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

   Returns the state of the device.

   267

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

   268

*/

   269

   270

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

   271

{

   272

    return eoe->opened;

   273

}

   274

   275

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

   276

   277

/**

   278

   Prints EoE object information.

   279

*/

   280

   281

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

   282

{

   283

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

   284

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

   285

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

   286

}

   287

   288

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

   289

 *  STATE PROCESSING FUNCTIONS

   290

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

   291

   292

/**

   293

   State: RX_START.

   294

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

   295

   slave's mailbox for a new command.

   296

*/

   297

   298

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

   299

{

   300

    ec_slave_mbox_prepare_check(eoe->slave);

   301

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

   302

    eoe->state = ec_eoe_state_rx_check;

   303

}

   304

   305

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

   306

   307

/**

   308

   State: RX_CHECK.

   309

   Processes the checking command sent in RX_START and issues a receive

   310

   command, if new data is available.

   311

*/

   312

   313

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

   314

{

   315

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

   316

        eoe->stats.rx_errors++;

   317

        eoe->state = ec_eoe_state_tx_start;

   318

        return;

   319

    }

   320

   321

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

   322

        eoe->state = ec_eoe_state_tx_start;

   323

        return;

   324

    }

   325

   326

    ec_slave_mbox_prepare_fetch(eoe->slave);

   327

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

   328

    eoe->state = ec_eoe_state_rx_fetch;

   329

}

   330

   331

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

   332

   333

/**

   334

   State: RX_FETCH.

   335

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

   336

   EoE command.

   337

*/

   338

   339

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

   340

{

   341

    size_t rec_size, data_size;

   342

    uint8_t *data, frame_type, last_fragment, time_appended;

   343

    uint8_t frame_number, fragment_offset, fragment_number;

   344

    off_t offset;

   345

   346

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

   347

        eoe->stats.rx_errors++;

   348

        eoe->state = ec_eoe_state_tx_start;

   349

        return;

   350

    }

   351

   352

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

   353

        eoe->stats.rx_errors++;

   354

        eoe->state = ec_eoe_state_tx_start;

   355

        return;

   356

    }

   357

   358

    frame_type = EC_READ_U16(data) & 0x000F;

   359

   360

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

   361

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

   362

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

   363

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

   364

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

   365

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

   366

   367

#if EOE_DEBUG_LEVEL > 0

   368

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

   369

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

   370

               frame_number,

   371

               last_fragment ? ", last fragment" : "",

   372

               time_appended ? ", + timestamp" : "",

   373

               time_appended ? rec_size - 8 : rec_size - 4);

   374

#endif

   375

   376

#if EOE_DEBUG_LEVEL > 1

   377

        EC_DBG("");

   378

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

   379

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

   380

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

   381

                printk("\n");

   382

                EC_DBG("");

   383

            }

   384

        }

   385

        printk("\n");

   386

#endif

   387

   388

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

   389

   390

        if (!fragment_number) {

   391

            if (eoe->rx_skb) {

   392

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

   393

                dev_kfree_skb(eoe->rx_skb);

   394

            }

   395

   396

            // new socket buffer

   397

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

   398

                if (printk_ratelimit())

   399

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

   400

                eoe->stats.rx_dropped++;

   401

                eoe->state = ec_eoe_state_tx_start;

   402

                return;

   403

            }

   404

   405

            eoe->rx_skb_offset = 0;

   406

            eoe->rx_skb_size = fragment_offset * 32;

   407

            eoe->rx_expected_fragment = 0;

   408

        }

   409

        else {

   410

            if (!eoe->rx_skb) {

   411

                eoe->stats.rx_dropped++;

   412

                eoe->state = ec_eoe_state_tx_start;

   413

                return;

   414

            }

   415

   416

            offset = fragment_offset * 32;

   417

            if (offset != eoe->rx_skb_offset ||

   418

                offset + data_size > eoe->rx_skb_size ||

   419

                fragment_number != eoe->rx_expected_fragment) {

   420

                eoe->stats.rx_errors++;

   421

                eoe->state = ec_eoe_state_tx_start;

   422

                dev_kfree_skb(eoe->rx_skb);

   423

                eoe->rx_skb = NULL;

   424

                return;

   425

            }

   426

        }

   427

   428

        // copy fragment into socket buffer

   429

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

   430

        eoe->rx_skb_offset += data_size;

   431

   432

        if (last_fragment) {

   433

            // update statistics

   434

            eoe->stats.rx_packets++;

   435

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

   436

   437

#if EOE_DEBUG_LEVEL > 0

   438

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

   439

                   eoe->rx_skb->len);

   440

#endif

   441

   442

            // pass socket buffer to network stack

   443

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

   444

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

   445

            eoe->rx_skb->ip_summed = CHECKSUM_UNNECESSARY;

   446

            if (netif_rx(eoe->rx_skb)) {

   447

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

   448

            }

   449

            eoe->rx_skb = NULL;

   450

   451

            eoe->state = ec_eoe_state_tx_start;

   452

        }

   453

        else {

   454

            eoe->rx_expected_fragment++;

   455

#if EOE_DEBUG_LEVEL > 0

   456

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

   457

                   eoe->rx_expected_fragment);

   458

#endif

   459

            eoe->state = ec_eoe_state_rx_start;

   460

        }

   461

    }

   462

    else {

   463

#if EOE_DEBUG_LEVEL > 0

   464

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

   465

#endif

   466

        eoe->stats.rx_dropped++;

   467

        eoe->state = ec_eoe_state_tx_start;

   468

    }

   469

}

   470

   471

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

   472

   473

/**

   474

   State: TX START.

   475

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

   476

   sequence is started instead.

   477

*/

   478

   479

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

   480

{

   481

#if EOE_DEBUG_LEVEL > 0

   482

    unsigned int wakeup;

   483

#endif

   484

   485

    spin_lock_bh(&eoe->tx_queue_lock);

   486

   487

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

   488

        spin_unlock_bh(&eoe->tx_queue_lock);

   489

        // no data available.

   490

        // start a new receive immediately.

   491

        ec_eoe_state_rx_start(eoe);

   492

        return;

   493

    }