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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#include <linux/can/led.h>
64
65#include "sja1000.h"
66
67#define DRV_NAME "sja1000"
68
69MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
70MODULE_LICENSE("Dual BSD/GPL");
71MODULE_DESCRIPTION(DRV_NAME "CAN netdevice driver");
72
73static 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
85static void sja1000_write_cmdreg(struct sja1000_priv *priv, u8 val)
86{
87 unsigned long flags;
88
89
90
91
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
99static int sja1000_is_absent(struct sja1000_priv *priv)
100{
101 return (priv->read_reg(priv, SJA1000_MOD) == 0xFF);
102}
103
104static 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
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, SJA1000_MOD);
119 int i;
120
121
122 priv->write_reg(priv, SJA1000_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
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
140static 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
149 if ((status & MOD_RM) == 0) {
150 priv->can.state = CAN_STATE_ERROR_ACTIVE;
151
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
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
177
178
179
180
181
182
183static void chipset_init(struct net_device *dev)
184{
185 struct sja1000_priv *priv = netdev_priv(dev);
186
187
188 priv->write_reg(priv, SJA1000_CDR, priv->cdr | CDR_PELICAN);
189
190
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
204static void sja1000_start(struct net_device *dev)
205{
206 struct sja1000_priv *priv = netdev_priv(dev);
207
208
209 if (priv->can.state != CAN_STATE_STOPPED)
210 set_reset_mode(dev);
211
212
213 if (!(priv->read_reg(priv, SJA1000_CDR) & CDR_PELICAN))
214 chipset_init(dev);
215
216
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
222 priv->read_reg(priv, SJA1000_IR);
223
224
225 set_normal_mode(dev);
226}
227
228static 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
244static 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
264static 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
277
278
279
280
281static 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 canid_t id;
288 uint8_t dreg;
289 u8 cmd_reg_val = 0x00;
290 int i;
291
292 if (can_dropped_invalid_skb(dev, skb))
293 return NETDEV_TX_OK;
294
295 netif_stop_queue(dev);
296
297 fi = can_get_cc_dlc(cf, priv->can.ctrlmode);
298 id = cf->can_id;
299
300 if (id & CAN_RTR_FLAG)
301 fi |= SJA1000_FI_RTR;
302
303 if (id & CAN_EFF_FLAG) {
304 fi |= SJA1000_FI_FF;
305 dreg = SJA1000_EFF_BUF;
306 priv->write_reg(priv, SJA1000_FI, fi);
307 priv->write_reg(priv, SJA1000_ID1, (id & 0x1fe00000) >> 21);
308 priv->write_reg(priv, SJA1000_ID2, (id & 0x001fe000) >> 13);
309 priv->write_reg(priv, SJA1000_ID3, (id & 0x00001fe0) >> 5);
310 priv->write_reg(priv, SJA1000_ID4, (id & 0x0000001f) << 3);
311 } else {
312 dreg = SJA1000_SFF_BUF;
313 priv->write_reg(priv, SJA1000_FI, fi);
314 priv->write_reg(priv, SJA1000_ID1, (id & 0x000007f8) >> 3);
315 priv->write_reg(priv, SJA1000_ID2, (id & 0x00000007) << 5);
316 }
317
318 for (i = 0; i < cf->len; i++)
319 priv->write_reg(priv, dreg++, cf->data[i]);
320
321 can_put_echo_skb(skb, dev, 0, 0);
322
323 if (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT)
324 cmd_reg_val |= CMD_AT;
325
326 if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
327 cmd_reg_val |= CMD_SRR;
328 else
329 cmd_reg_val |= CMD_TR;
330
331 sja1000_write_cmdreg(priv, cmd_reg_val);
332
333 return NETDEV_TX_OK;
334}
335
336static void sja1000_rx(struct net_device *dev)
337{
338 struct sja1000_priv *priv = netdev_priv(dev);
339 struct net_device_stats *stats = &dev->stats;
340 struct can_frame *cf;
341 struct sk_buff *skb;
342 uint8_t fi;
343 uint8_t dreg;
344 canid_t id;
345 int i;
346
347
348 skb = alloc_can_skb(dev, &cf);
349 if (skb == NULL)
350 return;
351
352 fi = priv->read_reg(priv, SJA1000_FI);
353
354 if (fi & SJA1000_FI_FF) {
355
356 dreg = SJA1000_EFF_BUF;
357 id = (priv->read_reg(priv, SJA1000_ID1) << 21)
358 | (priv->read_reg(priv, SJA1000_ID2) << 13)
359 | (priv->read_reg(priv, SJA1000_ID3) << 5)
360 | (priv->read_reg(priv, SJA1000_ID4) >> 3);
361 id |= CAN_EFF_FLAG;
362 } else {
363
364 dreg = SJA1000_SFF_BUF;
365 id = (priv->read_reg(priv, SJA1000_ID1) << 3)
366 | (priv->read_reg(priv, SJA1000_ID2) >> 5);
367 }
368
369 can_frame_set_cc_len(cf, fi & 0x0F, priv->can.ctrlmode);
370 if (fi & SJA1000_FI_RTR) {
371 id |= CAN_RTR_FLAG;
372 } else {
373 for (i = 0; i < cf->len; i++)
374 cf->data[i] = priv->read_reg(priv, dreg++);
375 }
376
377 cf->can_id = id;
378
379
380 sja1000_write_cmdreg(priv, CMD_RRB);
381
382 stats->rx_packets++;
383 stats->rx_bytes += cf->len;
384 netif_rx(skb);
385
386 can_led_event(dev, CAN_LED_EVENT_RX);
387}
388
389static int sja1000_err(struct net_device *dev, uint8_t isrc, uint8_t status)
390{
391 struct sja1000_priv *priv = netdev_priv(dev);
392 struct net_device_stats *stats = &dev->stats;
393 struct can_frame *cf;
394 struct sk_buff *skb;
395 enum can_state state = priv->can.state;
396 enum can_state rx_state, tx_state;
397 unsigned int rxerr, txerr;
398 uint8_t ecc, alc;
399
400 skb = alloc_can_err_skb(dev, &cf);
401 if (skb == NULL)
402 return -ENOMEM;
403
404 txerr = priv->read_reg(priv, SJA1000_TXERR);
405 rxerr = priv->read_reg(priv, SJA1000_RXERR);
406
407 cf->data[6] = txerr;
408 cf->data[7] = rxerr;
409
410 if (isrc & IRQ_DOI) {
411
412 netdev_dbg(dev, "data overrun interrupt\n");
413 cf->can_id |= CAN_ERR_CRTL;
414 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
415 stats->rx_over_errors++;
416 stats->rx_errors++;
417 sja1000_write_cmdreg(priv, CMD_CDO);
418 }
419
420 if (isrc & IRQ_EI) {
421
422 netdev_dbg(dev, "error warning interrupt\n");
423
424 if (status & SR_BS)
425 state = CAN_STATE_BUS_OFF;
426 else if (status & SR_ES)
427 state = CAN_STATE_ERROR_WARNING;
428 else
429 state = CAN_STATE_ERROR_ACTIVE;
430 }
431 if (isrc & IRQ_BEI) {
432
433 priv->can.can_stats.bus_error++;
434 stats->rx_errors++;
435
436 ecc = priv->read_reg(priv, SJA1000_ECC);
437
438 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
439
440
441 switch (ecc & ECC_MASK) {
442 case ECC_BIT:
443 cf->data[2] |= CAN_ERR_PROT_BIT;
444 break;
445 case ECC_FORM:
446 cf->data[2] |= CAN_ERR_PROT_FORM;
447 break;
448 case ECC_STUFF:
449 cf->data[2] |= CAN_ERR_PROT_STUFF;
450 break;
451 default:
452 break;
453 }
454
455
456 cf->data[3] = ecc & ECC_SEG;
457
458
459 if ((ecc & ECC_DIR) == 0)
460 cf->data[2] |= CAN_ERR_PROT_TX;
461 }
462 if (isrc & IRQ_EPI) {
463
464 netdev_dbg(dev, "error passive interrupt\n");
465
466 if (state == CAN_STATE_ERROR_PASSIVE)
467 state = CAN_STATE_ERROR_WARNING;
468 else
469 state = CAN_STATE_ERROR_PASSIVE;
470 }
471 if (isrc & IRQ_ALI) {
472
473 netdev_dbg(dev, "arbitration lost interrupt\n");
474 alc = priv->read_reg(priv, SJA1000_ALC);
475 priv->can.can_stats.arbitration_lost++;
476 cf->can_id |= CAN_ERR_LOSTARB;
477 cf->data[0] = alc & 0x1f;
478 }
479
480 if (state != priv->can.state) {
481 tx_state = txerr >= rxerr ? state : 0;
482 rx_state = txerr <= rxerr ? state : 0;
483
484 can_change_state(dev, cf, tx_state, rx_state);
485
486 if(state == CAN_STATE_BUS_OFF)
487 can_bus_off(dev);
488 }
489
490 stats->rx_packets++;
491 stats->rx_bytes += cf->len;
492 netif_rx(skb);
493
494 return 0;
495}
496
497irqreturn_t sja1000_interrupt(int irq, void *dev_id)
498{
499 struct net_device *dev = (struct net_device *)dev_id;
500 struct sja1000_priv *priv = netdev_priv(dev);
501 struct net_device_stats *stats = &dev->stats;
502 uint8_t isrc, status;
503 int n = 0;
504
505 if (priv->pre_irq)
506 priv->pre_irq(priv);
507
508
509 if (priv->read_reg(priv, SJA1000_IER) == IRQ_OFF)
510 goto out;
511
512 while ((isrc = priv->read_reg(priv, SJA1000_IR)) &&
513 (n < SJA1000_MAX_IRQ)) {
514
515 status = priv->read_reg(priv, SJA1000_SR);
516
517 if (status == 0xFF && sja1000_is_absent(priv))
518 goto out;
519
520 if (isrc & IRQ_WUI)
521 netdev_warn(dev, "wakeup interrupt\n");
522
523 if (isrc & IRQ_TI) {
524
525 if (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT &&
526 !(status & SR_TCS)) {
527 stats->tx_errors++;
528 can_free_echo_skb(dev, 0, NULL);
529 } else {
530
531 stats->tx_bytes +=
532 priv->read_reg(priv, SJA1000_FI) & 0xf;
533 stats->tx_packets++;
534 can_get_echo_skb(dev, 0, NULL);
535 }
536 netif_wake_queue(dev);
537 can_led_event(dev, CAN_LED_EVENT_TX);
538 }
539 if (isrc & IRQ_RI) {
540
541 while (status & SR_RBS) {
542 sja1000_rx(dev);
543 status = priv->read_reg(priv, SJA1000_SR);
544
545 if (status == 0xFF && sja1000_is_absent(priv))
546 goto out;
547 }
548 }
549 if (isrc & (IRQ_DOI | IRQ_EI | IRQ_BEI | IRQ_EPI | IRQ_ALI)) {
550
551 if (sja1000_err(dev, isrc, status))
552 break;
553 }
554 n++;
555 }
556out:
557 if (priv->post_irq)
558 priv->post_irq(priv);
559
560 if (n >= SJA1000_MAX_IRQ)
561 netdev_dbg(dev, "%d messages handled in ISR", n);
562
563 return (n) ? IRQ_HANDLED : IRQ_NONE;
564}
565EXPORT_SYMBOL_GPL(sja1000_interrupt);
566
567static int sja1000_open(struct net_device *dev)
568{
569 struct sja1000_priv *priv = netdev_priv(dev);
570 int err;
571
572
573 set_reset_mode(dev);
574
575
576 err = open_candev(dev);
577 if (err)
578 return err;
579
580
581 if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER)) {
582 err = request_irq(dev->irq, sja1000_interrupt, priv->irq_flags,
583 dev->name, (void *)dev);
584 if (err) {
585 close_candev(dev);
586 return -EAGAIN;
587 }
588 }
589
590
591 sja1000_start(dev);
592
593 can_led_event(dev, CAN_LED_EVENT_OPEN);
594
595 netif_start_queue(dev);
596
597 return 0;
598}
599
600static int sja1000_close(struct net_device *dev)
601{
602 struct sja1000_priv *priv = netdev_priv(dev);
603
604 netif_stop_queue(dev);
605 set_reset_mode(dev);
606
607 if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER))
608 free_irq(dev->irq, (void *)dev);
609
610 close_candev(dev);
611
612 can_led_event(dev, CAN_LED_EVENT_STOP);
613
614 return 0;
615}
616
617struct net_device *alloc_sja1000dev(int sizeof_priv)
618{
619 struct net_device *dev;
620 struct sja1000_priv *priv;
621
622 dev = alloc_candev(sizeof(struct sja1000_priv) + sizeof_priv,
623 SJA1000_ECHO_SKB_MAX);
624 if (!dev)
625 return NULL;
626
627 priv = netdev_priv(dev);
628
629 priv->dev = dev;
630 priv->can.bittiming_const = &sja1000_bittiming_const;
631 priv->can.do_set_bittiming = sja1000_set_bittiming;
632 priv->can.do_set_mode = sja1000_set_mode;
633 priv->can.do_get_berr_counter = sja1000_get_berr_counter;
634 priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
635 CAN_CTRLMODE_LISTENONLY |
636 CAN_CTRLMODE_3_SAMPLES |
637 CAN_CTRLMODE_ONE_SHOT |
638 CAN_CTRLMODE_BERR_REPORTING |
639 CAN_CTRLMODE_PRESUME_ACK |
640 CAN_CTRLMODE_CC_LEN8_DLC;
641
642 spin_lock_init(&priv->cmdreg_lock);
643
644 if (sizeof_priv)
645 priv->priv = (void *)priv + sizeof(struct sja1000_priv);
646
647 return dev;
648}
649EXPORT_SYMBOL_GPL(alloc_sja1000dev);
650
651void free_sja1000dev(struct net_device *dev)
652{
653 free_candev(dev);
654}
655EXPORT_SYMBOL_GPL(free_sja1000dev);
656
657static const struct net_device_ops sja1000_netdev_ops = {
658 .ndo_open = sja1000_open,
659 .ndo_stop = sja1000_close,
660 .ndo_start_xmit = sja1000_start_xmit,
661 .ndo_change_mtu = can_change_mtu,
662};
663
664int register_sja1000dev(struct net_device *dev)
665{
666 int ret;
667
668 if (!sja1000_probe_chip(dev))
669 return -ENODEV;
670
671 dev->flags |= IFF_ECHO;
672 dev->netdev_ops = &sja1000_netdev_ops;
673
674 set_reset_mode(dev);
675 chipset_init(dev);
676
677 ret = register_candev(dev);
678
679 if (!ret)
680 devm_can_led_init(dev);
681
682 return ret;
683}
684EXPORT_SYMBOL_GPL(register_sja1000dev);
685
686void unregister_sja1000dev(struct net_device *dev)
687{
688 set_reset_mode(dev);
689 unregister_candev(dev);
690}
691EXPORT_SYMBOL_GPL(unregister_sja1000dev);
692
693static __init int sja1000_init(void)
694{
695 printk(KERN_INFO "%s CAN netdevice driver\n", DRV_NAME);
696
697 return 0;
698}
699
700module_init(sja1000_init);
701
702static __exit void sja1000_exit(void)
703{
704 printk(KERN_INFO "%s: driver removed\n", DRV_NAME);
705}
706
707module_exit(sja1000_exit);
708