Merge tag 'drm-fixes-2020-01-10' of git://anongit.freedesktop.org/drm/drm
[linux-2.6-microblaze.git] / drivers / net / can / usb / gs_usb.c
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 */
33 enum 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
44 enum 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
51 enum 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
60 enum 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 */
66 struct 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
74 struct 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
89 struct gs_device_mode {
90         u32 mode;
91         u32 flags;
92 } __packed;
93
94 struct gs_device_state {
95         u32 state;
96         u32 rxerr;
97         u32 txerr;
98 } __packed;
99
100 struct gs_device_bittiming {
101         u32 prop_seg;
102         u32 phase_seg1;
103         u32 phase_seg2;
104         u32 sjw;
105         u32 brp;
106 } __packed;
107
108 struct 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
119 struct 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
134 struct 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
158 struct gs_tx_context {
159         struct gs_can *dev;
160         unsigned int echo_id;
161 };
162
163 struct 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 */
184 struct 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  */
194 static 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  */
215 static 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  */
222 static 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
238 static 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
265 static 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
290 static 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
409 static 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
447 static 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
462 static 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
569 static 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
688 static 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
721 static 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
728 static 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 */
762 static 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
781 static const struct ethtool_ops gs_usb_ethtool_ops = {
782         .set_phys_id = gs_usb_set_phys_id,
783 };
784
785 static 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
893 static 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
900 static 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->cur_altsetting->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->cur_altsetting->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
1003 static 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
1022 static 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
1030 MODULE_DEVICE_TABLE(usb, gs_usb_table);
1031
1032 static 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
1039 module_usb_driver(gs_usb_driver);
1040
1041 MODULE_AUTHOR("Maximilian Schneider <mws@schneidersoft.net>");
1042 MODULE_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.");
1046 MODULE_LICENSE("GPL v2");