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         void *rxbuf[MAX_RX_URBS];
 141         dma_addr_t rxbuf_dma[MAX_RX_URBS];
 142 };
 143
 144 /* tx frame */
 145 struct __packed usb_8dev_tx_msg {
 146         u8 begin;
 147         u8 flags;       /* RTR and EXT_ID flag */
 148         __be32 id;      /* upper 3 bits not used */
 149         u8 dlc;         /* data length code 0-8 bytes */
 150         u8 data[8];     /* 64-bit data */
 151         u8 end;
 152 };
 153
 154 /* rx frame */
 155 struct __packed usb_8dev_rx_msg {
 156         u8 begin;
 157         u8 type;                /* frame type */
 158         u8 flags;               /* RTR and EXT_ID flag */
 159         __be32 id;              /* upper 3 bits not used */
 160         u8 dlc;                 /* data length code 0-8 bytes */
 161         u8 data[8];             /* 64-bit data */
 162         __be32 timestamp;       /* 32-bit timestamp */
 163         u8 end;
 164 };
 165
 166 /* command frame */
 167 struct __packed usb_8dev_cmd_msg {
 168         u8 begin;
 169         u8 channel;     /* unknown - always 0 */
 170         u8 command;     /* command to execute */
 171         u8 opt1;        /* optional parameter / return value */
 172         u8 opt2;        /* optional parameter 2 */
 173         u8 data[10];    /* optional parameter and data */
 174         u8 end;
 175 };
 176
 177 static int usb_8dev_send_cmd_msg(struct usb_8dev_priv *priv, u8 *msg, int size)
 178 {
 179         int actual_length;
 180
 181         return usb_bulk_msg(priv->udev,
 182                             usb_sndbulkpipe(priv->udev, USB_8DEV_ENDP_CMD_TX),
 183                             msg, size, &actual_length, USB_8DEV_CMD_TIMEOUT);
 184 }
 185
 186 static int usb_8dev_wait_cmd_msg(struct usb_8dev_priv *priv, u8 *msg, int size,
 187                                 int *actual_length)
 188 {
 189         return usb_bulk_msg(priv->udev,
 190                             usb_rcvbulkpipe(priv->udev, USB_8DEV_ENDP_CMD_RX),
 191                             msg, size, actual_length, USB_8DEV_CMD_TIMEOUT);
 192 }
 193
 194 /* Send command to device and receive result.
 195  * Command was successful when opt1 = 0.
 196  */
 197 static int usb_8dev_send_cmd(struct usb_8dev_priv *priv,
 198                              struct usb_8dev_cmd_msg *out,
 199                              struct usb_8dev_cmd_msg *in)
 200 {
 201         int err;
 202         int num_bytes_read;
 203         struct net_device *netdev;
 204
 205         netdev = priv->netdev;
 206
 207         out->begin = USB_8DEV_CMD_START;
 208         out->end = USB_8DEV_CMD_END;
 209
 210         mutex_lock(&priv->usb_8dev_cmd_lock);
 211
 212         memcpy(priv->cmd_msg_buffer, out,
 213                 sizeof(struct usb_8dev_cmd_msg));
 214
 215         err = usb_8dev_send_cmd_msg(priv, priv->cmd_msg_buffer,
 216                                     sizeof(struct usb_8dev_cmd_msg));
 217         if (err < 0) {
 218                 netdev_err(netdev, "sending command message failed\n");
 219                 goto failed;
 220         }
 221
 222         err = usb_8dev_wait_cmd_msg(priv, priv->cmd_msg_buffer,
 223                                     sizeof(struct usb_8dev_cmd_msg),
 224                                     &num_bytes_read);
 225         if (err < 0) {
 226                 netdev_err(netdev, "no command message answer\n");
 227                 goto failed;
 228         }
 229
 230         memcpy(in, priv->cmd_msg_buffer, sizeof(struct usb_8dev_cmd_msg));
 231
 232         if (in->begin != USB_8DEV_CMD_START || in->end != USB_8DEV_CMD_END ||
 233                         num_bytes_read != 16 || in->opt1 != 0)
 234                 err = -EPROTO;
 235
 236 failed:
 237         mutex_unlock(&priv->usb_8dev_cmd_lock);
 238         return err;
 239 }
 240
 241 /* Send open command to device */
 242 static int usb_8dev_cmd_open(struct usb_8dev_priv *priv)
 243 {
 244         struct can_bittiming *bt = &priv->can.bittiming;
 245         struct usb_8dev_cmd_msg outmsg;
 246         struct usb_8dev_cmd_msg inmsg;
 247         u32 ctrlmode = priv->can.ctrlmode;
 248         u32 flags = USB_8DEV_STATUS_FRAME;
 249         __be32 beflags;
 250         __be16 bebrp;
 251
 252         memset(&outmsg, 0, sizeof(outmsg));
 253         outmsg.command = USB_8DEV_OPEN;
 254         outmsg.opt1 = USB_8DEV_BAUD_MANUAL;
 255         outmsg.data[0] = bt->prop_seg + bt->phase_seg1;
 256         outmsg.data[1] = bt->phase_seg2;
 257         outmsg.data[2] = bt->sjw;
 258
 259         /* BRP */
 260         bebrp = cpu_to_be16((u16)bt->brp);
 261         memcpy(&outmsg.data[3], &bebrp, sizeof(bebrp));
 262
 263         /* flags */
 264         if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
 265                 flags |= USB_8DEV_LOOPBACK;
 266         if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
 267                 flags |= USB_8DEV_SILENT;
 268         if (ctrlmode & CAN_CTRLMODE_ONE_SHOT)
 269                 flags |= USB_8DEV_DISABLE_AUTO_RESTRANS;
 270
 271         beflags = cpu_to_be32(flags);
 272         memcpy(&outmsg.data[5], &beflags, sizeof(beflags));
 273
 274         return usb_8dev_send_cmd(priv, &outmsg, &inmsg);
 275 }
 276
 277 /* Send close command to device */
 278 static int usb_8dev_cmd_close(struct usb_8dev_priv *priv)
 279 {
 280         struct usb_8dev_cmd_msg inmsg;
 281         struct usb_8dev_cmd_msg outmsg = {
 282                 .channel = 0,
 283                 .command = USB_8DEV_CLOSE,
 284                 .opt1 = 0,
 285                 .opt2 = 0
 286         };
 287
 288         return usb_8dev_send_cmd(priv, &outmsg, &inmsg);
 289 }
 290
 291 /* Get firmware and hardware version */
 292 static int usb_8dev_cmd_version(struct usb_8dev_priv *priv, u32 *res)
 293 {
 294         struct usb_8dev_cmd_msg inmsg;
 295         struct usb_8dev_cmd_msg outmsg = {
 296                 .channel = 0,
 297                 .command = USB_8DEV_GET_SOFTW_HARDW_VER,
 298                 .opt1 = 0,
 299                 .opt2 = 0
 300         };
 301
 302         int err = usb_8dev_send_cmd(priv, &outmsg, &inmsg);
 303         if (err)
 304                 return err;
 305
 306         *res = be32_to_cpup((__be32 *)inmsg.data);
 307
 308         return err;
 309 }
 310
 311 /* Set network device mode
 312  *
 313  * Maybe we should leave this function empty, because the device
 314  * set mode variable with open command.
 315  */
 316 static int usb_8dev_set_mode(struct net_device *netdev, enum can_mode mode)
 317 {
 318         struct usb_8dev_priv *priv = netdev_priv(netdev);
 319         int err = 0;
 320
 321         switch (mode) {
 322         case CAN_MODE_START:
 323                 err = usb_8dev_cmd_open(priv);
 324                 if (err)
 325                         netdev_warn(netdev, "couldn't start device");
 326                 break;
 327
 328         default:
 329                 return -EOPNOTSUPP;
 330         }
 331
 332         return err;
 333 }
 334
 335 /* Read error/status frames */
 336 static void usb_8dev_rx_err_msg(struct usb_8dev_priv *priv,
 337                                 struct usb_8dev_rx_msg *msg)
 338 {
 339         struct can_frame *cf;
 340         struct sk_buff *skb;
 341         struct net_device_stats *stats = &priv->netdev->stats;
 342
 343         /* Error message:
 344          * byte 0: Status
 345          * byte 1: bit   7: Receive Passive
 346          * byte 1: bit 0-6: Receive Error Counter
 347          * byte 2: Transmit Error Counter
 348          * byte 3: Always 0 (maybe reserved for future use)
 349          */
 350
 351         u8 state = msg->data[0];
 352         u8 rxerr = msg->data[1] & USB_8DEV_RP_MASK;
 353         u8 txerr = msg->data[2];
 354         int rx_errors = 0;
 355         int tx_errors = 0;
 356
 357         skb = alloc_can_err_skb(priv->netdev, &cf);
 358         if (!skb)
 359                 return;
 360
 361         switch (state) {
 362         case USB_8DEV_STATUSMSG_OK:
 363                 priv->can.state = CAN_STATE_ERROR_ACTIVE;
 364                 cf->can_id |= CAN_ERR_PROT;
 365                 cf->data[2] = CAN_ERR_PROT_ACTIVE;
 366                 break;
 367         case USB_8DEV_STATUSMSG_BUSOFF:
 368                 priv->can.state = CAN_STATE_BUS_OFF;
 369                 cf->can_id |= CAN_ERR_BUSOFF;
 370                 priv->can.can_stats.bus_off++;
 371                 can_bus_off(priv->netdev);
 372                 break;
 373         case USB_8DEV_STATUSMSG_OVERRUN:
 374         case USB_8DEV_STATUSMSG_BUSLIGHT:
 375         case USB_8DEV_STATUSMSG_BUSHEAVY:
 376                 cf->can_id |= CAN_ERR_CRTL;
 377                 break;
 378         default:
 379                 priv->can.state = CAN_STATE_ERROR_WARNING;
 380                 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
 381                 priv->can.can_stats.bus_error++;
 382                 break;
 383         }
 384
 385         switch (state) {
 386         case USB_8DEV_STATUSMSG_OK:
 387         case USB_8DEV_STATUSMSG_BUSOFF:
 388                 break;
 389         case USB_8DEV_STATUSMSG_ACK:
 390                 cf->can_id |= CAN_ERR_ACK;
 391                 tx_errors = 1;
 392                 break;
 393         case USB_8DEV_STATUSMSG_CRC:
 394                 cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
 395                 rx_errors = 1;
 396                 break;
 397         case USB_8DEV_STATUSMSG_BIT0:
 398                 cf->data[2] |= CAN_ERR_PROT_BIT0;
 399                 tx_errors = 1;
 400                 break;
 401         case USB_8DEV_STATUSMSG_BIT1:
 402                 cf->data[2] |= CAN_ERR_PROT_BIT1;
 403                 tx_errors = 1;
 404                 break;
 405         case USB_8DEV_STATUSMSG_FORM:
 406                 cf->data[2] |= CAN_ERR_PROT_FORM;
 407                 rx_errors = 1;
 408                 break;
 409         case USB_8DEV_STATUSMSG_STUFF:
 410                 cf->data[2] |= CAN_ERR_PROT_STUFF;
 411                 rx_errors = 1;
 412                 break;
 413         case USB_8DEV_STATUSMSG_OVERRUN:
 414                 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 415                 stats->rx_over_errors++;
 416                 rx_errors = 1;
 417                 break;
 418         case USB_8DEV_STATUSMSG_BUSLIGHT:
 419                 priv->can.state = CAN_STATE_ERROR_WARNING;
 420                 cf->data[1] = (txerr > rxerr) ?
 421                         CAN_ERR_CRTL_TX_WARNING :
 422                         CAN_ERR_CRTL_RX_WARNING;
 423                 priv->can.can_stats.error_warning++;
 424                 break;
 425         case USB_8DEV_STATUSMSG_BUSHEAVY:
 426                 priv->can.state = CAN_STATE_ERROR_PASSIVE;
 427                 cf->data[1] = (txerr > rxerr) ?
 428                         CAN_ERR_CRTL_TX_PASSIVE :
 429                         CAN_ERR_CRTL_RX_PASSIVE;
 430                 priv->can.can_stats.error_passive++;
 431                 break;
 432         default:
 433                 netdev_warn(priv->netdev,
 434                             "Unknown status/error message (%d)\n", state);
 435                 break;
 436         }
 437
 438         if (tx_errors) {
 439                 cf->data[2] |= CAN_ERR_PROT_TX;
 440                 stats->tx_errors++;
 441         }
 442
 443         if (rx_errors)
 444                 stats->rx_errors++;
 445         if (priv->can.state != CAN_STATE_BUS_OFF) {
 446                 cf->data[6] = txerr;
 447                 cf->data[7] = rxerr;
 448         }
 449
 450         priv->bec.txerr = txerr;
 451         priv->bec.rxerr = rxerr;
 452
 453         stats->rx_packets++;
 454         stats->rx_bytes += cf->can_dlc;
 455         netif_rx(skb);
 456 }
 457
 458 /* Read data and status frames */
 459 static void usb_8dev_rx_can_msg(struct usb_8dev_priv *priv,
 460                                 struct usb_8dev_rx_msg *msg)
 461 {
 462         struct can_frame *cf;
 463         struct sk_buff *skb;
 464         struct net_device_stats *stats = &priv->netdev->stats;
 465
 466         if (msg->type == USB_8DEV_TYPE_ERROR_FRAME &&
 467                    msg->flags == USB_8DEV_ERR_FLAG) {
 468                 usb_8dev_rx_err_msg(priv, msg);
 469         } else if (msg->type == USB_8DEV_TYPE_CAN_FRAME) {
 470                 skb = alloc_can_skb(priv->netdev, &cf);
 471                 if (!skb)
 472                         return;
 473
 474                 cf->can_id = be32_to_cpu(msg->id);
 475                 cf->can_dlc = get_can_dlc(msg->dlc & 0xF);
 476
 477                 if (msg->flags & USB_8DEV_EXTID)
 478                         cf->can_id |= CAN_EFF_FLAG;
 479
 480                 if (msg->flags & USB_8DEV_RTR)
 481                         cf->can_id |= CAN_RTR_FLAG;
 482                 else
 483                         memcpy(cf->data, msg->data, cf->can_dlc);
 484
 485                 stats->rx_packets++;
 486                 stats->rx_bytes += cf->can_dlc;
 487                 netif_rx(skb);
 488
 489                 can_led_event(priv->netdev, CAN_LED_EVENT_RX);
 490         } else {
 491                 netdev_warn(priv->netdev, "frame type %d unknown",
 492                          msg->type);
 493         }
 494
 495 }
 496
 497 /* Callback for reading data from device
 498  *
 499  * Check urb status, call read function and resubmit urb read operation.
 500  */
 501 static void usb_8dev_read_bulk_callback(struct urb *urb)
 502 {
 503         struct usb_8dev_priv *priv = urb->context;
 504         struct net_device *netdev;
 505         int retval;
 506         int pos = 0;
 507
 508         netdev = priv->netdev;
 509
 510         if (!netif_device_present(netdev))
 511                 return;
 512
 513         switch (urb->status) {
 514         case 0: /* success */
 515                 break;
 516
 517         case -ENOENT:
 518         case -EPIPE:
 519         case -EPROTO:
 520         case -ESHUTDOWN:
 521                 return;
 522
 523         default:
 524                 netdev_info(netdev, "Rx URB aborted (%d)\n",
 525                          urb->status);
 526                 goto resubmit_urb;
 527         }
 528
 529         while (pos < urb->actual_length) {
 530                 struct usb_8dev_rx_msg *msg;
 531
 532                 if (pos + sizeof(struct usb_8dev_rx_msg) > urb->actual_length) {
 533                         netdev_err(priv->netdev, "format error\n");
 534                         break;
 535                 }
 536
 537                 msg = (struct usb_8dev_rx_msg *)(urb->transfer_buffer + pos);
 538                 usb_8dev_rx_can_msg(priv, msg);
 539
 540                 pos += sizeof(struct usb_8dev_rx_msg);
 541         }
 542
 543 resubmit_urb:
 544         usb_fill_bulk_urb(urb, priv->udev,
 545                           usb_rcvbulkpipe(priv->udev, USB_8DEV_ENDP_DATA_RX),
 546                           urb->transfer_buffer, RX_BUFFER_SIZE,
 547                           usb_8dev_read_bulk_callback, priv);
 548
 549         retval = usb_submit_urb(urb, GFP_ATOMIC);
 550
 551         if (retval == -ENODEV)
 552                 netif_device_detach(netdev);
 553         else if (retval)
 554                 netdev_err(netdev,
 555                         "failed resubmitting read bulk urb: %d\n", retval);
 556 }
 557
 558 /* Callback handler for write operations
 559  *
 560  * Free allocated buffers, check transmit status and
 561  * calculate statistic.
 562  */
 563 static void usb_8dev_write_bulk_callback(struct urb *urb)
 564 {
 565         struct usb_8dev_tx_urb_context *context = urb->context;
 566         struct usb_8dev_priv *priv;
 567         struct net_device *netdev;
 568
 569         BUG_ON(!context);
 570
 571         priv = context->priv;
 572         netdev = priv->netdev;
 573
 574         /* free up our allocated buffer */
 575         usb_free_coherent(urb->dev, urb->transfer_buffer_length,
 576                           urb->transfer_buffer, urb->transfer_dma);
 577
 578         atomic_dec(&priv->active_tx_urbs);
 579
 580         if (!netif_device_present(netdev))
 581                 return;
 582
 583         if (urb->status)
 584                 netdev_info(netdev, "Tx URB aborted (%d)\n",
 585                          urb->status);
 586
 587         netdev->stats.tx_packets++;
 588         netdev->stats.tx_bytes += context->dlc;
 589
 590         can_get_echo_skb(netdev, context->echo_index);
 591
 592         can_led_event(netdev, CAN_LED_EVENT_TX);
 593
 594         /* Release context */
 595         context->echo_index = MAX_TX_URBS;
 596
 597         netif_wake_queue(netdev);
 598 }
 599
 600 /* Send data to device */
 601 static netdev_tx_t usb_8dev_start_xmit(struct sk_buff *skb,
 602                                       struct net_device *netdev)
 603 {
 604         struct usb_8dev_priv *priv = netdev_priv(netdev);
 605         struct net_device_stats *stats = &netdev->stats;
 606         struct can_frame *cf = (struct can_frame *) skb->data;
 607         struct usb_8dev_tx_msg *msg;
 608         struct urb *urb;
 609         struct usb_8dev_tx_urb_context *context = NULL;
 610         u8 *buf;
 611         int i, err;
 612         size_t size = sizeof(struct usb_8dev_tx_msg);
 613
 614         if (can_dropped_invalid_skb(netdev, skb))
 615                 return NETDEV_TX_OK;
 616
 617         /* create a URB, and a buffer for it, and copy the data to the URB */
 618         urb = usb_alloc_urb(0, GFP_ATOMIC);
 619         if (!urb)
 620                 goto nomem;
 621
 622         buf = usb_alloc_coherent(priv->udev, size, GFP_ATOMIC,
 623                                  &urb->transfer_dma);
 624         if (!buf) {
 625                 netdev_err(netdev, "No memory left for USB buffer\n");
 626                 goto nomembuf;
 627         }
 628
 629         memset(buf, 0, size);
 630
 631         msg = (struct usb_8dev_tx_msg *)buf;
 632         msg->begin = USB_8DEV_DATA_START;
 633         msg->flags = 0x00;
 634
 635         if (cf->can_id & CAN_RTR_FLAG)
 636                 msg->flags |= USB_8DEV_RTR;
 637
 638         if (cf->can_id & CAN_EFF_FLAG)
 639                 msg->flags |= USB_8DEV_EXTID;
 640
 641         msg->id = cpu_to_be32(cf->can_id & CAN_ERR_MASK);
 642         msg->dlc = cf->can_dlc;
 643         memcpy(msg->data, cf->data, cf->can_dlc);
 644         msg->end = USB_8DEV_DATA_END;
 645
 646         for (i = 0; i < MAX_TX_URBS; i++) {
 647                 if (priv->tx_contexts[i].echo_index == MAX_TX_URBS) {
 648                         context = &priv->tx_contexts[i];
 649                         break;
 650                 }
 651         }
 652
 653         /* May never happen! When this happens we'd more URBs in flight as
 654          * allowed (MAX_TX_URBS).
 655          */
 656         if (!context)
 657                 goto nofreecontext;
 658
 659         context->priv = priv;
 660         context->echo_index = i;
 661         context->dlc = cf->can_dlc;
 662
 663         usb_fill_bulk_urb(urb, priv->udev,
 664                           usb_sndbulkpipe(priv->udev, USB_8DEV_ENDP_DATA_TX),
 665                           buf, size, usb_8dev_write_bulk_callback, context);
 666         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 667         usb_anchor_urb(urb, &priv->tx_submitted);
 668
 669         can_put_echo_skb(skb, netdev, context->echo_index);
 670
 671         atomic_inc(&priv->active_tx_urbs);
 672
 673         err = usb_submit_urb(urb, GFP_ATOMIC);
 674         if (unlikely(err)) {
 675                 can_free_echo_skb(netdev, context->echo_index);
 676
 677                 usb_unanchor_urb(urb);
 678                 usb_free_coherent(priv->udev, size, buf, urb->transfer_dma);
 679
 680                 atomic_dec(&priv->active_tx_urbs);
 681
 682                 if (err == -ENODEV)
 683                         netif_device_detach(netdev);
 684                 else
 685                         netdev_warn(netdev, "failed tx_urb %d\n", err);
 686                 stats->tx_dropped++;
 687         } else if (atomic_read(&priv->active_tx_urbs) >= MAX_TX_URBS)
 688                 /* Slow down tx path */
 689                 netif_stop_queue(netdev);
 690
 691         /* Release our reference to this URB, the USB core will eventually free
 692          * it entirely.
 693          */
 694         usb_free_urb(urb);
 695
 696         return NETDEV_TX_OK;
 697
 698 nofreecontext:
 699         usb_free_coherent(priv->udev, size, buf, urb->transfer_dma);
 700         usb_free_urb(urb);
 701
 702         netdev_warn(netdev, "couldn't find free context");
 703
 704         return NETDEV_TX_BUSY;
 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                 dma_addr_t buf_dma;
 737
 738                 /* create a URB, and a buffer for it */
 739                 urb = usb_alloc_urb(0, GFP_KERNEL);
 740                 if (!urb) {
 741                         err = -ENOMEM;
 742                         break;
 743                 }
 744
 745                 buf = usb_alloc_coherent(priv->udev, RX_BUFFER_SIZE, GFP_KERNEL,
 746                                          &buf_dma);
 747                 if (!buf) {
 748                         netdev_err(netdev, "No memory left for USB buffer\n");
 749                         usb_free_urb(urb);
 750                         err = -ENOMEM;
 751                         break;
 752                 }
 753
 754                 urb->transfer_dma = buf_dma;
 755
 756                 usb_fill_bulk_urb(urb, priv->udev,
 757                                   usb_rcvbulkpipe(priv->udev,
 758                                                   USB_8DEV_ENDP_DATA_RX),
 759                                   buf, RX_BUFFER_SIZE,
 760                                   usb_8dev_read_bulk_callback, priv);
 761                 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 762                 usb_anchor_urb(urb, &priv->rx_submitted);
 763
 764                 err = usb_submit_urb(urb, GFP_KERNEL);
 765                 if (err) {
 766                         usb_unanchor_urb(urb);
 767                         usb_free_coherent(priv->udev, RX_BUFFER_SIZE, buf,
 768                                           urb->transfer_dma);
 769                         usb_free_urb(urb);
 770                         break;
 771                 }
 772
 773                 priv->rxbuf[i] = buf;
 774                 priv->rxbuf_dma[i] = buf_dma;
 775
 776                 /* Drop reference, USB core will take care of freeing it */
 777                 usb_free_urb(urb);
 778         }
 779
 780         /* Did we submit any URBs */
 781         if (i == 0) {
 782                 netdev_warn(netdev, "couldn't setup read URBs\n");
 783                 return err;
 784         }
 785
 786         /* Warn if we've couldn't transmit all the URBs */
 787         if (i < MAX_RX_URBS)
 788                 netdev_warn(netdev, "rx performance may be slow\n");
 789
 790         err = usb_8dev_cmd_open(priv);
 791         if (err)
 792                 goto failed;
 793
 794         priv->can.state = CAN_STATE_ERROR_ACTIVE;
 795
 796         return 0;
 797
 798 failed:
 799         if (err == -ENODEV)
 800                 netif_device_detach(priv->netdev);
 801
 802         netdev_warn(netdev, "couldn't submit control: %d\n", err);
 803
 804         return err;
 805 }
 806
 807 /* Open USB device */
 808 static int usb_8dev_open(struct net_device *netdev)
 809 {
 810         struct usb_8dev_priv *priv = netdev_priv(netdev);
 811         int err;
 812
 813         /* common open */
 814         err = open_candev(netdev);
 815         if (err)
 816                 return err;
 817
 818         can_led_event(netdev, CAN_LED_EVENT_OPEN);
 819
 820         /* finally start device */
 821         err = usb_8dev_start(priv);
 822         if (err) {
 823                 if (err == -ENODEV)
 824                         netif_device_detach(priv->netdev);
 825
 826                 netdev_warn(netdev, "couldn't start device: %d\n",
 827                          err);
 828
 829                 close_candev(netdev);
 830
 831                 return err;
 832         }
 833
 834         netif_start_queue(netdev);
 835
 836         return 0;
 837 }
 838
 839 static void unlink_all_urbs(struct usb_8dev_priv *priv)
 840 {
 841         int i;
 842
 843         usb_kill_anchored_urbs(&priv->rx_submitted);
 844
 845         for (i = 0; i < MAX_RX_URBS; ++i)
 846                 usb_free_coherent(priv->udev, RX_BUFFER_SIZE,
 847                                   priv->rxbuf[i], priv->rxbuf_dma[i]);
 848
 849         usb_kill_anchored_urbs(&priv->tx_submitted);
 850         atomic_set(&priv->active_tx_urbs, 0);
 851
 852         for (i = 0; i < MAX_TX_URBS; i++)
 853                 priv->tx_contexts[i].echo_index = MAX_TX_URBS;
 854 }
 855
 856 /* Close USB device */
 857 static int usb_8dev_close(struct net_device *netdev)
 858 {
 859         struct usb_8dev_priv *priv = netdev_priv(netdev);
 860         int err = 0;
 861
 862         /* Send CLOSE command to CAN controller */
 863         err = usb_8dev_cmd_close(priv);
 864         if (err)
 865                 netdev_warn(netdev, "couldn't stop device");
 866
 867         priv->can.state = CAN_STATE_STOPPED;
 868
 869         netif_stop_queue(netdev);
 870
 871         /* Stop polling */
 872         unlink_all_urbs(priv);
 873
 874         close_candev(netdev);
 875
 876         can_led_event(netdev, CAN_LED_EVENT_STOP);
 877
 878         return err;
 879 }
 880
 881 static const struct net_device_ops usb_8dev_netdev_ops = {
 882         .ndo_open = usb_8dev_open,
 883         .ndo_stop = usb_8dev_close,
 884         .ndo_start_xmit = usb_8dev_start_xmit,
 885         .ndo_change_mtu = can_change_mtu,
 886 };
 887
 888 static const struct can_bittiming_const usb_8dev_bittiming_const = {
 889         .name = "usb_8dev",
 890         .tseg1_min = 1,
 891         .tseg1_max = 16,
 892         .tseg2_min = 1,
 893         .tseg2_max = 8,
 894         .sjw_max = 4,
 895         .brp_min = 1,
 896         .brp_max = 1024,
 897         .brp_inc = 1,
 898 };
 899
 900 /* Probe USB device
 901  *
 902  * Check device and firmware.
 903  * Set supported modes and bittiming constants.
 904  * Allocate some memory.
 905  */
 906 static int usb_8dev_probe(struct usb_interface *intf,
 907                          const struct usb_device_id *id)
 908 {
 909         struct net_device *netdev;
 910         struct usb_8dev_priv *priv;
 911         int i, err = -ENOMEM;
 912         u32 version;
 913         char buf[18];
 914         struct usb_device *usbdev = interface_to_usbdev(intf);
 915
 916         /* product id looks strange, better we also check iProduct string */
 917         if (usb_string(usbdev, usbdev->descriptor.iProduct, buf,
 918                        sizeof(buf)) > 0 && strcmp(buf, "USB2CAN converter")) {
 919                 dev_info(&usbdev->dev, "ignoring: not an USB2CAN converter\n");
 920                 return -ENODEV;
 921         }
 922
 923         netdev = alloc_candev(sizeof(struct usb_8dev_priv), MAX_TX_URBS);
 924         if (!netdev) {
 925                 dev_err(&intf->dev, "Couldn't alloc candev\n");
 926                 return -ENOMEM;
 927         }
 928
 929         priv = netdev_priv(netdev);
 930
 931         priv->udev = usbdev;
 932         priv->netdev = netdev;
 933
 934         priv->can.state = CAN_STATE_STOPPED;
 935         priv->can.clock.freq = USB_8DEV_ABP_CLOCK;
 936         priv->can.bittiming_const = &usb_8dev_bittiming_const;
 937         priv->can.do_set_mode = usb_8dev_set_mode;
 938         priv->can.do_get_berr_counter = usb_8dev_get_berr_counter;
 939         priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
 940                                       CAN_CTRLMODE_LISTENONLY |
 941                                       CAN_CTRLMODE_ONE_SHOT;
 942
 943         netdev->netdev_ops = &usb_8dev_netdev_ops;
 944
 945         netdev->flags |= IFF_ECHO; /* we support local echo */
 946
 947         init_usb_anchor(&priv->rx_submitted);
 948
 949         init_usb_anchor(&priv->tx_submitted);
 950         atomic_set(&priv->active_tx_urbs, 0);
 951
 952         for (i = 0; i < MAX_TX_URBS; i++)
 953                 priv->tx_contexts[i].echo_index = MAX_TX_URBS;
 954
 955         priv->cmd_msg_buffer = devm_kzalloc(&intf->dev, sizeof(struct usb_8dev_cmd_msg),
 956                                             GFP_KERNEL);
 957         if (!priv->cmd_msg_buffer)
 958                 goto cleanup_candev;
 959
 960         usb_set_intfdata(intf, priv);
 961
 962         SET_NETDEV_DEV(netdev, &intf->dev);
 963
 964         mutex_init(&priv->usb_8dev_cmd_lock);
 965
 966         err = register_candev(netdev);
 967         if (err) {
 968                 netdev_err(netdev,
 969                         "couldn't register CAN device: %d\n", err);
 970                 goto cleanup_candev;
 971         }
 972
 973         err = usb_8dev_cmd_version(priv, &version);
 974         if (err) {
 975                 netdev_err(netdev, "can't get firmware version\n");
 976                 goto cleanup_unregister_candev;
 977         } else {
 978                 netdev_info(netdev,
 979                          "firmware: %d.%d, hardware: %d.%d\n",
 980                          (version>>24) & 0xff, (version>>16) & 0xff,
 981                          (version>>8) & 0xff, version & 0xff);
 982         }
 983
 984         devm_can_led_init(netdev);
 985
 986         return 0;
 987
 988 cleanup_unregister_candev:
 989         unregister_netdev(priv->netdev);
 990
 991 cleanup_candev:
 992         free_candev(netdev);
 993
 994         return err;
 995
 996 }
 997
 998 /* Called by the usb core when driver is unloaded or device is removed */
 999 static void usb_8dev_disconnect(struct usb_interface *intf)
1000 {
1001         struct usb_8dev_priv *priv = usb_get_intfdata(intf);
1002
1003         usb_set_intfdata(intf, NULL);
1004
1005         if (priv) {
1006                 netdev_info(priv->netdev, "device disconnected\n");
1007
1008                 unregister_netdev(priv->netdev);
1009                 unlink_all_urbs(priv);
1010                 free_candev(priv->netdev);
1011         }
1012
1013 }
1014
1015 static struct usb_driver usb_8dev_driver = {
1016         .name =         "usb_8dev",
1017         .probe =        usb_8dev_probe,
1018         .disconnect =   usb_8dev_disconnect,
1019         .id_table =     usb_8dev_table,
1020 };
1021
1022 module_usb_driver(usb_8dev_driver);
1023
1024 MODULE_AUTHOR("Bernd Krumboeck <krumboeck@universalnet.at>");
1025 MODULE_DESCRIPTION("CAN driver for 8 devices USB2CAN interfaces");
1026 MODULE_LICENSE("GPL v2");