centos man page for subsys_system_register

SUBSYS_SYSTEM_REGIST(9) 				   Device drivers infrastructure				   SUBSYS_SYSTEM_REGIST(9)

NAME
       subsys_system_register - register a subsystem at /sys/devices/system/

SYNOPSIS
       int subsys_system_register(struct bus_type * subsys, const struct attribute_group ** groups);

ARGUMENTS
       subsys
	   system subsystem

       groups
	   default attributes for the root device

DESCRIPTION
       All 'system' subsystems have a /sys/devices/system/<name> root device with the name of the subsystem. The root device can carry subsystem-
       wide attributes. All registered devices are below this single root device and are named after the subsystem with a simple enumeration
       number appended. The registered devices are not explicitely named; only 'id' in the device needs to be set.

       Do not use this interface for anything new, it exists for compatibility with bad ideas only. New subsystems should use plain subsystems;
       and add the subsystem-wide attributes should be added to the subsystem directory itself and not some create fake root-device placed in
       /sys/devices/system/<name>.

COPYRIGHT
Kernel Hackers Manual 3.10					     June 2014						   SUBSYS_SYSTEM_REGIST(9)