nixos: Added libinput configuration

like there was for synaptics

nixos/modules/module-list.nix

@@ -437,6 +437,7 @@
   ./services/x11/display-managers/lightdm.nix
   ./services/x11/display-managers/sddm.nix
   ./services/x11/display-managers/slim.nix
+  ./services/x11/hardware/libinput.nix
   ./services/x11/hardware/multitouch.nix
   ./services/x11/hardware/synaptics.nix
   ./services/x11/hardware/wacom.nix

nixos/modules/services/x11/hardware/libinput.nix

@@ -0,0 +1,125 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let cfg = config.services.xserver.libinput;
+in {
+
+  options = {
+
+    services.xserver.libinput = {
+
+      enable = mkOption {
+        type = types.bool;
+        default = false;
+        example = true;
+        description = "Whether to enable libinput support.";
+      };
+
+      dev = mkOption {
+        type = types.nullOr types.str;
+        default = null;
+        example = "/dev/input/event0";
+        description =
+          ''
+            Path for touchpad device.  Set to null to apply to any
+            auto-detected touchpad.
+          '';
+      };
+
+      accelSpeed = mkOption {
+        type = types.nullOr types.string;
+        default = null;
+        description = "Cursor acceleration (how fast speed increases from minSpeed to maxSpeed).";
+      };
+
+      buttonMapping = mkOption {
+        type = types.nullOr types.string;
+        default = null;
+        description =
+          ''
+            Sets the logical button mapping for this device, see XSetPointerMapping(3). The string  must
+            be  a  space-separated  list  of  button mappings in the order of the logical buttons on the
+            device, starting with button 1.  The default mapping is "1 2 3 ... 32". A mapping of 0 deac‐
+            tivates the button. Multiple buttons can have the same mapping.  Invalid mapping strings are
+            discarded and the default mapping is used for all buttons.  Buttons  not  specified  in  the
+            user's mapping use the default mapping. See section BUTTON MAPPING for more details.
+          '';
+      };
+
+      calibrationMatrix = mkOption {
+        type = types.nullOr types.string;
+        default = null;
+        description =
+          ''
+            A  string  of  9 space-separated floating point numbers.  Sets the calibration matrix to the
+            3x3 matrix where the first row is (abc), the second row is (def) and the third row is (ghi).
+          '';
+      };
+
+      tapping = mkOption {
+        type = types.bool;
+        default = true;
+        example = false;
+        description =
+          ''
+            Enables or disables tap-to-click behavior.
+          '';
+      };
+
+      tappingDragLock = mkOption {
+        type = types.bool;
+        default = true;
+        example = false;
+        description =
+          ''
+            Enables or disables drag lock during tapping behavior. When enabled, a finger up during tap-
+            and-drag will not immediately release the button. If the finger is set down again within the
+            timeout, the draging process continues.
+          '';
+      };
+
+
+      additionalOptions = mkOption {
+        type = types.str;
+        default = "";
+        example = ''
+          Option "RTCornerButton" "2"
+          Option "RBCornerButton" "3"
+        '';
+        description = ''
+          Additional options for libinput touchpad driver.
+        '';
+      };
+
+    };
+
+  };
+
+
+  config = mkIf cfg.enable {
+
+    services.xserver.modules = [ pkgs.xorg.xf86inputlibinput ];
+
+    environment.systemPackages = [ pkgs.xorg.xf86inputlibinput ];
+
+    services.xserver.config =
+      ''
+        # Automatically enable the libinput driver for all touchpads.
+        Section "InputClass"
+          Identifier "libinputConfiguration"
+          MatchIsTouchpad "on"
+          ${optionalString (cfg.dev != null) ''MatchDevicePath "${cfg.dev}"''}
+          Driver "libinput"
+          ${optionalString (cfg.accelSpeed != null) ''Option "AccelSpeed" "${cfg.accelSpeed}"''}
+          ${optionalString (cfg.buttonMapping != null) ''Option "ButtonMapping" "${cfg.buttonMapping}"''}
+          ${optionalString (cfg.calibrationMatrix != null) ''Option "CalibrationMatrix" "${cfg.calibrationMatrix}"''}
+          ${if cfg.tapping then ''Option "Tapping" "1"'' else ""}
+          ${if cfg.tappingDragLock then ''Option "TappingDragLock" "1"'' else ""}
+          ${cfg.additionalOptions}
+        EndSection
+      '';
+
+  };
+
+}