target/linux/generic/patches-3.9/820-usb_add_usb_find_device_by_name.patch

   1 --- a/drivers/usb/core/usb.c
   2 +++ b/drivers/usb/core/usb.c
   3 @@ -644,6 +644,71 @@ int __usb_get_extra_descriptor(char *buf
   4  }
   5  EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor);
   6
   7 +static struct usb_device *match_device_name(struct usb_device *dev,
   8 +                                           const char *name)
   9 +{
  10 +       struct usb_device *ret_dev = NULL;
  11 +       struct usb_device *childdev = NULL;
  12 +       int child;
  13 +
  14 +       dev_dbg(&dev->dev, "check for name %s ...\n", name);
  15 +
  16 +       /* see if this device matches */
  17 +       if (strcmp(dev_name(&dev->dev), name) == 0 ) {
  18 +               dev_dbg(&dev->dev, "matched this device!\n");
  19 +               ret_dev = usb_get_dev(dev);
  20 +               goto exit;
  21 +       }
  22 +       /* look through all of the children of this device */
  23 +       usb_hub_for_each_child(dev, child, childdev) {
  24 +               if (childdev) {
  25 +                       usb_lock_device(childdev);
  26 +                       ret_dev = match_device_name(childdev, name);
  27 +                       usb_unlock_device(childdev);
  28 +                       if (ret_dev)
  29 +                               goto exit;
  30 +               }
  31 +       }
  32 +exit:
  33 +       return ret_dev;
  34 +}
  35 +
  36 +/**
  37 + * usb_find_device_by_name - find a specific usb device in the system
  38 + * @name: the name of the device to find
  39 + *
  40 + * Returns a pointer to a struct usb_device if such a specified usb
  41 + * device is present in the system currently.  The usage count of the
  42 + * device will be incremented if a device is found.  Make sure to call
  43 + * usb_put_dev() when the caller is finished with the device.
  44 + *
  45 + * If a device with the specified bus id is not found, NULL is returned.
  46 + */
  47 +struct usb_device *usb_find_device_by_name(const char *name)
  48 +{
  49 +       struct list_head *buslist;
  50 +       struct usb_bus *bus;
  51 +       struct usb_device *dev = NULL;
  52 +
  53 +       mutex_lock(&usb_bus_list_lock);
  54 +       for (buslist = usb_bus_list.next;
  55 +            buslist != &usb_bus_list;
  56 +            buslist = buslist->next) {
  57 +               bus = container_of(buslist, struct usb_bus, bus_list);
  58 +               if (!bus->root_hub)
  59 +                       continue;
  60 +               usb_lock_device(bus->root_hub);
  61 +               dev = match_device_name(bus->root_hub, name);
  62 +               usb_unlock_device(bus->root_hub);
  63 +               if (dev)
  64 +                       goto exit;
  65 +       }
  66 +exit:
  67 +       mutex_unlock(&usb_bus_list_lock);
  68 +       return dev;
  69 +}
  70 +EXPORT_SYMBOL_GPL(usb_find_device_by_name);
  71 +
  72  /**
  73   * usb_alloc_coherent - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
  74   * @dev: device the buffer will be used with
  75 --- a/include/linux/usb.h
  76 +++ b/include/linux/usb.h
  77 @@ -677,6 +677,7 @@ static inline bool usb_device_supports_l
  78         return udev->bos->ss_cap->bmAttributes & USB_LTM_SUPPORT;
  79  }
  80
  81 +extern struct usb_device *usb_find_device_by_name(const char *name);
  82
  83  /*-------------------------------------------------------------------------*/
  84