[LWIP] 如何实现LWIP热插拔功能

LWIP 1.4.1

硬件stm32f429 HAL 1.8.1  UCOSIII

步骤如下

1、在lwip的opt.h中使能宏定义LWIP_NETIF_LINK_CALLBACK 链接发生变化时调用回调函数

 

2、在初始化结束后调用函数netif_set_link_callback，为网卡设置一个回调函数，回调参考代码如下

/**
  * @brief  Link callback function, this function is called on change of link status
  *         to update low level driver configuration.
* @param  netif: The network interface
  * @retval None
  */
void ethernetif_update_config(struct netif *netif)
{
  __IO uint32_t tickstart = 0;
  uint32_t regvalue = 0;
  
  if(netif_is_link_up(netif))
  { 
    /* Restart the auto-negotiation */
    if(heth.Init.AutoNegotiation != ETH_AUTONEGOTIATION_DISABLE)
    {
      /* Enable Auto-Negotiation */
      HAL_ETH_WritePHYRegister(&heth, PHY_BCR, PHY_AUTONEGOTIATION);
      
      /* Get tick */
      tickstart = HAL_GetTick();
      
      /* Wait until the auto-negotiation will be completed */
      do
      {
        HAL_ETH_ReadPHYRegister(&heth, PHY_BSR, &regvalue);
        
        /* Check for the Timeout ( 1s ) */
        if((HAL_GetTick() - tickstart ) > 1000)
        {     
          /* In case of timeout */ 
          goto error;
        }   
      } while (((regvalue & PHY_AUTONEGO_COMPLETE) != PHY_AUTONEGO_COMPLETE));
      
      /* Read the result of the auto-negotiation */
      HAL_ETH_ReadPHYRegister(&heth, PHY_SR, &regvalue);
      
      /* Configure the MAC with the Duplex Mode fixed by the auto-negotiation process */
      if((regvalue & PHY_DUPLEX_STATUS) != (uint32_t)RESET)
      {
        /* Set Ethernet duplex mode to Full-duplex following the auto-negotiation */
        heth.Init.DuplexMode = ETH_MODE_FULLDUPLEX;  
      }
      else
      {
        /* Set Ethernet duplex mode to Half-duplex following the auto-negotiation */
        heth.Init.DuplexMode = ETH_MODE_HALFDUPLEX;           
      }
      /* Configure the MAC with the speed fixed by the auto-negotiation process */
      if(regvalue & PHY_SPEED_STATUS)
      {  
        /* Set Ethernet speed to 10M following the auto-negotiation */
        heth.Init.Speed = ETH_SPEED_10M; 
      }
      else
      {   
        /* Set Ethernet speed to 100M following the auto-negotiation */ 
        heth.Init.Speed = ETH_SPEED_100M;
      }
    }
    else /* AutoNegotiation Disable */
    {
    error :
      /* Check parameters */
      assert_param(IS_ETH_SPEED(heth.Init.Speed));
      assert_param(IS_ETH_DUPLEX_MODE(heth.Init.DuplexMode));
      
      /* Set MAC Speed and Duplex Mode to PHY */
      HAL_ETH_WritePHYRegister(&heth, PHY_BCR, ((uint16_t)(heth.Init.DuplexMode >> 3) |
                                                     (uint16_t)(heth.Init.Speed >> 1))); 
    }

    /* ETHERNET MAC Re-Configuration */
    HAL_ETH_ConfigMAC(&heth, (ETH_MACInitTypeDef *) NULL);

    /* Restart MAC interface */
    HAL_ETH_Start(&heth);   
  }
  else
  {
    /* Stop MAC interface */
    HAL_ETH_Stop(&heth);
  }

  ethernetif_notify_conn_changed(netif);
}

 通知代码如下，可重新获取IP或者配置静态IP

/*插入网线的话重新获取IP操作*/
void ethernetif_notify_conn_changed(struct netif *netif)
{
    if(netif_is_link_up(netif) && !netif_is_up(netif))
    {
        netif_set_up(netif);
        extern err_t dhcp_start(struct netif *netif);
		dhcp_start(netif);
    }
}