1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * CAN driver for PEAK System PCAN-USB adapter
4 * Derived from the PCAN project file driver/src/pcan_usb.c
5 *
6 * Copyright (C) 2003-2010 PEAK System-Technik GmbH
7 * Copyright (C) 2011-2012 Stephane Grosjean <s.grosjean@peak-system.com>
8 *
9 * Many thanks to Klaus Hitschler <klaus.hitschler@gmx.de>
10 */
11#include <linux/unaligned.h>
12
13#include <linux/ethtool.h>
14#include <linux/module.h>
15#include <linux/netdevice.h>
16#include <linux/usb.h>
17
18#include <linux/can.h>
19#include <linux/can/dev.h>
20#include <linux/can/error.h>
21
22#include "pcan_usb_core.h"
23
24/* PCAN-USB Endpoints */
25#define PCAN_USB_EP_CMDOUT 1
26#define PCAN_USB_EP_CMDIN (PCAN_USB_EP_CMDOUT | USB_DIR_IN)
27#define PCAN_USB_EP_MSGOUT 2
28#define PCAN_USB_EP_MSGIN (PCAN_USB_EP_MSGOUT | USB_DIR_IN)
29
30/* PCAN-USB command struct */
31#define PCAN_USB_CMD_FUNC 0
32#define PCAN_USB_CMD_NUM 1
33#define PCAN_USB_CMD_ARGS 2
34#define PCAN_USB_CMD_ARGS_LEN 14
35#define PCAN_USB_CMD_LEN (PCAN_USB_CMD_ARGS + \
36 PCAN_USB_CMD_ARGS_LEN)
37
38/* PCAN-USB commands */
39#define PCAN_USB_CMD_BITRATE 1
40#define PCAN_USB_CMD_SET_BUS 3
41#define PCAN_USB_CMD_DEVID 4
42#define PCAN_USB_CMD_SN 6
43#define PCAN_USB_CMD_REGISTER 9
44#define PCAN_USB_CMD_EXT_VCC 10
45#define PCAN_USB_CMD_ERR_FR 11
46#define PCAN_USB_CMD_LED 12
47
48/* PCAN_USB_CMD_SET_BUS number arg */
49#define PCAN_USB_BUS_XCVER 2
50#define PCAN_USB_BUS_SILENT_MODE 3
51
52/* PCAN_USB_CMD_xxx functions */
53#define PCAN_USB_GET 1
54#define PCAN_USB_SET 2
55
56/* PCAN-USB command timeout (ms.) */
57#define PCAN_USB_COMMAND_TIMEOUT 1000
58
59/* PCAN-USB startup timeout (ms.) */
60#define PCAN_USB_STARTUP_TIMEOUT 10
61
62/* PCAN-USB rx/tx buffers size */
63#define PCAN_USB_RX_BUFFER_SIZE 64
64#define PCAN_USB_TX_BUFFER_SIZE 64
65
66#define PCAN_USB_MSG_HEADER_LEN 2
67
68#define PCAN_USB_MSG_TX_CAN 2 /* Tx msg is a CAN frame */
69
70/* PCAN-USB adapter internal clock (MHz) */
71#define PCAN_USB_CRYSTAL_HZ 16000000
72
73/* PCAN-USB USB message record status/len field */
74#define PCAN_USB_STATUSLEN_TIMESTAMP (1 << 7)
75#define PCAN_USB_STATUSLEN_INTERNAL (1 << 6)
76#define PCAN_USB_STATUSLEN_EXT_ID (1 << 5)
77#define PCAN_USB_STATUSLEN_RTR (1 << 4)
78#define PCAN_USB_STATUSLEN_DLC (0xf)
79
80/* PCAN-USB 4.1 CAN Id tx extended flags */
81#define PCAN_USB_TX_SRR 0x01 /* SJA1000 SRR command */
82#define PCAN_USB_TX_AT 0x02 /* SJA1000 AT command */
83
84/* PCAN-USB error flags */
85#define PCAN_USB_ERROR_TXFULL 0x01
86#define PCAN_USB_ERROR_RXQOVR 0x02
87#define PCAN_USB_ERROR_BUS_LIGHT 0x04
88#define PCAN_USB_ERROR_BUS_HEAVY 0x08
89#define PCAN_USB_ERROR_BUS_OFF 0x10
90#define PCAN_USB_ERROR_RXQEMPTY 0x20
91#define PCAN_USB_ERROR_QOVR 0x40
92#define PCAN_USB_ERROR_TXQFULL 0x80
93
94#define PCAN_USB_ERROR_BUS (PCAN_USB_ERROR_BUS_LIGHT | \
95 PCAN_USB_ERROR_BUS_HEAVY | \
96 PCAN_USB_ERROR_BUS_OFF)
97
98/* SJA1000 modes */
99#define SJA1000_MODE_NORMAL 0x00
100#define SJA1000_MODE_INIT 0x01
101
102/*
103 * tick duration = 42.666 us =>
104 * (tick_number * 44739243) >> 20 ~ (tick_number * 42666) / 1000
105 * accuracy = 10^-7
106 */
107#define PCAN_USB_TS_DIV_SHIFTER 20
108#define PCAN_USB_TS_US_PER_TICK 44739243
109
110/* PCAN-USB messages record types */
111#define PCAN_USB_REC_ERROR 1
112#define PCAN_USB_REC_ANALOG 2
113#define PCAN_USB_REC_BUSLOAD 3
114#define PCAN_USB_REC_TS 4
115#define PCAN_USB_REC_BUSEVT 5
116
117/* CAN bus events notifications selection mask */
118#define PCAN_USB_ERR_RXERR 0x02 /* ask for rxerr counter */
119#define PCAN_USB_ERR_TXERR 0x04 /* ask for txerr counter */
120
121/* This mask generates an usb packet each time the state of the bus changes.
122 * In other words, its interest is to know which side among rx and tx is
123 * responsible of the change of the bus state.
124 */
125#define PCAN_USB_BERR_MASK (PCAN_USB_ERR_RXERR | PCAN_USB_ERR_TXERR)
126
127/* identify bus event packets with rx/tx error counters */
128#define PCAN_USB_ERR_CNT_DEC 0x00 /* counters are decreasing */
129#define PCAN_USB_ERR_CNT_INC 0x80 /* counters are increasing */
130
131/* private to PCAN-USB adapter */
132struct pcan_usb {
133 struct peak_usb_device dev;
134 struct peak_time_ref time_ref;
135 struct timer_list restart_timer;
136 struct can_berr_counter bec;
137};
138
139/* incoming message context for decoding */
140struct pcan_usb_msg_context {
141 u16 ts16;
142 u8 prev_ts8;
143 u8 *ptr;
144 u8 *end;
145 u8 rec_cnt;
146 u8 rec_idx;
147 u8 rec_ts_idx;
148 struct net_device *netdev;
149 struct pcan_usb *pdev;
150};
151
152/*
153 * send a command
154 */
155static int pcan_usb_send_cmd(struct peak_usb_device *dev, u8 f, u8 n, u8 *p)
156{
157 int err;
158 int actual_length;
159
160 /* usb device unregistered? */
161 if (!(dev->state & PCAN_USB_STATE_CONNECTED))
162 return 0;
163
164 dev->cmd_buf[PCAN_USB_CMD_FUNC] = f;
165 dev->cmd_buf[PCAN_USB_CMD_NUM] = n;
166
167 if (p)
168 memcpy(dev->cmd_buf + PCAN_USB_CMD_ARGS,
169 p, PCAN_USB_CMD_ARGS_LEN);
170
171 err = usb_bulk_msg(usb_dev: dev->udev,
172 usb_sndbulkpipe(dev->udev, PCAN_USB_EP_CMDOUT),
173 data: dev->cmd_buf, PCAN_USB_CMD_LEN, actual_length: &actual_length,
174 PCAN_USB_COMMAND_TIMEOUT);
175 if (err)
176 netdev_err(dev: dev->netdev,
177 format: "sending cmd f=0x%x n=0x%x failure: %d\n",
178 f, n, err);
179 return err;
180}
181
182/*
183 * send a command then wait for its response
184 */
185static int pcan_usb_wait_rsp(struct peak_usb_device *dev, u8 f, u8 n, u8 *p)
186{
187 int err;
188 int actual_length;
189
190 /* usb device unregistered? */
191 if (!(dev->state & PCAN_USB_STATE_CONNECTED))
192 return 0;
193
194 /* first, send command */
195 err = pcan_usb_send_cmd(dev, f, n, NULL);
196 if (err)
197 return err;
198
199 err = usb_bulk_msg(usb_dev: dev->udev,
200 usb_rcvbulkpipe(dev->udev, PCAN_USB_EP_CMDIN),
201 data: dev->cmd_buf, PCAN_USB_CMD_LEN, actual_length: &actual_length,
202 PCAN_USB_COMMAND_TIMEOUT);
203 if (err)
204 netdev_err(dev: dev->netdev,
205 format: "waiting rsp f=0x%x n=0x%x failure: %d\n", f, n, err);
206 else if (p)
207 memcpy(p, dev->cmd_buf + PCAN_USB_CMD_ARGS,
208 PCAN_USB_CMD_ARGS_LEN);
209
210 return err;
211}
212
213static int pcan_usb_set_sja1000(struct peak_usb_device *dev, u8 mode)
214{
215 u8 args[PCAN_USB_CMD_ARGS_LEN] = {
216 [1] = mode,
217 };
218
219 return pcan_usb_send_cmd(dev, PCAN_USB_CMD_REGISTER, PCAN_USB_SET,
220 p: args);
221}
222
223static int pcan_usb_set_bus(struct peak_usb_device *dev, u8 onoff)
224{
225 u8 args[PCAN_USB_CMD_ARGS_LEN] = {
226 [0] = !!onoff,
227 };
228
229 return pcan_usb_send_cmd(dev, PCAN_USB_CMD_SET_BUS, PCAN_USB_BUS_XCVER,
230 p: args);
231}
232
233static int pcan_usb_set_silent(struct peak_usb_device *dev, u8 onoff)
234{
235 u8 args[PCAN_USB_CMD_ARGS_LEN] = {
236 [0] = !!onoff,
237 };
238
239 return pcan_usb_send_cmd(dev, PCAN_USB_CMD_SET_BUS,
240 PCAN_USB_BUS_SILENT_MODE, p: args);
241}
242
243/* send the cmd to be notified from bus errors */
244static int pcan_usb_set_err_frame(struct peak_usb_device *dev, u8 err_mask)
245{
246 u8 args[PCAN_USB_CMD_ARGS_LEN] = {
247 [0] = err_mask,
248 };
249
250 return pcan_usb_send_cmd(dev, PCAN_USB_CMD_ERR_FR, PCAN_USB_SET, p: args);
251}
252
253static int pcan_usb_set_ext_vcc(struct peak_usb_device *dev, u8 onoff)
254{
255 u8 args[PCAN_USB_CMD_ARGS_LEN] = {
256 [0] = !!onoff,
257 };
258
259 return pcan_usb_send_cmd(dev, PCAN_USB_CMD_EXT_VCC, PCAN_USB_SET, p: args);
260}
261
262static int pcan_usb_set_led(struct peak_usb_device *dev, u8 onoff)
263{
264 u8 args[PCAN_USB_CMD_ARGS_LEN] = {
265 [0] = !!onoff,
266 };
267
268 return pcan_usb_send_cmd(dev, PCAN_USB_CMD_LED, PCAN_USB_SET, p: args);
269}
270
271/*
272 * set bittiming value to can
273 */
274static int pcan_usb_set_bittiming(struct peak_usb_device *dev,
275 struct can_bittiming *bt)
276{
277 u8 args[PCAN_USB_CMD_ARGS_LEN];
278 u8 btr0, btr1;
279
280 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
281 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
282 (((bt->phase_seg2 - 1) & 0x7) << 4);
283 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
284 btr1 |= 0x80;
285
286 netdev_info(dev: dev->netdev, format: "setting BTR0=0x%02x BTR1=0x%02x\n",
287 btr0, btr1);
288
289 args[0] = btr1;
290 args[1] = btr0;
291
292 return pcan_usb_send_cmd(dev, PCAN_USB_CMD_BITRATE, PCAN_USB_SET, p: args);
293}
294
295/*
296 * init/reset can
297 */
298static int pcan_usb_write_mode(struct peak_usb_device *dev, u8 onoff)
299{
300 int err;
301
302 err = pcan_usb_set_bus(dev, onoff);
303 if (err)
304 return err;
305
306 if (!onoff) {
307 err = pcan_usb_set_sja1000(dev, SJA1000_MODE_INIT);
308 } else {
309 /* the PCAN-USB needs time to init */
310 set_current_state(TASK_INTERRUPTIBLE);
311 schedule_timeout(timeout: msecs_to_jiffies(PCAN_USB_STARTUP_TIMEOUT));
312 }
313
314 return err;
315}
316
317/*
318 * handle end of waiting for the device to reset
319 */
320static void pcan_usb_restart(struct timer_list *t)
321{
322 struct pcan_usb *pdev = timer_container_of(pdev, t, restart_timer);
323 struct peak_usb_device *dev = &pdev->dev;
324
325 /* notify candev and netdev */
326 peak_usb_restart_complete(dev);
327}
328
329/*
330 * handle the submission of the restart urb
331 */
332static void pcan_usb_restart_pending(struct urb *urb)
333{
334 struct pcan_usb *pdev = urb->context;
335
336 /* the PCAN-USB needs time to restart */
337 mod_timer(timer: &pdev->restart_timer,
338 expires: jiffies + msecs_to_jiffies(PCAN_USB_STARTUP_TIMEOUT));
339
340 /* can delete usb resources */
341 peak_usb_async_complete(urb);
342}
343
344/*
345 * handle asynchronous restart
346 */
347static int pcan_usb_restart_async(struct peak_usb_device *dev, struct urb *urb,
348 u8 *buf)
349{
350 struct pcan_usb *pdev = container_of(dev, struct pcan_usb, dev);
351
352 if (timer_pending(timer: &pdev->restart_timer))
353 return -EBUSY;
354
355 /* set bus on */
356 buf[PCAN_USB_CMD_FUNC] = 3;
357 buf[PCAN_USB_CMD_NUM] = 2;
358 buf[PCAN_USB_CMD_ARGS] = 1;
359
360 usb_fill_bulk_urb(urb, dev: dev->udev,
361 usb_sndbulkpipe(dev->udev, PCAN_USB_EP_CMDOUT),
362 transfer_buffer: buf, PCAN_USB_CMD_LEN,
363 complete_fn: pcan_usb_restart_pending, context: pdev);
364
365 return usb_submit_urb(urb, GFP_ATOMIC);
366}
367
368/*
369 * read serial number from device
370 */
371static int pcan_usb_get_serial(struct peak_usb_device *dev, u32 *serial_number)
372{
373 u8 args[PCAN_USB_CMD_ARGS_LEN];
374 int err;
375
376 err = pcan_usb_wait_rsp(dev, PCAN_USB_CMD_SN, PCAN_USB_GET, p: args);
377 if (err)
378 return err;
379 *serial_number = le32_to_cpup(p: (__le32 *)args);
380
381 return 0;
382}
383
384/*
385 * read can channel id from device
386 */
387static int pcan_usb_get_can_channel_id(struct peak_usb_device *dev, u32 *can_ch_id)
388{
389 u8 args[PCAN_USB_CMD_ARGS_LEN];
390 int err;
391
392 err = pcan_usb_wait_rsp(dev, PCAN_USB_CMD_DEVID, PCAN_USB_GET, p: args);
393 if (err)
394 netdev_err(dev: dev->netdev, format: "getting can channel id failure: %d\n", err);
395
396 else
397 *can_ch_id = args[0];
398
399 return err;
400}
401
402/* set a new CAN channel id in the flash memory of the device */
403static int pcan_usb_set_can_channel_id(struct peak_usb_device *dev, u32 can_ch_id)
404{
405 u8 args[PCAN_USB_CMD_ARGS_LEN];
406
407 /* this kind of device supports 8-bit values only */
408 if (can_ch_id > U8_MAX)
409 return -EINVAL;
410
411 /* during the flash process the device disconnects during ~1.25 s.:
412 * prohibit access when interface is UP
413 */
414 if (dev->netdev->flags & IFF_UP)
415 return -EBUSY;
416
417 args[0] = can_ch_id;
418 return pcan_usb_send_cmd(dev, PCAN_USB_CMD_DEVID, PCAN_USB_SET, p: args);
419}
420
421/*
422 * update current time ref with received timestamp
423 */
424static int pcan_usb_update_ts(struct pcan_usb_msg_context *mc)
425{
426 if ((mc->ptr + 2) > mc->end)
427 return -EINVAL;
428
429 mc->ts16 = get_unaligned_le16(p: mc->ptr);
430
431 if (mc->rec_idx > 0)
432 peak_usb_update_ts_now(time_ref: &mc->pdev->time_ref, ts_now: mc->ts16);
433 else
434 peak_usb_set_ts_now(time_ref: &mc->pdev->time_ref, ts_now: mc->ts16);
435
436 return 0;
437}
438
439/*
440 * decode received timestamp
441 */
442static int pcan_usb_decode_ts(struct pcan_usb_msg_context *mc, u8 first_packet)
443{
444 /* only 1st packet supplies a word timestamp */
445 if (first_packet) {
446 if ((mc->ptr + 2) > mc->end)
447 return -EINVAL;
448
449 mc->ts16 = get_unaligned_le16(p: mc->ptr);
450 mc->prev_ts8 = mc->ts16 & 0x00ff;
451
452 mc->ptr += 2;
453 } else {
454 u8 ts8;
455
456 if ((mc->ptr + 1) > mc->end)
457 return -EINVAL;
458
459 ts8 = *mc->ptr++;
460
461 if (ts8 < mc->prev_ts8)
462 mc->ts16 += 0x100;
463
464 mc->ts16 &= 0xff00;
465 mc->ts16 |= ts8;
466 mc->prev_ts8 = ts8;
467 }
468
469 return 0;
470}
471
472static int pcan_usb_decode_error(struct pcan_usb_msg_context *mc, u8 n,
473 u8 status_len)
474{
475 struct sk_buff *skb;
476 struct can_frame *cf;
477 enum can_state new_state = CAN_STATE_ERROR_ACTIVE;
478
479 /* ignore this error until 1st ts received */
480 if (n == PCAN_USB_ERROR_QOVR)
481 if (!mc->pdev->time_ref.tick_count)
482 return 0;
483
484 /* allocate an skb to store the error frame */
485 skb = alloc_can_err_skb(dev: mc->netdev, cf: &cf);
486
487 if (n & PCAN_USB_ERROR_RXQOVR) {
488 /* data overrun interrupt */
489 netdev_dbg(mc->netdev, "data overrun interrupt\n");
490 mc->netdev->stats.rx_over_errors++;
491 mc->netdev->stats.rx_errors++;
492 if (cf) {
493 cf->can_id |= CAN_ERR_CRTL;
494 cf->data[1] |= CAN_ERR_CRTL_RX_OVERFLOW;
495 }
496 }
497
498 if (n & PCAN_USB_ERROR_TXQFULL)
499 netdev_dbg(mc->netdev, "device Tx queue full)\n");
500
501 if (n & PCAN_USB_ERROR_BUS_OFF) {
502 new_state = CAN_STATE_BUS_OFF;
503 } else if (n & PCAN_USB_ERROR_BUS_HEAVY) {
504 new_state = ((mc->pdev->bec.txerr >= 128) ||
505 (mc->pdev->bec.rxerr >= 128)) ?
506 CAN_STATE_ERROR_PASSIVE :
507 CAN_STATE_ERROR_WARNING;
508 } else {
509 new_state = CAN_STATE_ERROR_ACTIVE;
510 }
511
512 /* handle change of state */
513 if (new_state != mc->pdev->dev.can.state) {
514 enum can_state tx_state =
515 (mc->pdev->bec.txerr >= mc->pdev->bec.rxerr) ?
516 new_state : 0;
517 enum can_state rx_state =
518 (mc->pdev->bec.txerr <= mc->pdev->bec.rxerr) ?
519 new_state : 0;
520
521 can_change_state(dev: mc->netdev, cf, tx_state, rx_state);
522
523 if (new_state == CAN_STATE_BUS_OFF) {
524 can_bus_off(dev: mc->netdev);
525 } else if (cf && (cf->can_id & CAN_ERR_CRTL)) {
526 /* Supply TX/RX error counters in case of
527 * controller error.
528 */
529 cf->can_id = CAN_ERR_CNT;
530 cf->data[6] = mc->pdev->bec.txerr;
531 cf->data[7] = mc->pdev->bec.rxerr;
532 }
533 }
534
535 if (!skb)
536 return -ENOMEM;
537
538 if (status_len & PCAN_USB_STATUSLEN_TIMESTAMP) {
539 struct skb_shared_hwtstamps *hwts = skb_hwtstamps(skb);
540
541 peak_usb_get_ts_time(time_ref: &mc->pdev->time_ref, ts: mc->ts16,
542 tv: &hwts->hwtstamp);
543 }
544
545 netif_rx(skb);
546
547 return 0;
548}
549
550/* decode bus event usb packet: first byte contains rxerr while 2nd one contains
551 * txerr.
552 */
553static int pcan_usb_handle_bus_evt(struct pcan_usb_msg_context *mc, u8 ir)
554{
555 struct pcan_usb *pdev = mc->pdev;
556
557 /* according to the content of the packet */
558 switch (ir) {
559 case PCAN_USB_ERR_CNT_DEC:
560 case PCAN_USB_ERR_CNT_INC:
561
562 /* save rx/tx error counters from in the device context */
563 pdev->bec.rxerr = mc->ptr[1];
564 pdev->bec.txerr = mc->ptr[2];
565 break;
566
567 default:
568 /* reserved */
569 break;
570 }
571
572 return 0;
573}
574
575/*
576 * decode non-data usb message
577 */
578static int pcan_usb_decode_status(struct pcan_usb_msg_context *mc,
579 u8 status_len)
580{
581 u8 rec_len = status_len & PCAN_USB_STATUSLEN_DLC;
582 u8 f, n;
583 int err;
584
585 /* check whether function and number can be read */
586 if ((mc->ptr + 2) > mc->end)
587 return -EINVAL;
588
589 f = mc->ptr[PCAN_USB_CMD_FUNC];
590 n = mc->ptr[PCAN_USB_CMD_NUM];
591 mc->ptr += PCAN_USB_CMD_ARGS;
592
593 if (status_len & PCAN_USB_STATUSLEN_TIMESTAMP) {
594 int err = pcan_usb_decode_ts(mc, first_packet: !mc->rec_ts_idx);
595
596 if (err)
597 return err;
598
599 /* Next packet in the buffer will have a timestamp on a single
600 * byte
601 */
602 mc->rec_ts_idx++;
603 }
604
605 switch (f) {
606 case PCAN_USB_REC_ERROR:
607 err = pcan_usb_decode_error(mc, n, status_len);
608 if (err)
609 return err;
610 break;
611
612 case PCAN_USB_REC_ANALOG:
613 /* analog values (ignored) */
614 rec_len = 2;
615 break;
616
617 case PCAN_USB_REC_BUSLOAD:
618 /* bus load (ignored) */
619 rec_len = 1;
620 break;
621
622 case PCAN_USB_REC_TS:
623 /* only timestamp */
624 if (pcan_usb_update_ts(mc))
625 return -EINVAL;
626 break;
627
628 case PCAN_USB_REC_BUSEVT:
629 /* bus event notifications (get rxerr/txerr) */
630 err = pcan_usb_handle_bus_evt(mc, ir: n);
631 if (err)
632 return err;
633 break;
634 default:
635 netdev_err(dev: mc->netdev, format: "unexpected function %u\n", f);
636 break;
637 }
638
639 if ((mc->ptr + rec_len) > mc->end)
640 return -EINVAL;
641
642 mc->ptr += rec_len;
643
644 return 0;
645}
646
647/*
648 * decode data usb message
649 */
650static int pcan_usb_decode_data(struct pcan_usb_msg_context *mc, u8 status_len)
651{
652 u8 rec_len = status_len & PCAN_USB_STATUSLEN_DLC;
653 struct sk_buff *skb;
654 struct can_frame *cf;
655 struct skb_shared_hwtstamps *hwts;
656 u32 can_id_flags;
657
658 skb = alloc_can_skb(dev: mc->netdev, cf: &cf);
659 if (!skb)
660 return -ENOMEM;
661
662 if (status_len & PCAN_USB_STATUSLEN_EXT_ID) {
663 if ((mc->ptr + 4) > mc->end)
664 goto decode_failed;
665
666 can_id_flags = get_unaligned_le32(p: mc->ptr);
667 cf->can_id = can_id_flags >> 3 | CAN_EFF_FLAG;
668 mc->ptr += 4;
669 } else {
670 if ((mc->ptr + 2) > mc->end)
671 goto decode_failed;
672
673 can_id_flags = get_unaligned_le16(p: mc->ptr);
674 cf->can_id = can_id_flags >> 5;
675 mc->ptr += 2;
676 }
677
678 can_frame_set_cc_len(cf, dlc: rec_len, ctrlmode: mc->pdev->dev.can.ctrlmode);
679
680 /* Only first packet timestamp is a word */
681 if (pcan_usb_decode_ts(mc, first_packet: !mc->rec_ts_idx))
682 goto decode_failed;
683
684 /* Next packet in the buffer will have a timestamp on a single byte */
685 mc->rec_ts_idx++;
686
687 /* read data */
688 memset(cf->data, 0x0, sizeof(cf->data));
689 if (status_len & PCAN_USB_STATUSLEN_RTR) {
690 cf->can_id |= CAN_RTR_FLAG;
691 } else {
692 if ((mc->ptr + rec_len) > mc->end)
693 goto decode_failed;
694
695 memcpy(cf->data, mc->ptr, cf->len);
696 mc->ptr += rec_len;
697
698 /* Ignore next byte (client private id) if SRR bit is set */
699 if (can_id_flags & PCAN_USB_TX_SRR)
700 mc->ptr++;
701
702 /* update statistics */
703 mc->netdev->stats.rx_bytes += cf->len;
704 }
705 mc->netdev->stats.rx_packets++;
706
707 /* convert timestamp into kernel time */
708 hwts = skb_hwtstamps(skb);
709 peak_usb_get_ts_time(time_ref: &mc->pdev->time_ref, ts: mc->ts16, tv: &hwts->hwtstamp);
710
711 /* push the skb */
712 netif_rx(skb);
713
714 return 0;
715
716decode_failed:
717 dev_kfree_skb(skb);
718 return -EINVAL;
719}
720
721/*
722 * process incoming message
723 */
724static int pcan_usb_decode_msg(struct peak_usb_device *dev, u8 *ibuf, u32 lbuf)
725{
726 struct pcan_usb_msg_context mc = {
727 .rec_cnt = ibuf[1],
728 .ptr = ibuf + PCAN_USB_MSG_HEADER_LEN,
729 .end = ibuf + lbuf,
730 .netdev = dev->netdev,
731 .pdev = container_of(dev, struct pcan_usb, dev),
732 };
733 int err;
734
735 for (err = 0; mc.rec_idx < mc.rec_cnt && !err; mc.rec_idx++) {
736 u8 sl = *mc.ptr++;
737
738 /* handle status and error frames here */
739 if (sl & PCAN_USB_STATUSLEN_INTERNAL) {
740 err = pcan_usb_decode_status(mc: &mc, status_len: sl);
741 /* handle normal can frames here */
742 } else {
743 err = pcan_usb_decode_data(mc: &mc, status_len: sl);
744 }
745 }
746
747 return err;
748}
749
750/*
751 * process any incoming buffer
752 */
753static int pcan_usb_decode_buf(struct peak_usb_device *dev, struct urb *urb)
754{
755 int err = 0;
756
757 if (urb->actual_length > PCAN_USB_MSG_HEADER_LEN) {
758 err = pcan_usb_decode_msg(dev, ibuf: urb->transfer_buffer,
759 lbuf: urb->actual_length);
760
761 } else if (urb->actual_length > 0) {
762 netdev_err(dev: dev->netdev, format: "usb message length error (%u)\n",
763 urb->actual_length);
764 err = -EINVAL;
765 }
766
767 return err;
768}
769
770/*
771 * process outgoing packet
772 */
773static int pcan_usb_encode_msg(struct peak_usb_device *dev, struct sk_buff *skb,
774 u8 *obuf, size_t *size)
775{
776 struct net_device *netdev = dev->netdev;
777 struct net_device_stats *stats = &netdev->stats;
778 struct can_frame *cf = (struct can_frame *)skb->data;
779 u32 can_id_flags = cf->can_id & CAN_ERR_MASK;
780 u8 *pc;
781
782 obuf[0] = PCAN_USB_MSG_TX_CAN;
783 obuf[1] = 1; /* only one CAN frame is stored in the packet */
784
785 pc = obuf + PCAN_USB_MSG_HEADER_LEN;
786
787 /* status/len byte */
788 *pc = can_get_cc_dlc(cf, ctrlmode: dev->can.ctrlmode);
789
790 if (cf->can_id & CAN_RTR_FLAG)
791 *pc |= PCAN_USB_STATUSLEN_RTR;
792
793 /* can id */
794 if (cf->can_id & CAN_EFF_FLAG) {
795 *pc |= PCAN_USB_STATUSLEN_EXT_ID;
796 pc++;
797
798 can_id_flags <<= 3;
799
800 if (dev->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
801 can_id_flags |= PCAN_USB_TX_SRR;
802
803 if (dev->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT)
804 can_id_flags |= PCAN_USB_TX_AT;
805
806 put_unaligned_le32(val: can_id_flags, p: pc);
807 pc += 4;
808 } else {
809 pc++;
810
811 can_id_flags <<= 5;
812
813 if (dev->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
814 can_id_flags |= PCAN_USB_TX_SRR;
815
816 if (dev->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT)
817 can_id_flags |= PCAN_USB_TX_AT;
818
819 put_unaligned_le16(val: can_id_flags, p: pc);
820 pc += 2;
821 }
822
823 /* can data */
824 if (!(cf->can_id & CAN_RTR_FLAG)) {
825 memcpy(pc, cf->data, cf->len);
826 pc += cf->len;
827 }
828
829 /* SRR bit needs a writer id (useless here) */
830 if (can_id_flags & PCAN_USB_TX_SRR)
831 *pc++ = 0x80;
832
833 obuf[(*size)-1] = (u8)(stats->tx_packets & 0xff);
834
835 return 0;
836}
837
838/* socket callback used to copy berr counters values received through USB */
839static int pcan_usb_get_berr_counter(const struct net_device *netdev,
840 struct can_berr_counter *bec)
841{
842 struct peak_usb_device *dev = netdev_priv(dev: netdev);
843 struct pcan_usb *pdev = container_of(dev, struct pcan_usb, dev);
844
845 *bec = pdev->bec;
846
847 /* must return 0 */
848 return 0;
849}
850
851/*
852 * start interface
853 */
854static int pcan_usb_start(struct peak_usb_device *dev)
855{
856 struct pcan_usb *pdev = container_of(dev, struct pcan_usb, dev);
857 int err;
858
859 /* number of bits used in timestamps read from adapter struct */
860 peak_usb_init_time_ref(time_ref: &pdev->time_ref, adapter: &pcan_usb);
861
862 pdev->bec.rxerr = 0;
863 pdev->bec.txerr = 0;
864
865 /* always ask the device for BERR reporting, to be able to switch from
866 * WARNING to PASSIVE state
867 */
868 err = pcan_usb_set_err_frame(dev, PCAN_USB_BERR_MASK);
869 if (err)
870 netdev_warn(dev: dev->netdev,
871 format: "Asking for BERR reporting error %u\n",
872 err);
873
874 /* if revision greater than 3, can put silent mode on/off */
875 if (dev->device_rev > 3) {
876 err = pcan_usb_set_silent(dev,
877 onoff: dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY);
878 if (err)
879 return err;
880 }
881
882 return pcan_usb_set_ext_vcc(dev, onoff: 0);
883}
884
885static int pcan_usb_init(struct peak_usb_device *dev)
886{
887 struct pcan_usb *pdev = container_of(dev, struct pcan_usb, dev);
888 u32 serial_number;
889 int err;
890
891 /* initialize a timer needed to wait for hardware restart */
892 timer_setup(&pdev->restart_timer, pcan_usb_restart, 0);
893
894 /*
895 * explicit use of dev_xxx() instead of netdev_xxx() here:
896 * information displayed are related to the device itself, not
897 * to the canx netdevice.
898 */
899 err = pcan_usb_get_serial(dev, serial_number: &serial_number);
900 if (err) {
901 dev_err(dev->netdev->dev.parent,
902 "unable to read %s serial number (err %d)\n",
903 pcan_usb.name, err);
904 return err;
905 }
906
907 dev_info(dev->netdev->dev.parent,
908 "PEAK-System %s adapter hwrev %u serial %08X (%u channel)\n",
909 pcan_usb.name, dev->device_rev, serial_number,
910 pcan_usb.ctrl_count);
911
912 /* Since rev 4.1, PCAN-USB is able to make single-shot as well as
913 * looped back frames.
914 */
915 if (dev->device_rev >= 41) {
916 struct can_priv *priv = netdev_priv(dev: dev->netdev);
917
918 priv->ctrlmode_supported |= CAN_CTRLMODE_ONE_SHOT |
919 CAN_CTRLMODE_LOOPBACK;
920 } else {
921 dev_info(dev->netdev->dev.parent,
922 "Firmware update available. Please contact support@peak-system.com\n");
923 }
924
925 return 0;
926}
927
928/*
929 * probe function for new PCAN-USB usb interface
930 */
931static int pcan_usb_probe(struct usb_interface *intf)
932{
933 struct usb_host_interface *if_desc;
934 int i;
935
936 if_desc = intf->altsetting;
937
938 /* check interface endpoint addresses */
939 for (i = 0; i < if_desc->desc.bNumEndpoints; i++) {
940 struct usb_endpoint_descriptor *ep = &if_desc->endpoint[i].desc;
941
942 switch (ep->bEndpointAddress) {
943 case PCAN_USB_EP_CMDOUT:
944 case PCAN_USB_EP_CMDIN:
945 case PCAN_USB_EP_MSGOUT:
946 case PCAN_USB_EP_MSGIN:
947 break;
948 default:
949 return -ENODEV;
950 }
951 }
952
953 return 0;
954}
955
956static int pcan_usb_set_phys_id(struct net_device *netdev,
957 enum ethtool_phys_id_state state)
958{
959 struct peak_usb_device *dev = netdev_priv(dev: netdev);
960 int err = 0;
961
962 switch (state) {
963 case ETHTOOL_ID_ACTIVE:
964 /* call ON/OFF twice a second */
965 return 2;
966
967 case ETHTOOL_ID_OFF:
968 err = pcan_usb_set_led(dev, onoff: 0);
969 break;
970
971 case ETHTOOL_ID_ON:
972 fallthrough;
973
974 case ETHTOOL_ID_INACTIVE:
975 /* restore LED default */
976 err = pcan_usb_set_led(dev, onoff: 1);
977 break;
978
979 default:
980 break;
981 }
982
983 return err;
984}
985
986/* This device only handles 8-bit CAN channel id. */
987static int pcan_usb_get_eeprom_len(struct net_device *netdev)
988{
989 return sizeof(u8);
990}
991
992static const struct ethtool_ops pcan_usb_ethtool_ops = {
993 .set_phys_id = pcan_usb_set_phys_id,
994 .get_ts_info = pcan_get_ts_info,
995 .get_eeprom_len = pcan_usb_get_eeprom_len,
996 .get_eeprom = peak_usb_get_eeprom,
997 .set_eeprom = peak_usb_set_eeprom,
998};
999
1000/*
1001 * describe the PCAN-USB adapter
1002 */
1003static const struct can_bittiming_const pcan_usb_const = {
1004 .name = "pcan_usb",
1005 .tseg1_min = 1,
1006 .tseg1_max = 16,
1007 .tseg2_min = 1,
1008 .tseg2_max = 8,
1009 .sjw_max = 4,
1010 .brp_min = 1,
1011 .brp_max = 64,
1012 .brp_inc = 1,
1013};
1014
1015const struct peak_usb_adapter pcan_usb = {
1016 .name = "PCAN-USB",
1017 .device_id = PCAN_USB_PRODUCT_ID,
1018 .ctrl_count = 1,
1019 .ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES | CAN_CTRLMODE_LISTENONLY |
1020 CAN_CTRLMODE_CC_LEN8_DLC,
1021 .clock = {
1022 .freq = PCAN_USB_CRYSTAL_HZ / 2,
1023 },
1024 .bittiming_const = &pcan_usb_const,
1025
1026 /* size of device private data */
1027 .sizeof_dev_private = sizeof(struct pcan_usb),
1028
1029 .ethtool_ops = &pcan_usb_ethtool_ops,
1030
1031 /* timestamps usage */
1032 .ts_used_bits = 16,
1033 .us_per_ts_scale = PCAN_USB_TS_US_PER_TICK, /* us=(ts*scale) */
1034 .us_per_ts_shift = PCAN_USB_TS_DIV_SHIFTER, /* >> shift */
1035
1036 /* give here messages in/out endpoints */
1037 .ep_msg_in = PCAN_USB_EP_MSGIN,
1038 .ep_msg_out = {PCAN_USB_EP_MSGOUT},
1039
1040 /* size of rx/tx usb buffers */
1041 .rx_buffer_size = PCAN_USB_RX_BUFFER_SIZE,
1042 .tx_buffer_size = PCAN_USB_TX_BUFFER_SIZE,
1043
1044 /* device callbacks */
1045 .intf_probe = pcan_usb_probe,
1046 .dev_init = pcan_usb_init,
1047 .dev_set_bus = pcan_usb_write_mode,
1048 .dev_set_bittiming = pcan_usb_set_bittiming,
1049 .dev_get_can_channel_id = pcan_usb_get_can_channel_id,
1050 .dev_set_can_channel_id = pcan_usb_set_can_channel_id,
1051 .dev_decode_buf = pcan_usb_decode_buf,
1052 .dev_encode_msg = pcan_usb_encode_msg,
1053 .dev_start = pcan_usb_start,
1054 .dev_restart_async = pcan_usb_restart_async,
1055 .do_get_berr_counter = pcan_usb_get_berr_counter,
1056};
1057

source code of linux/drivers/net/can/usb/peak_usb/pcan_usb.c