dtsoverlays

modules/nixos/hardware/raspberry-pi/pwm.nix

@@ -0,0 +1,26 @@
+{ config, lib, pkgs, namespace, ... }:
+let
+  cfg = config.${namespace}.hardware.raspberry-pi.pwm;
+  variant = config.${namespace}.hardware.raspberry-pi.variant;
+in
+{
+  options.${namespace}.hardware.raspberry-pi.pwm = {
+    enable = lib.mkEnableOption "enable pwm dt overlay";
+  };
+
+  config = lib.mkIf cfg.enable {
+    hardware.deviceTree = {
+      overlays = [
+        {
+          name = "enable-pwm";
+          filter = (if (variant == "5") then "*pi5*" else "*rpi-4-b*");
+          dtsFile = (
+            if (variant == "5") 
+            then "${pkgs.${namespace}.raspberrypi-overlays}/share/raspberrypi-overlays/pwm-pio-rp1.dts" 
+            else "${pkgs.${namespace}.raspberrypi-overlays}/share/raspberrypi-overlays/pwm1-overlay.dts"
+          );
+        }
+      ];
+    };
+  };
+}