/*
 * Handling of a single switch port
 *
 * Copyright (c) 2017 Savoir-faire Linux Inc.
 *	Vivien Didelot <vivien.didelot@savoirfairelinux.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#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_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)\n", state, err);
}

int dsa_port_enable(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);

	return 0;
}

void dsa_port_disable(struct dsa_port *dp)
{
	struct dsa_switch *ds = dp->ds;
	int port = dp->index;

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

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

int dsa_port_bridge_join(struct dsa_port *dp, struct net_device *br)
{
	struct dsa_notifier_bridge_info info = {
		.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_port_notify(dp, 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 = {
		.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_port_notify(dp, DSA_NOTIFIER_BRIDGE_LEAVE, &info);
	if (err)
		pr_err("DSA: failed to notify DSA_NOTIFIER_BRIDGE_LEAVE\n");

	/* 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);
}

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

	/* bridge skips -EOPNOTSUPP, so skip the prepare phase */
	if (switchdev_trans_ph_prepare(trans))
		return 0;

	if (ds->ops->port_vlan_filtering)
		return ds->ops->port_vlan_filtering(ds, dp->index,
						    vlan_filtering);

	return 0;
}

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_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,
	};

	/* Can be called from dsa_slave_port_obj_add() or
	 * dsa_slave_vlan_rx_add_vid()
	 */
	if (!dp->bridge_dev || br_vlan_enabled(dp->bridge_dev))
		return dsa_port_notify(dp, DSA_NOTIFIER_VLAN_ADD, &info);

	return 0;
}

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,
	};

	if (vlan->obj.orig_dev && netif_is_bridge_master(vlan->obj.orig_dev))
		return -EOPNOTSUPP;

	/* Can be called from dsa_slave_port_obj_del() or
	 * dsa_slave_vlan_rx_kill_vid()
	 */
	if (!dp->bridge_dev || br_vlan_enabled(dp->bridge_dev))
		return dsa_port_notify(dp, DSA_NOTIFIER_VLAN_DEL, &info);

	return 0;
}

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 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_config_init(phydev);
		if (err < 0)
			goto err_put_dev;

		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;
	int 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\n",
			port);
		return err;
	}

	phydev = of_phy_find_device(dn);

	mode = of_get_phy_mode(dn);
	if (mode < 0)
		mode = PHY_INTERFACE_MODE_NA;
	phydev->interface = mode;

	genphy_config_init(phydev);
	genphy_read_status(phydev);

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

	put_device(&phydev->mdio.dev);

	return 0;
}

int dsa_port_link_register_of(struct dsa_port *dp)
{
	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)
{
	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);