linux/drivers/net/can/usb/gs_usb.c
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   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 (Haftungsbeschr\xC3\xA4nkt).
   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 */
  41enum 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};
  49
  50enum gs_can_mode {
  51        /* reset a channel. turns it off */
  52        GS_CAN_MODE_RESET = 0,
  53        /* starts a channel */
  54        GS_CAN_MODE_START
  55};
  56
  57enum gs_can_state {
  58        GS_CAN_STATE_ERROR_ACTIVE = 0,
  59        GS_CAN_STATE_ERROR_WARNING,
  60        GS_CAN_STATE_ERROR_PASSIVE,
  61        GS_CAN_STATE_BUS_OFF,
  62        GS_CAN_STATE_STOPPED,
  63        GS_CAN_STATE_SLEEPING
  64};
  65
  66/* data types passed between host and device */
  67struct gs_host_config {
  68        u32 byte_order;
  69} __packed;
  70/* All data exchanged between host and device is exchanged in host byte order,
  71 * thanks to the struct gs_host_config byte_order member, which is sent first
  72 * to indicate the desired byte order.
  73 */
  74
  75struct gs_device_config {
  76        u8 reserved1;
  77        u8 reserved2;
  78        u8 reserved3;
  79        u8 icount;
  80        u32 sw_version;
  81        u32 hw_version;
  82} __packed;
  83
  84#define GS_CAN_MODE_NORMAL               0
  85#define GS_CAN_MODE_LISTEN_ONLY          (1<<0)
  86#define GS_CAN_MODE_LOOP_BACK            (1<<1)
  87#define GS_CAN_MODE_TRIPLE_SAMPLE        (1<<2)
  88#define GS_CAN_MODE_ONE_SHOT             (1<<3)
  89
  90struct gs_device_mode {
  91        u32 mode;
  92        u32 flags;
  93} __packed;
  94
  95struct gs_device_state {
  96        u32 state;
  97        u32 rxerr;
  98        u32 txerr;
  99} __packed;
 100
 101struct gs_device_bittiming {
 102        u32 prop_seg;
 103        u32 phase_seg1;
 104        u32 phase_seg2;
 105        u32 sjw;
 106        u32 brp;
 107} __packed;
 108
 109#define GS_CAN_FEATURE_LISTEN_ONLY      (1<<0)
 110#define GS_CAN_FEATURE_LOOP_BACK        (1<<1)
 111#define GS_CAN_FEATURE_TRIPLE_SAMPLE    (1<<2)
 112#define GS_CAN_FEATURE_ONE_SHOT         (1<<3)
 113
 114struct gs_device_bt_const {
 115        u32 feature;
 116        u32 fclk_can;
 117        u32 tseg1_min;
 118        u32 tseg1_max;
 119        u32 tseg2_min;
 120        u32 tseg2_max;
 121        u32 sjw_max;
 122        u32 brp_min;
 123        u32 brp_max;
 124        u32 brp_inc;
 125} __packed;
 126
 127#define GS_CAN_FLAG_OVERFLOW 1
 128
 129struct gs_host_frame {
 130        u32 echo_id;
 131        u32 can_id;
 132
 133        u8 can_dlc;
 134        u8 channel;
 135        u8 flags;
 136        u8 reserved;
 137
 138        u8 data[8];
 139} __packed;
 140/* The GS USB devices make use of the same flags and masks as in
 141 * linux/can.h and linux/can/error.h, and no additional mapping is necessary.
 142 */
 143
 144/* Only send a max of GS_MAX_TX_URBS frames per channel at a time. */
 145#define GS_MAX_TX_URBS 10
 146/* Only launch a max of GS_MAX_RX_URBS usb requests at a time. */
 147#define GS_MAX_RX_URBS 30
 148/* Maximum number of interfaces the driver supports per device.
 149 * Current hardware only supports 2 interfaces. The future may vary.
 150 */
 151#define GS_MAX_INTF 2
 152
 153struct gs_tx_context {
 154        struct gs_can *dev;
 155        unsigned int echo_id;
 156};
 157
 158struct gs_can {
 159        struct can_priv can; /* must be the first member */
 160
 161        struct gs_usb *parent;
 162
 163        struct net_device *netdev;
 164        struct usb_device *udev;
 165        struct usb_interface *iface;
 166
 167        struct can_bittiming_const bt_const;
 168        unsigned int channel;   /* channel number */
 169
 170        /* This lock prevents a race condition between xmit and receive. */
 171        spinlock_t tx_ctx_lock;
 172        struct gs_tx_context tx_context[GS_MAX_TX_URBS];
 173
 174        struct usb_anchor tx_submitted;
 175        atomic_t active_tx_urbs;
 176};
 177
 178/* usb interface struct */
 179struct gs_usb {
 180        struct gs_can *canch[GS_MAX_INTF];
 181        struct usb_anchor rx_submitted;
 182        atomic_t active_channels;
 183        struct usb_device *udev;
 184};
 185
 186/* 'allocate' a tx context.
 187 * returns a valid tx context or NULL if there is no space.
 188 */
 189static struct gs_tx_context *gs_alloc_tx_context(struct gs_can *dev)
 190{
 191        int i = 0;
 192        unsigned long flags;
 193
 194        spin_lock_irqsave(&dev->tx_ctx_lock, flags);
 195
 196        for (; i < GS_MAX_TX_URBS; i++) {
 197                if (dev->tx_context[i].echo_id == GS_MAX_TX_URBS) {
 198                        dev->tx_context[i].echo_id = i;
 199                        spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
 200                        return &dev->tx_context[i];
 201                }
 202        }
 203
 204        spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
 205        return NULL;
 206}
 207
 208/* releases a tx context
 209 */
 210static void gs_free_tx_context(struct gs_tx_context *txc)
 211{
 212        txc->echo_id = GS_MAX_TX_URBS;
 213}
 214
 215/* Get a tx context by id.
 216 */
 217static struct gs_tx_context *gs_get_tx_context(struct gs_can *dev, unsigned int id)
 218{
 219        unsigned long flags;
 220
 221        if (id < GS_MAX_TX_URBS) {
 222                spin_lock_irqsave(&dev->tx_ctx_lock, flags);
 223                if (dev->tx_context[id].echo_id == id) {
 224                        spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
 225                        return &dev->tx_context[id];
 226                }
 227                spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
 228        }
 229        return NULL;
 230}
 231
 232static int gs_cmd_reset(struct gs_usb *gsusb, struct gs_can *gsdev)
 233{
 234        struct gs_device_mode *dm;
 235        struct usb_interface *intf = gsdev->iface;
 236        int rc;
 237
 238        dm = kzalloc(sizeof(*dm), GFP_KERNEL);
 239        if (!dm)
 240                return -ENOMEM;
 241
 242        dm->mode = GS_CAN_MODE_RESET;
 243
 244        rc = usb_control_msg(interface_to_usbdev(intf),
 245                             usb_sndctrlpipe(interface_to_usbdev(intf), 0),
 246                             GS_USB_BREQ_MODE,
 247                             USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
 248                             gsdev->channel,
 249                             0,
 250                             dm,
 251                             sizeof(*dm),
 252                             1000);
 253
 254        return rc;
 255}
 256
 257static void gs_update_state(struct gs_can *dev, struct can_frame *cf)
 258{
 259        struct can_device_stats *can_stats = &dev->can.can_stats;
 260
 261        if (cf->can_id & CAN_ERR_RESTARTED) {
 262                dev->can.state = CAN_STATE_ERROR_ACTIVE;
 263                can_stats->restarts++;
 264        } else if (cf->can_id & CAN_ERR_BUSOFF) {
 265                dev->can.state = CAN_STATE_BUS_OFF;
 266                can_stats->bus_off++;
 267        } else if (cf->can_id & CAN_ERR_CRTL) {
 268                if ((cf->data[1] & CAN_ERR_CRTL_TX_WARNING) ||
 269                    (cf->data[1] & CAN_ERR_CRTL_RX_WARNING)) {
 270                        dev->can.state = CAN_STATE_ERROR_WARNING;
 271                        can_stats->error_warning++;
 272                } else if ((cf->data[1] & CAN_ERR_CRTL_TX_PASSIVE) ||
 273                           (cf->data[1] & CAN_ERR_CRTL_RX_PASSIVE)) {
 274                        dev->can.state = CAN_STATE_ERROR_PASSIVE;
 275                        can_stats->error_passive++;
 276                } else {
 277                        dev->can.state = CAN_STATE_ERROR_ACTIVE;
 278                }
 279        }
 280}
 281
 282static void gs_usb_receive_bulk_callback(struct urb *urb)
 283{
 284        struct gs_usb *usbcan = urb->context;
 285        struct gs_can *dev;
 286        struct net_device *netdev;
 287        int rc;
 288        struct net_device_stats *stats;
 289        struct gs_host_frame *hf = urb->transfer_buffer;
 290        struct gs_tx_context *txc;
 291        struct can_frame *cf;
 292        struct sk_buff *skb;
 293
 294        BUG_ON(!usbcan);
 295
 296        switch (urb->status) {
 297        case 0: /* success */
 298                break;
 299        case -ENOENT:
 300        case -ESHUTDOWN:
 301                return;
 302        default:
 303                /* do not resubmit aborted urbs. eg: when device goes down */
 304                return;
 305        }
 306
 307        /* device reports out of range channel id */
 308        if (hf->channel >= GS_MAX_INTF)
 309                goto resubmit_urb;
 310
 311        dev = usbcan->canch[hf->channel];
 312
 313        netdev = dev->netdev;
 314        stats = &netdev->stats;
 315
 316        if (!netif_device_present(netdev))
 317                return;
 318
 319        if (hf->echo_id == -1) { /* normal rx */
 320                skb = alloc_can_skb(dev->netdev, &cf);
 321                if (!skb)
 322                        return;
 323
 324                cf->can_id = hf->can_id;
 325
 326                cf->can_dlc = get_can_dlc(hf->can_dlc);
 327                memcpy(cf->data, hf->data, 8);
 328
 329                /* ERROR frames tell us information about the controller */
 330                if (hf->can_id & CAN_ERR_FLAG)
 331                        gs_update_state(dev, cf);
 332
 333                netdev->stats.rx_packets++;
 334                netdev->stats.rx_bytes += hf->can_dlc;
 335
 336                netif_rx(skb);
 337        } else { /* echo_id == hf->echo_id */
 338                if (hf->echo_id >= GS_MAX_TX_URBS) {
 339                        netdev_err(netdev,
 340                                   "Unexpected out of range echo id %d\n",
 341                                   hf->echo_id);
 342                        goto resubmit_urb;
 343                }
 344
 345                netdev->stats.tx_packets++;
 346                netdev->stats.tx_bytes += hf->can_dlc;
 347
 348                txc = gs_get_tx_context(dev, hf->echo_id);
 349
 350                /* bad devices send bad echo_ids. */
 351                if (!txc) {
 352                        netdev_err(netdev,
 353                                   "Unexpected unused echo id %d\n",
 354                                   hf->echo_id);
 355                        goto resubmit_urb;
 356                }
 357
 358                can_get_echo_skb(netdev, hf->echo_id);
 359
 360                gs_free_tx_context(txc);
 361
 362                netif_wake_queue(netdev);
 363        }
 364
 365        if (hf->flags & GS_CAN_FLAG_OVERFLOW) {
 366                skb = alloc_can_err_skb(netdev, &cf);
 367                if (!skb)
 368                        goto resubmit_urb;
 369
 370                cf->can_id |= CAN_ERR_CRTL;
 371                cf->can_dlc = CAN_ERR_DLC;
 372                cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 373                stats->rx_over_errors++;
 374                stats->rx_errors++;
 375                netif_rx(skb);
 376        }
 377
 378 resubmit_urb:
 379        usb_fill_bulk_urb(urb,
 380                          usbcan->udev,
 381                          usb_rcvbulkpipe(usbcan->udev, GSUSB_ENDPOINT_IN),
 382                          hf,
 383                          sizeof(struct gs_host_frame),
 384                          gs_usb_receive_bulk_callback,
 385                          usbcan
 386                          );
 387
 388        rc = usb_submit_urb(urb, GFP_ATOMIC);
 389
 390        /* USB failure take down all interfaces */
 391        if (rc == -ENODEV) {
 392                for (rc = 0; rc < GS_MAX_INTF; rc++) {
 393                        if (usbcan->canch[rc])
 394                                netif_device_detach(usbcan->canch[rc]->netdev);
 395                }
 396        }
 397}
 398
 399static int gs_usb_set_bittiming(struct net_device *netdev)
 400{
 401        struct gs_can *dev = netdev_priv(netdev);
 402        struct can_bittiming *bt = &dev->can.bittiming;
 403        struct usb_interface *intf = dev->iface;
 404        int rc;
 405        struct gs_device_bittiming *dbt;
 406
 407        dbt = kmalloc(sizeof(*dbt), GFP_KERNEL);
 408        if (!dbt)
 409                return -ENOMEM;
 410
 411        dbt->prop_seg = bt->prop_seg;
 412        dbt->phase_seg1 = bt->phase_seg1;
 413        dbt->phase_seg2 = bt->phase_seg2;
 414        dbt->sjw = bt->sjw;
 415        dbt->brp = bt->brp;
 416
 417        /* request bit timings */
 418        rc = usb_control_msg(interface_to_usbdev(intf),
 419                             usb_sndctrlpipe(interface_to_usbdev(intf), 0),
 420                             GS_USB_BREQ_BITTIMING,
 421                             USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
 422                             dev->channel,
 423                             0,
 424                             dbt,
 425                             sizeof(*dbt),
 426                             1000);
 427
 428        kfree(dbt);
 429
 430        if (rc < 0)
 431                dev_err(netdev->dev.parent, "Couldn't set bittimings (err=%d)",
 432                        rc);
 433
 434        return rc;
 435}
 436
 437static void gs_usb_xmit_callback(struct urb *urb)
 438{
 439        struct gs_tx_context *txc = urb->context;
 440        struct gs_can *dev = txc->dev;
 441        struct net_device *netdev = dev->netdev;
 442
 443        if (urb->status)
 444                netdev_info(netdev, "usb xmit fail %d\n", txc->echo_id);
 445
 446        usb_free_coherent(urb->dev,
 447                          urb->transfer_buffer_length,
 448                          urb->transfer_buffer,
 449                          urb->transfer_dma);
 450
 451        atomic_dec(&dev->active_tx_urbs);
 452
 453        if (!netif_device_present(netdev))
 454                return;
 455
 456        if (netif_queue_stopped(netdev))
 457                netif_wake_queue(netdev);
 458}
 459
 460static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb, struct net_device *netdev)
 461{
 462        struct gs_can *dev = netdev_priv(netdev);
 463        struct net_device_stats *stats = &dev->netdev->stats;
 464        struct urb *urb;
 465        struct gs_host_frame *hf;
 466        struct can_frame *cf;
 467        int rc;
 468        unsigned int idx;
 469        struct gs_tx_context *txc;
 470
 471        if (can_dropped_invalid_skb(netdev, skb))
 472                return NETDEV_TX_OK;
 473
 474        /* find an empty context to keep track of transmission */
 475        txc = gs_alloc_tx_context(dev);
 476        if (!txc)
 477                return NETDEV_TX_BUSY;
 478
 479        /* create a URB, and a buffer for it */
 480        urb = usb_alloc_urb(0, GFP_ATOMIC);
 481        if (!urb) {
 482                netdev_err(netdev, "No memory left for URB\n");
 483                goto nomem_urb;
 484        }
 485
 486        hf = usb_alloc_coherent(dev->udev, sizeof(*hf), GFP_ATOMIC,
 487                                &urb->transfer_dma);
 488        if (!hf) {
 489                netdev_err(netdev, "No memory left for USB buffer\n");
 490                goto nomem_hf;
 491        }
 492
 493        idx = txc->echo_id;
 494
 495        if (idx >= GS_MAX_TX_URBS) {
 496                netdev_err(netdev, "Invalid tx context %d\n", idx);
 497                goto badidx;
 498        }
 499
 500        hf->echo_id = idx;
 501        hf->channel = dev->channel;
 502
 503        cf = (struct can_frame *)skb->data;
 504
 505        hf->can_id = cf->can_id;
 506        hf->can_dlc = cf->can_dlc;
 507        memcpy(hf->data, cf->data, cf->can_dlc);
 508
 509        usb_fill_bulk_urb(urb, dev->udev,
 510                          usb_sndbulkpipe(dev->udev, GSUSB_ENDPOINT_OUT),
 511                          hf,
 512                          sizeof(*hf),
 513                          gs_usb_xmit_callback,
 514                          txc);
 515
 516        urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 517        usb_anchor_urb(urb, &dev->tx_submitted);
 518
 519        can_put_echo_skb(skb, netdev, idx);
 520
 521        atomic_inc(&dev->active_tx_urbs);
 522
 523        rc = usb_submit_urb(urb, GFP_ATOMIC);
 524        if (unlikely(rc)) {                     /* usb send failed */
 525                atomic_dec(&dev->active_tx_urbs);
 526
 527                can_free_echo_skb(netdev, idx);
 528                gs_free_tx_context(txc);
 529
 530                usb_unanchor_urb(urb);
 531                usb_free_coherent(dev->udev,
 532                                  sizeof(*hf),
 533                                  hf,
 534                                  urb->transfer_dma);
 535
 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
 569static 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                                netdev_err(netdev,
 590                                           "No memory left for URB\n");
 591                                return -ENOMEM;
 592                        }
 593
 594                        /* alloc rx buffer */
 595                        buf = usb_alloc_coherent(dev->udev,
 596                                                 sizeof(struct gs_host_frame),
 597                                                 GFP_KERNEL,
 598                                                 &urb->transfer_dma);
 599                        if (!buf) {
 600                                netdev_err(netdev,
 601                                           "No memory left for USB buffer\n");
 602                                usb_free_urb(urb);
 603                                return -ENOMEM;
 604                        }
 605
 606                        /* fill, anchor, and submit rx urb */
 607                        usb_fill_bulk_urb(urb,
 608                                          dev->udev,
 609                                          usb_rcvbulkpipe(dev->udev,
 610                                                          GSUSB_ENDPOINT_IN),
 611                                          buf,
 612                                          sizeof(struct gs_host_frame),
 613                                          gs_usb_receive_bulk_callback,
 614                                          parent);
 615                        urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 616
 617                        usb_anchor_urb(urb, &parent->rx_submitted);
 618
 619                        rc = usb_submit_urb(urb, GFP_KERNEL);
 620                        if (rc) {
 621                                if (rc == -ENODEV)
 622                                        netif_device_detach(dev->netdev);
 623
 624                                netdev_err(netdev,
 625                                           "usb_submit failed (err=%d)\n",
 626                                           rc);
 627
 628                                usb_unanchor_urb(urb);
 629                                break;
 630                        }
 631
 632                        /* Drop reference,
 633                         * USB core will take care of freeing it
 634                         */
 635                        usb_free_urb(urb);
 636                }
 637        }
 638
 639        dm = kmalloc(sizeof(*dm), GFP_KERNEL);
 640        if (!dm)
 641                return -ENOMEM;
 642
 643        /* flags */
 644        ctrlmode = dev->can.ctrlmode;
 645        dm->flags = 0;
 646
 647        if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
 648                dm->flags |= GS_CAN_MODE_LOOP_BACK;
 649        else if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
 650                dm->flags |= GS_CAN_MODE_LISTEN_ONLY;
 651
 652        /* Controller is not allowed to retry TX
 653         * this mode is unavailable on atmels uc3c hardware
 654         */
 655        if (ctrlmode & CAN_CTRLMODE_ONE_SHOT)
 656                dm->flags |= GS_CAN_MODE_ONE_SHOT;
 657
 658        if (ctrlmode & CAN_CTRLMODE_3_SAMPLES)
 659                dm->flags |= GS_CAN_MODE_TRIPLE_SAMPLE;
 660
 661        /* finally start device */
 662        dm->mode = GS_CAN_MODE_START;
 663        rc = usb_control_msg(interface_to_usbdev(dev->iface),
 664                             usb_sndctrlpipe(interface_to_usbdev(dev->iface), 0),
 665                             GS_USB_BREQ_MODE,
 666                             USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
 667                             dev->channel,
 668                             0,
 669                             dm,
 670                             sizeof(*dm),
 671                             1000);
 672
 673        if (rc < 0) {
 674                netdev_err(netdev, "Couldn't start device (err=%d)\n", rc);
 675                kfree(dm);
 676                return rc;
 677        }
 678
 679        kfree(dm);
 680
 681        dev->can.state = CAN_STATE_ERROR_ACTIVE;
 682
 683        if (!(dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY))
 684                netif_start_queue(netdev);
 685
 686        return 0;
 687}
 688
 689static int gs_can_close(struct net_device *netdev)
 690{
 691        int rc;
 692        struct gs_can *dev = netdev_priv(netdev);
 693        struct gs_usb *parent = dev->parent;
 694
 695        netif_stop_queue(netdev);
 696
 697        /* Stop polling */
 698        if (atomic_dec_and_test(&parent->active_channels))
 699                usb_kill_anchored_urbs(&parent->rx_submitted);
 700
 701        /* Stop sending URBs */
 702        usb_kill_anchored_urbs(&dev->tx_submitted);
 703        atomic_set(&dev->active_tx_urbs, 0);
 704
 705        /* reset the device */
 706        rc = gs_cmd_reset(parent, dev);
 707        if (rc < 0)
 708                netdev_warn(netdev, "Couldn't shutdown device (err=%d)", rc);
 709
 710        /* reset tx contexts */
 711        for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
 712                dev->tx_context[rc].dev = dev;
 713                dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
 714        }
 715
 716        /* close the netdev */
 717        close_candev(netdev);
 718
 719        return 0;
 720}
 721
 722static const struct net_device_ops gs_usb_netdev_ops = {
 723        .ndo_open = gs_can_open,
 724        .ndo_stop = gs_can_close,
 725        .ndo_start_xmit = gs_can_start_xmit,
 726        .ndo_change_mtu = can_change_mtu,
 727};
 728
 729static struct gs_can *gs_make_candev(unsigned int channel, struct usb_interface *intf)
 730{
 731        struct gs_can *dev;
 732        struct net_device *netdev;
 733        int rc;
 734        struct gs_device_bt_const *bt_const;
 735
 736        bt_const = kmalloc(sizeof(*bt_const), GFP_KERNEL);
 737        if (!bt_const)
 738                return ERR_PTR(-ENOMEM);
 739
 740        /* fetch bit timing constants */
 741        rc = usb_control_msg(interface_to_usbdev(intf),
 742                             usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
 743                             GS_USB_BREQ_BT_CONST,
 744                             USB_DIR_IN|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
 745                             channel,
 746                             0,
 747                             bt_const,
 748                             sizeof(*bt_const),
 749                             1000);
 750
 751        if (rc < 0) {
 752                dev_err(&intf->dev,
 753                        "Couldn't get bit timing const for channel (err=%d)\n",
 754                        rc);
 755                kfree(bt_const);
 756                return ERR_PTR(rc);
 757        }
 758
 759        /* create netdev */
 760        netdev = alloc_candev(sizeof(struct gs_can), GS_MAX_TX_URBS);
 761        if (!netdev) {
 762                dev_err(&intf->dev, "Couldn't allocate candev\n");
 763                kfree(bt_const);
 764                return ERR_PTR(-ENOMEM);
 765        }
 766
 767        dev = netdev_priv(netdev);
 768
 769        netdev->netdev_ops = &gs_usb_netdev_ops;
 770
 771        netdev->flags |= IFF_ECHO; /* we support full roundtrip echo */
 772
 773        /* dev settup */
 774        strcpy(dev->bt_const.name, "gs_usb");
 775        dev->bt_const.tseg1_min = bt_const->tseg1_min;
 776        dev->bt_const.tseg1_max = bt_const->tseg1_max;
 777        dev->bt_const.tseg2_min = bt_const->tseg2_min;
 778        dev->bt_const.tseg2_max = bt_const->tseg2_max;
 779        dev->bt_const.sjw_max = bt_const->sjw_max;
 780        dev->bt_const.brp_min = bt_const->brp_min;
 781        dev->bt_const.brp_max = bt_const->brp_max;
 782        dev->bt_const.brp_inc = bt_const->brp_inc;
 783
 784        dev->udev = interface_to_usbdev(intf);
 785        dev->iface = intf;
 786        dev->netdev = netdev;
 787        dev->channel = channel;
 788
 789        init_usb_anchor(&dev->tx_submitted);
 790        atomic_set(&dev->active_tx_urbs, 0);
 791        spin_lock_init(&dev->tx_ctx_lock);
 792        for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
 793                dev->tx_context[rc].dev = dev;
 794                dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
 795        }
 796
 797        /* can settup */
 798        dev->can.state = CAN_STATE_STOPPED;
 799        dev->can.clock.freq = bt_const->fclk_can;
 800        dev->can.bittiming_const = &dev->bt_const;
 801        dev->can.do_set_bittiming = gs_usb_set_bittiming;
 802
 803        dev->can.ctrlmode_supported = 0;
 804
 805        if (bt_const->feature & GS_CAN_FEATURE_LISTEN_ONLY)
 806                dev->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY;
 807
 808        if (bt_const->feature & GS_CAN_FEATURE_LOOP_BACK)
 809                dev->can.ctrlmode_supported |= CAN_CTRLMODE_LOOPBACK;
 810
 811        if (bt_const->feature & GS_CAN_FEATURE_TRIPLE_SAMPLE)
 812                dev->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
 813
 814        if (bt_const->feature & GS_CAN_FEATURE_ONE_SHOT)
 815                dev->can.ctrlmode_supported |= CAN_CTRLMODE_ONE_SHOT;
 816
 817        kfree(bt_const);
 818
 819        SET_NETDEV_DEV(netdev, &intf->dev);
 820
 821        rc = register_candev(dev->netdev);
 822        if (rc) {
 823                free_candev(dev->netdev);
 824                dev_err(&intf->dev, "Couldn't register candev (err=%d)\n", rc);
 825                return ERR_PTR(rc);
 826        }
 827
 828        return dev;
 829}
 830
 831static void gs_destroy_candev(struct gs_can *dev)
 832{
 833        unregister_candev(dev->netdev);
 834        usb_kill_anchored_urbs(&dev->tx_submitted);
 835        free_candev(dev->netdev);
 836}
 837
 838static int gs_usb_probe(struct usb_interface *intf, const struct usb_device_id *id)
 839{
 840        struct gs_usb *dev;
 841        int rc = -ENOMEM;
 842        unsigned int icount, i;
 843        struct gs_host_config *hconf;
 844        struct gs_device_config *dconf;
 845
 846        hconf = kmalloc(sizeof(*hconf), GFP_KERNEL);
 847        if (!hconf)
 848                return -ENOMEM;
 849
 850        hconf->byte_order = 0x0000beef;
 851
 852        /* send host config */
 853        rc = usb_control_msg(interface_to_usbdev(intf),
 854                             usb_sndctrlpipe(interface_to_usbdev(intf), 0),
 855                             GS_USB_BREQ_HOST_FORMAT,
 856                             USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
 857                             1,
 858                             intf->altsetting[0].desc.bInterfaceNumber,
 859                             hconf,
 860                             sizeof(*hconf),
 861                             1000);
 862
 863        kfree(hconf);
 864
 865        if (rc < 0) {
 866                dev_err(&intf->dev, "Couldn't send data format (err=%d)\n",
 867                        rc);
 868                return rc;
 869        }
 870
 871        dconf = kmalloc(sizeof(*dconf), GFP_KERNEL);
 872        if (!dconf)
 873                return -ENOMEM;
 874
 875        /* read device config */
 876        rc = usb_control_msg(interface_to_usbdev(intf),
 877                             usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
 878                             GS_USB_BREQ_DEVICE_CONFIG,
 879                             USB_DIR_IN|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
 880                             1,
 881                             intf->altsetting[0].desc.bInterfaceNumber,
 882                             dconf,
 883                             sizeof(*dconf),
 884                             1000);
 885        if (rc < 0) {
 886                dev_err(&intf->dev, "Couldn't get device config: (err=%d)\n",
 887                        rc);
 888
 889                kfree(dconf);
 890
 891                return rc;
 892        }
 893
 894        icount = dconf->icount+1;
 895
 896        kfree(dconf);
 897
 898        dev_info(&intf->dev, "Configuring for %d interfaces\n", icount);
 899
 900        if (icount > GS_MAX_INTF) {
 901                dev_err(&intf->dev,
 902                        "Driver cannot handle more that %d CAN interfaces\n",
 903                        GS_MAX_INTF);
 904                return -EINVAL;
 905        }
 906
 907        dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 908        if (!dev)
 909                return -ENOMEM;
 910        init_usb_anchor(&dev->rx_submitted);
 911
 912        atomic_set(&dev->active_channels, 0);
 913
 914        usb_set_intfdata(intf, dev);
 915        dev->udev = interface_to_usbdev(intf);
 916
 917        for (i = 0; i < icount; i++) {
 918                dev->canch[i] = gs_make_candev(i, intf);
 919                if (IS_ERR_OR_NULL(dev->canch[i])) {
 920                        /* save error code to return later */
 921                        rc = PTR_ERR(dev->canch[i]);
 922
 923                        /* on failure destroy previously created candevs */
 924                        icount = i;
 925                        for (i = 0; i < icount; i++)
 926                                gs_destroy_candev(dev->canch[i]);
 927
 928                        usb_kill_anchored_urbs(&dev->rx_submitted);
 929                        kfree(dev);
 930                        return rc;
 931                }
 932                dev->canch[i]->parent = dev;
 933        }
 934
 935        return 0;
 936}
 937
 938static void gs_usb_disconnect(struct usb_interface *intf)
 939{
 940        unsigned i;
 941        struct gs_usb *dev = usb_get_intfdata(intf);
 942        usb_set_intfdata(intf, NULL);
 943
 944        if (!dev) {
 945                dev_err(&intf->dev, "Disconnect (nodata)\n");
 946                return;
 947        }
 948
 949        for (i = 0; i < GS_MAX_INTF; i++)
 950                if (dev->canch[i])
 951                        gs_destroy_candev(dev->canch[i]);
 952
 953        usb_kill_anchored_urbs(&dev->rx_submitted);
 954        kfree(dev);
 955}
 956
 957static const struct usb_device_id gs_usb_table[] = {
 958        { USB_DEVICE_INTERFACE_NUMBER(USB_GSUSB_1_VENDOR_ID,
 959                                      USB_GSUSB_1_PRODUCT_ID, 0) },
 960        { USB_DEVICE_INTERFACE_NUMBER(USB_CANDLELIGHT_VENDOR_ID,
 961                                      USB_CANDLELIGHT_PRODUCT_ID, 0) },
 962        {} /* Terminating entry */
 963};
 964
 965MODULE_DEVICE_TABLE(usb, gs_usb_table);
 966
 967static struct usb_driver gs_usb_driver = {
 968        .name       = "gs_usb",
 969        .probe      = gs_usb_probe,
 970        .disconnect = gs_usb_disconnect,
 971        .id_table   = gs_usb_table,
 972};
 973
 974module_usb_driver(gs_usb_driver);
 975
 976MODULE_AUTHOR("Maximilian Schneider <mws@schneidersoft.net>");
 977MODULE_DESCRIPTION(
 978"Socket CAN device driver for Geschwister Schneider Technologie-, "
 979"Entwicklungs- und Vertriebs UG. USB2.0 to CAN interfaces\n"
 980"and bytewerk.org candleLight USB CAN interfaces.");
 981MODULE_LICENSE("GPL v2");
 982
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