Hi @martin_mig,
Thank you for the detailed response.
Complementing my last post, there is this community thread where it is confirmed that the hardware does not support multi-channel ADC conversion. Furthermore, the Invalid argument error you got is due to the function iio_validate_scan_mask_onehot used by the vf610 driver, which is used by the adc1 device tree node.
You can try adding an adc2 device tree node to your dtsi/dts files as described here. Just make sure to use different pins than the ones used by adc1.
About that multiplexer kernel patch you mentioned, I’m internally discussing it, and once I get a conclusion I will reach you as soon as possible.
Best regards,
André Morishita