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--- a/drivers/usb/core/usb.c
+++ b/drivers/usb/core/usb.c
@@ -644,6 +644,71 @@ int __usb_get_extra_descriptor(char *buf
}
EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor);
+static struct usb_device *match_device_name(struct usb_device *dev,
+ const char *name)
+{
+ struct usb_device *ret_dev = NULL;
+ struct usb_device *childdev = NULL;
+ int child;
+
+ dev_dbg(&dev->dev, "check for name %s ...\n", name);
+
+ /* see if this device matches */
+ if (strcmp(dev_name(&dev->dev), name) == 0 ) {
+ dev_dbg(&dev->dev, "matched this device!\n");
+ ret_dev = usb_get_dev(dev);
+ goto exit;
+ }
+ /* look through all of the children of this device */
+ usb_hub_for_each_child(dev, child, childdev) {
+ if (childdev) {
+ usb_lock_device(childdev);
+ ret_dev = match_device_name(childdev, name);
+ usb_unlock_device(childdev);
+ if (ret_dev)
+ goto exit;
+ }
+ }
+exit:
+ return ret_dev;
+}
+
+/**
+ * usb_find_device_by_name - find a specific usb device in the system
+ * @name: the name of the device to find
+ *
+ * Returns a pointer to a struct usb_device if such a specified usb
+ * device is present in the system currently. The usage count of the
+ * device will be incremented if a device is found. Make sure to call
+ * usb_put_dev() when the caller is finished with the device.
+ *
+ * If a device with the specified bus id is not found, NULL is returned.
+ */
+struct usb_device *usb_find_device_by_name(const char *name)
+{
+ struct list_head *buslist;
+ struct usb_bus *bus;
+ struct usb_device *dev = NULL;
+
+ mutex_lock(&usb_bus_list_lock);
+ for (buslist = usb_bus_list.next;
+ buslist != &usb_bus_list;
+ buslist = buslist->next) {
+ bus = container_of(buslist, struct usb_bus, bus_list);
+ if (!bus->root_hub)
+ continue;
+ usb_lock_device(bus->root_hub);
+ dev = match_device_name(bus->root_hub, name);
+ usb_unlock_device(bus->root_hub);
+ if (dev)
+ goto exit;
+ }
+exit:
+ mutex_unlock(&usb_bus_list_lock);
+ return dev;
+}
+EXPORT_SYMBOL_GPL(usb_find_device_by_name);
+
/**
* usb_alloc_coherent - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
* @dev: device the buffer will be used with
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -677,6 +677,7 @@ static inline bool usb_device_supports_l
return udev->bos->ss_cap->bmAttributes & USB_LTM_SUPPORT;
}
+extern struct usb_device *usb_find_device_by_name(const char *name);
/*-------------------------------------------------------------------------*/
|
