Jetson AGX cannot control the PAC.04 pin in version R36.3

[FANYX]

Hi,nvidia,
Jetson AGX cannot control the PAC.04 pin in version R36.3 - Jetson & Embedded Systems / Jetson AGX Orin - NVIDIA Developer Forums
n the link above, I inquired about the issue of the PAC.04 PIN not being able to output a high level. Through my verification, I found that although the GPIO status in the kernel debug appears to be correct, as follows:

However, when I went to read the corresponding register, I found that the register did not set the GPIO to output mode, but remained in the default input mode, as shown below:

After executing the following command, I successfully set the PAC.04 PIN to GPIO output mode and pulled it up to output a high level.

I am unsure why the device tree configuration was not synchronized to the register configuration. I would like to ask how to multiplex the PAC.04 pin as GPIO and set it to output mode in the driver development source code? Thank you!

[carolyuu]

Hi,
If the device cannot be flashed/booted, please refer to the page to get uart log from the device:
Jetson/General debug - eLinux.org
And get logs of host PC and Jetson device for reference. If you are using custom board, you can compare uart log of developer kit and custom board to get more information.
Also please check FAQs:
Jetson AGX Orin FAQ
If possible, we would suggest follow quick start in developer guide to re-flash the system:
Quick Start — NVIDIA Jetson Linux Developer Guide 1 documentation
And see if the issue still persists on a clean-flashed system.
Thanks!

[FANYX]

Hi,

I can start the system normally, which is a problem in the development.

[KevinFFF]

Hi FANYX,

@FANYX

I found that the register did not set the GPIO to output mode, but remained in the default input mode, as shown below:

0x02448020(PADCTL_G7_SOC_GPIO57_0) is the pinmux register which is configured through pinmux dtsi loaded in MB1. It is not relating to how you configure in device tree for kernel.

@FANYX

I would like to ask how to multiplex the PAC.04 pin as GPIO and set it to output mode

Please refer to Jetson AGX Orin Platform Adaptation and Bring-Up — NVIDIA Jetson Linux Developer Guide 1 documentation to configure the pinmux spreadsheet for your use case.

[FANYX]

HI,
In response to your above answer, I have two questions:

1. After jp6.0, is it impossible to modify pinmux directly in the kernel?

2. If the function of pin pin needs to be changed, can the reuse of PIN PIN pin only be changed by replacing the corresponding Pinmux.DTSI, gpio.dtsi and directly accessing the pinmux register?

[809656875]

@FANYX

PAC.04

gpioset --mode=wait gpiofind "PAC.04"=1

[FANYX]

Thank you very much for your reply. It is precisely because this method cannot work that I directly modify the pinmux register.

[809656875]

我最近也修改pinmux时遇到了一些问题，甚至刷机后usb也不能使用了， 正在解决中。

[KevinFFF]

@FANYX

After jp6.0, is it impossible to modify pinmux directly in the kernel?

If you are using the devkit, you can use Jetson-IO tool to enable some functions which is to configure the pinmux register. But if you want to control the pin(use it as GPIO output), you have to reflash the board to apply the change.

@FANYX

If the function of pin pin needs to be changed, can the reuse of PIN PIN pin only be changed by replacing the corresponding Pinmux.DTSI, gpio.dtsi and directly accessing the pinmux register?

Yes, you can modify those dtsi manually if you are familiar with them.
If not, we would suggest using pinmux spreadsheet.