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; version 2 of the License.

    12

 *

    13

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

    14

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

    15

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    16

 *  GNU General Public License for more details.

    17

 *

    18

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

    19

 *  along 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

/**

    25

   \file

    26

   Ethernet-over-EtherCAT (EoE).

    27

*/

    28

    29

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

    30

    31

#include <linux/etherdevice.h>

    32

    33

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

    34

#include "globals.h"

    35

#include "master.h"

    36

#include "slave.h"

    37

#include "mailbox.h"

    38

#include "ethernet.h"

    39

    40

#define EOE_DEBUG_LEVEL 0

    41

    42

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

    43

    44

void ec_eoe_flush(ec_eoe_t *);

    45

    46

// state functions

    47

void ec_eoe_state_rx_start(ec_eoe_t *);

    48

void ec_eoe_state_rx_check(ec_eoe_t *);

    49

void ec_eoe_state_rx_fetch(ec_eoe_t *);

    50

void ec_eoe_state_tx_start(ec_eoe_t *);

    51

void ec_eoe_state_tx_sent(ec_eoe_t *);

    52

    53

// net_device functions

    54

int ec_eoedev_open(struct net_device *);

    55

int ec_eoedev_stop(struct net_device *);

    56

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

    57

struct net_device_stats *ec_eoedev_stats(struct net_device *);

    58

    59

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

    60

    61

/**

    62

   EoE constructor.

    63

   Initializes the EoE object, creates a net_device and registeres it.

    64

*/

    65

    66

int ec_eoe_init(ec_eoe_t *eoe, /**< EoE object */

    67

                ec_slave_t *slave /**< assigned slave */

    68

                )

    69

{

    70

    ec_eoe_t **priv;

    71

    int result, i;

    72

    73

    eoe->slave = slave;

    74

    eoe->state = ec_eoe_state_rx_start;

    75

    eoe->opened = 0;

    76

    eoe->rx_skb = NULL;

    77

    eoe->rx_expected_fragment = 0;

    78

    INIT_LIST_HEAD(&eoe->tx_queue);

    79

    eoe->tx_frame = NULL;

    80

    eoe->tx_queue_active = 0;

    81

    eoe->tx_queued_frames = 0;

    82

    eoe->tx_queue_lock = SPIN_LOCK_UNLOCKED;

    83

    eoe->tx_frame_number = 0xFF;

    84

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

    85

    86

    if (!(eoe->dev =

    87

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

    88

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

    89

        goto out_return;

    90

    }

    91

    92

    // initialize net_device

    93

    eoe->dev->open = ec_eoedev_open;

    94

    eoe->dev->stop = ec_eoedev_stop;

    95

    eoe->dev->hard_start_xmit = ec_eoedev_tx;

    96

    eoe->dev->get_stats = ec_eoedev_stats;

    97

    98

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

    99

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

   100

   101

    // initialize private data

   102

    priv = netdev_priv(eoe->dev);

   103

    *priv = eoe;

   104

   105

    // Usually setting the MTU appropriately makes the upper layers

   106

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

   107

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

   108

    // is done "manually".

   109

#if 0

   110

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

   111

#endif

   112

   113

    // connect the net_device to the kernel

   114

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

   115

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

   116

        goto out_free;

   117

    }

   118

   119

    // make the last address octet unique

   120

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

   121

   122

    return 0;

   123

   124

 out_free:

   125

    free_netdev(eoe->dev);

   126

    eoe->dev = NULL;

   127

 out_return:

   128

    return -1;

   129

}

   130

   131

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

   132

   133

/**

   134

   EoE destructor.

   135

   Unregisteres the net_device and frees allocated memory.

   136

*/

   137

   138

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

   139

{

   140

    if (eoe->dev) {

   141

        unregister_netdev(eoe->dev);

   142

        free_netdev(eoe->dev);

   143

    }

   144

   145

    // empty transmit queue

   146

    ec_eoe_flush(eoe);

   147

   148

    if (eoe->tx_frame) {

   149

        dev_kfree_skb(eoe->tx_frame->skb);

   150

        kfree(eoe->tx_frame);

   151

    }

   152

   153

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

   154

}

   155

   156

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

   157

   158

/**

   159

   Empties the transmit queue.

   160

*/

   161

   162

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

   163

{

   164

    ec_eoe_frame_t *frame, *next;

   165

   166

    spin_lock_bh(&eoe->tx_queue_lock);

   167

   168

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

   169

        list_del(&frame->queue);

   170

        dev_kfree_skb(frame->skb);

   171

        kfree(frame);

   172

    }

   173

    eoe->tx_queued_frames = 0;

   174

   175

    spin_unlock_bh(&eoe->tx_queue_lock);

   176

}

   177

   178

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

   179

   180

/**

   181

   Sends a frame or the next fragment.

   182

*/

   183

   184

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

   185

{

   186

    size_t remaining_size, current_size, complete_offset;

   187

    unsigned int last_fragment;

   188

    uint8_t *data;

   189

#if EOE_DEBUG_LEVEL > 1

   190

    unsigned int i;

   191

#endif

   192

   193

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

   194

   195

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

   196

        current_size = remaining_size;

   197

        last_fragment = 1;

   198

    }

   199

    else {

   200

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

   201

        last_fragment = 0;

   202

    }

   203

   204

    if (eoe->tx_fragment_number) {

   205

        complete_offset = eoe->tx_offset / 32;

   206

    }

   207

    else {

   208

        complete_offset = remaining_size / 32 + 1;

   209

    }

   210

   211

#if EOE_DEBUG_LEVEL > 0

   212

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

   213

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

   214

           eoe->tx_fragment_number, current_size, complete_offset,

   215

           eoe->tx_queued_frames);

   216

#endif

   217

   218

#if EOE_DEBUG_LEVEL > 1

   219

    EC_DBG("");

   220

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

   221

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

   222

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

   223

            printk("\n");

   224

            EC_DBG("");

   225

        }

   226

    }

   227

    printk("\n");

   228

#endif

   229

   230

    if (!(data = ec_slave_mbox_prepare_send(eoe->slave, 0x02,

   231

                                            current_size + 4)))

   232

        return -1;

   233

   234

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

   235

    EC_WRITE_U8 (data + 1, last_fragment);

   236

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

   237

                            (complete_offset & 0x3F) << 6 |

   238

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

   239

   240

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

   241

    ec_master_queue_command(eoe->slave->master, &eoe->slave->mbox_command);

   242

   243

    eoe->tx_offset += current_size;

   244

    eoe->tx_fragment_number++;

   245

   246

    return 0;

   247

}

   248

   249

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

   250

   251

/**

   252

   Runs the EoE state machine.

   253

*/

   254

   255

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

   256

{

   257

    if (!eoe->opened) return;

   258

   259

    // call state function

   260

    eoe->state(eoe);

   261

}

   262

   263

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

   264

   265

/**

   266

   Prints EoE object information.

   267

*/

   268

   269

void ec_eoe_print(const ec_eoe_t *eoe /**< EoE object */)

   270

{

   271

    EC_INFO("  EoE slave %i\n", eoe->slave->ring_position);

   272

    EC_INFO("    Assigned device: %s (%s)\n", eoe->dev->name,

   273

            eoe->opened ? "opened" : "closed");

   274

}

   275

   276

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

   277

 *  STATE PROCESSING FUNCTIONS

   278

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

   279

   280

/**

   281

   State: RX_START.

   282

   Starts a new receiving sequence by queuing a command that checks the

   283

   slave's mailbox for a new command.

   284

*/

   285

   286

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

   287

{

   288

    ec_slave_mbox_prepare_check(eoe->slave);

   289

    ec_master_queue_command(eoe->slave->master, &eoe->slave->mbox_command);

   290

    eoe->state = ec_eoe_state_rx_check;

   291

}

   292

   293

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

   294

   295

/**

   296

   State: RX_CHECK.

   297

   Processes the checking command sent in RX_START and issues a receive

   298

   command, if new data is available.

   299

*/

   300

   301

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

   302

{

   303

    if (eoe->slave->mbox_command.state != EC_CMD_RECEIVED) {

   304

        eoe->stats.rx_errors++;

   305

        eoe->state = ec_eoe_state_tx_start;

   306

        return;

   307

    }

   308

   309

    if (!ec_slave_mbox_check(eoe->slave)) {

   310

        eoe->state = ec_eoe_state_tx_start;

   311

        return;

   312

    }

   313

   314

    ec_slave_mbox_prepare_fetch(eoe->slave);

   315

    ec_master_queue_command(eoe->slave->master, &eoe->slave->mbox_command);

   316

    eoe->state = ec_eoe_state_rx_fetch;

   317

}

   318

   319

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

   320

   321

/**

   322

   State: RX_FETCH.

   323

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

   324

   EoE command.

   325

*/

   326

   327

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

   328

{

   329

    size_t rec_size, data_size;

   330

    uint8_t *data, frame_type, last_fragment, time_appended;

   331

    uint8_t frame_number, fragment_offset, fragment_number;

   332

    off_t offset;

   333

   334

    if (eoe->slave->mbox_command.state != EC_CMD_RECEIVED) {

   335

        eoe->stats.rx_errors++;

   336

        eoe->state = ec_eoe_state_tx_start;

   337

        return;

   338

    }

   339

   340

    if (!(data = ec_slave_mbox_fetch(eoe->slave, 0x02, &rec_size))) {

   341

        eoe->stats.rx_errors++;

   342

        eoe->state = ec_eoe_state_tx_start;

   343

        return;

   344

    }

   345

   346

    frame_type = EC_READ_U16(data) & 0x000F;

   347

   348

    if (frame_type == 0x00) { // EoE Fragment Request

   349

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

   350

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

   351

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

   352

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

   353

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

   354

   355

#if EOE_DEBUG_LEVEL > 0

   356

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

   357

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

   358

               frame_number,

   359

               last_fragment ? ", last fragment" : "",

   360

               time_appended ? ", + timestamp" : "",

   361

               time_appended ? rec_size - 8 : rec_size - 4);

   362

#endif

   363

   364

#if EOE_DEBUG_LEVEL > 1

   365

        EC_DBG("");

   366

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

   367

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

   368

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

   369

                printk("\n");

   370

                EC_DBG("");

   371

            }

   372

        }

   373

        printk("\n");

   374

#endif

   375

   376

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

   377

   378

        if (!fragment_number) {

   379

            if (eoe->rx_skb) {

   380

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

   381

                dev_kfree_skb(eoe->rx_skb);

   382

            }

   383

   384

            // new socket buffer

   385

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

   386

                if (printk_ratelimit())

   387

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

   388

                eoe->stats.rx_dropped++;

   389

                eoe->state = ec_eoe_state_tx_start;

   390

                return;

   391

            }

   392

   393

            eoe->rx_skb_offset = 0;

   394

            eoe->rx_skb_size = fragment_offset * 32;

   395

            eoe->rx_expected_fragment = 0;

   396

        }

   397

        else {

   398

            if (!eoe->rx_skb) {

   399

                eoe->stats.rx_dropped++;

   400

                eoe->state = ec_eoe_state_tx_start;

   401

                return;

   402

            }

   403

   404

            offset = fragment_offset * 32;

   405

            if (offset != eoe->rx_skb_offset ||

   406

                offset + data_size > eoe->rx_skb_size ||

   407

                fragment_number != eoe->rx_expected_fragment) {

   408

                eoe->stats.rx_errors++;

   409

                eoe->state = ec_eoe_state_tx_start;

   410

                dev_kfree_skb(eoe->rx_skb);

   411

                eoe->rx_skb = NULL;

   412

                return;

   413

            }

   414

        }

   415

   416

        // copy fragment into socket buffer

   417

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

   418

        eoe->rx_skb_offset += data_size;

   419

   420

        if (last_fragment) {

   421

            // update statistics

   422

            eoe->stats.rx_packets++;

   423

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

   424

   425

#if EOE_DEBUG_LEVEL > 0

   426

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

   427

                   eoe->rx_skb->len);

   428

#endif

   429

   430

            // pass socket buffer to network stack

   431

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

   432

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

   433

            eoe->rx_skb->ip_summed = CHECKSUM_UNNECESSARY;

   434

            if (netif_rx(eoe->rx_skb)) {

   435

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

   436

            }

   437

            eoe->rx_skb = NULL;

   438

   439

            eoe->state = ec_eoe_state_tx_start;

   440

        }

   441

        else {

   442

            eoe->rx_expected_fragment++;

   443

#if EOE_DEBUG_LEVEL > 0

   444

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

   445

                   eoe->rx_expected_fragment);

   446

#endif

   447

            eoe->state = ec_eoe_state_rx_start;

   448

        }

   449

    }

   450

    else {

   451

#if EOE_DEBUG_LEVEL > 0

   452

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

   453

#endif

   454

        eoe->stats.rx_dropped++;

   455

        eoe->state = ec_eoe_state_tx_start;

   456

    }

   457

}

   458

   459

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

   460

   461

/**

   462

   State: TX START.

   463

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

   464

   sequence is started instead.

   465

*/

   466

   467

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

   468

{

   469

#if EOE_DEBUG_LEVEL > 0

   470

    unsigned int wakeup;

   471

#endif

   472

   473

    spin_lock_bh(&eoe->tx_queue_lock);

   474

   475

    if (!eoe->tx_queued_frames || list_empty(&eoe->tx_queue)) {

   476

        spin_unlock_bh(&eoe->tx_queue_lock);

   477

        // no data available.

   478

        // start a new receive immediately.

   479

        ec_eoe_state_rx_start(eoe);

   480

        return;

   481

    }

   482

   483

    // take the first frame out of the queue

   484

    eoe->tx_frame = list_entry(eoe->tx_queue.next, ec_eoe_frame_t, queue);

   485

    list_del(&eoe->tx_frame->queue);

   486

    if (!eoe->tx_queue_active &&

   487

        eoe->tx_queued_frames == EC_EOE_TX_QUEUE_SIZE / 2) {

   488

        netif_wake_queue(eoe->dev);

   489

        eoe->tx_queue_active = 1;

   490

#if EOE_DEBUG_LEVEL > 0

   491

        wakeup = 1;

   492

#endif

   493

    }

   494