AM68xx EVM GPIO pins error

Rakesh Thakur

Other Parts Discussed in Thread: AM68, TDA4VM

Hello friends/sir, I am a newbie in Embedded Linux. I am working on AM68xx EVM machine. There is a 40 pin expansion header pin on the EVM board in which GPIO0_27, GPIO0_36 and GPIO0_3 are connected to the processor. I have connected LEDs to these GPIO pins. GPIO driver available. After getting root access to the board, when I give the command echo 27 > /sys/class/gpio/export, an error is coming. export_store: invalid GPIO 27 -sh: echo: write error: invalid argument mux pin for gpio is 7 how to add it to dts file so gpio can receive it I have installed the SDK j721s2-evm-08_00_00_10 version for AM68xx EVMs.

over 2 years ago

0 Takuma Fujiwara over 2 years ago

TI__Guru 51863 points

Hi Rakesh,

Might be less intuitive, but GPIO0_27 is not necessarily gpio27 in sysfs. We have a FAQ here that should be applicable to AM68xx EVM for finding out which gpio number is GPIO0_27 in Linux: https://e2e.ti.com/support/processors-group/processors/f/processors-forum/918654/faq-tda4vm-dra829-am65xx-linux-configuring-gpios. Please note that the numbers used in the FAQ is for TDA4VM instead of AM68, so the example used in the FAQ will probably not work. However, the method to find out which gpio number would toggle GPIO0_27 can be used from the FAQ.

Alternatively, we provide some Python and C++ libraries for interfacing with the 40 pin expansion header pin here: https://software-dl.ti.com/jacinto7/esd/processor-sdk-linux-edgeai/AM68A/09_00_00/exports/edgeai_docs/devices/AM68A/linux/pi_hdr_programming.html.

Regards,

Takuma

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AM68xx EVM GPIO pins error