drivers/net/can/usb/gs_usb.c

   1 /* CAN driver for Geschwister Schneider USB/CAN devices
   2  * and bytewerk.org candleLight USB CAN interfaces.
   3  *
   4  * Copyright (C) 2013-2016 Geschwister Schneider Technologie-,
   5  * Entwicklungs- und Vertriebs UG (Haftungsbeschränkt).
   6  * Copyright (C) 2016 Hubert Denkmair
   7  *
   8  * Many thanks to all socketcan devs!
   9  *
  10  * This program is free software; you can redistribute it and/or modify it
  11  * under the terms of the GNU General Public License as published
  12  * by the Free Software Foundation; version 2 of the License.
  13  *
  14  * This program is distributed in the hope that it will be useful, but
  15  * WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  17  * General Public License for more details.
  18  */
  19
  20 #include <linux/init.h>
  21 #include <linux/signal.h>
  22 #include <linux/module.h>
  23 #include <linux/netdevice.h>
  24 #include <linux/usb.h>
  25
  26 #include <linux/can.h>
  27 #include <linux/can/dev.h>
  28 #include <linux/can/error.h>
  29
  30 /* Device specific constants */
  31 #define USB_GSUSB_1_VENDOR_ID      0x1d50
  32 #define USB_GSUSB_1_PRODUCT_ID     0x606f
  33
  34 #define USB_CANDLELIGHT_VENDOR_ID  0x1209
  35 #define USB_CANDLELIGHT_PRODUCT_ID 0x2323
  36
  37 #define GSUSB_ENDPOINT_IN          1
  38 #define GSUSB_ENDPOINT_OUT         2
  39
  40 /* Device specific constants */
  41 enum gs_usb_breq {
  42         GS_USB_BREQ_HOST_FORMAT = 0,
  43         GS_USB_BREQ_BITTIMING,
  44         GS_USB_BREQ_MODE,
  45         GS_USB_BREQ_BERR,
  46         GS_USB_BREQ_BT_CONST,
  47         GS_USB_BREQ_DEVICE_CONFIG,
  48         GS_USB_BREQ_TIMESTAMP,
  49         GS_USB_BREQ_IDENTIFY,
  50 };
  51
  52 enum gs_can_mode {
  53         /* reset a channel. turns it off */
  54         GS_CAN_MODE_RESET = 0,
  55         /* starts a channel */
  56         GS_CAN_MODE_START
  57 };
  58
  59 enum gs_can_state {
  60         GS_CAN_STATE_ERROR_ACTIVE = 0,
  61         GS_CAN_STATE_ERROR_WARNING,
  62         GS_CAN_STATE_ERROR_PASSIVE,
  63         GS_CAN_STATE_BUS_OFF,
  64         GS_CAN_STATE_STOPPED,
  65         GS_CAN_STATE_SLEEPING
  66 };
  67
  68 enum gs_can_identify_mode {
  69         GS_CAN_IDENTIFY_OFF = 0,
  70         GS_CAN_IDENTIFY_ON
  71 };
  72
  73 /* data types passed between host and device */
  74
  75 /* The firmware on the original USB2CAN by Geschwister Schneider
  76  * Technologie Entwicklungs- und Vertriebs UG exchanges all data
  77  * between the host and the device in host byte order. This is done
  78  * with the struct gs_host_config::byte_order member, which is sent
  79  * first to indicate the desired byte order.
  80  *
  81  * The widely used open source firmware candleLight doesn't support
  82  * this feature and exchanges the data in little endian byte order.
  83  */
  84 struct gs_host_config {
  85         __le32 byte_order;
  86 } __packed;
  87
  88 struct gs_device_config {
  89         u8 reserved1;
  90         u8 reserved2;
  91         u8 reserved3;
  92         u8 icount;
  93         __le32 sw_version;
  94         __le32 hw_version;
  95 } __packed;
  96
  97 #define GS_CAN_MODE_NORMAL               0
  98 #define GS_CAN_MODE_LISTEN_ONLY          BIT(0)
  99 #define GS_CAN_MODE_LOOP_BACK            BIT(1)
 100 #define GS_CAN_MODE_TRIPLE_SAMPLE        BIT(2)
 101 #define GS_CAN_MODE_ONE_SHOT             BIT(3)
 102
 103 struct gs_device_mode {
 104         __le32 mode;
 105         __le32 flags;
 106 } __packed;
 107
 108 struct gs_device_state {
 109         __le32 state;
 110         __le32 rxerr;
 111         __le32 txerr;
 112 } __packed;
 113
 114 struct gs_device_bittiming {
 115         __le32 prop_seg;
 116         __le32 phase_seg1;
 117         __le32 phase_seg2;
 118         __le32 sjw;
 119         __le32 brp;
 120 } __packed;
 121
 122 struct gs_identify_mode {
 123         __le32 mode;
 124 } __packed;
 125
 126 #define GS_CAN_FEATURE_LISTEN_ONLY      BIT(0)
 127 #define GS_CAN_FEATURE_LOOP_BACK        BIT(1)
 128 #define GS_CAN_FEATURE_TRIPLE_SAMPLE    BIT(2)
 129 #define GS_CAN_FEATURE_ONE_SHOT         BIT(3)
 130 #define GS_CAN_FEATURE_HW_TIMESTAMP     BIT(4)
 131 #define GS_CAN_FEATURE_IDENTIFY         BIT(5)
 132
 133 struct gs_device_bt_const {
 134         __le32 feature;
 135         __le32 fclk_can;
 136         __le32 tseg1_min;
 137         __le32 tseg1_max;
 138         __le32 tseg2_min;
 139         __le32 tseg2_max;
 140         __le32 sjw_max;
 141         __le32 brp_min;
 142         __le32 brp_max;
 143         __le32 brp_inc;
 144 } __packed;
 145
 146 #define GS_CAN_FLAG_OVERFLOW 1
 147
 148 struct gs_host_frame {
 149         u32 echo_id;
 150         __le32 can_id;
 151
 152         u8 can_dlc;
 153         u8 channel;
 154         u8 flags;
 155         u8 reserved;
 156
 157         u8 data[8];
 158 } __packed;
 159 /* The GS USB devices make use of the same flags and masks as in
 160  * linux/can.h and linux/can/error.h, and no additional mapping is necessary.
 161  */
 162
 163 /* Only send a max of GS_MAX_TX_URBS frames per channel at a time. */
 164 #define GS_MAX_TX_URBS 10
 165 /* Only launch a max of GS_MAX_RX_URBS usb requests at a time. */
 166 #define GS_MAX_RX_URBS 30
 167 /* Maximum number of interfaces the driver supports per device.
 168  * Current hardware only supports 2 interfaces. The future may vary.
 169  */
 170 #define GS_MAX_INTF 2
 171
 172 struct gs_tx_context {
 173         struct gs_can *dev;
 174         unsigned int echo_id;
 175 };
 176
 177 struct gs_can {
 178         struct can_priv can; /* must be the first member */
 179
 180         struct gs_usb *parent;
 181
 182         struct net_device *netdev;
 183         struct usb_device *udev;
 184         struct usb_interface *iface;
 185
 186         struct can_bittiming_const bt_const;
 187         unsigned int channel;   /* channel number */
 188
 189         /* This lock prevents a race condition between xmit and receive. */
 190         spinlock_t tx_ctx_lock;
 191         struct gs_tx_context tx_context[GS_MAX_TX_URBS];
 192
 193         struct usb_anchor tx_submitted;
 194         atomic_t active_tx_urbs;
 195 };
 196
 197 /* usb interface struct */
 198 struct gs_usb {
 199         struct gs_can *canch[GS_MAX_INTF];
 200         struct usb_anchor rx_submitted;
 201         atomic_t active_channels;
 202         struct usb_device *udev;
 203 };
 204
 205 /* 'allocate' a tx context.
 206  * returns a valid tx context or NULL if there is no space.
 207  */
 208 static struct gs_tx_context *gs_alloc_tx_context(struct gs_can *dev)
 209 {
 210         int i = 0;
 211         unsigned long flags;
 212
 213         spin_lock_irqsave(&dev->tx_ctx_lock, flags);
 214
 215         for (; i < GS_MAX_TX_URBS; i++) {
 216                 if (dev->tx_context[i].echo_id == GS_MAX_TX_URBS) {
 217                         dev->tx_context[i].echo_id = i;
 218                         spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
 219                         return &dev->tx_context[i];
 220                 }
 221         }
 222
 223         spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
 224         return NULL;
 225 }
 226
 227 /* releases a tx context
 228  */
 229 static void gs_free_tx_context(struct gs_tx_context *txc)
 230 {
 231         txc->echo_id = GS_MAX_TX_URBS;
 232 }
 233
 234 /* Get a tx context by id.
 235  */
 236 static struct gs_tx_context *gs_get_tx_context(struct gs_can *dev,
 237                                                unsigned int id)
 238 {
 239         unsigned long flags;
 240
 241         if (id < GS_MAX_TX_URBS) {
 242                 spin_lock_irqsave(&dev->tx_ctx_lock, flags);
 243                 if (dev->tx_context[id].echo_id == id) {
 244                         spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
 245                         return &dev->tx_context[id];
 246                 }
 247                 spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
 248         }
 249         return NULL;
 250 }
 251
 252 static int gs_cmd_reset(struct gs_usb *gsusb, struct gs_can *gsdev)
 253 {
 254         struct gs_device_mode *dm;
 255         struct usb_interface *intf = gsdev->iface;
 256         int rc;
 257
 258         dm = kzalloc(sizeof(*dm), GFP_KERNEL);
 259         if (!dm)
 260                 return -ENOMEM;
 261
 262         dm->mode = GS_CAN_MODE_RESET;
 263
 264         rc = usb_control_msg(interface_to_usbdev(intf),
 265                              usb_sndctrlpipe(interface_to_usbdev(intf), 0),
 266                              GS_USB_BREQ_MODE,
 267                              USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 268                              gsdev->channel,
 269                              0,
 270                              dm,
 271                              sizeof(*dm),
 272                              1000);
 273
 274         kfree(dm);
 275
 276         return rc;
 277 }
 278
 279 static void gs_update_state(struct gs_can *dev, struct can_frame *cf)
 280 {
 281         struct can_device_stats *can_stats = &dev->can.can_stats;
 282
 283         if (cf->can_id & CAN_ERR_RESTARTED) {
 284                 dev->can.state = CAN_STATE_ERROR_ACTIVE;
 285                 can_stats->restarts++;
 286         } else if (cf->can_id & CAN_ERR_BUSOFF) {
 287                 dev->can.state = CAN_STATE_BUS_OFF;
 288                 can_stats->bus_off++;
 289         } else if (cf->can_id & CAN_ERR_CRTL) {
 290                 if ((cf->data[1] & CAN_ERR_CRTL_TX_WARNING) ||
 291                     (cf->data[1] & CAN_ERR_CRTL_RX_WARNING)) {
 292                         dev->can.state = CAN_STATE_ERROR_WARNING;
 293                         can_stats->error_warning++;
 294                 } else if ((cf->data[1] & CAN_ERR_CRTL_TX_PASSIVE) ||
 295                            (cf->data[1] & CAN_ERR_CRTL_RX_PASSIVE)) {
 296                         dev->can.state = CAN_STATE_ERROR_PASSIVE;
 297                         can_stats->error_passive++;
 298                 } else {
 299                         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 300                 }
 301         }
 302 }
 303
 304 static void gs_usb_receive_bulk_callback(struct urb *urb)
 305 {
 306         struct gs_usb *usbcan = urb->context;
 307         struct gs_can *dev;
 308         struct net_device *netdev;
 309         int rc;
 310         struct net_device_stats *stats;
 311         struct gs_host_frame *hf = urb->transfer_buffer;
 312         struct gs_tx_context *txc;
 313         struct can_frame *cf;
 314         struct sk_buff *skb;
 315
 316         BUG_ON(!usbcan);
 317
 318         switch (urb->status) {
 319         case 0: /* success */
 320                 break;
 321         case -ENOENT:
 322         case -ESHUTDOWN:
 323                 return;
 324         default:
 325                 /* do not resubmit aborted urbs. eg: when device goes down */
 326                 return;
 327         }
 328
 329         /* device reports out of range channel id */
 330         if (hf->channel >= GS_MAX_INTF)
 331                 goto resubmit_urb;
 332
 333         dev = usbcan->canch[hf->channel];
 334
 335         netdev = dev->netdev;
 336         stats = &netdev->stats;
 337
 338         if (!netif_device_present(netdev))
 339                 return;
 340
 341         if (hf->echo_id == -1) { /* normal rx */
 342                 skb = alloc_can_skb(dev->netdev, &cf);
 343                 if (!skb)
 344                         return;
 345
 346                 cf->can_id = le32_to_cpu(hf->can_id);
 347
 348                 cf->can_dlc = get_can_dlc(hf->can_dlc);
 349                 memcpy(cf->data, hf->data, 8);
 350
 351                 /* ERROR frames tell us information about the controller */
 352                 if (le32_to_cpu(hf->can_id) & CAN_ERR_FLAG)
 353                         gs_update_state(dev, cf);
 354
 355                 netdev->stats.rx_packets++;
 356                 netdev->stats.rx_bytes += hf->can_dlc;
 357
 358                 netif_rx(skb);
 359         } else { /* echo_id == hf->echo_id */
 360                 if (hf->echo_id >= GS_MAX_TX_URBS) {
 361                         netdev_err(netdev,
 362                                    "Unexpected out of range echo id %d\n",
 363                                    hf->echo_id);
 364                         goto resubmit_urb;
 365                 }
 366
 367                 netdev->stats.tx_packets++;
 368                 netdev->stats.tx_bytes += hf->can_dlc;
 369
 370                 txc = gs_get_tx_context(dev, hf->echo_id);
 371
 372                 /* bad devices send bad echo_ids. */
 373                 if (!txc) {
 374                         netdev_err(netdev,
 375                                    "Unexpected unused echo id %d\n",
 376                                    hf->echo_id);
 377                         goto resubmit_urb;
 378                 }
 379
 380                 can_get_echo_skb(netdev, hf->echo_id);
 381
 382                 gs_free_tx_context(txc);
 383
 384                 atomic_dec(&dev->active_tx_urbs);
 385
 386                 netif_wake_queue(netdev);
 387         }
 388
 389         if (hf->flags & GS_CAN_FLAG_OVERFLOW) {
 390                 skb = alloc_can_err_skb(netdev, &cf);
 391                 if (!skb)
 392                         goto resubmit_urb;
 393
 394                 cf->can_id |= CAN_ERR_CRTL;
 395                 cf->can_dlc = CAN_ERR_DLC;
 396                 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 397                 stats->rx_over_errors++;
 398                 stats->rx_errors++;
 399                 netif_rx(skb);
 400         }
 401
 402  resubmit_urb:
 403         usb_fill_bulk_urb(urb,
 404                           usbcan->udev,
 405                           usb_rcvbulkpipe(usbcan->udev, GSUSB_ENDPOINT_IN),
 406                           hf,
 407                           sizeof(struct gs_host_frame),
 408                           gs_usb_receive_bulk_callback,
 409                           usbcan
 410                           );
 411
 412         rc = usb_submit_urb(urb, GFP_ATOMIC);
 413
 414         /* USB failure take down all interfaces */
 415         if (rc == -ENODEV) {
 416                 for (rc = 0; rc < GS_MAX_INTF; rc++) {
 417                         if (usbcan->canch[rc])
 418                                 netif_device_detach(usbcan->canch[rc]->netdev);
 419                 }
 420         }
 421 }
 422
 423 static int gs_usb_set_bittiming(struct net_device *netdev)
 424 {
 425         struct gs_can *dev = netdev_priv(netdev);
 426         struct can_bittiming *bt = &dev->can.bittiming;
 427         struct usb_interface *intf = dev->iface;
 428         int rc;
 429         struct gs_device_bittiming *dbt;
 430
 431         dbt = kmalloc(sizeof(*dbt), GFP_KERNEL);
 432         if (!dbt)
 433                 return -ENOMEM;
 434
 435         dbt->prop_seg = cpu_to_le32(bt->prop_seg);
 436         dbt->phase_seg1 = cpu_to_le32(bt->phase_seg1);
 437         dbt->phase_seg2 = cpu_to_le32(bt->phase_seg2);
 438         dbt->sjw = cpu_to_le32(bt->sjw);
 439         dbt->brp = cpu_to_le32(bt->brp);
 440
 441         /* request bit timings */
 442         rc = usb_control_msg(interface_to_usbdev(intf),
 443                              usb_sndctrlpipe(interface_to_usbdev(intf), 0),
 444                              GS_USB_BREQ_BITTIMING,
 445                              USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 446                              dev->channel,
 447                              0,
 448                              dbt,
 449                              sizeof(*dbt),
 450                              1000);
 451
 452         kfree(dbt);
 453
 454         if (rc < 0)
 455                 dev_err(netdev->dev.parent, "Couldn't set bittimings (err=%d)",
 456                         rc);
 457
 458         return (rc > 0) ? 0 : rc;
 459 }
 460
 461 static void gs_usb_xmit_callback(struct urb *urb)
 462 {
 463         struct gs_tx_context *txc = urb->context;
 464         struct gs_can *dev = txc->dev;
 465         struct net_device *netdev = dev->netdev;
 466
 467         if (urb->status)
 468                 netdev_info(netdev, "usb xmit fail %d\n", txc->echo_id);
 469
 470         usb_free_coherent(urb->dev,
 471                           urb->transfer_buffer_length,
 472                           urb->transfer_buffer,
 473                           urb->transfer_dma);
 474 }
 475
 476 static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb,
 477                                      struct net_device *netdev)
 478 {
 479         struct gs_can *dev = netdev_priv(netdev);
 480         struct net_device_stats *stats = &dev->netdev->stats;
 481         struct urb *urb;
 482         struct gs_host_frame *hf;
 483         struct can_frame *cf;
 484         int rc;
 485         unsigned int idx;
 486         struct gs_tx_context *txc;
 487
 488         if (can_dropped_invalid_skb(netdev, skb))
 489                 return NETDEV_TX_OK;
 490
 491         /* find an empty context to keep track of transmission */
 492         txc = gs_alloc_tx_context(dev);
 493         if (!txc)
 494                 return NETDEV_TX_BUSY;
 495
 496         /* create a URB, and a buffer for it */
 497         urb = usb_alloc_urb(0, GFP_ATOMIC);
 498         if (!urb)
 499                 goto nomem_urb;
 500
 501         hf = usb_alloc_coherent(dev->udev, sizeof(*hf), GFP_ATOMIC,
 502                                 &urb->transfer_dma);
 503         if (!hf) {
 504                 netdev_err(netdev, "No memory left for USB buffer\n");
 505                 goto nomem_hf;
 506         }
 507
 508         idx = txc->echo_id;
 509
 510         if (idx >= GS_MAX_TX_URBS) {
 511                 netdev_err(netdev, "Invalid tx context %d\n", idx);
 512                 goto badidx;
 513         }
 514
 515         hf->echo_id = idx;
 516         hf->channel = dev->channel;
 517
 518         cf = (struct can_frame *)skb->data;
 519
 520         hf->can_id = cpu_to_le32(cf->can_id);
 521         hf->can_dlc = cf->can_dlc;
 522         memcpy(hf->data, cf->data, cf->can_dlc);
 523
 524         usb_fill_bulk_urb(urb, dev->udev,
 525                           usb_sndbulkpipe(dev->udev, GSUSB_ENDPOINT_OUT),
 526                           hf,
 527                           sizeof(*hf),
 528                           gs_usb_xmit_callback,
 529                           txc);
 530
 531         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 532         usb_anchor_urb(urb, &dev->tx_submitted);
 533
 534         can_put_echo_skb(skb, netdev, idx);
 535
 536         atomic_inc(&dev->active_tx_urbs);
 537
 538         rc = usb_submit_urb(urb, GFP_ATOMIC);
 539         if (unlikely(rc)) {                     /* usb send failed */
 540                 atomic_dec(&dev->active_tx_urbs);
 541
 542                 can_free_echo_skb(netdev, idx);
 543                 gs_free_tx_context(txc);
 544
 545                 usb_unanchor_urb(urb);
 546                 usb_free_coherent(dev->udev,
 547                                   sizeof(*hf),
 548                                   hf,
 549                                   urb->transfer_dma);
 550
 551                 if (rc == -ENODEV) {
 552                         netif_device_detach(netdev);
 553                 } else {
 554                         netdev_err(netdev, "usb_submit failed (err=%d)\n", rc);
 555                         stats->tx_dropped++;
 556                 }
 557         } else {
 558                 /* Slow down tx path */
 559                 if (atomic_read(&dev->active_tx_urbs) >= GS_MAX_TX_URBS)
 560                         netif_stop_queue(netdev);
 561         }
 562
 563         /* let usb core take care of this urb */
 564         usb_free_urb(urb);
 565
 566         return NETDEV_TX_OK;
 567
 568  badidx:
 569         usb_free_coherent(dev->udev,
 570                           sizeof(*hf),
 571                           hf,
 572                           urb->transfer_dma);
 573  nomem_hf:
 574         usb_free_urb(urb);
 575
 576  nomem_urb:
 577         gs_free_tx_context(txc);
 578         dev_kfree_skb(skb);
 579         stats->tx_dropped++;
 580         return NETDEV_TX_OK;
 581 }
 582
 583 static int gs_can_open(struct net_device *netdev)
 584 {
 585         struct gs_can *dev = netdev_priv(netdev);
 586         struct gs_usb *parent = dev->parent;
 587         int rc, i;
 588         struct gs_device_mode *dm;
 589         u32 ctrlmode;
 590         u32 flags = 0;
 591
 592         rc = open_candev(netdev);
 593         if (rc)
 594                 return rc;
 595
 596         if (atomic_add_return(1, &parent->active_channels) == 1) {
 597                 for (i = 0; i < GS_MAX_RX_URBS; i++) {
 598                         struct urb *urb;
 599                         u8 *buf;
 600
 601                         /* alloc rx urb */
 602                         urb = usb_alloc_urb(0, GFP_KERNEL);
 603                         if (!urb)
 604                                 return -ENOMEM;
 605
 606                         /* alloc rx buffer */
 607                         buf = usb_alloc_coherent(dev->udev,
 608                                                  sizeof(struct gs_host_frame),
 609                                                  GFP_KERNEL,
 610                                                  &urb->transfer_dma);
 611                         if (!buf) {
 612                                 netdev_err(netdev,
 613                                            "No memory left for USB buffer\n");
 614                                 usb_free_urb(urb);
 615                                 return -ENOMEM;
 616                         }
 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_urb(urb);
 642                                 break;
 643                         }
 644
 645                         /* Drop reference,
 646                          * USB core will take care of freeing it
 647                          */
 648                         usb_free_urb(urb);
 649                 }
 650         }
 651
 652         dm = kmalloc(sizeof(*dm), GFP_KERNEL);
 653         if (!dm)
 654                 return -ENOMEM;
 655
 656         /* flags */
 657         ctrlmode = dev->can.ctrlmode;
 658
 659         if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
 660                 flags |= GS_CAN_MODE_LOOP_BACK;
 661         else if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
 662                 flags |= GS_CAN_MODE_LISTEN_ONLY;
 663
 664         /* Controller is not allowed to retry TX
 665          * this mode is unavailable on atmels uc3c hardware
 666          */
 667         if (ctrlmode & CAN_CTRLMODE_ONE_SHOT)
 668                 flags |= GS_CAN_MODE_ONE_SHOT;
 669
 670         if (ctrlmode & CAN_CTRLMODE_3_SAMPLES)
 671                 flags |= GS_CAN_MODE_TRIPLE_SAMPLE;
 672
 673         /* finally start device */
 674         dm->mode = cpu_to_le32(GS_CAN_MODE_START);
 675         dm->flags = cpu_to_le32(flags);
 676         rc = usb_control_msg(interface_to_usbdev(dev->iface),
 677                              usb_sndctrlpipe(interface_to_usbdev(dev->iface), 0),
 678                              GS_USB_BREQ_MODE,
 679                              USB_DIR_OUT | USB_TYPE_VENDOR |
 680                              USB_RECIP_INTERFACE,
 681                              dev->channel,
 682                              0,
 683                              dm,
 684                              sizeof(*dm),
 685                              1000);
 686
 687         if (rc < 0) {
 688                 netdev_err(netdev, "Couldn't start device (err=%d)\n", rc);
 689                 kfree(dm);
 690                 return rc;
 691         }
 692
 693         kfree(dm);
 694
 695         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 696
 697         if (!(dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY))
 698                 netif_start_queue(netdev);
 699
 700         return 0;
 701 }
 702
 703 static int gs_can_close(struct net_device *netdev)
 704 {
 705         int rc;
 706         struct gs_can *dev = netdev_priv(netdev);
 707         struct gs_usb *parent = dev->parent;
 708
 709         netif_stop_queue(netdev);
 710
 711         /* Stop polling */
 712         if (atomic_dec_and_test(&parent->active_channels))
 713                 usb_kill_anchored_urbs(&parent->rx_submitted);
 714
 715         /* Stop sending URBs */
 716         usb_kill_anchored_urbs(&dev->tx_submitted);
 717         atomic_set(&dev->active_tx_urbs, 0);
 718
 719         /* reset the device */
 720         rc = gs_cmd_reset(parent, dev);
 721         if (rc < 0)
 722                 netdev_warn(netdev, "Couldn't shutdown device (err=%d)", rc);
 723
 724         /* reset tx contexts */
 725         for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
 726                 dev->tx_context[rc].dev = dev;
 727                 dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
 728         }
 729
 730         /* close the netdev */
 731         close_candev(netdev);
 732
 733         return 0;
 734 }
 735
 736 static const struct net_device_ops gs_usb_netdev_ops = {
 737         .ndo_open = gs_can_open,
 738         .ndo_stop = gs_can_close,
 739         .ndo_start_xmit = gs_can_start_xmit,
 740         .ndo_change_mtu = can_change_mtu,
 741 };
 742
 743 static int gs_usb_set_identify(struct net_device *netdev, bool do_identify)
 744 {
 745         struct gs_can *dev = netdev_priv(netdev);
 746         struct gs_identify_mode *imode;
 747         int rc;
 748
 749         imode = kmalloc(sizeof(*imode), GFP_KERNEL);
 750
 751         if (!imode)
 752                 return -ENOMEM;
 753
 754         if (do_identify)
 755                 imode->mode = cpu_to_le32(GS_CAN_IDENTIFY_ON);
 756         else
 757                 imode->mode = cpu_to_le32(GS_CAN_IDENTIFY_OFF);
 758
 759         rc = usb_control_msg(interface_to_usbdev(dev->iface),
 760                              usb_sndctrlpipe(interface_to_usbdev(dev->iface),
 761                                              0),
 762                              GS_USB_BREQ_IDENTIFY,
 763                              USB_DIR_OUT | USB_TYPE_VENDOR |
 764                              USB_RECIP_INTERFACE,
 765                              dev->channel,
 766                              0,
 767                              imode,
 768                              sizeof(*imode),
 769                              100);
 770
 771         kfree(imode);
 772
 773         return (rc > 0) ? 0 : rc;
 774 }
 775
 776 /* blink LED's for finding the this interface */
 777 static int gs_usb_set_phys_id(struct net_device *dev,
 778                               enum ethtool_phys_id_state state)
 779 {
 780         int rc = 0;
 781
 782         switch (state) {
 783         case ETHTOOL_ID_ACTIVE:
 784                 rc = gs_usb_set_identify(dev, GS_CAN_IDENTIFY_ON);
 785                 break;
 786         case ETHTOOL_ID_INACTIVE:
 787                 rc = gs_usb_set_identify(dev, GS_CAN_IDENTIFY_OFF);
 788                 break;
 789         default:
 790                 break;
 791         }
 792
 793         return rc;
 794 }
 795
 796 static const struct ethtool_ops gs_usb_ethtool_ops = {
 797         .set_phys_id = gs_usb_set_phys_id,
 798 };
 799
 800 static struct gs_can *gs_make_candev(unsigned int channel,
 801                                      struct usb_interface *intf,
 802                                      struct gs_device_config *dconf)
 803 {
 804         struct gs_can *dev;
 805         struct net_device *netdev;
 806         int rc;
 807         struct gs_device_bt_const *bt_const;
 808         u32 feature;
 809
 810         bt_const = kmalloc(sizeof(*bt_const), GFP_KERNEL);
 811         if (!bt_const)
 812                 return ERR_PTR(-ENOMEM);
 813
 814         /* fetch bit timing constants */
 815         rc = usb_control_msg(interface_to_usbdev(intf),
 816                              usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
 817                              GS_USB_BREQ_BT_CONST,
 818                              USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 819                              channel,
 820                              0,
 821                              bt_const,
 822                              sizeof(*bt_const),
 823                              1000);
 824
 825         if (rc < 0) {
 826                 dev_err(&intf->dev,
 827                         "Couldn't get bit timing const for channel (err=%d)\n",
 828                         rc);
 829                 kfree(bt_const);
 830                 return ERR_PTR(rc);
 831         }
 832
 833         /* create netdev */
 834         netdev = alloc_candev(sizeof(struct gs_can), GS_MAX_TX_URBS);
 835         if (!netdev) {
 836                 dev_err(&intf->dev, "Couldn't allocate candev\n");
 837                 kfree(bt_const);
 838                 return ERR_PTR(-ENOMEM);
 839         }
 840
 841         dev = netdev_priv(netdev);
 842
 843         netdev->netdev_ops = &gs_usb_netdev_ops;
 844
 845         netdev->flags |= IFF_ECHO; /* we support full roundtrip echo */
 846
 847         /* dev settup */
 848         strcpy(dev->bt_const.name, "gs_usb");
 849         dev->bt_const.tseg1_min = le32_to_cpu(bt_const->tseg1_min);
 850         dev->bt_const.tseg1_max = le32_to_cpu(bt_const->tseg1_max);
 851         dev->bt_const.tseg2_min = le32_to_cpu(bt_const->tseg2_min);
 852         dev->bt_const.tseg2_max = le32_to_cpu(bt_const->tseg2_max);
 853         dev->bt_const.sjw_max = le32_to_cpu(bt_const->sjw_max);
 854         dev->bt_const.brp_min = le32_to_cpu(bt_const->brp_min);
 855         dev->bt_const.brp_max = le32_to_cpu(bt_const->brp_max);
 856         dev->bt_const.brp_inc = le32_to_cpu(bt_const->brp_inc);
 857
 858         dev->udev = interface_to_usbdev(intf);
 859         dev->iface = intf;
 860         dev->netdev = netdev;
 861         dev->channel = channel;
 862
 863         init_usb_anchor(&dev->tx_submitted);
 864         atomic_set(&dev->active_tx_urbs, 0);
 865         spin_lock_init(&dev->tx_ctx_lock);
 866         for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
 867                 dev->tx_context[rc].dev = dev;
 868                 dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
 869         }
 870
 871         /* can settup */
 872         dev->can.state = CAN_STATE_STOPPED;
 873         dev->can.clock.freq = le32_to_cpu(bt_const->fclk_can);
 874         dev->can.bittiming_const = &dev->bt_const;
 875         dev->can.do_set_bittiming = gs_usb_set_bittiming;
 876
 877         dev->can.ctrlmode_supported = 0;
 878
 879         feature = le32_to_cpu(bt_const->feature);
 880         if (feature & GS_CAN_FEATURE_LISTEN_ONLY)
 881                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY;
 882
 883         if (feature & GS_CAN_FEATURE_LOOP_BACK)
 884                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_LOOPBACK;
 885
 886         if (feature & GS_CAN_FEATURE_TRIPLE_SAMPLE)
 887                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
 888
 889         if (feature & GS_CAN_FEATURE_ONE_SHOT)
 890                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_ONE_SHOT;
 891
 892         SET_NETDEV_DEV(netdev, &intf->dev);
 893
 894         if (le32_to_cpu(dconf->sw_version) > 1)
 895                 if (feature & GS_CAN_FEATURE_IDENTIFY)
 896                         netdev->ethtool_ops = &gs_usb_ethtool_ops;
 897
 898         kfree(bt_const);
 899
 900         rc = register_candev(dev->netdev);
 901         if (rc) {
 902                 free_candev(dev->netdev);
 903                 dev_err(&intf->dev, "Couldn't register candev (err=%d)\n", rc);
 904                 return ERR_PTR(rc);
 905         }
 906
 907         return dev;
 908 }
 909
 910 static void gs_destroy_candev(struct gs_can *dev)
 911 {
 912         unregister_candev(dev->netdev);
 913         usb_kill_anchored_urbs(&dev->tx_submitted);
 914         free_candev(dev->netdev);
 915 }
 916
 917 static int gs_usb_probe(struct usb_interface *intf,
 918                         const struct usb_device_id *id)
 919 {
 920         struct gs_usb *dev;
 921         int rc = -ENOMEM;
 922         unsigned int icount, i;
 923         struct gs_host_config *hconf;
 924         struct gs_device_config *dconf;
 925
 926         hconf = kmalloc(sizeof(*hconf), GFP_KERNEL);
 927         if (!hconf)
 928                 return -ENOMEM;
 929
 930         hconf->byte_order = cpu_to_le32(0x0000beef);
 931
 932         /* send host config */
 933         rc = usb_control_msg(interface_to_usbdev(intf),
 934                              usb_sndctrlpipe(interface_to_usbdev(intf), 0),
 935                              GS_USB_BREQ_HOST_FORMAT,
 936                              USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 937                              1,
 938                              intf->cur_altsetting->desc.bInterfaceNumber,
 939                              hconf,
 940                              sizeof(*hconf),
 941                              1000);
 942
 943         kfree(hconf);
 944
 945         if (rc < 0) {
 946                 dev_err(&intf->dev, "Couldn't send data format (err=%d)\n",
 947                         rc);
 948                 return rc;
 949         }
 950
 951         dconf = kmalloc(sizeof(*dconf), GFP_KERNEL);
 952         if (!dconf)
 953                 return -ENOMEM;
 954
 955         /* read device config */
 956         rc = usb_control_msg(interface_to_usbdev(intf),
 957                              usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
 958                              GS_USB_BREQ_DEVICE_CONFIG,
 959                              USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 960                              1,
 961                              intf->cur_altsetting->desc.bInterfaceNumber,
 962                              dconf,
 963                              sizeof(*dconf),
 964                              1000);
 965         if (rc < 0) {
 966                 dev_err(&intf->dev, "Couldn't get device config: (err=%d)\n",
 967                         rc);
 968                 kfree(dconf);
 969                 return rc;
 970         }
 971
 972         icount = dconf->icount + 1;
 973         dev_info(&intf->dev, "Configuring for %d interfaces\n", icount);
 974
 975         if (icount > GS_MAX_INTF) {
 976                 dev_err(&intf->dev,
 977                         "Driver cannot handle more that %d CAN interfaces\n",
 978                         GS_MAX_INTF);
 979                 kfree(dconf);
 980                 return -EINVAL;
 981         }
 982
 983         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 984         if (!dev) {
 985                 kfree(dconf);
 986                 return -ENOMEM;
 987         }
 988
 989         init_usb_anchor(&dev->rx_submitted);
 990
 991         atomic_set(&dev->active_channels, 0);
 992
 993         usb_set_intfdata(intf, dev);
 994         dev->udev = interface_to_usbdev(intf);
 995
 996         for (i = 0; i < icount; i++) {
 997                 dev->canch[i] = gs_make_candev(i, intf, dconf);
 998                 if (IS_ERR_OR_NULL(dev->canch[i])) {
 999                         /* save error code to return later */
1000                         rc = PTR_ERR(dev->canch[i]);
1001
1002                         /* on failure destroy previously created candevs */
1003                         icount = i;
1004                         for (i = 0; i < icount; i++)
1005                                 gs_destroy_candev(dev->canch[i]);
1006
1007                         usb_kill_anchored_urbs(&dev->rx_submitted);
1008                         kfree(dconf);
1009                         kfree(dev);
1010                         return rc;
1011                 }
1012                 dev->canch[i]->parent = dev;
1013         }
1014
1015         kfree(dconf);
1016
1017         return 0;
1018 }
1019
1020 static void gs_usb_disconnect(struct usb_interface *intf)
1021 {
1022         unsigned i;
1023         struct gs_usb *dev = usb_get_intfdata(intf);
1024         usb_set_intfdata(intf, NULL);
1025
1026         if (!dev) {
1027                 dev_err(&intf->dev, "Disconnect (nodata)\n");
1028                 return;
1029         }
1030
1031         for (i = 0; i < GS_MAX_INTF; i++)
1032                 if (dev->canch[i])
1033                         gs_destroy_candev(dev->canch[i]);
1034
1035         usb_kill_anchored_urbs(&dev->rx_submitted);
1036         kfree(dev);
1037 }
1038
1039 static const struct usb_device_id gs_usb_table[] = {
1040         { USB_DEVICE_INTERFACE_NUMBER(USB_GSUSB_1_VENDOR_ID,
1041                                       USB_GSUSB_1_PRODUCT_ID, 0) },
1042         { USB_DEVICE_INTERFACE_NUMBER(USB_CANDLELIGHT_VENDOR_ID,
1043                                       USB_CANDLELIGHT_PRODUCT_ID, 0) },
1044         {} /* Terminating entry */
1045 };
1046
1047 MODULE_DEVICE_TABLE(usb, gs_usb_table);
1048
1049 static struct usb_driver gs_usb_driver = {
1050         .name       = "gs_usb",
1051         .probe      = gs_usb_probe,
1052         .disconnect = gs_usb_disconnect,
1053         .id_table   = gs_usb_table,
1054 };
1055
1056 module_usb_driver(gs_usb_driver);
1057
1058 MODULE_AUTHOR("Maximilian Schneider <mws@schneidersoft.net>");
1059 MODULE_DESCRIPTION(
1060 "Socket CAN device driver for Geschwister Schneider Technologie-, "
1061 "Entwicklungs- und Vertriebs UG. USB2.0 to CAN interfaces\n"
1062 "and bytewerk.org candleLight USB CAN interfaces.");
1063 MODULE_LICENSE("GPL v2");