Enable rtc wakeup

1 files changed, 45 insertions, 0 deletions

diff --git a/modules/rtc-wakeup.nix b/modules/rtc-wakeup.nix
new file mode 100644
index 0000000..9477838
--- /dev/null
+++ b/modules/rtc-wakeup.nix
@@ -0,0 +1,45 @@
+{ config, lib, pkgs, ... }:
+
+let cfg = config.orbekk.rtc-wakeup;
+in {
+  options = {
+    orbekk.rtc-wakeup = {
+      enable = lib.mkEnableOption "Enable automatic wakeup using rtc";
+      weekdayWakeupTime = lib.mkOption {
+        type = lib.types.str;
+        default = "05:55";
+        description = "Wakeup time on weekdays";
+      };
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    systemd.services.schedule-rtc-wakeup = {
+      description = "Schedule next wakeup time";
+      script = ''
+        if [[ ! $(cat /sys/class/rtc/rtc0/wakealarm) < $(date +%s) ]]; then
+          echo "No need to reschedule. Current alarm:"
+          cat /proc/driver/rtc
+        fi
+
+        if [[ $(date +%w) == "4" ]]; then
+          WAKEUP_TIME='monday ${cfg.weekdayWakeupTime}'
+        else
+          WAKEUP_TIME='tomorrow ${cfg.weekdayWakeupTime}'
+        fi
+
+        date -d "$WAKEUP_TIME" +%s > /sys/class/rtc/rtc0/wakealarm
+        echo "Scheduled wakeup time"
+        cat /proc/driver/rtc
+      '';
+    };
+    systemd.timers.schedule-rtc-wakeup = {
+      wantedBy = [ "multi-user.target" ];
+      timerConfig = {
+        Persistent = true;
+        OnBootSec = "1m";
+        OnUnitActiveSec = "24h";
+      };
+    };
+  };
+}