驱动开发之 DM9000 （for mini2440）

电玩女神 2021-07-26 14:11 397阅读 0赞

内核版本：linux-2.6.32.2  
实验平台：mini2440

1. 添加平台设备支持  
首先需要在mach-mini2440.c中包含头文件<linux/dm9000.h>，dm9000平台设备定义如下：

/* DM9000AEP 10/100 ethernet controller */
    
    #define MACH_MINI2440_DM9000_BASE (S3C2410_CS4 + 0x300)
    
    static struct resource mini2440_dm9000_resource[] = {
    	[0] = {
    		.start  = MACH_MINI2440_DM9000_BASE,
    		.end    = MACH_MINI2440_DM9000_BASE + 3,
    		.flags  = IORESOURCE_MEM,
    	},
    	[1] = {
    		.start  = MACH_MINI2440_DM9000_BASE + 4,
    		.end    = MACH_MINI2440_DM9000_BASE + 7,
    		.flags  = IORESOURCE_MEM,
    	},
    	[2] = {
    		.start  = IRQ_EINT7,
    		.end    = IRQ_EINT7,
    		.flags  = IORESOURCE_IRQ | IORESOURCE_IRQ_HIGHEDGE,
    	},
    };
    
    /*
     * The DM9000 has no eeprom, and it's MAC address is set by
     * the bootloader before starting the kernel.
     */
    static struct dm9000_plat_data mini2440_dm9000_platdata = {
    	.flags          = (DM9000_PLATF_16BITONLY | DM9000_PLATF_NO_EEPROM),
    };
    
    static struct platform_device mini2440_device_eth = {
    	.name           = "dm9000",
    	.id             = -1,
    	.num_resources  = ARRAY_SIZE(mini2440_dm9000_resource),
    	.resource       = mini2440_dm9000_resource,
    	.dev            = {
    		.platform_data = &mini2440_dm9000_platdata,
    	},
    };

最后需要将dm9000这个平台设备添加到mini2440\_devices这个平台设备数组里面，这样才能完成平台设备的注册。

static struct platform_device *mini2440_devices[] __initdata = {
            /* ... */
            &mini2440_device_eth,
    };

2. dm9000驱动修改  
drivers/net/dm9000.c这个驱动并不是为mini2440做准备的，需要做一些修改。  
包含相关头文件：

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

修改dm9000片选总线时序：

static int __init
    dm9000_init(void)
    {
    #if defined(CONFIG_ARCH_S3C2410)
            unsigned int oldval_bwscon = *(volatile unsigned int *)S3C2410_BWSCON;
            unsigned int oldval_bankcon4 = *(volatile unsigned int *)S3C2410_BANKCON4;
            *((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
    	/* ... */
    }

在dm9000\_probe函数中还需要给dm9000设置一个mac地址。

static int __devinit
    dm9000_probe(struct platform_device *pdev)
    {
    	/* ... */
            memcpy(ndev->dev_addr, "\x08\x90\x90\x90\x90\x90", 6);
            if (!is_valid_ether_addr(ndev->dev_addr))
                    dev_warn(db->dev, "%s: Invalid ethernet MAC address. Please "
                             "set using ifconfig\n", ndev->name);
    	/* ... */
    }

3. 配置内核

Device Drivers  --->
    	[*] Network device support  --->
    		[*]   Ethernet (10 or 100Mbit)  --->
    			<*>   DM9000 support
    			(4)     DM9000 maximum debug level

4. 编译下载，启动开发板

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5. 启动网络设备  
内核配置好之后，需要手动启动网络设备，使用如下命令：

ifconfig eth0 172.20.11.41 netmask 255.255.255.0 up

如下图所示：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTI1Nzc0NzQ_size_16_color_FFFFFF_t_70 1]

或者将上面的命令写入到启动脚本中，还可以使用ifconfig命令来停止网络设备：

ifconfig eth0 down

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