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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
68MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
69MODULE_LICENSE("Dual BSD/GPL");
70MODULE_DESCRIPTION(DRV_NAME "CAN netdevice driver");
71
72static const 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
84static void sja1000_write_cmdreg(struct sja1000_priv *priv, u8 val)
85{
86 unsigned long flags;
87
88
89
90
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
98static int sja1000_is_absent(struct sja1000_priv *priv)
99{
100 return (priv->read_reg(priv, REG_MOD) == 0xFF);
101}
102
103static 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
115static 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
122 priv->write_reg(priv, REG_IER, IRQ_OFF);
123
124 for (i = 0; i < 100; i++) {
125
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);
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
139static 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
147 if ((status & MOD_RM) == 0) {
148 priv->can.state = CAN_STATE_ERROR_ACTIVE;
149
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
159 if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
160 priv->write_reg(priv, REG_MOD, MOD_LOM);
161 else
162 priv->write_reg(priv, REG_MOD, 0x00);
163
164 udelay(10);
165
166 status = priv->read_reg(priv, REG_MOD);
167 }
168
169 netdev_err(dev, "setting SJA1000 into normal mode failed!\n");
170}
171
172static void sja1000_start(struct net_device *dev)
173{
174 struct sja1000_priv *priv = netdev_priv(dev);
175
176
177 if (priv->can.state != CAN_STATE_STOPPED)
178 set_reset_mode(dev);
179
180
181 priv->write_reg(priv, REG_TXERR, 0x0);
182 priv->write_reg(priv, REG_RXERR, 0x0);
183 priv->read_reg(priv, REG_ECC);
184
185
186 set_normal_mode(dev);
187}
188
189static int sja1000_set_mode(struct net_device *dev, enum can_mode mode)
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
205static 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
225static 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
238
239
240
241
242
243
244static void chipset_init(struct net_device *dev)
245{
246 struct sja1000_priv *priv = netdev_priv(dev);
247
248
249 priv->write_reg(priv, REG_CDR, priv->cdr | CDR_PELICAN);
250
251
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
267
268
269
270
271static 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 if (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT)
314 sja1000_write_cmdreg(priv, CMD_TR | CMD_AT);
315 else
316 sja1000_write_cmdreg(priv, CMD_TR);
317
318 return NETDEV_TX_OK;
319}
320
321static void sja1000_rx(struct net_device *dev)
322{
323 struct sja1000_priv *priv = netdev_priv(dev);
324 struct net_device_stats *stats = &dev->stats;
325 struct can_frame *cf;
326 struct sk_buff *skb;
327 uint8_t fi;
328 uint8_t dreg;
329 canid_t id;
330 int i;
331
332
333 skb = alloc_can_skb(dev, &cf);
334 if (skb == NULL)
335 return;
336
337 fi = priv->read_reg(priv, REG_FI);
338
339 if (fi & FI_FF) {
340
341 dreg = EFF_BUF;
342 id = (priv->read_reg(priv, REG_ID1) << (5 + 16))
343 | (priv->read_reg(priv, REG_ID2) << (5 + 8))
344 | (priv->read_reg(priv, REG_ID3) << 5)
345 | (priv->read_reg(priv, REG_ID4) >> 3);
346 id |= CAN_EFF_FLAG;
347 } else {
348
349 dreg = SFF_BUF;
350 id = (priv->read_reg(priv, REG_ID1) << 3)
351 | (priv->read_reg(priv, REG_ID2) >> 5);
352 }
353
354 cf->can_dlc = get_can_dlc(fi & 0x0F);
355 if (fi & FI_RTR) {
356 id |= CAN_RTR_FLAG;
357 } else {
358 for (i = 0; i < cf->can_dlc; i++)
359 cf->data[i] = priv->read_reg(priv, dreg++);
360 }
361
362 cf->can_id = id;
363
364
365 sja1000_write_cmdreg(priv, CMD_RRB);
366
367 netif_rx(skb);
368
369 stats->rx_packets++;
370 stats->rx_bytes += cf->can_dlc;
371}
372
373static int sja1000_err(struct net_device *dev, uint8_t isrc, uint8_t status)
374{
375 struct sja1000_priv *priv = netdev_priv(dev);
376 struct net_device_stats *stats = &dev->stats;
377 struct can_frame *cf;
378 struct sk_buff *skb;
379 enum can_state state = priv->can.state;
380 uint8_t ecc, alc;
381
382 skb = alloc_can_err_skb(dev, &cf);
383 if (skb == NULL)
384 return -ENOMEM;
385
386 if (isrc & IRQ_DOI) {
387
388 netdev_dbg(dev, "data overrun interrupt\n");
389 cf->can_id |= CAN_ERR_CRTL;
390 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
391 stats->rx_over_errors++;
392 stats->rx_errors++;
393 sja1000_write_cmdreg(priv, CMD_CDO);
394 }
395
396 if (isrc & IRQ_EI) {
397
398 netdev_dbg(dev, "error warning interrupt\n");
399
400 if (status & SR_BS) {
401 state = CAN_STATE_BUS_OFF;
402 cf->can_id |= CAN_ERR_BUSOFF;
403 can_bus_off(dev);
404 } else if (status & SR_ES) {
405 state = CAN_STATE_ERROR_WARNING;
406 } else
407 state = CAN_STATE_ERROR_ACTIVE;
408 }
409 if (isrc & IRQ_BEI) {
410
411 priv->can.can_stats.bus_error++;
412 stats->rx_errors++;
413
414 ecc = priv->read_reg(priv, REG_ECC);
415
416 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
417
418 switch (ecc & ECC_MASK) {
419 case ECC_BIT:
420 cf->data[2] |= CAN_ERR_PROT_BIT;
421 break;
422 case ECC_FORM:
423 cf->data[2] |= CAN_ERR_PROT_FORM;
424 break;
425 case ECC_STUFF:
426 cf->data[2] |= CAN_ERR_PROT_STUFF;
427 break;
428 default:
429 cf->data[2] |= CAN_ERR_PROT_UNSPEC;
430 cf->data[3] = ecc & ECC_SEG;
431 break;
432 }
433
434 if ((ecc & ECC_DIR) == 0)
435 cf->data[2] |= CAN_ERR_PROT_TX;
436 }
437 if (isrc & IRQ_EPI) {
438
439 netdev_dbg(dev, "error passive interrupt\n");
440 if (status & SR_ES)
441 state = CAN_STATE_ERROR_PASSIVE;
442 else
443 state = CAN_STATE_ERROR_ACTIVE;
444 }
445 if (isrc & IRQ_ALI) {
446
447 netdev_dbg(dev, "arbitration lost interrupt\n");
448 alc = priv->read_reg(priv, REG_ALC);
449 priv->can.can_stats.arbitration_lost++;
450 stats->tx_errors++;
451 cf->can_id |= CAN_ERR_LOSTARB;
452 cf->data[0] = alc & 0x1f;
453 }
454
455 if (state != priv->can.state && (state == CAN_STATE_ERROR_WARNING ||
456 state == CAN_STATE_ERROR_PASSIVE)) {
457 uint8_t rxerr = priv->read_reg(priv, REG_RXERR);
458 uint8_t txerr = priv->read_reg(priv, REG_TXERR);
459 cf->can_id |= CAN_ERR_CRTL;
460 if (state == CAN_STATE_ERROR_WARNING) {
461 priv->can.can_stats.error_warning++;
462 cf->data[1] = (txerr > rxerr) ?
463 CAN_ERR_CRTL_TX_WARNING :
464 CAN_ERR_CRTL_RX_WARNING;
465 } else {
466 priv->can.can_stats.error_passive++;
467 cf->data[1] = (txerr > rxerr) ?
468 CAN_ERR_CRTL_TX_PASSIVE :
469 CAN_ERR_CRTL_RX_PASSIVE;
470 }
471 cf->data[6] = txerr;
472 cf->data[7] = rxerr;
473 }
474
475 priv->can.state = state;
476
477 netif_rx(skb);
478
479 stats->rx_packets++;
480 stats->rx_bytes += cf->can_dlc;
481
482 return 0;
483}
484
485irqreturn_t sja1000_interrupt(int irq, void *dev_id)
486{
487 struct net_device *dev = (struct net_device *)dev_id;
488 struct sja1000_priv *priv = netdev_priv(dev);
489 struct net_device_stats *stats = &dev->stats;
490 uint8_t isrc, status;
491 int n = 0;
492
493
494 if (priv->read_reg(priv, REG_IER) == IRQ_OFF)
495 return IRQ_NONE;
496
497 if (priv->pre_irq)
498 priv->pre_irq(priv);
499
500 while ((isrc = priv->read_reg(priv, REG_IR)) && (n < SJA1000_MAX_IRQ)) {
501 n++;
502 status = priv->read_reg(priv, REG_SR);
503
504 if (status == 0xFF && sja1000_is_absent(priv))
505 return IRQ_NONE;
506
507 if (isrc & IRQ_WUI)
508 netdev_warn(dev, "wakeup interrupt\n");
509
510 if (isrc & IRQ_TI) {
511
512 if (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT &&
513 !(status & SR_TCS)) {
514 stats->tx_errors++;
515 can_free_echo_skb(dev, 0);
516 } else {
517
518 stats->tx_bytes +=
519 priv->read_reg(priv, REG_FI) & 0xf;
520 stats->tx_packets++;
521 can_get_echo_skb(dev, 0);
522 }
523 netif_wake_queue(dev);
524 }
525 if (isrc & IRQ_RI) {
526
527 while (status & SR_RBS) {
528 sja1000_rx(dev);
529 status = priv->read_reg(priv, REG_SR);
530
531 if (status == 0xFF && sja1000_is_absent(priv))
532 return IRQ_NONE;
533 }
534 }
535 if (isrc & (IRQ_DOI | IRQ_EI | IRQ_BEI | IRQ_EPI | IRQ_ALI)) {
536
537 if (sja1000_err(dev, isrc, status))
538 break;
539 }
540 }
541
542 if (priv->post_irq)
543 priv->post_irq(priv);
544
545 if (n >= SJA1000_MAX_IRQ)
546 netdev_dbg(dev, "%d messages handled in ISR", n);
547
548 return (n) ? IRQ_HANDLED : IRQ_NONE;
549}
550EXPORT_SYMBOL_GPL(sja1000_interrupt);
551
552static int sja1000_open(struct net_device *dev)
553{
554 struct sja1000_priv *priv = netdev_priv(dev);
555 int err;
556
557
558 set_reset_mode(dev);
559
560
561 err = open_candev(dev);
562 if (err)
563 return err;
564
565
566 if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER)) {
567 err = request_irq(dev->irq, sja1000_interrupt, priv->irq_flags,
568 dev->name, (void *)dev);
569 if (err) {
570 close_candev(dev);
571 return -EAGAIN;
572 }
573 }
574
575
576 sja1000_start(dev);
577
578 netif_start_queue(dev);
579
580 return 0;
581}
582
583static int sja1000_close(struct net_device *dev)
584{
585 struct sja1000_priv *priv = netdev_priv(dev);
586
587 netif_stop_queue(dev);
588 set_reset_mode(dev);
589
590 if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER))
591 free_irq(dev->irq, (void *)dev);
592
593 close_candev(dev);
594
595 return 0;
596}
597
598struct net_device *alloc_sja1000dev(int sizeof_priv)
599{
600 struct net_device *dev;
601 struct sja1000_priv *priv;
602
603 dev = alloc_candev(sizeof(struct sja1000_priv) + sizeof_priv,
604 SJA1000_ECHO_SKB_MAX);
605 if (!dev)
606 return NULL;
607
608 priv = netdev_priv(dev);
609
610 priv->dev = dev;
611 priv->can.bittiming_const = &sja1000_bittiming_const;
612 priv->can.do_set_bittiming = sja1000_set_bittiming;
613 priv->can.do_set_mode = sja1000_set_mode;
614 priv->can.do_get_berr_counter = sja1000_get_berr_counter;
615 priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
616 CAN_CTRLMODE_BERR_REPORTING | CAN_CTRLMODE_LISTENONLY |
617 CAN_CTRLMODE_ONE_SHOT;
618
619 spin_lock_init(&priv->cmdreg_lock);
620
621 if (sizeof_priv)
622 priv->priv = (void *)priv + sizeof(struct sja1000_priv);
623
624 return dev;
625}
626EXPORT_SYMBOL_GPL(alloc_sja1000dev);
627
628void free_sja1000dev(struct net_device *dev)
629{
630 free_candev(dev);
631}
632EXPORT_SYMBOL_GPL(free_sja1000dev);
633
634static const struct net_device_ops sja1000_netdev_ops = {
635 .ndo_open = sja1000_open,
636 .ndo_stop = sja1000_close,
637 .ndo_start_xmit = sja1000_start_xmit,
638};
639
640int register_sja1000dev(struct net_device *dev)
641{
642 if (!sja1000_probe_chip(dev))
643 return -ENODEV;
644
645 dev->flags |= IFF_ECHO;
646 dev->netdev_ops = &sja1000_netdev_ops;
647
648 set_reset_mode(dev);
649 chipset_init(dev);
650
651 return register_candev(dev);
652}
653EXPORT_SYMBOL_GPL(register_sja1000dev);
654
655void unregister_sja1000dev(struct net_device *dev)
656{
657 set_reset_mode(dev);
658 unregister_candev(dev);
659}
660EXPORT_SYMBOL_GPL(unregister_sja1000dev);
661
662static __init int sja1000_init(void)
663{
664 printk(KERN_INFO "%s CAN netdevice driver\n", DRV_NAME);
665
666 return 0;
667}
668
669module_init(sja1000_init);
670
671static __exit void sja1000_exit(void)
672{
673 printk(KERN_INFO "%s: driver removed\n", DRV_NAME);
674}
675
676module_exit(sja1000_exit);
677