Add accessible GPIO through linux OS in Jetson Nano

Autonomous Machines Jetson & Embedded Systems Jetson Nano
#1

Hello,

I want to access some GPIO through linux OS in Jetson Nano.

As I know, accessible GPIO in GPIO sysfs is mapped to expansion 40-pin header.

But What I want to access GPIO is not mapped to expansion header.

For example, UART0_CTS (SODIMM Pin No. 105) and GPIO06 (SODIMM Pin No. 130) is not mapped.

How can I access these pins via GPIO sysfs or memory address access? Or some else way?

#2

hi @jtlee

Please refer the following topic, hope this will help you Need the sysfs numbers for gpio in the jetson Nano reference design

thank you

#4

hello jtlee,

please also check this thread, Topic 144550, for several ways to access GPIOs. such as, kernel APIs, python scripts, C++ samples.

#6

hello
I think I should gpio access via

According from @ankithsingh, GPIO index is defined at $L4T_Sources/r32.4.3/Linux_for_Tegra/source/public/kernel/kernel-4.9/include/dt-bindings/gpio/tegra-gpio.h.

And I think accessing GPIO address should reference jetson-nano-gpio-example/gpionano.h at master · valentis/jetson-nano-gpio-example · GitHub .

But I don’t know how to get GPIO address exactly. In gpionano.h, GPIO_216’ address is 0x6000d60C, and GPIO_50’s address is 0x6000d108. However, GPIO06 = GPIO3_PI.00 = ( 8 * 8 ) + 0 = 64, so it is mapped to GPIO_64 but I don’t know get related GPIO address.

Can you teach me about GPIO address getting formula?

Thank you.

#8

please refer to GPIO DMA Address Map as see-also. thanks

#10

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