nixos/ddccontrol: init

(cherry picked from commit fc1e0e863c60dc9740304de36ffa883cbaddd760)

nixos/modules/module-list.nix

@@ -383,6 +383,7 @@
   ./services/hardware/bluetooth.nix
   ./services/hardware/bolt.nix
   ./services/hardware/brltty.nix
+  ./services/hardware/ddccontrol.nix
   ./services/hardware/fancontrol.nix
   ./services/hardware/freefall.nix
   ./services/hardware/fwupd.nix

nixos/modules/services/hardware/ddccontrol.nix

@@ -0,0 +1,36 @@
+{ config
+, lib
+, pkgs
+, ...
+}:
+
+let
+  cfg = config.services.ddccontrol;
+in
+
+{
+  ###### interface
+
+  options = {
+    services.ddccontrol = {
+      enable = lib.mkEnableOption "ddccontrol for controlling displays";
+    };
+  };
+
+  ###### implementation
+
+  config = lib.mkIf cfg.enable {
+    # Give users access to the "gddccontrol" tool
+    environment.systemPackages = [
+      pkgs.ddccontrol
+    ];
+
+    services.dbus.packages = [
+      pkgs.ddccontrol
+    ];
+
+    systemd.packages = [
+      pkgs.ddccontrol
+    ];
+  };
+}