RSL10 Basic Analog setup

I’m trying to get a basic analog reading and struggling a bit with the setup. Right now it always returns 0. Not sure what I’m missing.

    #define AIO      1
    /* Configure AIO pin as an analog input */
    DIO->CFG[AIO] = DIO_MODE_DISABLE | DIO_NO_PULL;

    /* Configure ADC */
    Sys_ADC_InputSelectConfig(AIO, ADC_POS_INPUT_GND | ADC_NEG_INPUT_GND);

    Sys_ADC_Set_Config(ADC_CONTINUOUS|ADC_PRESCALE_6400);

//    NVIC_EnableIRQ(DIO0_IRQn); // Do I need this?


...

        adc_value = ADC->DATA_TRIM_CH[AIO];
        PRINTF("AIO VAL: %d\n", adc_value);```