xref: /openbmc/linux/drivers/net/can/sja1000/sja1000.c (revision 63dc02bd)
1 /*
2  * sja1000.c -  Philips SJA1000 network device driver
3  *
4  * Copyright (c) 2003 Matthias Brukner, Trajet Gmbh, Rebenring 33,
5  * 38106 Braunschweig, GERMANY
6  *
7  * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
8  * All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of Volkswagen nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * Alternatively, provided that this notice is retained in full, this
23  * software may be distributed under the terms of the GNU General
24  * Public License ("GPL") version 2, in which case the provisions of the
25  * GPL apply INSTEAD OF those given above.
26  *
27  * The provided data structures and external interfaces from this code
28  * are not restricted to be used by modules with a GPL compatible license.
29  *
30  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
31  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
32  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
33  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
34  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
35  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
36  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
37  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
38  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
39  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
40  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
41  * DAMAGE.
42  *
43  */
44 
45 #include <linux/module.h>
46 #include <linux/init.h>
47 #include <linux/kernel.h>
48 #include <linux/sched.h>
49 #include <linux/types.h>
50 #include <linux/fcntl.h>
51 #include <linux/interrupt.h>
52 #include <linux/ptrace.h>
53 #include <linux/string.h>
54 #include <linux/errno.h>
55 #include <linux/netdevice.h>
56 #include <linux/if_arp.h>
57 #include <linux/if_ether.h>
58 #include <linux/skbuff.h>
59 #include <linux/delay.h>
60 
61 #include <linux/can/dev.h>
62 #include <linux/can/error.h>
63 
64 #include "sja1000.h"
65 
66 #define DRV_NAME "sja1000"
67 
68 MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
69 MODULE_LICENSE("Dual BSD/GPL");
70 MODULE_DESCRIPTION(DRV_NAME "CAN netdevice driver");
71 
72 static struct can_bittiming_const sja1000_bittiming_const = {
73 	.name = DRV_NAME,
74 	.tseg1_min = 1,
75 	.tseg1_max = 16,
76 	.tseg2_min = 1,
77 	.tseg2_max = 8,
78 	.sjw_max = 4,
79 	.brp_min = 1,
80 	.brp_max = 64,
81 	.brp_inc = 1,
82 };
83 
84 static void sja1000_write_cmdreg(struct sja1000_priv *priv, u8 val)
85 {
86 	unsigned long flags;
87 
88 	/*
89 	 * The command register needs some locking and time to settle
90 	 * the write_reg() operation - especially on SMP systems.
91 	 */
92 	spin_lock_irqsave(&priv->cmdreg_lock, flags);
93 	priv->write_reg(priv, REG_CMR, val);
94 	priv->read_reg(priv, REG_SR);
95 	spin_unlock_irqrestore(&priv->cmdreg_lock, flags);
96 }
97 
98 static int sja1000_is_absent(struct sja1000_priv *priv)
99 {
100 	return (priv->read_reg(priv, REG_MOD) == 0xFF);
101 }
102 
103 static int sja1000_probe_chip(struct net_device *dev)
104 {
105 	struct sja1000_priv *priv = netdev_priv(dev);
106 
107 	if (priv->reg_base && sja1000_is_absent(priv)) {
108 		printk(KERN_INFO "%s: probing @0x%lX failed\n",
109 		       DRV_NAME, dev->base_addr);
110 		return 0;
111 	}
112 	return -1;
113 }
114 
115 static void set_reset_mode(struct net_device *dev)
116 {
117 	struct sja1000_priv *priv = netdev_priv(dev);
118 	unsigned char status = priv->read_reg(priv, REG_MOD);
119 	int i;
120 
121 	/* disable interrupts */
122 	priv->write_reg(priv, REG_IER, IRQ_OFF);
123 
124 	for (i = 0; i < 100; i++) {
125 		/* check reset bit */
126 		if (status & MOD_RM) {
127 			priv->can.state = CAN_STATE_STOPPED;
128 			return;
129 		}
130 
131 		priv->write_reg(priv, REG_MOD, MOD_RM);	/* reset chip */
132 		udelay(10);
133 		status = priv->read_reg(priv, REG_MOD);
134 	}
135 
136 	netdev_err(dev, "setting SJA1000 into reset mode failed!\n");
137 }
138 
139 static void set_normal_mode(struct net_device *dev)
140 {
141 	struct sja1000_priv *priv = netdev_priv(dev);
142 	unsigned char status = priv->read_reg(priv, REG_MOD);
143 	int i;
144 
145 	for (i = 0; i < 100; i++) {
146 		/* check reset bit */
147 		if ((status & MOD_RM) == 0) {
148 			priv->can.state = CAN_STATE_ERROR_ACTIVE;
149 			/* enable interrupts */
150 			if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
151 				priv->write_reg(priv, REG_IER, IRQ_ALL);
152 			else
153 				priv->write_reg(priv, REG_IER,
154 						IRQ_ALL & ~IRQ_BEI);
155 			return;
156 		}
157 
158 		/* set chip to normal mode */
159 		priv->write_reg(priv, REG_MOD, 0x00);
160 		udelay(10);
161 		status = priv->read_reg(priv, REG_MOD);
162 	}
163 
164 	netdev_err(dev, "setting SJA1000 into normal mode failed!\n");
165 }
166 
167 static void sja1000_start(struct net_device *dev)
168 {
169 	struct sja1000_priv *priv = netdev_priv(dev);
170 
171 	/* leave reset mode */
172 	if (priv->can.state != CAN_STATE_STOPPED)
173 		set_reset_mode(dev);
174 
175 	/* Clear error counters and error code capture */
176 	priv->write_reg(priv, REG_TXERR, 0x0);
177 	priv->write_reg(priv, REG_RXERR, 0x0);
178 	priv->read_reg(priv, REG_ECC);
179 
180 	/* leave reset mode */
181 	set_normal_mode(dev);
182 }
183 
184 static int sja1000_set_mode(struct net_device *dev, enum can_mode mode)
185 {
186 	struct sja1000_priv *priv = netdev_priv(dev);
187 
188 	if (!priv->open_time)
189 		return -EINVAL;
190 
191 	switch (mode) {
192 	case CAN_MODE_START:
193 		sja1000_start(dev);
194 		if (netif_queue_stopped(dev))
195 			netif_wake_queue(dev);
196 		break;
197 
198 	default:
199 		return -EOPNOTSUPP;
200 	}
201 
202 	return 0;
203 }
204 
205 static int sja1000_set_bittiming(struct net_device *dev)
206 {
207 	struct sja1000_priv *priv = netdev_priv(dev);
208 	struct can_bittiming *bt = &priv->can.bittiming;
209 	u8 btr0, btr1;
210 
211 	btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
212 	btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
213 		(((bt->phase_seg2 - 1) & 0x7) << 4);
214 	if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
215 		btr1 |= 0x80;
216 
217 	netdev_info(dev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
218 
219 	priv->write_reg(priv, REG_BTR0, btr0);
220 	priv->write_reg(priv, REG_BTR1, btr1);
221 
222 	return 0;
223 }
224 
225 static int sja1000_get_berr_counter(const struct net_device *dev,
226 				    struct can_berr_counter *bec)
227 {
228 	struct sja1000_priv *priv = netdev_priv(dev);
229 
230 	bec->txerr = priv->read_reg(priv, REG_TXERR);
231 	bec->rxerr = priv->read_reg(priv, REG_RXERR);
232 
233 	return 0;
234 }
235 
236 /*
237  * initialize SJA1000 chip:
238  *   - reset chip
239  *   - set output mode
240  *   - set baudrate
241  *   - enable interrupts
242  *   - start operating mode
243  */
244 static void chipset_init(struct net_device *dev)
245 {
246 	struct sja1000_priv *priv = netdev_priv(dev);
247 
248 	/* set clock divider and output control register */
249 	priv->write_reg(priv, REG_CDR, priv->cdr | CDR_PELICAN);
250 
251 	/* set acceptance filter (accept all) */
252 	priv->write_reg(priv, REG_ACCC0, 0x00);
253 	priv->write_reg(priv, REG_ACCC1, 0x00);
254 	priv->write_reg(priv, REG_ACCC2, 0x00);
255 	priv->write_reg(priv, REG_ACCC3, 0x00);
256 
257 	priv->write_reg(priv, REG_ACCM0, 0xFF);
258 	priv->write_reg(priv, REG_ACCM1, 0xFF);
259 	priv->write_reg(priv, REG_ACCM2, 0xFF);
260 	priv->write_reg(priv, REG_ACCM3, 0xFF);
261 
262 	priv->write_reg(priv, REG_OCR, priv->ocr | OCR_MODE_NORMAL);
263 }
264 
265 /*
266  * transmit a CAN message
267  * message layout in the sk_buff should be like this:
268  * xx xx xx xx	 ff	 ll   00 11 22 33 44 55 66 77
269  * [  can-id ] [flags] [len] [can data (up to 8 bytes]
270  */
271 static netdev_tx_t sja1000_start_xmit(struct sk_buff *skb,
272 					    struct net_device *dev)
273 {
274 	struct sja1000_priv *priv = netdev_priv(dev);
275 	struct can_frame *cf = (struct can_frame *)skb->data;
276 	uint8_t fi;
277 	uint8_t dlc;
278 	canid_t id;
279 	uint8_t dreg;
280 	int i;
281 
282 	if (can_dropped_invalid_skb(dev, skb))
283 		return NETDEV_TX_OK;
284 
285 	netif_stop_queue(dev);
286 
287 	fi = dlc = cf->can_dlc;
288 	id = cf->can_id;
289 
290 	if (id & CAN_RTR_FLAG)
291 		fi |= FI_RTR;
292 
293 	if (id & CAN_EFF_FLAG) {
294 		fi |= FI_FF;
295 		dreg = EFF_BUF;
296 		priv->write_reg(priv, REG_FI, fi);
297 		priv->write_reg(priv, REG_ID1, (id & 0x1fe00000) >> (5 + 16));
298 		priv->write_reg(priv, REG_ID2, (id & 0x001fe000) >> (5 + 8));
299 		priv->write_reg(priv, REG_ID3, (id & 0x00001fe0) >> 5);
300 		priv->write_reg(priv, REG_ID4, (id & 0x0000001f) << 3);
301 	} else {
302 		dreg = SFF_BUF;
303 		priv->write_reg(priv, REG_FI, fi);
304 		priv->write_reg(priv, REG_ID1, (id & 0x000007f8) >> 3);
305 		priv->write_reg(priv, REG_ID2, (id & 0x00000007) << 5);
306 	}
307 
308 	for (i = 0; i < dlc; i++)
309 		priv->write_reg(priv, dreg++, cf->data[i]);
310 
311 	can_put_echo_skb(skb, dev, 0);
312 
313 	sja1000_write_cmdreg(priv, CMD_TR);
314 
315 	return NETDEV_TX_OK;
316 }
317 
318 static void sja1000_rx(struct net_device *dev)
319 {
320 	struct sja1000_priv *priv = netdev_priv(dev);
321 	struct net_device_stats *stats = &dev->stats;
322 	struct can_frame *cf;
323 	struct sk_buff *skb;
324 	uint8_t fi;
325 	uint8_t dreg;
326 	canid_t id;
327 	int i;
328 
329 	/* create zero'ed CAN frame buffer */
330 	skb = alloc_can_skb(dev, &cf);
331 	if (skb == NULL)
332 		return;
333 
334 	fi = priv->read_reg(priv, REG_FI);
335 
336 	if (fi & FI_FF) {
337 		/* extended frame format (EFF) */
338 		dreg = EFF_BUF;
339 		id = (priv->read_reg(priv, REG_ID1) << (5 + 16))
340 		    | (priv->read_reg(priv, REG_ID2) << (5 + 8))
341 		    | (priv->read_reg(priv, REG_ID3) << 5)
342 		    | (priv->read_reg(priv, REG_ID4) >> 3);
343 		id |= CAN_EFF_FLAG;
344 	} else {
345 		/* standard frame format (SFF) */
346 		dreg = SFF_BUF;
347 		id = (priv->read_reg(priv, REG_ID1) << 3)
348 		    | (priv->read_reg(priv, REG_ID2) >> 5);
349 	}
350 
351 	cf->can_dlc = get_can_dlc(fi & 0x0F);
352 	if (fi & FI_RTR) {
353 		id |= CAN_RTR_FLAG;
354 	} else {
355 		for (i = 0; i < cf->can_dlc; i++)
356 			cf->data[i] = priv->read_reg(priv, dreg++);
357 	}
358 
359 	cf->can_id = id;
360 
361 	/* release receive buffer */
362 	sja1000_write_cmdreg(priv, CMD_RRB);
363 
364 	netif_rx(skb);
365 
366 	stats->rx_packets++;
367 	stats->rx_bytes += cf->can_dlc;
368 }
369 
370 static int sja1000_err(struct net_device *dev, uint8_t isrc, uint8_t status)
371 {
372 	struct sja1000_priv *priv = netdev_priv(dev);
373 	struct net_device_stats *stats = &dev->stats;
374 	struct can_frame *cf;
375 	struct sk_buff *skb;
376 	enum can_state state = priv->can.state;
377 	uint8_t ecc, alc;
378 
379 	skb = alloc_can_err_skb(dev, &cf);
380 	if (skb == NULL)
381 		return -ENOMEM;
382 
383 	if (isrc & IRQ_DOI) {
384 		/* data overrun interrupt */
385 		netdev_dbg(dev, "data overrun interrupt\n");
386 		cf->can_id |= CAN_ERR_CRTL;
387 		cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
388 		stats->rx_over_errors++;
389 		stats->rx_errors++;
390 		sja1000_write_cmdreg(priv, CMD_CDO);	/* clear bit */
391 	}
392 
393 	if (isrc & IRQ_EI) {
394 		/* error warning interrupt */
395 		netdev_dbg(dev, "error warning interrupt\n");
396 
397 		if (status & SR_BS) {
398 			state = CAN_STATE_BUS_OFF;
399 			cf->can_id |= CAN_ERR_BUSOFF;
400 			can_bus_off(dev);
401 		} else if (status & SR_ES) {
402 			state = CAN_STATE_ERROR_WARNING;
403 		} else
404 			state = CAN_STATE_ERROR_ACTIVE;
405 	}
406 	if (isrc & IRQ_BEI) {
407 		/* bus error interrupt */
408 		priv->can.can_stats.bus_error++;
409 		stats->rx_errors++;
410 
411 		ecc = priv->read_reg(priv, REG_ECC);
412 
413 		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
414 
415 		switch (ecc & ECC_MASK) {
416 		case ECC_BIT:
417 			cf->data[2] |= CAN_ERR_PROT_BIT;
418 			break;
419 		case ECC_FORM:
420 			cf->data[2] |= CAN_ERR_PROT_FORM;
421 			break;
422 		case ECC_STUFF:
423 			cf->data[2] |= CAN_ERR_PROT_STUFF;
424 			break;
425 		default:
426 			cf->data[2] |= CAN_ERR_PROT_UNSPEC;
427 			cf->data[3] = ecc & ECC_SEG;
428 			break;
429 		}
430 		/* Error occurred during transmission? */
431 		if ((ecc & ECC_DIR) == 0)
432 			cf->data[2] |= CAN_ERR_PROT_TX;
433 	}
434 	if (isrc & IRQ_EPI) {
435 		/* error passive interrupt */
436 		netdev_dbg(dev, "error passive interrupt\n");
437 		if (status & SR_ES)
438 			state = CAN_STATE_ERROR_PASSIVE;
439 		else
440 			state = CAN_STATE_ERROR_ACTIVE;
441 	}
442 	if (isrc & IRQ_ALI) {
443 		/* arbitration lost interrupt */
444 		netdev_dbg(dev, "arbitration lost interrupt\n");
445 		alc = priv->read_reg(priv, REG_ALC);
446 		priv->can.can_stats.arbitration_lost++;
447 		stats->tx_errors++;
448 		cf->can_id |= CAN_ERR_LOSTARB;
449 		cf->data[0] = alc & 0x1f;
450 	}
451 
452 	if (state != priv->can.state && (state == CAN_STATE_ERROR_WARNING ||
453 					 state == CAN_STATE_ERROR_PASSIVE)) {
454 		uint8_t rxerr = priv->read_reg(priv, REG_RXERR);
455 		uint8_t txerr = priv->read_reg(priv, REG_TXERR);
456 		cf->can_id |= CAN_ERR_CRTL;
457 		if (state == CAN_STATE_ERROR_WARNING) {
458 			priv->can.can_stats.error_warning++;
459 			cf->data[1] = (txerr > rxerr) ?
460 				CAN_ERR_CRTL_TX_WARNING :
461 				CAN_ERR_CRTL_RX_WARNING;
462 		} else {
463 			priv->can.can_stats.error_passive++;
464 			cf->data[1] = (txerr > rxerr) ?
465 				CAN_ERR_CRTL_TX_PASSIVE :
466 				CAN_ERR_CRTL_RX_PASSIVE;
467 		}
468 		cf->data[6] = txerr;
469 		cf->data[7] = rxerr;
470 	}
471 
472 	priv->can.state = state;
473 
474 	netif_rx(skb);
475 
476 	stats->rx_packets++;
477 	stats->rx_bytes += cf->can_dlc;
478 
479 	return 0;
480 }
481 
482 irqreturn_t sja1000_interrupt(int irq, void *dev_id)
483 {
484 	struct net_device *dev = (struct net_device *)dev_id;
485 	struct sja1000_priv *priv = netdev_priv(dev);
486 	struct net_device_stats *stats = &dev->stats;
487 	uint8_t isrc, status;
488 	int n = 0;
489 
490 	/* Shared interrupts and IRQ off? */
491 	if (priv->read_reg(priv, REG_IER) == IRQ_OFF)
492 		return IRQ_NONE;
493 
494 	if (priv->pre_irq)
495 		priv->pre_irq(priv);
496 
497 	while ((isrc = priv->read_reg(priv, REG_IR)) && (n < SJA1000_MAX_IRQ)) {
498 		n++;
499 		status = priv->read_reg(priv, REG_SR);
500 		/* check for absent controller due to hw unplug */
501 		if (status == 0xFF && sja1000_is_absent(priv))
502 			return IRQ_NONE;
503 
504 		if (isrc & IRQ_WUI)
505 			netdev_warn(dev, "wakeup interrupt\n");
506 
507 		if (isrc & IRQ_TI) {
508 			/* transmission complete interrupt */
509 			stats->tx_bytes += priv->read_reg(priv, REG_FI) & 0xf;
510 			stats->tx_packets++;
511 			can_get_echo_skb(dev, 0);
512 			netif_wake_queue(dev);
513 		}
514 		if (isrc & IRQ_RI) {
515 			/* receive interrupt */
516 			while (status & SR_RBS) {
517 				sja1000_rx(dev);
518 				status = priv->read_reg(priv, REG_SR);
519 				/* check for absent controller */
520 				if (status == 0xFF && sja1000_is_absent(priv))
521 					return IRQ_NONE;
522 			}
523 		}
524 		if (isrc & (IRQ_DOI | IRQ_EI | IRQ_BEI | IRQ_EPI | IRQ_ALI)) {
525 			/* error interrupt */
526 			if (sja1000_err(dev, isrc, status))
527 				break;
528 		}
529 	}
530 
531 	if (priv->post_irq)
532 		priv->post_irq(priv);
533 
534 	if (n >= SJA1000_MAX_IRQ)
535 		netdev_dbg(dev, "%d messages handled in ISR", n);
536 
537 	return (n) ? IRQ_HANDLED : IRQ_NONE;
538 }
539 EXPORT_SYMBOL_GPL(sja1000_interrupt);
540 
541 static int sja1000_open(struct net_device *dev)
542 {
543 	struct sja1000_priv *priv = netdev_priv(dev);
544 	int err;
545 
546 	/* set chip into reset mode */
547 	set_reset_mode(dev);
548 
549 	/* common open */
550 	err = open_candev(dev);
551 	if (err)
552 		return err;
553 
554 	/* register interrupt handler, if not done by the device driver */
555 	if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER)) {
556 		err = request_irq(dev->irq, sja1000_interrupt, priv->irq_flags,
557 				  dev->name, (void *)dev);
558 		if (err) {
559 			close_candev(dev);
560 			return -EAGAIN;
561 		}
562 	}
563 
564 	/* init and start chi */
565 	sja1000_start(dev);
566 	priv->open_time = jiffies;
567 
568 	netif_start_queue(dev);
569 
570 	return 0;
571 }
572 
573 static int sja1000_close(struct net_device *dev)
574 {
575 	struct sja1000_priv *priv = netdev_priv(dev);
576 
577 	netif_stop_queue(dev);
578 	set_reset_mode(dev);
579 
580 	if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER))
581 		free_irq(dev->irq, (void *)dev);
582 
583 	close_candev(dev);
584 
585 	priv->open_time = 0;
586 
587 	return 0;
588 }
589 
590 struct net_device *alloc_sja1000dev(int sizeof_priv)
591 {
592 	struct net_device *dev;
593 	struct sja1000_priv *priv;
594 
595 	dev = alloc_candev(sizeof(struct sja1000_priv) + sizeof_priv,
596 		SJA1000_ECHO_SKB_MAX);
597 	if (!dev)
598 		return NULL;
599 
600 	priv = netdev_priv(dev);
601 
602 	priv->dev = dev;
603 	priv->can.bittiming_const = &sja1000_bittiming_const;
604 	priv->can.do_set_bittiming = sja1000_set_bittiming;
605 	priv->can.do_set_mode = sja1000_set_mode;
606 	priv->can.do_get_berr_counter = sja1000_get_berr_counter;
607 	priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
608 		CAN_CTRLMODE_BERR_REPORTING;
609 
610 	spin_lock_init(&priv->cmdreg_lock);
611 
612 	if (sizeof_priv)
613 		priv->priv = (void *)priv + sizeof(struct sja1000_priv);
614 
615 	return dev;
616 }
617 EXPORT_SYMBOL_GPL(alloc_sja1000dev);
618 
619 void free_sja1000dev(struct net_device *dev)
620 {
621 	free_candev(dev);
622 }
623 EXPORT_SYMBOL_GPL(free_sja1000dev);
624 
625 static const struct net_device_ops sja1000_netdev_ops = {
626        .ndo_open               = sja1000_open,
627        .ndo_stop               = sja1000_close,
628        .ndo_start_xmit         = sja1000_start_xmit,
629 };
630 
631 int register_sja1000dev(struct net_device *dev)
632 {
633 	if (!sja1000_probe_chip(dev))
634 		return -ENODEV;
635 
636 	dev->flags |= IFF_ECHO;	/* we support local echo */
637 	dev->netdev_ops = &sja1000_netdev_ops;
638 
639 	set_reset_mode(dev);
640 	chipset_init(dev);
641 
642 	return register_candev(dev);
643 }
644 EXPORT_SYMBOL_GPL(register_sja1000dev);
645 
646 void unregister_sja1000dev(struct net_device *dev)
647 {
648 	set_reset_mode(dev);
649 	unregister_candev(dev);
650 }
651 EXPORT_SYMBOL_GPL(unregister_sja1000dev);
652 
653 static __init int sja1000_init(void)
654 {
655 	printk(KERN_INFO "%s CAN netdevice driver\n", DRV_NAME);
656 
657 	return 0;
658 }
659 
660 module_init(sja1000_init);
661 
662 static __exit void sja1000_exit(void)
663 {
664 	printk(KERN_INFO "%s: driver removed\n", DRV_NAME);
665 }
666 
667 module_exit(sja1000_exit);
668