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11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/interrupt.h>
14#include <linux/delay.h>
15#include <linux/netdevice.h>
16#include <linux/if_arp.h>
17#include <linux/if_ether.h>
18#include <linux/list.h>
19#include <linux/can/dev.h>
20#include <linux/can/error.h>
21#include <linux/io.h>
22
23#include "mscan.h"
24
25static const struct can_bittiming_const mscan_bittiming_const = {
26 .name = "mscan",
27 .tseg1_min = 4,
28 .tseg1_max = 16,
29 .tseg2_min = 2,
30 .tseg2_max = 8,
31 .sjw_max = 4,
32 .brp_min = 1,
33 .brp_max = 64,
34 .brp_inc = 1,
35};
36
37struct mscan_state {
38 u8 mode;
39 u8 canrier;
40 u8 cantier;
41};
42
43static enum can_state state_map[] = {
44 CAN_STATE_ERROR_ACTIVE,
45 CAN_STATE_ERROR_WARNING,
46 CAN_STATE_ERROR_PASSIVE,
47 CAN_STATE_BUS_OFF
48};
49
50static int mscan_set_mode(struct net_device *dev, u8 mode)
51{
52 struct mscan_priv *priv = netdev_priv(dev);
53 struct mscan_regs __iomem *regs = priv->reg_base;
54 int ret = 0;
55 int i;
56 u8 canctl1;
57
58 if (mode != MSCAN_NORMAL_MODE) {
59 if (priv->tx_active) {
60 #
61 out_8(®s->cantarq, priv->tx_active);
62
63 out_8(®s->cantier, 0);
64 }
65
66 canctl1 = in_8(®s->canctl1);
67 if ((mode & MSCAN_SLPRQ) && !(canctl1 & MSCAN_SLPAK)) {
68 setbits8(®s->canctl0, MSCAN_SLPRQ);
69 for (i = 0; i < MSCAN_SET_MODE_RETRIES; i++) {
70 if (in_8(®s->canctl1) & MSCAN_SLPAK)
71 break;
72 udelay(100);
73 }
74
75
76
77
78
79
80
81
82
83
84
85 if (i >= MSCAN_SET_MODE_RETRIES)
86 netdev_dbg(dev,
87 "device failed to enter sleep mode. "
88 "We proceed anyhow.\n");
89 else
90 priv->can.state = CAN_STATE_SLEEPING;
91 }
92
93 if ((mode & MSCAN_INITRQ) && !(canctl1 & MSCAN_INITAK)) {
94 setbits8(®s->canctl0, MSCAN_INITRQ);
95 for (i = 0; i < MSCAN_SET_MODE_RETRIES; i++) {
96 if (in_8(®s->canctl1) & MSCAN_INITAK)
97 break;
98 }
99 if (i >= MSCAN_SET_MODE_RETRIES)
100 ret = -ENODEV;
101 }
102 if (!ret)
103 priv->can.state = CAN_STATE_STOPPED;
104
105 if (mode & MSCAN_CSWAI)
106 setbits8(®s->canctl0, MSCAN_CSWAI);
107
108 } else {
109 canctl1 = in_8(®s->canctl1);
110 if (canctl1 & (MSCAN_SLPAK | MSCAN_INITAK)) {
111 clrbits8(®s->canctl0, MSCAN_SLPRQ | MSCAN_INITRQ);
112 for (i = 0; i < MSCAN_SET_MODE_RETRIES; i++) {
113 canctl1 = in_8(®s->canctl1);
114 if (!(canctl1 & (MSCAN_INITAK | MSCAN_SLPAK)))
115 break;
116 }
117 if (i >= MSCAN_SET_MODE_RETRIES)
118 ret = -ENODEV;
119 else
120 priv->can.state = CAN_STATE_ERROR_ACTIVE;
121 }
122 }
123 return ret;
124}
125
126static int mscan_start(struct net_device *dev)
127{
128 struct mscan_priv *priv = netdev_priv(dev);
129 struct mscan_regs __iomem *regs = priv->reg_base;
130 u8 canrflg;
131 int err;
132
133 out_8(®s->canrier, 0);
134
135 INIT_LIST_HEAD(&priv->tx_head);
136 priv->prev_buf_id = 0;
137 priv->cur_pri = 0;
138 priv->tx_active = 0;
139 priv->shadow_canrier = 0;
140 priv->flags = 0;
141
142 if (priv->type == MSCAN_TYPE_MPC5121) {
143
144 if (in_8(®s->canmisc) & MSCAN_BOHOLD)
145 out_8(®s->canmisc, MSCAN_BOHOLD);
146 }
147
148 err = mscan_set_mode(dev, MSCAN_NORMAL_MODE);
149 if (err)
150 return err;
151
152 canrflg = in_8(®s->canrflg);
153 priv->shadow_statflg = canrflg & MSCAN_STAT_MSK;
154 priv->can.state = state_map[max(MSCAN_STATE_RX(canrflg),
155 MSCAN_STATE_TX(canrflg))];
156 out_8(®s->cantier, 0);
157
158
159 out_8(®s->canrier, MSCAN_RX_INTS_ENABLE);
160
161 return 0;
162}
163
164static int mscan_restart(struct net_device *dev)
165{
166 struct mscan_priv *priv = netdev_priv(dev);
167
168 if (priv->type == MSCAN_TYPE_MPC5121) {
169 struct mscan_regs __iomem *regs = priv->reg_base;
170
171 priv->can.state = CAN_STATE_ERROR_ACTIVE;
172 WARN(!(in_8(®s->canmisc) & MSCAN_BOHOLD),
173 "bus-off state expected\n");
174 out_8(®s->canmisc, MSCAN_BOHOLD);
175
176 out_8(®s->canrier, MSCAN_RX_INTS_ENABLE);
177 } else {
178 if (priv->can.state <= CAN_STATE_BUS_OFF)
179 mscan_set_mode(dev, MSCAN_INIT_MODE);
180 return mscan_start(dev);
181 }
182
183 return 0;
184}
185
186static netdev_tx_t mscan_start_xmit(struct sk_buff *skb, struct net_device *dev)
187{
188 struct can_frame *frame = (struct can_frame *)skb->data;
189 struct mscan_priv *priv = netdev_priv(dev);
190 struct mscan_regs __iomem *regs = priv->reg_base;
191 int i, rtr, buf_id;
192 u32 can_id;
193
194 if (can_dropped_invalid_skb(dev, skb))
195 return NETDEV_TX_OK;
196
197 out_8(®s->cantier, 0);
198
199 i = ~priv->tx_active & MSCAN_TXE;
200 buf_id = ffs(i) - 1;
201 switch (hweight8(i)) {
202 case 0:
203 netif_stop_queue(dev);
204 netdev_err(dev, "Tx Ring full when queue awake!\n");
205 return NETDEV_TX_BUSY;
206 case 1:
207
208
209
210
211 netif_stop_queue(dev);
212 fallthrough;
213 case 2:
214 if (buf_id < priv->prev_buf_id) {
215 priv->cur_pri++;
216 if (priv->cur_pri == 0xff) {
217 set_bit(F_TX_WAIT_ALL, &priv->flags);
218 netif_stop_queue(dev);
219 }
220 }
221 set_bit(F_TX_PROGRESS, &priv->flags);
222 break;
223 }
224 priv->prev_buf_id = buf_id;
225 out_8(®s->cantbsel, i);
226
227 rtr = frame->can_id & CAN_RTR_FLAG;
228
229
230 if (frame->can_id & CAN_EFF_FLAG) {
231 can_id = (frame->can_id & CAN_EFF_MASK)
232 << (MSCAN_EFF_RTR_SHIFT + 1);
233 if (rtr)
234 can_id |= 1 << MSCAN_EFF_RTR_SHIFT;
235 out_be16(®s->tx.idr3_2, can_id);
236
237 can_id >>= 16;
238
239 can_id = (can_id & 0x7) | ((can_id << 2) & 0xffe0)
240 | MSCAN_EFF_FLAGS;
241 } else {
242 can_id = (frame->can_id & CAN_SFF_MASK)
243 << (MSCAN_SFF_RTR_SHIFT + 1);
244 if (rtr)
245 can_id |= 1 << MSCAN_SFF_RTR_SHIFT;
246 }
247 out_be16(®s->tx.idr1_0, can_id);
248
249 if (!rtr) {
250 void __iomem *data = ®s->tx.dsr1_0;
251 u16 *payload = (u16 *)frame->data;
252
253 for (i = 0; i < frame->len / 2; i++) {
254 out_be16(data, *payload++);
255 data += 2 + _MSCAN_RESERVED_DSR_SIZE;
256 }
257
258 if (frame->len & 1)
259 out_8(data, frame->data[frame->len - 1]);
260 }
261
262 out_8(®s->tx.dlr, frame->len);
263 out_8(®s->tx.tbpr, priv->cur_pri);
264
265
266 out_8(®s->cantflg, 1 << buf_id);
267
268 if (!test_bit(F_TX_PROGRESS, &priv->flags))
269 netif_trans_update(dev);
270
271 list_add_tail(&priv->tx_queue[buf_id].list, &priv->tx_head);
272
273 can_put_echo_skb(skb, dev, buf_id, 0);
274
275
276 priv->tx_active |= 1 << buf_id;
277 out_8(®s->cantier, priv->tx_active);
278
279 return NETDEV_TX_OK;
280}
281
282static enum can_state get_new_state(struct net_device *dev, u8 canrflg)
283{
284 struct mscan_priv *priv = netdev_priv(dev);
285
286 if (unlikely(canrflg & MSCAN_CSCIF))
287 return state_map[max(MSCAN_STATE_RX(canrflg),
288 MSCAN_STATE_TX(canrflg))];
289
290 return priv->can.state;
291}
292
293static void mscan_get_rx_frame(struct net_device *dev, struct can_frame *frame)
294{
295 struct mscan_priv *priv = netdev_priv(dev);
296 struct mscan_regs __iomem *regs = priv->reg_base;
297 u32 can_id;
298 int i;
299
300 can_id = in_be16(®s->rx.idr1_0);
301 if (can_id & (1 << 3)) {
302 frame->can_id = CAN_EFF_FLAG;
303 can_id = ((can_id << 16) | in_be16(®s->rx.idr3_2));
304 can_id = ((can_id & 0xffe00000) |
305 ((can_id & 0x7ffff) << 2)) >> 2;
306 } else {
307 can_id >>= 4;
308 frame->can_id = 0;
309 }
310
311 frame->can_id |= can_id >> 1;
312 if (can_id & 1)
313 frame->can_id |= CAN_RTR_FLAG;
314
315 frame->len = can_cc_dlc2len(in_8(®s->rx.dlr) & 0xf);
316
317 if (!(frame->can_id & CAN_RTR_FLAG)) {
318 void __iomem *data = ®s->rx.dsr1_0;
319 u16 *payload = (u16 *)frame->data;
320
321 for (i = 0; i < frame->len / 2; i++) {
322 *payload++ = in_be16(data);
323 data += 2 + _MSCAN_RESERVED_DSR_SIZE;
324 }
325
326 if (frame->len & 1)
327 frame->data[frame->len - 1] = in_8(data);
328 }
329
330 out_8(®s->canrflg, MSCAN_RXF);
331}
332
333static void mscan_get_err_frame(struct net_device *dev, struct can_frame *frame,
334 u8 canrflg)
335{
336 struct mscan_priv *priv = netdev_priv(dev);
337 struct mscan_regs __iomem *regs = priv->reg_base;
338 struct net_device_stats *stats = &dev->stats;
339 enum can_state new_state;
340
341 netdev_dbg(dev, "error interrupt (canrflg=%#x)\n", canrflg);
342 frame->can_id = CAN_ERR_FLAG;
343
344 if (canrflg & MSCAN_OVRIF) {
345 frame->can_id |= CAN_ERR_CRTL;
346 frame->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
347 stats->rx_over_errors++;
348 stats->rx_errors++;
349 } else {
350 frame->data[1] = 0;
351 }
352
353 new_state = get_new_state(dev, canrflg);
354 if (new_state != priv->can.state) {
355 can_change_state(dev, frame,
356 state_map[MSCAN_STATE_TX(canrflg)],
357 state_map[MSCAN_STATE_RX(canrflg)]);
358
359 if (priv->can.state == CAN_STATE_BUS_OFF) {
360
361
362
363
364
365 if (priv->type != MSCAN_TYPE_MPC5121) {
366 out_8(®s->cantier, 0);
367 out_8(®s->canrier, 0);
368 setbits8(®s->canctl0,
369 MSCAN_SLPRQ | MSCAN_INITRQ);
370 }
371 can_bus_off(dev);
372 }
373 }
374 priv->shadow_statflg = canrflg & MSCAN_STAT_MSK;
375 frame->len = CAN_ERR_DLC;
376 out_8(®s->canrflg, MSCAN_ERR_IF);
377}
378
379static int mscan_rx_poll(struct napi_struct *napi, int quota)
380{
381 struct mscan_priv *priv = container_of(napi, struct mscan_priv, napi);
382 struct net_device *dev = napi->dev;
383 struct mscan_regs __iomem *regs = priv->reg_base;
384 struct net_device_stats *stats = &dev->stats;
385 int work_done = 0;
386 struct sk_buff *skb;
387 struct can_frame *frame;
388 u8 canrflg;
389
390 while (work_done < quota) {
391 canrflg = in_8(®s->canrflg);
392 if (!(canrflg & (MSCAN_RXF | MSCAN_ERR_IF)))
393 break;
394
395 skb = alloc_can_skb(dev, &frame);
396 if (!skb) {
397 if (printk_ratelimit())
398 netdev_notice(dev, "packet dropped\n");
399 stats->rx_dropped++;
400 out_8(®s->canrflg, canrflg);
401 continue;
402 }
403
404 if (canrflg & MSCAN_RXF)
405 mscan_get_rx_frame(dev, frame);
406 else if (canrflg & MSCAN_ERR_IF)
407 mscan_get_err_frame(dev, frame, canrflg);
408
409 stats->rx_packets++;
410 stats->rx_bytes += frame->len;
411 work_done++;
412 netif_receive_skb(skb);
413 }
414
415 if (work_done < quota) {
416 if (likely(napi_complete_done(&priv->napi, work_done))) {
417 clear_bit(F_RX_PROGRESS, &priv->flags);
418 if (priv->can.state < CAN_STATE_BUS_OFF)
419 out_8(®s->canrier, priv->shadow_canrier);
420 }
421 }
422 return work_done;
423}
424
425static irqreturn_t mscan_isr(int irq, void *dev_id)
426{
427 struct net_device *dev = (struct net_device *)dev_id;
428 struct mscan_priv *priv = netdev_priv(dev);
429 struct mscan_regs __iomem *regs = priv->reg_base;
430 struct net_device_stats *stats = &dev->stats;
431 u8 cantier, cantflg, canrflg;
432 irqreturn_t ret = IRQ_NONE;
433
434 cantier = in_8(®s->cantier) & MSCAN_TXE;
435 cantflg = in_8(®s->cantflg) & cantier;
436
437 if (cantier && cantflg) {
438 struct list_head *tmp, *pos;
439
440 list_for_each_safe(pos, tmp, &priv->tx_head) {
441 struct tx_queue_entry *entry =
442 list_entry(pos, struct tx_queue_entry, list);
443 u8 mask = entry->mask;
444
445 if (!(cantflg & mask))
446 continue;
447
448 out_8(®s->cantbsel, mask);
449 stats->tx_bytes += in_8(®s->tx.dlr);
450 stats->tx_packets++;
451 can_get_echo_skb(dev, entry->id, NULL);
452 priv->tx_active &= ~mask;
453 list_del(pos);
454 }
455
456 if (list_empty(&priv->tx_head)) {
457 clear_bit(F_TX_WAIT_ALL, &priv->flags);
458 clear_bit(F_TX_PROGRESS, &priv->flags);
459 priv->cur_pri = 0;
460 } else {
461 netif_trans_update(dev);
462 }
463
464 if (!test_bit(F_TX_WAIT_ALL, &priv->flags))
465 netif_wake_queue(dev);
466
467 out_8(®s->cantier, priv->tx_active);
468 ret = IRQ_HANDLED;
469 }
470
471 canrflg = in_8(®s->canrflg);
472 if ((canrflg & ~MSCAN_STAT_MSK) &&
473 !test_and_set_bit(F_RX_PROGRESS, &priv->flags)) {
474 if (canrflg & ~MSCAN_STAT_MSK) {
475 priv->shadow_canrier = in_8(®s->canrier);
476 out_8(®s->canrier, 0);
477 napi_schedule(&priv->napi);
478 ret = IRQ_HANDLED;
479 } else {
480 clear_bit(F_RX_PROGRESS, &priv->flags);
481 }
482 }
483 return ret;
484}
485
486static int mscan_do_set_mode(struct net_device *dev, enum can_mode mode)
487{
488 int ret = 0;
489
490 switch (mode) {
491 case CAN_MODE_START:
492 ret = mscan_restart(dev);
493 if (ret)
494 break;
495 if (netif_queue_stopped(dev))
496 netif_wake_queue(dev);
497 break;
498
499 default:
500 ret = -EOPNOTSUPP;
501 break;
502 }
503 return ret;
504}
505
506static int mscan_do_set_bittiming(struct net_device *dev)
507{
508 struct mscan_priv *priv = netdev_priv(dev);
509 struct mscan_regs __iomem *regs = priv->reg_base;
510 struct can_bittiming *bt = &priv->can.bittiming;
511 u8 btr0, btr1;
512
513 btr0 = BTR0_SET_BRP(bt->brp) | BTR0_SET_SJW(bt->sjw);
514 btr1 = (BTR1_SET_TSEG1(bt->prop_seg + bt->phase_seg1) |
515 BTR1_SET_TSEG2(bt->phase_seg2) |
516 BTR1_SET_SAM(priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES));
517
518 netdev_info(dev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
519
520 out_8(®s->canbtr0, btr0);
521 out_8(®s->canbtr1, btr1);
522
523 return 0;
524}
525
526static int mscan_get_berr_counter(const struct net_device *dev,
527 struct can_berr_counter *bec)
528{
529 struct mscan_priv *priv = netdev_priv(dev);
530 struct mscan_regs __iomem *regs = priv->reg_base;
531
532 bec->txerr = in_8(®s->cantxerr);
533 bec->rxerr = in_8(®s->canrxerr);
534
535 return 0;
536}
537
538static int mscan_open(struct net_device *dev)
539{
540 int ret;
541 struct mscan_priv *priv = netdev_priv(dev);
542 struct mscan_regs __iomem *regs = priv->reg_base;
543
544 ret = clk_prepare_enable(priv->clk_ipg);
545 if (ret)
546 goto exit_retcode;
547 ret = clk_prepare_enable(priv->clk_can);
548 if (ret)
549 goto exit_dis_ipg_clock;
550
551
552 ret = open_candev(dev);
553 if (ret)
554 goto exit_dis_can_clock;
555
556 napi_enable(&priv->napi);
557
558 ret = request_irq(dev->irq, mscan_isr, 0, dev->name, dev);
559 if (ret < 0) {
560 netdev_err(dev, "failed to attach interrupt\n");
561 goto exit_napi_disable;
562 }
563
564 if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
565 setbits8(®s->canctl1, MSCAN_LISTEN);
566 else
567 clrbits8(®s->canctl1, MSCAN_LISTEN);
568
569 ret = mscan_start(dev);
570 if (ret)
571 goto exit_free_irq;
572
573 netif_start_queue(dev);
574
575 return 0;
576
577exit_free_irq:
578 free_irq(dev->irq, dev);
579exit_napi_disable:
580 napi_disable(&priv->napi);
581 close_candev(dev);
582exit_dis_can_clock:
583 clk_disable_unprepare(priv->clk_can);
584exit_dis_ipg_clock:
585 clk_disable_unprepare(priv->clk_ipg);
586exit_retcode:
587 return ret;
588}
589
590static int mscan_close(struct net_device *dev)
591{
592 struct mscan_priv *priv = netdev_priv(dev);
593 struct mscan_regs __iomem *regs = priv->reg_base;
594
595 netif_stop_queue(dev);
596 napi_disable(&priv->napi);
597
598 out_8(®s->cantier, 0);
599 out_8(®s->canrier, 0);
600 mscan_set_mode(dev, MSCAN_INIT_MODE);
601 close_candev(dev);
602 free_irq(dev->irq, dev);
603
604 clk_disable_unprepare(priv->clk_can);
605 clk_disable_unprepare(priv->clk_ipg);
606
607 return 0;
608}
609
610static const struct net_device_ops mscan_netdev_ops = {
611 .ndo_open = mscan_open,
612 .ndo_stop = mscan_close,
613 .ndo_start_xmit = mscan_start_xmit,
614 .ndo_change_mtu = can_change_mtu,
615};
616
617int register_mscandev(struct net_device *dev, int mscan_clksrc)
618{
619 struct mscan_priv *priv = netdev_priv(dev);
620 struct mscan_regs __iomem *regs = priv->reg_base;
621 u8 ctl1;
622
623 ctl1 = in_8(®s->canctl1);
624 if (mscan_clksrc)
625 ctl1 |= MSCAN_CLKSRC;
626 else
627 ctl1 &= ~MSCAN_CLKSRC;
628
629 if (priv->type == MSCAN_TYPE_MPC5121) {
630 priv->can.do_get_berr_counter = mscan_get_berr_counter;
631 ctl1 |= MSCAN_BORM;
632 }
633
634 ctl1 |= MSCAN_CANE;
635 out_8(®s->canctl1, ctl1);
636 udelay(100);
637
638
639 out_be16(®s->canidar1_0, 0);
640 out_be16(®s->canidar3_2, 0);
641 out_be16(®s->canidar5_4, 0);
642 out_be16(®s->canidar7_6, 0);
643
644 out_be16(®s->canidmr1_0, 0xffff);
645 out_be16(®s->canidmr3_2, 0xffff);
646 out_be16(®s->canidmr5_4, 0xffff);
647 out_be16(®s->canidmr7_6, 0xffff);
648
649 out_8(®s->canidac, MSCAN_AF_32BIT);
650
651 mscan_set_mode(dev, MSCAN_INIT_MODE);
652
653 return register_candev(dev);
654}
655
656void unregister_mscandev(struct net_device *dev)
657{
658 struct mscan_priv *priv = netdev_priv(dev);
659 struct mscan_regs __iomem *regs = priv->reg_base;
660 mscan_set_mode(dev, MSCAN_INIT_MODE);
661 clrbits8(®s->canctl1, MSCAN_CANE);
662 unregister_candev(dev);
663}
664
665struct net_device *alloc_mscandev(void)
666{
667 struct net_device *dev;
668 struct mscan_priv *priv;
669 int i;
670
671 dev = alloc_candev(sizeof(struct mscan_priv), MSCAN_ECHO_SKB_MAX);
672 if (!dev)
673 return NULL;
674 priv = netdev_priv(dev);
675
676 dev->netdev_ops = &mscan_netdev_ops;
677
678 dev->flags |= IFF_ECHO;
679
680 netif_napi_add(dev, &priv->napi, mscan_rx_poll, 8);
681
682 priv->can.bittiming_const = &mscan_bittiming_const;
683 priv->can.do_set_bittiming = mscan_do_set_bittiming;
684 priv->can.do_set_mode = mscan_do_set_mode;
685 priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
686 CAN_CTRLMODE_LISTENONLY;
687
688 for (i = 0; i < TX_QUEUE_SIZE; i++) {
689 priv->tx_queue[i].id = i;
690 priv->tx_queue[i].mask = 1 << i;
691 }
692
693 return dev;
694}
695
696MODULE_AUTHOR("Andrey Volkov <avolkov@varma-el.com>");
697MODULE_LICENSE("GPL v2");
698MODULE_DESCRIPTION("CAN port driver for a MSCAN based chips");
699
