# Cooling devices

The performance of some of the components can be adjusted to reduce heat dissipation. These components are considered as cooling devices. 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 /sys/class/thermal/cooling_device<x>/cur_state` | Reads the existing mitigation state of the cooling device |
| `cat /sys/class/thermal/cooling_device<x>/max_state` | Reads the maximum supported mitigation state of the cooling<br>device |

Tab QCS6490/QCS5430
Tab QCS9075

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 for QCS6490/QCS5430

| Cooling devices | Description |
| --- | --- |
| `cpufreq-cpu<x>` | Cooling devices that are used to limit the maximum operating<br>frequency of the CPU to control CPU temperature.<br><br><ul class="simple"><br><li><p><code class="docutils literal notranslate"><span class="pre">X</span></code> – cluster CPU number</p></li><br><li><p><code class="docutils literal notranslate"><span class="pre">cpufreq-cpu0</span></code> – Silver cluster</p></li><br><li><p><code class="docutils literal notranslate"><span class="pre">cpufreq-cpu4</span></code> – Gold cluster</p></li><br><li><p><code class="docutils literal notranslate"><span class="pre">cpufreq-cpu7</span></code> – Prime cluster</p></li><br></ul> |

The following table lists the CPU cooling devices that the user space module of QCS9075 uses for CPU frequency mitigation:

Table : Available CPU cooling devices to user space for QCS6490/QCS5430

| Cooling devices | Description |
| --- | --- |
| `cpufreq-cpu<x>` | Cooling devices that are used to limit the maximum  operating<br>frequency of the CPU to control CPU temperature.<br><br><br><br>> <br>> <br>> <ul class="simple"><br>> <li><p><code class="docutils literal notranslate"><span class="pre">X</span></code> – cluster CPU number</p></li><br>> <li><p><code class="docutils literal notranslate"><span class="pre">cpufreq-cpu0</span></code> – Cluster0</p></li><br>> <li><p><code class="docutils literal notranslate"><span class="pre">cpufreq-cpu4</span></code> – Cluster1</p></li><br>> </ul> |

Note

The list of cooling devices for QCS8275 will be updated in a future release.

Last Published: Jan 26, 2025

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