CONFIG_ATARI_MIDI is not available for the default architecture x86.
Result is shown for architecture m68knommu
default or selected kernelversion does not have config value CONFIG_ATARI_MIDI.
Result is shown for kernelversion 3.19.8

Atari MIDI serial support


Linux Kernel Configuration
└─> Character devices
└─> Atari MIDI serial support

If you want to use your Atari's MIDI port in Linux, say Y.

To compile this driver as a module, choose M here.