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/init.h>

    23

#include <linux/kernel.h>

    24

#include <linux/kfifo.h>

    25

#include <linux/kthread.h>

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#include <linux/module.h>

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#include <linux/netdevice.h>

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#include <linux/spinlock.h>

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    30

#include "compat.h"

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#include "module.h"

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#include "netdev.h"

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#include "print.h"

    34

    35

/**

    36

 * EtherCAT frame to enable forwarding on EtherCAT Terminals

    37

 */

    38

static const UINT8 frameForwardEthernetFrames[] = {

    39

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

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

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

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	0x08,

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	0x00,

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	0x00, 0x00,

    45

	0x00, 0x01,

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	0x02, 0x00,

    47

	0x00, 0x00,

    48

	0x00, 0x00,

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	0x00, 0x00

    50

};

    51

    52

#define FIFO_LENGTH 64

    53

#define DMA_POLL_DELAY_RANGE_USECS 100, 100	/* time to sleep between rx/tx DMA polls */

    54

#define POLL_DELAY_RANGE_USECS 500, 1000	/* time to sleep between link state polls */

    55

    56

static void ec_poll(struct net_device *dev);

    57

static int run_poll_thread(void *data);

    58

static int run_rx_thread(void *data);

    59

static int run_tx_thread(void *data);

    60

    61

#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 35)

    62

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

    63

						      *storage);

    64

#endif

    65

static int ccat_eth_open(struct net_device *dev);

    66

static netdev_tx_t ccat_eth_start_xmit(struct sk_buff *skb,

    67

				       struct net_device *dev);

    68

static int ccat_eth_stop(struct net_device *dev);

    69

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

    70

			      size_t len);

    71

    72

static const struct net_device_ops ccat_eth_netdev_ops = {

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#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 35)

    74

	.ndo_get_stats64 = ccat_eth_get_stats64,

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#endif

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	.ndo_open = ccat_eth_open,

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	.ndo_start_xmit = ccat_eth_start_xmit,

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	.ndo_stop = ccat_eth_stop,

    79

};

    80

    81

static void ecdev_kfree_skb_any(struct sk_buff *skb)

    82

{

    83

	/* never release a skb in EtherCAT mode */

    84

}

    85

    86

static void ecdev_carrier_on(struct net_device *const netdev)

    87

{

    88

	struct ccat_eth_priv *const priv = netdev_priv(netdev);

    89

	ecdev_set_link(priv->ecdev, 1);

    90

}

    91

    92

static void ecdev_carrier_off(struct net_device *const netdev)

    93

{

    94

	struct ccat_eth_priv *const priv = netdev_priv(netdev);

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	ecdev_set_link(priv->ecdev, 0);

    96

}

    97

    98

static void ecdev_nop(struct net_device *const netdev)

    99

{

   100

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

   101

}

   102

   103

static void ecdev_tx_fifo_full(struct net_device *const dev,

   104

			       const struct ccat_eth_frame *const frame)

   105

{

   106

	/* we are polled -> there is nothing we can do in EtherCAT mode */

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}

   108

   109

static void unregister_ecdev(struct net_device *const netdev)

   110

{

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	struct ccat_eth_priv *const priv = netdev_priv(netdev);

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	ecdev_close(priv->ecdev);

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	ecdev_withdraw(priv->ecdev);

   114

}

   115

   116

typedef void (*fifo_add_function) (struct ccat_eth_frame *,

   117

				   struct ccat_eth_dma_fifo *);

   118

   119

static void ccat_eth_rx_fifo_add(struct ccat_eth_frame *frame,

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				 struct ccat_eth_dma_fifo *fifo)

   121

{

   122

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

   123

	const uint32_t addr_and_length = (1 << 31) | offset;

   124

	frame->received = 0;

   125

	iowrite32(addr_and_length, fifo->reg);

   126

}

   127

   128

static void ccat_eth_tx_fifo_add_free(struct ccat_eth_frame *frame,

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				      struct ccat_eth_dma_fifo *fifo)

   130

{

   131

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

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	frame->sent = 1;

   133

}

   134

   135

static void ccat_eth_tx_fifo_full(struct net_device *const dev,

   136

				  const struct ccat_eth_frame *const frame)

   137

{

   138

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   139

	netif_stop_queue(dev);

   140

	priv->next_tx_frame = frame;

   141

	wake_up_process(priv->tx_thread);

   142

}

   143

   144

static void ccat_eth_dma_fifo_reset(struct ccat_eth_dma_fifo *fifo)

   145

{

   146

	struct ccat_eth_frame *frame = fifo->dma.virt;

   147

	const struct ccat_eth_frame *const end = frame + FIFO_LENGTH;

   148

   149

	/* reset hw fifo */

   150

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

   151

	wmb();

   152

   153

	if (fifo->add) {

   154

		while (frame < end) {

   155

			fifo->add(frame, fifo);

   156

			++frame;

   157

		}

   158

	}

   159

}

   160

   161

static int ccat_eth_dma_fifo_init(struct ccat_eth_dma_fifo *fifo,

   162

				  void __iomem * const fifo_reg,

   163

				  fifo_add_function add, size_t channel,

   164

				  struct ccat_eth_priv *const priv)

   165

{

   166

	if (0 !=

   167

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

   168

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

   169

		pr_info("init DMA%llu memory failed.\n", (uint64_t) channel);

   170

		return -1;

   171

	}

   172

	fifo->add = add;

   173

	fifo->reg = fifo_reg;

   174

	return 0;

   175

}

   176

   177

/**

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

   179

 */

   180

static void ccat_eth_priv_free_dma(struct ccat_eth_priv *priv)

   181

{

   182

	/* reset hw fifo's */

   183

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

   184

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

   185

	wmb();

   186

   187

	/* release dma */

   188

	ccat_dma_free(&priv->rx_fifo.dma);

   189

	ccat_dma_free(&priv->tx_fifo.dma);

   190

	pr_debug("DMA fifo's stopped.\n");

   191

}

   192

   193

/**

   194

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

   195

 */

   196

static int ccat_eth_priv_init_dma(struct ccat_eth_priv *priv)

   197

{

   198

	if (ccat_eth_dma_fifo_init

   199

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

   200

	     priv->info.rxDmaChn, priv)) {

   201

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

   202

		return -1;

   203

	}

   204

   205

	if (ccat_eth_dma_fifo_init

   206

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

   207

	     priv->info.txDmaChn, priv)) {

   208

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

   209

		ccat_dma_free(&priv->rx_fifo.dma);

   210

		return -1;

   211

	}

   212

   213

	/* disable MAC filter */

   214

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

   215

	wmb();

   216

	return 0;

   217

}

   218

   219

/**

   220

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

   221

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

   222

 */

   223

static void ccat_eth_priv_init_mappings(struct ccat_eth_priv *priv)

   224

{

   225

	CCatInfoBlockOffs offsets;

   226

	void __iomem *const func_base =

   227

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

   228

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

   229

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

   230

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

   231

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

   232

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

   233

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

   234

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

   235

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

   236

}

   237

   238

/**

   239

 * Read link state from CCAT hardware

   240

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

   241

 */

   242

inline static size_t ccat_eth_priv_read_link_state(const struct ccat_eth_priv

   243

						   *const priv)

   244

{

   245

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

   246

}

   247

   248

#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 35)

   249

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

   250

						      *storage)

   251

{

   252

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   253

	CCatMacRegs mac;

   254

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

   255

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

   256

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

   257

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

   258

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

   259

	storage->rx_errors = mac.frameLenErrCnt + mac.dropFrameErrCnt + mac.crcErrCnt + mac.rxErrCnt;	/* bad packets received         */

   260

	//TODO __u64    tx_errors;              /* packet transmit problems     */

   261

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

   262

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

   263

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

   264

	//TODO __u64    collisions;

   265

   266

	/* detailed rx_errors: */

   267

	storage->rx_length_errors = mac.frameLenErrCnt;

   268

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

   269

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

   270

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

   271

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

   272

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

   273

   274

	/* detailed tx_errors */

   275

	//TODO __u64    tx_aborted_errors;

   276

	//TODO __u64    tx_carrier_errors;

   277

	//TODO __u64    tx_fifo_errors;

   278

	//TODO __u64    tx_heartbeat_errors;

   279

	//TODO __u64    tx_window_errors;

   280

   281

	/* for cslip etc */

   282

	//TODO __u64    rx_compressed;

   283

	//TODO __u64    tx_compressed;

   284

	return storage;

   285

}

   286

#endif

   287

   288

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

   289

				    const void __iomem * const addr)

   290

{

   291

	struct ccat_eth_priv *priv;

   292

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

   293

	priv = netdev_priv(netdev);

   294

	priv->netdev = netdev;

   295

	priv->ccatdev = ccatdev;

   296

   297

	/* ccat register mappings */

   298

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

   299

	ccat_eth_priv_init_mappings(priv);

   300

	ccat_print_function_info(priv);

   301

   302

	if (ccat_eth_priv_init_dma(priv)) {

   303

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

   304

		free_netdev(netdev);

   305

		return NULL;

   306

	}

   307

   308

	/* init netdev with MAC and stack callbacks */

   309

	memcpy_fromio(netdev->dev_addr, priv->reg.mii + 8, 6);

   310

	netdev->netdev_ops = &ccat_eth_netdev_ops;

   311

   312

	/* use as EtherCAT device? */

   313

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

   314

	if (priv->ecdev) {

   315

		priv->carrier_off = ecdev_carrier_off;

   316

		priv->carrier_on = ecdev_carrier_on;

   317

		priv->kfree_skb_any = ecdev_kfree_skb_any;

   318

		priv->start_queue = ecdev_nop;

   319

		priv->stop_queue = ecdev_nop;

   320

		priv->tx_fifo_full = ecdev_tx_fifo_full;

   321

		priv->unregister = unregister_ecdev;

   322

		if (ecdev_open(priv->ecdev)) {

   323

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

   324

			ecdev_withdraw(priv->ecdev);

   325

			ccat_eth_priv_free_dma(priv);

   326

			free_netdev(netdev);

   327

			return NULL;

   328

		}

   329

		return priv;

   330

	}

   331

   332

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

   333

	priv->carrier_off = netif_carrier_off;

   334

	priv->carrier_on = netif_carrier_on;

   335

	priv->kfree_skb_any = dev_kfree_skb_any;

   336

	priv->start_queue = netif_start_queue;

   337

	priv->stop_queue = netif_stop_queue;

   338

	priv->tx_fifo_full = ccat_eth_tx_fifo_full;

   339

	priv->unregister = unregister_netdev;

   340

	if (register_netdev(netdev)) {

   341

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

   342

		ccat_eth_priv_free_dma(priv);

   343

		free_netdev(netdev);

   344

		return NULL;

   345

	}

   346

	pr_info("registered %s as network device.\n", netdev->name);

   347

	priv->rx_thread = kthread_run(run_rx_thread, netdev, "%s_rx", DRV_NAME);

   348

	priv->tx_thread = kthread_run(run_tx_thread, netdev, "%s_tx", DRV_NAME);

   349

	return priv;

   350

}

   351

   352

void ccat_eth_remove(struct ccat_eth_priv *const priv)

   353

{

   354

	if (priv->rx_thread) {

   355

		kthread_stop(priv->rx_thread);

   356

	}

   357

	if (priv->tx_thread) {

   358

		kthread_stop(priv->tx_thread);

   359

	}

   360

	priv->unregister(priv->netdev);

   361

	ccat_eth_priv_free_dma(priv);

   362

	free_netdev(priv->netdev);

   363

	pr_debug("%s(): done\n", __FUNCTION__);

   364

}

   365

   366

static int ccat_eth_open(struct net_device *dev)

   367

{

   368

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   369

	priv->carrier_off(dev);

   370

	priv->poll_thread =

   371

	    kthread_run(run_poll_thread, dev, "%s_poll", DRV_NAME);

   372

   373

	//TODO

   374

	return 0;

   375

}

   376

   377

static const size_t CCATRXDESC_HEADER_LEN = 20;

   378

static void ccat_eth_receive(struct net_device *const dev,

   379

			     const struct ccat_eth_frame *const frame)

   380

{

   381

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   382

	const size_t len = frame->length - CCATRXDESC_HEADER_LEN;

   383

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

   384

	if (!skb) {

   385

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

   386

		atomic64_inc(&priv->rx_dropped);

   387

		return;

   388

	}

   389

	skb->dev = dev;

   390

	skb_reserve(skb, NET_IP_ALIGN);

   391

	skb_copy_to_linear_data(skb, frame->data, len);

   392

	skb_put(skb, len);

   393

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

   394

	skb->ip_summed = CHECKSUM_UNNECESSARY;

   395

	atomic64_add(len, &priv->rx_bytes);

   396

	netif_rx(skb);

   397

}

   398

   399

/**

   400

 * Rx handler in EtherCAT operation mode

   401

 * priv->ecdev should always be valid!

   402

 */

   403

static void ec_poll(struct net_device *dev)

   404

{

   405

	static size_t next = 0;

   406

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   407

	struct ccat_eth_frame *frame =

   408

	    ((struct ccat_eth_frame *)priv->rx_fifo.dma.virt) + next;

   409

	if (frame->received) {

   410

		ecdev_receive(priv->ecdev, frame->data,

   411

			      frame->length - CCATRXDESC_HEADER_LEN);

   412

		frame->received = 0;

   413

		ccat_eth_rx_fifo_add(frame, &priv->rx_fifo);

   414

		next = (next + 1) % FIFO_LENGTH;

   415

	} else {

   416

		//TODO dev_warn(&dev->dev, "%s(): frame was not ready\n", __FUNCTION__);

   417

	}

   418

}

   419

   420

static netdev_tx_t ccat_eth_start_xmit(struct sk_buff *skb,

   421

				       struct net_device *dev)

   422

{

   423

	static size_t next = 0;

   424

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   425

	struct ccat_eth_frame *const frame =

   426

	    ((struct ccat_eth_frame *)priv->tx_fifo.dma.virt);

   427

	uint32_t addr_and_length;

   428

   429

	if (skb_is_nonlinear(skb)) {

   430

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

   431

		atomic64_inc(&priv->tx_dropped);

   432

		priv->kfree_skb_any(skb);

   433

		return NETDEV_TX_OK;

   434

	}

   435

   436

	if (skb->len > sizeof(frame->data)) {

   437

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

   438

			(uint64_t) skb->len, (uint64_t) sizeof(frame->data));

   439

		atomic64_inc(&priv->tx_dropped);

   440

		priv->kfree_skb_any(skb);

   441

		return NETDEV_TX_OK;

   442

	}

   443

   444

	if (!frame[next].sent) {

   445

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

   446

		ccat_eth_tx_fifo_full(dev, &frame[next]);

   447

		return NETDEV_TX_BUSY;

   448

	}

   449

   450

	/* prepare frame in DMA memory */

   451

	frame[next].sent = 0;

   452

	frame[next].length = skb->len;

   453

	memcpy(frame[next].data, skb->data, skb->len);

   454

   455

	priv->kfree_skb_any(skb);

   456

   457

	addr_and_length = 8 + (next * sizeof(*frame));

   458

	addr_and_length +=

   459

	    ((frame[next].length + CCAT_DMA_FRAME_HEADER_LENGTH) / 8) << 24;

   460

	iowrite32(addr_and_length, priv->reg.tx_fifo);	/* add to DMA fifo */

   461

	atomic64_add(frame[next].length, &priv->tx_bytes);	/* update stats */

   462

   463

	next = (next + 1) % FIFO_LENGTH;

   464

	/* stop queue if tx ring is full */

   465

	if (!frame[next].sent) {

   466

		ccat_eth_tx_fifo_full(dev, &frame[next]);

   467

	}

   468

	return NETDEV_TX_OK;

   469

}

   470

   471

static int ccat_eth_stop(struct net_device *dev)

   472

{

   473

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   474

	priv->stop_queue(dev);

   475

	if (priv->poll_thread) {

   476

		/* TODO care about smp context? */

   477

		kthread_stop(priv->poll_thread);

   478

		priv->poll_thread = NULL;

   479

	}

   480

	netdev_info(dev, "stopped.\n");

   481

	return 0;

   482

}

   483

   484

static void ccat_eth_link_down(struct net_device *dev)

   485

{

   486

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   487

	priv->stop_queue(dev);

   488

	priv->carrier_off(dev);

   489

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

   490

}

   491

   492

static void ccat_eth_link_up(struct net_device *const dev)

   493

{

   494

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   495

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

   496

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

   497

	   speed == SPEED_100 ? 100 : 10,

   498

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

   499

   500

	ccat_eth_dma_fifo_reset(&priv->rx_fifo);

   501

	ccat_eth_dma_fifo_reset(&priv->tx_fifo);

   502

	ccat_eth_xmit_raw(dev, frameForwardEthernetFrames,

   503

			  sizeof(frameForwardEthernetFrames));

   504

	priv->carrier_on(dev);

   505

	priv->start_queue(dev);

   506

}

   507

   508

/**

   509

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

   510

 * @dev a valid net_device

   511

 * @data pointer to your raw buffer

   512

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

   513

 */

   514

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

   515

			      size_t len)

   516

{

   517

	struct sk_buff *skb = dev_alloc_skb(len);

   518

	skb->dev = dev;

   519

	skb_copy_to_linear_data(skb, data, len);

   520

	skb_put(skb, len);

   521

	ccat_eth_start_xmit(skb, dev);

   522

}

   523

   524

/**

   525

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

   526

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

   527

 */

   528

static int run_poll_thread(void *data)

   529

{

   530

	struct net_device *const dev = (struct net_device *)data;