xref: /rk3399_rockchip-uboot/drivers/usb/host/usb-uclass.c (revision 87e4c6020eff05133e40ab8b7b0e37e6a2be37e4)
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_SANDBOX
198 	struct udevice *dev;
199 
200 	/* Reset all enulation devices */
201 	ret = uclass_get(UCLASS_USB_EMUL, &uc);
202 	if (ret)
203 		return ret;
204 
205 	uclass_foreach_dev(dev, uc)
206 		usb_emul_reset(dev);
207 #endif
208 #ifdef CONFIG_USB_STORAGE
209 	usb_stor_reset();
210 #endif
211 	uc_priv->companion_device_count = 0;
212 	usb_started = 0;
213 
214 	return err;
215 }
216 
217 static void usb_scan_bus(struct udevice *bus, bool recurse)
218 {
219 	struct usb_bus_priv *priv;
220 	struct udevice *dev;
221 	int ret;
222 
223 	priv = dev_get_uclass_priv(bus);
224 
225 	assert(recurse);	/* TODO: Support non-recusive */
226 
227 	printf("scanning bus %d for devices... ", bus->seq);
228 	debug("\n");
229 	ret = usb_scan_device(bus, 0, USB_SPEED_FULL, &dev);
230 	if (ret)
231 		printf("failed, error %d\n", ret);
232 	else if (priv->next_addr == 0)
233 		printf("No USB Device found\n");
234 	else
235 		printf("%d USB Device(s) found\n", priv->next_addr);
236 }
237 
238 static void remove_inactive_children(struct uclass *uc, struct udevice *bus)
239 {
240 	uclass_foreach_dev(bus, uc) {
241 		struct udevice *dev, *next;
242 
243 		if (!device_active(bus))
244 			continue;
245 		device_foreach_child_safe(dev, next, bus) {
246 			if (!device_active(dev))
247 				device_unbind(dev);
248 		}
249 	}
250 }
251 
252 int usb_init(void)
253 {
254 	int controllers_initialized = 0;
255 	struct usb_uclass_priv *uc_priv;
256 	struct usb_bus_priv *priv;
257 	struct udevice *bus;
258 	struct uclass *uc;
259 	int count = 0;
260 	int ret;
261 
262 	asynch_allowed = 1;
263 
264 	ret = uclass_get(UCLASS_USB, &uc);
265 	if (ret)
266 		return ret;
267 
268 	uc_priv = uc->priv;
269 
270 	uclass_foreach_dev(bus, uc) {
271 		/* init low_level USB */
272 		printf("USB%d:   ", count);
273 		count++;
274 
275 #ifdef CONFIG_SANDBOX
276 		/*
277 		 * For Sandbox, we need scan the device tree each time when we
278 		 * start the USB stack, in order to re-create the emulated USB
279 		 * devices and bind drivers for them before we actually do the
280 		 * driver probe.
281 		 */
282 		ret = dm_scan_fdt_dev(bus);
283 		if (ret) {
284 			printf("Sandbox USB device scan failed (%d)\n", ret);
285 			continue;
286 		}
287 #endif
288 
289 		ret = device_probe(bus);
290 		if (ret == -ENODEV) {	/* No such device. */
291 			puts("Port not available.\n");
292 			controllers_initialized++;
293 			continue;
294 		}
295 
296 		if (ret) {		/* Other error. */
297 			printf("probe failed, error %d\n", ret);
298 			continue;
299 		}
300 		controllers_initialized++;
301 		usb_started = true;
302 	}
303 
304 	/*
305 	 * lowlevel init done, now scan the bus for devices i.e. search HUBs
306 	 * and configure them, first scan primary controllers.
307 	 */
308 	uclass_foreach_dev(bus, uc) {
309 		if (!device_active(bus))
310 			continue;
311 
312 		priv = dev_get_uclass_priv(bus);
313 		if (!priv->companion)
314 			usb_scan_bus(bus, true);
315 	}
316 
317 	/*
318 	 * Now that the primary controllers have been scanned and have handed
319 	 * over any devices they do not understand to their companions, scan
320 	 * the companions if necessary.
321 	 */
322 	if (uc_priv->companion_device_count) {
323 		uclass_foreach_dev(bus, uc) {
324 			if (!device_active(bus))
325 				continue;
326 
327 			priv = dev_get_uclass_priv(bus);
328 			if (priv->companion)
329 				usb_scan_bus(bus, true);
330 		}
331 	}
332 
333 	debug("scan end\n");
334 
335 	/* Remove any devices that were not found on this scan */
336 	remove_inactive_children(uc, bus);
337 
338 	ret = uclass_get(UCLASS_USB_HUB, &uc);
339 	if (ret)
340 		return ret;
341 	remove_inactive_children(uc, bus);
342 
343 	/* if we were not able to find at least one working bus, bail out */
344 	if (!count)
345 		printf("No controllers found\n");
346 	else if (controllers_initialized == 0)
347 		printf("USB error: all controllers failed lowlevel init\n");
348 
349 	return usb_started ? 0 : -1;
350 }
351 
352 /*
353  * TODO(sjg@chromium.org): Remove this legacy function. At present it is needed
354  * to support boards which use driver model for USB but not Ethernet, and want
355  * to use USB Ethernet.
356  *
357  * The #if clause is here to ensure that remains the only case.
358  */
359 #if !defined(CONFIG_DM_ETH) && defined(CONFIG_USB_HOST_ETHER)
360 static struct usb_device *find_child_devnum(struct udevice *parent, int devnum)
361 {
362 	struct usb_device *udev;
363 	struct udevice *dev;
364 
365 	if (!device_active(parent))
366 		return NULL;
367 	udev = dev_get_parent_priv(parent);
368 	if (udev->devnum == devnum)
369 		return udev;
370 
371 	for (device_find_first_child(parent, &dev);
372 	     dev;
373 	     device_find_next_child(&dev)) {
374 		udev = find_child_devnum(dev, devnum);
375 		if (udev)
376 			return udev;
377 	}
378 
379 	return NULL;
380 }
381 
382 struct usb_device *usb_get_dev_index(struct udevice *bus, int index)
383 {
384 	struct udevice *dev;
385 	int devnum = index + 1; /* Addresses are allocated from 1 on USB */
386 
387 	device_find_first_child(bus, &dev);
388 	if (!dev)
389 		return NULL;
390 
391 	return find_child_devnum(dev, devnum);
392 }
393 #endif
394 
395 int usb_setup_ehci_gadget(struct ehci_ctrl **ctlrp)
396 {
397 	struct usb_platdata *plat;
398 	struct udevice *dev;
399 	int ret;
400 
401 	/* Find the old device and remove it */
402 	ret = uclass_find_device_by_seq(UCLASS_USB, 0, true, &dev);
403 	if (ret)
404 		return ret;
405 	ret = device_remove(dev, DM_REMOVE_NORMAL);
406 	if (ret)
407 		return ret;
408 
409 	plat = dev_get_platdata(dev);
410 	plat->init_type = USB_INIT_DEVICE;
411 	ret = device_probe(dev);
412 	if (ret)
413 		return ret;
414 	*ctlrp = dev_get_priv(dev);
415 
416 	return 0;
417 }
418 
419 /* returns 0 if no match, 1 if match */
420 static int usb_match_device(const struct usb_device_descriptor *desc,
421 			    const struct usb_device_id *id)
422 {
423 	if ((id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
424 	    id->idVendor != le16_to_cpu(desc->idVendor))
425 		return 0;
426 
427 	if ((id->match_flags & USB_DEVICE_ID_MATCH_PRODUCT) &&
428 	    id->idProduct != le16_to_cpu(desc->idProduct))
429 		return 0;
430 
431 	/* No need to test id->bcdDevice_lo != 0, since 0 is never
432 	   greater than any unsigned number. */
433 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_LO) &&
434 	    (id->bcdDevice_lo > le16_to_cpu(desc->bcdDevice)))
435 		return 0;
436 
437 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_HI) &&
438 	    (id->bcdDevice_hi < le16_to_cpu(desc->bcdDevice)))
439 		return 0;
440 
441 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_CLASS) &&
442 	    (id->bDeviceClass != desc->bDeviceClass))
443 		return 0;
444 
445 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_SUBCLASS) &&
446 	    (id->bDeviceSubClass != desc->bDeviceSubClass))
447 		return 0;
448 
449 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_PROTOCOL) &&
450 	    (id->bDeviceProtocol != desc->bDeviceProtocol))
451 		return 0;
452 
453 	return 1;
454 }
455 
456 /* returns 0 if no match, 1 if match */
457 static int usb_match_one_id_intf(const struct usb_device_descriptor *desc,
458 			const struct usb_interface_descriptor *int_desc,
459 			const struct usb_device_id *id)
460 {
461 	/* The interface class, subclass, protocol and number should never be
462 	 * checked for a match if the device class is Vendor Specific,
463 	 * unless the match record specifies the Vendor ID. */
464 	if (desc->bDeviceClass == USB_CLASS_VENDOR_SPEC &&
465 	    !(id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
466 	    (id->match_flags & (USB_DEVICE_ID_MATCH_INT_CLASS |
467 				USB_DEVICE_ID_MATCH_INT_SUBCLASS |
468 				USB_DEVICE_ID_MATCH_INT_PROTOCOL |
469 				USB_DEVICE_ID_MATCH_INT_NUMBER)))
470 		return 0;
471 
472 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_CLASS) &&
473 	    (id->bInterfaceClass != int_desc->bInterfaceClass))
474 		return 0;
475 
476 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_SUBCLASS) &&
477 	    (id->bInterfaceSubClass != int_desc->bInterfaceSubClass))
478 		return 0;
479 
480 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_PROTOCOL) &&
481 	    (id->bInterfaceProtocol != int_desc->bInterfaceProtocol))
482 		return 0;
483 
484 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_NUMBER) &&
485 	    (id->bInterfaceNumber != int_desc->bInterfaceNumber))
486 		return 0;
487 
488 	return 1;
489 }
490 
491 /* returns 0 if no match, 1 if match */
492 static int usb_match_one_id(struct usb_device_descriptor *desc,
493 			    struct usb_interface_descriptor *int_desc,
494 			    const struct usb_device_id *id)
495 {
496 	if (!usb_match_device(desc, id))
497 		return 0;
498 
499 	return usb_match_one_id_intf(desc, int_desc, id);
500 }
501 
502 /**
503  * usb_find_and_bind_driver() - Find and bind the right USB driver
504  *
505  * This only looks at certain fields in the descriptor.
506  */
507 static int usb_find_and_bind_driver(struct udevice *parent,
508 				    struct usb_device_descriptor *desc,
509 				    struct usb_interface_descriptor *iface,
510 				    int bus_seq, int devnum,
511 				    struct udevice **devp)
512 {
513 	struct usb_driver_entry *start, *entry;
514 	int n_ents;
515 	int ret;
516 	char name[30], *str;
517 
518 	*devp = NULL;
519 	debug("%s: Searching for driver\n", __func__);
520 	start = ll_entry_start(struct usb_driver_entry, usb_driver_entry);
521 	n_ents = ll_entry_count(struct usb_driver_entry, usb_driver_entry);
522 	for (entry = start; entry != start + n_ents; entry++) {
523 		const struct usb_device_id *id;
524 		struct udevice *dev;
525 		const struct driver *drv;
526 		struct usb_dev_platdata *plat;
527 
528 		for (id = entry->match; id->match_flags; id++) {
529 			if (!usb_match_one_id(desc, iface, id))
530 				continue;
531 
532 			drv = entry->driver;
533 			/*
534 			 * We could pass the descriptor to the driver as
535 			 * platdata (instead of NULL) and allow its bind()
536 			 * method to return -ENOENT if it doesn't support this
537 			 * device. That way we could continue the search to
538 			 * find another driver. For now this doesn't seem
539 			 * necesssary, so just bind the first match.
540 			 */
541 			ret = device_bind(parent, drv, drv->name, NULL, -1,
542 					  &dev);
543 			if (ret)
544 				goto error;
545 			debug("%s: Match found: %s\n", __func__, drv->name);
546 			dev->driver_data = id->driver_info;
547 			plat = dev_get_parent_platdata(dev);
548 			plat->id = *id;
549 			*devp = dev;
550 			return 0;
551 		}
552 	}
553 
554 	/* Bind a generic driver so that the device can be used */
555 	snprintf(name, sizeof(name), "generic_bus_%x_dev_%x", bus_seq, devnum);
556 	str = strdup(name);
557 	if (!str)
558 		return -ENOMEM;
559 	ret = device_bind_driver(parent, "usb_dev_generic_drv", str, devp);
560 
561 error:
562 	debug("%s: No match found: %d\n", __func__, ret);
563 	return ret;
564 }
565 
566 /**
567  * usb_find_child() - Find an existing device which matches our needs
568  *
569  *
570  */
571 static int usb_find_child(struct udevice *parent,
572 			  struct usb_device_descriptor *desc,
573 			  struct usb_interface_descriptor *iface,
574 			  struct udevice **devp)
575 {
576 	struct udevice *dev;
577 
578 	*devp = NULL;
579 	for (device_find_first_child(parent, &dev);
580 	     dev;
581 	     device_find_next_child(&dev)) {
582 		struct usb_dev_platdata *plat = dev_get_parent_platdata(dev);
583 
584 		/* If this device is already in use, skip it */
585 		if (device_active(dev))
586 			continue;
587 		debug("   %s: name='%s', plat=%d, desc=%d\n", __func__,
588 		      dev->name, plat->id.bDeviceClass, desc->bDeviceClass);
589 		if (usb_match_one_id(desc, iface, &plat->id)) {
590 			*devp = dev;
591 			return 0;
592 		}
593 	}
594 
595 	return -ENOENT;
596 }
597 
598 int usb_scan_device(struct udevice *parent, int port,
599 		    enum usb_device_speed speed, struct udevice **devp)
600 {
601 	struct udevice *dev;
602 	bool created = false;
603 	struct usb_dev_platdata *plat;
604 	struct usb_bus_priv *priv;
605 	struct usb_device *parent_udev;
606 	int ret;
607 	ALLOC_CACHE_ALIGN_BUFFER(struct usb_device, udev, 1);
608 	struct usb_interface_descriptor *iface = &udev->config.if_desc[0].desc;
609 
610 	*devp = NULL;
611 	memset(udev, '\0', sizeof(*udev));
612 	udev->controller_dev = usb_get_bus(parent);
613 	priv = dev_get_uclass_priv(udev->controller_dev);
614 
615 	/*
616 	 * Somewhat nasty, this. We create a local device and use the normal
617 	 * USB stack to read its descriptor. Then we know what type of device
618 	 * to create for real.
619 	 *
620 	 * udev->dev is set to the parent, since we don't have a real device
621 	 * yet. The USB stack should not access udev.dev anyway, except perhaps
622 	 * to find the controller, and the controller will either be @parent,
623 	 * or some parent of @parent.
624 	 *
625 	 * Another option might be to create the device as a generic USB
626 	 * device, then morph it into the correct one when we know what it
627 	 * should be. This means that a generic USB device would morph into
628 	 * a network controller, or a USB flash stick, for example. However,
629 	 * we don't support such morphing and it isn't clear that it would
630 	 * be easy to do.
631 	 *
632 	 * Yet another option is to split out the USB stack parts of udev
633 	 * into something like a 'struct urb' (as Linux does) which can exist
634 	 * independently of any device. This feels cleaner, but calls for quite
635 	 * a big change to the USB stack.
636 	 *
637 	 * For now, the approach is to set up an empty udev, read its
638 	 * descriptor and assign it an address, then bind a real device and
639 	 * stash the resulting information into the device's parent
640 	 * platform data. Then when we probe it, usb_child_pre_probe() is called
641 	 * and it will pull the information out of the stash.
642 	 */
643 	udev->dev = parent;
644 	udev->speed = speed;
645 	udev->devnum = priv->next_addr + 1;
646 	udev->portnr = port;
647 	debug("Calling usb_setup_device(), portnr=%d\n", udev->portnr);
648 	parent_udev = device_get_uclass_id(parent) == UCLASS_USB_HUB ?
649 		dev_get_parent_priv(parent) : NULL;
650 	ret = usb_setup_device(udev, priv->desc_before_addr, parent_udev);
651 	debug("read_descriptor for '%s': ret=%d\n", parent->name, ret);
652 	if (ret)
653 		return ret;
654 	ret = usb_find_child(parent, &udev->descriptor, iface, &dev);
655 	debug("** usb_find_child returns %d\n", ret);
656 	if (ret) {
657 		if (ret != -ENOENT)
658 			return ret;
659 		ret = usb_find_and_bind_driver(parent, &udev->descriptor, iface,
660 					       udev->controller_dev->seq,
661 					       udev->devnum, &dev);
662 		if (ret)
663 			return ret;
664 		created = true;
665 	}
666 	plat = dev_get_parent_platdata(dev);
667 	debug("%s: Probing '%s', plat=%p\n", __func__, dev->name, plat);
668 	plat->devnum = udev->devnum;
669 	plat->udev = udev;
670 	priv->next_addr++;
671 	ret = device_probe(dev);
672 	if (ret) {
673 		debug("%s: Device '%s' probe failed\n", __func__, dev->name);
674 		priv->next_addr--;
675 		if (created)
676 			device_unbind(dev);
677 		return ret;
678 	}
679 	*devp = dev;
680 
681 	return 0;
682 }
683 
684 /*
685  * Detect if a USB device has been plugged or unplugged.
686  */
687 int usb_detect_change(void)
688 {
689 	struct udevice *hub;
690 	struct uclass *uc;
691 	int change = 0;
692 	int ret;
693 
694 	ret = uclass_get(UCLASS_USB_HUB, &uc);
695 	if (ret)
696 		return ret;
697 
698 	uclass_foreach_dev(hub, uc) {
699 		struct usb_device *udev;
700 		struct udevice *dev;
701 
702 		if (!device_active(hub))
703 			continue;
704 		for (device_find_first_child(hub, &dev);
705 		     dev;
706 		     device_find_next_child(&dev)) {
707 			struct usb_port_status status;
708 
709 			if (!device_active(dev))
710 				continue;
711 
712 			udev = dev_get_parent_priv(dev);
713 			if (usb_get_port_status(udev, udev->portnr, &status)
714 					< 0)
715 				/* USB request failed */
716 				continue;
717 
718 			if (le16_to_cpu(status.wPortChange) &
719 			    USB_PORT_STAT_C_CONNECTION)
720 				change++;
721 		}
722 	}
723 
724 	return change;
725 }
726 
727 static int usb_child_post_bind(struct udevice *dev)
728 {
729 	struct usb_dev_platdata *plat = dev_get_parent_platdata(dev);
730 	int val;
731 
732 	if (!dev_of_valid(dev))
733 		return 0;
734 
735 	/* We only support matching a few things */
736 	val = dev_read_u32_default(dev, "usb,device-class", -1);
737 	if (val != -1) {
738 		plat->id.match_flags |= USB_DEVICE_ID_MATCH_DEV_CLASS;
739 		plat->id.bDeviceClass = val;
740 	}
741 	val = dev_read_u32_default(dev, "usb,interface-class", -1);
742 	if (val != -1) {
743 		plat->id.match_flags |= USB_DEVICE_ID_MATCH_INT_CLASS;
744 		plat->id.bInterfaceClass = val;
745 	}
746 
747 	return 0;
748 }
749 
750 struct udevice *usb_get_bus(struct udevice *dev)
751 {
752 	struct udevice *bus;
753 
754 	for (bus = dev; bus && device_get_uclass_id(bus) != UCLASS_USB; )
755 		bus = bus->parent;
756 	if (!bus) {
757 		/* By design this cannot happen */
758 		assert(bus);
759 		debug("USB HUB '%s' does not have a controller\n", dev->name);
760 	}
761 
762 	return bus;
763 }
764 
765 int usb_child_pre_probe(struct udevice *dev)
766 {
767 	struct usb_device *udev = dev_get_parent_priv(dev);
768 	struct usb_dev_platdata *plat = dev_get_parent_platdata(dev);
769 	int ret;
770 
771 	if (plat->udev) {
772 		/*
773 		 * Copy over all the values set in the on stack struct
774 		 * usb_device in usb_scan_device() to our final struct
775 		 * usb_device for this dev.
776 		 */
777 		*udev = *(plat->udev);
778 		/* And clear plat->udev as it will not be valid for long */
779 		plat->udev = NULL;
780 		udev->dev = dev;
781 	} else {
782 		/*
783 		 * This happens with devices which are explicitly bound
784 		 * instead of being discovered through usb_scan_device()
785 		 * such as sandbox emul devices.
786 		 */
787 		udev->dev = dev;
788 		udev->controller_dev = usb_get_bus(dev);
789 		udev->devnum = plat->devnum;
790 
791 		/*
792 		 * udev did not go through usb_scan_device(), so we need to
793 		 * select the config and read the config descriptors.
794 		 */
795 		ret = usb_select_config(udev);
796 		if (ret)
797 			return ret;
798 	}
799 
800 	return 0;
801 }
802 
803 UCLASS_DRIVER(usb) = {
804 	.id		= UCLASS_USB,
805 	.name		= "usb",
806 	.flags		= DM_UC_FLAG_SEQ_ALIAS,
807 	.post_bind	= dm_scan_fdt_dev,
808 	.priv_auto_alloc_size = sizeof(struct usb_uclass_priv),
809 	.per_child_auto_alloc_size = sizeof(struct usb_device),
810 	.per_device_auto_alloc_size = sizeof(struct usb_bus_priv),
811 	.child_post_bind = usb_child_post_bind,
812 	.child_pre_probe = usb_child_pre_probe,
813 	.per_child_platdata_auto_alloc_size = sizeof(struct usb_dev_platdata),
814 };
815 
816 UCLASS_DRIVER(usb_dev_generic) = {
817 	.id		= UCLASS_USB_DEV_GENERIC,
818 	.name		= "usb_dev_generic",
819 };
820 
821 U_BOOT_DRIVER(usb_dev_generic_drv) = {
822 	.id		= UCLASS_USB_DEV_GENERIC,
823 	.name		= "usb_dev_generic_drv",
824 };
825