Note that SDL_CONTROLLER_BUTTON_AUX1 is sent for the PS4/PS5 touchpad button on the HIDAPI driver.
diff --git a/include/SDL_gamecontroller.h b/include/SDL_gamecontroller.h
index 87f08b2..d1350e4 100644
--- a/include/SDL_gamecontroller.h
+++ b/include/SDL_gamecontroller.h
@@ -363,7 +363,7 @@ typedef enum
SDL_CONTROLLER_BUTTON_DPAD_DOWN,
SDL_CONTROLLER_BUTTON_DPAD_LEFT,
SDL_CONTROLLER_BUTTON_DPAD_RIGHT,
- SDL_CONTROLLER_BUTTON_AUX1, // Xbox Elite paddle, Nintendo Switch Pro capture button
+ SDL_CONTROLLER_BUTTON_AUX1, // Xbox Elite paddle, PS4/PS5 touchpad button, Nintendo Switch Pro capture button
SDL_CONTROLLER_BUTTON_AUX2, // Xbox Elite paddle
SDL_CONTROLLER_BUTTON_AUX3, // Xbox Elite paddle
SDL_CONTROLLER_BUTTON_AUX4, // Xbox Elite paddle