Thermal Framework —
trip & cooling.

┌──────────────────────────────────────────────────────┐
│                  thermal core                        │
│                                                      │
│  thermal_zone_device   thermal_cooling_device        │
│         │                       │                    │
│    trip_points              cooling ops              │
│         │                       │                    │
│         └───── governor ────────┘                    │
│                (step_wise)                           │
└──────────┬────────────────────────┬─────────────────┘
           │                        │
    ┌──────▼──────┐          ┌──────▼──────┐
    │  Temp Sensor │          │ Cooling Dev │
    │  (NTC/SoC)   │          │(cpufreq/fan)│
    └─────────────┘          └─────────────┘

/ {
    thermal-zones {
        cpu_thermal: cpu-thermal {
            polling-delay-passive = <250>;  /* ms, passive trip kontrolü */
            polling-delay          = <1000>; /* ms, normal polling */

            /* Sıcaklık sensörü */
            thermal-sensors = <&cpu_tsens 0>;

            trips {
                cpu_alert0: cpu-alert-0 {
                    temperature = <70000>;  /* 70°C — milli-celsius */
                    hysteresis  = <2000>;   /* 2°C histerezis */
                    type = "passive";
                };
                cpu_alert1: cpu-alert-1 {
                    temperature = <80000>;  /* 80°C */
                    hysteresis  = <2000>;
                    type = "passive";
                };
                cpu_hot: cpu-hot {
                    temperature = <85000>;  /* 85°C */
                    hysteresis  = <2000>;
                    type = "hot";
                };
                cpu_crit: cpu-crit {
                    temperature = <95000>;  /* 95°C — kritik */
                    hysteresis  = <5000>;
                    type = "critical";
                };
            };

            cooling-maps {
                map0 {
                    trip = <&cpu_alert0>;
                    cooling-device = <&cpu0 THERMAL_NO_LIMIT 2>;
                    /* cooling state 0→2: frekansı %33 düşür */
                };
                map1 {
                    trip = <&cpu_alert1>;
                    cooling-device = <&cpu0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
                    /* maksimum soğutma */
                };
                map2 {
                    trip = <&cpu_alert0>;
                    cooling-device = <&fan0 1 3>;
                    /* fan state 1→3: düşük→yüksek hız */
                };
            };
        };
    };
};

thermal-zones {
    cpu_thermal:   cpu-thermal   { thermal-sensors = <&tsens 0>; ... };
    gpu_thermal:   gpu-thermal   { thermal-sensors = <&tsens 1>; ... };
    board_thermal: board-thermal { thermal-sensors = <&ntc_sensor>;  ... };
};

# cpu-thermal cooling device state'leri
cat /sys/class/thermal/cooling_device0/type
# thermal-cpufreq-0

cat /sys/class/thermal/cooling_device0/max_state
# 4  (4 = en yüksek throttling)

cat /sys/class/thermal/cooling_device0/cur_state
# 0  (şu an throttling yok)

# elle state değiştir (test için)
echo 2 > /sys/class/thermal/cooling_device0/cur_state

fan0: pwm-fan {
    compatible = "pwm-fan";
    pwms = <&pwm1 0 10000 0>;   /* 100Hz PWM */
    #cooling-cells = <2>;
    cooling-levels = <0 64 128 192 255>; /* 5 state: kapalı→tam */
};

# fan cooling device
cat /sys/class/thermal/cooling_device1/type
# pwm-fan

cat /sys/class/thermal/cooling_device1/max_state
# 4

# fan'ı orta hıza al (state 2)
echo 2 > /sys/class/thermal/cooling_device1/cur_state

gpu: gpu@ff300000 {
    compatible = "rockchip,rk3399-mali";
    #cooling-cells = <2>;
    operating-points-v2 = <&gpu_opp_table>;
};

/* thermal zone cooling-map'te */
map_gpu {
    trip = <&cpu_alert1>;
    cooling-device = <&gpu THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
};

# mevcut governor
cat /sys/class/thermal/thermal_zone0/policy
# step_wise

# mevcut seçenekler
cat /sys/class/thermal/thermal_zone0/available_policies
# step_wise fair_share bang_bang user_space

# user_space moduna geç (thermald için)
echo user_space > /sys/class/thermal/thermal_zone0/policy

for each trip_point (high → low sıcaklık):
    if temp >= trip_temp:
        if cur_state < max_state:
            cur_state++          /* bir adım daha soğut */
        break
    else if temp < (trip_temp - hysteresis):
        if cur_state > 0:
            cur_state--          /* bir adım gevşet */

# tüm thermal zone'ları listele
ls /sys/class/thermal/
# cooling_device0  cooling_device1  thermal_zone0  thermal_zone1

# zone0 sıcaklığını oku (milli-Celsius)
cat /sys/class/thermal/thermal_zone0/temp
# 52000  → 52°C

# zone0 tipi
cat /sys/class/thermal/thermal_zone0/type
# cpu-thermal

# trip point'leri oku
cat /sys/class/thermal/thermal_zone0/trip_point_0_temp
# 70000  → 70°C
cat /sys/class/thermal/thermal_zone0/trip_point_0_type
# passive

# tüm zone'ların sıcaklığını tek satırda izle
watch -n1 'for z in /sys/class/thermal/thermal_zone*/; do
    name=$(cat "${z}type" 2>/dev/null)
    temp=$(cat "${z}temp" 2>/dev/null)
    echo "${name}: $((temp/1000))°C"
done'

# cooling device durumu
for cd in /sys/class/thermal/cooling_device*/; do
    type=$(cat "${cd}type")
    cur=$(cat  "${cd}cur_state")
    max=$(cat  "${cd}max_state")
    echo "$type: $cur/$max"
done

# trip_point sıcaklığını değiştir (root gerekli)
echo 75000 > /sys/class/thermal/thermal_zone0/trip_point_0_temp

# thermal zone'u izleme moduna al veya devre dışı bırak
cat /sys/class/thermal/thermal_zone0/mode
# enabled

echo disabled > /sys/class/thermal/thermal_zone0/mode
echo enabled  > /sys/class/thermal/thermal_zone0/mode

# 4 CPU worker ile 60 saniye yükle
stress-ng --cpu 4 --timeout 60s &

# eş zamanlı sıcaklık ve frekans izle
while true; do
    temp=$(cat /sys/class/thermal/thermal_zone0/temp)
    freq=$(cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq)
    cstate=$(cat /sys/class/thermal/cooling_device0/cur_state 2>/dev/null || echo N/A)
    printf "[%s] Temp: %d°C  Freq: %dMHz  CoolState: %s\n" \
        "$(date +%T)" "$((temp/1000))" "$((freq/1000))" "$cstate"
    sleep 1
done

# Ubuntu/Debian
apt install thermald

# thermald başlat
systemctl enable --now thermald

# durum
systemctl status thermald
# ● thermald.service - Thermal Daemon Service
#   Loaded: loaded (/lib/systemd/system/thermald.service)
#   Active: active (running)

# özel thermal konfigürasyon
cat /etc/thermald/thermal-conf.xml
# thermald politikasını özelleştirmek için XML dosyasını düzenle

# debug modu
thermald --no-daemon --loglevel=debug 2>&1 | grep -E "(zone|trip|cool)"

#!/usr/bin/env python3
"""Kernel thermal event'lerini NETLINK üzerinden izle"""
import socket, struct

NETLINK_KOBJECT_UEVENT = 15
sock = socket.socket(socket.AF_NETLINK,
                     socket.SOCK_RAW,
                     NETLINK_KOBJECT_UEVENT)
sock.bind((0, 1))

print("Thermal event'ler bekleniyor...")
while True:
    data = sock.recv(4096).decode('utf-8', errors='ignore')
    if 'thermal' in data.lower() or 'TEMP' in data:
        events = [e for e in data.split('\x00') if e]
        for e in events:
            if any(k in e for k in ['TEMP', 'thermal', 'trip']):
                print(f"  {e}")

# ACPI thermal zone'ları listele
ls /sys/bus/acpi/devices/ | grep TZ
# ACPI0008:00  TZ00  TZ01

# ACPI thermal zone bilgisi
cat /sys/class/thermal/thermal_zone0/type
# acpitz

# acpi_dump ile ACPI tablolarını oku
acpidump | acpixtract -a
iasl -d DSDT.dat
grep -A20 "ThermalZone" DSDT.dsl | head -40

# thermal ACPI event'lerini izle
acpi_listen
# ACPI group thermal PNP0C14:00 0000005c 00000000

CONFIG_THERMAL=y
CONFIG_THERMAL_OF=y                 # Device Tree binding
CONFIG_THERMAL_STATISTICS=y        # sysfs istatistikleri
CONFIG_THERMAL_WRITABLE_TRIPS=y    # sysfs'ten trip değiştirme

# Governor'lar
CONFIG_THERMAL_GOV_STEP_WISE=y
CONFIG_THERMAL_GOV_BANG_BANG=y
CONFIG_THERMAL_GOV_FAIR_SHARE=y
CONFIG_THERMAL_GOV_USER_SPACE=y

# Cooling device'lar
CONFIG_CPU_THERMAL=y               # cpufreq cooling
CONFIG_DEVFREQ_THERMAL=y           # devfreq cooling
CONFIG_THERMAL_EMULATION=y         # test için sıcaklık emülasyonu

# Platform sensor driver'ları
CONFIG_IMX_THERMAL=y               # i.MX6/7/8 TMPMON
CONFIG_ROCKCHIP_THERMAL=y          # RK3368/3399/3568
CONFIG_BCM2711_THERMAL=y           # Raspberry Pi 4

# Harici sensörler (hwmon bridge)
CONFIG_NTC_THERMISTOR=y            # NTC termistör
CONFIG_SENSORS_BD70528=y           # ROHM BD718xx PMIC sensörü

/ {
    /* Sabit voltaj bölücü için */
    ntc_vref: ntc-vref {
        compatible = "voltage-divider";
        io-channels = <&adc 0>;
        output-ohms  = <10000>;     /* pull-up R: 10kΩ */
        full-ohms    = <20000>;     /* tam ölçek R */
    };

    ntc_temp: ntc-thermistor {
        compatible = "epcos,b57891s0103";  /* NTC B57891S0103A010 */
        io-channels = <&ntc_vref>;
        #thermal-sensor-cells = <0>;
    };

    thermal-zones {
        board_thermal: board-thermal {
            thermal-sensors = <&ntc_temp>;
            polling-delay = <5000>;
            trips {
                board_hot {
                    temperature = <60000>;
                    type = "hot";
                    hysteresis = <2000>;
                };
            };
        };
    };
};

# i.MX8 TMPMON thermal zone'ları
ls /sys/class/thermal/
# cooling_device0  thermal_zone0  thermal_zone1

cat /sys/class/thermal/thermal_zone0/type
# imx_thermal_zone

cat /sys/class/thermal/thermal_zone1/type
# imx_thermal_zone

# trip point yapısını oku
for i in 0 1 2; do
    temp=$(cat /sys/class/thermal/thermal_zone0/trip_point_${i}_temp 2>/dev/null)
    type=$(cat /sys/class/thermal/thermal_zone0/trip_point_${i}_type 2>/dev/null)
    echo "trip$i: ${temp}m°C ($((temp/1000))°C) — $type"
done
# trip0: 85000m°C (85°C) — passive
# trip1: 95000m°C (95°C) — hot
# trip2: 105000m°C (105°C) — critical

# cooling zincirini test et (stress ile)
stress-ng --cpu 4 --timeout 120s &
STRESS_PID=$!

while kill -0 $STRESS_PID 2>/dev/null; do
    temp=$(cat /sys/class/thermal/thermal_zone0/temp)
    freq=$(cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq)
    cstate=$(cat /sys/class/thermal/cooling_device0/cur_state)
    echo "[$(date +%T)] ${temp}m°C | ${freq}kHz | cooling_state=$cstate"
    sleep 2
done

# RPi'de iki yöntem: vcgencmd ve sysfs
vcgencmd measure_temp
# temp=52.1'C

cat /sys/class/thermal/thermal_zone0/temp
# 52104

# RPi throttling eşikleri:
# 80°C → CPU freq cap başlar
# 85°C → CPU throttle (1.5GHz → 600MHz)
# 90°C → ARM freq drop
# 95°C → critical

# overtemp LED göstergesi scripti
cat <<'EOF' > /usr/local/bin/thermal_led.sh
#!/bin/bash
TEMP_WARN=75000    # 75°C
TEMP_CRIT=85000    # 85°C
LED=/sys/class/leds/ACT/trigger

while true; do
    temp=$(cat /sys/class/thermal/thermal_zone0/temp)
    if [ "$temp" -ge "$TEMP_CRIT" ]; then
        echo "timer"   > $LED    # hızlı yanıp sönme
        logger -p daemon.warning "CPU CRITICAL TEMP: $((temp/1000))C"
    elif [ "$temp" -ge "$TEMP_WARN" ]; then
        echo "heartbeat" > $LED  # yavaş yanıp sönme
    else
        echo "none" > $LED       # normal
    fi
    sleep 5
done
EOF
chmod +x /usr/local/bin/thermal_led.sh

#!/usr/bin/env python3
"""
Özel thermal policy: sıcaklığa göre fan hızı + CPU freq kombinasyonu.
Gereksinim: thermal_zone0 user_space policy, fan ve cpufreq cooling device.
"""
import time, os, subprocess

ZONE   = "/sys/class/thermal/thermal_zone0"
FAN_CD = "/sys/class/thermal/cooling_device1"   # pwm-fan
CPU_CD = "/sys/class/thermal/cooling_device0"   # cpufreq

def read_temp():
    with open(f"{ZONE}/temp") as f:
        return int(f.read().strip()) // 1000  # °C

def set_cooling(device, state):
    with open(f"{device}/cur_state", 'w') as f:
        f.write(str(state))

def get_max_state(device):
    with open(f"{device}/max_state") as f:
        return int(f.read().strip())

def policy(temp_c):
    """Sıcaklığa göre fan ve CPU state döndür"""
    if   temp_c < 50: return 0, 0        # fan kapalı, CPU tam hız
    elif temp_c < 60: return 1, 0        # fan düşük, CPU normal
    elif temp_c < 70: return 2, 1        # fan orta, CPU hafif throttle
    elif temp_c < 80: return 3, 2        # fan yüksek, CPU throttle
    else:             return 4, 4        # fan max, CPU min

# user_space policy aktifleştir
with open(f"{ZONE}/policy", 'w') as f:
    f.write("user_space")

FAN_MAX = get_max_state(FAN_CD)
CPU_MAX = get_max_state(CPU_CD)

print("Thermal policy başlatıldı")
while True:
    temp = read_temp()
    fan_state, cpu_state = policy(temp)

    # state'leri sınırla
    fan_state = min(fan_state, FAN_MAX)
    cpu_state = min(cpu_state, CPU_MAX)

    set_cooling(FAN_CD, fan_state)
    set_cooling(CPU_CD, cpu_state)

    print(f"[{time.strftime('%H:%M:%S')}] "
          f"Temp={temp}°C  Fan={fan_state}/{FAN_MAX}  "
          f"CPU_throttle={cpu_state}/{CPU_MAX}")
    time.sleep(5)