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 "globals.h"

    45

#include "master.h"

    46

#include "slave.h"

    47

#include "mailbox.h"

    48

#include "ethernet.h"

    49

    50

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

    51

    52

/**

    53

 * Defines the debug level of EoE processing.

    54

 *

    55

 * 0 = No debug messages.

    56

 * 1 = Output actions.

    57

 * 2 = Output actions and frame data.

    58

 */

    59

    60

#define EOE_DEBUG_LEVEL 0

    61

    62

/** size of the EoE tx queue */

    63

#define EC_EOE_TX_QUEUE_SIZE 100

    64

    65

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

    66

    67

void ec_eoe_flush(ec_eoe_t *);

    68

    69

// state functions

    70

void ec_eoe_state_rx_start(ec_eoe_t *);

    71

void ec_eoe_state_rx_check(ec_eoe_t *);

    72

void ec_eoe_state_rx_fetch(ec_eoe_t *);

    73

void ec_eoe_state_tx_start(ec_eoe_t *);

    74

void ec_eoe_state_tx_sent(ec_eoe_t *);

    75

    76

// net_device functions

    77

int ec_eoedev_open(struct net_device *);

    78

int ec_eoedev_stop(struct net_device *);

    79

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

    80

struct net_device_stats *ec_eoedev_stats(struct net_device *);

    81

    82

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

    83

    84

/**

    85

 * EoE constructor.

    86

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

    87

 */

    88

    89

int ec_eoe_init(

    90

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

    91

        ec_slave_t *slave /**< EtherCAT slave */

    92

        )

    93

{

    94

    ec_eoe_t **priv;

    96

    char name[EC_DATAGRAM_NAME_SIZE];

    97

    98

    eoe->slave = slave;

    99

   100

    ec_datagram_init(&eoe->datagram);

   101

    eoe->queue_datagram = 0;

   102

    eoe->state = ec_eoe_state_rx_start;

   103

    eoe->opened = 0;

   104

    eoe->rx_skb = NULL;

   105

    eoe->rx_expected_fragment = 0;

   106

    INIT_LIST_HEAD(&eoe->tx_queue);

   107

    eoe->tx_frame = NULL;

   108

    eoe->tx_queue_active = 0;

   109

    eoe->tx_queued_frames = 0;

   110

    eoe->tx_queue_lock = SPIN_LOCK_UNLOCKED;

   111

    eoe->tx_frame_number = 0xFF;

   112

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

   113

   114

    eoe->rx_counter = 0;

   115

    eoe->tx_counter = 0;

   116

    eoe->rx_rate = 0;

   117

    eoe->tx_rate = 0;

   118

    eoe->rate_jiffies = 0;

   119

   120

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

   121

     * like hyphens etc. in interface names. */

   122

    if (slave->sii.alias) {

   123

        snprintf(name, EC_DATAGRAM_NAME_SIZE,

   124

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

   125

    } else {

   126

        snprintf(name, EC_DATAGRAM_NAME_SIZE,

   127

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

   128

    }

   129

   130

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

   131

   132

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

   133

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

   135

        goto out_return;

   136

    }

   137

   138

    // initialize net_device

   139

    eoe->dev->open = ec_eoedev_open;

   140

    eoe->dev->stop = ec_eoedev_stop;

   141

    eoe->dev->hard_start_xmit = ec_eoedev_tx;

   142

    eoe->dev->get_stats = ec_eoedev_stats;

   143

   144

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

   145

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

   146

   147

    // initialize private data

   148

    priv = netdev_priv(eoe->dev);

   149

    *priv = eoe;

   150

   151

    // Usually setting the MTU appropriately makes the upper layers

   152

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

   153

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

   154

    // is done "manually".

   155

#if 0

   156

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

   157

#endif

   158

   159

    // connect the net_device to the kernel

   163

        goto out_free;

   164

    }

   165

   166

    // make the last address octet unique

   167

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

   168

    return 0;

   169

   170

 out_free:

   171

    free_netdev(eoe->dev);

   172

    eoe->dev = NULL;

   173

 out_return:

   175

}

   176

   177

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

   178

   179

/**

   180

   EoE destructor.

   181

   Unregisteres the net_device and frees allocated memory.

   182

*/

   183

   184

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

   185

{

   186

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

   187

    free_netdev(eoe->dev);

   188

   189

    // empty transmit queue

   190

    ec_eoe_flush(eoe);

   191

   192

    if (eoe->tx_frame) {

   193

        dev_kfree_skb(eoe->tx_frame->skb);

   194

        kfree(eoe->tx_frame);

   195

    }

   196

   197

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

   198

   199

    ec_datagram_clear(&eoe->datagram);

   200

}

   201

   202

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

   203

   204

/**

   205

   Empties the transmit queue.

   206

*/

   207

   208

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

   209

{

   210

    ec_eoe_frame_t *frame, *next;

   211

   212

    spin_lock_bh(&eoe->tx_queue_lock);

   213

   214

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

   215

        list_del(&frame->queue);

   216

        dev_kfree_skb(frame->skb);

   217

        kfree(frame);

   218

    }

   219

    eoe->tx_queued_frames = 0;

   220

   221

    spin_unlock_bh(&eoe->tx_queue_lock);

   222

}

   223

   224

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

   225

   226

/**

   227

   Sends a frame or the next fragment.

   228

*/

   229

   230

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

   231

{

   232

    size_t remaining_size, current_size, complete_offset;

   233

    unsigned int last_fragment;

   234

    uint8_t *data;

   235

#if EOE_DEBUG_LEVEL > 1

   236

    unsigned int i;

   237

#endif

   238

   239

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

   240

   241

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

   242

        current_size = remaining_size;

   243

        last_fragment = 1;

   244

    }

   245

    else {

   246

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

   247

        last_fragment = 0;

   248

    }

   249

   250

    if (eoe->tx_fragment_number) {

   251

        complete_offset = eoe->tx_offset / 32;

   252

    }

   253

    else {

   254

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

   255

        complete_offset = remaining_size / 32 + 1;

   256

    }

   257

   258

#if EOE_DEBUG_LEVEL > 0

   259

    EC_INFO("EoE %s TX sending fragment %u%s with %u octets (%u)."

   260

           " %u frames queued.\n", eoe->dev->name, eoe->tx_fragment_number,

   261

           last_fragment ? "" : "+", current_size, complete_offset,

   262

           eoe->tx_queued_frames);

   263

#endif

   264

   265

#if EOE_DEBUG_LEVEL > 1

   266

    EC_INFO("");

   267

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

   268

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

   269

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

   270

            printk("\n");

   271

            EC_INFO("");

   272

        }

   273

    }

   274

    printk("\n");

   275

#endif

   276

   281

   282

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

   283

    EC_WRITE_U8 (data + 1, last_fragment);

   284

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

   285

                            (complete_offset & 0x3F) << 6 |

   286

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

   287

   288

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

   289

    eoe->queue_datagram = 1;

   290

   291

    eoe->tx_offset += current_size;

   292

    eoe->tx_fragment_number++;

   293

    return 0;

   294

}

   295

   296

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

   297

   298

/**

   299

   Runs the EoE state machine.

   300

*/

   301

   302

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

   303

{

   304

    if (!eoe->opened) return;

   305

   306

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

   307

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

   308

        return;

   309

   310

    // call state function

   311

    eoe->state(eoe);

   312

   313

    // update statistics

   314

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

   315

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

   316

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

   317

        eoe->rx_counter = 0;

   318

        eoe->tx_counter = 0;

   319

        eoe->rate_jiffies = jiffies;

   320

    }

   321

   322

    ec_datagram_output_stats(&eoe->datagram);

   323

}

   324

   325

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

   326

   327

/**

   328

 * Queues the datagram, if necessary.

   329

 */

   330

   331

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

   332

{

   333

   if (eoe->queue_datagram) {

   334

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

   335

       eoe->queue_datagram = 0;

   336

   }

   337

}

   338

   339

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

   340

   341

/**

   342

   Returns the state of the device.

   343

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

   344

*/

   345

   346

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

   347

{

   348

    return eoe->opened;

   349

}

   350

   351

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

   352

 *  STATE PROCESSING FUNCTIONS

   353

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

   354

   355

/**

   356

   State: RX_START.

   357

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

   358

   slave's mailbox for a new EoE datagram.

   359

*/

   360

   361

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

   362

{

   363

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

   364

        return;

   365

   366

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

   367

    eoe->queue_datagram = 1;

   368

    eoe->state = ec_eoe_state_rx_check;

   369

}

   370

   371

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

   372

   373

/**

   374

   State: RX_CHECK.

   375

   Processes the checking datagram sent in RX_START and issues a receive

   376

   datagram, if new data is available.

   377

*/

   378

   379

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

   380

{

   381

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

   382

        eoe->stats.rx_errors++;

   383

        eoe->state = ec_eoe_state_tx_start;

   384

        return;

   385

    }

   386

   387

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

   388

        eoe->state = ec_eoe_state_tx_start;

   389

        return;

   390

    }

   391

   392

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

   393

    eoe->queue_datagram = 1;

   394

    eoe->state = ec_eoe_state_rx_fetch;

   395

}

   396

   397

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

   398

   399

/**

   400

   State: RX_FETCH.

   401

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

   402

   EoE datagram.

   403

*/

   404

   405

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

   406

{

   407

    size_t rec_size, data_size;

   408

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

   409

    uint8_t frame_number, fragment_offset, fragment_number;

   410

    off_t offset;

   411

#if EOE_DEBUG_LEVEL > 1

   412

    unsigned int i;

   413

#endif

   414

   415

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

   416

        eoe->stats.rx_errors++;

   417

        eoe->state = ec_eoe_state_tx_start;

   418

        return;

   419

    }

   420

   424

        eoe->stats.rx_errors++;

   425

        eoe->state = ec_eoe_state_tx_start;

   426

        return;

   427

    }

   428

   429

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

   430

        eoe->stats.rx_errors++;

   431

        eoe->state = ec_eoe_state_tx_start;

   432

        return;

   433

    }

   434

   435

    frame_type = EC_READ_U16(data) & 0x000F;

   436

   437

    if (frame_type != 0x00) {

   438

#if EOE_DEBUG_LEVEL > 0

   439

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

   440

#endif

   441

        eoe->stats.rx_dropped++;

   442

        eoe->state = ec_eoe_state_tx_start;

   443

        return;

   444

    }

   445

   446

    // EoE Fragment Request received

   447

   448

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

   449

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

   450

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

   451

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

   452

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

   453

   454

#if EOE_DEBUG_LEVEL > 0

   455

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

   456

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

   457

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

   458

           time_appended ? ", + timestamp" : "",

   459

           time_appended ? rec_size - 8 : rec_size - 4);

   460

#endif

   461

   462

#if EOE_DEBUG_LEVEL > 1

   463

    EC_INFO("");

   464

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

   465

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

   466

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

   467

            printk("\n");

   468

            EC_INFO("");

   469

        }

   470

    }

   471

    printk("\n");

   472

#endif

   473

   474

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

   475

   476

    if (!fragment_number) {

   477

        if (eoe->rx_skb) {

   478

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

   479

            dev_kfree_skb(eoe->rx_skb);

   480

        }

   481

   482

        // new socket buffer

   483

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

   484

            if (printk_ratelimit())

   485

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

   486

            eoe->stats.rx_dropped++;

   487

            eoe->state = ec_eoe_state_tx_start;