text: /**
    ******************************************************************************
    * @file    LwIP/LwIP_HTTP_Server_Raw/Src/ethernetif.c
    * @author  MCD Application Team
    * @brief   This file implements Ethernet network interface drivers for lwIP
    ******************************************************************************
    * @attention
    *
    * <h2><center>&copy; Copyright (c) 2017 STMicroelectronics International N.V. 
    * All rights reserved.</center></h2>
    *
    * Redistribution and use in source and binary forms, with or without 
    * modification, are permitted, provided that the following conditions are met:
    *
    * 1. Redistribution of source code must retain the above copyright notice, 
    *    this list of conditions and the following disclaimer.
    * 2. Redistributions in binary form must reproduce the above copyright notice,
    *    this list of conditions and the following disclaimer in the documentation
    *    and/or other materials provided with the distribution.
    * 3. Neither the name of STMicroelectronics nor the names of other 
    *    contributors to this software may be used to endorse or promote products 
    *    derived from this software without specific written permission.
    * 4. This software, including modifications and/or derivative works of this 
    *    software, must execute solely and exclusively on microcontroller or
    *    microprocessor devices manufactured by or for STMicroelectronics.
    * 5. Redistribution and use of this software other than as permitted under 
    *    this license is void and will automatically terminate your rights under 
    *    this license. 
    *
    * THIS SOFTWARE IS PROVIDED BY STMICROELECTRONICS AND CONTRIBUTORS "AS IS" 
    * AND ANY EXPRESS, IMPLIED OR STATUTORY WARRANTIES, INCLUDING, BUT NOT 
    * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A 
    * PARTICULAR PURPOSE AND NON-INFRINGEMENT OF THIRD PARTY INTELLECTUAL PROPERTY
    * RIGHTS ARE DISCLAIMED TO THE FULLEST EXTENT PERMITTED BY LAW. IN NO EVENT 
    * SHALL STMICROELECTRONICS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
    * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, 
    * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 
    * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 
    * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
    * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    *
    ******************************************************************************
    */
  /* Includes ------------------------------------------------------------------*/
  #include "stm32f4xx_hal.h"
  #include "lwip/timeouts.h"
  #include "netif/etharp.h"
  #include "ethernetif.h"
  #include <string.h>
  
  /* Private typedef -----------------------------------------------------------*/
  /* Private define ------------------------------------------------------------*/
  /* Network interface name */
  #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 */
  
  ETH_HandleTypeDef EthHandle;
  
  /* Private function prototypes -----------------------------------------------*/
  /* 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;
    
    /* 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 ************************************************/
     /*
          ETH_MDIO -------------------------> PA2
          ETH_MDC --------------------------> PC1
          ETH_PPS_OUT ----------------------> PB5
          ETH_MII_CRS ----------------------> PH2
          ETH_MII_COL ----------------------> PH3
          ETH_MII_RX_ER --------------------> PI10
          ETH_MII_RXD2 ---------------------> PH6
          ETH_MII_RXD3 ---------------------> PH7
          ETH_MII_TX_CLK -------------------> PC3
          ETH_MII_TXD2 ---------------------> PC2
          ETH_MII_TXD3 ---------------------> PB8
          ETH_MII_RX_CLK/ETH_RMII_REF_CLK---> PA1
          ETH_MII_RX_DV/ETH_RMII_CRS_DV ----> PA7
          ETH_MII_RXD0/ETH_RMII_RXD0 -------> PC4
          ETH_MII_RXD1/ETH_RMII_RXD1 -------> PC5
          ETH_MII_TX_EN/ETH_RMII_TX_EN -----> PG11
          ETH_MII_TXD0/ETH_RMII_TXD0 -------> PG13
          ETH_MII_TXD1/ETH_RMII_TXD1 -------> PG14
                                                    */
  
    /* Configure PA1, PA2 , 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 PB5 and PB8 */
    GPIO_InitStructure.Pin = GPIO_PIN_5 | GPIO_PIN_8;
    HAL_GPIO_Init(GPIOB, &GPIO_InitStructure);
  
    /* Configure PC1, PC2, PC3, PC4 and PC5 */
    GPIO_InitStructure.Pin = GPIO_PIN_1 | GPIO_PIN_2 | GPIO_PIN_3 | GPIO_PIN_4 | GPIO_PIN_5;
    HAL_GPIO_Init(GPIOC, &GPIO_InitStructure);
                               
    /* Configure PG11, PG14 and PG13 */
    GPIO_InitStructure.Pin =  GPIO_PIN_11 | GPIO_PIN_13 | GPIO_PIN_14;
    HAL_GPIO_Init(GPIOG, &GPIO_InitStructure);
  
    /* Configure PH2, PH3, PH6, PH7 */
    GPIO_InitStructure.Pin = GPIO_PIN_2 | GPIO_PIN_3 | GPIO_PIN_6 | GPIO_PIN_7;
    HAL_GPIO_Init(GPIOH, &GPIO_InitStructure);
  
    /* Configure PI10 */
    GPIO_InitStructure.Pin = GPIO_PIN_10;
    HAL_GPIO_Init(GPIOI, &GPIO_InitStructure);
    
    /* Enable ETHERNET clock  */
    __HAL_RCC_ETH_CLK_ENABLE();
    
    if (heth->Init.MediaInterface == ETH_MEDIA_INTERFACE_MII)
    {
      /* Output HSE clock (25MHz) on MCO pin (PA8) to clock the PHY */
      HAL_RCC_MCOConfig(RCC_MCO1, RCC_MCO1SOURCE_HSE, RCC_MCODIV_1);
    }
  }
  
  /*******************************************************************************
                         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_MII;
    EthHandle.Init.RxMode = ETH_RXPOLLING_MODE;
    EthHandle.Init.ChecksumMode = ETH_CHECKSUM_BY_HARDWARE;
    EthHandle.Init.PhyAddress = DP83848_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 MAC hardware address length */
    netif->hwaddr_len = ETH_HWADDR_LEN;
    
    /* set 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;
    
    /* maximum transfer unit */
    netif->mtu = 1500;
    
    /* device capabilities */
    /* don't set NETIF_FLAG_ETHARP if this device is not an ethernet one */
    netif->flags |= NETIF_FLAG_BROADCAST | NETIF_FLAG_ETHARP;
    
    /* 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 availale 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;
    struct pbuf *q;
    uint16_t len;
    uint8_t *buffer;
    __IO ETH_DMADescTypeDef *dmarxdesc;
    uint32_t bufferoffset = 0;
    uint32_t payloadoffset = 0;
    uint32_t byteslefttocopy = 0;
    uint32_t i=0;
    
    if (HAL_ETH_GetReceivedFrame(&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( (uint8_t*)((uint8_t*)q->payload + payloadoffset), (uint8_t*)((uint8_t*)buffer + bufferoffset), (ETH_RX_BUF_SIZE - bufferoffset));
          
          /* Point to next descriptor */
          dmarxdesc = (ETH_DMADescTypeDef *)(dmarxdesc->Buffer2NextDescAddr);
          buffer = (uint8_t *)(dmarxdesc->Buffer1Addr);
          
          byteslefttocopy = byteslefttocopy - (ETH_RX_BUF_SIZE - bufferoffset);
          payloadoffset = payloadoffset + (ETH_RX_BUF_SIZE - bufferoffset);
          bufferoffset = 0;
        }
        
        /* Copy remaining data in pbuf */
        memcpy( (uint8_t*)((uint8_t*)q->payload + payloadoffset), (uint8_t*)((uint8_t*)buffer + bufferoffset), byteslefttocopy);
        bufferoffset = bufferoffset + byteslefttocopy;
      }
    } 
      
    /* Release descriptors to DMA */
    /* Point to first descriptor */
    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 should be called 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(struct netif *netif)
  {
    err_t err;
    struct pbuf *p;
    
    /* move received packet into a new pbuf */
    p = low_level_input(netif);
      
    /* no packet could be read, silently ignore this */
    if (p == NULL) return;
      
    /* entry point to the LwIP stack */
    err = netif->input(p, netif);
      
    if (err != ERR_OK)
    {
      LWIP_DEBUGF(NETIF_DEBUG, ("ethernetif_input: IP input error\n"));
      pbuf_free(p);
      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;
    /* We directly use etharp_output() here to save a function call.
     * You can instead declare your own function an call etharp_output()
     * from it if you have to do some checks before sending (e.g. if link
     * is available...) */
    netif->output = etharp_output;
    netif->linkoutput = low_level_output;
  
    /* initialize the hardware */
    low_level_init(netif);
  
    return ERR_OK;
  }
  
  /**
    * @brief  Returns the current time in milliseconds
    *         when LWIP_TIMERS == 1 and NO_SYS == 1
    * @param  None
    * @retval Current Time value
    */
  u32_t sys_now(void)
  {
    return HAL_GetTick();
  }
  
  /**
    * @brief  This function sets the netif link status.
    * @param  netif: the network interface
    * @retval None
    */
  void ethernetif_set_link(struct netif *netif)
  {
    uint32_t regvalue = 0;
    
    /* 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(netif);
      }
      else
      {
        netif_set_link_down(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****/
  