Workflow

Select the slave.

spi_select_slave(&spi_master_instance, &slave, true);

Start the transfer job.

dma_start_transfer_job(&example_resource_rx);
dma_start_transfer_job(&example_resource_tx);

Wait for transfer done.

while (!transfer_rx_is_done) {
    /* Wait for transfer done */
}

Deselect the slave.

spi_select_slave(&spi_master_instance, &slave, false);

Enter endless loop.

while (true) {
}