/*
 * 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_port_link_register_of(&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;
        struct dsa_port *dp;
        int i, ret;

        /*
         * Validate supplied switch configuration.
         */
        for (i = 0; i < ds->num_ports; i++) {
                char *name;

                dp = &ds->ports[i];

                name = cd->port_names[i];
                if (name == NULL)
                        continue;
                dp->name = name;

                if (!strcmp(name, "cpu")) {
                        if (dst->cpu_dp) {
                                netdev_err(master,
                                           "multiple cpu ports?!\n");
                                return -EINVAL;
                        }
                        dst->cpu_dp = &ds->ports[i];
                        dst->cpu_dp->master = master;
                        dp->type = DSA_PORT_TYPE_CPU;
                } else if (!strcmp(name, "dsa")) {
                        dp->type = DSA_PORT_TYPE_DSA;
                } else {
                        dp->type = DSA_PORT_TYPE_USER;
                }
                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 |= dsa_user_ports(ds);

        /*
         * 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) {
                const struct dsa_device_ops *tag_ops;
                enum dsa_tag_protocol tag_protocol;

                tag_protocol = ops->get_tag_protocol(ds, dst->cpu_dp->index);
                tag_ops = dsa_resolve_tag_protocol(tag_protocol);
                if (IS_ERR(tag_ops))
                        return PTR_ERR(tag_ops);

                dst->cpu_dp->tag_ops = tag_ops;

                /* Few copies for faster access in master receive hot path */
                dst->cpu_dp->rcv = dst->cpu_dp->tag_ops->rcv;
                dst->cpu_dp->dst = dst;
        }

        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 (!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 (!dsa_is_user_port(ds, i))
                        continue;

                ret = dsa_slave_create(&ds->ports[i]);
                if (ret < 0)
                        netdev_err(master, "[%d]: can't create dsa slave device for port %d(%s): %d\n",
                                   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\n",
                           index);

        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\n",
                           index);
                return ERR_PTR(-EINVAL);
        }
        netdev_info(master, "[%d]: detected a %s switch\n",
                    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 (!dsa_is_user_port(ds, port))
                        continue;

                if (!ds->ports[port].slave)
                        continue;

                dsa_slave_destroy(ds->ports[port].slave);
        }

        /* 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_port_link_unregister_of(&ds->ports[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)\n",
                                   i, PTR_ERR(ds));
                        continue;
                }

                dst->ds[i] = ds;

                ++configured;
        }

        /*
         * If no switch was found, exit cleanly
         */
        if (!configured)
                return -EPROBE_DEFER;

        return dsa_master_setup(dst->cpu_dp->master, dst->cpu_dp);
}

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;

        dsa_master_teardown(dst->cpu_dp->master);

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

                if (ds)
                        dsa_switch_destroy(ds);
        }

        dev_put(dst->cpu_dp->master);
}

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

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);
}