ethernetif.c

/**
  ******************************************************************************
  * @file    LwIP/LwIP_HTTP_Server_Socket_RTOS/Src/ethernetif.c
  * @author  MCD Application Team
  * @version V1.2.1
  * @date    13-March-2015
  * @brief   This file implements Ethernet network interface drivers for lwIP
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; COPYRIGHT(c) 2015 STMicroelectronics</center></h2>
  *
  * Licensed under MCD-ST Liberty SW License Agreement V2, (the "License");
  * You may not use this file except in compliance with the License.
  * You may obtain a copy of the License at:
  *
  *        http://www.st.com/software_license_agreement_liberty_v2
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  *
  ******************************************************************************
  */

/* Includes ------------------------------------------------------------------*/
#include "stm32f4xx_hal.h"
#include "lwip/opt.h"
#include "lwip/lwip_timers.h"
#include "netif/etharp.h"
#include "ethernetif.h"
#include <string.h>

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* The time to block waiting for input. */
#define TIME_WAITING_FOR_INPUT                 ( 100 )
/* Stack size of the interface thread */
#define INTERFACE_THREAD_STACK_SIZE            ( 350 )

/* Define those to better describe your network interface. */
#define IFNAME0 's'
#define IFNAME1 't'

/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
#if defined ( __ICCARM__ ) /*!< IAR Compiler */
  #pragma data_alignment=4
#endif
__ALIGN_BEGIN ETH_DMADescTypeDef  DMARxDscrTab[ETH_RXBUFNB] __ALIGN_END;/* Ethernet Rx MA Descriptor */

#if defined ( __ICCARM__ ) /*!< IAR Compiler */
  #pragma data_alignment=4
#endif
__ALIGN_BEGIN ETH_DMADescTypeDef  DMATxDscrTab[ETH_TXBUFNB] __ALIGN_END;/* Ethernet Tx DMA Descriptor */

#if defined ( __ICCARM__ ) /*!< IAR Compiler */
  #pragma data_alignment=4
#endif
__ALIGN_BEGIN uint8_t Rx_Buff[ETH_RXBUFNB][ETH_RX_BUF_SIZE] __ALIGN_END; /* Ethernet Receive Buffer */

#if defined ( __ICCARM__ ) /*!< IAR Compiler */
  #pragma data_alignment=4
#endif
__ALIGN_BEGIN uint8_t Tx_Buff[ETH_TXBUFNB][ETH_TX_BUF_SIZE] __ALIGN_END; /* Ethernet Transmit Buffer */

/* Semaphore to signal incoming packets */
osSemaphoreId s_xSemaphore = NULL;

/* Global Ethernet handle*/
ETH_HandleTypeDef EthHandle;

/* Private function prototypes -----------------------------------------------*/
static void ethernetif_input( void const * argument );

/* Private functions ---------------------------------------------------------*/
/*******************************************************************************
                       Ethernet MSP Routines
*******************************************************************************/
/**
  * @brief  Initializes the ETH MSP.
  * @param  heth: ETH handle
  * @retval None
  */
void HAL_ETH_MspInit(ETH_HandleTypeDef *heth)
{
  GPIO_InitTypeDef GPIO_InitStructure;

    __HAL_RCC_ETHMAC_CLK_ENABLE();
  __HAL_RCC_ETHMACTX_CLK_ENABLE();
  __HAL_RCC_ETHMACRX_CLK_ENABLE();

  /* Enable GPIOs clocks */
  __HAL_RCC_GPIOA_CLK_ENABLE();
  __HAL_RCC_GPIOB_CLK_ENABLE();
  __HAL_RCC_GPIOC_CLK_ENABLE();
  __HAL_RCC_GPIOF_CLK_ENABLE();
  __HAL_RCC_GPIOG_CLK_ENABLE();
  __HAL_RCC_GPIOH_CLK_ENABLE();
  __HAL_RCC_GPIOI_CLK_ENABLE();

    /* Ethernet pins configuration ************************************************/
   /*

        RMII
            ETH_MDIO --------------> PA2
            ETH_MDC ---------------> PC1
            ETH_RMII_REF_CLK-------> PA1
            ETH_RMII_CRS_DV -------> PA7
            ETH_RMII_RXD0   -------> PC4
      ETH_RMII_RXD1   -------> PC5
      ETH_RMII_TX_EN  -------> PB11
      ETH_RMII_TXD0   -------> PB12
      ETH_RMII_TXD1   -------> PB13
      ETH_RST_PIN     -------> PE2

                                                 */

  /* Configure PA1, PA2 and PA7 */
  GPIO_InitStructure.Pin = GPIO_PIN_1 | GPIO_PIN_2 | GPIO_PIN_7;
  GPIO_InitStructure.Speed = GPIO_SPEED_HIGH;
  GPIO_InitStructure.Mode = GPIO_MODE_AF_PP;
  GPIO_InitStructure.Pull = GPIO_NOPULL;
  GPIO_InitStructure.Alternate = GPIO_AF11_ETH;
  HAL_GPIO_Init(GPIOA, &GPIO_InitStructure);

  /* Configure PB11, PB12 and PB13 */
  GPIO_InitStructure.Pin = GPIO_PIN_11 | GPIO_PIN_12 | GPIO_PIN_13;
  HAL_GPIO_Init(GPIOB, &GPIO_InitStructure);

  /* Configure PC1, PC4 and PC5 */
  GPIO_InitStructure.Pin = GPIO_PIN_1 | GPIO_PIN_4 | GPIO_PIN_5;
  HAL_GPIO_Init(GPIOC, &GPIO_InitStructure);

    /* Configure PE2 */
  GPIO_InitStructure.Pin = GPIO_PIN_2;
    GPIO_InitStructure.Speed = GPIO_SPEED_FAST;
  GPIO_InitStructure.Mode = GPIO_MODE_OUTPUT_PP;
    GPIO_InitStructure.Pull = GPIO_PULLUP;
  HAL_GPIO_Init(GPIOE, &GPIO_InitStructure);

    HAL_GPIO_WritePin(GPIOE, GPIO_PIN_2, GPIO_PIN_RESET);
    osDelay(50);
    HAL_GPIO_WritePin(GPIOE, GPIO_PIN_2, GPIO_PIN_SET);
    osDelay(50);

  /* Enable the Ethernet global Interrupt */
  HAL_NVIC_SetPriority(ETH_IRQn, 12, 0);
    HAL_NVIC_EnableIRQ(ETH_IRQn);

  /* Enable ETHERNET clock  */
  __HAL_RCC_ETH_CLK_ENABLE();

}

/**
  * @brief  Ethernet Rx Transfer completed callback
  * @param  heth: ETH handle
  * @retval None
  */
void HAL_ETH_RxCpltCallback(ETH_HandleTypeDef *heth)
{
  osSemaphoreRelease(s_xSemaphore);
}

/**
  * @brief  Ethernet IRQ Handler
  * @param  None
  * @retval None
  */
void ETHERNET_IRQHandler(void)
{
  HAL_ETH_IRQHandler(&EthHandle);
}

/*******************************************************************************
                       LL Driver Interface ( LwIP stack --> ETH)
*******************************************************************************/
/**
  * @brief In this function, the hardware should be initialized.
  * Called from ethernetif_init().
  *
  * @param netif the already initialized lwip network interface structure
  *        for this ethernetif
  */
static void low_level_init(struct netif *netif)
{
  uint32_t regvalue = 0;
  uint8_t macaddress[6]= { MAC_ADDR0, MAC_ADDR1, MAC_ADDR2, MAC_ADDR3, MAC_ADDR4, MAC_ADDR5 };

  EthHandle.Instance = ETH;
  EthHandle.Init.MACAddr = macaddress;
  EthHandle.Init.AutoNegotiation = ETH_AUTONEGOTIATION_ENABLE;
  EthHandle.Init.Speed = ETH_SPEED_100M;
  EthHandle.Init.DuplexMode = ETH_MODE_FULLDUPLEX;
  EthHandle.Init.MediaInterface = ETH_MEDIA_INTERFACE_RMII;
  EthHandle.Init.RxMode = ETH_RXINTERRUPT_MODE;
  EthHandle.Init.ChecksumMode = ETH_CHECKSUM_BY_HARDWARE;
  EthHandle.Init.PhyAddress = LAN8720_PHY_ADDRESS;

  /* configure ethernet peripheral (GPIOs, clocks, MAC, DMA) */
  if (HAL_ETH_Init(&EthHandle) == HAL_OK)
  {
    /* Set netif link flag */
    netif->flags |= NETIF_FLAG_LINK_UP;
  }

  /* Initialize Tx Descriptors list: Chain Mode */
  HAL_ETH_DMATxDescListInit(&EthHandle, DMATxDscrTab, &Tx_Buff[0][0], ETH_TXBUFNB);

  /* Initialize Rx Descriptors list: Chain Mode  */
  HAL_ETH_DMARxDescListInit(&EthHandle, DMARxDscrTab, &Rx_Buff[0][0], ETH_RXBUFNB);

  /* set netif MAC hardware address length */
  netif->hwaddr_len = ETHARP_HWADDR_LEN;

  /* set netif MAC hardware address */
  netif->hwaddr[0] =  MAC_ADDR0;
  netif->hwaddr[1] =  MAC_ADDR1;
  netif->hwaddr[2] =  MAC_ADDR2;
  netif->hwaddr[3] =  MAC_ADDR3;
  netif->hwaddr[4] =  MAC_ADDR4;
  netif->hwaddr[5] =  MAC_ADDR5;

  /* set netif maximum transfer unit */
  netif->mtu = 1500;

  /* Accept broadcast address and ARP traffic */
  netif->flags |= NETIF_FLAG_BROADCAST | NETIF_FLAG_ETHARP;

  /* create a binary semaphore used for informing ethernetif of frame reception */
  osSemaphoreDef(SEM);
  s_xSemaphore = osSemaphoreCreate(osSemaphore(SEM) , 1 );

  /* create the task that handles the ETH_MAC */
  osThreadDef(Eth_if, ethernetif_input, osPriorityRealtime, 0, INTERFACE_THREAD_STACK_SIZE);
  osThreadCreate (osThread(Eth_if), netif);

  /* Enable MAC and DMA transmission and reception */
  HAL_ETH_Start(&EthHandle);

  /**** Configure PHY to generate an interrupt when Eth Link state changes ****/
  /* Read Register Configuration */
  HAL_ETH_ReadPHYRegister(&EthHandle, PHY_MICR, &regvalue);

  regvalue |= (PHY_MICR_INT_EN | PHY_MICR_INT_OE);

  /* Enable Interrupts */
  HAL_ETH_WritePHYRegister(&EthHandle, PHY_MICR, regvalue );

  /* Read Register Configuration */
  HAL_ETH_ReadPHYRegister(&EthHandle, PHY_MISR, &regvalue);

  regvalue |= PHY_MISR_LINK_INT_EN;

  /* Enable Interrupt on change of link status */
  HAL_ETH_WritePHYRegister(&EthHandle, PHY_MISR, regvalue);
}

/**
  * @brief This function should do the actual transmission of the packet. The packet is
  * contained in the pbuf that is passed to the function. This pbuf
  * might be chained.
  *
  * @param netif the lwip network interface structure for this ethernetif
  * @param p the MAC packet to send (e.g. IP packet including MAC addresses and type)
  * @return ERR_OK if the packet could be sent
  *         an err_t value if the packet couldn't be sent
  *
  * @note Returning ERR_MEM here if a DMA queue of your MAC is full can lead to
  *       strange results. You might consider waiting for space in the DMA queue
  *       to become available since the stack doesn't retry to send a packet
  *       dropped because of memory failure (except for the TCP timers).
  */
static err_t low_level_output(struct netif *netif, struct pbuf *p)
{
  err_t errval;
  struct pbuf *q;
  uint8_t *buffer = (uint8_t *)(EthHandle.TxDesc->Buffer1Addr);
  __IO ETH_DMADescTypeDef *DmaTxDesc;
  uint32_t framelength = 0;
  uint32_t bufferoffset = 0;
  uint32_t byteslefttocopy = 0;
  uint32_t payloadoffset = 0;

  DmaTxDesc = EthHandle.TxDesc;
  bufferoffset = 0;

  /* copy frame from pbufs to driver buffers */
  for(q = p; q != NULL; q = q->next)
  {
    /* Is this buffer available? If not, goto error */
    if((DmaTxDesc->Status & ETH_DMATXDESC_OWN) != (uint32_t)RESET)
    {
      errval = ERR_USE;
      goto error;
    }

    /* Get bytes in current lwIP buffer */
    byteslefttocopy = q->len;
    payloadoffset = 0;

    /* Check if the length of data to copy is bigger than Tx buffer size*/
    while( (byteslefttocopy + bufferoffset) > ETH_TX_BUF_SIZE )
    {
      /* Copy data to Tx buffer*/
      memcpy( (uint8_t*)((uint8_t*)buffer + bufferoffset), (uint8_t*)((uint8_t*)q->payload + payloadoffset), (ETH_TX_BUF_SIZE - bufferoffset) );

      /* Point to next descriptor */
      DmaTxDesc = (ETH_DMADescTypeDef *)(DmaTxDesc->Buffer2NextDescAddr);

      /* Check if the buffer is available */
      if((DmaTxDesc->Status & ETH_DMATXDESC_OWN) != (uint32_t)RESET)
      {
        errval = ERR_USE;
        goto error;
      }

      buffer = (uint8_t *)(DmaTxDesc->Buffer1Addr);

      byteslefttocopy = byteslefttocopy - (ETH_TX_BUF_SIZE - bufferoffset);
      payloadoffset = payloadoffset + (ETH_TX_BUF_SIZE - bufferoffset);
      framelength = framelength + (ETH_TX_BUF_SIZE - bufferoffset);
      bufferoffset = 0;
    }

    /* Copy the remaining bytes */
    memcpy( (uint8_t*)((uint8_t*)buffer + bufferoffset), (uint8_t*)((uint8_t*)q->payload + payloadoffset), byteslefttocopy );
    bufferoffset = bufferoffset + byteslefttocopy;
    framelength = framelength + byteslefttocopy;
  }

  /* Prepare transmit descriptors to give to DMA */
  HAL_ETH_TransmitFrame(&EthHandle, framelength);

  errval = ERR_OK;

error:

  /* When Transmit Underflow flag is set, clear it and issue a Transmit Poll Demand to resume transmission */
  if ((EthHandle.Instance->DMASR & ETH_DMASR_TUS) != (uint32_t)RESET)
  {
    /* Clear TUS ETHERNET DMA flag */
    EthHandle.Instance->DMASR = ETH_DMASR_TUS;

    /* Resume DMA transmission*/
    EthHandle.Instance->DMATPDR = 0;
  }
  return errval;
}

/**
  * @brief Should allocate a pbuf and transfer the bytes of the incoming
  * packet from the interface into the pbuf.
  *
  * @param netif the lwip network interface structure for this ethernetif
  * @return a pbuf filled with the received packet (including MAC header)
  *         NULL on memory error
  */
static struct pbuf * low_level_input(struct netif *netif)
{
  struct pbuf *p = NULL, *q = NULL;
  u16_t len = 0;
  uint8_t *buffer;
  __IO ETH_DMADescTypeDef *dmarxdesc;
  uint32_t bufferoffset = 0;
  uint32_t payloadoffset = 0;
  uint32_t byteslefttocopy = 0;
  uint32_t i=0;

  /* get received frame */
  if(HAL_ETH_GetReceivedFrame_IT(&EthHandle) != HAL_OK)
    return NULL;

  /* Obtain the size of the packet and put it into the "len" variable. */
  len = EthHandle.RxFrameInfos.length;
  buffer = (uint8_t *)EthHandle.RxFrameInfos.buffer;

  if (len > 0)
  {
    /* We allocate a pbuf chain of pbufs from the Lwip buffer pool */
    p = pbuf_alloc(PBUF_RAW, len, PBUF_POOL);
  }

  if (p != NULL)
  {
    dmarxdesc = EthHandle.RxFrameInfos.FSRxDesc;
    bufferoffset = 0;

    for(q = p; q != NULL; q = q->next)
    {
      byteslefttocopy = q->len;
      payloadoffset = 0;

      /* Check if the length of bytes to copy in current pbuf is bigger than Rx buffer size*/
      while( (byteslefttocopy + bufferoffset) > ETH_RX_BUF_SIZE )
      {
        /* Copy data to pbuf*/
        memcpy( (u8_t*)((u8_t*)q->payload + payloadoffset), (u8_t*)((u8_t*)buffer + bufferoffset), (ETH_RX_BUF_SIZE - bufferoffset));

        /* Point to next descriptor */
        dmarxdesc = (ETH_DMADescTypeDef *)(dmarxdesc->Buffer2NextDescAddr);
        buffer = (unsigned char *)(dmarxdesc->Buffer1Addr);

        byteslefttocopy = byteslefttocopy - (ETH_RX_BUF_SIZE - bufferoffset);
        payloadoffset = payloadoffset + (ETH_RX_BUF_SIZE - bufferoffset);
        bufferoffset = 0;
      }

      /* Copy remaining data in pbuf */
      memcpy( (u8_t*)((u8_t*)q->payload + payloadoffset), (u8_t*)((u8_t*)buffer + bufferoffset), byteslefttocopy);
      bufferoffset = bufferoffset + byteslefttocopy;
  }

   /* Release descriptors to DMA */
   dmarxdesc = EthHandle.RxFrameInfos.FSRxDesc;

    /* Set Own bit in Rx descriptors: gives the buffers back to DMA */
    for (i=0; i< EthHandle.RxFrameInfos.SegCount; i++)
    {
      dmarxdesc->Status |= ETH_DMARXDESC_OWN;
      dmarxdesc = (ETH_DMADescTypeDef *)(dmarxdesc->Buffer2NextDescAddr);
    }

    /* Clear Segment_Count */
    EthHandle.RxFrameInfos.SegCount =0;
  }

  /* When Rx Buffer unavailable flag is set: clear it and resume reception */
  if ((EthHandle.Instance->DMASR & ETH_DMASR_RBUS) != (uint32_t)RESET)
  {
    /* Clear RBUS ETHERNET DMA flag */
    EthHandle.Instance->DMASR = ETH_DMASR_RBUS;
    /* Resume DMA reception */
    EthHandle.Instance->DMARPDR = 0;
  }
  return p;
}


/**
  * @brief This function is the ethernetif_input task, it is processed when a packet
  * is ready to be read from the interface. It uses the function low_level_input()
  * that should handle the actual reception of bytes from the network
  * interface. Then the type of the received packet is determined and
  * the appropriate input function is called.
  *
  * @param netif the lwip network interface structure for this ethernetif
  */
void ethernetif_input( void const * argument )
{
  struct pbuf *p;
  struct netif *netif = (struct netif *) argument;

  for( ;; )
  {
    if (osSemaphoreWait( s_xSemaphore, TIME_WAITING_FOR_INPUT)==osOK)
    {
      do
      {
        p = low_level_input( netif );
        if (p != NULL)
        {
          if (netif->input( p, netif) != ERR_OK )
          {
            pbuf_free(p);
          }
        }
      }while(p!=NULL);
    }
  }
}

/**
  * @brief Should be called at the beginning of the program to set up the
  * network interface. It calls the function low_level_init() to do the
  * actual setup of the hardware.
  *
  * This function should be passed as a parameter to netif_add().
  *
  * @param netif the lwip network interface structure for this ethernetif
  * @return ERR_OK if the loopif is initialized
  *         ERR_MEM if private data couldn't be allocated
  *         any other err_t on error
  */
err_t ethernetif_init(struct netif *netif)
{
  LWIP_ASSERT("netif != NULL", (netif != NULL));

#if LWIP_NETIF_HOSTNAME
  /* Initialize interface hostname */
  netif->hostname = "lwip";
#endif /* LWIP_NETIF_HOSTNAME */

  netif->name[0] = IFNAME0;
  netif->name[1] = IFNAME1;

  netif->output = etharp_output;
  netif->linkoutput = low_level_output;

  /* initialize the hardware */
  low_level_init(netif);

  return ERR_OK;
}

/**
  * @brief  This function sets the netif link status.
  * @param  netif: the network interface
  * @retval None
  */
void ethernetif_set_link(void const *argument)
{
  uint32_t regvalue = 0;
  struct link_str *link_arg = (struct link_str *)argument;

  for(;;)
  {
    if (osSemaphoreWait( link_arg->semaphore, 100)== osOK)
    {
      /* Read PHY_MISR*/
      HAL_ETH_ReadPHYRegister(&EthHandle, PHY_MISR, &regvalue);

      /* Check whether the link interrupt has occurred or not */
      if((regvalue & PHY_LINK_INTERRUPT) != (uint16_t)RESET)
      {
        /* Read PHY_SR*/
        HAL_ETH_ReadPHYRegister(&EthHandle, PHY_SR, &regvalue);

        /* Check whether the link is up or down*/
        if((regvalue & PHY_LINK_STATUS)!= (uint16_t)RESET)
        {
          netif_set_link_up(link_arg->netif);
        }
        else
        {
          netif_set_link_down(link_arg->netif);
        }
      }
    }
  }
}

/**
  * @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(EthHandle.Init.AutoNegotiation != ETH_AUTONEGOTIATION_DISABLE)
    {
      /* Enable Auto-Negotiation */
      HAL_ETH_WritePHYRegister(&EthHandle, PHY_BCR, PHY_AUTONEGOTIATION);

      /* Get tick */
      tickstart = HAL_GetTick();

      /* Wait until the auto-negotiation will be completed */
      do
      {
        HAL_ETH_ReadPHYRegister(&EthHandle, 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(&EthHandle, 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 */
        EthHandle.Init.DuplexMode = ETH_MODE_FULLDUPLEX;
      }
      else
      {
        /* Set Ethernet duplex mode to Half-duplex following the auto-negotiation */
        EthHandle.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 */
        EthHandle.Init.Speed = ETH_SPEED_10M;
      }
      else
      {
        /* Set Ethernet speed to 100M following the auto-negotiation */
        EthHandle.Init.Speed = ETH_SPEED_100M;
      }
    }
    else /* AutoNegotiation Disable */
    {
    error :
      /* Check parameters */
      assert_param(IS_ETH_SPEED(EthHandle.Init.Speed));
      assert_param(IS_ETH_DUPLEX_MODE(EthHandle.Init.DuplexMode));

      /* Set MAC Speed and Duplex Mode to PHY */
      HAL_ETH_WritePHYRegister(&EthHandle, PHY_BCR, ((uint16_t)(EthHandle.Init.DuplexMode >> 3) |
                                                     (uint16_t)(EthHandle.Init.Speed >> 1)));
    }

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

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

  ethernetif_notify_conn_changed(netif);
}

/**
  * @brief  This function notify user about link status changement.
  * @param  netif: the network interface
  * @retval None
  */
__weak void ethernetif_notify_conn_changed(struct netif *netif)
{
  /* NOTE : This is function could be implemented in user file
            when the callback is needed,
  */
}
/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/