nixos: thinkfan configuration in /etc/nixos/configuration.nix

thinkfan.nix

# Thinkpad T440 

# postconditions:
# 1) status should be enabled:
# cat /proc/acpi/ibm/fan
# 2) No errors in systemd logs:
# journalctl -u thinkfan.service -f

services = {
  thinkfan = {
    enable = true;

    sensors = ''
      # Entries here discovered by:
      # find /sys/devices -type f -name "temp*_input"
      hwmon /sys/devices/platform/coretemp.0/hwmon/hwmon2/temp3_input
      hwmon /sys/devices/platform/coretemp.0/hwmon/hwmon2/temp1_input
      hwmon /sys/devices/platform/coretemp.0/hwmon/hwmon2/temp2_input
      hwmon /sys/devices/virtual/hwmon/hwmon1/temp1_input
    '';

    levels = ''
    (0,     0,      42)
    (1,     40,     47)
    (2,     45,     52)
    (3,     50,     57)
    (4,     55,     62)
    (5,     60,     77)
    (7,     73,     93)
    (127,   85,     32767)
    '';
  };
}