suse man page for class_find_device

CLASS_FIND_DEVICE(9)					   Device drivers infrastructure				      CLASS_FIND_DEVICE(9)

NAME
       class_find_device - device iterator for locating a particular device

SYNOPSIS
       struct device * class_find_device(struct class * class, struct device * start, void * data, int (*match) (struct device *, void *));

ARGUMENTS
       class
	   the class we're iterating

       start
	   Device to begin with

       data
	   data for the match function

       match
	   function to check device

DESCRIPTION
       This is similar to the class_for_each_dev function above, but it returns a reference to a device that is 'found' for later use, as
       determined by the match callback.

       The callback should return 0 if the device doesn't match and non-zero if it does. If the callback returns non-zero, this function will
       return to the caller and not iterate over any more devices.

       Note, you will need to drop the reference with put_device after use.

       fn is allowed to do anything including calling back into class code. There's no locking restriction.

COPYRIGHT
Kernel Hackers Manual 2.6.					     July 2010						      CLASS_FIND_DEVICE(9)