pcan_usb_core.c revision 823d7a1f761d6404babaab04cc8b1724186cf2c8
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
32MODULE_AUTHOR("Stephane Grosjean <s.grosjean@peak-system.com>");
33MODULE_DESCRIPTION("CAN driver for PEAK-System USB adapters");
34MODULE_LICENSE("GPL v2");
35
36/* Table of devices that work with this driver */
37static 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	{} /* Terminating entry */
41};
42
43MODULE_DEVICE_TABLE(usb, peak_usb_table);
44
45/* List of supported PCAN-USB adapters (NULL terminated list) */
46static struct peak_usb_adapter *peak_usb_adapters_list[] = {
47	&pcan_usb,
48	&pcan_usb_pro,
49	NULL,
50};
51
52/*
53 * dump memory
54 */
55#define DUMP_WIDTH	16
56void pcan_dump_mem(char *prompt, void *p, int l)
57{
58	pr_info("%s dumping %s (%d bytes):\n",
59		PCAN_USB_DRIVER_NAME, prompt ? prompt : "memory", l);
60	print_hex_dump(KERN_INFO, PCAN_USB_DRIVER_NAME " ", DUMP_PREFIX_NONE,
61		       DUMP_WIDTH, 1, p, l, false);
62}
63
64/*
65 * initialize a time_ref object with usb adapter own settings
66 */
67void peak_usb_init_time_ref(struct peak_time_ref *time_ref,
68			    struct peak_usb_adapter *adapter)
69{
70	if (time_ref) {
71		memset(time_ref, 0, sizeof(struct peak_time_ref));
72		time_ref->adapter = adapter;
73	}
74}
75
76static void peak_usb_add_us(struct timeval *tv, u32 delta_us)
77{
78	/* number of s. to add to final time */
79	u32 delta_s = delta_us / 1000000;
80
81	delta_us -= delta_s * 1000000;
82
83	tv->tv_usec += delta_us;
84	if (tv->tv_usec >= 1000000) {
85		tv->tv_usec -= 1000000;
86		delta_s++;
87	}
88	tv->tv_sec += delta_s;
89}
90
91/*
92 * sometimes, another now may be  more recent than current one...
93 */
94void peak_usb_update_ts_now(struct peak_time_ref *time_ref, u32 ts_now)
95{
96	time_ref->ts_dev_2 = ts_now;
97
98	/* should wait at least two passes before computing */
99	if (time_ref->tv_host.tv_sec > 0) {
100		u32 delta_ts = time_ref->ts_dev_2 - time_ref->ts_dev_1;
101
102		if (time_ref->ts_dev_2 < time_ref->ts_dev_1)
103			delta_ts &= (1 << time_ref->adapter->ts_used_bits) - 1;
104
105		time_ref->ts_total += delta_ts;
106	}
107}
108
109/*
110 * register device timestamp as now
111 */
112void peak_usb_set_ts_now(struct peak_time_ref *time_ref, u32 ts_now)
113{
114	if (time_ref->tv_host_0.tv_sec == 0) {
115		/* use monotonic clock to correctly compute further deltas */
116		time_ref->tv_host_0 = ktime_to_timeval(ktime_get());
117		time_ref->tv_host.tv_sec = 0;
118	} else {
119		/*
120		 * delta_us should not be >= 2^32 => delta_s should be < 4294
121		 * handle 32-bits wrapping here: if count of s. reaches 4200,
122		 * reset counters and change time base
123		 */
124		if (time_ref->tv_host.tv_sec != 0) {
125			u32 delta_s = time_ref->tv_host.tv_sec
126						- time_ref->tv_host_0.tv_sec;
127			if (delta_s > 4200) {
128				time_ref->tv_host_0 = time_ref->tv_host;
129				time_ref->ts_total = 0;
130			}
131		}
132
133		time_ref->tv_host = ktime_to_timeval(ktime_get());
134		time_ref->tick_count++;
135	}
136
137	time_ref->ts_dev_1 = time_ref->ts_dev_2;
138	peak_usb_update_ts_now(time_ref, ts_now);
139}
140
141/*
142 * compute timeval according to current ts and time_ref data
143 */
144void peak_usb_get_ts_tv(struct peak_time_ref *time_ref, u32 ts,
145			struct timeval *tv)
146{
147	/* protect from getting timeval before setting now */
148	if (time_ref->tv_host.tv_sec > 0) {
149		u64 delta_us;
150
151		delta_us = ts - time_ref->ts_dev_2;
152		if (ts < time_ref->ts_dev_2)
153			delta_us &= (1 << time_ref->adapter->ts_used_bits) - 1;
154
155		delta_us += time_ref->ts_total;
156
157		delta_us *= time_ref->adapter->us_per_ts_scale;
158		delta_us >>= time_ref->adapter->us_per_ts_shift;
159
160		*tv = time_ref->tv_host_0;
161		peak_usb_add_us(tv, (u32)delta_us);
162	} else {
163		*tv = ktime_to_timeval(ktime_get());
164	}
165}
166
167/*
168 * callback for bulk Rx urb
169 */
170static void peak_usb_read_bulk_callback(struct urb *urb)
171{
172	struct peak_usb_device *dev = urb->context;
173	struct net_device *netdev;
174	int err;
175
176	netdev = dev->netdev;
177
178	if (!netif_device_present(netdev))
179		return;
180
181	/* check reception status */
182	switch (urb->status) {
183	case 0:
184		/* success */
185		break;
186
187	case -EILSEQ:
188	case -ENOENT:
189	case -ECONNRESET:
190	case -ESHUTDOWN:
191		return;
192
193	default:
194		if (net_ratelimit())
195			netdev_err(netdev,
196				   "Rx urb aborted (%d)\n", urb->status);
197		goto resubmit_urb;
198	}
199
200	/* protect from any incoming empty msgs */
201	if ((urb->actual_length > 0) && (dev->adapter->dev_decode_buf)) {
202		/* handle these kinds of msgs only if _start callback called */
203		if (dev->state & PCAN_USB_STATE_STARTED) {
204			err = dev->adapter->dev_decode_buf(dev, urb);
205			if (err)
206				pcan_dump_mem("received usb message",
207					      urb->transfer_buffer,
208					      urb->transfer_buffer_length);
209		}
210	}
211
212resubmit_urb:
213	usb_fill_bulk_urb(urb, dev->udev,
214		usb_rcvbulkpipe(dev->udev, dev->ep_msg_in),
215		urb->transfer_buffer, dev->adapter->rx_buffer_size,
216		peak_usb_read_bulk_callback, dev);
217
218	usb_anchor_urb(urb, &dev->rx_submitted);
219	err = usb_submit_urb(urb, GFP_ATOMIC);
220	if (!err)
221		return;
222
223	usb_unanchor_urb(urb);
224
225	if (err == -ENODEV)
226		netif_device_detach(netdev);
227	else
228		netdev_err(netdev, "failed resubmitting read bulk urb: %d\n",
229			   err);
230}
231
232/*
233 * callback for bulk Tx urb
234 */
235static void peak_usb_write_bulk_callback(struct urb *urb)
236{
237	struct peak_tx_urb_context *context = urb->context;
238	struct peak_usb_device *dev;
239	struct net_device *netdev;
240
241	BUG_ON(!context);
242
243	dev = context->dev;
244	netdev = dev->netdev;
245
246	atomic_dec(&dev->active_tx_urbs);
247
248	if (!netif_device_present(netdev))
249		return;
250
251	/* check tx status */
252	switch (urb->status) {
253	case 0:
254		/* transmission complete */
255		netdev->stats.tx_packets++;
256		netdev->stats.tx_bytes += context->dlc;
257
258		/* prevent tx timeout */
259		netdev->trans_start = jiffies;
260		break;
261
262	default:
263		if (net_ratelimit())
264			netdev_err(netdev, "Tx urb aborted (%d)\n",
265				   urb->status);
266	case -EPROTO:
267	case -ENOENT:
268	case -ECONNRESET:
269	case -ESHUTDOWN:
270
271		break;
272	}
273
274	/* should always release echo skb and corresponding context */
275	can_get_echo_skb(netdev, context->echo_index);
276	context->echo_index = PCAN_USB_MAX_TX_URBS;
277
278	/* do wakeup tx queue in case of success only */
279	if (!urb->status)
280		netif_wake_queue(netdev);
281}
282
283/*
284 * called by netdev to send one skb on the CAN interface.
285 */
286static netdev_tx_t peak_usb_ndo_start_xmit(struct sk_buff *skb,
287					   struct net_device *netdev)
288{
289	struct peak_usb_device *dev = netdev_priv(netdev);
290	struct peak_tx_urb_context *context = NULL;
291	struct net_device_stats *stats = &netdev->stats;
292	struct can_frame *cf = (struct can_frame *)skb->data;
293	struct urb *urb;
294	u8 *obuf;
295	int i, err;
296	size_t size = dev->adapter->tx_buffer_size;
297
298	if (can_dropped_invalid_skb(netdev, skb))
299		return NETDEV_TX_OK;
300
301	for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++)
302		if (dev->tx_contexts[i].echo_index == PCAN_USB_MAX_TX_URBS) {
303			context = dev->tx_contexts + i;
304			break;
305		}
306
307	if (!context) {
308		/* should not occur except during restart */
309		return NETDEV_TX_BUSY;
310	}
311
312	urb = context->urb;
313	obuf = urb->transfer_buffer;
314
315	err = dev->adapter->dev_encode_msg(dev, skb, obuf, &size);
316	if (err) {
317		if (net_ratelimit())
318			netdev_err(netdev, "packet dropped\n");
319		dev_kfree_skb(skb);
320		stats->tx_dropped++;
321		return NETDEV_TX_OK;
322	}
323
324	context->echo_index = i;
325	context->dlc = cf->can_dlc;
326
327	usb_anchor_urb(urb, &dev->tx_submitted);
328
329	can_put_echo_skb(skb, netdev, context->echo_index);
330
331	atomic_inc(&dev->active_tx_urbs);
332
333	err = usb_submit_urb(urb, GFP_ATOMIC);
334	if (err) {
335		can_free_echo_skb(netdev, context->echo_index);
336
337		usb_unanchor_urb(urb);
338
339		/* this context is not used in fact */
340		context->echo_index = PCAN_USB_MAX_TX_URBS;
341
342		atomic_dec(&dev->active_tx_urbs);
343
344		switch (err) {
345		case -ENODEV:
346			netif_device_detach(netdev);
347			break;
348		default:
349			netdev_warn(netdev, "tx urb submitting failed err=%d\n",
350				    err);
351		case -ENOENT:
352			/* cable unplugged */
353			stats->tx_dropped++;
354		}
355	} else {
356		netdev->trans_start = jiffies;
357
358		/* slow down tx path */
359		if (atomic_read(&dev->active_tx_urbs) >= PCAN_USB_MAX_TX_URBS)
360			netif_stop_queue(netdev);
361	}
362
363	return NETDEV_TX_OK;
364}
365
366/*
367 * start the CAN interface.
368 * Rx and Tx urbs are allocated here. Rx urbs are submitted here.
369 */
370static int peak_usb_start(struct peak_usb_device *dev)
371{
372	struct net_device *netdev = dev->netdev;
373	int err, i;
374
375	for (i = 0; i < PCAN_USB_MAX_RX_URBS; i++) {
376		struct urb *urb;
377		u8 *buf;
378
379		/* create a URB, and a buffer for it, to receive usb messages */
380		urb = usb_alloc_urb(0, GFP_KERNEL);
381		if (!urb) {
382			netdev_err(netdev, "No memory left for URBs\n");
383			err = -ENOMEM;
384			break;
385		}
386
387		buf = kmalloc(dev->adapter->rx_buffer_size, GFP_KERNEL);
388		if (!buf) {
389			netdev_err(netdev, "No memory left for USB buffer\n");
390			usb_free_urb(urb);
391			err = -ENOMEM;
392			break;
393		}
394
395		usb_fill_bulk_urb(urb, dev->udev,
396			usb_rcvbulkpipe(dev->udev, dev->ep_msg_in),
397			buf, dev->adapter->rx_buffer_size,
398			peak_usb_read_bulk_callback, dev);
399
400		/* ask last usb_free_urb() to also kfree() transfer_buffer */
401		urb->transfer_flags |= URB_FREE_BUFFER;
402		usb_anchor_urb(urb, &dev->rx_submitted);
403
404		err = usb_submit_urb(urb, GFP_KERNEL);
405		if (err) {
406			if (err == -ENODEV)
407				netif_device_detach(dev->netdev);
408
409			usb_unanchor_urb(urb);
410			kfree(buf);
411			usb_free_urb(urb);
412			break;
413		}
414
415		/* drop reference, USB core will take care of freeing it */
416		usb_free_urb(urb);
417	}
418
419	/* did we submit any URBs? Warn if we was not able to submit all urbs */
420	if (i < PCAN_USB_MAX_RX_URBS) {
421		if (i == 0) {
422			netdev_err(netdev, "couldn't setup any rx URB\n");
423			return err;
424		}
425
426		netdev_warn(netdev, "rx performance may be slow\n");
427	}
428
429	/* pre-alloc tx buffers and corresponding urbs */
430	for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++) {
431		struct peak_tx_urb_context *context;
432		struct urb *urb;
433		u8 *buf;
434
435		/* create a URB and a buffer for it, to transmit usb messages */
436		urb = usb_alloc_urb(0, GFP_KERNEL);
437		if (!urb) {
438			netdev_err(netdev, "No memory left for URBs\n");
439			err = -ENOMEM;
440			break;
441		}
442
443		buf = kmalloc(dev->adapter->tx_buffer_size, GFP_KERNEL);
444		if (!buf) {
445			netdev_err(netdev, "No memory left for USB buffer\n");
446			usb_free_urb(urb);
447			err = -ENOMEM;
448			break;
449		}
450
451		context = dev->tx_contexts + i;
452		context->dev = dev;
453		context->urb = urb;
454
455		usb_fill_bulk_urb(urb, dev->udev,
456			usb_sndbulkpipe(dev->udev, dev->ep_msg_out),
457			buf, dev->adapter->tx_buffer_size,
458			peak_usb_write_bulk_callback, context);
459
460		/* ask last usb_free_urb() to also kfree() transfer_buffer */
461		urb->transfer_flags |= URB_FREE_BUFFER;
462	}
463
464	/* warn if we were not able to allocate enough tx contexts */
465	if (i < PCAN_USB_MAX_TX_URBS) {
466		if (i == 0) {
467			netdev_err(netdev, "couldn't setup any tx URB\n");
468			return err;
469		}
470
471		netdev_warn(netdev, "tx performance may be slow\n");
472	}
473
474	if (dev->adapter->dev_start) {
475		err = dev->adapter->dev_start(dev);
476		if (err)
477			goto failed;
478	}
479
480	dev->state |= PCAN_USB_STATE_STARTED;
481
482	/* can set bus on now */
483	if (dev->adapter->dev_set_bus) {
484		err = dev->adapter->dev_set_bus(dev, 1);
485		if (err)
486			goto failed;
487	}
488
489	dev->can.state = CAN_STATE_ERROR_ACTIVE;
490
491	return 0;
492
493failed:
494	if (err == -ENODEV)
495		netif_device_detach(dev->netdev);
496
497	netdev_warn(netdev, "couldn't submit control: %d\n", err);
498
499	return err;
500}
501
502/*
503 * called by netdev to open the corresponding CAN interface.
504 */
505static int peak_usb_ndo_open(struct net_device *netdev)
506{
507	struct peak_usb_device *dev = netdev_priv(netdev);
508	int err;
509
510	/* common open */
511	err = open_candev(netdev);
512	if (err)
513		return err;
514
515	/* finally start device */
516	err = peak_usb_start(dev);
517	if (err) {
518		netdev_err(netdev, "couldn't start device: %d\n", err);
519		close_candev(netdev);
520		return err;
521	}
522
523	netif_start_queue(netdev);
524
525	return 0;
526}
527
528/*
529 * unlink in-flight Rx and Tx urbs and free their memory.
530 */
531static void peak_usb_unlink_all_urbs(struct peak_usb_device *dev)
532{
533	int i;
534
535	/* free all Rx (submitted) urbs */
536	usb_kill_anchored_urbs(&dev->rx_submitted);
537
538	/* free unsubmitted Tx urbs first */
539	for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++) {
540		struct urb *urb = dev->tx_contexts[i].urb;
541
542		if (!urb ||
543		    dev->tx_contexts[i].echo_index != PCAN_USB_MAX_TX_URBS) {
544			/*
545			 * this urb is already released or always submitted,
546			 * let usb core free by itself
547			 */
548			continue;
549		}
550
551		usb_free_urb(urb);
552		dev->tx_contexts[i].urb = NULL;
553	}
554
555	/* then free all submitted Tx urbs */
556	usb_kill_anchored_urbs(&dev->tx_submitted);
557	atomic_set(&dev->active_tx_urbs, 0);
558}
559
560/*
561 * called by netdev to close the corresponding CAN interface.
562 */
563static int peak_usb_ndo_stop(struct net_device *netdev)
564{
565	struct peak_usb_device *dev = netdev_priv(netdev);
566
567	dev->state &= ~PCAN_USB_STATE_STARTED;
568	netif_stop_queue(netdev);
569
570	/* unlink all pending urbs and free used memory */
571	peak_usb_unlink_all_urbs(dev);
572
573	if (dev->adapter->dev_stop)
574		dev->adapter->dev_stop(dev);
575
576	close_candev(netdev);
577
578	dev->can.state = CAN_STATE_STOPPED;
579
580	/* can set bus off now */
581	if (dev->adapter->dev_set_bus) {
582		int err = dev->adapter->dev_set_bus(dev, 0);
583		if (err)
584			return err;
585	}
586
587	return 0;
588}
589
590/*
591 * handle end of waiting for the device to reset
592 */
593void peak_usb_restart_complete(struct peak_usb_device *dev)
594{
595	/* finally MUST update can state */
596	dev->can.state = CAN_STATE_ERROR_ACTIVE;
597
598	/* netdev queue can be awaken now */
599	netif_wake_queue(dev->netdev);
600}
601
602void peak_usb_async_complete(struct urb *urb)
603{
604	kfree(urb->transfer_buffer);
605	usb_free_urb(urb);
606}
607
608/*
609 * device (auto-)restart mechanism runs in a timer context =>
610 * MUST handle restart with asynchronous usb transfers
611 */
612static int peak_usb_restart(struct peak_usb_device *dev)
613{
614	struct urb *urb;
615	int err;
616	u8 *buf;
617
618	/*
619	 * if device doesn't define any asynchronous restart handler, simply
620	 * wake the netdev queue up
621	 */
622	if (!dev->adapter->dev_restart_async) {
623		peak_usb_restart_complete(dev);
624		return 0;
625	}
626
627	/* first allocate a urb to handle the asynchronous steps */
628	urb = usb_alloc_urb(0, GFP_ATOMIC);
629	if (!urb) {
630		netdev_err(dev->netdev, "no memory left for urb\n");
631		return -ENOMEM;
632	}
633
634	/* also allocate enough space for the commands to send */
635	buf = kmalloc(PCAN_USB_MAX_CMD_LEN, GFP_ATOMIC);
636	if (!buf) {
637		netdev_err(dev->netdev, "no memory left for async cmd\n");
638		usb_free_urb(urb);
639		return -ENOMEM;
640	}
641
642	/* call the device specific handler for the restart */
643	err = dev->adapter->dev_restart_async(dev, urb, buf);
644	if (!err)
645		return 0;
646
647	kfree(buf);
648	usb_free_urb(urb);
649
650	return err;
651}
652
653/*
654 * candev callback used to change CAN mode.
655 * Warning: this is called from a timer context!
656 */
657static int peak_usb_set_mode(struct net_device *netdev, enum can_mode mode)
658{
659	struct peak_usb_device *dev = netdev_priv(netdev);
660	int err = 0;
661
662	switch (mode) {
663	case CAN_MODE_START:
664		err = peak_usb_restart(dev);
665		if (err)
666			netdev_err(netdev, "couldn't start device (err %d)\n",
667				   err);
668		break;
669
670	default:
671		return -EOPNOTSUPP;
672	}
673
674	return err;
675}
676
677/*
678 * candev callback used to set device bitrate.
679 */
680static int peak_usb_set_bittiming(struct net_device *netdev)
681{
682	struct peak_usb_device *dev = netdev_priv(netdev);
683	struct can_bittiming *bt = &dev->can.bittiming;
684
685	if (dev->adapter->dev_set_bittiming) {
686		int err = dev->adapter->dev_set_bittiming(dev, bt);
687
688		if (err)
689			netdev_info(netdev, "couldn't set bitrate (err %d)\n",
690				err);
691		return err;
692	}
693
694	return 0;
695}
696
697static const struct net_device_ops peak_usb_netdev_ops = {
698	.ndo_open = peak_usb_ndo_open,
699	.ndo_stop = peak_usb_ndo_stop,
700	.ndo_start_xmit = peak_usb_ndo_start_xmit,
701};
702
703/*
704 * create one device which is attached to CAN controller #ctrl_idx of the
705 * usb adapter.
706 */
707static int peak_usb_create_dev(struct peak_usb_adapter *peak_usb_adapter,
708			       struct usb_interface *intf, int ctrl_idx)
709{
710	struct usb_device *usb_dev = interface_to_usbdev(intf);
711	int sizeof_candev = peak_usb_adapter->sizeof_dev_private;
712	struct peak_usb_device *dev;
713	struct net_device *netdev;
714	int i, err;
715	u16 tmp16;
716
717	if (sizeof_candev < sizeof(struct peak_usb_device))
718		sizeof_candev = sizeof(struct peak_usb_device);
719
720	netdev = alloc_candev(sizeof_candev, PCAN_USB_MAX_TX_URBS);
721	if (!netdev) {
722		dev_err(&intf->dev, "%s: couldn't alloc candev\n",
723			PCAN_USB_DRIVER_NAME);
724		return -ENOMEM;
725	}
726
727	dev = netdev_priv(netdev);
728
729	/* allocate a buffer large enough to send commands */
730	dev->cmd_buf = kmalloc(PCAN_USB_MAX_CMD_LEN, GFP_KERNEL);
731	if (!dev->cmd_buf) {
732		dev_err(&intf->dev, "%s: couldn't alloc cmd buffer\n",
733			PCAN_USB_DRIVER_NAME);
734		err = -ENOMEM;
735		goto lbl_set_intf_data;
736	}
737
738	dev->udev = usb_dev;
739	dev->netdev = netdev;
740	dev->adapter = peak_usb_adapter;
741	dev->ctrl_idx = ctrl_idx;
742	dev->state = PCAN_USB_STATE_CONNECTED;
743
744	dev->ep_msg_in = peak_usb_adapter->ep_msg_in;
745	dev->ep_msg_out = peak_usb_adapter->ep_msg_out[ctrl_idx];
746
747	dev->can.clock = peak_usb_adapter->clock;
748	dev->can.bittiming_const = &peak_usb_adapter->bittiming_const;
749	dev->can.do_set_bittiming = peak_usb_set_bittiming;
750	dev->can.do_set_mode = peak_usb_set_mode;
751	dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
752				      CAN_CTRLMODE_LISTENONLY;
753
754	netdev->netdev_ops = &peak_usb_netdev_ops;
755
756	netdev->flags |= IFF_ECHO; /* we support local echo */
757
758	init_usb_anchor(&dev->rx_submitted);
759
760	init_usb_anchor(&dev->tx_submitted);
761	atomic_set(&dev->active_tx_urbs, 0);
762
763	for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++)
764		dev->tx_contexts[i].echo_index = PCAN_USB_MAX_TX_URBS;
765
766	dev->prev_siblings = usb_get_intfdata(intf);
767	usb_set_intfdata(intf, dev);
768
769	SET_NETDEV_DEV(netdev, &intf->dev);
770
771	err = register_candev(netdev);
772	if (err) {
773		dev_err(&intf->dev, "couldn't register CAN device: %d\n", err);
774		goto lbl_free_cmd_buf;
775	}
776
777	if (dev->prev_siblings)
778		(dev->prev_siblings)->next_siblings = dev;
779
780	/* keep hw revision into the netdevice */
781	tmp16 = le16_to_cpu(usb_dev->descriptor.bcdDevice);
782	dev->device_rev = tmp16 >> 8;
783
784	if (dev->adapter->dev_init) {
785		err = dev->adapter->dev_init(dev);
786		if (err)
787			goto lbl_free_cmd_buf;
788	}
789
790	/* set bus off */
791	if (dev->adapter->dev_set_bus) {
792		err = dev->adapter->dev_set_bus(dev, 0);
793		if (err)
794			goto lbl_free_cmd_buf;
795	}
796
797	/* get device number early */
798	if (dev->adapter->dev_get_device_id)
799		dev->adapter->dev_get_device_id(dev, &dev->device_number);
800
801	netdev_info(netdev, "attached to %s channel %u (device %u)\n",
802			peak_usb_adapter->name, ctrl_idx, dev->device_number);
803
804	return 0;
805
806lbl_free_cmd_buf:
807	kfree(dev->cmd_buf);
808
809lbl_set_intf_data:
810	usb_set_intfdata(intf, dev->prev_siblings);
811	free_candev(netdev);
812
813	return err;
814}
815
816/*
817 * called by the usb core when the device is unplugged from the system
818 */
819static void peak_usb_disconnect(struct usb_interface *intf)
820{
821	struct peak_usb_device *dev;
822
823	/* unregister as many netdev devices as siblings */
824	for (dev = usb_get_intfdata(intf); dev; dev = dev->prev_siblings) {
825		struct net_device *netdev = dev->netdev;
826		char name[IFNAMSIZ];
827
828		dev->state &= ~PCAN_USB_STATE_CONNECTED;
829		strncpy(name, netdev->name, IFNAMSIZ);
830
831		unregister_netdev(netdev);
832		free_candev(netdev);
833
834		kfree(dev->cmd_buf);
835		dev->next_siblings = NULL;
836		if (dev->adapter->dev_free)
837			dev->adapter->dev_free(dev);
838
839		dev_info(&intf->dev, "%s removed\n", name);
840	}
841
842	usb_set_intfdata(intf, NULL);
843}
844
845/*
846 * probe function for new PEAK-System devices
847 */
848static int peak_usb_probe(struct usb_interface *intf,
849			  const struct usb_device_id *id)
850{
851	struct usb_device *usb_dev = interface_to_usbdev(intf);
852	struct peak_usb_adapter *peak_usb_adapter, **pp;
853	int i, err = -ENOMEM;
854
855	usb_dev = interface_to_usbdev(intf);
856
857	/* get corresponding PCAN-USB adapter */
858	for (pp = peak_usb_adapters_list; *pp; pp++)
859		if ((*pp)->device_id == usb_dev->descriptor.idProduct)
860			break;
861
862	peak_usb_adapter = *pp;
863	if (!peak_usb_adapter) {
864		/* should never come except device_id bad usage in this file */
865		pr_err("%s: didn't find device id. 0x%x in devices list\n",
866			PCAN_USB_DRIVER_NAME, usb_dev->descriptor.idProduct);
867		return -ENODEV;
868	}
869
870	/* got corresponding adapter: check if it handles current interface */
871	if (peak_usb_adapter->intf_probe) {
872		err = peak_usb_adapter->intf_probe(intf);
873		if (err)
874			return err;
875	}
876
877	for (i = 0; i < peak_usb_adapter->ctrl_count; i++) {
878		err = peak_usb_create_dev(peak_usb_adapter, intf, i);
879		if (err) {
880			/* deregister already created devices */
881			peak_usb_disconnect(intf);
882			break;
883		}
884	}
885
886	return err;
887}
888
889/* usb specific object needed to register this driver with the usb subsystem */
890static struct usb_driver peak_usb_driver = {
891	.name = PCAN_USB_DRIVER_NAME,
892	.disconnect = peak_usb_disconnect,
893	.probe = peak_usb_probe,
894	.id_table = peak_usb_table,
895};
896
897static int __init peak_usb_init(void)
898{
899	int err;
900
901	/* register this driver with the USB subsystem */
902	err = usb_register(&peak_usb_driver);
903	if (err)
904		pr_err("%s: usb_register failed (err %d)\n",
905			PCAN_USB_DRIVER_NAME, err);
906
907	return err;
908}
909
910static int peak_usb_do_device_exit(struct device *d, void *arg)
911{
912	struct usb_interface *intf = to_usb_interface(d);
913	struct peak_usb_device *dev;
914
915	/* stop as many netdev devices as siblings */
916	for (dev = usb_get_intfdata(intf); dev; dev = dev->prev_siblings) {
917		struct net_device *netdev = dev->netdev;
918
919		if (netif_device_present(netdev))
920			if (dev->adapter->dev_exit)
921				dev->adapter->dev_exit(dev);
922	}
923
924	return 0;
925}
926
927static void __exit peak_usb_exit(void)
928{
929	int err;
930
931	/* last chance do send any synchronous commands here */
932	err = driver_for_each_device(&peak_usb_driver.drvwrap.driver, NULL,
933				     NULL, peak_usb_do_device_exit);
934	if (err)
935		pr_err("%s: failed to stop all can devices (err %d)\n",
936			PCAN_USB_DRIVER_NAME, err);
937
938	/* deregister this driver with the USB subsystem */
939	usb_deregister(&peak_usb_driver);
940
941	pr_info("%s: PCAN-USB interfaces driver unloaded\n",
942		PCAN_USB_DRIVER_NAME);
943}
944
945module_init(peak_usb_init);
946module_exit(peak_usb_exit);
947