AMDGPU driver maintainer Alex Deucher posted patches for enabling the OEM I2C interface on AMD GPUs on Linux. This interface is necessary for OpenRGB to be able to communicate with and control RGB devices on the graphics card PCB and to this point has only been available to Windows users of OpenRGB. No changes should be necessary to OpenRGB itself, once you install an updated kernel with these changes then your supported AMD GPU should be detected! I have tested Alex's development branch and was able to control my ASUS TUF RX7800XT and Sapphire Nitro+ RX580 lighting.