[omarchy] Adopt ALS brightness daemon

[stevederico]

Pick one ALS auto-brightness daemon for Omarchy Mac and ship it. Kernel ALS is already in this tree. This is userspace policy: read lux, write apple-panel-bl (and maybe kbd_backlight) without fighting Hyprland's OSD.

The original tracker named asahi-brightnessd vs asahi-brightness. Those exact project names were not found as public repos or packages in this audit (2026-09-03). Do not pretend they are. Evaluate the daemons that actually exist, then adopt one.

Current state

Kernel, this tree:

• CONFIG_IIO_AOP_SENSOR_ALS=m and CONFIG_IIO_AOP_SENSOR_LAS=m in arch/arm64/configs/asahi.config.
• Driver: drivers/iio/common/aop_sensors/ (IIO_AOP_SENSOR_ALS).
• Calibration firmware apple/aop-als-cal.bin is extracted from macOS (Asahi installer / m1n1). Without it, lux reads 0 and the daemon is useless. Asahi 7.0 progress report: installer can refresh firmware; missing cal was the webcam-class footgun.
• Internal panel backlight is apple-panel-bl (dcp_backlight.c). Keyboard backlight is the kbd_backlight LED (PWM, see T8132 board files; M1/M2 have the same).

Daemons that exist (evaluate these):

Project	What it does	Desktop
juicecultus/asahi-auto-brightness	IIO sysfs lux → KDE ScreenBrightness D-Bus (SuppressIndicator). VD6286, tested J415 M2 Air.	KDE Plasma 6
omarchy-mac#303	User service: IIO illuminance → kbd_backlight LED (on in the dark, off in bright rooms). ExecCondition if hardware missing. Verified M2 Max apple,j414c. Keyboard only, not the panel.	Omarchy / systemd
max-baz/wluma	Wayland; ALS + screen contents. IIO or a socket.	Generic Wayland
KDE powerdevil ALS	Built-in, historically weak on Asahi (reason juicecultus exists).	KDE

Omarchy Mac is Hyprland + Quickshell, not KDE. A KDE-D-Bus daemon will not drive the panel there. That eliminates asahi-auto-brightness as a drop-in unless someone writes a Hyprland/brightnessctl backend.

Omarchy already has manual brightness keys. Collision with a daemon must be designed (manual override / hysteresis), or users will fight the slider.

Gap

1. Confirm ALS node: /sys/bus/iio/devices/iio:deviceN/in_illuminance_raw (name varies). Confirm aop-als-cal.bin is present on Omarchy Mac installs.
2. Choose one:
   • Extend omarchy-mac#303 to also write apple-panel-bl (smallest, already in the distro's style).
   • Package wluma with an IIO ALS source and Hyprland.
   • Write a 50-line systemd service: read IIO, brightnessctl --device=apple-panel-bl. Mark // yagni if it stays that small.
3. Do not ship two daemons.
4. Do not dim the Touch Bar (228600000.dsi.0). Same trap as [display] Brightness into Omarchy stack #71/Cannot seem to assign static IP AsahiLinux/linux#31.
5. If the original asahi-brightnessd/asahi-brightness repos turn up, re-evaluate; they were not locatable here.

Hardware

Needs an M1/M2 laptop with AOP ALS, after #69/AsahiLinux#30. No measurements on this fork.

Quick probe (when a machine exists):

ls /sys/bus/iio/devices/*/in_illuminance*
ls /lib/firmware/apple/aop-als-cal.bin
ls /sys/class/backlight/

Cover the webcam/ALS; lux should drop. If it stays 0, calibration is missing, not the daemon.

First steps

1. On an Omarchy Mac laptop, run the probe above. Attach paths.
2. Read omarchy-mac#303 and HDMI output doesn't seem to work, Macbook Pro M1 AsahiLinux/linux#219. Reuse their unit style.
3. Prototype panel control with brightnessctl --device=apple-panel-bl driven from a lux script. If that feels like macOS, package it. If not, try wluma.
4. Document the calibration-firmware step in Omarchy (re-run Asahi installer from macOS if lux is stuck at 0).

Done when

• One daemon is in the Omarchy Mac image, enabled only when IIO illuminance and apple-panel-bl exist.
• Manual brightness keys still win until the next large lux change (or a documented policy).
• Keyboard backlight policy is either that same daemon or HDMI port fails to output display signal after a resume AsahiLinux/linux#303, not a third service.
• This issue names the chosen project and the package name.

External WIP

• Status: external-WIP (daemon)
• Who: chaos_princess — AOP ALS + calibration firmware (Asahi 7.0). juicecultus/asahi-auto-brightness is a userspace option.
• Where: https://asahilinux.org/2026/04/progress-report-7-0/ ; https://github.com/juicecultus/asahi-auto-brightness
• Ours: package for Omarchy, do not rewrite the sensor driver.

Related

• [display] Brightness into Omarchy stack #71 Studio Display brightness (USB, no ALS)
• [omarchy] Package Touch Bar stack #74 Touch Bar backlight collision
• [omarchy] Test kernel under Omarchy Mac #73 Omarchy test
• [soc] Battery performance and power management #78 battery (ALS is not a power fix; idle is)

Sources

• This tree: CONFIG_IIO_AOP_SENSOR_ALS, dcp_backlight.c
• juicecultus/asahi-auto-brightness: https://github.com/juicecultus/asahi-auto-brightness
• ALS (Ambient Light Sensor) working on M2 MacBook Air — calibration extraction & auto-brightness AsahiLinux/docs#248: ALS (Ambient Light Sensor) working on M2 MacBook Air — calibration extraction & auto-brightness AsahiLinux/docs#248
• omarchy-mac#303: Drive keyboard backlight from the ambient light sensor omacom/omarchy-mac#303
• omarchy-mac#219: Prefer the DCP panel backlight on Apple Silicon Macs omacom/omarchy-mac#219
• Asahi Progress Report 7.0 (ALS calibration firmware): https://asahilinux.org/2026/04/progress-report-7-0/
• Deleted todo.md: "asahi-brightnessd vs asahi-brightness" — names not found as public repos in this audit