1

/**

     2

    Network Driver for Beckhoff CCAT communication controller

     3

    Copyright (C) 2014  Beckhoff Automation GmbH

     4

    Author: Patrick Bruenn <p.bruenn@beckhoff.com>

     5

     6

    This program is free software; you can redistribute it and/or modify

     7

    it under the terms of the GNU General Public License as published by

     8

    the Free Software Foundation; either version 2 of the License, or

     9

    (at your option) any later version.

    10

    11

    This program is distributed in the hope that it will be useful,

    12

    but WITHOUT ANY WARRANTY; without even the implied warranty of

    13

    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    14

    GNU General Public License for more details.

    15

    16

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

    17

    with this program; if not, write to the Free Software Foundation, Inc.,

    18

    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

    19

*/

    20

    21

#include <linux/etherdevice.h>

    22

#include <linux/kernel.h>

    23

#include <linux/module.h>

    24

#include <linux/netdevice.h>

    25

    26

#include "module.h"

    27

#include "netdev.h"

    28

    29

/**

    30

 * EtherCAT frame to enable forwarding on EtherCAT Terminals

    31

 */

    32

static const u8 frameForwardEthernetFrames[] = {

    33

	0x01, 0x01, 0x05, 0x01, 0x00, 0x00,

    34

	0x00, 0x1b, 0x21, 0x36, 0x1b, 0xce,

    35

	0x88, 0xa4, 0x0e, 0x10,

    36

	0x08,

    37

	0x00,

    38

	0x00, 0x00,

    39

	0x00, 0x01,

    40

	0x02, 0x00,

    41

	0x00, 0x00,

    42

	0x00, 0x00,

    43

	0x00, 0x00

    44

};

    45

    46

#define FIFO_LENGTH 64

    47

#define POLL_TIME ktime_set(0, 100 * NSEC_PER_USEC)

    48

    49

/**

    50

 * Helper to check if frame in tx dma memory was already marked as sent by CCAT

    51

 */

    52

static inline bool ccat_eth_frame_sent(const struct ccat_eth_frame *const frame)

    53

{

    54

	return le32_to_cpu(frame->tx_flags) & CCAT_FRAME_SENT;

    55

}

    56

    57

/**

    58

 * Helper to check if frame in tx dma memory was already marked as sent by CCAT

    59

 */

    60

static inline bool ccat_eth_frame_received(const struct ccat_eth_frame *const

    61

					   frame)

    62

{

    63

	return le32_to_cpu(frame->rx_flags) & CCAT_FRAME_RECEIVED;

    64

}

    65

    66

static void ecdev_kfree_skb_any(struct sk_buff *skb)

    67

{

    68

	/* never release a skb in EtherCAT mode */

    69

}

    70

    71

static bool ecdev_carrier_ok(const struct net_device *const netdev)

    72

{

    73

	struct ccat_eth_priv *const priv = netdev_priv(netdev);

    74

	return ecdev_get_link(priv->ecdev);

    75

}

    76

    77

static void ecdev_carrier_on(struct net_device *const netdev)

    78

{

    79

	struct ccat_eth_priv *const priv = netdev_priv(netdev);

    80

	ecdev_set_link(priv->ecdev, 1);

    81

}

    82

    83

static void ecdev_carrier_off(struct net_device *const netdev)

    84

{

    85

	struct ccat_eth_priv *const priv = netdev_priv(netdev);

    86

	ecdev_set_link(priv->ecdev, 0);

    87

}

    88

    89

static void ecdev_nop(struct net_device *const netdev)

    90

{

    91

	/* dummy called if nothing has to be done in EtherCAT operation mode */

    92

}

    93

    94

static void unregister_ecdev(struct net_device *const netdev)

    95

{

    96

	struct ccat_eth_priv *const priv = netdev_priv(netdev);

    97

	ecdev_close(priv->ecdev);

    98

	ecdev_withdraw(priv->ecdev);

    99

}

   100

   101

static void ccat_eth_fifo_inc(struct ccat_eth_dma_fifo *fifo)

   102

{

   103

	if (++fifo->next >= fifo->end)

   104

		fifo->next = fifo->dma.virt;

   105

}

   106

   107

typedef void (*fifo_add_function) (struct ccat_eth_dma_fifo *,

   108

				   struct ccat_eth_frame *);

   109

   110

static void ccat_eth_rx_fifo_add(struct ccat_eth_dma_fifo *fifo,

   111

				 struct ccat_eth_frame *frame)

   112

{

   113

	const size_t offset = ((void *)(frame) - fifo->dma.virt);

   114

	const u32 addr_and_length = (1 << 31) | offset;

   115

   116

	frame->rx_flags = cpu_to_le32(0);

   117

	iowrite32(addr_and_length, fifo->reg);

   118

}

   119

   120

static void ccat_eth_tx_fifo_add_free(struct ccat_eth_dma_fifo *fifo,

   121

				      struct ccat_eth_frame *frame)

   122

{

   123

	/* mark frame as ready to use for tx */

   124

	frame->tx_flags = cpu_to_le32(CCAT_FRAME_SENT);

   125

}

   126

   127

static void ccat_eth_dma_fifo_reset(struct ccat_eth_dma_fifo *fifo)

   128

{

   129

	/* reset hw fifo */

   130

	iowrite32(0, fifo->reg + 0x8);

   131

	wmb();

   132

   133

	if (fifo->add) {

   134

		fifo->next = fifo->dma.virt;

   135

		do {

   136

			fifo->add(fifo, fifo->next);

   137

			ccat_eth_fifo_inc(fifo);

   138

		} while (fifo->next != fifo->dma.virt);

   139

	}

   140

}

   141

   142

static int ccat_eth_dma_fifo_init(struct ccat_eth_dma_fifo *fifo,

   143

				  void __iomem * const fifo_reg,

   144

				  fifo_add_function add, size_t channel,

   145

				  struct ccat_eth_priv *const priv)

   146

{

   147

	if (0 !=

   148

	    ccat_dma_init(&fifo->dma, channel, priv->ccatdev->bar[2].ioaddr,

   149

			  &priv->ccatdev->pdev->dev)) {

   150

		pr_info("init DMA%llu memory failed.\n", (u64) channel);

   151

		return -1;

   152

	}

   153

	fifo->add = add;

   154

	fifo->end = ((struct ccat_eth_frame *)fifo->dma.virt) + FIFO_LENGTH;

   155

	fifo->reg = fifo_reg;

   156

	return 0;

   157

}

   158

   159

/**

   160

 * Stop both (Rx/Tx) DMA fifo's and free related management structures

   161

 */

   162

static void ccat_eth_priv_free_dma(struct ccat_eth_priv *priv)

   163

{

   164

	/* reset hw fifo's */

   165

	iowrite32(0, priv->rx_fifo.reg + 0x8);

   166

	iowrite32(0, priv->tx_fifo.reg + 0x8);

   167

	wmb();

   168

   169

	/* release dma */

   170

	ccat_dma_free(&priv->rx_fifo.dma);

   171

	ccat_dma_free(&priv->tx_fifo.dma);

   172

}

   173

   174

/**

   175

 * Initalizes both (Rx/Tx) DMA fifo's and related management structures

   176

 */

   177

static int ccat_eth_priv_init_dma(struct ccat_eth_priv *priv)

   178

{

   179

	if (ccat_eth_dma_fifo_init

   180

	    (&priv->rx_fifo, priv->reg.rx_fifo, ccat_eth_rx_fifo_add,

   181

	     priv->info.rx_dma_chan, priv)) {

   182

		pr_warn("init Rx DMA fifo failed.\n");

   183

		return -1;

   184

	}

   185

   186

	if (ccat_eth_dma_fifo_init

   187

	    (&priv->tx_fifo, priv->reg.tx_fifo, ccat_eth_tx_fifo_add_free,

   188

	     priv->info.tx_dma_chan, priv)) {

   189

		pr_warn("init Tx DMA fifo failed.\n");

   190

		ccat_dma_free(&priv->rx_fifo.dma);

   191

		return -1;

   192

	}

   193

   194

	/* disable MAC filter */

   195

	iowrite8(0, priv->reg.mii + 0x8 + 6);

   196

	wmb();

   197

	return 0;

   198

}

   199

   200

/**

   201

 * Initializes the CCat... members of the ccat_eth_priv structure.

   202

 * Call this function only if info and ioaddr are already initialized!

   203

 */

   204

static void ccat_eth_priv_init_mappings(struct ccat_eth_priv *priv)

   205

{

   206

	struct ccat_mac_infoblock offsets;

   207

	void __iomem *const func_base =

   208

	    priv->ccatdev->bar[0].ioaddr + priv->info.addr;

   209

   210

	memcpy_fromio(&offsets, func_base, sizeof(offsets));

   211

	priv->reg.mii = func_base + offsets.mii;

   212

	priv->reg.tx_fifo = func_base + offsets.tx_fifo;

   213

	priv->reg.rx_fifo = func_base + offsets.tx_fifo + 0x10;

   214

	priv->reg.mac = func_base + offsets.mac;

   215

	priv->reg.rx_mem = func_base + offsets.rx_mem;

   216

	priv->reg.tx_mem = func_base + offsets.tx_mem;

   217

	priv->reg.misc = func_base + offsets.misc;

   218

}

   219

   220

static netdev_tx_t ccat_eth_start_xmit(struct sk_buff *skb,

   221

				       struct net_device *dev)

   222

{

   223

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   224

	struct ccat_eth_dma_fifo *const fifo = &priv->tx_fifo;

   225

	u32 addr_and_length;

   226

   227

	if (skb_is_nonlinear(skb)) {

   228

		pr_warn("Non linear skb not supported -> drop frame.\n");

   229

		atomic64_inc(&priv->tx_dropped);

   230

		priv->kfree_skb_any(skb);

   231

		return NETDEV_TX_OK;

   232

	}

   233

   234

	if (skb->len > sizeof(fifo->next->data)) {

   235

		pr_warn("skb.len %llu exceeds dma buffer %llu -> drop frame.\n",

   236

			(u64) skb->len, (u64) sizeof(fifo->next->data));

   237

		atomic64_inc(&priv->tx_dropped);

   238

		priv->kfree_skb_any(skb);

   239

		return NETDEV_TX_OK;

   240

	}

   241

   242

	if (!ccat_eth_frame_sent(fifo->next)) {

   243

		netdev_err(dev, "BUG! Tx Ring full when queue awake!\n");

   244

		priv->stop_queue(priv->netdev);

   245

		return NETDEV_TX_BUSY;

   246

	}

   247

   248

	/* prepare frame in DMA memory */

   249

	fifo->next->tx_flags = cpu_to_le32(0);

   250

	fifo->next->length = cpu_to_le16(skb->len);

   251

	memcpy(fifo->next->data, skb->data, skb->len);

   252

   253

	/* Queue frame into CCAT TX-FIFO, CCAT ignores the first 8 bytes of the tx descriptor */

   254

	addr_and_length = offsetof(struct ccat_eth_frame, length);

   255

	addr_and_length += ((void *)fifo->next - fifo->dma.virt);

   256

	addr_and_length += ((skb->len + CCAT_ETH_FRAME_HEAD_LEN) / 8) << 24;

   257

	iowrite32(addr_and_length, priv->reg.tx_fifo);

   258

   259

	/* update stats */

   260

	atomic64_add(skb->len, &priv->tx_bytes);

   261

   262

	priv->kfree_skb_any(skb);

   263

   264

	ccat_eth_fifo_inc(fifo);

   265

	/* stop queue if tx ring is full */

   266

	if (!ccat_eth_frame_sent(fifo->next)) {

   267

		priv->stop_queue(priv->netdev);

   268

	}

   269

	return NETDEV_TX_OK;

   270

}

   271

   272

/**

   273

 * Function to transmit a raw buffer to the network (f.e. frameForwardEthernetFrames)

   274

 * @dev a valid net_device

   275

 * @data pointer to your raw buffer

   276

 * @len number of bytes in the raw buffer to transmit

   277

 */

   278

static void ccat_eth_xmit_raw(struct net_device *dev, const char *const data,

   279

			      size_t len)

   280

{

   281

	struct sk_buff *skb = dev_alloc_skb(len);

   282

   283

	skb->dev = dev;

   284

	skb_copy_to_linear_data(skb, data, len);

   285

	skb_put(skb, len);

   286

	ccat_eth_start_xmit(skb, dev);

   287

}

   288

   289

static void ccat_eth_receive(struct net_device *const dev,

   290

			     const void *const data, const size_t len)

   291

{

   292

	struct sk_buff *const skb = dev_alloc_skb(len + NET_IP_ALIGN);

   293

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   294

   295

	if (!skb) {

   296

		pr_info("%s() out of memory :-(\n", __FUNCTION__);

   297

		atomic64_inc(&priv->rx_dropped);

   298

		return;

   299

	}

   300

	skb->dev = dev;

   301

	skb_reserve(skb, NET_IP_ALIGN);

   302

	skb_copy_to_linear_data(skb, data, len);

   303

	skb_put(skb, len);

   304

	skb->protocol = eth_type_trans(skb, dev);

   305

	skb->ip_summed = CHECKSUM_UNNECESSARY;

   306

	atomic64_add(len, &priv->rx_bytes);

   307

	netif_rx(skb);

   308

}

   309

   310

static void ccat_eth_link_down(struct net_device *const dev)

   311

{

   312

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   313

   314

	priv->stop_queue(dev);

   315

	priv->carrier_off(dev);

   316

	netdev_info(dev, "NIC Link is Down\n");

   317

}

   318

   319

static void ccat_eth_link_up(struct net_device *const dev)

   320

{

   321

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   322

   323

	netdev_info(dev, "NIC Link is Up\n");

   324

	/* TODO netdev_info(dev, "NIC Link is Up %u Mbps %s Duplex\n",

   325

	   speed == SPEED_100 ? 100 : 10,

   326

	   cmd.duplex == DUPLEX_FULL ? "Full" : "Half"); */

   327

   328

	ccat_eth_dma_fifo_reset(&priv->rx_fifo);

   329

	ccat_eth_dma_fifo_reset(&priv->tx_fifo);

   330

   331

	/* TODO reset CCAT MAC register */

   332

   333

	ccat_eth_xmit_raw(dev, frameForwardEthernetFrames,

   334

			  sizeof(frameForwardEthernetFrames));

   335

	priv->carrier_on(dev);

   336

	priv->start_queue(dev);

   337

}

   338

   339

/**

   340

 * Read link state from CCAT hardware

   341

 * @return 1 if link is up, 0 if not

   342

 */

   343

inline static size_t ccat_eth_priv_read_link_state(const struct ccat_eth_priv

   344

						   *const priv)

   345

{

   346

	return (1 << 24) == (ioread32(priv->reg.mii + 0x8 + 4) & (1 << 24));

   347

}

   348

   349

/**

   350

 * Poll for link state changes

   351

 */

   352

static void poll_link(struct ccat_eth_priv *const priv)

   353

{

   354

	const size_t link = ccat_eth_priv_read_link_state(priv);

   355

   356

	if (link != priv->carrier_ok(priv->netdev)) {

   357

		if (link)

   358

			ccat_eth_link_up(priv->netdev);

   359

		else

   360

			ccat_eth_link_down(priv->netdev);

   361

	}

   362

}

   363

   364

/**

   365

 * Poll for available rx dma descriptors in ethernet operating mode

   366

 */

   367

static void poll_rx(struct ccat_eth_priv *const priv)

   368

{

   369

	static const size_t overhead = CCAT_ETH_FRAME_HEAD_LEN - 4;

   370

	struct ccat_eth_dma_fifo *const fifo = &priv->rx_fifo;

   371

   372

	/* TODO omit possible deadlock in situations with heavy traffic */

   373

	while (ccat_eth_frame_received(fifo->next)) {

   374

		const size_t len = le16_to_cpu(fifo->next->length) - overhead;

   375

		if (priv->ecdev) {

   376

			ecdev_receive(priv->ecdev, fifo->next->data, len);

   377

		} else {

   378

			ccat_eth_receive(priv->netdev, fifo->next->data, len);

   379

		}

   380

		ccat_eth_rx_fifo_add(fifo, fifo->next);

   381

		ccat_eth_fifo_inc(fifo);

   382

	}

   383

}

   384

   385

static void ec_poll_rx(struct net_device *dev)

   386

{

   387

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   388

	poll_rx(priv);

   389

}

   390

   391

/**

   392

 * Poll for available tx dma descriptors in ethernet operating mode

   393

 */

   394

static void poll_tx(struct ccat_eth_priv *const priv)

   395

{

   396

	if (ccat_eth_frame_sent(priv->tx_fifo.next)) {

   397

		netif_wake_queue(priv->netdev);

   398

	}

   399

}

   400

   401

/**

   402

 * Since CCAT doesn't support interrupts until now, we have to poll

   403

 * some status bits to recognize things like link change etc.

   404

 */

   405

static enum hrtimer_restart poll_timer_callback(struct hrtimer *timer)

   406

{

   407

	struct ccat_eth_priv *const priv =

   408

	    container_of(timer, struct ccat_eth_priv, poll_timer);

   409

   410

	poll_link(priv);

   411

	if(!priv->ecdev) {

   412

		poll_rx(priv);

   413

		poll_tx(priv);

   414

	}

   415

	hrtimer_forward_now(timer, POLL_TIME);

   416

	return HRTIMER_RESTART;

   417

}

   418

   419

static struct rtnl_link_stats64 *ccat_eth_get_stats64(struct net_device *dev, struct rtnl_link_stats64

   420

						      *storage)

   421

{

   422

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   423

	struct ccat_mac_register mac;

   424

	memcpy_fromio(&mac, priv->reg.mac, sizeof(mac));

   425

	storage->rx_packets = mac.rx_frames;	/* total packets received       */

   426

	storage->tx_packets = mac.tx_frames;	/* total packets transmitted    */

   427

	storage->rx_bytes = atomic64_read(&priv->rx_bytes);	/* total bytes received         */

   428

	storage->tx_bytes = atomic64_read(&priv->tx_bytes);	/* total bytes transmitted      */

   429

	storage->rx_errors = mac.frame_len_err + mac.rx_mem_full + mac.crc_err + mac.rx_err;	/* bad packets received         */

   430

	storage->tx_errors = mac.tx_mem_full;	/* packet transmit problems     */

   431

	storage->rx_dropped = atomic64_read(&priv->rx_dropped);	/* no space in linux buffers    */

   432

	storage->tx_dropped = atomic64_read(&priv->tx_dropped);	/* no space available in linux  */

   433

	//TODO __u64    multicast;              /* multicast packets received   */

   434

	//TODO __u64    collisions;

   435

   436

	/* detailed rx_errors: */

   437

	storage->rx_length_errors = mac.frame_len_err;

   438

	storage->rx_over_errors = mac.rx_mem_full;	/* receiver ring buff overflow  */

   439

	storage->rx_crc_errors = mac.crc_err;	/* recved pkt with crc error    */

   440

	storage->rx_frame_errors = mac.rx_err;	/* recv'd frame alignment error */

   441

	storage->rx_fifo_errors = mac.rx_mem_full;	/* recv'r fifo overrun          */

   442

	//TODO __u64    rx_missed_errors;       /* receiver missed packet       */

   443

   444

	/* detailed tx_errors */

   445

	//TODO __u64    tx_aborted_errors;

   446

	//TODO __u64    tx_carrier_errors;

   447

	//TODO __u64    tx_fifo_errors;

   448

	//TODO __u64    tx_heartbeat_errors;

   449

	//TODO __u64    tx_window_errors;

   450

   451

	/* for cslip etc */

   452

	//TODO __u64    rx_compressed;

   453

	//TODO __u64    tx_compressed;

   454

	return storage;

   455

}

   456

   457

static int ccat_eth_open(struct net_device *dev)

   458

{

   459

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   460

   461

	hrtimer_init(&priv->poll_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);

   462

	priv->poll_timer.function = poll_timer_callback;

   463

	hrtimer_start(&priv->poll_timer, POLL_TIME, HRTIMER_MODE_REL);

   464

	return 0;

   465

}

   466

   467

static int ccat_eth_stop(struct net_device *dev)

   468

{

   469

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   470

   471

	priv->stop_queue(dev);

   472

	hrtimer_cancel(&priv->poll_timer);

   473

	return 0;

   474

}

   475

   476

static const struct net_device_ops ccat_eth_netdev_ops = {

   477

	.ndo_get_stats64 = ccat_eth_get_stats64,

   478

	.ndo_open = ccat_eth_open,

   479

	.ndo_start_xmit = ccat_eth_start_xmit,

   480

	.ndo_stop = ccat_eth_stop,

   481

};

   482

   483

struct ccat_eth_priv *ccat_eth_init(const struct ccat_device *const ccatdev,

   484

				    const void __iomem * const addr)

   485

{

   486

	struct ccat_eth_priv *priv;

   487

	struct net_device *const netdev = alloc_etherdev(sizeof(*priv));

   488

   489

	priv = netdev_priv(netdev);

   490

	priv->netdev = netdev;

   491

	priv->ccatdev = ccatdev;

   492

   493

	/* ccat register mappings */

   494

	memcpy_fromio(&priv->info, addr, sizeof(priv->info));

   495

	ccat_eth_priv_init_mappings(priv);

   496

   497

	if (ccat_eth_priv_init_dma(priv)) {

   498

		pr_warn("%s(): DMA initialization failed.\n", __FUNCTION__);

   499

		free_netdev(netdev);

   500

		return NULL;

   501

	}

   502

   503

	/* init netdev with MAC and stack callbacks */

   504

	memcpy_fromio(netdev->dev_addr, priv->reg.mii + 8, netdev->addr_len);

   505

	netdev->netdev_ops = &ccat_eth_netdev_ops;

   506

   507

	/* use as EtherCAT device? */

   508

	priv->ecdev = ecdev_offer(netdev, ec_poll_rx, THIS_MODULE);

   509

	if (priv->ecdev) {

   510

		priv->carrier_off = ecdev_carrier_off;

   511

		priv->carrier_ok = ecdev_carrier_ok;

   512

		priv->carrier_on = ecdev_carrier_on;

   513

		priv->kfree_skb_any = ecdev_kfree_skb_any;

   514

		priv->start_queue = ecdev_nop;

   515

		priv->stop_queue = ecdev_nop;

   516

		priv->unregister = unregister_ecdev;

   517

   518

		priv->carrier_off(netdev);

   519

		if (ecdev_open(priv->ecdev)) {

   520

			pr_info("unable to register network device.\n");

   521

			ecdev_withdraw(priv->ecdev);

   522

			ccat_eth_priv_free_dma(priv);

   523

			free_netdev(netdev);

   524

			return NULL;

   525

		}

   526

		return priv;

   527

	}

   528

   529

	/* EtherCAT disabled -> prepare normal ethernet mode */

   530

	priv->carrier_off = netif_carrier_off;