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/ethtool.h>
  13 #include <linux/init.h>
  14 #include <linux/signal.h>
  15 #include <linux/module.h>
  16 #include <linux/netdevice.h>
  17 #include <linux/usb.h>
  18
  19 #include <linux/can.h>
  20 #include <linux/can/dev.h>
  21 #include <linux/can/error.h>
  22
  23 /* Device specific constants */
  24 #define USB_GSUSB_1_VENDOR_ID      0x1d50
  25 #define USB_GSUSB_1_PRODUCT_ID     0x606f
  26
  27 #define USB_CANDLELIGHT_VENDOR_ID  0x1209
  28 #define USB_CANDLELIGHT_PRODUCT_ID 0x2323
  29
  30 #define GSUSB_ENDPOINT_IN          1
  31 #define GSUSB_ENDPOINT_OUT         2
  32
  33 /* Device specific constants */
  34 enum gs_usb_breq {
  35         GS_USB_BREQ_HOST_FORMAT = 0,
  36         GS_USB_BREQ_BITTIMING,
  37         GS_USB_BREQ_MODE,
  38         GS_USB_BREQ_BERR,
  39         GS_USB_BREQ_BT_CONST,
  40         GS_USB_BREQ_DEVICE_CONFIG,
  41         GS_USB_BREQ_TIMESTAMP,
  42         GS_USB_BREQ_IDENTIFY,
  43 };
  44
  45 enum gs_can_mode {
  46         /* reset a channel. turns it off */
  47         GS_CAN_MODE_RESET = 0,
  48         /* starts a channel */
  49         GS_CAN_MODE_START
  50 };
  51
  52 enum gs_can_state {
  53         GS_CAN_STATE_ERROR_ACTIVE = 0,
  54         GS_CAN_STATE_ERROR_WARNING,
  55         GS_CAN_STATE_ERROR_PASSIVE,
  56         GS_CAN_STATE_BUS_OFF,
  57         GS_CAN_STATE_STOPPED,
  58         GS_CAN_STATE_SLEEPING
  59 };
  60
  61 enum gs_can_identify_mode {
  62         GS_CAN_IDENTIFY_OFF = 0,
  63         GS_CAN_IDENTIFY_ON
  64 };
  65
  66 /* data types passed between host and device */
  67 struct 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
  75 struct 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          BIT(0)
  86 #define GS_CAN_MODE_LOOP_BACK            BIT(1)
  87 #define GS_CAN_MODE_TRIPLE_SAMPLE        BIT(2)
  88 #define GS_CAN_MODE_ONE_SHOT             BIT(3)
  89
  90 struct gs_device_mode {
  91         u32 mode;
  92         u32 flags;
  93 } __packed;
  94
  95 struct gs_device_state {
  96         u32 state;
  97         u32 rxerr;
  98         u32 txerr;
  99 } __packed;
 100
 101 struct 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 struct gs_identify_mode {
 110         u32 mode;
 111 } __packed;
 112
 113 #define GS_CAN_FEATURE_LISTEN_ONLY      BIT(0)
 114 #define GS_CAN_FEATURE_LOOP_BACK        BIT(1)
 115 #define GS_CAN_FEATURE_TRIPLE_SAMPLE    BIT(2)
 116 #define GS_CAN_FEATURE_ONE_SHOT         BIT(3)
 117 #define GS_CAN_FEATURE_HW_TIMESTAMP     BIT(4)
 118 #define GS_CAN_FEATURE_IDENTIFY         BIT(5)
 119
 120 struct gs_device_bt_const {
 121         u32 feature;
 122         u32 fclk_can;
 123         u32 tseg1_min;
 124         u32 tseg1_max;
 125         u32 tseg2_min;
 126         u32 tseg2_max;
 127         u32 sjw_max;
 128         u32 brp_min;
 129         u32 brp_max;
 130         u32 brp_inc;
 131 } __packed;
 132
 133 #define GS_CAN_FLAG_OVERFLOW 1
 134
 135 struct gs_host_frame {
 136         u32 echo_id;
 137         u32 can_id;
 138
 139         u8 can_dlc;
 140         u8 channel;
 141         u8 flags;
 142         u8 reserved;
 143
 144         u8 data[8];
 145 } __packed;
 146 /* The GS USB devices make use of the same flags and masks as in
 147  * linux/can.h and linux/can/error.h, and no additional mapping is necessary.
 148  */
 149
 150 /* Only send a max of GS_MAX_TX_URBS frames per channel at a time. */
 151 #define GS_MAX_TX_URBS 10
 152 /* Only launch a max of GS_MAX_RX_URBS usb requests at a time. */
 153 #define GS_MAX_RX_URBS 30
 154 /* Maximum number of interfaces the driver supports per device.
 155  * Current hardware only supports 2 interfaces. The future may vary.
 156  */
 157 #define GS_MAX_INTF 2
 158
 159 struct gs_tx_context {
 160         struct gs_can *dev;
 161         unsigned int echo_id;
 162 };
 163
 164 struct gs_can {
 165         struct can_priv can; /* must be the first member */
 166
 167         struct gs_usb *parent;
 168
 169         struct net_device *netdev;
 170         struct usb_device *udev;
 171         struct usb_interface *iface;
 172
 173         struct can_bittiming_const bt_const;
 174         unsigned int channel;   /* channel number */
 175
 176         /* This lock prevents a race condition between xmit and receive. */
 177         spinlock_t tx_ctx_lock;
 178         struct gs_tx_context tx_context[GS_MAX_TX_URBS];
 179
 180         struct usb_anchor tx_submitted;
 181         atomic_t active_tx_urbs;
 182 };
 183
 184 /* usb interface struct */
 185 struct gs_usb {
 186         struct gs_can *canch[GS_MAX_INTF];
 187         struct usb_anchor rx_submitted;
 188         atomic_t active_channels;
 189         struct usb_device *udev;
 190 };
 191
 192 /* 'allocate' a tx context.
 193  * returns a valid tx context or NULL if there is no space.
 194  */
 195 static struct gs_tx_context *gs_alloc_tx_context(struct gs_can *dev)
 196 {
 197         int i = 0;
 198         unsigned long flags;
 199
 200         spin_lock_irqsave(&dev->tx_ctx_lock, flags);
 201
 202         for (; i < GS_MAX_TX_URBS; i++) {
 203                 if (dev->tx_context[i].echo_id == GS_MAX_TX_URBS) {
 204                         dev->tx_context[i].echo_id = i;
 205                         spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
 206                         return &dev->tx_context[i];
 207                 }
 208         }
 209
 210         spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
 211         return NULL;
 212 }
 213
 214 /* releases a tx context
 215  */
 216 static void gs_free_tx_context(struct gs_tx_context *txc)
 217 {
 218         txc->echo_id = GS_MAX_TX_URBS;
 219 }
 220
 221 /* Get a tx context by id.
 222  */
 223 static struct gs_tx_context *gs_get_tx_context(struct gs_can *dev,
 224                                                unsigned int id)
 225 {
 226         unsigned long flags;
 227
 228         if (id < GS_MAX_TX_URBS) {
 229                 spin_lock_irqsave(&dev->tx_ctx_lock, flags);
 230                 if (dev->tx_context[id].echo_id == id) {
 231                         spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
 232                         return &dev->tx_context[id];
 233                 }
 234                 spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
 235         }
 236         return NULL;
 237 }
 238
 239 static int gs_cmd_reset(struct gs_can *gsdev)
 240 {
 241         struct gs_device_mode *dm;
 242         struct usb_interface *intf = gsdev->iface;
 243         int rc;
 244
 245         dm = kzalloc(sizeof(*dm), GFP_KERNEL);
 246         if (!dm)
 247                 return -ENOMEM;
 248
 249         dm->mode = GS_CAN_MODE_RESET;
 250
 251         rc = usb_control_msg(interface_to_usbdev(intf),
 252                              usb_sndctrlpipe(interface_to_usbdev(intf), 0),
 253                              GS_USB_BREQ_MODE,
 254                              USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 255                              gsdev->channel,
 256                              0,
 257                              dm,
 258                              sizeof(*dm),
 259                              1000);
 260
 261         kfree(dm);
 262
 263         return rc;
 264 }
 265
 266 static void gs_update_state(struct gs_can *dev, struct can_frame *cf)
 267 {
 268         struct can_device_stats *can_stats = &dev->can.can_stats;
 269
 270         if (cf->can_id & CAN_ERR_RESTARTED) {
 271                 dev->can.state = CAN_STATE_ERROR_ACTIVE;
 272                 can_stats->restarts++;
 273         } else if (cf->can_id & CAN_ERR_BUSOFF) {
 274                 dev->can.state = CAN_STATE_BUS_OFF;
 275                 can_stats->bus_off++;
 276         } else if (cf->can_id & CAN_ERR_CRTL) {
 277                 if ((cf->data[1] & CAN_ERR_CRTL_TX_WARNING) ||
 278                     (cf->data[1] & CAN_ERR_CRTL_RX_WARNING)) {
 279                         dev->can.state = CAN_STATE_ERROR_WARNING;
 280                         can_stats->error_warning++;
 281                 } else if ((cf->data[1] & CAN_ERR_CRTL_TX_PASSIVE) ||
 282                            (cf->data[1] & CAN_ERR_CRTL_RX_PASSIVE)) {
 283                         dev->can.state = CAN_STATE_ERROR_PASSIVE;
 284                         can_stats->error_passive++;
 285                 } else {
 286                         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 287                 }
 288         }
 289 }
 290
 291 static void gs_usb_receive_bulk_callback(struct urb *urb)
 292 {
 293         struct gs_usb *usbcan = urb->context;
 294         struct gs_can *dev;
 295         struct net_device *netdev;
 296         int rc;
 297         struct net_device_stats *stats;
 298         struct gs_host_frame *hf = urb->transfer_buffer;
 299         struct gs_tx_context *txc;
 300         struct can_frame *cf;
 301         struct sk_buff *skb;
 302
 303         BUG_ON(!usbcan);
 304
 305         switch (urb->status) {
 306         case 0: /* success */
 307                 break;
 308         case -ENOENT:
 309         case -ESHUTDOWN:
 310                 return;
 311         default:
 312                 /* do not resubmit aborted urbs. eg: when device goes down */
 313                 return;
 314         }
 315
 316         /* device reports out of range channel id */
 317         if (hf->channel >= GS_MAX_INTF)
 318                 goto resubmit_urb;
 319
 320         dev = usbcan->canch[hf->channel];
 321
 322         netdev = dev->netdev;
 323         stats = &netdev->stats;
 324
 325         if (!netif_device_present(netdev))
 326                 return;
 327
 328         if (hf->echo_id == -1) { /* normal rx */
 329                 skb = alloc_can_skb(dev->netdev, &cf);
 330                 if (!skb)
 331                         return;
 332
 333                 cf->can_id = hf->can_id;
 334
 335                 can_frame_set_cc_len(cf, hf->can_dlc, dev->can.ctrlmode);
 336                 memcpy(cf->data, hf->data, 8);
 337
 338                 /* ERROR frames tell us information about the controller */
 339                 if (hf->can_id & CAN_ERR_FLAG)
 340                         gs_update_state(dev, cf);
 341
 342                 netdev->stats.rx_packets++;
 343                 netdev->stats.rx_bytes += hf->can_dlc;
 344
 345                 netif_rx(skb);
 346         } else { /* echo_id == hf->echo_id */
 347                 if (hf->echo_id >= GS_MAX_TX_URBS) {
 348                         netdev_err(netdev,
 349                                    "Unexpected out of range echo id %d\n",
 350                                    hf->echo_id);
 351                         goto resubmit_urb;
 352                 }
 353
 354                 netdev->stats.tx_packets++;
 355                 netdev->stats.tx_bytes += hf->can_dlc;
 356
 357                 txc = gs_get_tx_context(dev, hf->echo_id);
 358
 359                 /* bad devices send bad echo_ids. */
 360                 if (!txc) {
 361                         netdev_err(netdev,
 362                                    "Unexpected unused echo id %d\n",
 363                                    hf->echo_id);
 364                         goto resubmit_urb;
 365                 }
 366
 367                 can_get_echo_skb(netdev, hf->echo_id);
 368
 369                 gs_free_tx_context(txc);
 370
 371                 atomic_dec(&dev->active_tx_urbs);
 372
 373                 netif_wake_queue(netdev);
 374         }
 375
 376         if (hf->flags & GS_CAN_FLAG_OVERFLOW) {
 377                 skb = alloc_can_err_skb(netdev, &cf);
 378                 if (!skb)
 379                         goto resubmit_urb;
 380
 381                 cf->can_id |= CAN_ERR_CRTL;
 382                 cf->len = CAN_ERR_DLC;
 383                 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 384                 stats->rx_over_errors++;
 385                 stats->rx_errors++;
 386                 netif_rx(skb);
 387         }
 388
 389  resubmit_urb:
 390         usb_fill_bulk_urb(urb,
 391                           usbcan->udev,
 392                           usb_rcvbulkpipe(usbcan->udev, GSUSB_ENDPOINT_IN),
 393                           hf,
 394                           sizeof(struct gs_host_frame),
 395                           gs_usb_receive_bulk_callback,
 396                           usbcan
 397                           );
 398
 399         rc = usb_submit_urb(urb, GFP_ATOMIC);
 400
 401         /* USB failure take down all interfaces */
 402         if (rc == -ENODEV) {
 403                 for (rc = 0; rc < GS_MAX_INTF; rc++) {
 404                         if (usbcan->canch[rc])
 405                                 netif_device_detach(usbcan->canch[rc]->netdev);
 406                 }
 407         }
 408 }
 409
 410 static int gs_usb_set_bittiming(struct net_device *netdev)
 411 {
 412         struct gs_can *dev = netdev_priv(netdev);
 413         struct can_bittiming *bt = &dev->can.bittiming;
 414         struct usb_interface *intf = dev->iface;
 415         int rc;
 416         struct gs_device_bittiming *dbt;
 417
 418         dbt = kmalloc(sizeof(*dbt), GFP_KERNEL);
 419         if (!dbt)
 420                 return -ENOMEM;
 421
 422         dbt->prop_seg = bt->prop_seg;
 423         dbt->phase_seg1 = bt->phase_seg1;
 424         dbt->phase_seg2 = bt->phase_seg2;
 425         dbt->sjw = bt->sjw;
 426         dbt->brp = bt->brp;
 427
 428         /* request bit timings */
 429         rc = usb_control_msg(interface_to_usbdev(intf),
 430                              usb_sndctrlpipe(interface_to_usbdev(intf), 0),
 431                              GS_USB_BREQ_BITTIMING,
 432                              USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 433                              dev->channel,
 434                              0,
 435                              dbt,
 436                              sizeof(*dbt),
 437                              1000);
 438
 439         kfree(dbt);
 440
 441         if (rc < 0)
 442                 dev_err(netdev->dev.parent, "Couldn't set bittimings (err=%d)",
 443                         rc);
 444
 445         return (rc > 0) ? 0 : rc;
 446 }
 447
 448 static void gs_usb_xmit_callback(struct urb *urb)
 449 {
 450         struct gs_tx_context *txc = urb->context;
 451         struct gs_can *dev = txc->dev;
 452         struct net_device *netdev = dev->netdev;
 453
 454         if (urb->status)
 455                 netdev_info(netdev, "usb xmit fail %d\n", txc->echo_id);
 456
 457         usb_free_coherent(urb->dev,
 458                           urb->transfer_buffer_length,
 459                           urb->transfer_buffer,
 460                           urb->transfer_dma);
 461 }
 462
 463 static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb,
 464                                      struct net_device *netdev)
 465 {
 466         struct gs_can *dev = netdev_priv(netdev);
 467         struct net_device_stats *stats = &dev->netdev->stats;
 468         struct urb *urb;
 469         struct gs_host_frame *hf;
 470         struct can_frame *cf;
 471         int rc;
 472         unsigned int idx;
 473         struct gs_tx_context *txc;
 474
 475         if (can_dropped_invalid_skb(netdev, skb))
 476                 return NETDEV_TX_OK;
 477
 478         /* find an empty context to keep track of transmission */
 479         txc = gs_alloc_tx_context(dev);
 480         if (!txc)
 481                 return NETDEV_TX_BUSY;
 482
 483         /* create a URB, and a buffer for it */
 484         urb = usb_alloc_urb(0, GFP_ATOMIC);
 485         if (!urb)
 486                 goto nomem_urb;
 487
 488         hf = usb_alloc_coherent(dev->udev, sizeof(*hf), GFP_ATOMIC,
 489                                 &urb->transfer_dma);
 490         if (!hf) {
 491                 netdev_err(netdev, "No memory left for USB buffer\n");
 492                 goto nomem_hf;
 493         }
 494
 495         idx = txc->echo_id;
 496
 497         if (idx >= GS_MAX_TX_URBS) {
 498                 netdev_err(netdev, "Invalid tx context %d\n", idx);
 499                 goto badidx;
 500         }
 501
 502         hf->echo_id = idx;
 503         hf->channel = dev->channel;
 504
 505         cf = (struct can_frame *)skb->data;
 506
 507         hf->can_id = cf->can_id;
 508         hf->can_dlc = can_get_cc_dlc(cf, dev->can.ctrlmode);
 509
 510         memcpy(hf->data, cf->data, cf->len);
 511
 512         usb_fill_bulk_urb(urb, dev->udev,
 513                           usb_sndbulkpipe(dev->udev, GSUSB_ENDPOINT_OUT),
 514                           hf,
 515                           sizeof(*hf),
 516                           gs_usb_xmit_callback,
 517                           txc);
 518
 519         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 520         usb_anchor_urb(urb, &dev->tx_submitted);
 521
 522         can_put_echo_skb(skb, netdev, idx);
 523
 524         atomic_inc(&dev->active_tx_urbs);
 525
 526         rc = usb_submit_urb(urb, GFP_ATOMIC);
 527         if (unlikely(rc)) {                     /* usb send failed */
 528                 atomic_dec(&dev->active_tx_urbs);
 529
 530                 can_free_echo_skb(netdev, idx);
 531                 gs_free_tx_context(txc);
 532
 533                 usb_unanchor_urb(urb);
 534                 usb_free_coherent(dev->udev,
 535                                   sizeof(*hf),
 536                                   hf,
 537                                   urb->transfer_dma);
 538
 539                 if (rc == -ENODEV) {
 540                         netif_device_detach(netdev);
 541                 } else {
 542                         netdev_err(netdev, "usb_submit failed (err=%d)\n", rc);
 543                         stats->tx_dropped++;
 544                 }
 545         } else {
 546                 /* Slow down tx path */
 547                 if (atomic_read(&dev->active_tx_urbs) >= GS_MAX_TX_URBS)
 548                         netif_stop_queue(netdev);
 549         }
 550
 551         /* let usb core take care of this urb */
 552         usb_free_urb(urb);
 553
 554         return NETDEV_TX_OK;
 555
 556  badidx:
 557         usb_free_coherent(dev->udev,
 558                           sizeof(*hf),
 559                           hf,
 560                           urb->transfer_dma);
 561  nomem_hf:
 562         usb_free_urb(urb);
 563
 564  nomem_urb:
 565         gs_free_tx_context(txc);
 566         dev_kfree_skb(skb);
 567         stats->tx_dropped++;
 568         return NETDEV_TX_OK;
 569 }
 570
 571 static int gs_can_open(struct net_device *netdev)
 572 {
 573         struct gs_can *dev = netdev_priv(netdev);
 574         struct gs_usb *parent = dev->parent;
 575         int rc, i;
 576         struct gs_device_mode *dm;
 577         u32 ctrlmode;
 578
 579         rc = open_candev(netdev);
 580         if (rc)
 581                 return rc;
 582
 583         if (atomic_add_return(1, &parent->active_channels) == 1) {
 584                 for (i = 0; i < GS_MAX_RX_URBS; i++) {
 585                         struct urb *urb;
 586                         u8 *buf;
 587
 588                         /* alloc rx urb */
 589                         urb = usb_alloc_urb(0, GFP_KERNEL);
 590                         if (!urb)
 591                                 return -ENOMEM;
 592
 593                         /* alloc rx buffer */
 594                         buf = usb_alloc_coherent(dev->udev,
 595                                                  sizeof(struct gs_host_frame),
 596                                                  GFP_KERNEL,
 597                                                  &urb->transfer_dma);
 598                         if (!buf) {
 599                                 netdev_err(netdev,
 600                                            "No memory left for USB buffer\n");
 601                                 usb_free_urb(urb);
 602                                 return -ENOMEM;
 603                         }
 604
 605                         /* fill, anchor, and submit rx urb */
 606                         usb_fill_bulk_urb(urb,
 607                                           dev->udev,
 608                                           usb_rcvbulkpipe(dev->udev,
 609                                                           GSUSB_ENDPOINT_IN),
 610                                           buf,
 611                                           sizeof(struct gs_host_frame),
 612                                           gs_usb_receive_bulk_callback,
 613                                           parent);
 614                         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 615
 616                         usb_anchor_urb(urb, &parent->rx_submitted);
 617
 618                         rc = usb_submit_urb(urb, GFP_KERNEL);
 619                         if (rc) {
 620                                 if (rc == -ENODEV)
 621                                         netif_device_detach(dev->netdev);
 622
 623                                 netdev_err(netdev,
 624                                            "usb_submit failed (err=%d)\n",
 625                                            rc);
 626
 627                                 usb_unanchor_urb(urb);
 628                                 usb_free_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 |
 667                              USB_RECIP_INTERFACE,
 668                              dev->channel,
 669                              0,
 670                              dm,
 671                              sizeof(*dm),
 672                              1000);
 673
 674         if (rc < 0) {
 675                 netdev_err(netdev, "Couldn't start device (err=%d)\n", rc);
 676                 kfree(dm);
 677                 return rc;
 678         }
 679
 680         kfree(dm);
 681
 682         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 683
 684         if (!(dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY))
 685                 netif_start_queue(netdev);
 686
 687         return 0;
 688 }
 689
 690 static int gs_can_close(struct net_device *netdev)
 691 {
 692         int rc;
 693         struct gs_can *dev = netdev_priv(netdev);
 694         struct gs_usb *parent = dev->parent;
 695
 696         netif_stop_queue(netdev);
 697
 698         /* Stop polling */
 699         if (atomic_dec_and_test(&parent->active_channels))
 700                 usb_kill_anchored_urbs(&parent->rx_submitted);
 701
 702         /* Stop sending URBs */
 703         usb_kill_anchored_urbs(&dev->tx_submitted);
 704         atomic_set(&dev->active_tx_urbs, 0);
 705
 706         /* reset the device */
 707         rc = gs_cmd_reset(dev);
 708         if (rc < 0)
 709                 netdev_warn(netdev, "Couldn't shutdown device (err=%d)", rc);
 710
 711         /* reset tx contexts */
 712         for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
 713                 dev->tx_context[rc].dev = dev;
 714                 dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
 715         }
 716
 717         /* close the netdev */
 718         close_candev(netdev);
 719
 720         return 0;
 721 }
 722
 723 static const struct net_device_ops gs_usb_netdev_ops = {
 724         .ndo_open = gs_can_open,
 725         .ndo_stop = gs_can_close,
 726         .ndo_start_xmit = gs_can_start_xmit,
 727         .ndo_change_mtu = can_change_mtu,
 728 };
 729
 730 static int gs_usb_set_identify(struct net_device *netdev, bool do_identify)
 731 {
 732         struct gs_can *dev = netdev_priv(netdev);
 733         struct gs_identify_mode *imode;
 734         int rc;
 735
 736         imode = kmalloc(sizeof(*imode), GFP_KERNEL);
 737
 738         if (!imode)
 739                 return -ENOMEM;
 740
 741         if (do_identify)
 742                 imode->mode = GS_CAN_IDENTIFY_ON;
 743         else
 744                 imode->mode = GS_CAN_IDENTIFY_OFF;
 745
 746         rc = usb_control_msg(interface_to_usbdev(dev->iface),
 747                              usb_sndctrlpipe(interface_to_usbdev(dev->iface),
 748                                              0),
 749                              GS_USB_BREQ_IDENTIFY,
 750                              USB_DIR_OUT | USB_TYPE_VENDOR |
 751                              USB_RECIP_INTERFACE,
 752                              dev->channel,
 753                              0,
 754                              imode,
 755                              sizeof(*imode),
 756                              100);
 757
 758         kfree(imode);
 759
 760         return (rc > 0) ? 0 : rc;
 761 }
 762
 763 /* blink LED's for finding the this interface */
 764 static int gs_usb_set_phys_id(struct net_device *dev,
 765                               enum ethtool_phys_id_state state)
 766 {
 767         int rc = 0;
 768
 769         switch (state) {
 770         case ETHTOOL_ID_ACTIVE:
 771                 rc = gs_usb_set_identify(dev, GS_CAN_IDENTIFY_ON);
 772                 break;
 773         case ETHTOOL_ID_INACTIVE:
 774                 rc = gs_usb_set_identify(dev, GS_CAN_IDENTIFY_OFF);
 775                 break;
 776         default:
 777                 break;
 778         }
 779
 780         return rc;
 781 }
 782
 783 static const struct ethtool_ops gs_usb_ethtool_ops = {
 784         .set_phys_id = gs_usb_set_phys_id,
 785 };
 786
 787 static struct gs_can *gs_make_candev(unsigned int channel,
 788                                      struct usb_interface *intf,
 789                                      struct gs_device_config *dconf)
 790 {
 791         struct gs_can *dev;
 792         struct net_device *netdev;
 793         int rc;
 794         struct gs_device_bt_const *bt_const;
 795
 796         bt_const = kmalloc(sizeof(*bt_const), GFP_KERNEL);
 797         if (!bt_const)
 798                 return ERR_PTR(-ENOMEM);
 799
 800         /* fetch bit timing constants */
 801         rc = usb_control_msg(interface_to_usbdev(intf),
 802                              usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
 803                              GS_USB_BREQ_BT_CONST,
 804                              USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 805                              channel,
 806                              0,
 807                              bt_const,
 808                              sizeof(*bt_const),
 809                              1000);
 810
 811         if (rc < 0) {
 812                 dev_err(&intf->dev,
 813                         "Couldn't get bit timing const for channel (err=%d)\n",
 814                         rc);
 815                 kfree(bt_const);
 816                 return ERR_PTR(rc);
 817         }
 818
 819         /* create netdev */
 820         netdev = alloc_candev(sizeof(struct gs_can), GS_MAX_TX_URBS);
 821         if (!netdev) {
 822                 dev_err(&intf->dev, "Couldn't allocate candev\n");
 823                 kfree(bt_const);
 824                 return ERR_PTR(-ENOMEM);
 825         }
 826
 827         dev = netdev_priv(netdev);
 828
 829         netdev->netdev_ops = &gs_usb_netdev_ops;
 830
 831         netdev->flags |= IFF_ECHO; /* we support full roundtrip echo */
 832
 833         /* dev setup */
 834         strcpy(dev->bt_const.name, "gs_usb");
 835         dev->bt_const.tseg1_min = bt_const->tseg1_min;
 836         dev->bt_const.tseg1_max = bt_const->tseg1_max;
 837         dev->bt_const.tseg2_min = bt_const->tseg2_min;
 838         dev->bt_const.tseg2_max = bt_const->tseg2_max;
 839         dev->bt_const.sjw_max = bt_const->sjw_max;
 840         dev->bt_const.brp_min = bt_const->brp_min;
 841         dev->bt_const.brp_max = bt_const->brp_max;
 842         dev->bt_const.brp_inc = bt_const->brp_inc;
 843
 844         dev->udev = interface_to_usbdev(intf);
 845         dev->iface = intf;
 846         dev->netdev = netdev;
 847         dev->channel = channel;
 848
 849         init_usb_anchor(&dev->tx_submitted);
 850         atomic_set(&dev->active_tx_urbs, 0);
 851         spin_lock_init(&dev->tx_ctx_lock);
 852         for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
 853                 dev->tx_context[rc].dev = dev;
 854                 dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
 855         }
 856
 857         /* can setup */
 858         dev->can.state = CAN_STATE_STOPPED;
 859         dev->can.clock.freq = bt_const->fclk_can;
 860         dev->can.bittiming_const = &dev->bt_const;
 861         dev->can.do_set_bittiming = gs_usb_set_bittiming;
 862
 863         dev->can.ctrlmode_supported = CAN_CTRLMODE_CC_LEN8_DLC;
 864
 865         if (bt_const->feature & GS_CAN_FEATURE_LISTEN_ONLY)
 866                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY;
 867
 868         if (bt_const->feature & GS_CAN_FEATURE_LOOP_BACK)
 869                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_LOOPBACK;
 870
 871         if (bt_const->feature & GS_CAN_FEATURE_TRIPLE_SAMPLE)
 872                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
 873
 874         if (bt_const->feature & GS_CAN_FEATURE_ONE_SHOT)
 875                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_ONE_SHOT;
 876
 877         SET_NETDEV_DEV(netdev, &intf->dev);
 878
 879         if (dconf->sw_version > 1)
 880                 if (bt_const->feature & GS_CAN_FEATURE_IDENTIFY)
 881                         netdev->ethtool_ops = &gs_usb_ethtool_ops;
 882
 883         kfree(bt_const);
 884
 885         rc = register_candev(dev->netdev);
 886         if (rc) {
 887                 free_candev(dev->netdev);
 888                 dev_err(&intf->dev, "Couldn't register candev (err=%d)\n", rc);
 889                 return ERR_PTR(rc);
 890         }
 891
 892         return dev;
 893 }
 894
 895 static void gs_destroy_candev(struct gs_can *dev)
 896 {
 897         unregister_candev(dev->netdev);
 898         usb_kill_anchored_urbs(&dev->tx_submitted);
 899         free_candev(dev->netdev);
 900 }
 901
 902 static int gs_usb_probe(struct usb_interface *intf,
 903                         const struct usb_device_id *id)
 904 {
 905         struct gs_usb *dev;
 906         int rc = -ENOMEM;
 907         unsigned int icount, i;
 908         struct gs_host_config *hconf;
 909         struct gs_device_config *dconf;
 910
 911         hconf = kmalloc(sizeof(*hconf), GFP_KERNEL);
 912         if (!hconf)
 913                 return -ENOMEM;
 914
 915         hconf->byte_order = 0x0000beef;
 916
 917         /* send host config */
 918         rc = usb_control_msg(interface_to_usbdev(intf),
 919                              usb_sndctrlpipe(interface_to_usbdev(intf), 0),
 920                              GS_USB_BREQ_HOST_FORMAT,
 921                              USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 922                              1,
 923                              intf->cur_altsetting->desc.bInterfaceNumber,
 924                              hconf,
 925                              sizeof(*hconf),
 926                              1000);
 927
 928         kfree(hconf);
 929
 930         if (rc < 0) {
 931                 dev_err(&intf->dev, "Couldn't send data format (err=%d)\n",
 932                         rc);
 933                 return rc;
 934         }
 935
 936         dconf = kmalloc(sizeof(*dconf), GFP_KERNEL);
 937         if (!dconf)
 938                 return -ENOMEM;
 939
 940         /* read device config */
 941         rc = usb_control_msg(interface_to_usbdev(intf),
 942                              usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
 943                              GS_USB_BREQ_DEVICE_CONFIG,
 944                              USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 945                              1,
 946                              intf->cur_altsetting->desc.bInterfaceNumber,
 947                              dconf,
 948                              sizeof(*dconf),
 949                              1000);
 950         if (rc < 0) {
 951                 dev_err(&intf->dev, "Couldn't get device config: (err=%d)\n",
 952                         rc);
 953                 kfree(dconf);
 954                 return rc;
 955         }
 956
 957         icount = dconf->icount + 1;
 958         dev_info(&intf->dev, "Configuring for %d interfaces\n", icount);
 959
 960         if (icount > GS_MAX_INTF) {
 961                 dev_err(&intf->dev,
 962                         "Driver cannot handle more that %d CAN interfaces\n",
 963                         GS_MAX_INTF);
 964                 kfree(dconf);
 965                 return -EINVAL;
 966         }
 967
 968         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 969         if (!dev) {
 970                 kfree(dconf);
 971                 return -ENOMEM;
 972         }
 973
 974         init_usb_anchor(&dev->rx_submitted);
 975
 976         atomic_set(&dev->active_channels, 0);
 977
 978         usb_set_intfdata(intf, dev);
 979         dev->udev = interface_to_usbdev(intf);
 980
 981         for (i = 0; i < icount; i++) {
 982                 dev->canch[i] = gs_make_candev(i, intf, dconf);
 983                 if (IS_ERR_OR_NULL(dev->canch[i])) {
 984                         /* save error code to return later */
 985                         rc = PTR_ERR(dev->canch[i]);
 986
 987                         /* on failure destroy previously created candevs */
 988                         icount = i;
 989                         for (i = 0; i < icount; i++)
 990                                 gs_destroy_candev(dev->canch[i]);
 991
 992                         usb_kill_anchored_urbs(&dev->rx_submitted);
 993                         kfree(dconf);
 994                         kfree(dev);
 995                         return rc;
 996                 }
 997                 dev->canch[i]->parent = dev;
 998         }
 999
1000         kfree(dconf);
1001
1002         return 0;
1003 }
1004
1005 static void gs_usb_disconnect(struct usb_interface *intf)
1006 {
1007         unsigned i;
1008         struct gs_usb *dev = usb_get_intfdata(intf);
1009         usb_set_intfdata(intf, NULL);
1010
1011         if (!dev) {
1012                 dev_err(&intf->dev, "Disconnect (nodata)\n");
1013                 return;
1014         }
1015
1016         for (i = 0; i < GS_MAX_INTF; i++)
1017                 if (dev->canch[i])
1018                         gs_destroy_candev(dev->canch[i]);
1019
1020         usb_kill_anchored_urbs(&dev->rx_submitted);
1021         kfree(dev);
1022 }
1023
1024 static const struct usb_device_id gs_usb_table[] = {
1025         { USB_DEVICE_INTERFACE_NUMBER(USB_GSUSB_1_VENDOR_ID,
1026                                       USB_GSUSB_1_PRODUCT_ID, 0) },
1027         { USB_DEVICE_INTERFACE_NUMBER(USB_CANDLELIGHT_VENDOR_ID,
1028                                       USB_CANDLELIGHT_PRODUCT_ID, 0) },
1029         {} /* Terminating entry */
1030 };
1031
1032 MODULE_DEVICE_TABLE(usb, gs_usb_table);
1033
1034 static struct usb_driver gs_usb_driver = {
1035         .name       = "gs_usb",
1036         .probe      = gs_usb_probe,
1037         .disconnect = gs_usb_disconnect,
1038         .id_table   = gs_usb_table,
1039 };
1040
1041 module_usb_driver(gs_usb_driver);
1042
1043 MODULE_AUTHOR("Maximilian Schneider <mws@schneidersoft.net>");
1044 MODULE_DESCRIPTION(
1045 "Socket CAN device driver for Geschwister Schneider Technologie-, "
1046 "Entwicklungs- und Vertriebs UG. USB2.0 to CAN interfaces\n"
1047 "and bytewerk.org candleLight USB CAN interfaces.");
1048 MODULE_LICENSE("GPL v2");