linux系统读写eth网卡PHY寄存器工具mdio_cmd

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。

mdio_cmd.c

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <linux/if.h>
#include <linux/mii.h>
#include <linux/sockios.h>

#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>


#define DEVICE getenv("ETH_DEVICE")?getenv("ETH_DEVICE"):"eth0"

static int fd = -1;
static struct ifreq ifr;

static int mdio_read(int skfd, int location)
{
	struct mii_ioctl_data *mii = (struct mii_ioctl_data *)&ifr.ifr_data;
	mii->reg_num = location;
	if (ioctl(skfd, SIOCGMIIREG, &ifr) < 0) {
		fprintf(stderr, "SIOCGMIIREG on %s failed: %s\n", ifr.ifr_name,
				strerror(errno));
		return -1;
	}
	return mii->val_out;
}

static void mdio_write(int skfd, int location, int value)
{
	struct mii_ioctl_data *mii = (struct mii_ioctl_data *)&ifr.ifr_data;
	mii->reg_num = location;
	mii->val_in = value;
	if (ioctl(skfd, SIOCSMIIREG, &ifr) < 0) {
		fprintf(stderr, "SIOCSMIIREG on %s failed: %s\n", ifr.ifr_name,
				strerror(errno));
	}
}
static void help()
{
	printf("help :\n");
	printf("set ETH_DEVICE to change device\n");
	printf("\t\tmdio_cmd addr reg [val]\n");
}

int main(int argc, char *argv[])
{
	struct mii_ioctl_data *mii = (struct mii_ioctl_data *)&ifr.ifr_data;
	int addr, reg;
	int ret;
	fd = socket(AF_INET, SOCK_DGRAM,0);
	if (fd < 0) {
		perror("open");
		exit(1);
	}

	if (argc < 3) {
		//i2c_scan();
		help();
		return 1;
	}

	strncpy(ifr.ifr_name, DEVICE, IFNAMSIZ);
	addr = strtol(argv[1], NULL, 0);

	ret = ioctl(fd, SIOCGMIIPHY, &ifr);
	if (ret < 0) {
		fprintf(stderr, "SIOCGMIIPHY on %s failed: %s\n", ifr.ifr_name,
				strerror(errno));
		return 1;
	}

	if (addr != -1) {
		/* allow to overides phy id */
		mii->phy_id = addr;
	}

	printf("using phy at addr %x id=%04x%04x\n", mii->phy_id,
			mdio_read(fd, 2), mdio_read(fd, 3));

	reg = strtol(argv[2], NULL, 0);
	if (argc == 3)
		printf("reading : 0x%02x\n", mdio_read(fd, reg));
	else {
		printf("writting\n");
		mdio_write(fd, reg, strtol(argv[3], NULL, 0));
	}

	return 0;
}