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