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         void *rxbuf[GS_MAX_RX_URBS];
 196         dma_addr_t rxbuf_dma[GS_MAX_RX_URBS];
 197 };
 198
 199 /* usb interface struct */
 200 struct gs_usb {
 201         struct gs_can *canch[GS_MAX_INTF];
 202         struct usb_anchor rx_submitted;
 203         struct usb_device *udev;
 204         u8 active_channels;
 205 };
 206
 207 /* 'allocate' a tx context.
 208  * returns a valid tx context or NULL if there is no space.
 209  */
 210 static struct gs_tx_context *gs_alloc_tx_context(struct gs_can *dev)
 211 {
 212         int i = 0;
 213         unsigned long flags;
 214
 215         spin_lock_irqsave(&dev->tx_ctx_lock, flags);
 216
 217         for (; i < GS_MAX_TX_URBS; i++) {
 218                 if (dev->tx_context[i].echo_id == GS_MAX_TX_URBS) {
 219                         dev->tx_context[i].echo_id = i;
 220                         spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
 221                         return &dev->tx_context[i];
 222                 }
 223         }
 224
 225         spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
 226         return NULL;
 227 }
 228
 229 /* releases a tx context
 230  */
 231 static void gs_free_tx_context(struct gs_tx_context *txc)
 232 {
 233         txc->echo_id = GS_MAX_TX_URBS;
 234 }
 235
 236 /* Get a tx context by id.
 237  */
 238 static struct gs_tx_context *gs_get_tx_context(struct gs_can *dev,
 239                                                unsigned int id)
 240 {
 241         unsigned long flags;
 242
 243         if (id < GS_MAX_TX_URBS) {
 244                 spin_lock_irqsave(&dev->tx_ctx_lock, flags);
 245                 if (dev->tx_context[id].echo_id == id) {
 246                         spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
 247                         return &dev->tx_context[id];
 248                 }
 249                 spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
 250         }
 251         return NULL;
 252 }
 253
 254 static int gs_cmd_reset(struct gs_usb *gsusb, struct gs_can *gsdev)
 255 {
 256         struct gs_device_mode *dm;
 257         struct usb_interface *intf = gsdev->iface;
 258         int rc;
 259
 260         dm = kzalloc(sizeof(*dm), GFP_KERNEL);
 261         if (!dm)
 262                 return -ENOMEM;
 263
 264         dm->mode = GS_CAN_MODE_RESET;
 265
 266         rc = usb_control_msg(interface_to_usbdev(intf),
 267                              usb_sndctrlpipe(interface_to_usbdev(intf), 0),
 268                              GS_USB_BREQ_MODE,
 269                              USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 270                              gsdev->channel,
 271                              0,
 272                              dm,
 273                              sizeof(*dm),
 274                              1000);
 275
 276         kfree(dm);
 277
 278         return rc;
 279 }
 280
 281 static void gs_update_state(struct gs_can *dev, struct can_frame *cf)
 282 {
 283         struct can_device_stats *can_stats = &dev->can.can_stats;
 284
 285         if (cf->can_id & CAN_ERR_RESTARTED) {
 286                 dev->can.state = CAN_STATE_ERROR_ACTIVE;
 287                 can_stats->restarts++;
 288         } else if (cf->can_id & CAN_ERR_BUSOFF) {
 289                 dev->can.state = CAN_STATE_BUS_OFF;
 290                 can_stats->bus_off++;
 291         } else if (cf->can_id & CAN_ERR_CRTL) {
 292                 if ((cf->data[1] & CAN_ERR_CRTL_TX_WARNING) ||
 293                     (cf->data[1] & CAN_ERR_CRTL_RX_WARNING)) {
 294                         dev->can.state = CAN_STATE_ERROR_WARNING;
 295                         can_stats->error_warning++;
 296                 } else if ((cf->data[1] & CAN_ERR_CRTL_TX_PASSIVE) ||
 297                            (cf->data[1] & CAN_ERR_CRTL_RX_PASSIVE)) {
 298                         dev->can.state = CAN_STATE_ERROR_PASSIVE;
 299                         can_stats->error_passive++;
 300                 } else {
 301                         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 302                 }
 303         }
 304 }
 305
 306 static void gs_usb_receive_bulk_callback(struct urb *urb)
 307 {
 308         struct gs_usb *usbcan = urb->context;
 309         struct gs_can *dev;
 310         struct net_device *netdev;
 311         int rc;
 312         struct net_device_stats *stats;
 313         struct gs_host_frame *hf = urb->transfer_buffer;
 314         struct gs_tx_context *txc;
 315         struct can_frame *cf;
 316         struct sk_buff *skb;
 317
 318         BUG_ON(!usbcan);
 319
 320         switch (urb->status) {
 321         case 0: /* success */
 322                 break;
 323         case -ENOENT:
 324         case -ESHUTDOWN:
 325                 return;
 326         default:
 327                 /* do not resubmit aborted urbs. eg: when device goes down */
 328                 return;
 329         }
 330
 331         /* device reports out of range channel id */
 332         if (hf->channel >= GS_MAX_INTF)
 333                 goto device_detach;
 334
 335         dev = usbcan->canch[hf->channel];
 336
 337         netdev = dev->netdev;
 338         stats = &netdev->stats;
 339
 340         if (!netif_device_present(netdev))
 341                 return;
 342
 343         if (hf->echo_id == -1) { /* normal rx */
 344                 skb = alloc_can_skb(dev->netdev, &cf);
 345                 if (!skb)
 346                         return;
 347
 348                 cf->can_id = le32_to_cpu(hf->can_id);
 349
 350                 cf->can_dlc = get_can_dlc(hf->can_dlc);
 351                 memcpy(cf->data, hf->data, 8);
 352
 353                 /* ERROR frames tell us information about the controller */
 354                 if (le32_to_cpu(hf->can_id) & CAN_ERR_FLAG)
 355                         gs_update_state(dev, cf);
 356
 357                 netdev->stats.rx_packets++;
 358                 netdev->stats.rx_bytes += hf->can_dlc;
 359
 360                 netif_rx(skb);
 361         } else { /* echo_id == hf->echo_id */
 362                 if (hf->echo_id >= GS_MAX_TX_URBS) {
 363                         netdev_err(netdev,
 364                                    "Unexpected out of range echo id %d\n",
 365                                    hf->echo_id);
 366                         goto resubmit_urb;
 367                 }
 368
 369                 netdev->stats.tx_packets++;
 370                 netdev->stats.tx_bytes += hf->can_dlc;
 371
 372                 txc = gs_get_tx_context(dev, hf->echo_id);
 373
 374                 /* bad devices send bad echo_ids. */
 375                 if (!txc) {
 376                         netdev_err(netdev,
 377                                    "Unexpected unused echo id %d\n",
 378                                    hf->echo_id);
 379                         goto resubmit_urb;
 380                 }
 381
 382                 can_get_echo_skb(netdev, hf->echo_id);
 383
 384                 gs_free_tx_context(txc);
 385
 386                 atomic_dec(&dev->active_tx_urbs);
 387
 388                 netif_wake_queue(netdev);
 389         }
 390
 391         if (hf->flags & GS_CAN_FLAG_OVERFLOW) {
 392                 skb = alloc_can_err_skb(netdev, &cf);
 393                 if (!skb)
 394                         goto resubmit_urb;
 395
 396                 cf->can_id |= CAN_ERR_CRTL;
 397                 cf->can_dlc = CAN_ERR_DLC;
 398                 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 399                 stats->rx_over_errors++;
 400                 stats->rx_errors++;
 401                 netif_rx(skb);
 402         }
 403
 404  resubmit_urb:
 405         usb_fill_bulk_urb(urb,
 406                           usbcan->udev,
 407                           usb_rcvbulkpipe(usbcan->udev, GSUSB_ENDPOINT_IN),
 408                           hf,
 409                           sizeof(struct gs_host_frame),
 410                           gs_usb_receive_bulk_callback,
 411                           usbcan
 412                           );
 413
 414         rc = usb_submit_urb(urb, GFP_ATOMIC);
 415
 416         /* USB failure take down all interfaces */
 417         if (rc == -ENODEV) {
 418  device_detach:
 419                 for (rc = 0; rc < GS_MAX_INTF; rc++) {
 420                         if (usbcan->canch[rc])
 421                                 netif_device_detach(usbcan->canch[rc]->netdev);
 422                 }
 423         }
 424 }
 425
 426 static int gs_usb_set_bittiming(struct net_device *netdev)
 427 {
 428         struct gs_can *dev = netdev_priv(netdev);
 429         struct can_bittiming *bt = &dev->can.bittiming;
 430         struct usb_interface *intf = dev->iface;
 431         int rc;
 432         struct gs_device_bittiming *dbt;
 433
 434         dbt = kmalloc(sizeof(*dbt), GFP_KERNEL);
 435         if (!dbt)
 436                 return -ENOMEM;
 437
 438         dbt->prop_seg = cpu_to_le32(bt->prop_seg);
 439         dbt->phase_seg1 = cpu_to_le32(bt->phase_seg1);
 440         dbt->phase_seg2 = cpu_to_le32(bt->phase_seg2);
 441         dbt->sjw = cpu_to_le32(bt->sjw);
 442         dbt->brp = cpu_to_le32(bt->brp);
 443
 444         /* request bit timings */
 445         rc = usb_control_msg(interface_to_usbdev(intf),
 446                              usb_sndctrlpipe(interface_to_usbdev(intf), 0),
 447                              GS_USB_BREQ_BITTIMING,
 448                              USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 449                              dev->channel,
 450                              0,
 451                              dbt,
 452                              sizeof(*dbt),
 453                              1000);
 454
 455         kfree(dbt);
 456
 457         if (rc < 0)
 458                 dev_err(netdev->dev.parent, "Couldn't set bittimings (err=%d)",
 459                         rc);
 460
 461         return (rc > 0) ? 0 : rc;
 462 }
 463
 464 static void gs_usb_xmit_callback(struct urb *urb)
 465 {
 466         struct gs_tx_context *txc = urb->context;
 467         struct gs_can *dev = txc->dev;
 468         struct net_device *netdev = dev->netdev;
 469
 470         if (urb->status)
 471                 netdev_info(netdev, "usb xmit fail %d\n", txc->echo_id);
 472
 473         usb_free_coherent(urb->dev,
 474                           urb->transfer_buffer_length,
 475                           urb->transfer_buffer,
 476                           urb->transfer_dma);
 477 }
 478
 479 static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb,
 480                                      struct net_device *netdev)
 481 {
 482         struct gs_can *dev = netdev_priv(netdev);
 483         struct net_device_stats *stats = &dev->netdev->stats;
 484         struct urb *urb;
 485         struct gs_host_frame *hf;
 486         struct can_frame *cf;
 487         int rc;
 488         unsigned int idx;
 489         struct gs_tx_context *txc;
 490
 491         if (can_dropped_invalid_skb(netdev, skb))
 492                 return NETDEV_TX_OK;
 493
 494         /* find an empty context to keep track of transmission */
 495         txc = gs_alloc_tx_context(dev);
 496         if (!txc)
 497                 return NETDEV_TX_BUSY;
 498
 499         /* create a URB, and a buffer for it */
 500         urb = usb_alloc_urb(0, GFP_ATOMIC);
 501         if (!urb)
 502                 goto nomem_urb;
 503
 504         hf = usb_alloc_coherent(dev->udev, sizeof(*hf), GFP_ATOMIC,
 505                                 &urb->transfer_dma);
 506         if (!hf) {
 507                 netdev_err(netdev, "No memory left for USB buffer\n");
 508                 goto nomem_hf;
 509         }
 510
 511         idx = txc->echo_id;
 512
 513         if (idx >= GS_MAX_TX_URBS) {
 514                 netdev_err(netdev, "Invalid tx context %d\n", idx);
 515                 goto badidx;
 516         }
 517
 518         hf->echo_id = idx;
 519         hf->channel = dev->channel;
 520         hf->flags = 0;
 521         hf->reserved = 0;
 522
 523         cf = (struct can_frame *)skb->data;
 524
 525         hf->can_id = cpu_to_le32(cf->can_id);
 526         hf->can_dlc = cf->can_dlc;
 527         memcpy(hf->data, cf->data, cf->can_dlc);
 528
 529         usb_fill_bulk_urb(urb, dev->udev,
 530                           usb_sndbulkpipe(dev->udev, GSUSB_ENDPOINT_OUT),
 531                           hf,
 532                           sizeof(*hf),
 533                           gs_usb_xmit_callback,
 534                           txc);
 535
 536         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 537         usb_anchor_urb(urb, &dev->tx_submitted);
 538
 539         can_put_echo_skb(skb, netdev, idx);
 540
 541         atomic_inc(&dev->active_tx_urbs);
 542
 543         rc = usb_submit_urb(urb, GFP_ATOMIC);
 544         if (unlikely(rc)) {                     /* usb send failed */
 545                 atomic_dec(&dev->active_tx_urbs);
 546
 547                 can_free_echo_skb(netdev, idx);
 548                 gs_free_tx_context(txc);
 549
 550                 usb_unanchor_urb(urb);
 551                 usb_free_coherent(dev->udev,
 552                                   sizeof(*hf),
 553                                   hf,
 554                                   urb->transfer_dma);
 555
 556                 if (rc == -ENODEV) {
 557                         netif_device_detach(netdev);
 558                 } else {
 559                         netdev_err(netdev, "usb_submit failed (err=%d)\n", rc);
 560                         stats->tx_dropped++;
 561                 }
 562         } else {
 563                 /* Slow down tx path */
 564                 if (atomic_read(&dev->active_tx_urbs) >= GS_MAX_TX_URBS)
 565                         netif_stop_queue(netdev);
 566         }
 567
 568         /* let usb core take care of this urb */
 569         usb_free_urb(urb);
 570
 571         return NETDEV_TX_OK;
 572
 573  badidx:
 574         usb_free_coherent(dev->udev,
 575                           sizeof(*hf),
 576                           hf,
 577                           urb->transfer_dma);
 578  nomem_hf:
 579         usb_free_urb(urb);
 580
 581  nomem_urb:
 582         gs_free_tx_context(txc);
 583         dev_kfree_skb(skb);
 584         stats->tx_dropped++;
 585         return NETDEV_TX_OK;
 586 }
 587
 588 static int gs_can_open(struct net_device *netdev)
 589 {
 590         struct gs_can *dev = netdev_priv(netdev);
 591         struct gs_usb *parent = dev->parent;
 592         int rc, i;
 593         struct gs_device_mode *dm;
 594         u32 ctrlmode;
 595         u32 flags = 0;
 596
 597         rc = open_candev(netdev);
 598         if (rc)
 599                 return rc;
 600
 601         if (!parent->active_channels) {
 602                 for (i = 0; i < GS_MAX_RX_URBS; i++) {
 603                         struct urb *urb;
 604                         u8 *buf;
 605                         dma_addr_t buf_dma;
 606
 607                         /* alloc rx urb */
 608                         urb = usb_alloc_urb(0, GFP_KERNEL);
 609                         if (!urb)
 610                                 return -ENOMEM;
 611
 612                         /* alloc rx buffer */
 613                         buf = usb_alloc_coherent(dev->udev,
 614                                                  sizeof(struct gs_host_frame),
 615                                                  GFP_KERNEL,
 616                                                  &buf_dma);
 617                         if (!buf) {
 618                                 netdev_err(netdev,
 619                                            "No memory left for USB buffer\n");
 620                                 usb_free_urb(urb);
 621                                 return -ENOMEM;
 622                         }
 623
 624                         urb->transfer_dma = buf_dma;
 625
 626                         /* fill, anchor, and submit rx urb */
 627                         usb_fill_bulk_urb(urb,
 628                                           dev->udev,
 629                                           usb_rcvbulkpipe(dev->udev,
 630                                                           GSUSB_ENDPOINT_IN),
 631                                           buf,
 632                                           sizeof(struct gs_host_frame),
 633                                           gs_usb_receive_bulk_callback,
 634                                           parent);
 635                         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 636
 637                         usb_anchor_urb(urb, &parent->rx_submitted);
 638
 639                         rc = usb_submit_urb(urb, GFP_KERNEL);
 640                         if (rc) {
 641                                 if (rc == -ENODEV)
 642                                         netif_device_detach(dev->netdev);
 643
 644                                 netdev_err(netdev,
 645                                            "usb_submit failed (err=%d)\n",
 646                                            rc);
 647
 648                                 usb_unanchor_urb(urb);
 649                                 usb_free_coherent(dev->udev,
 650                                                   sizeof(struct gs_host_frame),
 651                                                   buf,
 652                                                   buf_dma);
 653                                 usb_free_urb(urb);
 654                                 break;
 655                         }
 656
 657                         dev->rxbuf[i] = buf;
 658                         dev->rxbuf_dma[i] = buf_dma;
 659
 660                         /* Drop reference,
 661                          * USB core will take care of freeing it
 662                          */
 663                         usb_free_urb(urb);
 664                 }
 665         }
 666
 667         dm = kmalloc(sizeof(*dm), GFP_KERNEL);
 668         if (!dm)
 669                 return -ENOMEM;
 670
 671         /* flags */
 672         ctrlmode = dev->can.ctrlmode;
 673
 674         if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
 675                 flags |= GS_CAN_MODE_LOOP_BACK;
 676         else if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
 677                 flags |= GS_CAN_MODE_LISTEN_ONLY;
 678
 679         /* Controller is not allowed to retry TX
 680          * this mode is unavailable on atmels uc3c hardware
 681          */
 682         if (ctrlmode & CAN_CTRLMODE_ONE_SHOT)
 683                 flags |= GS_CAN_MODE_ONE_SHOT;
 684
 685         if (ctrlmode & CAN_CTRLMODE_3_SAMPLES)
 686                 flags |= GS_CAN_MODE_TRIPLE_SAMPLE;
 687
 688         /* finally start device */
 689         dm->mode = cpu_to_le32(GS_CAN_MODE_START);
 690         dm->flags = cpu_to_le32(flags);
 691         rc = usb_control_msg(interface_to_usbdev(dev->iface),
 692                              usb_sndctrlpipe(interface_to_usbdev(dev->iface), 0),
 693                              GS_USB_BREQ_MODE,
 694                              USB_DIR_OUT | USB_TYPE_VENDOR |
 695                              USB_RECIP_INTERFACE,
 696                              dev->channel,
 697                              0,
 698                              dm,
 699                              sizeof(*dm),
 700                              1000);
 701
 702         if (rc < 0) {
 703                 netdev_err(netdev, "Couldn't start device (err=%d)\n", rc);
 704                 kfree(dm);
 705                 return rc;
 706         }
 707
 708         kfree(dm);
 709
 710         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 711
 712         parent->active_channels++;
 713         if (!(dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY))
 714                 netif_start_queue(netdev);
 715
 716         return 0;
 717 }
 718
 719 static int gs_can_close(struct net_device *netdev)
 720 {
 721         int rc;
 722         struct gs_can *dev = netdev_priv(netdev);
 723         struct gs_usb *parent = dev->parent;
 724         unsigned int i;
 725
 726         netif_stop_queue(netdev);
 727
 728         /* Stop polling */
 729         parent->active_channels--;
 730         if (!parent->active_channels) {
 731                 usb_kill_anchored_urbs(&parent->rx_submitted);
 732                 for (i = 0; i < GS_MAX_RX_URBS; i++)
 733                         usb_free_coherent(dev->udev,
 734                                           sizeof(struct gs_host_frame),
 735                                           dev->rxbuf[i],
 736                                           dev->rxbuf_dma[i]);
 737         }
 738
 739         /* Stop sending URBs */
 740         usb_kill_anchored_urbs(&dev->tx_submitted);
 741         atomic_set(&dev->active_tx_urbs, 0);
 742
 743         /* reset the device */
 744         rc = gs_cmd_reset(parent, dev);
 745         if (rc < 0)
 746                 netdev_warn(netdev, "Couldn't shutdown device (err=%d)", rc);
 747
 748         /* reset tx contexts */
 749         for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
 750                 dev->tx_context[rc].dev = dev;
 751                 dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
 752         }
 753
 754         /* close the netdev */
 755         close_candev(netdev);
 756
 757         return 0;
 758 }
 759
 760 static const struct net_device_ops gs_usb_netdev_ops = {
 761         .ndo_open = gs_can_open,
 762         .ndo_stop = gs_can_close,
 763         .ndo_start_xmit = gs_can_start_xmit,
 764         .ndo_change_mtu = can_change_mtu,
 765 };
 766
 767 static int gs_usb_set_identify(struct net_device *netdev, bool do_identify)
 768 {
 769         struct gs_can *dev = netdev_priv(netdev);
 770         struct gs_identify_mode *imode;
 771         int rc;
 772
 773         imode = kmalloc(sizeof(*imode), GFP_KERNEL);
 774
 775         if (!imode)
 776                 return -ENOMEM;
 777
 778         if (do_identify)
 779                 imode->mode = cpu_to_le32(GS_CAN_IDENTIFY_ON);
 780         else
 781                 imode->mode = cpu_to_le32(GS_CAN_IDENTIFY_OFF);
 782
 783         rc = usb_control_msg(interface_to_usbdev(dev->iface),
 784                              usb_sndctrlpipe(interface_to_usbdev(dev->iface),
 785                                              0),
 786                              GS_USB_BREQ_IDENTIFY,
 787                              USB_DIR_OUT | USB_TYPE_VENDOR |
 788                              USB_RECIP_INTERFACE,
 789                              dev->channel,
 790                              0,
 791                              imode,
 792                              sizeof(*imode),
 793                              100);
 794
 795         kfree(imode);
 796
 797         return (rc > 0) ? 0 : rc;
 798 }
 799
 800 /* blink LED's for finding the this interface */
 801 static int gs_usb_set_phys_id(struct net_device *dev,
 802                               enum ethtool_phys_id_state state)
 803 {
 804         int rc = 0;
 805
 806         switch (state) {
 807         case ETHTOOL_ID_ACTIVE:
 808                 rc = gs_usb_set_identify(dev, GS_CAN_IDENTIFY_ON);
 809                 break;
 810         case ETHTOOL_ID_INACTIVE:
 811                 rc = gs_usb_set_identify(dev, GS_CAN_IDENTIFY_OFF);
 812                 break;
 813         default:
 814                 break;
 815         }
 816
 817         return rc;
 818 }
 819
 820 static const struct ethtool_ops gs_usb_ethtool_ops = {
 821         .set_phys_id = gs_usb_set_phys_id,
 822 };
 823
 824 static struct gs_can *gs_make_candev(unsigned int channel,
 825                                      struct usb_interface *intf,
 826                                      struct gs_device_config *dconf)
 827 {
 828         struct gs_can *dev;
 829         struct net_device *netdev;
 830         int rc;
 831         struct gs_device_bt_const *bt_const;
 832         u32 feature;
 833
 834         bt_const = kmalloc(sizeof(*bt_const), GFP_KERNEL);
 835         if (!bt_const)
 836                 return ERR_PTR(-ENOMEM);
 837
 838         /* fetch bit timing constants */
 839         rc = usb_control_msg(interface_to_usbdev(intf),
 840                              usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
 841                              GS_USB_BREQ_BT_CONST,
 842                              USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 843                              channel,
 844                              0,
 845                              bt_const,
 846                              sizeof(*bt_const),
 847                              1000);
 848
 849         if (rc < 0) {
 850                 dev_err(&intf->dev,
 851                         "Couldn't get bit timing const for channel (err=%d)\n",
 852                         rc);
 853                 kfree(bt_const);
 854                 return ERR_PTR(rc);
 855         }
 856
 857         /* create netdev */
 858         netdev = alloc_candev(sizeof(struct gs_can), GS_MAX_TX_URBS);
 859         if (!netdev) {
 860                 dev_err(&intf->dev, "Couldn't allocate candev\n");
 861                 kfree(bt_const);
 862                 return ERR_PTR(-ENOMEM);
 863         }
 864
 865         dev = netdev_priv(netdev);
 866
 867         netdev->netdev_ops = &gs_usb_netdev_ops;
 868
 869         netdev->flags |= IFF_ECHO; /* we support full roundtrip echo */
 870
 871         /* dev settup */
 872         strcpy(dev->bt_const.name, "gs_usb");
 873         dev->bt_const.tseg1_min = le32_to_cpu(bt_const->tseg1_min);
 874         dev->bt_const.tseg1_max = le32_to_cpu(bt_const->tseg1_max);
 875         dev->bt_const.tseg2_min = le32_to_cpu(bt_const->tseg2_min);
 876         dev->bt_const.tseg2_max = le32_to_cpu(bt_const->tseg2_max);
 877         dev->bt_const.sjw_max = le32_to_cpu(bt_const->sjw_max);
 878         dev->bt_const.brp_min = le32_to_cpu(bt_const->brp_min);
 879         dev->bt_const.brp_max = le32_to_cpu(bt_const->brp_max);
 880         dev->bt_const.brp_inc = le32_to_cpu(bt_const->brp_inc);
 881
 882         dev->udev = interface_to_usbdev(intf);
 883         dev->iface = intf;
 884         dev->netdev = netdev;
 885         dev->channel = channel;
 886
 887         init_usb_anchor(&dev->tx_submitted);
 888         atomic_set(&dev->active_tx_urbs, 0);
 889         spin_lock_init(&dev->tx_ctx_lock);
 890         for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
 891                 dev->tx_context[rc].dev = dev;
 892                 dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
 893         }
 894
 895         /* can settup */
 896         dev->can.state = CAN_STATE_STOPPED;
 897         dev->can.clock.freq = le32_to_cpu(bt_const->fclk_can);
 898         dev->can.bittiming_const = &dev->bt_const;
 899         dev->can.do_set_bittiming = gs_usb_set_bittiming;
 900
 901         dev->can.ctrlmode_supported = 0;
 902
 903         feature = le32_to_cpu(bt_const->feature);
 904         if (feature & GS_CAN_FEATURE_LISTEN_ONLY)
 905                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY;
 906
 907         if (feature & GS_CAN_FEATURE_LOOP_BACK)
 908                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_LOOPBACK;
 909
 910         if (feature & GS_CAN_FEATURE_TRIPLE_SAMPLE)
 911                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
 912
 913         if (feature & GS_CAN_FEATURE_ONE_SHOT)
 914                 dev->can.ctrlmode_supported |= CAN_CTRLMODE_ONE_SHOT;
 915
 916         SET_NETDEV_DEV(netdev, &intf->dev);
 917
 918         if (le32_to_cpu(dconf->sw_version) > 1)
 919                 if (feature & GS_CAN_FEATURE_IDENTIFY)
 920                         netdev->ethtool_ops = &gs_usb_ethtool_ops;
 921
 922         kfree(bt_const);
 923
 924         rc = register_candev(dev->netdev);
 925         if (rc) {
 926                 free_candev(dev->netdev);
 927                 dev_err(&intf->dev, "Couldn't register candev (err=%d)\n", rc);
 928                 return ERR_PTR(rc);
 929         }
 930
 931         return dev;
 932 }
 933
 934 static void gs_destroy_candev(struct gs_can *dev)
 935 {
 936         unregister_candev(dev->netdev);
 937         usb_kill_anchored_urbs(&dev->tx_submitted);
 938         free_candev(dev->netdev);
 939 }
 940
 941 static int gs_usb_probe(struct usb_interface *intf,
 942                         const struct usb_device_id *id)
 943 {
 944         struct gs_usb *dev;
 945         int rc = -ENOMEM;
 946         unsigned int icount, i;
 947         struct gs_host_config *hconf;
 948         struct gs_device_config *dconf;
 949
 950         hconf = kmalloc(sizeof(*hconf), GFP_KERNEL);
 951         if (!hconf)
 952                 return -ENOMEM;
 953
 954         hconf->byte_order = cpu_to_le32(0x0000beef);
 955
 956         /* send host config */
 957         rc = usb_control_msg(interface_to_usbdev(intf),
 958                              usb_sndctrlpipe(interface_to_usbdev(intf), 0),
 959                              GS_USB_BREQ_HOST_FORMAT,
 960                              USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 961                              1,
 962                              intf->cur_altsetting->desc.bInterfaceNumber,
 963                              hconf,
 964                              sizeof(*hconf),
 965                              1000);
 966
 967         kfree(hconf);
 968
 969         if (rc < 0) {
 970                 dev_err(&intf->dev, "Couldn't send data format (err=%d)\n",
 971                         rc);
 972                 return rc;
 973         }
 974
 975         dconf = kmalloc(sizeof(*dconf), GFP_KERNEL);
 976         if (!dconf)
 977                 return -ENOMEM;
 978
 979         /* read device config */
 980         rc = usb_control_msg(interface_to_usbdev(intf),
 981                              usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
 982                              GS_USB_BREQ_DEVICE_CONFIG,
 983                              USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
 984                              1,
 985                              intf->cur_altsetting->desc.bInterfaceNumber,
 986                              dconf,
 987                              sizeof(*dconf),
 988                              1000);
 989         if (rc < 0) {
 990                 dev_err(&intf->dev, "Couldn't get device config: (err=%d)\n",
 991                         rc);
 992                 kfree(dconf);
 993                 return rc;
 994         }
 995
 996         icount = dconf->icount + 1;
 997         dev_info(&intf->dev, "Configuring for %d interfaces\n", icount);
 998
 999         if (icount > GS_MAX_INTF) {
1000                 dev_err(&intf->dev,
1001                         "Driver cannot handle more that %d CAN interfaces\n",
1002                         GS_MAX_INTF);
1003                 kfree(dconf);
1004                 return -EINVAL;
1005         }
1006
1007         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1008         if (!dev) {
1009                 kfree(dconf);
1010                 return -ENOMEM;
1011         }
1012
1013         init_usb_anchor(&dev->rx_submitted);
1014
1015         usb_set_intfdata(intf, dev);
1016         dev->udev = interface_to_usbdev(intf);
1017
1018         for (i = 0; i < icount; i++) {
1019                 dev->canch[i] = gs_make_candev(i, intf, dconf);
1020                 if (IS_ERR_OR_NULL(dev->canch[i])) {
1021                         /* save error code to return later */
1022                         rc = PTR_ERR(dev->canch[i]);
1023
1024                         /* on failure destroy previously created candevs */
1025                         icount = i;
1026                         for (i = 0; i < icount; i++)
1027                                 gs_destroy_candev(dev->canch[i]);
1028
1029                         usb_kill_anchored_urbs(&dev->rx_submitted);
1030                         kfree(dconf);
1031                         kfree(dev);
1032                         return rc;
1033                 }
1034                 dev->canch[i]->parent = dev;
1035         }
1036
1037         kfree(dconf);
1038
1039         return 0;
1040 }
1041
1042 static void gs_usb_disconnect(struct usb_interface *intf)
1043 {
1044         unsigned i;
1045         struct gs_usb *dev = usb_get_intfdata(intf);
1046         usb_set_intfdata(intf, NULL);
1047
1048         if (!dev) {
1049                 dev_err(&intf->dev, "Disconnect (nodata)\n");
1050                 return;
1051         }
1052
1053         for (i = 0; i < GS_MAX_INTF; i++)
1054                 if (dev->canch[i])
1055                         gs_destroy_candev(dev->canch[i]);
1056
1057         usb_kill_anchored_urbs(&dev->rx_submitted);
1058         kfree(dev);
1059 }
1060
1061 static const struct usb_device_id gs_usb_table[] = {
1062         { USB_DEVICE_INTERFACE_NUMBER(USB_GSUSB_1_VENDOR_ID,
1063                                       USB_GSUSB_1_PRODUCT_ID, 0) },
1064         { USB_DEVICE_INTERFACE_NUMBER(USB_CANDLELIGHT_VENDOR_ID,
1065                                       USB_CANDLELIGHT_PRODUCT_ID, 0) },
1066         {} /* Terminating entry */
1067 };
1068
1069 MODULE_DEVICE_TABLE(usb, gs_usb_table);
1070
1071 static struct usb_driver gs_usb_driver = {
1072         .name       = "gs_usb",
1073         .probe      = gs_usb_probe,
1074         .disconnect = gs_usb_disconnect,
1075         .id_table   = gs_usb_table,
1076 };
1077
1078 module_usb_driver(gs_usb_driver);
1079
1080 MODULE_AUTHOR("Maximilian Schneider <mws@schneidersoft.net>");
1081 MODULE_DESCRIPTION(
1082 "Socket CAN device driver for Geschwister Schneider Technologie-, "
1083 "Entwicklungs- und Vertriebs UG. USB2.0 to CAN interfaces\n"
1084 "and bytewerk.org candleLight USB CAN interfaces.");
1085 MODULE_LICENSE("GPL v2");