default or selected kernelversion does not have config value CONFIG_HYSDN_CAPI.
Result is shown for kernelversion 6.9.9
HYSDN CAPI 2.0 support
configname: CONFIG_HYSDN_CAPI
Linux Kernel Configuration
└─>Device Drivers
└─>ISDN support
└─>CAPI 2.0 subsystem
└─>HYSDN CAPI 2.0 support
In linux kernel since version 2.6.20 (release Date: 2007-02-04)
Say Y here if you like to use Hypercope's CAPI 2.0 interface.