drivers/net/can/usb/usb_8dev.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * CAN driver for "8 devices" USB2CAN converter
   4  *
   5  * Copyright (C) 2012 Bernd Krumboeck (krumboeck@universalnet.at)
   6  *
   7  * This driver is inspired by the 3.2.0 version of drivers/net/can/usb/ems_usb.c
   8  * and drivers/net/can/usb/esd_usb2.c
   9  *
  10  * Many thanks to Gerhard Bertelsmann (info@gerhard-bertelsmann.de)
  11  * for testing and fixing this driver. Also many thanks to "8 devices",
  12  * who were very cooperative and answered my questions.
  13  */
  14
  15 #include <linux/signal.h>
  16 #include <linux/slab.h>
  17 #include <linux/module.h>
  18 #include <linux/netdevice.h>
  19 #include <linux/usb.h>
  20
  21 #include <linux/can.h>
  22 #include <linux/can/dev.h>
  23 #include <linux/can/error.h>
  24 #include <linux/can/led.h>
  25
  26 /* driver constants */
  27 #define MAX_RX_URBS                     20
  28 #define MAX_TX_URBS                     20
  29 #define RX_BUFFER_SIZE                  64
  30
  31 /* vendor and product id */
  32 #define USB_8DEV_VENDOR_ID              0x0483
  33 #define USB_8DEV_PRODUCT_ID             0x1234
  34
  35 /* endpoints */
  36 enum usb_8dev_endpoint {
  37         USB_8DEV_ENDP_DATA_RX = 1,
  38         USB_8DEV_ENDP_DATA_TX,
  39         USB_8DEV_ENDP_CMD_RX,
  40         USB_8DEV_ENDP_CMD_TX
  41 };
  42
  43 /* device CAN clock */
  44 #define USB_8DEV_ABP_CLOCK              32000000
  45
  46 /* setup flags */
  47 #define USB_8DEV_SILENT                 0x01
  48 #define USB_8DEV_LOOPBACK               0x02
  49 #define USB_8DEV_DISABLE_AUTO_RESTRANS  0x04
  50 #define USB_8DEV_STATUS_FRAME           0x08
  51
  52 /* commands */
  53 enum usb_8dev_cmd {
  54         USB_8DEV_RESET = 1,
  55         USB_8DEV_OPEN,
  56         USB_8DEV_CLOSE,
  57         USB_8DEV_SET_SPEED,
  58         USB_8DEV_SET_MASK_FILTER,
  59         USB_8DEV_GET_STATUS,
  60         USB_8DEV_GET_STATISTICS,
  61         USB_8DEV_GET_SERIAL,
  62         USB_8DEV_GET_SOFTW_VER,
  63         USB_8DEV_GET_HARDW_VER,
  64         USB_8DEV_RESET_TIMESTAMP,
  65         USB_8DEV_GET_SOFTW_HARDW_VER
  66 };
  67
  68 /* command options */
  69 #define USB_8DEV_BAUD_MANUAL            0x09
  70 #define USB_8DEV_CMD_START              0x11
  71 #define USB_8DEV_CMD_END                0x22
  72
  73 #define USB_8DEV_CMD_SUCCESS            0
  74 #define USB_8DEV_CMD_ERROR              255
  75
  76 #define USB_8DEV_CMD_TIMEOUT            1000
  77
  78 /* frames */
  79 #define USB_8DEV_DATA_START             0x55
  80 #define USB_8DEV_DATA_END               0xAA
  81
  82 #define USB_8DEV_TYPE_CAN_FRAME         0
  83 #define USB_8DEV_TYPE_ERROR_FRAME       3
  84
  85 #define USB_8DEV_EXTID                  0x01
  86 #define USB_8DEV_RTR                    0x02
  87 #define USB_8DEV_ERR_FLAG               0x04
  88
  89 /* status */
  90 #define USB_8DEV_STATUSMSG_OK           0x00  /* Normal condition. */
  91 #define USB_8DEV_STATUSMSG_OVERRUN      0x01  /* Overrun occurred when sending */
  92 #define USB_8DEV_STATUSMSG_BUSLIGHT     0x02  /* Error counter has reached 96 */
  93 #define USB_8DEV_STATUSMSG_BUSHEAVY     0x03  /* Error count. has reached 128 */
  94 #define USB_8DEV_STATUSMSG_BUSOFF       0x04  /* Device is in BUSOFF */
  95 #define USB_8DEV_STATUSMSG_STUFF        0x20  /* Stuff Error */
  96 #define USB_8DEV_STATUSMSG_FORM         0x21  /* Form Error */
  97 #define USB_8DEV_STATUSMSG_ACK          0x23  /* Ack Error */
  98 #define USB_8DEV_STATUSMSG_BIT0         0x24  /* Bit1 Error */
  99 #define USB_8DEV_STATUSMSG_BIT1         0x25  /* Bit0 Error */
 100 #define USB_8DEV_STATUSMSG_CRC          0x27  /* CRC Error */
 101
 102 #define USB_8DEV_RP_MASK                0x7F  /* Mask for Receive Error Bit */
 103
 104
 105 /* table of devices that work with this driver */
 106 static const struct usb_device_id usb_8dev_table[] = {
 107         { USB_DEVICE(USB_8DEV_VENDOR_ID, USB_8DEV_PRODUCT_ID) },
 108         { }                                     /* Terminating entry */
 109 };
 110
 111 MODULE_DEVICE_TABLE(usb, usb_8dev_table);
 112
 113 struct usb_8dev_tx_urb_context {
 114         struct usb_8dev_priv *priv;
 115
 116         u32 echo_index;
 117         u8 dlc;
 118 };
 119
 120 /* Structure to hold all of our device specific stuff */
 121 struct usb_8dev_priv {
 122         struct can_priv can; /* must be the first member */
 123
 124         struct sk_buff *echo_skb[MAX_TX_URBS];
 125
 126         struct usb_device *udev;
 127         struct net_device *netdev;
 128
 129         atomic_t active_tx_urbs;
 130         struct usb_anchor tx_submitted;
 131         struct usb_8dev_tx_urb_context tx_contexts[MAX_TX_URBS];
 132
 133         struct usb_anchor rx_submitted;
 134
 135         struct can_berr_counter bec;
 136
 137         u8 *cmd_msg_buffer;
 138
 139         struct mutex usb_8dev_cmd_lock;
 140
 141 };
 142
 143 /* tx frame */
 144 struct __packed usb_8dev_tx_msg {
 145         u8 begin;
 146         u8 flags;       /* RTR and EXT_ID flag */
 147         __be32 id;      /* upper 3 bits not used */
 148         u8 dlc;         /* data length code 0-8 bytes */
 149         u8 data[8];     /* 64-bit data */
 150         u8 end;
 151 };
 152
 153 /* rx frame */
 154 struct __packed usb_8dev_rx_msg {
 155         u8 begin;
 156         u8 type;                /* frame type */
 157         u8 flags;               /* RTR and EXT_ID flag */
 158         __be32 id;              /* upper 3 bits not used */
 159         u8 dlc;                 /* data length code 0-8 bytes */
 160         u8 data[8];             /* 64-bit data */
 161         __be32 timestamp;       /* 32-bit timestamp */
 162         u8 end;
 163 };
 164
 165 /* command frame */
 166 struct __packed usb_8dev_cmd_msg {
 167         u8 begin;
 168         u8 channel;     /* unknown - always 0 */
 169         u8 command;     /* command to execute */
 170         u8 opt1;        /* optional parameter / return value */
 171         u8 opt2;        /* optional parameter 2 */
 172         u8 data[10];    /* optional parameter and data */
 173         u8 end;
 174 };
 175
 176 static int usb_8dev_send_cmd_msg(struct usb_8dev_priv *priv, u8 *msg, int size)
 177 {
 178         int actual_length;
 179
 180         return usb_bulk_msg(priv->udev,
 181                             usb_sndbulkpipe(priv->udev, USB_8DEV_ENDP_CMD_TX),
 182                             msg, size, &actual_length, USB_8DEV_CMD_TIMEOUT);
 183 }
 184
 185 static int usb_8dev_wait_cmd_msg(struct usb_8dev_priv *priv, u8 *msg, int size,
 186                                 int *actual_length)
 187 {
 188         return usb_bulk_msg(priv->udev,
 189                             usb_rcvbulkpipe(priv->udev, USB_8DEV_ENDP_CMD_RX),
 190                             msg, size, actual_length, USB_8DEV_CMD_TIMEOUT);
 191 }
 192
 193 /* Send command to device and receive result.
 194  * Command was successful when opt1 = 0.
 195  */
 196 static int usb_8dev_send_cmd(struct usb_8dev_priv *priv,
 197                              struct usb_8dev_cmd_msg *out,
 198                              struct usb_8dev_cmd_msg *in)
 199 {
 200         int err;
 201         int num_bytes_read;
 202         struct net_device *netdev;
 203
 204         netdev = priv->netdev;
 205
 206         out->begin = USB_8DEV_CMD_START;
 207         out->end = USB_8DEV_CMD_END;
 208
 209         mutex_lock(&priv->usb_8dev_cmd_lock);
 210
 211         memcpy(priv->cmd_msg_buffer, out,
 212                 sizeof(struct usb_8dev_cmd_msg));
 213
 214         err = usb_8dev_send_cmd_msg(priv, priv->cmd_msg_buffer,
 215                                     sizeof(struct usb_8dev_cmd_msg));
 216         if (err < 0) {
 217                 netdev_err(netdev, "sending command message failed\n");
 218                 goto failed;
 219         }
 220
 221         err = usb_8dev_wait_cmd_msg(priv, priv->cmd_msg_buffer,
 222                                     sizeof(struct usb_8dev_cmd_msg),
 223                                     &num_bytes_read);
 224         if (err < 0) {
 225                 netdev_err(netdev, "no command message answer\n");
 226                 goto failed;
 227         }
 228
 229         memcpy(in, priv->cmd_msg_buffer, sizeof(struct usb_8dev_cmd_msg));
 230
 231         if (in->begin != USB_8DEV_CMD_START || in->end != USB_8DEV_CMD_END ||
 232                         num_bytes_read != 16 || in->opt1 != 0)
 233                 err = -EPROTO;
 234
 235 failed:
 236         mutex_unlock(&priv->usb_8dev_cmd_lock);
 237         return err;
 238 }
 239
 240 /* Send open command to device */
 241 static int usb_8dev_cmd_open(struct usb_8dev_priv *priv)
 242 {
 243         struct can_bittiming *bt = &priv->can.bittiming;
 244         struct usb_8dev_cmd_msg outmsg;
 245         struct usb_8dev_cmd_msg inmsg;
 246         u32 ctrlmode = priv->can.ctrlmode;
 247         u32 flags = USB_8DEV_STATUS_FRAME;
 248         __be32 beflags;
 249         __be16 bebrp;
 250
 251         memset(&outmsg, 0, sizeof(outmsg));
 252         outmsg.command = USB_8DEV_OPEN;
 253         outmsg.opt1 = USB_8DEV_BAUD_MANUAL;
 254         outmsg.data[0] = bt->prop_seg + bt->phase_seg1;
 255         outmsg.data[1] = bt->phase_seg2;
 256         outmsg.data[2] = bt->sjw;
 257
 258         /* BRP */
 259         bebrp = cpu_to_be16((u16)bt->brp);
 260         memcpy(&outmsg.data[3], &bebrp, sizeof(bebrp));
 261
 262         /* flags */
 263         if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
 264                 flags |= USB_8DEV_LOOPBACK;
 265         if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
 266                 flags |= USB_8DEV_SILENT;
 267         if (ctrlmode & CAN_CTRLMODE_ONE_SHOT)
 268                 flags |= USB_8DEV_DISABLE_AUTO_RESTRANS;
 269
 270         beflags = cpu_to_be32(flags);
 271         memcpy(&outmsg.data[5], &beflags, sizeof(beflags));
 272
 273         return usb_8dev_send_cmd(priv, &outmsg, &inmsg);
 274 }
 275
 276 /* Send close command to device */
 277 static int usb_8dev_cmd_close(struct usb_8dev_priv *priv)
 278 {
 279         struct usb_8dev_cmd_msg inmsg;
 280         struct usb_8dev_cmd_msg outmsg = {
 281                 .channel = 0,
 282                 .command = USB_8DEV_CLOSE,
 283                 .opt1 = 0,
 284                 .opt2 = 0
 285         };
 286
 287         return usb_8dev_send_cmd(priv, &outmsg, &inmsg);
 288 }
 289
 290 /* Get firmware and hardware version */
 291 static int usb_8dev_cmd_version(struct usb_8dev_priv *priv, u32 *res)
 292 {
 293         struct usb_8dev_cmd_msg inmsg;
 294         struct usb_8dev_cmd_msg outmsg = {
 295                 .channel = 0,
 296                 .command = USB_8DEV_GET_SOFTW_HARDW_VER,
 297                 .opt1 = 0,
 298                 .opt2 = 0
 299         };
 300
 301         int err = usb_8dev_send_cmd(priv, &outmsg, &inmsg);
 302         if (err)
 303                 return err;
 304
 305         *res = be32_to_cpup((__be32 *)inmsg.data);
 306
 307         return err;
 308 }
 309
 310 /* Set network device mode
 311  *
 312  * Maybe we should leave this function empty, because the device
 313  * set mode variable with open command.
 314  */
 315 static int usb_8dev_set_mode(struct net_device *netdev, enum can_mode mode)
 316 {
 317         struct usb_8dev_priv *priv = netdev_priv(netdev);
 318         int err = 0;
 319
 320         switch (mode) {
 321         case CAN_MODE_START:
 322                 err = usb_8dev_cmd_open(priv);
 323                 if (err)
 324                         netdev_warn(netdev, "couldn't start device");
 325                 break;
 326
 327         default:
 328                 return -EOPNOTSUPP;
 329         }
 330
 331         return err;
 332 }
 333
 334 /* Read error/status frames */
 335 static void usb_8dev_rx_err_msg(struct usb_8dev_priv *priv,
 336                                 struct usb_8dev_rx_msg *msg)
 337 {
 338         struct can_frame *cf;
 339         struct sk_buff *skb;
 340         struct net_device_stats *stats = &priv->netdev->stats;
 341
 342         /* Error message:
 343          * byte 0: Status
 344          * byte 1: bit   7: Receive Passive
 345          * byte 1: bit 0-6: Receive Error Counter
 346          * byte 2: Transmit Error Counter
 347          * byte 3: Always 0 (maybe reserved for future use)
 348          */
 349
 350         u8 state = msg->data[0];
 351         u8 rxerr = msg->data[1] & USB_8DEV_RP_MASK;
 352         u8 txerr = msg->data[2];
 353         int rx_errors = 0;
 354         int tx_errors = 0;
 355
 356         skb = alloc_can_err_skb(priv->netdev, &cf);
 357         if (!skb)
 358                 return;
 359
 360         switch (state) {
 361         case USB_8DEV_STATUSMSG_OK:
 362                 priv->can.state = CAN_STATE_ERROR_ACTIVE;
 363                 cf->can_id |= CAN_ERR_PROT;
 364                 cf->data[2] = CAN_ERR_PROT_ACTIVE;
 365                 break;
 366         case USB_8DEV_STATUSMSG_BUSOFF:
 367                 priv->can.state = CAN_STATE_BUS_OFF;
 368                 cf->can_id |= CAN_ERR_BUSOFF;
 369                 priv->can.can_stats.bus_off++;
 370                 can_bus_off(priv->netdev);
 371                 break;
 372         case USB_8DEV_STATUSMSG_OVERRUN:
 373         case USB_8DEV_STATUSMSG_BUSLIGHT:
 374         case USB_8DEV_STATUSMSG_BUSHEAVY:
 375                 cf->can_id |= CAN_ERR_CRTL;
 376                 break;
 377         default:
 378                 priv->can.state = CAN_STATE_ERROR_WARNING;
 379                 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
 380                 priv->can.can_stats.bus_error++;
 381                 break;
 382         }
 383
 384         switch (state) {
 385         case USB_8DEV_STATUSMSG_OK:
 386         case USB_8DEV_STATUSMSG_BUSOFF:
 387                 break;
 388         case USB_8DEV_STATUSMSG_ACK:
 389                 cf->can_id |= CAN_ERR_ACK;
 390                 tx_errors = 1;
 391                 break;
 392         case USB_8DEV_STATUSMSG_CRC:
 393                 cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
 394                 rx_errors = 1;
 395                 break;
 396         case USB_8DEV_STATUSMSG_BIT0:
 397                 cf->data[2] |= CAN_ERR_PROT_BIT0;
 398                 tx_errors = 1;
 399                 break;
 400         case USB_8DEV_STATUSMSG_BIT1:
 401                 cf->data[2] |= CAN_ERR_PROT_BIT1;
 402                 tx_errors = 1;
 403                 break;
 404         case USB_8DEV_STATUSMSG_FORM:
 405                 cf->data[2] |= CAN_ERR_PROT_FORM;
 406                 rx_errors = 1;
 407                 break;
 408         case USB_8DEV_STATUSMSG_STUFF:
 409                 cf->data[2] |= CAN_ERR_PROT_STUFF;
 410                 rx_errors = 1;
 411                 break;
 412         case USB_8DEV_STATUSMSG_OVERRUN:
 413                 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 414                 stats->rx_over_errors++;
 415                 rx_errors = 1;
 416                 break;
 417         case USB_8DEV_STATUSMSG_BUSLIGHT:
 418                 priv->can.state = CAN_STATE_ERROR_WARNING;
 419                 cf->data[1] = (txerr > rxerr) ?
 420                         CAN_ERR_CRTL_TX_WARNING :
 421                         CAN_ERR_CRTL_RX_WARNING;
 422                 priv->can.can_stats.error_warning++;
 423                 break;
 424         case USB_8DEV_STATUSMSG_BUSHEAVY:
 425                 priv->can.state = CAN_STATE_ERROR_PASSIVE;
 426                 cf->data[1] = (txerr > rxerr) ?
 427                         CAN_ERR_CRTL_TX_PASSIVE :
 428                         CAN_ERR_CRTL_RX_PASSIVE;
 429                 priv->can.can_stats.error_passive++;
 430                 break;
 431         default:
 432                 netdev_warn(priv->netdev,
 433                             "Unknown status/error message (%d)\n", state);
 434                 break;
 435         }
 436
 437         if (tx_errors) {
 438                 cf->data[2] |= CAN_ERR_PROT_TX;
 439                 stats->tx_errors++;
 440         }
 441
 442         if (rx_errors)
 443                 stats->rx_errors++;
 444
 445         cf->data[6] = txerr;
 446         cf->data[7] = rxerr;
 447
 448         priv->bec.txerr = txerr;
 449         priv->bec.rxerr = rxerr;
 450
 451         stats->rx_packets++;
 452         stats->rx_bytes += cf->can_dlc;
 453         netif_rx(skb);
 454 }
 455
 456 /* Read data and status frames */
 457 static void usb_8dev_rx_can_msg(struct usb_8dev_priv *priv,
 458                                 struct usb_8dev_rx_msg *msg)
 459 {
 460         struct can_frame *cf;
 461         struct sk_buff *skb;
 462         struct net_device_stats *stats = &priv->netdev->stats;
 463
 464         if (msg->type == USB_8DEV_TYPE_ERROR_FRAME &&
 465                    msg->flags == USB_8DEV_ERR_FLAG) {
 466                 usb_8dev_rx_err_msg(priv, msg);
 467         } else if (msg->type == USB_8DEV_TYPE_CAN_FRAME) {
 468                 skb = alloc_can_skb(priv->netdev, &cf);
 469                 if (!skb)
 470                         return;
 471
 472                 cf->can_id = be32_to_cpu(msg->id);
 473                 cf->can_dlc = get_can_dlc(msg->dlc & 0xF);
 474
 475                 if (msg->flags & USB_8DEV_EXTID)
 476                         cf->can_id |= CAN_EFF_FLAG;
 477
 478                 if (msg->flags & USB_8DEV_RTR)
 479                         cf->can_id |= CAN_RTR_FLAG;
 480                 else
 481                         memcpy(cf->data, msg->data, cf->can_dlc);
 482
 483                 stats->rx_packets++;
 484                 stats->rx_bytes += cf->can_dlc;
 485                 netif_rx(skb);
 486
 487                 can_led_event(priv->netdev, CAN_LED_EVENT_RX);
 488         } else {
 489                 netdev_warn(priv->netdev, "frame type %d unknown",
 490                          msg->type);
 491         }
 492
 493 }
 494
 495 /* Callback for reading data from device
 496  *
 497  * Check urb status, call read function and resubmit urb read operation.
 498  */
 499 static void usb_8dev_read_bulk_callback(struct urb *urb)
 500 {
 501         struct usb_8dev_priv *priv = urb->context;
 502         struct net_device *netdev;
 503         int retval;
 504         int pos = 0;
 505
 506         netdev = priv->netdev;
 507
 508         if (!netif_device_present(netdev))
 509                 return;
 510
 511         switch (urb->status) {
 512         case 0: /* success */
 513                 break;
 514
 515         case -ENOENT:
 516         case -EPIPE:
 517         case -EPROTO:
 518         case -ESHUTDOWN:
 519                 return;
 520
 521         default:
 522                 netdev_info(netdev, "Rx URB aborted (%d)\n",
 523                          urb->status);
 524                 goto resubmit_urb;
 525         }
 526
 527         while (pos < urb->actual_length) {
 528                 struct usb_8dev_rx_msg *msg;
 529
 530                 if (pos + sizeof(struct usb_8dev_rx_msg) > urb->actual_length) {
 531                         netdev_err(priv->netdev, "format error\n");
 532                         break;
 533                 }
 534
 535                 msg = (struct usb_8dev_rx_msg *)(urb->transfer_buffer + pos);
 536                 usb_8dev_rx_can_msg(priv, msg);
 537
 538                 pos += sizeof(struct usb_8dev_rx_msg);
 539         }
 540
 541 resubmit_urb:
 542         usb_fill_bulk_urb(urb, priv->udev,
 543                           usb_rcvbulkpipe(priv->udev, USB_8DEV_ENDP_DATA_RX),
 544                           urb->transfer_buffer, RX_BUFFER_SIZE,
 545                           usb_8dev_read_bulk_callback, priv);
 546
 547         retval = usb_submit_urb(urb, GFP_ATOMIC);
 548
 549         if (retval == -ENODEV)
 550                 netif_device_detach(netdev);
 551         else if (retval)
 552                 netdev_err(netdev,
 553                         "failed resubmitting read bulk urb: %d\n", retval);
 554 }
 555
 556 /* Callback handler for write operations
 557  *
 558  * Free allocated buffers, check transmit status and
 559  * calculate statistic.
 560  */
 561 static void usb_8dev_write_bulk_callback(struct urb *urb)
 562 {
 563         struct usb_8dev_tx_urb_context *context = urb->context;
 564         struct usb_8dev_priv *priv;
 565         struct net_device *netdev;
 566
 567         BUG_ON(!context);
 568
 569         priv = context->priv;
 570         netdev = priv->netdev;
 571
 572         /* free up our allocated buffer */
 573         usb_free_coherent(urb->dev, urb->transfer_buffer_length,
 574                           urb->transfer_buffer, urb->transfer_dma);
 575
 576         atomic_dec(&priv->active_tx_urbs);
 577
 578         if (!netif_device_present(netdev))
 579                 return;
 580
 581         if (urb->status)
 582                 netdev_info(netdev, "Tx URB aborted (%d)\n",
 583                          urb->status);
 584
 585         netdev->stats.tx_packets++;
 586         netdev->stats.tx_bytes += context->dlc;
 587
 588         can_get_echo_skb(netdev, context->echo_index);
 589
 590         can_led_event(netdev, CAN_LED_EVENT_TX);
 591
 592         /* Release context */
 593         context->echo_index = MAX_TX_URBS;
 594
 595         netif_wake_queue(netdev);
 596 }
 597
 598 /* Send data to device */
 599 static netdev_tx_t usb_8dev_start_xmit(struct sk_buff *skb,
 600                                       struct net_device *netdev)
 601 {
 602         struct usb_8dev_priv *priv = netdev_priv(netdev);
 603         struct net_device_stats *stats = &netdev->stats;
 604         struct can_frame *cf = (struct can_frame *) skb->data;
 605         struct usb_8dev_tx_msg *msg;
 606         struct urb *urb;
 607         struct usb_8dev_tx_urb_context *context = NULL;
 608         u8 *buf;
 609         int i, err;
 610         size_t size = sizeof(struct usb_8dev_tx_msg);
 611
 612         if (can_dropped_invalid_skb(netdev, skb))
 613                 return NETDEV_TX_OK;
 614
 615         /* create a URB, and a buffer for it, and copy the data to the URB */
 616         urb = usb_alloc_urb(0, GFP_ATOMIC);
 617         if (!urb)
 618                 goto nomem;
 619
 620         buf = usb_alloc_coherent(priv->udev, size, GFP_ATOMIC,
 621                                  &urb->transfer_dma);
 622         if (!buf) {
 623                 netdev_err(netdev, "No memory left for USB buffer\n");
 624                 goto nomembuf;
 625         }
 626
 627         memset(buf, 0, size);
 628
 629         msg = (struct usb_8dev_tx_msg *)buf;
 630         msg->begin = USB_8DEV_DATA_START;
 631         msg->flags = 0x00;
 632
 633         if (cf->can_id & CAN_RTR_FLAG)
 634                 msg->flags |= USB_8DEV_RTR;
 635
 636         if (cf->can_id & CAN_EFF_FLAG)
 637                 msg->flags |= USB_8DEV_EXTID;
 638
 639         msg->id = cpu_to_be32(cf->can_id & CAN_ERR_MASK);
 640         msg->dlc = cf->can_dlc;
 641         memcpy(msg->data, cf->data, cf->can_dlc);
 642         msg->end = USB_8DEV_DATA_END;
 643
 644         for (i = 0; i < MAX_TX_URBS; i++) {
 645                 if (priv->tx_contexts[i].echo_index == MAX_TX_URBS) {
 646                         context = &priv->tx_contexts[i];
 647                         break;
 648                 }
 649         }
 650
 651         /* May never happen! When this happens we'd more URBs in flight as
 652          * allowed (MAX_TX_URBS).
 653          */
 654         if (!context)
 655                 goto nofreecontext;
 656
 657         context->priv = priv;
 658         context->echo_index = i;
 659         context->dlc = cf->can_dlc;
 660
 661         usb_fill_bulk_urb(urb, priv->udev,
 662                           usb_sndbulkpipe(priv->udev, USB_8DEV_ENDP_DATA_TX),
 663                           buf, size, usb_8dev_write_bulk_callback, context);
 664         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 665         usb_anchor_urb(urb, &priv->tx_submitted);
 666
 667         can_put_echo_skb(skb, netdev, context->echo_index);
 668
 669         atomic_inc(&priv->active_tx_urbs);
 670
 671         err = usb_submit_urb(urb, GFP_ATOMIC);
 672         if (unlikely(err))
 673                 goto failed;
 674         else if (atomic_read(&priv->active_tx_urbs) >= MAX_TX_URBS)
 675                 /* Slow down tx path */
 676                 netif_stop_queue(netdev);
 677
 678         /* Release our reference to this URB, the USB core will eventually free
 679          * it entirely.
 680          */
 681         usb_free_urb(urb);
 682
 683         return NETDEV_TX_OK;
 684
 685 nofreecontext:
 686         usb_free_coherent(priv->udev, size, buf, urb->transfer_dma);
 687         usb_free_urb(urb);
 688
 689         netdev_warn(netdev, "couldn't find free context");
 690
 691         return NETDEV_TX_BUSY;
 692
 693 failed:
 694         can_free_echo_skb(netdev, context->echo_index);
 695
 696         usb_unanchor_urb(urb);
 697         usb_free_coherent(priv->udev, size, buf, urb->transfer_dma);
 698
 699         atomic_dec(&priv->active_tx_urbs);
 700
 701         if (err == -ENODEV)
 702                 netif_device_detach(netdev);
 703         else
 704                 netdev_warn(netdev, "failed tx_urb %d\n", err);
 705
 706 nomembuf:
 707         usb_free_urb(urb);
 708
 709 nomem:
 710         dev_kfree_skb(skb);
 711         stats->tx_dropped++;
 712
 713         return NETDEV_TX_OK;
 714 }
 715
 716 static int usb_8dev_get_berr_counter(const struct net_device *netdev,
 717                                      struct can_berr_counter *bec)
 718 {
 719         struct usb_8dev_priv *priv = netdev_priv(netdev);
 720
 721         bec->txerr = priv->bec.txerr;
 722         bec->rxerr = priv->bec.rxerr;
 723
 724         return 0;
 725 }
 726
 727 /* Start USB device */
 728 static int usb_8dev_start(struct usb_8dev_priv *priv)
 729 {
 730         struct net_device *netdev = priv->netdev;
 731         int err, i;
 732
 733         for (i = 0; i < MAX_RX_URBS; i++) {
 734                 struct urb *urb = NULL;
 735                 u8 *buf;
 736
 737                 /* create a URB, and a buffer for it */
 738                 urb = usb_alloc_urb(0, GFP_KERNEL);
 739                 if (!urb) {
 740                         err = -ENOMEM;
 741                         break;
 742                 }
 743
 744                 buf = usb_alloc_coherent(priv->udev, RX_BUFFER_SIZE, GFP_KERNEL,
 745                                          &urb->transfer_dma);
 746                 if (!buf) {
 747                         netdev_err(netdev, "No memory left for USB buffer\n");
 748                         usb_free_urb(urb);
 749                         err = -ENOMEM;
 750                         break;
 751                 }
 752
 753                 usb_fill_bulk_urb(urb, priv->udev,
 754                                   usb_rcvbulkpipe(priv->udev,
 755                                                   USB_8DEV_ENDP_DATA_RX),
 756                                   buf, RX_BUFFER_SIZE,
 757                                   usb_8dev_read_bulk_callback, priv);
 758                 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 759                 usb_anchor_urb(urb, &priv->rx_submitted);
 760
 761                 err = usb_submit_urb(urb, GFP_KERNEL);
 762                 if (err) {
 763                         usb_unanchor_urb(urb);
 764                         usb_free_coherent(priv->udev, RX_BUFFER_SIZE, buf,
 765                                           urb->transfer_dma);
 766                         usb_free_urb(urb);
 767                         break;
 768                 }
 769
 770                 /* Drop reference, USB core will take care of freeing it */
 771                 usb_free_urb(urb);
 772         }
 773
 774         /* Did we submit any URBs */
 775         if (i == 0) {
 776                 netdev_warn(netdev, "couldn't setup read URBs\n");
 777                 return err;
 778         }
 779
 780         /* Warn if we've couldn't transmit all the URBs */
 781         if (i < MAX_RX_URBS)
 782                 netdev_warn(netdev, "rx performance may be slow\n");
 783
 784         err = usb_8dev_cmd_open(priv);
 785         if (err)
 786                 goto failed;
 787
 788         priv->can.state = CAN_STATE_ERROR_ACTIVE;
 789
 790         return 0;
 791
 792 failed:
 793         if (err == -ENODEV)
 794                 netif_device_detach(priv->netdev);
 795
 796         netdev_warn(netdev, "couldn't submit control: %d\n", err);
 797
 798         return err;
 799 }
 800
 801 /* Open USB device */
 802 static int usb_8dev_open(struct net_device *netdev)
 803 {
 804         struct usb_8dev_priv *priv = netdev_priv(netdev);
 805         int err;
 806
 807         /* common open */
 808         err = open_candev(netdev);
 809         if (err)
 810                 return err;
 811
 812         can_led_event(netdev, CAN_LED_EVENT_OPEN);
 813
 814         /* finally start device */
 815         err = usb_8dev_start(priv);
 816         if (err) {
 817                 if (err == -ENODEV)
 818                         netif_device_detach(priv->netdev);
 819
 820                 netdev_warn(netdev, "couldn't start device: %d\n",
 821                          err);
 822
 823                 close_candev(netdev);
 824
 825                 return err;
 826         }
 827
 828         netif_start_queue(netdev);
 829
 830         return 0;
 831 }
 832
 833 static void unlink_all_urbs(struct usb_8dev_priv *priv)
 834 {
 835         int i;
 836
 837         usb_kill_anchored_urbs(&priv->rx_submitted);
 838
 839         usb_kill_anchored_urbs(&priv->tx_submitted);
 840         atomic_set(&priv->active_tx_urbs, 0);
 841
 842         for (i = 0; i < MAX_TX_URBS; i++)
 843                 priv->tx_contexts[i].echo_index = MAX_TX_URBS;
 844 }
 845
 846 /* Close USB device */
 847 static int usb_8dev_close(struct net_device *netdev)
 848 {
 849         struct usb_8dev_priv *priv = netdev_priv(netdev);
 850         int err = 0;
 851
 852         /* Send CLOSE command to CAN controller */
 853         err = usb_8dev_cmd_close(priv);
 854         if (err)
 855                 netdev_warn(netdev, "couldn't stop device");
 856
 857         priv->can.state = CAN_STATE_STOPPED;
 858
 859         netif_stop_queue(netdev);
 860
 861         /* Stop polling */
 862         unlink_all_urbs(priv);
 863
 864         close_candev(netdev);
 865
 866         can_led_event(netdev, CAN_LED_EVENT_STOP);
 867
 868         return err;
 869 }
 870
 871 static const struct net_device_ops usb_8dev_netdev_ops = {
 872         .ndo_open = usb_8dev_open,
 873         .ndo_stop = usb_8dev_close,
 874         .ndo_start_xmit = usb_8dev_start_xmit,
 875         .ndo_change_mtu = can_change_mtu,
 876 };
 877
 878 static const struct can_bittiming_const usb_8dev_bittiming_const = {
 879         .name = "usb_8dev",
 880         .tseg1_min = 1,
 881         .tseg1_max = 16,
 882         .tseg2_min = 1,
 883         .tseg2_max = 8,
 884         .sjw_max = 4,
 885         .brp_min = 1,
 886         .brp_max = 1024,
 887         .brp_inc = 1,
 888 };
 889
 890 /* Probe USB device
 891  *
 892  * Check device and firmware.
 893  * Set supported modes and bittiming constants.
 894  * Allocate some memory.
 895  */
 896 static int usb_8dev_probe(struct usb_interface *intf,
 897                          const struct usb_device_id *id)
 898 {
 899         struct net_device *netdev;
 900         struct usb_8dev_priv *priv;
 901         int i, err = -ENOMEM;
 902         u32 version;
 903         char buf[18];
 904         struct usb_device *usbdev = interface_to_usbdev(intf);
 905
 906         /* product id looks strange, better we also check iProduct string */
 907         if (usb_string(usbdev, usbdev->descriptor.iProduct, buf,
 908                        sizeof(buf)) > 0 && strcmp(buf, "USB2CAN converter")) {
 909                 dev_info(&usbdev->dev, "ignoring: not an USB2CAN converter\n");
 910                 return -ENODEV;
 911         }
 912
 913         netdev = alloc_candev(sizeof(struct usb_8dev_priv), MAX_TX_URBS);
 914         if (!netdev) {
 915                 dev_err(&intf->dev, "Couldn't alloc candev\n");
 916                 return -ENOMEM;
 917         }
 918
 919         priv = netdev_priv(netdev);
 920
 921         priv->udev = usbdev;
 922         priv->netdev = netdev;
 923
 924         priv->can.state = CAN_STATE_STOPPED;
 925         priv->can.clock.freq = USB_8DEV_ABP_CLOCK;
 926         priv->can.bittiming_const = &usb_8dev_bittiming_const;
 927         priv->can.do_set_mode = usb_8dev_set_mode;
 928         priv->can.do_get_berr_counter = usb_8dev_get_berr_counter;
 929         priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
 930                                       CAN_CTRLMODE_LISTENONLY |
 931                                       CAN_CTRLMODE_ONE_SHOT;
 932
 933         netdev->netdev_ops = &usb_8dev_netdev_ops;
 934
 935         netdev->flags |= IFF_ECHO; /* we support local echo */
 936
 937         init_usb_anchor(&priv->rx_submitted);
 938
 939         init_usb_anchor(&priv->tx_submitted);
 940         atomic_set(&priv->active_tx_urbs, 0);
 941
 942         for (i = 0; i < MAX_TX_URBS; i++)
 943                 priv->tx_contexts[i].echo_index = MAX_TX_URBS;
 944
 945         priv->cmd_msg_buffer = devm_kzalloc(&intf->dev, sizeof(struct usb_8dev_cmd_msg),
 946                                             GFP_KERNEL);
 947         if (!priv->cmd_msg_buffer)
 948                 goto cleanup_candev;
 949
 950         usb_set_intfdata(intf, priv);
 951
 952         SET_NETDEV_DEV(netdev, &intf->dev);
 953
 954         mutex_init(&priv->usb_8dev_cmd_lock);
 955
 956         err = register_candev(netdev);
 957         if (err) {
 958                 netdev_err(netdev,
 959                         "couldn't register CAN device: %d\n", err);
 960                 goto cleanup_candev;
 961         }
 962
 963         err = usb_8dev_cmd_version(priv, &version);
 964         if (err) {
 965                 netdev_err(netdev, "can't get firmware version\n");
 966                 goto cleanup_unregister_candev;
 967         } else {
 968                 netdev_info(netdev,
 969                          "firmware: %d.%d, hardware: %d.%d\n",
 970                          (version>>24) & 0xff, (version>>16) & 0xff,
 971                          (version>>8) & 0xff, version & 0xff);
 972         }
 973
 974         devm_can_led_init(netdev);
 975
 976         return 0;
 977
 978 cleanup_unregister_candev:
 979         unregister_netdev(priv->netdev);
 980
 981 cleanup_candev:
 982         free_candev(netdev);
 983
 984         return err;
 985
 986 }
 987
 988 /* Called by the usb core when driver is unloaded or device is removed */
 989 static void usb_8dev_disconnect(struct usb_interface *intf)
 990 {
 991         struct usb_8dev_priv *priv = usb_get_intfdata(intf);
 992
 993         usb_set_intfdata(intf, NULL);
 994
 995         if (priv) {
 996                 netdev_info(priv->netdev, "device disconnected\n");
 997
 998                 unregister_netdev(priv->netdev);
 999                 unlink_all_urbs(priv);
1000                 free_candev(priv->netdev);
1001         }
1002
1003 }
1004
1005 static struct usb_driver usb_8dev_driver = {
1006         .name =         "usb_8dev",
1007         .probe =        usb_8dev_probe,
1008         .disconnect =   usb_8dev_disconnect,
1009         .id_table =     usb_8dev_table,
1010 };
1011
1012 module_usb_driver(usb_8dev_driver);
1013
1014 MODULE_AUTHOR("Bernd Krumboeck <krumboeck@universalnet.at>");
1015 MODULE_DESCRIPTION("CAN driver for 8 devices USB2CAN interfaces");
1016 MODULE_LICENSE("GPL v2");