//__devinit 内核优化宏，编译器通过这些宏把代码优化放到合适的内存空间，宏__devinit标志设备初始化代码 static int __devinitdm9000_probe(struct platform_device *pdev){//这个platform_data是在板级配置文件中设置的struct dm9000_plat_data *pdata = pdev->dev.platform_data;struct board_info *db;/* Point a board information structure *///网络设备驱动中两个重要结构体之一，另一个大名鼎鼎的结构体是skbuffstruct net_device *ndev;const unsigned char *mac_src;int ret = 0;int iosize;int i;u32 id_val;/* Init network device *///初始化网络设备结构体net_device，最终是调用了函数alloc_netdev_mq，有时间我想好好分析下这个函数ndev = alloc_etherdev(sizeof(struct board_info));if (!ndev) {//实际上就是printk啦,我忍不住想说linux的一大特点，就是喜欢用满天飞的define给别人起新名字dev_err(&pdev->dev, "could not allocate device.\n");return -ENOMEM;}SET_NETDEV_DEV(ndev, &pdev->dev);//最后还是printk。。。dev_dbg(&pdev->dev, "dm9000_probe()\n");/* setup board info structure *///让结构体指针指向结构体ndev内的的某个xx(xx还没搞懂是哪个变量或者结构体)db = netdev_priv(ndev);db->dev = &pdev->dev;db->ndev = ndev; //初始化自旋锁spin_lock_init(&db->lock);//初始化互斥锁mutex_init(&db->addr_lock);INIT_DELAYED_WORK(&db->phy_poll, dm9000_poll_work);//调用platform_get_resource获取资源填充结构体db,这个resource就是在板级配置//文件中填充的那个struct resouce.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 resources\n");ret = -ENOENT;goto out;}//继续填充结构体db中....,获取一个设备irq，这个irq也是板级配置文件中设置的//我的板上的两个dm9000分别分配了190,191.db->irq_wake = platform_get_irq(pdev, 1);if (db->irq_wake >= 0) {dev_dbg(db->dev, "wakeup irq %d\n", db->irq_wake);//注册中断函数dm9000_wol_interrupt，中断号为db->irq_wakeret = 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 {/* test to see if irq is really wakeup capable */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;}}}//计算即将申请内存大小，这个大小是板级配置文件中struct resouce 中.end减去.tart再加1//为什么要再加1?iosize = resource_size(db->addr_res);//我原来的理解是申请该大小内存区域，这个理解有偏差。//该函数的任务是检查申请的资源是否可用，如果可用则申请成功，//并标志为已经使用，其他驱动想再申请该资源时就会失败?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 area\n");ret = -EIO;goto out;}//把db->addr_res->start开始，大小iosize，物理空间映射到虚拟地址空间//这段虚拟地址空间开始地址是db->io_addrdb->io_addr = ioremap(db->addr_res->start, iosize);if (db->io_addr == NULL) {dev_err(db->dev, "failed to ioremap address reg\n");ret = -EINVAL;goto out;}//以下这段程序操作与上类似，因为dm9000提供了地址和数据两个访问口，所以映射了两个。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 area\n");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 reg\n");ret = -EINVAL;goto out;}/* fill in parameters for net-dev structure */ndev->base_addr = (unsigned long)db->io_addr;ndev->irq= db->irq_res->start;//设置dm9000位宽，根据板级配置文件中struct platform_data设置而定//由此可见，linux内核移植很大一部分工作是驱动移植，是必须要在读懂驱动的前提上进行的/* ensure at least we have a default set of IO routines */dm9000_set_io(db, iosize);/* check to see if anything is being over-ridden */if (pdata != NULL) {/* check to see if the driver wants to over-ride the * default IO width */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);/* check to see if there are any IO routine * over-rides *///以下三个参数很少设置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_POLLdb->flags |= DM9000_PLATF_SIMPLE_PHY;#endif//软件复位dm9000,实际上就是往dm9000寄存器NCR上写1dm9000_reset(db); //读dm9000id。如果读写时序正确，基本就能读到id.如果读id错误， //要么是时序错了，要么就是硬件存在问题，我就遇到过这个坑爹的问题， //如果硬件存在故障，这是驱动调试最痛苦痛苦的事情。/* try multiple times, DM9000 sometimes gets the read wrong */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 0x%08x\n", id_val);}if (id_val != DM9000_ID) {dev_err(db->dev, "wrong id: 0x%08x\n", id_val);ret = -ENODEV;goto out;}/* Identify what type of DM9000 we are working on *///读dm9000寄存器CHIPR确定类型id_val = ior(db, DM9000_CHIPR);dev_dbg(db->dev, "dm9000 revision 0x%02x\n", 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 %02x => defaulting to DM9000E\n", id_val);db->type = TYPE_DM9000E;}/* dm9000a/b are capable of hardware checksum offload */if (db->type == TYPE_DM9000A || db->type == TYPE_DM9000B) {db->can_csum = 1;db->rx_csum = 1;ndev->features |= NETIF_F_IP_CSUM;}/* from this point we assume that we have found a DM9000 *//* driver system function */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";/* try reading the node address from the attached 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)) {/* try reading from mac */mac_src = "chip";for (i = 0; i < 6; i++)ndev->dev_addr[i] = ior(db, i+DM9000_PAR);}if (!is_valid_ether_addr(ndev->dev_addr))dev_warn(db->dev, "%s: Invalid ethernet MAC address. Please " "set using ifconfig\n", ndev->name);////把ndev保存为平台设备pdev的私有数据，并可以调用platform_get_drvdata获取该数据platform_set_drvdata(pdev, ndev);//注册一个网络设备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;}
