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1/* CAN driver for Geschwister Schneider USB/CAN devices
2 * and bytewerk.org candleLight USB CAN interfaces.
3 *
4 * Copyright (C) 2013-2016 Geschwister Schneider Technologie-,
5 * Entwicklungs- und Vertriebs UG (Haftungsbeschränkt).
6 * Copyright (C) 2016 Hubert Denkmair
7 *
8 * Many thanks to all socketcan devs!
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
20#include <linux/init.h>
21#include <linux/signal.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/* Device specific constants */
31#define USB_GSUSB_1_VENDOR_ID 0x1d50
32#define USB_GSUSB_1_PRODUCT_ID 0x606f
33
34#define USB_CANDLELIGHT_VENDOR_ID 0x1209
35#define USB_CANDLELIGHT_PRODUCT_ID 0x2323
36
37#define GSUSB_ENDPOINT_IN 1
38#define GSUSB_ENDPOINT_OUT 2
39
40/* Device specific constants */
41enum gs_usb_breq {
42 GS_USB_BREQ_HOST_FORMAT = 0,
43 GS_USB_BREQ_BITTIMING,
44 GS_USB_BREQ_MODE,
45 GS_USB_BREQ_BERR,
46 GS_USB_BREQ_BT_CONST,
47 GS_USB_BREQ_DEVICE_CONFIG,
48 GS_USB_BREQ_TIMESTAMP,
49 GS_USB_BREQ_IDENTIFY,
50};
51
52enum gs_can_mode {
53 /* reset a channel. turns it off */
54 GS_CAN_MODE_RESET = 0,
55 /* starts a channel */
56 GS_CAN_MODE_START
57};
58
59enum gs_can_state {
60 GS_CAN_STATE_ERROR_ACTIVE = 0,
61 GS_CAN_STATE_ERROR_WARNING,
62 GS_CAN_STATE_ERROR_PASSIVE,
63 GS_CAN_STATE_BUS_OFF,
64 GS_CAN_STATE_STOPPED,
65 GS_CAN_STATE_SLEEPING
66};
67
68enum gs_can_identify_mode {
69 GS_CAN_IDENTIFY_OFF = 0,
70 GS_CAN_IDENTIFY_ON
71};
72
73/* data types passed between host and device */
74struct gs_host_config {
75 u32 byte_order;
76} __packed;
77/* All data exchanged between host and device is exchanged in host byte order,
78 * thanks to the struct gs_host_config byte_order member, which is sent first
79 * to indicate the desired byte order.
80 */
81
82struct gs_device_config {
83 u8 reserved1;
84 u8 reserved2;
85 u8 reserved3;
86 u8 icount;
87 u32 sw_version;
88 u32 hw_version;
89} __packed;
90
91#define GS_CAN_MODE_NORMAL 0
92#define GS_CAN_MODE_LISTEN_ONLY BIT(0)
93#define GS_CAN_MODE_LOOP_BACK BIT(1)
94#define GS_CAN_MODE_TRIPLE_SAMPLE BIT(2)
95#define GS_CAN_MODE_ONE_SHOT BIT(3)
96
97struct gs_device_mode {
98 u32 mode;
99 u32 flags;
100} __packed;
101
102struct gs_device_state {
103 u32 state;
104 u32 rxerr;
105 u32 txerr;
106} __packed;
107
108struct gs_device_bittiming {
109 u32 prop_seg;
110 u32 phase_seg1;
111 u32 phase_seg2;
112 u32 sjw;
113 u32 brp;
114} __packed;
115
116struct gs_identify_mode {
117 u32 mode;
118} __packed;
119
120#define GS_CAN_FEATURE_LISTEN_ONLY BIT(0)
121#define GS_CAN_FEATURE_LOOP_BACK BIT(1)
122#define GS_CAN_FEATURE_TRIPLE_SAMPLE BIT(2)
123#define GS_CAN_FEATURE_ONE_SHOT BIT(3)
124#define GS_CAN_FEATURE_HW_TIMESTAMP BIT(4)
125#define GS_CAN_FEATURE_IDENTIFY BIT(5)
126
127struct gs_device_bt_const {
128 u32 feature;
129 u32 fclk_can;
130 u32 tseg1_min;
131 u32 tseg1_max;
132 u32 tseg2_min;
133 u32 tseg2_max;
134 u32 sjw_max;
135 u32 brp_min;
136 u32 brp_max;
137 u32 brp_inc;
138} __packed;
139
140#define GS_CAN_FLAG_OVERFLOW 1
141
142struct gs_host_frame {
143 u32 echo_id;
144 u32 can_id;
145
146 u8 can_dlc;
147 u8 channel;
148 u8 flags;
149 u8 reserved;
150
151 u8 data[8];
152} __packed;
153/* The GS USB devices make use of the same flags and masks as in
154 * linux/can.h and linux/can/error.h, and no additional mapping is necessary.
155 */
156
157/* Only send a max of GS_MAX_TX_URBS frames per channel at a time. */
158#define GS_MAX_TX_URBS 10
159/* Only launch a max of GS_MAX_RX_URBS usb requests at a time. */
160#define GS_MAX_RX_URBS 30
161/* Maximum number of interfaces the driver supports per device.
162 * Current hardware only supports 2 interfaces. The future may vary.
163 */
164#define GS_MAX_INTF 2
165
166struct gs_tx_context {
167 struct gs_can *dev;
168 unsigned int echo_id;
169};
170
171struct gs_can {
172 struct can_priv can; /* must be the first member */
173
174 struct gs_usb *parent;
175
176 struct net_device *netdev;
177 struct usb_device *udev;
178 struct usb_interface *iface;
179
180 struct can_bittiming_const bt_const;
181 unsigned int channel; /* channel number */
182
183 /* This lock prevents a race condition between xmit and receive. */
184 spinlock_t tx_ctx_lock;
185 struct gs_tx_context tx_context[GS_MAX_TX_URBS];
186
187 struct usb_anchor tx_submitted;
188 atomic_t active_tx_urbs;
189};
190
191/* usb interface struct */
192struct gs_usb {
193 struct gs_can *canch[GS_MAX_INTF];
194 struct usb_anchor rx_submitted;
195 atomic_t active_channels;
196 struct usb_device *udev;
197};
198
199/* 'allocate' a tx context.
200 * returns a valid tx context or NULL if there is no space.
201 */
202static struct gs_tx_context *gs_alloc_tx_context(struct gs_can *dev)
203{
204 int i = 0;
205 unsigned long flags;
206
207 spin_lock_irqsave(&dev->tx_ctx_lock, flags);
208
209 for (; i < GS_MAX_TX_URBS; i++) {
210 if (dev->tx_context[i].echo_id == GS_MAX_TX_URBS) {
211 dev->tx_context[i].echo_id = i;
212 spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
213 return &dev->tx_context[i];
214 }
215 }
216
217 spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
218 return NULL;
219}
220
221/* releases a tx context
222 */
223static void gs_free_tx_context(struct gs_tx_context *txc)
224{
225 txc->echo_id = GS_MAX_TX_URBS;
226}
227
228/* Get a tx context by id.
229 */
230static struct gs_tx_context *gs_get_tx_context(struct gs_can *dev,
231 unsigned int id)
232{
233 unsigned long flags;
234
235 if (id < GS_MAX_TX_URBS) {
236 spin_lock_irqsave(&dev->tx_ctx_lock, flags);
237 if (dev->tx_context[id].echo_id == id) {
238 spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
239 return &dev->tx_context[id];
240 }
241 spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
242 }
243 return NULL;
244}
245
246static int gs_cmd_reset(struct gs_usb *gsusb, struct gs_can *gsdev)
247{
248 struct gs_device_mode *dm;
249 struct usb_interface *intf = gsdev->iface;
250 int rc;
251
252 dm = kzalloc(sizeof(*dm), GFP_KERNEL);
253 if (!dm)
254 return -ENOMEM;
255
256 dm->mode = GS_CAN_MODE_RESET;
257
258 rc = usb_control_msg(interface_to_usbdev(intf),
259 usb_sndctrlpipe(interface_to_usbdev(intf), 0),
260 GS_USB_BREQ_MODE,
261 USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
262 gsdev->channel,
263 0,
264 dm,
265 sizeof(*dm),
266 1000);
267
268 return rc;
269}
270
271static void gs_update_state(struct gs_can *dev, struct can_frame *cf)
272{
273 struct can_device_stats *can_stats = &dev->can.can_stats;
274
275 if (cf->can_id & CAN_ERR_RESTARTED) {
276 dev->can.state = CAN_STATE_ERROR_ACTIVE;
277 can_stats->restarts++;
278 } else if (cf->can_id & CAN_ERR_BUSOFF) {
279 dev->can.state = CAN_STATE_BUS_OFF;
280 can_stats->bus_off++;
281 } else if (cf->can_id & CAN_ERR_CRTL) {
282 if ((cf->data[1] & CAN_ERR_CRTL_TX_WARNING) ||
283 (cf->data[1] & CAN_ERR_CRTL_RX_WARNING)) {
284 dev->can.state = CAN_STATE_ERROR_WARNING;
285 can_stats->error_warning++;
286 } else if ((cf->data[1] & CAN_ERR_CRTL_TX_PASSIVE) ||
287 (cf->data[1] & CAN_ERR_CRTL_RX_PASSIVE)) {
288 dev->can.state = CAN_STATE_ERROR_PASSIVE;
289 can_stats->error_passive++;
290 } else {
291 dev->can.state = CAN_STATE_ERROR_ACTIVE;
292 }
293 }
294}
295
296static void gs_usb_receive_bulk_callback(struct urb *urb)
297{
298 struct gs_usb *usbcan = urb->context;
299 struct gs_can *dev;
300 struct net_device *netdev;
301 int rc;
302 struct net_device_stats *stats;
303 struct gs_host_frame *hf = urb->transfer_buffer;
304 struct gs_tx_context *txc;
305 struct can_frame *cf;
306 struct sk_buff *skb;
307
308 BUG_ON(!usbcan);
309
310 switch (urb->status) {
311 case 0: /* success */
312 break;
313 case -ENOENT:
314 case -ESHUTDOWN:
315 return;
316 default:
317 /* do not resubmit aborted urbs. eg: when device goes down */
318 return;
319 }
320
321 /* device reports out of range channel id */
322 if (hf->channel >= GS_MAX_INTF)
323 goto resubmit_urb;
324
325 dev = usbcan->canch[hf->channel];
326
327 netdev = dev->netdev;
328 stats = &netdev->stats;
329
330 if (!netif_device_present(netdev))
331 return;
332
333 if (hf->echo_id == -1) { /* normal rx */
334 skb = alloc_can_skb(dev->netdev, &cf);
335 if (!skb)
336 return;
337
338 cf->can_id = hf->can_id;
339
340 cf->can_dlc = get_can_dlc(hf->can_dlc);
341 memcpy(cf->data, hf->data, 8);
342
343 /* ERROR frames tell us information about the controller */
344 if (hf->can_id & CAN_ERR_FLAG)
345 gs_update_state(dev, cf);
346
347 netdev->stats.rx_packets++;
348 netdev->stats.rx_bytes += hf->can_dlc;
349
350 netif_rx(skb);
351 } else { /* echo_id == hf->echo_id */
352 if (hf->echo_id >= GS_MAX_TX_URBS) {
353 netdev_err(netdev,
354 "Unexpected out of range echo id %d\n",
355 hf->echo_id);
356 goto resubmit_urb;
357 }
358
359 netdev->stats.tx_packets++;
360 netdev->stats.tx_bytes += hf->can_dlc;
361
362 txc = gs_get_tx_context(dev, hf->echo_id);
363
364 /* bad devices send bad echo_ids. */
365 if (!txc) {
366 netdev_err(netdev,
367 "Unexpected unused echo id %d\n",
368 hf->echo_id);
369 goto resubmit_urb;
370 }
371
372 can_get_echo_skb(netdev, hf->echo_id);
373
374 gs_free_tx_context(txc);
375
376 netif_wake_queue(netdev);
377 }
378
379 if (hf->flags & GS_CAN_FLAG_OVERFLOW) {
380 skb = alloc_can_err_skb(netdev, &cf);
381 if (!skb)
382 goto resubmit_urb;
383
384 cf->can_id |= CAN_ERR_CRTL;
385 cf->can_dlc = CAN_ERR_DLC;
386 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
387 stats->rx_over_errors++;
388 stats->rx_errors++;
389 netif_rx(skb);
390 }
391
392 resubmit_urb:
393 usb_fill_bulk_urb(urb,
394 usbcan->udev,
395 usb_rcvbulkpipe(usbcan->udev, GSUSB_ENDPOINT_IN),
396 hf,
397 sizeof(struct gs_host_frame),
398 gs_usb_receive_bulk_callback,
399 usbcan
400 );
401
402 rc = usb_submit_urb(urb, GFP_ATOMIC);
403
404 /* USB failure take down all interfaces */
405 if (rc == -ENODEV) {
406 for (rc = 0; rc < GS_MAX_INTF; rc++) {
407 if (usbcan->canch[rc])
408 netif_device_detach(usbcan->canch[rc]->netdev);
409 }
410 }
411}
412
413static int gs_usb_set_bittiming(struct net_device *netdev)
414{
415 struct gs_can *dev = netdev_priv(netdev);
416 struct can_bittiming *bt = &dev->can.bittiming;
417 struct usb_interface *intf = dev->iface;
418 int rc;
419 struct gs_device_bittiming *dbt;
420
421 dbt = kmalloc(sizeof(*dbt), GFP_KERNEL);
422 if (!dbt)
423 return -ENOMEM;
424
425 dbt->prop_seg = bt->prop_seg;
426 dbt->phase_seg1 = bt->phase_seg1;
427 dbt->phase_seg2 = bt->phase_seg2;
428 dbt->sjw = bt->sjw;
429 dbt->brp = bt->brp;
430
431 /* request bit timings */
432 rc = usb_control_msg(interface_to_usbdev(intf),
433 usb_sndctrlpipe(interface_to_usbdev(intf), 0),
434 GS_USB_BREQ_BITTIMING,
435 USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
436 dev->channel,
437 0,
438 dbt,
439 sizeof(*dbt),
440 1000);
441
442 kfree(dbt);
443
444 if (rc < 0)
445 dev_err(netdev->dev.parent, "Couldn't set bittimings (err=%d)",
446 rc);
447
448 return rc;
449}
450
451static void gs_usb_xmit_callback(struct urb *urb)
452{
453 struct gs_tx_context *txc = urb->context;
454 struct gs_can *dev = txc->dev;
455 struct net_device *netdev = dev->netdev;
456
457 if (urb->status)
458 netdev_info(netdev, "usb xmit fail %d\n", txc->echo_id);
459
460 usb_free_coherent(urb->dev,
461 urb->transfer_buffer_length,
462 urb->transfer_buffer,
463 urb->transfer_dma);
464
465 atomic_dec(&dev->active_tx_urbs);
466
467 if (!netif_device_present(netdev))
468 return;
469
470 if (netif_queue_stopped(netdev))
471 netif_wake_queue(netdev);
472}
473
474static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb,
475 struct net_device *netdev)
476{
477 struct gs_can *dev = netdev_priv(netdev);
478 struct net_device_stats *stats = &dev->netdev->stats;
479 struct urb *urb;
480 struct gs_host_frame *hf;
481 struct can_frame *cf;
482 int rc;
483 unsigned int idx;
484 struct gs_tx_context *txc;
485
486 if (can_dropped_invalid_skb(netdev, skb))
487 return NETDEV_TX_OK;
488
489 /* find an empty context to keep track of transmission */
490 txc = gs_alloc_tx_context(dev);
491 if (!txc)
492 return NETDEV_TX_BUSY;
493
494 /* create a URB, and a buffer for it */
495 urb = usb_alloc_urb(0, GFP_ATOMIC);
496 if (!urb)
497 goto nomem_urb;
498
499 hf = usb_alloc_coherent(dev->udev, sizeof(*hf), GFP_ATOMIC,
500 &urb->transfer_dma);
501 if (!hf) {
502 netdev_err(netdev, "No memory left for USB buffer\n");
503 goto nomem_hf;
504 }
505
506 idx = txc->echo_id;
507
508 if (idx >= GS_MAX_TX_URBS) {
509 netdev_err(netdev, "Invalid tx context %d\n", idx);
510 goto badidx;
511 }
512
513 hf->echo_id = idx;
514 hf->channel = dev->channel;
515
516 cf = (struct can_frame *)skb->data;
517
518 hf->can_id = cf->can_id;
519 hf->can_dlc = cf->can_dlc;
520 memcpy(hf->data, cf->data, cf->can_dlc);
521
522 usb_fill_bulk_urb(urb, dev->udev,
523 usb_sndbulkpipe(dev->udev, GSUSB_ENDPOINT_OUT),
524 hf,
525 sizeof(*hf),
526 gs_usb_xmit_callback,
527 txc);
528
529 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
530 usb_anchor_urb(urb, &dev->tx_submitted);
531
532 can_put_echo_skb(skb, netdev, idx);
533
534 atomic_inc(&dev->active_tx_urbs);
535
536 rc = usb_submit_urb(urb, GFP_ATOMIC);
537 if (unlikely(rc)) { /* usb send failed */
538 atomic_dec(&dev->active_tx_urbs);
539
540 can_free_echo_skb(netdev, idx);
541 gs_free_tx_context(txc);
542
543 usb_unanchor_urb(urb);
544 usb_free_coherent(dev->udev,
545 sizeof(*hf),
546 hf,
547 urb->transfer_dma);
548
549
550 if (rc == -ENODEV) {
551 netif_device_detach(netdev);
552 } else {
553 netdev_err(netdev, "usb_submit failed (err=%d)\n", rc);
554 stats->tx_dropped++;
555 }
556 } else {
557 /* Slow down tx path */
558 if (atomic_read(&dev->active_tx_urbs) >= GS_MAX_TX_URBS)
559 netif_stop_queue(netdev);
560 }
561
562 /* let usb core take care of this urb */
563 usb_free_urb(urb);
564
565 return NETDEV_TX_OK;
566
567 badidx:
568 usb_free_coherent(dev->udev,
569 sizeof(*hf),
570 hf,
571 urb->transfer_dma);
572 nomem_hf:
573 usb_free_urb(urb);
574
575 nomem_urb:
576 gs_free_tx_context(txc);
577 dev_kfree_skb(skb);
578 stats->tx_dropped++;
579 return NETDEV_TX_OK;
580}
581
582static int gs_can_open(struct net_device *netdev)
583{
584 struct gs_can *dev = netdev_priv(netdev);
585 struct gs_usb *parent = dev->parent;
586 int rc, i;
587 struct gs_device_mode *dm;
588 u32 ctrlmode;
589
590 rc = open_candev(netdev);
591 if (rc)
592 return rc;
593
594 if (atomic_add_return(1, &parent->active_channels) == 1) {
595 for (i = 0; i < GS_MAX_RX_URBS; i++) {
596 struct urb *urb;
597 u8 *buf;
598
599 /* alloc rx urb */
600 urb = usb_alloc_urb(0, GFP_KERNEL);
601 if (!urb)
602 return -ENOMEM;
603
604 /* alloc rx buffer */
605 buf = usb_alloc_coherent(dev->udev,
606 sizeof(struct gs_host_frame),
607 GFP_KERNEL,
608 &urb->transfer_dma);
609 if (!buf) {
610 netdev_err(netdev,
611 "No memory left for USB buffer\n");
612 usb_free_urb(urb);
613 return -ENOMEM;
614 }
615
616 /* fill, anchor, and submit rx urb */
617 usb_fill_bulk_urb(urb,
618 dev->udev,
619 usb_rcvbulkpipe(dev->udev,
620 GSUSB_ENDPOINT_IN),
621 buf,
622 sizeof(struct gs_host_frame),
623 gs_usb_receive_bulk_callback,
624 parent);
625 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
626
627 usb_anchor_urb(urb, &parent->rx_submitted);
628
629 rc = usb_submit_urb(urb, GFP_KERNEL);
630 if (rc) {
631 if (rc == -ENODEV)
632 netif_device_detach(dev->netdev);
633
634 netdev_err(netdev,
635 "usb_submit failed (err=%d)\n",
636 rc);
637
638 usb_unanchor_urb(urb);
639 break;
640 }
641
642 /* Drop reference,
643 * USB core will take care of freeing it
644 */
645 usb_free_urb(urb);
646 }
647 }
648
649 dm = kmalloc(sizeof(*dm), GFP_KERNEL);
650 if (!dm)
651 return -ENOMEM;
652
653 /* flags */
654 ctrlmode = dev->can.ctrlmode;
655 dm->flags = 0;
656
657 if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
658 dm->flags |= GS_CAN_MODE_LOOP_BACK;
659 else if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
660 dm->flags |= GS_CAN_MODE_LISTEN_ONLY;
661
662 /* Controller is not allowed to retry TX
663 * this mode is unavailable on atmels uc3c hardware
664 */
665 if (ctrlmode & CAN_CTRLMODE_ONE_SHOT)
666 dm->flags |= GS_CAN_MODE_ONE_SHOT;
667
668 if (ctrlmode & CAN_CTRLMODE_3_SAMPLES)
669 dm->flags |= GS_CAN_MODE_TRIPLE_SAMPLE;
670
671 /* finally start device */
672 dm->mode = GS_CAN_MODE_START;
673 rc = usb_control_msg(interface_to_usbdev(dev->iface),
674 usb_sndctrlpipe(interface_to_usbdev(dev->iface), 0),
675 GS_USB_BREQ_MODE,
676 USB_DIR_OUT | USB_TYPE_VENDOR |
677 USB_RECIP_INTERFACE,
678 dev->channel,
679 0,
680 dm,
681 sizeof(*dm),
682 1000);
683
684 if (rc < 0) {
685 netdev_err(netdev, "Couldn't start device (err=%d)\n", rc);
686 kfree(dm);
687 return rc;
688 }
689
690 kfree(dm);
691
692 dev->can.state = CAN_STATE_ERROR_ACTIVE;
693
694 if (!(dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY))
695 netif_start_queue(netdev);
696
697 return 0;
698}
699
700static int gs_can_close(struct net_device *netdev)
701{
702 int rc;
703 struct gs_can *dev = netdev_priv(netdev);
704 struct gs_usb *parent = dev->parent;
705
706 netif_stop_queue(netdev);
707
708 /* Stop polling */
709 if (atomic_dec_and_test(&parent->active_channels))
710 usb_kill_anchored_urbs(&parent->rx_submitted);
711
712 /* Stop sending URBs */
713 usb_kill_anchored_urbs(&dev->tx_submitted);
714 atomic_set(&dev->active_tx_urbs, 0);
715
716 /* reset the device */
717 rc = gs_cmd_reset(parent, dev);
718 if (rc < 0)
719 netdev_warn(netdev, "Couldn't shutdown device (err=%d)", rc);
720
721 /* reset tx contexts */
722 for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
723 dev->tx_context[rc].dev = dev;
724 dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
725 }
726
727 /* close the netdev */
728 close_candev(netdev);
729
730 return 0;
731}
732
733static const struct net_device_ops gs_usb_netdev_ops = {
734 .ndo_open = gs_can_open,
735 .ndo_stop = gs_can_close,
736 .ndo_start_xmit = gs_can_start_xmit,
737 .ndo_change_mtu = can_change_mtu,
738};
739
740static int gs_usb_set_identify(struct net_device *netdev, bool do_identify)
741{
742 struct gs_can *dev = netdev_priv(netdev);
743 struct gs_identify_mode imode;
744 int rc;
745
746 if (do_identify)
747 imode.mode = GS_CAN_IDENTIFY_ON;
748 else
749 imode.mode = GS_CAN_IDENTIFY_OFF;
750
751 rc = usb_control_msg(interface_to_usbdev(dev->iface),
752 usb_sndctrlpipe(interface_to_usbdev(dev->iface),
753 0),
754 GS_USB_BREQ_IDENTIFY,
755 USB_DIR_OUT | USB_TYPE_VENDOR |
756 USB_RECIP_INTERFACE,
757 dev->channel,
758 0,
759 &imode,
760 sizeof(imode),
761 100);
762
763 return (rc > 0) ? 0 : rc;
764}
765
766/* blink LED's for finding the this interface */
767static int gs_usb_set_phys_id(struct net_device *dev,
768 enum ethtool_phys_id_state state)
769{
770 int rc = 0;
771
772 switch (state) {
773 case ETHTOOL_ID_ACTIVE:
774 rc = gs_usb_set_identify(dev, GS_CAN_IDENTIFY_ON);
775 break;
776 case ETHTOOL_ID_INACTIVE:
777 rc = gs_usb_set_identify(dev, GS_CAN_IDENTIFY_OFF);
778 break;
779 default:
780 break;
781 }
782
783 return rc;
784}
785
786static const struct ethtool_ops gs_usb_ethtool_ops = {
787 .set_phys_id = gs_usb_set_phys_id,
788};
789
790static struct gs_can *gs_make_candev(unsigned int channel,
791 struct usb_interface *intf,
792 struct gs_device_config *dconf)
793{
794 struct gs_can *dev;
795 struct net_device *netdev;
796 int rc;
797 struct gs_device_bt_const *bt_const;
798
799 bt_const = kmalloc(sizeof(*bt_const), GFP_KERNEL);
800 if (!bt_const)
801 return ERR_PTR(-ENOMEM);
802
803 /* fetch bit timing constants */
804 rc = usb_control_msg(interface_to_usbdev(intf),
805 usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
806 GS_USB_BREQ_BT_CONST,
807 USB_DIR_IN|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
808 channel,
809 0,
810 bt_const,
811 sizeof(*bt_const),
812 1000);
813
814 if (rc < 0) {
815 dev_err(&intf->dev,
816 "Couldn't get bit timing const for channel (err=%d)\n",
817 rc);
818 kfree(bt_const);
819 return ERR_PTR(rc);
820 }
821
822 /* create netdev */
823 netdev = alloc_candev(sizeof(struct gs_can), GS_MAX_TX_URBS);
824 if (!netdev) {
825 dev_err(&intf->dev, "Couldn't allocate candev\n");
826 kfree(bt_const);
827 return ERR_PTR(-ENOMEM);
828 }
829
830 dev = netdev_priv(netdev);
831
832 netdev->netdev_ops = &gs_usb_netdev_ops;
833
834 netdev->flags |= IFF_ECHO; /* we support full roundtrip echo */
835
836 /* dev settup */
837 strcpy(dev->bt_const.name, "gs_usb");
838 dev->bt_const.tseg1_min = bt_const->tseg1_min;
839 dev->bt_const.tseg1_max = bt_const->tseg1_max;
840 dev->bt_const.tseg2_min = bt_const->tseg2_min;
841 dev->bt_const.tseg2_max = bt_const->tseg2_max;
842 dev->bt_const.sjw_max = bt_const->sjw_max;
843 dev->bt_const.brp_min = bt_const->brp_min;
844 dev->bt_const.brp_max = bt_const->brp_max;
845 dev->bt_const.brp_inc = bt_const->brp_inc;
846
847 dev->udev = interface_to_usbdev(intf);
848 dev->iface = intf;
849 dev->netdev = netdev;
850 dev->channel = channel;
851
852 init_usb_anchor(&dev->tx_submitted);
853 atomic_set(&dev->active_tx_urbs, 0);
854 spin_lock_init(&dev->tx_ctx_lock);
855 for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
856 dev->tx_context[rc].dev = dev;
857 dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
858 }
859
860 /* can settup */
861 dev->can.state = CAN_STATE_STOPPED;
862 dev->can.clock.freq = bt_const->fclk_can;
863 dev->can.bittiming_const = &dev->bt_const;
864 dev->can.do_set_bittiming = gs_usb_set_bittiming;
865
866 dev->can.ctrlmode_supported = 0;
867
868 if (bt_const->feature & GS_CAN_FEATURE_LISTEN_ONLY)
869 dev->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY;
870
871 if (bt_const->feature & GS_CAN_FEATURE_LOOP_BACK)
872 dev->can.ctrlmode_supported |= CAN_CTRLMODE_LOOPBACK;
873
874 if (bt_const->feature & GS_CAN_FEATURE_TRIPLE_SAMPLE)
875 dev->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
876
877 if (bt_const->feature & GS_CAN_FEATURE_ONE_SHOT)
878 dev->can.ctrlmode_supported |= CAN_CTRLMODE_ONE_SHOT;
879
880 SET_NETDEV_DEV(netdev, &intf->dev);
881
882 if (dconf->sw_version > 1)
883 if (bt_const->feature & GS_CAN_FEATURE_IDENTIFY)
884 netdev->ethtool_ops = &gs_usb_ethtool_ops;
885
886 kfree(bt_const);
887
888 rc = register_candev(dev->netdev);
889 if (rc) {
890 free_candev(dev->netdev);
891 dev_err(&intf->dev, "Couldn't register candev (err=%d)\n", rc);
892 return ERR_PTR(rc);
893 }
894
895 return dev;
896}
897
898static void gs_destroy_candev(struct gs_can *dev)
899{
900 unregister_candev(dev->netdev);
901 usb_kill_anchored_urbs(&dev->tx_submitted);
902 free_candev(dev->netdev);
903}
904
905static int gs_usb_probe(struct usb_interface *intf,
906 const struct usb_device_id *id)
907{
908 struct gs_usb *dev;
909 int rc = -ENOMEM;
910 unsigned int icount, i;
911 struct gs_host_config *hconf;
912 struct gs_device_config *dconf;
913
914 hconf = kmalloc(sizeof(*hconf), GFP_KERNEL);
915 if (!hconf)
916 return -ENOMEM;
917
918 hconf->byte_order = 0x0000beef;
919
920 /* send host config */
921 rc = usb_control_msg(interface_to_usbdev(intf),
922 usb_sndctrlpipe(interface_to_usbdev(intf), 0),
923 GS_USB_BREQ_HOST_FORMAT,
924 USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
925 1,
926 intf->altsetting[0].desc.bInterfaceNumber,
927 hconf,
928 sizeof(*hconf),
929 1000);
930
931 kfree(hconf);
932
933 if (rc < 0) {
934 dev_err(&intf->dev, "Couldn't send data format (err=%d)\n",
935 rc);
936 return rc;
937 }
938
939 dconf = kmalloc(sizeof(*dconf), GFP_KERNEL);
940 if (!dconf)
941 return -ENOMEM;
942
943 /* read device config */
944 rc = usb_control_msg(interface_to_usbdev(intf),
945 usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
946 GS_USB_BREQ_DEVICE_CONFIG,
947 USB_DIR_IN|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
948 1,
949 intf->altsetting[0].desc.bInterfaceNumber,
950 dconf,
951 sizeof(*dconf),
952 1000);
953 if (rc < 0) {
954 dev_err(&intf->dev, "Couldn't get device config: (err=%d)\n",
955 rc);
956 kfree(dconf);
957 return rc;
958 }
959
960 icount = dconf->icount + 1;
961 dev_info(&intf->dev, "Configuring for %d interfaces\n", icount);
962
963 if (icount > GS_MAX_INTF) {
964 dev_err(&intf->dev,
965 "Driver cannot handle more that %d CAN interfaces\n",
966 GS_MAX_INTF);
967 kfree(dconf);
968 return -EINVAL;
969 }
970
971 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
972 if (!dev) {
973 kfree(dconf);
974 return -ENOMEM;
975 }
976
977 init_usb_anchor(&dev->rx_submitted);
978
979 atomic_set(&dev->active_channels, 0);
980
981 usb_set_intfdata(intf, dev);
982 dev->udev = interface_to_usbdev(intf);
983
984 for (i = 0; i < icount; i++) {
985 dev->canch[i] = gs_make_candev(i, intf, dconf);
986 if (IS_ERR_OR_NULL(dev->canch[i])) {
987 /* save error code to return later */
988 rc = PTR_ERR(dev->canch[i]);
989
990 /* on failure destroy previously created candevs */
991 icount = i;
992 for (i = 0; i < icount; i++)
993 gs_destroy_candev(dev->canch[i]);
994
995 usb_kill_anchored_urbs(&dev->rx_submitted);
996 kfree(dconf);
997 kfree(dev);
998 return rc;
999 }
1000 dev->canch[i]->parent = dev;
1001 }
1002
1003 kfree(dconf);
1004
1005 return 0;
1006}
1007
1008static void gs_usb_disconnect(struct usb_interface *intf)
1009{
1010 unsigned i;
1011 struct gs_usb *dev = usb_get_intfdata(intf);
1012 usb_set_intfdata(intf, NULL);
1013
1014 if (!dev) {
1015 dev_err(&intf->dev, "Disconnect (nodata)\n");
1016 return;
1017 }
1018
1019 for (i = 0; i < GS_MAX_INTF; i++)
1020 if (dev->canch[i])
1021 gs_destroy_candev(dev->canch[i]);
1022
1023 usb_kill_anchored_urbs(&dev->rx_submitted);
1024 kfree(dev);
1025}
1026
1027static const struct usb_device_id gs_usb_table[] = {
1028 { USB_DEVICE_INTERFACE_NUMBER(USB_GSUSB_1_VENDOR_ID,
1029 USB_GSUSB_1_PRODUCT_ID, 0) },
1030 { USB_DEVICE_INTERFACE_NUMBER(USB_CANDLELIGHT_VENDOR_ID,
1031 USB_CANDLELIGHT_PRODUCT_ID, 0) },
1032 {} /* Terminating entry */
1033};
1034
1035MODULE_DEVICE_TABLE(usb, gs_usb_table);
1036
1037static struct usb_driver gs_usb_driver = {
1038 .name = "gs_usb",
1039 .probe = gs_usb_probe,
1040 .disconnect = gs_usb_disconnect,
1041 .id_table = gs_usb_table,
1042};
1043
1044module_usb_driver(gs_usb_driver);
1045
1046MODULE_AUTHOR("Maximilian Schneider <mws@schneidersoft.net>");
1047MODULE_DESCRIPTION(
1048"Socket CAN device driver for Geschwister Schneider Technologie-, "
1049"Entwicklungs- und Vertriebs UG. USB2.0 to CAN interfaces\n"
1050"and bytewerk.org candleLight USB CAN interfaces.");
1051MODULE_LICENSE("GPL v2");