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                 netif_wake_queue(netdev);
 379         }
 380
 381         if (hf->flags & GS_CAN_FLAG_OVERFLOW) {
 382                 skb = alloc_can_err_skb(netdev, &cf);
 383                 if (!skb)
 384                         goto resubmit_urb;
 385
 386                 cf->can_id |= CAN_ERR_CRTL;
 387                 cf->can_dlc = CAN_ERR_DLC;
 388                 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 389                 stats->rx_over_errors++;
 390                 stats->rx_errors++;
 391                 netif_rx(skb);
 392         }
 393
 394  resubmit_urb:
 395         usb_fill_bulk_urb(urb,
 396                           usbcan->udev,
 397                           usb_rcvbulkpipe(usbcan->udev, GSUSB_ENDPOINT_IN),
 398                           hf,
 399                           sizeof(struct gs_host_frame),
 400                           gs_usb_receive_bulk_callback,
 401                           usbcan
 402                           );
 403
 404         rc = usb_submit_urb(urb, GFP_ATOMIC);
 405
 406         /* USB failure take down all interfaces */
 407         if (rc == -ENODEV) {
 408                 for (rc = 0; rc < GS_MAX_INTF; rc++) {
 409                         if (usbcan->canch[rc])
 410                                 netif_device_detach(usbcan->canch[rc]->netdev);
 411                 }
 412         }
 413 }
 414
 415 static int gs_usb_set_bittiming(struct net_device *netdev)
 416 {
 417         struct gs_can *dev = netdev_priv(netdev);
 418         struct can_bittiming *bt = &dev->can.bittiming;
 419         struct usb_interface *intf = dev->iface;
 420         int rc;
 421         struct gs_device_bittiming *dbt;
 422
 423         dbt = kmalloc(sizeof(*dbt), GFP_KERNEL);
 424         if (!dbt)
 425                 return -ENOMEM;
 426
 427         dbt->prop_seg = bt->prop_seg;
 428         dbt->phase_seg1 = bt->phase_seg1;
 429         dbt->phase_seg2 = bt->phase_seg2;
 430         dbt->sjw = bt->sjw;
 431         dbt->brp = bt->brp;
 432
 433         /* request bit timings */
 434         rc = usb_control_msg(interface_to_usbdev(intf),
 435                              usb_sndctrlpipe(interface_to_usbdev(intf), 0),
 436                              GS_USB_BREQ_BITTIMING,
 437                              USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 438                              dev->channel,
 439                              0,
 440                              dbt,
 441                              sizeof(*dbt),
 442                              1000);
 443
 444         kfree(dbt);
 445
 446         if (rc < 0)
 447                 dev_err(netdev->dev.parent, "Couldn't set bittimings (err=%d)",
 448                         rc);
 449
 450         return rc;
 451 }
 452
 453 static void gs_usb_xmit_callback(struct urb *urb)
 454 {
 455         struct gs_tx_context *txc = urb->context;
 456         struct gs_can *dev = txc->dev;
 457         struct net_device *netdev = dev->netdev;
 458
 459         if (urb->status)
 460                 netdev_info(netdev, "usb xmit fail %d\n", txc->echo_id);
 461
 462         usb_free_coherent(urb->dev,
 463                           urb->transfer_buffer_length,
 464                           urb->transfer_buffer,
 465                           urb->transfer_dma);
 466
 467         atomic_dec(&dev->active_tx_urbs);
 468
 469         if (!netif_device_present(netdev))
 470                 return;
 471
 472         if (netif_queue_stopped(netdev))
 473                 netif_wake_queue(netdev);
 474 }
 475
 476 static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb,
 477                                      struct net_device *netdev)
 478 {
 479         struct gs_can *dev = netdev_priv(netdev);
 480         struct net_device_stats *stats = &dev->netdev->stats;
 481         struct urb *urb;
 482         struct gs_host_frame *hf;
 483         struct can_frame *cf;
 484         int rc;
 485         unsigned int idx;
 486         struct gs_tx_context *txc;
 487
 488         if (can_dropped_invalid_skb(netdev, skb))
 489                 return NETDEV_TX_OK;
 490
 491         /* find an empty context to keep track of transmission */
 492         txc = gs_alloc_tx_context(dev);
 493         if (!txc)
 494                 return NETDEV_TX_BUSY;
 495
 496         /* create a URB, and a buffer for it */
 497         urb = usb_alloc_urb(0, GFP_ATOMIC);
 498         if (!urb)
 499                 goto nomem_urb;
 500
 501         hf = usb_alloc_coherent(dev->udev, sizeof(*hf), GFP_ATOMIC,
 502                                 &urb->transfer_dma);
 503         if (!hf) {
 504                 netdev_err(netdev, "No memory left for USB buffer\n");
 505                 goto nomem_hf;
 506         }
 507
 508         idx = txc->echo_id;
 509
 510         if (idx >= GS_MAX_TX_URBS) {
 511                 netdev_err(netdev, "Invalid tx context %d\n", idx);
 512                 goto badidx;
 513         }
 514
 515         hf->echo_id = idx;
 516         hf->channel = dev->channel;
 517
 518         cf = (struct can_frame *)skb->data;
 519
 520         hf->can_id = cf->can_id;
 521         hf->can_dlc = cf->can_dlc;
 522         memcpy(hf->data, cf->data, cf->can_dlc);
 523
 524         usb_fill_bulk_urb(urb, dev->udev,
 525                           usb_sndbulkpipe(dev->udev, GSUSB_ENDPOINT_OUT),
 526                           hf,
 527                           sizeof(*hf),
 528                           gs_usb_xmit_callback,
 529                           txc);
 530
 531         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 532         usb_anchor_urb(urb, &dev->tx_submitted);
 533
 534         can_put_echo_skb(skb, netdev, idx);
 535
 536         atomic_inc(&dev->active_tx_urbs);
 537
 538         rc = usb_submit_urb(urb, GFP_ATOMIC);
 539         if (unlikely(rc)) {                     /* usb send failed */
 540                 atomic_dec(&dev->active_tx_urbs);
 541
 542                 can_free_echo_skb(netdev, idx);
 543                 gs_free_tx_context(txc);
 544
 545                 usb_unanchor_urb(urb);
 546                 usb_free_coherent(dev->udev,
 547                                   sizeof(*hf),
 548                                   hf,
 549                                   urb->transfer_dma);
 550
 551                 if (rc == -ENODEV) {
 552                         netif_device_detach(netdev);
 553                 } else {
 554                         netdev_err(netdev, "usb_submit failed (err=%d)\n", rc);
 555                         stats->tx_dropped++;
 556                 }
 557         } else {
 558                 /* Slow down tx path */
 559                 if (atomic_read(&dev->active_tx_urbs) >= GS_MAX_TX_URBS)
 560                         netif_stop_queue(netdev);
 561         }
 562
 563         /* let usb core take care of this urb */
 564         usb_free_urb(urb);
 565
 566         return NETDEV_TX_OK;
 567
 568  badidx:
 569         usb_free_coherent(dev->udev,
 570                           sizeof(*hf),
 571                           hf,
 572                           urb->transfer_dma);
 573  nomem_hf:
 574         usb_free_urb(urb);
 575
 576  nomem_urb:
 577         gs_free_tx_context(txc);
 578         dev_kfree_skb(skb);
 579         stats->tx_dropped++;
 580         return NETDEV_TX_OK;
 581 }
 582
 583 static int gs_can_open(struct net_device *netdev)
 584 {
 585         struct gs_can *dev = netdev_priv(netdev);
 586         struct gs_usb *parent = dev->parent;
 587         int rc, i;
 588         struct gs_device_mode *dm;
 589         u32 ctrlmode;
 590
 591         rc = open_candev(netdev);
 592         if (rc)
 593                 return rc;
 594
 595         if (atomic_add_return(1, &parent->active_channels) == 1) {
 596                 for (i = 0; i < GS_MAX_RX_URBS; i++) {
 597                         struct urb *urb;
 598                         u8 *buf;
 599
 600                         /* alloc rx urb */
 601                         urb = usb_alloc_urb(0, GFP_KERNEL);
 602                         if (!urb)
 603                                 return -ENOMEM;
 604
 605                         /* alloc rx buffer */
 606                         buf = usb_alloc_coherent(dev->udev,
 607                                                  sizeof(struct gs_host_frame),
 608                                                  GFP_KERNEL,
 609                                                  &urb->transfer_dma);
 610                         if (!buf) {
 611                                 netdev_err(netdev,
 612                                            "No memory left for USB buffer\n");
 613                                 usb_free_urb(urb);
 614                                 return -ENOMEM;
 615                         }
 616
 617                         /* fill, anchor, and submit rx urb */
 618                         usb_fill_bulk_urb(urb,
 619                                           dev->udev,
 620                                           usb_rcvbulkpipe(dev->udev,
 621                                                           GSUSB_ENDPOINT_IN),
 622                                           buf,
 623                                           sizeof(struct gs_host_frame),
 624                                           gs_usb_receive_bulk_callback,
 625                                           parent);
 626                         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 627
 628                         usb_anchor_urb(urb, &parent->rx_submitted);
 629
 630                         rc = usb_submit_urb(urb, GFP_KERNEL);
 631                         if (rc) {
 632                                 if (rc == -ENODEV)
 633                                         netif_device_detach(dev->netdev);
 634
 635                                 netdev_err(netdev,
 636                                            "usb_submit failed (err=%d)\n",
 637                                            rc);
 638
 639                                 usb_unanchor_urb(urb);
 640                                 break;
 641                         }
 642
 643                         /* Drop reference,
 644                          * USB core will take care of freeing it
 645                          */
 646                         usb_free_urb(urb);
 647                 }
 648         }
 649
 650         dm = kmalloc(sizeof(*dm), GFP_KERNEL);
 651         if (!dm)
 652                 return -ENOMEM;
 653
 654         /* flags */
 655         ctrlmode = dev->can.ctrlmode;
 656         dm->flags = 0;
 657
 658         if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
 659                 dm->flags |= GS_CAN_MODE_LOOP_BACK;
 660         else if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
 661                 dm->flags |= GS_CAN_MODE_LISTEN_ONLY;
 662
 663         /* Controller is not allowed to retry TX
 664          * this mode is unavailable on atmels uc3c hardware
 665          */
 666         if (ctrlmode & CAN_CTRLMODE_ONE_SHOT)
 667                 dm->flags |= GS_CAN_MODE_ONE_SHOT;
 668
 669         if (ctrlmode & CAN_CTRLMODE_3_SAMPLES)
 670                 dm->flags |= GS_CAN_MODE_TRIPLE_SAMPLE;
 671
 672         /* finally start device */
 673         dm->mode = GS_CAN_MODE_START;
 674         rc = usb_control_msg(interface_to_usbdev(dev->iface),
 675                              usb_sndctrlpipe(interface_to_usbdev(dev->iface), 0),
 676                              GS_USB_BREQ_MODE,
 677                              USB_DIR_OUT | USB_TYPE_VENDOR |
 678                              USB_RECIP_INTERFACE,
 679                              dev->channel,
 680                              0,
 681                              dm,
 682                              sizeof(*dm),
 683                              1000);
 684
 685         if (rc < 0) {
 686                 netdev_err(netdev, "Couldn't start device (err=%d)\n", rc);
 687                 kfree(dm);
 688                 return rc;
 689         }
 690
 691         kfree(dm);
 692
 693         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 694
 695         if (!(dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY))
 696                 netif_start_queue(netdev);
 697
 698         return 0;
 699 }
 700
 701 static int gs_can_close(struct net_device *netdev)
 702 {
 703         int rc;
 704         struct gs_can *dev = netdev_priv(netdev);
 705         struct gs_usb *parent = dev->parent;
 706
 707         netif_stop_queue(netdev);
 708
 709         /* Stop polling */
 710         if (atomic_dec_and_test(&parent->active_channels))
 711                 usb_kill_anchored_urbs(&parent->rx_submitted);
 712
 713         /* Stop sending URBs */
 714         usb_kill_anchored_urbs(&dev->tx_submitted);
 715         atomic_set(&dev->active_tx_urbs, 0);
 716
 717         /* reset the device */
 718         rc = gs_cmd_reset(parent, dev);
 719         if (rc < 0)
 720                 netdev_warn(netdev, "Couldn't shutdown device (err=%d)", rc);
 721
 722         /* reset tx contexts */
 723         for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
 724                 dev->tx_context[rc].dev = dev;
 725                 dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
 726         }
 727
 728         /* close the netdev */
 729         close_candev(netdev);
 730
 731         return 0;
 732 }
 733
 734 static const struct net_device_ops gs_usb_netdev_ops = {
 735         .ndo_open = gs_can_open,
 736         .ndo_stop = gs_can_close,
 737         .ndo_start_xmit = gs_can_start_xmit,
 738         .ndo_change_mtu = can_change_mtu,
 739 };
 740
 741 static int gs_usb_set_identify(struct net_device *netdev, bool do_identify)
 742 {
 743         struct gs_can *dev = netdev_priv(netdev);
 744         struct gs_identify_mode *imode;
 745         int rc;
 746
 747         imode = kmalloc(sizeof(*imode), GFP_KERNEL);
 748
 749         if (!imode)
 750                 return -ENOMEM;
 751
 752         if (do_identify)
 753                 imode->mode = GS_CAN_IDENTIFY_ON;
 754         else
 755                 imode->mode = GS_CAN_IDENTIFY_OFF;
 756
 757         rc = usb_control_msg(interface_to_usbdev(dev->iface),
 758                              usb_sndctrlpipe(interface_to_usbdev(dev->iface),
 759                                              0),
 760                              GS_USB_BREQ_IDENTIFY,
 761                              USB_DIR_OUT | USB_TYPE_VENDOR |
 762                              USB_RECIP_INTERFACE,
 763                              dev->channel,
 764                              0,
 765                              imode,
 766                              sizeof(*imode),
 767                              100);
 768
 769         kfree(imode);
 770
 771         return (rc > 0) ? 0 : rc;
 772 }
 773
 774 /* blink LED's for finding the this interface */
 775 static int gs_usb_set_phys_id(struct net_device *dev,
 776                               enum ethtool_phys_id_state state)
 777 {
 778         int rc = 0;
 779
 780         switch (state) {
 781         case ETHTOOL_ID_ACTIVE:
 782                 rc = gs_usb_set_identify(dev, GS_CAN_IDENTIFY_ON);
 783                 break;
 784         case ETHTOOL_ID_INACTIVE:
 785                 rc = gs_usb_set_identify(dev, GS_CAN_IDENTIFY_OFF);
 786                 break;
 787         default:
 788                 break;
 789         }
 790
 791         return rc;
 792 }
 793
 794 static const struct ethtool_ops gs_usb_ethtool_ops = {
 795         .set_phys_id = gs_usb_set_phys_id,
 796 };
 797
 798 static struct gs_can *gs_make_candev(unsigned int channel,
 799                                      struct usb_interface *intf,
 800                                      struct gs_device_config *dconf)
 801 {
 802         struct gs_can *dev;
 803         struct net_device *netdev;
 804         int rc;
 805         struct gs_device_bt_const *bt_const;
 806
 807         bt_const = kmalloc(sizeof(*bt_const), GFP_KERNEL);
 808         if (!bt_const)
 809                 return ERR_PTR(-ENOMEM);
 810
 811         /* fetch bit timing constants */
 812         rc = usb_control_msg(interface_to_usbdev(intf),
 813                              usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
 814                              GS_USB_BREQ_BT_CONST,
 815                              USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 816                              channel,
 817                              0,
 818                              bt_const,
 819                              sizeof(*bt_const),
 820                              1000);
 821
 822         if (rc < 0) {
 823                 dev_err(&intf->dev,
 824                         "Couldn't get bit timing const for channel (err=%d)\n",
 825                         rc);
 826                 kfree(bt_const);
 827                 return ERR_PTR(rc);
 828         }
 829
 830         /* create netdev */
 831         netdev = alloc_candev(sizeof(struct gs_can), GS_MAX_TX_URBS);
 832         if (!netdev) {
 833                 dev_err(&intf->dev, "Couldn't allocate candev\n");
 834                 kfree(bt_const);
 835                 return ERR_PTR(-ENOMEM);
 836         }
 837
 838         dev = netdev_priv(netdev);
 839
 840         netdev->netdev_ops = &gs_usb_netdev_ops;
 841
 842         netdev->flags |= IFF_ECHO; /* we support full roundtrip echo */
 843
 844         /* dev settup */
 845         strcpy(dev->bt_const.name, "gs_usb");
 846         dev->bt_const.tseg1_min = bt_const->tseg1_min;
 847         dev->bt_const.tseg1_max = bt_const->tseg1_max;
 848         dev->bt_const.tseg2_min = bt_const->tseg2_min;
 849         dev->bt_const.tseg2_max = bt_const->tseg2_max;
 850         dev->bt_const.sjw_max = bt_const->sjw_max;
 851         dev->bt_const.brp_min = bt_const->brp_min;
 852         dev->bt_const.brp_max = bt_const->brp_max;
 853         dev->bt_const.brp_inc = bt_const->brp_inc;
 854
 855         dev->udev = interface_to_usbdev(intf);
 856         dev->iface = intf;
 857         dev->netdev = netdev;
 858         dev->channel = channel;
 859
 860         init_usb_anchor(&dev->tx_submitted);
 861         atomic_set(&dev->active_tx_urbs, 0);
 862         spin_lock_init(&dev->tx_ctx_lock);
 863         for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
 864                 dev->tx_context[rc].dev = dev;
 865                 dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
 866         }
 867
 868         /* can settup */
 869         dev->can.state = CAN_STATE_STOPPED;
 870         dev->can.clock.freq = bt_const->fclk_can;
 871         dev->can.bittiming_const = &dev->bt_const;
 872         dev->can.do_set_bittiming = gs_usb_set_bittiming;
 873
 874         dev->can.ctrlmode_supported = 0;
 875
 876         if (bt_const->feature & GS_CAN_FEATURE_LISTEN_ONLY)
 877                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY;
 878
 879         if (bt_const->feature & GS_CAN_FEATURE_LOOP_BACK)
 880                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_LOOPBACK;
 881
 882         if (bt_const->feature & GS_CAN_FEATURE_TRIPLE_SAMPLE)
 883                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
 884
 885         if (bt_const->feature & GS_CAN_FEATURE_ONE_SHOT)
 886                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_ONE_SHOT;
 887
 888         SET_NETDEV_DEV(netdev, &intf->dev);
 889
 890         if (dconf->sw_version > 1)
 891                 if (bt_const->feature & GS_CAN_FEATURE_IDENTIFY)
 892                         netdev->ethtool_ops = &gs_usb_ethtool_ops;
 893
 894         kfree(bt_const);
 895
 896         rc = register_candev(dev->netdev);
 897         if (rc) {
 898                 free_candev(dev->netdev);
 899                 dev_err(&intf->dev, "Couldn't register candev (err=%d)\n", rc);
 900                 return ERR_PTR(rc);
 901         }
 902
 903         return dev;
 904 }
 905
 906 static void gs_destroy_candev(struct gs_can *dev)
 907 {
 908         unregister_candev(dev->netdev);
 909         usb_kill_anchored_urbs(&dev->tx_submitted);
 910         free_candev(dev->netdev);
 911 }
 912
 913 static int gs_usb_probe(struct usb_interface *intf,
 914                         const struct usb_device_id *id)
 915 {
 916         struct gs_usb *dev;
 917         int rc = -ENOMEM;
 918         unsigned int icount, i;
 919         struct gs_host_config *hconf;
 920         struct gs_device_config *dconf;
 921
 922         hconf = kmalloc(sizeof(*hconf), GFP_KERNEL);
 923         if (!hconf)
 924                 return -ENOMEM;
 925
 926         hconf->byte_order = 0x0000beef;
 927
 928         /* send host config */
 929         rc = usb_control_msg(interface_to_usbdev(intf),
 930                              usb_sndctrlpipe(interface_to_usbdev(intf), 0),
 931                              GS_USB_BREQ_HOST_FORMAT,
 932                              USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 933                              1,
 934                              intf->altsetting[0].desc.bInterfaceNumber,
 935                              hconf,
 936                              sizeof(*hconf),
 937                              1000);
 938
 939         kfree(hconf);
 940
 941         if (rc < 0) {
 942                 dev_err(&intf->dev, "Couldn't send data format (err=%d)\n",
 943                         rc);
 944                 return rc;
 945         }
 946
 947         dconf = kmalloc(sizeof(*dconf), GFP_KERNEL);
 948         if (!dconf)
 949                 return -ENOMEM;
 950
 951         /* read device config */
 952         rc = usb_control_msg(interface_to_usbdev(intf),
 953                              usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
 954                              GS_USB_BREQ_DEVICE_CONFIG,
 955                              USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 956                              1,
 957                              intf->altsetting[0].desc.bInterfaceNumber,
 958                              dconf,
 959                              sizeof(*dconf),
 960                              1000);
 961         if (rc < 0) {
 962                 dev_err(&intf->dev, "Couldn't get device config: (err=%d)\n",
 963                         rc);
 964                 kfree(dconf);
 965                 return rc;
 966         }
 967
 968         icount = dconf->icount + 1;
 969         dev_info(&intf->dev, "Configuring for %d interfaces\n", icount);
 970
 971         if (icount > GS_MAX_INTF) {
 972                 dev_err(&intf->dev,
 973                         "Driver cannot handle more that %d CAN interfaces\n",
 974                         GS_MAX_INTF);
 975                 kfree(dconf);
 976                 return -EINVAL;
 977         }
 978
 979         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 980         if (!dev) {
 981                 kfree(dconf);
 982                 return -ENOMEM;
 983         }
 984
 985         init_usb_anchor(&dev->rx_submitted);
 986
 987         atomic_set(&dev->active_channels, 0);
 988
 989         usb_set_intfdata(intf, dev);
 990         dev->udev = interface_to_usbdev(intf);
 991
 992         for (i = 0; i < icount; i++) {
 993                 dev->canch[i] = gs_make_candev(i, intf, dconf);
 994                 if (IS_ERR_OR_NULL(dev->canch[i])) {
 995                         /* save error code to return later */
 996                         rc = PTR_ERR(dev->canch[i]);
 997
 998                         /* on failure destroy previously created candevs */
 999                         icount = i;
1000                         for (i = 0; i < icount; i++)
1001                                 gs_destroy_candev(dev->canch[i]);
1002
1003                         usb_kill_anchored_urbs(&dev->rx_submitted);
1004                         kfree(dconf);
1005                         kfree(dev);
1006                         return rc;
1007                 }
1008                 dev->canch[i]->parent = dev;
1009         }
1010
1011         kfree(dconf);
1012
1013         return 0;
1014 }
1015
1016 static void gs_usb_disconnect(struct usb_interface *intf)
1017 {
1018         unsigned i;
1019         struct gs_usb *dev = usb_get_intfdata(intf);
1020         usb_set_intfdata(intf, NULL);
1021
1022         if (!dev) {
1023                 dev_err(&intf->dev, "Disconnect (nodata)\n");
1024                 return;
1025         }
1026
1027         for (i = 0; i < GS_MAX_INTF; i++)
1028                 if (dev->canch[i])
1029                         gs_destroy_candev(dev->canch[i]);
1030
1031         usb_kill_anchored_urbs(&dev->rx_submitted);
1032         kfree(dev);
1033 }
1034
1035 static const struct usb_device_id gs_usb_table[] = {
1036         { USB_DEVICE_INTERFACE_NUMBER(USB_GSUSB_1_VENDOR_ID,
1037                                       USB_GSUSB_1_PRODUCT_ID, 0) },
1038         { USB_DEVICE_INTERFACE_NUMBER(USB_CANDLELIGHT_VENDOR_ID,
1039                                       USB_CANDLELIGHT_PRODUCT_ID, 0) },
1040         {} /* Terminating entry */
1041 };
1042
1043 MODULE_DEVICE_TABLE(usb, gs_usb_table);
1044
1045 static struct usb_driver gs_usb_driver = {
1046         .name       = "gs_usb",
1047         .probe      = gs_usb_probe,
1048         .disconnect = gs_usb_disconnect,
1049         .id_table   = gs_usb_table,
1050 };
1051
1052 module_usb_driver(gs_usb_driver);
1053
1054 MODULE_AUTHOR("Maximilian Schneider <mws@schneidersoft.net>");
1055 MODULE_DESCRIPTION(
1056 "Socket CAN device driver for Geschwister Schneider Technologie-, "
1057 "Entwicklungs- und Vertriebs UG. USB2.0 to CAN interfaces\n"
1058 "and bytewerk.org candleLight USB CAN interfaces.");
1059 MODULE_LICENSE("GPL v2");