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         kfree(dm);
 269
 270         return rc;
 271 }
 272
 273 static void gs_update_state(struct gs_can *dev, struct can_frame *cf)
 274 {
 275         struct can_device_stats *can_stats = &dev->can.can_stats;
 276
 277         if (cf->can_id & CAN_ERR_RESTARTED) {
 278                 dev->can.state = CAN_STATE_ERROR_ACTIVE;
 279                 can_stats->restarts++;
 280         } else if (cf->can_id & CAN_ERR_BUSOFF) {
 281                 dev->can.state = CAN_STATE_BUS_OFF;
 282                 can_stats->bus_off++;
 283         } else if (cf->can_id & CAN_ERR_CRTL) {
 284                 if ((cf->data[1] & CAN_ERR_CRTL_TX_WARNING) ||
 285                     (cf->data[1] & CAN_ERR_CRTL_RX_WARNING)) {
 286                         dev->can.state = CAN_STATE_ERROR_WARNING;
 287                         can_stats->error_warning++;
 288                 } else if ((cf->data[1] & CAN_ERR_CRTL_TX_PASSIVE) ||
 289                            (cf->data[1] & CAN_ERR_CRTL_RX_PASSIVE)) {
 290                         dev->can.state = CAN_STATE_ERROR_PASSIVE;
 291                         can_stats->error_passive++;
 292                 } else {
 293                         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 294                 }
 295         }
 296 }
 297
 298 static void gs_usb_receive_bulk_callback(struct urb *urb)
 299 {
 300         struct gs_usb *usbcan = urb->context;
 301         struct gs_can *dev;
 302         struct net_device *netdev;
 303         int rc;
 304         struct net_device_stats *stats;
 305         struct gs_host_frame *hf = urb->transfer_buffer;
 306         struct gs_tx_context *txc;
 307         struct can_frame *cf;
 308         struct sk_buff *skb;
 309
 310         BUG_ON(!usbcan);
 311
 312         switch (urb->status) {
 313         case 0: /* success */
 314                 break;
 315         case -ENOENT:
 316         case -ESHUTDOWN:
 317                 return;
 318         default:
 319                 /* do not resubmit aborted urbs. eg: when device goes down */
 320                 return;
 321         }
 322
 323         /* device reports out of range channel id */
 324         if (hf->channel >= GS_MAX_INTF)
 325                 goto resubmit_urb;
 326
 327         dev = usbcan->canch[hf->channel];
 328
 329         netdev = dev->netdev;
 330         stats = &netdev->stats;
 331
 332         if (!netif_device_present(netdev))
 333                 return;
 334
 335         if (hf->echo_id == -1) { /* normal rx */
 336                 skb = alloc_can_skb(dev->netdev, &cf);
 337                 if (!skb)
 338                         return;
 339
 340                 cf->can_id = hf->can_id;
 341
 342                 cf->can_dlc = get_can_dlc(hf->can_dlc);
 343                 memcpy(cf->data, hf->data, 8);
 344
 345                 /* ERROR frames tell us information about the controller */
 346                 if (hf->can_id & CAN_ERR_FLAG)
 347                         gs_update_state(dev, cf);
 348
 349                 netdev->stats.rx_packets++;
 350                 netdev->stats.rx_bytes += hf->can_dlc;
 351
 352                 netif_rx(skb);
 353         } else { /* echo_id == hf->echo_id */
 354                 if (hf->echo_id >= GS_MAX_TX_URBS) {
 355                         netdev_err(netdev,
 356                                    "Unexpected out of range echo id %d\n",
 357                                    hf->echo_id);
 358                         goto resubmit_urb;
 359                 }
 360
 361                 netdev->stats.tx_packets++;
 362                 netdev->stats.tx_bytes += hf->can_dlc;
 363
 364                 txc = gs_get_tx_context(dev, hf->echo_id);
 365
 366                 /* bad devices send bad echo_ids. */
 367                 if (!txc) {
 368                         netdev_err(netdev,
 369                                    "Unexpected unused echo id %d\n",
 370                                    hf->echo_id);
 371                         goto resubmit_urb;
 372                 }
 373
 374                 can_get_echo_skb(netdev, hf->echo_id);
 375
 376                 gs_free_tx_context(txc);
 377
 378                 atomic_dec(&dev->active_tx_urbs);
 379
 380                 netif_wake_queue(netdev);
 381         }
 382
 383         if (hf->flags & GS_CAN_FLAG_OVERFLOW) {
 384                 skb = alloc_can_err_skb(netdev, &cf);
 385                 if (!skb)
 386                         goto resubmit_urb;
 387
 388                 cf->can_id |= CAN_ERR_CRTL;
 389                 cf->can_dlc = CAN_ERR_DLC;
 390                 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 391                 stats->rx_over_errors++;
 392                 stats->rx_errors++;
 393                 netif_rx(skb);
 394         }
 395
 396  resubmit_urb:
 397         usb_fill_bulk_urb(urb,
 398                           usbcan->udev,
 399                           usb_rcvbulkpipe(usbcan->udev, GSUSB_ENDPOINT_IN),
 400                           hf,
 401                           sizeof(struct gs_host_frame),
 402                           gs_usb_receive_bulk_callback,
 403                           usbcan
 404                           );
 405
 406         rc = usb_submit_urb(urb, GFP_ATOMIC);
 407
 408         /* USB failure take down all interfaces */
 409         if (rc == -ENODEV) {
 410                 for (rc = 0; rc < GS_MAX_INTF; rc++) {
 411                         if (usbcan->canch[rc])
 412                                 netif_device_detach(usbcan->canch[rc]->netdev);
 413                 }
 414         }
 415 }
 416
 417 static int gs_usb_set_bittiming(struct net_device *netdev)
 418 {
 419         struct gs_can *dev = netdev_priv(netdev);
 420         struct can_bittiming *bt = &dev->can.bittiming;
 421         struct usb_interface *intf = dev->iface;
 422         int rc;
 423         struct gs_device_bittiming *dbt;
 424
 425         dbt = kmalloc(sizeof(*dbt), GFP_KERNEL);
 426         if (!dbt)
 427                 return -ENOMEM;
 428
 429         dbt->prop_seg = bt->prop_seg;
 430         dbt->phase_seg1 = bt->phase_seg1;
 431         dbt->phase_seg2 = bt->phase_seg2;
 432         dbt->sjw = bt->sjw;
 433         dbt->brp = bt->brp;
 434
 435         /* request bit timings */
 436         rc = usb_control_msg(interface_to_usbdev(intf),
 437                              usb_sndctrlpipe(interface_to_usbdev(intf), 0),
 438                              GS_USB_BREQ_BITTIMING,
 439                              USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 440                              dev->channel,
 441                              0,
 442                              dbt,
 443                              sizeof(*dbt),
 444                              1000);
 445
 446         kfree(dbt);
 447
 448         if (rc < 0)
 449                 dev_err(netdev->dev.parent, "Couldn't set bittimings (err=%d)",
 450                         rc);
 451
 452         return (rc > 0) ? 0 : rc;
 453 }
 454
 455 static void gs_usb_xmit_callback(struct urb *urb)
 456 {
 457         struct gs_tx_context *txc = urb->context;
 458         struct gs_can *dev = txc->dev;
 459         struct net_device *netdev = dev->netdev;
 460
 461         if (urb->status)
 462                 netdev_info(netdev, "usb xmit fail %d\n", txc->echo_id);
 463
 464         usb_free_coherent(urb->dev,
 465                           urb->transfer_buffer_length,
 466                           urb->transfer_buffer,
 467                           urb->transfer_dma);
 468 }
 469
 470 static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb,
 471                                      struct net_device *netdev)
 472 {
 473         struct gs_can *dev = netdev_priv(netdev);
 474         struct net_device_stats *stats = &dev->netdev->stats;
 475         struct urb *urb;
 476         struct gs_host_frame *hf;
 477         struct can_frame *cf;
 478         int rc;
 479         unsigned int idx;
 480         struct gs_tx_context *txc;
 481
 482         if (can_dropped_invalid_skb(netdev, skb))
 483                 return NETDEV_TX_OK;
 484
 485         /* find an empty context to keep track of transmission */
 486         txc = gs_alloc_tx_context(dev);
 487         if (!txc)
 488                 return NETDEV_TX_BUSY;
 489
 490         /* create a URB, and a buffer for it */
 491         urb = usb_alloc_urb(0, GFP_ATOMIC);
 492         if (!urb)
 493                 goto nomem_urb;
 494
 495         hf = usb_alloc_coherent(dev->udev, sizeof(*hf), GFP_ATOMIC,
 496                                 &urb->transfer_dma);
 497         if (!hf) {
 498                 netdev_err(netdev, "No memory left for USB buffer\n");
 499                 goto nomem_hf;
 500         }
 501
 502         idx = txc->echo_id;
 503
 504         if (idx >= GS_MAX_TX_URBS) {
 505                 netdev_err(netdev, "Invalid tx context %d\n", idx);
 506                 goto badidx;
 507         }
 508
 509         hf->echo_id = idx;
 510         hf->channel = dev->channel;
 511
 512         cf = (struct can_frame *)skb->data;
 513
 514         hf->can_id = cf->can_id;
 515         hf->can_dlc = cf->can_dlc;
 516         memcpy(hf->data, cf->data, cf->can_dlc);
 517
 518         usb_fill_bulk_urb(urb, dev->udev,
 519                           usb_sndbulkpipe(dev->udev, GSUSB_ENDPOINT_OUT),
 520                           hf,
 521                           sizeof(*hf),
 522                           gs_usb_xmit_callback,
 523                           txc);
 524
 525         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 526         usb_anchor_urb(urb, &dev->tx_submitted);
 527
 528         can_put_echo_skb(skb, netdev, idx);
 529
 530         atomic_inc(&dev->active_tx_urbs);
 531
 532         rc = usb_submit_urb(urb, GFP_ATOMIC);
 533         if (unlikely(rc)) {                     /* usb send failed */
 534                 atomic_dec(&dev->active_tx_urbs);
 535
 536                 can_free_echo_skb(netdev, idx);
 537                 gs_free_tx_context(txc);
 538
 539                 usb_unanchor_urb(urb);
 540                 usb_free_coherent(dev->udev,
 541                                   sizeof(*hf),
 542                                   hf,
 543                                   urb->transfer_dma);
 544
 545                 if (rc == -ENODEV) {
 546                         netif_device_detach(netdev);
 547                 } else {
 548                         netdev_err(netdev, "usb_submit failed (err=%d)\n", rc);
 549                         stats->tx_dropped++;
 550                 }
 551         } else {
 552                 /* Slow down tx path */
 553                 if (atomic_read(&dev->active_tx_urbs) >= GS_MAX_TX_URBS)
 554                         netif_stop_queue(netdev);
 555         }
 556
 557         /* let usb core take care of this urb */
 558         usb_free_urb(urb);
 559
 560         return NETDEV_TX_OK;
 561
 562  badidx:
 563         usb_free_coherent(dev->udev,
 564                           sizeof(*hf),
 565                           hf,
 566                           urb->transfer_dma);
 567  nomem_hf:
 568         usb_free_urb(urb);
 569
 570  nomem_urb:
 571         gs_free_tx_context(txc);
 572         dev_kfree_skb(skb);
 573         stats->tx_dropped++;
 574         return NETDEV_TX_OK;
 575 }
 576
 577 static int gs_can_open(struct net_device *netdev)
 578 {
 579         struct gs_can *dev = netdev_priv(netdev);
 580         struct gs_usb *parent = dev->parent;
 581         int rc, i;
 582         struct gs_device_mode *dm;
 583         u32 ctrlmode;
 584
 585         rc = open_candev(netdev);
 586         if (rc)
 587                 return rc;
 588
 589         if (atomic_add_return(1, &parent->active_channels) == 1) {
 590                 for (i = 0; i < GS_MAX_RX_URBS; i++) {
 591                         struct urb *urb;
 592                         u8 *buf;
 593
 594                         /* alloc rx urb */
 595                         urb = usb_alloc_urb(0, GFP_KERNEL);
 596                         if (!urb)
 597                                 return -ENOMEM;
 598
 599                         /* alloc rx buffer */
 600                         buf = usb_alloc_coherent(dev->udev,
 601                                                  sizeof(struct gs_host_frame),
 602                                                  GFP_KERNEL,
 603                                                  &urb->transfer_dma);
 604                         if (!buf) {
 605                                 netdev_err(netdev,
 606                                            "No memory left for USB buffer\n");
 607                                 usb_free_urb(urb);
 608                                 return -ENOMEM;
 609                         }
 610
 611                         /* fill, anchor, and submit rx urb */
 612                         usb_fill_bulk_urb(urb,
 613                                           dev->udev,
 614                                           usb_rcvbulkpipe(dev->udev,
 615                                                           GSUSB_ENDPOINT_IN),
 616                                           buf,
 617                                           sizeof(struct gs_host_frame),
 618                                           gs_usb_receive_bulk_callback,
 619                                           parent);
 620                         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 621
 622                         usb_anchor_urb(urb, &parent->rx_submitted);
 623
 624                         rc = usb_submit_urb(urb, GFP_KERNEL);
 625                         if (rc) {
 626                                 if (rc == -ENODEV)
 627                                         netif_device_detach(dev->netdev);
 628
 629                                 netdev_err(netdev,
 630                                            "usb_submit failed (err=%d)\n",
 631                                            rc);
 632
 633                                 usb_unanchor_urb(urb);
 634                                 break;
 635                         }
 636
 637                         /* Drop reference,
 638                          * USB core will take care of freeing it
 639                          */
 640                         usb_free_urb(urb);
 641                 }
 642         }
 643
 644         dm = kmalloc(sizeof(*dm), GFP_KERNEL);
 645         if (!dm)
 646                 return -ENOMEM;
 647
 648         /* flags */
 649         ctrlmode = dev->can.ctrlmode;
 650         dm->flags = 0;
 651
 652         if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
 653                 dm->flags |= GS_CAN_MODE_LOOP_BACK;
 654         else if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
 655                 dm->flags |= GS_CAN_MODE_LISTEN_ONLY;
 656
 657         /* Controller is not allowed to retry TX
 658          * this mode is unavailable on atmels uc3c hardware
 659          */
 660         if (ctrlmode & CAN_CTRLMODE_ONE_SHOT)
 661                 dm->flags |= GS_CAN_MODE_ONE_SHOT;
 662
 663         if (ctrlmode & CAN_CTRLMODE_3_SAMPLES)
 664                 dm->flags |= GS_CAN_MODE_TRIPLE_SAMPLE;
 665
 666         /* finally start device */
 667         dm->mode = GS_CAN_MODE_START;
 668         rc = usb_control_msg(interface_to_usbdev(dev->iface),
 669                              usb_sndctrlpipe(interface_to_usbdev(dev->iface), 0),
 670                              GS_USB_BREQ_MODE,
 671                              USB_DIR_OUT | USB_TYPE_VENDOR |
 672                              USB_RECIP_INTERFACE,
 673                              dev->channel,
 674                              0,
 675                              dm,
 676                              sizeof(*dm),
 677                              1000);
 678
 679         if (rc < 0) {
 680                 netdev_err(netdev, "Couldn't start device (err=%d)\n", rc);
 681                 kfree(dm);
 682                 return rc;
 683         }
 684
 685         kfree(dm);
 686
 687         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 688
 689         if (!(dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY))
 690                 netif_start_queue(netdev);
 691
 692         return 0;
 693 }
 694
 695 static int gs_can_close(struct net_device *netdev)
 696 {
 697         int rc;
 698         struct gs_can *dev = netdev_priv(netdev);
 699         struct gs_usb *parent = dev->parent;
 700
 701         netif_stop_queue(netdev);
 702
 703         /* Stop polling */
 704         if (atomic_dec_and_test(&parent->active_channels))
 705                 usb_kill_anchored_urbs(&parent->rx_submitted);
 706
 707         /* Stop sending URBs */
 708         usb_kill_anchored_urbs(&dev->tx_submitted);
 709         atomic_set(&dev->active_tx_urbs, 0);
 710
 711         /* reset the device */
 712         rc = gs_cmd_reset(parent, dev);
 713         if (rc < 0)
 714                 netdev_warn(netdev, "Couldn't shutdown device (err=%d)", rc);
 715
 716         /* reset tx contexts */
 717         for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
 718                 dev->tx_context[rc].dev = dev;
 719                 dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
 720         }
 721
 722         /* close the netdev */
 723         close_candev(netdev);
 724
 725         return 0;
 726 }
 727
 728 static const struct net_device_ops gs_usb_netdev_ops = {
 729         .ndo_open = gs_can_open,
 730         .ndo_stop = gs_can_close,
 731         .ndo_start_xmit = gs_can_start_xmit,
 732         .ndo_change_mtu = can_change_mtu,
 733 };
 734
 735 static int gs_usb_set_identify(struct net_device *netdev, bool do_identify)
 736 {
 737         struct gs_can *dev = netdev_priv(netdev);
 738         struct gs_identify_mode *imode;
 739         int rc;
 740
 741         imode = kmalloc(sizeof(*imode), GFP_KERNEL);
 742
 743         if (!imode)
 744                 return -ENOMEM;
 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         kfree(imode);
 764
 765         return (rc > 0) ? 0 : rc;
 766 }
 767
 768 /* blink LED's for finding the this interface */
 769 static int gs_usb_set_phys_id(struct net_device *dev,
 770                               enum ethtool_phys_id_state state)
 771 {
 772         int rc = 0;
 773
 774         switch (state) {
 775         case ETHTOOL_ID_ACTIVE:
 776                 rc = gs_usb_set_identify(dev, GS_CAN_IDENTIFY_ON);
 777                 break;
 778         case ETHTOOL_ID_INACTIVE:
 779                 rc = gs_usb_set_identify(dev, GS_CAN_IDENTIFY_OFF);
 780                 break;
 781         default:
 782                 break;
 783         }
 784
 785         return rc;
 786 }
 787
 788 static const struct ethtool_ops gs_usb_ethtool_ops = {
 789         .set_phys_id = gs_usb_set_phys_id,
 790 };
 791
 792 static struct gs_can *gs_make_candev(unsigned int channel,
 793                                      struct usb_interface *intf,
 794                                      struct gs_device_config *dconf)
 795 {
 796         struct gs_can *dev;
 797         struct net_device *netdev;
 798         int rc;
 799         struct gs_device_bt_const *bt_const;
 800
 801         bt_const = kmalloc(sizeof(*bt_const), GFP_KERNEL);
 802         if (!bt_const)
 803                 return ERR_PTR(-ENOMEM);
 804
 805         /* fetch bit timing constants */
 806         rc = usb_control_msg(interface_to_usbdev(intf),
 807                              usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
 808                              GS_USB_BREQ_BT_CONST,
 809                              USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 810                              channel,
 811                              0,
 812                              bt_const,
 813                              sizeof(*bt_const),
 814                              1000);
 815
 816         if (rc < 0) {
 817                 dev_err(&intf->dev,
 818                         "Couldn't get bit timing const for channel (err=%d)\n",
 819                         rc);
 820                 kfree(bt_const);
 821                 return ERR_PTR(rc);
 822         }
 823
 824         /* create netdev */
 825         netdev = alloc_candev(sizeof(struct gs_can), GS_MAX_TX_URBS);
 826         if (!netdev) {
 827                 dev_err(&intf->dev, "Couldn't allocate candev\n");
 828                 kfree(bt_const);
 829                 return ERR_PTR(-ENOMEM);
 830         }
 831
 832         dev = netdev_priv(netdev);
 833
 834         netdev->netdev_ops = &gs_usb_netdev_ops;
 835
 836         netdev->flags |= IFF_ECHO; /* we support full roundtrip echo */
 837
 838         /* dev settup */
 839         strcpy(dev->bt_const.name, "gs_usb");
 840         dev->bt_const.tseg1_min = bt_const->tseg1_min;
 841         dev->bt_const.tseg1_max = bt_const->tseg1_max;
 842         dev->bt_const.tseg2_min = bt_const->tseg2_min;
 843         dev->bt_const.tseg2_max = bt_const->tseg2_max;
 844         dev->bt_const.sjw_max = bt_const->sjw_max;
 845         dev->bt_const.brp_min = bt_const->brp_min;
 846         dev->bt_const.brp_max = bt_const->brp_max;
 847         dev->bt_const.brp_inc = bt_const->brp_inc;
 848
 849         dev->udev = interface_to_usbdev(intf);
 850         dev->iface = intf;
 851         dev->netdev = netdev;
 852         dev->channel = channel;
 853
 854         init_usb_anchor(&dev->tx_submitted);
 855         atomic_set(&dev->active_tx_urbs, 0);
 856         spin_lock_init(&dev->tx_ctx_lock);
 857         for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
 858                 dev->tx_context[rc].dev = dev;
 859                 dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
 860         }
 861
 862         /* can settup */
 863         dev->can.state = CAN_STATE_STOPPED;
 864         dev->can.clock.freq = bt_const->fclk_can;
 865         dev->can.bittiming_const = &dev->bt_const;
 866         dev->can.do_set_bittiming = gs_usb_set_bittiming;
 867
 868         dev->can.ctrlmode_supported = 0;
 869
 870         if (bt_const->feature & GS_CAN_FEATURE_LISTEN_ONLY)
 871                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY;
 872
 873         if (bt_const->feature & GS_CAN_FEATURE_LOOP_BACK)
 874                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_LOOPBACK;
 875
 876         if (bt_const->feature & GS_CAN_FEATURE_TRIPLE_SAMPLE)
 877                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
 878
 879         if (bt_const->feature & GS_CAN_FEATURE_ONE_SHOT)
 880                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_ONE_SHOT;
 881
 882         SET_NETDEV_DEV(netdev, &intf->dev);
 883
 884         if (dconf->sw_version > 1)
 885                 if (bt_const->feature & GS_CAN_FEATURE_IDENTIFY)
 886                         netdev->ethtool_ops = &gs_usb_ethtool_ops;
 887
 888         kfree(bt_const);
 889
 890         rc = register_candev(dev->netdev);
 891         if (rc) {
 892                 free_candev(dev->netdev);
 893                 dev_err(&intf->dev, "Couldn't register candev (err=%d)\n", rc);
 894                 return ERR_PTR(rc);
 895         }
 896
 897         return dev;
 898 }
 899
 900 static void gs_destroy_candev(struct gs_can *dev)
 901 {
 902         unregister_candev(dev->netdev);
 903         usb_kill_anchored_urbs(&dev->tx_submitted);
 904         free_candev(dev->netdev);
 905 }
 906
 907 static int gs_usb_probe(struct usb_interface *intf,
 908                         const struct usb_device_id *id)
 909 {
 910         struct gs_usb *dev;
 911         int rc = -ENOMEM;
 912         unsigned int icount, i;
 913         struct gs_host_config *hconf;
 914         struct gs_device_config *dconf;
 915
 916         hconf = kmalloc(sizeof(*hconf), GFP_KERNEL);
 917         if (!hconf)
 918                 return -ENOMEM;
 919
 920         hconf->byte_order = 0x0000beef;
 921
 922         /* send host config */
 923         rc = usb_control_msg(interface_to_usbdev(intf),
 924                              usb_sndctrlpipe(interface_to_usbdev(intf), 0),
 925                              GS_USB_BREQ_HOST_FORMAT,
 926                              USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 927                              1,
 928                              intf->altsetting[0].desc.bInterfaceNumber,
 929                              hconf,
 930                              sizeof(*hconf),
 931                              1000);
 932
 933         kfree(hconf);
 934
 935         if (rc < 0) {
 936                 dev_err(&intf->dev, "Couldn't send data format (err=%d)\n",
 937                         rc);
 938                 return rc;
 939         }
 940
 941         dconf = kmalloc(sizeof(*dconf), GFP_KERNEL);
 942         if (!dconf)
 943                 return -ENOMEM;
 944
 945         /* read device config */
 946         rc = usb_control_msg(interface_to_usbdev(intf),
 947                              usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
 948                              GS_USB_BREQ_DEVICE_CONFIG,
 949                              USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 950                              1,
 951                              intf->altsetting[0].desc.bInterfaceNumber,
 952                              dconf,
 953                              sizeof(*dconf),
 954                              1000);
 955         if (rc < 0) {
 956                 dev_err(&intf->dev, "Couldn't get device config: (err=%d)\n",
 957                         rc);
 958                 kfree(dconf);
 959                 return rc;
 960         }
 961
 962         icount = dconf->icount + 1;
 963         dev_info(&intf->dev, "Configuring for %d interfaces\n", icount);
 964
 965         if (icount > GS_MAX_INTF) {
 966                 dev_err(&intf->dev,
 967                         "Driver cannot handle more that %d CAN interfaces\n",
 968                         GS_MAX_INTF);
 969                 kfree(dconf);
 970                 return -EINVAL;
 971         }
 972
 973         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 974         if (!dev) {
 975                 kfree(dconf);
 976                 return -ENOMEM;
 977         }
 978
 979         init_usb_anchor(&dev->rx_submitted);
 980
 981         atomic_set(&dev->active_channels, 0);
 982
 983         usb_set_intfdata(intf, dev);
 984         dev->udev = interface_to_usbdev(intf);
 985
 986         for (i = 0; i < icount; i++) {
 987                 dev->canch[i] = gs_make_candev(i, intf, dconf);
 988                 if (IS_ERR_OR_NULL(dev->canch[i])) {
 989                         /* save error code to return later */
 990                         rc = PTR_ERR(dev->canch[i]);
 991
 992                         /* on failure destroy previously created candevs */
 993                         icount = i;
 994                         for (i = 0; i < icount; i++)
 995                                 gs_destroy_candev(dev->canch[i]);
 996
 997                         usb_kill_anchored_urbs(&dev->rx_submitted);
 998                         kfree(dconf);
 999                         kfree(dev);
1000                         return rc;
1001                 }
1002                 dev->canch[i]->parent = dev;
1003         }
1004
1005         kfree(dconf);
1006
1007         return 0;
1008 }
1009
1010 static void gs_usb_disconnect(struct usb_interface *intf)
1011 {
1012         unsigned i;
1013         struct gs_usb *dev = usb_get_intfdata(intf);
1014         usb_set_intfdata(intf, NULL);
1015
1016         if (!dev) {
1017                 dev_err(&intf->dev, "Disconnect (nodata)\n");
1018                 return;
1019         }
1020
1021         for (i = 0; i < GS_MAX_INTF; i++)
1022                 if (dev->canch[i])
1023                         gs_destroy_candev(dev->canch[i]);
1024
1025         usb_kill_anchored_urbs(&dev->rx_submitted);
1026         kfree(dev);
1027 }
1028
1029 static const struct usb_device_id gs_usb_table[] = {
1030         { USB_DEVICE_INTERFACE_NUMBER(USB_GSUSB_1_VENDOR_ID,
1031                                       USB_GSUSB_1_PRODUCT_ID, 0) },
1032         { USB_DEVICE_INTERFACE_NUMBER(USB_CANDLELIGHT_VENDOR_ID,
1033                                       USB_CANDLELIGHT_PRODUCT_ID, 0) },
1034         {} /* Terminating entry */
1035 };
1036
1037 MODULE_DEVICE_TABLE(usb, gs_usb_table);
1038
1039 static struct usb_driver gs_usb_driver = {
1040         .name       = "gs_usb",
1041         .probe      = gs_usb_probe,
1042         .disconnect = gs_usb_disconnect,
1043         .id_table   = gs_usb_table,
1044 };
1045
1046 module_usb_driver(gs_usb_driver);
1047
1048 MODULE_AUTHOR("Maximilian Schneider <mws@schneidersoft.net>");
1049 MODULE_DESCRIPTION(
1050 "Socket CAN device driver for Geschwister Schneider Technologie-, "
1051 "Entwicklungs- und Vertriebs UG. USB2.0 to CAN interfaces\n"
1052 "and bytewerk.org candleLight USB CAN interfaces.");
1053 MODULE_LICENSE("GPL v2");