/*
* 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:
* Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
* Sergey Lapin <slapin@ossfans.org>
* Maxim Gorbachyov <maxim.gorbachev@siemens.com>
* Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
*/
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/crc-ccitt.h>
#include <net/mac802154.h>
#include <net/wpan-phy.h>
#include "mac802154.h"
/* IEEE 802.15.4 transceivers can sleep during the xmit session, so process
* packets through the workqueue.
*/
struct xmit_work {
struct sk_buff *skb;
struct work_struct work;
struct mac802154_priv *priv;
u8 chan;
u8 page;
u8 xmit_attempts;
};
static void mac802154_xmit_worker(struct work_struct *work)
{
struct xmit_work *xw = container_of(work, struct xmit_work, work);
int res;
mutex_lock(&xw->priv->phy->pib_lock);
if (xw->priv->phy->current_channel != xw->chan ||
xw->priv->phy->current_page != xw->page) {
res = xw->priv->ops->set_channel(&xw->priv->hw,
xw->page,
xw->chan);
if (res) {
pr_debug("set_channel failed\n");
goto out;
}
}
res = xw->priv->ops->xmit(&xw->priv->hw, xw->skb);
out:
mutex_unlock(&xw->priv->phy->pib_lock);
if (res) {
if (xw->xmit_attempts++ < MAC802154_MAX_XMIT_ATTEMPTS) {
queue_work(xw->priv->dev_workqueue, &xw->work);
return;
} else
pr_debug("transmission failed for %d times",
MAC802154_MAX_XMIT_ATTEMPTS);
}
dev_kfree_skb(xw->skb);
kfree(xw);
}
netdev_tx_t mac802154_tx(struct mac802154_priv *priv, struct sk_buff *skb,
u8 page, u8 chan)
{
struct xmit_work *work;
if (!(priv->phy->channels_supported[page] & (1 << chan))) {
WARN_ON(1);
kfree_skb(skb);
return NETDEV_TX_OK;
}
mac802154_monitors_rx(mac802154_to_priv(&priv->hw), skb);
if (!(priv->hw.flags & IEEE802154_HW_OMIT_CKSUM)) {
u16 crc = crc_ccitt(0, skb->data, skb->len);
u8 *data = skb_put(skb, 2);
data[0] = crc & 0xff;
data[1] = crc >> 8;
}
if (skb_cow_head(skb, priv->hw.extra_tx_headroom)) {
kfree_skb(skb);
return NETDEV_TX_OK;
}
work = kzalloc(sizeof(struct xmit_work), GFP_ATOMIC);
if (!work) {
kfree_skb(skb);
return NETDEV_TX_BUSY;
}
INIT_WORK(&work->work, mac802154_xmit_worker);
work->skb = skb;
work->priv = priv;
work->page = page;
work->chan = chan;
work->xmit_attempts = 0;
queue_work(priv->dev_workqueue, &work->work);
return NETDEV_TX_OK;
}
