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 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 */
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_receive_bulk_callback(struct urb * urb)279 static void gs_usb_receive_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 device_detach;
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_receive_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 device_detach:
392 for (rc = 0; rc < GS_MAX_INTF; rc++) {
393 if (usbcan->canch[rc])
394 netif_device_detach(usbcan->canch[rc]->netdev);
395 }
396 }
397 }
398
gs_usb_set_bittiming(struct net_device * netdev)399 static int gs_usb_set_bittiming(struct net_device *netdev)
400 {
401 struct gs_can *dev = netdev_priv(netdev);
402 struct can_bittiming *bt = &dev->can.bittiming;
403 struct usb_interface *intf = dev->iface;
404 int rc;
405 struct gs_device_bittiming *dbt;
406
407 dbt = kmalloc(sizeof(*dbt), GFP_KERNEL);
408 if (!dbt)
409 return -ENOMEM;
410
411 dbt->prop_seg = bt->prop_seg;
412 dbt->phase_seg1 = bt->phase_seg1;
413 dbt->phase_seg2 = bt->phase_seg2;
414 dbt->sjw = bt->sjw;
415 dbt->brp = bt->brp;
416
417 /* request bit timings */
418 rc = usb_control_msg(interface_to_usbdev(intf),
419 usb_sndctrlpipe(interface_to_usbdev(intf), 0),
420 GS_USB_BREQ_BITTIMING,
421 USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
422 dev->channel,
423 0,
424 dbt,
425 sizeof(*dbt),
426 1000);
427
428 kfree(dbt);
429
430 if (rc < 0)
431 dev_err(netdev->dev.parent, "Couldn't set bittimings (err=%d)",
432 rc);
433
434 return (rc > 0) ? 0 : rc;
435 }
436
gs_usb_xmit_callback(struct urb * urb)437 static void gs_usb_xmit_callback(struct urb *urb)
438 {
439 struct gs_tx_context *txc = urb->context;
440 struct gs_can *dev = txc->dev;
441 struct net_device *netdev = dev->netdev;
442
443 if (urb->status)
444 netdev_info(netdev, "usb xmit fail %d\n", txc->echo_id);
445
446 usb_free_coherent(urb->dev,
447 urb->transfer_buffer_length,
448 urb->transfer_buffer,
449 urb->transfer_dma);
450 }
451
gs_can_start_xmit(struct sk_buff * skb,struct net_device * netdev)452 static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb, struct net_device *netdev)
453 {
454 struct gs_can *dev = netdev_priv(netdev);
455 struct net_device_stats *stats = &dev->netdev->stats;
456 struct urb *urb;
457 struct gs_host_frame *hf;
458 struct can_frame *cf;
459 int rc;
460 unsigned int idx;
461 struct gs_tx_context *txc;
462
463 if (can_dropped_invalid_skb(netdev, skb))
464 return NETDEV_TX_OK;
465
466 /* find an empty context to keep track of transmission */
467 txc = gs_alloc_tx_context(dev);
468 if (!txc)
469 return NETDEV_TX_BUSY;
470
471 /* create a URB, and a buffer for it */
472 urb = usb_alloc_urb(0, GFP_ATOMIC);
473 if (!urb) {
474 netdev_err(netdev, "No memory left for URB\n");
475 goto nomem_urb;
476 }
477
478 hf = usb_alloc_coherent(dev->udev, sizeof(*hf), GFP_ATOMIC,
479 &urb->transfer_dma);
480 if (!hf) {
481 netdev_err(netdev, "No memory left for USB buffer\n");
482 goto nomem_hf;
483 }
484
485 idx = txc->echo_id;
486
487 if (idx >= GS_MAX_TX_URBS) {
488 netdev_err(netdev, "Invalid tx context %d\n", idx);
489 goto badidx;
490 }
491
492 hf->echo_id = idx;
493 hf->channel = dev->channel;
494 hf->flags = 0;
495 hf->reserved = 0;
496
497 cf = (struct can_frame *)skb->data;
498
499 hf->can_id = cf->can_id;
500 hf->can_dlc = cf->can_dlc;
501 memcpy(hf->data, cf->data, cf->can_dlc);
502
503 usb_fill_bulk_urb(urb, dev->udev,
504 usb_sndbulkpipe(dev->udev, GSUSB_ENDPOINT_OUT),
505 hf,
506 sizeof(*hf),
507 gs_usb_xmit_callback,
508 txc);
509
510 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
511 usb_anchor_urb(urb, &dev->tx_submitted);
512
513 can_put_echo_skb(skb, netdev, idx);
514
515 atomic_inc(&dev->active_tx_urbs);
516
517 rc = usb_submit_urb(urb, GFP_ATOMIC);
518 if (unlikely(rc)) { /* usb send failed */
519 atomic_dec(&dev->active_tx_urbs);
520
521 can_free_echo_skb(netdev, idx);
522 gs_free_tx_context(txc);
523
524 usb_unanchor_urb(urb);
525 usb_free_coherent(dev->udev,
526 sizeof(*hf),
527 hf,
528 urb->transfer_dma);
529
530
531 if (rc == -ENODEV) {
532 netif_device_detach(netdev);
533 } else {
534 netdev_err(netdev, "usb_submit failed (err=%d)\n", rc);
535 stats->tx_dropped++;
536 }
537 } else {
538 /* Slow down tx path */
539 if (atomic_read(&dev->active_tx_urbs) >= GS_MAX_TX_URBS)
540 netif_stop_queue(netdev);
541 }
542
543 /* let usb core take care of this urb */
544 usb_free_urb(urb);
545
546 return NETDEV_TX_OK;
547
548 badidx:
549 usb_free_coherent(dev->udev,
550 sizeof(*hf),
551 hf,
552 urb->transfer_dma);
553 nomem_hf:
554 usb_free_urb(urb);
555
556 nomem_urb:
557 gs_free_tx_context(txc);
558 dev_kfree_skb(skb);
559 stats->tx_dropped++;
560 return NETDEV_TX_OK;
561 }
562
gs_can_open(struct net_device * netdev)563 static int gs_can_open(struct net_device *netdev)
564 {
565 struct gs_can *dev = netdev_priv(netdev);
566 struct gs_usb *parent = dev->parent;
567 int rc, i;
568 struct gs_device_mode *dm;
569 u32 ctrlmode;
570
571 rc = open_candev(netdev);
572 if (rc)
573 return rc;
574
575 if (atomic_add_return(1, &parent->active_channels) == 1) {
576 for (i = 0; i < GS_MAX_RX_URBS; i++) {
577 struct urb *urb;
578 u8 *buf;
579
580 /* alloc rx urb */
581 urb = usb_alloc_urb(0, GFP_KERNEL);
582 if (!urb) {
583 netdev_err(netdev,
584 "No memory left for URB\n");
585 return -ENOMEM;
586 }
587
588 /* alloc rx buffer */
589 buf = usb_alloc_coherent(dev->udev,
590 sizeof(struct gs_host_frame),
591 GFP_KERNEL,
592 &urb->transfer_dma);
593 if (!buf) {
594 netdev_err(netdev,
595 "No memory left for USB buffer\n");
596 usb_free_urb(urb);
597 return -ENOMEM;
598 }
599
600 /* fill, anchor, and submit rx urb */
601 usb_fill_bulk_urb(urb,
602 dev->udev,
603 usb_rcvbulkpipe(dev->udev,
604 GSUSB_ENDPOINT_IN),
605 buf,
606 sizeof(struct gs_host_frame),
607 gs_usb_receive_bulk_callback,
608 parent);
609 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
610
611 usb_anchor_urb(urb, &parent->rx_submitted);
612
613 rc = usb_submit_urb(urb, GFP_KERNEL);
614 if (rc) {
615 if (rc == -ENODEV)
616 netif_device_detach(dev->netdev);
617
618 netdev_err(netdev,
619 "usb_submit failed (err=%d)\n",
620 rc);
621
622 usb_unanchor_urb(urb);
623 usb_free_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
gs_can_close(struct net_device * netdev)684 static 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
717 static 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
gs_make_candev(unsigned int channel,struct usb_interface * intf)724 static 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
gs_destroy_candev(struct gs_can * dev)826 static 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
gs_usb_probe(struct usb_interface * intf,const struct usb_device_id * id)833 static 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->cur_altsetting->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->cur_altsetting->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
gs_usb_disconnect(struct usb_interface * intf)933 static 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
952 static 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
957 MODULE_DEVICE_TABLE(usb, gs_usb_table);
958
959 static 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
966 module_usb_driver(gs_usb_driver);
967
968 MODULE_AUTHOR("Maximilian Schneider <mws@schneidersoft.net>");
969 MODULE_DESCRIPTION(
970 "Socket CAN device driver for Geschwister Schneider Technologie-, "
971 "Entwicklungs- und Vertriebs UG. USB2.0 to CAN interfaces.");
972 MODULE_LICENSE("GPL v2");
973