CONFIG_REGMAP (not configurable)

modulename: regmap.ko

and/or

regcache-rbtree.ko

configname: CONFIG_REGMAP

Linux Kernel Configuration
└─>Device Drivers
└─>Generic Driver Options
└─>REGMAP
In linux kernel since version 3.1 (release Date: 2011-10-24)  
source code:
drivers/base//regmap/
selects
CONFIG_IRQ_DOMAIN
CONFIG_MDIO_BUS

is selected by
CONFIG_REGMAP_KUNIT