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/******************************************************************************

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 *

     3

 *  $Id$

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 *

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 *  Copyright (C) 2006-2008  Florian Pose, Ingenieurgemeinschaft IgH

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 *

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 *  This file is part of the IgH EtherCAT Master.

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 *

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 *  The IgH EtherCAT Master is free software; you can redistribute it and/or

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 *  modify it under the terms of the GNU General Public License version 2, as

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 *  published by the Free Software Foundation.

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 *

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 *  The IgH EtherCAT Master is distributed in the hope that it will be useful,

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 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

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 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General

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 *  Public License for more details.

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 *

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 *  You should have received a copy of the GNU General Public License along

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 *  with the IgH EtherCAT Master; if not, write to the Free Software

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 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

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 *

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 *  ---

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 *

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 *  The license mentioned above concerns the source code only. Using the

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 *  EtherCAT technology and brand is only permitted in compliance with the

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 *  industrial property and similar rights of Beckhoff Automation GmbH.

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 *

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 *****************************************************************************/

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/**

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   \file

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   Ethernet over EtherCAT (EoE).

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*/

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    35

/*****************************************************************************/

    36

    37

#include <linux/version.h>

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#include <linux/netdevice.h>

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#include <linux/etherdevice.h>

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    41

#include "globals.h"

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#include "master.h"

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#include "slave.h"

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#include "mailbox.h"

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#include "ethernet.h"

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    47

/*****************************************************************************/

    48

    49

/** Defines the debug level of EoE processing.

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 *

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 * 0 = No debug messages.

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 * 1 = Output warnings.

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 * 2 = Output actions.

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 * 3 = Output actions and frame data.

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 */

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#define EOE_DEBUG_LEVEL 1

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    58

/** Size of the EoE tx queue.

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 */

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#define EC_EOE_TX_QUEUE_SIZE 100

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    62

/** Number of tries.

    63

 */

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#define EC_EOE_TRIES 100

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    66

/*****************************************************************************/

    67

    68

void ec_eoe_flush(ec_eoe_t *);

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    70

// state functions

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void ec_eoe_state_rx_start(ec_eoe_t *);

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void ec_eoe_state_rx_check(ec_eoe_t *);

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void ec_eoe_state_rx_fetch(ec_eoe_t *);

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void ec_eoe_state_tx_start(ec_eoe_t *);

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void ec_eoe_state_tx_sent(ec_eoe_t *);

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// net_device functions

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int ec_eoedev_open(struct net_device *);

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int ec_eoedev_stop(struct net_device *);

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int ec_eoedev_tx(struct sk_buff *, struct net_device *);

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struct net_device_stats *ec_eoedev_stats(struct net_device *);

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    84

/*****************************************************************************/

    85

    86

#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 29)

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/** Device operations for EoE interfaces.

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 */

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static const struct net_device_ops ec_eoedev_ops = {

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    .ndo_open = ec_eoedev_open,

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    .ndo_stop = ec_eoedev_stop,

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    .ndo_start_xmit = ec_eoedev_tx,

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    .ndo_get_stats = ec_eoedev_stats,

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};

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#endif

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/*****************************************************************************/

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   122

/** EoE constructor.

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 *

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 * Initializes the EoE handler, creates a net_device and registers it.

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 *

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 * \return Zero on success, otherwise a negative error code.

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 */

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int ec_eoe_init(

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        ec_eoe_t *eoe, /**< EoE handler */

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        ec_slave_t *slave /**< EtherCAT slave */

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        )

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{

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    ec_eoe_t **priv;

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    char name[EC_DATAGRAM_NAME_SIZE];

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   141

    eoe->slave = slave;

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    ec_datagram_init(&eoe->datagram);

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    eoe->queue_datagram = 0;

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    eoe->state = ec_eoe_state_rx_start;

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    eoe->opened = 0;

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    eoe->rx_skb = NULL;

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    eoe->rx_expected_fragment = 0;

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    INIT_LIST_HEAD(&eoe->tx_queue);

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    eoe->tx_frame = NULL;

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    eoe->tx_queue_active = 0;

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    eoe->tx_queue_size = EC_EOE_TX_QUEUE_SIZE;

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    eoe->tx_queued_frames = 0;

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    sema_init(&eoe->tx_queue_sem, 1);

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    eoe->tx_frame_number = 0xFF;

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    memset(&eoe->stats, 0, sizeof(struct net_device_stats));

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    eoe->rx_counter = 0;

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    eoe->tx_counter = 0;

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    eoe->rx_rate = 0;

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    eoe->tx_rate = 0;

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    eoe->rate_jiffies = 0;

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    eoe->rx_idle = 1;

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    eoe->tx_idle = 1;

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    /* device name eoe<MASTER>[as]<SLAVE>, because networking scripts don't

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     * like hyphens etc. in interface names. */

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    if (slave->effective_alias) {

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        snprintf(name, EC_DATAGRAM_NAME_SIZE,

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                "eoe%ua%u", slave->master->index, slave->effective_alias);

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    } else {

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        snprintf(name, EC_DATAGRAM_NAME_SIZE,

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                "eoe%us%u", slave->master->index, slave->ring_position);

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    }

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    snprintf(eoe->datagram.name, EC_DATAGRAM_NAME_SIZE, name);

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    if (!(eoe->dev = alloc_netdev(sizeof(ec_eoe_t *), name, ether_setup))) {

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        EC_SLAVE_ERR(slave, "Unable to allocate net_device %s"

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                " for EoE handler!\n", name);

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        ret = -ENODEV;

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        goto out_return;

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    }

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    // initialize net_device

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#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 29)

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    eoe->dev->netdev_ops = &ec_eoedev_ops;

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#else

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    eoe->dev->open = ec_eoedev_open;

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    eoe->dev->stop = ec_eoedev_stop;

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    eoe->dev->hard_start_xmit = ec_eoedev_tx;

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    eoe->dev->get_stats = ec_eoedev_stats;

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#endif

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    // initialize private data

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    priv = netdev_priv(eoe->dev);

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    *priv = eoe;

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    // Usually setting the MTU appropriately makes the upper layers

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    // do the frame fragmenting. In some cases this doesn't work

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    // so the MTU is left on the Ethernet standard value and fragmenting

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    // is done "manually".

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#if 0

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    eoe->dev->mtu = slave->configured_rx_mailbox_size - ETH_HLEN - 10;

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#endif

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    // connect the net_device to the kernel

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    ret = register_netdev(eoe->dev);

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    if (ret) {

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        EC_SLAVE_ERR(slave, "Unable to register net_device:"

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                " error %i\n", ret);

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        goto out_free;

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    }

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    return 0;

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 out_free:

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    free_netdev(eoe->dev);

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    eoe->dev = NULL;

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 out_return:

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    return ret;

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}

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/*****************************************************************************/

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/** EoE destructor.

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 *

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 * Unregisteres the net_device and frees allocated memory.

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 */

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void ec_eoe_clear(ec_eoe_t *eoe /**< EoE handler */)

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{

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    unregister_netdev(eoe->dev); // possibly calls close callback

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    // empty transmit queue

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    ec_eoe_flush(eoe);

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    if (eoe->tx_frame) {

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        dev_kfree_skb(eoe->tx_frame->skb);

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        kfree(eoe->tx_frame);

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    }

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    if (eoe->rx_skb)

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        dev_kfree_skb(eoe->rx_skb);

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    free_netdev(eoe->dev);

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    ec_datagram_clear(&eoe->datagram);

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}

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/*****************************************************************************/

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/** Empties the transmit queue.

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 */

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void ec_eoe_flush(ec_eoe_t *eoe /**< EoE handler */)

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{

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    ec_eoe_frame_t *frame, *next;

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   307

    down(&eoe->tx_queue_sem);

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    list_for_each_entry_safe(frame, next, &eoe->tx_queue, queue) {

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        list_del(&frame->queue);

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        dev_kfree_skb(frame->skb);

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        kfree(frame);

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    }

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    eoe->tx_queued_frames = 0;

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    up(&eoe->tx_queue_sem);

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}

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/*****************************************************************************/

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/** Sends a frame or the next fragment.

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 *

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 * \return Zero on success, otherwise a negative error code.

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 */

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int ec_eoe_send(ec_eoe_t *eoe /**< EoE handler */)

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{

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    size_t remaining_size, current_size, complete_offset;

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    unsigned int last_fragment;

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    uint8_t *data;

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#if EOE_DEBUG_LEVEL >= 3

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    unsigned int i;

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#endif

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    remaining_size = eoe->tx_frame->skb->len - eoe->tx_offset;

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    if (remaining_size <= eoe->slave->configured_tx_mailbox_size - 10) {

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        current_size = remaining_size;

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        last_fragment = 1;

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    } else {

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        current_size = ((eoe->slave->configured_tx_mailbox_size - 10) / 32) * 32;

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        last_fragment = 0;

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    }

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   344

    if (eoe->tx_fragment_number) {

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        complete_offset = eoe->tx_offset / 32;

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    }

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    else {

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        // complete size in 32 bit blocks, rounded up.

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        complete_offset = remaining_size / 32 + 1;

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    }

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#if EOE_DEBUG_LEVEL >= 2

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    EC_SLAVE_DBG(slave, 0, "EoE %s TX sending fragment %u%s"

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            " with %u octets (%u). %u frames queued.\n",

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            eoe->dev->name, eoe->tx_fragment_number,

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            last_fragment ? "" : "+", current_size, complete_offset,

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            eoe->tx_queued_frames);

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#endif

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#if EOE_DEBUG_LEVEL >= 3

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    EC_SLAVE_DBG(master, 0, "");

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    for (i = 0; i < current_size; i++) {

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        printk("%02X ", eoe->tx_frame->skb->data[eoe->tx_offset + i]);

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        if ((i + 1) % 16 == 0) {

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            printk("\n");

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            EC_SLAVE_DBG(master, 0, "");

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        }

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    }

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    printk("\n");

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#endif

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    data = ec_slave_mbox_prepare_send(eoe->slave, &eoe->datagram,

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            EC_MBOX_TYPE_EOE, current_size + 4);

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    if (IS_ERR(data))

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        return PTR_ERR(data);

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    EC_WRITE_U8 (data, EC_EOE_FRAMETYPE_INIT_REQ); // Initiate EoE Request

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    EC_WRITE_U8 (data + 1, last_fragment);

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    EC_WRITE_U16(data + 2, ((eoe->tx_fragment_number & 0x3F) |

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                            (complete_offset & 0x3F) << 6 |

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                            (eoe->tx_frame_number & 0x0F) << 12));

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    memcpy(data + 4, eoe->tx_frame->skb->data + eoe->tx_offset, current_size);

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    eoe->queue_datagram = 1;

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    eoe->tx_offset += current_size;

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    eoe->tx_fragment_number++;

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    return 0;

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}

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/*****************************************************************************/

   392

   393

/** Runs the EoE state machine.

   394

 */

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void ec_eoe_run(ec_eoe_t *eoe /**< EoE handler */)

   396

{

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    if (!eoe->opened)

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        return;

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    // if the datagram was not sent, or is not yet received, skip this cycle

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    if (eoe->queue_datagram || eoe->datagram.state == EC_DATAGRAM_SENT)

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        return;

   403

   404

    // call state function

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    eoe->state(eoe);

   406

   407

    // update statistics

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    if (jiffies - eoe->rate_jiffies > HZ) {

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        eoe->rx_rate = eoe->rx_counter;

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        eoe->tx_rate = eoe->tx_counter;

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        eoe->rx_counter = 0;

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        eoe->tx_counter = 0;

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        eoe->rate_jiffies = jiffies;

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    }

   415

   416

    ec_datagram_output_stats(&eoe->datagram);

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}

   418

   419

/*****************************************************************************/

   420

   421

/** Queues the datagram, if necessary.

   422

 */

   423

void ec_eoe_queue(ec_eoe_t *eoe /**< EoE handler */)

   424

{

   425

   if (eoe->queue_datagram) {

   426

       ec_master_queue_datagram_ext(eoe->slave->master, &eoe->datagram);

   427

       eoe->queue_datagram = 0;

   428

   }

   429

}

   430

   431

/*****************************************************************************/

   432

   433

/** Returns the state of the device.

   434

 *

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 * \return 1 if the device is "up", 0 if it is "down"

   436

 */

   437

int ec_eoe_is_open(const ec_eoe_t *eoe /**< EoE handler */)

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{

   439

    return eoe->opened;

   440

}

   441

   442

/*****************************************************************************/

   443

   444

/** Returns the idle state.

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 *

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 * \retval 1 The device is idle.

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 * \retval 0 The device is busy.

   448

 */

   449

int ec_eoe_is_idle(const ec_eoe_t *eoe /**< EoE handler */)

   450

{

   451

    return eoe->rx_idle && eoe->tx_idle;

   452

}

   453

   454

/******************************************************************************

   455

 *  STATE PROCESSING FUNCTIONS

   456

 *****************************************************************************/

   457

   458

/** State: RX_START.

   459

 *

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 * Starts a new receiving sequence by queueing a datagram that checks the

   461

 * slave's mailbox for a new EoE datagram.

   462

 *

   463

 * \todo Use both devices.

   464

 */

   465

void ec_eoe_state_rx_start(ec_eoe_t *eoe /**< EoE handler */)

   466

{

   467

    if (eoe->slave->error_flag ||

   468

            !eoe->slave->master->devices[EC_DEVICE_MAIN].link_state) {

   469

        eoe->rx_idle = 1;

   470

        eoe->tx_idle = 1;

   471

        return;

   472

    }

   473

   474

    ec_slave_mbox_prepare_check(eoe->slave, &eoe->datagram);

   475

    eoe->queue_datagram = 1;

   476

    eoe->state = ec_eoe_state_rx_check;

   477

}

   478

   479

/*****************************************************************************/

   480

   481

/** State: RX_CHECK.

   482

 *

   483

 * Processes the checking datagram sent in RX_START and issues a receive

   484

 * datagram, if new data is available.

   485

 */

   486