system: add gps module

system/hardware/default.nix

@@ -6,5 +6,6 @@
     ./opengl.nix
     ./sound.nix
     ./binfmt.nix
+    ./gps.nix
   ];
 }

system/hardware/gps.nix

@@ -0,0 +1,48 @@
+{ config, lib, pkgs, ... }:
+let
+  cfg = config.nixfiles.hardware.gps;
+in
+{
+  options = {
+    nixfiles.hardware.gps = {
+      enable = lib.mkEnableOption "GPS configuration";
+      gpsdBridge = lib.mkOption {
+        description = "Whether to enable bridging of gpsd data to Geoclue2";
+        default = true;
+        example = false;
+        type = lib.types.bool;
+      };
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    services.geoclue2 = {
+      enable = true;
+    };
+
+    environment.etc."geoclue/conf.d/00-nmea-socket.conf".text = lib.mkIf cfg.gpsdBridge ''
+      [network-nmea]
+      enable=true
+      nmea-socket=/run/gpsd-nmea/nmea.sock
+    '';
+
+    # this could probably be a systemd socket but i don't know how to make those
+    systemd.services.gpsd-nmea-bridge = lib.mkIf cfg.gpsdBridge {
+        path = with pkgs; [
+          gpsd
+          coreutils
+          socat
+        ];
+        description = "gpsd to Geoclue2 GPS data bridge";
+        before = [ "geoclue.service" ];
+        wantedBy = [ "geoclue.service" "multi-user.target" ];
+        serviceConfig = {
+          RuntimeDirectory = "gpsd-nmea";
+          ExecStart = pkgs.writeShellScript "gpsd-nmea-bridge" "
+            exec socat -U UNIX-LISTEN:\${RUNTIME_DIRECTORY}/nmea.sock,fork,reuseaddr,mode=777 SYSTEM:'gpspipe -Br | stdbuf -oL tail -n+4'
+            ";
+        };
+      };
+    services.gpsd.enable = lib.mkIf cfg.gpsdBridge true;
+  };
+}