1

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

     2

 *

     3

 *  $Id$

     4

 *

     5

 *  Copyright (C) 2006  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

    10

 *  and/or modify it under the terms of the GNU General Public License

    11

 *  as published by the Free Software Foundation; either version 2 of the

    12

 *  License, or (at your option) any later version.

    13

 *

    14

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

    15

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

    16

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    17

 *  GNU General Public License for more details.

    18

 *

    19

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

    20

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

    21

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

    22

 *

    23

 *  The right to use EtherCAT Technology is granted and comes free of

    24

 *  charge under condition of compatibility of product made by

    25

 *  Licensee. People intending to distribute/sell products based on the

    26

 *  code, have to sign an agreement to guarantee that products using

    27

 *  software based on IgH EtherCAT master stay compatible with the actual

    28

 *  EtherCAT specification (which are released themselves as an open

    29

 *  standard) as the (only) precondition to have the right to use EtherCAT

    30

 *  Technology, IP and trade marks.

    31

 *

    32

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

    33

    34

/**

    35

   \file

    36

   Ethernet-over-EtherCAT (EoE).

    37

*/

    38

    39

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

    40

    41

#include <linux/netdevice.h>

    42

#include <linux/etherdevice.h>

    43

    44

#include "../include/ecrt.h"

    45

#include "globals.h"

    46

#include "master.h"

    47

#include "slave.h"

    48

#include "mailbox.h"

    49

#include "ethernet.h"

    50

    51

/**

    52

   Defines the debug level of EoE processing

    53

    54

   0 = No debug messages.

    55

   1 = Output actions.

    56

   2 = Output actions and frame data.

    57

*/

    58

    59

#define EOE_DEBUG_LEVEL 0

    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 registeres it.

    83

*/

    84

    85

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

    86

{

    87

    ec_eoe_t **priv;

    88

    int result, i;

    89

    90

    eoe->slave = NULL;

    91

    ec_datagram_init(&eoe->datagram);

    92

    eoe->state = ec_eoe_state_rx_start;

    93

    eoe->opened = 0;

    94

    eoe->rx_skb = NULL;

    95

    eoe->rx_expected_fragment = 0;

    96

    INIT_LIST_HEAD(&eoe->tx_queue);

    97

    eoe->tx_frame = NULL;

    98

    eoe->tx_queue_active = 0;

    99

    eoe->tx_queued_frames = 0;

   100

    eoe->tx_queue_lock = SPIN_LOCK_UNLOCKED;

   101

    eoe->tx_frame_number = 0xFF;

   102

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

   103

   104

    if (!(eoe->dev =

   105

          alloc_netdev(sizeof(ec_eoe_t *), "eoe%d", ether_setup))) {

   106

        EC_ERR("Unable to allocate net_device for EoE handler!\n");

   107

        goto out_return;

   108

    }

   109

   110

    // initialize net_device

   111

    eoe->dev->open = ec_eoedev_open;

   112

    eoe->dev->stop = ec_eoedev_stop;

   113

    eoe->dev->hard_start_xmit = ec_eoedev_tx;

   114

    eoe->dev->get_stats = ec_eoedev_stats;

   115

   116

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

   117

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

   118

   119

    // initialize private data

   120

    priv = netdev_priv(eoe->dev);

   121

    *priv = eoe;

   122

   123

    // Usually setting the MTU appropriately makes the upper layers

   124

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

   125

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

   126

    // is done "manually".

   127

#if 0

   128

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

   129

#endif

   130

   131

    // connect the net_device to the kernel

   132

    if ((result = register_netdev(eoe->dev))) {

   133

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

   134

        goto out_free;

   135

    }

   136

   137

    // make the last address octet unique

   138

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

   139

   140

    return 0;

   141

   142

 out_free:

   143

    free_netdev(eoe->dev);

   144

    eoe->dev = NULL;

   145

 out_return:

   146

    return -1;

   147

}

   148

   149

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

   150

   151

/**

   152

   EoE destructor.

   153

   Unregisteres the net_device and frees allocated memory.

   154

*/

   155

   156

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

   157

{

   158

    unregister_netdev(eoe->dev);

   159

    free_netdev(eoe->dev);

   160

   161

    // empty transmit queue

   162

    ec_eoe_flush(eoe);

   163

   164

    if (eoe->tx_frame) {

   165

        dev_kfree_skb(eoe->tx_frame->skb);

   166

        kfree(eoe->tx_frame);

   167

    }

   168

   169

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

   170

   171

    ec_datagram_clear(&eoe->datagram);

   172

}

   173

   174

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

   175

   176

/**

   177

   Empties the transmit queue.

   178

*/

   179

   180

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

   181

{

   182

    ec_eoe_frame_t *frame, *next;

   183

   184

    spin_lock_bh(&eoe->tx_queue_lock);

   185

   186

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

   187

        list_del(&frame->queue);

   188

        dev_kfree_skb(frame->skb);

   189

        kfree(frame);

   190

    }

   191

    eoe->tx_queued_frames = 0;

   192

   193

    spin_unlock_bh(&eoe->tx_queue_lock);

   194

}

   195

   196

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

   197

   198

/**

   199

   Sends a frame or the next fragment.

   200

*/

   201

   202

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

   203

{

   204

    size_t remaining_size, current_size, complete_offset;

   205

    unsigned int last_fragment;

   206

    uint8_t *data;

   207

#if EOE_DEBUG_LEVEL > 1

   208

    unsigned int i;

   209

#endif

   210

   211

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

   212

   213

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

   214

        current_size = remaining_size;

   215

        last_fragment = 1;

   216

    }

   217

    else {

   218

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

   219

        last_fragment = 0;

   220

    }

   221

   222

    if (eoe->tx_fragment_number) {

   223

        complete_offset = eoe->tx_offset / 32;

   224

    }

   225

    else {

   226

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

   227

        complete_offset = remaining_size / 32 + 1;

   228

    }

   229

   230

#if EOE_DEBUG_LEVEL > 0

   231

    EC_DBG("EoE TX sending %sfragment %i with %i octets (%i)."

   232

           " %i frames queued.\n", last_fragment ? "last " : "",

   233

           eoe->tx_fragment_number, current_size, complete_offset,

   234

           eoe->tx_queued_frames);

   235

#endif

   236

   237

#if EOE_DEBUG_LEVEL > 1

   238

    EC_DBG("");

   239

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

   240

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

   241

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

   242

            printk("\n");

   243

            EC_DBG("");

   244

        }

   245

    }

   246

    printk("\n");

   247

#endif

   248

   249

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

   250

                                            0x02, current_size + 4)))

   251

        return -1;

   252

   253

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

   254

    EC_WRITE_U8 (data + 1, last_fragment);

   255

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

   256

                            (complete_offset & 0x3F) << 6 |

   257

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

   258

   259

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

   260

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

   261

   262

    eoe->tx_offset += current_size;

   263

    eoe->tx_fragment_number++;

   264

    return 0;

   265

}

   266

   267

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

   268

   269

/**

   270

   Runs the EoE state machine.

   271

*/

   272

   273

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

   274

{

   275

    if (!eoe->opened) return;

   276

   277

    // call state function

   278

    eoe->state(eoe);

   279

}

   280

   281

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

   282

   283

/**

   284

   Returns the state of the device.

   285

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

   286

*/

   287

   288

unsigned int ec_eoe_active(const ec_eoe_t *eoe /**< EoE handler */)

   289

{

   290

    return eoe->slave && eoe->opened;

   291

}

   292

   293

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

   294

 *  STATE PROCESSING FUNCTIONS

   295

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

   296

   297

/**

   298

   State: RX_START.

   299

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

   300

   slave's mailbox for a new EoE datagram.

   301

*/

   302

   303

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

   304

{

   305

    if (!eoe->slave->online || !eoe->slave->master->device->link_state)

   306

        return;

   307

   308

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

   309

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

   310

    eoe->state = ec_eoe_state_rx_check;

   311

}

   312

   313

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

   314

   315

/**

   316

   State: RX_CHECK.

   317

   Processes the checking datagram sent in RX_START and issues a receive

   318

   datagram, if new data is available.

   319

*/

   320

   321

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

   322

{

   323

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

   324

        eoe->stats.rx_errors++;

   325

        eoe->state = ec_eoe_state_tx_start;

   326

        return;

   327

    }

   328

   329

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

   330

        eoe->state = ec_eoe_state_tx_start;

   331

        return;

   332

    }

   333

   334

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

   335

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

   336

    eoe->state = ec_eoe_state_rx_fetch;

   337

}

   338

   339

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

   340

   341

/**

   342

   State: RX_FETCH.

   343

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

   344

   EoE datagram.

   345

*/

   346

   347

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

   348

{

   349

    size_t rec_size, data_size;

   350

    uint8_t *data, frame_type, last_fragment, time_appended;

   351

    uint8_t frame_number, fragment_offset, fragment_number;

   352

    off_t offset;

   353

   354

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

   355

        eoe->stats.rx_errors++;

   356

        eoe->state = ec_eoe_state_tx_start;

   357

        return;

   358

    }

   359

   360

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

   361

                                     0x02, &rec_size))) {

   362

        eoe->stats.rx_errors++;

   363

        eoe->state = ec_eoe_state_tx_start;

   364

        return;

   365

    }

   366

   367

    frame_type = EC_READ_U16(data) & 0x000F;

   368

   369

    if (frame_type != 0x00) {

   370

#if EOE_DEBUG_LEVEL > 0

   371

        EC_DBG("other frame received.\n");

   372

#endif

   373

        eoe->stats.rx_dropped++;

   374

        eoe->state = ec_eoe_state_tx_start;

   375

        return;

   376

    }

   377

   378

    // EoE Fragment Request received

   379

   380

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

   381

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

   382

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

   383

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

   384

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

   385

   386

#if EOE_DEBUG_LEVEL > 0

   387

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

   388

           " %i octets\n", fragment_number, fragment_offset,

   389

           frame_number,

   390

           last_fragment ? ", last fragment" : "",

   391

           time_appended ? ", + timestamp" : "",

   392

           time_appended ? rec_size - 8 : rec_size - 4);

   393

#endif

   394

   395

#if EOE_DEBUG_LEVEL > 1

   396

    EC_DBG("");

   397

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

   398

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

   399

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

   400

            printk("\n");

   401

            EC_DBG("");

   402

        }

   403

    }

   404

    printk("\n");

   405

#endif

   406

   407

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

   408

   409

    if (!fragment_number) {

   410

        if (eoe->rx_skb) {

   411

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

   412

            dev_kfree_skb(eoe->rx_skb);

   413

        }

   414

   415

        // new socket buffer

   416

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

   417

            if (printk_ratelimit())

   418

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

   419

            eoe->stats.rx_dropped++;

   420

            eoe->state = ec_eoe_state_tx_start;

   421

            return;

   422

        }

   423

   424

        eoe->rx_skb_offset = 0;

   425

        eoe->rx_skb_size = fragment_offset * 32;

   426

        eoe->rx_expected_fragment = 0;

   427

    }

   428

    else {

   429

        if (!eoe->rx_skb) {

   430

            eoe->stats.rx_dropped++;

   431

            eoe->state = ec_eoe_state_tx_start;

   432

            return;

   433

        }

   434

   435

        offset = fragment_offset * 32;

   436

        if (offset != eoe->rx_skb_offset ||

   437

            offset + data_size > eoe->rx_skb_size ||

   438

            fragment_number != eoe->rx_expected_fragment) {

   439

            dev_kfree_skb(eoe->rx_skb);

   440

            eoe->rx_skb = NULL;

   441

            eoe->stats.rx_errors++;

   442

            eoe->state = ec_eoe_state_tx_start;

   443

            return;

   444

        }

   445

    }

   446

   447

    // copy fragment into socket buffer

   448

    memcpy(skb_put(eoe->rx_skb, data_size), data + 4, data_size);

   449

    eoe->rx_skb_offset += data_size;

   450

   451

    if (last_fragment) {

   452

        // update statistics

   453

        eoe->stats.rx_packets++;

   454

        eoe->stats.rx_bytes += eoe->rx_skb->len;

   455

   456

#if EOE_DEBUG_LEVEL > 0

   457

        EC_DBG("EoE RX frame completed with %u octets.\n",

   458

               eoe->rx_skb->len);

   459

#endif

   460

   461

        // pass socket buffer to network stack

   462

        eoe->rx_skb->dev = eoe->dev;

   463

        eoe->rx_skb->protocol = eth_type_trans(eoe->rx_skb, eoe->dev);

   464

        eoe->rx_skb->ip_summed = CHECKSUM_UNNECESSARY;

   465

        if (netif_rx(eoe->rx_skb)) {

   466

            EC_WARN("EoE RX netif_rx failed.\n");

   467

        }

   468

        eoe->rx_skb = NULL;

   469

   470

        eoe->state = ec_eoe_state_tx_start;

   471

    }

   472

    else {

   473

        eoe->rx_expected_fragment++;

   474

#if EOE_DEBUG_LEVEL > 0

   475

        EC_DBG("EoE RX expecting fragment %i\n",

   476

               eoe->rx_expected_fragment);

   477

#endif

   478

        eoe->state = ec_eoe_state_rx_start;

   479

    }

   480

}

   481

   482

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

   483

   484

/**

   485

   State: TX START.

   486

   Starts a new transmit sequence. If no data is available, a new receive

   487

   sequence is started instead.

   488

*/

   489

   490

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