/*
 * net/dsa/dsa.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/ctype.h>
#include <linux/device.h>
#include <linux/hwmon.h>
#include <linux/list.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <net/dsa.h>
#include <linux/of.h>
#include <linux/of_mdio.h>
#include <linux/of_platform.h>
#include <linux/of_net.h>
#include <linux/of_gpio.h>
#include <linux/sysfs.h>
#include <linux/phy_fixed.h>
#include <linux/gpio/consumer.h>
#include "dsa_priv.h"

char dsa_driver_version[] = "0.1";


/* 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 struct dsa_switch_driver *
dsa_switch_probe(struct device *host_dev, int sw_addr, char **_name)
{
        struct dsa_switch_driver *ret;
        struct list_head *list;
        char *name;

        ret = NULL;
        name = NULL;

        mutex_lock(&dsa_switch_drivers_mutex);
        list_for_each(list, &dsa_switch_drivers) {
                struct dsa_switch_driver *drv;

                drv = list_entry(list, struct dsa_switch_driver, list);

                name = drv->probe(host_dev, sw_addr);
                if (name != NULL) {
                        ret = drv;
                        break;
                }
        }
        mutex_unlock(&dsa_switch_drivers_mutex);

        *_name = name;

        return ret;
}

/* hwmon support ************************************************************/

#ifdef CONFIG_NET_DSA_HWMON

static ssize_t temp1_input_show(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        struct dsa_switch *ds = dev_get_drvdata(dev);
        int temp, ret;

        ret = ds->drv->get_temp(ds, &temp);
        if (ret < 0)
                return ret;

        return sprintf(buf, "%d\n", temp * 1000);
}
static DEVICE_ATTR_RO(temp1_input);

static ssize_t temp1_max_show(struct device *dev,
                              struct device_attribute *attr, char *buf)
{
        struct dsa_switch *ds = dev_get_drvdata(dev);
        int temp, ret;

        ret = ds->drv->get_temp_limit(ds, &temp);
        if (ret < 0)
                return ret;

        return sprintf(buf, "%d\n", temp * 1000);
}

static ssize_t temp1_max_store(struct device *dev,
                               struct device_attribute *attr, const char *buf,
                               size_t count)
{
        struct dsa_switch *ds = dev_get_drvdata(dev);
        int temp, ret;

        ret = kstrtoint(buf, 0, &temp);
        if (ret < 0)
                return ret;

        ret = ds->drv->set_temp_limit(ds, DIV_ROUND_CLOSEST(temp, 1000));
        if (ret < 0)
                return ret;

        return count;
}
static DEVICE_ATTR_RW(temp1_max);

static ssize_t temp1_max_alarm_show(struct device *dev,
                                    struct device_attribute *attr, char *buf)
{
        struct dsa_switch *ds = dev_get_drvdata(dev);
        bool alarm;
        int ret;

        ret = ds->drv->get_temp_alarm(ds, &alarm);
        if (ret < 0)
                return ret;

        return sprintf(buf, "%d\n", alarm);
}
static DEVICE_ATTR_RO(temp1_max_alarm);

static struct attribute *dsa_hwmon_attrs[] = {
        &dev_attr_temp1_input.attr,     /* 0 */
        &dev_attr_temp1_max.attr,       /* 1 */
        &dev_attr_temp1_max_alarm.attr, /* 2 */
        NULL
};

static umode_t dsa_hwmon_attrs_visible(struct kobject *kobj,
                                       struct attribute *attr, int index)
{
        struct device *dev = container_of(kobj, struct device, kobj);
        struct dsa_switch *ds = dev_get_drvdata(dev);
        struct dsa_switch_driver *drv = ds->drv;
        umode_t mode = attr->mode;

        if (index == 1) {
                if (!drv->get_temp_limit)
                        mode = 0;
                else if (!drv->set_temp_limit)
                        mode &= ~S_IWUSR;
        } else if (index == 2 && !drv->get_temp_alarm) {
                mode = 0;
        }
        return mode;
}

static const struct attribute_group dsa_hwmon_group = {
        .attrs = dsa_hwmon_attrs,
        .is_visible = dsa_hwmon_attrs_visible,
};
__ATTRIBUTE_GROUPS(dsa_hwmon);

#endif /* CONFIG_NET_DSA_HWMON */

/* basic switch operations **************************************************/
static int dsa_cpu_dsa_setup(struct dsa_switch *ds, struct net_device *master)
{
        struct dsa_chip_data *cd = ds->pd;
        struct device_node *port_dn;
        struct phy_device *phydev;
        int ret, port, mode;

        for (port = 0; port < DSA_MAX_PORTS; port++) {
                if (!(dsa_is_cpu_port(ds, port) || dsa_is_dsa_port(ds, port)))
                        continue;

                port_dn = cd->port_dn[port];
                if (of_phy_is_fixed_link(port_dn)) {
                        ret = of_phy_register_fixed_link(port_dn);
                        if (ret) {
                                netdev_err(master,
                                           "failed to register fixed PHY\n");
                                return ret;
                        }
                        phydev = of_phy_find_device(port_dn);

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

                        genphy_config_init(phydev);
                        genphy_read_status(phydev);
                        if (ds->drv->adjust_link)
                                ds->drv->adjust_link(ds, port, phydev);
                }
        }
        return 0;
}

static int dsa_switch_setup_one(struct dsa_switch *ds, struct device *parent)
{
        struct dsa_switch_driver *drv = ds->drv;
        struct dsa_switch_tree *dst = ds->dst;
        struct dsa_chip_data *pd = ds->pd;
        bool valid_name_found = false;
        int index = ds->index;
        int i, ret;

        /*
         * Validate supplied switch configuration.
         */
        for (i = 0; i < DSA_MAX_PORTS; i++) {
                char *name;

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

                if (!strcmp(name, "cpu")) {
                        if (dst->cpu_switch != -1) {
                                netdev_err(dst->master_netdev,
                                           "multiple cpu ports?!\n");
                                ret = -EINVAL;
                                goto out;
                        }
                        dst->cpu_switch = index;
                        dst->cpu_port = i;
                } else if (!strcmp(name, "dsa")) {
                        ds->dsa_port_mask |= 1 << i;
                } else {
                        ds->phys_port_mask |= 1 << i;
                }
                valid_name_found = true;
        }

        if (!valid_name_found && i == DSA_MAX_PORTS) {
                ret = -EINVAL;
                goto out;
        }

        /* Make the built-in MII bus mask match the number of ports,
         * switch drivers can override this later
         */
        ds->phys_mii_mask = ds->phys_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_switch == index) {
                switch (ds->tag_protocol) {
#ifdef CONFIG_NET_DSA_TAG_DSA
                case DSA_TAG_PROTO_DSA:
                        dst->rcv = dsa_netdev_ops.rcv;
                        break;
#endif
#ifdef CONFIG_NET_DSA_TAG_EDSA
                case DSA_TAG_PROTO_EDSA:
                        dst->rcv = edsa_netdev_ops.rcv;
                        break;
#endif
#ifdef CONFIG_NET_DSA_TAG_TRAILER
                case DSA_TAG_PROTO_TRAILER:
                        dst->rcv = trailer_netdev_ops.rcv;
                        break;
#endif
#ifdef CONFIG_NET_DSA_TAG_BRCM
                case DSA_TAG_PROTO_BRCM:
                        dst->rcv = brcm_netdev_ops.rcv;
                        break;
#endif
                case DSA_TAG_PROTO_NONE:
                        break;
                default:
                        ret = -ENOPROTOOPT;
                        goto out;
                }

                dst->tag_protocol = ds->tag_protocol;
        }

        /*
         * Do basic register setup.
         */
        ret = drv->setup(ds);
        if (ret < 0)
                goto out;

        ret = drv->set_addr(ds, dst->master_netdev->dev_addr);
        if (ret < 0)
                goto out;

        ds->slave_mii_bus = devm_mdiobus_alloc(parent);
        if (ds->slave_mii_bus == NULL) {
                ret = -ENOMEM;
                goto out;
        }
        dsa_slave_mii_bus_init(ds);

        ret = mdiobus_register(ds->slave_mii_bus);
        if (ret < 0)
                goto out;


        /*
         * Create network devices for physical switch ports.
         */
        for (i = 0; i < DSA_MAX_PORTS; i++) {
                if (!(ds->phys_port_mask & (1 << i)))
                        continue;

                ret = dsa_slave_create(ds, parent, i, pd->port_names[i]);
                if (ret < 0) {
                        netdev_err(dst->master_netdev, "[%d]: can't create dsa slave device for port %d(%s): %d\n",
                                   index, i, pd->port_names[i], ret);
                        ret = 0;
                }
        }

        /* Perform configuration of the CPU and DSA ports */
        ret = dsa_cpu_dsa_setup(ds, dst->master_netdev);
        if (ret < 0) {
                netdev_err(dst->master_netdev, "[%d] : can't configure CPU and DSA ports\n",
                           index);
                ret = 0;
        }

#ifdef CONFIG_NET_DSA_HWMON
        /* If the switch provides a temperature sensor,
         * register with hardware monitoring subsystem.
         * Treat registration error as non-fatal and ignore it.
         */
        if (drv->get_temp) {
                const char *netname = netdev_name(dst->master_netdev);
                char hname[IFNAMSIZ + 1];
                int i, j;

                /* Create valid hwmon 'name' attribute */
                for (i = j = 0; i < IFNAMSIZ && netname[i]; i++) {
                        if (isalnum(netname[i]))
                                hname[j++] = netname[i];
                }
                hname[j] = '\0';
                scnprintf(ds->hwmon_name, sizeof(ds->hwmon_name), "%s_dsa%d",
                          hname, index);
                ds->hwmon_dev = hwmon_device_register_with_groups(NULL,
                                        ds->hwmon_name, ds, dsa_hwmon_groups);
                if (IS_ERR(ds->hwmon_dev))
                        ds->hwmon_dev = NULL;
        }
#endif /* CONFIG_NET_DSA_HWMON */

        return ret;

out:
        return ret;
}

static struct dsa_switch *
dsa_switch_setup(struct dsa_switch_tree *dst, int index,
                 struct device *parent, struct device *host_dev)
{
        struct dsa_chip_data *pd = dst->pd->chip + index;
        struct dsa_switch_driver *drv;
        struct dsa_switch *ds;
        int ret;
        char *name;

        /*
         * Probe for switch model.
         */
        drv = dsa_switch_probe(host_dev, pd->sw_addr, &name);
        if (drv == NULL) {
                netdev_err(dst->master_netdev, "[%d]: could not detect attached switch\n",
                           index);
                return ERR_PTR(-EINVAL);
        }
        netdev_info(dst->master_netdev, "[%d]: detected a %s switch\n",
                    index, name);


        /*
         * Allocate and initialise switch state.
         */
        ds = devm_kzalloc(parent, sizeof(*ds) + drv->priv_size, GFP_KERNEL);
        if (ds == NULL)
                return ERR_PTR(-ENOMEM);

        ds->dst = dst;
        ds->index = index;
        ds->pd = pd;
        ds->drv = drv;
        ds->tag_protocol = drv->tag_protocol;
        ds->master_dev = host_dev;

        ret = dsa_switch_setup_one(ds, parent);
        if (ret)
                return ERR_PTR(ret);

        return ds;
}

static void dsa_switch_destroy(struct dsa_switch *ds)
{
        struct device_node *port_dn;
        struct phy_device *phydev;
        struct dsa_chip_data *cd = ds->pd;
        int port;

#ifdef CONFIG_NET_DSA_HWMON
        if (ds->hwmon_dev)
                hwmon_device_unregister(ds->hwmon_dev);
#endif

        /* Destroy network devices for physical switch ports. */
        for (port = 0; port < DSA_MAX_PORTS; port++) {
                if (!(ds->phys_port_mask & (1 << port)))
                        continue;

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

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

        /* Remove any fixed link PHYs */
        for (port = 0; port < DSA_MAX_PORTS; port++) {
                port_dn = cd->port_dn[port];
                if (of_phy_is_fixed_link(port_dn)) {
                        phydev = of_phy_find_device(port_dn);
                        if (phydev) {
                                phy_device_free(phydev);
                                of_node_put(port_dn);
                                fixed_phy_unregister(phydev);
                        }
                }
        }

        mdiobus_unregister(ds->slave_mii_bus);
}

#ifdef CONFIG_PM_SLEEP
static int dsa_switch_suspend(struct dsa_switch *ds)
{
        int i, ret = 0;

        /* Suspend slave network devices */
        for (i = 0; i < DSA_MAX_PORTS; i++) {
                if (!dsa_is_port_initialized(ds, i))
                        continue;

                ret = dsa_slave_suspend(ds->ports[i]);
                if (ret)
                        return ret;
        }

        if (ds->drv->suspend)
                ret = ds->drv->suspend(ds);

        return ret;
}

static int dsa_switch_resume(struct dsa_switch *ds)
{
        int i, ret = 0;

        if (ds->drv->resume)
                ret = ds->drv->resume(ds);

        if (ret)
                return ret;

        /* Resume slave network devices */
        for (i = 0; i < DSA_MAX_PORTS; i++) {
                if (!dsa_is_port_initialized(ds, i))
                        continue;

                ret = dsa_slave_resume(ds->ports[i]);
                if (ret)
                        return ret;
        }

        return 0;
}
#endif

/* 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);

static struct net_device *dev_to_net_device(struct device *dev)
{
        struct device *d;

        d = dev_find_class(dev, "net");
        if (d != NULL) {
                struct net_device *nd;

                nd = to_net_dev(d);
                dev_hold(nd);
                put_device(d);

                return nd;
        }

        return NULL;
}

#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;

        /* First time routing table allocation */
        if (!cd->rtable) {
                cd->rtable = kmalloc_array(pd->nr_chips, sizeof(s8),
                                           GFP_KERNEL);
                if (!cd->rtable)
                        return -ENOMEM;

                /* default to no valid uplink/downlink */
                memset(cd->rtable, -1, pd->nr_chips * sizeof(s8));
        }

        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++;
                }
                kfree(pd->chip[i].rtable);

                /* 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;
        int gpio;
        enum of_gpio_flags of_flags;
        unsigned long flags;
        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) {
                chip_index++;
                cd = &pd->chip[chip_index];

                cd->of_node = child;

                /* 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;
                }
                gpio = of_get_named_gpio_flags(child, "reset-gpios", 0,
                                               &of_flags);
                if (gpio_is_valid(gpio)) {
                        flags = (of_flags == OF_GPIO_ACTIVE_LOW ?
                                 GPIOF_ACTIVE_LOW : 0);
                        ret = devm_gpio_request_one(dev, gpio, flags,
                                                    "switch_reset");
                        if (ret)
                                goto out_free_chip;

                        cd->reset = gpio_to_desc(gpio);
                        gpiod_direction_output(cd->reset, 0);
                }

                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;
        dst->master_netdev = dev;
        dst->cpu_switch = -1;
        dst->cpu_port = -1;

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

                ds = dsa_switch_setup(dst, 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;

        /*
         * 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 = (void *)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;

        pr_notice_once("Distributed Switch Architecture driver version %s\n",
                       dsa_driver_version);

        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 = 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->master_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);
        }

        dev_put(dst->master_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)
{
}

static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
                          struct packet_type *pt, struct net_device *orig_dev)
{
        struct dsa_switch_tree *dst = dev->dsa_ptr;

        if (unlikely(dst == NULL)) {
                kfree_skb(skb);
                return 0;
        }

        return dst->rcv(skb, dev, pt, orig_dev);
}

static struct packet_type dsa_pack_type __read_mostly = {
        .type   = cpu_to_be16(ETH_P_XDSA),
        .func   = dsa_switch_rcv,
};

static struct notifier_block dsa_netdevice_nb __read_mostly = {
        .notifier_call  = dsa_slave_netdevice_event,
};

#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 = "brcm,bcm7445-switch-v4.0" },
        { .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,
        },
};

static int __init dsa_init_module(void)
{
        int rc;

        register_netdevice_notifier(&dsa_netdevice_nb);

        rc = platform_driver_register(&dsa_driver);
        if (rc)
                return rc;

        dev_add_pack(&dsa_pack_type);

        return 0;
}
module_init(dsa_init_module);

static void __exit dsa_cleanup_module(void)
{
        unregister_netdevice_notifier(&dsa_netdevice_nb);
        dev_remove_pack(&dsa_pack_type);
        platform_driver_unregister(&dsa_driver);
}
module_exit(dsa_cleanup_module);

MODULE_AUTHOR("Lennert Buytenhek <buytenh@wantstofly.org>");
MODULE_DESCRIPTION("Driver for Distributed Switch Architecture switch chips");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:dsa");