Linux v4.20-rc4 - drivers/siox/Kconfig
tristate "Eckelmann SIOX Support"
SIOX stands for Serial Input Output eXtension and is a synchronous
bus system invented by Eckelmann AG. It is used in their control and
remote monitoring systems for commercial and industrial refrigeration
to drive additional I/O units.
Unless you know better, it is probably safe to say "no" here.
tristate "SIOX GPIO bus driver"
SIOX bus driver that controls the four bus lines using GPIOs.