From 89773438b6583dd1dcaf33ad6d581eee697246f2 Mon Sep 17 00:00:00 2001
From: Ahmed Abdelhalim <pm@a14m.dev>
Date: Mon, 9 Feb 2026 19:00:45 +0100
Subject: Add brightness control using ddcutil to hyprland

The ddcutil is really slow by design and needing to wait the recommended
40-200ms after each request to get the response according to the ddc
protocol specifications.

For now this is a working draft, might switch to ddccontrol which is
much faster but limited to communicate over /dev/<id> which can't be
figured automatically or correlated with hyprctl monitors command
---
 roles/ddcutil/handlers/main.yml       | 12 +++++++++++
 roles/ddcutil/meta/argument_specs.yml |  6 ++++++
 roles/ddcutil/meta/main.yml           | 17 ++++++++++++++++
 roles/ddcutil/tasks/main.yml          | 38 +++++++++++++++++++++++++++++++++++
 4 files changed, 73 insertions(+)
 create mode 100644 roles/ddcutil/handlers/main.yml
 create mode 100644 roles/ddcutil/meta/argument_specs.yml
 create mode 100644 roles/ddcutil/meta/main.yml
 create mode 100644 roles/ddcutil/tasks/main.yml

(limited to 'roles/ddcutil')

diff --git a/roles/ddcutil/handlers/main.yml b/roles/ddcutil/handlers/main.yml
new file mode 100644
index 00000000..85720137
--- /dev/null
+++ b/roles/ddcutil/handlers/main.yml
@@ -0,0 +1,12 @@
+---
+- name: "Reload rules"
+  become: true
+  ansible.builtin.command:
+    cmd: "udevadm control --reload-rules"
+  changed_when: true
+
+- name: "Trigger rules"
+  become: true
+  ansible.builtin.command:
+    cmd: "udevadm trigger"
+  changed_when: true
diff --git a/roles/ddcutil/meta/argument_specs.yml b/roles/ddcutil/meta/argument_specs.yml
new file mode 100644
index 00000000..09847b93
--- /dev/null
+++ b/roles/ddcutil/meta/argument_specs.yml
@@ -0,0 +1,6 @@
+---
+argument_specs:
+  main:
+    short_description: "Install ddcutil on Linux distribution"
+    description: "Install ddcutil on Linux distribution"
+    options: {}
diff --git a/roles/ddcutil/meta/main.yml b/roles/ddcutil/meta/main.yml
new file mode 100644
index 00000000..025d3e11
--- /dev/null
+++ b/roles/ddcutil/meta/main.yml
@@ -0,0 +1,17 @@
+---
+dependencies: []
+galaxy_info:
+  author: "a14m"
+  description: "Install ddcutil"
+  license: "MIT"
+  min_ansible_version: "2.18"
+  platforms:
+    - name: "ArchLinux"
+      versions:
+        - "all"
+    - name: "Ubuntu"
+      versions:
+        - "noble"
+    - name: "Debian"
+      versions:
+        - "bookworm"
diff --git a/roles/ddcutil/tasks/main.yml b/roles/ddcutil/tasks/main.yml
new file mode 100644
index 00000000..feef8683
--- /dev/null
+++ b/roles/ddcutil/tasks/main.yml
@@ -0,0 +1,38 @@
+---
+- name: "Ensure ddcutil is installed"
+  become: true
+  ansible.builtin.package:
+    name: "ddcutil"
+    state: "present"
+
+- name: "Ensure kernel module is loaded on boot"
+  become: true
+  ansible.builtin.copy:
+    dest: "/etc/modules-load.d/i2c.conf"
+    mode: "0644"
+    content: |
+      i2c-dev
+
+- name: "Ensure i2c group is created"
+  become: true
+  ansible.builtin.group:
+    name: "i2c"
+    state: "present"
+
+- name: "Ensure $USER is added to i2c group"
+  become: true
+  ansible.builtin.user:
+    name: "{{ ansible_facts['env']['USER'] }}"
+    groups: "i2c"
+    append: true
+
+- name: "Create udev rule for i2c device permissions"
+  become: true
+  ansible.builtin.copy:
+    dest: "/etc/udev/rules.d/99-i2c.rules"
+    mode: "0644"
+    content: |
+      KERNEL=="i2c-[0-9]*", GROUP="i2c", MODE="0660"
+  notify:
+    - "Reload rules"
+    - "Trigger rules"
-- 
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