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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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    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

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    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>

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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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    28

#include "compat.h"

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#include "module.h"

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#include "netdev.h"

    31

    32

/**

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 * EtherCAT frame to enable forwarding on EtherCAT Terminals

    34

 */

    35

static const u8 frameForwardEthernetFrames[] = {

    36

	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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};

    48

    49

#define FIFO_LENGTH 64

    50

static void ec_poll(struct net_device *dev);

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static enum hrtimer_restart poll_timer_callback(struct hrtimer *timer);

    52

    53

#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);

    56

#endif

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static int ccat_eth_open(struct net_device *dev);

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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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    64

static const struct net_device_ops ccat_eth_netdev_ops = {

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

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	.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,

    70

	.ndo_stop = ccat_eth_stop,

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};

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    73

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 */

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}

    77

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static bool ecdev_carrier_ok(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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	return ecdev_get_link(priv->ecdev);

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}

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    84

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);

    88

}

    89

    90

static void ecdev_carrier_off(struct net_device *const netdev)

    91

{

    92

	struct ccat_eth_priv *const priv = netdev_priv(netdev);

    93

	ecdev_set_link(priv->ecdev, 0);

    94

}

    95

    96

static void ecdev_nop(struct net_device *const netdev)

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{

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

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}

   100

   101

static void ecdev_tx_fifo_full(struct ccat_eth_priv *const priv,

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			       const struct ccat_eth_frame *const frame)

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{

   104

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

   105

}

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   107

static void unregister_ecdev(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_close(priv->ecdev);

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	ecdev_withdraw(priv->ecdev);

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}

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typedef void (*fifo_add_function) (struct ccat_eth_frame *,

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				   struct ccat_eth_dma_fifo *);

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   117

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

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   123

	frame->received = 0;

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	iowrite32(addr_and_length, fifo->reg);

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}

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   127

static void ccat_eth_tx_fifo_add_free(struct ccat_eth_frame *frame,

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				      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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}

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static void ccat_eth_tx_fifo_full(struct ccat_eth_priv *const priv,

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				  const struct ccat_eth_frame *const frame)

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{

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	priv->stop_queue(priv->netdev);

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	priv->next_tx_frame = frame;

   139

}

   140

   141

static void ccat_eth_dma_fifo_reset(struct ccat_eth_dma_fifo *fifo)

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{

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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;

   145

   146

	/* reset hw fifo */

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

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	wmb();

   149

   150

	if (fifo->add) {

   151

		while (frame < end) {

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			fifo->add(frame, fifo);

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			++frame;

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		}

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	}

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}

   157

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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,

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				  struct ccat_eth_priv *const priv)

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{

   163

	if (0 !=

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

   165

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

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

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		return -1;

   168

	}

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	fifo->add = add;

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	fifo->reg = fifo_reg;

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	return 0;

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}

   173

   174

/**

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

   176

 */

   177

static void ccat_eth_priv_free_dma(struct ccat_eth_priv *priv)

   178

{

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	/* reset hw fifo's */

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

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

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	wmb();

   183

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	/* release dma */

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	ccat_dma_free(&priv->rx_fifo.dma);

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	ccat_dma_free(&priv->tx_fifo.dma);

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}

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/**

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

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 */

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static int ccat_eth_priv_init_dma(struct ccat_eth_priv *priv)

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{

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	if (ccat_eth_dma_fifo_init

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

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

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		return -1;

   199

	}

   200

   201

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

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		ccat_dma_free(&priv->rx_fifo.dma);

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		return -1;

   207

	}

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	/* disable MAC filter */

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

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	wmb();

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	return 0;

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}

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/**

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

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

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 */

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static void ccat_eth_priv_init_mappings(struct ccat_eth_priv *priv)

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{

   222

	void __iomem *const func_base =

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   225

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

   233

}

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   235

/**

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 * Read link state from CCAT hardware

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

   238

 */

   239

inline static size_t ccat_eth_priv_read_link_state(const struct ccat_eth_priv

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						   *const priv)

   241

{

   242

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

   243

}

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   245

#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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{

   249

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   251

   252

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

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

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

   259

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

   260

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

   261

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

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	//TODO __u64    collisions;

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   264

	/* detailed rx_errors: */

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

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   272

	/* detailed tx_errors */

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	//TODO __u64    tx_aborted_errors;

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	//TODO __u64    tx_carrier_errors;

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	//TODO __u64    tx_fifo_errors;

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	//TODO __u64    tx_heartbeat_errors;

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	//TODO __u64    tx_window_errors;

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	/* for cslip etc */

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	//TODO __u64    rx_compressed;

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	//TODO __u64    tx_compressed;

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	return storage;

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}

   284

#endif

   285

   286

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

   287

				    const void __iomem * const addr)

   288

{

   289

	struct ccat_eth_priv *priv;

   290

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

   291

   292

	priv = netdev_priv(netdev);

   293

	priv->netdev = netdev;

   294

	priv->ccatdev = ccatdev;

   295

   296

	/* ccat register mappings */

   297

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

   298

	ccat_eth_priv_init_mappings(priv);

   302

   303

	if (ccat_eth_priv_init_dma(priv)) {

   304

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

   305

		free_netdev(netdev);

   306

		return NULL;

   307

	}

   308

   309

	/* init netdev with MAC and stack callbacks */

   311

	netdev->netdev_ops = &ccat_eth_netdev_ops;

   312

   313

	/* use as EtherCAT device? */

   314

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

   315

	if (priv->ecdev) {

   316

		priv->carrier_off = ecdev_carrier_off;

   317

		priv->carrier_ok = ecdev_carrier_ok;

   318

		priv->carrier_on = ecdev_carrier_on;

   319

		priv->kfree_skb_any = ecdev_kfree_skb_any;

   320

		priv->start_queue = ecdev_nop;

   321

		priv->stop_queue = ecdev_nop;

   322

		priv->tx_fifo_full = ecdev_tx_fifo_full;

   323

		priv->unregister = unregister_ecdev;

   324

   325

		priv->carrier_off(netdev);

   326

		if (ecdev_open(priv->ecdev)) {

   327

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

   328

			ecdev_withdraw(priv->ecdev);

   329

			ccat_eth_priv_free_dma(priv);

   330

			free_netdev(netdev);

   331

			return NULL;

   332

		}

   333

		return priv;

   334

	}

   335

   336

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

   337

	priv->carrier_off = netif_carrier_off;

   338

	priv->carrier_ok = netif_carrier_ok;

   339

	priv->carrier_on = netif_carrier_on;

   340

	priv->kfree_skb_any = dev_kfree_skb_any;

   341

	priv->start_queue = netif_start_queue;

   342

	priv->stop_queue = netif_stop_queue;

   343

	priv->tx_fifo_full = ccat_eth_tx_fifo_full;

   344

	priv->unregister = unregister_netdev;

   345

   346

	priv->carrier_off(netdev);

   347

	if (register_netdev(netdev)) {

   348

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

   349

		ccat_eth_priv_free_dma(priv);

   350

		free_netdev(netdev);

   351

		return NULL;

   352

	}

   353

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

   354

	return priv;

   355

}

   356

   357

void ccat_eth_remove(struct ccat_eth_priv *const priv)

   358

{

   359

	priv->unregister(priv->netdev);

   360

	ccat_eth_priv_free_dma(priv);

   361

	free_netdev(priv->netdev);

   362

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

   363

}

   364

   365

static int ccat_eth_open(struct net_device *dev)

   366

{

   367

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   368

   369

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

   370

	priv->poll_timer.function = poll_timer_callback;

   371

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

   372

		      HRTIMER_MODE_REL);

   373

	return 0;

   374

}

   375

   376

static const size_t CCATRXDESC_HEADER_LEN = 20;

   377

static void ccat_eth_receive(struct net_device *const dev,

   378

			     const struct ccat_eth_frame *const frame)

   379

{

   380

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   381

	const size_t len = frame->length - CCATRXDESC_HEADER_LEN;

   382

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

   383

   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

	u32 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

			(u64) skb->len, (u64) 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(priv, &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 +=

   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(priv, &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

   475

	priv->stop_queue(dev);

   476

	hrtimer_cancel(&priv->poll_timer);

   477

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

   478

	return 0;

   479

}

   480

   481

static void ccat_eth_link_down(struct net_device *dev)

   482

{

   483

	struct ccat_eth_priv *const priv = netdev_priv(dev);

   484

   485

	priv->stop_queue(dev);

   486

	priv->carrier_off(dev);

   487

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

   488

}

   489

   490

static void ccat_eth_link_up(struct net_device *const dev)

   491

{