1 /*
2  * CAN driver for PEAK System USB adapters
3  * Derived from the PCAN project file driver/src/pcan_usb_core.c
4  *
5  * Copyright (C) 2003-2010 PEAK System-Technik GmbH
6  * Copyright (C) 2010-2012 Stephane Grosjean <s.grosjean@peak-system.com>
7  *
8  * Many thanks to Klaus Hitschler <klaus.hitschler@gmx.de>
9  *
10  * This program is free software; you can redistribute it and/or modify it
11  * under the terms of the GNU General Public License as published
12  * by the Free Software Foundation; version 2 of the License.
13  *
14  * This program is distributed in the hope that it will be useful, but
15  * WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17  * General Public License for more details.
18  */
19 #include <linux/init.h>
20 #include <linux/signal.h>
21 #include <linux/slab.h>
22 #include <linux/module.h>
23 #include <linux/netdevice.h>
24 #include <linux/usb.h>
25 
26 #include <linux/can.h>
27 #include <linux/can/dev.h>
28 #include <linux/can/error.h>
29 
30 #include "pcan_usb_core.h"
31 
32 MODULE_AUTHOR("Stephane Grosjean <s.grosjean@peak-system.com>");
33 MODULE_DESCRIPTION("CAN driver for PEAK-System USB adapters");
34 MODULE_LICENSE("GPL v2");
35 
36 /* Table of devices that work with this driver */
37 static struct usb_device_id peak_usb_table[] = {
38 	{USB_DEVICE(PCAN_USB_VENDOR_ID, PCAN_USB_PRODUCT_ID)},
39 	{USB_DEVICE(PCAN_USB_VENDOR_ID, PCAN_USBPRO_PRODUCT_ID)},
40 	{USB_DEVICE(PCAN_USB_VENDOR_ID, PCAN_USBFD_PRODUCT_ID)},
41 	{USB_DEVICE(PCAN_USB_VENDOR_ID, PCAN_USBPROFD_PRODUCT_ID)},
42 	{USB_DEVICE(PCAN_USB_VENDOR_ID, PCAN_USBCHIP_PRODUCT_ID)},
43 	{USB_DEVICE(PCAN_USB_VENDOR_ID, PCAN_USBX6_PRODUCT_ID)},
44 	{} /* Terminating entry */
45 };
46 
47 MODULE_DEVICE_TABLE(usb, peak_usb_table);
48 
49 /* List of supported PCAN-USB adapters (NULL terminated list) */
50 static const struct peak_usb_adapter *const peak_usb_adapters_list[] = {
51 	&pcan_usb,
52 	&pcan_usb_pro,
53 	&pcan_usb_fd,
54 	&pcan_usb_pro_fd,
55 	&pcan_usb_chip,
56 	&pcan_usb_x6,
57 };
58 
59 /*
60  * dump memory
61  */
62 #define DUMP_WIDTH	16
63 void pcan_dump_mem(char *prompt, void *p, int l)
64 {
65 	pr_info("%s dumping %s (%d bytes):\n",
66 		PCAN_USB_DRIVER_NAME, prompt ? prompt : "memory", l);
67 	print_hex_dump(KERN_INFO, PCAN_USB_DRIVER_NAME " ", DUMP_PREFIX_NONE,
68 		       DUMP_WIDTH, 1, p, l, false);
69 }
70 
71 /*
72  * initialize a time_ref object with usb adapter own settings
73  */
74 void peak_usb_init_time_ref(struct peak_time_ref *time_ref,
75 			    const struct peak_usb_adapter *adapter)
76 {
77 	if (time_ref) {
78 		memset(time_ref, 0, sizeof(struct peak_time_ref));
79 		time_ref->adapter = adapter;
80 	}
81 }
82 
83 /*
84  * sometimes, another now may be  more recent than current one...
85  */
86 void peak_usb_update_ts_now(struct peak_time_ref *time_ref, u32 ts_now)
87 {
88 	time_ref->ts_dev_2 = ts_now;
89 
90 	/* should wait at least two passes before computing */
91 	if (ktime_to_ns(time_ref->tv_host) > 0) {
92 		u32 delta_ts = time_ref->ts_dev_2 - time_ref->ts_dev_1;
93 
94 		if (time_ref->ts_dev_2 < time_ref->ts_dev_1)
95 			delta_ts &= (1 << time_ref->adapter->ts_used_bits) - 1;
96 
97 		time_ref->ts_total += delta_ts;
98 	}
99 }
100 
101 /*
102  * register device timestamp as now
103  */
104 void peak_usb_set_ts_now(struct peak_time_ref *time_ref, u32 ts_now)
105 {
106 	if (ktime_to_ns(time_ref->tv_host_0) == 0) {
107 		/* use monotonic clock to correctly compute further deltas */
108 		time_ref->tv_host_0 = ktime_get();
109 		time_ref->tv_host = ktime_set(0, 0);
110 	} else {
111 		/*
112 		 * delta_us should not be >= 2^32 => delta should be < 4294s
113 		 * handle 32-bits wrapping here: if count of s. reaches 4200,
114 		 * reset counters and change time base
115 		 */
116 		if (ktime_to_ns(time_ref->tv_host)) {
117 			ktime_t delta = ktime_sub(time_ref->tv_host,
118 						  time_ref->tv_host_0);
119 			if (ktime_to_ns(delta) > (4200ull * NSEC_PER_SEC)) {
120 				time_ref->tv_host_0 = time_ref->tv_host;
121 				time_ref->ts_total = 0;
122 			}
123 		}
124 
125 		time_ref->tv_host = ktime_get();
126 		time_ref->tick_count++;
127 	}
128 
129 	time_ref->ts_dev_1 = time_ref->ts_dev_2;
130 	peak_usb_update_ts_now(time_ref, ts_now);
131 }
132 
133 /*
134  * compute time according to current ts and time_ref data
135  */
136 void peak_usb_get_ts_time(struct peak_time_ref *time_ref, u32 ts, ktime_t *time)
137 {
138 	/* protect from getting time before setting now */
139 	if (ktime_to_ns(time_ref->tv_host)) {
140 		u64 delta_us;
141 
142 		delta_us = ts - time_ref->ts_dev_2;
143 		if (ts < time_ref->ts_dev_2)
144 			delta_us &= (1 << time_ref->adapter->ts_used_bits) - 1;
145 
146 		delta_us += time_ref->ts_total;
147 
148 		delta_us *= time_ref->adapter->us_per_ts_scale;
149 		delta_us >>= time_ref->adapter->us_per_ts_shift;
150 
151 		*time = ktime_add_us(time_ref->tv_host_0, delta_us);
152 	} else {
153 		*time = ktime_get();
154 	}
155 }
156 
157 /*
158  * post received skb after having set any hw timestamp
159  */
160 int peak_usb_netif_rx(struct sk_buff *skb,
161 		      struct peak_time_ref *time_ref, u32 ts_low)
162 {
163 	struct skb_shared_hwtstamps *hwts = skb_hwtstamps(skb);
164 
165 	peak_usb_get_ts_time(time_ref, ts_low, &hwts->hwtstamp);
166 
167 	return netif_rx(skb);
168 }
169 
170 /*
171  * callback for bulk Rx urb
172  */
173 static void peak_usb_read_bulk_callback(struct urb *urb)
174 {
175 	struct peak_usb_device *dev = urb->context;
176 	struct net_device *netdev;
177 	int err;
178 
179 	netdev = dev->netdev;
180 
181 	if (!netif_device_present(netdev))
182 		return;
183 
184 	/* check reception status */
185 	switch (urb->status) {
186 	case 0:
187 		/* success */
188 		break;
189 
190 	case -EILSEQ:
191 	case -ENOENT:
192 	case -ECONNRESET:
193 	case -ESHUTDOWN:
194 		return;
195 
196 	default:
197 		if (net_ratelimit())
198 			netdev_err(netdev,
199 				   "Rx urb aborted (%d)\n", urb->status);
200 		goto resubmit_urb;
201 	}
202 
203 	/* protect from any incoming empty msgs */
204 	if ((urb->actual_length > 0) && (dev->adapter->dev_decode_buf)) {
205 		/* handle these kinds of msgs only if _start callback called */
206 		if (dev->state & PCAN_USB_STATE_STARTED) {
207 			err = dev->adapter->dev_decode_buf(dev, urb);
208 			if (err)
209 				pcan_dump_mem("received usb message",
210 					      urb->transfer_buffer,
211 					      urb->transfer_buffer_length);
212 		}
213 	}
214 
215 resubmit_urb:
216 	usb_fill_bulk_urb(urb, dev->udev,
217 		usb_rcvbulkpipe(dev->udev, dev->ep_msg_in),
218 		urb->transfer_buffer, dev->adapter->rx_buffer_size,
219 		peak_usb_read_bulk_callback, dev);
220 
221 	usb_anchor_urb(urb, &dev->rx_submitted);
222 	err = usb_submit_urb(urb, GFP_ATOMIC);
223 	if (!err)
224 		return;
225 
226 	usb_unanchor_urb(urb);
227 
228 	if (err == -ENODEV)
229 		netif_device_detach(netdev);
230 	else
231 		netdev_err(netdev, "failed resubmitting read bulk urb: %d\n",
232 			   err);
233 }
234 
235 /*
236  * callback for bulk Tx urb
237  */
238 static void peak_usb_write_bulk_callback(struct urb *urb)
239 {
240 	struct peak_tx_urb_context *context = urb->context;
241 	struct peak_usb_device *dev;
242 	struct net_device *netdev;
243 
244 	BUG_ON(!context);
245 
246 	dev = context->dev;
247 	netdev = dev->netdev;
248 
249 	atomic_dec(&dev->active_tx_urbs);
250 
251 	if (!netif_device_present(netdev))
252 		return;
253 
254 	/* check tx status */
255 	switch (urb->status) {
256 	case 0:
257 		/* transmission complete */
258 		netdev->stats.tx_packets++;
259 		netdev->stats.tx_bytes += context->data_len;
260 
261 		/* prevent tx timeout */
262 		netif_trans_update(netdev);
263 		break;
264 
265 	default:
266 		if (net_ratelimit())
267 			netdev_err(netdev, "Tx urb aborted (%d)\n",
268 				   urb->status);
269 	case -EPROTO:
270 	case -ENOENT:
271 	case -ECONNRESET:
272 	case -ESHUTDOWN:
273 
274 		break;
275 	}
276 
277 	/* should always release echo skb and corresponding context */
278 	can_get_echo_skb(netdev, context->echo_index);
279 	context->echo_index = PCAN_USB_MAX_TX_URBS;
280 
281 	/* do wakeup tx queue in case of success only */
282 	if (!urb->status)
283 		netif_wake_queue(netdev);
284 }
285 
286 /*
287  * called by netdev to send one skb on the CAN interface.
288  */
289 static netdev_tx_t peak_usb_ndo_start_xmit(struct sk_buff *skb,
290 					   struct net_device *netdev)
291 {
292 	struct peak_usb_device *dev = netdev_priv(netdev);
293 	struct peak_tx_urb_context *context = NULL;
294 	struct net_device_stats *stats = &netdev->stats;
295 	struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
296 	struct urb *urb;
297 	u8 *obuf;
298 	int i, err;
299 	size_t size = dev->adapter->tx_buffer_size;
300 
301 	if (can_dropped_invalid_skb(netdev, skb))
302 		return NETDEV_TX_OK;
303 
304 	for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++)
305 		if (dev->tx_contexts[i].echo_index == PCAN_USB_MAX_TX_URBS) {
306 			context = dev->tx_contexts + i;
307 			break;
308 		}
309 
310 	if (!context) {
311 		/* should not occur except during restart */
312 		return NETDEV_TX_BUSY;
313 	}
314 
315 	urb = context->urb;
316 	obuf = urb->transfer_buffer;
317 
318 	err = dev->adapter->dev_encode_msg(dev, skb, obuf, &size);
319 	if (err) {
320 		if (net_ratelimit())
321 			netdev_err(netdev, "packet dropped\n");
322 		dev_kfree_skb(skb);
323 		stats->tx_dropped++;
324 		return NETDEV_TX_OK;
325 	}
326 
327 	context->echo_index = i;
328 
329 	/* Note: this works with CANFD frames too */
330 	context->data_len = cfd->len;
331 
332 	usb_anchor_urb(urb, &dev->tx_submitted);
333 
334 	can_put_echo_skb(skb, netdev, context->echo_index);
335 
336 	atomic_inc(&dev->active_tx_urbs);
337 
338 	err = usb_submit_urb(urb, GFP_ATOMIC);
339 	if (err) {
340 		can_free_echo_skb(netdev, context->echo_index);
341 
342 		usb_unanchor_urb(urb);
343 
344 		/* this context is not used in fact */
345 		context->echo_index = PCAN_USB_MAX_TX_URBS;
346 
347 		atomic_dec(&dev->active_tx_urbs);
348 
349 		switch (err) {
350 		case -ENODEV:
351 			netif_device_detach(netdev);
352 			break;
353 		default:
354 			netdev_warn(netdev, "tx urb submitting failed err=%d\n",
355 				    err);
356 		case -ENOENT:
357 			/* cable unplugged */
358 			stats->tx_dropped++;
359 		}
360 	} else {
361 		netif_trans_update(netdev);
362 
363 		/* slow down tx path */
364 		if (atomic_read(&dev->active_tx_urbs) >= PCAN_USB_MAX_TX_URBS)
365 			netif_stop_queue(netdev);
366 	}
367 
368 	return NETDEV_TX_OK;
369 }
370 
371 /*
372  * start the CAN interface.
373  * Rx and Tx urbs are allocated here. Rx urbs are submitted here.
374  */
375 static int peak_usb_start(struct peak_usb_device *dev)
376 {
377 	struct net_device *netdev = dev->netdev;
378 	int err, i;
379 
380 	for (i = 0; i < PCAN_USB_MAX_RX_URBS; i++) {
381 		struct urb *urb;
382 		u8 *buf;
383 
384 		/* create a URB, and a buffer for it, to receive usb messages */
385 		urb = usb_alloc_urb(0, GFP_KERNEL);
386 		if (!urb) {
387 			err = -ENOMEM;
388 			break;
389 		}
390 
391 		buf = kmalloc(dev->adapter->rx_buffer_size, GFP_KERNEL);
392 		if (!buf) {
393 			usb_free_urb(urb);
394 			err = -ENOMEM;
395 			break;
396 		}
397 
398 		usb_fill_bulk_urb(urb, dev->udev,
399 			usb_rcvbulkpipe(dev->udev, dev->ep_msg_in),
400 			buf, dev->adapter->rx_buffer_size,
401 			peak_usb_read_bulk_callback, dev);
402 
403 		/* ask last usb_free_urb() to also kfree() transfer_buffer */
404 		urb->transfer_flags |= URB_FREE_BUFFER;
405 		usb_anchor_urb(urb, &dev->rx_submitted);
406 
407 		err = usb_submit_urb(urb, GFP_KERNEL);
408 		if (err) {
409 			if (err == -ENODEV)
410 				netif_device_detach(dev->netdev);
411 
412 			usb_unanchor_urb(urb);
413 			kfree(buf);
414 			usb_free_urb(urb);
415 			break;
416 		}
417 
418 		/* drop reference, USB core will take care of freeing it */
419 		usb_free_urb(urb);
420 	}
421 
422 	/* did we submit any URBs? Warn if we was not able to submit all urbs */
423 	if (i < PCAN_USB_MAX_RX_URBS) {
424 		if (i == 0) {
425 			netdev_err(netdev, "couldn't setup any rx URB\n");
426 			return err;
427 		}
428 
429 		netdev_warn(netdev, "rx performance may be slow\n");
430 	}
431 
432 	/* pre-alloc tx buffers and corresponding urbs */
433 	for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++) {
434 		struct peak_tx_urb_context *context;
435 		struct urb *urb;
436 		u8 *buf;
437 
438 		/* create a URB and a buffer for it, to transmit usb messages */
439 		urb = usb_alloc_urb(0, GFP_KERNEL);
440 		if (!urb) {
441 			err = -ENOMEM;
442 			break;
443 		}
444 
445 		buf = kmalloc(dev->adapter->tx_buffer_size, GFP_KERNEL);
446 		if (!buf) {
447 			usb_free_urb(urb);
448 			err = -ENOMEM;
449 			break;
450 		}
451 
452 		context = dev->tx_contexts + i;
453 		context->dev = dev;
454 		context->urb = urb;
455 
456 		usb_fill_bulk_urb(urb, dev->udev,
457 			usb_sndbulkpipe(dev->udev, dev->ep_msg_out),
458 			buf, dev->adapter->tx_buffer_size,
459 			peak_usb_write_bulk_callback, context);
460 
461 		/* ask last usb_free_urb() to also kfree() transfer_buffer */
462 		urb->transfer_flags |= URB_FREE_BUFFER;
463 	}
464 
465 	/* warn if we were not able to allocate enough tx contexts */
466 	if (i < PCAN_USB_MAX_TX_URBS) {
467 		if (i == 0) {
468 			netdev_err(netdev, "couldn't setup any tx URB\n");
469 			goto err_tx;
470 		}
471 
472 		netdev_warn(netdev, "tx performance may be slow\n");
473 	}
474 
475 	if (dev->adapter->dev_start) {
476 		err = dev->adapter->dev_start(dev);
477 		if (err)
478 			goto err_adapter;
479 	}
480 
481 	dev->state |= PCAN_USB_STATE_STARTED;
482 
483 	/* can set bus on now */
484 	if (dev->adapter->dev_set_bus) {
485 		err = dev->adapter->dev_set_bus(dev, 1);
486 		if (err)
487 			goto err_adapter;
488 	}
489 
490 	dev->can.state = CAN_STATE_ERROR_ACTIVE;
491 
492 	return 0;
493 
494 err_adapter:
495 	if (err == -ENODEV)
496 		netif_device_detach(dev->netdev);
497 
498 	netdev_warn(netdev, "couldn't submit control: %d\n", err);
499 
500 	for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++) {
501 		usb_free_urb(dev->tx_contexts[i].urb);
502 		dev->tx_contexts[i].urb = NULL;
503 	}
504 err_tx:
505 	usb_kill_anchored_urbs(&dev->rx_submitted);
506 
507 	return err;
508 }
509 
510 /*
511  * called by netdev to open the corresponding CAN interface.
512  */
513 static int peak_usb_ndo_open(struct net_device *netdev)
514 {
515 	struct peak_usb_device *dev = netdev_priv(netdev);
516 	int err;
517 
518 	/* common open */
519 	err = open_candev(netdev);
520 	if (err)
521 		return err;
522 
523 	/* finally start device */
524 	err = peak_usb_start(dev);
525 	if (err) {
526 		netdev_err(netdev, "couldn't start device: %d\n", err);
527 		close_candev(netdev);
528 		return err;
529 	}
530 
531 	netif_start_queue(netdev);
532 
533 	return 0;
534 }
535 
536 /*
537  * unlink in-flight Rx and Tx urbs and free their memory.
538  */
539 static void peak_usb_unlink_all_urbs(struct peak_usb_device *dev)
540 {
541 	int i;
542 
543 	/* free all Rx (submitted) urbs */
544 	usb_kill_anchored_urbs(&dev->rx_submitted);
545 
546 	/* free unsubmitted Tx urbs first */
547 	for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++) {
548 		struct urb *urb = dev->tx_contexts[i].urb;
549 
550 		if (!urb ||
551 		    dev->tx_contexts[i].echo_index != PCAN_USB_MAX_TX_URBS) {
552 			/*
553 			 * this urb is already released or always submitted,
554 			 * let usb core free by itself
555 			 */
556 			continue;
557 		}
558 
559 		usb_free_urb(urb);
560 		dev->tx_contexts[i].urb = NULL;
561 	}
562 
563 	/* then free all submitted Tx urbs */
564 	usb_kill_anchored_urbs(&dev->tx_submitted);
565 	atomic_set(&dev->active_tx_urbs, 0);
566 }
567 
568 /*
569  * called by netdev to close the corresponding CAN interface.
570  */
571 static int peak_usb_ndo_stop(struct net_device *netdev)
572 {
573 	struct peak_usb_device *dev = netdev_priv(netdev);
574 
575 	dev->state &= ~PCAN_USB_STATE_STARTED;
576 	netif_stop_queue(netdev);
577 
578 	/* unlink all pending urbs and free used memory */
579 	peak_usb_unlink_all_urbs(dev);
580 
581 	if (dev->adapter->dev_stop)
582 		dev->adapter->dev_stop(dev);
583 
584 	close_candev(netdev);
585 
586 	dev->can.state = CAN_STATE_STOPPED;
587 
588 	/* can set bus off now */
589 	if (dev->adapter->dev_set_bus) {
590 		int err = dev->adapter->dev_set_bus(dev, 0);
591 		if (err)
592 			return err;
593 	}
594 
595 	return 0;
596 }
597 
598 /*
599  * handle end of waiting for the device to reset
600  */
601 void peak_usb_restart_complete(struct peak_usb_device *dev)
602 {
603 	/* finally MUST update can state */
604 	dev->can.state = CAN_STATE_ERROR_ACTIVE;
605 
606 	/* netdev queue can be awaken now */
607 	netif_wake_queue(dev->netdev);
608 }
609 
610 void peak_usb_async_complete(struct urb *urb)
611 {
612 	kfree(urb->transfer_buffer);
613 	usb_free_urb(urb);
614 }
615 
616 /*
617  * device (auto-)restart mechanism runs in a timer context =>
618  * MUST handle restart with asynchronous usb transfers
619  */
620 static int peak_usb_restart(struct peak_usb_device *dev)
621 {
622 	struct urb *urb;
623 	int err;
624 	u8 *buf;
625 
626 	/*
627 	 * if device doesn't define any asynchronous restart handler, simply
628 	 * wake the netdev queue up
629 	 */
630 	if (!dev->adapter->dev_restart_async) {
631 		peak_usb_restart_complete(dev);
632 		return 0;
633 	}
634 
635 	/* first allocate a urb to handle the asynchronous steps */
636 	urb = usb_alloc_urb(0, GFP_ATOMIC);
637 	if (!urb)
638 		return -ENOMEM;
639 
640 	/* also allocate enough space for the commands to send */
641 	buf = kmalloc(PCAN_USB_MAX_CMD_LEN, GFP_ATOMIC);
642 	if (!buf) {
643 		usb_free_urb(urb);
644 		return -ENOMEM;
645 	}
646 
647 	/* call the device specific handler for the restart */
648 	err = dev->adapter->dev_restart_async(dev, urb, buf);
649 	if (!err)
650 		return 0;
651 
652 	kfree(buf);
653 	usb_free_urb(urb);
654 
655 	return err;
656 }
657 
658 /*
659  * candev callback used to change CAN mode.
660  * Warning: this is called from a timer context!
661  */
662 static int peak_usb_set_mode(struct net_device *netdev, enum can_mode mode)
663 {
664 	struct peak_usb_device *dev = netdev_priv(netdev);
665 	int err = 0;
666 
667 	switch (mode) {
668 	case CAN_MODE_START:
669 		err = peak_usb_restart(dev);
670 		if (err)
671 			netdev_err(netdev, "couldn't start device (err %d)\n",
672 				   err);
673 		break;
674 
675 	default:
676 		return -EOPNOTSUPP;
677 	}
678 
679 	return err;
680 }
681 
682 /*
683  * candev callback used to set device nominal/arbitration bitrate.
684  */
685 static int peak_usb_set_bittiming(struct net_device *netdev)
686 {
687 	struct peak_usb_device *dev = netdev_priv(netdev);
688 	const struct peak_usb_adapter *pa = dev->adapter;
689 
690 	if (pa->dev_set_bittiming) {
691 		struct can_bittiming *bt = &dev->can.bittiming;
692 		int err = pa->dev_set_bittiming(dev, bt);
693 
694 		if (err)
695 			netdev_info(netdev, "couldn't set bitrate (err %d)\n",
696 				    err);
697 		return err;
698 	}
699 
700 	return 0;
701 }
702 
703 /*
704  * candev callback used to set device data bitrate.
705  */
706 static int peak_usb_set_data_bittiming(struct net_device *netdev)
707 {
708 	struct peak_usb_device *dev = netdev_priv(netdev);
709 	const struct peak_usb_adapter *pa = dev->adapter;
710 
711 	if (pa->dev_set_data_bittiming) {
712 		struct can_bittiming *bt = &dev->can.data_bittiming;
713 		int err = pa->dev_set_data_bittiming(dev, bt);
714 
715 		if (err)
716 			netdev_info(netdev,
717 				    "couldn't set data bitrate (err %d)\n",
718 				    err);
719 
720 		return err;
721 	}
722 
723 	return 0;
724 }
725 
726 static const struct net_device_ops peak_usb_netdev_ops = {
727 	.ndo_open = peak_usb_ndo_open,
728 	.ndo_stop = peak_usb_ndo_stop,
729 	.ndo_start_xmit = peak_usb_ndo_start_xmit,
730 	.ndo_change_mtu = can_change_mtu,
731 };
732 
733 /*
734  * create one device which is attached to CAN controller #ctrl_idx of the
735  * usb adapter.
736  */
737 static int peak_usb_create_dev(const struct peak_usb_adapter *peak_usb_adapter,
738 			       struct usb_interface *intf, int ctrl_idx)
739 {
740 	struct usb_device *usb_dev = interface_to_usbdev(intf);
741 	int sizeof_candev = peak_usb_adapter->sizeof_dev_private;
742 	struct peak_usb_device *dev;
743 	struct net_device *netdev;
744 	int i, err;
745 	u16 tmp16;
746 
747 	if (sizeof_candev < sizeof(struct peak_usb_device))
748 		sizeof_candev = sizeof(struct peak_usb_device);
749 
750 	netdev = alloc_candev(sizeof_candev, PCAN_USB_MAX_TX_URBS);
751 	if (!netdev) {
752 		dev_err(&intf->dev, "%s: couldn't alloc candev\n",
753 			PCAN_USB_DRIVER_NAME);
754 		return -ENOMEM;
755 	}
756 
757 	dev = netdev_priv(netdev);
758 
759 	/* allocate a buffer large enough to send commands */
760 	dev->cmd_buf = kmalloc(PCAN_USB_MAX_CMD_LEN, GFP_KERNEL);
761 	if (!dev->cmd_buf) {
762 		err = -ENOMEM;
763 		goto lbl_free_candev;
764 	}
765 
766 	dev->udev = usb_dev;
767 	dev->netdev = netdev;
768 	dev->adapter = peak_usb_adapter;
769 	dev->ctrl_idx = ctrl_idx;
770 	dev->state = PCAN_USB_STATE_CONNECTED;
771 
772 	dev->ep_msg_in = peak_usb_adapter->ep_msg_in;
773 	dev->ep_msg_out = peak_usb_adapter->ep_msg_out[ctrl_idx];
774 
775 	dev->can.clock = peak_usb_adapter->clock;
776 	dev->can.bittiming_const = peak_usb_adapter->bittiming_const;
777 	dev->can.do_set_bittiming = peak_usb_set_bittiming;
778 	dev->can.data_bittiming_const = peak_usb_adapter->data_bittiming_const;
779 	dev->can.do_set_data_bittiming = peak_usb_set_data_bittiming;
780 	dev->can.do_set_mode = peak_usb_set_mode;
781 	dev->can.do_get_berr_counter = peak_usb_adapter->do_get_berr_counter;
782 	dev->can.ctrlmode_supported = peak_usb_adapter->ctrlmode_supported;
783 
784 	netdev->netdev_ops = &peak_usb_netdev_ops;
785 
786 	netdev->flags |= IFF_ECHO; /* we support local echo */
787 
788 	init_usb_anchor(&dev->rx_submitted);
789 
790 	init_usb_anchor(&dev->tx_submitted);
791 	atomic_set(&dev->active_tx_urbs, 0);
792 
793 	for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++)
794 		dev->tx_contexts[i].echo_index = PCAN_USB_MAX_TX_URBS;
795 
796 	dev->prev_siblings = usb_get_intfdata(intf);
797 	usb_set_intfdata(intf, dev);
798 
799 	SET_NETDEV_DEV(netdev, &intf->dev);
800 	netdev->dev_id = ctrl_idx;
801 
802 	err = register_candev(netdev);
803 	if (err) {
804 		dev_err(&intf->dev, "couldn't register CAN device: %d\n", err);
805 		goto lbl_restore_intf_data;
806 	}
807 
808 	if (dev->prev_siblings)
809 		(dev->prev_siblings)->next_siblings = dev;
810 
811 	/* keep hw revision into the netdevice */
812 	tmp16 = le16_to_cpu(usb_dev->descriptor.bcdDevice);
813 	dev->device_rev = tmp16 >> 8;
814 
815 	if (dev->adapter->dev_init) {
816 		err = dev->adapter->dev_init(dev);
817 		if (err)
818 			goto lbl_unregister_candev;
819 	}
820 
821 	/* set bus off */
822 	if (dev->adapter->dev_set_bus) {
823 		err = dev->adapter->dev_set_bus(dev, 0);
824 		if (err)
825 			goto lbl_unregister_candev;
826 	}
827 
828 	/* get device number early */
829 	if (dev->adapter->dev_get_device_id)
830 		dev->adapter->dev_get_device_id(dev, &dev->device_number);
831 
832 	netdev_info(netdev, "attached to %s channel %u (device %u)\n",
833 			peak_usb_adapter->name, ctrl_idx, dev->device_number);
834 
835 	return 0;
836 
837 lbl_unregister_candev:
838 	unregister_candev(netdev);
839 
840 lbl_restore_intf_data:
841 	usb_set_intfdata(intf, dev->prev_siblings);
842 	kfree(dev->cmd_buf);
843 
844 lbl_free_candev:
845 	free_candev(netdev);
846 
847 	return err;
848 }
849 
850 /*
851  * called by the usb core when the device is unplugged from the system
852  */
853 static void peak_usb_disconnect(struct usb_interface *intf)
854 {
855 	struct peak_usb_device *dev;
856 	struct peak_usb_device *dev_prev_siblings;
857 
858 	/* unregister as many netdev devices as siblings */
859 	for (dev = usb_get_intfdata(intf); dev; dev = dev_prev_siblings) {
860 		struct net_device *netdev = dev->netdev;
861 		char name[IFNAMSIZ];
862 
863 		dev_prev_siblings = dev->prev_siblings;
864 		dev->state &= ~PCAN_USB_STATE_CONNECTED;
865 		strncpy(name, netdev->name, IFNAMSIZ);
866 
867 		unregister_netdev(netdev);
868 
869 		kfree(dev->cmd_buf);
870 		dev->next_siblings = NULL;
871 		if (dev->adapter->dev_free)
872 			dev->adapter->dev_free(dev);
873 
874 		free_candev(netdev);
875 		dev_info(&intf->dev, "%s removed\n", name);
876 	}
877 
878 	usb_set_intfdata(intf, NULL);
879 }
880 
881 /*
882  * probe function for new PEAK-System devices
883  */
884 static int peak_usb_probe(struct usb_interface *intf,
885 			  const struct usb_device_id *id)
886 {
887 	struct usb_device *usb_dev = interface_to_usbdev(intf);
888 	const u16 usb_id_product = le16_to_cpu(usb_dev->descriptor.idProduct);
889 	const struct peak_usb_adapter *peak_usb_adapter = NULL;
890 	int i, err = -ENOMEM;
891 
892 	/* get corresponding PCAN-USB adapter */
893 	for (i = 0; i < ARRAY_SIZE(peak_usb_adapters_list); i++)
894 		if (peak_usb_adapters_list[i]->device_id == usb_id_product) {
895 			peak_usb_adapter = peak_usb_adapters_list[i];
896 			break;
897 		}
898 
899 	if (!peak_usb_adapter) {
900 		/* should never come except device_id bad usage in this file */
901 		pr_err("%s: didn't find device id. 0x%x in devices list\n",
902 			PCAN_USB_DRIVER_NAME, usb_id_product);
903 		return -ENODEV;
904 	}
905 
906 	/* got corresponding adapter: check if it handles current interface */
907 	if (peak_usb_adapter->intf_probe) {
908 		err = peak_usb_adapter->intf_probe(intf);
909 		if (err)
910 			return err;
911 	}
912 
913 	for (i = 0; i < peak_usb_adapter->ctrl_count; i++) {
914 		err = peak_usb_create_dev(peak_usb_adapter, intf, i);
915 		if (err) {
916 			/* deregister already created devices */
917 			peak_usb_disconnect(intf);
918 			break;
919 		}
920 	}
921 
922 	return err;
923 }
924 
925 /* usb specific object needed to register this driver with the usb subsystem */
926 static struct usb_driver peak_usb_driver = {
927 	.name = PCAN_USB_DRIVER_NAME,
928 	.disconnect = peak_usb_disconnect,
929 	.probe = peak_usb_probe,
930 	.id_table = peak_usb_table,
931 };
932 
933 static int __init peak_usb_init(void)
934 {
935 	int err;
936 
937 	/* register this driver with the USB subsystem */
938 	err = usb_register(&peak_usb_driver);
939 	if (err)
940 		pr_err("%s: usb_register failed (err %d)\n",
941 			PCAN_USB_DRIVER_NAME, err);
942 
943 	return err;
944 }
945 
946 static int peak_usb_do_device_exit(struct device *d, void *arg)
947 {
948 	struct usb_interface *intf = to_usb_interface(d);
949 	struct peak_usb_device *dev;
950 
951 	/* stop as many netdev devices as siblings */
952 	for (dev = usb_get_intfdata(intf); dev; dev = dev->prev_siblings) {
953 		struct net_device *netdev = dev->netdev;
954 
955 		if (netif_device_present(netdev))
956 			if (dev->adapter->dev_exit)
957 				dev->adapter->dev_exit(dev);
958 	}
959 
960 	return 0;
961 }
962 
963 static void __exit peak_usb_exit(void)
964 {
965 	int err;
966 
967 	/* last chance do send any synchronous commands here */
968 	err = driver_for_each_device(&peak_usb_driver.drvwrap.driver, NULL,
969 				     NULL, peak_usb_do_device_exit);
970 	if (err)
971 		pr_err("%s: failed to stop all can devices (err %d)\n",
972 			PCAN_USB_DRIVER_NAME, err);
973 
974 	/* deregister this driver with the USB subsystem */
975 	usb_deregister(&peak_usb_driver);
976 
977 	pr_info("%s: PCAN-USB interfaces driver unloaded\n",
978 		PCAN_USB_DRIVER_NAME);
979 }
980 
981 module_init(peak_usb_init);
982 module_exit(peak_usb_exit);
983