Looking detailed information accessing GPIOs of T2-OLinuXino-LIME-e4Gs16M-IND

[chirag.mistry]

I am using T2-OLinuXino-LIME-e4Gs16M-IND Olimex board and I am looking to access and program its GPIOs. But I could not find proper document or link for A20 LIME board's GPIO pin information, its mapping and about programming it on Linux and Python. Online link talk about A10 board. I could find one PDF but it is talking about A20 Micro board. Provide link or pdf file about accessing GPIOs of T2-OLinuXino-LIME-e4Gs16M-IND Olimex board on Linux.

Regards
Chirag

[LubOlimex]

This might be helpful for initial understanding and simple tests: https://olimex.wordpress.com/2019/01/25/working-with-a20-olinuxino-or-som-gpios-when-using-new-armbian-based-a20-universal-linux-image/

For further reading check here: https://www.kernel.org/doc/Documentation/gpio/sysfs.txt

If you wish for the recommended approach and automatic usage in your code check here: https://github.com/brgl/libgpiod

[winfried]

FYI, (mabe late but ...)
Searched also very long a half year ago for this info, writing a kernelmodule doing PWM-pulses on many GPIOs, ( since Olimex A20 (T2) is an GPIO-Monster ;-)

https://git.iem.at/ritsch/gpio-asr

and compiled a spreadsheet (libre-calc) there, also in PULLups and boot states, maybe you can use it, expand it.

https://git.iem.at/ritsch/gpio-asr/blob/master/A20_LIME2_GPIOs-usable.ods


maybe you can use it improve it, ...

[olecom]

> I am using T2-OLinuXino-LIME-e4Gs16M-IND Olimex board and I am looking to access and program its GPIOs. But I could not find proper document or link for A20 LIME board's GPIO pin information, its mapping

Here is GPIO mapping and connectivity information:
https://github.com/OLIMEX/OLINUXINO/blob/master/HARDWARE/A20-OLinuXino-LIME/1.%20Latest%20hardware%20revision/A20-OLinuXino-Lime_Rev_I1.pdf

> about programming it on Linux and Python

Library to access GPIO (and other I/O):
https://github.com/OLIMEX/OLINUXINO/tree/master/SOFTWARE/Python/pyA20-Lime
https://github.com/rubitwa/pySUNXI
https://github.com/rubitwa/sunxi_gpio_lib

Also it can be useful to study RaspberryPI GPIO C library sources and examples:
https://www.airspayce.com/mikem/bcm2835/
But it applies to single GPIO port and not 2 or 3 A20/T2 SoC has access on LIME* boards.

Break down of what happens or raw GPIO accessing code can be found here:
https://elinux.org/RPi_GPIO_Code_Samples#Direct_register_access