xref: /rk3399_rockchip-uboot/drivers/usb/host/usb-uclass.c (revision e8ea5e8c8568c8cbb752e524e8eb74f776f5e262)
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 int usb_init(void)
206 {
207 	int controllers_initialized = 0;
208 	struct usb_uclass_priv *uc_priv;
209 	struct usb_bus_priv *priv;
210 	struct udevice *bus;
211 	struct uclass *uc;
212 	int count = 0;
213 	int ret;
214 
215 	asynch_allowed = 1;
216 	usb_hub_reset();
217 
218 	ret = uclass_get(UCLASS_USB, &uc);
219 	if (ret)
220 		return ret;
221 
222 	uc_priv = uc->priv;
223 
224 	uclass_foreach_dev(bus, uc) {
225 		/* init low_level USB */
226 		printf("USB%d:   ", count);
227 		count++;
228 		ret = device_probe(bus);
229 		if (ret == -ENODEV) {	/* No such device. */
230 			puts("Port not available.\n");
231 			controllers_initialized++;
232 			continue;
233 		}
234 
235 		if (ret) {		/* Other error. */
236 			printf("probe failed, error %d\n", ret);
237 			continue;
238 		}
239 		controllers_initialized++;
240 		usb_started = true;
241 	}
242 
243 	/*
244 	 * lowlevel init done, now scan the bus for devices i.e. search HUBs
245 	 * and configure them, first scan primary controllers.
246 	 */
247 	uclass_foreach_dev(bus, uc) {
248 		if (!device_active(bus))
249 			continue;
250 
251 		priv = dev_get_uclass_priv(bus);
252 		if (!priv->companion)
253 			usb_scan_bus(bus, true);
254 	}
255 
256 	/*
257 	 * Now that the primary controllers have been scanned and have handed
258 	 * over any devices they do not understand to their companions, scan
259 	 * the companions if necessary.
260 	 */
261 	if (uc_priv->companion_device_count) {
262 		uclass_foreach_dev(bus, uc) {
263 			if (!device_active(bus))
264 				continue;
265 
266 			priv = dev_get_uclass_priv(bus);
267 			if (priv->companion)
268 				usb_scan_bus(bus, true);
269 		}
270 	}
271 
272 	debug("scan end\n");
273 	/* if we were not able to find at least one working bus, bail out */
274 	if (!count)
275 		printf("No controllers found\n");
276 	else if (controllers_initialized == 0)
277 		printf("USB error: all controllers failed lowlevel init\n");
278 
279 	return usb_started ? 0 : -1;
280 }
281 
282 /*
283  * TODO(sjg@chromium.org): Remove this legacy function. At present it is needed
284  * to support boards which use driver model for USB but not Ethernet, and want
285  * to use USB Ethernet.
286  *
287  * The #if clause is here to ensure that remains the only case.
288  */
289 #if !defined(CONFIG_DM_ETH) && defined(CONFIG_USB_HOST_ETHER)
290 static struct usb_device *find_child_devnum(struct udevice *parent, int devnum)
291 {
292 	struct usb_device *udev;
293 	struct udevice *dev;
294 
295 	if (!device_active(parent))
296 		return NULL;
297 	udev = dev_get_parent_priv(parent);
298 	if (udev->devnum == devnum)
299 		return udev;
300 
301 	for (device_find_first_child(parent, &dev);
302 	     dev;
303 	     device_find_next_child(&dev)) {
304 		udev = find_child_devnum(dev, devnum);
305 		if (udev)
306 			return udev;
307 	}
308 
309 	return NULL;
310 }
311 
312 struct usb_device *usb_get_dev_index(struct udevice *bus, int index)
313 {
314 	struct udevice *dev;
315 	int devnum = index + 1; /* Addresses are allocated from 1 on USB */
316 
317 	device_find_first_child(bus, &dev);
318 	if (!dev)
319 		return NULL;
320 
321 	return find_child_devnum(dev, devnum);
322 }
323 #endif
324 
325 int usb_post_bind(struct udevice *dev)
326 {
327 	/* Scan the bus for devices */
328 	return dm_scan_fdt_node(dev, gd->fdt_blob, dev->of_offset, false);
329 }
330 
331 int usb_setup_ehci_gadget(struct ehci_ctrl **ctlrp)
332 {
333 	struct usb_platdata *plat;
334 	struct udevice *dev;
335 	int ret;
336 
337 	/* Find the old device and remove it */
338 	ret = uclass_find_device_by_seq(UCLASS_USB, 0, true, &dev);
339 	if (ret)
340 		return ret;
341 	ret = device_remove(dev);
342 	if (ret)
343 		return ret;
344 
345 	plat = dev_get_platdata(dev);
346 	plat->init_type = USB_INIT_DEVICE;
347 	ret = device_probe(dev);
348 	if (ret)
349 		return ret;
350 	*ctlrp = dev_get_priv(dev);
351 
352 	return 0;
353 }
354 
355 /* returns 0 if no match, 1 if match */
356 int usb_match_device(const struct usb_device_descriptor *desc,
357 		     const struct usb_device_id *id)
358 {
359 	if ((id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
360 	    id->idVendor != le16_to_cpu(desc->idVendor))
361 		return 0;
362 
363 	if ((id->match_flags & USB_DEVICE_ID_MATCH_PRODUCT) &&
364 	    id->idProduct != le16_to_cpu(desc->idProduct))
365 		return 0;
366 
367 	/* No need to test id->bcdDevice_lo != 0, since 0 is never
368 	   greater than any unsigned number. */
369 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_LO) &&
370 	    (id->bcdDevice_lo > le16_to_cpu(desc->bcdDevice)))
371 		return 0;
372 
373 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_HI) &&
374 	    (id->bcdDevice_hi < le16_to_cpu(desc->bcdDevice)))
375 		return 0;
376 
377 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_CLASS) &&
378 	    (id->bDeviceClass != desc->bDeviceClass))
379 		return 0;
380 
381 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_SUBCLASS) &&
382 	    (id->bDeviceSubClass != desc->bDeviceSubClass))
383 		return 0;
384 
385 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_PROTOCOL) &&
386 	    (id->bDeviceProtocol != desc->bDeviceProtocol))
387 		return 0;
388 
389 	return 1;
390 }
391 
392 /* returns 0 if no match, 1 if match */
393 int usb_match_one_id_intf(const struct usb_device_descriptor *desc,
394 			  const struct usb_interface_descriptor *int_desc,
395 			  const struct usb_device_id *id)
396 {
397 	/* The interface class, subclass, protocol and number should never be
398 	 * checked for a match if the device class is Vendor Specific,
399 	 * unless the match record specifies the Vendor ID. */
400 	if (desc->bDeviceClass == USB_CLASS_VENDOR_SPEC &&
401 	    !(id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
402 	    (id->match_flags & (USB_DEVICE_ID_MATCH_INT_CLASS |
403 				USB_DEVICE_ID_MATCH_INT_SUBCLASS |
404 				USB_DEVICE_ID_MATCH_INT_PROTOCOL |
405 				USB_DEVICE_ID_MATCH_INT_NUMBER)))
406 		return 0;
407 
408 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_CLASS) &&
409 	    (id->bInterfaceClass != int_desc->bInterfaceClass))
410 		return 0;
411 
412 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_SUBCLASS) &&
413 	    (id->bInterfaceSubClass != int_desc->bInterfaceSubClass))
414 		return 0;
415 
416 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_PROTOCOL) &&
417 	    (id->bInterfaceProtocol != int_desc->bInterfaceProtocol))
418 		return 0;
419 
420 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_NUMBER) &&
421 	    (id->bInterfaceNumber != int_desc->bInterfaceNumber))
422 		return 0;
423 
424 	return 1;
425 }
426 
427 /* returns 0 if no match, 1 if match */
428 int usb_match_one_id(struct usb_device_descriptor *desc,
429 		     struct usb_interface_descriptor *int_desc,
430 		     const struct usb_device_id *id)
431 {
432 	if (!usb_match_device(desc, id))
433 		return 0;
434 
435 	return usb_match_one_id_intf(desc, int_desc, id);
436 }
437 
438 /**
439  * usb_find_and_bind_driver() - Find and bind the right USB driver
440  *
441  * This only looks at certain fields in the descriptor.
442  */
443 static int usb_find_and_bind_driver(struct udevice *parent,
444 				    struct usb_device_descriptor *desc,
445 				    struct usb_interface_descriptor *iface,
446 				    int bus_seq, int devnum,
447 				    struct udevice **devp)
448 {
449 	struct usb_driver_entry *start, *entry;
450 	int n_ents;
451 	int ret;
452 	char name[30], *str;
453 
454 	*devp = NULL;
455 	debug("%s: Searching for driver\n", __func__);
456 	start = ll_entry_start(struct usb_driver_entry, usb_driver_entry);
457 	n_ents = ll_entry_count(struct usb_driver_entry, usb_driver_entry);
458 	for (entry = start; entry != start + n_ents; entry++) {
459 		const struct usb_device_id *id;
460 		struct udevice *dev;
461 		const struct driver *drv;
462 		struct usb_dev_platdata *plat;
463 
464 		for (id = entry->match; id->match_flags; id++) {
465 			if (!usb_match_one_id(desc, iface, id))
466 				continue;
467 
468 			drv = entry->driver;
469 			/*
470 			 * We could pass the descriptor to the driver as
471 			 * platdata (instead of NULL) and allow its bind()
472 			 * method to return -ENOENT if it doesn't support this
473 			 * device. That way we could continue the search to
474 			 * find another driver. For now this doesn't seem
475 			 * necesssary, so just bind the first match.
476 			 */
477 			ret = device_bind(parent, drv, drv->name, NULL, -1,
478 					  &dev);
479 			if (ret)
480 				goto error;
481 			debug("%s: Match found: %s\n", __func__, drv->name);
482 			dev->driver_data = id->driver_info;
483 			plat = dev_get_parent_platdata(dev);
484 			plat->id = *id;
485 			*devp = dev;
486 			return 0;
487 		}
488 	}
489 
490 	/* Bind a generic driver so that the device can be used */
491 	snprintf(name, sizeof(name), "generic_bus_%x_dev_%x", bus_seq, devnum);
492 	str = strdup(name);
493 	if (!str)
494 		return -ENOMEM;
495 	ret = device_bind_driver(parent, "usb_dev_generic_drv", str, devp);
496 
497 error:
498 	debug("%s: No match found: %d\n", __func__, ret);
499 	return ret;
500 }
501 
502 /**
503  * usb_find_child() - Find an existing device which matches our needs
504  *
505  *
506  */
507 static int usb_find_child(struct udevice *parent,
508 			  struct usb_device_descriptor *desc,
509 			  struct usb_interface_descriptor *iface,
510 			  struct udevice **devp)
511 {
512 	struct udevice *dev;
513 
514 	*devp = NULL;
515 	for (device_find_first_child(parent, &dev);
516 	     dev;
517 	     device_find_next_child(&dev)) {
518 		struct usb_dev_platdata *plat = dev_get_parent_platdata(dev);
519 
520 		/* If this device is already in use, skip it */
521 		if (device_active(dev))
522 			continue;
523 		debug("   %s: name='%s', plat=%d, desc=%d\n", __func__,
524 		      dev->name, plat->id.bDeviceClass, desc->bDeviceClass);
525 		if (usb_match_one_id(desc, iface, &plat->id)) {
526 			*devp = dev;
527 			return 0;
528 		}
529 	}
530 
531 	return -ENOENT;
532 }
533 
534 int usb_scan_device(struct udevice *parent, int port,
535 		    enum usb_device_speed speed, struct udevice **devp)
536 {
537 	struct udevice *dev;
538 	bool created = false;
539 	struct usb_dev_platdata *plat;
540 	struct usb_bus_priv *priv;
541 	struct usb_device *parent_udev;
542 	int ret;
543 	ALLOC_CACHE_ALIGN_BUFFER(struct usb_device, udev, 1);
544 	struct usb_interface_descriptor *iface = &udev->config.if_desc[0].desc;
545 
546 	*devp = NULL;
547 	memset(udev, '\0', sizeof(*udev));
548 	udev->controller_dev = usb_get_bus(parent);
549 	priv = dev_get_uclass_priv(udev->controller_dev);
550 
551 	/*
552 	 * Somewhat nasty, this. We create a local device and use the normal
553 	 * USB stack to read its descriptor. Then we know what type of device
554 	 * to create for real.
555 	 *
556 	 * udev->dev is set to the parent, since we don't have a real device
557 	 * yet. The USB stack should not access udev.dev anyway, except perhaps
558 	 * to find the controller, and the controller will either be @parent,
559 	 * or some parent of @parent.
560 	 *
561 	 * Another option might be to create the device as a generic USB
562 	 * device, then morph it into the correct one when we know what it
563 	 * should be. This means that a generic USB device would morph into
564 	 * a network controller, or a USB flash stick, for example. However,
565 	 * we don't support such morphing and it isn't clear that it would
566 	 * be easy to do.
567 	 *
568 	 * Yet another option is to split out the USB stack parts of udev
569 	 * into something like a 'struct urb' (as Linux does) which can exist
570 	 * independently of any device. This feels cleaner, but calls for quite
571 	 * a big change to the USB stack.
572 	 *
573 	 * For now, the approach is to set up an empty udev, read its
574 	 * descriptor and assign it an address, then bind a real device and
575 	 * stash the resulting information into the device's parent
576 	 * platform data. Then when we probe it, usb_child_pre_probe() is called
577 	 * and it will pull the information out of the stash.
578 	 */
579 	udev->dev = parent;
580 	udev->speed = speed;
581 	udev->devnum = priv->next_addr + 1;
582 	udev->portnr = port;
583 	debug("Calling usb_setup_device(), portnr=%d\n", udev->portnr);
584 	parent_udev = device_get_uclass_id(parent) == UCLASS_USB_HUB ?
585 		dev_get_parent_priv(parent) : NULL;
586 	ret = usb_setup_device(udev, priv->desc_before_addr, parent_udev);
587 	debug("read_descriptor for '%s': ret=%d\n", parent->name, ret);
588 	if (ret)
589 		return ret;
590 	ret = usb_find_child(parent, &udev->descriptor, iface, &dev);
591 	debug("** usb_find_child returns %d\n", ret);
592 	if (ret) {
593 		if (ret != -ENOENT)
594 			return ret;
595 		ret = usb_find_and_bind_driver(parent, &udev->descriptor, iface,
596 					       udev->controller_dev->seq,
597 					       udev->devnum, &dev);
598 		if (ret)
599 			return ret;
600 		created = true;
601 	}
602 	plat = dev_get_parent_platdata(dev);
603 	debug("%s: Probing '%s', plat=%p\n", __func__, dev->name, plat);
604 	plat->devnum = udev->devnum;
605 	plat->udev = udev;
606 	priv->next_addr++;
607 	ret = device_probe(dev);
608 	if (ret) {
609 		debug("%s: Device '%s' probe failed\n", __func__, dev->name);
610 		priv->next_addr--;
611 		if (created)
612 			device_unbind(dev);
613 		return ret;
614 	}
615 	*devp = dev;
616 
617 	return 0;
618 }
619 
620 /*
621  * Detect if a USB device has been plugged or unplugged.
622  */
623 int usb_detect_change(void)
624 {
625 	struct udevice *hub;
626 	struct uclass *uc;
627 	int change = 0;
628 	int ret;
629 
630 	ret = uclass_get(UCLASS_USB_HUB, &uc);
631 	if (ret)
632 		return ret;
633 
634 	uclass_foreach_dev(hub, uc) {
635 		struct usb_device *udev;
636 		struct udevice *dev;
637 
638 		if (!device_active(hub))
639 			continue;
640 		for (device_find_first_child(hub, &dev);
641 		     dev;
642 		     device_find_next_child(&dev)) {
643 			struct usb_port_status status;
644 
645 			if (!device_active(dev))
646 				continue;
647 
648 			udev = dev_get_parent_priv(dev);
649 			if (usb_get_port_status(udev, udev->portnr, &status)
650 					< 0)
651 				/* USB request failed */
652 				continue;
653 
654 			if (le16_to_cpu(status.wPortChange) &
655 			    USB_PORT_STAT_C_CONNECTION)
656 				change++;
657 		}
658 	}
659 
660 	return change;
661 }
662 
663 int usb_child_post_bind(struct udevice *dev)
664 {
665 	struct usb_dev_platdata *plat = dev_get_parent_platdata(dev);
666 	const void *blob = gd->fdt_blob;
667 	int val;
668 
669 	if (dev->of_offset == -1)
670 		return 0;
671 
672 	/* We only support matching a few things */
673 	val = fdtdec_get_int(blob, dev->of_offset, "usb,device-class", -1);
674 	if (val != -1) {
675 		plat->id.match_flags |= USB_DEVICE_ID_MATCH_DEV_CLASS;
676 		plat->id.bDeviceClass = val;
677 	}
678 	val = fdtdec_get_int(blob, dev->of_offset, "usb,interface-class", -1);
679 	if (val != -1) {
680 		plat->id.match_flags |= USB_DEVICE_ID_MATCH_INT_CLASS;
681 		plat->id.bInterfaceClass = val;
682 	}
683 
684 	return 0;
685 }
686 
687 struct udevice *usb_get_bus(struct udevice *dev)
688 {
689 	struct udevice *bus;
690 
691 	for (bus = dev; bus && device_get_uclass_id(bus) != UCLASS_USB; )
692 		bus = bus->parent;
693 	if (!bus) {
694 		/* By design this cannot happen */
695 		assert(bus);
696 		debug("USB HUB '%s' does not have a controller\n", dev->name);
697 	}
698 
699 	return bus;
700 }
701 
702 int usb_child_pre_probe(struct udevice *dev)
703 {
704 	struct usb_device *udev = dev_get_parent_priv(dev);
705 	struct usb_dev_platdata *plat = dev_get_parent_platdata(dev);
706 	int ret;
707 
708 	if (plat->udev) {
709 		/*
710 		 * Copy over all the values set in the on stack struct
711 		 * usb_device in usb_scan_device() to our final struct
712 		 * usb_device for this dev.
713 		 */
714 		*udev = *(plat->udev);
715 		/* And clear plat->udev as it will not be valid for long */
716 		plat->udev = NULL;
717 		udev->dev = dev;
718 	} else {
719 		/*
720 		 * This happens with devices which are explicitly bound
721 		 * instead of being discovered through usb_scan_device()
722 		 * such as sandbox emul devices.
723 		 */
724 		udev->dev = dev;
725 		udev->controller_dev = usb_get_bus(dev);
726 		udev->devnum = plat->devnum;
727 
728 		/*
729 		 * udev did not go through usb_scan_device(), so we need to
730 		 * select the config and read the config descriptors.
731 		 */
732 		ret = usb_select_config(udev);
733 		if (ret)
734 			return ret;
735 	}
736 
737 	return 0;
738 }
739 
740 UCLASS_DRIVER(usb) = {
741 	.id		= UCLASS_USB,
742 	.name		= "usb",
743 	.flags		= DM_UC_FLAG_SEQ_ALIAS,
744 	.post_bind	= usb_post_bind,
745 	.priv_auto_alloc_size = sizeof(struct usb_uclass_priv),
746 	.per_child_auto_alloc_size = sizeof(struct usb_device),
747 	.per_device_auto_alloc_size = sizeof(struct usb_bus_priv),
748 	.child_post_bind = usb_child_post_bind,
749 	.child_pre_probe = usb_child_pre_probe,
750 	.per_child_platdata_auto_alloc_size = sizeof(struct usb_dev_platdata),
751 };
752 
753 UCLASS_DRIVER(usb_dev_generic) = {
754 	.id		= UCLASS_USB_DEV_GENERIC,
755 	.name		= "usb_dev_generic",
756 };
757 
758 U_BOOT_DRIVER(usb_dev_generic_drv) = {
759 	.id		= UCLASS_USB_DEV_GENERIC,
760 	.name		= "usb_dev_generic_drv",
761 };
762