ARM-Linux驅(qū)動--DM9000網(wǎng)卡驅(qū)動分析（二）硬件平臺：FL2440（s3c2440）內(nèi)核版本：2.6.35
主機平臺：Ubuntu11.04
內(nèi)核版本：2.6.39
交叉編譯器：arm-linuc-gcc4.3.2
原創(chuàng)作品，轉(zhuǎn)載請標明出處http://blog.csdn.net/yming0221/article/details/6615027
本文接上文
ARM-Linux驅(qū)動--DM9000網(wǎng)卡驅(qū)動分析（一）
ARM-Linux驅(qū)動--DM9000網(wǎng)卡驅(qū)動分析（二）
下面開始看網(wǎng)卡設(shè)備的打開、關(guān)閉函數(shù)和操作函數(shù)
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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
};
1、DM9000的打開函數(shù)
由于在函數(shù)alloc_netdev_mq()中分配net_device和網(wǎng)卡的私有數(shù)據(jù)是一起分配的，詳見函數(shù)的實現(xiàn)
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struct net_device *alloc_netdev_mq(int sizeof_priv, const char *name,
void (*setup)(struct net_device *), unsigned int queue_count)
{
...................
alloc_size = sizeof(struct net_device);
if (sizeof_priv) {
alloc_size = ALIGN(alloc_size, NETDEV_ALIGN);
alloc_size += sizeof_priv;
}
alloc_size += NETDEV_ALIGN - 1;
p = kzalloc(alloc_size, GFP_KERNEL);
if (!p) {
printk(KERN_ERR "alloc_netdev: Unable to allocate device.n");
return NULL;
}
tx = kcalloc(queue_count, sizeof(struct netdev_queue), GFP_KERNEL);
if (!tx) {
printk(KERN_ERR "alloc_netdev: Unable to allocate "
"tx qdiscs.n");
goto free_p;
}
#ifdef CONFIG_RPS
rx = kcalloc(queue_count, sizeof(struct netdev_rx_queue), GFP_KERNEL);
if (!rx) {
printk(KERN_ERR "alloc_netdev: Unable to allocate "
"rx queues.n");
goto free_tx;
}
..............
}
所以使用函數(shù)netdev_priv()函數(shù)返回的是網(wǎng)卡的私有數(shù)據(jù)的地址，函數(shù)的實現(xiàn)如下：
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static inline void *netdev_priv(const struct net_device *dev)
{
return (char *)dev + ALIGN(sizeof(struct net_device), NETDEV_ALIGN);
}
這樣兩者會同時生存和消失。
dm9000_open()函數(shù)
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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 %sn", dev->name);
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;
dm9000_reset(db);
dm9000_init_dm9000(dev);
db->dbug_cnt = 0;
mii_check_media(&db->mii, netif_msg_link(db), 1);
netif_start_queue(dev);
dm9000_schedule_poll(db);
return 0;
}
2、網(wǎng)卡關(guān)閉函數(shù)
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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 %sn", ndev->name);
cancel_delayed_work_sync(&db->phy_poll);
netif_stop_queue(ndev);
netif_carrier_off(ndev);
free_irq(ndev->irq, ndev);
dm9000_shutdown(ndev);
return 0;
}
下面是調(diào)用的dm9000_shutdown(ndev)函數(shù)，該函數(shù)的功能是復(fù)位phy，配置寄存器GPR位0為1，關(guān)閉dm9000電源，配置寄存器IMR位7為1，disable中斷，配置寄存器RCR，disable接收
函數(shù)如下:
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static void
dm9000_shutdown(struct net_device *dev)
{
board_info_t *db = netdev_priv(dev);
dm9000_phy_write(dev, 0, MII_BMCR, BMCR_RESET);
iow(db, DM9000_GPR, 0x01);
iow(db, DM9000_IMR, IMR_PAR);
iow(db, DM9000_RCR, 0x00);
}
3、接下來了解一下數(shù)據(jù)的發(fā)送函數(shù)dm9000_start_xmit
上圖可以看出DM9000的SRAM中地址0x0000到0x0BFF是TXBuffer，從0x0C00到0x3FFF是RXBuffer，包的有效數(shù)據(jù)必須提前放到TXBuffer緩沖區(qū)，使用端口命令來選擇MWCMD寄存器。最后設(shè)置TXCR寄存器的bit[0]TXREQ來自動發(fā)送包。
發(fā)送包的步驟如下:
（1）檢查存儲器寬度，通過讀取ISR的bit[7:6]來確定位數(shù)
（2）寫數(shù)據(jù)到TXSRAM
（3）寫傳輸長度到TXPLL和TXPLH寄存器
（4）設(shè)置TXCR的bit[0]TXREQ來發(fā)送包
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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)
return NETDEV_TX_BUSY;
spin_lock_irqsave(&db->lock, flags);
writeb(DM9000_MWCMD, db->io_addr);
(db->outblk)(db->io_data, skb->data, skb->len);
dev->stats.tx_bytes += skb->len;
db->tx_pkt_cnt++;
if (db->tx_pkt_cnt == 1) {
dm9000_send_packet(dev, skb->ip_summed, skb->len);
} else {
db->queue_pkt_len = skb->len;
db->queue_ip_summed = skb->ip_summed;
netif_stop_queue(dev);
}
spin_unlock_irqrestore(&db->lock, flags);
dev_kfree_skb(skb);
return NETDEV_TX_OK;
}
上面函數(shù)調(diào)用下面的函數(shù) dm9000_send_packet來發(fā)送數(shù)據(jù)
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static void dm9000_send_packet(struct net_device *dev,
int ip_summed,
u16 pkt_len)
{
board_info_t *dm = to_dm9000_board(dev);
if (dm->ip_summed != ip_summed) {
if (ip_summed == CHECKSUM_NONE)
iow(dm, DM9000_TCCR, 0);
else
iow(dm, DM9000_TCCR, TCCR_IP | TCCR_UDP | TCCR_TCP);
dm->ip_summed = ip_summed;
}
iow(dm, DM9000_TXPLL, pkt_len);
iow(dm, DM9000_TXPLH, pkt_len >> 8);
iow(dm, DM9000_TCR, TCR_TXREQ);
}
5、下面看一下當一個數(shù)據(jù)包發(fā)送完成后的中斷處理函數(shù)dm9000_tx_done
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static void dm9000_tx_done(struct net_device *dev, board_info_t *db)
{
int tx_status = ior(db, DM9000_NSR);
if (tx_status & (NSR_TX2END | NSR_TX1END)) {
db->tx_pkt_cnt--;
dev->stats.tx_packets++;
if (netif_msg_tx_done(db))
dev_dbg(db->dev, "tx done, NSR xn", tx_status);
if (db->tx_pkt_cnt > 0)
dm9000_send_packet(dev, db->queue_ip_summed,
db->queue_pkt_len);
netif_wake_queue(dev);
}
}
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