cfg80211 - wireless configuration API

modulename: cfg80211.ko

configname: CONFIG_CFG80211

Linux Kernel Configuration
└─>Networking support
└─>cfg80211 - wireless configuration API
In linux kernel since version 2.6.22 (release Date: 2007-07-08)  
cfg80211 is the Linux wireless LAN (802.11) configuration API.
Enable this if you have a wireless device.

For more information refer to documentation on the wireless wiki:

When built as a module it will be called cfg80211.

source code: