Copy diabdat.mpq from your CD (or GoG install folder) to:
/media/home/.local/share/diasurgical/devilution/diabdat.mpq

diabdat.mpq filename must be lowercase.

Game saves and diablo.ini are located at:
/media/home/.local/share/diasurgical/devilution/

Controls:

- Left analog or D-Pad: move hero
- A: attack nearby enemies, talk to townspeople and merchants, pickup/place items in the inventory, OK while in main menu
- B: select spell, back while in menus
- X: pickup items, open nearby chests and doors, use item in the inventory
- Y: cast spell, delete character while in main menu
- L1: use health item from belt
- R1: use mana potion from belt
- L2 or Start + Left: character sheet
- R2 or Start + Right: inventory
- Left analog click or Start + Down: toggle automap
- Start + Up or Start + Select: game menu
- Start + Left: character info
- Start + Right: inventory
- Select + A/B/X/Y: Spell hotkeys
- Right analog: move automap or simulate mouse
- Right analog click or Select + L1: left mouse click
- Select + Right analog click or Select + R1: right mouse click
- Select + L2 or Start + Y: quest log
- Select + R2 or Start + B: spell book

Source: https://github.com/diasurgical/devilutionX/
