net: asix: ax88772: migrate to phylink

There are some exotic ax88772 based devices which may require
functionality provide by the phylink framework. For example:
- US100A20SFP, USB 2.0 auf LWL Converter with SFP Cage
- AX88772B USB to 100Base-TX Ethernet (with RMII) demo board, where it
  is possible to switch between internal PHY and external RMII based
  connection.

So, convert this driver to phylink as soon as possible.

Tested with:
- AX88772A + internal PHY
- AX88772B + external DP83TD510E T1L PHY

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/usb/Kconfig

@@ -168,7 +168,7 @@ config USB_NET_AX8817X
 	tristate "ASIX AX88xxx Based USB 2.0 Ethernet Adapters"
 	depends on USB_USBNET
 	select CRC32
-	select PHYLIB
+	select PHYLINK
 	select AX88796B_PHY
 	imply NET_SELFTESTS
 	default y

drivers/net/usb/asix.h

@@ -27,6 +27,7 @@
 #include <linux/if_vlan.h>
 #include <linux/phy.h>
 #include <net/selftests.h>
+#include <linux/phylink.h>
 
 #define DRIVER_VERSION "22-Dec-2011"
 #define DRIVER_NAME "asix"
@@ -185,6 +186,8 @@ struct asix_common_private {
 	struct mii_bus *mdio;
 	struct phy_device *phydev;
 	struct phy_device *phydev_int;
+	struct phylink *phylink;
+	struct phylink_config phylink_config;
 	u16 phy_addr;
 	bool embd_phy;
 	u8 chipcode;

drivers/net/usb/asix_devices.c

@@ -343,7 +343,7 @@ static int ax88772_reset(struct usbnet *dev)
 	if (ret < 0)
 		goto out;
 
-	phy_start(priv->phydev);
+	phylink_start(priv->phylink);
 
 	return 0;
 
@@ -590,8 +590,11 @@ static void ax88772_suspend(struct usbnet *dev)
 	struct asix_common_private *priv = dev->driver_priv;
 	u16 medium;
 
-	if (netif_running(dev->net))
-		phy_stop(priv->phydev);
+	if (netif_running(dev->net)) {
+		rtnl_lock();
+		phylink_suspend(priv->phylink, false);
+		rtnl_unlock();
+	}
 
 	/* Stop MAC operation */
 	medium = asix_read_medium_status(dev, 1);
@@ -622,8 +625,11 @@ static void ax88772_resume(struct usbnet *dev)
 		if (!priv->reset(dev, 1))
 			break;
 
-	if (netif_running(dev->net))
-		phy_start(priv->phydev);
+	if (netif_running(dev->net)) {
+		rtnl_lock();
+		phylink_resume(priv->phylink);
+		rtnl_unlock();
+	}
 }
 
 static int asix_resume(struct usb_interface *intf)
@@ -667,8 +673,7 @@ static int ax88772_init_phy(struct usbnet *dev)
 		return -ENODEV;
 	}
 
-	ret = phy_connect_direct(dev->net, priv->phydev, &asix_adjust_link,
-				 PHY_INTERFACE_MODE_INTERNAL);
+	ret = phylink_connect_phy(priv->phylink, priv->phydev);
 	if (ret) {
 		netdev_err(dev->net, "Could not connect PHY\n");
 		return ret;
@@ -688,6 +693,9 @@ static int ax88772_init_phy(struct usbnet *dev)
 	 */
 	priv->phydev_int = mdiobus_get_phy(priv->mdio, AX_EMBD_PHY_ADDR);
 	if (!priv->phydev_int) {
+		rtnl_lock();
+		phylink_disconnect_phy(priv->phylink);
+		rtnl_unlock();
 		netdev_err(dev->net, "Could not find internal PHY\n");
 		return -ENODEV;
 	}
@@ -698,6 +706,89 @@ static int ax88772_init_phy(struct usbnet *dev)
 	return 0;
 }
 
+static void ax88772_mac_config(struct phylink_config *config, unsigned int mode,
+			      const struct phylink_link_state *state)
+{
+	/* Nothing to do */
+}
+
+static void ax88772_mac_link_down(struct phylink_config *config,
+				 unsigned int mode, phy_interface_t interface)
+{
+	struct usbnet *dev = netdev_priv(to_net_dev(config->dev));
+
+	asix_write_medium_mode(dev, 0, 0);
+	usbnet_link_change(dev, false, false);
+}
+
+static void ax88772_mac_link_up(struct phylink_config *config,
+			       struct phy_device *phy,
+			       unsigned int mode, phy_interface_t interface,
+			       int speed, int duplex,
+			       bool tx_pause, bool rx_pause)
+{
+	struct usbnet *dev = netdev_priv(to_net_dev(config->dev));
+	u16 m = AX_MEDIUM_AC | AX_MEDIUM_RE;
+
+	m |= duplex ? AX_MEDIUM_FD : 0;
+
+	switch (speed) {
+	case SPEED_100:
+		m |= AX_MEDIUM_PS;
+		break;
+	case SPEED_10:
+		break;
+	default:
+		return;
+	}
+
+	if (tx_pause)
+		m |= AX_MEDIUM_TFC;
+
+	if (rx_pause)
+		m |= AX_MEDIUM_RFC;
+
+	asix_write_medium_mode(dev, m, 0);
+	usbnet_link_change(dev, true, false);
+}
+
+static const struct phylink_mac_ops ax88772_phylink_mac_ops = {
+	.validate = phylink_generic_validate,
+	.mac_config = ax88772_mac_config,
+	.mac_link_down = ax88772_mac_link_down,
+	.mac_link_up = ax88772_mac_link_up,
+};
+
+static int ax88772_phylink_setup(struct usbnet *dev)
+{
+	struct asix_common_private *priv = dev->driver_priv;
+	phy_interface_t phy_if_mode;
+	struct phylink *phylink;
+
+	priv->phylink_config.dev = &dev->net->dev;
+	priv->phylink_config.type = PHYLINK_NETDEV;
+	priv->phylink_config.mac_capabilities = MAC_SYM_PAUSE | MAC_ASYM_PAUSE |
+		MAC_10 | MAC_100;
+
+	__set_bit(PHY_INTERFACE_MODE_INTERNAL,
+		  priv->phylink_config.supported_interfaces);
+	__set_bit(PHY_INTERFACE_MODE_RMII,
+		  priv->phylink_config.supported_interfaces);
+
+	if (priv->embd_phy)
+		phy_if_mode = PHY_INTERFACE_MODE_INTERNAL;
+	else
+		phy_if_mode = PHY_INTERFACE_MODE_RMII;
+
+	phylink = phylink_create(&priv->phylink_config, dev->net->dev.fwnode,
+				 phy_if_mode, &ax88772_phylink_mac_ops);
+	if (IS_ERR(phylink))
+		return PTR_ERR(phylink);
+
+	priv->phylink = phylink;
+	return 0;
+}
+
 static int ax88772_bind(struct usbnet *dev, struct usb_interface *intf)
 {
 	struct asix_common_private *priv;
@@ -788,14 +879,22 @@ static int ax88772_bind(struct usbnet *dev, struct usb_interface *intf)
 	if (ret)
 		return ret;
 
-	return ax88772_init_phy(dev);
+	ret = ax88772_phylink_setup(dev);
+	if (ret)
+		return ret;
+
+	ret = ax88772_init_phy(dev);
+	if (ret)
+		phylink_destroy(priv->phylink);
+
+	return ret;
 }
 
 static int ax88772_stop(struct usbnet *dev)
 {
 	struct asix_common_private *priv = dev->driver_priv;
 
-	phy_stop(priv->phydev);
+	phylink_stop(priv->phylink);
 
 	return 0;
 }
@@ -804,7 +903,10 @@ static void ax88772_unbind(struct usbnet *dev, struct usb_interface *intf)
 {
 	struct asix_common_private *priv = dev->driver_priv;
 
-	phy_disconnect(priv->phydev);
+	rtnl_lock();
+	phylink_disconnect_phy(priv->phylink);
+	rtnl_unlock();
+	phylink_destroy(priv->phylink);
 	asix_rx_fixup_common_free(dev->driver_priv);
 }