core/hid: Add fallback to fullkey controllers

src/core/hid/emulated_controller.cpp

@@ -879,10 +879,36 @@ void EmulatedController::SetSupportedNpadStyleTag(NpadStyleTag supported_styles)
     if (!is_connected) {
         return;
     }
-    if (!IsControllerSupported()) {
+    if (IsControllerSupported()) {
+        return;
+    }
+
+    Disconnect();
+
+    // Fallback fullkey controllers to Pro controllers
+    if (IsControllerFullkey() && supported_style_tag.fullkey) {
+        LOG_WARNING(Service_HID, "Reconnecting controller type {} as Pro controller", npad_type);
+        SetNpadStyleIndex(NpadStyleIndex::ProController);
+        Connect();
+        return;
+    }
+
     LOG_ERROR(Service_HID, "Controller type {} is not supported. Disconnecting controller",
               npad_type);
-        Disconnect();
+}
+
+bool EmulatedController::IsControllerFullkey(bool use_temporary_value) const {
+    const auto type = is_configuring && use_temporary_value ? tmp_npad_type : npad_type;
+    switch (type) {
+    case NpadStyleIndex::ProController:
+    case NpadStyleIndex::GameCube:
+    case NpadStyleIndex::NES:
+    case NpadStyleIndex::SNES:
+    case NpadStyleIndex::N64:
+    case NpadStyleIndex::SegaGenesis:
+        return true;
+    default:
+        return false;
     }
 }
 

src/core/hid/emulated_controller.h

@@ -320,6 +320,12 @@ private:
     /// Set the params for TAS devices
     void LoadTASParams();
 
+    /**
+     * @param use_temporary_value If true tmp_npad_type will be used
+     * @return true if the controller style is fullkey
+     */
+    bool IsControllerFullkey(bool use_temporary_value = false) const;
+
     /**
      * Checks the current controller type against the supported_style_tag
      * @param use_temporary_value If true tmp_npad_type will be used