lwIP - TCP echo server in STM32F769-Discovery

[Omar Suárez]

Posted on February 22, 2018 at 16:21

Hello,

I am trying to make an example application consisting in a TCP echo server using the RAW from the lwIP stack just to understand how it works. I am using the STM32F769NI - Discovery board as the target which mounts the PHY LAN8742A. I am using the examples in the STM32F7Cube HAL to prepare my project but I am a stuck in the ethernetif.c file.

I can find some examples in the F7Cube HAL using the EVAL boards but those mount a different PHY (DP83848) and also in the F4Cube HAL but with the same problem, different PHY. The fact is that the PHY are different one from another so I can not use the 'hal_conf.h' code with the PHY registers as in those examples. I need to change the use of the registers and the configuration of the interrupts from the PHY.

I am new to the lwIP so I am not sure how to configure the Discovery PHY to use it in the same way as the one in the EVAL boards.

Below I attach the code for the two functions inside the 'eterhnetif.c' file which use those registers (defined in the hal_conf.h) to set up the interrupts needed for this TCP echo application.

/* ethernetif.c file */

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/**

  * @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);    }  }}

/* ethernetif.c file */

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/**

  * @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);}

Anyone has configured a project to work as TCP echo server using the Discovery board or the PHY mounted on it (LAN8742A)? How can I configure the PHY to work the same way as in the EVAL board application?

Thanks in advanced,

Omar

#ethernet-stm32f7 #stm32f7-hal #phy #tcp/ip

[Omar Suárez]

Posted on February 22, 2018 at 16:23

Note that the registers configured in the DP83848 are PHY_SR, PHY_MISR and PHY_MICR.