centos man page for bus_for_each_dev

BUS_FOR_EACH_DEV(9)					   Device drivers infrastructure				       BUS_FOR_EACH_DEV(9)

NAME
       bus_for_each_dev - device iterator.

SYNOPSIS
       int bus_for_each_dev(struct bus_type * bus, struct device * start, void * data, int (*fn) (struct device *, void *));

ARGUMENTS
       bus
	   bus type.

       start
	   device to start iterating from.

       data
	   data for the callback.

       fn
	   function to be called for each device.

DESCRIPTION
       Iterate over bus's list of devices, and call fn for each, passing it data. If start is not NULL, we use that device to begin iterating
       from.

       We check the return of fn each time. If it returns anything other than 0, we break out and return that value.

NOTE
       The device that returns a non-zero value is not retained in any way, nor is its refcount incremented. If the caller needs to retain this
       data, it should do so, and increment the reference count in the supplied callback.

COPYRIGHT
Kernel Hackers Manual 3.10					     June 2014						       BUS_FOR_EACH_DEV(9)