760 	if (plat->udev) {
761 		/*
762 		 * Copy over all the values set in the on stack struct
763 		 * usb_device in usb_scan_device() to our final struct
764 		 * usb_device for this dev.
765 		 */
766 		*udev = *(plat->udev);
767 		/* And clear plat->udev as it will not be valid for long */
768 		plat->udev = NULL;
769 		udev->dev = dev;
770 	} else {
771 		/*
772 		 * This happens with devices which are explicitly bound
773 		 * instead of being discovered through usb_scan_device()
774 		 * such as sandbox emul devices.
775 		 */
776 		udev->dev = dev;
777 		udev->controller_dev = usb_get_bus(dev);
778 		udev->devnum = plat->devnum;
779 
780 		/*
781 		 * udev did not go through usb_scan_device(), so we need to
782 		 * select the config and read the config descriptors.
783 		 */
784 		ret = usb_select_config(udev);
785 		if (ret)
786 			return ret;
787 	}
788 
789 	return 0;
790 }
791 
792 UCLASS_DRIVER(usb) = {
793 	.id		= UCLASS_USB,
794 	.name		= "usb",
795 	.flags		= DM_UC_FLAG_SEQ_ALIAS,
796 	.post_bind	= dm_scan_fdt_dev,
797 	.priv_auto_alloc_size = sizeof(struct usb_uclass_priv),
798 	.per_child_auto_alloc_size = sizeof(struct usb_device),
799 	.per_device_auto_alloc_size = sizeof(struct usb_bus_priv),
800 	.child_post_bind = usb_child_post_bind,
801 	.child_pre_probe = usb_child_pre_probe,
802 	.per_child_platdata_auto_alloc_size = sizeof(struct usb_dev_platdata),
803 };
804 
805 UCLASS_DRIVER(usb_dev_generic) = {
806 	.id		= UCLASS_USB_DEV_GENERIC,
807 	.name		= "usb_dev_generic",
808 };
809 
810 U_BOOT_DRIVER(usb_dev_generic_drv) = {
811 	.id		= UCLASS_USB_DEV_GENERIC,
812 	.name		= "usb_dev_generic_drv",
813 };
814