apple/macbook-pro/12-1: PM: set cpuFreqGovernor and power Up/Down commands (#214)

Co-authored-by: Jörg Thalheim <Mic92@users.noreply.github.com>

apple/macbook-pro/12-1/README.md

@@ -0,0 +1,15 @@
+# MacBook Pro 12,1
+
+## Wireless won't get reconnected after resume/hibernate
+
+The wifi driver is unloaded before suspend/hibernate to workaround driver issues.
+This means it might be required to restart your wifi deamon i.e. wpa_supplicant:
+
+```nix
+powerManagement.powerUpCommands = ''
+  ${pkgs.systemd}/bin/systemctl restart wpa_supplicant.service
+'';
+};
+```
+
+You can apply this to your network management software of choice.

apple/macbook-pro/12-1/default.nix

@@ -1,4 +1,4 @@
-{ lib, ... }:
+{ lib, pkgs, ... }:
 
 {
   imports = [
@@ -7,6 +7,17 @@
     <nixpkgs/nixos/modules/hardware/network/broadcom-43xx.nix>
   ];
 
+  powerManagement = {
+    # enable gradually increasing/decreasing CPU frequency, rather than using
+    # "powersave", which would keep CPU frequency at 0.8GHz.
+    cpuFreqGovernor = lib.mkDefault "conservative";
+
+    # brcmfmac being loaded during hibernation would not let a successful resume
+    # https://bugzilla.kernel.org/show_bug.cgi?id=101681#c116
+    powerUpCommands = lib.mkBefore "${pkgs.kmod}/bin/modprobe brcmfmac";
+    powerDownCommands = lib.mkBefore "${pkgs.kmod}/bin/rmmod brcmfmac";
+  };
+
   # USB subsystem wakes up MBP right after suspend unless we disable it.
   services.udev.extraRules = lib.mkDefault ''
     SUBSYSTEM=="pci", KERNEL=="0000:00:14.0", ATTR{power/wakeup}="disabled"