Hi,
You can enable continuous conversion in ADC_SC3[ADCO] register. Then a new conversion will be automatically triggered on completion of the previous one on the same channel (or configuration) until it is aborted (see 38.5.4.3 Aborting conversions). When each conversion is done, ADC interrupt can be triggered, so you can collect data in the interrupt handler.
To reduce load of the CPU, the conversion can be initiated with hardware trigger through PDB or TRGMUX. Also, the ADC can trigger a DMA request on conversion completion.
There is an example code Example S32K144 PDB ADC trigger DMA ISR S32DS, which can help.
Regards,
Daniel