SDAA069 August   2025 TDA4VL-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 Overview of TDA4VL SoC
    2. 1.2 Purpose of the Document
    3. 1.3 Target Audience and Applications
    4. 1.4 Problem Statement
  5. 2Dynamic Frequency Scaling (DFS) in Linux
    1. 2.1 What is DFS?
    2. 2.2 Linux CPUFREQ Framework
    3. 2.3 Supported CPUFREQ Governors
    4. 2.4 DFS Support Status on TI SoCs
  6. 3Linux Thermal Framework
    1. 3.1 Thermal Zones and Trip Points
    2. 3.2 Cooling Mechanisms: Passive vs Active
    3. 3.3 Role of DFS in Passive Cooling
  7. 4Thermal Support on TDA4VL Devices
    1. 4.1 VTM and Bandgap Sensor Initialization
    2. 4.2 Temperature Monitoring via k3_j7xxx_bandgap Driver
  8. 5Enabling CPU Cooling on TDA4VL
    1. 5.1 Patch to Enable CPU Cooling
    2. 5.2 Testing the Cooling Functionality on TDA4VL
  9. 6Scalability Across TDA4 and Sitara Devices
    1. 6.1 Adapting the Implementation
  10. 7Summary
  11. 8References

4.2 Temperature Monitoring via k3_j7xxx_bandgap Driver

The k3_j7xxx_bandgap driver performs low level initialization of thermal sensors and provides software hooks to register thermal zones. Features include:

  • Reading real-time temperatures from the A72 cores, GPU, and other key regions of the SoC.
  • Mapping each physical sensor to a logical thermal zone.
  • Integration with Linux thermal core to trigger trip points

This functionality enables developers to observe thermal behavior and plan cooling strategies, even before active/passive cooling mechanisms are implemented.