nixpkgs/nixos/modules/services/misc/tuxclocker.nix

{ config, pkgs, lib, ... }:
let
  cfg = config.programs.tuxclocker;
in
{
  options.programs.tuxclocker = {
    enable = lib.mkEnableOption ''
      TuxClocker, a hardware control and monitoring program
    '';

    enableAMD = lib.mkEnableOption ''
      AMD GPU controls.
      Sets the `amdgpu.ppfeaturemask` kernel parameter to 0xfffd7fff to enable all TuxClocker controls
    '';

    enabledNVIDIADevices = lib.mkOption {
      type = lib.types.listOf lib.types.int;
      default = [ ];
      example = [ 0 1 ];
      description = ''
        Enable NVIDIA GPU controls for a device by index.
        Sets the `Coolbits` Xorg option to enable all TuxClocker controls.
      '';
    };

    useUnfree = lib.mkOption {
      type = lib.types.bool;
      default = false;
      example = true;
      description = ''
        Whether to use components requiring unfree dependencies.
        Disabling this allows you to get everything from the binary cache.
      '';
    };
  };

  config = let
      package = if cfg.useUnfree then pkgs.tuxclocker else pkgs.tuxclocker-without-unfree;
    in
      lib.mkIf cfg.enable {
        environment.systemPackages = [
          package
        ];

        services.dbus.packages = [
          package
        ];

        # MSR is used for some features
        boot.kernelModules = [ "msr" ];

        # https://download.nvidia.com/XFree86/Linux-x86_64/430.14/README/xconfigoptions.html#Coolbits
        services.xserver.config = let
          configSection = (i: ''
            Section "Device"
              Driver "nvidia"
              Option "Coolbits" "31"
              Identifier "Device-nvidia[${toString i}]"
            EndSection
          '');
        in
          lib.concatStrings (map configSection cfg.enabledNVIDIADevices);

        # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/gpu/drm/amd/include/amd_shared.h#n207
        # Enable everything modifiable in TuxClocker
        boot.kernelParams = lib.mkIf cfg.enableAMD [ "amdgpu.ppfeaturemask=0xfffd7fff" ];
      };
}