fixes

hosts/desktop/boot.nix

@@ -11,7 +11,10 @@ in
     kernelModules = [
       "nct6775"
       "kvm-amd"
+      "i2c-dev"
+      "ddcci_backlight"
     ];
+    extraModulePackages = [config.boot.kernelPackages.ddcci-driver];
     loader = {
       efi = {
         canTouchEfiVariables = true;

hosts/desktop/configuration.nix

@@ -16,13 +16,19 @@ let
     VISUAL = "${pkgs.vscodium}/bin/codium --wait";
   };
   systemPackages = with pkgsVersion; [
+    acpilight
     aha
     aspell
     aspellDicts.en
     aspellDicts.en-computers
     aspellDicts.en-science
     borgbackup
+    brightnessctl
     # brscan5
+    ddcui
+    ddcutil
+    ddccontrol
+    ddccontrol-db
     efibootmgr
     kdePackages.ksvg
     memtest86-efi
@@ -170,4 +176,8 @@ in
     libvirtd.enable = lib.mkDefault true;
     waydroid.enable = lib.mkDefault true;
   };
+
+  services.udev.extraRules = ''
+    KERNEL=="i2c-[0-9]*", GROUP="i2c", MODE="0660"
+  '';
 }

hosts/desktop/users.nix

@@ -15,6 +15,8 @@ in
       "input"
       "scanner"
       "lp"
+      "video"
+      "i2c"
     ]; # Enable ‘sudo’ for the user.
     hashedPasswordFile = passwordFile;
     shell = pkgsVersion.zsh;