STM32F207+DP83848+RT-THREAD实现网线拔插重连试验

我在刚开始遇到这个问题的时候，上网搜了下，讲得都不是很清楚。不非是“重新初始化”、”重新初始化MAC“，但是都是在文字表面。下面直接上代码，附上的代码是自己测试通过的。
1、通过DP83848配置为link状态变化，相应管教会有电平变化（具体看手册），从而触发STM32外部中断，通知STM32网线状态。下面是配置PHY

/************************************************************
**配置DP83848芯片当网线状态变化时产生一个变化电平通知MCU。
*************************************************************/
uint32_t Eth_Link_PHYITConfig(uint16_t PHYAddress)
{
/* PHY registers */
uint32_t tmpreg = 0;
tmpreg = ETH_ReadPHYRegister(PHYAddress, 2);
tmpreg = ETH_ReadPHYRegister(PHYAddress, 3);
/* Read MICR register */
tmpreg = ETH_ReadPHYRegister(PHYAddress, PHY_MICR);
/* Enable output interrupt events to signal via the INT pin */
tmpreg |= (uint32_t)PHY_MICR_INT_EN | PHY_MICR_INT_OE;
if(!(ETH_WritePHYRegister(PHYAddress, PHY_MICR, tmpreg)))
{
/* Return ERROR in case of write timeout */
return ETH_ERROR;
}
/* Read MISR register */
tmpreg = ETH_ReadPHYRegister(PHYAddress, PHY_MISR);
/* Enable Interrupt on change of link status */
tmpreg |= (uint32_t)PHY_MISR_LINK_INT_EN;
if(!(ETH_WritePHYRegister(PHYAddress, PHY_MISR, tmpreg)))
{
/* Return ERROR in case of write timeout */
return ETH_ERROR;
}
/* Return SUCCESS */
return ETH_SUCCESS;
}

2、代码是配置STM32的管脚为下降沿触发中断：

/***********************************************************
***配置GPIOA3为下降沿触发中断，通知MCU网线连接状态变化。
************************************************************/
void Eth_Link_EXTIConfig(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
EXTI_InitTypeDef EXTI_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;

/* Enable the INT (PB14) Clock */
RCC_AHB1PeriphClockCmd(ETH_LINK_GPIO_CLK, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);

/* Configure INT pin as input */
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_InitStructure.GPIO_Pin = ETH_LINK_PIN;
GPIO_Init(ETH_LINK_GPIO_PORT, &GPIO_InitStructure);

/* Connect EXTI Line to INT Pin */
SYSCFG_EXTILineConfig(ETH_LINK_EXTI_PORT_SOURCE, ETH_LINK_EXTI_PIN_SOURCE);

/* Configure EXTI line */
EXTI_InitStructure.EXTI_Line = ETH_LINK_EXTI_LINE;
EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
EXTI_InitStructure.EXTI_LineCmd = ENABLE;
EXTI_Init(&EXTI_InitStructure);

/* Enable and set the EXTI interrupt to the highest priority */
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
NVIC_InitStructure.NVIC_IRQChannel = EXTI3_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}

3、MAC和DMA相关初始化代码（这部分的初始化我们再系统启动的时候已经初始化过了）

static void ETH_MACDMA_Config(void)
{
ETH_InitTypeDef ETH_InitStructure;

/* Enable ETHERNET clock  */
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_ETH_MAC | RCC_AHB1Periph_ETH_MAC_Tx |
RCC_AHB1Periph_ETH_MAC_Rx, ENABLE);

/* Reset ETHERNET on AHB Bus */
ETH_DeInit();
/* Software reset */
ETH_SoftwareReset();
/* Wait for software reset */
while (ETH_GetSoftwareResetStatus() == SET);
/* ETHERNET Configuration --------------------------------------------------*/
/* Call ETH_StructInit if you don't like to configure all ETH_InitStructure parameter */
ETH_StructInit(Ð_InitStructure);
/* Fill ETH_InitStructure parametrs */
/*------------------------   MAC   -----------------------------------*/
ETH_InitStructure.ETH_AutoNegotiation = ETH_AutoNegotiation_Enable;
//ETH_InitStructure.ETH_AutoNegotiation = ETH_AutoNegotiation_Disable;
//  ETH_InitStructure.ETH_Speed = ETH_Speed_10M;
//  ETH_InitStructure.ETH_Mode = ETH_Mode_FullDuplex;
ETH_InitStructure.ETH_LoopbackMode = ETH_LoopbackMode_Disable;
ETH_InitStructure.ETH_RetryTransmission = ETH_RetryTransmission_Disable;
ETH_InitStructure.ETH_AutomaticPadCRCStrip = ETH_AutomaticPadCRCStrip_Disable;
ETH_InitStructure.ETH_ReceiveAll = ETH_ReceiveAll_Disable;
ETH_InitStructure.ETH_BroadcastFramesReception = ETH_BroadcastFramesReception_Enable;
ETH_InitStructure.ETH_PromiscuousMode = ETH_PromiscuousMode_Disable;
ETH_InitStructure.ETH_MulticastFramesFilter = ETH_MulticastFramesFilter_Perfect;
ETH_InitStructure.ETH_UnicastFramesFilter = ETH_UnicastFramesFilter_Perfect;
#ifdef CHECKSUM_BY_HARDWARE
ETH_InitStructure.ETH_ChecksumOffload = ETH_ChecksumOffload_Enable;
#endif
/*------------------------   DMA   -----------------------------------*/
/* When we use the Checksum offload feature, we need to enable the Store and Forward mode:
the store and forward guarantee that a whole frame is stored in the FIFO, so the MAC can insert/verify the checksum,
if the checksum is OK the DMA can handle the frame otherwise the frame is dropped */
ETH_InitStructure.ETH_DropTCPIPChecksumErrorFrame = ETH_DropTCPIPChecksumErrorFrame_Enable;
ETH_InitStructure.ETH_ReceiveStoreForward = ETH_ReceiveStoreForward_Enable;
ETH_InitStructure.ETH_TransmitStoreForward = ETH_TransmitStoreForward_Enable;
ETH_InitStructure.ETH_ForwardErrorFrames = ETH_ForwardErrorFrames_Disable;
ETH_InitStructure.ETH_ForwardUndersizedGoodFrames = ETH_ForwardUndersizedGoodFrames_Disable;
ETH_InitStructure.ETH_SecondFrameOperate = ETH_SecondFrameOperate_Enable;
ETH_InitStructure.ETH_AddressAlignedBeats = ETH_AddressAlignedBeats_Enable;
ETH_InitStructure.ETH_FixedBurst = ETH_FixedBurst_Enable;
ETH_InitStructure.ETH_RxDMABurstLength = ETH_RxDMABurstLength_32Beat;
ETH_InitStructure.ETH_TxDMABurstLength = ETH_TxDMABurstLength_32Beat;
ETH_InitStructure.ETH_DMAArbitration = ETH_DMAArbitration_RoundRobin_RxTx_2_1;
/* Configure Ethernet */
if( ETH_Init(Ð_InitStructure, DP83848_PHY_ADDRESS) ==  ETH_ERROR )
rt_kprintf("ETH init error, may be no link\n");
{
/* Configure the PHY to generate an interrupt on change of link status */
Eth_Link_PHYITConfig(DP83848_PHY_ADDRESS);
/* Configure the EXTI for Ethernet link status. */
Eth_Link_EXTIConfig();
}
/* Enable the Ethernet Rx Interrupt */
ETH_DMAITConfig(ETH_DMA_IT_NIS | ETH_DMA_IT_R , ENABLE);
}

4、网卡和DMA结构体初始化和使能网卡：

static rt_err_t rt_stm32_eth_init(rt_device_t dev)
{
int i;
/* MAC address configuration */
ETH_MACAddressConfig(ETH_MAC_Address0, (u8*)&stm32_eth_device.dev_addr[0]);

/* Initialize Tx Descriptors list: Chain Mode */
ETH_DMATxDescChainInit(DMATxDscrTab, &Tx_Buff[0][0], ETH_TXBUFNB);
/* Initialize Rx Descriptors list: Chain Mode  */
ETH_DMARxDescChainInit(DMARxDscrTab, &Rx_Buff[0][0], ETH_RXBUFNB);

/* Enable Ethernet Rx interrrupt */
{
for(i=0; i<ETH_RXBUFNB; i++)
{
ETH_DMARxDescReceiveITConfig(&DMARxDscrTab[i], ENABLE);
}
}
#ifdef CHECKSUM_BY_HARDWARE
/* Enable the checksum insertion for the Tx frames */
{
for(i=0; i<ETH_TXBUFNB; i++)
{
ETH_DMATxDescChecksumInsertionConfig(&DMATxDscrTab[i], ETH_DMATxDesc_ChecksumTCPUDPICMPFull);
}
}
#endif

{
uint16_t tmp, i=10000;
tmp = ETH_ReadPHYRegister(DP83848_PHY_ADDRESS, PHY_CR);
ETH_WritePHYRegister(DP83848_PHY_ADDRESS, PHY_CDCTRL1, BIST_CONT_MODE );
ETH_WritePHYRegister(DP83848_PHY_ADDRESS, PHY_CR, tmp | BIST_START );//BIST_START

while(i--);

//tmp =  ETH_ReadPHYRegister(DP83848_PHY_ADDRESS, PHY_CR);

if( ETH_ReadPHYRegister(DP83848_PHY_ADDRESS, PHY_CR) & BIST_STATUS == BIST_STATUS )
{
rt_kprintf("BIST pass\n");
}
else
{
uint16_t ctrl;

ctrl = ETH_ReadPHYRegister(DP83848_PHY_ADDRESS, PHY_CDCTRL1);
rt_kprintf("BIST faild count =%d\n", BIST_ERROR_COUNT(ctrl) );
}
tmp &= ~BIST_START; //Stop BIST
ETH_WritePHYRegister(DP83848_PHY_ADDRESS, PHY_CR, tmp);
}

/* Enable MAC and DMA transmission and reception */
ETH_Start();
return RT_EOK;
}

以上的代码都是初始化之类的，没有什么，是下面是实现网线热拔插功能主要函数；

/**********************************************
**当网线连接状态判断是出于连接状态还是拔开状态，
**若为连接状态就根据实际情况重新配置MAC和DMA。
**********************************************/
void Eth_Link_ITHandler(uint16_t PHYAddress)
{
/* Check whether the link interrupt has occurred or not */
if(((ETH_ReadPHYRegister(PHYAddress, PHY_MISR)) & PHY_LINK_STATUS) != 0)
{
uint16_t status  = ETH_ReadPHYRegister(PHYAddress, PHY_BSR);
if(status & (PHY_AutoNego_Complete | PHY_Linked_Status)){
init_dma_mac();//初始化MAC和DMA相关参数
rt_kprintf("qqx enter net_link is  connect.\n\r");
}
else{
rt_kprintf("qqx enter net_link is  out\n\r");
}
}
}

//初始化MAC和DMA相关参数
void init_dma_mac(void)
{
rt_device_t stm32_eth_device;
ETH_MACDMA_Config();
stm32_eth_device = rt_device_find("e0");
rt_stm32_eth_init(stm32_eth_device);
}

/*************************************************
**MCU外部中断入口函数，当STM32相应管教检测到下降沿
**变化则就会进入此中断函数。
*************************************************/
void EXTI3_IRQHandler(void)
{
if(EXTI_GetITStatus(ETH_LINK_EXTI_LINE) != RESET)
{
Eth_Link_ITHandler(DP83848_PHY_ADDRESS);
/* Clear interrupt pending bit */
EXTI_ClearITPendingBit(ETH_LINK_EXTI_LINE);
}
}

总体的步骤是：进入中断后调用Eth_Link_ITHandler(DP83848_PHY_ADDRESS); ->

(1)ETH_MACDMA_Config();

(2)rt_stm32_eth_init(stm32_eth_device);//通过设备查找函数找到“e0（按照自己实际名称）”设备并初始化这个网络设备，

这样不管网线在什么时候拔插都可以联通，完美解决热拔插网线的问题。