STX104_DAC_BASE
err = regmap_write(priv->aio_data_map, STX104_DAC_BASE, 0);
err = regmap_write(priv->aio_data_map, STX104_DAC_BASE + STX104_AIO_DATA_STRIDE, 0);
#define STX104_DAC_OFFSET(_channel) (STX104_DAC_BASE + STX104_AIO_DATA_STRIDE * (_channel))