drivers/net/can/usb/gs_usb.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* CAN driver for Geschwister Schneider USB/CAN devices
   3  * and bytewerk.org candleLight USB CAN interfaces.
   4  *
   5  * Copyright (C) 2013-2016 Geschwister Schneider Technologie-,
   6  * Entwicklungs- und Vertriebs UG (Haftungsbeschränkt).
   7  * Copyright (C) 2016 Hubert Denkmair
   8  *
   9  * Many thanks to all socketcan devs!
  10  */
  11
  12 #include <linux/init.h>
  13 #include <linux/signal.h>
  14 #include <linux/module.h>
  15 #include <linux/netdevice.h>
  16 #include <linux/usb.h>
  17
  18 #include <linux/can.h>
  19 #include <linux/can/dev.h>
  20 #include <linux/can/error.h>
  21
  22 /* Device specific constants */
  23 #define USB_GSUSB_1_VENDOR_ID      0x1d50
  24 #define USB_GSUSB_1_PRODUCT_ID     0x606f
  25
  26 #define USB_CANDLELIGHT_VENDOR_ID  0x1209
  27 #define USB_CANDLELIGHT_PRODUCT_ID 0x2323
  28
  29 #define GSUSB_ENDPOINT_IN          1
  30 #define GSUSB_ENDPOINT_OUT         2
  31
  32 /* Device specific constants */
  33 enum gs_usb_breq {
  34         GS_USB_BREQ_HOST_FORMAT = 0,
  35         GS_USB_BREQ_BITTIMING,
  36         GS_USB_BREQ_MODE,
  37         GS_USB_BREQ_BERR,
  38         GS_USB_BREQ_BT_CONST,
  39         GS_USB_BREQ_DEVICE_CONFIG,
  40         GS_USB_BREQ_TIMESTAMP,
  41         GS_USB_BREQ_IDENTIFY,
  42 };
  43
  44 enum gs_can_mode {
  45         /* reset a channel. turns it off */
  46         GS_CAN_MODE_RESET = 0,
  47         /* starts a channel */
  48         GS_CAN_MODE_START
  49 };
  50
  51 enum gs_can_state {
  52         GS_CAN_STATE_ERROR_ACTIVE = 0,
  53         GS_CAN_STATE_ERROR_WARNING,
  54         GS_CAN_STATE_ERROR_PASSIVE,
  55         GS_CAN_STATE_BUS_OFF,
  56         GS_CAN_STATE_STOPPED,
  57         GS_CAN_STATE_SLEEPING
  58 };
  59
  60 enum gs_can_identify_mode {
  61         GS_CAN_IDENTIFY_OFF = 0,
  62         GS_CAN_IDENTIFY_ON
  63 };
  64
  65 /* data types passed between host and device */
  66
  67 /* The firmware on the original USB2CAN by Geschwister Schneider
  68  * Technologie Entwicklungs- und Vertriebs UG exchanges all data
  69  * between the host and the device in host byte order. This is done
  70  * with the struct gs_host_config::byte_order member, which is sent
  71  * first to indicate the desired byte order.
  72  *
  73  * The widely used open source firmware candleLight doesn't support
  74  * this feature and exchanges the data in little endian byte order.
  75  */
  76 struct gs_host_config {
  77         __le32 byte_order;
  78 } __packed;
  79
  80 struct gs_device_config {
  81         u8 reserved1;
  82         u8 reserved2;
  83         u8 reserved3;
  84         u8 icount;
  85         __le32 sw_version;
  86         __le32 hw_version;
  87 } __packed;
  88
  89 #define GS_CAN_MODE_NORMAL               0
  90 #define GS_CAN_MODE_LISTEN_ONLY          BIT(0)
  91 #define GS_CAN_MODE_LOOP_BACK            BIT(1)
  92 #define GS_CAN_MODE_TRIPLE_SAMPLE        BIT(2)
  93 #define GS_CAN_MODE_ONE_SHOT             BIT(3)
  94
  95 struct gs_device_mode {
  96         __le32 mode;
  97         __le32 flags;
  98 } __packed;
  99
 100 struct gs_device_state {
 101         __le32 state;
 102         __le32 rxerr;
 103         __le32 txerr;
 104 } __packed;
 105
 106 struct gs_device_bittiming {
 107         __le32 prop_seg;
 108         __le32 phase_seg1;
 109         __le32 phase_seg2;
 110         __le32 sjw;
 111         __le32 brp;
 112 } __packed;
 113
 114 struct gs_identify_mode {
 115         __le32 mode;
 116 } __packed;
 117
 118 #define GS_CAN_FEATURE_LISTEN_ONLY      BIT(0)
 119 #define GS_CAN_FEATURE_LOOP_BACK        BIT(1)
 120 #define GS_CAN_FEATURE_TRIPLE_SAMPLE    BIT(2)
 121 #define GS_CAN_FEATURE_ONE_SHOT         BIT(3)
 122 #define GS_CAN_FEATURE_HW_TIMESTAMP     BIT(4)
 123 #define GS_CAN_FEATURE_IDENTIFY         BIT(5)
 124
 125 struct gs_device_bt_const {
 126         __le32 feature;
 127         __le32 fclk_can;
 128         __le32 tseg1_min;
 129         __le32 tseg1_max;
 130         __le32 tseg2_min;
 131         __le32 tseg2_max;
 132         __le32 sjw_max;
 133         __le32 brp_min;
 134         __le32 brp_max;
 135         __le32 brp_inc;
 136 } __packed;
 137
 138 #define GS_CAN_FLAG_OVERFLOW 1
 139
 140 struct gs_host_frame {
 141         u32 echo_id;
 142         __le32 can_id;
 143
 144         u8 can_dlc;
 145         u8 channel;
 146         u8 flags;
 147         u8 reserved;
 148
 149         u8 data[8];
 150 } __packed;
 151 /* The GS USB devices make use of the same flags and masks as in
 152  * linux/can.h and linux/can/error.h, and no additional mapping is necessary.
 153  */
 154
 155 /* Only send a max of GS_MAX_TX_URBS frames per channel at a time. */
 156 #define GS_MAX_TX_URBS 10
 157 /* Only launch a max of GS_MAX_RX_URBS usb requests at a time. */
 158 #define GS_MAX_RX_URBS 30
 159 /* Maximum number of interfaces the driver supports per device.
 160  * Current hardware only supports 2 interfaces. The future may vary.
 161  */
 162 #define GS_MAX_INTF 2
 163
 164 struct gs_tx_context {
 165         struct gs_can *dev;
 166         unsigned int echo_id;
 167 };
 168
 169 struct gs_can {
 170         struct can_priv can; /* must be the first member */
 171
 172         struct gs_usb *parent;
 173
 174         struct net_device *netdev;
 175         struct usb_device *udev;
 176         struct usb_interface *iface;
 177
 178         struct can_bittiming_const bt_const;
 179         unsigned int channel;   /* channel number */
 180
 181         /* This lock prevents a race condition between xmit and receive. */
 182         spinlock_t tx_ctx_lock;
 183         struct gs_tx_context tx_context[GS_MAX_TX_URBS];
 184
 185         struct usb_anchor tx_submitted;
 186         atomic_t active_tx_urbs;
 187         void *rxbuf[GS_MAX_RX_URBS];
 188         dma_addr_t rxbuf_dma[GS_MAX_RX_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         struct usb_device *udev;
 196         u8 active_channels;
 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_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 device_detach;
 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 = le32_to_cpu(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 (le32_to_cpu(hf->can_id) & CAN_ERR_FLAG)
 347                         gs_update_state(dev, cf);
 348
 349                 netdev->stats.rx_packets++;
 350                 netdev->stats.rx_bytes += hf->can_dlc;
 351
 352                 netif_rx(skb);
 353         } else { /* echo_id == hf->echo_id */
 354                 if (hf->echo_id >= GS_MAX_TX_URBS) {
 355                         netdev_err(netdev,
 356                                    "Unexpected out of range echo id %d\n",
 357                                    hf->echo_id);
 358                         goto resubmit_urb;
 359                 }
 360
 361                 netdev->stats.tx_packets++;
 362                 netdev->stats.tx_bytes += hf->can_dlc;
 363
 364                 txc = gs_get_tx_context(dev, hf->echo_id);
 365
 366                 /* bad devices send bad echo_ids. */
 367                 if (!txc) {
 368                         netdev_err(netdev,
 369                                    "Unexpected unused echo id %d\n",
 370                                    hf->echo_id);
 371                         goto resubmit_urb;
 372                 }
 373
 374                 can_get_echo_skb(netdev, hf->echo_id);
 375
 376                 gs_free_tx_context(txc);
 377
 378                 atomic_dec(&dev->active_tx_urbs);
 379
 380                 netif_wake_queue(netdev);
 381         }
 382
 383         if (hf->flags & GS_CAN_FLAG_OVERFLOW) {
 384                 skb = alloc_can_err_skb(netdev, &cf);
 385                 if (!skb)
 386                         goto resubmit_urb;
 387
 388                 cf->can_id |= CAN_ERR_CRTL;
 389                 cf->can_dlc = CAN_ERR_DLC;
 390                 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 391                 stats->rx_over_errors++;
 392                 stats->rx_errors++;
 393                 netif_rx(skb);
 394         }
 395
 396  resubmit_urb:
 397         usb_fill_bulk_urb(urb,
 398                           usbcan->udev,
 399                           usb_rcvbulkpipe(usbcan->udev, GSUSB_ENDPOINT_IN),
 400                           hf,
 401                           sizeof(struct gs_host_frame),
 402                           gs_usb_receive_bulk_callback,
 403                           usbcan
 404                           );
 405
 406         rc = usb_submit_urb(urb, GFP_ATOMIC);
 407
 408         /* USB failure take down all interfaces */
 409         if (rc == -ENODEV) {
 410  device_detach:
 411                 for (rc = 0; rc < GS_MAX_INTF; rc++) {
 412                         if (usbcan->canch[rc])
 413                                 netif_device_detach(usbcan->canch[rc]->netdev);
 414                 }
 415         }
 416 }
 417
 418 static int gs_usb_set_bittiming(struct net_device *netdev)
 419 {
 420         struct gs_can *dev = netdev_priv(netdev);
 421         struct can_bittiming *bt = &dev->can.bittiming;
 422         struct usb_interface *intf = dev->iface;
 423         int rc;
 424         struct gs_device_bittiming *dbt;
 425
 426         dbt = kmalloc(sizeof(*dbt), GFP_KERNEL);
 427         if (!dbt)
 428                 return -ENOMEM;
 429
 430         dbt->prop_seg = cpu_to_le32(bt->prop_seg);
 431         dbt->phase_seg1 = cpu_to_le32(bt->phase_seg1);
 432         dbt->phase_seg2 = cpu_to_le32(bt->phase_seg2);
 433         dbt->sjw = cpu_to_le32(bt->sjw);
 434         dbt->brp = cpu_to_le32(bt->brp);
 435
 436         /* request bit timings */
 437         rc = usb_control_msg(interface_to_usbdev(intf),
 438                              usb_sndctrlpipe(interface_to_usbdev(intf), 0),
 439                              GS_USB_BREQ_BITTIMING,
 440                              USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 441                              dev->channel,
 442                              0,
 443                              dbt,
 444                              sizeof(*dbt),
 445                              1000);
 446
 447         kfree(dbt);
 448
 449         if (rc < 0)
 450                 dev_err(netdev->dev.parent, "Couldn't set bittimings (err=%d)",
 451                         rc);
 452
 453         return (rc > 0) ? 0 : rc;
 454 }
 455
 456 static void gs_usb_xmit_callback(struct urb *urb)
 457 {
 458         struct gs_tx_context *txc = urb->context;
 459         struct gs_can *dev = txc->dev;
 460         struct net_device *netdev = dev->netdev;
 461
 462         if (urb->status)
 463                 netdev_info(netdev, "usb xmit fail %d\n", txc->echo_id);
 464
 465         usb_free_coherent(urb->dev,
 466                           urb->transfer_buffer_length,
 467                           urb->transfer_buffer,
 468                           urb->transfer_dma);
 469 }
 470
 471 static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb,
 472                                      struct net_device *netdev)
 473 {
 474         struct gs_can *dev = netdev_priv(netdev);
 475         struct net_device_stats *stats = &dev->netdev->stats;
 476         struct urb *urb;
 477         struct gs_host_frame *hf;
 478         struct can_frame *cf;
 479         int rc;
 480         unsigned int idx;
 481         struct gs_tx_context *txc;
 482
 483         if (can_dropped_invalid_skb(netdev, skb))
 484                 return NETDEV_TX_OK;
 485
 486         /* find an empty context to keep track of transmission */
 487         txc = gs_alloc_tx_context(dev);
 488         if (!txc)
 489                 return NETDEV_TX_BUSY;
 490
 491         /* create a URB, and a buffer for it */
 492         urb = usb_alloc_urb(0, GFP_ATOMIC);
 493         if (!urb)
 494                 goto nomem_urb;
 495
 496         hf = usb_alloc_coherent(dev->udev, sizeof(*hf), GFP_ATOMIC,
 497                                 &urb->transfer_dma);
 498         if (!hf) {
 499                 netdev_err(netdev, "No memory left for USB buffer\n");
 500                 goto nomem_hf;
 501         }
 502
 503         idx = txc->echo_id;
 504
 505         if (idx >= GS_MAX_TX_URBS) {
 506                 netdev_err(netdev, "Invalid tx context %d\n", idx);
 507                 goto badidx;
 508         }
 509
 510         hf->echo_id = idx;
 511         hf->channel = dev->channel;
 512         hf->flags = 0;
 513         hf->reserved = 0;
 514
 515         cf = (struct can_frame *)skb->data;
 516
 517         hf->can_id = cpu_to_le32(cf->can_id);
 518         hf->can_dlc = cf->can_dlc;
 519         memcpy(hf->data, cf->data, cf->can_dlc);
 520
 521         usb_fill_bulk_urb(urb, dev->udev,
 522                           usb_sndbulkpipe(dev->udev, GSUSB_ENDPOINT_OUT),
 523                           hf,
 524                           sizeof(*hf),
 525                           gs_usb_xmit_callback,
 526                           txc);
 527
 528         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 529         usb_anchor_urb(urb, &dev->tx_submitted);
 530
 531         can_put_echo_skb(skb, netdev, idx);
 532
 533         atomic_inc(&dev->active_tx_urbs);
 534
 535         rc = usb_submit_urb(urb, GFP_ATOMIC);
 536         if (unlikely(rc)) {                     /* usb send failed */
 537                 atomic_dec(&dev->active_tx_urbs);
 538
 539                 can_free_echo_skb(netdev, idx);
 540                 gs_free_tx_context(txc);
 541
 542                 usb_unanchor_urb(urb);
 543                 usb_free_coherent(dev->udev,
 544                                   sizeof(*hf),
 545                                   hf,
 546                                   urb->transfer_dma);
 547
 548                 if (rc == -ENODEV) {
 549                         netif_device_detach(netdev);
 550                 } else {
 551                         netdev_err(netdev, "usb_submit failed (err=%d)\n", rc);
 552                         stats->tx_dropped++;
 553                 }
 554         } else {
 555                 /* Slow down tx path */
 556                 if (atomic_read(&dev->active_tx_urbs) >= GS_MAX_TX_URBS)
 557                         netif_stop_queue(netdev);
 558         }
 559
 560         /* let usb core take care of this urb */
 561         usb_free_urb(urb);
 562
 563         return NETDEV_TX_OK;
 564
 565  badidx:
 566         usb_free_coherent(dev->udev,
 567                           sizeof(*hf),
 568                           hf,
 569                           urb->transfer_dma);
 570  nomem_hf:
 571         usb_free_urb(urb);
 572
 573  nomem_urb:
 574         gs_free_tx_context(txc);
 575         dev_kfree_skb(skb);
 576         stats->tx_dropped++;
 577         return NETDEV_TX_OK;
 578 }
 579
 580 static int gs_can_open(struct net_device *netdev)
 581 {
 582         struct gs_can *dev = netdev_priv(netdev);
 583         struct gs_usb *parent = dev->parent;
 584         int rc, i;
 585         struct gs_device_mode *dm;
 586         u32 ctrlmode;
 587         u32 flags = 0;
 588
 589         rc = open_candev(netdev);
 590         if (rc)
 591                 return rc;
 592
 593         if (!parent->active_channels) {
 594                 for (i = 0; i < GS_MAX_RX_URBS; i++) {
 595                         struct urb *urb;
 596                         u8 *buf;
 597                         dma_addr_t buf_dma;
 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                                                  &buf_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                         urb->transfer_dma = buf_dma;
 617
 618                         /* fill, anchor, and submit rx urb */
 619                         usb_fill_bulk_urb(urb,
 620                                           dev->udev,
 621                                           usb_rcvbulkpipe(dev->udev,
 622                                                           GSUSB_ENDPOINT_IN),
 623                                           buf,
 624                                           sizeof(struct gs_host_frame),
 625                                           gs_usb_receive_bulk_callback,
 626                                           parent);
 627                         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 628
 629                         usb_anchor_urb(urb, &parent->rx_submitted);
 630
 631                         rc = usb_submit_urb(urb, GFP_KERNEL);
 632                         if (rc) {
 633                                 if (rc == -ENODEV)
 634                                         netif_device_detach(dev->netdev);
 635
 636                                 netdev_err(netdev,
 637                                            "usb_submit failed (err=%d)\n",
 638                                            rc);
 639
 640                                 usb_unanchor_urb(urb);
 641                                 usb_free_coherent(dev->udev,
 642                                                   sizeof(struct gs_host_frame),
 643                                                   buf,
 644                                                   buf_dma);
 645                                 usb_free_urb(urb);
 646                                 break;
 647                         }
 648
 649                         dev->rxbuf[i] = buf;
 650                         dev->rxbuf_dma[i] = buf_dma;
 651
 652                         /* Drop reference,
 653                          * USB core will take care of freeing it
 654                          */
 655                         usb_free_urb(urb);
 656                 }
 657         }
 658
 659         dm = kmalloc(sizeof(*dm), GFP_KERNEL);
 660         if (!dm)
 661                 return -ENOMEM;
 662
 663         /* flags */
 664         ctrlmode = dev->can.ctrlmode;
 665
 666         if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
 667                 flags |= GS_CAN_MODE_LOOP_BACK;
 668         else if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
 669                 flags |= GS_CAN_MODE_LISTEN_ONLY;
 670
 671         /* Controller is not allowed to retry TX
 672          * this mode is unavailable on atmels uc3c hardware
 673          */
 674         if (ctrlmode & CAN_CTRLMODE_ONE_SHOT)
 675                 flags |= GS_CAN_MODE_ONE_SHOT;
 676
 677         if (ctrlmode & CAN_CTRLMODE_3_SAMPLES)
 678                 flags |= GS_CAN_MODE_TRIPLE_SAMPLE;
 679
 680         /* finally start device */
 681         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 682         dm->mode = cpu_to_le32(GS_CAN_MODE_START);
 683         dm->flags = cpu_to_le32(flags);
 684         rc = usb_control_msg(interface_to_usbdev(dev->iface),
 685                              usb_sndctrlpipe(interface_to_usbdev(dev->iface), 0),
 686                              GS_USB_BREQ_MODE,
 687                              USB_DIR_OUT | USB_TYPE_VENDOR |
 688                              USB_RECIP_INTERFACE,
 689                              dev->channel,
 690                              0,
 691                              dm,
 692                              sizeof(*dm),
 693                              1000);
 694
 695         if (rc < 0) {
 696                 netdev_err(netdev, "Couldn't start device (err=%d)\n", rc);
 697                 kfree(dm);
 698                 dev->can.state = CAN_STATE_STOPPED;
 699                 return rc;
 700         }
 701
 702         kfree(dm);
 703
 704         parent->active_channels++;
 705         if (!(dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY))
 706                 netif_start_queue(netdev);
 707
 708         return 0;
 709 }
 710
 711 static int gs_can_close(struct net_device *netdev)
 712 {
 713         int rc;
 714         struct gs_can *dev = netdev_priv(netdev);
 715         struct gs_usb *parent = dev->parent;
 716         unsigned int i;
 717
 718         netif_stop_queue(netdev);
 719
 720         /* Stop polling */
 721         parent->active_channels--;
 722         if (!parent->active_channels) {
 723                 usb_kill_anchored_urbs(&parent->rx_submitted);
 724                 for (i = 0; i < GS_MAX_RX_URBS; i++)
 725                         usb_free_coherent(dev->udev,
 726                                           sizeof(struct gs_host_frame),
 727                                           dev->rxbuf[i],
 728                                           dev->rxbuf_dma[i]);
 729         }
 730
 731         /* Stop sending URBs */
 732         usb_kill_anchored_urbs(&dev->tx_submitted);
 733         atomic_set(&dev->active_tx_urbs, 0);
 734
 735         /* reset the device */
 736         rc = gs_cmd_reset(dev);
 737         if (rc < 0)
 738                 netdev_warn(netdev, "Couldn't shutdown device (err=%d)", rc);
 739
 740         /* reset tx contexts */
 741         for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
 742                 dev->tx_context[rc].dev = dev;
 743                 dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
 744         }
 745
 746         /* close the netdev */
 747         close_candev(netdev);
 748
 749         return 0;
 750 }
 751
 752 static const struct net_device_ops gs_usb_netdev_ops = {
 753         .ndo_open = gs_can_open,
 754         .ndo_stop = gs_can_close,
 755         .ndo_start_xmit = gs_can_start_xmit,
 756         .ndo_change_mtu = can_change_mtu,
 757 };
 758
 759 static int gs_usb_set_identify(struct net_device *netdev, bool do_identify)
 760 {
 761         struct gs_can *dev = netdev_priv(netdev);
 762         struct gs_identify_mode *imode;
 763         int rc;
 764
 765         imode = kmalloc(sizeof(*imode), GFP_KERNEL);
 766
 767         if (!imode)
 768                 return -ENOMEM;
 769
 770         if (do_identify)
 771                 imode->mode = cpu_to_le32(GS_CAN_IDENTIFY_ON);
 772         else
 773                 imode->mode = cpu_to_le32(GS_CAN_IDENTIFY_OFF);
 774
 775         rc = usb_control_msg(interface_to_usbdev(dev->iface),
 776                              usb_sndctrlpipe(interface_to_usbdev(dev->iface),
 777                                              0),
 778                              GS_USB_BREQ_IDENTIFY,
 779                              USB_DIR_OUT | USB_TYPE_VENDOR |
 780                              USB_RECIP_INTERFACE,
 781                              dev->channel,
 782                              0,
 783                              imode,
 784                              sizeof(*imode),
 785                              100);
 786
 787         kfree(imode);
 788
 789         return (rc > 0) ? 0 : rc;
 790 }
 791
 792 /* blink LED's for finding the this interface */
 793 static int gs_usb_set_phys_id(struct net_device *dev,
 794                               enum ethtool_phys_id_state state)
 795 {
 796         int rc = 0;
 797
 798         switch (state) {
 799         case ETHTOOL_ID_ACTIVE:
 800                 rc = gs_usb_set_identify(dev, GS_CAN_IDENTIFY_ON);
 801                 break;
 802         case ETHTOOL_ID_INACTIVE:
 803                 rc = gs_usb_set_identify(dev, GS_CAN_IDENTIFY_OFF);
 804                 break;
 805         default:
 806                 break;
 807         }
 808
 809         return rc;
 810 }
 811
 812 static const struct ethtool_ops gs_usb_ethtool_ops = {
 813         .set_phys_id = gs_usb_set_phys_id,
 814 };
 815
 816 static struct gs_can *gs_make_candev(unsigned int channel,
 817                                      struct usb_interface *intf,
 818                                      struct gs_device_config *dconf)
 819 {
 820         struct gs_can *dev;
 821         struct net_device *netdev;
 822         int rc;
 823         struct gs_device_bt_const *bt_const;
 824         u32 feature;
 825
 826         bt_const = kmalloc(sizeof(*bt_const), GFP_KERNEL);
 827         if (!bt_const)
 828                 return ERR_PTR(-ENOMEM);
 829
 830         /* fetch bit timing constants */
 831         rc = usb_control_msg(interface_to_usbdev(intf),
 832                              usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
 833                              GS_USB_BREQ_BT_CONST,
 834                              USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 835                              channel,
 836                              0,
 837                              bt_const,
 838                              sizeof(*bt_const),
 839                              1000);
 840
 841         if (rc < 0) {
 842                 dev_err(&intf->dev,
 843                         "Couldn't get bit timing const for channel (err=%d)\n",
 844                         rc);
 845                 kfree(bt_const);
 846                 return ERR_PTR(rc);
 847         }
 848
 849         /* create netdev */
 850         netdev = alloc_candev(sizeof(struct gs_can), GS_MAX_TX_URBS);
 851         if (!netdev) {
 852                 dev_err(&intf->dev, "Couldn't allocate candev\n");
 853                 kfree(bt_const);
 854                 return ERR_PTR(-ENOMEM);
 855         }
 856
 857         dev = netdev_priv(netdev);
 858
 859         netdev->netdev_ops = &gs_usb_netdev_ops;
 860
 861         netdev->flags |= IFF_ECHO; /* we support full roundtrip echo */
 862
 863         /* dev setup */
 864         strcpy(dev->bt_const.name, "gs_usb");
 865         dev->bt_const.tseg1_min = le32_to_cpu(bt_const->tseg1_min);
 866         dev->bt_const.tseg1_max = le32_to_cpu(bt_const->tseg1_max);
 867         dev->bt_const.tseg2_min = le32_to_cpu(bt_const->tseg2_min);
 868         dev->bt_const.tseg2_max = le32_to_cpu(bt_const->tseg2_max);
 869         dev->bt_const.sjw_max = le32_to_cpu(bt_const->sjw_max);
 870         dev->bt_const.brp_min = le32_to_cpu(bt_const->brp_min);
 871         dev->bt_const.brp_max = le32_to_cpu(bt_const->brp_max);
 872         dev->bt_const.brp_inc = le32_to_cpu(bt_const->brp_inc);
 873
 874         dev->udev = interface_to_usbdev(intf);
 875         dev->iface = intf;
 876         dev->netdev = netdev;
 877         dev->channel = channel;
 878
 879         init_usb_anchor(&dev->tx_submitted);
 880         atomic_set(&dev->active_tx_urbs, 0);
 881         spin_lock_init(&dev->tx_ctx_lock);
 882         for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
 883                 dev->tx_context[rc].dev = dev;
 884                 dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
 885         }
 886
 887         /* can setup */
 888         dev->can.state = CAN_STATE_STOPPED;
 889         dev->can.clock.freq = le32_to_cpu(bt_const->fclk_can);
 890         dev->can.bittiming_const = &dev->bt_const;
 891         dev->can.do_set_bittiming = gs_usb_set_bittiming;
 892
 893         dev->can.ctrlmode_supported = 0;
 894
 895         feature = le32_to_cpu(bt_const->feature);
 896         if (feature & GS_CAN_FEATURE_LISTEN_ONLY)
 897                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY;
 898
 899         if (feature & GS_CAN_FEATURE_LOOP_BACK)
 900                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_LOOPBACK;
 901
 902         if (feature & GS_CAN_FEATURE_TRIPLE_SAMPLE)
 903                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
 904
 905         if (feature & GS_CAN_FEATURE_ONE_SHOT)
 906                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_ONE_SHOT;
 907
 908         SET_NETDEV_DEV(netdev, &intf->dev);
 909
 910         if (le32_to_cpu(dconf->sw_version) > 1)
 911                 if (feature & GS_CAN_FEATURE_IDENTIFY)
 912                         netdev->ethtool_ops = &gs_usb_ethtool_ops;
 913
 914         kfree(bt_const);
 915
 916         rc = register_candev(dev->netdev);
 917         if (rc) {
 918                 free_candev(dev->netdev);
 919                 dev_err(&intf->dev, "Couldn't register candev (err=%d)\n", rc);
 920                 return ERR_PTR(rc);
 921         }
 922
 923         return dev;
 924 }
 925
 926 static void gs_destroy_candev(struct gs_can *dev)
 927 {
 928         unregister_candev(dev->netdev);
 929         usb_kill_anchored_urbs(&dev->tx_submitted);
 930         free_candev(dev->netdev);
 931 }
 932
 933 static int gs_usb_probe(struct usb_interface *intf,
 934                         const struct usb_device_id *id)
 935 {
 936         struct gs_usb *dev;
 937         int rc = -ENOMEM;
 938         unsigned int icount, i;
 939         struct gs_host_config *hconf;
 940         struct gs_device_config *dconf;
 941
 942         hconf = kmalloc(sizeof(*hconf), GFP_KERNEL);
 943         if (!hconf)
 944                 return -ENOMEM;
 945
 946         hconf->byte_order = cpu_to_le32(0x0000beef);
 947
 948         /* send host config */
 949         rc = usb_control_msg(interface_to_usbdev(intf),
 950                              usb_sndctrlpipe(interface_to_usbdev(intf), 0),
 951                              GS_USB_BREQ_HOST_FORMAT,
 952                              USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 953                              1,
 954                              intf->cur_altsetting->desc.bInterfaceNumber,
 955                              hconf,
 956                              sizeof(*hconf),
 957                              1000);
 958
 959         kfree(hconf);
 960
 961         if (rc < 0) {
 962                 dev_err(&intf->dev, "Couldn't send data format (err=%d)\n",
 963                         rc);
 964                 return rc;
 965         }
 966
 967         dconf = kmalloc(sizeof(*dconf), GFP_KERNEL);
 968         if (!dconf)
 969                 return -ENOMEM;
 970
 971         /* read device config */
 972         rc = usb_control_msg(interface_to_usbdev(intf),
 973                              usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
 974                              GS_USB_BREQ_DEVICE_CONFIG,
 975                              USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 976                              1,
 977                              intf->cur_altsetting->desc.bInterfaceNumber,
 978                              dconf,
 979                              sizeof(*dconf),
 980                              1000);
 981         if (rc < 0) {
 982                 dev_err(&intf->dev, "Couldn't get device config: (err=%d)\n",
 983                         rc);
 984                 kfree(dconf);
 985                 return rc;
 986         }
 987
 988         icount = dconf->icount + 1;
 989         dev_info(&intf->dev, "Configuring for %d interfaces\n", icount);
 990
 991         if (icount > GS_MAX_INTF) {
 992                 dev_err(&intf->dev,
 993                         "Driver cannot handle more that %d CAN interfaces\n",
 994                         GS_MAX_INTF);
 995                 kfree(dconf);
 996                 return -EINVAL;
 997         }
 998
 999         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1000         if (!dev) {
1001                 kfree(dconf);
1002                 return -ENOMEM;
1003         }
1004
1005         init_usb_anchor(&dev->rx_submitted);
1006
1007         usb_set_intfdata(intf, dev);
1008         dev->udev = interface_to_usbdev(intf);
1009
1010         for (i = 0; i < icount; i++) {
1011                 dev->canch[i] = gs_make_candev(i, intf, dconf);
1012                 if (IS_ERR_OR_NULL(dev->canch[i])) {
1013                         /* save error code to return later */
1014                         rc = PTR_ERR(dev->canch[i]);
1015
1016                         /* on failure destroy previously created candevs */
1017                         icount = i;
1018                         for (i = 0; i < icount; i++)
1019                                 gs_destroy_candev(dev->canch[i]);
1020
1021                         usb_kill_anchored_urbs(&dev->rx_submitted);
1022                         kfree(dconf);
1023                         kfree(dev);
1024                         return rc;
1025                 }
1026                 dev->canch[i]->parent = dev;
1027         }
1028
1029         kfree(dconf);
1030
1031         return 0;
1032 }
1033
1034 static void gs_usb_disconnect(struct usb_interface *intf)
1035 {
1036         unsigned i;
1037         struct gs_usb *dev = usb_get_intfdata(intf);
1038         usb_set_intfdata(intf, NULL);
1039
1040         if (!dev) {
1041                 dev_err(&intf->dev, "Disconnect (nodata)\n");
1042                 return;
1043         }
1044
1045         for (i = 0; i < GS_MAX_INTF; i++)
1046                 if (dev->canch[i])
1047                         gs_destroy_candev(dev->canch[i]);
1048
1049         usb_kill_anchored_urbs(&dev->rx_submitted);
1050         kfree(dev);
1051 }
1052
1053 static const struct usb_device_id gs_usb_table[] = {
1054         { USB_DEVICE_INTERFACE_NUMBER(USB_GSUSB_1_VENDOR_ID,
1055                                       USB_GSUSB_1_PRODUCT_ID, 0) },
1056         { USB_DEVICE_INTERFACE_NUMBER(USB_CANDLELIGHT_VENDOR_ID,
1057                                       USB_CANDLELIGHT_PRODUCT_ID, 0) },
1058         {} /* Terminating entry */
1059 };
1060
1061 MODULE_DEVICE_TABLE(usb, gs_usb_table);
1062
1063 static struct usb_driver gs_usb_driver = {
1064         .name       = "gs_usb",
1065         .probe      = gs_usb_probe,
1066         .disconnect = gs_usb_disconnect,
1067         .id_table   = gs_usb_table,
1068 };
1069
1070 module_usb_driver(gs_usb_driver);
1071
1072 MODULE_AUTHOR("Maximilian Schneider <mws@schneidersoft.net>");
1073 MODULE_DESCRIPTION(
1074 "Socket CAN device driver for Geschwister Schneider Technologie-, "
1075 "Entwicklungs- und Vertriebs UG. USB2.0 to CAN interfaces\n"
1076 "and bytewerk.org candleLight USB CAN interfaces.");
1077 MODULE_LICENSE("GPL v2");