fakelb.c

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/*
 * Loopback IEEE 802.15.4 interface
 *
 * Copyright 2007-2012 Siemens AG
 *
 * 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.
 *
 * Written by:
 * Sergey Lapin <[email protected]>
 * Dmitry Eremin-Solenikov <[email protected]>
 * Alexander Smirnov <[email protected]>
 */

#include <linux/module.h>
#include <linux/timer.h>
#include <linux/platform_device.h>
#include <linux/netdevice.h>
#include <linux/spinlock.h>
#include <net/mac802154.h>
#include <net/wpan-phy.h>

static int numlbs = 1;

struct fakelb_dev_priv {
    struct ieee802154_dev *dev;

    struct list_head list;
    struct fakelb_priv *fake;

    spinlock_t lock;
    bool working;
};

struct fakelb_priv {
    struct list_head list;
    rwlock_t lock;
};

static int
fakelb_hw_ed(struct ieee802154_dev *dev, u8 *level)
{
    might_sleep();
    BUG_ON(!level);
    *level = 0xbe;

    return 0;
}

static int
fakelb_hw_channel(struct ieee802154_dev *dev, int page, int channel)
{
    pr_debug("set channel to %d\n", channel);

    might_sleep();
    dev->phy->current_page = page;
    dev->phy->current_channel = channel;

    return 0;
}

static void
fakelb_hw_deliver(struct fakelb_dev_priv *priv, struct sk_buff *skb)
{
    struct sk_buff *newskb;

    spin_lock(&priv->lock);
    if (priv->working) {
        newskb = pskb_copy(skb, GFP_ATOMIC);
        ieee802154_rx_irqsafe(priv->dev, newskb, 0xcc);
    }
    spin_unlock(&priv->lock);
}

static int
fakelb_hw_xmit(struct ieee802154_dev *dev, struct sk_buff *skb)
{
    struct fakelb_dev_priv *priv = dev->priv;
    struct fakelb_priv *fake = priv->fake;

    might_sleep();

    read_lock_bh(&fake->lock);
    if (priv->list.next == priv->list.prev) {
        /* we are the only one device */
        fakelb_hw_deliver(priv, skb);
    } else {
        struct fakelb_dev_priv *dp;
        list_for_each_entry(dp, &priv->fake->list, list) {
            if (dp != priv &&
                (dp->dev->phy->current_channel ==
                 priv->dev->phy->current_channel))
                fakelb_hw_deliver(dp, skb);
        }
    }
    read_unlock_bh(&fake->lock);

    return 0;
}

static int
fakelb_hw_start(struct ieee802154_dev *dev) {
    struct fakelb_dev_priv *priv = dev->priv;
    int ret = 0;

    spin_lock(&priv->lock);
    if (priv->working)
        ret = -EBUSY;
    else
        priv->working = 1;
    spin_unlock(&priv->lock);

    return ret;
}

static void
fakelb_hw_stop(struct ieee802154_dev *dev) {
    struct fakelb_dev_priv *priv = dev->priv;

    spin_lock(&priv->lock);
    priv->working = 0;
    spin_unlock(&priv->lock);
}

static struct ieee802154_ops fakelb_ops = {
    .owner = THIS_MODULE,
    .xmit = fakelb_hw_xmit,
    .ed = fakelb_hw_ed,
    .set_channel = fakelb_hw_channel,
    .start = fakelb_hw_start,
    .stop = fakelb_hw_stop,
};

/* Number of dummy devices to be set up by this module. */
module_param(numlbs, int, 0);
MODULE_PARM_DESC(numlbs, " number of pseudo devices");

static int fakelb_add_one(struct device *dev, struct fakelb_priv *fake)
{
    struct fakelb_dev_priv *priv;
    int err;
    struct ieee802154_dev *ieee;

    ieee = ieee802154_alloc_device(sizeof(*priv), &fakelb_ops);
    if (!ieee)
        return -ENOMEM;

    priv = ieee->priv;
    priv->dev = ieee;

    /* 868 MHz BPSK 802.15.4-2003 */
    ieee->phy->channels_supported[0] |= 1;
    /* 915 MHz BPSK 802.15.4-2003 */
    ieee->phy->channels_supported[0] |= 0x7fe;
    /* 2.4 GHz O-QPSK 802.15.4-2003 */
    ieee->phy->channels_supported[0] |= 0x7FFF800;
    /* 868 MHz ASK 802.15.4-2006 */
    ieee->phy->channels_supported[1] |= 1;
    /* 915 MHz ASK 802.15.4-2006 */
    ieee->phy->channels_supported[1] |= 0x7fe;
    /* 868 MHz O-QPSK 802.15.4-2006 */
    ieee->phy->channels_supported[2] |= 1;
    /* 915 MHz O-QPSK 802.15.4-2006 */
    ieee->phy->channels_supported[2] |= 0x7fe;
    /* 2.4 GHz CSS 802.15.4a-2007 */
    ieee->phy->channels_supported[3] |= 0x3fff;
    /* UWB Sub-gigahertz 802.15.4a-2007 */
    ieee->phy->channels_supported[4] |= 1;
    /* UWB Low band 802.15.4a-2007 */
    ieee->phy->channels_supported[4] |= 0x1e;
    /* UWB High band 802.15.4a-2007 */
    ieee->phy->channels_supported[4] |= 0xffe0;
    /* 750 MHz O-QPSK 802.15.4c-2009 */
    ieee->phy->channels_supported[5] |= 0xf;
    /* 750 MHz MPSK 802.15.4c-2009 */
    ieee->phy->channels_supported[5] |= 0xf0;
    /* 950 MHz BPSK 802.15.4d-2009 */
    ieee->phy->channels_supported[6] |= 0x3ff;
    /* 950 MHz GFSK 802.15.4d-2009 */
    ieee->phy->channels_supported[6] |= 0x3ffc00;

    INIT_LIST_HEAD(&priv->list);
    priv->fake = fake;

    spin_lock_init(&priv->lock);

    ieee->parent = dev;

    err = ieee802154_register_device(ieee);
    if (err)
        goto err_reg;

    write_lock_bh(&fake->lock);
    list_add_tail(&priv->list, &fake->list);
    write_unlock_bh(&fake->lock);

    return 0;

err_reg:
    ieee802154_free_device(priv->dev);
    return err;
}

static void fakelb_del(struct fakelb_dev_priv *priv)
{
    write_lock_bh(&priv->fake->lock);
    list_del(&priv->list);
    write_unlock_bh(&priv->fake->lock);

    ieee802154_unregister_device(priv->dev);
    ieee802154_free_device(priv->dev);
}

static int __devinit fakelb_probe(struct platform_device *pdev)
{
    struct fakelb_priv *priv;
    struct fakelb_dev_priv *dp;
    int err = -ENOMEM;
    int i;

    priv = kzalloc(sizeof(struct fakelb_priv), GFP_KERNEL);
    if (!priv)
        goto err_alloc;

    INIT_LIST_HEAD(&priv->list);
    rwlock_init(&priv->lock);

    for (i = 0; i < numlbs; i++) {
        err = fakelb_add_one(&pdev->dev, priv);
        if (err < 0)
            goto err_slave;
    }

    platform_set_drvdata(pdev, priv);
    dev_info(&pdev->dev, "added ieee802154 hardware\n");
    return 0;

err_slave:
    list_for_each_entry(dp, &priv->list, list)
        fakelb_del(dp);
    kfree(priv);
err_alloc:
    return err;
}

static int __devexit fakelb_remove(struct platform_device *pdev)
{
    struct fakelb_priv *priv = platform_get_drvdata(pdev);
    struct fakelb_dev_priv *dp, *temp;

    list_for_each_entry_safe(dp, temp, &priv->list, list)
        fakelb_del(dp);
    kfree(priv);

    return 0;
}

static struct platform_device *ieee802154fake_dev;

static struct platform_driver ieee802154fake_driver = {
    .probe = fakelb_probe,
    .remove = __devexit_p(fakelb_remove),
    .driver = {
            .name = "ieee802154fakelb",
            .owner = THIS_MODULE,
    },
};

static __init int fakelb_init_module(void)
{
    ieee802154fake_dev = platform_device_register_simple(
                 "ieee802154fakelb", -1, NULL, 0);
    return platform_driver_register(&ieee802154fake_driver);
}

static __exit void fake_remove_module(void)
{
    platform_driver_unregister(&ieee802154fake_driver);
    platform_device_unregister(ieee802154fake_dev);
}

module_init(fakelb_init_module);
module_exit(fake_remove_module);
MODULE_LICENSE("GPL");