Man page 9 : class_for_each_device

class_for_each_device - device iterator

int class_for_each_device(struct class *  class , struct device *  start , void *  data , int (* fn ) (struct device *, void *));

class
    the class weAqre iterating

start
    the device to start with in the list, if any.

data
    data for the callback

fn
    function to be called for each device

Iterate over classAqs list of devices, and call fn for each, passing it data. If start is set, the list iteration will start there, otherwise if it is NULL, the iteration starts at the beginning of the list.

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

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