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/**

     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.

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    11

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

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    but WITHOUT ANY WARRANTY; without even the implied warranty of

    13

    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

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    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.,

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    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>

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    28

#include "compat.h"

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#include "module.h"

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#include "netdev.h"

    31

#include "print.h"

    32

    33

/**

    34

 * EtherCAT frame to enable forwarding on EtherCAT Terminals

    35

 */

    37

	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,

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	0x00, 0x01,

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	0x02, 0x00,

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	0x00, 0x00,

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	0x00, 0x00,

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	0x00, 0x00

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};

    49

    50

#define FIFO_LENGTH 64

    51

static void ec_poll(struct net_device *dev);

    53

    54

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

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

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						      *storage);

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#endif

    58

static int ccat_eth_open(struct net_device *dev);

    59

static netdev_tx_t ccat_eth_start_xmit(struct sk_buff *skb,

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				       struct net_device *dev);

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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,

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			      size_t len);

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static const struct net_device_ops ccat_eth_netdev_ops = {

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

    67

	.ndo_get_stats64 = ccat_eth_get_stats64,

    68

#endif

    69

	.ndo_open = ccat_eth_open,

    70

	.ndo_start_xmit = ccat_eth_start_xmit,

    71

	.ndo_stop = ccat_eth_stop,

    72

};

    73

    74

static void ecdev_kfree_skb_any(struct sk_buff *skb)

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{

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	/* never release a skb in EtherCAT mode */

    77

}

    78

    85

static void ecdev_carrier_on(struct net_device *const netdev)

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{

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	struct ccat_eth_priv *const priv = netdev_priv(netdev);

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	ecdev_set_link(priv->ecdev, 1);

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}

    90

    91

static void ecdev_carrier_off(struct net_device *const netdev)

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{

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	struct ccat_eth_priv *const priv = netdev_priv(netdev);

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	ecdev_set_link(priv->ecdev, 0);

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}

    96

    97

static void ecdev_nop(struct net_device *const netdev)

    98

{

    99

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

   100

}

   101

   103

			       const struct ccat_eth_frame *const frame)

   104

{

   105

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

   106

}

   107

   108

static void unregister_ecdev(struct net_device *const netdev)

   109

{

   110

	struct ccat_eth_priv *const priv = netdev_priv(netdev);

   111

	ecdev_close(priv->ecdev);

   112

	ecdev_withdraw(priv->ecdev);

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}

   114

   115

typedef void (*fifo_add_function) (struct ccat_eth_frame *,

   116

				   struct ccat_eth_dma_fifo *);

   117

   118

static void ccat_eth_rx_fifo_add(struct ccat_eth_frame *frame,

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				 struct ccat_eth_dma_fifo *fifo)

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{

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

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	frame->received = 0;

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	iowrite32(addr_and_length, fifo->reg);

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}

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static void ccat_eth_tx_fifo_add_free(struct ccat_eth_frame *frame,

   129

				      struct ccat_eth_dma_fifo *fifo)

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{

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

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	frame->sent = 1;

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}

   134

   136

				  const struct ccat_eth_frame *const frame)

   137

{

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	priv->next_tx_frame = frame;

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}

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static void ccat_eth_dma_fifo_reset(struct ccat_eth_dma_fifo *fifo)

   143

{

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

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	const struct ccat_eth_frame *const end = frame + FIFO_LENGTH;

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	/* reset hw fifo */

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

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	wmb();

   150

   151

	if (fifo->add) {

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		while (frame < end) {

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			fifo->add(frame, fifo);

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			++frame;

   155

		}

   156

	}

   157

}

   158

   159

static int ccat_eth_dma_fifo_init(struct ccat_eth_dma_fifo *fifo,

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				  void __iomem * const fifo_reg,

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				  fifo_add_function add, size_t channel,

   162

				  struct ccat_eth_priv *const priv)

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{

   164

	if (0 !=

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

   166

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

   168

		return -1;

   169

	}

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	fifo->add = add;

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	fifo->reg = fifo_reg;

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	return 0;

   173

}

   174

   175

/**

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

   177

 */

   178

static void ccat_eth_priv_free_dma(struct ccat_eth_priv *priv)

   179

{

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	/* reset hw fifo's */

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

   182

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

   183

	wmb();

   184

   185

	/* release dma */

   186

	ccat_dma_free(&priv->rx_fifo.dma);

   187

	ccat_dma_free(&priv->tx_fifo.dma);

   188

}

   189

   190

/**

   191

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

   192

 */

   193

static int ccat_eth_priv_init_dma(struct ccat_eth_priv *priv)

   194

{

   195

	if (ccat_eth_dma_fifo_init

   196

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

   197

	     priv->info.rxDmaChn, priv)) {

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

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		return -1;

   200

	}

   201

   202

	if (ccat_eth_dma_fifo_init

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

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	     priv->info.txDmaChn, priv)) {

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

   206

		ccat_dma_free(&priv->rx_fifo.dma);

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		return -1;

   208

	}

   209

   210

	/* disable MAC filter */

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

   212

	wmb();

   213

	return 0;

   214

}

   215

   216

/**

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

   218

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

   219

 */

   220

static void ccat_eth_priv_init_mappings(struct ccat_eth_priv *priv)

   221

{

   222

	CCatInfoBlockOffs offsets;

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	void __iomem *const func_base =

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

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

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

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

   229

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

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

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

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

   233

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

   234

}

   235

   236

/**

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 * Read link state from CCAT hardware

   238

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

   239

 */

   240

inline static size_t ccat_eth_priv_read_link_state(const struct ccat_eth_priv

   241

						   *const priv)

   242

{

   243

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

   244

}

   245

   246

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

   247

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

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						      *storage)

   249

{

   250

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   251

	CCatMacRegs mac;

   253

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

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

   255

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

   256

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

   257

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

   258

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

   259

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

   260

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

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

   262

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

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	//TODO __u64    collisions;

   264

   265

	/* detailed rx_errors: */

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	storage->rx_length_errors = mac.frameLenErrCnt;

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

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

   269

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

   270

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

   271

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

   272

   273

	/* detailed tx_errors */

   274

	//TODO __u64    tx_aborted_errors;

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	//TODO __u64    tx_carrier_errors;

   276

	//TODO __u64    tx_fifo_errors;

   277

	//TODO __u64    tx_heartbeat_errors;

   278

	//TODO __u64    tx_window_errors;

   279

   280

	/* for cslip etc */

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	//TODO __u64    rx_compressed;

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	//TODO __u64    tx_compressed;

   283

	return storage;

   284

}

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#endif

   286

   287

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

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				    const void __iomem * const addr)

   289

{

   290

	struct ccat_eth_priv *priv;

   291

	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;

   317

		priv->carrier_on = ecdev_carrier_on;

   318

		priv->kfree_skb_any = ecdev_kfree_skb_any;

   319

		priv->start_queue = ecdev_nop;

   320

		priv->stop_queue = ecdev_nop;

   321

		priv->tx_fifo_full = ecdev_tx_fifo_full;

   322

		priv->unregister = unregister_ecdev;

   323

		if (ecdev_open(priv->ecdev)) {

   324

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

   325

			ecdev_withdraw(priv->ecdev);

   326

			ccat_eth_priv_free_dma(priv);

   327

			free_netdev(netdev);

   328

			return NULL;

   329

		}

   330

		return priv;

   331

	}

   332

   333

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

   334

	priv->carrier_off = netif_carrier_off;

   336

	priv->carrier_on = netif_carrier_on;

   337

	priv->kfree_skb_any = dev_kfree_skb_any;

   338

	priv->start_queue = netif_start_queue;

   339

	priv->stop_queue = netif_stop_queue;

   340

	priv->tx_fifo_full = ccat_eth_tx_fifo_full;

   341

	priv->unregister = unregister_netdev;

   342

	if (register_netdev(netdev)) {

   343

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

   344

		ccat_eth_priv_free_dma(priv);

   345

		free_netdev(netdev);

   346

		return NULL;

   347

	}

   348

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

   349

	return priv;

   350

}

   351

   352

void ccat_eth_remove(struct ccat_eth_priv *const priv)

   353

{

   354

	priv->unregister(priv->netdev);

   355

	ccat_eth_priv_free_dma(priv);

   356

	free_netdev(priv->netdev);

   357

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

   358

}

   359

   360

static int ccat_eth_open(struct net_device *dev)

   361

{

   362

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   364

	priv->carrier_off(dev);

   369

	return 0;

   370

}

   371

   372

static const size_t CCATRXDESC_HEADER_LEN = 20;

   373

static void ccat_eth_receive(struct net_device *const dev,

   374

			     const struct ccat_eth_frame *const frame)

   375

{

   376

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   377

	const size_t len = frame->length - CCATRXDESC_HEADER_LEN;

   378

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

   380

	if (!skb) {

   381

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

   382

		atomic64_inc(&priv->rx_dropped);

   383

		return;

   384

	}

   385

	skb->dev = dev;

   386

	skb_reserve(skb, NET_IP_ALIGN);

   387

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

   388

	skb_put(skb, len);

   389

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

   390

	skb->ip_summed = CHECKSUM_UNNECESSARY;

   391

	atomic64_add(len, &priv->rx_bytes);

   392

	netif_rx(skb);

   393

}

   394

   395

/**

   396

 * Rx handler in EtherCAT operation mode

   397

 * priv->ecdev should always be valid!

   398

 */

   399

static void ec_poll(struct net_device *dev)

   400

{

   401

	static size_t next = 0;

   402

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   403

	struct ccat_eth_frame *frame =

   404

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

   405

	if (frame->received) {

   406

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

   407

			      frame->length - CCATRXDESC_HEADER_LEN);

   408

		frame->received = 0;

   409

		ccat_eth_rx_fifo_add(frame, &priv->rx_fifo);

   410

		next = (next + 1) % FIFO_LENGTH;

   411

	} else {

   412

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

   413

	}

   414

}

   415

   416

static netdev_tx_t ccat_eth_start_xmit(struct sk_buff *skb,

   417

				       struct net_device *dev)

   418

{

   419

	static size_t next = 0;

   420

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   421

	struct ccat_eth_frame *const frame =

   422

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

   424

   425

	if (skb_is_nonlinear(skb)) {

   426

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

   427

		atomic64_inc(&priv->tx_dropped);

   428

		priv->kfree_skb_any(skb);

   429

		return NETDEV_TX_OK;

   430

	}

   431

   432

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

   433

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

   435

		atomic64_inc(&priv->tx_dropped);

   436

		priv->kfree_skb_any(skb);

   437

		return NETDEV_TX_OK;

   438

	}

   439

   440

	if (!frame[next].sent) {

   441

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

   443

		return NETDEV_TX_BUSY;

   444

	}

   445

   446

	/* prepare frame in DMA memory */

   447

	frame[next].sent = 0;

   448

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

   449

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

   450

   451

	priv->kfree_skb_any(skb);

   452

   453

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

   454

	addr_and_length +=

   455

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

   456

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

   457

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

   458

   459

	next = (next + 1) % FIFO_LENGTH;

   460

	/* stop queue if tx ring is full */

   461

	if (!frame[next].sent) {

   463

	}

   464

	return NETDEV_TX_OK;

   465

}

   466

   467

static int ccat_eth_stop(struct net_device *dev)

   468

{

   469

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   471

	priv->stop_queue(dev);

   473

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

   474

	return 0;

   475

}

   476

   477

static void ccat_eth_link_down(struct net_device *dev)

   478

{

   479

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   481

	priv->stop_queue(dev);

   482

	priv->carrier_off(dev);

   483

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

   484

}

   485

   486

static void ccat_eth_link_up(struct net_device *const dev)

   487

{

   488

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   490

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

   491

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

   492

	   speed == SPEED_100 ? 100 : 10,