I too am having trouble with this gamepad. It is not being recognized in the F10 menu when trying to remap, and it works fine in other emulators. The controller shows up as a USB Wheel in Emulation Station.
I’m using an xbox controller and this is fixable by using the –dpad-as-button option with xboxdrv. The only problem is that this remaps ALL the button numbers on the controller, so you have to remap all the buttons for the rest of the emulators too.
This may not be helpful since you’re not using an xbox controller, but I thought I’d mention it since this was the first result in google for my problem.
Did anyone find a solution to this issue? I’m using a Hori Gem Pad for PS3, which works perfectly once set in all other emulators except GPSP. It will only recognise the left analogue stick for control. Normally I wouldn’t mind too much but for some reason it is extremely sensitive, making navigating the GPSP menu a nightmare.
The official PS4 pad also has issue with mapping the dpad in GPSP. Everywhere else it works perfectly. The stick is good enough for me, but I’d really like the option for platformers in the future. It’s not as much of a concern for RPGs like Pokemon though.