1 files changed, 108 insertions, 0 deletions
diff --git a/nixos/modules/tasks/trackpoint.nix b/nixos/modules/tasks/trackpoint.nix
new file mode 100644
index 00000000000..029d8a00295
--- /dev/null
+++ b/nixos/modules/tasks/trackpoint.nix
@@ -0,0 +1,108 @@
+{ config, lib, ... }:
+
+with lib;
+
+{
+  ###### interface
+
+  options = {
+
+    hardware.trackpoint = {
+
+      enable = mkOption {
+        default = false;
+        type = types.bool;
+        description = ''
+          Enable sensitivity and speed configuration for trackpoints.
+        '';
+      };
+
+      sensitivity = mkOption {
+        default = 128;
+        example = 255;
+        type = types.int;
+        description = ''
+          Configure the trackpoint sensitivity. By default, the kernel
+          configures 128.
+        '';
+      };
+
+      speed = mkOption {
+        default = 97;
+        example = 255;
+        type = types.int;
+        description = ''
+          Configure the trackpoint speed. By default, the kernel
+          configures 97.
+        '';
+      };
+
+      emulateWheel = mkOption {
+        default = false;
+        type = types.bool;
+        description = ''
+          Enable scrolling while holding the middle mouse button.
+        '';
+      };
+
+      fakeButtons = mkOption {
+        default = false;
+        type = types.bool;
+        description = ''
+          Switch to "bare" PS/2 mouse support in case Trackpoint buttons are not recognized
+          properly. This can happen for example on models like the L430, T450, T450s, on
+          which the Trackpoint buttons are actually a part of the Synaptics touchpad.
+        '';
+      };
+
+      device = mkOption {
+        default = "TPPS/2 IBM TrackPoint";
+        type = types.str;
+        description = ''
+          The device name of the trackpoint. You can check with xinput.
+          Some newer devices (example x1c6) use "TPPS/2 Elan TrackPoint".
+        '';
+      };
+
+    };
+
+  };
+
+
+  ###### implementation
+
+  config =
+  let cfg = config.hardware.trackpoint; in
+  mkMerge [
+    (mkIf cfg.enable {
+      services.udev.extraRules =
+      ''
+        ACTION=="add|change", SUBSYSTEM=="input", ATTR{name}=="${cfg.device}", ATTR{device/speed}="${toString cfg.speed}", ATTR{device/sensitivity}="${toString cfg.sensitivity}"
+      '';
+
+      system.activationScripts.trackpoint =
+        ''
+          ${config.systemd.package}/bin/udevadm trigger --attr-match=name="${cfg.device}"
+        '';
+    })
+
+    (mkIf (cfg.emulateWheel) {
+      services.xserver.inputClassSections = [
+        ''
+          Identifier "Trackpoint Wheel Emulation"
+          MatchProduct "${if cfg.fakeButtons then "PS/2 Generic Mouse" else "ETPS/2 Elantech TrackPoint|Elantech PS/2 TrackPoint|TPPS/2 IBM TrackPoint|DualPoint Stick|Synaptics Inc. Composite TouchPad / TrackPoint|ThinkPad USB Keyboard with TrackPoint|USB Trackpoint pointing device|Composite TouchPad / TrackPoint|${cfg.device}"}"
+          MatchDevicePath "/dev/input/event*"
+          Option "EmulateWheel" "true"
+          Option "EmulateWheelButton" "2"
+          Option "Emulate3Buttons" "false"
+          Option "XAxisMapping" "6 7"
+          Option "YAxisMapping" "4 5"
+        ''
+      ];
+    })
+
+    (mkIf cfg.fakeButtons {
+      boot.extraModprobeConfig = "options psmouse proto=bare";
+    })
+  ];
+}