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/module.h>

    25

#include <linux/netdevice.h>

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#include <linux/spinlock.h>

    27

    28

#include "module.h"

    29

#include "netdev.h"

    30

    31

/**

    32

 * EtherCAT frame to enable forwarding on EtherCAT Terminals

    33

 */

    34

static const u8 frameForwardEthernetFrames[] = {

    35

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

    36

	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,

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	0x00, 0x01,

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	0x02, 0x00,

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	0x00, 0x00,

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	0x00, 0x00,

    45

	0x00, 0x00

    46

};

    47

    48

#define FIFO_LENGTH 64

    49

static void ec_poll(struct net_device *dev);

    50

static enum hrtimer_restart poll_timer_callback(struct hrtimer *timer);

    51

    52

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

    53

						      *storage);

    54

static int ccat_eth_open(struct net_device *dev);

    55

static netdev_tx_t ccat_eth_start_xmit(struct sk_buff *skb,

    56

				       struct net_device *dev);

    57

static int ccat_eth_stop(struct net_device *dev);

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

    59

			      size_t len);

    60

    61

static const struct net_device_ops ccat_eth_netdev_ops = {

    62

	.ndo_get_stats64 = ccat_eth_get_stats64,

    63

	.ndo_open = ccat_eth_open,

    64

	.ndo_start_xmit = ccat_eth_start_xmit,

    65

	.ndo_stop = ccat_eth_stop,

    66

};

    67

    68

static void ecdev_kfree_skb_any(struct sk_buff *skb)

    69

{

    70

	/* never release a skb in EtherCAT mode */

    71

}

    72

    74

{

    75

	struct ccat_eth_priv *const priv = netdev_priv(netdev);

    76

	return ecdev_get_link(priv->ecdev);

    77

}

    78

    79

static void ecdev_carrier_on(struct net_device *const netdev)

    80

{

    81

	struct ccat_eth_priv *const priv = netdev_priv(netdev);

    82

	ecdev_set_link(priv->ecdev, 1);

    83

}

    84

    85

static void ecdev_carrier_off(struct net_device *const netdev)

    86

{

    87

	struct ccat_eth_priv *const priv = netdev_priv(netdev);

    88

	ecdev_set_link(priv->ecdev, 0);

    89

}

    90

    91

static void ecdev_nop(struct net_device *const netdev)

    92

{

    93

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

    94

}

    95

    96

static void ecdev_tx_fifo_full(struct ccat_eth_priv *const priv,

    97

			       const struct ccat_eth_frame *const frame)

    98

{

    99

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

   100

}

   101

   102

static void unregister_ecdev(struct net_device *const netdev)

   103

{

   104

	struct ccat_eth_priv *const priv = netdev_priv(netdev);

   105

	ecdev_close(priv->ecdev);

   106

	ecdev_withdraw(priv->ecdev);

   107

}

   108

   109

typedef void (*fifo_add_function) (struct ccat_eth_frame *,

   110

				   struct ccat_eth_dma_fifo *);

   111

   112

static void ccat_eth_rx_fifo_add(struct ccat_eth_frame *frame,

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				 struct ccat_eth_dma_fifo *fifo)

   114

{

   115

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

   116

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

   117

   118

	frame->received = 0;

   119

	iowrite32(addr_and_length, fifo->reg);

   120

}

   121

   122

static void ccat_eth_tx_fifo_add_free(struct ccat_eth_frame *frame,

   123

				      struct ccat_eth_dma_fifo *fifo)

   124

{

   125

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

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	frame->sent = 1;

   127

}

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   129

static void ccat_eth_tx_fifo_full(struct ccat_eth_priv *const priv,

   130

				  const struct ccat_eth_frame *const frame)

   131

{

   132

	priv->stop_queue(priv->netdev);

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	priv->next_tx_frame = frame;

   134

}

   135

   136

static void ccat_eth_dma_fifo_reset(struct ccat_eth_dma_fifo *fifo)

   137

{

   138

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

   139

	const struct ccat_eth_frame *const end = frame + FIFO_LENGTH;

   140

   141

	/* reset hw fifo */

   142

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

   143

	wmb();

   144

   145

	if (fifo->add) {

   146

		while (frame < end) {

   147

			fifo->add(frame, fifo);

   148

			++frame;

   149

		}

   150

	}

   151

}

   152

   153

static int ccat_eth_dma_fifo_init(struct ccat_eth_dma_fifo *fifo,

   154

				  void __iomem * const fifo_reg,

   155

				  fifo_add_function add, size_t channel,

   156

				  struct ccat_eth_priv *const priv)

   157

{

   158

	if (0 !=

   159

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

   160

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

   161

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

   162

		return -1;

   163

	}

   164

	fifo->add = add;

   165

	fifo->reg = fifo_reg;

   166

	return 0;

   167

}

   168

   169

/**

   170

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

   171

 */

   172

static void ccat_eth_priv_free_dma(struct ccat_eth_priv *priv)

   173

{

   174

	/* reset hw fifo's */

   175

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

   176

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

   177

	wmb();

   178

   179

	/* release dma */

   180

	ccat_dma_free(&priv->rx_fifo.dma);

   181

	ccat_dma_free(&priv->tx_fifo.dma);

   182

}

   183

   184

/**

   185

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

   186

 */

   187

static int ccat_eth_priv_init_dma(struct ccat_eth_priv *priv)

   188

{

   189

	if (ccat_eth_dma_fifo_init

   190

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

   191

	     priv->info.rx_dma_chan, priv)) {

   192

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

   193

		return -1;

   194

	}

   195

   196

	if (ccat_eth_dma_fifo_init

   197

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

   198

	     priv->info.tx_dma_chan, priv)) {

   199

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

   200

		ccat_dma_free(&priv->rx_fifo.dma);

   201

		return -1;

   202

	}

   203

   204

	/* disable MAC filter */

   205

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

   206

	wmb();

   207

	return 0;

   208

}

   209

   210

/**

   211

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

   212

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

   213

 */

   214

static void ccat_eth_priv_init_mappings(struct ccat_eth_priv *priv)

   215

{

   216

	struct ccat_mac_infoblock offsets;

   217

	void __iomem *const func_base =

   218

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

   219

   220

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

   221

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

   222

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

   223

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

   224

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

   225

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

   226

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

   227

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

   228

}

   229

   230

/**

   231

 * Read link state from CCAT hardware

   232

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

   233

 */

   234

inline static size_t ccat_eth_priv_read_link_state(const struct ccat_eth_priv

   235

						   *const priv)

   236

{

   237

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

   238

}

   239

   240

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

   241

						      *storage)

   242

{

   243

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   244

	struct ccat_mac_register mac;

   245

   246

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

   247

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

   248

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

   249

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

   250

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

   251

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

   252

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

   253

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

   254

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

   255

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

   256

	//TODO __u64    collisions;

   257

   258

	/* detailed rx_errors: */

   259

	storage->rx_length_errors = mac.frame_len_err;

   260

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

   261

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

   262

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

   263

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

   264

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

   265

   266

	/* detailed tx_errors */

   267

	//TODO __u64    tx_aborted_errors;

   268

	//TODO __u64    tx_carrier_errors;

   269

	//TODO __u64    tx_fifo_errors;

   270

	//TODO __u64    tx_heartbeat_errors;

   271

	//TODO __u64    tx_window_errors;

   272

   273

	/* for cslip etc */

   274

	//TODO __u64    rx_compressed;

   275

	//TODO __u64    tx_compressed;

   276

	return storage;

   277

}

   278

   279

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

   280

				    const void __iomem * const addr)

   281

{

   282

	struct ccat_eth_priv *priv;

   283

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

   284

   285

	priv = netdev_priv(netdev);

   286

	priv->netdev = netdev;

   287

	priv->ccatdev = ccatdev;

   288

   289

	/* ccat register mappings */

   290

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

   291

	ccat_eth_priv_init_mappings(priv);

   292

	/* XXX disabled in release

   293

	 * ccat_print_function_info(priv);

   294

	 */

   295

   296

	if (ccat_eth_priv_init_dma(priv)) {

   297

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

   298

		free_netdev(netdev);

   299

		return NULL;

   300

	}

   301

   302

	/* init netdev with MAC and stack callbacks */

   303

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

   304

	netdev->netdev_ops = &ccat_eth_netdev_ops;

   305

   306

	/* use as EtherCAT device? */

   307

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

   308

	if (priv->ecdev) {

   309

		priv->carrier_off = ecdev_carrier_off;

   310

		priv->carrier_ok = ecdev_carrier_ok;

   311

		priv->carrier_on = ecdev_carrier_on;

   312

		priv->kfree_skb_any = ecdev_kfree_skb_any;

   313

		priv->start_queue = ecdev_nop;

   314

		priv->stop_queue = ecdev_nop;

   315

		priv->tx_fifo_full = ecdev_tx_fifo_full;

   316

		priv->unregister = unregister_ecdev;

   317

   318

		priv->carrier_off(netdev);

   319

		if (ecdev_open(priv->ecdev)) {

   320

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

   321

			ecdev_withdraw(priv->ecdev);

   322

			ccat_eth_priv_free_dma(priv);

   323

			free_netdev(netdev);

   324

			return NULL;

   325

		}

   326

		return priv;

   327

	}

   328

   329

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

   330

	priv->carrier_off = netif_carrier_off;

   331

	priv->carrier_ok = netif_carrier_ok;

   332

	priv->carrier_on = netif_carrier_on;

   333

	priv->kfree_skb_any = dev_kfree_skb_any;

   334

	priv->start_queue = netif_start_queue;

   335

	priv->stop_queue = netif_stop_queue;

   336

	priv->tx_fifo_full = ccat_eth_tx_fifo_full;

   337

	priv->unregister = unregister_netdev;

   338

   339

	priv->carrier_off(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

	return priv;

   348

}

   349

   350

void ccat_eth_remove(struct ccat_eth_priv *const priv)

   351

{

   352

	priv->unregister(priv->netdev);

   353

	ccat_eth_priv_free_dma(priv);

   354

	free_netdev(priv->netdev);

   355

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

   356

}

   357

   358

static int ccat_eth_open(struct net_device *dev)

   359

{

   360

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   361

   362

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

   363

	priv->poll_timer.function = poll_timer_callback;

   364

	hrtimer_start(&priv->poll_timer, ktime_set(0, 100000),

   365

		      HRTIMER_MODE_REL);

   366

	return 0;

   367

}

   368

   369

static const size_t CCATRXDESC_HEADER_LEN = 20;

   370

static void ccat_eth_receive(struct net_device *const dev,

   371

			     const struct ccat_eth_frame *const frame)

   372

{

   373

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   374

	const size_t len = frame->length - CCATRXDESC_HEADER_LEN;

   375

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

   376

   377

	if (!skb) {

   378

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

   379

		atomic64_inc(&priv->rx_dropped);

   380

		return;

   381

	}

   382

	skb->dev = dev;

   383

	skb_reserve(skb, NET_IP_ALIGN);

   384

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

   385

	skb_put(skb, len);

   386

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

   387

	skb->ip_summed = CHECKSUM_UNNECESSARY;

   388

	atomic64_add(len, &priv->rx_bytes);

   389

	netif_rx(skb);

   390

}

   391

   392

/**

   393

 * Rx handler in EtherCAT operation mode

   394

 * priv->ecdev should always be valid!

   395

 */

   396

static void ec_poll(struct net_device *dev)

   397

{

   398

	static size_t next = 0;

   399

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   400

	struct ccat_eth_frame *frame =

   401

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

   402

	if (frame->received) {

   403

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

   404

			      frame->length - CCATRXDESC_HEADER_LEN);

   405

		frame->received = 0;

   406

		ccat_eth_rx_fifo_add(frame, &priv->rx_fifo);

   407

		next = (next + 1) % FIFO_LENGTH;

   408

	} else {

   409

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

   410

	}

   411

}

   412

   413

static netdev_tx_t ccat_eth_start_xmit(struct sk_buff *skb,

   414

				       struct net_device *dev)

   415

{

   416

	static size_t next = 0;

   417

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   418

	struct ccat_eth_frame *const frame =

   419

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

   420

	u32 addr_and_length;

   421

   422

	if (skb_is_nonlinear(skb)) {

   423

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

   424

		atomic64_inc(&priv->tx_dropped);

   425

		priv->kfree_skb_any(skb);

   426

		return NETDEV_TX_OK;

   427

	}

   428

   429

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

   430

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

   431

			(u64) skb->len, (u64) sizeof(frame->data));

   432

		atomic64_inc(&priv->tx_dropped);

   433

		priv->kfree_skb_any(skb);

   434

		return NETDEV_TX_OK;

   435

	}

   436

   437

	if (!frame[next].sent) {

   438

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

   439

		ccat_eth_tx_fifo_full(priv, &frame[next]);

   440

		return NETDEV_TX_BUSY;

   441

	}

   442

   443

	/* prepare frame in DMA memory */

   444

	frame[next].sent = 0;

   445

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

   446

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

   447

   448

	priv->kfree_skb_any(skb);

   449

   450

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

   451

	addr_and_length +=

   452

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

   453

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

   454

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

   455

   456

	next = (next + 1) % FIFO_LENGTH;

   457

	/* stop queue if tx ring is full */

   458

	if (!frame[next].sent) {

   459

		ccat_eth_tx_fifo_full(priv, &frame[next]);

   460

	}

   461

	return NETDEV_TX_OK;

   462

}

   463

   464

static int ccat_eth_stop(struct net_device *dev)

   465

{

   466

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   467

   468

	priv->stop_queue(dev);

   469

	hrtimer_cancel(&priv->poll_timer);

   470

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

   471

	return 0;

   472

}

   473

   474

static void ccat_eth_link_down(struct net_device *dev)

   475

{

   476

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   477

   478

	priv->stop_queue(dev);

   479

	priv->carrier_off(dev);

   480

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

   481

}

   482

   483

static void ccat_eth_link_up(struct net_device *const dev)

   484

{

   485

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   486

   487

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

   488

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

   489

	   speed == SPEED_100 ? 100 : 10,

   490

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

   491

   492