Accessing ethernet phy driver from linux user space - linux

Question

i want to access ethernet phy driver from linux user space,
In uboot we can directly access phy registers using mii commands
similarly i want to read and write phy registers from linux user space .
cause there is no major or minor number comes in case of phy driver(maybe cause its a network driver)
how to do it.and is it possible

Answer 1

There are the following ioctl requests for that purpose:
#define SIOCGMIIREG 0x8948 /* Read MII PHY register. */
#define SIOCSMIIREG 0x8949 /* Write MII PHY register. */
And MII register constants are defined in:
#include <linux/mii.h>
Example:
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <net/if.h>
#include <sys/ioctl.h>
#include <linux/mii.h>
#include <linux/sockios.h>
int main()
{
struct ifreq ifr;
memset(&ifr, 0, sizeof(ifr));
strcpy(ifr.ifr_name, "eth1");
struct mii_ioctl_data* mii = (struct mii_ioctl_data*)(&ifr.ifr_data);
mii->phy_id = 1;
mii->reg_num = MII_BMSR;
mii->val_in = 0;
mii->val_out = 0;
const int fd = socket(AF_INET, SOCK_DGRAM, 0);
if (fd != -1)
{
if (ioctl(fd, SIOCGMIIREG, &ifr) != -1)
{
printf("MII_BMSR = 0x%04hX \n", mii->val_out);
printf("BMSR_LSTATUS = %d \n", (mii->val_out & BMSR_LSTATUS) ? 1 : 0);
}
close(fd);
}
return 0;
}

Answer 2

Try to use mii-tool or ethtool. Look at the sources of those programs how to get access to phy api.