Function netdev_lower_register

drivers/net/netdev_upperhalf.c:1369–1452

 ****************************************************************************/

int netdev_lower_register(FAR struct netdev_lowerhalf_s *dev,
                          enum net_lltype_e lltype)
{
  FAR struct netdev_upperhalf_s *upper;
  size_t extra_size;
  int cpu = 0;
  int ret;

  if (dev == NULL || dev->ops == NULL ||
      dev->ops->transmit == NULL || dev->ops->receive == NULL)
    {
      nerr("ERROR: Invalid lower half device\n");
      return -EINVAL;
    }

  if (dev->quota_ptr == NULL)
    {
      dev->quota_ptr = dev->quota;
    }

  if (quota_is_valid(dev) == false)
    {
      return -EINVAL;
    }

  switch (dev->rxtype)
    {
      case NETDEV_RX_WORK:
        extra_size = sizeof(struct work_s);
        break;
      case NETDEV_RX_DIRECT:
        extra_size = 0; /* No extra size needed for direct mode */
        break;
      case NETDEV_RX_THREAD:
        extra_size = sizeof(struct netdev_thread_s);
        cpu = 1;
        break;
      case NETDEV_RX_THREAD_RSS:
        extra_size = sizeof(struct netdev_thread_s) * CONFIG_SMP_NCPUS;
        cpu = CONFIG_SMP_NCPUS;
        break;
      default:
        nerr("ERROR: Unrecognized device rxtype: %d\n", dev->rxtype);
        return -EINVAL;
    }

  if ((upper = netdev_upper_alloc(dev, extra_size)) == NULL)
    {
      return -ENOMEM;
    }

  upper->txing = false;

  dev->netdev.d_ifup    = netdev_upper_ifup;
  dev->netdev.d_ifdown  = netdev_upper_ifdown;
  dev->netdev.d_txavail = netdev_upper_txavail;
#ifdef CONFIG_NET_MCASTGROUP
  dev->netdev.d_addmac  = netdev_upper_addmac;