refactor: change to litterate config

Configuration is now held by the `.org` files. All `.nix` files are
tangled from the org-mode files.

modules/hardware/input/corne.nix

@@ -1,17 +1,9 @@
 {
   flake.modules.nixos.corne = {
-    lib,
-    config,
-    ...
-  }:
-    with lib; let
-      cfg = config.mySystem.hardware.input.corne;
-    in {
-      options.mySystem.hardware.input.corne.allowHidAccess = mkEnableOption "Enable HID access to the corne keyboard";
-      config.services.udev = mkIf cfg.allowHidAccess {
-        extraRules = ''
-          KERNEL=="hidraw*", SUBSYSTEM=="hidraw", ATTRS{serial}=="*vial:f64c2b3c*", MODE="0660", GROUP="users", TAG+="uaccess", TAG+="udev-acl"
-        '';
-      };
+    services.udev = {
+      extraRules = ''
+        KERNEL=="hidraw*", SUBSYSTEM=="hidraw", ATTRS{serial}=="*vial:f64c2b3c*", MODE="0660", GROUP="users", TAG+="uaccess", TAG+="udev-acl"
+      '';
     };
+  };
 }

modules/hardware/input/corne.org

@@ -0,0 +1,32 @@
+#+title: Corne Keyboard
+#+setupfile: ../../headers
+
+* Corne Keyboard
+I use a Corne (=crkbd=), a small split ergonomic keyboard, flashed with
+[[https://get.vial.today/][Vial]], a QMK-based firmware that lets me remap keys live from a GUI
+instead of having to reflash the keyboard every time I want to tweak
+my layout. Here’s the skeleton of the =nixos.corne= module.
+#+begin_src nix :tangle yes
+{
+  flake.modules.nixos.corne = {
+    <<udev-rule>>
+  };
+}
+#+end_src
+
+** Granting HID Access
+By default, the =hidraw= device nodes created for the keyboard are only
+accessible to root, which means Vial can’t talk to it without running
+as root too. Instead, I add a =udev= rule matching my keyboard’s Vial
+identifier (the part after =vial:= is the keyboard’s unique unlock ID,
+burned into its firmware) and grant the =users= group read/write access
+to it, tagging it for =uaccess= / =udev-acl= so it’s also picked up by the
+logged-in session’s ACLs.
+#+name: udev-rule
+#+begin_src nix
+services.udev = {
+  extraRules = ''
+    KERNEL=="hidraw*", SUBSYSTEM=="hidraw", ATTRS{serial}=="*vial:f64c2b3c*", MODE="0660", GROUP="users", TAG+="uaccess", TAG+="udev-acl"
+  '';
+};
+#+end_src

modules/hardware/input/disable-ibm-trackpoint.nix

@@ -0,0 +1,7 @@
+{
+  flake.modules.nixos.disable-ibm-trackpoint = {
+    services.udev.extraRules = ''
+      ATTRS{name}=="*TPPS/2 IBM TrackPoint", ENV{ID_INPUT}="", ENV{ID_INPUT_MOUSE}="", ENV{ID_INPUT_POINTINGSTICK}=""
+    '';
+  };
+}

modules/hardware/input/disable-ibm-trackpoint.org

@@ -0,0 +1,30 @@
+#+title: Disable the IBM TrackPoint
+#+setupfile: ../../headers
+
+* Disable the IBM TrackPoint
+My ThinkPads come with IBM’s TrackPoint, the little red nub sitting
+between the =G=, =H= and =B= keys. I don’t want it active, though, it has a
+drift and I cannot fix it unless I change my keyboard. Thus, this
+module exposes a way to turn it off. Here’s the skeleton of the
+=nixos.disable-ibm-trackpoint= module.
+#+begin_src nix :tangle yes
+{
+  flake.modules.nixos.disable-ibm-trackpoint = {
+    <<udev-rule>>
+  };
+}
+#+end_src
+
+** Disabling the TrackPoint
+The TrackPoint shows up to the input stack as a regular pointer
+device, so to disable it I can’t simply blacklist a driver — libinput
+and friends would still pick it up through =evdev=. Instead, I match it
+by its device name and clear the =ID_INPUT=, =ID_INPUT_MOUSE= and
+=ID_INPUT_POINTINGSTICK= udev properties on it, which tells the input
+stack to simply ignore the device as a pointing device.
+#+name: udev-rule
+#+begin_src nix
+services.udev.extraRules = ''
+  ATTRS{name}=="*TPPS/2 IBM TrackPoint", ENV{ID_INPUT}="", ENV{ID_INPUT_MOUSE}="", ENV{ID_INPUT_POINTINGSTICK}=""
+'';
+#+end_src

modules/hardware/input/ibm-trackpoint.nix

@@ -1,17 +0,0 @@
-{
-  flake.modules.nixos.ibm-trackpoint = {
-    lib,
-    config,
-    ...
-  }:
-    with lib; let
-      cfg = config.mySystem.hardware.input.ibmTrackpoint;
-    in {
-      options.mySystem.hardware.input.ibmTrackpoint.disable = mkEnableOption "Disable IBM’s trackpoint on ThinkPad";
-      config.services.udev = mkIf cfg.disable {
-        extraRules = ''
-          ATTRS{name}=="*TPPS/2 IBM TrackPoint", ENV{ID_INPUT}="", ENV{ID_INPUT_MOUSE}="", ENV{ID_INPUT_POINTINGSTICK}=""
-        '';
-      };
-    };
-}

modules/hardware/input/opentablet.nix

@@ -1,19 +1,9 @@
 {
   flake.modules.nixos.opentablet = {
-    lib,
-    config,
-    ...
-  }:
-    with lib; let
-      cfg = config.mySystem.hardware.input.opentablet;
-    in {
-      options.mySystem.hardware.input.opentablet.enable = mkEnableOption "Enables OpenTablet drivers";
-      config = mkIf cfg.enable {
-        hardware.opentabletdriver = {
-          inherit (cfg) enable;
-          daemon.enable = true;
-        };
-        boot.kernelModules = ["wacom"];
-      };
+    hardware.opentabletdriver = {
+      enable = true;
+      daemon.enable = true;
     };
+    boot.kernelModules = ["wacom"];
+  };
 }

modules/hardware/input/opentablet.org

@@ -0,0 +1,30 @@
+#+title: OpenTabletDriver
+#+setupfile: ../../headers
+
+* OpenTabletDriver
+Some of my machines are hooked up to a graphics tablet, a Wacom
+Bamboo, driven by [[https://opentabletdriver.net/][OpenTabletDriver]]. I remember buying it for 15€, what
+a deal that was! Anyway, since most of my hosts don’t have a tablet
+attached, this is exposed as a regular toggle rather than enabled
+unconditionally. Here’s the skeleton of the =nixos.opentablet= module.
+#+begin_src nix :tangle yes
+{
+  flake.modules.nixos.opentablet = {
+    <<config>>
+  };
+}
+#+end_src
+
+** Enabling the Driver
+Enabling OpenTabletDriver proper is just a matter of turning on the
+module and its daemon. I also need to explicitly load the =wacom=
+kernel module, since my tablet (like most of them) identifies itself
+as a Wacom device at the hardware level regardless of brand.
+#+name: config
+#+begin_src nix
+hardware.opentabletdriver = {
+  enable = true;
+  daemon.enable = true;
+};
+boot.kernelModules = ["wacom"];
+#+end_src

modules/hardware/input/trackball.org

@@ -0,0 +1,22 @@
+#+title: Trackball
+#+setupfile: ../../headers
+
+* Trackball
+I use a trackball on some of my machines, and I middle-click by
+pressing the left and right buttons together rather than through a
+dedicated button. That’s the only downside of the two trackballs I
+own; otherwise, I can’t recommend one enough. Here’s the
+=nixos.trackball= module enabling this behaviour.
+#+begin_src nix :tangle yes
+{
+  flake.modules.nixos.trackball = {
+    <<middle-emulation>>
+  };
+}
+#+end_src
+
+Enabling middle-click emulation is simple:
+#+name: middle-emulation
+#+begin_src nix
+services.libinput.mouse.middleEmulation = true;
+#+end_src