CONFIG_MFD_CORE (not configurable)

modulename: mfd-core.ko

configname: CONFIG_MFD_CORE

Linux Kernel Configuration
└─>Device Drivers
└─>Multifunction device drivers
└─>MFD_CORE
In linux kernel since version 2.6.27 (release Date: 2008-10-09)  
source code:
drivers/mfd/mfd-core.c

is selected by
CONFIG_FB_TMIO