displaylink service: init

(cherry picked from commit bc493ccfcc)

nixos/modules/hardware/video/displaylink.nix

@@ -0,0 +1,61 @@
+{ config, lib, ... }:
+
+with lib;
+
+let
+
+  enabled = elem "displaylink" config.services.xserver.videoDrivers;
+
+  displaylink = config.boot.kernelPackages.displaylink;
+
+in
+
+{
+
+  config = mkIf enabled {
+
+    boot.extraModulePackages = [ displaylink ];
+
+    boot.kernelModules = [ "evdi" ];
+
+    # Those are taken from displaylink-installer.sh and from Arch Linux AUR package.
+
+    services.udev.extraRules = ''
+      ACTION=="add", SUBSYSTEM=="usb", ATTR{idVendor}=="17e9", ATTR{bNumInterfaces}=="*5", TAG+="uaccess"
+    '';
+
+    powerManagement.powerDownCommands = ''
+      #flush any bytes in pipe
+      while read -n 1 -t 1 SUSPEND_RESULT < /tmp/PmMessagesPort_out; do : ; done;
+
+      #suspend DisplayLinkManager
+      echo "S" > /tmp/PmMessagesPort_in
+
+      #wait until suspend of DisplayLinkManager finish
+      read -n 1 -t 10 SUSPEND_RESULT < /tmp/PmMessagesPort_out
+    '';
+
+    powerManagement.resumeCommands = ''
+      #resume DisplayLinkManager
+      echo "R" > /tmp/PmMessagesPort_in
+    '';
+
+    systemd.services.displaylink = {
+      description = "DisplayLink Manager Service";
+      after = [ "display-manager.service" ];
+      wantedBy = [ "graphical.target" ];
+
+      serviceConfig = {
+        ExecStart = "${displaylink}/bin/DisplayLinkManager";
+        Restart = "always";
+        RestartSec = 5;
+      };
+
+      preStart = ''
+        mkdir -p /var/log/displaylink
+      '';
+    };
+
+  };
+
+}

nixos/modules/module-list.nix

@@ -40,6 +40,7 @@
   ./hardware/video/amdgpu.nix
   ./hardware/video/ati.nix
   ./hardware/video/bumblebee.nix
+  ./hardware/video/displaylink.nix
   ./hardware/video/nvidia.nix
   ./hardware/video/webcam/facetimehd.nix
   ./i18n/input-method/default.nix