/*
   * net/dsa/legacy.c - Hardware switch handling
   * Copyright (c) 2008-2009 Marvell Semiconductor
   * Copyright (c) 2013 Florian Fainelli <florian@openwrt.org>
   *
   * 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/device.h>
  #include <linux/list.h>
  #include <linux/platform_device.h>
  #include <linux/slab.h>
  #include <linux/module.h>
  #include <linux/of.h>
  #include <linux/of_mdio.h>
  #include <linux/of_platform.h>
  #include <linux/of_net.h>
  #include <linux/netdevice.h>
  #include <linux/sysfs.h>
  #include <linux/phy_fixed.h>
  #include <linux/etherdevice.h>

  #include "dsa_priv.h"
  
  /* switch driver registration ***********************************************/
  static DEFINE_MUTEX(dsa_switch_drivers_mutex);
  static LIST_HEAD(dsa_switch_drivers);
  
  void register_switch_driver(struct dsa_switch_driver *drv)
  {
  	mutex_lock(&dsa_switch_drivers_mutex);
  	list_add_tail(&drv->list, &dsa_switch_drivers);
  	mutex_unlock(&dsa_switch_drivers_mutex);
  }
  EXPORT_SYMBOL_GPL(register_switch_driver);
  
  void unregister_switch_driver(struct dsa_switch_driver *drv)
  {
  	mutex_lock(&dsa_switch_drivers_mutex);
  	list_del_init(&drv->list);
  	mutex_unlock(&dsa_switch_drivers_mutex);
  }
  EXPORT_SYMBOL_GPL(unregister_switch_driver);
  
  static const struct dsa_switch_ops *
  dsa_switch_probe(struct device *parent, struct device *host_dev, int sw_addr,
  		 const char **_name, void **priv)
  {
  	const struct dsa_switch_ops *ret;
  	struct list_head *list;
  	const char *name;
  
  	ret = NULL;
  	name = NULL;
  
  	mutex_lock(&dsa_switch_drivers_mutex);
  	list_for_each(list, &dsa_switch_drivers) {
  		const struct dsa_switch_ops *ops;
  		struct dsa_switch_driver *drv;
  
  		drv = list_entry(list, struct dsa_switch_driver, list);
  		ops = drv->ops;
  
  		name = ops->probe(parent, host_dev, sw_addr, priv);
  		if (name != NULL) {
  			ret = ops;
  			break;
  		}
  	}
  	mutex_unlock(&dsa_switch_drivers_mutex);
  
  	*_name = name;
  
  	return ret;
  }
  
  /* basic switch operations **************************************************/

  static int dsa_cpu_dsa_setups(struct dsa_switch *ds)

  {

  	int ret, port;
  
  	for (port = 0; port < ds->num_ports; port++) {
  		if (!(dsa_is_cpu_port(ds, port) || dsa_is_dsa_port(ds, port)))
  			continue;

  		ret = dsa_cpu_dsa_setup(&ds->ports[port]);

  		if (ret)
  			return ret;
  	}
  	return 0;
  }

  static int dsa_switch_setup_one(struct dsa_switch *ds,
  				struct net_device *master)

  {
  	const struct dsa_switch_ops *ops = ds->ops;
  	struct dsa_switch_tree *dst = ds->dst;
  	struct dsa_chip_data *cd = ds->cd;
  	bool valid_name_found = false;
  	int index = ds->index;
  	int i, ret;
  
  	/*
  	 * Validate supplied switch configuration.
  	 */
  	for (i = 0; i < ds->num_ports; i++) {
  		char *name;
  
  		name = cd->port_names[i];
  		if (name == NULL)
  			continue;
  
  		if (!strcmp(name, "cpu")) {

  			if (dst->cpu_dp) {

  				netdev_err(master,

  					   "multiple cpu ports?!
  ");
  				return -EINVAL;
  			}

  			dst->cpu_dp = &ds->ports[i];

  			dst->cpu_dp->netdev = master;

  			ds->cpu_port_mask |= 1 << i;
  		} else if (!strcmp(name, "dsa")) {
  			ds->dsa_port_mask |= 1 << i;
  		} else {
  			ds->enabled_port_mask |= 1 << i;
  		}
  		valid_name_found = true;
  	}
  
  	if (!valid_name_found && i == ds->num_ports)
  		return -EINVAL;
  
  	/* Make the built-in MII bus mask match the number of ports,
  	 * switch drivers can override this later
  	 */
  	ds->phys_mii_mask = ds->enabled_port_mask;
  
  	/*
  	 * If the CPU connects to this switch, set the switch tree
  	 * tagging protocol to the preferred tagging format of this
  	 * switch.
  	 */

  	if (dst->cpu_dp->ds == ds) {

  		enum dsa_tag_protocol tag_protocol;
  
  		tag_protocol = ops->get_tag_protocol(ds);
  		dst->tag_ops = dsa_resolve_tag_protocol(tag_protocol);
  		if (IS_ERR(dst->tag_ops))
  			return PTR_ERR(dst->tag_ops);
  
  		dst->rcv = dst->tag_ops->rcv;
  	}
  
  	memcpy(ds->rtable, cd->rtable, sizeof(ds->rtable));
  
  	/*
  	 * Do basic register setup.
  	 */
  	ret = ops->setup(ds);
  	if (ret < 0)
  		return ret;
  
  	ret = dsa_switch_register_notifier(ds);
  	if (ret)
  		return ret;
  
  	if (ops->set_addr) {

  		ret = ops->set_addr(ds, master->dev_addr);

  		if (ret < 0)
  			return ret;
  	}
  
  	if (!ds->slave_mii_bus && ops->phy_read) {

  		ds->slave_mii_bus = devm_mdiobus_alloc(ds->dev);

  		if (!ds->slave_mii_bus)
  			return -ENOMEM;
  		dsa_slave_mii_bus_init(ds);
  
  		ret = mdiobus_register(ds->slave_mii_bus);
  		if (ret < 0)
  			return ret;
  	}
  
  	/*
  	 * Create network devices for physical switch ports.
  	 */
  	for (i = 0; i < ds->num_ports; i++) {
  		ds->ports[i].dn = cd->port_dn[i];

  		ds->ports[i].cpu_dp = dst->cpu_dp;

  
  		if (!(ds->enabled_port_mask & (1 << i)))
  			continue;

  		ret = dsa_slave_create(&ds->ports[i], cd->port_names[i]);

  		if (ret < 0)

  			netdev_err(master, "[%d]: can't create dsa slave device for port %d(%s): %d
  ",

  				   index, i, cd->port_names[i], ret);
  	}
  
  	/* Perform configuration of the CPU and DSA ports */

  	ret = dsa_cpu_dsa_setups(ds);

  	if (ret < 0)

  		netdev_err(master, "[%d] : can't configure CPU and DSA ports
  ",

  			   index);

  	ret = dsa_cpu_port_ethtool_setup(ds->dst->cpu_dp);

  	if (ret)
  		return ret;
  
  	return 0;
  }
  
  static struct dsa_switch *

  dsa_switch_setup(struct dsa_switch_tree *dst, struct net_device *master,
  		 int index, struct device *parent, struct device *host_dev)

  {
  	struct dsa_chip_data *cd = dst->pd->chip + index;
  	const struct dsa_switch_ops *ops;
  	struct dsa_switch *ds;
  	int ret;
  	const char *name;
  	void *priv;
  
  	/*
  	 * Probe for switch model.
  	 */
  	ops = dsa_switch_probe(parent, host_dev, cd->sw_addr, &name, &priv);
  	if (!ops) {

  		netdev_err(master, "[%d]: could not detect attached switch
  ",

  			   index);
  		return ERR_PTR(-EINVAL);
  	}

  	netdev_info(master, "[%d]: detected a %s switch
  ",

  		    index, name);
  
  
  	/*
  	 * Allocate and initialise switch state.
  	 */
  	ds = dsa_switch_alloc(parent, DSA_MAX_PORTS);
  	if (!ds)
  		return ERR_PTR(-ENOMEM);
  
  	ds->dst = dst;
  	ds->index = index;
  	ds->cd = cd;
  	ds->ops = ops;
  	ds->priv = priv;

  	ret = dsa_switch_setup_one(ds, master);

  	if (ret)
  		return ERR_PTR(ret);
  
  	return ds;
  }
  
  static void dsa_switch_destroy(struct dsa_switch *ds)
  {
  	int port;
  
  	/* Destroy network devices for physical switch ports. */
  	for (port = 0; port < ds->num_ports; port++) {
  		if (!(ds->enabled_port_mask & (1 << port)))
  			continue;
  
  		if (!ds->ports[port].netdev)
  			continue;
  
  		dsa_slave_destroy(ds->ports[port].netdev);
  	}
  
  	/* Disable configuration of the CPU and DSA ports */
  	for (port = 0; port < ds->num_ports; port++) {
  		if (!(dsa_is_cpu_port(ds, port) || dsa_is_dsa_port(ds, port)))
  			continue;
  		dsa_cpu_dsa_destroy(&ds->ports[port]);
  
  		/* Clearing a bit which is not set does no harm */
  		ds->cpu_port_mask |= ~(1 << port);
  		ds->dsa_port_mask |= ~(1 << port);
  	}
  
  	if (ds->slave_mii_bus && ds->ops->phy_read)
  		mdiobus_unregister(ds->slave_mii_bus);
  
  	dsa_switch_unregister_notifier(ds);
  }

  /* platform driver init and cleanup *****************************************/
  static int dev_is_class(struct device *dev, void *class)
  {
  	if (dev->class != NULL && !strcmp(dev->class->name, class))
  		return 1;
  
  	return 0;
  }
  
  static struct device *dev_find_class(struct device *parent, char *class)
  {
  	if (dev_is_class(parent, class)) {
  		get_device(parent);
  		return parent;
  	}
  
  	return device_find_child(parent, class, dev_is_class);
  }
  
  struct mii_bus *dsa_host_dev_to_mii_bus(struct device *dev)
  {
  	struct device *d;
  
  	d = dev_find_class(dev, "mdio_bus");
  	if (d != NULL) {
  		struct mii_bus *bus;
  
  		bus = to_mii_bus(d);
  		put_device(d);
  
  		return bus;
  	}
  
  	return NULL;
  }
  EXPORT_SYMBOL_GPL(dsa_host_dev_to_mii_bus);
  
  #ifdef CONFIG_OF
  static int dsa_of_setup_routing_table(struct dsa_platform_data *pd,
  					struct dsa_chip_data *cd,
  					int chip_index, int port_index,
  					struct device_node *link)
  {
  	const __be32 *reg;
  	int link_sw_addr;
  	struct device_node *parent_sw;
  	int len;
  
  	parent_sw = of_get_parent(link);
  	if (!parent_sw)
  		return -EINVAL;
  
  	reg = of_get_property(parent_sw, "reg", &len);
  	if (!reg || (len != sizeof(*reg) * 2))
  		return -EINVAL;
  
  	/*
  	 * Get the destination switch number from the second field of its 'reg'
  	 * property, i.e. for "reg = <0x19 1>" sw_addr is '1'.
  	 */
  	link_sw_addr = be32_to_cpup(reg + 1);
  
  	if (link_sw_addr >= pd->nr_chips)
  		return -EINVAL;
  
  	cd->rtable[link_sw_addr] = port_index;
  
  	return 0;
  }
  
  static int dsa_of_probe_links(struct dsa_platform_data *pd,
  			      struct dsa_chip_data *cd,
  			      int chip_index, int port_index,
  			      struct device_node *port,
  			      const char *port_name)
  {
  	struct device_node *link;
  	int link_index;
  	int ret;
  
  	for (link_index = 0;; link_index++) {
  		link = of_parse_phandle(port, "link", link_index);
  		if (!link)
  			break;
  
  		if (!strcmp(port_name, "dsa") && pd->nr_chips > 1) {
  			ret = dsa_of_setup_routing_table(pd, cd, chip_index,
  							 port_index, link);
  			if (ret)
  				return ret;
  		}
  	}
  	return 0;
  }
  
  static void dsa_of_free_platform_data(struct dsa_platform_data *pd)
  {
  	int i;
  	int port_index;
  
  	for (i = 0; i < pd->nr_chips; i++) {
  		port_index = 0;
  		while (port_index < DSA_MAX_PORTS) {
  			kfree(pd->chip[i].port_names[port_index]);
  			port_index++;
  		}
  
  		/* Drop our reference to the MDIO bus device */
  		if (pd->chip[i].host_dev)
  			put_device(pd->chip[i].host_dev);
  	}
  	kfree(pd->chip);
  }
  
  static int dsa_of_probe(struct device *dev)
  {
  	struct device_node *np = dev->of_node;
  	struct device_node *child, *mdio, *ethernet, *port;
  	struct mii_bus *mdio_bus, *mdio_bus_switch;
  	struct net_device *ethernet_dev;
  	struct dsa_platform_data *pd;
  	struct dsa_chip_data *cd;
  	const char *port_name;
  	int chip_index, port_index;
  	const unsigned int *sw_addr, *port_reg;
  	u32 eeprom_len;
  	int ret;
  
  	mdio = of_parse_phandle(np, "dsa,mii-bus", 0);
  	if (!mdio)
  		return -EINVAL;
  
  	mdio_bus = of_mdio_find_bus(mdio);
  	if (!mdio_bus)
  		return -EPROBE_DEFER;
  
  	ethernet = of_parse_phandle(np, "dsa,ethernet", 0);
  	if (!ethernet) {
  		ret = -EINVAL;
  		goto out_put_mdio;
  	}
  
  	ethernet_dev = of_find_net_device_by_node(ethernet);
  	if (!ethernet_dev) {
  		ret = -EPROBE_DEFER;
  		goto out_put_mdio;
  	}
  
  	pd = kzalloc(sizeof(*pd), GFP_KERNEL);
  	if (!pd) {
  		ret = -ENOMEM;
  		goto out_put_ethernet;
  	}
  
  	dev->platform_data = pd;
  	pd->of_netdev = ethernet_dev;
  	pd->nr_chips = of_get_available_child_count(np);
  	if (pd->nr_chips > DSA_MAX_SWITCHES)
  		pd->nr_chips = DSA_MAX_SWITCHES;
  
  	pd->chip = kcalloc(pd->nr_chips, sizeof(struct dsa_chip_data),
  			   GFP_KERNEL);
  	if (!pd->chip) {
  		ret = -ENOMEM;
  		goto out_free;
  	}
  
  	chip_index = -1;
  	for_each_available_child_of_node(np, child) {
  		int i;
  
  		chip_index++;
  		cd = &pd->chip[chip_index];
  
  		cd->of_node = child;
  
  		/* Initialize the routing table */
  		for (i = 0; i < DSA_MAX_SWITCHES; ++i)
  			cd->rtable[i] = DSA_RTABLE_NONE;
  
  		/* When assigning the host device, increment its refcount */
  		cd->host_dev = get_device(&mdio_bus->dev);
  
  		sw_addr = of_get_property(child, "reg", NULL);
  		if (!sw_addr)
  			continue;
  
  		cd->sw_addr = be32_to_cpup(sw_addr);
  		if (cd->sw_addr >= PHY_MAX_ADDR)
  			continue;
  
  		if (!of_property_read_u32(child, "eeprom-length", &eeprom_len))
  			cd->eeprom_len = eeprom_len;
  
  		mdio = of_parse_phandle(child, "mii-bus", 0);
  		if (mdio) {
  			mdio_bus_switch = of_mdio_find_bus(mdio);
  			if (!mdio_bus_switch) {
  				ret = -EPROBE_DEFER;
  				goto out_free_chip;
  			}
  
  			/* Drop the mdio_bus device ref, replacing the host
  			 * device with the mdio_bus_switch device, keeping
  			 * the refcount from of_mdio_find_bus() above.
  			 */
  			put_device(cd->host_dev);
  			cd->host_dev = &mdio_bus_switch->dev;
  		}
  
  		for_each_available_child_of_node(child, port) {
  			port_reg = of_get_property(port, "reg", NULL);
  			if (!port_reg)
  				continue;
  
  			port_index = be32_to_cpup(port_reg);
  			if (port_index >= DSA_MAX_PORTS)
  				break;
  
  			port_name = of_get_property(port, "label", NULL);
  			if (!port_name)
  				continue;
  
  			cd->port_dn[port_index] = port;
  
  			cd->port_names[port_index] = kstrdup(port_name,
  					GFP_KERNEL);
  			if (!cd->port_names[port_index]) {
  				ret = -ENOMEM;
  				goto out_free_chip;
  			}
  
  			ret = dsa_of_probe_links(pd, cd, chip_index,
  						 port_index, port, port_name);
  			if (ret)
  				goto out_free_chip;
  
  		}
  	}
  
  	/* The individual chips hold their own refcount on the mdio bus,
  	 * so drop ours */
  	put_device(&mdio_bus->dev);
  
  	return 0;
  
  out_free_chip:
  	dsa_of_free_platform_data(pd);
  out_free:
  	kfree(pd);
  	dev->platform_data = NULL;
  out_put_ethernet:
  	put_device(&ethernet_dev->dev);
  out_put_mdio:
  	put_device(&mdio_bus->dev);
  	return ret;
  }
  
  static void dsa_of_remove(struct device *dev)
  {
  	struct dsa_platform_data *pd = dev->platform_data;
  
  	if (!dev->of_node)
  		return;
  
  	dsa_of_free_platform_data(pd);
  	put_device(&pd->of_netdev->dev);
  	kfree(pd);
  }
  #else
  static inline int dsa_of_probe(struct device *dev)
  {
  	return 0;
  }
  
  static inline void dsa_of_remove(struct device *dev)
  {
  }
  #endif
  
  static int dsa_setup_dst(struct dsa_switch_tree *dst, struct net_device *dev,
  			 struct device *parent, struct dsa_platform_data *pd)
  {
  	int i;
  	unsigned configured = 0;
  
  	dst->pd = pd;

  
  	for (i = 0; i < pd->nr_chips; i++) {
  		struct dsa_switch *ds;

  		ds = dsa_switch_setup(dst, dev, i, parent, pd->chip[i].host_dev);

  		if (IS_ERR(ds)) {
  			netdev_err(dev, "[%d]: couldn't create dsa switch instance (error %ld)
  ",
  				   i, PTR_ERR(ds));
  			continue;
  		}
  
  		dst->ds[i] = ds;
  
  		++configured;
  	}
  
  	/*
  	 * If no switch was found, exit cleanly
  	 */
  	if (!configured)
  		return -EPROBE_DEFER;
  
  	/*
  	 * If we use a tagging format that doesn't have an ethertype
  	 * field, make sure that all packets from this point on get
  	 * sent to the tag format's receive function.
  	 */
  	wmb();

  	dev->dsa_ptr = dst;

  
  	return 0;
  }
  
  static int dsa_probe(struct platform_device *pdev)
  {
  	struct dsa_platform_data *pd = pdev->dev.platform_data;
  	struct net_device *dev;
  	struct dsa_switch_tree *dst;
  	int ret;
  
  	if (pdev->dev.of_node) {
  		ret = dsa_of_probe(&pdev->dev);
  		if (ret)
  			return ret;
  
  		pd = pdev->dev.platform_data;
  	}
  
  	if (pd == NULL || (pd->netdev == NULL && pd->of_netdev == NULL))
  		return -EINVAL;
  
  	if (pd->of_netdev) {
  		dev = pd->of_netdev;
  		dev_hold(dev);
  	} else {
  		dev = dsa_dev_to_net_device(pd->netdev);
  	}
  	if (dev == NULL) {
  		ret = -EPROBE_DEFER;
  		goto out;
  	}
  
  	if (dev->dsa_ptr != NULL) {
  		dev_put(dev);
  		ret = -EEXIST;
  		goto out;
  	}
  
  	dst = devm_kzalloc(&pdev->dev, sizeof(*dst), GFP_KERNEL);
  	if (dst == NULL) {
  		dev_put(dev);
  		ret = -ENOMEM;
  		goto out;
  	}
  
  	platform_set_drvdata(pdev, dst);
  
  	ret = dsa_setup_dst(dst, dev, &pdev->dev, pd);
  	if (ret) {
  		dev_put(dev);
  		goto out;
  	}
  
  	return 0;
  
  out:
  	dsa_of_remove(&pdev->dev);
  
  	return ret;
  }
  
  static void dsa_remove_dst(struct dsa_switch_tree *dst)
  {
  	int i;

  	dst->cpu_dp->netdev->dsa_ptr = NULL;

  
  	/* If we used a tagging format that doesn't have an ethertype
  	 * field, make sure that all packets from this point get sent
  	 * without the tag and go through the regular receive path.
  	 */
  	wmb();
  
  	for (i = 0; i < dst->pd->nr_chips; i++) {
  		struct dsa_switch *ds = dst->ds[i];
  
  		if (ds)
  			dsa_switch_destroy(ds);
  	}

  	dsa_cpu_port_ethtool_restore(dst->cpu_dp);

  	dev_put(dst->cpu_dp->netdev);

  }
  
  static int dsa_remove(struct platform_device *pdev)
  {
  	struct dsa_switch_tree *dst = platform_get_drvdata(pdev);
  
  	dsa_remove_dst(dst);
  	dsa_of_remove(&pdev->dev);
  
  	return 0;
  }
  
  static void dsa_shutdown(struct platform_device *pdev)
  {
  }
  
  #ifdef CONFIG_PM_SLEEP
  static int dsa_suspend(struct device *d)
  {
  	struct platform_device *pdev = to_platform_device(d);
  	struct dsa_switch_tree *dst = platform_get_drvdata(pdev);
  	int i, ret = 0;
  
  	for (i = 0; i < dst->pd->nr_chips; i++) {
  		struct dsa_switch *ds = dst->ds[i];
  
  		if (ds != NULL)
  			ret = dsa_switch_suspend(ds);
  	}
  
  	return ret;
  }
  
  static int dsa_resume(struct device *d)
  {
  	struct platform_device *pdev = to_platform_device(d);
  	struct dsa_switch_tree *dst = platform_get_drvdata(pdev);
  	int i, ret = 0;
  
  	for (i = 0; i < dst->pd->nr_chips; i++) {
  		struct dsa_switch *ds = dst->ds[i];
  
  		if (ds != NULL)
  			ret = dsa_switch_resume(ds);
  	}
  
  	return ret;
  }
  #endif

  /* legacy way, bypassing the bridge *****************************************/
  int dsa_legacy_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
  		       struct net_device *dev,
  		       const unsigned char *addr, u16 vid,
  		       u16 flags)
  {
  	struct dsa_slave_priv *p = netdev_priv(dev);
  	struct dsa_port *dp = p->dp;
  
  	return dsa_port_fdb_add(dp, addr, vid);
  }
  
  int dsa_legacy_fdb_del(struct ndmsg *ndm, struct nlattr *tb[],
  		       struct net_device *dev,
  		       const unsigned char *addr, u16 vid)
  {
  	struct dsa_slave_priv *p = netdev_priv(dev);
  	struct dsa_port *dp = p->dp;
  
  	return dsa_port_fdb_del(dp, addr, vid);
  }

  static SIMPLE_DEV_PM_OPS(dsa_pm_ops, dsa_suspend, dsa_resume);
  
  static const struct of_device_id dsa_of_match_table[] = {
  	{ .compatible = "marvell,dsa", },
  	{}
  };
  MODULE_DEVICE_TABLE(of, dsa_of_match_table);
  
  static struct platform_driver dsa_driver = {
  	.probe		= dsa_probe,
  	.remove		= dsa_remove,
  	.shutdown	= dsa_shutdown,
  	.driver = {
  		.name	= "dsa",
  		.of_match_table = dsa_of_match_table,
  		.pm	= &dsa_pm_ops,
  	},
  };
  
  int dsa_legacy_register(void)
  {
  	return platform_driver_register(&dsa_driver);
  }
  
  void dsa_legacy_unregister(void)
  {
  	platform_driver_unregister(&dsa_driver);
  }