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 device_detach;
 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  device_detach:
 417                 for (rc = 0; rc < GS_MAX_INTF; rc++) {
 418                         if (usbcan->canch[rc])
 419                                 netif_device_detach(usbcan->canch[rc]->netdev);
 420                 }
 421         }
 422 }
 423
 424 static int gs_usb_set_bittiming(struct net_device *netdev)
 425 {
 426         struct gs_can *dev = netdev_priv(netdev);
 427         struct can_bittiming *bt = &dev->can.bittiming;
 428         struct usb_interface *intf = dev->iface;
 429         int rc;
 430         struct gs_device_bittiming *dbt;
 431
 432         dbt = kmalloc(sizeof(*dbt), GFP_KERNEL);
 433         if (!dbt)
 434                 return -ENOMEM;
 435
 436         dbt->prop_seg = cpu_to_le32(bt->prop_seg);
 437         dbt->phase_seg1 = cpu_to_le32(bt->phase_seg1);
 438         dbt->phase_seg2 = cpu_to_le32(bt->phase_seg2);
 439         dbt->sjw = cpu_to_le32(bt->sjw);
 440         dbt->brp = cpu_to_le32(bt->brp);
 441
 442         /* request bit timings */
 443         rc = usb_control_msg(interface_to_usbdev(intf),
 444                              usb_sndctrlpipe(interface_to_usbdev(intf), 0),
 445                              GS_USB_BREQ_BITTIMING,
 446                              USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 447                              dev->channel,
 448                              0,
 449                              dbt,
 450                              sizeof(*dbt),
 451                              1000);
 452
 453         kfree(dbt);
 454
 455         if (rc < 0)
 456                 dev_err(netdev->dev.parent, "Couldn't set bittimings (err=%d)",
 457                         rc);
 458
 459         return (rc > 0) ? 0 : rc;
 460 }
 461
 462 static void gs_usb_xmit_callback(struct urb *urb)
 463 {
 464         struct gs_tx_context *txc = urb->context;
 465         struct gs_can *dev = txc->dev;
 466         struct net_device *netdev = dev->netdev;
 467
 468         if (urb->status)
 469                 netdev_info(netdev, "usb xmit fail %d\n", txc->echo_id);
 470
 471         usb_free_coherent(urb->dev,
 472                           urb->transfer_buffer_length,
 473                           urb->transfer_buffer,
 474                           urb->transfer_dma);
 475 }
 476
 477 static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb,
 478                                      struct net_device *netdev)
 479 {
 480         struct gs_can *dev = netdev_priv(netdev);
 481         struct net_device_stats *stats = &dev->netdev->stats;
 482         struct urb *urb;
 483         struct gs_host_frame *hf;
 484         struct can_frame *cf;
 485         int rc;
 486         unsigned int idx;
 487         struct gs_tx_context *txc;
 488
 489         if (can_dropped_invalid_skb(netdev, skb))
 490                 return NETDEV_TX_OK;
 491
 492         /* find an empty context to keep track of transmission */
 493         txc = gs_alloc_tx_context(dev);
 494         if (!txc)
 495                 return NETDEV_TX_BUSY;
 496
 497         /* create a URB, and a buffer for it */
 498         urb = usb_alloc_urb(0, GFP_ATOMIC);
 499         if (!urb)
 500                 goto nomem_urb;
 501
 502         hf = usb_alloc_coherent(dev->udev, sizeof(*hf), GFP_ATOMIC,
 503                                 &urb->transfer_dma);
 504         if (!hf) {
 505                 netdev_err(netdev, "No memory left for USB buffer\n");
 506                 goto nomem_hf;
 507         }
 508
 509         idx = txc->echo_id;
 510
 511         if (idx >= GS_MAX_TX_URBS) {
 512                 netdev_err(netdev, "Invalid tx context %d\n", idx);
 513                 goto badidx;
 514         }
 515
 516         hf->echo_id = idx;
 517         hf->channel = dev->channel;
 518         hf->flags = 0;
 519         hf->reserved = 0;
 520
 521         cf = (struct can_frame *)skb->data;
 522
 523         hf->can_id = cpu_to_le32(cf->can_id);
 524         hf->can_dlc = cf->can_dlc;
 525         memcpy(hf->data, cf->data, cf->can_dlc);
 526
 527         usb_fill_bulk_urb(urb, dev->udev,
 528                           usb_sndbulkpipe(dev->udev, GSUSB_ENDPOINT_OUT),
 529                           hf,
 530                           sizeof(*hf),
 531                           gs_usb_xmit_callback,
 532                           txc);
 533
 534         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 535         usb_anchor_urb(urb, &dev->tx_submitted);
 536
 537         can_put_echo_skb(skb, netdev, idx);
 538
 539         atomic_inc(&dev->active_tx_urbs);
 540
 541         rc = usb_submit_urb(urb, GFP_ATOMIC);
 542         if (unlikely(rc)) {                     /* usb send failed */
 543                 atomic_dec(&dev->active_tx_urbs);
 544
 545                 can_free_echo_skb(netdev, idx);
 546                 gs_free_tx_context(txc);
 547
 548                 usb_unanchor_urb(urb);
 549                 usb_free_coherent(dev->udev,
 550                                   sizeof(*hf),
 551                                   hf,
 552                                   urb->transfer_dma);
 553
 554                 if (rc == -ENODEV) {
 555                         netif_device_detach(netdev);
 556                 } else {
 557                         netdev_err(netdev, "usb_submit failed (err=%d)\n", rc);
 558                         stats->tx_dropped++;
 559                 }
 560         } else {
 561                 /* Slow down tx path */
 562                 if (atomic_read(&dev->active_tx_urbs) >= GS_MAX_TX_URBS)
 563                         netif_stop_queue(netdev);
 564         }
 565
 566         /* let usb core take care of this urb */
 567         usb_free_urb(urb);
 568
 569         return NETDEV_TX_OK;
 570
 571  badidx:
 572         usb_free_coherent(dev->udev,
 573                           sizeof(*hf),
 574                           hf,
 575                           urb->transfer_dma);
 576  nomem_hf:
 577         usb_free_urb(urb);
 578
 579  nomem_urb:
 580         gs_free_tx_context(txc);
 581         dev_kfree_skb(skb);
 582         stats->tx_dropped++;
 583         return NETDEV_TX_OK;
 584 }
 585
 586 static int gs_can_open(struct net_device *netdev)
 587 {
 588         struct gs_can *dev = netdev_priv(netdev);
 589         struct gs_usb *parent = dev->parent;
 590         int rc, i;
 591         struct gs_device_mode *dm;
 592         u32 ctrlmode;
 593         u32 flags = 0;
 594
 595         rc = open_candev(netdev);
 596         if (rc)
 597                 return rc;
 598
 599         if (atomic_add_return(1, &parent->active_channels) == 1) {
 600                 for (i = 0; i < GS_MAX_RX_URBS; i++) {
 601                         struct urb *urb;
 602                         u8 *buf;
 603
 604                         /* alloc rx urb */
 605                         urb = usb_alloc_urb(0, GFP_KERNEL);
 606                         if (!urb)
 607                                 return -ENOMEM;
 608
 609                         /* alloc rx buffer */
 610                         buf = usb_alloc_coherent(dev->udev,
 611                                                  sizeof(struct gs_host_frame),
 612                                                  GFP_KERNEL,
 613                                                  &urb->transfer_dma);
 614                         if (!buf) {
 615                                 netdev_err(netdev,
 616                                            "No memory left for USB buffer\n");
 617                                 usb_free_urb(urb);
 618                                 return -ENOMEM;
 619                         }
 620
 621                         /* fill, anchor, and submit rx urb */
 622                         usb_fill_bulk_urb(urb,
 623                                           dev->udev,
 624                                           usb_rcvbulkpipe(dev->udev,
 625                                                           GSUSB_ENDPOINT_IN),
 626                                           buf,
 627                                           sizeof(struct gs_host_frame),
 628                                           gs_usb_receive_bulk_callback,
 629                                           parent);
 630                         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 631
 632                         usb_anchor_urb(urb, &parent->rx_submitted);
 633
 634                         rc = usb_submit_urb(urb, GFP_KERNEL);
 635                         if (rc) {
 636                                 if (rc == -ENODEV)
 637                                         netif_device_detach(dev->netdev);
 638
 639                                 netdev_err(netdev,
 640                                            "usb_submit failed (err=%d)\n",
 641                                            rc);
 642
 643                                 usb_unanchor_urb(urb);
 644                                 usb_free_urb(urb);
 645                                 break;
 646                         }
 647
 648                         /* Drop reference,
 649                          * USB core will take care of freeing it
 650                          */
 651                         usb_free_urb(urb);
 652                 }
 653         }
 654
 655         dm = kmalloc(sizeof(*dm), GFP_KERNEL);
 656         if (!dm)
 657                 return -ENOMEM;
 658
 659         /* flags */
 660         ctrlmode = dev->can.ctrlmode;
 661
 662         if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
 663                 flags |= GS_CAN_MODE_LOOP_BACK;
 664         else if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
 665                 flags |= GS_CAN_MODE_LISTEN_ONLY;
 666
 667         /* Controller is not allowed to retry TX
 668          * this mode is unavailable on atmels uc3c hardware
 669          */
 670         if (ctrlmode & CAN_CTRLMODE_ONE_SHOT)
 671                 flags |= GS_CAN_MODE_ONE_SHOT;
 672
 673         if (ctrlmode & CAN_CTRLMODE_3_SAMPLES)
 674                 flags |= GS_CAN_MODE_TRIPLE_SAMPLE;
 675
 676         /* finally start device */
 677         dm->mode = cpu_to_le32(GS_CAN_MODE_START);
 678         dm->flags = cpu_to_le32(flags);
 679         rc = usb_control_msg(interface_to_usbdev(dev->iface),
 680                              usb_sndctrlpipe(interface_to_usbdev(dev->iface), 0),
 681                              GS_USB_BREQ_MODE,
 682                              USB_DIR_OUT | USB_TYPE_VENDOR |
 683                              USB_RECIP_INTERFACE,
 684                              dev->channel,
 685                              0,
 686                              dm,
 687                              sizeof(*dm),
 688                              1000);
 689
 690         if (rc < 0) {
 691                 netdev_err(netdev, "Couldn't start device (err=%d)\n", rc);
 692                 kfree(dm);
 693                 return rc;
 694         }
 695
 696         kfree(dm);
 697
 698         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 699
 700         if (!(dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY))
 701                 netif_start_queue(netdev);
 702
 703         return 0;
 704 }
 705
 706 static int gs_can_close(struct net_device *netdev)
 707 {
 708         int rc;
 709         struct gs_can *dev = netdev_priv(netdev);
 710         struct gs_usb *parent = dev->parent;
 711
 712         netif_stop_queue(netdev);
 713
 714         /* Stop polling */
 715         if (atomic_dec_and_test(&parent->active_channels))
 716                 usb_kill_anchored_urbs(&parent->rx_submitted);
 717
 718         /* Stop sending URBs */
 719         usb_kill_anchored_urbs(&dev->tx_submitted);
 720         atomic_set(&dev->active_tx_urbs, 0);
 721
 722         /* reset the device */
 723         rc = gs_cmd_reset(parent, dev);
 724         if (rc < 0)
 725                 netdev_warn(netdev, "Couldn't shutdown device (err=%d)", rc);
 726
 727         /* reset tx contexts */
 728         for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
 729                 dev->tx_context[rc].dev = dev;
 730                 dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
 731         }
 732
 733         /* close the netdev */
 734         close_candev(netdev);
 735
 736         return 0;
 737 }
 738
 739 static const struct net_device_ops gs_usb_netdev_ops = {
 740         .ndo_open = gs_can_open,
 741         .ndo_stop = gs_can_close,
 742         .ndo_start_xmit = gs_can_start_xmit,
 743         .ndo_change_mtu = can_change_mtu,
 744 };
 745
 746 static int gs_usb_set_identify(struct net_device *netdev, bool do_identify)
 747 {
 748         struct gs_can *dev = netdev_priv(netdev);
 749         struct gs_identify_mode *imode;
 750         int rc;
 751
 752         imode = kmalloc(sizeof(*imode), GFP_KERNEL);
 753
 754         if (!imode)
 755                 return -ENOMEM;
 756
 757         if (do_identify)
 758                 imode->mode = cpu_to_le32(GS_CAN_IDENTIFY_ON);
 759         else
 760                 imode->mode = cpu_to_le32(GS_CAN_IDENTIFY_OFF);
 761
 762         rc = usb_control_msg(interface_to_usbdev(dev->iface),
 763                              usb_sndctrlpipe(interface_to_usbdev(dev->iface),
 764                                              0),
 765                              GS_USB_BREQ_IDENTIFY,
 766                              USB_DIR_OUT | USB_TYPE_VENDOR |
 767                              USB_RECIP_INTERFACE,
 768                              dev->channel,
 769                              0,
 770                              imode,
 771                              sizeof(*imode),
 772                              100);
 773
 774         kfree(imode);
 775
 776         return (rc > 0) ? 0 : rc;
 777 }
 778
 779 /* blink LED's for finding the this interface */
 780 static int gs_usb_set_phys_id(struct net_device *dev,
 781                               enum ethtool_phys_id_state state)
 782 {
 783         int rc = 0;
 784
 785         switch (state) {
 786         case ETHTOOL_ID_ACTIVE:
 787                 rc = gs_usb_set_identify(dev, GS_CAN_IDENTIFY_ON);
 788                 break;
 789         case ETHTOOL_ID_INACTIVE:
 790                 rc = gs_usb_set_identify(dev, GS_CAN_IDENTIFY_OFF);
 791                 break;
 792         default:
 793                 break;
 794         }
 795
 796         return rc;
 797 }
 798
 799 static const struct ethtool_ops gs_usb_ethtool_ops = {
 800         .set_phys_id = gs_usb_set_phys_id,
 801 };
 802
 803 static struct gs_can *gs_make_candev(unsigned int channel,
 804                                      struct usb_interface *intf,
 805                                      struct gs_device_config *dconf)
 806 {
 807         struct gs_can *dev;
 808         struct net_device *netdev;
 809         int rc;
 810         struct gs_device_bt_const *bt_const;
 811         u32 feature;
 812
 813         bt_const = kmalloc(sizeof(*bt_const), GFP_KERNEL);
 814         if (!bt_const)
 815                 return ERR_PTR(-ENOMEM);
 816
 817         /* fetch bit timing constants */
 818         rc = usb_control_msg(interface_to_usbdev(intf),
 819                              usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
 820                              GS_USB_BREQ_BT_CONST,
 821                              USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 822                              channel,
 823                              0,
 824                              bt_const,
 825                              sizeof(*bt_const),
 826                              1000);
 827
 828         if (rc < 0) {
 829                 dev_err(&intf->dev,
 830                         "Couldn't get bit timing const for channel (err=%d)\n",
 831                         rc);
 832                 kfree(bt_const);
 833                 return ERR_PTR(rc);
 834         }
 835
 836         /* create netdev */
 837         netdev = alloc_candev(sizeof(struct gs_can), GS_MAX_TX_URBS);
 838         if (!netdev) {
 839                 dev_err(&intf->dev, "Couldn't allocate candev\n");
 840                 kfree(bt_const);
 841                 return ERR_PTR(-ENOMEM);
 842         }
 843
 844         dev = netdev_priv(netdev);
 845
 846         netdev->netdev_ops = &gs_usb_netdev_ops;
 847
 848         netdev->flags |= IFF_ECHO; /* we support full roundtrip echo */
 849
 850         /* dev settup */
 851         strcpy(dev->bt_const.name, "gs_usb");
 852         dev->bt_const.tseg1_min = le32_to_cpu(bt_const->tseg1_min);
 853         dev->bt_const.tseg1_max = le32_to_cpu(bt_const->tseg1_max);
 854         dev->bt_const.tseg2_min = le32_to_cpu(bt_const->tseg2_min);
 855         dev->bt_const.tseg2_max = le32_to_cpu(bt_const->tseg2_max);
 856         dev->bt_const.sjw_max = le32_to_cpu(bt_const->sjw_max);
 857         dev->bt_const.brp_min = le32_to_cpu(bt_const->brp_min);
 858         dev->bt_const.brp_max = le32_to_cpu(bt_const->brp_max);
 859         dev->bt_const.brp_inc = le32_to_cpu(bt_const->brp_inc);
 860
 861         dev->udev = interface_to_usbdev(intf);
 862         dev->iface = intf;
 863         dev->netdev = netdev;
 864         dev->channel = channel;
 865
 866         init_usb_anchor(&dev->tx_submitted);
 867         atomic_set(&dev->active_tx_urbs, 0);
 868         spin_lock_init(&dev->tx_ctx_lock);
 869         for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
 870                 dev->tx_context[rc].dev = dev;
 871                 dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
 872         }
 873
 874         /* can settup */
 875         dev->can.state = CAN_STATE_STOPPED;
 876         dev->can.clock.freq = le32_to_cpu(bt_const->fclk_can);
 877         dev->can.bittiming_const = &dev->bt_const;
 878         dev->can.do_set_bittiming = gs_usb_set_bittiming;
 879
 880         dev->can.ctrlmode_supported = 0;
 881
 882         feature = le32_to_cpu(bt_const->feature);
 883         if (feature & GS_CAN_FEATURE_LISTEN_ONLY)
 884                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY;
 885
 886         if (feature & GS_CAN_FEATURE_LOOP_BACK)
 887                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_LOOPBACK;
 888
 889         if (feature & GS_CAN_FEATURE_TRIPLE_SAMPLE)
 890                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
 891
 892         if (feature & GS_CAN_FEATURE_ONE_SHOT)
 893                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_ONE_SHOT;
 894
 895         SET_NETDEV_DEV(netdev, &intf->dev);
 896
 897         if (le32_to_cpu(dconf->sw_version) > 1)
 898                 if (feature & GS_CAN_FEATURE_IDENTIFY)
 899                         netdev->ethtool_ops = &gs_usb_ethtool_ops;
 900
 901         kfree(bt_const);
 902
 903         rc = register_candev(dev->netdev);
 904         if (rc) {
 905                 free_candev(dev->netdev);
 906                 dev_err(&intf->dev, "Couldn't register candev (err=%d)\n", rc);
 907                 return ERR_PTR(rc);
 908         }
 909
 910         return dev;
 911 }
 912
 913 static void gs_destroy_candev(struct gs_can *dev)
 914 {
 915         unregister_candev(dev->netdev);
 916         usb_kill_anchored_urbs(&dev->tx_submitted);
 917         free_candev(dev->netdev);
 918 }
 919
 920 static int gs_usb_probe(struct usb_interface *intf,
 921                         const struct usb_device_id *id)
 922 {
 923         struct gs_usb *dev;
 924         int rc = -ENOMEM;
 925         unsigned int icount, i;
 926         struct gs_host_config *hconf;
 927         struct gs_device_config *dconf;
 928
 929         hconf = kmalloc(sizeof(*hconf), GFP_KERNEL);
 930         if (!hconf)
 931                 return -ENOMEM;
 932
 933         hconf->byte_order = cpu_to_le32(0x0000beef);
 934
 935         /* send host config */
 936         rc = usb_control_msg(interface_to_usbdev(intf),
 937                              usb_sndctrlpipe(interface_to_usbdev(intf), 0),
 938                              GS_USB_BREQ_HOST_FORMAT,
 939                              USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 940                              1,
 941                              intf->cur_altsetting->desc.bInterfaceNumber,
 942                              hconf,
 943                              sizeof(*hconf),
 944                              1000);
 945
 946         kfree(hconf);
 947
 948         if (rc < 0) {
 949                 dev_err(&intf->dev, "Couldn't send data format (err=%d)\n",
 950                         rc);
 951                 return rc;
 952         }
 953
 954         dconf = kmalloc(sizeof(*dconf), GFP_KERNEL);
 955         if (!dconf)
 956                 return -ENOMEM;
 957
 958         /* read device config */
 959         rc = usb_control_msg(interface_to_usbdev(intf),
 960                              usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
 961                              GS_USB_BREQ_DEVICE_CONFIG,
 962                              USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 963                              1,
 964                              intf->cur_altsetting->desc.bInterfaceNumber,
 965                              dconf,
 966                              sizeof(*dconf),
 967                              1000);
 968         if (rc < 0) {
 969                 dev_err(&intf->dev, "Couldn't get device config: (err=%d)\n",
 970                         rc);
 971                 kfree(dconf);
 972                 return rc;
 973         }
 974
 975         icount = dconf->icount + 1;
 976         dev_info(&intf->dev, "Configuring for %d interfaces\n", icount);
 977
 978         if (icount > GS_MAX_INTF) {
 979                 dev_err(&intf->dev,
 980                         "Driver cannot handle more that %d CAN interfaces\n",
 981                         GS_MAX_INTF);
 982                 kfree(dconf);
 983                 return -EINVAL;
 984         }
 985
 986         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 987         if (!dev) {
 988                 kfree(dconf);
 989                 return -ENOMEM;
 990         }
 991
 992         init_usb_anchor(&dev->rx_submitted);
 993
 994         atomic_set(&dev->active_channels, 0);
 995
 996         usb_set_intfdata(intf, dev);
 997         dev->udev = interface_to_usbdev(intf);
 998
 999         for (i = 0; i < icount; i++) {
1000                 dev->canch[i] = gs_make_candev(i, intf, dconf);
1001                 if (IS_ERR_OR_NULL(dev->canch[i])) {
1002                         /* save error code to return later */
1003                         rc = PTR_ERR(dev->canch[i]);
1004
1005                         /* on failure destroy previously created candevs */
1006                         icount = i;
1007                         for (i = 0; i < icount; i++)
1008                                 gs_destroy_candev(dev->canch[i]);
1009
1010                         usb_kill_anchored_urbs(&dev->rx_submitted);
1011                         kfree(dconf);
1012                         kfree(dev);
1013                         return rc;
1014                 }
1015                 dev->canch[i]->parent = dev;
1016         }
1017
1018         kfree(dconf);
1019
1020         return 0;
1021 }
1022
1023 static void gs_usb_disconnect(struct usb_interface *intf)
1024 {
1025         unsigned i;
1026         struct gs_usb *dev = usb_get_intfdata(intf);
1027         usb_set_intfdata(intf, NULL);
1028
1029         if (!dev) {
1030                 dev_err(&intf->dev, "Disconnect (nodata)\n");
1031                 return;
1032         }
1033
1034         for (i = 0; i < GS_MAX_INTF; i++)
1035                 if (dev->canch[i])
1036                         gs_destroy_candev(dev->canch[i]);
1037
1038         usb_kill_anchored_urbs(&dev->rx_submitted);
1039         kfree(dev);
1040 }
1041
1042 static const struct usb_device_id gs_usb_table[] = {
1043         { USB_DEVICE_INTERFACE_NUMBER(USB_GSUSB_1_VENDOR_ID,
1044                                       USB_GSUSB_1_PRODUCT_ID, 0) },
1045         { USB_DEVICE_INTERFACE_NUMBER(USB_CANDLELIGHT_VENDOR_ID,
1046                                       USB_CANDLELIGHT_PRODUCT_ID, 0) },
1047         {} /* Terminating entry */
1048 };
1049
1050 MODULE_DEVICE_TABLE(usb, gs_usb_table);
1051
1052 static struct usb_driver gs_usb_driver = {
1053         .name       = "gs_usb",
1054         .probe      = gs_usb_probe,
1055         .disconnect = gs_usb_disconnect,
1056         .id_table   = gs_usb_table,
1057 };
1058
1059 module_usb_driver(gs_usb_driver);
1060
1061 MODULE_AUTHOR("Maximilian Schneider <mws@schneidersoft.net>");
1062 MODULE_DESCRIPTION(
1063 "Socket CAN device driver for Geschwister Schneider Technologie-, "
1064 "Entwicklungs- und Vertriebs UG. USB2.0 to CAN interfaces\n"
1065 "and bytewerk.org candleLight USB CAN interfaces.");
1066 MODULE_LICENSE("GPL v2");