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         void *rxbuf[MAX_RX_URBS];
 152         dma_addr_t rxbuf_dma[MAX_RX_URBS];
 153 };
 154
 155 /* tx frame */
 156 struct __packed usb_8dev_tx_msg {
 157         u8 begin;
 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         u8 end;
 163 };
 164
 165 /* rx frame */
 166 struct __packed usb_8dev_rx_msg {
 167         u8 begin;
 168         u8 type;                /* frame type */
 169         u8 flags;               /* RTR and EXT_ID flag */
 170         __be32 id;              /* upper 3 bits not used */
 171         u8 dlc;                 /* data length code 0-8 bytes */
 172         u8 data[8];             /* 64-bit data */
 173         __be32 timestamp;       /* 32-bit timestamp */
 174         u8 end;
 175 };
 176
 177 /* command frame */
 178 struct __packed usb_8dev_cmd_msg {
 179         u8 begin;
 180         u8 channel;     /* unkown - always 0 */
 181         u8 command;     /* command to execute */
 182         u8 opt1;        /* optional parameter / return value */
 183         u8 opt2;        /* optional parameter 2 */
 184         u8 data[10];    /* optional parameter and data */
 185         u8 end;
 186 };
 187
 188 static int usb_8dev_send_cmd_msg(struct usb_8dev_priv *priv, u8 *msg, int size)
 189 {
 190         int actual_length;
 191
 192         return usb_bulk_msg(priv->udev,
 193                             usb_sndbulkpipe(priv->udev, USB_8DEV_ENDP_CMD_TX),
 194                             msg, size, &actual_length, USB_8DEV_CMD_TIMEOUT);
 195 }
 196
 197 static int usb_8dev_wait_cmd_msg(struct usb_8dev_priv *priv, u8 *msg, int size,
 198                                 int *actual_length)
 199 {
 200         return usb_bulk_msg(priv->udev,
 201                             usb_rcvbulkpipe(priv->udev, USB_8DEV_ENDP_CMD_RX),
 202                             msg, size, actual_length, USB_8DEV_CMD_TIMEOUT);
 203 }
 204
 205 /* Send command to device and receive result.
 206  * Command was successful when opt1 = 0.
 207  */
 208 static int usb_8dev_send_cmd(struct usb_8dev_priv *priv,
 209                              struct usb_8dev_cmd_msg *out,
 210                              struct usb_8dev_cmd_msg *in)
 211 {
 212         int err;
 213         int num_bytes_read;
 214         struct net_device *netdev;
 215
 216         netdev = priv->netdev;
 217
 218         out->begin = USB_8DEV_CMD_START;
 219         out->end = USB_8DEV_CMD_END;
 220
 221         mutex_lock(&priv->usb_8dev_cmd_lock);
 222
 223         memcpy(priv->cmd_msg_buffer, out,
 224                 sizeof(struct usb_8dev_cmd_msg));
 225
 226         err = usb_8dev_send_cmd_msg(priv, priv->cmd_msg_buffer,
 227                                     sizeof(struct usb_8dev_cmd_msg));
 228         if (err < 0) {
 229                 netdev_err(netdev, "sending command message failed\n");
 230                 goto failed;
 231         }
 232
 233         err = usb_8dev_wait_cmd_msg(priv, priv->cmd_msg_buffer,
 234                                     sizeof(struct usb_8dev_cmd_msg),
 235                                     &num_bytes_read);
 236         if (err < 0) {
 237                 netdev_err(netdev, "no command message answer\n");
 238                 goto failed;
 239         }
 240
 241         memcpy(in, priv->cmd_msg_buffer, sizeof(struct usb_8dev_cmd_msg));
 242
 243         if (in->begin != USB_8DEV_CMD_START || in->end != USB_8DEV_CMD_END ||
 244                         num_bytes_read != 16 || in->opt1 != 0)
 245                 err = -EPROTO;
 246
 247 failed:
 248         mutex_unlock(&priv->usb_8dev_cmd_lock);
 249         return err;
 250 }
 251
 252 /* Send open command to device */
 253 static int usb_8dev_cmd_open(struct usb_8dev_priv *priv)
 254 {
 255         struct can_bittiming *bt = &priv->can.bittiming;
 256         struct usb_8dev_cmd_msg outmsg;
 257         struct usb_8dev_cmd_msg inmsg;
 258         u32 ctrlmode = priv->can.ctrlmode;
 259         u32 flags = USB_8DEV_STATUS_FRAME;
 260         __be32 beflags;
 261         __be16 bebrp;
 262
 263         memset(&outmsg, 0, sizeof(outmsg));
 264         outmsg.command = USB_8DEV_OPEN;
 265         outmsg.opt1 = USB_8DEV_BAUD_MANUAL;
 266         outmsg.data[0] = bt->prop_seg + bt->phase_seg1;
 267         outmsg.data[1] = bt->phase_seg2;
 268         outmsg.data[2] = bt->sjw;
 269
 270         /* BRP */
 271         bebrp = cpu_to_be16((u16)bt->brp);
 272         memcpy(&outmsg.data[3], &bebrp, sizeof(bebrp));
 273
 274         /* flags */
 275         if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
 276                 flags |= USB_8DEV_LOOPBACK;
 277         if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
 278                 flags |= USB_8DEV_SILENT;
 279         if (ctrlmode & CAN_CTRLMODE_ONE_SHOT)
 280                 flags |= USB_8DEV_DISABLE_AUTO_RESTRANS;
 281
 282         beflags = cpu_to_be32(flags);
 283         memcpy(&outmsg.data[5], &beflags, sizeof(beflags));
 284
 285         return usb_8dev_send_cmd(priv, &outmsg, &inmsg);
 286 }
 287
 288 /* Send close command to device */
 289 static int usb_8dev_cmd_close(struct usb_8dev_priv *priv)
 290 {
 291         struct usb_8dev_cmd_msg inmsg;
 292         struct usb_8dev_cmd_msg outmsg = {
 293                 .channel = 0,
 294                 .command = USB_8DEV_CLOSE,
 295                 .opt1 = 0,
 296                 .opt2 = 0
 297         };
 298
 299         return usb_8dev_send_cmd(priv, &outmsg, &inmsg);
 300 }
 301
 302 /* Get firmware and hardware version */
 303 static int usb_8dev_cmd_version(struct usb_8dev_priv *priv, u32 *res)
 304 {
 305         struct usb_8dev_cmd_msg inmsg;
 306         struct usb_8dev_cmd_msg outmsg = {
 307                 .channel = 0,
 308                 .command = USB_8DEV_GET_SOFTW_HARDW_VER,
 309                 .opt1 = 0,
 310                 .opt2 = 0
 311         };
 312
 313         int err = usb_8dev_send_cmd(priv, &outmsg, &inmsg);
 314         if (err)
 315                 return err;
 316
 317         *res = be32_to_cpup((__be32 *)inmsg.data);
 318
 319         return err;
 320 }
 321
 322 /* Set network device mode
 323  *
 324  * Maybe we should leave this function empty, because the device
 325  * set mode variable with open command.
 326  */
 327 static int usb_8dev_set_mode(struct net_device *netdev, enum can_mode mode)
 328 {
 329         struct usb_8dev_priv *priv = netdev_priv(netdev);
 330         int err = 0;
 331
 332         switch (mode) {
 333         case CAN_MODE_START:
 334                 err = usb_8dev_cmd_open(priv);
 335                 if (err)
 336                         netdev_warn(netdev, "couldn't start device");
 337                 break;
 338
 339         default:
 340                 return -EOPNOTSUPP;
 341         }
 342
 343         return err;
 344 }
 345
 346 /* Read error/status frames */
 347 static void usb_8dev_rx_err_msg(struct usb_8dev_priv *priv,
 348                                 struct usb_8dev_rx_msg *msg)
 349 {
 350         struct can_frame *cf;
 351         struct sk_buff *skb;
 352         struct net_device_stats *stats = &priv->netdev->stats;
 353
 354         /* Error message:
 355          * byte 0: Status
 356          * byte 1: bit   7: Receive Passive
 357          * byte 1: bit 0-6: Receive Error Counter
 358          * byte 2: Transmit Error Counter
 359          * byte 3: Always 0 (maybe reserved for future use)
 360          */
 361
 362         u8 state = msg->data[0];
 363         u8 rxerr = msg->data[1] & USB_8DEV_RP_MASK;
 364         u8 txerr = msg->data[2];
 365         int rx_errors = 0;
 366         int tx_errors = 0;
 367
 368         skb = alloc_can_err_skb(priv->netdev, &cf);
 369         if (!skb)
 370                 return;
 371
 372         switch (state) {
 373         case USB_8DEV_STATUSMSG_OK:
 374                 priv->can.state = CAN_STATE_ERROR_ACTIVE;
 375                 cf->can_id |= CAN_ERR_PROT;
 376                 cf->data[2] = CAN_ERR_PROT_ACTIVE;
 377                 break;
 378         case USB_8DEV_STATUSMSG_BUSOFF:
 379                 priv->can.state = CAN_STATE_BUS_OFF;
 380                 cf->can_id |= CAN_ERR_BUSOFF;
 381                 priv->can.can_stats.bus_off++;
 382                 can_bus_off(priv->netdev);
 383                 break;
 384         case USB_8DEV_STATUSMSG_OVERRUN:
 385         case USB_8DEV_STATUSMSG_BUSLIGHT:
 386         case USB_8DEV_STATUSMSG_BUSHEAVY:
 387                 cf->can_id |= CAN_ERR_CRTL;
 388                 break;
 389         default:
 390                 priv->can.state = CAN_STATE_ERROR_WARNING;
 391                 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
 392                 priv->can.can_stats.bus_error++;
 393                 break;
 394         }
 395
 396         switch (state) {
 397         case USB_8DEV_STATUSMSG_OK:
 398         case USB_8DEV_STATUSMSG_BUSOFF:
 399                 break;
 400         case USB_8DEV_STATUSMSG_ACK:
 401                 cf->can_id |= CAN_ERR_ACK;
 402                 tx_errors = 1;
 403                 break;
 404         case USB_8DEV_STATUSMSG_CRC:
 405                 cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
 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         if (priv->can.state != CAN_STATE_BUS_OFF) {
 457                 cf->data[6] = txerr;
 458                 cf->data[7] = rxerr;
 459         }
 460
 461         priv->bec.txerr = txerr;
 462         priv->bec.rxerr = rxerr;
 463
 464         stats->rx_packets++;
 465         stats->rx_bytes += cf->can_dlc;
 466         netif_rx(skb);
 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                 stats->rx_packets++;
 497                 stats->rx_bytes += cf->can_dlc;
 498                 netif_rx(skb);
 499
 500                 can_led_event(priv->netdev, CAN_LED_EVENT_RX);
 501         } else {
 502                 netdev_warn(priv->netdev, "frame type %d unknown",
 503                          msg->type);
 504         }
 505
 506 }
 507
 508 /* Callback for reading data from device
 509  *
 510  * Check urb status, call read function and resubmit urb read operation.
 511  */
 512 static void usb_8dev_read_bulk_callback(struct urb *urb)
 513 {
 514         struct usb_8dev_priv *priv = urb->context;
 515         struct net_device *netdev;
 516         int retval;
 517         int pos = 0;
 518
 519         netdev = priv->netdev;
 520
 521         if (!netif_device_present(netdev))
 522                 return;
 523
 524         switch (urb->status) {
 525         case 0: /* success */
 526                 break;
 527
 528         case -ENOENT:
 529         case -EPIPE:
 530         case -EPROTO:
 531         case -ESHUTDOWN:
 532                 return;
 533
 534         default:
 535                 netdev_info(netdev, "Rx URB aborted (%d)\n",
 536                          urb->status);
 537                 goto resubmit_urb;
 538         }
 539
 540         while (pos < urb->actual_length) {
 541                 struct usb_8dev_rx_msg *msg;
 542
 543                 if (pos + sizeof(struct usb_8dev_rx_msg) > urb->actual_length) {
 544                         netdev_err(priv->netdev, "format error\n");
 545                         break;
 546                 }
 547
 548                 msg = (struct usb_8dev_rx_msg *)(urb->transfer_buffer + pos);
 549                 usb_8dev_rx_can_msg(priv, msg);
 550
 551                 pos += sizeof(struct usb_8dev_rx_msg);
 552         }
 553
 554 resubmit_urb:
 555         usb_fill_bulk_urb(urb, priv->udev,
 556                           usb_rcvbulkpipe(priv->udev, USB_8DEV_ENDP_DATA_RX),
 557                           urb->transfer_buffer, RX_BUFFER_SIZE,
 558                           usb_8dev_read_bulk_callback, priv);
 559
 560         retval = usb_submit_urb(urb, GFP_ATOMIC);
 561
 562         if (retval == -ENODEV)
 563                 netif_device_detach(netdev);
 564         else if (retval)
 565                 netdev_err(netdev,
 566                         "failed resubmitting read bulk urb: %d\n", retval);
 567 }
 568
 569 /* Callback handler for write operations
 570  *
 571  * Free allocated buffers, check transmit status and
 572  * calculate statistic.
 573  */
 574 static void usb_8dev_write_bulk_callback(struct urb *urb)
 575 {
 576         struct usb_8dev_tx_urb_context *context = urb->context;
 577         struct usb_8dev_priv *priv;
 578         struct net_device *netdev;
 579
 580         BUG_ON(!context);
 581
 582         priv = context->priv;
 583         netdev = priv->netdev;
 584
 585         /* free up our allocated buffer */
 586         usb_free_coherent(urb->dev, urb->transfer_buffer_length,
 587                           urb->transfer_buffer, urb->transfer_dma);
 588
 589         atomic_dec(&priv->active_tx_urbs);
 590
 591         if (!netif_device_present(netdev))
 592                 return;
 593
 594         if (urb->status)
 595                 netdev_info(netdev, "Tx URB aborted (%d)\n",
 596                          urb->status);
 597
 598         netdev->stats.tx_packets++;
 599         netdev->stats.tx_bytes += context->dlc;
 600
 601         can_get_echo_skb(netdev, context->echo_index);
 602
 603         can_led_event(netdev, CAN_LED_EVENT_TX);
 604
 605         /* Release context */
 606         context->echo_index = MAX_TX_URBS;
 607
 608         netif_wake_queue(netdev);
 609 }
 610
 611 /* Send data to device */
 612 static netdev_tx_t usb_8dev_start_xmit(struct sk_buff *skb,
 613                                       struct net_device *netdev)
 614 {
 615         struct usb_8dev_priv *priv = netdev_priv(netdev);
 616         struct net_device_stats *stats = &netdev->stats;
 617         struct can_frame *cf = (struct can_frame *) skb->data;
 618         struct usb_8dev_tx_msg *msg;
 619         struct urb *urb;
 620         struct usb_8dev_tx_urb_context *context = NULL;
 621         u8 *buf;
 622         int i, err;
 623         size_t size = sizeof(struct usb_8dev_tx_msg);
 624
 625         if (can_dropped_invalid_skb(netdev, skb))
 626                 return NETDEV_TX_OK;
 627
 628         /* create a URB, and a buffer for it, and copy the data to the URB */
 629         urb = usb_alloc_urb(0, GFP_ATOMIC);
 630         if (!urb)
 631                 goto nomem;
 632
 633         buf = usb_alloc_coherent(priv->udev, size, GFP_ATOMIC,
 634                                  &urb->transfer_dma);
 635         if (!buf) {
 636                 netdev_err(netdev, "No memory left for USB buffer\n");
 637                 goto nomembuf;
 638         }
 639
 640         memset(buf, 0, size);
 641
 642         msg = (struct usb_8dev_tx_msg *)buf;
 643         msg->begin = USB_8DEV_DATA_START;
 644         msg->flags = 0x00;
 645
 646         if (cf->can_id & CAN_RTR_FLAG)
 647                 msg->flags |= USB_8DEV_RTR;
 648
 649         if (cf->can_id & CAN_EFF_FLAG)
 650                 msg->flags |= USB_8DEV_EXTID;
 651
 652         msg->id = cpu_to_be32(cf->can_id & CAN_ERR_MASK);
 653         msg->dlc = cf->can_dlc;
 654         memcpy(msg->data, cf->data, cf->can_dlc);
 655         msg->end = USB_8DEV_DATA_END;
 656
 657         for (i = 0; i < MAX_TX_URBS; i++) {
 658                 if (priv->tx_contexts[i].echo_index == MAX_TX_URBS) {
 659                         context = &priv->tx_contexts[i];
 660                         break;
 661                 }
 662         }
 663
 664         /* May never happen! When this happens we'd more URBs in flight as
 665          * allowed (MAX_TX_URBS).
 666          */
 667         if (!context)
 668                 goto nofreecontext;
 669
 670         context->priv = priv;
 671         context->echo_index = i;
 672         context->dlc = cf->can_dlc;
 673
 674         usb_fill_bulk_urb(urb, priv->udev,
 675                           usb_sndbulkpipe(priv->udev, USB_8DEV_ENDP_DATA_TX),
 676                           buf, size, usb_8dev_write_bulk_callback, context);
 677         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 678         usb_anchor_urb(urb, &priv->tx_submitted);
 679
 680         can_put_echo_skb(skb, netdev, context->echo_index);
 681
 682         atomic_inc(&priv->active_tx_urbs);
 683
 684         err = usb_submit_urb(urb, GFP_ATOMIC);
 685         if (unlikely(err)) {
 686                 can_free_echo_skb(netdev, context->echo_index);
 687
 688                 usb_unanchor_urb(urb);
 689                 usb_free_coherent(priv->udev, size, buf, urb->transfer_dma);
 690
 691                 atomic_dec(&priv->active_tx_urbs);
 692
 693                 if (err == -ENODEV)
 694                         netif_device_detach(netdev);
 695                 else
 696                         netdev_warn(netdev, "failed tx_urb %d\n", err);
 697                 stats->tx_dropped++;
 698         } else if (atomic_read(&priv->active_tx_urbs) >= MAX_TX_URBS)
 699                 /* Slow down tx path */
 700                 netif_stop_queue(netdev);
 701
 702         /* Release our reference to this URB, the USB core will eventually free
 703          * it entirely.
 704          */
 705         usb_free_urb(urb);
 706
 707         return NETDEV_TX_OK;
 708
 709 nofreecontext:
 710         usb_free_coherent(priv->udev, size, buf, urb->transfer_dma);
 711         usb_free_urb(urb);
 712
 713         netdev_warn(netdev, "couldn't find free context");
 714
 715         return NETDEV_TX_BUSY;
 716
 717 nomembuf:
 718         usb_free_urb(urb);
 719
 720 nomem:
 721         dev_kfree_skb(skb);
 722         stats->tx_dropped++;
 723
 724         return NETDEV_TX_OK;
 725 }
 726
 727 static int usb_8dev_get_berr_counter(const struct net_device *netdev,
 728                                      struct can_berr_counter *bec)
 729 {
 730         struct usb_8dev_priv *priv = netdev_priv(netdev);
 731
 732         bec->txerr = priv->bec.txerr;
 733         bec->rxerr = priv->bec.rxerr;
 734
 735         return 0;
 736 }
 737
 738 /* Start USB device */
 739 static int usb_8dev_start(struct usb_8dev_priv *priv)
 740 {
 741         struct net_device *netdev = priv->netdev;
 742         int err, i;
 743
 744         for (i = 0; i < MAX_RX_URBS; i++) {
 745                 struct urb *urb = NULL;
 746                 u8 *buf;
 747                 dma_addr_t buf_dma;
 748
 749                 /* create a URB, and a buffer for it */
 750                 urb = usb_alloc_urb(0, GFP_KERNEL);
 751                 if (!urb) {
 752                         err = -ENOMEM;
 753                         break;
 754                 }
 755
 756                 buf = usb_alloc_coherent(priv->udev, RX_BUFFER_SIZE, GFP_KERNEL,
 757                                          &buf_dma);
 758                 if (!buf) {
 759                         netdev_err(netdev, "No memory left for USB buffer\n");
 760                         usb_free_urb(urb);
 761                         err = -ENOMEM;
 762                         break;
 763                 }
 764
 765                 urb->transfer_dma = buf_dma;
 766
 767                 usb_fill_bulk_urb(urb, priv->udev,
 768                                   usb_rcvbulkpipe(priv->udev,
 769                                                   USB_8DEV_ENDP_DATA_RX),
 770                                   buf, RX_BUFFER_SIZE,
 771                                   usb_8dev_read_bulk_callback, priv);
 772                 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 773                 usb_anchor_urb(urb, &priv->rx_submitted);
 774
 775                 err = usb_submit_urb(urb, GFP_KERNEL);
 776                 if (err) {
 777                         usb_unanchor_urb(urb);
 778                         usb_free_coherent(priv->udev, RX_BUFFER_SIZE, buf,
 779                                           urb->transfer_dma);
 780                         usb_free_urb(urb);
 781                         break;
 782                 }
 783
 784                 priv->rxbuf[i] = buf;
 785                 priv->rxbuf_dma[i] = buf_dma;
 786
 787                 /* Drop reference, USB core will take care of freeing it */
 788                 usb_free_urb(urb);
 789         }
 790
 791         /* Did we submit any URBs */
 792         if (i == 0) {
 793                 netdev_warn(netdev, "couldn't setup read URBs\n");
 794                 return err;
 795         }
 796
 797         /* Warn if we've couldn't transmit all the URBs */
 798         if (i < MAX_RX_URBS)
 799                 netdev_warn(netdev, "rx performance may be slow\n");
 800
 801         err = usb_8dev_cmd_open(priv);
 802         if (err)
 803                 goto failed;
 804
 805         priv->can.state = CAN_STATE_ERROR_ACTIVE;
 806
 807         return 0;
 808
 809 failed:
 810         if (err == -ENODEV)
 811                 netif_device_detach(priv->netdev);
 812
 813         netdev_warn(netdev, "couldn't submit control: %d\n", err);
 814
 815         return err;
 816 }
 817
 818 /* Open USB device */
 819 static int usb_8dev_open(struct net_device *netdev)
 820 {
 821         struct usb_8dev_priv *priv = netdev_priv(netdev);
 822         int err;
 823
 824         /* common open */
 825         err = open_candev(netdev);
 826         if (err)
 827                 return err;
 828
 829         can_led_event(netdev, CAN_LED_EVENT_OPEN);
 830
 831         /* finally start device */
 832         err = usb_8dev_start(priv);
 833         if (err) {
 834                 if (err == -ENODEV)
 835                         netif_device_detach(priv->netdev);
 836
 837                 netdev_warn(netdev, "couldn't start device: %d\n",
 838                          err);
 839
 840                 close_candev(netdev);
 841
 842                 return err;
 843         }
 844
 845         netif_start_queue(netdev);
 846
 847         return 0;
 848 }
 849
 850 static void unlink_all_urbs(struct usb_8dev_priv *priv)
 851 {
 852         int i;
 853
 854         usb_kill_anchored_urbs(&priv->rx_submitted);
 855
 856         for (i = 0; i < MAX_RX_URBS; ++i)
 857                 usb_free_coherent(priv->udev, RX_BUFFER_SIZE,
 858                                   priv->rxbuf[i], priv->rxbuf_dma[i]);
 859
 860         usb_kill_anchored_urbs(&priv->tx_submitted);
 861         atomic_set(&priv->active_tx_urbs, 0);
 862
 863         for (i = 0; i < MAX_TX_URBS; i++)
 864                 priv->tx_contexts[i].echo_index = MAX_TX_URBS;
 865 }
 866
 867 /* Close USB device */
 868 static int usb_8dev_close(struct net_device *netdev)
 869 {
 870         struct usb_8dev_priv *priv = netdev_priv(netdev);
 871         int err = 0;
 872
 873         /* Send CLOSE command to CAN controller */
 874         err = usb_8dev_cmd_close(priv);
 875         if (err)
 876                 netdev_warn(netdev, "couldn't stop device");
 877
 878         priv->can.state = CAN_STATE_STOPPED;
 879
 880         netif_stop_queue(netdev);
 881
 882         /* Stop polling */
 883         unlink_all_urbs(priv);
 884
 885         close_candev(netdev);
 886
 887         can_led_event(netdev, CAN_LED_EVENT_STOP);
 888
 889         return err;
 890 }
 891
 892 static const struct net_device_ops usb_8dev_netdev_ops = {
 893         .ndo_open = usb_8dev_open,
 894         .ndo_stop = usb_8dev_close,
 895         .ndo_start_xmit = usb_8dev_start_xmit,
 896         .ndo_change_mtu = can_change_mtu,
 897 };
 898
 899 static const struct can_bittiming_const usb_8dev_bittiming_const = {
 900         .name = "usb_8dev",
 901         .tseg1_min = 1,
 902         .tseg1_max = 16,
 903         .tseg2_min = 1,
 904         .tseg2_max = 8,
 905         .sjw_max = 4,
 906         .brp_min = 1,
 907         .brp_max = 1024,
 908         .brp_inc = 1,
 909 };
 910
 911 /* Probe USB device
 912  *
 913  * Check device and firmware.
 914  * Set supported modes and bittiming constants.
 915  * Allocate some memory.
 916  */
 917 static int usb_8dev_probe(struct usb_interface *intf,
 918                          const struct usb_device_id *id)
 919 {
 920         struct net_device *netdev;
 921         struct usb_8dev_priv *priv;
 922         int i, err = -ENOMEM;
 923         u32 version;
 924         char buf[18];
 925         struct usb_device *usbdev = interface_to_usbdev(intf);
 926
 927         /* product id looks strange, better we also check iProduct string */
 928         if (usb_string(usbdev, usbdev->descriptor.iProduct, buf,
 929                        sizeof(buf)) > 0 && strcmp(buf, "USB2CAN converter")) {
 930                 dev_info(&usbdev->dev, "ignoring: not an USB2CAN converter\n");
 931                 return -ENODEV;
 932         }
 933
 934         netdev = alloc_candev(sizeof(struct usb_8dev_priv), MAX_TX_URBS);
 935         if (!netdev) {
 936                 dev_err(&intf->dev, "Couldn't alloc candev\n");
 937                 return -ENOMEM;
 938         }
 939
 940         priv = netdev_priv(netdev);
 941
 942         priv->udev = usbdev;
 943         priv->netdev = netdev;
 944
 945         priv->can.state = CAN_STATE_STOPPED;
 946         priv->can.clock.freq = USB_8DEV_ABP_CLOCK;
 947         priv->can.bittiming_const = &usb_8dev_bittiming_const;
 948         priv->can.do_set_mode = usb_8dev_set_mode;
 949         priv->can.do_get_berr_counter = usb_8dev_get_berr_counter;
 950         priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
 951                                       CAN_CTRLMODE_LISTENONLY |
 952                                       CAN_CTRLMODE_ONE_SHOT;
 953
 954         netdev->netdev_ops = &usb_8dev_netdev_ops;
 955
 956         netdev->flags |= IFF_ECHO; /* we support local echo */
 957
 958         init_usb_anchor(&priv->rx_submitted);
 959
 960         init_usb_anchor(&priv->tx_submitted);
 961         atomic_set(&priv->active_tx_urbs, 0);
 962
 963         for (i = 0; i < MAX_TX_URBS; i++)
 964                 priv->tx_contexts[i].echo_index = MAX_TX_URBS;
 965
 966         priv->cmd_msg_buffer = devm_kzalloc(&intf->dev, sizeof(struct usb_8dev_cmd_msg),
 967                                             GFP_KERNEL);
 968         if (!priv->cmd_msg_buffer)
 969                 goto cleanup_candev;
 970
 971         usb_set_intfdata(intf, priv);
 972
 973         SET_NETDEV_DEV(netdev, &intf->dev);
 974
 975         mutex_init(&priv->usb_8dev_cmd_lock);
 976
 977         err = register_candev(netdev);
 978         if (err) {
 979                 netdev_err(netdev,
 980                         "couldn't register CAN device: %d\n", err);
 981                 goto cleanup_candev;
 982         }
 983
 984         err = usb_8dev_cmd_version(priv, &version);
 985         if (err) {
 986                 netdev_err(netdev, "can't get firmware version\n");
 987                 goto cleanup_unregister_candev;
 988         } else {
 989                 netdev_info(netdev,
 990                          "firmware: %d.%d, hardware: %d.%d\n",
 991                          (version>>24) & 0xff, (version>>16) & 0xff,
 992                          (version>>8) & 0xff, version & 0xff);
 993         }
 994
 995         devm_can_led_init(netdev);
 996
 997         return 0;
 998
 999 cleanup_unregister_candev:
1000         unregister_netdev(priv->netdev);
1001
1002 cleanup_candev:
1003         free_candev(netdev);
1004
1005         return err;
1006
1007 }
1008
1009 /* Called by the usb core when driver is unloaded or device is removed */
1010 static void usb_8dev_disconnect(struct usb_interface *intf)
1011 {
1012         struct usb_8dev_priv *priv = usb_get_intfdata(intf);
1013
1014         usb_set_intfdata(intf, NULL);
1015
1016         if (priv) {
1017                 netdev_info(priv->netdev, "device disconnected\n");
1018
1019                 unregister_netdev(priv->netdev);
1020                 unlink_all_urbs(priv);
1021                 free_candev(priv->netdev);
1022         }
1023
1024 }
1025
1026 static struct usb_driver usb_8dev_driver = {
1027         .name =         "usb_8dev",
1028         .probe =        usb_8dev_probe,
1029         .disconnect =   usb_8dev_disconnect,
1030         .id_table =     usb_8dev_table,
1031 };
1032
1033 module_usb_driver(usb_8dev_driver);
1034
1035 MODULE_AUTHOR("Bernd Krumboeck <krumboeck@universalnet.at>");
1036 MODULE_DESCRIPTION("CAN driver for 8 devices USB2CAN interfaces");
1037 MODULE_LICENSE("GPL v2");