Simplify PWM and i2c loading using nixos-hardware

flake.nix

@@ -3,24 +3,29 @@
 
   inputs = {
     nixpkgs.url = "nixpkgs/nixos-unstable";
-    agenix.url = "github:ryantm/agenix";
+    agenix = {
-    agenix.inputs.nixpkgs.follows = "nixpkgs";
+      url = "github:ryantm/agenix";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+    nixos-hardware.url = "github:NixOS/nixos-hardware";
   };
 
-  outputs = { self, nixpkgs, agenix, ... }@inputs:
+  outputs = { self, nixpkgs, agenix, nixos-hardware, ... }@inputs:
     let
       system = "aarch64-linux";
 
-      pkgs = import pkgs {
+      pkgs = import pkgs { inherit system; };
-        inherit system;
-      };
 
       lib = nixpkgs.lib;
 
     in {
       nixosConfigurations.zion = lib.nixosSystem {
         inherit system;
-        modules = [ (import ./configuration.nix) agenix.nixosModules.age ];
+        modules = [
+          (import ./configuration.nix)
+          agenix.nixosModules.age
+          nixos-hardware.nixosModules.raspberry-pi-4
+        ];
         specialArgs = { inherit inputs; };
       };
 

modules/device.nix

@@ -15,37 +15,25 @@ with pkgs;
   ];
 
   # Enable SATA-HAT GPIO features
-  boot.loader.grub.enable = false;
+  boot.loader = {
+    grub.enable = false;
+    generic-extlinux-compatible.enable = lib.mkForce false;
+  };
   boot.loader.raspberryPi = {
     enable = true;
     version = 4;
     firmwareConfig = ''
       iomem=relaxed
       strict-devmem=0
-      dtoverlay=pwm-2chan,pin=12,func=4,pin2=13,func2=4
       dtoverlay=w1-gpio
-      dtparam=i2c1=on
     '';
   };
 
-  # Load PWM hardware timers
   boot.kernelModules = [ "pwm_bcm2835" "w1-gpio" "w1-therm" ];
-  hardware.deviceTree = {
+  # Load PWM hardware timers
-    enable = true;
+  hardware.raspberry-pi."4".pwm0.enable = true;
-    filter = "*-rpi-*.dtb";
-    overlays = [
-      {
-        name = "pwm-2chan";
-        dtboFile = "${device-tree_rpi.overlays}/pwm-2chan.dtbo";
-      }
-      {
-        name = "w1-gpio";
-        dtboFile = "${device-tree_rpi.overlays}/w1-gpio.dtbo";
-      }
-    ];
-  };
 
   # Enable I2C
-  hardware.i2c.enable = true;
+  hardware.raspberry-pi."4".i2c1.enable = true;
 
 }

modules/periodic.nix

@@ -30,23 +30,14 @@ in {
   };
 
   # Enable SATA HAT
-  systemd.services.sata-hat = let
+  systemd.services.sata-hat = {
-    overlay-directory =
-      "/boot/nixos/4mamyanz1hlc4wz3c427qjh6rabngwvj-linux-5.10.17-1.20210303-dtbs/overlays/";
-  in {
     description = "Enable software support for SATA Hat";
     wantedBy = [ "zfs-import.target" ];
     script = ''
-      ${pkgs.bash}/bin/bash -c "/etc/nixos/scripts/SATA-hat.sh on"
+      ${pkgs.bash}/bin/bash -c "/home/coolneng/system/scripts/SATA-hat.sh on"
-    '';
-    preStart = ''
-      ${pkgs.libraspberrypi}/bin/dtoverlay -d ${overlay-directory} pwm-2chan pin=12 func=4 pin2=13 func2=4
-      ${pkgs.libraspberrypi}/bin/dtoverlay -d ${overlay-directory} w1-gpio
     '';
     preStop = ''
-      ${pkgs.libraspberrypi}/bin/dtoverlay -r -d ${overlay-directory} pwm-2chan
+      ${pkgs.bash}/bin/bash -c "/home/coolneng/system/scripts/SATA-hat.sh off"
-      ${pkgs.libraspberrypi}/bin/dtoverlay -r -d ${overlay-directory} w1-gpio
-      ${pkgs.bash}/bin/bash -c "/etc/nixos/scripts/SATA-hat.sh off"
     '';
     serviceConfig = {
       Type = "oneshot";