I am using the Duovero COM with parlor extension board. I need to use the onboard ADC.

I tried the code from https://github.com/scottellis/polladc
However, it says invalid argument for each read.

I am not sure whether it is because the fact that overo and duovero uses different PMIC,
where one is TWL4030, the other is TWL6030.

Does anyone  happen to know how to use the ADC module? My question might be stupid since I am quite new to embedded linux but please help and I will appreciate it.

Yiyao HU