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        GS_USB_BREQ_TIMESTAMP,
  49        GS_USB_BREQ_IDENTIFY,
  50};
  51
  52enum 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
  59enum 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
  68enum 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 */
  74struct 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
  82struct 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
  97struct gs_device_mode {
  98        u32 mode;
  99        u32 flags;
 100} __packed;
 101
 102struct gs_device_state {
 103        u32 state;
 104        u32 rxerr;
 105        u32 txerr;
 106} __packed;
 107
 108struct gs_device_bittiming {
 109        u32 prop_seg;
 110        u32 phase_seg1;
 111        u32 phase_seg2;
 112        u32 sjw;
 113        u32 brp;
 114} __packed;
 115
 116struct 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
 127struct 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
 142struct 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
 166struct gs_tx_context {
 167        struct gs_can *dev;
 168        unsigned int echo_id;
 169};
 170
 171struct 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 */
 192struct 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 */
 202static 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 */
 223static 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 */
 230static 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
 246static int gs_cmd_reset(struct gs_usb *gsusb, struct gs_can *gsdev)
 247{
 248        struct gs_device_mode *dm;
 249        struct usb_interface *intf = gsdev->iface;
 250        int rc;
 251
 252        dm = kzalloc(sizeof(*dm), GFP_KERNEL);
 253        if (!dm)
 254                return -ENOMEM;
 255
 256        dm->mode = GS_CAN_MODE_RESET;
 257
 258        rc = usb_control_msg(interface_to_usbdev(intf),
 259                             usb_sndctrlpipe(interface_to_usbdev(intf), 0),
 260                             GS_USB_BREQ_MODE,
 261                             USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
 262                             gsdev->channel,
 263                             0,
 264                             dm,
 265                             sizeof(*dm),
 266                             1000);
 267
 268        return rc;
 269}
 270
 271static void gs_update_state(struct gs_can *dev, struct can_frame *cf)
 272{
 273        struct can_device_stats *can_stats = &dev->can.can_stats;
 274
 275        if (cf->can_id & CAN_ERR_RESTARTED) {
 276                dev->can.state = CAN_STATE_ERROR_ACTIVE;
 277                can_stats->restarts++;
 278        } else if (cf->can_id & CAN_ERR_BUSOFF) {
 279                dev->can.state = CAN_STATE_BUS_OFF;
 280                can_stats->bus_off++;
 281        } else if (cf->can_id & CAN_ERR_CRTL) {
 282                if ((cf->data[1] & CAN_ERR_CRTL_TX_WARNING) ||
 283                    (cf->data[1] & CAN_ERR_CRTL_RX_WARNING)) {
 284                        dev->can.state = CAN_STATE_ERROR_WARNING;
 285                        can_stats->error_warning++;
 286                } else if ((cf->data[1] & CAN_ERR_CRTL_TX_PASSIVE) ||
 287                           (cf->data[1] & CAN_ERR_CRTL_RX_PASSIVE)) {
 288                        dev->can.state = CAN_STATE_ERROR_PASSIVE;
 289                        can_stats->error_passive++;
 290                } else {
 291                        dev->can.state = CAN_STATE_ERROR_ACTIVE;
 292                }
 293        }
 294}
 295
 296static void gs_usb_receive_bulk_callback(struct urb *urb)
 297{
 298        struct gs_usb *usbcan = urb->context;
 299        struct gs_can *dev;
 300        struct net_device *netdev;
 301        int rc;
 302        struct net_device_stats *stats;
 303        struct gs_host_frame *hf = urb->transfer_buffer;
 304        struct gs_tx_context *txc;
 305        struct can_frame *cf;
 306        struct sk_buff *skb;
 307
 308        BUG_ON(!usbcan);
 309
 310        switch (urb->status) {
 311        case 0: /* success */
 312                break;
 313        case -ENOENT:
 314        case -ESHUTDOWN:
 315                return;
 316        default:
 317                /* do not resubmit aborted urbs. eg: when device goes down */
 318                return;
 319        }
 320
 321        /* device reports out of range channel id */
 322        if (hf->channel >= GS_MAX_INTF)
 323                goto resubmit_urb;
 324
 325        dev = usbcan->canch[hf->channel];
 326
 327        netdev = dev->netdev;
 328        stats = &netdev->stats;
 329
 330        if (!netif_device_present(netdev))
 331                return;
 332
 333        if (hf->echo_id == -1) { /* normal rx */
 334                skb = alloc_can_skb(dev->netdev, &cf);
 335                if (!skb)
 336                        return;
 337
 338                cf->can_id = hf->can_id;
 339
 340                cf->can_dlc = get_can_dlc(hf->can_dlc);
 341                memcpy(cf->data, hf->data, 8);
 342
 343                /* ERROR frames tell us information about the controller */
 344                if (hf->can_id & CAN_ERR_FLAG)
 345                        gs_update_state(dev, cf);
 346
 347                netdev->stats.rx_packets++;
 348                netdev->stats.rx_bytes += hf->can_dlc;
 349
 350                netif_rx(skb);
 351        } else { /* echo_id == hf->echo_id */
 352                if (hf->echo_id >= GS_MAX_TX_URBS) {
 353                        netdev_err(netdev,
 354                                   "Unexpected out of range echo id %d\n",
 355                                   hf->echo_id);
 356                        goto resubmit_urb;
 357                }
 358
 359                netdev->stats.tx_packets++;
 360                netdev->stats.tx_bytes += hf->can_dlc;
 361
 362                txc = gs_get_tx_context(dev, hf->echo_id);
 363
 364                /* bad devices send bad echo_ids. */
 365                if (!txc) {
 366                        netdev_err(netdev,
 367                                   "Unexpected unused echo id %d\n",
 368                                   hf->echo_id);
 369                        goto resubmit_urb;
 370                }
 371
 372                can_get_echo_skb(netdev, hf->echo_id);
 373
 374                gs_free_tx_context(txc);
 375
 376                netif_wake_queue(netdev);
 377        }
 378
 379        if (hf->flags & GS_CAN_FLAG_OVERFLOW) {
 380                skb = alloc_can_err_skb(netdev, &cf);
 381                if (!skb)
 382                        goto resubmit_urb;
 383
 384                cf->can_id |= CAN_ERR_CRTL;
 385                cf->can_dlc = CAN_ERR_DLC;
 386                cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 387                stats->rx_over_errors++;
 388                stats->rx_errors++;
 389                netif_rx(skb);
 390        }
 391
 392 resubmit_urb:
 393        usb_fill_bulk_urb(urb,
 394                          usbcan->udev,
 395                          usb_rcvbulkpipe(usbcan->udev, GSUSB_ENDPOINT_IN),
 396                          hf,
 397                          sizeof(struct gs_host_frame),
 398                          gs_usb_receive_bulk_callback,
 399                          usbcan
 400                          );
 401
 402        rc = usb_submit_urb(urb, GFP_ATOMIC);
 403
 404        /* USB failure take down all interfaces */
 405        if (rc == -ENODEV) {
 406                for (rc = 0; rc < GS_MAX_INTF; rc++) {
 407                        if (usbcan->canch[rc])
 408                                netif_device_detach(usbcan->canch[rc]->netdev);
 409                }
 410        }
 411}
 412
 413static int gs_usb_set_bittiming(struct net_device *netdev)
 414{
 415        struct gs_can *dev = netdev_priv(netdev);
 416        struct can_bittiming *bt = &dev->can.bittiming;
 417        struct usb_interface *intf = dev->iface;
 418        int rc;
 419        struct gs_device_bittiming *dbt;
 420
 421        dbt = kmalloc(sizeof(*dbt), GFP_KERNEL);
 422        if (!dbt)
 423                return -ENOMEM;
 424
 425        dbt->prop_seg = bt->prop_seg;
 426        dbt->phase_seg1 = bt->phase_seg1;
 427        dbt->phase_seg2 = bt->phase_seg2;
 428        dbt->sjw = bt->sjw;
 429        dbt->brp = bt->brp;
 430
 431        /* request bit timings */
 432        rc = usb_control_msg(interface_to_usbdev(intf),
 433                             usb_sndctrlpipe(interface_to_usbdev(intf), 0),
 434                             GS_USB_BREQ_BITTIMING,
 435                             USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
 436                             dev->channel,
 437                             0,
 438                             dbt,
 439                             sizeof(*dbt),
 440                             1000);
 441
 442        kfree(dbt);
 443
 444        if (rc < 0)
 445                dev_err(netdev->dev.parent, "Couldn't set bittimings (err=%d)",
 446                        rc);
 447
 448        return rc;
 449}
 450
 451static void gs_usb_xmit_callback(struct urb *urb)
 452{
 453        struct gs_tx_context *txc = urb->context;
 454        struct gs_can *dev = txc->dev;
 455        struct net_device *netdev = dev->netdev;
 456
 457        if (urb->status)
 458                netdev_info(netdev, "usb xmit fail %d\n", txc->echo_id);
 459
 460        usb_free_coherent(urb->dev,
 461                          urb->transfer_buffer_length,
 462                          urb->transfer_buffer,
 463                          urb->transfer_dma);
 464
 465        atomic_dec(&dev->active_tx_urbs);
 466
 467        if (!netif_device_present(netdev))
 468                return;
 469
 470        if (netif_queue_stopped(netdev))
 471                netif_wake_queue(netdev);
 472}
 473
 474static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb,
 475                                     struct net_device *netdev)
 476{
 477        struct gs_can *dev = netdev_priv(netdev);
 478        struct net_device_stats *stats = &dev->netdev->stats;
 479        struct urb *urb;
 480        struct gs_host_frame *hf;
 481        struct can_frame *cf;
 482        int rc;
 483        unsigned int idx;
 484        struct gs_tx_context *txc;
 485
 486        if (can_dropped_invalid_skb(netdev, skb))
 487                return NETDEV_TX_OK;
 488
 489        /* find an empty context to keep track of transmission */
 490        txc = gs_alloc_tx_context(dev);
 491        if (!txc)
 492                return NETDEV_TX_BUSY;
 493
 494        /* create a URB, and a buffer for it */
 495        urb = usb_alloc_urb(0, GFP_ATOMIC);
 496        if (!urb)
 497                goto nomem_urb;
 498
 499        hf = usb_alloc_coherent(dev->udev, sizeof(*hf), GFP_ATOMIC,
 500                                &urb->transfer_dma);
 501        if (!hf) {
 502                netdev_err(netdev, "No memory left for USB buffer\n");
 503                goto nomem_hf;
 504        }
 505
 506        idx = txc->echo_id;
 507
 508        if (idx >= GS_MAX_TX_URBS) {
 509                netdev_err(netdev, "Invalid tx context %d\n", idx);
 510                goto badidx;
 511        }
 512
 513        hf->echo_id = idx;
 514        hf->channel = dev->channel;
 515
 516        cf = (struct can_frame *)skb->data;
 517
 518        hf->can_id = cf->can_id;
 519        hf->can_dlc = cf->can_dlc;
 520        memcpy(hf->data, cf->data, cf->can_dlc);
 521
 522        usb_fill_bulk_urb(urb, dev->udev,
 523                          usb_sndbulkpipe(dev->udev, GSUSB_ENDPOINT_OUT),
 524                          hf,
 525                          sizeof(*hf),
 526                          gs_usb_xmit_callback,
 527                          txc);
 528
 529        urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 530        usb_anchor_urb(urb, &dev->tx_submitted);
 531
 532        can_put_echo_skb(skb, netdev, idx);
 533
 534        atomic_inc(&dev->active_tx_urbs);
 535
 536        rc = usb_submit_urb(urb, GFP_ATOMIC);
 537        if (unlikely(rc)) {                     /* usb send failed */
 538                atomic_dec(&dev->active_tx_urbs);
 539
 540                can_free_echo_skb(netdev, idx);
 541                gs_free_tx_context(txc);
 542
 543                usb_unanchor_urb(urb);
 544                usb_free_coherent(dev->udev,
 545                                  sizeof(*hf),
 546                                  hf,
 547                                  urb->transfer_dma);
 548
 549
 550                if (rc == -ENODEV) {
 551                        netif_device_detach(netdev);
 552                } else {
 553                        netdev_err(netdev, "usb_submit failed (err=%d)\n", rc);
 554                        stats->tx_dropped++;
 555                }
 556        } else {
 557                /* Slow down tx path */
 558                if (atomic_read(&dev->active_tx_urbs) >= GS_MAX_TX_URBS)
 559                        netif_stop_queue(netdev);
 560        }
 561
 562        /* let usb core take care of this urb */
 563        usb_free_urb(urb);
 564
 565        return NETDEV_TX_OK;
 566
 567 badidx:
 568        usb_free_coherent(dev->udev,
 569                          sizeof(*hf),
 570                          hf,
 571                          urb->transfer_dma);
 572 nomem_hf:
 573        usb_free_urb(urb);
 574
 575 nomem_urb:
 576        gs_free_tx_context(txc);
 577        dev_kfree_skb(skb);
 578        stats->tx_dropped++;
 579        return NETDEV_TX_OK;
 580}
 581
 582static int gs_can_open(struct net_device *netdev)
 583{
 584        struct gs_can *dev = netdev_priv(netdev);
 585        struct gs_usb *parent = dev->parent;
 586        int rc, i;
 587        struct gs_device_mode *dm;
 588        u32 ctrlmode;
 589
 590        rc = open_candev(netdev);
 591        if (rc)
 592                return rc;
 593
 594        if (atomic_add_return(1, &parent->active_channels) == 1) {
 595                for (i = 0; i < GS_MAX_RX_URBS; i++) {
 596                        struct urb *urb;
 597                        u8 *buf;
 598
 599                        /* alloc rx urb */
 600                        urb = usb_alloc_urb(0, GFP_KERNEL);
 601                        if (!urb)
 602                                return -ENOMEM;
 603
 604                        /* alloc rx buffer */
 605                        buf = usb_alloc_coherent(dev->udev,
 606                                                 sizeof(struct gs_host_frame),
 607                                                 GFP_KERNEL,
 608                                                 &urb->transfer_dma);
 609                        if (!buf) {
 610                                netdev_err(netdev,
 611                                           "No memory left for USB buffer\n");
 612                                usb_free_urb(urb);
 613                                return -ENOMEM;
 614                        }
 615
 616                        /* fill, anchor, and submit rx urb */
 617                        usb_fill_bulk_urb(urb,
 618                                          dev->udev,
 619                                          usb_rcvbulkpipe(dev->udev,
 620                                                          GSUSB_ENDPOINT_IN),
 621                                          buf,
 622                                          sizeof(struct gs_host_frame),
 623                                          gs_usb_receive_bulk_callback,
 624                                          parent);
 625                        urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 626
 627                        usb_anchor_urb(urb, &parent->rx_submitted);
 628
 629                        rc = usb_submit_urb(urb, GFP_KERNEL);
 630                        if (rc) {
 631                                if (rc == -ENODEV)
 632                                        netif_device_detach(dev->netdev);
 633
 634                                netdev_err(netdev,
 635                                           "usb_submit failed (err=%d)\n",
 636                                           rc);
 637
 638                                usb_unanchor_urb(urb);
 639                                break;
 640                        }
 641
 642                        /* Drop reference,
 643                         * USB core will take care of freeing it
 644                         */
 645                        usb_free_urb(urb);
 646                }
 647        }
 648
 649        dm = kmalloc(sizeof(*dm), GFP_KERNEL);
 650        if (!dm)
 651                return -ENOMEM;
 652
 653        /* flags */
 654        ctrlmode = dev->can.ctrlmode;
 655        dm->flags = 0;
 656
 657        if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
 658                dm->flags |= GS_CAN_MODE_LOOP_BACK;
 659        else if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
 660                dm->flags |= GS_CAN_MODE_LISTEN_ONLY;
 661
 662        /* Controller is not allowed to retry TX
 663         * this mode is unavailable on atmels uc3c hardware
 664         */
 665        if (ctrlmode & CAN_CTRLMODE_ONE_SHOT)
 666                dm->flags |= GS_CAN_MODE_ONE_SHOT;
 667
 668        if (ctrlmode & CAN_CTRLMODE_3_SAMPLES)
 669                dm->flags |= GS_CAN_MODE_TRIPLE_SAMPLE;
 670
 671        /* finally start device */
 672        dm->mode = GS_CAN_MODE_START;
 673        rc = usb_control_msg(interface_to_usbdev(dev->iface),
 674                             usb_sndctrlpipe(interface_to_usbdev(dev->iface), 0),
 675                             GS_USB_BREQ_MODE,
 676                             USB_DIR_OUT | USB_TYPE_VENDOR |
 677                             USB_RECIP_INTERFACE,
 678                             dev->channel,
 679                             0,
 680                             dm,
 681                             sizeof(*dm),
 682                             1000);
 683
 684        if (rc < 0) {
 685                netdev_err(netdev, "Couldn't start device (err=%d)\n", rc);
 686                kfree(dm);
 687                return rc;
 688        }
 689
 690        kfree(dm);
 691
 692        dev->can.state = CAN_STATE_ERROR_ACTIVE;
 693
 694        if (!(dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY))
 695                netif_start_queue(netdev);
 696
 697        return 0;
 698}
 699
 700static int gs_can_close(struct net_device *netdev)
 701{
 702        int rc;
 703        struct gs_can *dev = netdev_priv(netdev);
 704        struct gs_usb *parent = dev->parent;
 705
 706        netif_stop_queue(netdev);
 707
 708        /* Stop polling */
 709        if (atomic_dec_and_test(&parent->active_channels))
 710                usb_kill_anchored_urbs(&parent->rx_submitted);
 711
 712        /* Stop sending URBs */
 713        usb_kill_anchored_urbs(&dev->tx_submitted);
 714        atomic_set(&dev->active_tx_urbs, 0);
 715
 716        /* reset the device */
 717        rc = gs_cmd_reset(parent, dev);
 718        if (rc < 0)
 719                netdev_warn(netdev, "Couldn't shutdown device (err=%d)", rc);
 720
 721        /* reset tx contexts */
 722        for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
 723                dev->tx_context[rc].dev = dev;
 724                dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
 725        }
 726
 727        /* close the netdev */
 728        close_candev(netdev);
 729
 730        return 0;
 731}
 732
 733static const struct net_device_ops gs_usb_netdev_ops = {
 734        .ndo_open = gs_can_open,
 735        .ndo_stop = gs_can_close,
 736        .ndo_start_xmit = gs_can_start_xmit,
 737        .ndo_change_mtu = can_change_mtu,
 738};
 739
 740static int gs_usb_set_identify(struct net_device *netdev, bool do_identify)
 741{
 742        struct gs_can *dev = netdev_priv(netdev);
 743        struct gs_identify_mode imode;
 744        int rc;
 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        return (rc > 0) ? 0 : rc;
 764}
 765
 766/* blink LED's for finding the this interface */
 767static int gs_usb_set_phys_id(struct net_device *dev,
 768                              enum ethtool_phys_id_state state)
 769{
 770        int rc = 0;
 771
 772        switch (state) {
 773        case ETHTOOL_ID_ACTIVE:
 774                rc = gs_usb_set_identify(dev, GS_CAN_IDENTIFY_ON);
 775                break;
 776        case ETHTOOL_ID_INACTIVE:
 777                rc = gs_usb_set_identify(dev, GS_CAN_IDENTIFY_OFF);
 778                break;
 779        default:
 780                break;
 781        }
 782
 783        return rc;
 784}
 785
 786static const struct ethtool_ops gs_usb_ethtool_ops = {
 787        .set_phys_id = gs_usb_set_phys_id,
 788};
 789
 790static struct gs_can *gs_make_candev(unsigned int channel,
 791                                     struct usb_interface *intf,
 792                                     struct gs_device_config *dconf)
 793{
 794        struct gs_can *dev;
 795        struct net_device *netdev;
 796        int rc;
 797        struct gs_device_bt_const *bt_const;
 798
 799        bt_const = kmalloc(sizeof(*bt_const), GFP_KERNEL);
 800        if (!bt_const)
 801                return ERR_PTR(-ENOMEM);
 802
 803        /* fetch bit timing constants */
 804        rc = usb_control_msg(interface_to_usbdev(intf),
 805                             usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
 806                             GS_USB_BREQ_BT_CONST,
 807                             USB_DIR_IN|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
 808                             channel,
 809                             0,
 810                             bt_const,
 811                             sizeof(*bt_const),
 812                             1000);
 813
 814        if (rc < 0) {
 815                dev_err(&intf->dev,
 816                        "Couldn't get bit timing const for channel (err=%d)\n",
 817                        rc);
 818                kfree(bt_const);
 819                return ERR_PTR(rc);
 820        }
 821
 822        /* create netdev */
 823        netdev = alloc_candev(sizeof(struct gs_can), GS_MAX_TX_URBS);
 824        if (!netdev) {
 825                dev_err(&intf->dev, "Couldn't allocate candev\n");
 826                kfree(bt_const);
 827                return ERR_PTR(-ENOMEM);
 828        }
 829
 830        dev = netdev_priv(netdev);
 831
 832        netdev->netdev_ops = &gs_usb_netdev_ops;
 833
 834        netdev->flags |= IFF_ECHO; /* we support full roundtrip echo */
 835
 836        /* dev settup */
 837        strcpy(dev->bt_const.name, "gs_usb");
 838        dev->bt_const.tseg1_min = bt_const->tseg1_min;
 839        dev->bt_const.tseg1_max = bt_const->tseg1_max;
 840        dev->bt_const.tseg2_min = bt_const->tseg2_min;
 841        dev->bt_const.tseg2_max = bt_const->tseg2_max;
 842        dev->bt_const.sjw_max = bt_const->sjw_max;
 843        dev->bt_const.brp_min = bt_const->brp_min;
 844        dev->bt_const.brp_max = bt_const->brp_max;
 845        dev->bt_const.brp_inc = bt_const->brp_inc;
 846
 847        dev->udev = interface_to_usbdev(intf);
 848        dev->iface = intf;
 849        dev->netdev = netdev;
 850        dev->channel = channel;
 851
 852        init_usb_anchor(&dev->tx_submitted);
 853        atomic_set(&dev->active_tx_urbs, 0);
 854        spin_lock_init(&dev->tx_ctx_lock);
 855        for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
 856                dev->tx_context[rc].dev = dev;
 857                dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
 858        }
 859
 860        /* can settup */
 861        dev->can.state = CAN_STATE_STOPPED;
 862        dev->can.clock.freq = bt_const->fclk_can;
 863        dev->can.bittiming_const = &dev->bt_const;
 864        dev->can.do_set_bittiming = gs_usb_set_bittiming;
 865
 866        dev->can.ctrlmode_supported = 0;
 867
 868        if (bt_const->feature & GS_CAN_FEATURE_LISTEN_ONLY)
 869                dev->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY;
 870
 871        if (bt_const->feature & GS_CAN_FEATURE_LOOP_BACK)
 872                dev->can.ctrlmode_supported |= CAN_CTRLMODE_LOOPBACK;
 873
 874        if (bt_const->feature & GS_CAN_FEATURE_TRIPLE_SAMPLE)
 875                dev->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
 876
 877        if (bt_const->feature & GS_CAN_FEATURE_ONE_SHOT)
 878                dev->can.ctrlmode_supported |= CAN_CTRLMODE_ONE_SHOT;
 879
 880        SET_NETDEV_DEV(netdev, &intf->dev);
 881
 882        if (dconf->sw_version > 1)
 883                if (bt_const->feature & GS_CAN_FEATURE_IDENTIFY)
 884                        netdev->ethtool_ops = &gs_usb_ethtool_ops;
 885
 886        kfree(bt_const);
 887
 888        rc = register_candev(dev->netdev);
 889        if (rc) {
 890                free_candev(dev->netdev);
 891                dev_err(&intf->dev, "Couldn't register candev (err=%d)\n", rc);
 892                return ERR_PTR(rc);
 893        }
 894
 895        return dev;
 896}
 897
 898static void gs_destroy_candev(struct gs_can *dev)
 899{
 900        unregister_candev(dev->netdev);
 901        usb_kill_anchored_urbs(&dev->tx_submitted);
 902        free_candev(dev->netdev);
 903}
 904
 905static int gs_usb_probe(struct usb_interface *intf,
 906                        const struct usb_device_id *id)
 907{
 908        struct gs_usb *dev;
 909        int rc = -ENOMEM;
 910        unsigned int icount, i;
 911        struct gs_host_config hconf = {
 912                .byte_order = 0x0000beef,
 913        };
 914        struct gs_device_config dconf;
 915
 916        /* send host config */
 917        rc = usb_control_msg(interface_to_usbdev(intf),
 918                             usb_sndctrlpipe(interface_to_usbdev(intf), 0),
 919                             GS_USB_BREQ_HOST_FORMAT,
 920                             USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
 921                             1,
 922                             intf->altsetting[0].desc.bInterfaceNumber,
 923                             &hconf,
 924                             sizeof(hconf),
 925                             1000);
 926
 927        if (rc < 0) {
 928                dev_err(&intf->dev, "Couldn't send data format (err=%d)\n",
 929                        rc);
 930                return rc;
 931        }
 932
 933        /* read device config */
 934        rc = usb_control_msg(interface_to_usbdev(intf),
 935                             usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
 936                             GS_USB_BREQ_DEVICE_CONFIG,
 937                             USB_DIR_IN|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
 938                             1,
 939                             intf->altsetting[0].desc.bInterfaceNumber,
 940                             &dconf,
 941                             sizeof(dconf),
 942                             1000);
 943        if (rc < 0) {
 944                dev_err(&intf->dev, "Couldn't get device config: (err=%d)\n",
 945                        rc);
 946                return rc;
 947        }
 948
 949        icount = dconf.icount + 1;
 950        dev_info(&intf->dev, "Configuring for %d interfaces\n", icount);
 951
 952        if (icount > GS_MAX_INTF) {
 953                dev_err(&intf->dev,
 954                        "Driver cannot handle more that %d CAN interfaces\n",
 955                        GS_MAX_INTF);
 956                return -EINVAL;
 957        }
 958
 959        dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 960        if (!dev)
 961                return -ENOMEM;
 962        init_usb_anchor(&dev->rx_submitted);
 963
 964        atomic_set(&dev->active_channels, 0);
 965
 966        usb_set_intfdata(intf, dev);
 967        dev->udev = interface_to_usbdev(intf);
 968
 969        for (i = 0; i < icount; i++) {
 970                dev->canch[i] = gs_make_candev(i, intf, &dconf);
 971                if (IS_ERR_OR_NULL(dev->canch[i])) {
 972                        /* save error code to return later */
 973                        rc = PTR_ERR(dev->canch[i]);
 974
 975                        /* on failure destroy previously created candevs */
 976                        icount = i;
 977                        for (i = 0; i < icount; i++)
 978                                gs_destroy_candev(dev->canch[i]);
 979
 980                        usb_kill_anchored_urbs(&dev->rx_submitted);
 981                        kfree(dev);
 982                        return rc;
 983                }
 984                dev->canch[i]->parent = dev;
 985        }
 986
 987        return 0;
 988}
 989
 990static void gs_usb_disconnect(struct usb_interface *intf)
 991{
 992        unsigned i;
 993        struct gs_usb *dev = usb_get_intfdata(intf);
 994        usb_set_intfdata(intf, NULL);
 995
 996        if (!dev) {
 997                dev_err(&intf->dev, "Disconnect (nodata)\n");
 998                return;
 999        }
1000
1001        for (i = 0; i < GS_MAX_INTF; i++)
1002                if (dev->canch[i])
1003                        gs_destroy_candev(dev->canch[i]);
1004
1005        usb_kill_anchored_urbs(&dev->rx_submitted);
1006        kfree(dev);
1007}
1008
1009static const struct usb_device_id gs_usb_table[] = {
1010        { USB_DEVICE_INTERFACE_NUMBER(USB_GSUSB_1_VENDOR_ID,
1011                                      USB_GSUSB_1_PRODUCT_ID, 0) },
1012        { USB_DEVICE_INTERFACE_NUMBER(USB_CANDLELIGHT_VENDOR_ID,
1013                                      USB_CANDLELIGHT_PRODUCT_ID, 0) },
1014        {} /* Terminating entry */
1015};
1016
1017MODULE_DEVICE_TABLE(usb, gs_usb_table);
1018
1019static struct usb_driver gs_usb_driver = {
1020        .name       = "gs_usb",
1021        .probe      = gs_usb_probe,
1022        .disconnect = gs_usb_disconnect,
1023        .id_table   = gs_usb_table,
1024};
1025
1026module_usb_driver(gs_usb_driver);
1027
1028MODULE_AUTHOR("Maximilian Schneider <mws@schneidersoft.net>");
1029MODULE_DESCRIPTION(
1030"Socket CAN device driver for Geschwister Schneider Technologie-, "
1031"Entwicklungs- und Vertriebs UG. USB2.0 to CAN interfaces\n"
1032"and bytewerk.org candleLight USB CAN interfaces.");
1033MODULE_LICENSE("GPL v2");
1034
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