Tutorials:SDL is correct. The left and upper face buttons are X and Y on the Dingoo A320, but Y and X on the GCW Zero. Those are just changed labels, i.e. X on the Dingoo A320 is the same SDL_key as Y on the GCW Zero.
The downside is that, if you ask a user to press X in a Dingoo application, the GCW Zero user will press what the application thinks is Y. So, on the GCW Zero the user must be told to press X for SDLK_LSHIFT, or that the label for SDLK_LSHIFT s/he just pressed is X, not Y.