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 */
36 enum 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
45 enum 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
52 enum 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 */
62 struct 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
70 struct 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
85 struct gs_device_mode {
86 u32 mode;
87 u32 flags;
88 } __packed;
89
90 struct gs_device_state {
91 u32 state;
92 u32 rxerr;
93 u32 txerr;
94 } __packed;
95
96 struct 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
109 struct 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
124 struct 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
148 struct gs_tx_context {
149 struct gs_can *dev;
150 unsigned int echo_id;
151 };
152
153 struct 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 recieve. */
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 */
174 struct 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 */
gs_alloc_tx_context(struct gs_can * dev)184 static 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 */
gs_free_tx_context(struct gs_tx_context * txc)205 static 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 */
gs_get_tx_context(struct gs_can * dev,unsigned int id)212 static 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
gs_cmd_reset(struct gs_usb * gsusb,struct gs_can * gsdev)227 static 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 kfree(dm);
250
251 return rc;
252 }
253
gs_update_state(struct gs_can * dev,struct can_frame * cf)254 static void gs_update_state(struct gs_can *dev, struct can_frame *cf)
255 {
256 struct can_device_stats *can_stats = &dev->can.can_stats;
257
258 if (cf->can_id & CAN_ERR_RESTARTED) {
259 dev->can.state = CAN_STATE_ERROR_ACTIVE;
260 can_stats->restarts++;
261 } else if (cf->can_id & CAN_ERR_BUSOFF) {
262 dev->can.state = CAN_STATE_BUS_OFF;
263 can_stats->bus_off++;
264 } else if (cf->can_id & CAN_ERR_CRTL) {
265 if ((cf->data[1] & CAN_ERR_CRTL_TX_WARNING) ||
266 (cf->data[1] & CAN_ERR_CRTL_RX_WARNING)) {
267 dev->can.state = CAN_STATE_ERROR_WARNING;
268 can_stats->error_warning++;
269 } else if ((cf->data[1] & CAN_ERR_CRTL_TX_PASSIVE) ||
270 (cf->data[1] & CAN_ERR_CRTL_RX_PASSIVE)) {
271 dev->can.state = CAN_STATE_ERROR_PASSIVE;
272 can_stats->error_passive++;
273 } else {
274 dev->can.state = CAN_STATE_ERROR_ACTIVE;
275 }
276 }
277 }
278
gs_usb_recieve_bulk_callback(struct urb * urb)279 static void gs_usb_recieve_bulk_callback(struct urb *urb)
280 {
281 struct gs_usb *usbcan = urb->context;
282 struct gs_can *dev;
283 struct net_device *netdev;
284 int rc;
285 struct net_device_stats *stats;
286 struct gs_host_frame *hf = urb->transfer_buffer;
287 struct gs_tx_context *txc;
288 struct can_frame *cf;
289 struct sk_buff *skb;
290
291 BUG_ON(!usbcan);
292
293 switch (urb->status) {
294 case 0: /* success */
295 break;
296 case -ENOENT:
297 case -ESHUTDOWN:
298 return;
299 default:
300 /* do not resubmit aborted urbs. eg: when device goes down */
301 return;
302 }
303
304 /* device reports out of range channel id */
305 if (hf->channel >= GS_MAX_INTF)
306 goto resubmit_urb;
307
308 dev = usbcan->canch[hf->channel];
309
310 netdev = dev->netdev;
311 stats = &netdev->stats;
312
313 if (!netif_device_present(netdev))
314 return;
315
316 if (hf->echo_id == -1) { /* normal rx */
317 skb = alloc_can_skb(dev->netdev, &cf);
318 if (!skb)
319 return;
320
321 cf->can_id = hf->can_id;
322
323 cf->can_dlc = get_can_dlc(hf->can_dlc);
324 memcpy(cf->data, hf->data, 8);
325
326 /* ERROR frames tell us information about the controller */
327 if (hf->can_id & CAN_ERR_FLAG)
328 gs_update_state(dev, cf);
329
330 netdev->stats.rx_packets++;
331 netdev->stats.rx_bytes += hf->can_dlc;
332
333 netif_rx(skb);
334 } else { /* echo_id == hf->echo_id */
335 if (hf->echo_id >= GS_MAX_TX_URBS) {
336 netdev_err(netdev,
337 "Unexpected out of range echo id %d\n",
338 hf->echo_id);
339 goto resubmit_urb;
340 }
341
342 netdev->stats.tx_packets++;
343 netdev->stats.tx_bytes += hf->can_dlc;
344
345 txc = gs_get_tx_context(dev, hf->echo_id);
346
347 /* bad devices send bad echo_ids. */
348 if (!txc) {
349 netdev_err(netdev,
350 "Unexpected unused echo id %d\n",
351 hf->echo_id);
352 goto resubmit_urb;
353 }
354
355 can_get_echo_skb(netdev, hf->echo_id);
356
357 gs_free_tx_context(txc);
358
359 atomic_dec(&dev->active_tx_urbs);
360
361 netif_wake_queue(netdev);
362 }
363
364 if (hf->flags & GS_CAN_FLAG_OVERFLOW) {
365 skb = alloc_can_err_skb(netdev, &cf);
366 if (!skb)
367 goto resubmit_urb;
368
369 cf->can_id |= CAN_ERR_CRTL;
370 cf->can_dlc = CAN_ERR_DLC;
371 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
372 stats->rx_over_errors++;
373 stats->rx_errors++;
374 netif_rx(skb);
375 }
376
377 resubmit_urb:
378 usb_fill_bulk_urb(urb,
379 usbcan->udev,
380 usb_rcvbulkpipe(usbcan->udev, GSUSB_ENDPOINT_IN),
381 hf,
382 sizeof(struct gs_host_frame),
383 gs_usb_recieve_bulk_callback,
384 usbcan
385 );
386
387 rc = usb_submit_urb(urb, GFP_ATOMIC);
388
389 /* USB failure take down all interfaces */
390 if (rc == -ENODEV) {
391 for (rc = 0; rc < GS_MAX_INTF; rc++) {
392 if (usbcan->canch[rc])
393 netif_device_detach(usbcan->canch[rc]->netdev);
394 }
395 }
396 }
397
gs_usb_set_bittiming(struct net_device * netdev)398 static int gs_usb_set_bittiming(struct net_device *netdev)
399 {
400 struct gs_can *dev = netdev_priv(netdev);
401 struct can_bittiming *bt = &dev->can.bittiming;
402 struct usb_interface *intf = dev->iface;
403 int rc;
404 struct gs_device_bittiming *dbt;
405
406 dbt = kmalloc(sizeof(*dbt), GFP_KERNEL);
407 if (!dbt)
408 return -ENOMEM;
409
410 dbt->prop_seg = bt->prop_seg;
411 dbt->phase_seg1 = bt->phase_seg1;
412 dbt->phase_seg2 = bt->phase_seg2;
413 dbt->sjw = bt->sjw;
414 dbt->brp = bt->brp;
415
416 /* request bit timings */
417 rc = usb_control_msg(interface_to_usbdev(intf),
418 usb_sndctrlpipe(interface_to_usbdev(intf), 0),
419 GS_USB_BREQ_BITTIMING,
420 USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
421 dev->channel,
422 0,
423 dbt,
424 sizeof(*dbt),
425 1000);
426
427 kfree(dbt);
428
429 if (rc < 0)
430 dev_err(netdev->dev.parent, "Couldn't set bittimings (err=%d)",
431 rc);
432
433 return (rc > 0) ? 0 : rc;
434 }
435
gs_usb_xmit_callback(struct urb * urb)436 static void gs_usb_xmit_callback(struct urb *urb)
437 {
438 struct gs_tx_context *txc = urb->context;
439 struct gs_can *dev = txc->dev;
440 struct net_device *netdev = dev->netdev;
441
442 if (urb->status)
443 netdev_info(netdev, "usb xmit fail %d\n", txc->echo_id);
444
445 usb_free_coherent(urb->dev,
446 urb->transfer_buffer_length,
447 urb->transfer_buffer,
448 urb->transfer_dma);
449 }
450
gs_can_start_xmit(struct sk_buff * skb,struct net_device * netdev)451 static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb, struct net_device *netdev)
452 {
453 struct gs_can *dev = netdev_priv(netdev);
454 struct net_device_stats *stats = &dev->netdev->stats;
455 struct urb *urb;
456 struct gs_host_frame *hf;
457 struct can_frame *cf;
458 int rc;
459 unsigned int idx;
460 struct gs_tx_context *txc;
461
462 if (can_dropped_invalid_skb(netdev, skb))
463 return NETDEV_TX_OK;
464
465 /* find an empty context to keep track of transmission */
466 txc = gs_alloc_tx_context(dev);
467 if (!txc)
468 return NETDEV_TX_BUSY;
469
470 /* create a URB, and a buffer for it */
471 urb = usb_alloc_urb(0, GFP_ATOMIC);
472 if (!urb) {
473 netdev_err(netdev, "No memory left for URB\n");
474 goto nomem_urb;
475 }
476
477 hf = usb_alloc_coherent(dev->udev, sizeof(*hf), GFP_ATOMIC,
478 &urb->transfer_dma);
479 if (!hf) {
480 netdev_err(netdev, "No memory left for USB buffer\n");
481 goto nomem_hf;
482 }
483
484 idx = txc->echo_id;
485
486 if (idx >= GS_MAX_TX_URBS) {
487 netdev_err(netdev, "Invalid tx context %d\n", idx);
488 goto badidx;
489 }
490
491 hf->echo_id = idx;
492 hf->channel = dev->channel;
493
494 cf = (struct can_frame *)skb->data;
495
496 hf->can_id = cf->can_id;
497 hf->can_dlc = cf->can_dlc;
498 memcpy(hf->data, cf->data, cf->can_dlc);
499
500 usb_fill_bulk_urb(urb, dev->udev,
501 usb_sndbulkpipe(dev->udev, GSUSB_ENDPOINT_OUT),
502 hf,
503 sizeof(*hf),
504 gs_usb_xmit_callback,
505 txc);
506
507 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
508 usb_anchor_urb(urb, &dev->tx_submitted);
509
510 can_put_echo_skb(skb, netdev, idx);
511
512 atomic_inc(&dev->active_tx_urbs);
513
514 rc = usb_submit_urb(urb, GFP_ATOMIC);
515 if (unlikely(rc)) { /* usb send failed */
516 atomic_dec(&dev->active_tx_urbs);
517
518 can_free_echo_skb(netdev, idx);
519 gs_free_tx_context(txc);
520
521 usb_unanchor_urb(urb);
522 usb_free_coherent(dev->udev,
523 sizeof(*hf),
524 hf,
525 urb->transfer_dma);
526
527
528 if (rc == -ENODEV) {
529 netif_device_detach(netdev);
530 } else {
531 netdev_err(netdev, "usb_submit failed (err=%d)\n", rc);
532 stats->tx_dropped++;
533 }
534 } else {
535 /* Slow down tx path */
536 if (atomic_read(&dev->active_tx_urbs) >= GS_MAX_TX_URBS)
537 netif_stop_queue(netdev);
538 }
539
540 /* let usb core take care of this urb */
541 usb_free_urb(urb);
542
543 return NETDEV_TX_OK;
544
545 badidx:
546 usb_free_coherent(dev->udev,
547 sizeof(*hf),
548 hf,
549 urb->transfer_dma);
550 nomem_hf:
551 usb_free_urb(urb);
552
553 nomem_urb:
554 gs_free_tx_context(txc);
555 dev_kfree_skb(skb);
556 stats->tx_dropped++;
557 return NETDEV_TX_OK;
558 }
559
gs_can_open(struct net_device * netdev)560 static int gs_can_open(struct net_device *netdev)
561 {
562 struct gs_can *dev = netdev_priv(netdev);
563 struct gs_usb *parent = dev->parent;
564 int rc, i;
565 struct gs_device_mode *dm;
566 u32 ctrlmode;
567
568 rc = open_candev(netdev);
569 if (rc)
570 return rc;
571
572 if (atomic_add_return(1, &parent->active_channels) == 1) {
573 for (i = 0; i < GS_MAX_RX_URBS; i++) {
574 struct urb *urb;
575 u8 *buf;
576
577 /* alloc rx urb */
578 urb = usb_alloc_urb(0, GFP_KERNEL);
579 if (!urb) {
580 netdev_err(netdev,
581 "No memory left for URB\n");
582 return -ENOMEM;
583 }
584
585 /* alloc rx buffer */
586 buf = usb_alloc_coherent(dev->udev,
587 sizeof(struct gs_host_frame),
588 GFP_KERNEL,
589 &urb->transfer_dma);
590 if (!buf) {
591 netdev_err(netdev,
592 "No memory left for USB buffer\n");
593 usb_free_urb(urb);
594 return -ENOMEM;
595 }
596
597 /* fill, anchor, and submit rx urb */
598 usb_fill_bulk_urb(urb,
599 dev->udev,
600 usb_rcvbulkpipe(dev->udev,
601 GSUSB_ENDPOINT_IN),
602 buf,
603 sizeof(struct gs_host_frame),
604 gs_usb_recieve_bulk_callback,
605 parent);
606 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
607
608 usb_anchor_urb(urb, &parent->rx_submitted);
609
610 rc = usb_submit_urb(urb, GFP_KERNEL);
611 if (rc) {
612 if (rc == -ENODEV)
613 netif_device_detach(dev->netdev);
614
615 netdev_err(netdev,
616 "usb_submit failed (err=%d)\n",
617 rc);
618
619 usb_unanchor_urb(urb);
620 break;
621 }
622
623 /* Drop reference,
624 * USB core will take care of freeing it
625 */
626 usb_free_urb(urb);
627 }
628 }
629
630 dm = kmalloc(sizeof(*dm), GFP_KERNEL);
631 if (!dm)
632 return -ENOMEM;
633
634 /* flags */
635 ctrlmode = dev->can.ctrlmode;
636 dm->flags = 0;
637
638 if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
639 dm->flags |= GS_CAN_MODE_LOOP_BACK;
640 else if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
641 dm->flags |= GS_CAN_MODE_LISTEN_ONLY;
642
643 /* Controller is not allowed to retry TX
644 * this mode is unavailable on atmels uc3c hardware
645 */
646 if (ctrlmode & CAN_CTRLMODE_ONE_SHOT)
647 dm->flags |= GS_CAN_MODE_ONE_SHOT;
648
649 if (ctrlmode & CAN_CTRLMODE_3_SAMPLES)
650 dm->flags |= GS_CAN_MODE_TRIPLE_SAMPLE;
651
652 /* finally start device */
653 dm->mode = GS_CAN_MODE_START;
654 rc = usb_control_msg(interface_to_usbdev(dev->iface),
655 usb_sndctrlpipe(interface_to_usbdev(dev->iface), 0),
656 GS_USB_BREQ_MODE,
657 USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
658 dev->channel,
659 0,
660 dm,
661 sizeof(*dm),
662 1000);
663
664 if (rc < 0) {
665 netdev_err(netdev, "Couldn't start device (err=%d)\n", rc);
666 kfree(dm);
667 return rc;
668 }
669
670 kfree(dm);
671
672 dev->can.state = CAN_STATE_ERROR_ACTIVE;
673
674 if (!(dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY))
675 netif_start_queue(netdev);
676
677 return 0;
678 }
679
gs_can_close(struct net_device * netdev)680 static int gs_can_close(struct net_device *netdev)
681 {
682 int rc;
683 struct gs_can *dev = netdev_priv(netdev);
684 struct gs_usb *parent = dev->parent;
685
686 netif_stop_queue(netdev);
687
688 /* Stop polling */
689 if (atomic_dec_and_test(&parent->active_channels))
690 usb_kill_anchored_urbs(&parent->rx_submitted);
691
692 /* Stop sending URBs */
693 usb_kill_anchored_urbs(&dev->tx_submitted);
694 atomic_set(&dev->active_tx_urbs, 0);
695
696 /* reset the device */
697 rc = gs_cmd_reset(parent, dev);
698 if (rc < 0)
699 netdev_warn(netdev, "Couldn't shutdown device (err=%d)", rc);
700
701 /* reset tx contexts */
702 for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
703 dev->tx_context[rc].dev = dev;
704 dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
705 }
706
707 /* close the netdev */
708 close_candev(netdev);
709
710 return 0;
711 }
712
713 static const struct net_device_ops gs_usb_netdev_ops = {
714 .ndo_open = gs_can_open,
715 .ndo_stop = gs_can_close,
716 .ndo_start_xmit = gs_can_start_xmit,
717 .ndo_change_mtu = can_change_mtu,
718 };
719
gs_make_candev(unsigned int channel,struct usb_interface * intf)720 static struct gs_can *gs_make_candev(unsigned int channel, struct usb_interface *intf)
721 {
722 struct gs_can *dev;
723 struct net_device *netdev;
724 int rc;
725 struct gs_device_bt_const *bt_const;
726
727 bt_const = kmalloc(sizeof(*bt_const), GFP_KERNEL);
728 if (!bt_const)
729 return ERR_PTR(-ENOMEM);
730
731 /* fetch bit timing constants */
732 rc = usb_control_msg(interface_to_usbdev(intf),
733 usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
734 GS_USB_BREQ_BT_CONST,
735 USB_DIR_IN|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
736 channel,
737 0,
738 bt_const,
739 sizeof(*bt_const),
740 1000);
741
742 if (rc < 0) {
743 dev_err(&intf->dev,
744 "Couldn't get bit timing const for channel (err=%d)\n",
745 rc);
746 kfree(bt_const);
747 return ERR_PTR(rc);
748 }
749
750 /* create netdev */
751 netdev = alloc_candev(sizeof(struct gs_can), GS_MAX_TX_URBS);
752 if (!netdev) {
753 dev_err(&intf->dev, "Couldn't allocate candev\n");
754 kfree(bt_const);
755 return ERR_PTR(-ENOMEM);
756 }
757
758 dev = netdev_priv(netdev);
759
760 netdev->netdev_ops = &gs_usb_netdev_ops;
761
762 netdev->flags |= IFF_ECHO; /* we support full roundtrip echo */
763
764 /* dev settup */
765 strcpy(dev->bt_const.name, "gs_usb");
766 dev->bt_const.tseg1_min = bt_const->tseg1_min;
767 dev->bt_const.tseg1_max = bt_const->tseg1_max;
768 dev->bt_const.tseg2_min = bt_const->tseg2_min;
769 dev->bt_const.tseg2_max = bt_const->tseg2_max;
770 dev->bt_const.sjw_max = bt_const->sjw_max;
771 dev->bt_const.brp_min = bt_const->brp_min;
772 dev->bt_const.brp_max = bt_const->brp_max;
773 dev->bt_const.brp_inc = bt_const->brp_inc;
774
775 dev->udev = interface_to_usbdev(intf);
776 dev->iface = intf;
777 dev->netdev = netdev;
778 dev->channel = channel;
779
780 init_usb_anchor(&dev->tx_submitted);
781 atomic_set(&dev->active_tx_urbs, 0);
782 spin_lock_init(&dev->tx_ctx_lock);
783 for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
784 dev->tx_context[rc].dev = dev;
785 dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
786 }
787
788 /* can settup */
789 dev->can.state = CAN_STATE_STOPPED;
790 dev->can.clock.freq = bt_const->fclk_can;
791 dev->can.bittiming_const = &dev->bt_const;
792 dev->can.do_set_bittiming = gs_usb_set_bittiming;
793
794 dev->can.ctrlmode_supported = 0;
795
796 if (bt_const->feature & GS_CAN_FEATURE_LISTEN_ONLY)
797 dev->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY;
798
799 if (bt_const->feature & GS_CAN_FEATURE_LOOP_BACK)
800 dev->can.ctrlmode_supported |= CAN_CTRLMODE_LOOPBACK;
801
802 if (bt_const->feature & GS_CAN_FEATURE_TRIPLE_SAMPLE)
803 dev->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
804
805 if (bt_const->feature & GS_CAN_FEATURE_ONE_SHOT)
806 dev->can.ctrlmode_supported |= CAN_CTRLMODE_ONE_SHOT;
807
808 kfree(bt_const);
809
810 SET_NETDEV_DEV(netdev, &intf->dev);
811
812 rc = register_candev(dev->netdev);
813 if (rc) {
814 free_candev(dev->netdev);
815 dev_err(&intf->dev, "Couldn't register candev (err=%d)\n", rc);
816 return ERR_PTR(rc);
817 }
818
819 return dev;
820 }
821
gs_destroy_candev(struct gs_can * dev)822 static void gs_destroy_candev(struct gs_can *dev)
823 {
824 unregister_candev(dev->netdev);
825 usb_kill_anchored_urbs(&dev->tx_submitted);
826 free_candev(dev->netdev);
827 }
828
gs_usb_probe(struct usb_interface * intf,const struct usb_device_id * id)829 static int gs_usb_probe(struct usb_interface *intf, const struct usb_device_id *id)
830 {
831 struct gs_usb *dev;
832 int rc = -ENOMEM;
833 unsigned int icount, i;
834 struct gs_host_config *hconf;
835 struct gs_device_config *dconf;
836
837 hconf = kmalloc(sizeof(*hconf), GFP_KERNEL);
838 if (!hconf)
839 return -ENOMEM;
840
841 hconf->byte_order = 0x0000beef;
842
843 /* send host config */
844 rc = usb_control_msg(interface_to_usbdev(intf),
845 usb_sndctrlpipe(interface_to_usbdev(intf), 0),
846 GS_USB_BREQ_HOST_FORMAT,
847 USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
848 1,
849 intf->altsetting[0].desc.bInterfaceNumber,
850 hconf,
851 sizeof(*hconf),
852 1000);
853
854 kfree(hconf);
855
856 if (rc < 0) {
857 dev_err(&intf->dev, "Couldn't send data format (err=%d)\n",
858 rc);
859 return rc;
860 }
861
862 dconf = kmalloc(sizeof(*dconf), GFP_KERNEL);
863 if (!dconf)
864 return -ENOMEM;
865
866 /* read device config */
867 rc = usb_control_msg(interface_to_usbdev(intf),
868 usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
869 GS_USB_BREQ_DEVICE_CONFIG,
870 USB_DIR_IN|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
871 1,
872 intf->altsetting[0].desc.bInterfaceNumber,
873 dconf,
874 sizeof(*dconf),
875 1000);
876 if (rc < 0) {
877 dev_err(&intf->dev, "Couldn't get device config: (err=%d)\n",
878 rc);
879
880 kfree(dconf);
881
882 return rc;
883 }
884
885 icount = dconf->icount+1;
886
887 kfree(dconf);
888
889 dev_info(&intf->dev, "Configuring for %d interfaces\n", icount);
890
891 if (icount > GS_MAX_INTF) {
892 dev_err(&intf->dev,
893 "Driver cannot handle more that %d CAN interfaces\n",
894 GS_MAX_INTF);
895 return -EINVAL;
896 }
897
898 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
899 init_usb_anchor(&dev->rx_submitted);
900
901 atomic_set(&dev->active_channels, 0);
902
903 usb_set_intfdata(intf, dev);
904 dev->udev = interface_to_usbdev(intf);
905
906 for (i = 0; i < icount; i++) {
907 dev->canch[i] = gs_make_candev(i, intf);
908 if (IS_ERR_OR_NULL(dev->canch[i])) {
909 /* save error code to return later */
910 rc = PTR_ERR(dev->canch[i]);
911
912 /* on failure destroy previously created candevs */
913 icount = i;
914 for (i = 0; i < icount; i++)
915 gs_destroy_candev(dev->canch[i]);
916
917 usb_kill_anchored_urbs(&dev->rx_submitted);
918 kfree(dev);
919 return rc;
920 }
921 dev->canch[i]->parent = dev;
922 }
923
924 return 0;
925 }
926
gs_usb_disconnect(struct usb_interface * intf)927 static void gs_usb_disconnect(struct usb_interface *intf)
928 {
929 unsigned i;
930 struct gs_usb *dev = usb_get_intfdata(intf);
931 usb_set_intfdata(intf, NULL);
932
933 if (!dev) {
934 dev_err(&intf->dev, "Disconnect (nodata)\n");
935 return;
936 }
937
938 for (i = 0; i < GS_MAX_INTF; i++)
939 if (dev->canch[i])
940 gs_destroy_candev(dev->canch[i]);
941
942 usb_kill_anchored_urbs(&dev->rx_submitted);
943 kfree(dev);
944 }
945
946 static const struct usb_device_id gs_usb_table[] = {
947 {USB_DEVICE(USB_GSUSB_1_VENDOR_ID, USB_GSUSB_1_PRODUCT_ID)},
948 {} /* Terminating entry */
949 };
950
951 MODULE_DEVICE_TABLE(usb, gs_usb_table);
952
953 static struct usb_driver gs_usb_driver = {
954 .name = "gs_usb",
955 .probe = gs_usb_probe,
956 .disconnect = gs_usb_disconnect,
957 .id_table = gs_usb_table,
958 };
959
960 module_usb_driver(gs_usb_driver);
961
962 MODULE_AUTHOR("Maximilian Schneider <mws@schneidersoft.net>");
963 MODULE_DESCRIPTION(
964 "Socket CAN device driver for Geschwister Schneider Technologie-, "
965 "Entwicklungs- und Vertriebs UG. USB2.0 to CAN interfaces.");
966 MODULE_LICENSE("GPL v2");
967