kernel/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                 priv->can.can_stats.bus_off++;
 381                 can_bus_off(priv->netdev);
 382                 break;
 383         case USB_8DEV_STATUSMSG_OVERRUN:
 384         case USB_8DEV_STATUSMSG_BUSLIGHT:
 385         case USB_8DEV_STATUSMSG_BUSHEAVY:
 386                 cf->can_id |= CAN_ERR_CRTL;
 387                 break;
 388         default:
 389                 priv->can.state = CAN_STATE_ERROR_WARNING;
 390                 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
 391                 priv->can.can_stats.bus_error++;
 392                 break;
 393         }
 394
 395         switch (state) {
 396         case USB_8DEV_STATUSMSG_OK:
 397         case USB_8DEV_STATUSMSG_BUSOFF:
 398                 break;
 399         case USB_8DEV_STATUSMSG_ACK:
 400                 cf->can_id |= CAN_ERR_ACK;
 401                 tx_errors = 1;
 402                 break;
 403         case USB_8DEV_STATUSMSG_CRC:
 404                 cf->data[2] |= CAN_ERR_PROT_UNSPEC;
 405                 cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ |
 406                                CAN_ERR_PROT_LOC_CRC_DEL;
 407                 rx_errors = 1;
 408                 break;
 409         case USB_8DEV_STATUSMSG_BIT0:
 410                 cf->data[2] |= CAN_ERR_PROT_BIT0;
 411                 tx_errors = 1;
 412                 break;
 413         case USB_8DEV_STATUSMSG_BIT1:
 414                 cf->data[2] |= CAN_ERR_PROT_BIT1;
 415                 tx_errors = 1;
 416                 break;
 417         case USB_8DEV_STATUSMSG_FORM:
 418                 cf->data[2] |= CAN_ERR_PROT_FORM;
 419                 rx_errors = 1;
 420                 break;
 421         case USB_8DEV_STATUSMSG_STUFF:
 422                 cf->data[2] |= CAN_ERR_PROT_STUFF;
 423                 rx_errors = 1;
 424                 break;
 425         case USB_8DEV_STATUSMSG_OVERRUN:
 426                 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 427                 stats->rx_over_errors++;
 428                 rx_errors = 1;
 429                 break;
 430         case USB_8DEV_STATUSMSG_BUSLIGHT:
 431                 priv->can.state = CAN_STATE_ERROR_WARNING;
 432                 cf->data[1] = (txerr > rxerr) ?
 433                         CAN_ERR_CRTL_TX_WARNING :
 434                         CAN_ERR_CRTL_RX_WARNING;
 435                 priv->can.can_stats.error_warning++;
 436                 break;
 437         case USB_8DEV_STATUSMSG_BUSHEAVY:
 438                 priv->can.state = CAN_STATE_ERROR_PASSIVE;
 439                 cf->data[1] = (txerr > rxerr) ?
 440                         CAN_ERR_CRTL_TX_PASSIVE :
 441                         CAN_ERR_CRTL_RX_PASSIVE;
 442                 priv->can.can_stats.error_passive++;
 443                 break;
 444         default:
 445                 netdev_warn(priv->netdev,
 446                             "Unknown status/error message (%d)\n", state);
 447                 break;
 448         }
 449
 450         if (tx_errors) {
 451                 cf->data[2] |= CAN_ERR_PROT_TX;
 452                 stats->tx_errors++;
 453         }
 454
 455         if (rx_errors)
 456                 stats->rx_errors++;
 457
 458         cf->data[6] = txerr;
 459         cf->data[7] = rxerr;
 460
 461         priv->bec.txerr = txerr;
 462         priv->bec.rxerr = rxerr;
 463
 464         netif_rx(skb);
 465
 466         stats->rx_packets++;
 467         stats->rx_bytes += cf->can_dlc;
 468 }
 469
 470 /* Read data and status frames */
 471 static void usb_8dev_rx_can_msg(struct usb_8dev_priv *priv,
 472                                 struct usb_8dev_rx_msg *msg)
 473 {
 474         struct can_frame *cf;
 475         struct sk_buff *skb;
 476         struct net_device_stats *stats = &priv->netdev->stats;
 477
 478         if (msg->type == USB_8DEV_TYPE_ERROR_FRAME &&
 479                    msg->flags == USB_8DEV_ERR_FLAG) {
 480                 usb_8dev_rx_err_msg(priv, msg);
 481         } else if (msg->type == USB_8DEV_TYPE_CAN_FRAME) {
 482                 skb = alloc_can_skb(priv->netdev, &cf);
 483                 if (!skb)
 484                         return;
 485
 486                 cf->can_id = be32_to_cpu(msg->id);
 487                 cf->can_dlc = get_can_dlc(msg->dlc & 0xF);
 488
 489                 if (msg->flags & USB_8DEV_EXTID)
 490                         cf->can_id |= CAN_EFF_FLAG;
 491
 492                 if (msg->flags & USB_8DEV_RTR)
 493                         cf->can_id |= CAN_RTR_FLAG;
 494                 else
 495                         memcpy(cf->data, msg->data, cf->can_dlc);
 496
 497                 netif_rx(skb);
 498
 499                 stats->rx_packets++;
 500                 stats->rx_bytes += cf->can_dlc;
 501
 502                 can_led_event(priv->netdev, CAN_LED_EVENT_RX);
 503         } else {
 504                 netdev_warn(priv->netdev, "frame type %d unknown",
 505                          msg->type);
 506         }
 507
 508 }
 509
 510 /* Callback for reading data from device
 511  *
 512  * Check urb status, call read function and resubmit urb read operation.
 513  */
 514 static void usb_8dev_read_bulk_callback(struct urb *urb)
 515 {
 516         struct usb_8dev_priv *priv = urb->context;
 517         struct net_device *netdev;
 518         int retval;
 519         int pos = 0;
 520
 521         netdev = priv->netdev;
 522
 523         if (!netif_device_present(netdev))
 524                 return;
 525
 526         switch (urb->status) {
 527         case 0: /* success */
 528                 break;
 529
 530         case -ENOENT:
 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                 netdev_err(netdev, "No memory left for URBs\n");
 632                 goto nomem;
 633         }
 634
 635         buf = usb_alloc_coherent(priv->udev, size, GFP_ATOMIC,
 636                                  &urb->transfer_dma);
 637         if (!buf) {
 638                 netdev_err(netdev, "No memory left for USB buffer\n");
 639                 goto nomembuf;
 640         }
 641
 642         memset(buf, 0, size);
 643
 644         msg = (struct usb_8dev_tx_msg *)buf;
 645         msg->begin = USB_8DEV_DATA_START;
 646         msg->flags = 0x00;
 647
 648         if (cf->can_id & CAN_RTR_FLAG)
 649                 msg->flags |= USB_8DEV_RTR;
 650
 651         if (cf->can_id & CAN_EFF_FLAG)
 652                 msg->flags |= USB_8DEV_EXTID;
 653
 654         msg->id = cpu_to_be32(cf->can_id & CAN_ERR_MASK);
 655         msg->dlc = cf->can_dlc;
 656         memcpy(msg->data, cf->data, cf->can_dlc);
 657         msg->end = USB_8DEV_DATA_END;
 658
 659         for (i = 0; i < MAX_TX_URBS; i++) {
 660                 if (priv->tx_contexts[i].echo_index == MAX_TX_URBS) {
 661                         context = &priv->tx_contexts[i];
 662                         break;
 663                 }
 664         }
 665
 666         /* May never happen! When this happens we'd more URBs in flight as
 667          * allowed (MAX_TX_URBS).
 668          */
 669         if (!context)
 670                 goto nofreecontext;
 671
 672         context->priv = priv;
 673         context->echo_index = i;
 674         context->dlc = cf->can_dlc;
 675
 676         usb_fill_bulk_urb(urb, priv->udev,
 677                           usb_sndbulkpipe(priv->udev, USB_8DEV_ENDP_DATA_TX),
 678                           buf, size, usb_8dev_write_bulk_callback, context);
 679         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 680         usb_anchor_urb(urb, &priv->tx_submitted);
 681
 682         can_put_echo_skb(skb, netdev, context->echo_index);
 683
 684         atomic_inc(&priv->active_tx_urbs);
 685
 686         err = usb_submit_urb(urb, GFP_ATOMIC);
 687         if (unlikely(err))
 688                 goto failed;
 689         else if (atomic_read(&priv->active_tx_urbs) >= MAX_TX_URBS)
 690                 /* Slow down tx path */
 691                 netif_stop_queue(netdev);
 692
 693         /* Release our reference to this URB, the USB core will eventually free
 694          * it entirely.
 695          */
 696         usb_free_urb(urb);
 697
 698         return NETDEV_TX_OK;
 699
 700 nofreecontext:
 701         usb_free_coherent(priv->udev, size, buf, urb->transfer_dma);
 702         usb_free_urb(urb);
 703
 704         netdev_warn(netdev, "couldn't find free context");
 705
 706         return NETDEV_TX_BUSY;
 707
 708 failed:
 709         can_free_echo_skb(netdev, context->echo_index);
 710
 711         usb_unanchor_urb(urb);
 712         usb_free_coherent(priv->udev, size, buf, urb->transfer_dma);
 713
 714         atomic_dec(&priv->active_tx_urbs);
 715
 716         if (err == -ENODEV)
 717                 netif_device_detach(netdev);
 718         else
 719                 netdev_warn(netdev, "failed tx_urb %d\n", err);
 720
 721 nomembuf:
 722         usb_free_urb(urb);
 723
 724 nomem:
 725         dev_kfree_skb(skb);
 726         stats->tx_dropped++;
 727
 728         return NETDEV_TX_OK;
 729 }
 730
 731 static int usb_8dev_get_berr_counter(const struct net_device *netdev,
 732                                      struct can_berr_counter *bec)
 733 {
 734         struct usb_8dev_priv *priv = netdev_priv(netdev);
 735
 736         bec->txerr = priv->bec.txerr;
 737         bec->rxerr = priv->bec.rxerr;
 738
 739         return 0;
 740 }
 741
 742 /* Start USB device */
 743 static int usb_8dev_start(struct usb_8dev_priv *priv)
 744 {
 745         struct net_device *netdev = priv->netdev;
 746         int err, i;
 747
 748         for (i = 0; i < MAX_RX_URBS; i++) {
 749                 struct urb *urb = NULL;
 750                 u8 *buf;
 751
 752                 /* create a URB, and a buffer for it */
 753                 urb = usb_alloc_urb(0, GFP_KERNEL);
 754                 if (!urb) {
 755                         netdev_err(netdev, "No memory left for URBs\n");
 756                         err = -ENOMEM;
 757                         break;
 758                 }
 759
 760                 buf = usb_alloc_coherent(priv->udev, RX_BUFFER_SIZE, GFP_KERNEL,
 761                                          &urb->transfer_dma);
 762                 if (!buf) {
 763                         netdev_err(netdev, "No memory left for USB buffer\n");
 764                         usb_free_urb(urb);
 765                         err = -ENOMEM;
 766                         break;
 767                 }
 768
 769                 usb_fill_bulk_urb(urb, priv->udev,
 770                                   usb_rcvbulkpipe(priv->udev,
 771                                                   USB_8DEV_ENDP_DATA_RX),
 772                                   buf, RX_BUFFER_SIZE,
 773                                   usb_8dev_read_bulk_callback, priv);
 774                 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 775                 usb_anchor_urb(urb, &priv->rx_submitted);
 776
 777                 err = usb_submit_urb(urb, GFP_KERNEL);
 778                 if (err) {
 779                         usb_unanchor_urb(urb);
 780                         usb_free_coherent(priv->udev, RX_BUFFER_SIZE, buf,
 781                                           urb->transfer_dma);
 782                         usb_free_urb(urb);
 783                         break;
 784                 }
 785
 786                 /* Drop reference, USB core will take care of freeing it */
 787                 usb_free_urb(urb);
 788         }
 789
 790         /* Did we submit any URBs */
 791         if (i == 0) {
 792                 netdev_warn(netdev, "couldn't setup read URBs\n");
 793                 return err;
 794         }
 795
 796         /* Warn if we've couldn't transmit all the URBs */
 797         if (i < MAX_RX_URBS)
 798                 netdev_warn(netdev, "rx performance may be slow\n");
 799
 800         err = usb_8dev_cmd_open(priv);
 801         if (err)
 802                 goto failed;
 803
 804         priv->can.state = CAN_STATE_ERROR_ACTIVE;
 805
 806         return 0;
 807
 808 failed:
 809         if (err == -ENODEV)
 810                 netif_device_detach(priv->netdev);
 811
 812         netdev_warn(netdev, "couldn't submit control: %d\n", err);
 813
 814         return err;
 815 }
 816
 817 /* Open USB device */
 818 static int usb_8dev_open(struct net_device *netdev)
 819 {
 820         struct usb_8dev_priv *priv = netdev_priv(netdev);
 821         int err;
 822
 823         /* common open */
 824         err = open_candev(netdev);
 825         if (err)
 826                 return err;
 827
 828         can_led_event(netdev, CAN_LED_EVENT_OPEN);
 829
 830         /* finally start device */
 831         err = usb_8dev_start(priv);
 832         if (err) {
 833                 if (err == -ENODEV)
 834                         netif_device_detach(priv->netdev);
 835
 836                 netdev_warn(netdev, "couldn't start device: %d\n",
 837                          err);
 838
 839                 close_candev(netdev);
 840
 841                 return err;
 842         }
 843
 844         netif_start_queue(netdev);
 845
 846         return 0;
 847 }
 848
 849 static void unlink_all_urbs(struct usb_8dev_priv *priv)
 850 {
 851         int i;
 852
 853         usb_kill_anchored_urbs(&priv->rx_submitted);
 854
 855         usb_kill_anchored_urbs(&priv->tx_submitted);
 856         atomic_set(&priv->active_tx_urbs, 0);
 857
 858         for (i = 0; i < MAX_TX_URBS; i++)
 859                 priv->tx_contexts[i].echo_index = MAX_TX_URBS;
 860 }
 861
 862 /* Close USB device */
 863 static int usb_8dev_close(struct net_device *netdev)
 864 {
 865         struct usb_8dev_priv *priv = netdev_priv(netdev);
 866         int err = 0;
 867
 868         /* Send CLOSE command to CAN controller */
 869         err = usb_8dev_cmd_close(priv);
 870         if (err)
 871                 netdev_warn(netdev, "couldn't stop device");
 872
 873         priv->can.state = CAN_STATE_STOPPED;
 874
 875         netif_stop_queue(netdev);
 876
 877         /* Stop polling */
 878         unlink_all_urbs(priv);
 879
 880         close_candev(netdev);
 881
 882         can_led_event(netdev, CAN_LED_EVENT_STOP);
 883
 884         return err;
 885 }
 886
 887 static const struct net_device_ops usb_8dev_netdev_ops = {
 888         .ndo_open = usb_8dev_open,
 889         .ndo_stop = usb_8dev_close,
 890         .ndo_start_xmit = usb_8dev_start_xmit,
 891         .ndo_change_mtu = can_change_mtu,
 892 };
 893
 894 static const struct can_bittiming_const usb_8dev_bittiming_const = {
 895         .name = "usb_8dev",
 896         .tseg1_min = 1,
 897         .tseg1_max = 16,
 898         .tseg2_min = 1,
 899         .tseg2_max = 8,
 900         .sjw_max = 4,
 901         .brp_min = 1,
 902         .brp_max = 1024,
 903         .brp_inc = 1,
 904 };
 905
 906 /* Probe USB device
 907  *
 908  * Check device and firmware.
 909  * Set supported modes and bittiming constants.
 910  * Allocate some memory.
 911  */
 912 static int usb_8dev_probe(struct usb_interface *intf,
 913                          const struct usb_device_id *id)
 914 {
 915         struct net_device *netdev;
 916         struct usb_8dev_priv *priv;
 917         int i, err = -ENOMEM;
 918         u32 version;
 919         char buf[18];
 920         struct usb_device *usbdev = interface_to_usbdev(intf);
 921
 922         /* product id looks strange, better we also check iProduct string */
 923         if (usb_string(usbdev, usbdev->descriptor.iProduct, buf,
 924                        sizeof(buf)) > 0 && strcmp(buf, "USB2CAN converter")) {
 925                 dev_info(&usbdev->dev, "ignoring: not an USB2CAN converter\n");
 926                 return -ENODEV;
 927         }
 928
 929         netdev = alloc_candev(sizeof(struct usb_8dev_priv), MAX_TX_URBS);
 930         if (!netdev) {
 931                 dev_err(&intf->dev, "Couldn't alloc candev\n");
 932                 return -ENOMEM;
 933         }
 934
 935         priv = netdev_priv(netdev);
 936
 937         priv->udev = usbdev;
 938         priv->netdev = netdev;
 939
 940         priv->can.state = CAN_STATE_STOPPED;
 941         priv->can.clock.freq = USB_8DEV_ABP_CLOCK;
 942         priv->can.bittiming_const = &usb_8dev_bittiming_const;
 943         priv->can.do_set_mode = usb_8dev_set_mode;
 944         priv->can.do_get_berr_counter = usb_8dev_get_berr_counter;
 945         priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
 946                                       CAN_CTRLMODE_LISTENONLY |
 947                                       CAN_CTRLMODE_ONE_SHOT;
 948
 949         netdev->netdev_ops = &usb_8dev_netdev_ops;
 950
 951         netdev->flags |= IFF_ECHO; /* we support local echo */
 952
 953         init_usb_anchor(&priv->rx_submitted);
 954
 955         init_usb_anchor(&priv->tx_submitted);
 956         atomic_set(&priv->active_tx_urbs, 0);
 957
 958         for (i = 0; i < MAX_TX_URBS; i++)
 959                 priv->tx_contexts[i].echo_index = MAX_TX_URBS;
 960
 961         priv->cmd_msg_buffer = kzalloc(sizeof(struct usb_8dev_cmd_msg),
 962                                       GFP_KERNEL);
 963         if (!priv->cmd_msg_buffer)
 964                 goto cleanup_candev;
 965
 966         usb_set_intfdata(intf, priv);
 967
 968         SET_NETDEV_DEV(netdev, &intf->dev);
 969
 970         mutex_init(&priv->usb_8dev_cmd_lock);
 971
 972         err = register_candev(netdev);
 973         if (err) {
 974                 netdev_err(netdev,
 975                         "couldn't register CAN device: %d\n", err);
 976                 goto cleanup_cmd_msg_buffer;
 977         }
 978
 979         err = usb_8dev_cmd_version(priv, &version);
 980         if (err) {
 981                 netdev_err(netdev, "can't get firmware version\n");
 982                 goto cleanup_unregister_candev;
 983         } else {
 984                 netdev_info(netdev,
 985                          "firmware: %d.%d, hardware: %d.%d\n",
 986                          (version>>24) & 0xff, (version>>16) & 0xff,
 987                          (version>>8) & 0xff, version & 0xff);
 988         }
 989
 990         devm_can_led_init(netdev);
 991
 992         return 0;
 993
 994 cleanup_unregister_candev:
 995         unregister_netdev(priv->netdev);
 996
 997 cleanup_cmd_msg_buffer:
 998         kfree(priv->cmd_msg_buffer);
 999
1000 cleanup_candev:
1001         free_candev(netdev);
1002
1003         return err;
1004
1005 }
1006
1007 /* Called by the usb core when driver is unloaded or device is removed */
1008 static void usb_8dev_disconnect(struct usb_interface *intf)
1009 {
1010         struct usb_8dev_priv *priv = usb_get_intfdata(intf);
1011
1012         usb_set_intfdata(intf, NULL);
1013
1014         if (priv) {
1015                 netdev_info(priv->netdev, "device disconnected\n");
1016
1017                 unregister_netdev(priv->netdev);
1018                 free_candev(priv->netdev);
1019
1020                 unlink_all_urbs(priv);
1021         }
1022
1023 }
1024
1025 static struct usb_driver usb_8dev_driver = {
1026         .name =         "usb_8dev",
1027         .probe =        usb_8dev_probe,
1028         .disconnect =   usb_8dev_disconnect,
1029         .id_table =     usb_8dev_table,
1030 };
1031
1032 module_usb_driver(usb_8dev_driver);
1033
1034 MODULE_AUTHOR("Bernd Krumboeck <krumboeck@universalnet.at>");
1035 MODULE_DESCRIPTION("CAN driver for 8 devices USB2CAN interfaces");
1036 MODULE_LICENSE("GPL v2");