Serial device bus

modulename: serdev.ko

configname: CONFIG_SERIAL_DEV_BUS

Linux Kernel Configuration
└─>Device Drivers
└─>Character devices
└─>Serial device bus
In linux kernel since version 3.10 (release Date: 2013-06-30)  
Core support for devices connected via a serial port.

Note that you typically also want to enable TTY port controller support.

source code:
drivers/tty/serdev/