xref: /openbmc/linux/drivers/net/can/sja1000/sja1000.c (revision 6d99a79c)
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 #include <linux/can/led.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 	/* set clock divider and output control register */
188 	priv->write_reg(priv, SJA1000_CDR, priv->cdr | CDR_PELICAN);
189 
190 	/* set acceptance filter (accept all) */
191 	priv->write_reg(priv, SJA1000_ACCC0, 0x00);
192 	priv->write_reg(priv, SJA1000_ACCC1, 0x00);
193 	priv->write_reg(priv, SJA1000_ACCC2, 0x00);
194 	priv->write_reg(priv, SJA1000_ACCC3, 0x00);
195 
196 	priv->write_reg(priv, SJA1000_ACCM0, 0xFF);
197 	priv->write_reg(priv, SJA1000_ACCM1, 0xFF);
198 	priv->write_reg(priv, SJA1000_ACCM2, 0xFF);
199 	priv->write_reg(priv, SJA1000_ACCM3, 0xFF);
200 
201 	priv->write_reg(priv, SJA1000_OCR, priv->ocr | OCR_MODE_NORMAL);
202 }
203 
204 static void sja1000_start(struct net_device *dev)
205 {
206 	struct sja1000_priv *priv = netdev_priv(dev);
207 
208 	/* leave reset mode */
209 	if (priv->can.state != CAN_STATE_STOPPED)
210 		set_reset_mode(dev);
211 
212 	/* Initialize chip if uninitialized at this stage */
213 	if (!(priv->read_reg(priv, SJA1000_CDR) & CDR_PELICAN))
214 		chipset_init(dev);
215 
216 	/* Clear error counters and error code capture */
217 	priv->write_reg(priv, SJA1000_TXERR, 0x0);
218 	priv->write_reg(priv, SJA1000_RXERR, 0x0);
219 	priv->read_reg(priv, SJA1000_ECC);
220 
221 	/* clear interrupt flags */
222 	priv->read_reg(priv, SJA1000_IR);
223 
224 	/* leave reset mode */
225 	set_normal_mode(dev);
226 }
227 
228 static int sja1000_set_mode(struct net_device *dev, enum can_mode mode)
229 {
230 	switch (mode) {
231 	case CAN_MODE_START:
232 		sja1000_start(dev);
233 		if (netif_queue_stopped(dev))
234 			netif_wake_queue(dev);
235 		break;
236 
237 	default:
238 		return -EOPNOTSUPP;
239 	}
240 
241 	return 0;
242 }
243 
244 static int sja1000_set_bittiming(struct net_device *dev)
245 {
246 	struct sja1000_priv *priv = netdev_priv(dev);
247 	struct can_bittiming *bt = &priv->can.bittiming;
248 	u8 btr0, btr1;
249 
250 	btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
251 	btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
252 		(((bt->phase_seg2 - 1) & 0x7) << 4);
253 	if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
254 		btr1 |= 0x80;
255 
256 	netdev_info(dev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
257 
258 	priv->write_reg(priv, SJA1000_BTR0, btr0);
259 	priv->write_reg(priv, SJA1000_BTR1, btr1);
260 
261 	return 0;
262 }
263 
264 static int sja1000_get_berr_counter(const struct net_device *dev,
265 				    struct can_berr_counter *bec)
266 {
267 	struct sja1000_priv *priv = netdev_priv(dev);
268 
269 	bec->txerr = priv->read_reg(priv, SJA1000_TXERR);
270 	bec->rxerr = priv->read_reg(priv, SJA1000_RXERR);
271 
272 	return 0;
273 }
274 
275 /*
276  * transmit a CAN message
277  * message layout in the sk_buff should be like this:
278  * xx xx xx xx	 ff	 ll   00 11 22 33 44 55 66 77
279  * [  can-id ] [flags] [len] [can data (up to 8 bytes]
280  */
281 static netdev_tx_t sja1000_start_xmit(struct sk_buff *skb,
282 					    struct net_device *dev)
283 {
284 	struct sja1000_priv *priv = netdev_priv(dev);
285 	struct can_frame *cf = (struct can_frame *)skb->data;
286 	uint8_t fi;
287 	uint8_t dlc;
288 	canid_t id;
289 	uint8_t dreg;
290 	u8 cmd_reg_val = 0x00;
291 	int i;
292 
293 	if (can_dropped_invalid_skb(dev, skb))
294 		return NETDEV_TX_OK;
295 
296 	netif_stop_queue(dev);
297 
298 	fi = dlc = cf->can_dlc;
299 	id = cf->can_id;
300 
301 	if (id & CAN_RTR_FLAG)
302 		fi |= SJA1000_FI_RTR;
303 
304 	if (id & CAN_EFF_FLAG) {
305 		fi |= SJA1000_FI_FF;
306 		dreg = SJA1000_EFF_BUF;
307 		priv->write_reg(priv, SJA1000_FI, fi);
308 		priv->write_reg(priv, SJA1000_ID1, (id & 0x1fe00000) >> 21);
309 		priv->write_reg(priv, SJA1000_ID2, (id & 0x001fe000) >> 13);
310 		priv->write_reg(priv, SJA1000_ID3, (id & 0x00001fe0) >> 5);
311 		priv->write_reg(priv, SJA1000_ID4, (id & 0x0000001f) << 3);
312 	} else {
313 		dreg = SJA1000_SFF_BUF;
314 		priv->write_reg(priv, SJA1000_FI, fi);
315 		priv->write_reg(priv, SJA1000_ID1, (id & 0x000007f8) >> 3);
316 		priv->write_reg(priv, SJA1000_ID2, (id & 0x00000007) << 5);
317 	}
318 
319 	for (i = 0; i < dlc; i++)
320 		priv->write_reg(priv, dreg++, cf->data[i]);
321 
322 	can_put_echo_skb(skb, dev, 0);
323 
324 	if (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT)
325 		cmd_reg_val |= CMD_AT;
326 
327 	if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
328 		cmd_reg_val |= CMD_SRR;
329 	else
330 		cmd_reg_val |= CMD_TR;
331 
332 	sja1000_write_cmdreg(priv, cmd_reg_val);
333 
334 	return NETDEV_TX_OK;
335 }
336 
337 static void sja1000_rx(struct net_device *dev)
338 {
339 	struct sja1000_priv *priv = netdev_priv(dev);
340 	struct net_device_stats *stats = &dev->stats;
341 	struct can_frame *cf;
342 	struct sk_buff *skb;
343 	uint8_t fi;
344 	uint8_t dreg;
345 	canid_t id;
346 	int i;
347 
348 	/* create zero'ed CAN frame buffer */
349 	skb = alloc_can_skb(dev, &cf);
350 	if (skb == NULL)
351 		return;
352 
353 	fi = priv->read_reg(priv, SJA1000_FI);
354 
355 	if (fi & SJA1000_FI_FF) {
356 		/* extended frame format (EFF) */
357 		dreg = SJA1000_EFF_BUF;
358 		id = (priv->read_reg(priv, SJA1000_ID1) << 21)
359 		    | (priv->read_reg(priv, SJA1000_ID2) << 13)
360 		    | (priv->read_reg(priv, SJA1000_ID3) << 5)
361 		    | (priv->read_reg(priv, SJA1000_ID4) >> 3);
362 		id |= CAN_EFF_FLAG;
363 	} else {
364 		/* standard frame format (SFF) */
365 		dreg = SJA1000_SFF_BUF;
366 		id = (priv->read_reg(priv, SJA1000_ID1) << 3)
367 		    | (priv->read_reg(priv, SJA1000_ID2) >> 5);
368 	}
369 
370 	cf->can_dlc = get_can_dlc(fi & 0x0F);
371 	if (fi & SJA1000_FI_RTR) {
372 		id |= CAN_RTR_FLAG;
373 	} else {
374 		for (i = 0; i < cf->can_dlc; i++)
375 			cf->data[i] = priv->read_reg(priv, dreg++);
376 	}
377 
378 	cf->can_id = id;
379 
380 	/* release receive buffer */
381 	sja1000_write_cmdreg(priv, CMD_RRB);
382 
383 	stats->rx_packets++;
384 	stats->rx_bytes += cf->can_dlc;
385 	netif_rx(skb);
386 
387 	can_led_event(dev, CAN_LED_EVENT_RX);
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 	cf->data[6] = txerr;
409 	cf->data[7] = rxerr;
410 
411 	if (isrc & IRQ_DOI) {
412 		/* data overrun interrupt */
413 		netdev_dbg(dev, "data overrun interrupt\n");
414 		cf->can_id |= CAN_ERR_CRTL;
415 		cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
416 		stats->rx_over_errors++;
417 		stats->rx_errors++;
418 		sja1000_write_cmdreg(priv, CMD_CDO);	/* clear bit */
419 	}
420 
421 	if (isrc & IRQ_EI) {
422 		/* error warning interrupt */
423 		netdev_dbg(dev, "error warning interrupt\n");
424 
425 		if (status & SR_BS)
426 			state = CAN_STATE_BUS_OFF;
427 		else if (status & SR_ES)
428 			state = CAN_STATE_ERROR_WARNING;
429 		else
430 			state = CAN_STATE_ERROR_ACTIVE;
431 	}
432 	if (isrc & IRQ_BEI) {
433 		/* bus error interrupt */
434 		priv->can.can_stats.bus_error++;
435 		stats->rx_errors++;
436 
437 		ecc = priv->read_reg(priv, SJA1000_ECC);
438 
439 		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
440 
441 		/* set error type */
442 		switch (ecc & ECC_MASK) {
443 		case ECC_BIT:
444 			cf->data[2] |= CAN_ERR_PROT_BIT;
445 			break;
446 		case ECC_FORM:
447 			cf->data[2] |= CAN_ERR_PROT_FORM;
448 			break;
449 		case ECC_STUFF:
450 			cf->data[2] |= CAN_ERR_PROT_STUFF;
451 			break;
452 		default:
453 			break;
454 		}
455 
456 		/* set error location */
457 		cf->data[3] = ecc & ECC_SEG;
458 
459 		/* Error occurred during transmission? */
460 		if ((ecc & ECC_DIR) == 0)
461 			cf->data[2] |= CAN_ERR_PROT_TX;
462 	}
463 	if (isrc & IRQ_EPI) {
464 		/* error passive interrupt */
465 		netdev_dbg(dev, "error passive interrupt\n");
466 
467 		if (state == CAN_STATE_ERROR_PASSIVE)
468 			state = CAN_STATE_ERROR_WARNING;
469 		else
470 			state = CAN_STATE_ERROR_PASSIVE;
471 	}
472 	if (isrc & IRQ_ALI) {
473 		/* arbitration lost interrupt */
474 		netdev_dbg(dev, "arbitration lost interrupt\n");
475 		alc = priv->read_reg(priv, SJA1000_ALC);
476 		priv->can.can_stats.arbitration_lost++;
477 		stats->tx_errors++;
478 		cf->can_id |= CAN_ERR_LOSTARB;
479 		cf->data[0] = alc & 0x1f;
480 	}
481 
482 	if (state != priv->can.state) {
483 		tx_state = txerr >= rxerr ? state : 0;
484 		rx_state = txerr <= rxerr ? state : 0;
485 
486 		can_change_state(dev, cf, tx_state, rx_state);
487 
488 		if(state == CAN_STATE_BUS_OFF)
489 			can_bus_off(dev);
490 	}
491 
492 	stats->rx_packets++;
493 	stats->rx_bytes += cf->can_dlc;
494 	netif_rx(skb);
495 
496 	return 0;
497 }
498 
499 irqreturn_t sja1000_interrupt(int irq, void *dev_id)
500 {
501 	struct net_device *dev = (struct net_device *)dev_id;
502 	struct sja1000_priv *priv = netdev_priv(dev);
503 	struct net_device_stats *stats = &dev->stats;
504 	uint8_t isrc, status;
505 	int n = 0;
506 
507 	if (priv->pre_irq)
508 		priv->pre_irq(priv);
509 
510 	/* Shared interrupts and IRQ off? */
511 	if (priv->read_reg(priv, SJA1000_IER) == IRQ_OFF)
512 		goto out;
513 
514 	while ((isrc = priv->read_reg(priv, SJA1000_IR)) &&
515 	       (n < SJA1000_MAX_IRQ)) {
516 
517 		status = priv->read_reg(priv, SJA1000_SR);
518 		/* check for absent controller due to hw unplug */
519 		if (status == 0xFF && sja1000_is_absent(priv))
520 			goto out;
521 
522 		if (isrc & IRQ_WUI)
523 			netdev_warn(dev, "wakeup interrupt\n");
524 
525 		if (isrc & IRQ_TI) {
526 			/* transmission buffer released */
527 			if (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT &&
528 			    !(status & SR_TCS)) {
529 				stats->tx_errors++;
530 				can_free_echo_skb(dev, 0);
531 			} else {
532 				/* transmission complete */
533 				stats->tx_bytes +=
534 					priv->read_reg(priv, SJA1000_FI) & 0xf;
535 				stats->tx_packets++;
536 				can_get_echo_skb(dev, 0);
537 			}
538 			netif_wake_queue(dev);
539 			can_led_event(dev, CAN_LED_EVENT_TX);
540 		}
541 		if (isrc & IRQ_RI) {
542 			/* receive interrupt */
543 			while (status & SR_RBS) {
544 				sja1000_rx(dev);
545 				status = priv->read_reg(priv, SJA1000_SR);
546 				/* check for absent controller */
547 				if (status == 0xFF && sja1000_is_absent(priv))
548 					goto out;
549 			}
550 		}
551 		if (isrc & (IRQ_DOI | IRQ_EI | IRQ_BEI | IRQ_EPI | IRQ_ALI)) {
552 			/* error interrupt */
553 			if (sja1000_err(dev, isrc, status))
554 				break;
555 		}
556 		n++;
557 	}
558 out:
559 	if (priv->post_irq)
560 		priv->post_irq(priv);
561 
562 	if (n >= SJA1000_MAX_IRQ)
563 		netdev_dbg(dev, "%d messages handled in ISR", n);
564 
565 	return (n) ? IRQ_HANDLED : IRQ_NONE;
566 }
567 EXPORT_SYMBOL_GPL(sja1000_interrupt);
568 
569 static int sja1000_open(struct net_device *dev)
570 {
571 	struct sja1000_priv *priv = netdev_priv(dev);
572 	int err;
573 
574 	/* set chip into reset mode */
575 	set_reset_mode(dev);
576 
577 	/* common open */
578 	err = open_candev(dev);
579 	if (err)
580 		return err;
581 
582 	/* register interrupt handler, if not done by the device driver */
583 	if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER)) {
584 		err = request_irq(dev->irq, sja1000_interrupt, priv->irq_flags,
585 				  dev->name, (void *)dev);
586 		if (err) {
587 			close_candev(dev);
588 			return -EAGAIN;
589 		}
590 	}
591 
592 	/* init and start chi */
593 	sja1000_start(dev);
594 
595 	can_led_event(dev, CAN_LED_EVENT_OPEN);
596 
597 	netif_start_queue(dev);
598 
599 	return 0;
600 }
601 
602 static int sja1000_close(struct net_device *dev)
603 {
604 	struct sja1000_priv *priv = netdev_priv(dev);
605 
606 	netif_stop_queue(dev);
607 	set_reset_mode(dev);
608 
609 	if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER))
610 		free_irq(dev->irq, (void *)dev);
611 
612 	close_candev(dev);
613 
614 	can_led_event(dev, CAN_LED_EVENT_STOP);
615 
616 	return 0;
617 }
618 
619 struct net_device *alloc_sja1000dev(int sizeof_priv)
620 {
621 	struct net_device *dev;
622 	struct sja1000_priv *priv;
623 
624 	dev = alloc_candev(sizeof(struct sja1000_priv) + sizeof_priv,
625 		SJA1000_ECHO_SKB_MAX);
626 	if (!dev)
627 		return NULL;
628 
629 	priv = netdev_priv(dev);
630 
631 	priv->dev = dev;
632 	priv->can.bittiming_const = &sja1000_bittiming_const;
633 	priv->can.do_set_bittiming = sja1000_set_bittiming;
634 	priv->can.do_set_mode = sja1000_set_mode;
635 	priv->can.do_get_berr_counter = sja1000_get_berr_counter;
636 	priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
637 				       CAN_CTRLMODE_LISTENONLY |
638 				       CAN_CTRLMODE_3_SAMPLES |
639 				       CAN_CTRLMODE_ONE_SHOT |
640 				       CAN_CTRLMODE_BERR_REPORTING |
641 				       CAN_CTRLMODE_PRESUME_ACK;
642 
643 	spin_lock_init(&priv->cmdreg_lock);
644 
645 	if (sizeof_priv)
646 		priv->priv = (void *)priv + sizeof(struct sja1000_priv);
647 
648 	return dev;
649 }
650 EXPORT_SYMBOL_GPL(alloc_sja1000dev);
651 
652 void free_sja1000dev(struct net_device *dev)
653 {
654 	free_candev(dev);
655 }
656 EXPORT_SYMBOL_GPL(free_sja1000dev);
657 
658 static const struct net_device_ops sja1000_netdev_ops = {
659 	.ndo_open	= sja1000_open,
660 	.ndo_stop	= sja1000_close,
661 	.ndo_start_xmit	= sja1000_start_xmit,
662 	.ndo_change_mtu	= can_change_mtu,
663 };
664 
665 int register_sja1000dev(struct net_device *dev)
666 {
667 	int ret;
668 
669 	if (!sja1000_probe_chip(dev))
670 		return -ENODEV;
671 
672 	dev->flags |= IFF_ECHO;	/* we support local echo */
673 	dev->netdev_ops = &sja1000_netdev_ops;
674 
675 	set_reset_mode(dev);
676 	chipset_init(dev);
677 
678 	ret =  register_candev(dev);
679 
680 	if (!ret)
681 		devm_can_led_init(dev);
682 
683 	return ret;
684 }
685 EXPORT_SYMBOL_GPL(register_sja1000dev);
686 
687 void unregister_sja1000dev(struct net_device *dev)
688 {
689 	set_reset_mode(dev);
690 	unregister_candev(dev);
691 }
692 EXPORT_SYMBOL_GPL(unregister_sja1000dev);
693 
694 static __init int sja1000_init(void)
695 {
696 	printk(KERN_INFO "%s CAN netdevice driver\n", DRV_NAME);
697 
698 	return 0;
699 }
700 
701 module_init(sja1000_init);
702 
703 static __exit void sja1000_exit(void)
704 {
705 	printk(KERN_INFO "%s: driver removed\n", DRV_NAME);
706 }
707 
708 module_exit(sja1000_exit);
709