#!/usr/bin/perl

$static_speed_low=0x02;
$static_speed_high=0x12;   # This is the speed value at 100% demand
                           # ie what we consider the point we don't
                           # really want to get hotter but still
                           # tolerate.  It's quite a bit of a misnomer
                           # - we keep increasing the speed rapidly
                           # beyond that up to 0xFF if necessary, but
                           # it's perhaps a scaling factor.
$ipmi_inlet_sensorname  ="Inlet Temp";
$ipmi_exhaust_sensorname="Exhaust Temp";

$default_exhaust_threshold=50; # The exhaust temperature we use, set
                               # from above, which we fail back to
                               # letting the drac control the fans
$base_temp     = 26;       # No fans when below this temp
$desired_temp1 = 36;       # Aim to keep the temperature below this
$desired_temp2 = 44;       # Really ramp up fans above this
$desired_temp3 = 50;       # Really ramp up fans above this
$demand1       = 5;        # Prescaled (not taking into effect static_speed_low/high) demand at temp1
$demand2       = 40;       # Prescaled (not taking into effect static_speed_low/high) demand at temp2
$demand3       = 200;      # Prescaled (not taking into effect static_speed_low/high) demand at temp3

$hysteresis    = 2;        # Don't ramp up velocity unless demand
                           # difference is greater than this.  Ramp
                           # down ASAP however, to bias quietness, and
                           # thus end up removing noise changes for
                           # just small changes in computing

# We can optionally just tell all fans to stick to the one speed:
# @daemons=(0xff);
@daemons=qw(0 1 2 3 4 5);

sub custom_temperature_calculation {
  # FIXME: it would be good to share memory between the 6 daemons and
  # not call ipmitool 6 times in parallel just to discard the value of
  # 4 of them.
  #
  # These devices must be present, or the daemon will fail when
  # starting.  Remove them from the calculation if you don't have one
  # (eg, GPU).  I manually worked out roughly which fans correspond to
  # dropping the temperature of each device, by ramping that fan up to
  # a high velocity and observing how quickly the temperature drops.
  #
  # You should manually run `sensors -j` and ensure that every device
  # that has a temperature is somewhow included in the calculation of
  # at least one fan speed.  Note that drivetemp devices may already
  # be included via $*_drives averages below.
  my $gpu       = $sensors_ref->{"amdgpu-pci-0400"}{"edge"}{"temp1_input"};           # 0.2*fan3 + 0.5*fan4 + 0.3*fan5
  my $raid_card = max(raid_controller_temp(),raid_controller_battery_temp());         # fan4+fan5;
  my $left_cpu  = $sensors_ref->{"coretemp-isa-0000"}{"Package id 0"}{"temp1_input"}; # fan2;
  my $right_cpu = $sensors_ref->{"coretemp-isa-0001"}{"Package id 1"}{"temp1_input"}; # fan4;

  # You might want to factor in NVME drives too, that might appear
  # through the `sensors -j` structure as eg:
  # $sensors_ref->{"nvme-pci-0100"}{"temp composite Samsung-EVO-970-1TB"}{"temp1_input"}
  #
  # You might find that while "temp composite Samsung-EVO-970-1TB"
  # (heatsink) is the bit you're cooling, "temp sensor 2
  # Samsung-EVO-970-1TB" (maybe the silicon itself) is uncomfortably
  # higher than the composite reading.  So monitor that hotter sensor
  # instead to add more fan demand.

  # For the drives, there's no need to map each /dev/sd? onto their
  # dynamic positioning inside the chassis.  Just code each path as it
  # maps from /dev/disk/by-path to how it appears on your backplane
  # physically.  I used: `dd if=/dev/disk/by-path/.... of=/dev/null`
  # to work out the pattern that's appropriate to my LFF R730XD (4x3
  # 3.5" drives at front, 2 2.5" drives at rear; hence why I don't
  # know which of 12 and 13 are left or right rear - I can't pull my
  # machine out far enough to watch the blinkenlights).  The averages
  # disregard any drives that are not present or spundown and
  # inaccessible to SMART temperature sensing (the daemon will
  # fallback to idrac control if you define a mapping where one fan
  # doesn't cool *any devices*.  If you were sure there was nothing
  # that could be cooled from that fan (no PCIe cards, no CPU or RAM
  # in right hand socket, no drives on right hand side, no drac, no
  # RAID controller, etc), you could just set weighted_temp to 1 (not
  # 0 - that's still an error).

  # So let's calculate the average temperatures of drives in each
  # vertical arrangement (the rear drives draw their airflow from the
  # two leftmost fans, so just average them).  If you have 2.5" SFF
  # drive backplane, or a 1RU chassis, or..., your calculation will be
  # different.
  my $left_outside_drives =
    average(hddtemp("/dev/disk/by-path/pci-0000:02:00.0-scsi-0:0:0:0"),   # front top SSD
            hddtemp("/dev/disk/by-path/pci-0000:02:00.0-scsi-0:0:1:0"),   # front middle SSD
            hddtemp("/dev/disk/by-path/pci-0000:02:00.0-scsi-0:0:2:0"));  # front bottom HDD
  my $left_middle_drives =
    average(hddtemp("/dev/disk/by-path/pci-0000:02:00.0-scsi-0:0:3:0"),   # front top SSD
            hddtemp("/dev/disk/by-path/pci-0000:02:00.0-scsi-0:0:4:0"),   # front middle HDD
            hddtemp("/dev/disk/by-path/pci-0000:02:00.0-scsi-0:0:5:0"));  # front bottom HDD
  my $right_middle_drives =
    average(hddtemp("/dev/disk/by-path/pci-0000:02:00.0-scsi-0:0:6:0"),   # front top HDD
            hddtemp("/dev/disk/by-path/pci-0000:02:00.0-scsi-0:0:7:0"),   # front middle HDD
            hddtemp("/dev/disk/by-path/pci-0000:02:00.0-scsi-0:0:8:0"));  # front bottom HDD
  my $right_outside_drives =
    average(hddtemp("/dev/disk/by-path/pci-0000:02:00.0-scsi-0:0:9:0"),   # front top HDD
            hddtemp("/dev/disk/by-path/pci-0000:02:00.0-scsi-0:0:10:0"),  # front middle HDD
            hddtemp("/dev/disk/by-path/pci-0000:02:00.0-scsi-0:0:11:0")); # front bottom HDD
  my $rear_drives =
    average(hddtemp("/dev/disk/by-path/pci-0000:02:00.0-scsi-0:0:12:0"),  # rear SSD (left or right? Dunno, just average over both
            hddtemp("/dev/disk/by-path/pci-0000:02:00.0-scsi-0:0:13:0")); # of them, and contribute both to both fan 1 and fan 2)

  if (print_stats_once()) {
    print "gpu=$gpu, raid_card=$raid_card, cpus=$left_cpu, $right_cpu\n";
    print "drives = $left_outside_drives, $left_middle_drives, $right_middle_drives, $right_outside_drives ; $rear_drives\n";
  }

  # My original mapping to spin up all fans in sync was:
  # Two thirds weighted CPU temps vs hdd temps, but if the HDD temps
  # creep above this value, use them exclusively (more important to
  # keep them cool than the CPUs):
  # weighted_temp = max(
  #                   average(average(@cputemps), average(@coretemps), average(@hddtemps)),
  #                       average(@hddtemps));

  # FIXME: probably want to take into account ambient temperature - if
  # the difference between weighted_temp and ambient_temp is small
  # because ambient_temp is large, then less need to run the fans
  # because there's still low power demands, to a point, but
  # eventually we have to keep all components under a threshold, so
  # maybe it makes sense to just ignore ambient_temp.

  # FIXME: better hysteresis function than what's in set_fans_servo()

  # It is more important to keep both SSDs and HDDs cool than CPUs.
  # You can replace cooked CPUs, and they'll throttle before that
  # point anyway.  We could put different offsets or multipliers on
  # them.  As it is here, we weight drives 3 times more important than
  # CPU in the final weighting.

  # Contribution needed from each to cool the drives alone:
  my $fan0_drive_weighted_temp = average($left_outside_drives, $rear_drives);
  my $fan1_drive_weighted_temp = average($left_outside_drives, $left_middle_drives, $rear_drives);
  my $fan2_drive_weighted_temp = $left_middle_drives;
  my $fan3_drive_weighted_temp = $right_middle_drives;
  my $fan4_drive_weighted_temp = average($right_middle_drives, $right_outside_drives);
  my $fan5_drive_weighted_temp = $right_outside_drives;

  my @fan_weighted_temp;

  # Contribution from drives, CPUs, raid controller, GPU:
  $fan_weighted_temp[0] = $fan0_drive_weighted_temp;
  $fan_weighted_temp[1] = $fan1_drive_weighted_temp;
  $fan_weighted_temp[2] = weighted_average(3,$fan2_drive_weighted_temp,                       2,$left_cpu);
  $fan_weighted_temp[3] = weighted_average(3,$fan3_drive_weighted_temp, 1,$gpu);
  $fan_weighted_temp[4] = weighted_average(3,$fan4_drive_weighted_temp, 1,$gpu, 1,$raid_card, 2,$right_cpu);
  $fan_weighted_temp[5] = weighted_average(3,$fan5_drive_weighted_temp, 1,$gpu, 1,$raid_card);

  # Which fans are being controlled by this daemon?  0xff = all fans,
  # 0x00 to 0x05 for individual fans from left to right viewing from the
  # front

  return $fan_weighted_temp[$fans];
}