func: void omap_mcbsp_i2s_attach(struct omap_mcbsp_s *s, I2SCodec *slave)
  
  {
  
      s->codec = slave;
  
      slave->rx_swallow = qemu_allocate_irqs(omap_mcbsp_i2s_swallow, s, 1)[0];
  
      slave->tx_start = qemu_allocate_irqs(omap_mcbsp_i2s_start, s, 1)[0];
  
  }
  