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23#include <linux/kernel.h>
24#include <linux/module.h>
25#include <linux/interrupt.h>
26#include <linux/delay.h>
27#include <linux/netdevice.h>
28#include <linux/if_arp.h>
29#include <linux/if_ether.h>
30#include <linux/list.h>
31#include <linux/can/dev.h>
32#include <linux/can/error.h>
33#include <linux/io.h>
34
35#include "mscan.h"
36
37static struct can_bittiming_const mscan_bittiming_const = {
38 .name = "mscan",
39 .tseg1_min = 4,
40 .tseg1_max = 16,
41 .tseg2_min = 2,
42 .tseg2_max = 8,
43 .sjw_max = 4,
44 .brp_min = 1,
45 .brp_max = 64,
46 .brp_inc = 1,
47};
48
49struct mscan_state {
50 u8 mode;
51 u8 canrier;
52 u8 cantier;
53};
54
55static enum can_state state_map[] = {
56 CAN_STATE_ERROR_ACTIVE,
57 CAN_STATE_ERROR_WARNING,
58 CAN_STATE_ERROR_PASSIVE,
59 CAN_STATE_BUS_OFF
60};
61
62static int mscan_set_mode(struct net_device *dev, u8 mode)
63{
64 struct mscan_priv *priv = netdev_priv(dev);
65 struct mscan_regs __iomem *regs = priv->reg_base;
66 int ret = 0;
67 int i;
68 u8 canctl1;
69
70 if (mode != MSCAN_NORMAL_MODE) {
71 if (priv->tx_active) {
72 #
73 out_8(®s->cantarq, priv->tx_active);
74
75 out_8(®s->cantier, 0);
76 }
77
78 canctl1 = in_8(®s->canctl1);
79 if ((mode & MSCAN_SLPRQ) && !(canctl1 & MSCAN_SLPAK)) {
80 setbits8(®s->canctl0, MSCAN_SLPRQ);
81 for (i = 0; i < MSCAN_SET_MODE_RETRIES; i++) {
82 if (in_8(®s->canctl1) & MSCAN_SLPAK)
83 break;
84 udelay(100);
85 }
86
87
88
89
90
91
92
93
94
95
96
97 if (i >= MSCAN_SET_MODE_RETRIES)
98 dev_dbg(dev->dev.parent,
99 "device failed to enter sleep mode. "
100 "We proceed anyhow.\n");
101 else
102 priv->can.state = CAN_STATE_SLEEPING;
103 }
104
105 if ((mode & MSCAN_INITRQ) && !(canctl1 & MSCAN_INITAK)) {
106 setbits8(®s->canctl0, MSCAN_INITRQ);
107 for (i = 0; i < MSCAN_SET_MODE_RETRIES; i++) {
108 if (in_8(®s->canctl1) & MSCAN_INITAK)
109 break;
110 }
111 if (i >= MSCAN_SET_MODE_RETRIES)
112 ret = -ENODEV;
113 }
114 if (!ret)
115 priv->can.state = CAN_STATE_STOPPED;
116
117 if (mode & MSCAN_CSWAI)
118 setbits8(®s->canctl0, MSCAN_CSWAI);
119
120 } else {
121 canctl1 = in_8(®s->canctl1);
122 if (canctl1 & (MSCAN_SLPAK | MSCAN_INITAK)) {
123 clrbits8(®s->canctl0, MSCAN_SLPRQ | MSCAN_INITRQ);
124 for (i = 0; i < MSCAN_SET_MODE_RETRIES; i++) {
125 canctl1 = in_8(®s->canctl1);
126 if (!(canctl1 & (MSCAN_INITAK | MSCAN_SLPAK)))
127 break;
128 }
129 if (i >= MSCAN_SET_MODE_RETRIES)
130 ret = -ENODEV;
131 else
132 priv->can.state = CAN_STATE_ERROR_ACTIVE;
133 }
134 }
135 return ret;
136}
137
138static int mscan_start(struct net_device *dev)
139{
140 struct mscan_priv *priv = netdev_priv(dev);
141 struct mscan_regs __iomem *regs = priv->reg_base;
142 u8 canrflg;
143 int err;
144
145 out_8(®s->canrier, 0);
146
147 INIT_LIST_HEAD(&priv->tx_head);
148 priv->prev_buf_id = 0;
149 priv->cur_pri = 0;
150 priv->tx_active = 0;
151 priv->shadow_canrier = 0;
152 priv->flags = 0;
153
154 if (priv->type == MSCAN_TYPE_MPC5121) {
155
156 if (in_8(®s->canmisc) & MSCAN_BOHOLD)
157 out_8(®s->canmisc, MSCAN_BOHOLD);
158 }
159
160 err = mscan_set_mode(dev, MSCAN_NORMAL_MODE);
161 if (err)
162 return err;
163
164 canrflg = in_8(®s->canrflg);
165 priv->shadow_statflg = canrflg & MSCAN_STAT_MSK;
166 priv->can.state = state_map[max(MSCAN_STATE_RX(canrflg),
167 MSCAN_STATE_TX(canrflg))];
168 out_8(®s->cantier, 0);
169
170
171 out_8(®s->canrier, MSCAN_RX_INTS_ENABLE);
172
173 return 0;
174}
175
176static int mscan_restart(struct net_device *dev)
177{
178 struct mscan_priv *priv = netdev_priv(dev);
179
180 if (priv->type == MSCAN_TYPE_MPC5121) {
181 struct mscan_regs __iomem *regs = priv->reg_base;
182
183 priv->can.state = CAN_STATE_ERROR_ACTIVE;
184 WARN(!(in_8(®s->canmisc) & MSCAN_BOHOLD),
185 "bus-off state expected\n");
186 out_8(®s->canmisc, MSCAN_BOHOLD);
187
188 out_8(®s->canrier, MSCAN_RX_INTS_ENABLE);
189 } else {
190 if (priv->can.state <= CAN_STATE_BUS_OFF)
191 mscan_set_mode(dev, MSCAN_INIT_MODE);
192 return mscan_start(dev);
193 }
194
195 return 0;
196}
197
198static netdev_tx_t mscan_start_xmit(struct sk_buff *skb, struct net_device *dev)
199{
200 struct can_frame *frame = (struct can_frame *)skb->data;
201 struct mscan_priv *priv = netdev_priv(dev);
202 struct mscan_regs __iomem *regs = priv->reg_base;
203 int i, rtr, buf_id;
204 u32 can_id;
205
206 if (can_dropped_invalid_skb(dev, skb))
207 return NETDEV_TX_OK;
208
209 out_8(®s->cantier, 0);
210
211 i = ~priv->tx_active & MSCAN_TXE;
212 buf_id = ffs(i) - 1;
213 switch (hweight8(i)) {
214 case 0:
215 netif_stop_queue(dev);
216 dev_err(dev->dev.parent, "Tx Ring full when queue awake!\n");
217 return NETDEV_TX_BUSY;
218 case 1:
219
220
221
222
223 netif_stop_queue(dev);
224 case 2:
225 if (buf_id < priv->prev_buf_id) {
226 priv->cur_pri++;
227 if (priv->cur_pri == 0xff) {
228 set_bit(F_TX_WAIT_ALL, &priv->flags);
229 netif_stop_queue(dev);
230 }
231 }
232 set_bit(F_TX_PROGRESS, &priv->flags);
233 break;
234 }
235 priv->prev_buf_id = buf_id;
236 out_8(®s->cantbsel, i);
237
238 rtr = frame->can_id & CAN_RTR_FLAG;
239
240
241 if (frame->can_id & CAN_EFF_FLAG) {
242 can_id = (frame->can_id & CAN_EFF_MASK)
243 << (MSCAN_EFF_RTR_SHIFT + 1);
244 if (rtr)
245 can_id |= 1 << MSCAN_EFF_RTR_SHIFT;
246 out_be16(®s->tx.idr3_2, can_id);
247
248 can_id >>= 16;
249
250 can_id = (can_id & 0x7) | ((can_id << 2) & 0xffe0)
251 | MSCAN_EFF_FLAGS;
252 } else {
253 can_id = (frame->can_id & CAN_SFF_MASK)
254 << (MSCAN_SFF_RTR_SHIFT + 1);
255 if (rtr)
256 can_id |= 1 << MSCAN_SFF_RTR_SHIFT;
257 }
258 out_be16(®s->tx.idr1_0, can_id);
259
260 if (!rtr) {
261 void __iomem *data = ®s->tx.dsr1_0;
262 u16 *payload = (u16 *)frame->data;
263
264 for (i = 0; i < frame->can_dlc / 2; i++) {
265 out_be16(data, *payload++);
266 data += 2 + _MSCAN_RESERVED_DSR_SIZE;
267 }
268
269 if (frame->can_dlc & 1)
270 out_8(data, frame->data[frame->can_dlc - 1]);
271 }
272
273 out_8(®s->tx.dlr, frame->can_dlc);
274 out_8(®s->tx.tbpr, priv->cur_pri);
275
276
277 out_8(®s->cantflg, 1 << buf_id);
278
279 if (!test_bit(F_TX_PROGRESS, &priv->flags))
280 dev->trans_start = jiffies;
281
282 list_add_tail(&priv->tx_queue[buf_id].list, &priv->tx_head);
283
284 can_put_echo_skb(skb, dev, buf_id);
285
286
287 priv->tx_active |= 1 << buf_id;
288 out_8(®s->cantier, priv->tx_active);
289
290 return NETDEV_TX_OK;
291}
292
293
294static enum can_state check_set_state(struct net_device *dev, u8 canrflg)
295{
296 struct mscan_priv *priv = netdev_priv(dev);
297 enum can_state state, old_state = priv->can.state;
298
299 if (canrflg & MSCAN_CSCIF && old_state <= CAN_STATE_BUS_OFF) {
300 state = state_map[max(MSCAN_STATE_RX(canrflg),
301 MSCAN_STATE_TX(canrflg))];
302 priv->can.state = state;
303 }
304 return old_state;
305}
306
307static void mscan_get_rx_frame(struct net_device *dev, struct can_frame *frame)
308{
309 struct mscan_priv *priv = netdev_priv(dev);
310 struct mscan_regs __iomem *regs = priv->reg_base;
311 u32 can_id;
312 int i;
313
314 can_id = in_be16(®s->rx.idr1_0);
315 if (can_id & (1 << 3)) {
316 frame->can_id = CAN_EFF_FLAG;
317 can_id = ((can_id << 16) | in_be16(®s->rx.idr3_2));
318 can_id = ((can_id & 0xffe00000) |
319 ((can_id & 0x7ffff) << 2)) >> 2;
320 } else {
321 can_id >>= 4;
322 frame->can_id = 0;
323 }
324
325 frame->can_id |= can_id >> 1;
326 if (can_id & 1)
327 frame->can_id |= CAN_RTR_FLAG;
328
329 frame->can_dlc = get_can_dlc(in_8(®s->rx.dlr) & 0xf);
330
331 if (!(frame->can_id & CAN_RTR_FLAG)) {
332 void __iomem *data = ®s->rx.dsr1_0;
333 u16 *payload = (u16 *)frame->data;
334
335 for (i = 0; i < frame->can_dlc / 2; i++) {
336 *payload++ = in_be16(data);
337 data += 2 + _MSCAN_RESERVED_DSR_SIZE;
338 }
339
340 if (frame->can_dlc & 1)
341 frame->data[frame->can_dlc - 1] = in_8(data);
342 }
343
344 out_8(®s->canrflg, MSCAN_RXF);
345}
346
347static void mscan_get_err_frame(struct net_device *dev, struct can_frame *frame,
348 u8 canrflg)
349{
350 struct mscan_priv *priv = netdev_priv(dev);
351 struct mscan_regs __iomem *regs = priv->reg_base;
352 struct net_device_stats *stats = &dev->stats;
353 enum can_state old_state;
354
355 dev_dbg(dev->dev.parent, "error interrupt (canrflg=%#x)\n", canrflg);
356 frame->can_id = CAN_ERR_FLAG;
357
358 if (canrflg & MSCAN_OVRIF) {
359 frame->can_id |= CAN_ERR_CRTL;
360 frame->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
361 stats->rx_over_errors++;
362 stats->rx_errors++;
363 } else {
364 frame->data[1] = 0;
365 }
366
367 old_state = check_set_state(dev, canrflg);
368
369 if (old_state != priv->can.state) {
370 switch (priv->can.state) {
371 case CAN_STATE_ERROR_WARNING:
372 frame->can_id |= CAN_ERR_CRTL;
373 priv->can.can_stats.error_warning++;
374 if ((priv->shadow_statflg & MSCAN_RSTAT_MSK) <
375 (canrflg & MSCAN_RSTAT_MSK))
376 frame->data[1] |= CAN_ERR_CRTL_RX_WARNING;
377 if ((priv->shadow_statflg & MSCAN_TSTAT_MSK) <
378 (canrflg & MSCAN_TSTAT_MSK))
379 frame->data[1] |= CAN_ERR_CRTL_TX_WARNING;
380 break;
381 case CAN_STATE_ERROR_PASSIVE:
382 frame->can_id |= CAN_ERR_CRTL;
383 priv->can.can_stats.error_passive++;
384 frame->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
385 break;
386 case CAN_STATE_BUS_OFF:
387 frame->can_id |= CAN_ERR_BUSOFF;
388
389
390
391
392
393 if (priv->type != MSCAN_TYPE_MPC5121) {
394 out_8(®s->cantier, 0);
395 out_8(®s->canrier, 0);
396 setbits8(®s->canctl0,
397 MSCAN_SLPRQ | MSCAN_INITRQ);
398 }
399 can_bus_off(dev);
400 break;
401 default:
402 break;
403 }
404 }
405 priv->shadow_statflg = canrflg & MSCAN_STAT_MSK;
406 frame->can_dlc = CAN_ERR_DLC;
407 out_8(®s->canrflg, MSCAN_ERR_IF);
408}
409
410static int mscan_rx_poll(struct napi_struct *napi, int quota)
411{
412 struct mscan_priv *priv = container_of(napi, struct mscan_priv, napi);
413 struct net_device *dev = napi->dev;
414 struct mscan_regs __iomem *regs = priv->reg_base;
415 struct net_device_stats *stats = &dev->stats;
416 int npackets = 0;
417 int ret = 1;
418 struct sk_buff *skb;
419 struct can_frame *frame;
420 u8 canrflg;
421
422 while (npackets < quota) {
423 canrflg = in_8(®s->canrflg);
424 if (!(canrflg & (MSCAN_RXF | MSCAN_ERR_IF)))
425 break;
426
427 skb = alloc_can_skb(dev, &frame);
428 if (!skb) {
429 if (printk_ratelimit())
430 dev_notice(dev->dev.parent, "packet dropped\n");
431 stats->rx_dropped++;
432 out_8(®s->canrflg, canrflg);
433 continue;
434 }
435
436 if (canrflg & MSCAN_RXF)
437 mscan_get_rx_frame(dev, frame);
438 else if (canrflg & MSCAN_ERR_IF)
439 mscan_get_err_frame(dev, frame, canrflg);
440
441 stats->rx_packets++;
442 stats->rx_bytes += frame->can_dlc;
443 npackets++;
444 netif_receive_skb(skb);
445 }
446
447 if (!(in_8(®s->canrflg) & (MSCAN_RXF | MSCAN_ERR_IF))) {
448 napi_complete(&priv->napi);
449 clear_bit(F_RX_PROGRESS, &priv->flags);
450 if (priv->can.state < CAN_STATE_BUS_OFF)
451 out_8(®s->canrier, priv->shadow_canrier);
452 ret = 0;
453 }
454 return ret;
455}
456
457static irqreturn_t mscan_isr(int irq, void *dev_id)
458{
459 struct net_device *dev = (struct net_device *)dev_id;
460 struct mscan_priv *priv = netdev_priv(dev);
461 struct mscan_regs __iomem *regs = priv->reg_base;
462 struct net_device_stats *stats = &dev->stats;
463 u8 cantier, cantflg, canrflg;
464 irqreturn_t ret = IRQ_NONE;
465
466 cantier = in_8(®s->cantier) & MSCAN_TXE;
467 cantflg = in_8(®s->cantflg) & cantier;
468
469 if (cantier && cantflg) {
470 struct list_head *tmp, *pos;
471
472 list_for_each_safe(pos, tmp, &priv->tx_head) {
473 struct tx_queue_entry *entry =
474 list_entry(pos, struct tx_queue_entry, list);
475 u8 mask = entry->mask;
476
477 if (!(cantflg & mask))
478 continue;
479
480 out_8(®s->cantbsel, mask);
481 stats->tx_bytes += in_8(®s->tx.dlr);
482 stats->tx_packets++;
483 can_get_echo_skb(dev, entry->id);
484 priv->tx_active &= ~mask;
485 list_del(pos);
486 }
487
488 if (list_empty(&priv->tx_head)) {
489 clear_bit(F_TX_WAIT_ALL, &priv->flags);
490 clear_bit(F_TX_PROGRESS, &priv->flags);
491 priv->cur_pri = 0;
492 } else {
493 dev->trans_start = jiffies;
494 }
495
496 if (!test_bit(F_TX_WAIT_ALL, &priv->flags))
497 netif_wake_queue(dev);
498
499 out_8(®s->cantier, priv->tx_active);
500 ret = IRQ_HANDLED;
501 }
502
503 canrflg = in_8(®s->canrflg);
504 if ((canrflg & ~MSCAN_STAT_MSK) &&
505 !test_and_set_bit(F_RX_PROGRESS, &priv->flags)) {
506 if (canrflg & ~MSCAN_STAT_MSK) {
507 priv->shadow_canrier = in_8(®s->canrier);
508 out_8(®s->canrier, 0);
509 napi_schedule(&priv->napi);
510 ret = IRQ_HANDLED;
511 } else {
512 clear_bit(F_RX_PROGRESS, &priv->flags);
513 }
514 }
515 return ret;
516}
517
518static int mscan_do_set_mode(struct net_device *dev, enum can_mode mode)
519{
520 struct mscan_priv *priv = netdev_priv(dev);
521 int ret = 0;
522
523 if (!priv->open_time)
524 return -EINVAL;
525
526 switch (mode) {
527 case CAN_MODE_START:
528 ret = mscan_restart(dev);
529 if (ret)
530 break;
531 if (netif_queue_stopped(dev))
532 netif_wake_queue(dev);
533 break;
534
535 default:
536 ret = -EOPNOTSUPP;
537 break;
538 }
539 return ret;
540}
541
542static int mscan_do_set_bittiming(struct net_device *dev)
543{
544 struct mscan_priv *priv = netdev_priv(dev);
545 struct mscan_regs __iomem *regs = priv->reg_base;
546 struct can_bittiming *bt = &priv->can.bittiming;
547 u8 btr0, btr1;
548
549 btr0 = BTR0_SET_BRP(bt->brp) | BTR0_SET_SJW(bt->sjw);
550 btr1 = (BTR1_SET_TSEG1(bt->prop_seg + bt->phase_seg1) |
551 BTR1_SET_TSEG2(bt->phase_seg2) |
552 BTR1_SET_SAM(priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES));
553
554 dev_info(dev->dev.parent, "setting BTR0=0x%02x BTR1=0x%02x\n",
555 btr0, btr1);
556
557 out_8(®s->canbtr0, btr0);
558 out_8(®s->canbtr1, btr1);
559
560 return 0;
561}
562
563static int mscan_open(struct net_device *dev)
564{
565 int ret;
566 struct mscan_priv *priv = netdev_priv(dev);
567 struct mscan_regs __iomem *regs = priv->reg_base;
568
569
570 ret = open_candev(dev);
571 if (ret)
572 return ret;
573
574 napi_enable(&priv->napi);
575
576 ret = request_irq(dev->irq, mscan_isr, 0, dev->name, dev);
577 if (ret < 0) {
578 dev_err(dev->dev.parent, "failed to attach interrupt\n");
579 goto exit_napi_disable;
580 }
581
582 priv->open_time = jiffies;
583
584 if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
585 setbits8(®s->canctl1, MSCAN_LISTEN);
586 else
587 clrbits8(®s->canctl1, MSCAN_LISTEN);
588
589 ret = mscan_start(dev);
590 if (ret)
591 goto exit_free_irq;
592
593 netif_start_queue(dev);
594
595 return 0;
596
597exit_free_irq:
598 priv->open_time = 0;
599 free_irq(dev->irq, dev);
600exit_napi_disable:
601 napi_disable(&priv->napi);
602 close_candev(dev);
603 return ret;
604}
605
606static int mscan_close(struct net_device *dev)
607{
608 struct mscan_priv *priv = netdev_priv(dev);
609 struct mscan_regs __iomem *regs = priv->reg_base;
610
611 netif_stop_queue(dev);
612 napi_disable(&priv->napi);
613
614 out_8(®s->cantier, 0);
615 out_8(®s->canrier, 0);
616 mscan_set_mode(dev, MSCAN_INIT_MODE);
617 close_candev(dev);
618 free_irq(dev->irq, dev);
619 priv->open_time = 0;
620
621 return 0;
622}
623
624static const struct net_device_ops mscan_netdev_ops = {
625 .ndo_open = mscan_open,
626 .ndo_stop = mscan_close,
627 .ndo_start_xmit = mscan_start_xmit,
628};
629
630int register_mscandev(struct net_device *dev, int mscan_clksrc)
631{
632 struct mscan_priv *priv = netdev_priv(dev);
633 struct mscan_regs __iomem *regs = priv->reg_base;
634 u8 ctl1;
635
636 ctl1 = in_8(®s->canctl1);
637 if (mscan_clksrc)
638 ctl1 |= MSCAN_CLKSRC;
639 else
640 ctl1 &= ~MSCAN_CLKSRC;
641
642 if (priv->type == MSCAN_TYPE_MPC5121)
643 ctl1 |= MSCAN_BORM;
644
645 ctl1 |= MSCAN_CANE;
646 out_8(®s->canctl1, ctl1);
647 udelay(100);
648
649
650 out_be16(®s->canidar1_0, 0);
651 out_be16(®s->canidar3_2, 0);
652 out_be16(®s->canidar5_4, 0);
653 out_be16(®s->canidar7_6, 0);
654
655 out_be16(®s->canidmr1_0, 0xffff);
656 out_be16(®s->canidmr3_2, 0xffff);
657 out_be16(®s->canidmr5_4, 0xffff);
658 out_be16(®s->canidmr7_6, 0xffff);
659
660 out_8(®s->canidac, MSCAN_AF_32BIT);
661
662 mscan_set_mode(dev, MSCAN_INIT_MODE);
663
664 return register_candev(dev);
665}
666
667void unregister_mscandev(struct net_device *dev)
668{
669 struct mscan_priv *priv = netdev_priv(dev);
670 struct mscan_regs __iomem *regs = priv->reg_base;
671 mscan_set_mode(dev, MSCAN_INIT_MODE);
672 clrbits8(®s->canctl1, MSCAN_CANE);
673 unregister_candev(dev);
674}
675
676struct net_device *alloc_mscandev(void)
677{
678 struct net_device *dev;
679 struct mscan_priv *priv;
680 int i;
681
682 dev = alloc_candev(sizeof(struct mscan_priv), MSCAN_ECHO_SKB_MAX);
683 if (!dev)
684 return NULL;
685 priv = netdev_priv(dev);
686
687 dev->netdev_ops = &mscan_netdev_ops;
688
689 dev->flags |= IFF_ECHO;
690
691 netif_napi_add(dev, &priv->napi, mscan_rx_poll, 8);
692
693 priv->can.bittiming_const = &mscan_bittiming_const;
694 priv->can.do_set_bittiming = mscan_do_set_bittiming;
695 priv->can.do_set_mode = mscan_do_set_mode;
696 priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
697 CAN_CTRLMODE_LISTENONLY;
698
699 for (i = 0; i < TX_QUEUE_SIZE; i++) {
700 priv->tx_queue[i].id = i;
701 priv->tx_queue[i].mask = 1 << i;
702 }
703
704 return dev;
705}
706
707MODULE_AUTHOR("Andrey Volkov <avolkov@varma-el.com>");
708MODULE_LICENSE("GPL v2");
709MODULE_DESCRIPTION("CAN port driver for a MSCAN based chips");
710