How to Notify main.c of ADC Conversion Completion in Zephyr?

[higginsa1]

I have an ADC driver for which I wrote a shield that continuously performs ADC conversions. My main.c needs to retrieve the ADC values as soon as a conversion is complete.

The shield includes an ISR that is triggered when the conversion finishes. Immediately after that—outside the ISR—main.c should call adc_read() to fetch the result.

What would be an elegant and efficient way, in Zephyr style, to notify main.c that the conversion is complete?
Would a callback in main.c that starts a thread be a suitable approach? Or is it better to set a semaphore from the ISR?

I’m looking for a clean and fast solution, since the ADC values need to be retrieved with minimal delay.