1

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

     2

 *

     3

 *  $Id$

     4

 *

     5

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

     6

 *

     7

 *  This file is part of the IgH EtherCAT Master.

     8

 *

     9

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

    10

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

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 *  published by the Free Software Foundation.

    12

 *

    13

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

    14

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

    15

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

    16

 *  Public License for more details.

    17

 *

    18

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

    19

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

    20

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

    21

 *

    22

 *  ---

    23

 *

    24

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

    25

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

    26

 *  industrial property and similar rights of Beckhoff Automation GmbH.

    27

 *

    28

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

    29

    30

/**

    31

   \file

    32

   Ethernet over EtherCAT (EoE).

    33

*/

    34

    35

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

    36

    37

#include <linux/netdevice.h>

    38

#include <linux/etherdevice.h>

    39

    40

#include "globals.h"

    41

#include "master.h"

    42

#include "slave.h"

    43

#include "mailbox.h"

    44

#include "ethernet.h"

    45

    46

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

    47

    48

/**

    49

 * Defines the debug level of EoE processing.

    50

 *

    51

 * 0 = No debug messages.

    52

 * 1 = Output actions.

    53

 * 2 = Output actions and frame data.

    54

 */

    55

    56

#define EOE_DEBUG_LEVEL 0

    57

    58

/** size of the EoE tx queue */

    59

#define EC_EOE_TX_QUEUE_SIZE 100

    60

    61

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

    62

    63

void ec_eoe_flush(ec_eoe_t *);

    64

    65

// state functions

    66

void ec_eoe_state_rx_start(ec_eoe_t *);

    67

void ec_eoe_state_rx_check(ec_eoe_t *);

    68

void ec_eoe_state_rx_fetch(ec_eoe_t *);

    69

void ec_eoe_state_tx_start(ec_eoe_t *);

    70

void ec_eoe_state_tx_sent(ec_eoe_t *);

    71

    72

// net_device functions

    73

int ec_eoedev_open(struct net_device *);

    74

int ec_eoedev_stop(struct net_device *);

    75

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

    76

struct net_device_stats *ec_eoedev_stats(struct net_device *);

    77

    78

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

    79

    80

/**

    81

 * EoE constructor.

    82

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

    83

 */

    84

    85

int ec_eoe_init(

    86

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

    87

        ec_slave_t *slave /**< EtherCAT slave */

    88

        )

    89

{

    90

    ec_eoe_t **priv;

    91

    int i, ret = 0;

    92

    char name[EC_DATAGRAM_NAME_SIZE];

    93

    94

    eoe->slave = slave;

    95

    96

    ec_datagram_init(&eoe->datagram);

    97

    eoe->queue_datagram = 0;

    98

    eoe->state = ec_eoe_state_rx_start;

    99

    eoe->opened = 0;

   100

    eoe->rx_skb = NULL;

   101

    eoe->rx_expected_fragment = 0;

   102

    INIT_LIST_HEAD(&eoe->tx_queue);

   103

    eoe->tx_frame = NULL;

   104

    eoe->tx_queue_active = 0;

   106

    eoe->tx_queued_frames = 0;

   107

    eoe->tx_queue_lock = SPIN_LOCK_UNLOCKED;

   108

    eoe->tx_frame_number = 0xFF;

   109

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

   110

   111

    eoe->rx_counter = 0;

   112

    eoe->tx_counter = 0;

   113

    eoe->rx_rate = 0;

   114

    eoe->tx_rate = 0;

   115

    eoe->rate_jiffies = 0;

   116

   117

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

   118

     * like hyphens etc. in interface names. */

   119

    if (slave->sii.alias) {

   120

        snprintf(name, EC_DATAGRAM_NAME_SIZE,

   121

                "eoe%ua%u", slave->master->index, slave->sii.alias);

   122

    } else {

   123

        snprintf(name, EC_DATAGRAM_NAME_SIZE,

   124

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

   125

    }

   126

   127

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

   128

   129

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

   130

        EC_ERR("Unable to allocate net_device %s for EoE handler!\n", name);

   131

        ret = -ENODEV;

   132

        goto out_return;

   133

    }

   134

   135

    // initialize net_device

   136

    eoe->dev->open = ec_eoedev_open;

   137

    eoe->dev->stop = ec_eoedev_stop;

   138

    eoe->dev->hard_start_xmit = ec_eoedev_tx;

   139

    eoe->dev->get_stats = ec_eoedev_stats;

   140

   141

    for (i = 0; i < ETH_ALEN; i++)

   142

        eoe->dev->dev_addr[i] = i | (i << 4);

   143

   144

    // initialize private data

   145

    priv = netdev_priv(eoe->dev);

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    *priv = eoe;

   147

   148

    // Usually setting the MTU appropriately makes the upper layers

   149

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

   150

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

   151

    // is done "manually".

   152

#if 0

   153

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

   154

#endif

   155

   156

    // connect the net_device to the kernel

   157

    ret = register_netdev(eoe->dev);

   158

    if (ret) {

   159

        EC_ERR("Unable to register net_device: error %i\n", ret);

   160

        goto out_free;

   161

    }

   162

   163

    // make the last address octet unique

   164

    eoe->dev->dev_addr[ETH_ALEN - 1] = (uint8_t) eoe->dev->ifindex;

   165

    return 0;

   166

   167

 out_free:

   168

    free_netdev(eoe->dev);

   169

    eoe->dev = NULL;

   170

 out_return:

   171

    return ret;

   172

}

   173

   174

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

   175

   176

/**

   177

   EoE destructor.

   178

   Unregisteres the net_device and frees allocated memory.

   179

*/

   180

   181

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

   182

{

   183

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

   184

    free_netdev(eoe->dev);

   185

   186

    // empty transmit queue

   187

    ec_eoe_flush(eoe);

   188

   189

    if (eoe->tx_frame) {

   190

        dev_kfree_skb(eoe->tx_frame->skb);

   191

        kfree(eoe->tx_frame);

   192

    }

   193

   194

    if (eoe->rx_skb) dev_kfree_skb(eoe->rx_skb);

   195

   196

    ec_datagram_clear(&eoe->datagram);

   197

}

   198

   199

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

   200

   201

/**

   202

   Empties the transmit queue.

   203

*/

   204

   205

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

   206

{

   207

    ec_eoe_frame_t *frame, *next;

   208

   209

    spin_lock_bh(&eoe->tx_queue_lock);

   210

   211

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

   212

        list_del(&frame->queue);

   213

        dev_kfree_skb(frame->skb);

   214

        kfree(frame);

   215

    }

   216

    eoe->tx_queued_frames = 0;

   217

   218

    spin_unlock_bh(&eoe->tx_queue_lock);

   219

}

   220

   221

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

   222

   223

/**

   224

   Sends a frame or the next fragment.

   225

*/

   226

   227

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

   228

{

   229

    size_t remaining_size, current_size, complete_offset;

   230

    unsigned int last_fragment;

   231

    uint8_t *data;

   232

#if EOE_DEBUG_LEVEL > 1

   233

    unsigned int i;

   234

#endif

   235

   236

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

   237

   238

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

   239

        current_size = remaining_size;

   240

        last_fragment = 1;

   241

    } else {

   242

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

   243

        last_fragment = 0;

   244

    }

   245

   246

    if (eoe->tx_fragment_number) {

   247

        complete_offset = eoe->tx_offset / 32;

   248

    }

   249

    else {

   250

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

   251

        complete_offset = remaining_size / 32 + 1;

   252

    }

   253

   254

#if EOE_DEBUG_LEVEL > 0

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    EC_DBG("EoE %s TX sending fragment %u%s with %u octets (%u)."

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           " %u frames queued.\n", 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);

   259

#endif

   260

   261

#if EOE_DEBUG_LEVEL > 1

   262

    EC_DBG("");

   263

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

   264

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

   265

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

   266

            printk("\n");

   267

            EC_DBG("");

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        }

   269

    }

   270

    printk("\n");

   271

#endif

   272

   273

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

   274

            0x02, current_size + 4);

   275

    if (IS_ERR(data))

   276

        return PTR_ERR(data);

   277

   278

    EC_WRITE_U8 (data,     0x00); // eoe fragment req.

   279

    EC_WRITE_U8 (data + 1, last_fragment);

   280

    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));

   283

   284

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

   285

    eoe->queue_datagram = 1;

   286

   287

    eoe->tx_offset += current_size;

   288

    eoe->tx_fragment_number++;

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    return 0;

   290

}

   291

   292

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

   293

   294

/**

   295

   Runs the EoE state machine.

   296

*/

   297

   298

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

   299

{

   300

    if (!eoe->opened)

   301

        return;

   302

   303

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

   304

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

   305

        return;

   306

   307

    // call state function

   308

    eoe->state(eoe);

   309

   310

    // update statistics

   311

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

   314

        eoe->rx_counter = 0;

   315

        eoe->tx_counter = 0;

   316

        eoe->rate_jiffies = jiffies;

   317

    }

   318

   319

    ec_datagram_output_stats(&eoe->datagram);

   320

}

   321

   322

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

   323

   324

/**

   325

 * Queues the datagram, if necessary.

   326

 */

   327

   328

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

   329

{

   330

   if (eoe->queue_datagram) {

   331

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

   332

       eoe->queue_datagram = 0;

   333

   }

   334

}

   335

   336

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

   337

   338

/**

   339

   Returns the state of the device.

   340

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

   341

*/

   342

   343

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

   344

{

   345

    return eoe->opened;

   346

}

   347

   348

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

   349

 *  STATE PROCESSING FUNCTIONS

   350

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

   351

   352

/**

   353

   State: RX_START.

   354

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

   355

   slave's mailbox for a new EoE datagram.

   356

*/

   357

   358

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

   359

{

   360

    if (eoe->slave->error_flag || !eoe->slave->master->main_device.link_state)

   361

        return;

   362

   363

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

   364

    eoe->queue_datagram = 1;

   365

    eoe->state = ec_eoe_state_rx_check;

   366

}

   367

   368

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

   369

   370

/**

   371

   State: RX_CHECK.

   372

   Processes the checking datagram sent in RX_START and issues a receive

   373

   datagram, if new data is available.

   374

*/

   375

   376

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

   377

{

   378

    if (eoe->datagram.state != EC_DATAGRAM_RECEIVED) {

   379

        eoe->stats.rx_errors++;

   380

        eoe->state = ec_eoe_state_tx_start;

   381

        return;

   382

    }

   383

   384

    if (!ec_slave_mbox_check(&eoe->datagram)) {

   385

        eoe->state = ec_eoe_state_tx_start;

   386

        return;

   387

    }

   388

   389

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

   390

    eoe->queue_datagram = 1;

   391

    eoe->state = ec_eoe_state_rx_fetch;

   392

}

   393

   394

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

   395

   396

/**

   397

   State: RX_FETCH.

   398

   Checks if the requested data of RX_CHECK was received and processes the

   399

   EoE datagram.

   400

*/

   401

   402

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

   403

{

   404

    size_t rec_size, data_size;

   405

    uint8_t *data, frame_type, last_fragment, time_appended, mbox_prot;

   406

    uint8_t frame_number, fragment_offset, fragment_number;

   407

    off_t offset;

   408

#if EOE_DEBUG_LEVEL > 1

   409

    unsigned int i;

   410

#endif

   411

   412

    if (eoe->datagram.state != EC_DATAGRAM_RECEIVED) {

   413

        eoe->stats.rx_errors++;

   414

        eoe->state = ec_eoe_state_tx_start;

   415

        return;

   416

    }

   417

   418

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

   419

            &mbox_prot, &rec_size);

   420

    if (IS_ERR(data)) {

   421

        eoe->stats.rx_errors++;

   422

        eoe->state = ec_eoe_state_tx_start;

   423

        return;

   424

    }

   425

   426

    if (mbox_prot != 0x02) { // EoE FIXME mailbox handler necessary

   427

        eoe->stats.rx_errors++;

   428

        eoe->state = ec_eoe_state_tx_start;

   429

        return;

   430

    }

   431

   432

    frame_type = EC_READ_U16(data) & 0x000F;

   433

   434

    if (frame_type != 0x00) {

   435

#if EOE_DEBUG_LEVEL > 0

   436

        EC_DBG("EoE %s: Other frame received.\n", eoe->dev->name);

   437

#endif

   438

        eoe->stats.rx_dropped++;

   439

        eoe->state = ec_eoe_state_tx_start;

   440

        return;

   441

    }

   442

   443

    // EoE Fragment Request received

   444

   445

    last_fragment = (EC_READ_U16(data) >> 8) & 0x0001;

   446

    time_appended = (EC_READ_U16(data) >> 9) & 0x0001;

   447

    fragment_number = EC_READ_U16(data + 2) & 0x003F;

   448

    fragment_offset = (EC_READ_U16(data + 2) >> 6) & 0x003F;

   449

    frame_number = (EC_READ_U16(data + 2) >> 12) & 0x000F;

   450

   451

#if EOE_DEBUG_LEVEL > 0

   452

    EC_DBG("EoE %s RX fragment %u%s, offset %u, frame %u%s,"

   453

           " %u octets\n", eoe->dev->name, fragment_number,

   454

           last_fragment ? "" : "+", fragment_offset, frame_number, 

   455

           time_appended ? ", + timestamp" : "",

   456

           time_appended ? rec_size - 8 : rec_size - 4);

   457

#endif

   458

   459

#if EOE_DEBUG_LEVEL > 1

   460

    EC_DBG("");

   461

    for (i = 0; i < rec_size - 4; i++) {

   462

        printk("%02X ", data[i + 4]);

   463

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

   464

            printk("\n");

   465

            EC_DBG("");

   466

        }

   467

    }

   468

    printk("\n");

   469

#endif

   470

   471

    data_size = time_appended ? rec_size - 8 : rec_size - 4;

   472

   473

    if (!fragment_number) {

   474

        if (eoe->rx_skb) {

   475

            EC_WARN("EoE RX freeing old socket buffer...\n");

   476

            dev_kfree_skb(eoe->rx_skb);

   477

        }

   478

   479

        // new socket buffer

   480

        if (!(eoe->rx_skb = dev_alloc_skb(fragment_offset * 32))) {

   481

            if (printk_ratelimit())

   482

                EC_WARN("EoE RX low on mem. frame dropped.\n");

   483

            eoe->stats.rx_dropped++;

   484

            eoe->state = ec_eoe_state_tx_start;

   485

            return;

   486

        }

   487