xref: /openbmc/linux/drivers/net/ethernet/ec_bhf.c (revision b8b350af)
1 // SPDX-License-Identifier: GPL-2.0-only
2  /*
3  * drivers/net/ethernet/ec_bhf.c
4  *
5  * Copyright (C) 2014 Darek Marcinkiewicz <reksio@newterm.pl>
6  */
7 
8 /* This is a driver for EtherCAT master module present on CCAT FPGA.
9  * Those can be found on Bechhoff CX50xx industrial PCs.
10  */
11 
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/moduleparam.h>
15 #include <linux/pci.h>
16 #include <linux/init.h>
17 
18 #include <linux/netdevice.h>
19 #include <linux/etherdevice.h>
20 #include <linux/ip.h>
21 #include <linux/skbuff.h>
22 #include <linux/hrtimer.h>
23 #include <linux/interrupt.h>
24 #include <linux/stat.h>
25 
26 #define TIMER_INTERVAL_NSEC	20000
27 
28 #define INFO_BLOCK_SIZE		0x10
29 #define INFO_BLOCK_TYPE		0x0
30 #define INFO_BLOCK_REV		0x2
31 #define INFO_BLOCK_BLK_CNT	0x4
32 #define INFO_BLOCK_TX_CHAN	0x4
33 #define INFO_BLOCK_RX_CHAN	0x5
34 #define INFO_BLOCK_OFFSET	0x8
35 
36 #define EC_MII_OFFSET		0x4
37 #define EC_FIFO_OFFSET		0x8
38 #define EC_MAC_OFFSET		0xc
39 
40 #define MAC_FRAME_ERR_CNT	0x0
41 #define MAC_RX_ERR_CNT		0x1
42 #define MAC_CRC_ERR_CNT		0x2
43 #define MAC_LNK_LST_ERR_CNT	0x3
44 #define MAC_TX_FRAME_CNT	0x10
45 #define MAC_RX_FRAME_CNT	0x14
46 #define MAC_TX_FIFO_LVL		0x20
47 #define MAC_DROPPED_FRMS	0x28
48 #define MAC_CONNECTED_CCAT_FLAG	0x78
49 
50 #define MII_MAC_ADDR		0x8
51 #define MII_MAC_FILT_FLAG	0xe
52 #define MII_LINK_STATUS		0xf
53 
54 #define FIFO_TX_REG		0x0
55 #define FIFO_TX_RESET		0x8
56 #define FIFO_RX_REG		0x10
57 #define FIFO_RX_ADDR_VALID	(1u << 31)
58 #define FIFO_RX_RESET		0x18
59 
60 #define DMA_CHAN_OFFSET		0x1000
61 #define DMA_CHAN_SIZE		0x8
62 
63 #define DMA_WINDOW_SIZE_MASK	0xfffffffc
64 
65 #define ETHERCAT_MASTER_ID	0x14
66 
67 static const struct pci_device_id ids[] = {
68 	{ PCI_DEVICE(0x15ec, 0x5000), },
69 	{ 0, }
70 };
71 MODULE_DEVICE_TABLE(pci, ids);
72 
73 struct rx_header {
74 #define RXHDR_NEXT_ADDR_MASK	0xffffffu
75 #define RXHDR_NEXT_VALID	(1u << 31)
76 	__le32 next;
77 #define RXHDR_NEXT_RECV_FLAG	0x1
78 	__le32 recv;
79 #define RXHDR_LEN_MASK		0xfffu
80 	__le16 len;
81 	__le16 port;
82 	__le32 reserved;
83 	u8 timestamp[8];
84 } __packed;
85 
86 #define PKT_PAYLOAD_SIZE	0x7e8
87 struct rx_desc {
88 	struct rx_header header;
89 	u8 data[PKT_PAYLOAD_SIZE];
90 } __packed;
91 
92 struct tx_header {
93 	__le16 len;
94 #define TX_HDR_PORT_0		0x1
95 #define TX_HDR_PORT_1		0x2
96 	u8 port;
97 	u8 ts_enable;
98 #define TX_HDR_SENT		0x1
99 	__le32 sent;
100 	u8 timestamp[8];
101 } __packed;
102 
103 struct tx_desc {
104 	struct tx_header header;
105 	u8 data[PKT_PAYLOAD_SIZE];
106 } __packed;
107 
108 #define FIFO_SIZE		64
109 
110 static long polling_frequency = TIMER_INTERVAL_NSEC;
111 
112 struct bhf_dma {
113 	u8 *buf;
114 	size_t len;
115 	dma_addr_t buf_phys;
116 
117 	u8 *alloc;
118 	size_t alloc_len;
119 	dma_addr_t alloc_phys;
120 };
121 
122 struct ec_bhf_priv {
123 	struct net_device *net_dev;
124 	struct pci_dev *dev;
125 
126 	void __iomem *io;
127 	void __iomem *dma_io;
128 
129 	struct hrtimer hrtimer;
130 
131 	int tx_dma_chan;
132 	int rx_dma_chan;
133 	void __iomem *ec_io;
134 	void __iomem *fifo_io;
135 	void __iomem *mii_io;
136 	void __iomem *mac_io;
137 
138 	struct bhf_dma rx_buf;
139 	struct rx_desc *rx_descs;
140 	int rx_dnext;
141 	int rx_dcount;
142 
143 	struct bhf_dma tx_buf;
144 	struct tx_desc *tx_descs;
145 	int tx_dcount;
146 	int tx_dnext;
147 
148 	u64 stat_rx_bytes;
149 	u64 stat_tx_bytes;
150 };
151 
152 #define PRIV_TO_DEV(priv) (&(priv)->dev->dev)
153 
154 static void ec_bhf_reset(struct ec_bhf_priv *priv)
155 {
156 	iowrite8(0, priv->mac_io + MAC_FRAME_ERR_CNT);
157 	iowrite8(0, priv->mac_io + MAC_RX_ERR_CNT);
158 	iowrite8(0, priv->mac_io + MAC_CRC_ERR_CNT);
159 	iowrite8(0, priv->mac_io + MAC_LNK_LST_ERR_CNT);
160 	iowrite32(0, priv->mac_io + MAC_TX_FRAME_CNT);
161 	iowrite32(0, priv->mac_io + MAC_RX_FRAME_CNT);
162 	iowrite8(0, priv->mac_io + MAC_DROPPED_FRMS);
163 
164 	iowrite8(0, priv->fifo_io + FIFO_TX_RESET);
165 	iowrite8(0, priv->fifo_io + FIFO_RX_RESET);
166 
167 	iowrite8(0, priv->mac_io + MAC_TX_FIFO_LVL);
168 }
169 
170 static void ec_bhf_send_packet(struct ec_bhf_priv *priv, struct tx_desc *desc)
171 {
172 	u32 len = le16_to_cpu(desc->header.len) + sizeof(desc->header);
173 	u32 addr = (u8 *)desc - priv->tx_buf.buf;
174 
175 	iowrite32((ALIGN(len, 8) << 24) | addr, priv->fifo_io + FIFO_TX_REG);
176 }
177 
178 static int ec_bhf_desc_sent(struct tx_desc *desc)
179 {
180 	return le32_to_cpu(desc->header.sent) & TX_HDR_SENT;
181 }
182 
183 static void ec_bhf_process_tx(struct ec_bhf_priv *priv)
184 {
185 	if (unlikely(netif_queue_stopped(priv->net_dev))) {
186 		/* Make sure that we perceive changes to tx_dnext. */
187 		smp_rmb();
188 
189 		if (ec_bhf_desc_sent(&priv->tx_descs[priv->tx_dnext]))
190 			netif_wake_queue(priv->net_dev);
191 	}
192 }
193 
194 static int ec_bhf_pkt_received(struct rx_desc *desc)
195 {
196 	return le32_to_cpu(desc->header.recv) & RXHDR_NEXT_RECV_FLAG;
197 }
198 
199 static void ec_bhf_add_rx_desc(struct ec_bhf_priv *priv, struct rx_desc *desc)
200 {
201 	iowrite32(FIFO_RX_ADDR_VALID | ((u8 *)(desc) - priv->rx_buf.buf),
202 		  priv->fifo_io + FIFO_RX_REG);
203 }
204 
205 static void ec_bhf_process_rx(struct ec_bhf_priv *priv)
206 {
207 	struct rx_desc *desc = &priv->rx_descs[priv->rx_dnext];
208 
209 	while (ec_bhf_pkt_received(desc)) {
210 		int pkt_size = (le16_to_cpu(desc->header.len) &
211 			       RXHDR_LEN_MASK) - sizeof(struct rx_header) - 4;
212 		u8 *data = desc->data;
213 		struct sk_buff *skb;
214 
215 		skb = netdev_alloc_skb_ip_align(priv->net_dev, pkt_size);
216 		if (skb) {
217 			skb_put_data(skb, data, pkt_size);
218 			skb->protocol = eth_type_trans(skb, priv->net_dev);
219 			priv->stat_rx_bytes += pkt_size;
220 
221 			netif_rx(skb);
222 		} else {
223 			dev_err_ratelimited(PRIV_TO_DEV(priv),
224 					    "Couldn't allocate a skb_buff for a packet of size %u\n",
225 					    pkt_size);
226 		}
227 
228 		desc->header.recv = 0;
229 
230 		ec_bhf_add_rx_desc(priv, desc);
231 
232 		priv->rx_dnext = (priv->rx_dnext + 1) % priv->rx_dcount;
233 		desc = &priv->rx_descs[priv->rx_dnext];
234 	}
235 }
236 
237 static enum hrtimer_restart ec_bhf_timer_fun(struct hrtimer *timer)
238 {
239 	struct ec_bhf_priv *priv = container_of(timer, struct ec_bhf_priv,
240 						hrtimer);
241 	ec_bhf_process_rx(priv);
242 	ec_bhf_process_tx(priv);
243 
244 	if (!netif_running(priv->net_dev))
245 		return HRTIMER_NORESTART;
246 
247 	hrtimer_forward_now(timer, polling_frequency);
248 	return HRTIMER_RESTART;
249 }
250 
251 static int ec_bhf_setup_offsets(struct ec_bhf_priv *priv)
252 {
253 	struct device *dev = PRIV_TO_DEV(priv);
254 	unsigned block_count, i;
255 	void __iomem *ec_info;
256 
257 	block_count = ioread8(priv->io + INFO_BLOCK_BLK_CNT);
258 	for (i = 0; i < block_count; i++) {
259 		u16 type = ioread16(priv->io + i * INFO_BLOCK_SIZE +
260 				    INFO_BLOCK_TYPE);
261 		if (type == ETHERCAT_MASTER_ID)
262 			break;
263 	}
264 	if (i == block_count) {
265 		dev_err(dev, "EtherCAT master with DMA block not found\n");
266 		return -ENODEV;
267 	}
268 
269 	ec_info = priv->io + i * INFO_BLOCK_SIZE;
270 
271 	priv->tx_dma_chan = ioread8(ec_info + INFO_BLOCK_TX_CHAN);
272 	priv->rx_dma_chan = ioread8(ec_info + INFO_BLOCK_RX_CHAN);
273 
274 	priv->ec_io = priv->io + ioread32(ec_info + INFO_BLOCK_OFFSET);
275 	priv->mii_io = priv->ec_io + ioread32(priv->ec_io + EC_MII_OFFSET);
276 	priv->fifo_io = priv->ec_io + ioread32(priv->ec_io + EC_FIFO_OFFSET);
277 	priv->mac_io = priv->ec_io + ioread32(priv->ec_io + EC_MAC_OFFSET);
278 
279 	return 0;
280 }
281 
282 static netdev_tx_t ec_bhf_start_xmit(struct sk_buff *skb,
283 				     struct net_device *net_dev)
284 {
285 	struct ec_bhf_priv *priv = netdev_priv(net_dev);
286 	struct tx_desc *desc;
287 	unsigned len;
288 
289 	desc = &priv->tx_descs[priv->tx_dnext];
290 
291 	skb_copy_and_csum_dev(skb, desc->data);
292 	len = skb->len;
293 
294 	memset(&desc->header, 0, sizeof(desc->header));
295 	desc->header.len = cpu_to_le16(len);
296 	desc->header.port = TX_HDR_PORT_0;
297 
298 	ec_bhf_send_packet(priv, desc);
299 
300 	priv->tx_dnext = (priv->tx_dnext + 1) % priv->tx_dcount;
301 
302 	if (!ec_bhf_desc_sent(&priv->tx_descs[priv->tx_dnext])) {
303 		/* Make sure that updates to tx_dnext are perceived
304 		 * by timer routine.
305 		 */
306 		smp_wmb();
307 
308 		netif_stop_queue(net_dev);
309 	}
310 
311 	priv->stat_tx_bytes += len;
312 
313 	dev_kfree_skb(skb);
314 
315 	return NETDEV_TX_OK;
316 }
317 
318 static int ec_bhf_alloc_dma_mem(struct ec_bhf_priv *priv,
319 				struct bhf_dma *buf,
320 				int channel,
321 				int size)
322 {
323 	int offset = channel * DMA_CHAN_SIZE + DMA_CHAN_OFFSET;
324 	struct device *dev = PRIV_TO_DEV(priv);
325 	u32 mask;
326 
327 	iowrite32(0xffffffff, priv->dma_io + offset);
328 
329 	mask = ioread32(priv->dma_io + offset);
330 	mask &= DMA_WINDOW_SIZE_MASK;
331 
332 	/* We want to allocate a chunk of memory that is:
333 	 * - aligned to the mask we just read
334 	 * - is of size 2^mask bytes (at most)
335 	 * In order to ensure that we will allocate buffer of
336 	 * 2 * 2^mask bytes.
337 	 */
338 	buf->len = min_t(int, ~mask + 1, size);
339 	buf->alloc_len = 2 * buf->len;
340 
341 	buf->alloc = dma_alloc_coherent(dev, buf->alloc_len, &buf->alloc_phys,
342 					GFP_KERNEL);
343 	if (buf->alloc == NULL) {
344 		dev_err(dev, "Failed to allocate buffer\n");
345 		return -ENOMEM;
346 	}
347 
348 	buf->buf_phys = (buf->alloc_phys + buf->len) & mask;
349 	buf->buf = buf->alloc + (buf->buf_phys - buf->alloc_phys);
350 
351 	iowrite32(0, priv->dma_io + offset + 4);
352 	iowrite32(buf->buf_phys, priv->dma_io + offset);
353 
354 	return 0;
355 }
356 
357 static void ec_bhf_setup_tx_descs(struct ec_bhf_priv *priv)
358 {
359 	int i = 0;
360 
361 	priv->tx_dcount = priv->tx_buf.len / sizeof(struct tx_desc);
362 	priv->tx_descs = (struct tx_desc *)priv->tx_buf.buf;
363 	priv->tx_dnext = 0;
364 
365 	for (i = 0; i < priv->tx_dcount; i++)
366 		priv->tx_descs[i].header.sent = cpu_to_le32(TX_HDR_SENT);
367 }
368 
369 static void ec_bhf_setup_rx_descs(struct ec_bhf_priv *priv)
370 {
371 	int i;
372 
373 	priv->rx_dcount = priv->rx_buf.len / sizeof(struct rx_desc);
374 	priv->rx_descs = (struct rx_desc *)priv->rx_buf.buf;
375 	priv->rx_dnext = 0;
376 
377 	for (i = 0; i < priv->rx_dcount; i++) {
378 		struct rx_desc *desc = &priv->rx_descs[i];
379 		u32 next;
380 
381 		if (i != priv->rx_dcount - 1)
382 			next = (u8 *)(desc + 1) - priv->rx_buf.buf;
383 		else
384 			next = 0;
385 		next |= RXHDR_NEXT_VALID;
386 		desc->header.next = cpu_to_le32(next);
387 		desc->header.recv = 0;
388 		ec_bhf_add_rx_desc(priv, desc);
389 	}
390 }
391 
392 static int ec_bhf_open(struct net_device *net_dev)
393 {
394 	struct ec_bhf_priv *priv = netdev_priv(net_dev);
395 	struct device *dev = PRIV_TO_DEV(priv);
396 	int err = 0;
397 
398 	ec_bhf_reset(priv);
399 
400 	err = ec_bhf_alloc_dma_mem(priv, &priv->rx_buf, priv->rx_dma_chan,
401 				   FIFO_SIZE * sizeof(struct rx_desc));
402 	if (err) {
403 		dev_err(dev, "Failed to allocate rx buffer\n");
404 		goto out;
405 	}
406 	ec_bhf_setup_rx_descs(priv);
407 
408 	err = ec_bhf_alloc_dma_mem(priv, &priv->tx_buf, priv->tx_dma_chan,
409 				   FIFO_SIZE * sizeof(struct tx_desc));
410 	if (err) {
411 		dev_err(dev, "Failed to allocate tx buffer\n");
412 		goto error_rx_free;
413 	}
414 	iowrite8(0, priv->mii_io + MII_MAC_FILT_FLAG);
415 	ec_bhf_setup_tx_descs(priv);
416 
417 	netif_start_queue(net_dev);
418 
419 	hrtimer_init(&priv->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
420 	priv->hrtimer.function = ec_bhf_timer_fun;
421 	hrtimer_start(&priv->hrtimer, polling_frequency, HRTIMER_MODE_REL);
422 
423 	return 0;
424 
425 error_rx_free:
426 	dma_free_coherent(dev, priv->rx_buf.alloc_len, priv->rx_buf.alloc,
427 			  priv->rx_buf.alloc_len);
428 out:
429 	return err;
430 }
431 
432 static int ec_bhf_stop(struct net_device *net_dev)
433 {
434 	struct ec_bhf_priv *priv = netdev_priv(net_dev);
435 	struct device *dev = PRIV_TO_DEV(priv);
436 
437 	hrtimer_cancel(&priv->hrtimer);
438 
439 	ec_bhf_reset(priv);
440 
441 	netif_tx_disable(net_dev);
442 
443 	dma_free_coherent(dev, priv->tx_buf.alloc_len,
444 			  priv->tx_buf.alloc, priv->tx_buf.alloc_phys);
445 	dma_free_coherent(dev, priv->rx_buf.alloc_len,
446 			  priv->rx_buf.alloc, priv->rx_buf.alloc_phys);
447 
448 	return 0;
449 }
450 
451 static void
452 ec_bhf_get_stats(struct net_device *net_dev,
453 		 struct rtnl_link_stats64 *stats)
454 {
455 	struct ec_bhf_priv *priv = netdev_priv(net_dev);
456 
457 	stats->rx_errors = ioread8(priv->mac_io + MAC_RX_ERR_CNT) +
458 				ioread8(priv->mac_io + MAC_CRC_ERR_CNT) +
459 				ioread8(priv->mac_io + MAC_FRAME_ERR_CNT);
460 	stats->rx_packets = ioread32(priv->mac_io + MAC_RX_FRAME_CNT);
461 	stats->tx_packets = ioread32(priv->mac_io + MAC_TX_FRAME_CNT);
462 	stats->rx_dropped = ioread8(priv->mac_io + MAC_DROPPED_FRMS);
463 
464 	stats->tx_bytes = priv->stat_tx_bytes;
465 	stats->rx_bytes = priv->stat_rx_bytes;
466 }
467 
468 static const struct net_device_ops ec_bhf_netdev_ops = {
469 	.ndo_start_xmit		= ec_bhf_start_xmit,
470 	.ndo_open		= ec_bhf_open,
471 	.ndo_stop		= ec_bhf_stop,
472 	.ndo_get_stats64	= ec_bhf_get_stats,
473 	.ndo_validate_addr	= eth_validate_addr,
474 	.ndo_set_mac_address	= eth_mac_addr
475 };
476 
477 static int ec_bhf_probe(struct pci_dev *dev, const struct pci_device_id *id)
478 {
479 	struct net_device *net_dev;
480 	struct ec_bhf_priv *priv;
481 	void __iomem *dma_io;
482 	void __iomem *io;
483 	int err = 0;
484 
485 	err = pci_enable_device(dev);
486 	if (err)
487 		return err;
488 
489 	pci_set_master(dev);
490 
491 	err = dma_set_mask_and_coherent(&dev->dev, DMA_BIT_MASK(32));
492 	if (err) {
493 		dev_err(&dev->dev,
494 			"Required dma mask not supported, failed to initialize device\n");
495 		goto err_disable_dev;
496 	}
497 
498 	err = pci_request_regions(dev, "ec_bhf");
499 	if (err) {
500 		dev_err(&dev->dev, "Failed to request pci memory regions\n");
501 		goto err_disable_dev;
502 	}
503 
504 	io = pci_iomap(dev, 0, 0);
505 	if (!io) {
506 		dev_err(&dev->dev, "Failed to map pci card memory bar 0");
507 		err = -EIO;
508 		goto err_release_regions;
509 	}
510 
511 	dma_io = pci_iomap(dev, 2, 0);
512 	if (!dma_io) {
513 		dev_err(&dev->dev, "Failed to map pci card memory bar 2");
514 		err = -EIO;
515 		goto err_unmap;
516 	}
517 
518 	net_dev = alloc_etherdev(sizeof(struct ec_bhf_priv));
519 	if (net_dev == NULL) {
520 		err = -ENOMEM;
521 		goto err_unmap_dma_io;
522 	}
523 
524 	pci_set_drvdata(dev, net_dev);
525 	SET_NETDEV_DEV(net_dev, &dev->dev);
526 
527 	net_dev->features = 0;
528 	net_dev->flags |= IFF_NOARP;
529 
530 	net_dev->netdev_ops = &ec_bhf_netdev_ops;
531 
532 	priv = netdev_priv(net_dev);
533 	priv->net_dev = net_dev;
534 	priv->io = io;
535 	priv->dma_io = dma_io;
536 	priv->dev = dev;
537 
538 	err = ec_bhf_setup_offsets(priv);
539 	if (err < 0)
540 		goto err_free_net_dev;
541 
542 	memcpy_fromio(net_dev->dev_addr, priv->mii_io + MII_MAC_ADDR, 6);
543 
544 	err = register_netdev(net_dev);
545 	if (err < 0)
546 		goto err_free_net_dev;
547 
548 	return 0;
549 
550 err_free_net_dev:
551 	free_netdev(net_dev);
552 err_unmap_dma_io:
553 	pci_iounmap(dev, dma_io);
554 err_unmap:
555 	pci_iounmap(dev, io);
556 err_release_regions:
557 	pci_release_regions(dev);
558 err_disable_dev:
559 	pci_clear_master(dev);
560 	pci_disable_device(dev);
561 
562 	return err;
563 }
564 
565 static void ec_bhf_remove(struct pci_dev *dev)
566 {
567 	struct net_device *net_dev = pci_get_drvdata(dev);
568 	struct ec_bhf_priv *priv = netdev_priv(net_dev);
569 
570 	unregister_netdev(net_dev);
571 
572 	pci_iounmap(dev, priv->dma_io);
573 	pci_iounmap(dev, priv->io);
574 
575 	free_netdev(net_dev);
576 
577 	pci_release_regions(dev);
578 	pci_clear_master(dev);
579 	pci_disable_device(dev);
580 }
581 
582 static struct pci_driver pci_driver = {
583 	.name		= "ec_bhf",
584 	.id_table	= ids,
585 	.probe		= ec_bhf_probe,
586 	.remove		= ec_bhf_remove,
587 };
588 module_pci_driver(pci_driver);
589 
590 module_param(polling_frequency, long, 0444);
591 MODULE_PARM_DESC(polling_frequency, "Polling timer frequency in ns");
592 
593 MODULE_LICENSE("GPL");
594 MODULE_AUTHOR("Dariusz Marcinkiewicz <reksio@newterm.pl>");
595