by checking davinci_emac.c, it's not supported now...
static int emac_devioctl(struct net_device *ndev, struct ifreq *ifrq, int cmd)
{
dev_warn(&ndev->dev, "DaVinci EMAC: ioctl not supported\n");
if (!(netif_running(ndev)))
return -EINVAL;
/* TODO: Add phy read and write and private statistics get feature */
return -EOPNOTSUPP;
}