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                 if (rc == -ENODEV) {
 550                         netif_device_detach(netdev);
 551                 } else {
 552                         netdev_err(netdev, "usb_submit failed (err=%d)\n", rc);
 553                         stats->tx_dropped++;
 554                 }
 555         } else {
 556                 /* Slow down tx path */
 557                 if (atomic_read(&dev->active_tx_urbs) >= GS_MAX_TX_URBS)
 558                         netif_stop_queue(netdev);
 559         }
 560
 561         /* let usb core take care of this urb */
 562         usb_free_urb(urb);
 563
 564         return NETDEV_TX_OK;
 565
 566  badidx:
 567         usb_free_coherent(dev->udev,
 568                           sizeof(*hf),
 569                           hf,
 570                           urb->transfer_dma);
 571  nomem_hf:
 572         usb_free_urb(urb);
 573
 574  nomem_urb:
 575         gs_free_tx_context(txc);
 576         dev_kfree_skb(skb);
 577         stats->tx_dropped++;
 578         return NETDEV_TX_OK;
 579 }
 580
 581 static int gs_can_open(struct net_device *netdev)
 582 {
 583         struct gs_can *dev = netdev_priv(netdev);
 584         struct gs_usb *parent = dev->parent;
 585         int rc, i;
 586         struct gs_device_mode *dm;
 587         u32 ctrlmode;
 588
 589         rc = open_candev(netdev);
 590         if (rc)
 591                 return rc;
 592
 593         if (atomic_add_return(1, &parent->active_channels) == 1) {
 594                 for (i = 0; i < GS_MAX_RX_URBS; i++) {
 595                         struct urb *urb;
 596                         u8 *buf;
 597
 598                         /* alloc rx urb */
 599                         urb = usb_alloc_urb(0, GFP_KERNEL);
 600                         if (!urb)
 601                                 return -ENOMEM;
 602
 603                         /* alloc rx buffer */
 604                         buf = usb_alloc_coherent(dev->udev,
 605                                                  sizeof(struct gs_host_frame),
 606                                                  GFP_KERNEL,
 607                                                  &urb->transfer_dma);
 608                         if (!buf) {
 609                                 netdev_err(netdev,
 610                                            "No memory left for USB buffer\n");
 611                                 usb_free_urb(urb);
 612                                 return -ENOMEM;
 613                         }
 614
 615                         /* fill, anchor, and submit rx urb */
 616                         usb_fill_bulk_urb(urb,
 617                                           dev->udev,
 618                                           usb_rcvbulkpipe(dev->udev,
 619                                                           GSUSB_ENDPOINT_IN),
 620                                           buf,
 621                                           sizeof(struct gs_host_frame),
 622                                           gs_usb_receive_bulk_callback,
 623                                           parent);
 624                         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 625
 626                         usb_anchor_urb(urb, &parent->rx_submitted);
 627
 628                         rc = usb_submit_urb(urb, GFP_KERNEL);
 629                         if (rc) {
 630                                 if (rc == -ENODEV)
 631                                         netif_device_detach(dev->netdev);
 632
 633                                 netdev_err(netdev,
 634                                            "usb_submit failed (err=%d)\n",
 635                                            rc);
 636
 637                                 usb_unanchor_urb(urb);
 638                                 break;
 639                         }
 640
 641                         /* Drop reference,
 642                          * USB core will take care of freeing it
 643                          */
 644                         usb_free_urb(urb);
 645                 }
 646         }
 647
 648         dm = kmalloc(sizeof(*dm), GFP_KERNEL);
 649         if (!dm)
 650                 return -ENOMEM;
 651
 652         /* flags */
 653         ctrlmode = dev->can.ctrlmode;
 654         dm->flags = 0;
 655
 656         if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
 657                 dm->flags |= GS_CAN_MODE_LOOP_BACK;
 658         else if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
 659                 dm->flags |= GS_CAN_MODE_LISTEN_ONLY;
 660
 661         /* Controller is not allowed to retry TX
 662          * this mode is unavailable on atmels uc3c hardware
 663          */
 664         if (ctrlmode & CAN_CTRLMODE_ONE_SHOT)
 665                 dm->flags |= GS_CAN_MODE_ONE_SHOT;
 666
 667         if (ctrlmode & CAN_CTRLMODE_3_SAMPLES)
 668                 dm->flags |= GS_CAN_MODE_TRIPLE_SAMPLE;
 669
 670         /* finally start device */
 671         dm->mode = GS_CAN_MODE_START;
 672         rc = usb_control_msg(interface_to_usbdev(dev->iface),
 673                              usb_sndctrlpipe(interface_to_usbdev(dev->iface), 0),
 674                              GS_USB_BREQ_MODE,
 675                              USB_DIR_OUT | USB_TYPE_VENDOR |
 676                              USB_RECIP_INTERFACE,
 677                              dev->channel,
 678                              0,
 679                              dm,
 680                              sizeof(*dm),
 681                              1000);
 682
 683         if (rc < 0) {
 684                 netdev_err(netdev, "Couldn't start device (err=%d)\n", rc);
 685                 kfree(dm);
 686                 return rc;
 687         }
 688
 689         kfree(dm);
 690
 691         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 692
 693         if (!(dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY))
 694                 netif_start_queue(netdev);
 695
 696         return 0;
 697 }
 698
 699 static int gs_can_close(struct net_device *netdev)
 700 {
 701         int rc;
 702         struct gs_can *dev = netdev_priv(netdev);
 703         struct gs_usb *parent = dev->parent;
 704
 705         netif_stop_queue(netdev);
 706
 707         /* Stop polling */
 708         if (atomic_dec_and_test(&parent->active_channels))
 709                 usb_kill_anchored_urbs(&parent->rx_submitted);
 710
 711         /* Stop sending URBs */
 712         usb_kill_anchored_urbs(&dev->tx_submitted);
 713         atomic_set(&dev->active_tx_urbs, 0);
 714
 715         /* reset the device */
 716         rc = gs_cmd_reset(parent, dev);
 717         if (rc < 0)
 718                 netdev_warn(netdev, "Couldn't shutdown device (err=%d)", rc);
 719
 720         /* reset tx contexts */
 721         for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
 722                 dev->tx_context[rc].dev = dev;
 723                 dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
 724         }
 725
 726         /* close the netdev */
 727         close_candev(netdev);
 728
 729         return 0;
 730 }
 731
 732 static const struct net_device_ops gs_usb_netdev_ops = {
 733         .ndo_open = gs_can_open,
 734         .ndo_stop = gs_can_close,
 735         .ndo_start_xmit = gs_can_start_xmit,
 736         .ndo_change_mtu = can_change_mtu,
 737 };
 738
 739 static int gs_usb_set_identify(struct net_device *netdev, bool do_identify)
 740 {
 741         struct gs_can *dev = netdev_priv(netdev);
 742         struct gs_identify_mode *imode;
 743         int rc;
 744
 745         imode = kmalloc(sizeof(*imode), GFP_KERNEL);
 746
 747         if (!imode)
 748                 return -ENOMEM;
 749
 750         if (do_identify)
 751                 imode->mode = GS_CAN_IDENTIFY_ON;
 752         else
 753                 imode->mode = GS_CAN_IDENTIFY_OFF;
 754
 755         rc = usb_control_msg(interface_to_usbdev(dev->iface),
 756                              usb_sndctrlpipe(interface_to_usbdev(dev->iface),
 757                                              0),
 758                              GS_USB_BREQ_IDENTIFY,
 759                              USB_DIR_OUT | USB_TYPE_VENDOR |
 760                              USB_RECIP_INTERFACE,
 761                              dev->channel,
 762                              0,
 763                              imode,
 764                              sizeof(*imode),
 765                              100);
 766
 767         kfree(imode);
 768
 769         return (rc > 0) ? 0 : rc;
 770 }
 771
 772 /* blink LED's for finding the this interface */
 773 static int gs_usb_set_phys_id(struct net_device *dev,
 774                               enum ethtool_phys_id_state state)
 775 {
 776         int rc = 0;
 777
 778         switch (state) {
 779         case ETHTOOL_ID_ACTIVE:
 780                 rc = gs_usb_set_identify(dev, GS_CAN_IDENTIFY_ON);
 781                 break;
 782         case ETHTOOL_ID_INACTIVE:
 783                 rc = gs_usb_set_identify(dev, GS_CAN_IDENTIFY_OFF);
 784                 break;
 785         default:
 786                 break;
 787         }
 788
 789         return rc;
 790 }
 791
 792 static const struct ethtool_ops gs_usb_ethtool_ops = {
 793         .set_phys_id = gs_usb_set_phys_id,
 794 };
 795
 796 static struct gs_can *gs_make_candev(unsigned int channel,
 797                                      struct usb_interface *intf,
 798                                      struct gs_device_config *dconf)
 799 {
 800         struct gs_can *dev;
 801         struct net_device *netdev;
 802         int rc;
 803         struct gs_device_bt_const *bt_const;
 804
 805         bt_const = kmalloc(sizeof(*bt_const), GFP_KERNEL);
 806         if (!bt_const)
 807                 return ERR_PTR(-ENOMEM);
 808
 809         /* fetch bit timing constants */
 810         rc = usb_control_msg(interface_to_usbdev(intf),
 811                              usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
 812                              GS_USB_BREQ_BT_CONST,
 813                              USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 814                              channel,
 815                              0,
 816                              bt_const,
 817                              sizeof(*bt_const),
 818                              1000);
 819
 820         if (rc < 0) {
 821                 dev_err(&intf->dev,
 822                         "Couldn't get bit timing const for channel (err=%d)\n",
 823                         rc);
 824                 kfree(bt_const);
 825                 return ERR_PTR(rc);
 826         }
 827
 828         /* create netdev */
 829         netdev = alloc_candev(sizeof(struct gs_can), GS_MAX_TX_URBS);
 830         if (!netdev) {
 831                 dev_err(&intf->dev, "Couldn't allocate candev\n");
 832                 kfree(bt_const);
 833                 return ERR_PTR(-ENOMEM);
 834         }
 835
 836         dev = netdev_priv(netdev);
 837
 838         netdev->netdev_ops = &gs_usb_netdev_ops;
 839
 840         netdev->flags |= IFF_ECHO; /* we support full roundtrip echo */
 841
 842         /* dev settup */
 843         strcpy(dev->bt_const.name, "gs_usb");
 844         dev->bt_const.tseg1_min = bt_const->tseg1_min;
 845         dev->bt_const.tseg1_max = bt_const->tseg1_max;
 846         dev->bt_const.tseg2_min = bt_const->tseg2_min;
 847         dev->bt_const.tseg2_max = bt_const->tseg2_max;
 848         dev->bt_const.sjw_max = bt_const->sjw_max;
 849         dev->bt_const.brp_min = bt_const->brp_min;
 850         dev->bt_const.brp_max = bt_const->brp_max;
 851         dev->bt_const.brp_inc = bt_const->brp_inc;
 852
 853         dev->udev = interface_to_usbdev(intf);
 854         dev->iface = intf;
 855         dev->netdev = netdev;
 856         dev->channel = channel;
 857
 858         init_usb_anchor(&dev->tx_submitted);
 859         atomic_set(&dev->active_tx_urbs, 0);
 860         spin_lock_init(&dev->tx_ctx_lock);
 861         for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
 862                 dev->tx_context[rc].dev = dev;
 863                 dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
 864         }
 865
 866         /* can settup */
 867         dev->can.state = CAN_STATE_STOPPED;
 868         dev->can.clock.freq = bt_const->fclk_can;
 869         dev->can.bittiming_const = &dev->bt_const;
 870         dev->can.do_set_bittiming = gs_usb_set_bittiming;
 871
 872         dev->can.ctrlmode_supported = 0;
 873
 874         if (bt_const->feature & GS_CAN_FEATURE_LISTEN_ONLY)
 875                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY;
 876
 877         if (bt_const->feature & GS_CAN_FEATURE_LOOP_BACK)
 878                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_LOOPBACK;
 879
 880         if (bt_const->feature & GS_CAN_FEATURE_TRIPLE_SAMPLE)
 881                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
 882
 883         if (bt_const->feature & GS_CAN_FEATURE_ONE_SHOT)
 884                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_ONE_SHOT;
 885
 886         SET_NETDEV_DEV(netdev, &intf->dev);
 887
 888         if (dconf->sw_version > 1)
 889                 if (bt_const->feature & GS_CAN_FEATURE_IDENTIFY)
 890                         netdev->ethtool_ops = &gs_usb_ethtool_ops;
 891
 892         kfree(bt_const);
 893
 894         rc = register_candev(dev->netdev);
 895         if (rc) {
 896                 free_candev(dev->netdev);
 897                 dev_err(&intf->dev, "Couldn't register candev (err=%d)\n", rc);
 898                 return ERR_PTR(rc);
 899         }
 900
 901         return dev;
 902 }
 903
 904 static void gs_destroy_candev(struct gs_can *dev)
 905 {
 906         unregister_candev(dev->netdev);
 907         usb_kill_anchored_urbs(&dev->tx_submitted);
 908         free_candev(dev->netdev);
 909 }
 910
 911 static int gs_usb_probe(struct usb_interface *intf,
 912                         const struct usb_device_id *id)
 913 {
 914         struct gs_usb *dev;
 915         int rc = -ENOMEM;
 916         unsigned int icount, i;
 917         struct gs_host_config *hconf;
 918         struct gs_device_config *dconf;
 919
 920         hconf = kmalloc(sizeof(*hconf), GFP_KERNEL);
 921         if (!hconf)
 922                 return -ENOMEM;
 923
 924         hconf->byte_order = 0x0000beef;
 925
 926         /* send host config */
 927         rc = usb_control_msg(interface_to_usbdev(intf),
 928                              usb_sndctrlpipe(interface_to_usbdev(intf), 0),
 929                              GS_USB_BREQ_HOST_FORMAT,
 930                              USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 931                              1,
 932                              intf->altsetting[0].desc.bInterfaceNumber,
 933                              hconf,
 934                              sizeof(*hconf),
 935                              1000);
 936
 937         kfree(hconf);
 938
 939         if (rc < 0) {
 940                 dev_err(&intf->dev, "Couldn't send data format (err=%d)\n",
 941                         rc);
 942                 return rc;
 943         }
 944
 945         dconf = kmalloc(sizeof(*dconf), GFP_KERNEL);
 946         if (!dconf)
 947                 return -ENOMEM;
 948
 949         /* read device config */
 950         rc = usb_control_msg(interface_to_usbdev(intf),
 951                              usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
 952                              GS_USB_BREQ_DEVICE_CONFIG,
 953                              USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 954                              1,
 955                              intf->altsetting[0].desc.bInterfaceNumber,
 956                              dconf,
 957                              sizeof(*dconf),
 958                              1000);
 959         if (rc < 0) {
 960                 dev_err(&intf->dev, "Couldn't get device config: (err=%d)\n",
 961                         rc);
 962                 kfree(dconf);
 963                 return rc;
 964         }
 965
 966         icount = dconf->icount + 1;
 967         dev_info(&intf->dev, "Configuring for %d interfaces\n", icount);
 968
 969         if (icount > GS_MAX_INTF) {
 970                 dev_err(&intf->dev,
 971                         "Driver cannot handle more that %d CAN interfaces\n",
 972                         GS_MAX_INTF);
 973                 kfree(dconf);
 974                 return -EINVAL;
 975         }
 976
 977         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 978         if (!dev) {
 979                 kfree(dconf);
 980                 return -ENOMEM;
 981         }
 982
 983         init_usb_anchor(&dev->rx_submitted);
 984
 985         atomic_set(&dev->active_channels, 0);
 986
 987         usb_set_intfdata(intf, dev);
 988         dev->udev = interface_to_usbdev(intf);
 989
 990         for (i = 0; i < icount; i++) {
 991                 dev->canch[i] = gs_make_candev(i, intf, dconf);
 992                 if (IS_ERR_OR_NULL(dev->canch[i])) {
 993                         /* save error code to return later */
 994                         rc = PTR_ERR(dev->canch[i]);
 995
 996                         /* on failure destroy previously created candevs */
 997                         icount = i;
 998                         for (i = 0; i < icount; i++)
 999                                 gs_destroy_candev(dev->canch[i]);
1000
1001                         usb_kill_anchored_urbs(&dev->rx_submitted);
1002                         kfree(dconf);
1003                         kfree(dev);
1004                         return rc;
1005                 }
1006                 dev->canch[i]->parent = dev;
1007         }
1008
1009         kfree(dconf);
1010
1011         return 0;
1012 }
1013
1014 static void gs_usb_disconnect(struct usb_interface *intf)
1015 {
1016         unsigned i;
1017         struct gs_usb *dev = usb_get_intfdata(intf);
1018         usb_set_intfdata(intf, NULL);
1019
1020         if (!dev) {
1021                 dev_err(&intf->dev, "Disconnect (nodata)\n");
1022                 return;
1023         }
1024
1025         for (i = 0; i < GS_MAX_INTF; i++)
1026                 if (dev->canch[i])
1027                         gs_destroy_candev(dev->canch[i]);
1028
1029         usb_kill_anchored_urbs(&dev->rx_submitted);
1030         kfree(dev);
1031 }
1032
1033 static const struct usb_device_id gs_usb_table[] = {
1034         { USB_DEVICE_INTERFACE_NUMBER(USB_GSUSB_1_VENDOR_ID,
1035                                       USB_GSUSB_1_PRODUCT_ID, 0) },
1036         { USB_DEVICE_INTERFACE_NUMBER(USB_CANDLELIGHT_VENDOR_ID,
1037                                       USB_CANDLELIGHT_PRODUCT_ID, 0) },
1038         {} /* Terminating entry */
1039 };
1040
1041 MODULE_DEVICE_TABLE(usb, gs_usb_table);
1042
1043 static struct usb_driver gs_usb_driver = {
1044         .name       = "gs_usb",
1045         .probe      = gs_usb_probe,
1046         .disconnect = gs_usb_disconnect,
1047         .id_table   = gs_usb_table,
1048 };
1049
1050 module_usb_driver(gs_usb_driver);
1051
1052 MODULE_AUTHOR("Maximilian Schneider <mws@schneidersoft.net>");
1053 MODULE_DESCRIPTION(
1054 "Socket CAN device driver for Geschwister Schneider Technologie-, "
1055 "Entwicklungs- und Vertriebs UG. USB2.0 to CAN interfaces\n"
1056 "and bytewerk.org candleLight USB CAN interfaces.");
1057 MODULE_LICENSE("GPL v2");