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  1 /*
  2 * drivers/net/ethernet/ec_bhf.c
  3 *
  4 * Copyright (C) 2014 Darek Marcinkiewicz <reksio@newterm.pl>
  5 *
  6 * This software is licensed under the terms of the GNU General Public
  7 * License version 2, as published by the Free Software Foundation, and
  8 * may be copied, distributed, and modified under those terms.
  9 *
 10 * This program is distributed in the hope that it will be useful,
 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 13 * GNU General Public License for more details.
 14 *
 15 */
 16
 17/* This is a driver for EtherCAT master module present on CCAT FPGA.
 18 * Those can be found on Bechhoff CX50xx industrial PCs.
 19 */
 20
 21#include <linux/kernel.h>
 22#include <linux/module.h>
 23#include <linux/moduleparam.h>
 24#include <linux/pci.h>
 25#include <linux/init.h>
 26
 27#include <linux/netdevice.h>
 28#include <linux/etherdevice.h>
 29#include <linux/ip.h>
 30#include <linux/skbuff.h>
 31#include <linux/hrtimer.h>
 32#include <linux/interrupt.h>
 33#include <linux/stat.h>
 34
 35#define TIMER_INTERVAL_NSEC	20000
 36
 37#define INFO_BLOCK_SIZE		0x10
 38#define INFO_BLOCK_TYPE		0x0
 39#define INFO_BLOCK_REV		0x2
 40#define INFO_BLOCK_BLK_CNT	0x4
 41#define INFO_BLOCK_TX_CHAN	0x4
 42#define INFO_BLOCK_RX_CHAN	0x5
 43#define INFO_BLOCK_OFFSET	0x8
 44
 45#define EC_MII_OFFSET		0x4
 46#define EC_FIFO_OFFSET		0x8
 47#define EC_MAC_OFFSET		0xc
 48
 49#define MAC_FRAME_ERR_CNT	0x0
 50#define MAC_RX_ERR_CNT		0x1
 51#define MAC_CRC_ERR_CNT		0x2
 52#define MAC_LNK_LST_ERR_CNT	0x3
 53#define MAC_TX_FRAME_CNT	0x10
 54#define MAC_RX_FRAME_CNT	0x14
 55#define MAC_TX_FIFO_LVL		0x20
 56#define MAC_DROPPED_FRMS	0x28
 57#define MAC_CONNECTED_CCAT_FLAG	0x78
 58
 59#define MII_MAC_ADDR		0x8
 60#define MII_MAC_FILT_FLAG	0xe
 61#define MII_LINK_STATUS		0xf
 62
 63#define FIFO_TX_REG		0x0
 64#define FIFO_TX_RESET		0x8
 65#define FIFO_RX_REG		0x10
 66#define FIFO_RX_ADDR_VALID	(1u << 31)
 67#define FIFO_RX_RESET		0x18
 68
 69#define DMA_CHAN_OFFSET		0x1000
 70#define DMA_CHAN_SIZE		0x8
 71
 72#define DMA_WINDOW_SIZE_MASK	0xfffffffc
 73
 74#define ETHERCAT_MASTER_ID	0x14
 75
 76static struct pci_device_id ids[] = {
 77	{ PCI_DEVICE(0x15ec, 0x5000), },
 78	{ 0, }
 79};
 80MODULE_DEVICE_TABLE(pci, ids);
 81
 82struct rx_header {
 83#define RXHDR_NEXT_ADDR_MASK	0xffffffu
 84#define RXHDR_NEXT_VALID	(1u << 31)
 85	__le32 next;
 86#define RXHDR_NEXT_RECV_FLAG	0x1
 87	__le32 recv;
 88#define RXHDR_LEN_MASK		0xfffu
 89	__le16 len;
 90	__le16 port;
 91	__le32 reserved;
 92	u8 timestamp[8];
 93} __packed;
 94
 95#define PKT_PAYLOAD_SIZE	0x7e8
 96struct rx_desc {
 97	struct rx_header header;
 98	u8 data[PKT_PAYLOAD_SIZE];
 99} __packed;
100
101struct tx_header {
102	__le16 len;
103#define TX_HDR_PORT_0		0x1
104#define TX_HDR_PORT_1		0x2
105	u8 port;
106	u8 ts_enable;
107#define TX_HDR_SENT		0x1
108	__le32 sent;
109	u8 timestamp[8];
110} __packed;
111
112struct tx_desc {
113	struct tx_header header;
114	u8 data[PKT_PAYLOAD_SIZE];
115} __packed;
116
117#define FIFO_SIZE		64
118
119static long polling_frequency = TIMER_INTERVAL_NSEC;
120
121struct bhf_dma {
122	u8 *buf;
123	size_t len;
124	dma_addr_t buf_phys;
125
126	u8 *alloc;
127	size_t alloc_len;
128	dma_addr_t alloc_phys;
129};
130
131struct ec_bhf_priv {
132	struct net_device *net_dev;
133	struct pci_dev *dev;
134
135	void __iomem *io;
136	void __iomem *dma_io;
137
138	struct hrtimer hrtimer;
139
140	int tx_dma_chan;
141	int rx_dma_chan;
142	void __iomem *ec_io;
143	void __iomem *fifo_io;
144	void __iomem *mii_io;
145	void __iomem *mac_io;
146
147	struct bhf_dma rx_buf;
148	struct rx_desc *rx_descs;
149	int rx_dnext;
150	int rx_dcount;
151
152	struct bhf_dma tx_buf;
153	struct tx_desc *tx_descs;
154	int tx_dcount;
155	int tx_dnext;
156
157	u64 stat_rx_bytes;
158	u64 stat_tx_bytes;
159};
160
161#define PRIV_TO_DEV(priv) (&(priv)->dev->dev)
162
163static void ec_bhf_reset(struct ec_bhf_priv *priv)
164{
165	iowrite8(0, priv->mac_io + MAC_FRAME_ERR_CNT);
166	iowrite8(0, priv->mac_io + MAC_RX_ERR_CNT);
167	iowrite8(0, priv->mac_io + MAC_CRC_ERR_CNT);
168	iowrite8(0, priv->mac_io + MAC_LNK_LST_ERR_CNT);
169	iowrite32(0, priv->mac_io + MAC_TX_FRAME_CNT);
170	iowrite32(0, priv->mac_io + MAC_RX_FRAME_CNT);
171	iowrite8(0, priv->mac_io + MAC_DROPPED_FRMS);
172
173	iowrite8(0, priv->fifo_io + FIFO_TX_RESET);
174	iowrite8(0, priv->fifo_io + FIFO_RX_RESET);
175
176	iowrite8(0, priv->mac_io + MAC_TX_FIFO_LVL);
177}
178
179static void ec_bhf_send_packet(struct ec_bhf_priv *priv, struct tx_desc *desc)
180{
181	u32 len = le16_to_cpu(desc->header.len) + sizeof(desc->header);
182	u32 addr = (u8 *)desc - priv->tx_buf.buf;
183
184	iowrite32((ALIGN(len, 8) << 24) | addr, priv->fifo_io + FIFO_TX_REG);
185}
186
187static int ec_bhf_desc_sent(struct tx_desc *desc)
188{
189	return le32_to_cpu(desc->header.sent) & TX_HDR_SENT;
190}
191
192static void ec_bhf_process_tx(struct ec_bhf_priv *priv)
193{
194	if (unlikely(netif_queue_stopped(priv->net_dev))) {
195		/* Make sure that we perceive changes to tx_dnext. */
196		smp_rmb();
197
198		if (ec_bhf_desc_sent(&priv->tx_descs[priv->tx_dnext]))
199			netif_wake_queue(priv->net_dev);
200	}
201}
202
203static int ec_bhf_pkt_received(struct rx_desc *desc)
204{
205	return le32_to_cpu(desc->header.recv) & RXHDR_NEXT_RECV_FLAG;
206}
207
208static void ec_bhf_add_rx_desc(struct ec_bhf_priv *priv, struct rx_desc *desc)
209{
210	iowrite32(FIFO_RX_ADDR_VALID | ((u8 *)(desc) - priv->rx_buf.buf),
211		  priv->fifo_io + FIFO_RX_REG);
212}
213
214static void ec_bhf_process_rx(struct ec_bhf_priv *priv)
215{
216	struct rx_desc *desc = &priv->rx_descs[priv->rx_dnext];
217
218	while (ec_bhf_pkt_received(desc)) {
219		int pkt_size = (le16_to_cpu(desc->header.len) &
220			       RXHDR_LEN_MASK) - sizeof(struct rx_header) - 4;
221		u8 *data = desc->data;
222		struct sk_buff *skb;
223
224		skb = netdev_alloc_skb_ip_align(priv->net_dev, pkt_size);
225		if (skb) {
226			memcpy(skb_put(skb, pkt_size), data, pkt_size);
227			skb->protocol = eth_type_trans(skb, priv->net_dev);
228			priv->stat_rx_bytes += pkt_size;
229
230			netif_rx(skb);
231		} else {
232			dev_err_ratelimited(PRIV_TO_DEV(priv),
233					    "Couldn't allocate a skb_buff for a packet of size %u\n",
234					    pkt_size);
235		}
236
237		desc->header.recv = 0;
238
239		ec_bhf_add_rx_desc(priv, desc);
240
241		priv->rx_dnext = (priv->rx_dnext + 1) % priv->rx_dcount;
242		desc = &priv->rx_descs[priv->rx_dnext];
243	}
244}
245
246static enum hrtimer_restart ec_bhf_timer_fun(struct hrtimer *timer)
247{
248	struct ec_bhf_priv *priv = container_of(timer, struct ec_bhf_priv,
249						hrtimer);
250	ec_bhf_process_rx(priv);
251	ec_bhf_process_tx(priv);
252
253	if (!netif_running(priv->net_dev))
254		return HRTIMER_NORESTART;
255
256	hrtimer_forward_now(timer, ktime_set(0, polling_frequency));
257	return HRTIMER_RESTART;
258}
259
260static int ec_bhf_setup_offsets(struct ec_bhf_priv *priv)
261{
262	struct device *dev = PRIV_TO_DEV(priv);
263	unsigned block_count, i;
264	void __iomem *ec_info;
265
266	block_count = ioread8(priv->io + INFO_BLOCK_BLK_CNT);
267	for (i = 0; i < block_count; i++) {
268		u16 type = ioread16(priv->io + i * INFO_BLOCK_SIZE +
269				    INFO_BLOCK_TYPE);
270		if (type == ETHERCAT_MASTER_ID)
271			break;
272	}
273	if (i == block_count) {
274		dev_err(dev, "EtherCAT master with DMA block not found\n");
275		return -ENODEV;
276	}
277
278	ec_info = priv->io + i * INFO_BLOCK_SIZE;
279
280	priv->tx_dma_chan = ioread8(ec_info + INFO_BLOCK_TX_CHAN);
281	priv->rx_dma_chan = ioread8(ec_info + INFO_BLOCK_RX_CHAN);
282
283	priv->ec_io = priv->io + ioread32(ec_info + INFO_BLOCK_OFFSET);
284	priv->mii_io = priv->ec_io + ioread32(priv->ec_io + EC_MII_OFFSET);
285	priv->fifo_io = priv->ec_io + ioread32(priv->ec_io + EC_FIFO_OFFSET);
286	priv->mac_io = priv->ec_io + ioread32(priv->ec_io + EC_MAC_OFFSET);
287
288	return 0;
289}
290
291static netdev_tx_t ec_bhf_start_xmit(struct sk_buff *skb,
292				     struct net_device *net_dev)
293{
294	struct ec_bhf_priv *priv = netdev_priv(net_dev);
295	struct tx_desc *desc;
296	unsigned len;
297
298	desc = &priv->tx_descs[priv->tx_dnext];
299
300	skb_copy_and_csum_dev(skb, desc->data);
301	len = skb->len;
302
303	memset(&desc->header, 0, sizeof(desc->header));
304	desc->header.len = cpu_to_le16(len);
305	desc->header.port = TX_HDR_PORT_0;
306
307	ec_bhf_send_packet(priv, desc);
308
309	priv->tx_dnext = (priv->tx_dnext + 1) % priv->tx_dcount;
310
311	if (!ec_bhf_desc_sent(&priv->tx_descs[priv->tx_dnext])) {
312		/* Make sure that updates to tx_dnext are perceived
313		 * by timer routine.
314		 */
315		smp_wmb();
316
317		netif_stop_queue(net_dev);
318	}
319
320	priv->stat_tx_bytes += len;
321
322	dev_kfree_skb(skb);
323
324	return NETDEV_TX_OK;
325}
326
327static int ec_bhf_alloc_dma_mem(struct ec_bhf_priv *priv,
328				struct bhf_dma *buf,
329				int channel,
330				int size)
331{
332	int offset = channel * DMA_CHAN_SIZE + DMA_CHAN_OFFSET;
333	struct device *dev = PRIV_TO_DEV(priv);
334	u32 mask;
335
336	iowrite32(0xffffffff, priv->dma_io + offset);
337
338	mask = ioread32(priv->dma_io + offset);
339	mask &= DMA_WINDOW_SIZE_MASK;
340
341	/* We want to allocate a chunk of memory that is:
342	 * - aligned to the mask we just read
343	 * - is of size 2^mask bytes (at most)
344	 * In order to ensure that we will allocate buffer of
345	 * 2 * 2^mask bytes.
346	 */
347	buf->len = min_t(int, ~mask + 1, size);
348	buf->alloc_len = 2 * buf->len;
349
350	buf->alloc = dma_alloc_coherent(dev, buf->alloc_len, &buf->alloc_phys,
351					GFP_KERNEL);
352	if (buf->alloc == NULL) {
353		dev_err(dev, "Failed to allocate buffer\n");
354		return -ENOMEM;
355	}
356
357	buf->buf_phys = (buf->alloc_phys + buf->len) & mask;
358	buf->buf = buf->alloc + (buf->buf_phys - buf->alloc_phys);
359
360	iowrite32(0, priv->dma_io + offset + 4);
361	iowrite32(buf->buf_phys, priv->dma_io + offset);
362
363	return 0;
364}
365
366static void ec_bhf_setup_tx_descs(struct ec_bhf_priv *priv)
367{
368	int i = 0;
369
370	priv->tx_dcount = priv->tx_buf.len / sizeof(struct tx_desc);
371	priv->tx_descs = (struct tx_desc *)priv->tx_buf.buf;
372	priv->tx_dnext = 0;
373
374	for (i = 0; i < priv->tx_dcount; i++)
375		priv->tx_descs[i].header.sent = cpu_to_le32(TX_HDR_SENT);
376}
377
378static void ec_bhf_setup_rx_descs(struct ec_bhf_priv *priv)
379{
380	int i;
381
382	priv->rx_dcount = priv->rx_buf.len / sizeof(struct rx_desc);
383	priv->rx_descs = (struct rx_desc *)priv->rx_buf.buf;
384	priv->rx_dnext = 0;
385
386	for (i = 0; i < priv->rx_dcount; i++) {
387		struct rx_desc *desc = &priv->rx_descs[i];
388		u32 next;
389
390		if (i != priv->rx_dcount - 1)
391			next = (u8 *)(desc + 1) - priv->rx_buf.buf;
392		else
393			next = 0;
394		next |= RXHDR_NEXT_VALID;
395		desc->header.next = cpu_to_le32(next);
396		desc->header.recv = 0;
397		ec_bhf_add_rx_desc(priv, desc);
398	}
399}
400
401static int ec_bhf_open(struct net_device *net_dev)
402{
403	struct ec_bhf_priv *priv = netdev_priv(net_dev);
404	struct device *dev = PRIV_TO_DEV(priv);
405	int err = 0;
406
407	ec_bhf_reset(priv);
408
409	err = ec_bhf_alloc_dma_mem(priv, &priv->rx_buf, priv->rx_dma_chan,
410				   FIFO_SIZE * sizeof(struct rx_desc));
411	if (err) {
412		dev_err(dev, "Failed to allocate rx buffer\n");
413		goto out;
414	}
415	ec_bhf_setup_rx_descs(priv);
416
417	err = ec_bhf_alloc_dma_mem(priv, &priv->tx_buf, priv->tx_dma_chan,
418				   FIFO_SIZE * sizeof(struct tx_desc));
419	if (err) {
420		dev_err(dev, "Failed to allocate tx buffer\n");
421		goto error_rx_free;
422	}
423	iowrite8(0, priv->mii_io + MII_MAC_FILT_FLAG);
424	ec_bhf_setup_tx_descs(priv);
425
426	netif_start_queue(net_dev);
427
428	hrtimer_init(&priv->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
429	priv->hrtimer.function = ec_bhf_timer_fun;
430	hrtimer_start(&priv->hrtimer, ktime_set(0, polling_frequency),
431		      HRTIMER_MODE_REL);
432
433	return 0;
434
435error_rx_free:
436	dma_free_coherent(dev, priv->rx_buf.alloc_len, priv->rx_buf.alloc,
437			  priv->rx_buf.alloc_len);
438out:
439	return err;
440}
441
442static int ec_bhf_stop(struct net_device *net_dev)
443{
444	struct ec_bhf_priv *priv = netdev_priv(net_dev);
445	struct device *dev = PRIV_TO_DEV(priv);
446
447	hrtimer_cancel(&priv->hrtimer);
448
449	ec_bhf_reset(priv);
450
451	netif_tx_disable(net_dev);
452
453	dma_free_coherent(dev, priv->tx_buf.alloc_len,
454			  priv->tx_buf.alloc, priv->tx_buf.alloc_phys);
455	dma_free_coherent(dev, priv->rx_buf.alloc_len,
456			  priv->rx_buf.alloc, priv->rx_buf.alloc_phys);
457
458	return 0;
459}
460
461static struct rtnl_link_stats64 *
462ec_bhf_get_stats(struct net_device *net_dev,
463		 struct rtnl_link_stats64 *stats)
464{
465	struct ec_bhf_priv *priv = netdev_priv(net_dev);
466
467	stats->rx_errors = ioread8(priv->mac_io + MAC_RX_ERR_CNT) +
468				ioread8(priv->mac_io + MAC_CRC_ERR_CNT) +
469				ioread8(priv->mac_io + MAC_FRAME_ERR_CNT);
470	stats->rx_packets = ioread32(priv->mac_io + MAC_RX_FRAME_CNT);
471	stats->tx_packets = ioread32(priv->mac_io + MAC_TX_FRAME_CNT);
472	stats->rx_dropped = ioread8(priv->mac_io + MAC_DROPPED_FRMS);
473
474	stats->tx_bytes = priv->stat_tx_bytes;
475	stats->rx_bytes = priv->stat_rx_bytes;
476
477	return stats;
478}
479
480static const struct net_device_ops ec_bhf_netdev_ops = {
481	.ndo_start_xmit		= ec_bhf_start_xmit,
482	.ndo_open		= ec_bhf_open,
483	.ndo_stop		= ec_bhf_stop,
484	.ndo_get_stats64	= ec_bhf_get_stats,
485	.ndo_change_mtu		= eth_change_mtu,
486	.ndo_validate_addr	= eth_validate_addr,
487	.ndo_set_mac_address	= eth_mac_addr
488};
489
490static int ec_bhf_probe(struct pci_dev *dev, const struct pci_device_id *id)
491{
492	struct net_device *net_dev;
493	struct ec_bhf_priv *priv;
494	void __iomem *dma_io;
495	void __iomem *io;
496	int err = 0;
497
498	err = pci_enable_device(dev);
499	if (err)
500		return err;
501
502	pci_set_master(dev);
503
504	err = pci_set_dma_mask(dev, DMA_BIT_MASK(32));
505	if (err) {
506		dev_err(&dev->dev,
507			"Required dma mask not supported, failed to initialize device\n");
508		err = -EIO;
509		goto err_disable_dev;
510	}
511
512	err = pci_set_consistent_dma_mask(dev, DMA_BIT_MASK(32));
513	if (err) {
514		dev_err(&dev->dev,
515			"Required dma mask not supported, failed to initialize device\n");
516		goto err_disable_dev;
517	}
518
519	err = pci_request_regions(dev, "ec_bhf");
520	if (err) {
521		dev_err(&dev->dev, "Failed to request pci memory regions\n");
522		goto err_disable_dev;
523	}
524
525	io = pci_iomap(dev, 0, 0);
526	if (!io) {
527		dev_err(&dev->dev, "Failed to map pci card memory bar 0");
528		err = -EIO;
529		goto err_release_regions;
530	}
531
532	dma_io = pci_iomap(dev, 2, 0);
533	if (!dma_io) {
534		dev_err(&dev->dev, "Failed to map pci card memory bar 2");
535		err = -EIO;
536		goto err_unmap;
537	}
538
539	net_dev = alloc_etherdev(sizeof(struct ec_bhf_priv));
540	if (net_dev == NULL) {
541		err = -ENOMEM;
542		goto err_unmap_dma_io;
543	}
544
545	pci_set_drvdata(dev, net_dev);
546	SET_NETDEV_DEV(net_dev, &dev->dev);
547
548	net_dev->features = 0;
549	net_dev->flags |= IFF_NOARP;
550
551	net_dev->netdev_ops = &ec_bhf_netdev_ops;
552
553	priv = netdev_priv(net_dev);
554	priv->net_dev = net_dev;
555	priv->io = io;
556	priv->dma_io = dma_io;
557	priv->dev = dev;
558
559	err = ec_bhf_setup_offsets(priv);
560	if (err < 0)
561		goto err_free_net_dev;
562
563	memcpy_fromio(net_dev->dev_addr, priv->mii_io + MII_MAC_ADDR, 6);
564
565	err = register_netdev(net_dev);
566	if (err < 0)
567		goto err_free_net_dev;
568
569	return 0;
570
571err_free_net_dev:
572	free_netdev(net_dev);
573err_unmap_dma_io:
574	pci_iounmap(dev, dma_io);
575err_unmap:
576	pci_iounmap(dev, io);
577err_release_regions:
578	pci_release_regions(dev);
579err_disable_dev:
580	pci_clear_master(dev);
581	pci_disable_device(dev);
582
583	return err;
584}
585
586static void ec_bhf_remove(struct pci_dev *dev)
587{
588	struct net_device *net_dev = pci_get_drvdata(dev);
589	struct ec_bhf_priv *priv = netdev_priv(net_dev);
590
591	unregister_netdev(net_dev);
592	free_netdev(net_dev);
593
594	pci_iounmap(dev, priv->dma_io);
595	pci_iounmap(dev, priv->io);
596	pci_release_regions(dev);
597	pci_clear_master(dev);
598	pci_disable_device(dev);
599}
600
601static struct pci_driver pci_driver = {
602	.name		= "ec_bhf",
603	.id_table	= ids,
604	.probe		= ec_bhf_probe,
605	.remove		= ec_bhf_remove,
606};
607module_pci_driver(pci_driver);
608
609module_param(polling_frequency, long, S_IRUGO);
610MODULE_PARM_DESC(polling_frequency, "Polling timer frequency in ns");
611
612MODULE_LICENSE("GPL");
613MODULE_AUTHOR("Dariusz Marcinkiewicz <reksio@newterm.pl>");