SDAA427 July   2026 AFE7900 , AFE7901 , AFE7903 , AFE7906 , AFE7950 , AFE7950-SP , AFE7951 , AFE7953 , AFE7954 , AFE7955 , AFE7958

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Linux Kernel Driver
    1. 2.1 Linux Kernel Driver using PetaLinux Tools
    2. 2.2 Linux Kernel Driver Using Yocto Project
      1. 2.2.1 Overview of the Yocto Project
      2. 2.2.2 Host System Requirements
      3. 2.2.3 Setting Up a Yocto Build Environment
      4. 2.2.4 Configuring Board Specific Layers
      5. 2.2.5 Integrating the AFE79xx Yocto Layer
      6. 2.2.6 Verifying the Integration
      7. 2.2.7 Troubleshooting
    3. 2.3 Preparing Linux Boot Images
    4. 2.4 Operating the AFE79xx Device from User Space
  6. 3Building the AFE79xx SDK in Application Layer
    1. 3.1 Building Linux Kernel Without AFE79xx SDK using PetaLinux Tools
    2. 3.2 Integrating SPI with AFE79xx in User Space
  7. 4Reference Design for ZCU102 FPGA with Processor and SPI
    1. 4.1 Configuring the Zynq Processor
    2. 4.2 Configuring the SPI Interface
    3. 4.3 Generating Hardware Description
    4. 4.4 Booting ZCU102 Board with SD Card
  8. 5Summary
  9. 6References

2.2.7 Troubleshooting

Table 2-2 Troubleshooting
Issue Symptom Resolution
Module not loading at boot lsmod shows no afe79 entry Verify IMAGE_INSTALL:append = " afe79" is present in local.conf. Check that /etc/modules-load.d/afe79.conf exists on the target.
Build syntax errors BitBake parse errors related to IMAGE_INSTALL or KERNEL_MODULE_AUTOLOAD Verify Yocto version. Use underscore syntax for versions older than Honister.
Driver probe fails No initialization messages in dmesg Verify the device tree contains a node with compatible = "ti,afe79xx" on the correct SPI bus with status = "okay".
Device files not created /dev/afe79* not present Check dmesg for driver binding errors. Verify the SPI controller is enabled in the device tree.
SPI communication failure Application returns incorrect read values or errors Verify the correct device file is used. Confirm the SPI frequency and mode match the hardware. For Xilinx platforms, verify that the FPGA bitstream correctly routes SPI signals through the FMC connector to the AFE79xx device.
Nested build directory Configurations reset unexpectedly Always source the environment script from the project root directory, never from inside the build directory. Delete any nested build subdirectory if created accidentally.