网卡芯片为realteak 8201

1.  net_device结构体的分配和注册

     1) "/drivers/net/ethernet/sun7i/sun7i_wemac.c"

     wemac_probe()

             ndev = alloc_etherdev(sizeof(struct wemac_board_info));     分配

             ret = register_netdev(ndev);                                                   注册

     2) alloc_etherdev定义在 "/include/linux/etherdevice.h"

    #define alloc_etherdev(sizeof_priv) alloc_etherdev_mq(sizeof_priv, 1)
     #define alloc_etherdev_mq(sizeof_priv, count) alloc_etherdev_mqs(sizeof_priv, count, count)

    3) alloc_etherdev_mqs定义在 "/net/ethernet/eth.c"

     struct net_device *alloc_etherdev_mqs(int sizeof_priv, unsigned int txqs,
                      unsigned int rxqs)
     {
              return alloc_netdev_mqs(sizeof_priv, "eth%d", ether_setup, txqs, rxqs);
     }

2. 发包函数

   "/drivers/net/ethernet/sun7i/sun7i_wemac.c"

    /*
       *  Hardware start transmission.
       *  Send a packet to media from the upper layer.
    */
     static int wemac_start_xmit(struct sk_buff *skb, struct net_device *dev)

             1) dev->stats.tx_bytes += skb->len;              发包统计信息

             2)将skb数据写入网卡

             /* set TX len */
             writel(skb->len, db->emac_vbase + EMAC_TX_PL0_REG);
             /* start translate from fifo to phy */
            writel(readl(db->emac_vbase + EMAC_TX_CTL0_REG)
                | 1, db->emac_vbase + EMAC_TX_CTL0_REG);
             dev->trans_start = jiffies;    /* save the time stamp */

             3) 释放skb

             dev_kfree_skb(skb);                                   释放skb

             4) netif_stop_queue(dev);                         停止队列，数据发送完后由中断处理程序来唤醒队列

3. 中断处理程序

    static irqreturn_t wemac_interrupt(int irq, void *dev_id)

     1)  wemac_tx_done(dev, db, int_status)

          当数据发送完后，产生中断，此函数调用，然后调用netif_wake_queue(dev)来唤醒队列

    2)  wemac_rx(dev)

          接收数据包，最终调用netif_rx接收skb

4. MAC地址设置

   "/drivers/net/ethernet/sun7i/sun7i_wemac.c"

   static int wemac_set_mac_address(struct net_device *dev, void *p)