PPSSPP supports Xbox, PlayStation, Nintendo, and generic Bluetooth/USB gamepads on all platforms.
Desktop: Connect via USB or Bluetooth. Open Settings → Controls → Control Mapping, select a PSP button, then press the corresponding controller button. PPSSPP auto-detects most popular pads.
Android: Pair your controller in system Bluetooth settings first. Map buttons under Settings → Controls. On-screen touch controls hide when a physical controller is connected.
iOS: MFi-certified controllers and many Bluetooth pads work out of the box. Map buttons under Settings → Controls if defaults are incorrect.