# Cooling devices

Source: [https://docs.qualcomm.com/doc/80-70015-30/topic/coolingdevices.html](https://docs.qualcomm.com/doc/80-70015-30/topic/coolingdevices.html)

Cooling devices are the components whose performance can be adjusted to reduce heat
        dissipation. The 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` command 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 Qualcomm Linux |
| `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 the maximum supported mitigation state of the cooling<br>                                device |

The following table lists the CPU cooling devices that the user space module of
            QCS6490/QCS5430 uses 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__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> |

Note: For QCS9075, the list of cooling devices will be
                updated in a future release.

**Parent Topic:** [Interfaces](https://docs.qualcomm.com/doc/80-70015-30/topic/thermal-interfaces.html)

Last Published: Oct 16, 2024

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