Do Jetson Orin Nano/NX GPIO Support Hardware Interrupt Function (INT)?

Issue Overview

Users are inquiring about the support for hardware interrupt functionality (INT) in the GPIO pins of the Nvidia Jetson Orin Nano/NX development boards. The main symptoms include:

• Lack of Clarity: Users have noted that the official documentation, specifically the "Jetson_Orin_NX_Orin_Nano_Pin_Descriptions.xlsx," does not clearly indicate which GPIO pins support hardware interrupts.

• Context of Inquiry: The issue arises during the setup phase, particularly when users are trying to implement GPIO wake events and need to understand which pins can be configured for this purpose.

• Hardware Specifications: The discussion references specific GPIO pins, such as GPIO00 and GPIO02, which are marked as supporting wake functionality, while others are either marked as not supporting it or left unmarked (greyed out).

• Frequency of Issue: This appears to be a common concern among users looking to utilize GPIO features effectively in their projects.

• Impact on User Experience: The ambiguity regarding GPIO capabilities may hinder development efforts, particularly for projects that rely on efficient power management and wake functionalities.

Possible Causes

• Documentation Limitations: The official documentation may not provide comprehensive details regarding the interrupt capabilities of all GPIO pins.

• Hardware Design Choices: Certain GPIO pins may inherently lack the capability for hardware interrupts due to design limitations or intended use cases.

• Configuration Errors: Users might misinterpret the pinmux spreadsheet or overlook specific configurations required for enabling interrupts.

• Driver Issues: Potential bugs or limitations in the drivers could affect how GPIO functionalities are exposed to users.

• User Misunderstanding: Users may not fully grasp how to configure or utilize GPIO pins for interrupt functions based on existing documentation.

Troubleshooting Steps, Solutions & Fixes

1. Review Documentation:

   • Check the latest version of the Jetson Linux Developer Guide and relevant pinmux spreadsheets for updates on GPIO capabilities.
   • Specifically refer to sections discussing wake-up sources and interrupt configurations.

2. Identify Supported Pins:

   • From the pinmux spreadsheet, identify GPIO pins with an ID marked as "Yes" in the Wake column. Currently noted are:
     • Supported for Wake: GPIO00, GPIO02
     • Not Supported for Wake: GPIO06, GPIO10
     • Unmarked (Grey): GPIO01, GPIO03-GPIO05, GPIO07-GPIO09, GPIO11-GPIO14

3. Testing Configuration:

   • Utilize commands to configure and test the identified GPIO pins for wake functionality.
   • Example command to set a pin as an input:

     echo "GPIO_PIN_NUMBER" > /sys/class/gpio/export
     echo "in" > /sys/class/gpio/GPIO_PIN_NUMBER/direction
     

4. Check Driver Updates:

   • Ensure that you are using the latest drivers compatible with your Jetson Orin Nano/NX board.
   • Update firmware if necessary by following instructions in the Nvidia documentation.

5. Consult Community Resources:

   • Engage with Nvidia forums or community discussions for shared experiences regarding specific GPIO configurations.
   • Look for any user-contributed solutions that address similar issues.

6. Testing with Different Configurations:

   • If possible, test with different hardware setups or configurations to isolate whether the issue is hardware-specific or configuration-related.

7. Best Practices for Future Prevention:

   • Regularly check Nvidia’s official documentation for updates on hardware capabilities.
   • Maintain a clear understanding of your project requirements concerning GPIO functionalities before selecting hardware components.

8. Unresolved Aspects:

   • Further clarification is needed regarding the grey-marked GPIO pins and their capabilities for wake functions.
   • Users should continue to seek updates from Nvidia regarding any potential changes in future documentation releases or software updates.

By following these steps and utilizing available resources, users can better navigate the complexities surrounding GPIO functionalities on the Jetson Orin Nano/NX boards.