Enable I2C, I2s, SPI in boot-config file?

[pas059]

Hi,

starting with the info given in the post KnReLe, i write a little app in C++ that uses i2c0 bus. This works but requires the app to be executed as root. As i'm not a linux expert, i were looking for a solution and find the following so that this i2c bus could be used all the time outside root:

1. create a user group (for instance i2cuser) and add rock64 (my user account) to the group 
      $sudo addgroup i2cuser   $sudo usermod -a -G i2cuser rock64
   
2. create a script /usr/local/sbin/i2c0add.sh :
   
   Code:

   #!/bin/bash
#script to add i2c-0 to the devices
echo Create /dev/i2c-0
enable_dtoverlay i2c0 i2c@ff150000 okay
#change owner:group of /dev/i2c-0
chown root:i2cuser /dev/i2c-0
   
   
   
3. create a systemd service file /etc/systemd/system/i2c0add.service :
   
   Code:

   [Unit]
Description=Service to create i2c0 device
After=sockets.target

[Service]
Type=oneshot
RemainAfterExit=no
ExecStart=/usr/local/sbin/i2c0add.sh

[Install]
WantedBy=multi-user.target
   
   
   
4. enable the execution of the service at startup:
     $sudo systemctl enable /etc/systemd/system/i2c0add.service
   

I hope that i did not forget something. I not sure that this is the best solution but this works.
In addition, linux version is 18.04 LTS (Bionic Beaver)
I am also looking for a solution for using the gpio lines as non root, but until now without success. 
If someone has a solution....



Regards