nixpkgs/nixos/modules/hardware/steam-hardware.nix

{ config, lib, pkgs, ... }:
let

  cfg = config.hardware.steam-hardware;

in

{
  options.hardware.steam-hardware = {
    enable = lib.mkOption {
      type = lib.types.bool;
      default = false;
      description = "Enable udev rules for Steam hardware such as the Steam Controller, other supported controllers and the HTC Vive";
    };
  };

  config = lib.mkIf cfg.enable {
    services.udev.packages = [
      pkgs.steamPackages.steam
    ];

    # The uinput module needs to be loaded in order to trigger the udev rules
    # defined in the steam package for setting permissions on /dev/uinput.
    #
    # If the udev rules are not triggered, some controllers won't work with
    # steam.
    boot.kernelModules = [ "uinput" ];
  };
}