Question Regarding the Correct Procedure for Applying Pinmux Settings on Jetson Orin Nano (L4T R36.4.4)

[rfhead]

Hello,

I would like to ask about the correct procedure for applying the dtsi files (pinmux, padvoltage, gpio) generated by the official Pinmux configuration Excel sheet to a custom board featuring a Jetson Orin Nano (L4T R36.4.4).

Current Situation & Challenges

Our ultimate goal is to correctly apply the settings generated from the Excel sheet to our custom board. We have attempted several methods based on the official documentation but have encountered various errors, which has left us unsure of the proper procedure for the L4T R36.4.4 release.

Summary of Attempts:

1. Directly Modifying the Kernel DTS:
   We tried placing the pinmux and padvoltage dtsi files in the BCT directory and then directly modifying the DTS file related to the P3767 module to include our gpio.dtsi. However, this approach failed with an I2C error during boot, which was caused by an incomplete padvoltage file. More fundamentally, we are facing the initial problem of not being able to locate the correct base DTS file for the Orin Nano (e.g., tegra234-p3768...) in the source tree.

2. Device Tree Overlay (DTBO):
   We also attempted to apply the settings via a Device Tree Overlay, but we abandoned this method due to compilation errors.

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Specific Questions:

1. For a custom Orin Nano board on L4T R36.4.4, what is the current, most reliable, and recommended workflow for applying the pinmux.dtsi, padvoltage.dtsi, and gpio.dtsi files generated by the Pinmux Excel sheet?

2. Should the GPIO settings (from gpio.dtsi) be applied by the bootloader (BCT), or is the correct method to include them in the kernel DTS?

3. If editing the kernel DTS is required, where can we obtain the correct source file for the Orin Nano?

Our objective is simply to implement the hardware configuration as designed in the Excel sheet. We would greatly appreciate any guidance on the most robust procedure to achieve this.

Thank you.

[KevinFFF]

Hi rfhead,

@rfhead

Directly Modifying the Kernel DTS:

@rfhead

Should the GPIO settings (from gpio.dtsi) be applied by the bootloader (BCT), or is the correct method to include them in the kernel DTS?

Please note that pinmux/gpio dtsi are loaded in early boot (MB1) rather than kernel so that there’s nothing to do with kernel device tree.

@rfhead

For a custom Orin Nano board on L4T R36.4.4, what is the current, most reliable, and recommended workflow for applying the pinmux.dtsi, padvoltage.dtsi, and gpio.dtsi files generated by the Pinmux Excel sheet?

Please confirm gpio.dtsi is included(specified) in pinmux.dtsi first.
You can refer to Jetson Orin NX and Nano Series — NVIDIA Jetson Linux Developer Guide to put them to the correct path in your BSP package.
After you’ve put them to correct path, please also confirm if you’ve specified PINMUX_CONFIG and PMC_CONFIG in board config.