drivers/usb/host/usb-uclass.c - platform/external/u-boot - Gitiles

 // SPDX-License-Identifier: GPL-2.0+
 /*
  * (C) Copyright 2015 Google, Inc
  * Written by Simon Glass <sjg@chromium.org>
  *
  * usb_match_device() modified from Linux kernel v4.0.
  */

 #include <common.h>
 #include <dm.h>
 #include <errno.h>
 #include <log.h>
 #include <memalign.h>
 #include <usb.h>
 #include <dm/device-internal.h>
 #include <dm/lists.h>
 #include <dm/uclass-internal.h>

 extern bool usb_started; /* flag for the started/stopped USB status */
 static bool asynch_allowed;

 struct usb_uclass_priv {
 	int companion_device_count;
 };

 int usb_lock_async(struct usb_device *udev, int lock)
 {
 	struct udevice *bus = udev->controller_dev;
 	struct dm_usb_ops *ops = usb_get_ops(bus);

 	if (!ops->lock_async)
 		return -ENOSYS;

 	return ops->lock_async(bus, lock);
 }

 int usb_disable_asynch(int disable)
 {
 	int old_value = asynch_allowed;

 	asynch_allowed = !disable;
 	return old_value;
 }

 int submit_int_msg(struct usb_device *udev, unsigned long pipe, void *buffer,
 		   int length, int interval, bool nonblock)
 {
 	struct udevice *bus = udev->controller_dev;
 	struct dm_usb_ops *ops = usb_get_ops(bus);

 	if (!ops->interrupt)
 		return -ENOSYS;

 	return ops->interrupt(bus, udev, pipe, buffer, length, interval,
 			      nonblock);
 }

 int submit_control_msg(struct usb_device *udev, unsigned long pipe,
 		       void *buffer, int length, struct devrequest *setup)
 {
 	struct udevice *bus = udev->controller_dev;
 	struct dm_usb_ops *ops = usb_get_ops(bus);
 	struct usb_uclass_priv *uc_priv = uclass_get_priv(bus->uclass);
 	int err;

 	if (!ops->control)
 		return -ENOSYS;

 	err = ops->control(bus, udev, pipe, buffer, length, setup);
 	if (setup->request == USB_REQ_SET_FEATURE &&
 	    setup->requesttype == USB_RT_PORT &&
 	    setup->value == cpu_to_le16(USB_PORT_FEAT_RESET) &&
 	    err == -ENXIO) {
 		/* Device handed over to companion after port reset */
 		uc_priv->companion_device_count++;
 	}

 	return err;
 }

 int submit_bulk_msg(struct usb_device *udev, unsigned long pipe, void *buffer,
 		    int length)
 {
 	struct udevice *bus = udev->controller_dev;
 	struct dm_usb_ops *ops = usb_get_ops(bus);

 	if (!ops->bulk)
 		return -ENOSYS;

 	return ops->bulk(bus, udev, pipe, buffer, length);
 }

 struct int_queue *create_int_queue(struct usb_device *udev,
 		unsigned long pipe, int queuesize, int elementsize,
 		void *buffer, int interval)
 {
 	struct udevice *bus = udev->controller_dev;
 	struct dm_usb_ops *ops = usb_get_ops(bus);

 	if (!ops->create_int_queue)
 		return NULL;

 	return ops->create_int_queue(bus, udev, pipe, queuesize, elementsize,
 				     buffer, interval);
 }

 void *poll_int_queue(struct usb_device *udev, struct int_queue *queue)
 {
 	struct udevice *bus = udev->controller_dev;
 	struct dm_usb_ops *ops = usb_get_ops(bus);

 	if (!ops->poll_int_queue)
 		return NULL;

 	return ops->poll_int_queue(bus, udev, queue);
 }

 int destroy_int_queue(struct usb_device *udev, struct int_queue *queue)
 {
 	struct udevice *bus = udev->controller_dev;
 	struct dm_usb_ops *ops = usb_get_ops(bus);

 	if (!ops->destroy_int_queue)
 		return -ENOSYS;

 	return ops->destroy_int_queue(bus, udev, queue);
 }

 int usb_alloc_device(struct usb_device *udev)
 {
 	struct udevice *bus = udev->controller_dev;
 	struct dm_usb_ops *ops = usb_get_ops(bus);

 	/* This is only requird by some controllers - current XHCI */
 	if (!ops->alloc_device)
 		return 0;

 	return ops->alloc_device(bus, udev);
 }

 int usb_reset_root_port(struct usb_device *udev)
 {
 	struct udevice *bus = udev->controller_dev;
 	struct dm_usb_ops *ops = usb_get_ops(bus);

 	if (!ops->reset_root_port)
 		return -ENOSYS;

 	return ops->reset_root_port(bus, udev);
 }

 int usb_update_hub_device(struct usb_device *udev)
 {
 	struct udevice *bus = udev->controller_dev;
 	struct dm_usb_ops *ops = usb_get_ops(bus);

 	if (!ops->update_hub_device)
 		return -ENOSYS;

 	return ops->update_hub_device(bus, udev);
 }

 int usb_get_max_xfer_size(struct usb_device *udev, size_t *size)
 {
 	struct udevice *bus = udev->controller_dev;
 	struct dm_usb_ops *ops = usb_get_ops(bus);

 	if (!ops->get_max_xfer_size)
 		return -ENOSYS;

 	return ops->get_max_xfer_size(bus, size);
 }

 int usb_stop(void)
 {
 	struct udevice *bus;
 	struct udevice *rh;
 	struct uclass *uc;
 	struct usb_uclass_priv *uc_priv;
 	int err = 0, ret;

 	/* De-activate any devices that have been activated */
 	ret = uclass_get(UCLASS_USB, &uc);
 	if (ret)
 		return ret;

 	uc_priv = uclass_get_priv(uc);

 	uclass_foreach_dev(bus, uc) {
 		ret = device_remove(bus, DM_REMOVE_NORMAL);
 		if (ret && !err)
 			err = ret;

 		/* Locate root hub device */
 		device_find_first_child(bus, &rh);
 		if (rh) {
 			/*
 			 * All USB devices are children of root hub.
 			 * Unbinding root hub will unbind all of its children.
 			 */
 			ret = device_unbind(rh);
 			if (ret && !err)
 				err = ret;
 		}
 	}

 #ifdef CONFIG_USB_STORAGE
 	usb_stor_reset();
 #endif
 	uc_priv->companion_device_count = 0;
 	usb_started = 0;

 	return err;
 }

 static void usb_scan_bus(struct udevice *bus, bool recurse)
 {
 	struct usb_bus_priv *priv;
 	struct udevice *dev;
 	int ret;

 	priv = dev_get_uclass_priv(bus);

 	assert(recurse);	/* TODO: Support non-recusive */

 	printf("scanning bus %s for devices... ", bus->name);
 	debug("\n");
 	ret = usb_scan_device(bus, 0, USB_SPEED_FULL, &dev);
 	if (ret)
 		printf("failed, error %d\n", ret);
 	else if (priv->next_addr == 0)
 		printf("No USB Device found\n");
 	else
 		printf("%d USB Device(s) found\n", priv->next_addr);
 }

 static void remove_inactive_children(struct uclass *uc, struct udevice *bus)
 {
 	uclass_foreach_dev(bus, uc) {
 		struct udevice *dev, *next;

 		if (!device_active(bus))
 			continue;
 		device_foreach_child_safe(dev, next, bus) {
 			if (!device_active(dev))
 				device_unbind(dev);
 		}
 	}
 }

 int usb_init(void)
 {
 	int controllers_initialized = 0;
 	struct usb_uclass_priv *uc_priv;
 	struct usb_bus_priv *priv;
 	struct udevice *bus;
 	struct uclass *uc;
 	int ret;

 	asynch_allowed = 1;

 	ret = uclass_get(UCLASS_USB, &uc);
 	if (ret)
 		return ret;

 	uc_priv = uclass_get_priv(uc);

 	uclass_foreach_dev(bus, uc) {
 		/* init low_level USB */
 		printf("Bus %s: ", bus->name);

 #ifdef CONFIG_SANDBOX
 		/*
 		 * For Sandbox, we need scan the device tree each time when we
 		 * start the USB stack, in order to re-create the emulated USB
 		 * devices and bind drivers for them before we actually do the
 		 * driver probe.
 		 */
 		ret = dm_scan_fdt_dev(bus);
 		if (ret) {
 			printf("Sandbox USB device scan failed (%d)\n", ret);
 			continue;
 		}
 #endif

 		ret = device_probe(bus);
 		if (ret == -ENODEV) {	/* No such device. */
 			puts("Port not available.\n");
 			controllers_initialized++;
 			continue;
 		}

 		if (ret) {		/* Other error. */
 			printf("probe failed, error %d\n", ret);
 			continue;
 		}
 		controllers_initialized++;
 		usb_started = true;
 	}

 	/*
 	 * lowlevel init done, now scan the bus for devices i.e. search HUBs
 	 * and configure them, first scan primary controllers.
 	 */
 	uclass_foreach_dev(bus, uc) {
 		if (!device_active(bus))
 			continue;

 		priv = dev_get_uclass_priv(bus);
 		if (!priv->companion)
 			usb_scan_bus(bus, true);
 	}

 	/*
 	 * Now that the primary controllers have been scanned and have handed
 	 * over any devices they do not understand to their companions, scan
 	 * the companions if necessary.
 	 */
 	if (uc_priv->companion_device_count) {
 		uclass_foreach_dev(bus, uc) {
 			if (!device_active(bus))
 				continue;

 			priv = dev_get_uclass_priv(bus);
 			if (priv->companion)
 				usb_scan_bus(bus, true);
 		}
 	}

 	debug("scan end\n");

 	/* Remove any devices that were not found on this scan */
 	remove_inactive_children(uc, bus);

 	ret = uclass_get(UCLASS_USB_HUB, &uc);
 	if (ret)
 		return ret;
 	remove_inactive_children(uc, bus);

 	/* if we were not able to find at least one working bus, bail out */
 	if (controllers_initialized == 0)
 		printf("No working controllers found\n");

 	return usb_started ? 0 : -1;
 }

 /*
  * TODO(sjg@chromium.org): Remove this legacy function. At present it is needed
  * to support boards which use driver model for USB but not Ethernet, and want
  * to use USB Ethernet.
  *
  * The #if clause is here to ensure that remains the only case.
  */
 #if !defined(CONFIG_DM_ETH) && defined(CONFIG_USB_HOST_ETHER)
 static struct usb_device *find_child_devnum(struct udevice *parent, int devnum)
 {
 	struct usb_device *udev;
 	struct udevice *dev;

 	if (!device_active(parent))
 		return NULL;
 	udev = dev_get_parent_priv(parent);
 	if (udev->devnum == devnum)
 		return udev;

 	for (device_find_first_child(parent, &dev);
 	     dev;
 	     device_find_next_child(&dev)) {
 		udev = find_child_devnum(dev, devnum);
 		if (udev)
 			return udev;
 	}

 	return NULL;
 }

 struct usb_device *usb_get_dev_index(struct udevice *bus, int index)
 {
 	struct udevice *dev;
 	int devnum = index + 1; /* Addresses are allocated from 1 on USB */

 	device_find_first_child(bus, &dev);
 	if (!dev)
 		return NULL;

 	return find_child_devnum(dev, devnum);
 }
 #endif

 int usb_setup_ehci_gadget(struct ehci_ctrl **ctlrp)
 {
 	struct usb_plat *plat;
 	struct udevice *dev;
 	int ret;

 	/* Find the old device and remove it */
 	ret = uclass_find_device_by_seq(UCLASS_USB, 0, &dev);
 	if (ret)
 		return ret;
 	ret = device_remove(dev, DM_REMOVE_NORMAL);
 	if (ret)
 		return ret;

 	plat = dev_get_plat(dev);
 	plat->init_type = USB_INIT_DEVICE;
 	ret = device_probe(dev);
 	if (ret)
 		return ret;
 	*ctlrp = dev_get_priv(dev);

 	return 0;
 }

 int usb_remove_ehci_gadget(struct ehci_ctrl **ctlrp)
 {
 	struct udevice *dev;
 	int ret;

 	/* Find the old device and remove it */
 	ret = uclass_find_device_by_seq(UCLASS_USB, 0, &dev);
 	if (ret)
 		return ret;
 	ret = device_remove(dev, DM_REMOVE_NORMAL);
 	if (ret)
 		return ret;

 	*ctlrp = NULL;

 	return 0;
 }

 /* returns 0 if no match, 1 if match */
 static int usb_match_device(const struct usb_device_descriptor *desc,
 			    const struct usb_device_id *id)
 {
 	if ((id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
 	    id->idVendor != desc->idVendor)
 		return 0;

 	if ((id->match_flags & USB_DEVICE_ID_MATCH_PRODUCT) &&
 	    id->idProduct != desc->idProduct)
 		return 0;

 	/* No need to test id->bcdDevice_lo != 0, since 0 is never
 	   greater than any unsigned number. */
 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_LO) &&
 	    (id->bcdDevice_lo > desc->bcdDevice))
 		return 0;

 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_HI) &&
 	    (id->bcdDevice_hi < desc->bcdDevice))
 		return 0;

 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_CLASS) &&
 	    (id->bDeviceClass != desc->bDeviceClass))
 		return 0;

 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_SUBCLASS) &&
 	    (id->bDeviceSubClass != desc->bDeviceSubClass))
 		return 0;

 	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_PROTOCOL) &&
 	    (id->bDeviceProtocol != desc->bDeviceProtocol))
 		return 0;

 	return 1;
 }

 /* returns 0 if no match, 1 if match */
 static int usb_match_one_id_intf(const struct usb_device_descriptor *desc,
 			const struct usb_interface_descriptor *int_desc,
 			const struct usb_device_id *id)
 {
 	/* The interface class, subclass, protocol and number should never be
 	 * checked for a match if the device class is Vendor Specific,
 	 * unless the match record specifies the Vendor ID. */
 	if (desc->bDeviceClass == USB_CLASS_VENDOR_SPEC &&
 	    !(id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
 	    (id->match_flags & (USB_DEVICE_ID_MATCH_INT_CLASS |
 				USB_DEVICE_ID_MATCH_INT_SUBCLASS |
 				USB_DEVICE_ID_MATCH_INT_PROTOCOL |
 				USB_DEVICE_ID_MATCH_INT_NUMBER)))
 		return 0;

 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_CLASS) &&
 	    (id->bInterfaceClass != int_desc->bInterfaceClass))
 		return 0;

 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_SUBCLASS) &&
 	    (id->bInterfaceSubClass != int_desc->bInterfaceSubClass))
 		return 0;

 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_PROTOCOL) &&
 	    (id->bInterfaceProtocol != int_desc->bInterfaceProtocol))
 		return 0;

 	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_NUMBER) &&
 	    (id->bInterfaceNumber != int_desc->bInterfaceNumber))
 		return 0;

 	return 1;
 }

 /* returns 0 if no match, 1 if match */
 static int usb_match_one_id(struct usb_device_descriptor *desc,
 			    struct usb_interface_descriptor *int_desc,
 			    const struct usb_device_id *id)
 {
 	if (!usb_match_device(desc, id))
 		return 0;

 	return usb_match_one_id_intf(desc, int_desc, id);
 }

 static ofnode usb_get_ofnode(struct udevice *hub, int port)
 {
 	ofnode node;
 	u32 reg;

 	if (!dev_has_ofnode(hub))
 		return ofnode_null();

 	/*
 	 * The USB controller and its USB hub are two different udevices,
 	 * but the device tree has only one node for both. Thus we are
 	 * assigning this node to both udevices.
 	 * If port is zero, the controller scans its root hub, thus we
 	 * are using the same ofnode as the controller here.
 	 */
 	if (!port)
 		return dev_ofnode(hub);

 	ofnode_for_each_subnode(node, dev_ofnode(hub)) {
 		if (ofnode_read_u32(node, "reg", &reg))
 			continue;

 		if (reg == port)
 			return node;
 	}

 	return ofnode_null();
 }

 /**
  * usb_find_and_bind_driver() - Find and bind the right USB driver
  *
  * This only looks at certain fields in the descriptor.
  */
 static int usb_find_and_bind_driver(struct udevice *parent,
 				    struct usb_device_descriptor *desc,
 				    struct usb_interface_descriptor *iface,
 				    int bus_seq, int devnum, int port,
 				    struct udevice **devp)
 {
 	struct usb_driver_entry *start, *entry;
 	int n_ents;
 	int ret;
 	char name[30], *str;
 	ofnode node = usb_get_ofnode(parent, port);

 	*devp = NULL;
 	debug("%s: Searching for driver\n", __func__);
 	start = ll_entry_start(struct usb_driver_entry, usb_driver_entry);
 	n_ents = ll_entry_count(struct usb_driver_entry, usb_driver_entry);
 	for (entry = start; entry != start + n_ents; entry++) {
 		const struct usb_device_id *id;
 		struct udevice *dev;
 		const struct driver *drv;
 		struct usb_dev_plat *plat;

 		for (id = entry->match; id->match_flags; id++) {
 			if (!usb_match_one_id(desc, iface, id))
 				continue;

 			drv = entry->driver;
 			/*
 			 * We could pass the descriptor to the driver as
 			 * plat (instead of NULL) and allow its bind()
 			 * method to return -ENOENT if it doesn't support this
 			 * device. That way we could continue the search to
 			 * find another driver. For now this doesn't seem
 			 * necesssary, so just bind the first match.
 			 */
 			ret = device_bind(parent, drv, drv->name, NULL, node,
 					  &dev);
 			if (ret)
 				goto error;
 			debug("%s: Match found: %s\n", __func__, drv->name);
 			dev->driver_data = id->driver_info;
 			plat = dev_get_parent_plat(dev);
 			plat->id = *id;
 			*devp = dev;
 			return 0;
 		}
 	}

 	/* Bind a generic driver so that the device can be used */
 	snprintf(name, sizeof(name), "generic_bus_%x_dev_%x", bus_seq, devnum);
 	str = strdup(name);
 	if (!str)
 		return -ENOMEM;
 	ret = device_bind_driver(parent, "usb_dev_generic_drv", str, devp);

 error:
 	debug("%s: No match found: %d\n", __func__, ret);
 	return ret;
 }

 /**
  * usb_find_child() - Find an existing device which matches our needs
  *
  *
  */
 static int usb_find_child(struct udevice *parent,
 			  struct usb_device_descriptor *desc,
 			  struct usb_interface_descriptor *iface,
 			  struct udevice **devp)
 {
 	struct udevice *dev;

 	*devp = NULL;
 	for (device_find_first_child(parent, &dev);
 	     dev;
 	     device_find_next_child(&dev)) {
 		struct usb_dev_plat *plat = dev_get_parent_plat(dev);

 		/* If this device is already in use, skip it */
 		if (device_active(dev))
 			continue;
 		debug("   %s: name='%s', plat=%d, desc=%d\n", __func__,
 		      dev->name, plat->id.bDeviceClass, desc->bDeviceClass);
 		if (usb_match_one_id(desc, iface, &plat->id)) {
 			*devp = dev;
 			return 0;
 		}
 	}

 	return -ENOENT;
 }

 int usb_scan_device(struct udevice *parent, int port,
 		    enum usb_device_speed speed, struct udevice **devp)
 {
 	struct udevice *dev;
 	bool created = false;
 	struct usb_dev_plat *plat;
 	struct usb_bus_priv *priv;
 	struct usb_device *parent_udev;
 	int ret;
 	ALLOC_CACHE_ALIGN_BUFFER(struct usb_device, udev, 1);
 	struct usb_interface_descriptor *iface = &udev->config.if_desc[0].desc;

 	*devp = NULL;
 	memset(udev, '\0', sizeof(*udev));
 	udev->controller_dev = usb_get_bus(parent);
 	priv = dev_get_uclass_priv(udev->controller_dev);

 	/*
 	 * Somewhat nasty, this. We create a local device and use the normal
 	 * USB stack to read its descriptor. Then we know what type of device
 	 * to create for real.
 	 *
 	 * udev->dev is set to the parent, since we don't have a real device
 	 * yet. The USB stack should not access udev.dev anyway, except perhaps
 	 * to find the controller, and the controller will either be @parent,
 	 * or some parent of @parent.
 	 *
 	 * Another option might be to create the device as a generic USB
 	 * device, then morph it into the correct one when we know what it
 	 * should be. This means that a generic USB device would morph into
 	 * a network controller, or a USB flash stick, for example. However,
 	 * we don't support such morphing and it isn't clear that it would
 	 * be easy to do.
 	 *
 	 * Yet another option is to split out the USB stack parts of udev
 	 * into something like a 'struct urb' (as Linux does) which can exist
 	 * independently of any device. This feels cleaner, but calls for quite
 	 * a big change to the USB stack.
 	 *
 	 * For now, the approach is to set up an empty udev, read its
 	 * descriptor and assign it an address, then bind a real device and
 	 * stash the resulting information into the device's parent
 	 * platform data. Then when we probe it, usb_child_pre_probe() is called
 	 * and it will pull the information out of the stash.
 	 */
 	udev->dev = parent;
 	udev->speed = speed;
 	udev->devnum = priv->next_addr + 1;
 	udev->portnr = port;
 	debug("Calling usb_setup_device(), portnr=%d\n", udev->portnr);
 	parent_udev = device_get_uclass_id(parent) == UCLASS_USB_HUB ?
 		dev_get_parent_priv(parent) : NULL;
 	ret = usb_setup_device(udev, priv->desc_before_addr, parent_udev);
 	debug("read_descriptor for '%s': ret=%d\n", parent->name, ret);
 	if (ret)
 		return ret;
 	ret = usb_find_child(parent, &udev->descriptor, iface, &dev);
 	debug("** usb_find_child returns %d\n", ret);
 	if (ret) {
 		if (ret != -ENOENT)
 			return ret;
 		ret = usb_find_and_bind_driver(parent, &udev->descriptor,
 					       iface,
 					       dev_seq(udev->controller_dev),
 					       udev->devnum, port, &dev);
 		if (ret)
 			return ret;
 		created = true;
 	}
 	plat = dev_get_parent_plat(dev);
 	debug("%s: Probing '%s', plat=%p\n", __func__, dev->name, plat);
 	plat->devnum = udev->devnum;
 	plat->udev = udev;
 	priv->next_addr++;
 	ret = device_probe(dev);
 	if (ret) {
 		debug("%s: Device '%s' probe failed\n", __func__, dev->name);
 		priv->next_addr--;
 		if (created)
 			device_unbind(dev);
 		return ret;
 	}
 	*devp = dev;

 	return 0;
 }

 /*
  * Detect if a USB device has been plugged or unplugged.
  */
 int usb_detect_change(void)
 {
 	struct udevice *hub;
 	struct uclass *uc;
 	int change = 0;
 	int ret;

 	ret = uclass_get(UCLASS_USB_HUB, &uc);
 	if (ret)
 		return ret;

 	uclass_foreach_dev(hub, uc) {
 		struct usb_device *udev;
 		struct udevice *dev;

 		if (!device_active(hub))
 			continue;
 		for (device_find_first_child(hub, &dev);
 		     dev;
 		     device_find_next_child(&dev)) {
 			struct usb_port_status status;

 			if (!device_active(dev))
 				continue;

 			udev = dev_get_parent_priv(dev);
 			if (usb_get_port_status(udev, udev->portnr, &status)
 					< 0)
 				/* USB request failed */
 				continue;

 			if (le16_to_cpu(status.wPortChange) &
 			    USB_PORT_STAT_C_CONNECTION)
 				change++;
 		}
 	}

 	return change;
 }

 static int usb_child_post_bind(struct udevice *dev)
 {
 	struct usb_dev_plat *plat = dev_get_parent_plat(dev);
 	int val;

 	if (!dev_has_ofnode(dev))
 		return 0;

 	/* We only support matching a few things */
 	val = dev_read_u32_default(dev, "usb,device-class", -1);
 	if (val != -1) {
 		plat->id.match_flags |= USB_DEVICE_ID_MATCH_DEV_CLASS;
 		plat->id.bDeviceClass = val;
 	}
 	val = dev_read_u32_default(dev, "usb,interface-class", -1);
 	if (val != -1) {
 		plat->id.match_flags |= USB_DEVICE_ID_MATCH_INT_CLASS;
 		plat->id.bInterfaceClass = val;
 	}

 	return 0;
 }

 struct udevice *usb_get_bus(struct udevice *dev)
 {
 	struct udevice *bus;

 	for (bus = dev; bus && device_get_uclass_id(bus) != UCLASS_USB; )
 		bus = bus->parent;
 	if (!bus) {
 		/* By design this cannot happen */
 		assert(bus);
 		debug("USB HUB '%s' does not have a controller\n", dev->name);
 	}

 	return bus;
 }

 int usb_child_pre_probe(struct udevice *dev)
 {
 	struct usb_device *udev = dev_get_parent_priv(dev);
 	struct usb_dev_plat *plat = dev_get_parent_plat(dev);
 	int ret;

 	if (plat->udev) {
 		/*
 		 * Copy over all the values set in the on stack struct
 		 * usb_device in usb_scan_device() to our final struct
 		 * usb_device for this dev.
 		 */
 		*udev = *(plat->udev);
 		/* And clear plat->udev as it will not be valid for long */
 		plat->udev = NULL;
 		udev->dev = dev;
 	} else {
 		/*
 		 * This happens with devices which are explicitly bound
 		 * instead of being discovered through usb_scan_device()
 		 * such as sandbox emul devices.
 		 */
 		udev->dev = dev;
 		udev->controller_dev = usb_get_bus(dev);
 		udev->devnum = plat->devnum;

 		/*
 		 * udev did not go through usb_scan_device(), so we need to
 		 * select the config and read the config descriptors.
 		 */
 		ret = usb_select_config(udev);
 		if (ret)
 			return ret;
 	}

 	return 0;
 }

 UCLASS_DRIVER(usb) = {
 	.id		= UCLASS_USB,
 	.name		= "usb",
 	.flags		= DM_UC_FLAG_SEQ_ALIAS,
 	.post_bind	= dm_scan_fdt_dev,
 	.priv_auto	= sizeof(struct usb_uclass_priv),
 	.per_child_auto	= sizeof(struct usb_device),
 	.per_device_auto	= sizeof(struct usb_bus_priv),
 	.child_post_bind = usb_child_post_bind,
 	.child_pre_probe = usb_child_pre_probe,
 	.per_child_plat_auto	= sizeof(struct usb_dev_plat),
 };

 UCLASS_DRIVER(usb_dev_generic) = {
 	.id		= UCLASS_USB_DEV_GENERIC,
 	.name		= "usb_dev_generic",
 };

 U_BOOT_DRIVER(usb_dev_generic_drv) = {
 	.id		= UCLASS_USB_DEV_GENERIC,
 	.name		= "usb_dev_generic_drv",
 };
	// SPDX-License-Identifier: GPL-2.0+
	/*
	* (C) Copyright 2015 Google, Inc
	* Written by Simon Glass <sjg@chromium.org>
	*
	* usb_match_device() modified from Linux kernel v4.0.
	*/

	#include <common.h>
	#include <dm.h>
	#include <errno.h>
	#include <log.h>
	#include <memalign.h>
	#include <usb.h>
	#include <dm/device-internal.h>
	#include <dm/lists.h>
	#include <dm/uclass-internal.h>

	extern bool usb_started; /* flag for the started/stopped USB status */
	static bool asynch_allowed;

	struct usb_uclass_priv {
	int companion_device_count;
	};

	int usb_lock_async(struct usb_device *udev, int lock)
	{
	struct udevice *bus = udev->controller_dev;
	struct dm_usb_ops *ops = usb_get_ops(bus);

	if (!ops->lock_async)
	return -ENOSYS;

	return ops->lock_async(bus, lock);
	}

	int usb_disable_asynch(int disable)
	{
	int old_value = asynch_allowed;

	asynch_allowed = !disable;
	return old_value;
	}

	int submit_int_msg(struct usb_device udev, unsigned long pipe, void buffer,
	int length, int interval, bool nonblock)
	{
	struct udevice *bus = udev->controller_dev;
	struct dm_usb_ops *ops = usb_get_ops(bus);

	if (!ops->interrupt)
	return -ENOSYS;

	return ops->interrupt(bus, udev, pipe, buffer, length, interval,
	nonblock);
	}

	int submit_control_msg(struct usb_device *udev, unsigned long pipe,
	void buffer, int length, struct devrequest setup)
	{
	struct udevice *bus = udev->controller_dev;
	struct dm_usb_ops *ops = usb_get_ops(bus);
	struct usb_uclass_priv *uc_priv = uclass_get_priv(bus->uclass);
	int err;

	if (!ops->control)
	return -ENOSYS;

	err = ops->control(bus, udev, pipe, buffer, length, setup);
	if (setup->request == USB_REQ_SET_FEATURE &&
	setup->requesttype == USB_RT_PORT &&
	setup->value == cpu_to_le16(USB_PORT_FEAT_RESET) &&
	err == -ENXIO) {
	/* Device handed over to companion after port reset */
	uc_priv->companion_device_count++;
	}

	return err;
	}

	int submit_bulk_msg(struct usb_device udev, unsigned long pipe, void buffer,
	int length)
	{
	struct udevice *bus = udev->controller_dev;
	struct dm_usb_ops *ops = usb_get_ops(bus);

	if (!ops->bulk)
	return -ENOSYS;

	return ops->bulk(bus, udev, pipe, buffer, length);
	}

	struct int_queue create_int_queue(struct usb_device udev,
	unsigned long pipe, int queuesize, int elementsize,
	void *buffer, int interval)
	{
	struct udevice *bus = udev->controller_dev;
	struct dm_usb_ops *ops = usb_get_ops(bus);

	if (!ops->create_int_queue)
	return NULL;

	return ops->create_int_queue(bus, udev, pipe, queuesize, elementsize,
	buffer, interval);
	}

	void poll_int_queue(struct usb_device udev, struct int_queue *queue)
	{
	struct udevice *bus = udev->controller_dev;
	struct dm_usb_ops *ops = usb_get_ops(bus);

	if (!ops->poll_int_queue)
	return NULL;

	return ops->poll_int_queue(bus, udev, queue);
	}

	int destroy_int_queue(struct usb_device udev, struct int_queue queue)
	{
	struct udevice *bus = udev->controller_dev;
	struct dm_usb_ops *ops = usb_get_ops(bus);

	if (!ops->destroy_int_queue)
	return -ENOSYS;

	return ops->destroy_int_queue(bus, udev, queue);
	}

	int usb_alloc_device(struct usb_device *udev)
	{
	struct udevice *bus = udev->controller_dev;
	struct dm_usb_ops *ops = usb_get_ops(bus);

	/* This is only requird by some controllers - current XHCI */
	if (!ops->alloc_device)
	return 0;

	return ops->alloc_device(bus, udev);
	}

	int usb_reset_root_port(struct usb_device *udev)
	{
	struct udevice *bus = udev->controller_dev;
	struct dm_usb_ops *ops = usb_get_ops(bus);

	if (!ops->reset_root_port)
	return -ENOSYS;

	return ops->reset_root_port(bus, udev);
	}

	int usb_update_hub_device(struct usb_device *udev)
	{
	struct udevice *bus = udev->controller_dev;
	struct dm_usb_ops *ops = usb_get_ops(bus);

	if (!ops->update_hub_device)
	return -ENOSYS;

	return ops->update_hub_device(bus, udev);
	}

	int usb_get_max_xfer_size(struct usb_device udev, size_t size)
	{
	struct udevice *bus = udev->controller_dev;
	struct dm_usb_ops *ops = usb_get_ops(bus);

	if (!ops->get_max_xfer_size)
	return -ENOSYS;

	return ops->get_max_xfer_size(bus, size);
	}

	int usb_stop(void)
	{
	struct udevice *bus;
	struct udevice *rh;
	struct uclass *uc;
	struct usb_uclass_priv *uc_priv;
	int err = 0, ret;

	/* De-activate any devices that have been activated */
	ret = uclass_get(UCLASS_USB, &uc);
	if (ret)
	return ret;

	uc_priv = uclass_get_priv(uc);

	uclass_foreach_dev(bus, uc) {
	ret = device_remove(bus, DM_REMOVE_NORMAL);
	if (ret && !err)
	err = ret;

	/* Locate root hub device */
	device_find_first_child(bus, &rh);
	if (rh) {
	/*
	* All USB devices are children of root hub.
	* Unbinding root hub will unbind all of its children.
	*/
	ret = device_unbind(rh);
	if (ret && !err)
	err = ret;
	}
	}

	#ifdef CONFIG_USB_STORAGE
	usb_stor_reset();
	#endif
	uc_priv->companion_device_count = 0;
	usb_started = 0;

	return err;
	}

	static void usb_scan_bus(struct udevice *bus, bool recurse)
	{
	struct usb_bus_priv *priv;
	struct udevice *dev;
	int ret;

	priv = dev_get_uclass_priv(bus);

	assert(recurse); /* TODO: Support non-recusive */

	printf("scanning bus %s for devices... ", bus->name);
	debug("\n");
	ret = usb_scan_device(bus, 0, USB_SPEED_FULL, &dev);
	if (ret)
	printf("failed, error %d\n", ret);
	else if (priv->next_addr == 0)
	printf("No USB Device found\n");
	else
	printf("%d USB Device(s) found\n", priv->next_addr);
	}

	static void remove_inactive_children(struct uclass uc, struct udevice bus)
	{
	uclass_foreach_dev(bus, uc) {
	struct udevice dev, next;

	if (!device_active(bus))
	continue;
	device_foreach_child_safe(dev, next, bus) {
	if (!device_active(dev))
	device_unbind(dev);
	}
	}
	}

	int usb_init(void)
	{
	int controllers_initialized = 0;
	struct usb_uclass_priv *uc_priv;
	struct usb_bus_priv *priv;
	struct udevice *bus;
	struct uclass *uc;
	int ret;

	asynch_allowed = 1;

	ret = uclass_get(UCLASS_USB, &uc);
	if (ret)
	return ret;

	uc_priv = uclass_get_priv(uc);

	uclass_foreach_dev(bus, uc) {
	/* init low_level USB */
	printf("Bus %s: ", bus->name);

	#ifdef CONFIG_SANDBOX
	/*
	* For Sandbox, we need scan the device tree each time when we
	* start the USB stack, in order to re-create the emulated USB
	* devices and bind drivers for them before we actually do the
	* driver probe.
	*/
	ret = dm_scan_fdt_dev(bus);
	if (ret) {
	printf("Sandbox USB device scan failed (%d)\n", ret);
	continue;
	}
	#endif

	ret = device_probe(bus);
	if (ret == -ENODEV) { /* No such device. */
	puts("Port not available.\n");
	controllers_initialized++;
	continue;
	}

	if (ret) { /* Other error. */
	printf("probe failed, error %d\n", ret);
	continue;
	}
	controllers_initialized++;
	usb_started = true;
	}

	/*
	* lowlevel init done, now scan the bus for devices i.e. search HUBs
	* and configure them, first scan primary controllers.
	*/
	uclass_foreach_dev(bus, uc) {
	if (!device_active(bus))
	continue;

	priv = dev_get_uclass_priv(bus);
	if (!priv->companion)
	usb_scan_bus(bus, true);
	}

	/*
	* Now that the primary controllers have been scanned and have handed
	* over any devices they do not understand to their companions, scan
	* the companions if necessary.
	*/
	if (uc_priv->companion_device_count) {
	uclass_foreach_dev(bus, uc) {
	if (!device_active(bus))
	continue;

	priv = dev_get_uclass_priv(bus);
	if (priv->companion)
	usb_scan_bus(bus, true);
	}
	}

	debug("scan end\n");

	/* Remove any devices that were not found on this scan */
	remove_inactive_children(uc, bus);

	ret = uclass_get(UCLASS_USB_HUB, &uc);
	if (ret)
	return ret;
	remove_inactive_children(uc, bus);

	/* if we were not able to find at least one working bus, bail out */
	if (controllers_initialized == 0)
	printf("No working controllers found\n");

	return usb_started ? 0 : -1;
	}

	/*
	* TODO(sjg@chromium.org): Remove this legacy function. At present it is needed
	* to support boards which use driver model for USB but not Ethernet, and want
	* to use USB Ethernet.
	*
	* The #if clause is here to ensure that remains the only case.
	*/
	#if !defined(CONFIG_DM_ETH) && defined(CONFIG_USB_HOST_ETHER)
	static struct usb_device find_child_devnum(struct udevice parent, int devnum)
	{
	struct usb_device *udev;
	struct udevice *dev;

	if (!device_active(parent))
	return NULL;
	udev = dev_get_parent_priv(parent);
	if (udev->devnum == devnum)
	return udev;

	for (device_find_first_child(parent, &dev);
	dev;
	device_find_next_child(&dev)) {
	udev = find_child_devnum(dev, devnum);
	if (udev)
	return udev;
	}

	return NULL;
	}

	struct usb_device usb_get_dev_index(struct udevice bus, int index)
	{
	struct udevice *dev;
	int devnum = index + 1; /* Addresses are allocated from 1 on USB */

	device_find_first_child(bus, &dev);
	if (!dev)
	return NULL;

	return find_child_devnum(dev, devnum);
	}
	#endif

	int usb_setup_ehci_gadget(struct ehci_ctrl **ctlrp)
	{
	struct usb_plat *plat;
	struct udevice *dev;
	int ret;

	/* Find the old device and remove it */
	ret = uclass_find_device_by_seq(UCLASS_USB, 0, &dev);
	if (ret)
	return ret;
	ret = device_remove(dev, DM_REMOVE_NORMAL);
	if (ret)
	return ret;

	plat = dev_get_plat(dev);
	plat->init_type = USB_INIT_DEVICE;
	ret = device_probe(dev);
	if (ret)
	return ret;
	*ctlrp = dev_get_priv(dev);

	return 0;
	}

	int usb_remove_ehci_gadget(struct ehci_ctrl **ctlrp)
	{
	struct udevice *dev;
	int ret;

	/* Find the old device and remove it */
	ret = uclass_find_device_by_seq(UCLASS_USB, 0, &dev);
	if (ret)
	return ret;
	ret = device_remove(dev, DM_REMOVE_NORMAL);
	if (ret)
	return ret;

	*ctlrp = NULL;

	return 0;
	}

	/* returns 0 if no match, 1 if match */
	static int usb_match_device(const struct usb_device_descriptor *desc,
	const struct usb_device_id *id)
	{
	if ((id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
	id->idVendor != desc->idVendor)
	return 0;

	if ((id->match_flags & USB_DEVICE_ID_MATCH_PRODUCT) &&
	id->idProduct != desc->idProduct)
	return 0;

	/* No need to test id->bcdDevice_lo != 0, since 0 is never
	greater than any unsigned number. */
	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_LO) &&
	(id->bcdDevice_lo > desc->bcdDevice))
	return 0;

	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_HI) &&
	(id->bcdDevice_hi < desc->bcdDevice))
	return 0;

	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_CLASS) &&
	(id->bDeviceClass != desc->bDeviceClass))
	return 0;

	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_SUBCLASS) &&
	(id->bDeviceSubClass != desc->bDeviceSubClass))
	return 0;

	if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_PROTOCOL) &&
	(id->bDeviceProtocol != desc->bDeviceProtocol))
	return 0;

	return 1;
	}

	/* returns 0 if no match, 1 if match */
	static int usb_match_one_id_intf(const struct usb_device_descriptor *desc,
	const struct usb_interface_descriptor *int_desc,
	const struct usb_device_id *id)
	{
	/* The interface class, subclass, protocol and number should never be
	* checked for a match if the device class is Vendor Specific,
	* unless the match record specifies the Vendor ID. */
	if (desc->bDeviceClass == USB_CLASS_VENDOR_SPEC &&
	!(id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) &&
	(id->match_flags & (USB_DEVICE_ID_MATCH_INT_CLASS \|
	USB_DEVICE_ID_MATCH_INT_SUBCLASS \|
	USB_DEVICE_ID_MATCH_INT_PROTOCOL \|
	USB_DEVICE_ID_MATCH_INT_NUMBER)))
	return 0;

	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_CLASS) &&
	(id->bInterfaceClass != int_desc->bInterfaceClass))
	return 0;

	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_SUBCLASS) &&
	(id->bInterfaceSubClass != int_desc->bInterfaceSubClass))
	return 0;

	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_PROTOCOL) &&
	(id->bInterfaceProtocol != int_desc->bInterfaceProtocol))
	return 0;

	if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_NUMBER) &&
	(id->bInterfaceNumber != int_desc->bInterfaceNumber))
	return 0;

	return 1;
	}

	/* returns 0 if no match, 1 if match */
	static int usb_match_one_id(struct usb_device_descriptor *desc,
	struct usb_interface_descriptor *int_desc,
	const struct usb_device_id *id)
	{
	if (!usb_match_device(desc, id))
	return 0;

	return usb_match_one_id_intf(desc, int_desc, id);
	}

	static ofnode usb_get_ofnode(struct udevice *hub, int port)
	{
	ofnode node;
	u32 reg;

	if (!dev_has_ofnode(hub))
	return ofnode_null();

	/*
	* The USB controller and its USB hub are two different udevices,
	* but the device tree has only one node for both. Thus we are
	* assigning this node to both udevices.
	* If port is zero, the controller scans its root hub, thus we
	* are using the same ofnode as the controller here.
	*/
	if (!port)
	return dev_ofnode(hub);

	ofnode_for_each_subnode(node, dev_ofnode(hub)) {
	if (ofnode_read_u32(node, "reg", &reg))
	continue;

	if (reg == port)
	return node;
	}

	return ofnode_null();
	}

	/**
	* usb_find_and_bind_driver() - Find and bind the right USB driver
	*
	* This only looks at certain fields in the descriptor.
	*/
	static int usb_find_and_bind_driver(struct udevice *parent,
	struct usb_device_descriptor *desc,
	struct usb_interface_descriptor *iface,
	int bus_seq, int devnum, int port,
	struct udevice **devp)
	{
	struct usb_driver_entry start, entry;
	int n_ents;
	int ret;
	char name[30], *str;
	ofnode node = usb_get_ofnode(parent, port);

	*devp = NULL;
	debug("%s: Searching for driver\n", __func__);
	start = ll_entry_start(struct usb_driver_entry, usb_driver_entry);
	n_ents = ll_entry_count(struct usb_driver_entry, usb_driver_entry);
	for (entry = start; entry != start + n_ents; entry++) {
	const struct usb_device_id *id;
	struct udevice *dev;
	const struct driver *drv;
	struct usb_dev_plat *plat;

	for (id = entry->match; id->match_flags; id++) {
	if (!usb_match_one_id(desc, iface, id))
	continue;

	drv = entry->driver;
	/*
	* We could pass the descriptor to the driver as
	* plat (instead of NULL) and allow its bind()
	* method to return -ENOENT if it doesn't support this
	* device. That way we could continue the search to
	* find another driver. For now this doesn't seem
	* necesssary, so just bind the first match.
	*/
	ret = device_bind(parent, drv, drv->name, NULL, node,
	&dev);
	if (ret)
	goto error;
	debug("%s: Match found: %s\n", __func__, drv->name);
	dev->driver_data = id->driver_info;
	plat = dev_get_parent_plat(dev);
	plat->id = *id;
	*devp = dev;
	return 0;
	}
	}

	/* Bind a generic driver so that the device can be used */
	snprintf(name, sizeof(name), "generic_bus_%x_dev_%x", bus_seq, devnum);
	str = strdup(name);
	if (!str)
	return -ENOMEM;
	ret = device_bind_driver(parent, "usb_dev_generic_drv", str, devp);

	error:
	debug("%s: No match found: %d\n", __func__, ret);
	return ret;
	}

	/**
	* usb_find_child() - Find an existing device which matches our needs
	*
	*
	*/
	static int usb_find_child(struct udevice *parent,
	struct usb_device_descriptor *desc,
	struct usb_interface_descriptor *iface,
	struct udevice **devp)
	{
	struct udevice *dev;

	*devp = NULL;
	for (device_find_first_child(parent, &dev);
	dev;
	device_find_next_child(&dev)) {
	struct usb_dev_plat *plat = dev_get_parent_plat(dev);

	/* If this device is already in use, skip it */
	if (device_active(dev))
	continue;
	debug(" %s: name='%s', plat=%d, desc=%d\n", __func__,
	dev->name, plat->id.bDeviceClass, desc->bDeviceClass);
	if (usb_match_one_id(desc, iface, &plat->id)) {
	*devp = dev;
	return 0;
	}
	}

	return -ENOENT;
	}

	int usb_scan_device(struct udevice *parent, int port,
	enum usb_device_speed speed, struct udevice **devp)
	{
	struct udevice *dev;
	bool created = false;
	struct usb_dev_plat *plat;
	struct usb_bus_priv *priv;
	struct usb_device *parent_udev;
	int ret;
	ALLOC_CACHE_ALIGN_BUFFER(struct usb_device, udev, 1);
	struct usb_interface_descriptor *iface = &udev->config.if_desc[0].desc;

	*devp = NULL;
	memset(udev, '\0', sizeof(*udev));
	udev->controller_dev = usb_get_bus(parent);
	priv = dev_get_uclass_priv(udev->controller_dev);

	/*
	* Somewhat nasty, this. We create a local device and use the normal
	* USB stack to read its descriptor. Then we know what type of device
	* to create for real.
	*
	* udev->dev is set to the parent, since we don't have a real device
	* yet. The USB stack should not access udev.dev anyway, except perhaps
	* to find the controller, and the controller will either be @parent,
	* or some parent of @parent.
	*
	* Another option might be to create the device as a generic USB
	* device, then morph it into the correct one when we know what it
	* should be. This means that a generic USB device would morph into
	* a network controller, or a USB flash stick, for example. However,
	* we don't support such morphing and it isn't clear that it would
	* be easy to do.
	*
	* Yet another option is to split out the USB stack parts of udev
	* into something like a 'struct urb' (as Linux does) which can exist
	* independently of any device. This feels cleaner, but calls for quite
	* a big change to the USB stack.
	*
	* For now, the approach is to set up an empty udev, read its
	* descriptor and assign it an address, then bind a real device and
	* stash the resulting information into the device's parent
	* platform data. Then when we probe it, usb_child_pre_probe() is called
	* and it will pull the information out of the stash.
	*/
	udev->dev = parent;
	udev->speed = speed;
	udev->devnum = priv->next_addr + 1;
	udev->portnr = port;
	debug("Calling usb_setup_device(), portnr=%d\n", udev->portnr);
	parent_udev = device_get_uclass_id(parent) == UCLASS_USB_HUB ?
	dev_get_parent_priv(parent) : NULL;
	ret = usb_setup_device(udev, priv->desc_before_addr, parent_udev);
	debug("read_descriptor for '%s': ret=%d\n", parent->name, ret);
	if (ret)
	return ret;
	ret = usb_find_child(parent, &udev->descriptor, iface, &dev);
	debug("** usb_find_child returns %d\n", ret);
	if (ret) {
	if (ret != -ENOENT)
	return ret;
	ret = usb_find_and_bind_driver(parent, &udev->descriptor,
	iface,
	dev_seq(udev->controller_dev),
	udev->devnum, port, &dev);
	if (ret)
	return ret;
	created = true;
	}
	plat = dev_get_parent_plat(dev);
	debug("%s: Probing '%s', plat=%p\n", __func__, dev->name, plat);
	plat->devnum = udev->devnum;
	plat->udev = udev;
	priv->next_addr++;
	ret = device_probe(dev);
	if (ret) {
	debug("%s: Device '%s' probe failed\n", __func__, dev->name);
	priv->next_addr--;
	if (created)
	device_unbind(dev);
	return ret;
	}
	*devp = dev;

	return 0;
	}

	/*
	* Detect if a USB device has been plugged or unplugged.
	*/
	int usb_detect_change(void)
	{
	struct udevice *hub;
	struct uclass *uc;
	int change = 0;
	int ret;

	ret = uclass_get(UCLASS_USB_HUB, &uc);
	if (ret)
	return ret;

	uclass_foreach_dev(hub, uc) {
	struct usb_device *udev;
	struct udevice *dev;

	if (!device_active(hub))
	continue;
	for (device_find_first_child(hub, &dev);
	dev;
	device_find_next_child(&dev)) {
	struct usb_port_status status;

	if (!device_active(dev))
	continue;

	udev = dev_get_parent_priv(dev);
	if (usb_get_port_status(udev, udev->portnr, &status)
	< 0)
	/* USB request failed */
	continue;

	if (le16_to_cpu(status.wPortChange) &
	USB_PORT_STAT_C_CONNECTION)
	change++;
	}
	}

	return change;
	}

	static int usb_child_post_bind(struct udevice *dev)
	{
	struct usb_dev_plat *plat = dev_get_parent_plat(dev);
	int val;

	if (!dev_has_ofnode(dev))
	return 0;

	/* We only support matching a few things */
	val = dev_read_u32_default(dev, "usb,device-class", -1);
	if (val != -1) {
	plat->id.match_flags \|= USB_DEVICE_ID_MATCH_DEV_CLASS;
	plat->id.bDeviceClass = val;
	}
	val = dev_read_u32_default(dev, "usb,interface-class", -1);
	if (val != -1) {
	plat->id.match_flags \|= USB_DEVICE_ID_MATCH_INT_CLASS;
	plat->id.bInterfaceClass = val;
	}

	return 0;
	}

	struct udevice usb_get_bus(struct udevice dev)
	{
	struct udevice *bus;

	for (bus = dev; bus && device_get_uclass_id(bus) != UCLASS_USB; )
	bus = bus->parent;
	if (!bus) {
	/* By design this cannot happen */
	assert(bus);
	debug("USB HUB '%s' does not have a controller\n", dev->name);
	}

	return bus;
	}

	int usb_child_pre_probe(struct udevice *dev)
	{
	struct usb_device *udev = dev_get_parent_priv(dev);
	struct usb_dev_plat *plat = dev_get_parent_plat(dev);
	int ret;

	if (plat->udev) {
	/*
	* Copy over all the values set in the on stack struct
	* usb_device in usb_scan_device() to our final struct
	* usb_device for this dev.
	*/
	udev = (plat->udev);
	/* And clear plat->udev as it will not be valid for long */
	plat->udev = NULL;
	udev->dev = dev;
	} else {
	/*
	* This happens with devices which are explicitly bound
	* instead of being discovered through usb_scan_device()
	* such as sandbox emul devices.
	*/
	udev->dev = dev;
	udev->controller_dev = usb_get_bus(dev);
	udev->devnum = plat->devnum;

	/*
	* udev did not go through usb_scan_device(), so we need to
	* select the config and read the config descriptors.
	*/
	ret = usb_select_config(udev);
	if (ret)
	return ret;
	}

	return 0;
	}

	UCLASS_DRIVER(usb) = {
	.id = UCLASS_USB,
	.name = "usb",
	.flags = DM_UC_FLAG_SEQ_ALIAS,
	.post_bind = dm_scan_fdt_dev,
	.priv_auto = sizeof(struct usb_uclass_priv),
	.per_child_auto = sizeof(struct usb_device),
	.per_device_auto = sizeof(struct usb_bus_priv),
	.child_post_bind = usb_child_post_bind,
	.child_pre_probe = usb_child_pre_probe,
	.per_child_plat_auto = sizeof(struct usb_dev_plat),
	};

	UCLASS_DRIVER(usb_dev_generic) = {
	.id = UCLASS_USB_DEV_GENERIC,
	.name = "usb_dev_generic",
	};

	U_BOOT_DRIVER(usb_dev_generic_drv) = {
	.id = UCLASS_USB_DEV_GENERIC,
	.name = "usb_dev_generic_drv",
	};