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

7 files changed, 202 insertions, 0 deletions

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"
diff --git a/roles/hyprland/files/scripts/brightness.sh b/roles/hyprland/files/scripts/brightness.sh
new file mode 100644
index 00000000..10a33d8b
--- /dev/null
+++ b/roles/hyprland/files/scripts/brightness.sh
@@ -0,0 +1,117 @@
+#!/bin/bash
+
+# Original Inspiration:
+#  - https://github.com/basecamp/omarchy/issues/2509
+#  - https://albert.nz/hyprland-brightness
+# ---------------------
+
+# Get focused monitor name
+get_focused_display_name() {
+    hyprctl monitors -j | jq -r '.[] | select(.focused == true) | .name'
+}
+
+# Get focused monitor serial
+get_focused_display_serial() {
+    hyprctl monitors -j | jq -r '.[] | select(.focused == true) | .serial'
+}
+
+set_brightness_ddcutil() {
+    local display_serial="$1"
+    local step="$2"
+    local direction="$3"
+    ddcutil \
+        --noconfig \
+        --skip-ddc-checks \
+        --sleep-multiplier=0.1 \
+        --sn="$display_serial" \
+        setvcp 10 $direction "$step"
+}
+
+set_brightness_brightnessctl() {
+    local step="$1"
+    local direction="$2"
+    brightnessctl set "${step}%${direction}"
+}
+
+get_brightness_ddcutil() {
+    local display_serial="$1"
+    ddcutil \
+        --noconfig \
+        --skip-ddc-checks \
+        --sleep-multiplier=0.1 \
+        --sn="$display_serial" \
+        --terse getvcp 10 \
+        | awk '{print $4}'
+}
+
+get_brightness_brightnessctl() {
+    brightnessctl -m | cut -d, -f4 | sed 's/%//'
+}
+
+
+# Get current brightness for a specific monitor
+get_current_brightness() {
+    local display_name=$(get_focused_display_name)
+    local display_serial=$(get_focused_display_serial)
+    if [ "$display_name" = "eDP-1" ]; then
+        echo "$(get_brightness_brightnessctl)"
+    elif [ -n "$display_serial" ]; then
+        echo "$(get_brightness_ddcutil $display_serial)"
+    else
+        echo "N/A"
+    fi
+}
+
+# Set brightness for a specific monitor
+set_brightness() {
+    local step="$1"
+    local direction="$2"
+    local display_name=$(get_focused_display_name)
+    local display_serial=$(get_focused_display_serial)
+
+    if [ "$display_name" = "eDP-1" ]; then
+        set_brighntess_brightnessctl $step $direction
+    elif [ -n "$display_serial" ]; then
+        set_brightness_ddcutil $display_serial $step $direction
+    else
+        return
+    fi
+
+    notify $display_serial $display_name $(get_current_brightness)
+}
+
+notify() {
+    serial="$1"
+    name="$2"
+    value="$3"
+    notify-send -e \
+        -h string:x-canonical-private-synchronous:brightness-$serial \
+        -u low \
+        "Brightness" \
+        "   $name: $value%"
+}
+
+STEP="${2:-1}"
+case "$1" in
+    "--get")
+        value=$(get_current_brightness)
+        echo "${value}%"
+        ;;
+    "--set")
+        set_brightness $STEP
+        ;;
+    "--inc")
+        set_brightness $STEP +
+        ;;
+    "--dec")
+        set_brightness $STEP -
+        ;;
+    *)
+        echo -e "Usage:"
+        echo -e "  --get          to get current brightness value"
+        echo -e "  --set [arg]    to set current brightness value to [arg]%"
+        echo -e "  --inc [arg]    to increment current brightness value by [arg]%"
+        echo -e "  --dec [arg]    to decrement current brightness value by [arg]%"
+        exit 0
+        ;;
+esac
diff --git a/roles/hyprland/meta/main.yml b/roles/hyprland/meta/main.yml
index 8794e8c6..5ef0b024 100644
--- a/roles/hyprland/meta/main.yml
+++ b/roles/hyprland/meta/main.yml
@@ -6,6 +6,7 @@ dependencies:
   - role: "mako"
   - role: "pipewire"
   - role: "brightnessctl"
+  - role: "ddcutil"
   - role: "font"
   - role: "aur_font"
   - role: "waybar"
diff --git a/roles/hyprland/tasks/main.yml b/roles/hyprland/tasks/main.yml
index 5255a318..fc8c0f29 100644
--- a/roles/hyprland/tasks/main.yml
+++ b/roles/hyprland/tasks/main.yml
@@ -36,6 +36,7 @@
     mode: "0755"
   loop:
     - "/etc/hypr"
+    - "/etc/hypr/scripts"
     - "{{ ansible_facts['env']['HOME'] }}/.config/hypr"
 
 - name: "Configure system defaults"
@@ -89,3 +90,13 @@
         block: |
           # System defaults
           source = /etc/hypr/hypridle.conf
+
+- name: "Copy hyprland scripts"
+  become: true
+  ansible.builtin.copy:
+    src: "{{ item.src }}"
+    dest: "{{ item.dest }}"
+    mode: "0755"
+  loop:
+    - src: "scripts/brightness.sh"
+      dest: "/etc/hypr/scripts/brightness.sh"