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
ec_bhf_reset(struct ec_bhf_priv * priv)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
ec_bhf_send_packet(struct ec_bhf_priv * priv,struct tx_desc * desc)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
ec_bhf_desc_sent(struct tx_desc * desc)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
ec_bhf_process_tx(struct ec_bhf_priv * priv)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
ec_bhf_pkt_received(struct rx_desc * desc)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
ec_bhf_add_rx_desc(struct ec_bhf_priv * priv,struct rx_desc * desc)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
ec_bhf_process_rx(struct ec_bhf_priv * priv)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
ec_bhf_timer_fun(struct hrtimer * timer)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
ec_bhf_setup_offsets(struct ec_bhf_priv * priv)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
ec_bhf_start_xmit(struct sk_buff * skb,struct net_device * net_dev)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
ec_bhf_alloc_dma_mem(struct ec_bhf_priv * priv,struct bhf_dma * buf,int channel,int size)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
ec_bhf_setup_tx_descs(struct ec_bhf_priv * priv)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
ec_bhf_setup_rx_descs(struct ec_bhf_priv * priv)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
ec_bhf_open(struct net_device * net_dev)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
ec_bhf_stop(struct net_device * net_dev)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
ec_bhf_get_stats(struct net_device * net_dev,struct rtnl_link_stats64 * stats)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
ec_bhf_probe(struct pci_dev * dev,const struct pci_device_id * id)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 = pci_set_dma_mask(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 err = -EIO;
496 goto err_disable_dev;
497 }
498
499 err = pci_set_consistent_dma_mask(dev, DMA_BIT_MASK(32));
500 if (err) {
501 dev_err(&dev->dev,
502 "Required dma mask not supported, failed to initialize device\n");
503 goto err_disable_dev;
504 }
505
506 err = pci_request_regions(dev, "ec_bhf");
507 if (err) {
508 dev_err(&dev->dev, "Failed to request pci memory regions\n");
509 goto err_disable_dev;
510 }
511
512 io = pci_iomap(dev, 0, 0);
513 if (!io) {
514 dev_err(&dev->dev, "Failed to map pci card memory bar 0");
515 err = -EIO;
516 goto err_release_regions;
517 }
518
519 dma_io = pci_iomap(dev, 2, 0);
520 if (!dma_io) {
521 dev_err(&dev->dev, "Failed to map pci card memory bar 2");
522 err = -EIO;
523 goto err_unmap;
524 }
525
526 net_dev = alloc_etherdev(sizeof(struct ec_bhf_priv));
527 if (net_dev == NULL) {
528 err = -ENOMEM;
529 goto err_unmap_dma_io;
530 }
531
532 pci_set_drvdata(dev, net_dev);
533 SET_NETDEV_DEV(net_dev, &dev->dev);
534
535 net_dev->features = 0;
536 net_dev->flags |= IFF_NOARP;
537
538 net_dev->netdev_ops = &ec_bhf_netdev_ops;
539
540 priv = netdev_priv(net_dev);
541 priv->net_dev = net_dev;
542 priv->io = io;
543 priv->dma_io = dma_io;
544 priv->dev = dev;
545
546 err = ec_bhf_setup_offsets(priv);
547 if (err < 0)
548 goto err_free_net_dev;
549
550 memcpy_fromio(net_dev->dev_addr, priv->mii_io + MII_MAC_ADDR, 6);
551
552 err = register_netdev(net_dev);
553 if (err < 0)
554 goto err_free_net_dev;
555
556 return 0;
557
558 err_free_net_dev:
559 free_netdev(net_dev);
560 err_unmap_dma_io:
561 pci_iounmap(dev, dma_io);
562 err_unmap:
563 pci_iounmap(dev, io);
564 err_release_regions:
565 pci_release_regions(dev);
566 err_disable_dev:
567 pci_clear_master(dev);
568 pci_disable_device(dev);
569
570 return err;
571 }
572
ec_bhf_remove(struct pci_dev * dev)573 static void ec_bhf_remove(struct pci_dev *dev)
574 {
575 struct net_device *net_dev = pci_get_drvdata(dev);
576 struct ec_bhf_priv *priv = netdev_priv(net_dev);
577
578 unregister_netdev(net_dev);
579 free_netdev(net_dev);
580
581 pci_iounmap(dev, priv->dma_io);
582 pci_iounmap(dev, priv->io);
583 pci_release_regions(dev);
584 pci_clear_master(dev);
585 pci_disable_device(dev);
586 }
587
588 static struct pci_driver pci_driver = {
589 .name = "ec_bhf",
590 .id_table = ids,
591 .probe = ec_bhf_probe,
592 .remove = ec_bhf_remove,
593 };
594 module_pci_driver(pci_driver);
595
596 module_param(polling_frequency, long, 0444);
597 MODULE_PARM_DESC(polling_frequency, "Polling timer frequency in ns");
598
599 MODULE_LICENSE("GPL");
600 MODULE_AUTHOR("Dariusz Marcinkiewicz <reksio@newterm.pl>");
601
