drivers/net/can/usb/gs_usb.c

   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 */
  41 enum 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
  52 enum 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
  59 enum 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
  68 enum 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 */
  74 struct 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
  82 struct 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
  97 struct gs_device_mode {
  98         u32 mode;
  99         u32 flags;
 100 } __packed;
 101
 102 struct gs_device_state {
 103         u32 state;
 104         u32 rxerr;
 105         u32 txerr;
 106 } __packed;
 107
 108 struct gs_device_bittiming {
 109         u32 prop_seg;
 110         u32 phase_seg1;
 111         u32 phase_seg2;
 112         u32 sjw;
 113         u32 brp;
 114 } __packed;
 115
 116 struct 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
 127 struct 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
 142 struct 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
 166 struct gs_tx_context {
 167         struct gs_can *dev;
 168         unsigned int echo_id;
 169 };
 170
 171 struct 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 */
 192 struct 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  */
 202 static 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  */
 223 static 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  */
 230 static 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
 246 static 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
 271 static 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
 296 static 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
 413 static 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
 451 static 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
 474 static 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
 582 static 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
 700 static 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
 733 static 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
 740 static 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 */
 767 static 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
 786 static const struct ethtool_ops gs_usb_ethtool_ops = {
 787         .set_phys_id = gs_usb_set_phys_id,
 788 };
 789
 790 static 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
 898 static 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
 905 static 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                 .byte_order = 0x0000beef,
 913         };
 914         struct gs_device_config dconf;
 915
 916         /* send host config */
 917         rc = usb_control_msg(interface_to_usbdev(intf),
 918                              usb_sndctrlpipe(interface_to_usbdev(intf), 0),
 919                              GS_USB_BREQ_HOST_FORMAT,
 920                              USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
 921                              1,
 922                              intf->altsetting[0].desc.bInterfaceNumber,
 923                              &hconf,
 924                              sizeof(hconf),
 925                              1000);
 926
 927         if (rc < 0) {
 928                 dev_err(&intf->dev, "Couldn't send data format (err=%d)\n",
 929                         rc);
 930                 return rc;
 931         }
 932
 933         /* read device config */
 934         rc = usb_control_msg(interface_to_usbdev(intf),
 935                              usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
 936                              GS_USB_BREQ_DEVICE_CONFIG,
 937                              USB_DIR_IN|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
 938                              1,
 939                              intf->altsetting[0].desc.bInterfaceNumber,
 940                              &dconf,
 941                              sizeof(dconf),
 942                              1000);
 943         if (rc < 0) {
 944                 dev_err(&intf->dev, "Couldn't get device config: (err=%d)\n",
 945                         rc);
 946                 return rc;
 947         }
 948
 949         icount = dconf.icount + 1;
 950         dev_info(&intf->dev, "Configuring for %d interfaces\n", icount);
 951
 952         if (icount > GS_MAX_INTF) {
 953                 dev_err(&intf->dev,
 954                         "Driver cannot handle more that %d CAN interfaces\n",
 955                         GS_MAX_INTF);
 956                 return -EINVAL;
 957         }
 958
 959         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 960         if (!dev)
 961                 return -ENOMEM;
 962         init_usb_anchor(&dev->rx_submitted);
 963
 964         atomic_set(&dev->active_channels, 0);
 965
 966         usb_set_intfdata(intf, dev);
 967         dev->udev = interface_to_usbdev(intf);
 968
 969         for (i = 0; i < icount; i++) {
 970                 dev->canch[i] = gs_make_candev(i, intf, &dconf);
 971                 if (IS_ERR_OR_NULL(dev->canch[i])) {
 972                         /* save error code to return later */
 973                         rc = PTR_ERR(dev->canch[i]);
 974
 975                         /* on failure destroy previously created candevs */
 976                         icount = i;
 977                         for (i = 0; i < icount; i++)
 978                                 gs_destroy_candev(dev->canch[i]);
 979
 980                         usb_kill_anchored_urbs(&dev->rx_submitted);
 981                         kfree(dev);
 982                         return rc;
 983                 }
 984                 dev->canch[i]->parent = dev;
 985         }
 986
 987         return 0;
 988 }
 989
 990 static void gs_usb_disconnect(struct usb_interface *intf)
 991 {
 992         unsigned i;
 993         struct gs_usb *dev = usb_get_intfdata(intf);
 994         usb_set_intfdata(intf, NULL);
 995
 996         if (!dev) {
 997                 dev_err(&intf->dev, "Disconnect (nodata)\n");
 998                 return;
 999         }
1000
1001         for (i = 0; i < GS_MAX_INTF; i++)
1002                 if (dev->canch[i])
1003                         gs_destroy_candev(dev->canch[i]);
1004
1005         usb_kill_anchored_urbs(&dev->rx_submitted);
1006         kfree(dev);
1007 }
1008
1009 static const struct usb_device_id gs_usb_table[] = {
1010         { USB_DEVICE_INTERFACE_NUMBER(USB_GSUSB_1_VENDOR_ID,
1011                                       USB_GSUSB_1_PRODUCT_ID, 0) },
1012         { USB_DEVICE_INTERFACE_NUMBER(USB_CANDLELIGHT_VENDOR_ID,
1013                                       USB_CANDLELIGHT_PRODUCT_ID, 0) },
1014         {} /* Terminating entry */
1015 };
1016
1017 MODULE_DEVICE_TABLE(usb, gs_usb_table);
1018
1019 static struct usb_driver gs_usb_driver = {
1020         .name       = "gs_usb",
1021         .probe      = gs_usb_probe,
1022         .disconnect = gs_usb_disconnect,
1023         .id_table   = gs_usb_table,
1024 };
1025
1026 module_usb_driver(gs_usb_driver);
1027
1028 MODULE_AUTHOR("Maximilian Schneider <mws@schneidersoft.net>");
1029 MODULE_DESCRIPTION(
1030 "Socket CAN device driver for Geschwister Schneider Technologie-, "
1031 "Entwicklungs- und Vertriebs UG. USB2.0 to CAN interfaces\n"
1032 "and bytewerk.org candleLight USB CAN interfaces.");
1033 MODULE_LICENSE("GPL v2");