CONFIG_MISDN_HDLC (not configurable)

modulename: isdnhdlc.ko

configname: CONFIG_MISDN_HDLC

Linux Kernel Configuration
└─>Device Drivers
└─>ISDN support
└─>Modular ISDN driver
└─>MISDN_HDLC
In linux kernel since version 5.1 (release Date: 2019-05-05)  
source code: