Add laptop settings

system/roles/laptop/power/default.nix

@@ -0,0 +1,66 @@
+{lib, config, pkgs, ...}: let
+  inherit (lib) mkDefault;
+in{
+  hardware.acpilight.enable = true;
+
+  environment.systemPackages = with pkgs; [
+    acpi
+    powertop
+  ];
+
+  services = {
+    # handle ACPI events
+    acpid.enable = true;
+
+    # allows changing system behavior based upon user-selected power profiles
+    power-profiles-daemon.enable = true;
+
+    # temperature target on battery
+    undervolt = {
+      tempBat = 65; # deg C
+      package = pkgs.undervolt;
+    };
+
+    # superior power management
+    auto-cpufreq = {
+      enable = true;
+
+      # define the profiles
+      # (you can manually switch between profiles using `powerprofilesctl` cmd)
+      settings = let
+        MHz = x: x * 1000;
+      in {
+        battery = {
+          governor = "powersave";
+          scaling_min_freq = mkDefault (MHz 1200);
+          scaling_max_freq = mkDefault (MHz 1800);
+          turbo = "never";
+        };
+
+        charger = {
+          governor = "performance";
+          scaling_min_freq = mkDefault (MHz 1800);
+          scaling_max_freq = mkDefault (MHz 3800);
+          turbo = "auto";
+        };
+      };
+    };
+
+    # DBus service that provides power management support to applications
+    upower = {
+      enable = true;
+      percentageLow = 15;
+      percentageCritical = 5;
+      percentageAction = 3;
+      criticalPowerAction = "Hibernate";
+    };
+  };
+
+  boot = {
+    kernelModules = ["acpi_call"];
+    extraModulePackages = with config.boot.kernelPackages; [
+      acpi_call
+      cpupower
+    ];
+  };
+}