S3C2440驱动简析——DM9000网卡驱动（4）

     本文我们主要来分析.probe的第一个操作函数组dm9000_netdev_ops（一个结构体），贴出该结构体代码如下

static const struct net_device_ops dm9000_netdev_ops = {.ndo_open= dm9000_open,.ndo_stop= dm9000_stop,.ndo_start_xmit= dm9000_start_xmit,.ndo_tx_timeout= dm9000_timeout,.ndo_set_multicast_list= dm9000_hash_table,.ndo_do_ioctl= dm9000_ioctl,.ndo_change_mtu= eth_change_mtu,.ndo_validate_addr= eth_validate_addr,.ndo_set_mac_address= eth_mac_addr,#ifdef CONFIG_NET_POLL_CONTROLLER.ndo_poll_controller= dm9000_poll_controller,#endif};

这里定义了操作net_device的一些重要操作，分别介绍如下：

 

1.dm9000_open

static int dm9000_open(struct net_device *dev){board_info_t *db = netdev_priv(dev);unsigned long irqflags = db->irq_res->flags & IRQF_TRIGGER_MASK;if (netif_msg_ifup(db))dev_dbg(db->dev, "enabling %s/n", dev->name);/* If there is no IRQ type specified, default to something that * may work, and tell the user that this is a problem */if (irqflags == IRQF_TRIGGER_NONE)dev_warn(db->dev, "WARNING: no IRQ resource flags set./n");irqflags |= IRQF_SHARED;if (request_irq(dev->irq, dm9000_interrupt, irqflags, dev->name, dev))return -EAGAIN; //申请中断资源/* GPIO0 on pre-activate PHY, Reg 1F is not set by reset */iow(db, DM9000_GPR, 0);/* REG_1F bit0 activate phyxcer */mdelay(1); /* delay needs by DM9000B *//* Initialize DM9000 board */dm9000_reset(db); //复位DM9000芯片 dm9000_init_dm9000(dev); //配置DM9000芯片内寄存器，使其能工作/* Init driver variable */db->dbug_cnt = 0;mii_check_media(&db->mii, netif_msg_link(db), 1); //检测mii接口的状态netif_start_queue(dev); //启动设备工作队列dm9000_schedule_poll(db); //阻塞return 0;}

 

2.dm9000_stop

static int dm9000_stop(struct net_device *ndev){board_info_t *db = netdev_priv(ndev);if (netif_msg_ifdown(db))dev_dbg(db->dev, "shutting down %s/n", ndev->name);cancel_delayed_work_sync(&db->phy_poll); //取消设备阻塞netif_stop_queue(ndev); //停止工作队列netif_carrier_off(ndev); /* free interrupt */free_irq(ndev->irq, ndev); //释放中断资源dm9000_shutdown(ndev);return 0;}

其工作与open函数基本是相对应的，主要是资源的释放和停止设备发送队列。

 

3.dm9000_start_xmit

static int dm9000_start_xmit(struct sk_buff *skb, struct net_device *dev){unsigned long flags;board_info_t *db = netdev_priv(dev);dm9000_dbg(db, 3, "%s:/n", __func__);if (db->tx_pkt_cnt > 1) //检查设备是否忙状态return NETDEV_TX_BUSY;spin_lock_irqsave(&db->lock, flags); //上锁的同时记录中断状态/* Move data to DM9000 TX RAM */writeb(DM9000_MWCMD, db->io_addr); //写数据到DM9000的发送缓冲区(db->outblk)(db->io_data, skb->data, skb->len);dev->stats.tx_bytes += skb->len;db->tx_pkt_cnt++;/* TX control: First packet immediately send, second packet queue */if (db->tx_pkt_cnt == 1) { //第一个队列立刻发送dm9000_send_packet(dev, skb->ip_summed, skb->len);} else { /* Second packet */db->queue_pkt_len = skb->len;db->queue_ip_summed = skb->ip_summed;netif_stop_queue(dev);}spin_unlock_irqrestore(&db->lock, flags); //解锁，恢复上锁前的中断状态/* free this SKB */dev_kfree_skb(skb); //释放skbreturn NETDEV_TX_OK;}

主要功能是将从上层传入的数据发送到media中。

 

4.dm9000_timeout

static void dm9000_timeout(struct net_device *dev){board_info_t *db = netdev_priv(dev);u8 reg_save;unsigned long flags;/* Save previous register address */spin_lock_irqsave(&db->lock, flags); //上锁reg_save = readb(db->io_addr); //把残留数据保存起来netif_stop_queue(dev); dm9000_reset(db);dm9000_init_dm9000(dev);/* We can accept TX packets again */dev->trans_start = jiffies; /* prevent tx timeout */netif_wake_queue(dev);/* Restore previous register address */writeb(reg_save, db->io_addr); //复原上次的残留数据spin_unlock_irqrestore(&db->lock, flags); //解锁}

看门狗被触发后调用此函数，主要执行设备的重启动作。

 

5.dm9000_hash_table

static void dm9000_hash_table(struct net_device *dev){board_info_t *db = netdev_priv(dev);unsigned long flags;spin_lock_irqsave(&db->lock, flags);dm9000_hash_table_unlocked(dev);spin_unlock_irqrestore(&db->lock, flags);}

核心函数dm9000_hash_table_unlocked(dev)完成设置组播地址的功能。

 

6.dm9000_ioctl

static int dm9000_ioctl(struct net_device *dev, struct ifreq *req, int cmd){board_info_t *dm = to_dm9000_board(dev);if (!netif_running(dev))return -EINVAL;return generic_mii_ioctl(&dm->mii, if_mii(req), cmd, NULL);}

核心函数 generic_mii_ioctl(&dm->mii, if_mii(req), cmd, NULL)代码如下

int generic_mii_ioctl(struct mii_if_info *mii_if, struct mii_ioctl_data *mii_data, int cmd, unsigned int *duplex_chg_out){int rc = 0;unsigned int duplex_changed = 0;if (duplex_chg_out)*duplex_chg_out = 0;mii_data->phy_id &= mii_if->phy_id_mask;mii_data->reg_num &= mii_if->reg_num_mask;switch(cmd) {case SIOCGMIIPHY:mii_data->phy_id = mii_if->phy_id;/* fall through */case SIOCGMIIREG:mii_data->val_out =mii_if->mdio_read(mii_if->dev, mii_data->phy_id, mii_data->reg_num);break;case SIOCSMIIREG: {u16 val = mii_data->val_in;if (mii_data->phy_id == mii_if->phy_id) {switch(mii_data->reg_num) {case MII_BMCR: {unsigned int new_duplex = 0;if (val & (BMCR_RESET|BMCR_ANENABLE))mii_if->force_media = 0;elsemii_if->force_media = 1;if (mii_if->force_media && (val & BMCR_FULLDPLX))new_duplex = 1;if (mii_if->full_duplex != new_duplex) {duplex_changed = 1;mii_if->full_duplex = new_duplex;}break;}case MII_ADVERTISE:mii_if->advertising = val;break;default:/* do nothing */break;}}mii_if->mdio_write(mii_if->dev, mii_data->phy_id, mii_data->reg_num, val);break;}default:rc = -EOPNOTSUPP;break;}if ((rc == 0) && (duplex_chg_out) && (duplex_changed))*duplex_chg_out = 1;return rc;}

一个非常熟悉的switch case 结构函数，具体完成的动作这里不细讲啦~

 

7.eth_change_mtu

int eth_change_mtu(struct net_device *dev, int new_mtu){if (new_mtu < 68 || new_mtu > ETH_DATA_LEN)return -EINVAL;dev->mtu = new_mtu;return 0;}

修改MTU值

 

8.eth_validate_addr

int eth_validate_addr(struct net_device *dev){if (!is_valid_ether_addr(dev->dev_addr))return -EADDRNOTAVAIL;return 0;}

判断地址是否全0xff或全0，非法

 

9.eth_mac_addr

int eth_mac_addr(struct net_device *dev, void *p){struct sockaddr *addr = p;if (netif_running(dev))return -EBUSY;if (!is_valid_ether_addr(addr->sa_data))return -EADDRNOTAVAIL;memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);return 0;}

把addr的sa_data成员绑定到设备地址

 

10.dm9000_poll_controller

static void dm9000_poll_controller(struct net_device *dev){disable_irq(dev->irq);dm9000_interrupt(dev->irq, dev);enable_irq(dev->irq);}

函数dm9000_interrupt如下

static irqreturn_t dm9000_interrupt(int irq, void *dev_id){struct net_device *dev = dev_id;board_info_t *db = netdev_priv(dev);int int_status;unsigned long flags;u8 reg_save;dm9000_dbg(db, 3, "entering %s/n", __func__);/* A real interrupt coming *//* holders of db->lock must always block IRQs */spin_lock_irqsave(&db->lock, flags);/* Save previous register address */reg_save = readb(db->io_addr);/* Disable all interrupts */iow(db, DM9000_IMR, IMR_PAR); //关中断/* Got DM9000 interrupt status */int_status = ior(db, DM9000_ISR);//获取中断状态iow(db, DM9000_ISR, int_status);//清除中断状态if (netif_msg_intr(db))dev_dbg(db->dev, "interrupt status %02x/n", int_status); //根据状态来判定是接收还是发送触发的中断/* Received the coming packet */if (int_status & ISR_PRS) //接收dm9000_rx(dev);/* Trnasmit Interrupt check */if (int_status & ISR_PTS) //发送dm9000_tx_done(dev, db);if (db->type != TYPE_DM9000E) {if (int_status & ISR_LNKCHNG) {/* fire a link-change request */schedule_delayed_work(&db->phy_poll, 1);}}/* Re-enable interrupt mask */iow(db, DM9000_IMR, db->imr_all);/* Restore previous register address */writeb(reg_save, db->io_addr);spin_unlock_irqrestore(&db->lock, flags);return IRQ_HANDLED;}

 

 

到此为止，已经粗略的介绍完dm9000_netdev_ops的各个重要的操作。本博文应该是这个系列的倒数第二篇了，最后一篇用来分析dm9000_ethtod_ops的操作，敬请关注~

 

 

 

本系列课程链接地址

DM9000网卡驱动（1）http://blog.csdn.net/jarvis_xian/archive/2011/06/10/6537446.aspx
DM9000网卡驱动（2）http://blog.csdn.net/jarvis_xian/archive/2011/06/12/6539931.aspx
DM9000网卡驱动（3）http://blog.csdn.net/jarvis_xian/archive/2011/06/13/6542411.aspx
DM9000网卡驱动（4）http://blog.csdn.net/jarvis_xian/archive/2011/06/15/6545109.aspx
DM9000网卡驱动（5）http://blog.csdn.net/jarvis_xian/archive/2011/06/15/6547203.aspx