Write iptsd configuration file.

microsoft/surface/common/ipts/default.nix

@@ -1,18 +1,39 @@
 { config, lib, pkgs, ... }:
 
 let
-  inherit (lib) mkDefault mkEnableOption mkIf mkMerge;
+  inherit (lib) mkDefault mkEnableOption mkIf mkMerge mkOption types;
 
   cfg = config.microsoft-surface.ipts;
 
-in {
+  iptsConfFile = pkgs.writeTextFile {
+    name = "iptsd.conf";
+    text = lib.generators.toINI { } cfg.config;
+  };
+
+in
+{
   options.microsoft-surface.ipts = {
     enable = mkEnableOption "Enable IPTSd for Microsoft Surface";
+
+    config = mkOption {
+      type = types.attrs;
+      default = { };
+      description = ''
+        Values to wrote to iptsd.conf, first key is section, second key is property.
+        See the example config; https://github.com/linux-surface/iptsd/blob/v1.4.0/etc/iptsd.conf
+      '';
+      example = ''
+        DFT = {
+          ButtonMinMag = 1000;
+        };
+      '';
+    };
   };
 
   config = mkMerge [
     {
       microsoft-surface.ipts.enable = mkDefault false;
+
     }
 
     (mkIf cfg.enable {
@@ -22,6 +43,8 @@ in {
         script = "iptsd $(iptsd-find-hidraw)";
         wantedBy = [ "multi-user.target" ];
       };
+
+      environment.etc."iptsd/iptsd.conf".source = "${iptsConfFile}";
     })
   ];
 }