usb_for_each_dev(9) centos man page | unix.com

USB_FOR_EACH_DEV(9)						   USB Core APIs					       USB_FOR_EACH_DEV(9)

NAME
       usb_for_each_dev - iterate over all USB devices in the system

SYNOPSIS
       int usb_for_each_dev(void * data, int (*fn) (struct usb_device *, void *));

ARGUMENTS
       data
	   data pointer that will be handed to the callback function

       fn
	   callback function to be called for each USB device

DESCRIPTION
       Iterate over all USB devices and call fn for each, passing it data. If it returns anything other than 0, we break the iteration prematurely
       and return that value.

COPYRIGHT
Kernel Hackers Manual 3.10					     June 2014						       USB_FOR_EACH_DEV(9)