1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (C) 2021 in-tech smart charging GmbH
3  *
4  * driver is based on micrel/ks8851_spi.c
5  */
6 
7 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
8 
9 #include <linux/interrupt.h>
10 #include <linux/module.h>
11 #include <linux/kernel.h>
12 #include <linux/netdevice.h>
13 #include <linux/etherdevice.h>
14 #include <linux/ethtool.h>
15 #include <linux/cache.h>
16 #include <linux/debugfs.h>
17 #include <linux/seq_file.h>
18 
19 #include <linux/spi/spi.h>
20 #include <linux/of_net.h>
21 
22 #define MSG_DEFAULT	(NETIF_MSG_DRV | NETIF_MSG_PROBE | NETIF_MSG_LINK | \
23 			 NETIF_MSG_TIMER)
24 
25 #define DRV_NAME	"mse102x"
26 
27 #define DET_CMD		0x0001
28 #define DET_SOF		0x0002
29 #define DET_DFT		0x55AA
30 
31 #define CMD_SHIFT	12
32 #define CMD_RTS		(0x1 << CMD_SHIFT)
33 #define CMD_CTR		(0x2 << CMD_SHIFT)
34 
35 #define CMD_MASK	GENMASK(15, CMD_SHIFT)
36 #define LEN_MASK	GENMASK(CMD_SHIFT - 1, 0)
37 
38 #define DET_CMD_LEN	4
39 #define DET_SOF_LEN	2
40 #define DET_DFT_LEN	2
41 
42 #define MIN_FREQ_HZ	6000000
43 #define MAX_FREQ_HZ	7142857
44 
45 struct mse102x_stats {
46 	u64 xfer_err;
47 	u64 invalid_cmd;
48 	u64 invalid_ctr;
49 	u64 invalid_dft;
50 	u64 invalid_len;
51 	u64 invalid_rts;
52 	u64 invalid_sof;
53 	u64 tx_timeout;
54 };
55 
56 static const char mse102x_gstrings_stats[][ETH_GSTRING_LEN] = {
57 	"SPI transfer errors",
58 	"Invalid command",
59 	"Invalid CTR",
60 	"Invalid DFT",
61 	"Invalid frame length",
62 	"Invalid RTS",
63 	"Invalid SOF",
64 	"TX timeout",
65 };
66 
67 struct mse102x_net {
68 	struct net_device	*ndev;
69 
70 	u8			rxd[8];
71 	u8			txd[8];
72 
73 	u32			msg_enable ____cacheline_aligned;
74 
75 	struct sk_buff_head	txq;
76 	struct mse102x_stats	stats;
77 };
78 
79 struct mse102x_net_spi {
80 	struct mse102x_net	mse102x;
81 	struct mutex		lock;		/* Protect SPI frame transfer */
82 	struct work_struct	tx_work;
83 	struct spi_device	*spidev;
84 	struct spi_message	spi_msg;
85 	struct spi_transfer	spi_xfer;
86 
87 #ifdef CONFIG_DEBUG_FS
88 	struct dentry		*device_root;
89 #endif
90 };
91 
92 #define to_mse102x_spi(mse) container_of((mse), struct mse102x_net_spi, mse102x)
93 
94 #ifdef CONFIG_DEBUG_FS
95 
96 static int mse102x_info_show(struct seq_file *s, void *what)
97 {
98 	struct mse102x_net_spi *mses = s->private;
99 
100 	seq_printf(s, "TX ring size        : %u\n",
101 		   skb_queue_len(&mses->mse102x.txq));
102 
103 	seq_printf(s, "IRQ                 : %d\n",
104 		   mses->spidev->irq);
105 
106 	seq_printf(s, "SPI effective speed : %lu\n",
107 		   (unsigned long)mses->spi_xfer.effective_speed_hz);
108 	seq_printf(s, "SPI mode            : %x\n",
109 		   mses->spidev->mode);
110 
111 	return 0;
112 }
113 DEFINE_SHOW_ATTRIBUTE(mse102x_info);
114 
115 static void mse102x_init_device_debugfs(struct mse102x_net_spi *mses)
116 {
117 	mses->device_root = debugfs_create_dir(dev_name(&mses->mse102x.ndev->dev),
118 					       NULL);
119 
120 	debugfs_create_file("info", S_IFREG | 0444, mses->device_root, mses,
121 			    &mse102x_info_fops);
122 }
123 
124 static void mse102x_remove_device_debugfs(struct mse102x_net_spi *mses)
125 {
126 	debugfs_remove_recursive(mses->device_root);
127 }
128 
129 #else /* CONFIG_DEBUG_FS */
130 
131 static void mse102x_init_device_debugfs(struct mse102x_net_spi *mses)
132 {
133 }
134 
135 static void mse102x_remove_device_debugfs(struct mse102x_net_spi *mses)
136 {
137 }
138 
139 #endif
140 
141 /* SPI register read/write calls.
142  *
143  * All these calls issue SPI transactions to access the chip's registers. They
144  * all require that the necessary lock is held to prevent accesses when the
145  * chip is busy transferring packet data.
146  */
147 
148 static void mse102x_tx_cmd_spi(struct mse102x_net *mse, u16 cmd)
149 {
150 	struct mse102x_net_spi *mses = to_mse102x_spi(mse);
151 	struct spi_transfer *xfer = &mses->spi_xfer;
152 	struct spi_message *msg = &mses->spi_msg;
153 	__be16 txb[2];
154 	int ret;
155 
156 	txb[0] = cpu_to_be16(DET_CMD);
157 	txb[1] = cpu_to_be16(cmd);
158 
159 	xfer->tx_buf = txb;
160 	xfer->rx_buf = NULL;
161 	xfer->len = DET_CMD_LEN;
162 
163 	ret = spi_sync(mses->spidev, msg);
164 	if (ret < 0) {
165 		netdev_err(mse->ndev, "%s: spi_sync() failed: %d\n",
166 			   __func__, ret);
167 		mse->stats.xfer_err++;
168 	}
169 }
170 
171 static int mse102x_rx_cmd_spi(struct mse102x_net *mse, u8 *rxb)
172 {
173 	struct mse102x_net_spi *mses = to_mse102x_spi(mse);
174 	struct spi_transfer *xfer = &mses->spi_xfer;
175 	struct spi_message *msg = &mses->spi_msg;
176 	__be16 *txb = (__be16 *)mse->txd;
177 	__be16 *cmd = (__be16 *)mse->rxd;
178 	u8 *trx = mse->rxd;
179 	int ret;
180 
181 	txb[0] = 0;
182 	txb[1] = 0;
183 
184 	xfer->tx_buf = txb;
185 	xfer->rx_buf = trx;
186 	xfer->len = DET_CMD_LEN;
187 
188 	ret = spi_sync(mses->spidev, msg);
189 	if (ret < 0) {
190 		netdev_err(mse->ndev, "%s: spi_sync() failed: %d\n",
191 			   __func__, ret);
192 		mse->stats.xfer_err++;
193 	} else if (*cmd != cpu_to_be16(DET_CMD)) {
194 		net_dbg_ratelimited("%s: Unexpected response (0x%04x)\n",
195 				    __func__, *cmd);
196 		mse->stats.invalid_cmd++;
197 		ret = -EIO;
198 	} else {
199 		memcpy(rxb, trx + 2, 2);
200 	}
201 
202 	return ret;
203 }
204 
205 static inline void mse102x_push_header(struct sk_buff *skb)
206 {
207 	__be16 *header = skb_push(skb, DET_SOF_LEN);
208 
209 	*header = cpu_to_be16(DET_SOF);
210 }
211 
212 static inline void mse102x_put_footer(struct sk_buff *skb)
213 {
214 	__be16 *footer = skb_put(skb, DET_DFT_LEN);
215 
216 	*footer = cpu_to_be16(DET_DFT);
217 }
218 
219 static int mse102x_tx_frame_spi(struct mse102x_net *mse, struct sk_buff *txp,
220 				unsigned int pad)
221 {
222 	struct mse102x_net_spi *mses = to_mse102x_spi(mse);
223 	struct spi_transfer *xfer = &mses->spi_xfer;
224 	struct spi_message *msg = &mses->spi_msg;
225 	struct sk_buff *tskb;
226 	int ret;
227 
228 	netif_dbg(mse, tx_queued, mse->ndev, "%s: skb %p, %d@%p\n",
229 		  __func__, txp, txp->len, txp->data);
230 
231 	if ((skb_headroom(txp) < DET_SOF_LEN) ||
232 	    (skb_tailroom(txp) < DET_DFT_LEN + pad)) {
233 		tskb = skb_copy_expand(txp, DET_SOF_LEN, DET_DFT_LEN + pad,
234 				       GFP_KERNEL);
235 		if (!tskb)
236 			return -ENOMEM;
237 
238 		dev_kfree_skb(txp);
239 		txp = tskb;
240 	}
241 
242 	mse102x_push_header(txp);
243 
244 	if (pad)
245 		skb_put_zero(txp, pad);
246 
247 	mse102x_put_footer(txp);
248 
249 	xfer->tx_buf = txp->data;
250 	xfer->rx_buf = NULL;
251 	xfer->len = txp->len;
252 
253 	ret = spi_sync(mses->spidev, msg);
254 	if (ret < 0) {
255 		netdev_err(mse->ndev, "%s: spi_sync() failed: %d\n",
256 			   __func__, ret);
257 		mse->stats.xfer_err++;
258 	}
259 
260 	return ret;
261 }
262 
263 static int mse102x_rx_frame_spi(struct mse102x_net *mse, u8 *buff,
264 				unsigned int frame_len)
265 {
266 	struct mse102x_net_spi *mses = to_mse102x_spi(mse);
267 	struct spi_transfer *xfer = &mses->spi_xfer;
268 	struct spi_message *msg = &mses->spi_msg;
269 	__be16 *sof = (__be16 *)buff;
270 	__be16 *dft = (__be16 *)(buff + DET_SOF_LEN + frame_len);
271 	int ret;
272 
273 	xfer->rx_buf = buff;
274 	xfer->tx_buf = NULL;
275 	xfer->len = DET_SOF_LEN + frame_len + DET_DFT_LEN;
276 
277 	ret = spi_sync(mses->spidev, msg);
278 	if (ret < 0) {
279 		netdev_err(mse->ndev, "%s: spi_sync() failed: %d\n",
280 			   __func__, ret);
281 		mse->stats.xfer_err++;
282 	} else if (*sof != cpu_to_be16(DET_SOF)) {
283 		netdev_dbg(mse->ndev, "%s: SPI start of frame is invalid (0x%04x)\n",
284 			   __func__, *sof);
285 		mse->stats.invalid_sof++;
286 		ret = -EIO;
287 	} else if (*dft != cpu_to_be16(DET_DFT)) {
288 		netdev_dbg(mse->ndev, "%s: SPI frame tail is invalid (0x%04x)\n",
289 			   __func__, *dft);
290 		mse->stats.invalid_dft++;
291 		ret = -EIO;
292 	}
293 
294 	return ret;
295 }
296 
297 static void mse102x_dump_packet(const char *msg, int len, const char *data)
298 {
299 	printk(KERN_DEBUG ": %s - packet len:%d\n", msg, len);
300 	print_hex_dump(KERN_DEBUG, "pk data: ", DUMP_PREFIX_OFFSET, 16, 1,
301 		       data, len, true);
302 }
303 
304 static void mse102x_rx_pkt_spi(struct mse102x_net *mse)
305 {
306 	struct sk_buff *skb;
307 	unsigned int rxalign;
308 	unsigned int rxlen;
309 	__be16 rx = 0;
310 	u16 cmd_resp;
311 	u8 *rxpkt;
312 	int ret;
313 
314 	mse102x_tx_cmd_spi(mse, CMD_CTR);
315 	ret = mse102x_rx_cmd_spi(mse, (u8 *)&rx);
316 	cmd_resp = be16_to_cpu(rx);
317 
318 	if (ret || ((cmd_resp & CMD_MASK) != CMD_RTS)) {
319 		usleep_range(50, 100);
320 
321 		mse102x_tx_cmd_spi(mse, CMD_CTR);
322 		ret = mse102x_rx_cmd_spi(mse, (u8 *)&rx);
323 		if (ret)
324 			return;
325 
326 		cmd_resp = be16_to_cpu(rx);
327 		if ((cmd_resp & CMD_MASK) != CMD_RTS) {
328 			net_dbg_ratelimited("%s: Unexpected response (0x%04x)\n",
329 					    __func__, cmd_resp);
330 			mse->stats.invalid_rts++;
331 			return;
332 		}
333 
334 		net_dbg_ratelimited("%s: Unexpected response to first CMD\n",
335 				    __func__);
336 	}
337 
338 	rxlen = cmd_resp & LEN_MASK;
339 	if (!rxlen) {
340 		net_dbg_ratelimited("%s: No frame length defined\n", __func__);
341 		mse->stats.invalid_len++;
342 		return;
343 	}
344 
345 	rxalign = ALIGN(rxlen + DET_SOF_LEN + DET_DFT_LEN, 4);
346 	skb = netdev_alloc_skb_ip_align(mse->ndev, rxalign);
347 	if (!skb)
348 		return;
349 
350 	/* 2 bytes Start of frame (before ethernet header)
351 	 * 2 bytes Data frame tail (after ethernet frame)
352 	 * They are copied, but ignored.
353 	 */
354 	rxpkt = skb_put(skb, rxlen) - DET_SOF_LEN;
355 	if (mse102x_rx_frame_spi(mse, rxpkt, rxlen)) {
356 		mse->ndev->stats.rx_errors++;
357 		dev_kfree_skb(skb);
358 		return;
359 	}
360 
361 	if (netif_msg_pktdata(mse))
362 		mse102x_dump_packet(__func__, skb->len, skb->data);
363 
364 	skb->protocol = eth_type_trans(skb, mse->ndev);
365 	netif_rx_ni(skb);
366 
367 	mse->ndev->stats.rx_packets++;
368 	mse->ndev->stats.rx_bytes += rxlen;
369 }
370 
371 static int mse102x_tx_pkt_spi(struct mse102x_net *mse, struct sk_buff *txb,
372 			      unsigned long work_timeout)
373 {
374 	unsigned int pad = 0;
375 	__be16 rx = 0;
376 	u16 cmd_resp;
377 	int ret;
378 	bool first = true;
379 
380 	if (txb->len < 60)
381 		pad = 60 - txb->len;
382 
383 	while (1) {
384 		mse102x_tx_cmd_spi(mse, CMD_RTS | (txb->len + pad));
385 		ret = mse102x_rx_cmd_spi(mse, (u8 *)&rx);
386 		cmd_resp = be16_to_cpu(rx);
387 
388 		if (!ret) {
389 			/* ready to send frame ? */
390 			if (cmd_resp == CMD_CTR)
391 				break;
392 
393 			net_dbg_ratelimited("%s: Unexpected response (0x%04x)\n",
394 					    __func__, cmd_resp);
395 			mse->stats.invalid_ctr++;
396 		}
397 
398 		/* It's not predictable how long / many retries it takes to
399 		 * send at least one packet, so TX timeouts are possible.
400 		 * That's the reason why the netdev watchdog is not used here.
401 		 */
402 		if (time_after(jiffies, work_timeout))
403 			return -ETIMEDOUT;
404 
405 		if (first) {
406 			/* throttle at first issue */
407 			netif_stop_queue(mse->ndev);
408 			/* fast retry */
409 			usleep_range(50, 100);
410 			first = false;
411 		} else {
412 			msleep(20);
413 		}
414 	}
415 
416 	ret = mse102x_tx_frame_spi(mse, txb, pad);
417 	if (ret)
418 		net_dbg_ratelimited("%s: Failed to send (%d), drop frame\n",
419 				    __func__, ret);
420 
421 	return ret;
422 }
423 
424 #define TX_QUEUE_MAX 10
425 
426 static void mse102x_tx_work(struct work_struct *work)
427 {
428 	/* Make sure timeout is sufficient to transfer TX_QUEUE_MAX frames */
429 	unsigned long work_timeout = jiffies + msecs_to_jiffies(1000);
430 	struct mse102x_net_spi *mses;
431 	struct mse102x_net *mse;
432 	struct sk_buff *txb;
433 	int ret = 0;
434 
435 	mses = container_of(work, struct mse102x_net_spi, tx_work);
436 	mse = &mses->mse102x;
437 
438 	while ((txb = skb_dequeue(&mse->txq))) {
439 		mutex_lock(&mses->lock);
440 		ret = mse102x_tx_pkt_spi(mse, txb, work_timeout);
441 		mutex_unlock(&mses->lock);
442 		if (ret) {
443 			mse->ndev->stats.tx_dropped++;
444 		} else {
445 			mse->ndev->stats.tx_bytes += txb->len;
446 			mse->ndev->stats.tx_packets++;
447 		}
448 
449 		dev_kfree_skb(txb);
450 	}
451 
452 	if (ret == -ETIMEDOUT) {
453 		if (netif_msg_timer(mse))
454 			netdev_err(mse->ndev, "tx work timeout\n");
455 
456 		mse->stats.tx_timeout++;
457 	}
458 
459 	netif_wake_queue(mse->ndev);
460 }
461 
462 static netdev_tx_t mse102x_start_xmit_spi(struct sk_buff *skb,
463 					  struct net_device *ndev)
464 {
465 	struct mse102x_net *mse = netdev_priv(ndev);
466 	struct mse102x_net_spi *mses = to_mse102x_spi(mse);
467 
468 	netif_dbg(mse, tx_queued, ndev,
469 		  "%s: skb %p, %d@%p\n", __func__, skb, skb->len, skb->data);
470 
471 	skb_queue_tail(&mse->txq, skb);
472 
473 	if (skb_queue_len(&mse->txq) >= TX_QUEUE_MAX)
474 		netif_stop_queue(ndev);
475 
476 	schedule_work(&mses->tx_work);
477 
478 	return NETDEV_TX_OK;
479 }
480 
481 static void mse102x_init_mac(struct mse102x_net *mse, struct device_node *np)
482 {
483 	struct net_device *ndev = mse->ndev;
484 	int ret = of_get_ethdev_address(np, ndev);
485 
486 	if (ret) {
487 		eth_hw_addr_random(ndev);
488 		netdev_err(ndev, "Using random MAC address: %pM\n",
489 			   ndev->dev_addr);
490 	}
491 }
492 
493 /* Assumption: this is called for every incoming packet */
494 static irqreturn_t mse102x_irq(int irq, void *_mse)
495 {
496 	struct mse102x_net *mse = _mse;
497 	struct mse102x_net_spi *mses = to_mse102x_spi(mse);
498 
499 	mutex_lock(&mses->lock);
500 	mse102x_rx_pkt_spi(mse);
501 	mutex_unlock(&mses->lock);
502 
503 	return IRQ_HANDLED;
504 }
505 
506 static int mse102x_net_open(struct net_device *ndev)
507 {
508 	struct mse102x_net *mse = netdev_priv(ndev);
509 	int ret;
510 
511 	ret = request_threaded_irq(ndev->irq, NULL, mse102x_irq, IRQF_ONESHOT,
512 				   ndev->name, mse);
513 	if (ret < 0) {
514 		netdev_err(ndev, "Failed to get irq: %d\n", ret);
515 		return ret;
516 	}
517 
518 	netif_dbg(mse, ifup, ndev, "opening\n");
519 
520 	netif_start_queue(ndev);
521 
522 	netif_carrier_on(ndev);
523 
524 	netif_dbg(mse, ifup, ndev, "network device up\n");
525 
526 	return 0;
527 }
528 
529 static int mse102x_net_stop(struct net_device *ndev)
530 {
531 	struct mse102x_net *mse = netdev_priv(ndev);
532 	struct mse102x_net_spi *mses = to_mse102x_spi(mse);
533 
534 	netif_info(mse, ifdown, ndev, "shutting down\n");
535 
536 	netif_carrier_off(mse->ndev);
537 
538 	/* stop any outstanding work */
539 	flush_work(&mses->tx_work);
540 
541 	netif_stop_queue(ndev);
542 
543 	skb_queue_purge(&mse->txq);
544 
545 	free_irq(ndev->irq, mse);
546 
547 	return 0;
548 }
549 
550 static const struct net_device_ops mse102x_netdev_ops = {
551 	.ndo_open		= mse102x_net_open,
552 	.ndo_stop		= mse102x_net_stop,
553 	.ndo_start_xmit		= mse102x_start_xmit_spi,
554 	.ndo_set_mac_address	= eth_mac_addr,
555 	.ndo_validate_addr	= eth_validate_addr,
556 };
557 
558 /* ethtool support */
559 
560 static void mse102x_get_drvinfo(struct net_device *ndev,
561 				struct ethtool_drvinfo *di)
562 {
563 	strscpy(di->driver, DRV_NAME, sizeof(di->driver));
564 	strscpy(di->bus_info, dev_name(ndev->dev.parent), sizeof(di->bus_info));
565 }
566 
567 static u32 mse102x_get_msglevel(struct net_device *ndev)
568 {
569 	struct mse102x_net *mse = netdev_priv(ndev);
570 
571 	return mse->msg_enable;
572 }
573 
574 static void mse102x_set_msglevel(struct net_device *ndev, u32 to)
575 {
576 	struct mse102x_net *mse = netdev_priv(ndev);
577 
578 	mse->msg_enable = to;
579 }
580 
581 static void mse102x_get_ethtool_stats(struct net_device *ndev,
582 				      struct ethtool_stats *estats, u64 *data)
583 {
584 	struct mse102x_net *mse = netdev_priv(ndev);
585 	struct mse102x_stats *st = &mse->stats;
586 
587 	memcpy(data, st, ARRAY_SIZE(mse102x_gstrings_stats) * sizeof(u64));
588 }
589 
590 static void mse102x_get_strings(struct net_device *ndev, u32 stringset, u8 *buf)
591 {
592 	switch (stringset) {
593 	case ETH_SS_STATS:
594 		memcpy(buf, &mse102x_gstrings_stats,
595 		       sizeof(mse102x_gstrings_stats));
596 		break;
597 	default:
598 		WARN_ON(1);
599 		break;
600 	}
601 }
602 
603 static int mse102x_get_sset_count(struct net_device *ndev, int sset)
604 {
605 	switch (sset) {
606 	case ETH_SS_STATS:
607 		return ARRAY_SIZE(mse102x_gstrings_stats);
608 	default:
609 		return -EINVAL;
610 	}
611 }
612 
613 static const struct ethtool_ops mse102x_ethtool_ops = {
614 	.get_drvinfo		= mse102x_get_drvinfo,
615 	.get_link		= ethtool_op_get_link,
616 	.get_msglevel		= mse102x_get_msglevel,
617 	.set_msglevel		= mse102x_set_msglevel,
618 	.get_ethtool_stats	= mse102x_get_ethtool_stats,
619 	.get_strings		= mse102x_get_strings,
620 	.get_sset_count		= mse102x_get_sset_count,
621 };
622 
623 /* driver bus management functions */
624 
625 #ifdef CONFIG_PM_SLEEP
626 
627 static int mse102x_suspend(struct device *dev)
628 {
629 	struct mse102x_net *mse = dev_get_drvdata(dev);
630 	struct net_device *ndev = mse->ndev;
631 
632 	if (netif_running(ndev)) {
633 		netif_device_detach(ndev);
634 		mse102x_net_stop(ndev);
635 	}
636 
637 	return 0;
638 }
639 
640 static int mse102x_resume(struct device *dev)
641 {
642 	struct mse102x_net *mse = dev_get_drvdata(dev);
643 	struct net_device *ndev = mse->ndev;
644 
645 	if (netif_running(ndev)) {
646 		mse102x_net_open(ndev);
647 		netif_device_attach(ndev);
648 	}
649 
650 	return 0;
651 }
652 #endif
653 
654 static SIMPLE_DEV_PM_OPS(mse102x_pm_ops, mse102x_suspend, mse102x_resume);
655 
656 static int mse102x_probe_spi(struct spi_device *spi)
657 {
658 	struct device *dev = &spi->dev;
659 	struct mse102x_net_spi *mses;
660 	struct net_device *ndev;
661 	struct mse102x_net *mse;
662 	int ret;
663 
664 	spi->bits_per_word = 8;
665 	spi->mode |= SPI_MODE_3;
666 	/* enforce minimum speed to ensure device functionality */
667 	spi->master->min_speed_hz = MIN_FREQ_HZ;
668 
669 	if (!spi->max_speed_hz)
670 		spi->max_speed_hz = MAX_FREQ_HZ;
671 
672 	if (spi->max_speed_hz < MIN_FREQ_HZ ||
673 	    spi->max_speed_hz > MAX_FREQ_HZ) {
674 		dev_err(&spi->dev, "SPI max frequency out of range (min: %u, max: %u)\n",
675 			MIN_FREQ_HZ, MAX_FREQ_HZ);
676 		return -EINVAL;
677 	}
678 
679 	ret = spi_setup(spi);
680 	if (ret < 0) {
681 		dev_err(&spi->dev, "Unable to setup SPI device: %d\n", ret);
682 		return ret;
683 	}
684 
685 	ndev = devm_alloc_etherdev(dev, sizeof(struct mse102x_net_spi));
686 	if (!ndev)
687 		return -ENOMEM;
688 
689 	ndev->needed_tailroom += ALIGN(DET_DFT_LEN, 4);
690 	ndev->needed_headroom += ALIGN(DET_SOF_LEN, 4);
691 	ndev->priv_flags &= ~IFF_TX_SKB_SHARING;
692 	ndev->tx_queue_len = 100;
693 
694 	mse = netdev_priv(ndev);
695 	mses = to_mse102x_spi(mse);
696 
697 	mses->spidev = spi;
698 	mutex_init(&mses->lock);
699 	INIT_WORK(&mses->tx_work, mse102x_tx_work);
700 
701 	/* initialise pre-made spi transfer messages */
702 	spi_message_init(&mses->spi_msg);
703 	spi_message_add_tail(&mses->spi_xfer, &mses->spi_msg);
704 
705 	ndev->irq = spi->irq;
706 	mse->ndev = ndev;
707 
708 	/* set the default message enable */
709 	mse->msg_enable = netif_msg_init(-1, MSG_DEFAULT);
710 
711 	skb_queue_head_init(&mse->txq);
712 
713 	SET_NETDEV_DEV(ndev, dev);
714 
715 	dev_set_drvdata(dev, mse);
716 
717 	netif_carrier_off(mse->ndev);
718 	ndev->netdev_ops = &mse102x_netdev_ops;
719 	ndev->ethtool_ops = &mse102x_ethtool_ops;
720 
721 	mse102x_init_mac(mse, dev->of_node);
722 
723 	ret = register_netdev(ndev);
724 	if (ret) {
725 		dev_err(dev, "failed to register network device: %d\n", ret);
726 		return ret;
727 	}
728 
729 	mse102x_init_device_debugfs(mses);
730 
731 	return 0;
732 }
733 
734 static int mse102x_remove_spi(struct spi_device *spi)
735 {
736 	struct mse102x_net *mse = dev_get_drvdata(&spi->dev);
737 	struct mse102x_net_spi *mses = to_mse102x_spi(mse);
738 
739 	if (netif_msg_drv(mse))
740 		dev_info(&spi->dev, "remove\n");
741 
742 	mse102x_remove_device_debugfs(mses);
743 	unregister_netdev(mse->ndev);
744 
745 	return 0;
746 }
747 
748 static const struct of_device_id mse102x_match_table[] = {
749 	{ .compatible = "vertexcom,mse1021" },
750 	{ .compatible = "vertexcom,mse1022" },
751 	{ }
752 };
753 MODULE_DEVICE_TABLE(of, mse102x_match_table);
754 
755 static struct spi_driver mse102x_driver = {
756 	.driver = {
757 		.name = DRV_NAME,
758 		.of_match_table = mse102x_match_table,
759 		.pm = &mse102x_pm_ops,
760 	},
761 	.probe = mse102x_probe_spi,
762 	.remove = mse102x_remove_spi,
763 };
764 module_spi_driver(mse102x_driver);
765 
766 MODULE_DESCRIPTION("MSE102x Network driver");
767 MODULE_AUTHOR("Stefan Wahren <stefan.wahren@in-tech.com>");
768 MODULE_LICENSE("GPL");
769 MODULE_ALIAS("spi:" DRV_NAME);
770