[xpadneo] Moved to it's own config. Adds an env var for steam.

system/features/bluetooth.nix

@@ -1,6 +1,9 @@
 { pkgs, ... }:
 {
+  # Enable bluetooth.
+  hardware.bluetooth.enable = true;
 
+  # Install the management service and packages.
   environment.systemPackages = with pkgs; [
     bluez
   ];

system/features/xpadneo.nix

@@ -0,0 +1,26 @@
+_: {
+  hardware = {
+    # Wireless xbox controllers
+    xpadneo = {
+      enable = true;
+      settings = {
+        disable_mouse = 1;
+      };
+    };
+
+    # Hardwired xbox controllers.
+    xone.enable = true;
+  };
+
+  # disable_ertm is required for xpadneo to connect properly and establish a
+  # data connection.  enable_autosuspend is to prevent Linux from putting the
+  # BT radio to sleep and causing a disconnect.
+  boot.extraModprobeConfig = ''
+    options bluetooth disable_ertm=1
+    options btusb enable_autosuspend=0
+  '';
+
+  # Steam also needs HID API to be off so SDL will read directly from evdev,
+  # otherwise it won't get any events from xpadneo.
+  environment.sessionVariables.SDL_JOYSTICK_HIDAPI = "0";
+}