mdio总线通信

下面代码描述了在用户层访问smi／mdio总线，读写phy芯片寄存器的通用代码。Linux内核2.6以上通用。将下面代码编译后，将可执行文件a.out 重命名为mdiomdio eth0 1 读取phy寄存器1的数值
mdio eth0 0 0x1120 将0x1120写入 phy寄存器1eth0 为mac层控制器的名称，一般为eth0 或mgmt0。#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <linux/mii.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <linux/sockios.h>
#include <linux/types.h>
#include <netinet/in.h>
#define reteck（ret）
if（ret < 0）{
printf（"%m！ "%s" : line: %d ", __func__, __LINE__）;
goto lab;
}#define help（）
printf（"mdio: "）;
printf（"read operation: mdio reg_addr "）;
printf（"write operation: mdio reg_addr value "）;
printf（"For example: "）;
printf（"mdio eth0 1 "）;
printf（"mdio eth0 0 0x12 "）;
exit（0）;int sockfd;int main（int argc, char *argv[]）{

if（argc == 1 || ！strcmp（argv[1], "-h"））{
help（）;
}

struct mii_ioctl_data *mii = NULL;
struct ifreq ifr;
int ret; memset（&ifr, 0, sizeof（ifr））;
strncpy（ifr.ifr_name, argv[1], IFNAMSIZ - 1）; sockfd = socket（PF_LOCAL, SOCK_DGRAM, 0）;
reteck（sockfd）; //get phy address in smi bus
ret = ioctl（sockfd, SIOCGMIIPHY, &ifr）;
reteck（ret）; mii = （struct mii_ioctl_data*）&ifr.ifr_data; if（argc == 3）{ mii->reg_num = （uint16_t）strtoul（argv[2], NULL, 0）;

ret = ioctl（sockfd, SIOCGMIIREG, &ifr）;
reteck（ret）;

printf（"read phy addr: 0x%x reg: 0x%x value : 0x%x ", mii->phy_id, mii->reg_num, mii->val_out）;
}else if（argc == 4）{ mii->reg_num = （uint16_t）strtoul（argv[2], NULL, 0）;
mii->val_in = （uint16_t）strtoul（argv[3], NULL, 0）; ret = ioctl（sockfd, SIOCSMIIREG, &ifr）;
reteck（ret）; printf（"write phy addr: 0x%x reg: 0x%x value : 0x%x ", mii->phy_id, mii->reg_num, mii->val_in）;
}lab:
close（sockfd）;
return 0;
}