usb_string_id — allocate an unused string ID
int usb_string_id ( | struct usb_composite_dev * cdev); |
usb_string_id() is called from bind callbacks to allocate
string IDs. Drivers for functions, configurations, or gadgets will
then store that ID in the appropriate descriptors and string table.
All string identifier should be allocated using this routine, to ensure that for example different functions don't wrongly assign different meanings to the same identifier.