xref: /openbmc/linux/drivers/net/can/sja1000/sja1000.c (revision b5efb4e6)
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 
sja1000_write_cmdreg(struct sja1000_priv * priv,u8 val)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 
sja1000_is_absent(struct sja1000_priv * priv)99 static int sja1000_is_absent(struct sja1000_priv *priv)
100 {
101 	return (priv->read_reg(priv, SJA1000_MOD) == 0xFF);
102 }
103 
sja1000_probe_chip(struct net_device * dev)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 
set_reset_mode(struct net_device * dev)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 
set_normal_mode(struct net_device * dev)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  */
chipset_init(struct net_device * dev)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 
sja1000_start(struct net_device * dev)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 
sja1000_set_mode(struct net_device * dev,enum can_mode mode)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 
sja1000_set_bittiming(struct net_device * dev)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 
sja1000_get_berr_counter(const struct net_device * dev,struct can_berr_counter * bec)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  */
sja1000_start_xmit(struct sk_buff * skb,struct net_device * dev)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 
sja1000_rx(struct net_device * dev)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 
sja1000_reset_interrupt(int irq,void * dev_id)390 static irqreturn_t sja1000_reset_interrupt(int irq, void *dev_id)
391 {
392 	struct net_device *dev = (struct net_device *)dev_id;
393 
394 	netdev_dbg(dev, "performing a soft reset upon overrun\n");
395 
396 	netif_tx_lock(dev);
397 
398 	can_free_echo_skb(dev, 0, NULL);
399 	sja1000_set_mode(dev, CAN_MODE_START);
400 
401 	netif_tx_unlock(dev);
402 
403 	return IRQ_HANDLED;
404 }
405 
sja1000_err(struct net_device * dev,uint8_t isrc,uint8_t status)406 static int sja1000_err(struct net_device *dev, uint8_t isrc, uint8_t status)
407 {
408 	struct sja1000_priv *priv = netdev_priv(dev);
409 	struct net_device_stats *stats = &dev->stats;
410 	struct can_frame *cf;
411 	struct sk_buff *skb;
412 	enum can_state state = priv->can.state;
413 	enum can_state rx_state, tx_state;
414 	unsigned int rxerr, txerr;
415 	uint8_t ecc, alc;
416 	int ret = 0;
417 
418 	skb = alloc_can_err_skb(dev, &cf);
419 	if (skb == NULL)
420 		return -ENOMEM;
421 
422 	txerr = priv->read_reg(priv, SJA1000_TXERR);
423 	rxerr = priv->read_reg(priv, SJA1000_RXERR);
424 
425 	if (isrc & IRQ_DOI) {
426 		/* data overrun interrupt */
427 		netdev_dbg(dev, "data overrun interrupt\n");
428 		cf->can_id |= CAN_ERR_CRTL;
429 		cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
430 		stats->rx_over_errors++;
431 		stats->rx_errors++;
432 		sja1000_write_cmdreg(priv, CMD_CDO);	/* clear bit */
433 
434 		/* Some controllers needs additional handling upon overrun
435 		 * condition: the controller may sometimes be totally confused
436 		 * and refuse any new frame while its buffer is empty. The only
437 		 * way to re-sync the read vs. write buffer offsets is to
438 		 * stop any current handling and perform a reset.
439 		 */
440 		if (priv->flags & SJA1000_QUIRK_RESET_ON_OVERRUN)
441 			ret = IRQ_WAKE_THREAD;
442 	}
443 
444 	if (isrc & IRQ_EI) {
445 		/* error warning interrupt */
446 		netdev_dbg(dev, "error warning interrupt\n");
447 
448 		if (status & SR_BS)
449 			state = CAN_STATE_BUS_OFF;
450 		else if (status & SR_ES)
451 			state = CAN_STATE_ERROR_WARNING;
452 		else
453 			state = CAN_STATE_ERROR_ACTIVE;
454 	}
455 	if (state != CAN_STATE_BUS_OFF) {
456 		cf->can_id |= CAN_ERR_CNT;
457 		cf->data[6] = txerr;
458 		cf->data[7] = rxerr;
459 	}
460 	if (isrc & IRQ_BEI) {
461 		/* bus error interrupt */
462 		priv->can.can_stats.bus_error++;
463 		stats->rx_errors++;
464 
465 		ecc = priv->read_reg(priv, SJA1000_ECC);
466 
467 		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
468 
469 		/* set error type */
470 		switch (ecc & ECC_MASK) {
471 		case ECC_BIT:
472 			cf->data[2] |= CAN_ERR_PROT_BIT;
473 			break;
474 		case ECC_FORM:
475 			cf->data[2] |= CAN_ERR_PROT_FORM;
476 			break;
477 		case ECC_STUFF:
478 			cf->data[2] |= CAN_ERR_PROT_STUFF;
479 			break;
480 		default:
481 			break;
482 		}
483 
484 		/* set error location */
485 		cf->data[3] = ecc & ECC_SEG;
486 
487 		/* Error occurred during transmission? */
488 		if ((ecc & ECC_DIR) == 0)
489 			cf->data[2] |= CAN_ERR_PROT_TX;
490 	}
491 	if (isrc & IRQ_EPI) {
492 		/* error passive interrupt */
493 		netdev_dbg(dev, "error passive interrupt\n");
494 
495 		if (state == CAN_STATE_ERROR_PASSIVE)
496 			state = CAN_STATE_ERROR_WARNING;
497 		else
498 			state = CAN_STATE_ERROR_PASSIVE;
499 	}
500 	if (isrc & IRQ_ALI) {
501 		/* arbitration lost interrupt */
502 		netdev_dbg(dev, "arbitration lost interrupt\n");
503 		alc = priv->read_reg(priv, SJA1000_ALC);
504 		priv->can.can_stats.arbitration_lost++;
505 		cf->can_id |= CAN_ERR_LOSTARB;
506 		cf->data[0] = alc & 0x1f;
507 	}
508 
509 	if (state != priv->can.state) {
510 		tx_state = txerr >= rxerr ? state : 0;
511 		rx_state = txerr <= rxerr ? state : 0;
512 
513 		can_change_state(dev, cf, tx_state, rx_state);
514 
515 		if(state == CAN_STATE_BUS_OFF)
516 			can_bus_off(dev);
517 	}
518 
519 	netif_rx(skb);
520 
521 	return ret;
522 }
523 
sja1000_interrupt(int irq,void * dev_id)524 irqreturn_t sja1000_interrupt(int irq, void *dev_id)
525 {
526 	struct net_device *dev = (struct net_device *)dev_id;
527 	struct sja1000_priv *priv = netdev_priv(dev);
528 	struct net_device_stats *stats = &dev->stats;
529 	uint8_t isrc, status;
530 	irqreturn_t ret = 0;
531 	int n = 0, err;
532 
533 	if (priv->pre_irq)
534 		priv->pre_irq(priv);
535 
536 	/* Shared interrupts and IRQ off? */
537 	if (priv->read_reg(priv, SJA1000_IER) == IRQ_OFF)
538 		goto out;
539 
540 	while ((isrc = priv->read_reg(priv, SJA1000_IR)) &&
541 	       (n < SJA1000_MAX_IRQ)) {
542 
543 		status = priv->read_reg(priv, SJA1000_SR);
544 		/* check for absent controller due to hw unplug */
545 		if (status == 0xFF && sja1000_is_absent(priv))
546 			goto out;
547 
548 		if (isrc & IRQ_WUI)
549 			netdev_warn(dev, "wakeup interrupt\n");
550 
551 		if (isrc & IRQ_TI) {
552 			/* transmission buffer released */
553 			if (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT &&
554 			    !(status & SR_TCS)) {
555 				stats->tx_errors++;
556 				can_free_echo_skb(dev, 0, NULL);
557 			} else {
558 				/* transmission complete */
559 				stats->tx_bytes += can_get_echo_skb(dev, 0, NULL);
560 				stats->tx_packets++;
561 			}
562 			netif_wake_queue(dev);
563 		}
564 		if (isrc & IRQ_RI) {
565 			/* receive interrupt */
566 			while (status & SR_RBS) {
567 				sja1000_rx(dev);
568 				status = priv->read_reg(priv, SJA1000_SR);
569 				/* check for absent controller */
570 				if (status == 0xFF && sja1000_is_absent(priv))
571 					goto out;
572 			}
573 		}
574 		if (isrc & (IRQ_DOI | IRQ_EI | IRQ_BEI | IRQ_EPI | IRQ_ALI)) {
575 			/* error interrupt */
576 			err = sja1000_err(dev, isrc, status);
577 			if (err == IRQ_WAKE_THREAD)
578 				ret = err;
579 			if (err)
580 				break;
581 		}
582 		n++;
583 	}
584 out:
585 	if (!ret)
586 		ret = (n) ? IRQ_HANDLED : IRQ_NONE;
587 
588 	if (priv->post_irq)
589 		priv->post_irq(priv);
590 
591 	if (n >= SJA1000_MAX_IRQ)
592 		netdev_dbg(dev, "%d messages handled in ISR", n);
593 
594 	return ret;
595 }
596 EXPORT_SYMBOL_GPL(sja1000_interrupt);
597 
sja1000_open(struct net_device * dev)598 static int sja1000_open(struct net_device *dev)
599 {
600 	struct sja1000_priv *priv = netdev_priv(dev);
601 	int err;
602 
603 	/* set chip into reset mode */
604 	set_reset_mode(dev);
605 
606 	/* common open */
607 	err = open_candev(dev);
608 	if (err)
609 		return err;
610 
611 	/* register interrupt handler, if not done by the device driver */
612 	if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER)) {
613 		err = request_threaded_irq(dev->irq, sja1000_interrupt,
614 					   sja1000_reset_interrupt,
615 					   priv->irq_flags, dev->name, (void *)dev);
616 		if (err) {
617 			close_candev(dev);
618 			return -EAGAIN;
619 		}
620 	}
621 
622 	/* init and start chi */
623 	sja1000_start(dev);
624 
625 	netif_start_queue(dev);
626 
627 	return 0;
628 }
629 
sja1000_close(struct net_device * dev)630 static int sja1000_close(struct net_device *dev)
631 {
632 	struct sja1000_priv *priv = netdev_priv(dev);
633 
634 	netif_stop_queue(dev);
635 	set_reset_mode(dev);
636 
637 	if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER))
638 		free_irq(dev->irq, (void *)dev);
639 
640 	close_candev(dev);
641 
642 	return 0;
643 }
644 
alloc_sja1000dev(int sizeof_priv)645 struct net_device *alloc_sja1000dev(int sizeof_priv)
646 {
647 	struct net_device *dev;
648 	struct sja1000_priv *priv;
649 
650 	dev = alloc_candev(sizeof(struct sja1000_priv) + sizeof_priv,
651 		SJA1000_ECHO_SKB_MAX);
652 	if (!dev)
653 		return NULL;
654 
655 	priv = netdev_priv(dev);
656 
657 	priv->dev = dev;
658 	priv->can.bittiming_const = &sja1000_bittiming_const;
659 	priv->can.do_set_bittiming = sja1000_set_bittiming;
660 	priv->can.do_set_mode = sja1000_set_mode;
661 	priv->can.do_get_berr_counter = sja1000_get_berr_counter;
662 	priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
663 				       CAN_CTRLMODE_LISTENONLY |
664 				       CAN_CTRLMODE_3_SAMPLES |
665 				       CAN_CTRLMODE_ONE_SHOT |
666 				       CAN_CTRLMODE_BERR_REPORTING |
667 				       CAN_CTRLMODE_PRESUME_ACK |
668 				       CAN_CTRLMODE_CC_LEN8_DLC;
669 
670 	spin_lock_init(&priv->cmdreg_lock);
671 
672 	if (sizeof_priv)
673 		priv->priv = (void *)priv + sizeof(struct sja1000_priv);
674 
675 	return dev;
676 }
677 EXPORT_SYMBOL_GPL(alloc_sja1000dev);
678 
free_sja1000dev(struct net_device * dev)679 void free_sja1000dev(struct net_device *dev)
680 {
681 	free_candev(dev);
682 }
683 EXPORT_SYMBOL_GPL(free_sja1000dev);
684 
685 static const struct net_device_ops sja1000_netdev_ops = {
686 	.ndo_open	= sja1000_open,
687 	.ndo_stop	= sja1000_close,
688 	.ndo_start_xmit	= sja1000_start_xmit,
689 	.ndo_change_mtu	= can_change_mtu,
690 };
691 
692 static const struct ethtool_ops sja1000_ethtool_ops = {
693 	.get_ts_info = ethtool_op_get_ts_info,
694 };
695 
register_sja1000dev(struct net_device * dev)696 int register_sja1000dev(struct net_device *dev)
697 {
698 	if (!sja1000_probe_chip(dev))
699 		return -ENODEV;
700 
701 	dev->flags |= IFF_ECHO;	/* we support local echo */
702 	dev->netdev_ops = &sja1000_netdev_ops;
703 	dev->ethtool_ops = &sja1000_ethtool_ops;
704 
705 	set_reset_mode(dev);
706 	chipset_init(dev);
707 
708 	return register_candev(dev);
709 }
710 EXPORT_SYMBOL_GPL(register_sja1000dev);
711 
unregister_sja1000dev(struct net_device * dev)712 void unregister_sja1000dev(struct net_device *dev)
713 {
714 	set_reset_mode(dev);
715 	unregister_candev(dev);
716 }
717 EXPORT_SYMBOL_GPL(unregister_sja1000dev);
718 
sja1000_init(void)719 static __init int sja1000_init(void)
720 {
721 	printk(KERN_INFO "%s CAN netdevice driver\n", DRV_NAME);
722 
723 	return 0;
724 }
725 
726 module_init(sja1000_init);
727 
sja1000_exit(void)728 static __exit void sja1000_exit(void)
729 {
730 	printk(KERN_INFO "%s: driver removed\n", DRV_NAME);
731 }
732 
733 module_exit(sja1000_exit);
734