It seems that in my experiments I got lost in the wrong place) I was led astray mainly by this information. https://github.com/armbian/sunxi-DT-overlays/blob/master/examples/spi-mcp251x.dts With the default driver and with the correct parameters, everything works and the terminal does not freeze, he...

Starting from kernel version 5.5 to 5.11.2, when connecting the CAN module MCP2515 and when entering commands in the terminal ip link set can0 up type can bitrate 500000 ifconfig can0 up terminal freezes The reason for this is the call to this subroutine ret = mcp251x_hw_wake (spi); in this driver c...

It may help you https://buildroot.org/
More serious http://www.linuxfromscratch.org/

or update the kernel in a working distribution and customize it for yourself

sudo apt-get install alsa-utils

alsamixer

Compile on Nano PI NEO. example terminal Log in Nano PI NEO via SSH ssh root@192.168.0.50 mkdir /usr/my_device close the terminal .... open terminal sshfs root@192.168.0.50:/usr/my_device /home/user/my_device Your local computer will have a folder with Nano Pi NEO Working on the local x86 computer, ...

https://github.com/brgl/libgpiod for C, C++, PYTHON

http://wiki.friendlyarm.com/wiki/index.php/CPU 2.1 CPU DVFS 2.1.1 Linux-4.14 All H3 based boards have the same DVFS setting and the setting is in the "arch/arm/boot/dts/sun8i-h3-nanopi.dtsi" file: &cpu0 { operating-points = < 1008000 1300000 816000 1100000 624000 1100000 480000 1100000...

http://wiki.friendlyarm.com/wiki/images ... 180320.pdf
page POWER 02

RT8059
https://www.richtek.com/assets/product_ ... 059-05.pdf

DC-DC 1A
A couple of LEDs stand for experimentation ))), but you should not load all the same, it feeds the board

CVBS this is a video output

or via USB, I2C, SPI )))

or UNO Dock V2.0 for NanoPi NEO
https://www.friendlyarm.com/index.php?r ... uct_id=188
http://wiki.friendlyarm.com/wiki/index. ... oPi_NEO/zh
SCHEMATIC
http://wiki.friendlyarm.com/wiki/images ... k_v2.0.pdf

There is no interrupt handling in user space, only in the kernel area.

status = "disabled"; status = "okay" i2c@1c2ac00 { compatible = "allwinner,sun6i-a31-i2c"; reg = <0x1c2ac00 0x400>; interrupts = <0x0 0x6 0x4>; clocks = <0x3 0x3b>; resets = <0x3 0x2e>; pinctrl-names = "default"; pinctrl-0 = <0x17>; status = "okay"; ...

Nano pi Neo i2c@1c2ac00 { compatible = "allwinner,sun6i-a31-i2c"; reg = <0x1c2ac00 0x400>; interrupts = <0x0 0x6 0x4>; clocks = <0x3 0x3b>; resets = <0x3 0x2e>; pinctrl-names = "default"; pinctrl-0 = <0x17>; status = "okay"; #address-cells = <0x1>; #size-cells = <0x0>; ...