net: xilinx: emaclite: add minimal ndo_do_ioctl hook

This hook only implements a minimal set of ioctl hooks to be able to access
MII regs by using phytool.
When using this simple MAC controller, it's pretty difficult to do
debugging of the PHY chip without checking MII regs.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Reviewed-by: Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/xilinx/xilinx_emaclite.c

@@ -1252,12 +1252,29 @@ xemaclite_poll_controller(struct net_device *ndev)
 }
 #endif
 
+/* Ioctl MII Interface */
+static int xemaclite_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
+{
+	if (!dev->phydev || !netif_running(dev))
+		return -EINVAL;
+
+	switch (cmd) {
+	case SIOCGMIIPHY:
+	case SIOCGMIIREG:
+	case SIOCSMIIREG:
+		return phy_mii_ioctl(dev->phydev, rq, cmd);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
 static const struct net_device_ops xemaclite_netdev_ops = {
 	.ndo_open		= xemaclite_open,
 	.ndo_stop		= xemaclite_close,
 	.ndo_start_xmit		= xemaclite_send,
 	.ndo_set_mac_address	= xemaclite_set_mac_address,
 	.ndo_tx_timeout		= xemaclite_tx_timeout,
+	.ndo_do_ioctl		= xemaclite_ioctl,
 #ifdef CONFIG_NET_POLL_CONTROLLER
 	.ndo_poll_controller = xemaclite_poll_controller,
 #endif