xref: /openbmc/linux/drivers/net/ethernet/ec_bhf.c (revision ae213c44)
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 
76 static const struct pci_device_id ids[] = {
77 	{ PCI_DEVICE(0x15ec, 0x5000), },
78 	{ 0, }
79 };
80 MODULE_DEVICE_TABLE(pci, ids);
81 
82 struct 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
96 struct rx_desc {
97 	struct rx_header header;
98 	u8 data[PKT_PAYLOAD_SIZE];
99 } __packed;
100 
101 struct 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 
112 struct tx_desc {
113 	struct tx_header header;
114 	u8 data[PKT_PAYLOAD_SIZE];
115 } __packed;
116 
117 #define FIFO_SIZE		64
118 
119 static long polling_frequency = TIMER_INTERVAL_NSEC;
120 
121 struct 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 
131 struct 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 
163 static 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 
179 static 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 
187 static int ec_bhf_desc_sent(struct tx_desc *desc)
188 {
189 	return le32_to_cpu(desc->header.sent) & TX_HDR_SENT;
190 }
191 
192 static 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 
203 static int ec_bhf_pkt_received(struct rx_desc *desc)
204 {
205 	return le32_to_cpu(desc->header.recv) & RXHDR_NEXT_RECV_FLAG;
206 }
207 
208 static 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 
214 static 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 			skb_put_data(skb, 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 
246 static 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, polling_frequency);
257 	return HRTIMER_RESTART;
258 }
259 
260 static 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 
291 static 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 
327 static 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 
366 static 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 
378 static 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 
401 static 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, polling_frequency, HRTIMER_MODE_REL);
431 
432 	return 0;
433 
434 error_rx_free:
435 	dma_free_coherent(dev, priv->rx_buf.alloc_len, priv->rx_buf.alloc,
436 			  priv->rx_buf.alloc_len);
437 out:
438 	return err;
439 }
440 
441 static int ec_bhf_stop(struct net_device *net_dev)
442 {
443 	struct ec_bhf_priv *priv = netdev_priv(net_dev);
444 	struct device *dev = PRIV_TO_DEV(priv);
445 
446 	hrtimer_cancel(&priv->hrtimer);
447 
448 	ec_bhf_reset(priv);
449 
450 	netif_tx_disable(net_dev);
451 
452 	dma_free_coherent(dev, priv->tx_buf.alloc_len,
453 			  priv->tx_buf.alloc, priv->tx_buf.alloc_phys);
454 	dma_free_coherent(dev, priv->rx_buf.alloc_len,
455 			  priv->rx_buf.alloc, priv->rx_buf.alloc_phys);
456 
457 	return 0;
458 }
459 
460 static void
461 ec_bhf_get_stats(struct net_device *net_dev,
462 		 struct rtnl_link_stats64 *stats)
463 {
464 	struct ec_bhf_priv *priv = netdev_priv(net_dev);
465 
466 	stats->rx_errors = ioread8(priv->mac_io + MAC_RX_ERR_CNT) +
467 				ioread8(priv->mac_io + MAC_CRC_ERR_CNT) +
468 				ioread8(priv->mac_io + MAC_FRAME_ERR_CNT);
469 	stats->rx_packets = ioread32(priv->mac_io + MAC_RX_FRAME_CNT);
470 	stats->tx_packets = ioread32(priv->mac_io + MAC_TX_FRAME_CNT);
471 	stats->rx_dropped = ioread8(priv->mac_io + MAC_DROPPED_FRMS);
472 
473 	stats->tx_bytes = priv->stat_tx_bytes;
474 	stats->rx_bytes = priv->stat_rx_bytes;
475 }
476 
477 static const struct net_device_ops ec_bhf_netdev_ops = {
478 	.ndo_start_xmit		= ec_bhf_start_xmit,
479 	.ndo_open		= ec_bhf_open,
480 	.ndo_stop		= ec_bhf_stop,
481 	.ndo_get_stats64	= ec_bhf_get_stats,
482 	.ndo_validate_addr	= eth_validate_addr,
483 	.ndo_set_mac_address	= eth_mac_addr
484 };
485 
486 static int ec_bhf_probe(struct pci_dev *dev, const struct pci_device_id *id)
487 {
488 	struct net_device *net_dev;
489 	struct ec_bhf_priv *priv;
490 	void __iomem *dma_io;
491 	void __iomem *io;
492 	int err = 0;
493 
494 	err = pci_enable_device(dev);
495 	if (err)
496 		return err;
497 
498 	pci_set_master(dev);
499 
500 	err = pci_set_dma_mask(dev, DMA_BIT_MASK(32));
501 	if (err) {
502 		dev_err(&dev->dev,
503 			"Required dma mask not supported, failed to initialize device\n");
504 		err = -EIO;
505 		goto err_disable_dev;
506 	}
507 
508 	err = pci_set_consistent_dma_mask(dev, DMA_BIT_MASK(32));
509 	if (err) {
510 		dev_err(&dev->dev,
511 			"Required dma mask not supported, failed to initialize device\n");
512 		goto err_disable_dev;
513 	}
514 
515 	err = pci_request_regions(dev, "ec_bhf");
516 	if (err) {
517 		dev_err(&dev->dev, "Failed to request pci memory regions\n");
518 		goto err_disable_dev;
519 	}
520 
521 	io = pci_iomap(dev, 0, 0);
522 	if (!io) {
523 		dev_err(&dev->dev, "Failed to map pci card memory bar 0");
524 		err = -EIO;
525 		goto err_release_regions;
526 	}
527 
528 	dma_io = pci_iomap(dev, 2, 0);
529 	if (!dma_io) {
530 		dev_err(&dev->dev, "Failed to map pci card memory bar 2");
531 		err = -EIO;
532 		goto err_unmap;
533 	}
534 
535 	net_dev = alloc_etherdev(sizeof(struct ec_bhf_priv));
536 	if (net_dev == NULL) {
537 		err = -ENOMEM;
538 		goto err_unmap_dma_io;
539 	}
540 
541 	pci_set_drvdata(dev, net_dev);
542 	SET_NETDEV_DEV(net_dev, &dev->dev);
543 
544 	net_dev->features = 0;
545 	net_dev->flags |= IFF_NOARP;
546 
547 	net_dev->netdev_ops = &ec_bhf_netdev_ops;
548 
549 	priv = netdev_priv(net_dev);
550 	priv->net_dev = net_dev;
551 	priv->io = io;
552 	priv->dma_io = dma_io;
553 	priv->dev = dev;
554 
555 	err = ec_bhf_setup_offsets(priv);
556 	if (err < 0)
557 		goto err_free_net_dev;
558 
559 	memcpy_fromio(net_dev->dev_addr, priv->mii_io + MII_MAC_ADDR, 6);
560 
561 	err = register_netdev(net_dev);
562 	if (err < 0)
563 		goto err_free_net_dev;
564 
565 	return 0;
566 
567 err_free_net_dev:
568 	free_netdev(net_dev);
569 err_unmap_dma_io:
570 	pci_iounmap(dev, dma_io);
571 err_unmap:
572 	pci_iounmap(dev, io);
573 err_release_regions:
574 	pci_release_regions(dev);
575 err_disable_dev:
576 	pci_clear_master(dev);
577 	pci_disable_device(dev);
578 
579 	return err;
580 }
581 
582 static void ec_bhf_remove(struct pci_dev *dev)
583 {
584 	struct net_device *net_dev = pci_get_drvdata(dev);
585 	struct ec_bhf_priv *priv = netdev_priv(net_dev);
586 
587 	unregister_netdev(net_dev);
588 	free_netdev(net_dev);
589 
590 	pci_iounmap(dev, priv->dma_io);
591 	pci_iounmap(dev, priv->io);
592 	pci_release_regions(dev);
593 	pci_clear_master(dev);
594 	pci_disable_device(dev);
595 }
596 
597 static struct pci_driver pci_driver = {
598 	.name		= "ec_bhf",
599 	.id_table	= ids,
600 	.probe		= ec_bhf_probe,
601 	.remove		= ec_bhf_remove,
602 };
603 module_pci_driver(pci_driver);
604 
605 module_param(polling_frequency, long, 0444);
606 MODULE_PARM_DESC(polling_frequency, "Polling timer frequency in ns");
607 
608 MODULE_LICENSE("GPL");
609 MODULE_AUTHOR("Dariusz Marcinkiewicz <reksio@newterm.pl>");
610