VADC_CONV_TIME_MIN_US
retry = interval_us / VADC_CONV_TIME_MIN_US;
usleep_range(VADC_CONV_TIME_MIN_US, VADC_CONV_TIME_MAX_US);
timeout = BIT(prop->avg_samples) * VADC_CONV_TIME_MIN_US * 2;
ret = vadc_poll_wait_eoc(vadc, VADC_CONV_TIME_MIN_US);