# Cooling devices

Source: [https://docs.qualcomm.com/doc/80-70014-30/topic/coolingdevices.html](https://docs.qualcomm.com/doc/80-70014-30/topic/coolingdevices.html)

Devices whose performance can be controlled to reduce heat dissipation are referred
        to as cooling devices. CPU cores are cooling devices as their performance can be lowered to
        reduce heat dissipation.

For more information on cooling devices, see [index: kernel/git/torvalds/linux.git](https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/thermal/thermal-cooling-devices.yaml?h=v6.6).

The following table lists the `sysfs` commands that describes how to read
            information about cooling devices. 
Note: `<x>`
                in the table represents cooling device ID.

Table : Description of commands for cooling devices

| Commands | Description |
| --- | --- |
| `cat /sys/class/thermal/cooling_device*` | Reads the list of cooling devices on the platform |
| `cat<br>                                    /sys/class/thermal/cooling_device<x>/cur_state` | Reads the existing mitigation state of the cooling device |
| `cat<br>                                    /sys/class/thermal/cooling_device<x>/max_state` | Reads maximum supported mitigation state of the cooling<br>                                device |

The following table lists the CPU cooling devices that the user space module can use for
            CPU frequency mitigation:

Table : Available CPU cooling devices to user space

| Cooling devices | Description |
| --- | --- |
| `cpufreq-cpu<x>` | Cooling devices that can be used to limit the maximum operating<br>                                frequency of the CPU to control CPU temperature.<ul class="ul" id="coolingdevices__ul_ojh_ch5_l1c"><br>                                    <li class="li"><code class="ph codeph">X</code> – cluster CPU number</li><br><br>                                    <li class="li"><code class="ph codeph">cpufreq-cpu0</code> – Silver cluster</li><br><br>                                    <li class="li"><code class="ph codeph">cpufreq-cpu4</code> – Gold cluster</li><br><br>                                    <li class="li"><code class="ph codeph">cpufreq-cpu7</code> – Prime cluster</li><br><br>                                </ul> |

**Parent Topic:** [Interfaces](https://docs.qualcomm.com/doc/80-70014-30/topic/thermal-interfaces.html)

Last Published: Jul 15, 2024

[Previous Topic
Thermal zone](https://docs.qualcomm.com/bundle/publicresource/80-70014-30/topics/thermalzone.md) [Next Topic
Notification to user space](https://docs.qualcomm.com/bundle/publicresource/80-70014-30/topics/notificationtouserspace.md)