drivers/net/can/usb/usb_8dev.c

   1 /*
   2  * CAN driver for "8 devices" USB2CAN converter
   3  *
   4  * Copyright (C) 2012 Bernd Krumboeck (krumboeck@universalnet.at)
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published
   8  * by the Free Software Foundation; version 2 of the License.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program.
  17  *
  18  * This driver is inspired by the 3.2.0 version of drivers/net/can/usb/ems_usb.c
  19  * and drivers/net/can/usb/esd_usb2.c
  20  *
  21  * Many thanks to Gerhard Bertelsmann (info@gerhard-bertelsmann.de)
  22  * for testing and fixing this driver. Also many thanks to "8 devices",
  23  * who were very cooperative and answered my questions.
  24  */
  25
  26 #include <linux/signal.h>
  27 #include <linux/slab.h>
  28 #include <linux/module.h>
  29 #include <linux/netdevice.h>
  30 #include <linux/usb.h>
  31
  32 #include <linux/can.h>
  33 #include <linux/can/dev.h>
  34 #include <linux/can/error.h>
  35 #include <linux/can/led.h>
  36
  37 /* driver constants */
  38 #define MAX_RX_URBS                     20
  39 #define MAX_TX_URBS                     20
  40 #define RX_BUFFER_SIZE                  64
  41
  42 /* vendor and product id */
  43 #define USB_8DEV_VENDOR_ID              0x0483
  44 #define USB_8DEV_PRODUCT_ID             0x1234
  45
  46 /* endpoints */
  47 enum usb_8dev_endpoint {
  48         USB_8DEV_ENDP_DATA_RX = 1,
  49         USB_8DEV_ENDP_DATA_TX,
  50         USB_8DEV_ENDP_CMD_RX,
  51         USB_8DEV_ENDP_CMD_TX
  52 };
  53
  54 /* device CAN clock */
  55 #define USB_8DEV_ABP_CLOCK              32000000
  56
  57 /* setup flags */
  58 #define USB_8DEV_SILENT                 0x01
  59 #define USB_8DEV_LOOPBACK               0x02
  60 #define USB_8DEV_DISABLE_AUTO_RESTRANS  0x04
  61 #define USB_8DEV_STATUS_FRAME           0x08
  62
  63 /* commands */
  64 enum usb_8dev_cmd {
  65         USB_8DEV_RESET = 1,
  66         USB_8DEV_OPEN,
  67         USB_8DEV_CLOSE,
  68         USB_8DEV_SET_SPEED,
  69         USB_8DEV_SET_MASK_FILTER,
  70         USB_8DEV_GET_STATUS,
  71         USB_8DEV_GET_STATISTICS,
  72         USB_8DEV_GET_SERIAL,
  73         USB_8DEV_GET_SOFTW_VER,
  74         USB_8DEV_GET_HARDW_VER,
  75         USB_8DEV_RESET_TIMESTAMP,
  76         USB_8DEV_GET_SOFTW_HARDW_VER
  77 };
  78
  79 /* command options */
  80 #define USB_8DEV_BAUD_MANUAL            0x09
  81 #define USB_8DEV_CMD_START              0x11
  82 #define USB_8DEV_CMD_END                0x22
  83
  84 #define USB_8DEV_CMD_SUCCESS            0
  85 #define USB_8DEV_CMD_ERROR              255
  86
  87 #define USB_8DEV_CMD_TIMEOUT            1000
  88
  89 /* frames */
  90 #define USB_8DEV_DATA_START             0x55
  91 #define USB_8DEV_DATA_END               0xAA
  92
  93 #define USB_8DEV_TYPE_CAN_FRAME         0
  94 #define USB_8DEV_TYPE_ERROR_FRAME       3
  95
  96 #define USB_8DEV_EXTID                  0x01
  97 #define USB_8DEV_RTR                    0x02
  98 #define USB_8DEV_ERR_FLAG               0x04
  99
 100 /* status */
 101 #define USB_8DEV_STATUSMSG_OK           0x00  /* Normal condition. */
 102 #define USB_8DEV_STATUSMSG_OVERRUN      0x01  /* Overrun occured when sending */
 103 #define USB_8DEV_STATUSMSG_BUSLIGHT     0x02  /* Error counter has reached 96 */
 104 #define USB_8DEV_STATUSMSG_BUSHEAVY     0x03  /* Error count. has reached 128 */
 105 #define USB_8DEV_STATUSMSG_BUSOFF       0x04  /* Device is in BUSOFF */
 106 #define USB_8DEV_STATUSMSG_STUFF        0x20  /* Stuff Error */
 107 #define USB_8DEV_STATUSMSG_FORM         0x21  /* Form Error */
 108 #define USB_8DEV_STATUSMSG_ACK          0x23  /* Ack Error */
 109 #define USB_8DEV_STATUSMSG_BIT0         0x24  /* Bit1 Error */
 110 #define USB_8DEV_STATUSMSG_BIT1         0x25  /* Bit0 Error */
 111 #define USB_8DEV_STATUSMSG_CRC          0x27  /* CRC Error */
 112
 113 #define USB_8DEV_RP_MASK                0x7F  /* Mask for Receive Error Bit */
 114
 115
 116 /* table of devices that work with this driver */
 117 static const struct usb_device_id usb_8dev_table[] = {
 118         { USB_DEVICE(USB_8DEV_VENDOR_ID, USB_8DEV_PRODUCT_ID) },
 119         { }                                     /* Terminating entry */
 120 };
 121
 122 MODULE_DEVICE_TABLE(usb, usb_8dev_table);
 123
 124 struct usb_8dev_tx_urb_context {
 125         struct usb_8dev_priv *priv;
 126
 127         u32 echo_index;
 128         u8 dlc;
 129 };
 130
 131 /* Structure to hold all of our device specific stuff */
 132 struct usb_8dev_priv {
 133         struct can_priv can; /* must be the first member */
 134
 135         struct sk_buff *echo_skb[MAX_TX_URBS];
 136
 137         struct usb_device *udev;
 138         struct net_device *netdev;
 139
 140         atomic_t active_tx_urbs;
 141         struct usb_anchor tx_submitted;
 142         struct usb_8dev_tx_urb_context tx_contexts[MAX_TX_URBS];
 143
 144         struct usb_anchor rx_submitted;
 145
 146         struct can_berr_counter bec;
 147
 148         u8 *cmd_msg_buffer;
 149
 150         struct mutex usb_8dev_cmd_lock;
 151
 152 };
 153
 154 /* tx frame */
 155 struct __packed usb_8dev_tx_msg {
 156         u8 begin;
 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         u8 end;
 162 };
 163
 164 /* rx frame */
 165 struct __packed usb_8dev_rx_msg {
 166         u8 begin;
 167         u8 type;                /* frame type */
 168         u8 flags;               /* RTR and EXT_ID flag */
 169         __be32 id;              /* upper 3 bits not used */
 170         u8 dlc;                 /* data length code 0-8 bytes */
 171         u8 data[8];             /* 64-bit data */
 172         __be32 timestamp;       /* 32-bit timestamp */
 173         u8 end;
 174 };
 175
 176 /* command frame */
 177 struct __packed usb_8dev_cmd_msg {
 178         u8 begin;
 179         u8 channel;     /* unkown - always 0 */
 180         u8 command;     /* command to execute */
 181         u8 opt1;        /* optional parameter / return value */
 182         u8 opt2;        /* optional parameter 2 */
 183         u8 data[10];    /* optional parameter and data */
 184         u8 end;
 185 };
 186
 187 static int usb_8dev_send_cmd_msg(struct usb_8dev_priv *priv, u8 *msg, int size)
 188 {
 189         int actual_length;
 190
 191         return usb_bulk_msg(priv->udev,
 192                             usb_sndbulkpipe(priv->udev, USB_8DEV_ENDP_CMD_TX),
 193                             msg, size, &actual_length, USB_8DEV_CMD_TIMEOUT);
 194 }
 195
 196 static int usb_8dev_wait_cmd_msg(struct usb_8dev_priv *priv, u8 *msg, int size,
 197                                 int *actual_length)
 198 {
 199         return usb_bulk_msg(priv->udev,
 200                             usb_rcvbulkpipe(priv->udev, USB_8DEV_ENDP_CMD_RX),
 201                             msg, size, actual_length, USB_8DEV_CMD_TIMEOUT);
 202 }
 203
 204 /* Send command to device and receive result.
 205  * Command was successful when opt1 = 0.
 206  */
 207 static int usb_8dev_send_cmd(struct usb_8dev_priv *priv,
 208                              struct usb_8dev_cmd_msg *out,
 209                              struct usb_8dev_cmd_msg *in)
 210 {
 211         int err;
 212         int num_bytes_read;
 213         struct net_device *netdev;
 214
 215         netdev = priv->netdev;
 216
 217         out->begin = USB_8DEV_CMD_START;
 218         out->end = USB_8DEV_CMD_END;
 219
 220         mutex_lock(&priv->usb_8dev_cmd_lock);
 221
 222         memcpy(priv->cmd_msg_buffer, out,
 223                 sizeof(struct usb_8dev_cmd_msg));
 224
 225         err = usb_8dev_send_cmd_msg(priv, priv->cmd_msg_buffer,
 226                                     sizeof(struct usb_8dev_cmd_msg));
 227         if (err < 0) {
 228                 netdev_err(netdev, "sending command message failed\n");
 229                 goto failed;
 230         }
 231
 232         err = usb_8dev_wait_cmd_msg(priv, priv->cmd_msg_buffer,
 233                                     sizeof(struct usb_8dev_cmd_msg),
 234                                     &num_bytes_read);
 235         if (err < 0) {
 236                 netdev_err(netdev, "no command message answer\n");
 237                 goto failed;
 238         }
 239
 240         memcpy(in, priv->cmd_msg_buffer, sizeof(struct usb_8dev_cmd_msg));
 241
 242         if (in->begin != USB_8DEV_CMD_START || in->end != USB_8DEV_CMD_END ||
 243                         num_bytes_read != 16 || in->opt1 != 0)
 244                 err = -EPROTO;
 245
 246 failed:
 247         mutex_unlock(&priv->usb_8dev_cmd_lock);
 248         return err;
 249 }
 250
 251 /* Send open command to device */
 252 static int usb_8dev_cmd_open(struct usb_8dev_priv *priv)
 253 {
 254         struct can_bittiming *bt = &priv->can.bittiming;
 255         struct usb_8dev_cmd_msg outmsg;
 256         struct usb_8dev_cmd_msg inmsg;
 257         u32 ctrlmode = priv->can.ctrlmode;
 258         u32 flags = USB_8DEV_STATUS_FRAME;
 259         __be32 beflags;
 260         __be16 bebrp;
 261
 262         memset(&outmsg, 0, sizeof(outmsg));
 263         outmsg.command = USB_8DEV_OPEN;
 264         outmsg.opt1 = USB_8DEV_BAUD_MANUAL;
 265         outmsg.data[0] = bt->prop_seg + bt->phase_seg1;
 266         outmsg.data[1] = bt->phase_seg2;
 267         outmsg.data[2] = bt->sjw;
 268
 269         /* BRP */
 270         bebrp = cpu_to_be16((u16)bt->brp);
 271         memcpy(&outmsg.data[3], &bebrp, sizeof(bebrp));
 272
 273         /* flags */
 274         if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
 275                 flags |= USB_8DEV_LOOPBACK;
 276         if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
 277                 flags |= USB_8DEV_SILENT;
 278         if (ctrlmode & CAN_CTRLMODE_ONE_SHOT)
 279                 flags |= USB_8DEV_DISABLE_AUTO_RESTRANS;
 280
 281         beflags = cpu_to_be32(flags);
 282         memcpy(&outmsg.data[5], &beflags, sizeof(beflags));
 283
 284         return usb_8dev_send_cmd(priv, &outmsg, &inmsg);
 285 }
 286
 287 /* Send close command to device */
 288 static int usb_8dev_cmd_close(struct usb_8dev_priv *priv)
 289 {
 290         struct usb_8dev_cmd_msg inmsg;
 291         struct usb_8dev_cmd_msg outmsg = {
 292                 .channel = 0,
 293                 .command = USB_8DEV_CLOSE,
 294                 .opt1 = 0,
 295                 .opt2 = 0
 296         };
 297
 298         return usb_8dev_send_cmd(priv, &outmsg, &inmsg);
 299 }
 300
 301 /* Get firmware and hardware version */
 302 static int usb_8dev_cmd_version(struct usb_8dev_priv *priv, u32 *res)
 303 {
 304         struct usb_8dev_cmd_msg inmsg;
 305         struct usb_8dev_cmd_msg outmsg = {
 306                 .channel = 0,
 307                 .command = USB_8DEV_GET_SOFTW_HARDW_VER,
 308                 .opt1 = 0,
 309                 .opt2 = 0
 310         };
 311
 312         int err = usb_8dev_send_cmd(priv, &outmsg, &inmsg);
 313         if (err)
 314                 return err;
 315
 316         *res = be32_to_cpup((__be32 *)inmsg.data);
 317
 318         return err;
 319 }
 320
 321 /* Set network device mode
 322  *
 323  * Maybe we should leave this function empty, because the device
 324  * set mode variable with open command.
 325  */
 326 static int usb_8dev_set_mode(struct net_device *netdev, enum can_mode mode)
 327 {
 328         struct usb_8dev_priv *priv = netdev_priv(netdev);
 329         int err = 0;
 330
 331         switch (mode) {
 332         case CAN_MODE_START:
 333                 err = usb_8dev_cmd_open(priv);
 334                 if (err)
 335                         netdev_warn(netdev, "couldn't start device");
 336                 break;
 337
 338         default:
 339                 return -EOPNOTSUPP;
 340         }
 341
 342         return err;
 343 }
 344
 345 /* Read error/status frames */
 346 static void usb_8dev_rx_err_msg(struct usb_8dev_priv *priv,
 347                                 struct usb_8dev_rx_msg *msg)
 348 {
 349         struct can_frame *cf;
 350         struct sk_buff *skb;
 351         struct net_device_stats *stats = &priv->netdev->stats;
 352
 353         /* Error message:
 354          * byte 0: Status
 355          * byte 1: bit   7: Receive Passive
 356          * byte 1: bit 0-6: Receive Error Counter
 357          * byte 2: Transmit Error Counter
 358          * byte 3: Always 0 (maybe reserved for future use)
 359          */
 360
 361         u8 state = msg->data[0];
 362         u8 rxerr = msg->data[1] & USB_8DEV_RP_MASK;
 363         u8 txerr = msg->data[2];
 364         int rx_errors = 0;
 365         int tx_errors = 0;
 366
 367         skb = alloc_can_err_skb(priv->netdev, &cf);
 368         if (!skb)
 369                 return;
 370
 371         switch (state) {
 372         case USB_8DEV_STATUSMSG_OK:
 373                 priv->can.state = CAN_STATE_ERROR_ACTIVE;
 374                 cf->can_id |= CAN_ERR_PROT;
 375                 cf->data[2] = CAN_ERR_PROT_ACTIVE;
 376                 break;
 377         case USB_8DEV_STATUSMSG_BUSOFF:
 378                 priv->can.state = CAN_STATE_BUS_OFF;
 379                 cf->can_id |= CAN_ERR_BUSOFF;
 380                 can_bus_off(priv->netdev);
 381                 break;
 382         case USB_8DEV_STATUSMSG_OVERRUN:
 383         case USB_8DEV_STATUSMSG_BUSLIGHT:
 384         case USB_8DEV_STATUSMSG_BUSHEAVY:
 385                 cf->can_id |= CAN_ERR_CRTL;
 386                 break;
 387         default:
 388                 priv->can.state = CAN_STATE_ERROR_WARNING;
 389                 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
 390                 priv->can.can_stats.bus_error++;
 391                 break;
 392         }
 393
 394         switch (state) {
 395         case USB_8DEV_STATUSMSG_OK:
 396         case USB_8DEV_STATUSMSG_BUSOFF:
 397                 break;
 398         case USB_8DEV_STATUSMSG_ACK:
 399                 cf->can_id |= CAN_ERR_ACK;
 400                 tx_errors = 1;
 401                 break;
 402         case USB_8DEV_STATUSMSG_CRC:
 403                 cf->data[2] |= CAN_ERR_PROT_UNSPEC;
 404                 cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ |
 405                                CAN_ERR_PROT_LOC_CRC_DEL;
 406                 rx_errors = 1;
 407                 break;
 408         case USB_8DEV_STATUSMSG_BIT0:
 409                 cf->data[2] |= CAN_ERR_PROT_BIT0;
 410                 tx_errors = 1;
 411                 break;
 412         case USB_8DEV_STATUSMSG_BIT1:
 413                 cf->data[2] |= CAN_ERR_PROT_BIT1;
 414                 tx_errors = 1;
 415                 break;
 416         case USB_8DEV_STATUSMSG_FORM:
 417                 cf->data[2] |= CAN_ERR_PROT_FORM;
 418                 rx_errors = 1;
 419                 break;
 420         case USB_8DEV_STATUSMSG_STUFF:
 421                 cf->data[2] |= CAN_ERR_PROT_STUFF;
 422                 rx_errors = 1;
 423                 break;
 424         case USB_8DEV_STATUSMSG_OVERRUN:
 425                 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 426                 stats->rx_over_errors++;
 427                 rx_errors = 1;
 428                 break;
 429         case USB_8DEV_STATUSMSG_BUSLIGHT:
 430                 priv->can.state = CAN_STATE_ERROR_WARNING;
 431                 cf->data[1] = (txerr > rxerr) ?
 432                         CAN_ERR_CRTL_TX_WARNING :
 433                         CAN_ERR_CRTL_RX_WARNING;
 434                 priv->can.can_stats.error_warning++;
 435                 break;
 436         case USB_8DEV_STATUSMSG_BUSHEAVY:
 437                 priv->can.state = CAN_STATE_ERROR_PASSIVE;
 438                 cf->data[1] = (txerr > rxerr) ?
 439                         CAN_ERR_CRTL_TX_PASSIVE :
 440                         CAN_ERR_CRTL_RX_PASSIVE;
 441                 priv->can.can_stats.error_passive++;
 442                 break;
 443         default:
 444                 netdev_warn(priv->netdev,
 445                             "Unknown status/error message (%d)\n", state);
 446                 break;
 447         }
 448
 449         if (tx_errors) {
 450                 cf->data[2] |= CAN_ERR_PROT_TX;
 451                 stats->tx_errors++;
 452         }
 453
 454         if (rx_errors)
 455                 stats->rx_errors++;
 456
 457         cf->data[6] = txerr;
 458         cf->data[7] = rxerr;
 459
 460         priv->bec.txerr = txerr;
 461         priv->bec.rxerr = rxerr;
 462
 463         netif_rx(skb);
 464
 465         stats->rx_packets++;
 466         stats->rx_bytes += cf->can_dlc;
 467 }
 468
 469 /* Read data and status frames */
 470 static void usb_8dev_rx_can_msg(struct usb_8dev_priv *priv,
 471                                 struct usb_8dev_rx_msg *msg)
 472 {
 473         struct can_frame *cf;
 474         struct sk_buff *skb;
 475         struct net_device_stats *stats = &priv->netdev->stats;
 476
 477         if (msg->type == USB_8DEV_TYPE_ERROR_FRAME &&
 478                    msg->flags == USB_8DEV_ERR_FLAG) {
 479                 usb_8dev_rx_err_msg(priv, msg);
 480         } else if (msg->type == USB_8DEV_TYPE_CAN_FRAME) {
 481                 skb = alloc_can_skb(priv->netdev, &cf);
 482                 if (!skb)
 483                         return;
 484
 485                 cf->can_id = be32_to_cpu(msg->id);
 486                 cf->can_dlc = get_can_dlc(msg->dlc & 0xF);
 487
 488                 if (msg->flags & USB_8DEV_EXTID)
 489                         cf->can_id |= CAN_EFF_FLAG;
 490
 491                 if (msg->flags & USB_8DEV_RTR)
 492                         cf->can_id |= CAN_RTR_FLAG;
 493                 else
 494                         memcpy(cf->data, msg->data, cf->can_dlc);
 495
 496                 netif_rx(skb);
 497
 498                 stats->rx_packets++;
 499                 stats->rx_bytes += cf->can_dlc;
 500
 501                 can_led_event(priv->netdev, CAN_LED_EVENT_RX);
 502         } else {
 503                 netdev_warn(priv->netdev, "frame type %d unknown",
 504                          msg->type);
 505         }
 506
 507 }
 508
 509 /* Callback for reading data from device
 510  *
 511  * Check urb status, call read function and resubmit urb read operation.
 512  */
 513 static void usb_8dev_read_bulk_callback(struct urb *urb)
 514 {
 515         struct usb_8dev_priv *priv = urb->context;
 516         struct net_device *netdev;
 517         int retval;
 518         int pos = 0;
 519
 520         netdev = priv->netdev;
 521
 522         if (!netif_device_present(netdev))
 523                 return;
 524
 525         switch (urb->status) {
 526         case 0: /* success */
 527                 break;
 528
 529         case -ENOENT:
 530         case -ESHUTDOWN:
 531                 return;
 532
 533         default:
 534                 netdev_info(netdev, "Rx URB aborted (%d)\n",
 535                          urb->status);
 536                 goto resubmit_urb;
 537         }
 538
 539         while (pos < urb->actual_length) {
 540                 struct usb_8dev_rx_msg *msg;
 541
 542                 if (pos + sizeof(struct usb_8dev_rx_msg) > urb->actual_length) {
 543                         netdev_err(priv->netdev, "format error\n");
 544                         break;
 545                 }
 546
 547                 msg = (struct usb_8dev_rx_msg *)(urb->transfer_buffer + pos);
 548                 usb_8dev_rx_can_msg(priv, msg);
 549
 550                 pos += sizeof(struct usb_8dev_rx_msg);
 551         }
 552
 553 resubmit_urb:
 554         usb_fill_bulk_urb(urb, priv->udev,
 555                           usb_rcvbulkpipe(priv->udev, USB_8DEV_ENDP_DATA_RX),
 556                           urb->transfer_buffer, RX_BUFFER_SIZE,
 557                           usb_8dev_read_bulk_callback, priv);
 558
 559         retval = usb_submit_urb(urb, GFP_ATOMIC);
 560
 561         if (retval == -ENODEV)
 562                 netif_device_detach(netdev);
 563         else if (retval)
 564                 netdev_err(netdev,
 565                         "failed resubmitting read bulk urb: %d\n", retval);
 566 }
 567
 568 /* Callback handler for write operations
 569  *
 570  * Free allocated buffers, check transmit status and
 571  * calculate statistic.
 572  */
 573 static void usb_8dev_write_bulk_callback(struct urb *urb)
 574 {
 575         struct usb_8dev_tx_urb_context *context = urb->context;
 576         struct usb_8dev_priv *priv;
 577         struct net_device *netdev;
 578
 579         BUG_ON(!context);
 580
 581         priv = context->priv;
 582         netdev = priv->netdev;
 583
 584         /* free up our allocated buffer */
 585         usb_free_coherent(urb->dev, urb->transfer_buffer_length,
 586                           urb->transfer_buffer, urb->transfer_dma);
 587
 588         atomic_dec(&priv->active_tx_urbs);
 589
 590         if (!netif_device_present(netdev))
 591                 return;
 592
 593         if (urb->status)
 594                 netdev_info(netdev, "Tx URB aborted (%d)\n",
 595                          urb->status);
 596
 597         netdev->stats.tx_packets++;
 598         netdev->stats.tx_bytes += context->dlc;
 599
 600         can_get_echo_skb(netdev, context->echo_index);
 601
 602         can_led_event(netdev, CAN_LED_EVENT_TX);
 603
 604         /* Release context */
 605         context->echo_index = MAX_TX_URBS;
 606
 607         netif_wake_queue(netdev);
 608 }
 609
 610 /* Send data to device */
 611 static netdev_tx_t usb_8dev_start_xmit(struct sk_buff *skb,
 612                                       struct net_device *netdev)
 613 {
 614         struct usb_8dev_priv *priv = netdev_priv(netdev);
 615         struct net_device_stats *stats = &netdev->stats;
 616         struct can_frame *cf = (struct can_frame *) skb->data;
 617         struct usb_8dev_tx_msg *msg;
 618         struct urb *urb;
 619         struct usb_8dev_tx_urb_context *context = NULL;
 620         u8 *buf;
 621         int i, err;
 622         size_t size = sizeof(struct usb_8dev_tx_msg);
 623
 624         if (can_dropped_invalid_skb(netdev, skb))
 625                 return NETDEV_TX_OK;
 626
 627         /* create a URB, and a buffer for it, and copy the data to the URB */
 628         urb = usb_alloc_urb(0, GFP_ATOMIC);
 629         if (!urb) {
 630                 netdev_err(netdev, "No memory left for URBs\n");
 631                 goto nomem;
 632         }
 633
 634         buf = usb_alloc_coherent(priv->udev, size, GFP_ATOMIC,
 635                                  &urb->transfer_dma);
 636         if (!buf) {
 637                 netdev_err(netdev, "No memory left for USB buffer\n");
 638                 goto nomembuf;
 639         }
 640
 641         memset(buf, 0, size);
 642
 643         msg = (struct usb_8dev_tx_msg *)buf;
 644         msg->begin = USB_8DEV_DATA_START;
 645         msg->flags = 0x00;
 646
 647         if (cf->can_id & CAN_RTR_FLAG)
 648                 msg->flags |= USB_8DEV_RTR;
 649
 650         if (cf->can_id & CAN_EFF_FLAG)
 651                 msg->flags |= USB_8DEV_EXTID;
 652
 653         msg->id = cpu_to_be32(cf->can_id & CAN_ERR_MASK);
 654         msg->dlc = cf->can_dlc;
 655         memcpy(msg->data, cf->data, cf->can_dlc);
 656         msg->end = USB_8DEV_DATA_END;
 657
 658         for (i = 0; i < MAX_TX_URBS; i++) {
 659                 if (priv->tx_contexts[i].echo_index == MAX_TX_URBS) {
 660                         context = &priv->tx_contexts[i];
 661                         break;
 662                 }
 663         }
 664
 665         /* May never happen! When this happens we'd more URBs in flight as
 666          * allowed (MAX_TX_URBS).
 667          */
 668         if (!context)
 669                 goto nofreecontext;
 670
 671         context->priv = priv;
 672         context->echo_index = i;
 673         context->dlc = cf->can_dlc;
 674
 675         usb_fill_bulk_urb(urb, priv->udev,
 676                           usb_sndbulkpipe(priv->udev, USB_8DEV_ENDP_DATA_TX),
 677                           buf, size, usb_8dev_write_bulk_callback, context);
 678         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 679         usb_anchor_urb(urb, &priv->tx_submitted);
 680
 681         can_put_echo_skb(skb, netdev, context->echo_index);
 682
 683         atomic_inc(&priv->active_tx_urbs);
 684
 685         err = usb_submit_urb(urb, GFP_ATOMIC);
 686         if (unlikely(err))
 687                 goto failed;
 688         else if (atomic_read(&priv->active_tx_urbs) >= MAX_TX_URBS)
 689                 /* Slow down tx path */
 690                 netif_stop_queue(netdev);
 691
 692         /* Release our reference to this URB, the USB core will eventually free
 693          * it entirely.
 694          */
 695         usb_free_urb(urb);
 696
 697         return NETDEV_TX_OK;
 698
 699 nofreecontext:
 700         usb_free_coherent(priv->udev, size, buf, urb->transfer_dma);
 701         usb_free_urb(urb);
 702
 703         netdev_warn(netdev, "couldn't find free context");
 704
 705         return NETDEV_TX_BUSY;
 706
 707 failed:
 708         can_free_echo_skb(netdev, context->echo_index);
 709
 710         usb_unanchor_urb(urb);
 711         usb_free_coherent(priv->udev, size, buf, urb->transfer_dma);
 712
 713         atomic_dec(&priv->active_tx_urbs);
 714
 715         if (err == -ENODEV)
 716                 netif_device_detach(netdev);
 717         else
 718                 netdev_warn(netdev, "failed tx_urb %d\n", err);
 719
 720 nomembuf:
 721         usb_free_urb(urb);
 722
 723 nomem:
 724         dev_kfree_skb(skb);
 725         stats->tx_dropped++;
 726
 727         return NETDEV_TX_OK;
 728 }
 729
 730 static int usb_8dev_get_berr_counter(const struct net_device *netdev,
 731                                      struct can_berr_counter *bec)
 732 {
 733         struct usb_8dev_priv *priv = netdev_priv(netdev);
 734
 735         bec->txerr = priv->bec.txerr;
 736         bec->rxerr = priv->bec.rxerr;
 737
 738         return 0;
 739 }
 740
 741 /* Start USB device */
 742 static int usb_8dev_start(struct usb_8dev_priv *priv)
 743 {
 744         struct net_device *netdev = priv->netdev;
 745         int err, i;
 746
 747         for (i = 0; i < MAX_RX_URBS; i++) {
 748                 struct urb *urb = NULL;
 749                 u8 *buf;
 750
 751                 /* create a URB, and a buffer for it */
 752                 urb = usb_alloc_urb(0, GFP_KERNEL);
 753                 if (!urb) {
 754                         netdev_err(netdev, "No memory left for URBs\n");
 755                         err = -ENOMEM;
 756                         break;
 757                 }
 758
 759                 buf = usb_alloc_coherent(priv->udev, RX_BUFFER_SIZE, GFP_KERNEL,
 760                                          &urb->transfer_dma);
 761                 if (!buf) {
 762                         netdev_err(netdev, "No memory left for USB buffer\n");
 763                         usb_free_urb(urb);
 764                         err = -ENOMEM;
 765                         break;
 766                 }
 767
 768                 usb_fill_bulk_urb(urb, priv->udev,
 769                                   usb_rcvbulkpipe(priv->udev,
 770                                                   USB_8DEV_ENDP_DATA_RX),
 771                                   buf, RX_BUFFER_SIZE,
 772                                   usb_8dev_read_bulk_callback, priv);
 773                 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 774                 usb_anchor_urb(urb, &priv->rx_submitted);
 775
 776                 err = usb_submit_urb(urb, GFP_KERNEL);
 777                 if (err) {
 778                         usb_unanchor_urb(urb);
 779                         usb_free_coherent(priv->udev, RX_BUFFER_SIZE, buf,
 780                                           urb->transfer_dma);
 781                         usb_free_urb(urb);
 782                         break;
 783                 }
 784
 785                 /* Drop reference, USB core will take care of freeing it */
 786                 usb_free_urb(urb);
 787         }
 788
 789         /* Did we submit any URBs */
 790         if (i == 0) {
 791                 netdev_warn(netdev, "couldn't setup read URBs\n");
 792                 return err;
 793         }
 794
 795         /* Warn if we've couldn't transmit all the URBs */
 796         if (i < MAX_RX_URBS)
 797                 netdev_warn(netdev, "rx performance may be slow\n");
 798
 799         err = usb_8dev_cmd_open(priv);
 800         if (err)
 801                 goto failed;
 802
 803         priv->can.state = CAN_STATE_ERROR_ACTIVE;
 804
 805         return 0;
 806
 807 failed:
 808         if (err == -ENODEV)
 809                 netif_device_detach(priv->netdev);
 810
 811         netdev_warn(netdev, "couldn't submit control: %d\n", err);
 812
 813         return err;
 814 }
 815
 816 /* Open USB device */
 817 static int usb_8dev_open(struct net_device *netdev)
 818 {
 819         struct usb_8dev_priv *priv = netdev_priv(netdev);
 820         int err;
 821
 822         /* common open */
 823         err = open_candev(netdev);
 824         if (err)
 825                 return err;
 826
 827         can_led_event(netdev, CAN_LED_EVENT_OPEN);
 828
 829         /* finally start device */
 830         err = usb_8dev_start(priv);
 831         if (err) {
 832                 if (err == -ENODEV)
 833                         netif_device_detach(priv->netdev);
 834
 835                 netdev_warn(netdev, "couldn't start device: %d\n",
 836                          err);
 837
 838                 close_candev(netdev);
 839
 840                 return err;
 841         }
 842
 843         netif_start_queue(netdev);
 844
 845         return 0;
 846 }
 847
 848 static void unlink_all_urbs(struct usb_8dev_priv *priv)
 849 {
 850         int i;
 851
 852         usb_kill_anchored_urbs(&priv->rx_submitted);
 853
 854         usb_kill_anchored_urbs(&priv->tx_submitted);
 855         atomic_set(&priv->active_tx_urbs, 0);
 856
 857         for (i = 0; i < MAX_TX_URBS; i++)
 858                 priv->tx_contexts[i].echo_index = MAX_TX_URBS;
 859 }
 860
 861 /* Close USB device */
 862 static int usb_8dev_close(struct net_device *netdev)
 863 {
 864         struct usb_8dev_priv *priv = netdev_priv(netdev);
 865         int err = 0;
 866
 867         /* Send CLOSE command to CAN controller */
 868         err = usb_8dev_cmd_close(priv);
 869         if (err)
 870                 netdev_warn(netdev, "couldn't stop device");
 871
 872         priv->can.state = CAN_STATE_STOPPED;
 873
 874         netif_stop_queue(netdev);
 875
 876         /* Stop polling */
 877         unlink_all_urbs(priv);
 878
 879         close_candev(netdev);
 880
 881         can_led_event(netdev, CAN_LED_EVENT_STOP);
 882
 883         return err;
 884 }
 885
 886 static const struct net_device_ops usb_8dev_netdev_ops = {
 887         .ndo_open = usb_8dev_open,
 888         .ndo_stop = usb_8dev_close,
 889         .ndo_start_xmit = usb_8dev_start_xmit,
 890         .ndo_change_mtu = can_change_mtu,
 891 };
 892
 893 static const struct can_bittiming_const usb_8dev_bittiming_const = {
 894         .name = "usb_8dev",
 895         .tseg1_min = 1,
 896         .tseg1_max = 16,
 897         .tseg2_min = 1,
 898         .tseg2_max = 8,
 899         .sjw_max = 4,
 900         .brp_min = 1,
 901         .brp_max = 1024,
 902         .brp_inc = 1,
 903 };
 904
 905 /* Probe USB device
 906  *
 907  * Check device and firmware.
 908  * Set supported modes and bittiming constants.
 909  * Allocate some memory.
 910  */
 911 static int usb_8dev_probe(struct usb_interface *intf,
 912                          const struct usb_device_id *id)
 913 {
 914         struct net_device *netdev;
 915         struct usb_8dev_priv *priv;
 916         int i, err = -ENOMEM;
 917         u32 version;
 918         char buf[18];
 919         struct usb_device *usbdev = interface_to_usbdev(intf);
 920
 921         /* product id looks strange, better we also check iProduct string */
 922         if (usb_string(usbdev, usbdev->descriptor.iProduct, buf,
 923                        sizeof(buf)) > 0 && strcmp(buf, "USB2CAN converter")) {
 924                 dev_info(&usbdev->dev, "ignoring: not an USB2CAN converter\n");
 925                 return -ENODEV;
 926         }
 927
 928         netdev = alloc_candev(sizeof(struct usb_8dev_priv), MAX_TX_URBS);
 929         if (!netdev) {
 930                 dev_err(&intf->dev, "Couldn't alloc candev\n");
 931                 return -ENOMEM;
 932         }
 933
 934         priv = netdev_priv(netdev);
 935
 936         priv->udev = usbdev;
 937         priv->netdev = netdev;
 938
 939         priv->can.state = CAN_STATE_STOPPED;
 940         priv->can.clock.freq = USB_8DEV_ABP_CLOCK;
 941         priv->can.bittiming_const = &usb_8dev_bittiming_const;
 942         priv->can.do_set_mode = usb_8dev_set_mode;
 943         priv->can.do_get_berr_counter = usb_8dev_get_berr_counter;
 944         priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
 945                                       CAN_CTRLMODE_LISTENONLY |
 946                                       CAN_CTRLMODE_ONE_SHOT;
 947
 948         netdev->netdev_ops = &usb_8dev_netdev_ops;
 949
 950         netdev->flags |= IFF_ECHO; /* we support local echo */
 951
 952         init_usb_anchor(&priv->rx_submitted);
 953
 954         init_usb_anchor(&priv->tx_submitted);
 955         atomic_set(&priv->active_tx_urbs, 0);
 956
 957         for (i = 0; i < MAX_TX_URBS; i++)
 958                 priv->tx_contexts[i].echo_index = MAX_TX_URBS;
 959
 960         priv->cmd_msg_buffer = kzalloc(sizeof(struct usb_8dev_cmd_msg),
 961                                       GFP_KERNEL);
 962         if (!priv->cmd_msg_buffer)
 963                 goto cleanup_candev;
 964
 965         usb_set_intfdata(intf, priv);
 966
 967         SET_NETDEV_DEV(netdev, &intf->dev);
 968
 969         mutex_init(&priv->usb_8dev_cmd_lock);
 970
 971         err = register_candev(netdev);
 972         if (err) {
 973                 netdev_err(netdev,
 974                         "couldn't register CAN device: %d\n", err);
 975                 goto cleanup_cmd_msg_buffer;
 976         }
 977
 978         err = usb_8dev_cmd_version(priv, &version);
 979         if (err) {
 980                 netdev_err(netdev, "can't get firmware version\n");
 981                 goto cleanup_unregister_candev;
 982         } else {
 983                 netdev_info(netdev,
 984                          "firmware: %d.%d, hardware: %d.%d\n",
 985                          (version>>24) & 0xff, (version>>16) & 0xff,
 986                          (version>>8) & 0xff, version & 0xff);
 987         }
 988
 989         devm_can_led_init(netdev);
 990
 991         return 0;
 992
 993 cleanup_unregister_candev:
 994         unregister_netdev(priv->netdev);
 995
 996 cleanup_cmd_msg_buffer:
 997         kfree(priv->cmd_msg_buffer);
 998
 999 cleanup_candev:
1000         free_candev(netdev);
1001
1002         return err;
1003
1004 }
1005
1006 /* Called by the usb core when driver is unloaded or device is removed */
1007 static void usb_8dev_disconnect(struct usb_interface *intf)
1008 {
1009         struct usb_8dev_priv *priv = usb_get_intfdata(intf);
1010
1011         usb_set_intfdata(intf, NULL);
1012
1013         if (priv) {
1014                 netdev_info(priv->netdev, "device disconnected\n");
1015
1016                 unregister_netdev(priv->netdev);
1017                 free_candev(priv->netdev);
1018
1019                 unlink_all_urbs(priv);
1020         }
1021
1022 }
1023
1024 static struct usb_driver usb_8dev_driver = {
1025         .name =         "usb_8dev",
1026         .probe =        usb_8dev_probe,
1027         .disconnect =   usb_8dev_disconnect,
1028         .id_table =     usb_8dev_table,
1029 };
1030
1031 module_usb_driver(usb_8dev_driver);
1032
1033 MODULE_AUTHOR("Bernd Krumboeck <krumboeck@universalnet.at>");
1034 MODULE_DESCRIPTION("CAN driver for 8 devices USB2CAN interfaces");
1035 MODULE_LICENSE("GPL v2");