// SPDX-License-Identifier: GPL-2.0-or-later

  /*
   * Handling of a single switch port
   *
   * Copyright (c) 2017 Savoir-faire Linux Inc.
   *	Vivien Didelot <vivien.didelot@savoirfairelinux.com>

   */
  
  #include <linux/if_bridge.h>

  #include <linux/notifier.h>

  #include <linux/of_mdio.h>
  #include <linux/of_net.h>

  
  #include "dsa_priv.h"

  static int dsa_broadcast(unsigned long e, void *v)
  {
  	struct dsa_switch_tree *dst;
  	int err = 0;
  
  	list_for_each_entry(dst, &dsa_tree_list, list) {
  		struct raw_notifier_head *nh = &dst->nh;
  
  		err = raw_notifier_call_chain(nh, e, v);
  		err = notifier_to_errno(err);
  		if (err)
  			break;
  	}
  
  	return err;
  }

  static int dsa_port_notify(const struct dsa_port *dp, unsigned long e, void *v)

  {
  	struct raw_notifier_head *nh = &dp->ds->dst->nh;
  	int err;
  
  	err = raw_notifier_call_chain(nh, e, v);
  
  	return notifier_to_errno(err);
  }

  int dsa_port_set_state(struct dsa_port *dp, u8 state,
  		       struct switchdev_trans *trans)
  {
  	struct dsa_switch *ds = dp->ds;
  	int port = dp->index;
  
  	if (switchdev_trans_ph_prepare(trans))
  		return ds->ops->port_stp_state_set ? 0 : -EOPNOTSUPP;
  
  	if (ds->ops->port_stp_state_set)
  		ds->ops->port_stp_state_set(ds, port, state);
  
  	if (ds->ops->port_fast_age) {
  		/* Fast age FDB entries or flush appropriate forwarding database
  		 * for the given port, if we are moving it from Learning or
  		 * Forwarding state, to Disabled or Blocking or Listening state.
  		 */
  
  		if ((dp->stp_state == BR_STATE_LEARNING ||
  		     dp->stp_state == BR_STATE_FORWARDING) &&
  		    (state == BR_STATE_DISABLED ||
  		     state == BR_STATE_BLOCKING ||
  		     state == BR_STATE_LISTENING))
  			ds->ops->port_fast_age(ds, port);
  	}
  
  	dp->stp_state = state;
  
  	return 0;
  }

  static void dsa_port_set_state_now(struct dsa_port *dp, u8 state)

  {
  	int err;
  
  	err = dsa_port_set_state(dp, state, NULL);
  	if (err)
  		pr_err("DSA: failed to set STP state %u (%d)
  ", state, err);
  }

  int dsa_port_enable_rt(struct dsa_port *dp, struct phy_device *phy)

  {

  	struct dsa_switch *ds = dp->ds;
  	int port = dp->index;
  	int err;
  
  	if (ds->ops->port_enable) {
  		err = ds->ops->port_enable(ds, port, phy);
  		if (err)
  			return err;
  	}

  	if (!dp->bridge_dev)
  		dsa_port_set_state_now(dp, BR_STATE_FORWARDING);

  	if (dp->pl)
  		phylink_start(dp->pl);

  	return 0;
  }

  int dsa_port_enable(struct dsa_port *dp, struct phy_device *phy)
  {
  	int err;
  
  	rtnl_lock();
  	err = dsa_port_enable_rt(dp, phy);
  	rtnl_unlock();
  
  	return err;
  }
  
  void dsa_port_disable_rt(struct dsa_port *dp)

  {
  	struct dsa_switch *ds = dp->ds;
  	int port = dp->index;

  	if (dp->pl)
  		phylink_stop(dp->pl);

  	if (!dp->bridge_dev)
  		dsa_port_set_state_now(dp, BR_STATE_DISABLED);

  
  	if (ds->ops->port_disable)

  		ds->ops->port_disable(ds, port);

  }

  void dsa_port_disable(struct dsa_port *dp)
  {
  	rtnl_lock();
  	dsa_port_disable_rt(dp);
  	rtnl_unlock();
  }

  int dsa_port_bridge_join(struct dsa_port *dp, struct net_device *br)
  {
  	struct dsa_notifier_bridge_info info = {

  		.tree_index = dp->ds->dst->index,

  		.sw_index = dp->ds->index,
  		.port = dp->index,
  		.br = br,
  	};
  	int err;

  	/* Set the flooding mode before joining the port in the switch */
  	err = dsa_port_bridge_flags(dp, BR_FLOOD | BR_MCAST_FLOOD, NULL);
  	if (err)
  		return err;
  
  	/* Here the interface is already bridged. Reflect the current
  	 * configuration so that drivers can program their chips accordingly.

  	 */
  	dp->bridge_dev = br;

  	err = dsa_broadcast(DSA_NOTIFIER_BRIDGE_JOIN, &info);

  
  	/* The bridging is rolled back on error */

  	if (err) {
  		dsa_port_bridge_flags(dp, 0, NULL);

  		dp->bridge_dev = NULL;

  	}

  
  	return err;
  }
  
  void dsa_port_bridge_leave(struct dsa_port *dp, struct net_device *br)
  {
  	struct dsa_notifier_bridge_info info = {

  		.tree_index = dp->ds->dst->index,

  		.sw_index = dp->ds->index,
  		.port = dp->index,
  		.br = br,
  	};
  	int err;
  
  	/* Here the port is already unbridged. Reflect the current configuration
  	 * so that drivers can program their chips accordingly.
  	 */
  	dp->bridge_dev = NULL;

  	err = dsa_broadcast(DSA_NOTIFIER_BRIDGE_LEAVE, &info);

  	if (err)
  		pr_err("DSA: failed to notify DSA_NOTIFIER_BRIDGE_LEAVE
  ");

  	/* Port is leaving the bridge, disable flooding */
  	dsa_port_bridge_flags(dp, 0, NULL);

  	/* Port left the bridge, put in BR_STATE_DISABLED by the bridge layer,
  	 * so allow it to be in BR_STATE_FORWARDING to be kept functional
  	 */
  	dsa_port_set_state_now(dp, BR_STATE_FORWARDING);
  }

  /* Must be called under rcu_read_lock() */

  static bool dsa_port_can_apply_vlan_filtering(struct dsa_port *dp,
  					      bool vlan_filtering)
  {
  	struct dsa_switch *ds = dp->ds;

  	int err, i;
  
  	/* VLAN awareness was off, so the question is "can we turn it on".
  	 * We may have had 8021q uppers, those need to go. Make sure we don't
  	 * enter an inconsistent state: deny changing the VLAN awareness state
  	 * as long as we have 8021q uppers.
  	 */
  	if (vlan_filtering && dsa_is_user_port(ds, dp->index)) {
  		struct net_device *upper_dev, *slave = dp->slave;
  		struct net_device *br = dp->bridge_dev;
  		struct list_head *iter;
  
  		netdev_for_each_upper_dev_rcu(slave, upper_dev, iter) {
  			struct bridge_vlan_info br_info;
  			u16 vid;
  
  			if (!is_vlan_dev(upper_dev))
  				continue;
  
  			vid = vlan_dev_vlan_id(upper_dev);
  
  			/* br_vlan_get_info() returns -EINVAL or -ENOENT if the
  			 * device, respectively the VID is not found, returning
  			 * 0 means success, which is a failure for us here.
  			 */
  			err = br_vlan_get_info(br, vid, &br_info);
  			if (err == 0) {
  				dev_err(ds->dev, "Must remove upper %s first
  ",
  					upper_dev->name);
  				return false;
  			}
  		}
  	}

  
  	if (!ds->vlan_filtering_is_global)
  		return true;
  
  	/* For cases where enabling/disabling VLAN awareness is global to the
  	 * switch, we need to handle the case where multiple bridges span
  	 * different ports of the same switch device and one of them has a
  	 * different setting than what is being requested.
  	 */
  	for (i = 0; i < ds->num_ports; i++) {
  		struct net_device *other_bridge;
  
  		other_bridge = dsa_to_port(ds, i)->bridge_dev;
  		if (!other_bridge)
  			continue;
  		/* If it's the same bridge, it also has same
  		 * vlan_filtering setting => no need to check
  		 */
  		if (other_bridge == dp->bridge_dev)
  			continue;
  		if (br_vlan_enabled(other_bridge) != vlan_filtering) {
  			dev_err(ds->dev, "VLAN filtering is a global setting
  ");
  			return false;
  		}
  	}
  	return true;
  }

  int dsa_port_vlan_filtering(struct dsa_port *dp, bool vlan_filtering,
  			    struct switchdev_trans *trans)
  {
  	struct dsa_switch *ds = dp->ds;

  	int err;

  	if (switchdev_trans_ph_prepare(trans)) {

  		bool apply;

  		if (!ds->ops->port_vlan_filtering)
  			return -EOPNOTSUPP;

  		/* We are called from dsa_slave_switchdev_blocking_event(),
  		 * which is not under rcu_read_lock(), unlike
  		 * dsa_slave_switchdev_event().
  		 */
  		rcu_read_lock();
  		apply = dsa_port_can_apply_vlan_filtering(dp, vlan_filtering);
  		rcu_read_unlock();
  		if (!apply)

  			return -EINVAL;

  	}

  	if (dsa_port_is_vlan_filtering(dp) == vlan_filtering)
  		return 0;

  	err = ds->ops->port_vlan_filtering(ds, dp->index, vlan_filtering,
  					   trans);

  	if (err)
  		return err;

  	if (switchdev_trans_ph_commit(trans)) {
  		if (ds->vlan_filtering_is_global)
  			ds->vlan_filtering = vlan_filtering;
  		else
  			dp->vlan_filtering = vlan_filtering;
  	}

  	return 0;
  }

  /* This enforces legacy behavior for switch drivers which assume they can't
   * receive VLAN configuration when enslaved to a bridge with vlan_filtering=0
   */
  bool dsa_port_skip_vlan_configuration(struct dsa_port *dp)
  {
  	struct dsa_switch *ds = dp->ds;
  
  	if (!dp->bridge_dev)
  		return false;
  
  	return (!ds->configure_vlan_while_not_filtering &&
  		!br_vlan_enabled(dp->bridge_dev));
  }

  int dsa_port_ageing_time(struct dsa_port *dp, clock_t ageing_clock,
  			 struct switchdev_trans *trans)
  {
  	unsigned long ageing_jiffies = clock_t_to_jiffies(ageing_clock);
  	unsigned int ageing_time = jiffies_to_msecs(ageing_jiffies);

  	struct dsa_notifier_ageing_time_info info = {
  		.ageing_time = ageing_time,

  		.trans = trans,
  	};

  	if (switchdev_trans_ph_prepare(trans))
  		return dsa_port_notify(dp, DSA_NOTIFIER_AGEING_TIME, &info);

  	dp->ageing_time = ageing_time;

  	return dsa_port_notify(dp, DSA_NOTIFIER_AGEING_TIME, &info);

  }

  int dsa_port_pre_bridge_flags(const struct dsa_port *dp, unsigned long flags,
  			      struct switchdev_trans *trans)
  {
  	struct dsa_switch *ds = dp->ds;
  
  	if (!ds->ops->port_egress_floods ||
  	    (flags & ~(BR_FLOOD | BR_MCAST_FLOOD)))
  		return -EINVAL;
  
  	return 0;
  }

  int dsa_port_bridge_flags(const struct dsa_port *dp, unsigned long flags,
  			  struct switchdev_trans *trans)
  {
  	struct dsa_switch *ds = dp->ds;
  	int port = dp->index;
  	int err = 0;
  
  	if (switchdev_trans_ph_prepare(trans))
  		return 0;
  
  	if (ds->ops->port_egress_floods)
  		err = ds->ops->port_egress_floods(ds, port, flags & BR_FLOOD,
  						  flags & BR_MCAST_FLOOD);
  
  	return err;
  }

  int dsa_port_mrouter(struct dsa_port *dp, bool mrouter,
  		     struct switchdev_trans *trans)
  {
  	struct dsa_switch *ds = dp->ds;
  	int port = dp->index;
  
  	if (switchdev_trans_ph_prepare(trans))
  		return ds->ops->port_egress_floods ? 0 : -EOPNOTSUPP;
  
  	return ds->ops->port_egress_floods(ds, port, true, mrouter);
  }

  int dsa_port_mtu_change(struct dsa_port *dp, int new_mtu,
  			bool propagate_upstream)
  {
  	struct dsa_notifier_mtu_info info = {
  		.sw_index = dp->ds->index,
  		.propagate_upstream = propagate_upstream,
  		.port = dp->index,
  		.mtu = new_mtu,
  	};
  
  	return dsa_port_notify(dp, DSA_NOTIFIER_MTU, &info);
  }

  int dsa_port_fdb_add(struct dsa_port *dp, const unsigned char *addr,
  		     u16 vid)

  {

  	struct dsa_notifier_fdb_info info = {
  		.sw_index = dp->ds->index,
  		.port = dp->index,

  		.addr = addr,
  		.vid = vid,

  	};

  	return dsa_port_notify(dp, DSA_NOTIFIER_FDB_ADD, &info);

  }

  int dsa_port_fdb_del(struct dsa_port *dp, const unsigned char *addr,
  		     u16 vid)

  {

  	struct dsa_notifier_fdb_info info = {
  		.sw_index = dp->ds->index,
  		.port = dp->index,

  		.addr = addr,
  		.vid = vid,

  	};

  	return dsa_port_notify(dp, DSA_NOTIFIER_FDB_DEL, &info);

  }

  int dsa_port_fdb_dump(struct dsa_port *dp, dsa_fdb_dump_cb_t *cb, void *data)
  {
  	struct dsa_switch *ds = dp->ds;
  	int port = dp->index;
  
  	if (!ds->ops->port_fdb_dump)
  		return -EOPNOTSUPP;
  
  	return ds->ops->port_fdb_dump(ds, port, cb, data);
  }

  int dsa_port_mdb_add(const struct dsa_port *dp,

  		     const struct switchdev_obj_port_mdb *mdb,
  		     struct switchdev_trans *trans)
  {

  	struct dsa_notifier_mdb_info info = {
  		.sw_index = dp->ds->index,
  		.port = dp->index,
  		.trans = trans,
  		.mdb = mdb,
  	};

  	return dsa_port_notify(dp, DSA_NOTIFIER_MDB_ADD, &info);

  }

  int dsa_port_mdb_del(const struct dsa_port *dp,

  		     const struct switchdev_obj_port_mdb *mdb)
  {

  	struct dsa_notifier_mdb_info info = {
  		.sw_index = dp->ds->index,
  		.port = dp->index,
  		.mdb = mdb,
  	};

  	return dsa_port_notify(dp, DSA_NOTIFIER_MDB_DEL, &info);

  }

  int dsa_port_vlan_add(struct dsa_port *dp,
  		      const struct switchdev_obj_port_vlan *vlan,
  		      struct switchdev_trans *trans)
  {

  	struct dsa_notifier_vlan_info info = {
  		.sw_index = dp->ds->index,
  		.port = dp->index,
  		.trans = trans,
  		.vlan = vlan,
  	};

  	return dsa_port_notify(dp, DSA_NOTIFIER_VLAN_ADD, &info);

  }
  
  int dsa_port_vlan_del(struct dsa_port *dp,
  		      const struct switchdev_obj_port_vlan *vlan)
  {

  	struct dsa_notifier_vlan_info info = {
  		.sw_index = dp->ds->index,
  		.port = dp->index,
  		.vlan = vlan,
  	};

  	return dsa_port_notify(dp, DSA_NOTIFIER_VLAN_DEL, &info);

  }

  static struct phy_device *dsa_port_get_phy_device(struct dsa_port *dp)

  {

  	struct device_node *phy_dn;

  	struct phy_device *phydev;

  	phy_dn = of_parse_phandle(dp->dn, "phy-handle", 0);

  	if (!phy_dn)

  		return NULL;

  
  	phydev = of_phy_find_device(phy_dn);
  	if (!phydev) {

  		of_node_put(phy_dn);
  		return ERR_PTR(-EPROBE_DEFER);

  	}

  	of_node_put(phy_dn);

  	return phydev;
  }

  static void dsa_port_phylink_validate(struct phylink_config *config,
  				      unsigned long *supported,
  				      struct phylink_link_state *state)

  {
  	struct dsa_port *dp = container_of(config, struct dsa_port, pl_config);
  	struct dsa_switch *ds = dp->ds;
  
  	if (!ds->ops->phylink_validate)
  		return;
  
  	ds->ops->phylink_validate(ds, dp->index, supported, state);
  }

  static void dsa_port_phylink_mac_pcs_get_state(struct phylink_config *config,
  					       struct phylink_link_state *state)

  {
  	struct dsa_port *dp = container_of(config, struct dsa_port, pl_config);
  	struct dsa_switch *ds = dp->ds;

  	int err;

  	/* Only called for inband modes */
  	if (!ds->ops->phylink_mac_link_state) {
  		state->link = 0;
  		return;
  	}

  	err = ds->ops->phylink_mac_link_state(ds, dp->index, state);
  	if (err < 0) {
  		dev_err(ds->dev, "p%d: phylink_mac_link_state() failed: %d
  ",
  			dp->index, err);

  		state->link = 0;

  	}

  }

  static void dsa_port_phylink_mac_config(struct phylink_config *config,
  					unsigned int mode,
  					const struct phylink_link_state *state)

  {
  	struct dsa_port *dp = container_of(config, struct dsa_port, pl_config);
  	struct dsa_switch *ds = dp->ds;
  
  	if (!ds->ops->phylink_mac_config)
  		return;
  
  	ds->ops->phylink_mac_config(ds, dp->index, mode, state);
  }

  static void dsa_port_phylink_mac_an_restart(struct phylink_config *config)

  {
  	struct dsa_port *dp = container_of(config, struct dsa_port, pl_config);
  	struct dsa_switch *ds = dp->ds;
  
  	if (!ds->ops->phylink_mac_an_restart)
  		return;
  
  	ds->ops->phylink_mac_an_restart(ds, dp->index);
  }

  static void dsa_port_phylink_mac_link_down(struct phylink_config *config,
  					   unsigned int mode,
  					   phy_interface_t interface)

  {
  	struct dsa_port *dp = container_of(config, struct dsa_port, pl_config);

  	struct phy_device *phydev = NULL;

  	struct dsa_switch *ds = dp->ds;

  	if (dsa_is_user_port(ds, dp->index))
  		phydev = dp->slave->phydev;

  	if (!ds->ops->phylink_mac_link_down) {

  		if (ds->ops->adjust_link && phydev)
  			ds->ops->adjust_link(ds, dp->index, phydev);

  		return;
  	}
  
  	ds->ops->phylink_mac_link_down(ds, dp->index, mode, interface);
  }

  static void dsa_port_phylink_mac_link_up(struct phylink_config *config,

  					 struct phy_device *phydev,

  					 unsigned int mode,
  					 phy_interface_t interface,

  					 int speed, int duplex,
  					 bool tx_pause, bool rx_pause)

  {
  	struct dsa_port *dp = container_of(config, struct dsa_port, pl_config);

  	struct dsa_switch *ds = dp->ds;
  
  	if (!ds->ops->phylink_mac_link_up) {

  		if (ds->ops->adjust_link && phydev)
  			ds->ops->adjust_link(ds, dp->index, phydev);

  		return;
  	}

  	ds->ops->phylink_mac_link_up(ds, dp->index, mode, interface, phydev,
  				     speed, duplex, tx_pause, rx_pause);

  }

  
  const struct phylink_mac_ops dsa_port_phylink_mac_ops = {
  	.validate = dsa_port_phylink_validate,

  	.mac_pcs_get_state = dsa_port_phylink_mac_pcs_get_state,

  	.mac_config = dsa_port_phylink_mac_config,
  	.mac_an_restart = dsa_port_phylink_mac_an_restart,
  	.mac_link_down = dsa_port_phylink_mac_link_down,
  	.mac_link_up = dsa_port_phylink_mac_link_up,
  };

  static int dsa_port_setup_phy_of(struct dsa_port *dp, bool enable)
  {
  	struct dsa_switch *ds = dp->ds;
  	struct phy_device *phydev;
  	int port = dp->index;
  	int err = 0;
  
  	phydev = dsa_port_get_phy_device(dp);
  	if (!phydev)
  		return 0;
  
  	if (IS_ERR(phydev))
  		return PTR_ERR(phydev);

  	if (enable) {

  		err = genphy_resume(phydev);
  		if (err < 0)
  			goto err_put_dev;
  
  		err = genphy_read_status(phydev);
  		if (err < 0)
  			goto err_put_dev;
  	} else {
  		err = genphy_suspend(phydev);
  		if (err < 0)
  			goto err_put_dev;
  	}
  
  	if (ds->ops->adjust_link)
  		ds->ops->adjust_link(ds, port, phydev);
  
  	dev_dbg(ds->dev, "enabled port's phy: %s", phydev_name(phydev));
  
  err_put_dev:
  	put_device(&phydev->mdio.dev);

  	return err;
  }
  
  static int dsa_port_fixed_link_register_of(struct dsa_port *dp)

  {
  	struct device_node *dn = dp->dn;
  	struct dsa_switch *ds = dp->ds;
  	struct phy_device *phydev;
  	int port = dp->index;

  	phy_interface_t mode;

  	int err;

  	err = of_phy_register_fixed_link(dn);
  	if (err) {
  		dev_err(ds->dev,
  			"failed to register the fixed PHY of port %d
  ",
  			port);
  		return err;
  	}

  	phydev = of_phy_find_device(dn);

  	err = of_get_phy_mode(dn, &mode);
  	if (err)

  		mode = PHY_INTERFACE_MODE_NA;
  	phydev->interface = mode;

  	genphy_read_status(phydev);

  	if (ds->ops->adjust_link)
  		ds->ops->adjust_link(ds, port, phydev);

  	put_device(&phydev->mdio.dev);

  
  	return 0;
  }

  static int dsa_port_phylink_register(struct dsa_port *dp)
  {
  	struct dsa_switch *ds = dp->ds;
  	struct device_node *port_dn = dp->dn;

  	phy_interface_t mode;
  	int err;

  	err = of_get_phy_mode(port_dn, &mode);
  	if (err)

  		mode = PHY_INTERFACE_MODE_NA;
  
  	dp->pl_config.dev = ds->dev;
  	dp->pl_config.type = PHYLINK_DEV;

  	dp->pl_config.pcs_poll = ds->pcs_poll;

  
  	dp->pl = phylink_create(&dp->pl_config, of_fwnode_handle(port_dn),
  				mode, &dsa_port_phylink_mac_ops);
  	if (IS_ERR(dp->pl)) {
  		pr_err("error creating PHYLINK: %ld
  ", PTR_ERR(dp->pl));
  		return PTR_ERR(dp->pl);
  	}
  
  	err = phylink_of_phy_connect(dp->pl, port_dn, 0);

  	if (err && err != -ENODEV) {

  		pr_err("could not attach to PHY: %d
  ", err);
  		goto err_phy_connect;
  	}

  	return 0;
  
  err_phy_connect:
  	phylink_destroy(dp->pl);
  	return err;
  }

  int dsa_port_link_register_of(struct dsa_port *dp)

  {

  	struct dsa_switch *ds = dp->ds;

  	struct device_node *phy_np;

  	int port = dp->index;

  	if (!ds->ops->adjust_link) {
  		phy_np = of_parse_phandle(dp->dn, "phy-handle", 0);

  		if (of_phy_is_fixed_link(dp->dn) || phy_np) {
  			if (ds->ops->phylink_mac_link_down)
  				ds->ops->phylink_mac_link_down(ds, port,
  					MLO_AN_FIXED, PHY_INTERFACE_MODE_NA);

  			return dsa_port_phylink_register(dp);

  		}

  		return 0;
  	}

  
  	dev_warn(ds->dev,
  		 "Using legacy PHYLIB callbacks. Please migrate to PHYLINK!
  ");

  	if (of_phy_is_fixed_link(dp->dn))
  		return dsa_port_fixed_link_register_of(dp);
  	else
  		return dsa_port_setup_phy_of(dp, true);
  }

  void dsa_port_link_unregister_of(struct dsa_port *dp)
  {

  	struct dsa_switch *ds = dp->ds;

  	if (!ds->ops->adjust_link && dp->pl) {

  		rtnl_lock();
  		phylink_disconnect_phy(dp->pl);
  		rtnl_unlock();
  		phylink_destroy(dp->pl);

  		dp->pl = NULL;

  		return;
  	}

  	if (of_phy_is_fixed_link(dp->dn))
  		of_phy_deregister_fixed_link(dp->dn);
  	else
  		dsa_port_setup_phy_of(dp, false);

  }

  
  int dsa_port_get_phy_strings(struct dsa_port *dp, uint8_t *data)
  {
  	struct phy_device *phydev;
  	int ret = -EOPNOTSUPP;
  
  	if (of_phy_is_fixed_link(dp->dn))
  		return ret;
  
  	phydev = dsa_port_get_phy_device(dp);
  	if (IS_ERR_OR_NULL(phydev))
  		return ret;
  
  	ret = phy_ethtool_get_strings(phydev, data);
  	put_device(&phydev->mdio.dev);
  
  	return ret;
  }
  EXPORT_SYMBOL_GPL(dsa_port_get_phy_strings);
  
  int dsa_port_get_ethtool_phy_stats(struct dsa_port *dp, uint64_t *data)
  {
  	struct phy_device *phydev;
  	int ret = -EOPNOTSUPP;
  
  	if (of_phy_is_fixed_link(dp->dn))
  		return ret;
  
  	phydev = dsa_port_get_phy_device(dp);
  	if (IS_ERR_OR_NULL(phydev))
  		return ret;
  
  	ret = phy_ethtool_get_stats(phydev, NULL, data);
  	put_device(&phydev->mdio.dev);
  
  	return ret;
  }
  EXPORT_SYMBOL_GPL(dsa_port_get_ethtool_phy_stats);
  
  int dsa_port_get_phy_sset_count(struct dsa_port *dp)
  {
  	struct phy_device *phydev;
  	int ret = -EOPNOTSUPP;
  
  	if (of_phy_is_fixed_link(dp->dn))
  		return ret;
  
  	phydev = dsa_port_get_phy_device(dp);
  	if (IS_ERR_OR_NULL(phydev))
  		return ret;
  
  	ret = phy_ethtool_get_sset_count(phydev);
  	put_device(&phydev->mdio.dev);
  
  	return ret;
  }
  EXPORT_SYMBOL_GPL(dsa_port_get_phy_sset_count);