硬件平臺：FL2440（s3c2440）內(nèi)核版本：2.6.35
主機平臺：Ubuntu 11.04
內(nèi)核版本：2.6.39
原創(chuàng)作品，轉(zhuǎn)載請標明出處http://blog.csdn.net/yming0221/article/details/6612623
下面開始分析具體的代碼，這里由于使DM9000驅(qū)動更容易理解，在不影響基本的功能的前提下，這里將盡可能的簡化該驅(qū)動（如：去掉該驅(qū)動中支持電源管理的功能）
分析該驅(qū)動
1、首先看一下該驅(qū)動的平臺設(shè)備驅(qū)動的結(jié)構(gòu)體定義
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static struct platform_driver dm9000_driver = {
.driver = {
.name = "dm9000",
.owner = THIS_MODULE,
},
.probe = dm9000_probe,
.remove = __devexit_p(dm9000_drv_remove),
};
在執(zhí)行insmod后內(nèi)核自動那個執(zhí)行下面的函數(shù)
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static int __init
dm9000_init(void)
{
printk(KERN_INFO "%s Ethernet Driver, V%sn", CARDNAME, DRV_VERSION);
return platform_driver_register(&dm9000_driver);
}
調(diào)用函數(shù)platform_driver_register()函數(shù)注冊驅(qū)動。
3、自動執(zhí)行驅(qū)動的probe函數(shù)，進行資源的探測和申請資源。
其中BWSCON為總線寬度 等待控制寄存器
其中第[19:18]位的作用如下
下面函數(shù)中將兩位設(shè)置為11，也就是WAIT使能，bank4使用UB/LB。
alloc_etherdev()函數(shù)分配一個網(wǎng)絡(luò)設(shè)備的結(jié)構(gòu)體，原型在include/linux/etherdevice.h
原型如下：
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extern struct net_device *alloc_etherdev_mq(int sizeof_priv, unsigned int queue_count);
#define alloc_etherdev(sizeof_priv) alloc_etherdev_mq(sizeof_priv, 1)
該函數(shù)中需要將獲得的資源信息存儲在一個結(jié)構(gòu)體中，定義如下：
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typedef struct board_info {
void __iomem *io_addr;
void __iomem *io_data;
u16 irq;
u16 tx_pkt_cnt;
u16 queue_pkt_len;
u16 queue_start_addr;
u16 queue_ip_summed;
u16 dbug_cnt;
u8 io_mode;
u8 phy_addr;
u8 imr_all;
unsigned int flags;
unsigned int in_suspend :1;
unsigned int wake_supported :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;
struct resource *addr_res;
struct resource *data_res;
struct resource *addr_req;
struct resource *data_req;
struct resource *irq_res;
int irq_wake;
struct mutex addr_lock;
struct delayed_work phy_poll;
struct net_device *ndev;
spinlock_t lock;
struct mii_if_info mii;
u32 msg_enable;
u32 wake_state;
int rx_csum;
int can_csum;
int ip_summed;
} board_info_t;
下面是probe函數(shù)，
其中有個函數(shù)db = netdev_priv(ndev)
該函數(shù)實際上是返回網(wǎng)卡私有成員的數(shù)據(jù)結(jié)構(gòu)地址
函數(shù)如下，定義在include/linux/net_device.h中
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static inline void *netdev_priv(const struct net_device *dev)
{
return (char *)dev + ALIGN(sizeof(struct net_device), NETDEV_ALIGN);
}
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static int __devinit
dm9000_probe(struct platform_device *pdev)
{
struct dm9000_plat_data *pdata = pdev->dev.platform_data;
struct board_info *db;
struct net_device *ndev;
const unsigned char *mac_src;
int ret = 0;
int iosize;
int i;
u32 id_val;
unsigned char ne_def_eth_mac_addr[]={0x00,0x12,0x34,0x56,0x80,0x49};
static void *bwscon;
static void *gpfcon;
static void *extint0;
static void *intmsk;
#define BWSCON (0x48000000)
#define GPFCON (0x56000050)
#define EXTINT0 (0x56000088)
#define INTMSK (0x4A000008)
bwscon=ioremap_nocache(BWSCON,0x0000004);
gpfcon=ioremap_nocache(GPFCON,0x0000004);
extint0=ioremap_nocache(EXTINT0,0x0000004);
intmsk=ioremap_nocache(INTMSK,0x0000004);
writel( readl(bwscon)|0xc0000,bwscon);
writel( (readl(gpfcon) & ~(0x3 << 14)) | (0x2 << 14), gpfcon);
writel( readl(gpfcon) | (0x1 << 7), gpfcon); // Disable pull-up，不使能上拉
writel( (readl(extint0) & ~(0xf << 28)) | (0x4 << 28), extint0); //rising edge，設(shè)置上升沿觸發(fā)中斷
writel( (readl(intmsk)) & ~0x80, intmsk);
ndev = alloc_etherdev(sizeof(struct board_info));
if (!ndev) {
dev_err(&pdev->dev, "could not allocate device.n");
return -ENOMEM;
}
SET_NETDEV_DEV(ndev, &pdev->dev);
dev_dbg(&pdev->dev, "dm9000_probe()n");
db = netdev_priv(ndev);
db->dev = &pdev->dev;
db->ndev = ndev;
spin_lock_init(&db->lock);
mutex_init(&db->addr_lock);
INIT_DELAYED_WORK(&db->phy_poll, dm9000_poll_work);
db->addr_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
db->data_res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
db->irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
if (db->addr_res == NULL || db->data_res == NULL ||
db->irq_res == NULL) {
dev_err(db->dev, "insufficient resourcesn");
ret = -ENOENT;
goto out;
}
db->irq_wake = platform_get_irq(pdev, 1);
if (db->irq_wake >= 0) {
dev_dbg(db->dev, "wakeup irq %dn", db->irq_wake);
ret = request_irq(db->irq_wake, dm9000_wol_interrupt,
IRQF_SHARED, dev_name(db->dev), ndev);
if (ret) {
dev_err(db->dev, "cannot get wakeup irq (%d)n", ret);
} else {
ret = set_irq_wake(db->irq_wake, 1);
if (ret) {
dev_err(db->dev, "irq %d cannot set wakeup (%d)n",
db->irq_wake, ret);
ret = 0;
} else {
set_irq_wake(db->irq_wake, 0);
db->wake_supported = 1;
}
}
}
iosize = resource_size(db->addr_res);
db->addr_req = request_mem_region(db->addr_res->start, iosize,
pdev->name);
if (db->addr_req == NULL) {
dev_err(db->dev, "cannot claim address reg arean");
ret = -EIO;
goto out;
}
db->io_addr = ioremap(db->addr_res->start, iosize);
if (db->io_addr == NULL) {
dev_err(db->dev, "failed to ioremap address regn");
ret = -EINVAL;
goto out;
}
iosize = resource_size(db->data_res);
db->data_req = request_mem_region(db->data_res->start, iosize,
pdev->name);
if (db->data_req == NULL) {
dev_err(db->dev, "cannot claim data reg arean");
ret = -EIO;
goto out;
}
db->io_data = ioremap(db->data_res->start, iosize);
if (db->io_data == NULL) {
dev_err(db->dev, "failed to ioremap data regn");
ret = -EINVAL;
goto out;
}
ndev->base_addr = (unsigned long)db->io_addr;
ndev->irq = db->irq_res->start;
dm9000_set_io(db, iosize);
if (pdata != NULL) {
if (pdata->flags & DM9000_PLATF_8BITONLY)
dm9000_set_io(db, 1);
if (pdata->flags & DM9000_PLATF_16BITONLY)
dm9000_set_io(db, 2);
if (pdata->flags & DM9000_PLATF_32BITONLY)
dm9000_set_io(db, 4);
if (pdata->inblk != NULL)
db->inblk = pdata->inblk;
if (pdata->outblk != NULL)
db->outblk = pdata->outblk;
if (pdata->dumpblk != NULL)
db->dumpblk = pdata->dumpblk;
db->flags = pdata->flags;
}
#ifdef CONFIG_DM9000_FORCE_SIMPLE_PHY_POLL
db->flags |= DM9000_PLATF_SIMPLE_PHY;
#endif
dm9000_reset(db);
for (i = 0; i < 8; i++) {
id_val = ior(db, DM9000_VIDL);
id_val |= (u32)ior(db, DM9000_VIDH) << 8;
id_val |= (u32)ior(db, DM9000_PIDL) << 16;
id_val |= (u32)ior(db, DM9000_PIDH) << 24;
if (id_val == DM9000_ID)
break;
dev_err(db->dev, "read wrong id 0xxn", id_val);
}
if (id_val != DM9000_ID) {
dev_err(db->dev, "wrong id: 0xxn", id_val);
ret = -ENODEV;
goto out;
}
id_val = ior(db, DM9000_CHIPR);
dev_dbg(db->dev, "dm9000 revision 0xxn", id_val);
switch (id_val) {
case CHIPR_DM9000A:
db->type = TYPE_DM9000A;
break;
case CHIPR_DM9000B:
db->type = TYPE_DM9000B;
break;
default:
dev_dbg(db->dev, "ID x => defaulting to DM9000En", id_val);
db->type = TYPE_DM9000E;
}
if (db->type == TYPE_DM9000A || db->type == TYPE_DM9000B) {
db->can_csum = 1;
db->rx_csum = 1;
ndev->features |= NETIF_F_IP_CSUM;
}
ether_setup(ndev);
ndev->netdev_ops = &dm9000_netdev_ops;
ndev->watchdog_timeo = msecs_to_jiffies(watchdog);
ndev->ethtool_ops = &dm9000_ethtool_ops;
db->msg_enable = NETIF_MSG_LINK;
db->mii.phy_id_mask = 0x1f;
db->mii.reg_num_mask = 0x1f;
db->mii.force_media = 0;
db->mii.full_duplex = 0;
db->mii.dev = ndev;
db->mii.mdio_read = dm9000_phy_read;
db->mii.mdio_write = dm9000_phy_write;
mac_src = "eeprom";
for (i = 0; i < 6; i += 2)
dm9000_read_eeprom(db, i / 2, ndev->dev_addr+i);
if (!is_valid_ether_addr(ndev->dev_addr) && pdata != NULL) {
mac_src = "platform data";
memcpy(ndev->dev_addr, pdata->dev_addr, 6);
}
if (!is_valid_ether_addr(ndev->dev_addr)) {
mac_src = "chip";
for (i = 0; i < 6; i++)
ndev->dev_addr[i] = ne_def_eth_mac_addr[i];
}
if (!is_valid_ether_addr(ndev->dev_addr))
dev_warn(db->dev, "%s: Invalid ethernet MAC address. Please "
"set using ifconfign", ndev->name);
platform_set_drvdata(pdev, ndev);
ret = register_netdev(ndev);
if (ret == 0)
printk(KERN_INFO "%s: dm9000%c at %p,%p IRQ %d MAC: %pM (%s)n",
ndev->name, dm9000_type_to_char(db->type),
db->io_addr, db->io_data, ndev->irq,
ndev->dev_addr, mac_src);
return 0;
out:
dev_err(db->dev, "not found (%d).n", ret);
dm9000_release_board(pdev, db);
free_netdev(ndev);
return ret;
}
這樣，最后完成了網(wǎng)絡(luò)設(shè)備的數(shù)據(jù)保存到總線上，將網(wǎng)絡(luò)設(shè)備注冊到內(nèi)核。
4、設(shè)備的移除函數(shù)
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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);
dev_dbg(&pdev->dev, "released and freed devicen");
return 0;
}
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