DM9000

先看如下关于dm9000和mini2440的连接图：

 

从上面可以简单得出这些：
a. dm9000的访问地址为BANK4的基址（也许是通过上面的nGCS4看出来的）。
b. 只有一根地址线ADDR2。
c. 总线位宽为16位，有nWAIT信号。
d. 使用中断引脚为EINT7（使用GPF7实现的）。

一 增加DM9000平台设备
增加平台设备前首先要先定义该平台设备，这主要修改arch/arm/plat-s3c24xx/devs.c文件。
1.添加头文件，在devs.c文件的头文件引入处添加如下代码：

#include <linux/dm9000.h>

2.定义dm9000平台资源，在devs.c文件的合适处添加如下代码（其实看一下源文件就知道合适的意思）：

 /* DM9000 */static struct resource s3c_dm9k_resource[] = { [0] = { .start = S3C2410_CS4, .end = S3C2410_CS4 + 3, .flags = IORESOURCE_MEM, }, [1] = { .start = S3C2410_CS4 + 4, .end = S3C2410_CS4 + 4 + 3, .flags = IORESOURCE_MEM, }, [2] = { .start = IRQ_EINT7, .end = IRQ_EINT7, .flags = IORESOURCE_IRQ | IRQF_TRIGGER_RISING, }};/* for the moment we limit ourselves to 16bit IO until some * better IO routines can be written and tested*/static struct dm9000_plat_data s3c_dm9k_platdata = { .flags = DM9000_PLATF_16BITONLY,};struct platform_device s3c_device_dm9k = { .name = "dm9000", .id = 0, .num_resources = ARRAY_SIZE(s3c_dm9k_resource), .resource = s3c_dm9k_resource, .dev = { .platform_data = &s3c_dm9k_platdata, }};EXPORT_SYMBOL(s3c_device_dm9k);  

NOTE:
a.s3c_dm9k_resource数组定义了3个资源：两个内存空间和一个中断号。数组项0、1定义了访问dm9000时使用的地址。在dm9000的芯片手册上有如下的介绍：

    CMD Command Type
         When high, the access of this command cycle is DATA port
         When low, the access of this command cycle is ADDRESS port

 

 

 

所以数组项0、1的.start域就容易理解了，S3C2410_CS4中addr2为0，表示传输地址；S3C2410_CS4 + 4中addr2为1，表示传输数据。数组项[2]定义的中断号就较容易理解。
b.结构s3c_dm9k_platdata中指定了数据总线宽度为16。
c.结构s3c_device_dm9k就是dm9000的平台设备，其中.resource和.dev项分别指向前面定义的s3c_dm9k_resource和s3c_dm9k_platdata。

3.把定义的平台设备加入到内核设备列表中，在common-smdk.c文件的smdk_devs数组中添加一下代码：(我的为mach-mini2440.c文件mini2440_devices数组)

&s3c_device_dm9k,

这样，系统启动时就会把这个数组中的设备注册到内核中。

二 修改dm9000.c文件
对dm9000的枚举最终由dm9000_probe函数来实现。
1.添加头文件，在dm9000.c的头文件引入处增加以下代码，定义了一些寄存器的宏定义：

#if defined(CONFIG_ARCH_S3C2410)#include <mach/regs-mem.h>#endif

2.修改probe函数，通过设置存储控制器使BANK4可用，修改后的dm9000_probe函数如下，其中修改的地方都由CONFIG_ARCH_S3C2410包括：

/* * Search DM9000 board, allocate space and register it */static int __devinitdm9000_probe(struct platform_device *pdev){struct dm9000_plat_data *pdata = pdev->dev.platform_data;struct board_info *db;/* Point a board information structure */struct net_device *ndev;const unsigned char *mac_src;int ret = 0;int iosize;int i;u32 id_val;#if defined(CONFIG_ARCH_S3C2410)unsigned int oldval_bwscon = *(volatile unsigned int *)S3C2410_BWSCON;unsigned int oldval_bankcon4 = *(volatile unsigned int *)S3C2410_BANKCON4;#endif/* Init network device */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");#if defined(CONFIG_ARCH_S3C2410)*((volatile unsigned int *)S3C2410_BWSCON) =(oldval_bwscon & ~(3<<16)) | S3C2410_BWSCON_DW4_16 | S3C2410_BWSCON_WS4 | S3C2410_BWSCON_ST4;*((volatile unsigned int *)S3C2410_BANKCON4) = 0x1f7c;#endif/* setup board info structure */db = netdev_priv(ndev);memset(db, 0, sizeof(*db));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 resources/n");ret = -ENOENT;goto out;}iosize = res_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 area/n");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 reg/n");ret = -EINVAL;goto out;}iosize = res_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;/* 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 */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;#endifdm9000_reset(db);/* 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 */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;}/* from this point we assume that we have found a DM9000 *//* driver system function */ether_setup(ndev);ndev->open = &dm9000_open;ndev->hard_start_xmit = &dm9000_start_xmit;ndev->tx_timeout = &dm9000_timeout;ndev->watchdog_timeo = msecs_to_jiffies(watchdog);ndev->stop = &dm9000_stop;ndev->set_multicast_list = &dm9000_hash_table;ndev->ethtool_ops = &dm9000_ethtool_ops;ndev->do_ioctl = &dm9000_ioctl;#ifdef CONFIG_NET_POLL_CONTROLLERndev->poll_controller = &dm9000_poll_controller;#endifdb->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;#if defined(CONFIG_ARCH_S3C2410)printk("Now use the default MAC address: 08:90:90:90:90:90/n");mac_src = "friendly-arm";ndev->dev_addr[0] = 0x08;ndev->dev_addr[1] = 0x90;ndev->dev_addr[2] = 0x90;ndev->dev_addr[3] = 0x90;ndev->dev_addr[4] = 0x90;ndev->dev_addr[5] = 0x90;#elsemac_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);#endifplatform_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:#if defined(CONFIG_ARCH_S3C2410) *(volatile unsigned int *)S3C2410_BWSCON = oldval_bwscon; *(volatile unsigned int *)S3C2410_BANKCON4 = oldval_bankcon4;#endifdev_err(db->dev, "not found (%d)./n", ret);dm9000_release_board(pdev, db);free_netdev(ndev);return ret;}

a.第24-27行定义了两个变量，用来保存BWSCON和BANKCON4的值，下面将会用到。

b.第32-39对BANK4进行了设置。首先设置BWSCON，

#if defined(CONFIG_ARCH_S3C2410)*((volatile unsigned int *)S3C2410_BWSCON) =(oldval_bwscon & ~(3<<16)) | S3C2410_BWSCON_DW4_16 | S3C2410_BWSCON_WS4 | S3C2410_BWSCON_ST4;*((volatile unsigned int *)S3C2410_BANKCON4) = 0x1f7c;#endif  

主要是设置了总线宽度16，nWAIT，ST。（具体的可以参考s3c2440数据手册的BUS WIDTH & WAIT CONTROL REGISTER (BWSCON)）。然后设置BANKCON4的时间参数，值为0×1f7c（pmc:normal Tacp:6clk Tcah:4clk Tcoh:1clk Tacc:14clk Tcos:4clk 具体可以参考s3c2440数据手册的BANK CONTROL REGISTER）

c.第209-216的代码是我自己给注释的，据其意思，上面首先给MAC赋值，然后检测合法性，但经实践，判断语句总成立，所以在linux启动注册dm9000时总输出Invalid ethernet MAC address.反正后面也会再次给MAC地址赋值，所以干脆把这几行代码注释掉。

d.第218-227行就是给MAC地址赋值的，听说赋什么值都可以，有这么神奇吗？

e.第266-269行恢复寄存器原来的值。

f.以上的步骤和代码都是参考书上的，但可惜的是，按照上面步骤去修改，系统能成功加载dm9000驱动，但无法ping通，这个事确实让我很苦恼，上网找了很多资料，最后发现大多数都需要调用writel来设置BWSCON、GPFCON和中断等。所以无计之下参考了mini2440中的一段代码，出自附送光盘的无操作系统代码测试的dm9000部分。

到此，代码的移植到此为止，然后是配置内核，以使用dm9000。在

-> Device Drivers                                                            --> Network device support                                                   --> Network device support (NETDEVICES [=y])                                    --> Ethernet (10 or 100Mbit) 

处将DM9000网卡选为编译进内核。
然后在/etc/init.d/rcS文件的开始处加入

ifconfig eth0 192.168.1.22<pre>当然，ip地址是因人而定的，尽量设为和PC在同一个网段。重新将内核下载到开发板后启动，有如下提示：<pre lang="text">dm9000 Ethernet DriverHello, I use the MAC with 08:00:3e:26:0a:5b:eth0: dm9000 at c4852000,c4854004 IRQ 51 MAC: 08:00:3e:26:0a:5b......eth0: link downeth0: link up, 100Mbps, full-duplex, lpa 0x41E1

然后将开发板和PC机连在同一个网段上，终于ping通了PC机了。