nixos/hardware: add FreeJoy udev rules

nixos/modules/hardware/freejoy.nix

@@ -0,0 +1,54 @@
+{
+  lib,
+  config,
+  options,
+  ...
+}:
+let
+  cfg = config.hardware.freejoy;
+  opt = options.hardware.freejoy;
+in
+{
+  options.hardware.stlink = {
+    enable = lib.mkEnableOption "udev rules for FreeJoy USB devices";
+    owner = lib.mkOption {
+      type = lib.types.str;
+      default = "root";
+      example = "nobody";
+      description = "Owner of FreeJoy devices";
+    };
+    group = lib.mkOption {
+      type = lib.types.str;
+      default = "plugdev";
+      example = "nobody";
+      description = "Group of FreeJoy devices";
+    };
+    mode = lib.mkOption {
+      type = lib.types.str;
+      default = "0660";
+      example = "0640";
+      description = "Mode of FreeJoy devices";
+    };
+  };
+
+  config = lib.mkMerge [
+    (lib.mkIf cfg.enable {
+      assertions = [
+        {
+          assertion = builtins.hasAttr cfg.owner config.users.users;
+          message = "Owner '${cfg.owner}' set in `${opt.owner}` is not configured via `${options.users.users}.\"${cfg.owner}\"`.";
+        }
+        {
+          assertion = (cfg.group == opt.group.default) || (builtins.hasAttr cfg.group config.users.groups);
+          message = "Group '${cfg.group}' set in `${opt.group}` is not configured via `${options.users.groups}.\"${cfg.group}\"`.";
+        }
+      ];
+      services.udev.extraRules = ''
+        ENV{ID_VENDOR}=="FreeJoy", OWNER="${cfg.owner}", GROUP="${cfg.group}", MODE="${cfg.mode}"
+      '';
+      users.groups.plugdev = lib.mkIf (config.group == "plugdev") { };
+    })
+  ];
+
+  meta.maintainers = with lib.maintainers; [ pandapip1 ];
+}