Hello,
The /dev/ttyS3 - exists,
SPI - stopped via /boot/script.bin,
but bytes do not really come to output pin.
I wonder we could fix to start it to work. Please guide me. Thanks in advance!

I think you should check Dependencies and Regulators: The error message you mentioned (sun8i-h3-pinctrl 1c20800.pinctrl: supply vcc-pc not found, using dummy regulator) indicates a missing regulator dependency for the pin controller. Moreover, you should review your device tree to ensure that the ne...

I am experiencing the same issue. Did you find any solution?