refactor: split modemmanager stuff into own file

hosts/by-name/moby/default.nix

@@ -116,14 +116,6 @@
   # enable rotation sensor
   hardware.sensor.iio.enable = true;
 
-  # TODO: move elsewhere...
-  systemd.services.ModemManager.serviceConfig = {
-    # N.B.: the extra "" in ExecStart serves to force upstream ExecStart to be ignored
-    ExecStart = [ "" "${pkgs.modemmanager}/bin/ModemManager --debug" ];
-    # --debug sets DEBUG level logging: so reset
-    ExecStartPost = [ "${pkgs.modemmanager}/bin/mmcli --set-logging=INFO" ];
-  };
-
   services.udev.extraRules = let
     chmod = "${pkgs.coreutils}/bin/chmod";
     chown = "${pkgs.coreutils}/bin/chown";
@@ -134,8 +126,5 @@
 
     # make Pinephone front LEDs writable by user.
     SUBSYSTEM=="leds", DEVPATH=="*/*:indicator", RUN+="${chmod} g+w /sys%p/brightness", RUN+="${chown} :video /sys%p/brightness"
-
-    # make Modem controllable by user
-    DRIVER=="modem-power", RUN+="${chmod} g+w /sys%p/powered", RUN+="${chown} :networkmanager /sys%p/powered"
   '';
 }

hosts/common/programs/default.nix

@@ -74,6 +74,7 @@
     ./megapixels.nix
     ./mepo.nix
     ./mimeo
+    ./modemmanager.nix
     ./mopidy.nix
     ./mpv
     ./msmtp.nix

hosts/common/programs/eg25-control.nix

@@ -1,9 +1,11 @@
-{ config, lib, ... }:
+{ config, lib, pkgs, ... }:
 let
   cfg = config.sane.programs.eg25-control;
 in
 {
   sane.programs.eg25-control = {
+    suggestedPrograms = [ "modemmanager" ];
+
     services.eg25-control-powered = {
       description = "eg25-control-powered: power to the Qualcomm eg25 modem used by PinePhone";
       startCommand = "eg25-control --power-on --verbose";
@@ -45,6 +47,7 @@ in
     requires = [ "network-online.target" ];
     # wantedBy = [ "network-online.target" ]; # auto-start immediately after boot
   };
+
   users = lib.mkIf cfg.enabled {
     groups.eg25-control = {};
     users.eg25-control = {
@@ -61,4 +64,11 @@ in
     # to persist agps data, i think.
     { user = "eg25-control"; group = "eg25-control"; path = "/var/lib/eg25-control"; }
   ];
+  services.udev.extraRules = let
+    chmod = "${pkgs.coreutils}/bin/chmod";
+    chown = "${pkgs.coreutils}/bin/chown";
+  in ''
+    # make Modem controllable by user
+    DRIVER=="modem-power", RUN+="${chmod} g+w /sys%p/powered", RUN+="${chown} :networkmanager /sys%p/powered"
+  '';
 }

hosts/common/programs/modemmanager.nix

@@ -0,0 +1,18 @@
+{ config, lib, pkgs, ... }:
+let
+  cfg = config.sane.programs.modemmanager;
+in
+{
+  sane.programs.modemmanager = {};
+
+  systemd.services.ModemManager = lib.mkIf cfg.enabled {
+    serviceConfig = {
+      # only if started with `--debug` does mmcli let us issue AT commands like
+      # `mmcli --modem any --command=<AT_CMD>`
+      # N.B.: the extra "" in ExecStart serves to force upstream ExecStart to be ignored
+      ExecStart = [ "" "${pkgs.modemmanager}/bin/ModemManager --debug" ];
+      # --debug sets DEBUG level logging: so reset
+      ExecStartPost = [ "${pkgs.modemmanager}/bin/mmcli --set-logging=INFO" ];
+    };
+  };
+}