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;

   105

    eoe->tx_queued_frames = 0;

   106

    eoe->tx_queue_lock = SPIN_LOCK_UNLOCKED;

   107

    eoe->tx_frame_number = 0xFF;

   108

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

   109

   110

    eoe->rx_counter = 0;

   111

    eoe->tx_counter = 0;

   112

    eoe->rx_rate = 0;

   113

    eoe->tx_rate = 0;

   114

    eoe->rate_jiffies = 0;

   115

   116

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

   117

     * like hyphens etc. in interface names. */

   118

    if (slave->sii.alias) {

   119

        snprintf(name, EC_DATAGRAM_NAME_SIZE,

   120

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

   121

    } else {

   122

        snprintf(name, EC_DATAGRAM_NAME_SIZE,

   123

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

   124

    }

   125

   126

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

   127

   128

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

   129

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

   130

        ret = -ENODEV;

   131

        goto out_return;

   132

    }

   133

   134

    // initialize net_device

   135

    eoe->dev->open = ec_eoedev_open;

   136

    eoe->dev->stop = ec_eoedev_stop;

   137

    eoe->dev->hard_start_xmit = ec_eoedev_tx;

   138

    eoe->dev->get_stats = ec_eoedev_stats;

   139

   140

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

   141

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

   142

   143

    // initialize private data

   144

    priv = netdev_priv(eoe->dev);

   145

    *priv = eoe;

   146

   147

    // Usually setting the MTU appropriately makes the upper layers

   148

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

   149

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

   150

    // is done "manually".

   151

#if 0

   152

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

   153

#endif

   154

   155

    // connect the net_device to the kernel

   156

    ret = register_netdev(eoe->dev);

   157

    if (ret) {

   158

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

   159

        goto out_free;

   160

    }

   161

   162

    // make the last address octet unique

   163

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

   164

    return 0;

   165

   166

 out_free:

   167

    free_netdev(eoe->dev);

   168

    eoe->dev = NULL;

   169

 out_return:

   170

    return ret;

   171

}

   172

   173

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

   174

   175

/**

   176

   EoE destructor.

   177

   Unregisteres the net_device and frees allocated memory.

   178

*/

   179

   180

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

   181

{

   182

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

   183

    free_netdev(eoe->dev);

   184

   185

    // empty transmit queue

   186

    ec_eoe_flush(eoe);

   187

   188

    if (eoe->tx_frame) {

   189

        dev_kfree_skb(eoe->tx_frame->skb);

   190

        kfree(eoe->tx_frame);

   191

    }

   192

   193

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

   194

   195

    ec_datagram_clear(&eoe->datagram);

   196

}

   197

   198

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

   199

   200

/**

   201

   Empties the transmit queue.

   202

*/

   203

   204

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

   205

{

   206

    ec_eoe_frame_t *frame, *next;

   207

   208

    spin_lock_bh(&eoe->tx_queue_lock);

   209

   210

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

   211

        list_del(&frame->queue);

   212

        dev_kfree_skb(frame->skb);

   213

        kfree(frame);

   214

    }

   215

    eoe->tx_queued_frames = 0;

   216

   217

    spin_unlock_bh(&eoe->tx_queue_lock);

   218

}

   219

   220

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

   221

   222

/**

   223

   Sends a frame or the next fragment.

   224

*/

   225

   226

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

   227

{

   228

    size_t remaining_size, current_size, complete_offset;

   229

    unsigned int last_fragment;

   230

    uint8_t *data;

   231

#if EOE_DEBUG_LEVEL > 1

   232

    unsigned int i;

   233

#endif

   234

   235

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

   236

   237

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

   238

        current_size = remaining_size;

   239

        last_fragment = 1;

   240

    } else {

   241

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

   242

        last_fragment = 0;

   243

    }

   244

   245

    if (eoe->tx_fragment_number) {

   246

        complete_offset = eoe->tx_offset / 32;

   247

    }

   248

    else {

   249

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

   250

        complete_offset = remaining_size / 32 + 1;

   251

    }

   252

   253

#if EOE_DEBUG_LEVEL > 0

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    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,

   257

           eoe->tx_queued_frames);

   258

#endif

   259

   260

#if EOE_DEBUG_LEVEL > 1

   261

    EC_INFO("");

   262

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

   263

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

   264

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

   265

            printk("\n");

   266

            EC_INFO("");

   267

        }

   268

    }

   269

    printk("\n");

   270

#endif

   271

   272

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

   273

            0x02, current_size + 4);

   274

    if (IS_ERR(data))

   275

        return PTR_ERR(data);

   276

   277

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

   278

    EC_WRITE_U8 (data + 1, last_fragment);

   279

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

   280

                            (complete_offset & 0x3F) << 6 |

   281

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

   282

   283

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

   284

    eoe->queue_datagram = 1;

   285

   286

    eoe->tx_offset += current_size;

   287

    eoe->tx_fragment_number++;

   288

    return 0;

   289

}

   290

   291

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

   292

   293

/**

   294

   Runs the EoE state machine.

   295

*/

   296

   297

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

   298

{

   299

    if (!eoe->opened) return;

   300

   301

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

   302

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

   303

        return;

   304

   305

    // call state function

   306

    eoe->state(eoe);

   307

   308

    // update statistics

   309

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

   310

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

   311

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

   312

        eoe->rx_counter = 0;

   313

        eoe->tx_counter = 0;

   314

        eoe->rate_jiffies = jiffies;

   315

    }

   316

   317

    ec_datagram_output_stats(&eoe->datagram);

   318

}

   319

   320

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

   321

   322

/**

   323

 * Queues the datagram, if necessary.

   324

 */

   325

   326

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

   327

{

   328

   if (eoe->queue_datagram) {

   329

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

   330

       eoe->queue_datagram = 0;

   331

   }

   332

}

   333

   334

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

   335

   336

/**

   337

   Returns the state of the device.

   338

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

   339

*/

   340

   341

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

   342

{

   343

    return eoe->opened;

   344

}

   345

   346

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

   347

 *  STATE PROCESSING FUNCTIONS

   348

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

   349

   350

/**

   351

   State: RX_START.

   352

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

   353

   slave's mailbox for a new EoE datagram.

   354

*/

   355

   356

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

   357

{

   358

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

   359

        return;

   360

   361

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

   362

    eoe->queue_datagram = 1;

   363

    eoe->state = ec_eoe_state_rx_check;

   364

}

   365

   366

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

   367

   368

/**

   369

   State: RX_CHECK.

   370

   Processes the checking datagram sent in RX_START and issues a receive

   371

   datagram, if new data is available.

   372

*/

   373

   374

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

   375

{

   376

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

   377

        eoe->stats.rx_errors++;

   378

        eoe->state = ec_eoe_state_tx_start;

   379

        return;

   380

    }

   381

   382

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

   383

        eoe->state = ec_eoe_state_tx_start;

   384

        return;

   385

    }

   386

   387

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

   388

    eoe->queue_datagram = 1;

   389

    eoe->state = ec_eoe_state_rx_fetch;

   390

}

   391

   392

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

   393

   394

/**

   395

   State: RX_FETCH.

   396

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

   397

   EoE datagram.

   398

*/

   399

   400

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

   401

{

   402

    size_t rec_size, data_size;

   403

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

   404

    uint8_t frame_number, fragment_offset, fragment_number;

   405

    off_t offset;

   406

#if EOE_DEBUG_LEVEL > 1

   407

    unsigned int i;

   408

#endif

   409

   410

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

   411

        eoe->stats.rx_errors++;

   412

        eoe->state = ec_eoe_state_tx_start;

   413

        return;

   414

    }

   415

   416

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

   417

            &mbox_prot, &rec_size);

   418

    if (IS_ERR(data)) {

   419

        eoe->stats.rx_errors++;

   420

        eoe->state = ec_eoe_state_tx_start;

   421

        return;

   422

    }

   423

   424

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

   425

        eoe->stats.rx_errors++;

   426

        eoe->state = ec_eoe_state_tx_start;

   427

        return;

   428

    }

   429

   430

    frame_type = EC_READ_U16(data) & 0x000F;

   431

   432

    if (frame_type != 0x00) {

   433

#if EOE_DEBUG_LEVEL > 0

   434

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

   435

#endif

   436

        eoe->stats.rx_dropped++;

   437

        eoe->state = ec_eoe_state_tx_start;

   438

        return;

   439

    }

   440

   441

    // EoE Fragment Request received

   442

   443

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

   444

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

   445

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

   446

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

   447

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

   448

   449

#if EOE_DEBUG_LEVEL > 0

   450

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

   451

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

   452

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

   453

           time_appended ? ", + timestamp" : "",

   454

           time_appended ? rec_size - 8 : rec_size - 4);

   455

#endif

   456

   457

#if EOE_DEBUG_LEVEL > 1

   458

    EC_INFO("");

   459

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

   460

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

   461

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

   462

            printk("\n");

   463

            EC_INFO("");

   464

        }

   465

    }

   466

    printk("\n");

   467

#endif

   468

   469

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

   470

   471

    if (!fragment_number) {

   472

        if (eoe->rx_skb) {

   473

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

   474

            dev_kfree_skb(eoe->rx_skb);

   475

        }

   476

   477

        // new socket buffer

   478

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

   479

            if (printk_ratelimit())

   480

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

   481

            eoe->stats.rx_dropped++;

   482

            eoe->state = ec_eoe_state_tx_start;

   483

            return;

   484

        }

   485

   486

        eoe->rx_skb_offset = 0;

   487

        eoe->rx_skb_size = fragment_offset * 32;