xref: /linux/drivers/net/can/sja1000/sja1000.c (revision 2da68a77) 
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/ethtool.h>
56 #include <linux/netdevice.h>
57 #include <linux/if_arp.h>
58 #include <linux/if_ether.h>
59 #include <linux/skbuff.h>
60 #include <linux/delay.h>
61 
62 #include <linux/can/dev.h>
63 #include <linux/can/error.h>
64 
65 #include "sja1000.h"
66 
67 #define DRV_NAME "sja1000"
68 
69 MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
70 MODULE_LICENSE("Dual BSD/GPL");
71 MODULE_DESCRIPTION(DRV_NAME "CAN netdevice driver");
72 
73 static const struct can_bittiming_const sja1000_bittiming_const = {
74 	.name = DRV_NAME,
75 	.tseg1_min = 1,
76 	.tseg1_max = 16,
77 	.tseg2_min = 1,
78 	.tseg2_max = 8,
79 	.sjw_max = 4,
80 	.brp_min = 1,
81 	.brp_max = 64,
82 	.brp_inc = 1,
83 };
84 
85 static void sja1000_write_cmdreg(struct sja1000_priv *priv, u8 val)
86 {
87 	unsigned long flags;
88 
89 	/*
90 	 * The command register needs some locking and time to settle
91 	 * the write_reg() operation - especially on SMP systems.
92 	 */
93 	spin_lock_irqsave(&priv->cmdreg_lock, flags);
94 	priv->write_reg(priv, SJA1000_CMR, val);
95 	priv->read_reg(priv, SJA1000_SR);
96 	spin_unlock_irqrestore(&priv->cmdreg_lock, flags);
97 }
98 
99 static int sja1000_is_absent(struct sja1000_priv *priv)
100 {
101 	return (priv->read_reg(priv, SJA1000_MOD) == 0xFF);
102 }
103 
104 static int sja1000_probe_chip(struct net_device *dev)
105 {
106 	struct sja1000_priv *priv = netdev_priv(dev);
107 
108 	if (priv->reg_base && sja1000_is_absent(priv)) {
109 		netdev_err(dev, "probing failed\n");
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, SJA1000_MOD);
119 	int i;
120 
121 	/* disable interrupts */
122 	priv->write_reg(priv, SJA1000_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 		/* reset chip */
132 		priv->write_reg(priv, SJA1000_MOD, MOD_RM);
133 		udelay(10);
134 		status = priv->read_reg(priv, SJA1000_MOD);
135 	}
136 
137 	netdev_err(dev, "setting SJA1000 into reset mode failed!\n");
138 }
139 
140 static void set_normal_mode(struct net_device *dev)
141 {
142 	struct sja1000_priv *priv = netdev_priv(dev);
143 	unsigned char status = priv->read_reg(priv, SJA1000_MOD);
144 	u8 mod_reg_val = 0x00;
145 	int i;
146 
147 	for (i = 0; i < 100; i++) {
148 		/* check reset bit */
149 		if ((status & MOD_RM) == 0) {
150 			priv->can.state = CAN_STATE_ERROR_ACTIVE;
151 			/* enable interrupts */
152 			if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
153 				priv->write_reg(priv, SJA1000_IER, IRQ_ALL);
154 			else
155 				priv->write_reg(priv, SJA1000_IER,
156 						IRQ_ALL & ~IRQ_BEI);
157 			return;
158 		}
159 
160 		/* set chip to normal mode */
161 		if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
162 			mod_reg_val |= MOD_LOM;
163 		if (priv->can.ctrlmode & CAN_CTRLMODE_PRESUME_ACK)
164 			mod_reg_val |= MOD_STM;
165 		priv->write_reg(priv, SJA1000_MOD, mod_reg_val);
166 
167 		udelay(10);
168 
169 		status = priv->read_reg(priv, SJA1000_MOD);
170 	}
171 
172 	netdev_err(dev, "setting SJA1000 into normal mode failed!\n");
173 }
174 
175 /*
176  * initialize SJA1000 chip:
177  *   - reset chip
178  *   - set output mode
179  *   - set baudrate
180  *   - enable interrupts
181  *   - start operating mode
182  */
183 static void chipset_init(struct net_device *dev)
184 {
185 	struct sja1000_priv *priv = netdev_priv(dev);
186 
187 	if (!(priv->flags & SJA1000_QUIRK_NO_CDR_REG))
188 		/* set clock divider and output control register */
189 		priv->write_reg(priv, SJA1000_CDR, priv->cdr | CDR_PELICAN);
190 
191 	/* set acceptance filter (accept all) */
192 	priv->write_reg(priv, SJA1000_ACCC0, 0x00);
193 	priv->write_reg(priv, SJA1000_ACCC1, 0x00);
194 	priv->write_reg(priv, SJA1000_ACCC2, 0x00);
195 	priv->write_reg(priv, SJA1000_ACCC3, 0x00);
196 
197 	priv->write_reg(priv, SJA1000_ACCM0, 0xFF);
198 	priv->write_reg(priv, SJA1000_ACCM1, 0xFF);
199 	priv->write_reg(priv, SJA1000_ACCM2, 0xFF);
200 	priv->write_reg(priv, SJA1000_ACCM3, 0xFF);
201 
202 	priv->write_reg(priv, SJA1000_OCR, priv->ocr | OCR_MODE_NORMAL);
203 }
204 
205 static void sja1000_start(struct net_device *dev)
206 {
207 	struct sja1000_priv *priv = netdev_priv(dev);
208 
209 	/* leave reset mode */
210 	if (priv->can.state != CAN_STATE_STOPPED)
211 		set_reset_mode(dev);
212 
213 	/* Initialize chip if uninitialized at this stage */
214 	if (!(priv->flags & SJA1000_QUIRK_NO_CDR_REG ||
215 	      priv->read_reg(priv, SJA1000_CDR) & CDR_PELICAN))
216 		chipset_init(dev);
217 
218 	/* Clear error counters and error code capture */
219 	priv->write_reg(priv, SJA1000_TXERR, 0x0);
220 	priv->write_reg(priv, SJA1000_RXERR, 0x0);
221 	priv->read_reg(priv, SJA1000_ECC);
222 
223 	/* clear interrupt flags */
224 	priv->read_reg(priv, SJA1000_IR);
225 
226 	/* leave reset mode */
227 	set_normal_mode(dev);
228 }
229 
230 static int sja1000_set_mode(struct net_device *dev, enum can_mode mode)
231 {
232 	switch (mode) {
233 	case CAN_MODE_START:
234 		sja1000_start(dev);
235 		if (netif_queue_stopped(dev))
236 			netif_wake_queue(dev);
237 		break;
238 
239 	default:
240 		return -EOPNOTSUPP;
241 	}
242 
243 	return 0;
244 }
245 
246 static int sja1000_set_bittiming(struct net_device *dev)
247 {
248 	struct sja1000_priv *priv = netdev_priv(dev);
249 	struct can_bittiming *bt = &priv->can.bittiming;
250 	u8 btr0, btr1;
251 
252 	btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
253 	btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
254 		(((bt->phase_seg2 - 1) & 0x7) << 4);
255 	if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
256 		btr1 |= 0x80;
257 
258 	netdev_info(dev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
259 
260 	priv->write_reg(priv, SJA1000_BTR0, btr0);
261 	priv->write_reg(priv, SJA1000_BTR1, btr1);
262 
263 	return 0;
264 }
265 
266 static int sja1000_get_berr_counter(const struct net_device *dev,
267 				    struct can_berr_counter *bec)
268 {
269 	struct sja1000_priv *priv = netdev_priv(dev);
270 
271 	bec->txerr = priv->read_reg(priv, SJA1000_TXERR);
272 	bec->rxerr = priv->read_reg(priv, SJA1000_RXERR);
273 
274 	return 0;
275 }
276 
277 /*
278  * transmit a CAN message
279  * message layout in the sk_buff should be like this:
280  * xx xx xx xx	 ff	 ll   00 11 22 33 44 55 66 77
281  * [  can-id ] [flags] [len] [can data (up to 8 bytes]
282  */
283 static netdev_tx_t sja1000_start_xmit(struct sk_buff *skb,
284 					    struct net_device *dev)
285 {
286 	struct sja1000_priv *priv = netdev_priv(dev);
287 	struct can_frame *cf = (struct can_frame *)skb->data;
288 	uint8_t fi;
289 	canid_t id;
290 	uint8_t dreg;
291 	u8 cmd_reg_val = 0x00;
292 	int i;
293 
294 	if (can_dev_dropped_skb(dev, skb))
295 		return NETDEV_TX_OK;
296 
297 	netif_stop_queue(dev);
298 
299 	fi = can_get_cc_dlc(cf, priv->can.ctrlmode);
300 	id = cf->can_id;
301 
302 	if (id & CAN_RTR_FLAG)
303 		fi |= SJA1000_FI_RTR;
304 
305 	if (id & CAN_EFF_FLAG) {
306 		fi |= SJA1000_FI_FF;
307 		dreg = SJA1000_EFF_BUF;
308 		priv->write_reg(priv, SJA1000_FI, fi);
309 		priv->write_reg(priv, SJA1000_ID1, (id & 0x1fe00000) >> 21);
310 		priv->write_reg(priv, SJA1000_ID2, (id & 0x001fe000) >> 13);
311 		priv->write_reg(priv, SJA1000_ID3, (id & 0x00001fe0) >> 5);
312 		priv->write_reg(priv, SJA1000_ID4, (id & 0x0000001f) << 3);
313 	} else {
314 		dreg = SJA1000_SFF_BUF;
315 		priv->write_reg(priv, SJA1000_FI, fi);
316 		priv->write_reg(priv, SJA1000_ID1, (id & 0x000007f8) >> 3);
317 		priv->write_reg(priv, SJA1000_ID2, (id & 0x00000007) << 5);
318 	}
319 
320 	for (i = 0; i < cf->len; i++)
321 		priv->write_reg(priv, dreg++, cf->data[i]);
322 
323 	can_put_echo_skb(skb, dev, 0, 0);
324 
325 	if (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT)
326 		cmd_reg_val |= CMD_AT;
327 
328 	if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
329 		cmd_reg_val |= CMD_SRR;
330 	else
331 		cmd_reg_val |= CMD_TR;
332 
333 	sja1000_write_cmdreg(priv, cmd_reg_val);
334 
335 	return NETDEV_TX_OK;
336 }
337 
338 static void sja1000_rx(struct net_device *dev)
339 {
340 	struct sja1000_priv *priv = netdev_priv(dev);
341 	struct net_device_stats *stats = &dev->stats;
342 	struct can_frame *cf;
343 	struct sk_buff *skb;
344 	uint8_t fi;
345 	uint8_t dreg;
346 	canid_t id;
347 	int i;
348 
349 	/* create zero'ed CAN frame buffer */
350 	skb = alloc_can_skb(dev, &cf);
351 	if (skb == NULL)
352 		return;
353 
354 	fi = priv->read_reg(priv, SJA1000_FI);
355 
356 	if (fi & SJA1000_FI_FF) {
357 		/* extended frame format (EFF) */
358 		dreg = SJA1000_EFF_BUF;
359 		id = (priv->read_reg(priv, SJA1000_ID1) << 21)
360 		    | (priv->read_reg(priv, SJA1000_ID2) << 13)
361 		    | (priv->read_reg(priv, SJA1000_ID3) << 5)
362 		    | (priv->read_reg(priv, SJA1000_ID4) >> 3);
363 		id |= CAN_EFF_FLAG;
364 	} else {
365 		/* standard frame format (SFF) */
366 		dreg = SJA1000_SFF_BUF;
367 		id = (priv->read_reg(priv, SJA1000_ID1) << 3)
368 		    | (priv->read_reg(priv, SJA1000_ID2) >> 5);
369 	}
370 
371 	can_frame_set_cc_len(cf, fi & 0x0F, priv->can.ctrlmode);
372 	if (fi & SJA1000_FI_RTR) {
373 		id |= CAN_RTR_FLAG;
374 	} else {
375 		for (i = 0; i < cf->len; i++)
376 			cf->data[i] = priv->read_reg(priv, dreg++);
377 
378 		stats->rx_bytes += cf->len;
379 	}
380 	stats->rx_packets++;
381 
382 	cf->can_id = id;
383 
384 	/* release receive buffer */
385 	sja1000_write_cmdreg(priv, CMD_RRB);
386 
387 	netif_rx(skb);
388 }
389 
390 static int sja1000_err(struct net_device *dev, uint8_t isrc, uint8_t status)
391 {
392 	struct sja1000_priv *priv = netdev_priv(dev);
393 	struct net_device_stats *stats = &dev->stats;
394 	struct can_frame *cf;
395 	struct sk_buff *skb;
396 	enum can_state state = priv->can.state;
397 	enum can_state rx_state, tx_state;
398 	unsigned int rxerr, txerr;
399 	uint8_t ecc, alc;
400 
401 	skb = alloc_can_err_skb(dev, &cf);
402 	if (skb == NULL)
403 		return -ENOMEM;
404 
405 	txerr = priv->read_reg(priv, SJA1000_TXERR);
406 	rxerr = priv->read_reg(priv, SJA1000_RXERR);
407 
408 	if (isrc & IRQ_DOI) {
409 		/* data overrun interrupt */
410 		netdev_dbg(dev, "data overrun interrupt\n");
411 		cf->can_id |= CAN_ERR_CRTL;
412 		cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
413 		stats->rx_over_errors++;
414 		stats->rx_errors++;
415 		sja1000_write_cmdreg(priv, CMD_CDO);	/* clear bit */
416 	}
417 
418 	if (isrc & IRQ_EI) {
419 		/* error warning interrupt */
420 		netdev_dbg(dev, "error warning interrupt\n");
421 
422 		if (status & SR_BS)
423 			state = CAN_STATE_BUS_OFF;
424 		else if (status & SR_ES)
425 			state = CAN_STATE_ERROR_WARNING;
426 		else
427 			state = CAN_STATE_ERROR_ACTIVE;
428 	}
429 	if (state != CAN_STATE_BUS_OFF) {
430 		cf->can_id |= CAN_ERR_CNT;
431 		cf->data[6] = txerr;
432 		cf->data[7] = rxerr;
433 	}
434 	if (isrc & IRQ_BEI) {
435 		/* bus error interrupt */
436 		priv->can.can_stats.bus_error++;
437 		stats->rx_errors++;
438 
439 		ecc = priv->read_reg(priv, SJA1000_ECC);
440 
441 		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
442 
443 		/* set error type */
444 		switch (ecc & ECC_MASK) {
445 		case ECC_BIT:
446 			cf->data[2] |= CAN_ERR_PROT_BIT;
447 			break;
448 		case ECC_FORM:
449 			cf->data[2] |= CAN_ERR_PROT_FORM;
450 			break;
451 		case ECC_STUFF:
452 			cf->data[2] |= CAN_ERR_PROT_STUFF;
453 			break;
454 		default:
455 			break;
456 		}
457 
458 		/* set error location */
459 		cf->data[3] = ecc & ECC_SEG;
460 
461 		/* Error occurred during transmission? */
462 		if ((ecc & ECC_DIR) == 0)
463 			cf->data[2] |= CAN_ERR_PROT_TX;
464 	}
465 	if (isrc & IRQ_EPI) {
466 		/* error passive interrupt */
467 		netdev_dbg(dev, "error passive interrupt\n");
468 
469 		if (state == CAN_STATE_ERROR_PASSIVE)
470 			state = CAN_STATE_ERROR_WARNING;
471 		else
472 			state = CAN_STATE_ERROR_PASSIVE;
473 	}
474 	if (isrc & IRQ_ALI) {
475 		/* arbitration lost interrupt */
476 		netdev_dbg(dev, "arbitration lost interrupt\n");
477 		alc = priv->read_reg(priv, SJA1000_ALC);
478 		priv->can.can_stats.arbitration_lost++;
479 		cf->can_id |= CAN_ERR_LOSTARB;
480 		cf->data[0] = alc & 0x1f;
481 	}
482 
483 	if (state != priv->can.state) {
484 		tx_state = txerr >= rxerr ? state : 0;
485 		rx_state = txerr <= rxerr ? state : 0;
486 
487 		can_change_state(dev, cf, tx_state, rx_state);
488 
489 		if(state == CAN_STATE_BUS_OFF)
490 			can_bus_off(dev);
491 	}
492 
493 	netif_rx(skb);
494 
495 	return 0;
496 }
497 
498 irqreturn_t sja1000_interrupt(int irq, void *dev_id)
499 {
500 	struct net_device *dev = (struct net_device *)dev_id;
501 	struct sja1000_priv *priv = netdev_priv(dev);
502 	struct net_device_stats *stats = &dev->stats;
503 	uint8_t isrc, status;
504 	int n = 0;
505 
506 	if (priv->pre_irq)
507 		priv->pre_irq(priv);
508 
509 	/* Shared interrupts and IRQ off? */
510 	if (priv->read_reg(priv, SJA1000_IER) == IRQ_OFF)
511 		goto out;
512 
513 	while ((isrc = priv->read_reg(priv, SJA1000_IR)) &&
514 	       (n < SJA1000_MAX_IRQ)) {
515 
516 		status = priv->read_reg(priv, SJA1000_SR);
517 		/* check for absent controller due to hw unplug */
518 		if (status == 0xFF && sja1000_is_absent(priv))
519 			goto out;
520 
521 		if (isrc & IRQ_WUI)
522 			netdev_warn(dev, "wakeup interrupt\n");
523 
524 		if (isrc & IRQ_TI) {
525 			/* transmission buffer released */
526 			if (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT &&
527 			    !(status & SR_TCS)) {
528 				stats->tx_errors++;
529 				can_free_echo_skb(dev, 0, NULL);
530 			} else {
531 				/* transmission complete */
532 				stats->tx_bytes += can_get_echo_skb(dev, 0, NULL);
533 				stats->tx_packets++;
534 			}
535 			netif_wake_queue(dev);
536 		}
537 		if (isrc & IRQ_RI) {
538 			/* receive interrupt */
539 			while (status & SR_RBS) {
540 				sja1000_rx(dev);
541 				status = priv->read_reg(priv, SJA1000_SR);
542 				/* check for absent controller */
543 				if (status == 0xFF && sja1000_is_absent(priv))
544 					goto out;
545 			}
546 		}
547 		if (isrc & (IRQ_DOI | IRQ_EI | IRQ_BEI | IRQ_EPI | IRQ_ALI)) {
548 			/* error interrupt */
549 			if (sja1000_err(dev, isrc, status))
550 				break;
551 		}
552 		n++;
553 	}
554 out:
555 	if (priv->post_irq)
556 		priv->post_irq(priv);
557 
558 	if (n >= SJA1000_MAX_IRQ)
559 		netdev_dbg(dev, "%d messages handled in ISR", n);
560 
561 	return (n) ? IRQ_HANDLED : IRQ_NONE;
562 }
563 EXPORT_SYMBOL_GPL(sja1000_interrupt);
564 
565 static int sja1000_open(struct net_device *dev)
566 {
567 	struct sja1000_priv *priv = netdev_priv(dev);
568 	int err;
569 
570 	/* set chip into reset mode */
571 	set_reset_mode(dev);
572 
573 	/* common open */
574 	err = open_candev(dev);
575 	if (err)
576 		return err;
577 
578 	/* register interrupt handler, if not done by the device driver */
579 	if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER)) {
580 		err = request_irq(dev->irq, sja1000_interrupt, priv->irq_flags,
581 				  dev->name, (void *)dev);
582 		if (err) {
583 			close_candev(dev);
584 			return -EAGAIN;
585 		}
586 	}
587 
588 	/* init and start chi */
589 	sja1000_start(dev);
590 
591 	netif_start_queue(dev);
592 
593 	return 0;
594 }
595 
596 static int sja1000_close(struct net_device *dev)
597 {
598 	struct sja1000_priv *priv = netdev_priv(dev);
599 
600 	netif_stop_queue(dev);
601 	set_reset_mode(dev);
602 
603 	if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER))
604 		free_irq(dev->irq, (void *)dev);
605 
606 	close_candev(dev);
607 
608 	return 0;
609 }
610 
611 struct net_device *alloc_sja1000dev(int sizeof_priv)
612 {
613 	struct net_device *dev;
614 	struct sja1000_priv *priv;
615 
616 	dev = alloc_candev(sizeof(struct sja1000_priv) + sizeof_priv,
617 		SJA1000_ECHO_SKB_MAX);
618 	if (!dev)
619 		return NULL;
620 
621 	priv = netdev_priv(dev);
622 
623 	priv->dev = dev;
624 	priv->can.bittiming_const = &sja1000_bittiming_const;
625 	priv->can.do_set_bittiming = sja1000_set_bittiming;
626 	priv->can.do_set_mode = sja1000_set_mode;
627 	priv->can.do_get_berr_counter = sja1000_get_berr_counter;
628 	priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
629 				       CAN_CTRLMODE_LISTENONLY |
630 				       CAN_CTRLMODE_3_SAMPLES |
631 				       CAN_CTRLMODE_ONE_SHOT |
632 				       CAN_CTRLMODE_BERR_REPORTING |
633 				       CAN_CTRLMODE_PRESUME_ACK |
634 				       CAN_CTRLMODE_CC_LEN8_DLC;
635 
636 	spin_lock_init(&priv->cmdreg_lock);
637 
638 	if (sizeof_priv)
639 		priv->priv = (void *)priv + sizeof(struct sja1000_priv);
640 
641 	return dev;
642 }
643 EXPORT_SYMBOL_GPL(alloc_sja1000dev);
644 
645 void free_sja1000dev(struct net_device *dev)
646 {
647 	free_candev(dev);
648 }
649 EXPORT_SYMBOL_GPL(free_sja1000dev);
650 
651 static const struct net_device_ops sja1000_netdev_ops = {
652 	.ndo_open	= sja1000_open,
653 	.ndo_stop	= sja1000_close,
654 	.ndo_start_xmit	= sja1000_start_xmit,
655 	.ndo_change_mtu	= can_change_mtu,
656 };
657 
658 static const struct ethtool_ops sja1000_ethtool_ops = {
659 	.get_ts_info = ethtool_op_get_ts_info,
660 };
661 
662 int register_sja1000dev(struct net_device *dev)
663 {
664 	if (!sja1000_probe_chip(dev))
665 		return -ENODEV;
666 
667 	dev->flags |= IFF_ECHO;	/* we support local echo */
668 	dev->netdev_ops = &sja1000_netdev_ops;
669 	dev->ethtool_ops = &sja1000_ethtool_ops;
670 
671 	set_reset_mode(dev);
672 	chipset_init(dev);
673 
674 	return register_candev(dev);
675 }
676 EXPORT_SYMBOL_GPL(register_sja1000dev);
677 
678 void unregister_sja1000dev(struct net_device *dev)
679 {
680 	set_reset_mode(dev);
681 	unregister_candev(dev);
682 }
683 EXPORT_SYMBOL_GPL(unregister_sja1000dev);
684 
685 static __init int sja1000_init(void)
686 {
687 	printk(KERN_INFO "%s CAN netdevice driver\n", DRV_NAME);
688 
689 	return 0;
690 }
691 
692 module_init(sja1000_init);
693 
694 static __exit void sja1000_exit(void)
695 {
696 	printk(KERN_INFO "%s: driver removed\n", DRV_NAME);
697 }
698 
699 module_exit(sja1000_exit);
700