xref: /openbmc/qemu/hw/net/can/can_sja1000.c (revision 93e0932b)
1 /*
2  * CAN device - SJA1000 chip emulation for QEMU
3  *
4  * Copyright (c) 2013-2014 Jin Yang
5  * Copyright (c) 2014-2018 Pavel Pisa
6  *
7  * Initial development supported by Google GSoC 2013 from RTEMS project slot
8  *
9  * Permission is hereby granted, free of charge, to any person obtaining a copy
10  * of this software and associated documentation files (the "Software"), to deal
11  * in the Software without restriction, including without limitation the rights
12  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
13  * copies of the Software, and to permit persons to whom the Software is
14  * furnished to do so, subject to the following conditions:
15  *
16  * The above copyright notice and this permission notice shall be included in
17  * all copies or substantial portions of the Software.
18  *
19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
22  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
23  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
24  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
25  * THE SOFTWARE.
26  */
27 
28 #include "qemu/osdep.h"
29 #include "qemu/log.h"
30 #include "chardev/char.h"
31 #include "hw/irq.h"
32 #include "migration/vmstate.h"
33 #include "net/can_emu.h"
34 
35 #include "can_sja1000.h"
36 
37 #ifndef DEBUG_FILTER
38 #define DEBUG_FILTER 0
39 #endif /*DEBUG_FILTER*/
40 
41 #ifndef DEBUG_CAN
42 #define DEBUG_CAN 0
43 #endif /*DEBUG_CAN*/
44 
45 #define DPRINTF(fmt, ...) \
46     do { \
47         if (DEBUG_CAN) { \
48             qemu_log("[cansja]: " fmt , ## __VA_ARGS__); \
49         } \
50     } while (0)
51 
52 static void can_sja_software_reset(CanSJA1000State *s)
53 {
54     s->mode        &= ~0x31;
55     s->mode        |= 0x01;
56     s->status_pel  &= ~0x37;
57     s->status_pel  |= 0x34;
58 
59     s->rxbuf_start = 0x00;
60     s->rxmsg_cnt   = 0x00;
61     s->rx_cnt      = 0x00;
62 }
63 
64 void can_sja_hardware_reset(CanSJA1000State *s)
65 {
66     /* Reset by hardware, p10 */
67     s->mode        = 0x01;
68     s->status_pel  = 0x3c;
69     s->interrupt_pel = 0x00;
70     s->clock       = 0x00;
71     s->rxbuf_start = 0x00;
72     s->rxmsg_cnt   = 0x00;
73     s->rx_cnt      = 0x00;
74 
75     s->control     = 0x01;
76     s->status_bas  = 0x0c;
77     s->interrupt_bas = 0x00;
78 
79     qemu_irq_lower(s->irq);
80 }
81 
82 static
83 void can_sja_single_filter(struct qemu_can_filter *filter,
84             const uint8_t *acr,  const uint8_t *amr, int extended)
85 {
86     if (extended) {
87         filter->can_id = (uint32_t)acr[0] << 21;
88         filter->can_id |= (uint32_t)acr[1] << 13;
89         filter->can_id |= (uint32_t)acr[2] << 5;
90         filter->can_id |= (uint32_t)acr[3] >> 3;
91         if (acr[3] & 4) {
92             filter->can_id |= QEMU_CAN_RTR_FLAG;
93         }
94 
95         filter->can_mask = (uint32_t)amr[0] << 21;
96         filter->can_mask |= (uint32_t)amr[1] << 13;
97         filter->can_mask |= (uint32_t)amr[2] << 5;
98         filter->can_mask |= (uint32_t)amr[3] >> 3;
99         filter->can_mask = ~filter->can_mask & QEMU_CAN_EFF_MASK;
100         if (!(amr[3] & 4)) {
101             filter->can_mask |= QEMU_CAN_RTR_FLAG;
102         }
103     } else {
104         filter->can_id = (uint32_t)acr[0] << 3;
105         filter->can_id |= (uint32_t)acr[1] >> 5;
106         if (acr[1] & 0x10) {
107             filter->can_id |= QEMU_CAN_RTR_FLAG;
108         }
109 
110         filter->can_mask = (uint32_t)amr[0] << 3;
111         filter->can_mask |= (uint32_t)amr[1] << 5;
112         filter->can_mask = ~filter->can_mask & QEMU_CAN_SFF_MASK;
113         if (!(amr[1] & 0x10)) {
114             filter->can_mask |= QEMU_CAN_RTR_FLAG;
115         }
116     }
117 }
118 
119 static
120 void can_sja_dual_filter(struct qemu_can_filter *filter,
121             const uint8_t *acr,  const uint8_t *amr, int extended)
122 {
123     if (extended) {
124         filter->can_id = (uint32_t)acr[0] << 21;
125         filter->can_id |= (uint32_t)acr[1] << 13;
126 
127         filter->can_mask = (uint32_t)amr[0] << 21;
128         filter->can_mask |= (uint32_t)amr[1] << 13;
129         filter->can_mask = ~filter->can_mask & QEMU_CAN_EFF_MASK & ~0x1fff;
130     } else {
131         filter->can_id = (uint32_t)acr[0] << 3;
132         filter->can_id |= (uint32_t)acr[1] >> 5;
133         if (acr[1] & 0x10) {
134             filter->can_id |= QEMU_CAN_RTR_FLAG;
135         }
136 
137         filter->can_mask = (uint32_t)amr[0] << 3;
138         filter->can_mask |= (uint32_t)amr[1] >> 5;
139         filter->can_mask = ~filter->can_mask & QEMU_CAN_SFF_MASK;
140         if (!(amr[1] & 0x10)) {
141             filter->can_mask |= QEMU_CAN_RTR_FLAG;
142         }
143     }
144 }
145 
146 /* Details in DS-p22, what we need to do here is to test the data. */
147 static
148 int can_sja_accept_filter(CanSJA1000State *s,
149                                  const qemu_can_frame *frame)
150 {
151 
152     struct qemu_can_filter filter;
153 
154     if (s->clock & 0x80) { /* PeliCAN Mode */
155         if (s->mode & (1 << 3)) { /* Single mode. */
156             if (frame->can_id & QEMU_CAN_EFF_FLAG) { /* EFF */
157                 can_sja_single_filter(&filter,
158                     s->code_mask + 0, s->code_mask + 4, 1);
159 
160                 if (!can_bus_filter_match(&filter, frame->can_id)) {
161                     return 0;
162                 }
163             } else { /* SFF */
164                 can_sja_single_filter(&filter,
165                     s->code_mask + 0, s->code_mask + 4, 0);
166 
167                 if (!can_bus_filter_match(&filter, frame->can_id)) {
168                     return 0;
169                 }
170 
171                 if (frame->can_id & QEMU_CAN_RTR_FLAG) { /* RTR */
172                     return 1;
173                 }
174 
175                 if (frame->can_dlc == 0) {
176                     return 1;
177                 }
178 
179                 if ((frame->data[0] & ~(s->code_mask[6])) !=
180                    (s->code_mask[2] & ~(s->code_mask[6]))) {
181                     return 0;
182                 }
183 
184                 if (frame->can_dlc < 2) {
185                     return 1;
186                 }
187 
188                 if ((frame->data[1] & ~(s->code_mask[7])) ==
189                     (s->code_mask[3] & ~(s->code_mask[7]))) {
190                     return 1;
191                 }
192 
193                 return 0;
194             }
195         } else { /* Dual mode */
196             if (frame->can_id & QEMU_CAN_EFF_FLAG) { /* EFF */
197                 can_sja_dual_filter(&filter,
198                     s->code_mask + 0, s->code_mask + 4, 1);
199 
200                 if (can_bus_filter_match(&filter, frame->can_id)) {
201                     return 1;
202                 }
203 
204                 can_sja_dual_filter(&filter,
205                     s->code_mask + 2, s->code_mask + 6, 1);
206 
207                 if (can_bus_filter_match(&filter, frame->can_id)) {
208                     return 1;
209                 }
210 
211                 return 0;
212             } else {
213                 can_sja_dual_filter(&filter,
214                     s->code_mask + 0, s->code_mask + 4, 0);
215 
216                 if (can_bus_filter_match(&filter, frame->can_id)) {
217                     uint8_t expect;
218                     uint8_t mask;
219                     expect = s->code_mask[1] << 4;
220                     expect |= s->code_mask[3] & 0x0f;
221 
222                     mask = s->code_mask[5] << 4;
223                     mask |= s->code_mask[7] & 0x0f;
224                         mask = ~mask & 0xff;
225 
226                     if ((frame->data[0] & mask) ==
227                         (expect & mask)) {
228                         return 1;
229                     }
230                 }
231 
232                 can_sja_dual_filter(&filter,
233                     s->code_mask + 2, s->code_mask + 6, 0);
234 
235                 if (can_bus_filter_match(&filter, frame->can_id)) {
236                     return 1;
237                 }
238 
239                 return 0;
240             }
241         }
242     }
243 
244     return 1;
245 }
246 
247 static void can_display_msg(const char *prefix, const qemu_can_frame *msg)
248 {
249     int i;
250     FILE *logfile = qemu_log_trylock();
251 
252     if (logfile) {
253         fprintf(logfile, "%s%03X [%01d] %s %s",
254                 prefix,
255                 msg->can_id & QEMU_CAN_EFF_MASK,
256                 msg->can_dlc,
257                 msg->can_id & QEMU_CAN_EFF_FLAG ? "EFF" : "SFF",
258                 msg->can_id & QEMU_CAN_RTR_FLAG ? "RTR" : "DAT");
259 
260         for (i = 0; i < msg->can_dlc; i++) {
261             fprintf(logfile, " %02X", msg->data[i]);
262         }
263         fprintf(logfile, "\n");
264         qemu_log_unlock(logfile);
265     }
266 }
267 
268 static void buff2frame_pel(const uint8_t *buff, qemu_can_frame *frame)
269 {
270     uint8_t i;
271 
272     frame->flags = 0;
273     frame->can_id = 0;
274     if (buff[0] & 0x40) { /* RTR */
275         frame->can_id = QEMU_CAN_RTR_FLAG;
276     }
277     frame->can_dlc = buff[0] & 0x0f;
278 
279     if (frame->can_dlc > 8) {
280         frame->can_dlc = 8;
281     }
282 
283     if (buff[0] & 0x80) { /* Extended */
284         frame->can_id |= QEMU_CAN_EFF_FLAG;
285         frame->can_id |= buff[1] << 21; /* ID.28~ID.21 */
286         frame->can_id |= buff[2] << 13; /* ID.20~ID.13 */
287         frame->can_id |= buff[3] <<  5;
288         frame->can_id |= buff[4] >>  3;
289         for (i = 0; i < frame->can_dlc; i++) {
290             frame->data[i] = buff[5 + i];
291         }
292         for (; i < 8; i++) {
293             frame->data[i] = 0;
294         }
295     } else {
296         frame->can_id |= buff[1] <<  3;
297         frame->can_id |= buff[2] >>  5;
298         for (i = 0; i < frame->can_dlc; i++) {
299             frame->data[i] = buff[3 + i];
300         }
301         for (; i < 8; i++) {
302             frame->data[i] = 0;
303         }
304     }
305 }
306 
307 
308 static void buff2frame_bas(const uint8_t *buff, qemu_can_frame *frame)
309 {
310     uint8_t i;
311 
312     frame->flags = 0;
313     frame->can_id = ((buff[0] << 3) & (0xff << 3)) + ((buff[1] >> 5) & 0x07);
314     if (buff[1] & 0x10) { /* RTR */
315         frame->can_id = QEMU_CAN_RTR_FLAG;
316     }
317     frame->can_dlc = buff[1] & 0x0f;
318 
319     if (frame->can_dlc > 8) {
320         frame->can_dlc = 8;
321     }
322 
323     for (i = 0; i < frame->can_dlc; i++) {
324         frame->data[i] = buff[2 + i];
325     }
326     for (; i < 8; i++) {
327         frame->data[i] = 0;
328     }
329 }
330 
331 
332 static int frame2buff_pel(const qemu_can_frame *frame, uint8_t *buff)
333 {
334     int i;
335     int dlen = frame->can_dlc;
336 
337     if (frame->can_id & QEMU_CAN_ERR_FLAG) { /* error frame, NOT support now. */
338         return -1;
339     }
340 
341     if (dlen > 8) {
342         return -1;
343     }
344 
345     buff[0] = 0x0f & frame->can_dlc; /* DLC */
346     if (frame->can_id & QEMU_CAN_RTR_FLAG) { /* RTR */
347         buff[0] |= (1 << 6);
348     }
349     if (frame->can_id & QEMU_CAN_EFF_FLAG) { /* EFF */
350         buff[0] |= (1 << 7);
351         buff[1] = extract32(frame->can_id, 21, 8); /* ID.28~ID.21 */
352         buff[2] = extract32(frame->can_id, 13, 8); /* ID.20~ID.13 */
353         buff[3] = extract32(frame->can_id, 5, 8);  /* ID.12~ID.05 */
354         buff[4] = extract32(frame->can_id, 0, 5) << 3; /* ID.04~ID.00,xxx */
355         for (i = 0; i < dlen; i++) {
356             buff[5 + i] = frame->data[i];
357         }
358         return dlen + 5;
359     } else { /* SFF */
360         buff[1] = extract32(frame->can_id, 3, 8); /* ID.10~ID.03 */
361         buff[2] = extract32(frame->can_id, 0, 3) << 5; /* ID.02~ID.00,xxxxx */
362         for (i = 0; i < dlen; i++) {
363             buff[3 + i] = frame->data[i];
364         }
365 
366         return dlen + 3;
367     }
368 
369     return -1;
370 }
371 
372 static int frame2buff_bas(const qemu_can_frame *frame, uint8_t *buff)
373 {
374     int i;
375     int dlen = frame->can_dlc;
376 
377      /*
378       * EFF, no support for BasicMode
379       * No use for Error frames now,
380       * they could be used in future to update SJA1000 error state
381       */
382     if ((frame->can_id & QEMU_CAN_EFF_FLAG) ||
383        (frame->can_id & QEMU_CAN_ERR_FLAG)) {
384         return -1;
385     }
386 
387     if (dlen > 8) {
388         return -1;
389     }
390 
391     buff[0] = extract32(frame->can_id, 3, 8); /* ID.10~ID.03 */
392     buff[1] = extract32(frame->can_id, 0, 3) << 5; /* ID.02~ID.00,xxxxx */
393     if (frame->can_id & QEMU_CAN_RTR_FLAG) { /* RTR */
394         buff[1] |= (1 << 4);
395     }
396     buff[1] |= frame->can_dlc & 0x0f;
397     for (i = 0; i < dlen; i++) {
398         buff[2 + i] = frame->data[i];
399     }
400 
401     return dlen + 2;
402 }
403 
404 static void can_sja_update_pel_irq(CanSJA1000State *s)
405 {
406     if (s->interrupt_en & s->interrupt_pel) {
407         qemu_irq_raise(s->irq);
408     } else {
409         qemu_irq_lower(s->irq);
410     }
411 }
412 
413 static void can_sja_update_bas_irq(CanSJA1000State *s)
414 {
415     if ((s->control >> 1) & s->interrupt_bas) {
416         qemu_irq_raise(s->irq);
417     } else {
418         qemu_irq_lower(s->irq);
419     }
420 }
421 
422 void can_sja_mem_write(CanSJA1000State *s, hwaddr addr, uint64_t val,
423                        unsigned size)
424 {
425     qemu_can_frame   frame;
426     uint32_t         tmp;
427     uint8_t          tmp8, count;
428 
429 
430     DPRINTF("write 0x%02llx addr 0x%02x\n",
431             (unsigned long long)val, (unsigned int)addr);
432 
433     if (addr > CAN_SJA_MEM_SIZE) {
434         return;
435     }
436 
437     if (s->clock & 0x80) { /* PeliCAN Mode */
438         switch (addr) {
439         case SJA_MOD: /* Mode register */
440             s->mode = 0x1f & val;
441             if ((s->mode & 0x01) && ((val & 0x01) == 0)) {
442                 /* Go to operation mode from reset mode. */
443                 if (s->mode & (1 << 3)) { /* Single mode. */
444                     /* For EFF */
445                     can_sja_single_filter(&s->filter[0],
446                         s->code_mask + 0, s->code_mask + 4, 1);
447 
448                     /* For SFF */
449                     can_sja_single_filter(&s->filter[1],
450                         s->code_mask + 0, s->code_mask + 4, 0);
451 
452                     can_bus_client_set_filters(&s->bus_client, s->filter, 2);
453                 } else { /* Dual mode */
454                     /* For EFF */
455                     can_sja_dual_filter(&s->filter[0],
456                         s->code_mask + 0, s->code_mask + 4, 1);
457 
458                     can_sja_dual_filter(&s->filter[1],
459                         s->code_mask + 2, s->code_mask + 6, 1);
460 
461                     /* For SFF */
462                     can_sja_dual_filter(&s->filter[2],
463                         s->code_mask + 0, s->code_mask + 4, 0);
464 
465                     can_sja_dual_filter(&s->filter[3],
466                         s->code_mask + 2, s->code_mask + 6, 0);
467 
468                     can_bus_client_set_filters(&s->bus_client, s->filter, 4);
469                 }
470 
471                 s->rxmsg_cnt = 0;
472                 s->rx_cnt = 0;
473             }
474             break;
475 
476         case SJA_CMR: /* Command register. */
477             if (0x01 & val) { /* Send transmission request. */
478                 buff2frame_pel(s->tx_buff, &frame);
479                 if (DEBUG_FILTER) {
480                     can_display_msg("[cansja]: Tx request " , &frame);
481                 }
482 
483                 /*
484                  * Clear transmission complete status,
485                  * and Transmit Buffer Status.
486                  * write to the backends.
487                  */
488                 s->status_pel &= ~(3 << 2);
489 
490                 can_bus_client_send(&s->bus_client, &frame, 1);
491 
492                 /*
493                  * Set transmission complete status
494                  * and Transmit Buffer Status.
495                  */
496                 s->status_pel |= (3 << 2);
497 
498                 /* Clear transmit status. */
499                 s->status_pel &= ~(1 << 5);
500                 s->interrupt_pel |= 0x02;
501                 can_sja_update_pel_irq(s);
502             }
503             if (0x04 & val) { /* Release Receive Buffer */
504                 if (s->rxmsg_cnt <= 0) {
505                     break;
506                 }
507 
508                 tmp8 = s->rx_buff[s->rxbuf_start]; count = 0;
509                 if (tmp8 & (1 << 7)) { /* EFF */
510                     count += 2;
511                 }
512                 count += 3;
513                 if (!(tmp8 & (1 << 6))) { /* DATA */
514                     count += (tmp8 & 0x0f);
515                 }
516 
517                 if (DEBUG_FILTER) {
518                     qemu_log("[cansja]: message released from "
519                              "Rx FIFO cnt=%d, count=%d\n", s->rx_cnt, count);
520                 }
521 
522                 s->rxbuf_start += count;
523                 s->rxbuf_start %= SJA_RCV_BUF_LEN;
524 
525                 s->rx_cnt -= count;
526                 s->rxmsg_cnt--;
527                 if (s->rxmsg_cnt == 0) {
528                     s->status_pel &= ~(1 << 0);
529                     s->interrupt_pel &= ~(1 << 0);
530                     can_sja_update_pel_irq(s);
531                 }
532             }
533             if (0x08 & val) { /* Clear data overrun */
534                 s->status_pel &= ~(1 << 1);
535                 s->interrupt_pel &= ~(1 << 3);
536                 can_sja_update_pel_irq(s);
537             }
538             break;
539         case SJA_SR: /* Status register */
540         case SJA_IR: /* Interrupt register */
541             break; /* Do nothing */
542         case SJA_IER: /* Interrupt enable register */
543             s->interrupt_en = val;
544             break;
545         case 16: /* RX frame information addr16-28. */
546             s->status_pel |= (1 << 5); /* Set transmit status. */
547             /* fallthrough */
548         case 17 ... 28:
549             if (s->mode & 0x01) { /* Reset mode */
550                 if (addr < 24) {
551                     s->code_mask[addr - 16] = val;
552                 }
553             } else { /* Operation mode */
554                 s->tx_buff[addr - 16] = val; /* Store to TX buffer directly. */
555             }
556             break;
557         case SJA_CDR:
558             s->clock = val;
559             break;
560         }
561     } else { /* Basic Mode */
562         switch (addr) {
563         case SJA_BCAN_CTR: /* Control register, addr 0 */
564             if ((s->control & 0x01) && ((val & 0x01) == 0)) {
565                 /* Go to operation mode from reset mode. */
566                 s->filter[0].can_id = (s->code << 3) & (0xff << 3);
567                 tmp = (~(s->mask << 3)) & (0xff << 3);
568                 tmp |= QEMU_CAN_EFF_FLAG; /* Only Basic CAN Frame. */
569                 s->filter[0].can_mask = tmp;
570                 can_bus_client_set_filters(&s->bus_client, s->filter, 1);
571 
572                 s->rxmsg_cnt = 0;
573                 s->rx_cnt = 0;
574             } else if (!(s->control & 0x01) && !(val & 0x01)) {
575                 can_sja_software_reset(s);
576             }
577 
578             s->control = 0x1f & val;
579             break;
580         case SJA_BCAN_CMR: /* Command register, addr 1 */
581             if (0x01 & val) { /* Send transmission request. */
582                 buff2frame_bas(s->tx_buff, &frame);
583                 if (DEBUG_FILTER) {
584                     can_display_msg("[cansja]: Tx request " , &frame);
585                 }
586 
587                 /*
588                  * Clear transmission complete status,
589                  * and Transmit Buffer Status.
590                  */
591                 s->status_bas &= ~(3 << 2);
592 
593                 /* write to the backends. */
594                 can_bus_client_send(&s->bus_client, &frame, 1);
595 
596                 /*
597                  * Set transmission complete status,
598                  * and Transmit Buffer Status.
599                  */
600                 s->status_bas |= (3 << 2);
601 
602                 /* Clear transmit status. */
603                 s->status_bas &= ~(1 << 5);
604                 s->interrupt_bas |= 0x02;
605                 can_sja_update_bas_irq(s);
606             }
607             if (0x04 & val) { /* Release Receive Buffer */
608                 if (s->rxmsg_cnt <= 0) {
609                     break;
610                 }
611 
612                 tmp8 = s->rx_buff[(s->rxbuf_start + 1) % SJA_RCV_BUF_LEN];
613                 count = 2 + (tmp8 & 0x0f);
614 
615                 if (DEBUG_FILTER) {
616                     qemu_log("[cansja]: message released from "
617                              "Rx FIFO cnt=%d, count=%d\n", s->rx_cnt, count);
618                 }
619 
620                 s->rxbuf_start += count;
621                 s->rxbuf_start %= SJA_RCV_BUF_LEN;
622                 s->rx_cnt -= count;
623                 s->rxmsg_cnt--;
624 
625                 if (s->rxmsg_cnt == 0) {
626                     s->status_bas &= ~(1 << 0);
627                     s->interrupt_bas &= ~(1 << 0);
628                     can_sja_update_bas_irq(s);
629                 }
630             }
631             if (0x08 & val) { /* Clear data overrun */
632                 s->status_bas &= ~(1 << 1);
633                 s->interrupt_bas &= ~(1 << 3);
634                 can_sja_update_bas_irq(s);
635             }
636             break;
637         case 4:
638             s->code = val;
639             break;
640         case 5:
641             s->mask = val;
642             break;
643         case 10:
644             s->status_bas |= (1 << 5); /* Set transmit status. */
645             /* fallthrough */
646         case 11 ... 19:
647             if ((s->control & 0x01) == 0) { /* Operation mode */
648                 s->tx_buff[addr - 10] = val; /* Store to TX buffer directly. */
649             }
650             break;
651         case SJA_CDR:
652             s->clock = val;
653             break;
654         }
655     }
656 }
657 
658 uint64_t can_sja_mem_read(CanSJA1000State *s, hwaddr addr, unsigned size)
659 {
660     uint64_t temp = 0;
661 
662     DPRINTF("read addr 0x%02x ...\n", (unsigned int)addr);
663 
664     if (addr > CAN_SJA_MEM_SIZE) {
665         return 0;
666     }
667 
668     if (s->clock & 0x80) { /* PeliCAN Mode */
669         switch (addr) {
670         case SJA_MOD: /* Mode register, addr 0 */
671             temp = s->mode;
672             break;
673         case SJA_CMR: /* Command register, addr 1 */
674             temp = 0x00; /* Command register, cannot be read. */
675             break;
676         case SJA_SR: /* Status register, addr 2 */
677             temp = s->status_pel;
678             break;
679         case SJA_IR: /* Interrupt register, addr 3 */
680             temp = s->interrupt_pel;
681             s->interrupt_pel = 0;
682             if (s->rxmsg_cnt) {
683                 s->interrupt_pel |= (1 << 0); /* Receive interrupt. */
684             }
685             can_sja_update_pel_irq(s);
686             break;
687         case SJA_IER: /* Interrupt enable register, addr 4 */
688             temp = s->interrupt_en;
689             break;
690         case 5: /* Reserved */
691         case 6: /* Bus timing 0, hardware related, not support now. */
692         case 7: /* Bus timing 1, hardware related, not support now. */
693         case 8: /*
694                  * Output control register, hardware related,
695                  * not supported for now.
696                  */
697         case 9: /* Test. */
698         case 10 ... 15: /* Reserved */
699             temp = 0x00;
700             break;
701 
702         case 16 ... 28:
703             if (s->mode & 0x01) { /* Reset mode */
704                 if (addr < 24) {
705                     temp = s->code_mask[addr - 16];
706                 } else {
707                     temp = 0x00;
708                 }
709             } else { /* Operation mode */
710                 temp = s->rx_buff[(s->rxbuf_start + addr - 16) %
711                        SJA_RCV_BUF_LEN];
712             }
713             break;
714         case SJA_CDR:
715             temp = s->clock;
716             break;
717         default:
718             temp = 0xff;
719         }
720     } else { /* Basic Mode */
721         switch (addr) {
722         case SJA_BCAN_CTR: /* Control register, addr 0 */
723             temp = s->control;
724             break;
725         case SJA_BCAN_SR: /* Status register, addr 2 */
726             temp = s->status_bas;
727             break;
728         case SJA_BCAN_IR: /* Interrupt register, addr 3 */
729             temp = s->interrupt_bas;
730             s->interrupt_bas = 0;
731             if (s->rxmsg_cnt) {
732                 s->interrupt_bas |= (1 << 0); /* Receive interrupt. */
733             }
734             can_sja_update_bas_irq(s);
735             break;
736         case 4:
737             temp = s->code;
738             break;
739         case 5:
740             temp = s->mask;
741             break;
742         case 20 ... 29:
743             temp = s->rx_buff[(s->rxbuf_start + addr - 20) % SJA_RCV_BUF_LEN];
744             break;
745         case 31:
746             temp = s->clock;
747             break;
748         default:
749             temp = 0xff;
750             break;
751         }
752     }
753     DPRINTF("read addr 0x%02x, %d bytes, content 0x%02lx\n",
754             (int)addr, size, (long unsigned int)temp);
755 
756     return temp;
757 }
758 
759 bool can_sja_can_receive(CanBusClientState *client)
760 {
761     CanSJA1000State *s = container_of(client, CanSJA1000State, bus_client);
762 
763     if (s->clock & 0x80) { /* PeliCAN Mode */
764         if (s->mode & 0x01) { /* reset mode. */
765             return false;
766         }
767     } else { /* BasicCAN mode */
768         if (s->control & 0x01) {
769             return false;
770         }
771     }
772 
773     return true; /* always return true, when operation mode */
774 }
775 
776 ssize_t can_sja_receive(CanBusClientState *client, const qemu_can_frame *frames,
777                         size_t frames_cnt)
778 {
779     CanSJA1000State *s = container_of(client, CanSJA1000State, bus_client);
780     static uint8_t rcv[SJA_MSG_MAX_LEN];
781     int i;
782     int ret = -1;
783     const qemu_can_frame *frame = frames;
784 
785     if (frames_cnt <= 0) {
786         return 0;
787     }
788     if (frame->flags & QEMU_CAN_FRMF_TYPE_FD) {
789         if (DEBUG_FILTER) {
790             can_display_msg("[cansja]: ignor fd frame ", frame);
791         }
792         return 1;
793     }
794 
795     if (DEBUG_FILTER) {
796         can_display_msg("[cansja]: receive ", frame);
797     }
798 
799     if (s->clock & 0x80) { /* PeliCAN Mode */
800 
801         /* the CAN controller is receiving a message */
802         s->status_pel |= (1 << 4);
803 
804         if (can_sja_accept_filter(s, frame) == 0) {
805             s->status_pel &= ~(1 << 4);
806             if (DEBUG_FILTER) {
807                 qemu_log("[cansja]: filter rejects message\n");
808             }
809             return ret;
810         }
811 
812         ret = frame2buff_pel(frame, rcv);
813         if (ret < 0) {
814             s->status_pel &= ~(1 << 4);
815             if (DEBUG_FILTER) {
816                 qemu_log("[cansja]: message store failed\n");
817             }
818             return ret; /* maybe not support now. */
819         }
820 
821         if (s->rx_cnt + ret > SJA_RCV_BUF_LEN) { /* Data overrun. */
822             s->status_pel |= (1 << 1); /* Overrun status */
823             s->interrupt_pel |= (1 << 3);
824             s->status_pel &= ~(1 << 4);
825             if (DEBUG_FILTER) {
826                 qemu_log("[cansja]: receive FIFO overrun\n");
827             }
828             can_sja_update_pel_irq(s);
829             return ret;
830         }
831         s->rx_cnt += ret;
832         s->rxmsg_cnt++;
833         if (DEBUG_FILTER) {
834             qemu_log("[cansja]: message stored in receive FIFO\n");
835         }
836 
837         for (i = 0; i < ret; i++) {
838             s->rx_buff[(s->rx_ptr++) % SJA_RCV_BUF_LEN] = rcv[i];
839         }
840         s->rx_ptr %= SJA_RCV_BUF_LEN; /* update the pointer. */
841 
842         s->status_pel |= 0x01; /* Set the Receive Buffer Status. DS-p23 */
843         s->interrupt_pel |= 0x01;
844         s->status_pel &= ~(1 << 4);
845         s->status_pel |= (1 << 0);
846         can_sja_update_pel_irq(s);
847     } else { /* BasicCAN mode */
848 
849         /* the CAN controller is receiving a message */
850         s->status_bas |= (1 << 4);
851 
852         ret = frame2buff_bas(frame, rcv);
853         if (ret < 0) {
854             s->status_bas &= ~(1 << 4);
855             if (DEBUG_FILTER) {
856                 qemu_log("[cansja]: message store failed\n");
857             }
858             return ret; /* maybe not support now. */
859         }
860 
861         if (s->rx_cnt + ret > SJA_RCV_BUF_LEN) { /* Data overrun. */
862             s->status_bas |= (1 << 1); /* Overrun status */
863             s->status_bas &= ~(1 << 4);
864             s->interrupt_bas |= (1 << 3);
865             can_sja_update_bas_irq(s);
866             if (DEBUG_FILTER) {
867                 qemu_log("[cansja]: receive FIFO overrun\n");
868             }
869             return ret;
870         }
871         s->rx_cnt += ret;
872         s->rxmsg_cnt++;
873 
874         if (DEBUG_FILTER) {
875             qemu_log("[cansja]: message stored\n");
876         }
877 
878         for (i = 0; i < ret; i++) {
879             s->rx_buff[(s->rx_ptr++) % SJA_RCV_BUF_LEN] = rcv[i];
880         }
881         s->rx_ptr %= SJA_RCV_BUF_LEN; /* update the pointer. */
882 
883         s->status_bas |= 0x01; /* Set the Receive Buffer Status. DS-p15 */
884         s->status_bas &= ~(1 << 4);
885         s->interrupt_bas |= (1 << 0);
886         can_sja_update_bas_irq(s);
887     }
888     return 1;
889 }
890 
891 static CanBusClientInfo can_sja_bus_client_info = {
892     .can_receive = can_sja_can_receive,
893     .receive = can_sja_receive,
894 };
895 
896 
897 int can_sja_connect_to_bus(CanSJA1000State *s, CanBusState *bus)
898 {
899     s->bus_client.info = &can_sja_bus_client_info;
900 
901     if (!bus) {
902         return -EINVAL;
903     }
904 
905     if (can_bus_insert_client(bus, &s->bus_client) < 0) {
906         return -1;
907     }
908 
909     return 0;
910 }
911 
912 void can_sja_disconnect(CanSJA1000State *s)
913 {
914     can_bus_remove_client(&s->bus_client);
915 }
916 
917 int can_sja_init(CanSJA1000State *s, qemu_irq irq)
918 {
919     s->irq = irq;
920 
921     qemu_irq_lower(s->irq);
922 
923     can_sja_hardware_reset(s);
924 
925     return 0;
926 }
927 
928 const VMStateDescription vmstate_qemu_can_filter = {
929     .name = "qemu_can_filter",
930     .version_id = 1,
931     .minimum_version_id = 1,
932     .fields = (VMStateField[]) {
933         VMSTATE_UINT32(can_id, qemu_can_filter),
934         VMSTATE_UINT32(can_mask, qemu_can_filter),
935         VMSTATE_END_OF_LIST()
936     }
937 };
938 
939 static int can_sja_post_load(void *opaque, int version_id)
940 {
941     CanSJA1000State *s = opaque;
942     if (s->clock & 0x80) { /* PeliCAN Mode */
943         can_sja_update_pel_irq(s);
944     } else {
945         can_sja_update_bas_irq(s);
946     }
947     return 0;
948 }
949 
950 /* VMState is needed for live migration of QEMU images */
951 const VMStateDescription vmstate_can_sja = {
952     .name = "can_sja",
953     .version_id = 1,
954     .minimum_version_id = 1,
955     .post_load = can_sja_post_load,
956     .fields = (VMStateField[]) {
957         VMSTATE_UINT8(mode, CanSJA1000State),
958 
959         VMSTATE_UINT8(status_pel, CanSJA1000State),
960         VMSTATE_UINT8(interrupt_pel, CanSJA1000State),
961         VMSTATE_UINT8(interrupt_en, CanSJA1000State),
962         VMSTATE_UINT8(rxmsg_cnt, CanSJA1000State),
963         VMSTATE_UINT8(rxbuf_start, CanSJA1000State),
964         VMSTATE_UINT8(clock, CanSJA1000State),
965 
966         VMSTATE_BUFFER(code_mask, CanSJA1000State),
967         VMSTATE_BUFFER(tx_buff, CanSJA1000State),
968 
969         VMSTATE_BUFFER(rx_buff, CanSJA1000State),
970 
971         VMSTATE_UINT32(rx_ptr, CanSJA1000State),
972         VMSTATE_UINT32(rx_cnt, CanSJA1000State),
973 
974         VMSTATE_UINT8(control, CanSJA1000State),
975 
976         VMSTATE_UINT8(status_bas, CanSJA1000State),
977         VMSTATE_UINT8(interrupt_bas, CanSJA1000State),
978         VMSTATE_UINT8(code, CanSJA1000State),
979         VMSTATE_UINT8(mask, CanSJA1000State),
980 
981         VMSTATE_STRUCT_ARRAY(filter, CanSJA1000State, 4, 0,
982                              vmstate_qemu_can_filter, qemu_can_filter),
983 
984 
985         VMSTATE_END_OF_LIST()
986     }
987 };
988