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1// SPDX-License-Identifier: GPL-2.0-only
2/* CAN driver for Geschwister Schneider USB/CAN devices
3 * and bytewerk.org candleLight USB CAN interfaces.
4 *
5 * Copyright (C) 2013-2016 Geschwister Schneider Technologie-,
6 * Entwicklungs- und Vertriebs UG (Haftungsbeschränkt).
7 * Copyright (C) 2016 Hubert Denkmair
8 *
9 * Many thanks to all socketcan devs!
10 */
11
12#include <linux/init.h>
13#include <linux/signal.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/* Device specific constants */
23#define USB_GSUSB_1_VENDOR_ID 0x1d50
24#define USB_GSUSB_1_PRODUCT_ID 0x606f
25
26#define USB_CANDLELIGHT_VENDOR_ID 0x1209
27#define USB_CANDLELIGHT_PRODUCT_ID 0x2323
28
29#define GSUSB_ENDPOINT_IN 1
30#define GSUSB_ENDPOINT_OUT 2
31
32/* Device specific constants */
33enum gs_usb_breq {
34 GS_USB_BREQ_HOST_FORMAT = 0,
35 GS_USB_BREQ_BITTIMING,
36 GS_USB_BREQ_MODE,
37 GS_USB_BREQ_BERR,
38 GS_USB_BREQ_BT_CONST,
39 GS_USB_BREQ_DEVICE_CONFIG,
40 GS_USB_BREQ_TIMESTAMP,
41 GS_USB_BREQ_IDENTIFY,
42};
43
44enum gs_can_mode {
45 /* reset a channel. turns it off */
46 GS_CAN_MODE_RESET = 0,
47 /* starts a channel */
48 GS_CAN_MODE_START
49};
50
51enum gs_can_state {
52 GS_CAN_STATE_ERROR_ACTIVE = 0,
53 GS_CAN_STATE_ERROR_WARNING,
54 GS_CAN_STATE_ERROR_PASSIVE,
55 GS_CAN_STATE_BUS_OFF,
56 GS_CAN_STATE_STOPPED,
57 GS_CAN_STATE_SLEEPING
58};
59
60enum gs_can_identify_mode {
61 GS_CAN_IDENTIFY_OFF = 0,
62 GS_CAN_IDENTIFY_ON
63};
64
65/* data types passed between host and device */
66struct gs_host_config {
67 u32 byte_order;
68} __packed;
69/* All data exchanged between host and device is exchanged in host byte order,
70 * thanks to the struct gs_host_config byte_order member, which is sent first
71 * to indicate the desired byte order.
72 */
73
74struct gs_device_config {
75 u8 reserved1;
76 u8 reserved2;
77 u8 reserved3;
78 u8 icount;
79 u32 sw_version;
80 u32 hw_version;
81} __packed;
82
83#define GS_CAN_MODE_NORMAL 0
84#define GS_CAN_MODE_LISTEN_ONLY BIT(0)
85#define GS_CAN_MODE_LOOP_BACK BIT(1)
86#define GS_CAN_MODE_TRIPLE_SAMPLE BIT(2)
87#define GS_CAN_MODE_ONE_SHOT BIT(3)
88
89struct gs_device_mode {
90 u32 mode;
91 u32 flags;
92} __packed;
93
94struct gs_device_state {
95 u32 state;
96 u32 rxerr;
97 u32 txerr;
98} __packed;
99
100struct gs_device_bittiming {
101 u32 prop_seg;
102 u32 phase_seg1;
103 u32 phase_seg2;
104 u32 sjw;
105 u32 brp;
106} __packed;
107
108struct gs_identify_mode {
109 u32 mode;
110} __packed;
111
112#define GS_CAN_FEATURE_LISTEN_ONLY BIT(0)
113#define GS_CAN_FEATURE_LOOP_BACK BIT(1)
114#define GS_CAN_FEATURE_TRIPLE_SAMPLE BIT(2)
115#define GS_CAN_FEATURE_ONE_SHOT BIT(3)
116#define GS_CAN_FEATURE_HW_TIMESTAMP BIT(4)
117#define GS_CAN_FEATURE_IDENTIFY BIT(5)
118
119struct gs_device_bt_const {
120 u32 feature;
121 u32 fclk_can;
122 u32 tseg1_min;
123 u32 tseg1_max;
124 u32 tseg2_min;
125 u32 tseg2_max;
126 u32 sjw_max;
127 u32 brp_min;
128 u32 brp_max;
129 u32 brp_inc;
130} __packed;
131
132#define GS_CAN_FLAG_OVERFLOW 1
133
134struct gs_host_frame {
135 u32 echo_id;
136 u32 can_id;
137
138 u8 can_dlc;
139 u8 channel;
140 u8 flags;
141 u8 reserved;
142
143 u8 data[8];
144} __packed;
145/* The GS USB devices make use of the same flags and masks as in
146 * linux/can.h and linux/can/error.h, and no additional mapping is necessary.
147 */
148
149/* Only send a max of GS_MAX_TX_URBS frames per channel at a time. */
150#define GS_MAX_TX_URBS 10
151/* Only launch a max of GS_MAX_RX_URBS usb requests at a time. */
152#define GS_MAX_RX_URBS 30
153/* Maximum number of interfaces the driver supports per device.
154 * Current hardware only supports 2 interfaces. The future may vary.
155 */
156#define GS_MAX_INTF 2
157
158struct gs_tx_context {
159 struct gs_can *dev;
160 unsigned int echo_id;
161};
162
163struct gs_can {
164 struct can_priv can; /* must be the first member */
165
166 struct gs_usb *parent;
167
168 struct net_device *netdev;
169 struct usb_device *udev;
170 struct usb_interface *iface;
171
172 struct can_bittiming_const bt_const;
173 unsigned int channel; /* channel number */
174
175 /* This lock prevents a race condition between xmit and receive. */
176 spinlock_t tx_ctx_lock;
177 struct gs_tx_context tx_context[GS_MAX_TX_URBS];
178
179 struct usb_anchor tx_submitted;
180 atomic_t active_tx_urbs;
181};
182
183/* usb interface struct */
184struct gs_usb {
185 struct gs_can *canch[GS_MAX_INTF];
186 struct usb_anchor rx_submitted;
187 atomic_t active_channels;
188 struct usb_device *udev;
189};
190
191/* 'allocate' a tx context.
192 * returns a valid tx context or NULL if there is no space.
193 */
194static struct gs_tx_context *gs_alloc_tx_context(struct gs_can *dev)
195{
196 int i = 0;
197 unsigned long flags;
198
199 spin_lock_irqsave(&dev->tx_ctx_lock, flags);
200
201 for (; i < GS_MAX_TX_URBS; i++) {
202 if (dev->tx_context[i].echo_id == GS_MAX_TX_URBS) {
203 dev->tx_context[i].echo_id = i;
204 spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
205 return &dev->tx_context[i];
206 }
207 }
208
209 spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
210 return NULL;
211}
212
213/* releases a tx context
214 */
215static void gs_free_tx_context(struct gs_tx_context *txc)
216{
217 txc->echo_id = GS_MAX_TX_URBS;
218}
219
220/* Get a tx context by id.
221 */
222static struct gs_tx_context *gs_get_tx_context(struct gs_can *dev,
223 unsigned int id)
224{
225 unsigned long flags;
226
227 if (id < GS_MAX_TX_URBS) {
228 spin_lock_irqsave(&dev->tx_ctx_lock, flags);
229 if (dev->tx_context[id].echo_id == id) {
230 spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
231 return &dev->tx_context[id];
232 }
233 spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
234 }
235 return NULL;
236}
237
238static int gs_cmd_reset(struct gs_can *gsdev)
239{
240 struct gs_device_mode *dm;
241 struct usb_interface *intf = gsdev->iface;
242 int rc;
243
244 dm = kzalloc(sizeof(*dm), GFP_KERNEL);
245 if (!dm)
246 return -ENOMEM;
247
248 dm->mode = GS_CAN_MODE_RESET;
249
250 rc = usb_control_msg(interface_to_usbdev(intf),
251 usb_sndctrlpipe(interface_to_usbdev(intf), 0),
252 GS_USB_BREQ_MODE,
253 USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
254 gsdev->channel,
255 0,
256 dm,
257 sizeof(*dm),
258 1000);
259
260 kfree(dm);
261
262 return rc;
263}
264
265static void gs_update_state(struct gs_can *dev, struct can_frame *cf)
266{
267 struct can_device_stats *can_stats = &dev->can.can_stats;
268
269 if (cf->can_id & CAN_ERR_RESTARTED) {
270 dev->can.state = CAN_STATE_ERROR_ACTIVE;
271 can_stats->restarts++;
272 } else if (cf->can_id & CAN_ERR_BUSOFF) {
273 dev->can.state = CAN_STATE_BUS_OFF;
274 can_stats->bus_off++;
275 } else if (cf->can_id & CAN_ERR_CRTL) {
276 if ((cf->data[1] & CAN_ERR_CRTL_TX_WARNING) ||
277 (cf->data[1] & CAN_ERR_CRTL_RX_WARNING)) {
278 dev->can.state = CAN_STATE_ERROR_WARNING;
279 can_stats->error_warning++;
280 } else if ((cf->data[1] & CAN_ERR_CRTL_TX_PASSIVE) ||
281 (cf->data[1] & CAN_ERR_CRTL_RX_PASSIVE)) {
282 dev->can.state = CAN_STATE_ERROR_PASSIVE;
283 can_stats->error_passive++;
284 } else {
285 dev->can.state = CAN_STATE_ERROR_ACTIVE;
286 }
287 }
288}
289
290static void gs_usb_receive_bulk_callback(struct urb *urb)
291{
292 struct gs_usb *usbcan = urb->context;
293 struct gs_can *dev;
294 struct net_device *netdev;
295 int rc;
296 struct net_device_stats *stats;
297 struct gs_host_frame *hf = urb->transfer_buffer;
298 struct gs_tx_context *txc;
299 struct can_frame *cf;
300 struct sk_buff *skb;
301
302 BUG_ON(!usbcan);
303
304 switch (urb->status) {
305 case 0: /* success */
306 break;
307 case -ENOENT:
308 case -ESHUTDOWN:
309 return;
310 default:
311 /* do not resubmit aborted urbs. eg: when device goes down */
312 return;
313 }
314
315 /* device reports out of range channel id */
316 if (hf->channel >= GS_MAX_INTF)
317 goto resubmit_urb;
318
319 dev = usbcan->canch[hf->channel];
320
321 netdev = dev->netdev;
322 stats = &netdev->stats;
323
324 if (!netif_device_present(netdev))
325 return;
326
327 if (hf->echo_id == -1) { /* normal rx */
328 skb = alloc_can_skb(dev->netdev, &cf);
329 if (!skb)
330 return;
331
332 cf->can_id = hf->can_id;
333
334 cf->can_dlc = get_can_dlc(hf->can_dlc);
335 memcpy(cf->data, hf->data, 8);
336
337 /* ERROR frames tell us information about the controller */
338 if (hf->can_id & CAN_ERR_FLAG)
339 gs_update_state(dev, cf);
340
341 netdev->stats.rx_packets++;
342 netdev->stats.rx_bytes += hf->can_dlc;
343
344 netif_rx(skb);
345 } else { /* echo_id == hf->echo_id */
346 if (hf->echo_id >= GS_MAX_TX_URBS) {
347 netdev_err(netdev,
348 "Unexpected out of range echo id %d\n",
349 hf->echo_id);
350 goto resubmit_urb;
351 }
352
353 netdev->stats.tx_packets++;
354 netdev->stats.tx_bytes += hf->can_dlc;
355
356 txc = gs_get_tx_context(dev, hf->echo_id);
357
358 /* bad devices send bad echo_ids. */
359 if (!txc) {
360 netdev_err(netdev,
361 "Unexpected unused echo id %d\n",
362 hf->echo_id);
363 goto resubmit_urb;
364 }
365
366 can_get_echo_skb(netdev, hf->echo_id);
367
368 gs_free_tx_context(txc);
369
370 atomic_dec(&dev->active_tx_urbs);
371
372 netif_wake_queue(netdev);
373 }
374
375 if (hf->flags & GS_CAN_FLAG_OVERFLOW) {
376 skb = alloc_can_err_skb(netdev, &cf);
377 if (!skb)
378 goto resubmit_urb;
379
380 cf->can_id |= CAN_ERR_CRTL;
381 cf->can_dlc = CAN_ERR_DLC;
382 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
383 stats->rx_over_errors++;
384 stats->rx_errors++;
385 netif_rx(skb);
386 }
387
388 resubmit_urb:
389 usb_fill_bulk_urb(urb,
390 usbcan->udev,
391 usb_rcvbulkpipe(usbcan->udev, GSUSB_ENDPOINT_IN),
392 hf,
393 sizeof(struct gs_host_frame),
394 gs_usb_receive_bulk_callback,
395 usbcan
396 );
397
398 rc = usb_submit_urb(urb, GFP_ATOMIC);
399
400 /* USB failure take down all interfaces */
401 if (rc == -ENODEV) {
402 for (rc = 0; rc < GS_MAX_INTF; rc++) {
403 if (usbcan->canch[rc])
404 netif_device_detach(usbcan->canch[rc]->netdev);
405 }
406 }
407}
408
409static int gs_usb_set_bittiming(struct net_device *netdev)
410{
411 struct gs_can *dev = netdev_priv(netdev);
412 struct can_bittiming *bt = &dev->can.bittiming;
413 struct usb_interface *intf = dev->iface;
414 int rc;
415 struct gs_device_bittiming *dbt;
416
417 dbt = kmalloc(sizeof(*dbt), GFP_KERNEL);
418 if (!dbt)
419 return -ENOMEM;
420
421 dbt->prop_seg = bt->prop_seg;
422 dbt->phase_seg1 = bt->phase_seg1;
423 dbt->phase_seg2 = bt->phase_seg2;
424 dbt->sjw = bt->sjw;
425 dbt->brp = bt->brp;
426
427 /* request bit timings */
428 rc = usb_control_msg(interface_to_usbdev(intf),
429 usb_sndctrlpipe(interface_to_usbdev(intf), 0),
430 GS_USB_BREQ_BITTIMING,
431 USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
432 dev->channel,
433 0,
434 dbt,
435 sizeof(*dbt),
436 1000);
437
438 kfree(dbt);
439
440 if (rc < 0)
441 dev_err(netdev->dev.parent, "Couldn't set bittimings (err=%d)",
442 rc);
443
444 return (rc > 0) ? 0 : rc;
445}
446
447static void gs_usb_xmit_callback(struct urb *urb)
448{
449 struct gs_tx_context *txc = urb->context;
450 struct gs_can *dev = txc->dev;
451 struct net_device *netdev = dev->netdev;
452
453 if (urb->status)
454 netdev_info(netdev, "usb xmit fail %d\n", txc->echo_id);
455
456 usb_free_coherent(urb->dev,
457 urb->transfer_buffer_length,
458 urb->transfer_buffer,
459 urb->transfer_dma);
460}
461
462static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb,
463 struct net_device *netdev)
464{
465 struct gs_can *dev = netdev_priv(netdev);
466 struct net_device_stats *stats = &dev->netdev->stats;
467 struct urb *urb;
468 struct gs_host_frame *hf;
469 struct can_frame *cf;
470 int rc;
471 unsigned int idx;
472 struct gs_tx_context *txc;
473
474 if (can_dropped_invalid_skb(netdev, skb))
475 return NETDEV_TX_OK;
476
477 /* find an empty context to keep track of transmission */
478 txc = gs_alloc_tx_context(dev);
479 if (!txc)
480 return NETDEV_TX_BUSY;
481
482 /* create a URB, and a buffer for it */
483 urb = usb_alloc_urb(0, GFP_ATOMIC);
484 if (!urb)
485 goto nomem_urb;
486
487 hf = usb_alloc_coherent(dev->udev, sizeof(*hf), GFP_ATOMIC,
488 &urb->transfer_dma);
489 if (!hf) {
490 netdev_err(netdev, "No memory left for USB buffer\n");
491 goto nomem_hf;
492 }
493
494 idx = txc->echo_id;
495
496 if (idx >= GS_MAX_TX_URBS) {
497 netdev_err(netdev, "Invalid tx context %d\n", idx);
498 goto badidx;
499 }
500
501 hf->echo_id = idx;
502 hf->channel = dev->channel;
503
504 cf = (struct can_frame *)skb->data;
505
506 hf->can_id = cf->can_id;
507 hf->can_dlc = cf->can_dlc;
508 memcpy(hf->data, cf->data, cf->can_dlc);
509
510 usb_fill_bulk_urb(urb, dev->udev,
511 usb_sndbulkpipe(dev->udev, GSUSB_ENDPOINT_OUT),
512 hf,
513 sizeof(*hf),
514 gs_usb_xmit_callback,
515 txc);
516
517 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
518 usb_anchor_urb(urb, &dev->tx_submitted);
519
520 can_put_echo_skb(skb, netdev, idx);
521
522 atomic_inc(&dev->active_tx_urbs);
523
524 rc = usb_submit_urb(urb, GFP_ATOMIC);
525 if (unlikely(rc)) { /* usb send failed */
526 atomic_dec(&dev->active_tx_urbs);
527
528 can_free_echo_skb(netdev, idx);
529 gs_free_tx_context(txc);
530
531 usb_unanchor_urb(urb);
532 usb_free_coherent(dev->udev,
533 sizeof(*hf),
534 hf,
535 urb->transfer_dma);
536
537 if (rc == -ENODEV) {
538 netif_device_detach(netdev);
539 } else {
540 netdev_err(netdev, "usb_submit failed (err=%d)\n", rc);
541 stats->tx_dropped++;
542 }
543 } else {
544 /* Slow down tx path */
545 if (atomic_read(&dev->active_tx_urbs) >= GS_MAX_TX_URBS)
546 netif_stop_queue(netdev);
547 }
548
549 /* let usb core take care of this urb */
550 usb_free_urb(urb);
551
552 return NETDEV_TX_OK;
553
554 badidx:
555 usb_free_coherent(dev->udev,
556 sizeof(*hf),
557 hf,
558 urb->transfer_dma);
559 nomem_hf:
560 usb_free_urb(urb);
561
562 nomem_urb:
563 gs_free_tx_context(txc);
564 dev_kfree_skb(skb);
565 stats->tx_dropped++;
566 return NETDEV_TX_OK;
567}
568
569static int gs_can_open(struct net_device *netdev)
570{
571 struct gs_can *dev = netdev_priv(netdev);
572 struct gs_usb *parent = dev->parent;
573 int rc, i;
574 struct gs_device_mode *dm;
575 u32 ctrlmode;
576
577 rc = open_candev(netdev);
578 if (rc)
579 return rc;
580
581 if (atomic_add_return(1, &parent->active_channels) == 1) {
582 for (i = 0; i < GS_MAX_RX_URBS; i++) {
583 struct urb *urb;
584 u8 *buf;
585
586 /* alloc rx urb */
587 urb = usb_alloc_urb(0, GFP_KERNEL);
588 if (!urb)
589 return -ENOMEM;
590
591 /* alloc rx buffer */
592 buf = usb_alloc_coherent(dev->udev,
593 sizeof(struct gs_host_frame),
594 GFP_KERNEL,
595 &urb->transfer_dma);
596 if (!buf) {
597 netdev_err(netdev,
598 "No memory left for USB buffer\n");
599 usb_free_urb(urb);
600 return -ENOMEM;
601 }
602
603 /* fill, anchor, and submit rx urb */
604 usb_fill_bulk_urb(urb,
605 dev->udev,
606 usb_rcvbulkpipe(dev->udev,
607 GSUSB_ENDPOINT_IN),
608 buf,
609 sizeof(struct gs_host_frame),
610 gs_usb_receive_bulk_callback,
611 parent);
612 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
613
614 usb_anchor_urb(urb, &parent->rx_submitted);
615
616 rc = usb_submit_urb(urb, GFP_KERNEL);
617 if (rc) {
618 if (rc == -ENODEV)
619 netif_device_detach(dev->netdev);
620
621 netdev_err(netdev,
622 "usb_submit failed (err=%d)\n",
623 rc);
624
625 usb_unanchor_urb(urb);
626 usb_free_urb(urb);
627 break;
628 }
629
630 /* Drop reference,
631 * USB core will take care of freeing it
632 */
633 usb_free_urb(urb);
634 }
635 }
636
637 dm = kmalloc(sizeof(*dm), GFP_KERNEL);
638 if (!dm)
639 return -ENOMEM;
640
641 /* flags */
642 ctrlmode = dev->can.ctrlmode;
643 dm->flags = 0;
644
645 if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
646 dm->flags |= GS_CAN_MODE_LOOP_BACK;
647 else if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
648 dm->flags |= GS_CAN_MODE_LISTEN_ONLY;
649
650 /* Controller is not allowed to retry TX
651 * this mode is unavailable on atmels uc3c hardware
652 */
653 if (ctrlmode & CAN_CTRLMODE_ONE_SHOT)
654 dm->flags |= GS_CAN_MODE_ONE_SHOT;
655
656 if (ctrlmode & CAN_CTRLMODE_3_SAMPLES)
657 dm->flags |= GS_CAN_MODE_TRIPLE_SAMPLE;
658
659 /* finally start device */
660 dm->mode = GS_CAN_MODE_START;
661 rc = usb_control_msg(interface_to_usbdev(dev->iface),
662 usb_sndctrlpipe(interface_to_usbdev(dev->iface), 0),
663 GS_USB_BREQ_MODE,
664 USB_DIR_OUT | USB_TYPE_VENDOR |
665 USB_RECIP_INTERFACE,
666 dev->channel,
667 0,
668 dm,
669 sizeof(*dm),
670 1000);
671
672 if (rc < 0) {
673 netdev_err(netdev, "Couldn't start device (err=%d)\n", rc);
674 kfree(dm);
675 return rc;
676 }
677
678 kfree(dm);
679
680 dev->can.state = CAN_STATE_ERROR_ACTIVE;
681
682 if (!(dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY))
683 netif_start_queue(netdev);
684
685 return 0;
686}
687
688static int gs_can_close(struct net_device *netdev)
689{
690 int rc;
691 struct gs_can *dev = netdev_priv(netdev);
692 struct gs_usb *parent = dev->parent;
693
694 netif_stop_queue(netdev);
695
696 /* Stop polling */
697 if (atomic_dec_and_test(&parent->active_channels))
698 usb_kill_anchored_urbs(&parent->rx_submitted);
699
700 /* Stop sending URBs */
701 usb_kill_anchored_urbs(&dev->tx_submitted);
702 atomic_set(&dev->active_tx_urbs, 0);
703
704 /* reset the device */
705 rc = gs_cmd_reset(dev);
706 if (rc < 0)
707 netdev_warn(netdev, "Couldn't shutdown device (err=%d)", rc);
708
709 /* reset tx contexts */
710 for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
711 dev->tx_context[rc].dev = dev;
712 dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
713 }
714
715 /* close the netdev */
716 close_candev(netdev);
717
718 return 0;
719}
720
721static const struct net_device_ops gs_usb_netdev_ops = {
722 .ndo_open = gs_can_open,
723 .ndo_stop = gs_can_close,
724 .ndo_start_xmit = gs_can_start_xmit,
725 .ndo_change_mtu = can_change_mtu,
726};
727
728static int gs_usb_set_identify(struct net_device *netdev, bool do_identify)
729{
730 struct gs_can *dev = netdev_priv(netdev);
731 struct gs_identify_mode *imode;
732 int rc;
733
734 imode = kmalloc(sizeof(*imode), GFP_KERNEL);
735
736 if (!imode)
737 return -ENOMEM;
738
739 if (do_identify)
740 imode->mode = GS_CAN_IDENTIFY_ON;
741 else
742 imode->mode = GS_CAN_IDENTIFY_OFF;
743
744 rc = usb_control_msg(interface_to_usbdev(dev->iface),
745 usb_sndctrlpipe(interface_to_usbdev(dev->iface),
746 0),
747 GS_USB_BREQ_IDENTIFY,
748 USB_DIR_OUT | USB_TYPE_VENDOR |
749 USB_RECIP_INTERFACE,
750 dev->channel,
751 0,
752 imode,
753 sizeof(*imode),
754 100);
755
756 kfree(imode);
757
758 return (rc > 0) ? 0 : rc;
759}
760
761/* blink LED's for finding the this interface */
762static int gs_usb_set_phys_id(struct net_device *dev,
763 enum ethtool_phys_id_state state)
764{
765 int rc = 0;
766
767 switch (state) {
768 case ETHTOOL_ID_ACTIVE:
769 rc = gs_usb_set_identify(dev, GS_CAN_IDENTIFY_ON);
770 break;
771 case ETHTOOL_ID_INACTIVE:
772 rc = gs_usb_set_identify(dev, GS_CAN_IDENTIFY_OFF);
773 break;
774 default:
775 break;
776 }
777
778 return rc;
779}
780
781static const struct ethtool_ops gs_usb_ethtool_ops = {
782 .set_phys_id = gs_usb_set_phys_id,
783};
784
785static struct gs_can *gs_make_candev(unsigned int channel,
786 struct usb_interface *intf,
787 struct gs_device_config *dconf)
788{
789 struct gs_can *dev;
790 struct net_device *netdev;
791 int rc;
792 struct gs_device_bt_const *bt_const;
793
794 bt_const = kmalloc(sizeof(*bt_const), GFP_KERNEL);
795 if (!bt_const)
796 return ERR_PTR(-ENOMEM);
797
798 /* fetch bit timing constants */
799 rc = usb_control_msg(interface_to_usbdev(intf),
800 usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
801 GS_USB_BREQ_BT_CONST,
802 USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
803 channel,
804 0,
805 bt_const,
806 sizeof(*bt_const),
807 1000);
808
809 if (rc < 0) {
810 dev_err(&intf->dev,
811 "Couldn't get bit timing const for channel (err=%d)\n",
812 rc);
813 kfree(bt_const);
814 return ERR_PTR(rc);
815 }
816
817 /* create netdev */
818 netdev = alloc_candev(sizeof(struct gs_can), GS_MAX_TX_URBS);
819 if (!netdev) {
820 dev_err(&intf->dev, "Couldn't allocate candev\n");
821 kfree(bt_const);
822 return ERR_PTR(-ENOMEM);
823 }
824
825 dev = netdev_priv(netdev);
826
827 netdev->netdev_ops = &gs_usb_netdev_ops;
828
829 netdev->flags |= IFF_ECHO; /* we support full roundtrip echo */
830
831 /* dev settup */
832 strcpy(dev->bt_const.name, "gs_usb");
833 dev->bt_const.tseg1_min = bt_const->tseg1_min;
834 dev->bt_const.tseg1_max = bt_const->tseg1_max;
835 dev->bt_const.tseg2_min = bt_const->tseg2_min;
836 dev->bt_const.tseg2_max = bt_const->tseg2_max;
837 dev->bt_const.sjw_max = bt_const->sjw_max;
838 dev->bt_const.brp_min = bt_const->brp_min;
839 dev->bt_const.brp_max = bt_const->brp_max;
840 dev->bt_const.brp_inc = bt_const->brp_inc;
841
842 dev->udev = interface_to_usbdev(intf);
843 dev->iface = intf;
844 dev->netdev = netdev;
845 dev->channel = channel;
846
847 init_usb_anchor(&dev->tx_submitted);
848 atomic_set(&dev->active_tx_urbs, 0);
849 spin_lock_init(&dev->tx_ctx_lock);
850 for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
851 dev->tx_context[rc].dev = dev;
852 dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
853 }
854
855 /* can settup */
856 dev->can.state = CAN_STATE_STOPPED;
857 dev->can.clock.freq = bt_const->fclk_can;
858 dev->can.bittiming_const = &dev->bt_const;
859 dev->can.do_set_bittiming = gs_usb_set_bittiming;
860
861 dev->can.ctrlmode_supported = 0;
862
863 if (bt_const->feature & GS_CAN_FEATURE_LISTEN_ONLY)
864 dev->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY;
865
866 if (bt_const->feature & GS_CAN_FEATURE_LOOP_BACK)
867 dev->can.ctrlmode_supported |= CAN_CTRLMODE_LOOPBACK;
868
869 if (bt_const->feature & GS_CAN_FEATURE_TRIPLE_SAMPLE)
870 dev->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
871
872 if (bt_const->feature & GS_CAN_FEATURE_ONE_SHOT)
873 dev->can.ctrlmode_supported |= CAN_CTRLMODE_ONE_SHOT;
874
875 SET_NETDEV_DEV(netdev, &intf->dev);
876
877 if (dconf->sw_version > 1)
878 if (bt_const->feature & GS_CAN_FEATURE_IDENTIFY)
879 netdev->ethtool_ops = &gs_usb_ethtool_ops;
880
881 kfree(bt_const);
882
883 rc = register_candev(dev->netdev);
884 if (rc) {
885 free_candev(dev->netdev);
886 dev_err(&intf->dev, "Couldn't register candev (err=%d)\n", rc);
887 return ERR_PTR(rc);
888 }
889
890 return dev;
891}
892
893static void gs_destroy_candev(struct gs_can *dev)
894{
895 unregister_candev(dev->netdev);
896 usb_kill_anchored_urbs(&dev->tx_submitted);
897 free_candev(dev->netdev);
898}
899
900static int gs_usb_probe(struct usb_interface *intf,
901 const struct usb_device_id *id)
902{
903 struct gs_usb *dev;
904 int rc = -ENOMEM;
905 unsigned int icount, i;
906 struct gs_host_config *hconf;
907 struct gs_device_config *dconf;
908
909 hconf = kmalloc(sizeof(*hconf), GFP_KERNEL);
910 if (!hconf)
911 return -ENOMEM;
912
913 hconf->byte_order = 0x0000beef;
914
915 /* send host config */
916 rc = usb_control_msg(interface_to_usbdev(intf),
917 usb_sndctrlpipe(interface_to_usbdev(intf), 0),
918 GS_USB_BREQ_HOST_FORMAT,
919 USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
920 1,
921 intf->altsetting[0].desc.bInterfaceNumber,
922 hconf,
923 sizeof(*hconf),
924 1000);
925
926 kfree(hconf);
927
928 if (rc < 0) {
929 dev_err(&intf->dev, "Couldn't send data format (err=%d)\n",
930 rc);
931 return rc;
932 }
933
934 dconf = kmalloc(sizeof(*dconf), GFP_KERNEL);
935 if (!dconf)
936 return -ENOMEM;
937
938 /* read device config */
939 rc = usb_control_msg(interface_to_usbdev(intf),
940 usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
941 GS_USB_BREQ_DEVICE_CONFIG,
942 USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
943 1,
944 intf->altsetting[0].desc.bInterfaceNumber,
945 dconf,
946 sizeof(*dconf),
947 1000);
948 if (rc < 0) {
949 dev_err(&intf->dev, "Couldn't get device config: (err=%d)\n",
950 rc);
951 kfree(dconf);
952 return rc;
953 }
954
955 icount = dconf->icount + 1;
956 dev_info(&intf->dev, "Configuring for %d interfaces\n", icount);
957
958 if (icount > GS_MAX_INTF) {
959 dev_err(&intf->dev,
960 "Driver cannot handle more that %d CAN interfaces\n",
961 GS_MAX_INTF);
962 kfree(dconf);
963 return -EINVAL;
964 }
965
966 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
967 if (!dev) {
968 kfree(dconf);
969 return -ENOMEM;
970 }
971
972 init_usb_anchor(&dev->rx_submitted);
973
974 atomic_set(&dev->active_channels, 0);
975
976 usb_set_intfdata(intf, dev);
977 dev->udev = interface_to_usbdev(intf);
978
979 for (i = 0; i < icount; i++) {
980 dev->canch[i] = gs_make_candev(i, intf, dconf);
981 if (IS_ERR_OR_NULL(dev->canch[i])) {
982 /* save error code to return later */
983 rc = PTR_ERR(dev->canch[i]);
984
985 /* on failure destroy previously created candevs */
986 icount = i;
987 for (i = 0; i < icount; i++)
988 gs_destroy_candev(dev->canch[i]);
989
990 usb_kill_anchored_urbs(&dev->rx_submitted);
991 kfree(dconf);
992 kfree(dev);
993 return rc;
994 }
995 dev->canch[i]->parent = dev;
996 }
997
998 kfree(dconf);
999
1000 return 0;
1001}
1002
1003static void gs_usb_disconnect(struct usb_interface *intf)
1004{
1005 unsigned i;
1006 struct gs_usb *dev = usb_get_intfdata(intf);
1007 usb_set_intfdata(intf, NULL);
1008
1009 if (!dev) {
1010 dev_err(&intf->dev, "Disconnect (nodata)\n");
1011 return;
1012 }
1013
1014 for (i = 0; i < GS_MAX_INTF; i++)
1015 if (dev->canch[i])
1016 gs_destroy_candev(dev->canch[i]);
1017
1018 usb_kill_anchored_urbs(&dev->rx_submitted);
1019 kfree(dev);
1020}
1021
1022static const struct usb_device_id gs_usb_table[] = {
1023 { USB_DEVICE_INTERFACE_NUMBER(USB_GSUSB_1_VENDOR_ID,
1024 USB_GSUSB_1_PRODUCT_ID, 0) },
1025 { USB_DEVICE_INTERFACE_NUMBER(USB_CANDLELIGHT_VENDOR_ID,
1026 USB_CANDLELIGHT_PRODUCT_ID, 0) },
1027 {} /* Terminating entry */
1028};
1029
1030MODULE_DEVICE_TABLE(usb, gs_usb_table);
1031
1032static struct usb_driver gs_usb_driver = {
1033 .name = "gs_usb",
1034 .probe = gs_usb_probe,
1035 .disconnect = gs_usb_disconnect,
1036 .id_table = gs_usb_table,
1037};
1038
1039module_usb_driver(gs_usb_driver);
1040
1041MODULE_AUTHOR("Maximilian Schneider <mws@schneidersoft.net>");
1042MODULE_DESCRIPTION(
1043"Socket CAN device driver for Geschwister Schneider Technologie-, "
1044"Entwicklungs- und Vertriebs UG. USB2.0 to CAN interfaces\n"
1045"and bytewerk.org candleLight USB CAN interfaces.");
1046MODULE_LICENSE("GPL v2");
1/* CAN driver for Geschwister Schneider USB/CAN devices.
2 *
3 * Copyright (C) 2013 Geschwister Schneider Technologie-,
4 * Entwicklungs- und Vertriebs UG (Haftungsbeschränkt).
5 *
6 * Many thanks to all socketcan devs!
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published
10 * by the Free Software Foundation; version 2 of the License.
11 *
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
16 */
17
18#include <linux/init.h>
19#include <linux/signal.h>
20#include <linux/module.h>
21#include <linux/netdevice.h>
22#include <linux/usb.h>
23
24#include <linux/can.h>
25#include <linux/can/dev.h>
26#include <linux/can/error.h>
27
28/* Device specific constants */
29#define USB_GSUSB_1_VENDOR_ID 0x1d50
30#define USB_GSUSB_1_PRODUCT_ID 0x606f
31
32#define GSUSB_ENDPOINT_IN 1
33#define GSUSB_ENDPOINT_OUT 2
34
35/* Device specific constants */
36enum gs_usb_breq {
37 GS_USB_BREQ_HOST_FORMAT = 0,
38 GS_USB_BREQ_BITTIMING,
39 GS_USB_BREQ_MODE,
40 GS_USB_BREQ_BERR,
41 GS_USB_BREQ_BT_CONST,
42 GS_USB_BREQ_DEVICE_CONFIG
43};
44
45enum gs_can_mode {
46 /* reset a channel. turns it off */
47 GS_CAN_MODE_RESET = 0,
48 /* starts a channel */
49 GS_CAN_MODE_START
50};
51
52enum gs_can_state {
53 GS_CAN_STATE_ERROR_ACTIVE = 0,
54 GS_CAN_STATE_ERROR_WARNING,
55 GS_CAN_STATE_ERROR_PASSIVE,
56 GS_CAN_STATE_BUS_OFF,
57 GS_CAN_STATE_STOPPED,
58 GS_CAN_STATE_SLEEPING
59};
60
61/* data types passed between host and device */
62struct gs_host_config {
63 u32 byte_order;
64} __packed;
65/* All data exchanged between host and device is exchanged in host byte order,
66 * thanks to the struct gs_host_config byte_order member, which is sent first
67 * to indicate the desired byte order.
68 */
69
70struct gs_device_config {
71 u8 reserved1;
72 u8 reserved2;
73 u8 reserved3;
74 u8 icount;
75 u32 sw_version;
76 u32 hw_version;
77} __packed;
78
79#define GS_CAN_MODE_NORMAL 0
80#define GS_CAN_MODE_LISTEN_ONLY (1<<0)
81#define GS_CAN_MODE_LOOP_BACK (1<<1)
82#define GS_CAN_MODE_TRIPLE_SAMPLE (1<<2)
83#define GS_CAN_MODE_ONE_SHOT (1<<3)
84
85struct gs_device_mode {
86 u32 mode;
87 u32 flags;
88} __packed;
89
90struct gs_device_state {
91 u32 state;
92 u32 rxerr;
93 u32 txerr;
94} __packed;
95
96struct gs_device_bittiming {
97 u32 prop_seg;
98 u32 phase_seg1;
99 u32 phase_seg2;
100 u32 sjw;
101 u32 brp;
102} __packed;
103
104#define GS_CAN_FEATURE_LISTEN_ONLY (1<<0)
105#define GS_CAN_FEATURE_LOOP_BACK (1<<1)
106#define GS_CAN_FEATURE_TRIPLE_SAMPLE (1<<2)
107#define GS_CAN_FEATURE_ONE_SHOT (1<<3)
108
109struct gs_device_bt_const {
110 u32 feature;
111 u32 fclk_can;
112 u32 tseg1_min;
113 u32 tseg1_max;
114 u32 tseg2_min;
115 u32 tseg2_max;
116 u32 sjw_max;
117 u32 brp_min;
118 u32 brp_max;
119 u32 brp_inc;
120} __packed;
121
122#define GS_CAN_FLAG_OVERFLOW 1
123
124struct gs_host_frame {
125 u32 echo_id;
126 u32 can_id;
127
128 u8 can_dlc;
129 u8 channel;
130 u8 flags;
131 u8 reserved;
132
133 u8 data[8];
134} __packed;
135/* The GS USB devices make use of the same flags and masks as in
136 * linux/can.h and linux/can/error.h, and no additional mapping is necessary.
137 */
138
139/* Only send a max of GS_MAX_TX_URBS frames per channel at a time. */
140#define GS_MAX_TX_URBS 10
141/* Only launch a max of GS_MAX_RX_URBS usb requests at a time. */
142#define GS_MAX_RX_URBS 30
143/* Maximum number of interfaces the driver supports per device.
144 * Current hardware only supports 2 interfaces. The future may vary.
145 */
146#define GS_MAX_INTF 2
147
148struct gs_tx_context {
149 struct gs_can *dev;
150 unsigned int echo_id;
151};
152
153struct gs_can {
154 struct can_priv can; /* must be the first member */
155
156 struct gs_usb *parent;
157
158 struct net_device *netdev;
159 struct usb_device *udev;
160 struct usb_interface *iface;
161
162 struct can_bittiming_const bt_const;
163 unsigned int channel; /* channel number */
164
165 /* This lock prevents a race condition between xmit and receive. */
166 spinlock_t tx_ctx_lock;
167 struct gs_tx_context tx_context[GS_MAX_TX_URBS];
168
169 struct usb_anchor tx_submitted;
170 atomic_t active_tx_urbs;
171};
172
173/* usb interface struct */
174struct gs_usb {
175 struct gs_can *canch[GS_MAX_INTF];
176 struct usb_anchor rx_submitted;
177 atomic_t active_channels;
178 struct usb_device *udev;
179};
180
181/* 'allocate' a tx context.
182 * returns a valid tx context or NULL if there is no space.
183 */
184static struct gs_tx_context *gs_alloc_tx_context(struct gs_can *dev)
185{
186 int i = 0;
187 unsigned long flags;
188
189 spin_lock_irqsave(&dev->tx_ctx_lock, flags);
190
191 for (; i < GS_MAX_TX_URBS; i++) {
192 if (dev->tx_context[i].echo_id == GS_MAX_TX_URBS) {
193 dev->tx_context[i].echo_id = i;
194 spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
195 return &dev->tx_context[i];
196 }
197 }
198
199 spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
200 return NULL;
201}
202
203/* releases a tx context
204 */
205static void gs_free_tx_context(struct gs_tx_context *txc)
206{
207 txc->echo_id = GS_MAX_TX_URBS;
208}
209
210/* Get a tx context by id.
211 */
212static struct gs_tx_context *gs_get_tx_context(struct gs_can *dev, unsigned int id)
213{
214 unsigned long flags;
215
216 if (id < GS_MAX_TX_URBS) {
217 spin_lock_irqsave(&dev->tx_ctx_lock, flags);
218 if (dev->tx_context[id].echo_id == id) {
219 spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
220 return &dev->tx_context[id];
221 }
222 spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
223 }
224 return NULL;
225}
226
227static int gs_cmd_reset(struct gs_usb *gsusb, struct gs_can *gsdev)
228{
229 struct gs_device_mode *dm;
230 struct usb_interface *intf = gsdev->iface;
231 int rc;
232
233 dm = kzalloc(sizeof(*dm), GFP_KERNEL);
234 if (!dm)
235 return -ENOMEM;
236
237 dm->mode = GS_CAN_MODE_RESET;
238
239 rc = usb_control_msg(interface_to_usbdev(intf),
240 usb_sndctrlpipe(interface_to_usbdev(intf), 0),
241 GS_USB_BREQ_MODE,
242 USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
243 gsdev->channel,
244 0,
245 dm,
246 sizeof(*dm),
247 1000);
248
249 return rc;
250}
251
252static void gs_update_state(struct gs_can *dev, struct can_frame *cf)
253{
254 struct can_device_stats *can_stats = &dev->can.can_stats;
255
256 if (cf->can_id & CAN_ERR_RESTARTED) {
257 dev->can.state = CAN_STATE_ERROR_ACTIVE;
258 can_stats->restarts++;
259 } else if (cf->can_id & CAN_ERR_BUSOFF) {
260 dev->can.state = CAN_STATE_BUS_OFF;
261 can_stats->bus_off++;
262 } else if (cf->can_id & CAN_ERR_CRTL) {
263 if ((cf->data[1] & CAN_ERR_CRTL_TX_WARNING) ||
264 (cf->data[1] & CAN_ERR_CRTL_RX_WARNING)) {
265 dev->can.state = CAN_STATE_ERROR_WARNING;
266 can_stats->error_warning++;
267 } else if ((cf->data[1] & CAN_ERR_CRTL_TX_PASSIVE) ||
268 (cf->data[1] & CAN_ERR_CRTL_RX_PASSIVE)) {
269 dev->can.state = CAN_STATE_ERROR_PASSIVE;
270 can_stats->error_passive++;
271 } else {
272 dev->can.state = CAN_STATE_ERROR_ACTIVE;
273 }
274 }
275}
276
277static void gs_usb_receive_bulk_callback(struct urb *urb)
278{
279 struct gs_usb *usbcan = urb->context;
280 struct gs_can *dev;
281 struct net_device *netdev;
282 int rc;
283 struct net_device_stats *stats;
284 struct gs_host_frame *hf = urb->transfer_buffer;
285 struct gs_tx_context *txc;
286 struct can_frame *cf;
287 struct sk_buff *skb;
288
289 BUG_ON(!usbcan);
290
291 switch (urb->status) {
292 case 0: /* success */
293 break;
294 case -ENOENT:
295 case -ESHUTDOWN:
296 return;
297 default:
298 /* do not resubmit aborted urbs. eg: when device goes down */
299 return;
300 }
301
302 /* device reports out of range channel id */
303 if (hf->channel >= GS_MAX_INTF)
304 goto resubmit_urb;
305
306 dev = usbcan->canch[hf->channel];
307
308 netdev = dev->netdev;
309 stats = &netdev->stats;
310
311 if (!netif_device_present(netdev))
312 return;
313
314 if (hf->echo_id == -1) { /* normal rx */
315 skb = alloc_can_skb(dev->netdev, &cf);
316 if (!skb)
317 return;
318
319 cf->can_id = hf->can_id;
320
321 cf->can_dlc = get_can_dlc(hf->can_dlc);
322 memcpy(cf->data, hf->data, 8);
323
324 /* ERROR frames tell us information about the controller */
325 if (hf->can_id & CAN_ERR_FLAG)
326 gs_update_state(dev, cf);
327
328 netdev->stats.rx_packets++;
329 netdev->stats.rx_bytes += hf->can_dlc;
330
331 netif_rx(skb);
332 } else { /* echo_id == hf->echo_id */
333 if (hf->echo_id >= GS_MAX_TX_URBS) {
334 netdev_err(netdev,
335 "Unexpected out of range echo id %d\n",
336 hf->echo_id);
337 goto resubmit_urb;
338 }
339
340 netdev->stats.tx_packets++;
341 netdev->stats.tx_bytes += hf->can_dlc;
342
343 txc = gs_get_tx_context(dev, hf->echo_id);
344
345 /* bad devices send bad echo_ids. */
346 if (!txc) {
347 netdev_err(netdev,
348 "Unexpected unused echo id %d\n",
349 hf->echo_id);
350 goto resubmit_urb;
351 }
352
353 can_get_echo_skb(netdev, hf->echo_id);
354
355 gs_free_tx_context(txc);
356
357 netif_wake_queue(netdev);
358 }
359
360 if (hf->flags & GS_CAN_FLAG_OVERFLOW) {
361 skb = alloc_can_err_skb(netdev, &cf);
362 if (!skb)
363 goto resubmit_urb;
364
365 cf->can_id |= CAN_ERR_CRTL;
366 cf->can_dlc = CAN_ERR_DLC;
367 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
368 stats->rx_over_errors++;
369 stats->rx_errors++;
370 netif_rx(skb);
371 }
372
373 resubmit_urb:
374 usb_fill_bulk_urb(urb,
375 usbcan->udev,
376 usb_rcvbulkpipe(usbcan->udev, GSUSB_ENDPOINT_IN),
377 hf,
378 sizeof(struct gs_host_frame),
379 gs_usb_receive_bulk_callback,
380 usbcan
381 );
382
383 rc = usb_submit_urb(urb, GFP_ATOMIC);
384
385 /* USB failure take down all interfaces */
386 if (rc == -ENODEV) {
387 for (rc = 0; rc < GS_MAX_INTF; rc++) {
388 if (usbcan->canch[rc])
389 netif_device_detach(usbcan->canch[rc]->netdev);
390 }
391 }
392}
393
394static int gs_usb_set_bittiming(struct net_device *netdev)
395{
396 struct gs_can *dev = netdev_priv(netdev);
397 struct can_bittiming *bt = &dev->can.bittiming;
398 struct usb_interface *intf = dev->iface;
399 int rc;
400 struct gs_device_bittiming *dbt;
401
402 dbt = kmalloc(sizeof(*dbt), GFP_KERNEL);
403 if (!dbt)
404 return -ENOMEM;
405
406 dbt->prop_seg = bt->prop_seg;
407 dbt->phase_seg1 = bt->phase_seg1;
408 dbt->phase_seg2 = bt->phase_seg2;
409 dbt->sjw = bt->sjw;
410 dbt->brp = bt->brp;
411
412 /* request bit timings */
413 rc = usb_control_msg(interface_to_usbdev(intf),
414 usb_sndctrlpipe(interface_to_usbdev(intf), 0),
415 GS_USB_BREQ_BITTIMING,
416 USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
417 dev->channel,
418 0,
419 dbt,
420 sizeof(*dbt),
421 1000);
422
423 kfree(dbt);
424
425 if (rc < 0)
426 dev_err(netdev->dev.parent, "Couldn't set bittimings (err=%d)",
427 rc);
428
429 return rc;
430}
431
432static void gs_usb_xmit_callback(struct urb *urb)
433{
434 struct gs_tx_context *txc = urb->context;
435 struct gs_can *dev = txc->dev;
436 struct net_device *netdev = dev->netdev;
437
438 if (urb->status)
439 netdev_info(netdev, "usb xmit fail %d\n", txc->echo_id);
440
441 usb_free_coherent(urb->dev,
442 urb->transfer_buffer_length,
443 urb->transfer_buffer,
444 urb->transfer_dma);
445
446 atomic_dec(&dev->active_tx_urbs);
447
448 if (!netif_device_present(netdev))
449 return;
450
451 if (netif_queue_stopped(netdev))
452 netif_wake_queue(netdev);
453}
454
455static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb, struct net_device *netdev)
456{
457 struct gs_can *dev = netdev_priv(netdev);
458 struct net_device_stats *stats = &dev->netdev->stats;
459 struct urb *urb;
460 struct gs_host_frame *hf;
461 struct can_frame *cf;
462 int rc;
463 unsigned int idx;
464 struct gs_tx_context *txc;
465
466 if (can_dropped_invalid_skb(netdev, skb))
467 return NETDEV_TX_OK;
468
469 /* find an empty context to keep track of transmission */
470 txc = gs_alloc_tx_context(dev);
471 if (!txc)
472 return NETDEV_TX_BUSY;
473
474 /* create a URB, and a buffer for it */
475 urb = usb_alloc_urb(0, GFP_ATOMIC);
476 if (!urb) {
477 netdev_err(netdev, "No memory left for URB\n");
478 goto nomem_urb;
479 }
480
481 hf = usb_alloc_coherent(dev->udev, sizeof(*hf), GFP_ATOMIC,
482 &urb->transfer_dma);
483 if (!hf) {
484 netdev_err(netdev, "No memory left for USB buffer\n");
485 goto nomem_hf;
486 }
487
488 idx = txc->echo_id;
489
490 if (idx >= GS_MAX_TX_URBS) {
491 netdev_err(netdev, "Invalid tx context %d\n", idx);
492 goto badidx;
493 }
494
495 hf->echo_id = idx;
496 hf->channel = dev->channel;
497
498 cf = (struct can_frame *)skb->data;
499
500 hf->can_id = cf->can_id;
501 hf->can_dlc = cf->can_dlc;
502 memcpy(hf->data, cf->data, cf->can_dlc);
503
504 usb_fill_bulk_urb(urb, dev->udev,
505 usb_sndbulkpipe(dev->udev, GSUSB_ENDPOINT_OUT),
506 hf,
507 sizeof(*hf),
508 gs_usb_xmit_callback,
509 txc);
510
511 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
512 usb_anchor_urb(urb, &dev->tx_submitted);
513
514 can_put_echo_skb(skb, netdev, idx);
515
516 atomic_inc(&dev->active_tx_urbs);
517
518 rc = usb_submit_urb(urb, GFP_ATOMIC);
519 if (unlikely(rc)) { /* usb send failed */
520 atomic_dec(&dev->active_tx_urbs);
521
522 can_free_echo_skb(netdev, idx);
523 gs_free_tx_context(txc);
524
525 usb_unanchor_urb(urb);
526 usb_free_coherent(dev->udev,
527 sizeof(*hf),
528 hf,
529 urb->transfer_dma);
530
531
532 if (rc == -ENODEV) {
533 netif_device_detach(netdev);
534 } else {
535 netdev_err(netdev, "usb_submit failed (err=%d)\n", rc);
536 stats->tx_dropped++;
537 }
538 } else {
539 /* Slow down tx path */
540 if (atomic_read(&dev->active_tx_urbs) >= GS_MAX_TX_URBS)
541 netif_stop_queue(netdev);
542 }
543
544 /* let usb core take care of this urb */
545 usb_free_urb(urb);
546
547 return NETDEV_TX_OK;
548
549 badidx:
550 usb_free_coherent(dev->udev,
551 sizeof(*hf),
552 hf,
553 urb->transfer_dma);
554 nomem_hf:
555 usb_free_urb(urb);
556
557 nomem_urb:
558 gs_free_tx_context(txc);
559 dev_kfree_skb(skb);
560 stats->tx_dropped++;
561 return NETDEV_TX_OK;
562}
563
564static int gs_can_open(struct net_device *netdev)
565{
566 struct gs_can *dev = netdev_priv(netdev);
567 struct gs_usb *parent = dev->parent;
568 int rc, i;
569 struct gs_device_mode *dm;
570 u32 ctrlmode;
571
572 rc = open_candev(netdev);
573 if (rc)
574 return rc;
575
576 if (atomic_add_return(1, &parent->active_channels) == 1) {
577 for (i = 0; i < GS_MAX_RX_URBS; i++) {
578 struct urb *urb;
579 u8 *buf;
580
581 /* alloc rx urb */
582 urb = usb_alloc_urb(0, GFP_KERNEL);
583 if (!urb) {
584 netdev_err(netdev,
585 "No memory left for URB\n");
586 return -ENOMEM;
587 }
588
589 /* alloc rx buffer */
590 buf = usb_alloc_coherent(dev->udev,
591 sizeof(struct gs_host_frame),
592 GFP_KERNEL,
593 &urb->transfer_dma);
594 if (!buf) {
595 netdev_err(netdev,
596 "No memory left for USB buffer\n");
597 usb_free_urb(urb);
598 return -ENOMEM;
599 }
600
601 /* fill, anchor, and submit rx urb */
602 usb_fill_bulk_urb(urb,
603 dev->udev,
604 usb_rcvbulkpipe(dev->udev,
605 GSUSB_ENDPOINT_IN),
606 buf,
607 sizeof(struct gs_host_frame),
608 gs_usb_receive_bulk_callback,
609 parent);
610 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
611
612 usb_anchor_urb(urb, &parent->rx_submitted);
613
614 rc = usb_submit_urb(urb, GFP_KERNEL);
615 if (rc) {
616 if (rc == -ENODEV)
617 netif_device_detach(dev->netdev);
618
619 netdev_err(netdev,
620 "usb_submit failed (err=%d)\n",
621 rc);
622
623 usb_unanchor_urb(urb);
624 break;
625 }
626
627 /* Drop reference,
628 * USB core will take care of freeing it
629 */
630 usb_free_urb(urb);
631 }
632 }
633
634 dm = kmalloc(sizeof(*dm), GFP_KERNEL);
635 if (!dm)
636 return -ENOMEM;
637
638 /* flags */
639 ctrlmode = dev->can.ctrlmode;
640 dm->flags = 0;
641
642 if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
643 dm->flags |= GS_CAN_MODE_LOOP_BACK;
644 else if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
645 dm->flags |= GS_CAN_MODE_LISTEN_ONLY;
646
647 /* Controller is not allowed to retry TX
648 * this mode is unavailable on atmels uc3c hardware
649 */
650 if (ctrlmode & CAN_CTRLMODE_ONE_SHOT)
651 dm->flags |= GS_CAN_MODE_ONE_SHOT;
652
653 if (ctrlmode & CAN_CTRLMODE_3_SAMPLES)
654 dm->flags |= GS_CAN_MODE_TRIPLE_SAMPLE;
655
656 /* finally start device */
657 dm->mode = GS_CAN_MODE_START;
658 rc = usb_control_msg(interface_to_usbdev(dev->iface),
659 usb_sndctrlpipe(interface_to_usbdev(dev->iface), 0),
660 GS_USB_BREQ_MODE,
661 USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
662 dev->channel,
663 0,
664 dm,
665 sizeof(*dm),
666 1000);
667
668 if (rc < 0) {
669 netdev_err(netdev, "Couldn't start device (err=%d)\n", rc);
670 kfree(dm);
671 return rc;
672 }
673
674 kfree(dm);
675
676 dev->can.state = CAN_STATE_ERROR_ACTIVE;
677
678 if (!(dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY))
679 netif_start_queue(netdev);
680
681 return 0;
682}
683
684static int gs_can_close(struct net_device *netdev)
685{
686 int rc;
687 struct gs_can *dev = netdev_priv(netdev);
688 struct gs_usb *parent = dev->parent;
689
690 netif_stop_queue(netdev);
691
692 /* Stop polling */
693 if (atomic_dec_and_test(&parent->active_channels))
694 usb_kill_anchored_urbs(&parent->rx_submitted);
695
696 /* Stop sending URBs */
697 usb_kill_anchored_urbs(&dev->tx_submitted);
698 atomic_set(&dev->active_tx_urbs, 0);
699
700 /* reset the device */
701 rc = gs_cmd_reset(parent, dev);
702 if (rc < 0)
703 netdev_warn(netdev, "Couldn't shutdown device (err=%d)", rc);
704
705 /* reset tx contexts */
706 for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
707 dev->tx_context[rc].dev = dev;
708 dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
709 }
710
711 /* close the netdev */
712 close_candev(netdev);
713
714 return 0;
715}
716
717static const struct net_device_ops gs_usb_netdev_ops = {
718 .ndo_open = gs_can_open,
719 .ndo_stop = gs_can_close,
720 .ndo_start_xmit = gs_can_start_xmit,
721 .ndo_change_mtu = can_change_mtu,
722};
723
724static struct gs_can *gs_make_candev(unsigned int channel, struct usb_interface *intf)
725{
726 struct gs_can *dev;
727 struct net_device *netdev;
728 int rc;
729 struct gs_device_bt_const *bt_const;
730
731 bt_const = kmalloc(sizeof(*bt_const), GFP_KERNEL);
732 if (!bt_const)
733 return ERR_PTR(-ENOMEM);
734
735 /* fetch bit timing constants */
736 rc = usb_control_msg(interface_to_usbdev(intf),
737 usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
738 GS_USB_BREQ_BT_CONST,
739 USB_DIR_IN|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
740 channel,
741 0,
742 bt_const,
743 sizeof(*bt_const),
744 1000);
745
746 if (rc < 0) {
747 dev_err(&intf->dev,
748 "Couldn't get bit timing const for channel (err=%d)\n",
749 rc);
750 kfree(bt_const);
751 return ERR_PTR(rc);
752 }
753
754 /* create netdev */
755 netdev = alloc_candev(sizeof(struct gs_can), GS_MAX_TX_URBS);
756 if (!netdev) {
757 dev_err(&intf->dev, "Couldn't allocate candev\n");
758 kfree(bt_const);
759 return ERR_PTR(-ENOMEM);
760 }
761
762 dev = netdev_priv(netdev);
763
764 netdev->netdev_ops = &gs_usb_netdev_ops;
765
766 netdev->flags |= IFF_ECHO; /* we support full roundtrip echo */
767
768 /* dev settup */
769 strcpy(dev->bt_const.name, "gs_usb");
770 dev->bt_const.tseg1_min = bt_const->tseg1_min;
771 dev->bt_const.tseg1_max = bt_const->tseg1_max;
772 dev->bt_const.tseg2_min = bt_const->tseg2_min;
773 dev->bt_const.tseg2_max = bt_const->tseg2_max;
774 dev->bt_const.sjw_max = bt_const->sjw_max;
775 dev->bt_const.brp_min = bt_const->brp_min;
776 dev->bt_const.brp_max = bt_const->brp_max;
777 dev->bt_const.brp_inc = bt_const->brp_inc;
778
779 dev->udev = interface_to_usbdev(intf);
780 dev->iface = intf;
781 dev->netdev = netdev;
782 dev->channel = channel;
783
784 init_usb_anchor(&dev->tx_submitted);
785 atomic_set(&dev->active_tx_urbs, 0);
786 spin_lock_init(&dev->tx_ctx_lock);
787 for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
788 dev->tx_context[rc].dev = dev;
789 dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
790 }
791
792 /* can settup */
793 dev->can.state = CAN_STATE_STOPPED;
794 dev->can.clock.freq = bt_const->fclk_can;
795 dev->can.bittiming_const = &dev->bt_const;
796 dev->can.do_set_bittiming = gs_usb_set_bittiming;
797
798 dev->can.ctrlmode_supported = 0;
799
800 if (bt_const->feature & GS_CAN_FEATURE_LISTEN_ONLY)
801 dev->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY;
802
803 if (bt_const->feature & GS_CAN_FEATURE_LOOP_BACK)
804 dev->can.ctrlmode_supported |= CAN_CTRLMODE_LOOPBACK;
805
806 if (bt_const->feature & GS_CAN_FEATURE_TRIPLE_SAMPLE)
807 dev->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
808
809 if (bt_const->feature & GS_CAN_FEATURE_ONE_SHOT)
810 dev->can.ctrlmode_supported |= CAN_CTRLMODE_ONE_SHOT;
811
812 kfree(bt_const);
813
814 SET_NETDEV_DEV(netdev, &intf->dev);
815
816 rc = register_candev(dev->netdev);
817 if (rc) {
818 free_candev(dev->netdev);
819 dev_err(&intf->dev, "Couldn't register candev (err=%d)\n", rc);
820 return ERR_PTR(rc);
821 }
822
823 return dev;
824}
825
826static void gs_destroy_candev(struct gs_can *dev)
827{
828 unregister_candev(dev->netdev);
829 usb_kill_anchored_urbs(&dev->tx_submitted);
830 free_candev(dev->netdev);
831}
832
833static int gs_usb_probe(struct usb_interface *intf, const struct usb_device_id *id)
834{
835 struct gs_usb *dev;
836 int rc = -ENOMEM;
837 unsigned int icount, i;
838 struct gs_host_config *hconf;
839 struct gs_device_config *dconf;
840
841 hconf = kmalloc(sizeof(*hconf), GFP_KERNEL);
842 if (!hconf)
843 return -ENOMEM;
844
845 hconf->byte_order = 0x0000beef;
846
847 /* send host config */
848 rc = usb_control_msg(interface_to_usbdev(intf),
849 usb_sndctrlpipe(interface_to_usbdev(intf), 0),
850 GS_USB_BREQ_HOST_FORMAT,
851 USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
852 1,
853 intf->altsetting[0].desc.bInterfaceNumber,
854 hconf,
855 sizeof(*hconf),
856 1000);
857
858 kfree(hconf);
859
860 if (rc < 0) {
861 dev_err(&intf->dev, "Couldn't send data format (err=%d)\n",
862 rc);
863 return rc;
864 }
865
866 dconf = kmalloc(sizeof(*dconf), GFP_KERNEL);
867 if (!dconf)
868 return -ENOMEM;
869
870 /* read device config */
871 rc = usb_control_msg(interface_to_usbdev(intf),
872 usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
873 GS_USB_BREQ_DEVICE_CONFIG,
874 USB_DIR_IN|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
875 1,
876 intf->altsetting[0].desc.bInterfaceNumber,
877 dconf,
878 sizeof(*dconf),
879 1000);
880 if (rc < 0) {
881 dev_err(&intf->dev, "Couldn't get device config: (err=%d)\n",
882 rc);
883
884 kfree(dconf);
885
886 return rc;
887 }
888
889 icount = dconf->icount+1;
890
891 kfree(dconf);
892
893 dev_info(&intf->dev, "Configuring for %d interfaces\n", icount);
894
895 if (icount > GS_MAX_INTF) {
896 dev_err(&intf->dev,
897 "Driver cannot handle more that %d CAN interfaces\n",
898 GS_MAX_INTF);
899 return -EINVAL;
900 }
901
902 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
903 if (!dev)
904 return -ENOMEM;
905 init_usb_anchor(&dev->rx_submitted);
906
907 atomic_set(&dev->active_channels, 0);
908
909 usb_set_intfdata(intf, dev);
910 dev->udev = interface_to_usbdev(intf);
911
912 for (i = 0; i < icount; i++) {
913 dev->canch[i] = gs_make_candev(i, intf);
914 if (IS_ERR_OR_NULL(dev->canch[i])) {
915 /* save error code to return later */
916 rc = PTR_ERR(dev->canch[i]);
917
918 /* on failure destroy previously created candevs */
919 icount = i;
920 for (i = 0; i < icount; i++)
921 gs_destroy_candev(dev->canch[i]);
922
923 usb_kill_anchored_urbs(&dev->rx_submitted);
924 kfree(dev);
925 return rc;
926 }
927 dev->canch[i]->parent = dev;
928 }
929
930 return 0;
931}
932
933static void gs_usb_disconnect(struct usb_interface *intf)
934{
935 unsigned i;
936 struct gs_usb *dev = usb_get_intfdata(intf);
937 usb_set_intfdata(intf, NULL);
938
939 if (!dev) {
940 dev_err(&intf->dev, "Disconnect (nodata)\n");
941 return;
942 }
943
944 for (i = 0; i < GS_MAX_INTF; i++)
945 if (dev->canch[i])
946 gs_destroy_candev(dev->canch[i]);
947
948 usb_kill_anchored_urbs(&dev->rx_submitted);
949 kfree(dev);
950}
951
952static const struct usb_device_id gs_usb_table[] = {
953 {USB_DEVICE(USB_GSUSB_1_VENDOR_ID, USB_GSUSB_1_PRODUCT_ID)},
954 {} /* Terminating entry */
955};
956
957MODULE_DEVICE_TABLE(usb, gs_usb_table);
958
959static struct usb_driver gs_usb_driver = {
960 .name = "gs_usb",
961 .probe = gs_usb_probe,
962 .disconnect = gs_usb_disconnect,
963 .id_table = gs_usb_table,
964};
965
966module_usb_driver(gs_usb_driver);
967
968MODULE_AUTHOR("Maximilian Schneider <mws@schneidersoft.net>");
969MODULE_DESCRIPTION(
970"Socket CAN device driver for Geschwister Schneider Technologie-, "
971"Entwicklungs- und Vertriebs UG. USB2.0 to CAN interfaces.");
972MODULE_LICENSE("GPL v2");