Enable IIO configuration via configfs

modulename: industrialio-configfs.ko

configname: CONFIG_IIO_CONFIGFS

Linux Kernel Configuration
└─>Device Drivers
└─>Industrial I/O support
└─>Enable IIO configuration via configfs
In linux kernel since version 4.1 (release Date: 2015-06-21)  
This allows configuring various IIO bits through configfs
(e.g. software triggers). For more info see
Documentation/iio/iio_configfs.rst.

source code: