imx8MP Verdin SOM GPIO Pin issue

Technical Support
,
1

Hello Team,

We are developing a product based on Toradex Verdin imx8MP.

We are using GPIO1_IO08 pin for reading / writing some data. But this pin is automatically toggling when on the Board.

As per arch/arm64/boot/dts/freescale/imx8mp-verdin.dtsi device tree this pin is not used anywhere else.

pinctrl_gpio6: gpio6grp {
fsl,pins =
<MX8MP_IOMUXC_GPIO1_IO08__GPIO1_IO08 0x184>; /* SODIMM 218 */
};

We are clueless why this pin is automatically toggling…

When we make this pin low using gpioset -c gpiochip1 8=0 then that pin will low.

But when we make this pin high using gpioset -c gpiochip1 8=1 then that pin start toggling.

Any clue or solution what may be the reason behind this behaviour of this gpio pin.

Thanks and Regards,

VIVEK TOL

2

Hi, I’m the Toradex AI Assistant.

I might make mistakes or occasionally get you wrong. Our support team will step in if needed.

I’d be glad to help with your GPIO1_IO08 pin issue on the Verdin iMX8MP. To provide the most accurate guidance, could you let me know which OS and version you are running? This will help me give you the specific solution for your platform (1).

Common platforms include:

  • OS: Torizon OS 6.x, Torizon OS 7.x, Yocto BSP 6.x, Yocto BSP 7.x
  • Hardware: Verdin iMX8M Plus on various carrier boards (Dahlia, Mallow, Development Board)

You can also use the tdx-info command to get detailed system information: Getting Device Information with Tdx-Info | Toradex Developer Center

Preliminary Analysis

Based on your description, the toggling behavior when setting the pin high suggests there might be:

  1. Pin conflict - Another peripheral or device tree node might be claiming the same pin
  2. Incorrect pinmux configuration - The pin might not be properly configured as GPIO
  3. Hardware interference - External circuitry affecting the pin behavior

Initial Troubleshooting Steps

While I gather your platform details, you can check:

  1. Verify pin configuration using device tree overlays as documented (1)
  2. Check for pin conflicts by examining the complete device tree (2)
  3. Review pinmux settings to ensure proper GPIO configuration (2)

Once you provide your OS version, I can give you specific device tree overlay examples and pinmux configurations to resolve this GPIO toggling issue.

Best regards,
Toradex AI Assistant.

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3

Yes, this pin is not used at the module level. However, it can still be used on the carrier board level, as it done in the case here.

In this situation, you may not be able to toggle the pin with gpioset if another driver has already taken ownership of it.

Please check exactly which Device Tree and Device Tree overlays are being used in your setup.