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DM9000 网卡驱动程序分析
平台：MINI2440
系统：Linux-2.6.36.2
mach-s3c2410/include/mach/map.h：
#define S3C2410_CS4 (0x20000000) //AEN接nGCS4，BANK4
mach-mini2440.c：
#define MACH_MINI2440_DM9K_BASE (S3C2410_CS4 + 0x300) //TXD[2:0]悬空
static struct resource mini2440_dm9k_resource[] = {
[0] = {
.start = MACH_MINI2440_DM9K_BASE,
.end = MACH_MINI2440_DM9K_BASE + 3,
.flags = IORESOURCE_MEM
},
[1] = {
.start = MACH_MINI2440_DM9K_BASE + 4,
.end = MACH_MINI2440_DM9K_BASE + 7,
.flags = IORESOURCE_MEM
},
[2] = {
.start = IRQ_EINT7, //中断使用了EINT7.
.end = IRQ_EINT7,
.flags = IORESOURCE_IRQ | IORESOURCE_IRQ_HIGHEDGE,
}
};DM9000平台设备的定义：static struct dm9000_plat_data mini2440_dm9k_pdata = http://www.mamicode.com/{>板子初始化时将平台设备驱动加载到总线上：static struct platform_device *mini2440_devices[] __initdata = http://www.mamicode.com/{>dm9000.c：platform_driver与重要操作函数：static struct platform_driver dm9000_driver = {
.driver = {
.name = "dm9000",
.owner = THIS_MODULE,
},
.probe = dm9000_probe,
.remove = __devexit_p(dm9000_drv_remove),
.suspend = dm9000_drv_suspend,
.resume = dm9000_drv_resume,
};net_device_ops与重要操作函数：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
};ethtool_ops：static const struct ethtool_ops dm9000_ethtool_ops = { //查询与设置网卡的参数
.get_drvinfo = dm9000_get_drvinfo,
.get_settings = dm9000_get_settings,
.set_settings = dm9000_set_settings,
.get_msglevel = dm9000_get_msglevel,
.set_msglevel = dm9000_set_msglevel,
.nway_reset = dm9000_nway_reset,
.get_link = dm9000_get_link,
.get_eeprom_len = dm9000_get_eeprom_len,
.get_eeprom = dm9000_get_eeprom,
.set_eeprom = dm9000_set_eeprom,
};board_info结构体，内容是与芯片相关的信息：typedef struct board_info {
void __iomem *io_addr; /* Register I/O base address */
void __iomem *io_data; /* Data I/O address */
u16 irq; /* IRQ */
u16 tx_pkt_cnt;
u16 queue_pkt_len;
u16 queue_start_addr;
u16 dbug_cnt;
u8 io_mode; /* 0:word, 2:byte */
u8 phy_addr;
u8 imr_all;
unsigned int flags;
unsigned int in_suspend :1;
int debug_level;
enum dm9000_type type;
void (*inblk)(void __iomem *port, void *data, int length);
void (*outblk)(void __iomem *port, void *data, int length);
void (*dumpblk)(void __iomem *port, int length);
struct device *dev; /* parent device */
struct resource *addr_res; /* resources found */
struct resource *data_res;
struct resource *addr_req; /* resources requested */
struct resource *data_req;
struct resource *irq_res;
struct mutex addr_lock; /* phy and eeprom access lock */
struct delayed_work phy_poll;
struct net_device *ndev;
spinlock_t lock;
struct mii_if_info mii;
u32 msg_enable;
} board_info_t;注册平台驱动：static int __init dm9000_init(void)
{
printk(KERN_INFO "%s Ethernet Driver, V%s/n", CARDNAME, DRV_VERSION);
return platform_driver_register(&dm9000_driver);
}
完成match之后执行Probe函数，获得资源信息，最终注册网络设备。dm9000_remove：在卸载时使用，释放内存空间：
static int __devexit dm9000_drv_remove(struct platform_device *pdev)
{
struct net_device *ndev = platform_get_drvdata(pdev);
platform_set_drvdata(pdev, NULL);
unregister_netdev(ndev);
dm9000_release_board(pdev, (board_info_t *) netdev_priv(ndev));
free_netdev(ndev); /* free device structure */
dev_dbg(&pdev->dev, "released and freed device/n");
return 0;
}dm9000_suspend：并没有将网络设备从内核移除，只是标志设备为removed状态，并设置挂起标志位，最后关闭设备：static int dm9000_drv_suspend(struct platform_device *dev, pm_message_t state)
{
struct net_device *ndev = platform_get_drvdata(dev);
board_info_t *db;
if (ndev) {
db = netdev_priv(ndev);
db->in_suspend = 1;
if (netif_running(ndev)) {
netif_device_detach(ndev);
dm9000_shutdown(ndev);
}
}
return 0;
}dm9000_resume：static int dm9000_drv_resume(struct platform_device *dev)
{
struct net_device *ndev = platform_get_drvdata(dev);
board_info_t *db = netdev_priv(ndev);
if (ndev) {
if (netif_running(ndev)) {
dm9000_reset(db);
dm9000_init_dm9000(ndev);
netif_device_attach(ndev);//标志为attach状态。
}
db->in_suspend = 0;
}
return 0;
}dm9000_open：向内核注册中断：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)) //注册中断
return -EAGAIN;
/* Initialize DM9000 board */
dm9000_reset(db);
dm9000_init_dm9000(dev);
/* Init driver variable */
db->dbug_cnt = 0;
mii_check_media(&db->mii, netif_msg_link(db), 1);
netif_start_queue(dev);
dm9000_schedule_poll(db);
return 0;
}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);
netif_stop_queue(ndev);
netif_carrier_off(ndev);
free_irq(ndev->irq, ndev);
dm9000_shutdown(ndev);
return 0;
}dm9000_start_xmit()：发送数据包函数：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;
/*获得自旋锁*/
spin_lock_irqsave(&db->lock, flags);
/* Move data to DM9000 TX RAM */
writeb(DM9000_MWCMD, db->io_addr);
(db->outblk)(db->io_data, skb->data, skb->len);//将skbuffer中的data写入DM9000的TX RAM，并计数
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) { //如果是第一个包
/* Set TX length to DM9000 */
iow(db, DM9000_TXPLL, skb->len);
iow(db, DM9000_TXPLH, skb->len >> 8);
/* Issue TX polling command */
iow(db, DM9000_TCR, TCR_TXREQ); /* Cleared after TX complete */
dev->trans_start = jiffies; /* save the time stamp */
} else { //不是第一个包
/* Second packet */
db->queue_pkt_len = skb->len;
netif_stop_queue(dev);
}
/*释放自旋锁*/
spin_unlock_irqrestore(&db->lock, flags);
/* free this SKB */
dev_kfree_skb(skb);
return 0;
}dm9000_timeout()：超时调用：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 */ //保存寄存器地址
reg_save = readb(db->io_addr);
spin_lock_irqsave(&db->lock, flags);
netif_stop_queue(dev); //停止队列
dm9000_reset(db);
dm9000_init_dm9000(dev); //重启并初始化DM9000
/* We can accept TX packets again */
dev->trans_start = jiffies;
netif_wake_queue(dev); //唤醒队列
/* Restore previous register address */ //恢复寄存器地址
writeb(reg_save, db->io_addr);
spin_unlock_irqrestore(&db->lock, flags);
}dm9000_hash_table()：设置组播地址：static void dm9000_hash_table(struct net_device *dev)
{
board_info_t *db = netdev_priv(dev);
struct dev_mc_list *mcptr = dev->mc_list;
int mc_cnt = dev->mc_count;
int i, oft;
u32 hash_val;
u16 hash_table[4];
u8 rcr = RCR_DIS_LONG | RCR_DIS_CRC | RCR_RXEN;
unsigned long flags;
dm9000_dbg(db, 1, "entering %s/n", __func__);
spin_lock_irqsave(&db->lock, flags);
for (i = 0, oft = DM9000_PAR; i < 6; i++, oft++)
iow(db, oft, dev->dev_addr[i]);
/* Clear Hash Table */
for (i = 0; i < 4; i++)
hash_table[i] = 0x0;
/* broadcast address */
hash_table[3] = 0x8000;
if (dev->flags & IFF_PROMISC)
rcr |= RCR_PRMSC;
if (dev->flags & IFF_ALLMULTI)
rcr |= RCR_ALL;
/* the multicast address in Hash Table : 64 bits */
for (i = 0; i < mc_cnt; i++, mcptr = mcptr->next) {
hash_val = ether_crc_le(6, mcptr->dmi_addr) & 0x3f;
hash_table[hash_val / 16] |= (u16) 1 << (hash_val % 16);
}
/* Write the hash table to MAC MD table */
for (i = 0, oft = DM9000_MAR; i < 4; i++) {
iow(db, oft++, hash_table[i]);
iow(db, oft++, hash_table[i] >> 8);
}
iow(db, DM9000_RCR, rcr);
spin_unlock_irqrestore(&db->lock, flags);
}
dm9000_rx()：接收函数：static void dm9000_rx(struct net_device *dev)
{
board_info_t *db = netdev_priv(dev);
struct dm9000_rxhdr rxhdr;
struct sk_buff *skb;
u8 rxbyte, *rdptr;
bool GoodPacket;
int RxLen;
/* Check packet ready or not */
do {
ior(db, DM9000_MRCMDX); /* Dummy read */
/* Get most updated data */
rxbyte = readb(db->io_data);
/* Status check: this byte must be 0 or 1 */
if (rxbyte > DM9000_PKT_RDY) {
dev_warn(db->dev, "status check fail: %d/n", rxbyte);
iow(db, DM9000_RCR, 0x00); /* Stop Device */
iow(db, DM9000_ISR, IMR_PAR); /* Stop INT request */
return;
}
if (rxbyte != DM9000_PKT_RDY)
return;
/* A packet ready now & Get status/length */
GoodPacket = true;
writeb(DM9000_MRCMD, db->io_addr);
(db->inblk)(db->io_data, &rxhdr, sizeof(rxhdr));//读四个字节到rxhdr变量
RxLen = le16_to_cpu(rxhdr.RxLen);
if (netif_msg_rx_status(db))
dev_dbg(db->dev, "RX: status %02x, length %04x/n",
rxhdr.RxStatus, RxLen);
/* Packet Status check */
if (RxLen < 0x40) {
GoodPacket = false;
if (netif_msg_rx_err(db))
dev_dbg(db->dev, "RX: Bad Packet (runt)/n");
}
if (RxLen > DM9000_PKT_MAX) {
dev_dbg(db->dev, "RST: RX Len:%x/n", RxLen);
}
/* rxhdr.RxStatus is identical to RSR register. */
if (rxhdr.RxStatus & (RSR_FOE | RSR_CE | RSR_AE |
RSR_PLE | RSR_RWTO |
RSR_LCS | RSR_RF)) {
GoodPacket = false;
if (rxhdr.RxStatus & RSR_FOE) {
if (netif_msg_rx_err(db))
dev_dbg(db->dev, "fifo error/n");
dev->stats.rx_fifo_errors++;
}
if (rxhdr.RxStatus & RSR_CE) {
if (netif_msg_rx_err(db))
dev_dbg(db->dev, "crc error/n");
dev->stats.rx_crc_errors++;
}
if (rxhdr.RxStatus & RSR_RF) {
if (netif_msg_rx_err(db))
dev_dbg(db->dev, "length error/n");
dev->stats.rx_length_errors++;
}
}
/* Move data from DM9000 */ //将RX SRAM中的data放到sk_buffer。
if (GoodPacket
&& ((skb = dev_alloc_skb(RxLen + 4)) != NULL)) {
skb_reserve(skb, 2);
rdptr = (u8 *) skb_put(skb, RxLen - 4);
/* Read received packet from RX SRAM */
(db->inblk)(db->io_data, rdptr, RxLen);
dev->stats.rx_bytes += RxLen;
/* Pass to upper layer */
skb->protocol = eth_type_trans(skb, dev);
netif_rx(skb);
dev->stats.rx_packets++;
} else {
/* need to dump the packet's data */
(db->dumpblk)(db->io_data, RxLen);
}
} while (rxbyte == DM9000_PKT_RDY);
}dm9000_interrupt：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);
/* Got DM9000 interrupt status */
int_status = ior(db, DM9000_ISR); /* Got ISR */
iow(db, DM9000_ISR, int_status); /* Clear ISR status */
if (netif_msg_intr(db))
dev_dbg(db->dev, "interrupt status %02x/n", int_status);
/* Received the coming packet */
if (int_status & ISR_PRS)
dm9000_rx(dev); //取数据
/* Trnasmit Interrupt check */
if (int_status & ISR_PTS)
dm9000_tx_done(dev, db); //调用done函数
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;
}dm9000_tx_done：static void dm9000_tx_done(struct net_device *dev, board_info_t *db)
{
int tx_status = ior(db, DM9000_NSR); /* Got TX status */ //读取NSR的状态，得知发送的状态
if (tx_status & (NSR_TX2END | NSR_TX1END)) {
/* One packet sent complete */
db->tx_pkt_cnt--;
dev->stats.tx_packets++;
if (netif_msg_tx_done(db))
dev_dbg(db->dev, "tx done, NSR %02x/n", tx_status);
/* Queue packet check & send */
if (db->tx_pkt_cnt > 0) {
iow(db, DM9000_TXPLL, db->queue_pkt_len);
iow(db, DM9000_TXPLH, db->queue_pkt_len >> 8);
iow(db, DM9000_TCR, TCR_TXREQ);
dev->trans_start = jiffies;
} //通知内核可以将待发送的数据包进入发送队列
netif_wake_queue(dev);
}
}DM9000 网卡驱动程序分析
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