CONFIG_ISDN_HDLC (not configurable)

modulename: isdnhdlc.ko

configname: CONFIG_ISDN_HDLC

Linux Kernel Configuration
└─>Device Drivers
└─>ISDN support
└─>ISDN_HDLC
In linux kernel since version 2.6.32 (release Date: 2009-12-02)  
source code:
drivers/isdn/i4l/isdnhdlc.c

depends
CONFIG_ISDN

is depended by
CONFIG_HISAX_ST5481