refac(boar): DDCCI loading (but no cigar yet)

home/i3/default.nix

@@ -378,7 +378,7 @@ in {
           # See https://discourse.nixos.org/t/brightness-control-of-external-monitors-with-ddcci-backlight/8639/10
           # For some reason this has to run from userland, after the xSession is started
           {
-            command = "sudo /home/farlion/code/nixos-config/home/xsession/boar_ddc_fix.sh";
+            command = "sudo /home/farlion/code/nixos-config/home/xsession/boar_ddcci_fix.sh";
             notification = false;
           }
         ];

home/i3status-rust.nix

@@ -243,7 +243,7 @@ in {
             # }
             {
               block = "backlight";
-              device = "ddcci5";
+              device = "ddcci0";
               click = [
                 {
                   button = "left";

home/xsession/boar_ddcci_fix.sh

@@ -0,0 +1,28 @@
+#! /run/current-system/sw/bin/bash
+set -euo pipefail
+
+# See https://discourse.nixos.org/t/brightness-control-of-external-monitors-with-ddcci-backlight/8639/10
+
+sleep 5
+
+echo Trying to attach ddcci to i2c-7
+counter=10
+while [ $counter -gt 0 ]; do
+	if ddcutil getvcp 10 -b 7; then
+		echo ddcci 0x37 >/sys/bus/i2c/devices/i2c-7/new_device
+		break
+	fi
+	sleep 1
+	counter=$((counter - 1))
+done
+
+# echo Trying to attach ddcci to i2c-5
+# counter=10
+# while [ $counter -gt 0 ]; do
+# 	if ddcutil getvcp 10 -b 5; then
+# 		echo ddcci 0x37 >/sys/bus/i2c/devices/i2c-5/new_device
+# 		break
+# 	fi
+# 	sleep 1
+# 	counter=$((counter - 1))
+# done

machines/boar/system.nix

@@ -1,6 +1,7 @@
 {
   lib,
   config,
+  pkgs,
   ...
 }: {
   # Use the systemd-boot EFI boot loader.
@@ -13,12 +14,18 @@
   # External monitors brightness control
   # See https://discourse.nixos.org/t/brightness-control-of-external-monitors-with-ddcci-backlight/8639/11
   boot.extraModulePackages = with config.boot.kernelPackages; [ddcci-driver];
+  boot.initrd.kernelModules = ["ddcci_backlight"];
+  environment.systemPackages = [pkgs.ddcutil];
+  services.ddccontrol.enable = true;
+  hardware.i2c.enable = true;
+  users.users.farlion.extraGroups = ["i2c"];
+
   security.sudo.extraRules = [
     {
       users = ["farlion"];
       commands = [
         {
-          command = "/home/farlion/code/nixos-config/home/xsession/boar_ddc_fix.sh";
+          command = "/home/farlion/code/nixos-config/home/xsession/boar_ddcci_fix.sh";
           options = ["NOPASSWD" "SETENV"];
         }
       ];

packages/default.nix

@@ -24,7 +24,6 @@
   cht-sh
   cntr # for Nix sandbox breakpointHook debugging
   dconf
-  ddcutil # For external monitor management, used by home/xsession/boar_ddc_fix.sh
   delta # Syntax highlighter for git
   unstable.devenv
   difftastic

system/screens.nix

@@ -1,9 +1,4 @@
-{pkgs, ...}: {
-  # Controlling external screens
-  services.ddccontrol.enable = true;
-  hardware.i2c.enable = true;
-  users.users.farlion.extraGroups = ["i2c"];
-
+{...}: {
   # For redshift
   services.geoclue2.enable = true;
 }