In the R28.1/R28.2.0 the gpio A23 can't set direction

From the document Jetson_TX1_Generic_Customer_Pinmux_Customer_Release,I know the pin A23(GPIO_EXP0_INT) Customer Usage as GPIO03_PL.01.And I follow the Adaption Guid method calculate the gpio number is 89.

In the L4T version R24.2.1,I can control this pin using the following method:

echo “89”|sudo tee /sys/class/gpio/export
echo “out”|sudo tee /sys/class/gpio/gpio89/direction
echo “1”|sudo tee /sys/class/gpio/gpio89/value

but in the R28.1/R28.2.0 it’s error. I can’t set the gpio direction.The information prompt is: Invalid argument.

Can you help me

I just wonder if this can only be modified through pinmux after rel-28.
Could you try to modify it in pinmux spreadsheet?

For an echo which fails, can you “cat” the same file? E.g., if “echo out” fails to direction, what do you get from “sudo cat /sys/class/gpio/gpio89/direction”?

“cat” the same file, I get the information is “in”.

hi WayneWWW,
if this only can be modified through pinmux after rel-28,as a gpio it is not available.


Are you still able to set the GPIO to lo/hi?


Set the GPIO value “Operation not permitted”.

I wonder if there is any driver that is using this pin. Not have time to check.

How about other pin? Are they still working fine?

I found in the hardware file tegra210-jetson-cv-base-p2597-2180-a00.dts have the node tca9539_74@74,it used the pin.
but in the R24.2.1 version,it is also used.

Other pins are still working fine.

Maybe this driver is not enabled on r24.2.1. Could you compare the log and see if it is true?

I found that the R28.1/R28.2 to R24.2.1 more GPIO_PCA953X_IRQ driver.

R24.2.1 log :
pca953x 1-0074:no regulator found for vcc,Assuming vcc is always powerd
gpio wake21 for gpio89
gpiochip_add: registered GPIOs 1008 to 1023 on device:tca9539
gpiochip_add: registered GPIOs 496 to 511 on device :tca9539

In the R28.1 I commented out the “Interrupts=<TEGRA_GPIO(L, 1), 0X0>;” ,then the gpio is all right.

But I don’t know what will happen to this,Tca9539 chip should be on the development board.