nixos/apple-touchbar: init module (#350219)

nixos/doc/manual/release-notes/rl-2411.section.md

@@ -190,6 +190,8 @@
 
 - [Zapret](https://github.com/bol-van/zapret), a DPI bypass tool. Available as [services.zapret](option.html#opt-services.zapret).
 
+- [tiny-dfr](https://github.com/WhatAmISupposedToPutHere/tiny-dfr), a dynamic function row daemon for the Touch Bar found on some Apple laptops. Available as [hardware.apple.touchBar.enable](options.html#opt-hardware.apple.touchBar.enable).
+
 ## Backward Incompatibilities {#sec-release-24.11-incompatibilities}
 
 - The `sound` options have been removed or renamed, as they had a lot of unintended side effects. See [below](#sec-release-24.11-migration-sound) for details.

nixos/modules/hardware/apple-touchbar.nix

@@ -0,0 +1,43 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+
+let
+  cfg = config.hardware.apple.touchBar;
+  format = pkgs.formats.toml { };
+  cfgFile = format.generate "config.toml" cfg.settings;
+in
+{
+  options.hardware.apple.touchBar = {
+    enable = lib.mkEnableOption "support for the Touch Bar on some Apple laptops using tiny-dfr";
+    package = lib.mkPackageOption pkgs "tiny-dfr" { };
+
+    settings = lib.mkOption {
+      type = format.type;
+      default = { };
+      description = ''
+        Configuration for tiny-dfr. See [example configuration][1] for available options.
+
+        [1]: https://github.com/WhatAmISupposedToPutHere/tiny-dfr/blob/master/share/tiny-dfr/config.toml
+      '';
+      example = lib.literalExpression ''
+        {
+          MediaLayerDefault = true;
+          ShowButtonOutlines = false;
+          EnablePixelShift = true;
+        }
+      '';
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    systemd.packages = [ cfg.package ];
+    services.udev.packages = [ cfg.package ];
+
+    environment.etc."tiny-dfr/config.toml".source = cfgFile;
+    systemd.services.tiny-dfr.restartTriggers = [ cfgFile ];
+  };
+}

nixos/modules/module-list.nix

@@ -48,6 +48,7 @@
   ./config/zram.nix
   ./hardware/acpilight.nix
   ./hardware/all-firmware.nix
+  ./hardware/apple-touchbar.nix
   ./hardware/bladeRF.nix
   ./hardware/brillo.nix
   ./hardware/ckb-next.nix