ieee802154_dev.c

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/*
 * Copyright (C) 2007-2012 Siemens AG
 *
 * Written by:
 * Alexander Smirnov <[email protected]>
 *
 * Based on the code from 'linux-zigbee.sourceforge.net' project.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/netdevice.h>

#include <net/netlink.h>
#include <linux/nl802154.h>
#include <net/mac802154.h>
#include <net/route.h>
#include <net/wpan-phy.h>

#include "mac802154.h"

int mac802154_slave_open(struct net_device *dev)
{
    struct mac802154_sub_if_data *priv = netdev_priv(dev);
    struct mac802154_priv *ipriv = priv->hw;
    int res = 0;

    if (ipriv->open_count++ == 0) {
        res = ipriv->ops->start(&ipriv->hw);
        WARN_ON(res);
        if (res)
            goto err;
    }

    if (ipriv->ops->ieee_addr) {
        res = ipriv->ops->ieee_addr(&ipriv->hw, dev->dev_addr);
        WARN_ON(res);
        if (res)
            goto err;
        mac802154_dev_set_ieee_addr(dev);
    }

    netif_start_queue(dev);
    return 0;
err:
    priv->hw->open_count--;

    return res;
}

int mac802154_slave_close(struct net_device *dev)
{
    struct mac802154_sub_if_data *priv = netdev_priv(dev);
    struct mac802154_priv *ipriv = priv->hw;

    netif_stop_queue(dev);

    if (!--ipriv->open_count)
        ipriv->ops->stop(&ipriv->hw);

    return 0;
}

static int
mac802154_netdev_register(struct wpan_phy *phy, struct net_device *dev)
{
    struct mac802154_sub_if_data *priv;
    struct mac802154_priv *ipriv;
    int err;

    ipriv = wpan_phy_priv(phy);

    priv = netdev_priv(dev);
    priv->dev = dev;
    priv->hw = ipriv;

    dev->needed_headroom = ipriv->hw.extra_tx_headroom;

    SET_NETDEV_DEV(dev, &ipriv->phy->dev);

    mutex_lock(&ipriv->slaves_mtx);
    if (!ipriv->running) {
        mutex_unlock(&ipriv->slaves_mtx);
        return -ENODEV;
    }
    mutex_unlock(&ipriv->slaves_mtx);

    err = register_netdev(dev);
    if (err < 0)
        return err;

    rtnl_lock();
    mutex_lock(&ipriv->slaves_mtx);
    list_add_tail_rcu(&priv->list, &ipriv->slaves);
    mutex_unlock(&ipriv->slaves_mtx);
    rtnl_unlock();

    return 0;
}

static void
mac802154_del_iface(struct wpan_phy *phy, struct net_device *dev)
{
    struct mac802154_sub_if_data *sdata;
    ASSERT_RTNL();

    sdata = netdev_priv(dev);

    BUG_ON(sdata->hw->phy != phy);

    mutex_lock(&sdata->hw->slaves_mtx);
    list_del_rcu(&sdata->list);
    mutex_unlock(&sdata->hw->slaves_mtx);

    synchronize_rcu();
    unregister_netdevice(sdata->dev);
}

static struct net_device *
mac802154_add_iface(struct wpan_phy *phy, const char *name, int type)
{
    struct net_device *dev;
    int err = -ENOMEM;

    switch (type) {
    case IEEE802154_DEV_MONITOR:
        dev = alloc_netdev(sizeof(struct mac802154_sub_if_data),
                   name, mac802154_monitor_setup);
        break;
    case IEEE802154_DEV_WPAN:
        dev = alloc_netdev(sizeof(struct mac802154_sub_if_data),
                   name, mac802154_wpan_setup);
        break;
    default:
        dev = NULL;
        err = -EINVAL;
        break;
    }
    if (!dev)
        goto err;

    err = mac802154_netdev_register(phy, dev);
    if (err)
        goto err_free;

    dev_hold(dev); /* we return an incremented device refcount */
    return dev;

err_free:
    free_netdev(dev);
err:
    return ERR_PTR(err);
}

struct ieee802154_dev *
ieee802154_alloc_device(size_t priv_data_len, struct ieee802154_ops *ops)
{
    struct wpan_phy *phy;
    struct mac802154_priv *priv;
    size_t priv_size;

    if (!ops || !ops->xmit || !ops->ed || !ops->start ||
        !ops->stop || !ops->set_channel) {
        printk(KERN_ERR
               "undefined IEEE802.15.4 device operations\n");
        return NULL;
    }

    /* Ensure 32-byte alignment of our private data and hw private data.
     * We use the wpan_phy priv data for both our mac802154_priv and for
     * the driver's private data
     *
     * in memory it'll be like this:
     *
     * +-----------------------+
     * | struct wpan_phy       |
     * +-----------------------+
     * | struct mac802154_priv |
     * +-----------------------+
     * | driver's private data |
     * +-----------------------+
     *
     * Due to ieee802154 layer isn't aware of driver and MAC structures,
     * so lets allign them here.
     */

    priv_size = ALIGN(sizeof(*priv), NETDEV_ALIGN) + priv_data_len;

    phy = wpan_phy_alloc(priv_size);
    if (!phy) {
        printk(KERN_ERR
               "failure to allocate master IEEE802.15.4 device\n");
        return NULL;
    }

    priv = wpan_phy_priv(phy);
    priv->hw.phy = priv->phy = phy;
    priv->hw.priv = (char *)priv + ALIGN(sizeof(*priv), NETDEV_ALIGN);
    priv->ops = ops;

    INIT_LIST_HEAD(&priv->slaves);
    mutex_init(&priv->slaves_mtx);

    return &priv->hw;
}
EXPORT_SYMBOL(ieee802154_alloc_device);

void ieee802154_free_device(struct ieee802154_dev *hw)
{
    struct mac802154_priv *priv = mac802154_to_priv(hw);

    BUG_ON(!list_empty(&priv->slaves));

    wpan_phy_free(priv->phy);

    mutex_destroy(&priv->slaves_mtx);
}
EXPORT_SYMBOL(ieee802154_free_device);

int ieee802154_register_device(struct ieee802154_dev *dev)
{
    struct mac802154_priv *priv = mac802154_to_priv(dev);
    int rc = -ENOMEM;

    priv->dev_workqueue =
        create_singlethread_workqueue(wpan_phy_name(priv->phy));
    if (!priv->dev_workqueue)
        goto out;

    wpan_phy_set_dev(priv->phy, priv->hw.parent);

    priv->phy->add_iface = mac802154_add_iface;
    priv->phy->del_iface = mac802154_del_iface;

    rc = wpan_phy_register(priv->phy);
    if (rc < 0)
        goto out_wq;

    rtnl_lock();

    mutex_lock(&priv->slaves_mtx);
    priv->running = MAC802154_DEVICE_RUN;
    mutex_unlock(&priv->slaves_mtx);

    rtnl_unlock();

    return 0;

out_wq:
    destroy_workqueue(priv->dev_workqueue);
out:
    return rc;
}
EXPORT_SYMBOL(ieee802154_register_device);

void ieee802154_unregister_device(struct ieee802154_dev *dev)
{
    struct mac802154_priv *priv = mac802154_to_priv(dev);
    struct mac802154_sub_if_data *sdata, *next;

    flush_workqueue(priv->dev_workqueue);
    destroy_workqueue(priv->dev_workqueue);

    rtnl_lock();

    mutex_lock(&priv->slaves_mtx);
    priv->running = MAC802154_DEVICE_STOPPED;
    mutex_unlock(&priv->slaves_mtx);

    list_for_each_entry_safe(sdata, next, &priv->slaves, list) {
        mutex_lock(&sdata->hw->slaves_mtx);
        list_del(&sdata->list);
        mutex_unlock(&sdata->hw->slaves_mtx);

        unregister_netdevice(sdata->dev);
    }

    rtnl_unlock();

    wpan_phy_unregister(priv->phy);
}
EXPORT_SYMBOL(ieee802154_unregister_device);

MODULE_DESCRIPTION("IEEE 802.15.4 implementation");
MODULE_LICENSE("GPL v2");