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

    11

 *  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

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

    23

 *  the industrial property and similar rights of Beckhoff Automation GmbH.

    24

 *

    25

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

    26

    27

/**

    28

   \file

    29

   Ethernet over EtherCAT (EoE).

    30

*/

    31

    32

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

    33

    34

#include <linux/netdevice.h>

    35

#include <linux/etherdevice.h>

    36

    37

#include "globals.h"

    38

#include "master.h"

    39

#include "slave.h"

    40

#include "mailbox.h"

    41

#include "ethernet.h"

    42

    43

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

    44

    45

/**

    46

 * Defines the debug level of EoE processing.

    47

 *

    48

 * 0 = No debug messages.

    49

 * 1 = Output actions.

    50

 * 2 = Output actions and frame data.

    51

 */

    52

    53

#define EOE_DEBUG_LEVEL 0

    54

    55

/** size of the EoE tx queue */

    56

#define EC_EOE_TX_QUEUE_SIZE 100

    57

    58

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

    59

    60

void ec_eoe_flush(ec_eoe_t *);

    61

    62

// state functions

    63

void ec_eoe_state_rx_start(ec_eoe_t *);

    64

void ec_eoe_state_rx_check(ec_eoe_t *);

    65

void ec_eoe_state_rx_fetch(ec_eoe_t *);

    66

void ec_eoe_state_tx_start(ec_eoe_t *);

    67

void ec_eoe_state_tx_sent(ec_eoe_t *);

    68

    69

// net_device functions

    70

int ec_eoedev_open(struct net_device *);

    71

int ec_eoedev_stop(struct net_device *);

    72

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

    73

struct net_device_stats *ec_eoedev_stats(struct net_device *);

    74

    75

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

    76

    77

/**

    78

 * EoE constructor.

    79

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

    80

 */

    81

    82

int ec_eoe_init(

    83

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

    84

        ec_slave_t *slave /**< EtherCAT slave */

    85

        )

    86

{

    87

    ec_eoe_t **priv;

    88

    int i, ret = 0;

    89

    char name[EC_DATAGRAM_NAME_SIZE];

    90

    91

    eoe->slave = slave;

    92

    93

    ec_datagram_init(&eoe->datagram);

    94

    eoe->queue_datagram = 0;

    95

    eoe->state = ec_eoe_state_rx_start;

    96

    eoe->opened = 0;

    97

    eoe->rx_skb = NULL;

    98

    eoe->rx_expected_fragment = 0;

    99

    INIT_LIST_HEAD(&eoe->tx_queue);

   100

    eoe->tx_frame = NULL;

   101

    eoe->tx_queue_active = 0;

   102

    eoe->tx_queued_frames = 0;

   103

    eoe->tx_queue_lock = SPIN_LOCK_UNLOCKED;

   104

    eoe->tx_frame_number = 0xFF;

   105

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

   106

   107

    eoe->rx_counter = 0;

   108

    eoe->tx_counter = 0;

   109

    eoe->rx_rate = 0;

   110

    eoe->tx_rate = 0;

   111

    eoe->rate_jiffies = 0;

   112

   113

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

   114

     * like hyphens etc. in interface names. */

   115

    if (slave->sii.alias) {

   116

        snprintf(name, EC_DATAGRAM_NAME_SIZE,

   117

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

   118

    } else {

   119

        snprintf(name, EC_DATAGRAM_NAME_SIZE,

   120

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

   121

    }

   122

   123

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

   124

   125

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

   126

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

   127

        ret = -ENODEV;

   128

        goto out_return;

   129

    }

   130

   131

    // initialize net_device

   132

    eoe->dev->open = ec_eoedev_open;

   133

    eoe->dev->stop = ec_eoedev_stop;

   134

    eoe->dev->hard_start_xmit = ec_eoedev_tx;

   135

    eoe->dev->get_stats = ec_eoedev_stats;

   136

   137

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

   138

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

   139

   140

    // initialize private data

   141

    priv = netdev_priv(eoe->dev);

   142

    *priv = eoe;

   143

   144

    // Usually setting the MTU appropriately makes the upper layers

   145

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

   146

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

   147

    // is done "manually".

   148

#if 0

   149

    eoe->dev->mtu = slave->sii.rx_mailbox_size - ETH_HLEN - 10;

   150

#endif

   151

   152

    // connect the net_device to the kernel

   153

    ret = register_netdev(eoe->dev);

   154

    if (ret) {

   155

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

   156

        goto out_free;

   157

    }

   158

   159

    // make the last address octet unique

   160

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

   161

    return 0;

   162

   163

 out_free:

   164

    free_netdev(eoe->dev);

   165

    eoe->dev = NULL;

   166

 out_return:

   167

    return ret;

   168

}

   169

   170

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

   171

   172

/**

   173

   EoE destructor.

   174

   Unregisteres the net_device and frees allocated memory.

   175

*/

   176

   177

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

   178

{

   179

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

   180

    free_netdev(eoe->dev);

   181

   182

    // empty transmit queue

   183

    ec_eoe_flush(eoe);

   184

   185

    if (eoe->tx_frame) {

   186

        dev_kfree_skb(eoe->tx_frame->skb);

   187

        kfree(eoe->tx_frame);

   188

    }

   189

   190

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

   191

   192

    ec_datagram_clear(&eoe->datagram);

   193

}

   194

   195

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

   196

   197

/**

   198

   Empties the transmit queue.

   199

*/

   200

   201

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

   202

{

   203

    ec_eoe_frame_t *frame, *next;

   204

   205

    spin_lock_bh(&eoe->tx_queue_lock);

   206

   207

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

   208

        list_del(&frame->queue);

   209

        dev_kfree_skb(frame->skb);

   210

        kfree(frame);

   211

    }

   212

    eoe->tx_queued_frames = 0;

   213

   214

    spin_unlock_bh(&eoe->tx_queue_lock);

   215

}

   216

   217

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

   218

   219

/**

   220

   Sends a frame or the next fragment.

   221

*/

   222

   223

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

   224

{

   225

    size_t remaining_size, current_size, complete_offset;

   226

    unsigned int last_fragment;

   227

    uint8_t *data;

   228

#if EOE_DEBUG_LEVEL > 1

   229

    unsigned int i;

   230

#endif

   231

   232

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

   233

   234

    if (remaining_size <= eoe->slave->sii.tx_mailbox_size - 10) {

   235

        current_size = remaining_size;

   236

        last_fragment = 1;

   237

    }

   238

    else {

   239

        current_size = ((eoe->slave->sii.tx_mailbox_size - 10) / 32) * 32;

   240

        last_fragment = 0;

   241

    }

   242

   243

    if (eoe->tx_fragment_number) {

   244

        complete_offset = eoe->tx_offset / 32;

   245

    }

   246

    else {

   247

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

   248

        complete_offset = remaining_size / 32 + 1;

   249

    }

   250

   251

#if EOE_DEBUG_LEVEL > 0

   252

    EC_INFO("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,

   255

           eoe->tx_queued_frames);

   256

#endif

   257

   258

#if EOE_DEBUG_LEVEL > 1

   259

    EC_INFO("");

   260

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

   261

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

   262

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

   263

            printk("\n");

   264

            EC_INFO("");

   265

        }

   266

    }

   267

    printk("\n");

   268

#endif

   269

   270

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

   271

            0x02, current_size + 4);

   272

    if (IS_ERR(data))

   273

        return PTR_ERR(data);

   274

   275

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

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    EC_WRITE_U8 (data + 1, last_fragment);

   277

    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));

   280

   281

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

   282

    eoe->queue_datagram = 1;

   283

   284

    eoe->tx_offset += current_size;

   285

    eoe->tx_fragment_number++;

   286

    return 0;

   287

}

   288

   289

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

   290

   291

/**

   292

   Runs the EoE state machine.

   293

*/

   294

   295

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

   296

{

   297

    if (!eoe->opened) return;

   298

   299

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

   300

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

   301

        return;

   302

   303

    // call state function

   304

    eoe->state(eoe);

   305

   306

    // update statistics

   307

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

   308

        eoe->rx_rate = eoe->rx_counter * 8;

   309

        eoe->tx_rate = eoe->tx_counter * 8;

   310

        eoe->rx_counter = 0;

   311

        eoe->tx_counter = 0;

   312

        eoe->rate_jiffies = jiffies;

   313

    }

   314

   315

    ec_datagram_output_stats(&eoe->datagram);

   316

}

   317

   318

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

   319

   320

/**

   321

 * Queues the datagram, if necessary.

   322

 */

   323

   324

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

   325

{

   326

   if (eoe->queue_datagram) {

   327

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

   328

       eoe->queue_datagram = 0;

   329

   }

   330

}

   331

   332

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

   333

   334

/**

   335

   Returns the state of the device.

   336

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

   337

*/

   338

   339

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

   340

{

   341

    return eoe->opened;

   342

}

   343

   344

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

   345

 *  STATE PROCESSING FUNCTIONS

   346

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

   347

   348

/**

   349

   State: RX_START.

   350

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

   351

   slave's mailbox for a new EoE datagram.

   352

*/

   353

   354

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

   355

{

   356

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

   357

        return;

   358

   359

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

   360

    eoe->queue_datagram = 1;

   361

    eoe->state = ec_eoe_state_rx_check;

   362

}

   363

   364

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

   365

   366

/**

   367

   State: RX_CHECK.

   368

   Processes the checking datagram sent in RX_START and issues a receive

   369

   datagram, if new data is available.

   370

*/

   371

   372

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

   373

{

   374

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

   375

        eoe->stats.rx_errors++;

   376

        eoe->state = ec_eoe_state_tx_start;

   377

        return;

   378

    }

   379

   380

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

   381

        eoe->state = ec_eoe_state_tx_start;

   382

        return;

   383

    }

   384

   385

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

   386

    eoe->queue_datagram = 1;

   387

    eoe->state = ec_eoe_state_rx_fetch;

   388

}

   389

   390

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

   391

   392

/**

   393

   State: RX_FETCH.

   394

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

   395

   EoE datagram.

   396

*/

   397

   398

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

   399

{

   400

    size_t rec_size, data_size;

   401

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

   402

    uint8_t frame_number, fragment_offset, fragment_number;

   403

    off_t offset;

   404

#if EOE_DEBUG_LEVEL > 1

   405

    unsigned int i;

   406

#endif

   407

   408

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

   409

        eoe->stats.rx_errors++;

   410

        eoe->state = ec_eoe_state_tx_start;

   411

        return;

   412

    }

   413

   414

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

   415

            &mbox_prot, &rec_size);

   416

    if (IS_ERR(data)) {

   417

        eoe->stats.rx_errors++;

   418

        eoe->state = ec_eoe_state_tx_start;

   419

        return;

   420

    }

   421

   422

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

   423

        eoe->stats.rx_errors++;

   424

        eoe->state = ec_eoe_state_tx_start;

   425

        return;

   426

    }

   427

   428

    frame_type = EC_READ_U16(data) & 0x000F;

   429

   430

    if (frame_type != 0x00) {

   431

#if EOE_DEBUG_LEVEL > 0

   432

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

   433

#endif

   434

        eoe->stats.rx_dropped++;

   435

        eoe->state = ec_eoe_state_tx_start;

   436

        return;

   437

    }

   438

   439

    // EoE Fragment Request received

   440

   441

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

   442

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

   443

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

   444

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

   445

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

   446

   447

#if EOE_DEBUG_LEVEL > 0

   448

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

   449

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

   450

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

   451

           time_appended ? ", + timestamp" : "",

   452

           time_appended ? rec_size - 8 : rec_size - 4);

   453

#endif

   454

   455

#if EOE_DEBUG_LEVEL > 1

   456

    EC_INFO("");

   457

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

   458

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

   459

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

   460

            printk("\n");

   461

            EC_INFO("");

   462

        }

   463

    }

   464

    printk("\n");

   465

#endif

   466

   467

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

   468

   469

    if (!fragment_number) {

   470

        if (eoe->rx_skb) {

   471

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

   472

            dev_kfree_skb(eoe->rx_skb);

   473

        }

   474

   475

        // new socket buffer

   476

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

   477

            if (printk_ratelimit())

   478

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

   479

            eoe->stats.rx_dropped++;

   480

            eoe->state = ec_eoe_state_tx_start;

   481

            return;

   482

        }

   483

   484

        eoe->rx_skb_offset = 0;

   485

        eoe->rx_skb_size = fragment_offset * 32;

   486

        eoe->rx_expected_fragment = 0;

   487

    }