# Thermal architecture The thermal architecture shows how the Qualcomm Linux thermal framework interacts with temperature sensors (Tsens) hardware, cooling map interfaces, and user space clients. **Figure : Thermal architecture** Table : Description of the components of thermal architecture | Components of thermal architecture | Description | | --- | --- | | Thermal device tree |

A thermal device tree consists of various thermal zones.

A thermal zone is configured for every Tsens.

Each thermal zone consists of sensor hardware
information, different levels of thermal thresholds, and
their respective cooling actions.

All rules for a thermal zone are defined in the device
tree.

| | Thermal framework | The thermal framework parses the thermal zone rules from the
device tree and configures Tsens hardware to generate
interrupts when temperature crosses the threshold. | | Thermal governor |

The thermal governor is a temperature monitor algorithm
that controls the temperature of a thermal zone.

It mitigates the cooling devices associated with the zone
and keeps the temperature within the limit.

On receiving an interrupt notification from Tsens
hardware, the thermal framework uses a stepwise thermal
governor to communicate the cooling actions to the
cooling map interface (CPU frequency driver).

| | Cooling map interface |

A cooling map interface is a collection of devices that
can be throttled to reduce the temperature of Qualcomm
Linux.

Every trip instance of the thermal zone is associated
with a cooling device.

The thermal core framework aggregates all the cooling
device instance requests and places the aggregated
requests to the cooling device.

| | User space clients | User space clients use the following interfaces to
communicate with the thermal framework:

>
>
>

The sysfs interface is used to read the temperature
> of Tsens and kernel trip information.

The Netlink interface gets information on Tsens
> temperature notifications.

| ## Thermal mitigation policies Qualcomm Linux uses in-built software and hardware mitigation policies to regulate the device’s thermal behavior. The thermal framework applies the mitigation policies when required and operates through the following policies: - Monitors the thermal response of the system using on-die Tsens - Applies mitigation based on thermal threshold limits defined in the device tree - Implements software throttling, hardware throttling, software shutdown, and hardware shutdown mitigation policies to control temperature The following tables list the temperatures at which in-built software and hardware mitigation occur. Tab QCS6490/QCS5430 Tab IQ-9075 Tab IQ-8275 Tab IQ-615 Table: Temperature for hardware and software throttling for QCS6490/QCS5430 | Mitigation actions | CPU | NSP | GPU | | --- | --- | --- | --- | | Software throttling | | 110 ºC

Mitigation action: Frequency throttling | 105 ºC

Mitigation action: Frequency throttling | | Hardware throttling | 95 ºC/105 ºC

Note

105 °C thermal mitigation is applied only for 300-AA parts.

Mitigation action: Frequency throttling | 102 ºC

Mitigation action: Frequency throttling | Not applicable | | Software shutdown | 118 ºC

Mitigation action: Device shutdown | | | | Hardware shutdown | 120 ºC

Mitigation action: Device shutdown | | | See lemans.dtsi to review the kernel thermal rules. Table: Temperature for hardware and software throttling for Dragonwing IQ-9075 | Mitigation actions | CPU | NSP | GPU | | --- | --- | --- | --- | | Software throttling | | 105 ºC

Mitigation action: Frequency throttling | 105 ºC

Mitigation action: Frequency throttling | | Hardware throttling | 110 ºC

Mitigation action: Frequency throttling | 110 ºC

Mitigation action: Frequency throttling | Not applicable | | Software shutdown | 118 ºC

Mitigation action: Device shutdown | | | | Hardware shutdown | 120 ºC

Mitigation action: Device shutdown | | | See qcs8300.dtsi to review kernel thermal rules. Table: Temperature for hardware and software throttling for Qualcomm® Dragonwing™ IQ-8275 | Mitigation actions | CPU | NSP | GPU | | --- | --- | --- | --- | | Software throttling | | 105 ºC

Mitigation action: Frequency throttling | 105 ºC

Mitigation action: Frequency throttling | | Hardware throttling | 110 ºC

Mitigation action: Frequency throttling | 110 ºC

Mitigation action: Frequency throttling | Not applicable | | Software shutdown | 118 ºC

Mitigation action: Device shutdown | | | | Hardware shutdown | 120 ºC

Mitigation action: Device shutdown | | | See talos.dtsi to review kernel thermal rules. Table: Temperature for hardware and software throttling for Dragonwing IQ-615 | Mitigation actions | CPU | NSP | GPU | | --- | --- | --- | --- | | Software throttling | | 105/110 ºC

Mitigation action: Frequency throttling | 105 ºC

Mitigation action: Frequency throttling | | Hardware throttling | 105 ºC

Mitigation action: Frequency throttling | 102 ºC

Mitigation action: Frequency throttling | Not applicable | | Software shutdown | 118 ºC

Mitigation action: Device shutdown | | | | Hardware shutdown | 120 ºC

Mitigation action: Device shutdown | | | Note The core idle injection functionality will be enabled in future release. ## Next steps - [Learn about thermal interfaces](https://docs.qualcomm.com/doc/80-80020-30/topic/thermal-interfaces.html#thermal-interfaces) Last Published: Feb 27, 2026 [Previous Topic Get started with thermal management workflow](https://docs.qualcomm.com/bundle/publicresource/80-80020-30/topics/get-started-thermal.md) [Next Topic Learn about thermal interfaces](https://docs.qualcomm.com/bundle/publicresource/80-80020-30/topics/thermal-interfaces.md)