drivers/net/can/usb/usb_8dev.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * CAN driver for "8 devices" USB2CAN converter
   4  *
   5  * Copyright (C) 2012 Bernd Krumboeck ([email protected])
   6  *
   7  * This driver is inspired by the 3.2.0 version of drivers/net/can/usb/ems_usb.c
   8  * and drivers/net/can/usb/esd_usb2.c
   9  *
  10  * Many thanks to Gerhard Bertelsmann ([email protected])
  11  * for testing and fixing this driver. Also many thanks to "8 devices",
  12  * who were very cooperative and answered my questions.
  13  */
  14
  15 #include <linux/signal.h>
  16 #include <linux/slab.h>
  17 #include <linux/module.h>
  18 #include <linux/netdevice.h>
  19 #include <linux/usb.h>
  20
  21 #include <linux/can.h>
  22 #include <linux/can/dev.h>
  23 #include <linux/can/error.h>
  24 #include <linux/can/led.h>
  25
  26 /* driver constants */
  27 #define MAX_RX_URBS                     20
  28 #define MAX_TX_URBS                     20
  29 #define RX_BUFFER_SIZE                  64
  30
  31 /* vendor and product id */
  32 #define USB_8DEV_VENDOR_ID              0x0483
  33 #define USB_8DEV_PRODUCT_ID             0x1234
  34
  35 /* endpoints */
  36 enum usb_8dev_endpoint {
  37         USB_8DEV_ENDP_DATA_RX = 1,
  38         USB_8DEV_ENDP_DATA_TX,
  39         USB_8DEV_ENDP_CMD_RX,
  40         USB_8DEV_ENDP_CMD_TX
  41 };
  42
  43 /* device CAN clock */
  44 #define USB_8DEV_ABP_CLOCK              32000000
  45
  46 /* setup flags */
  47 #define USB_8DEV_SILENT                 0x01
  48 #define USB_8DEV_LOOPBACK               0x02
  49 #define USB_8DEV_DISABLE_AUTO_RESTRANS  0x04
  50 #define USB_8DEV_STATUS_FRAME           0x08
  51
  52 /* commands */
  53 enum usb_8dev_cmd {
  54         USB_8DEV_RESET = 1,
  55         USB_8DEV_OPEN,
  56         USB_8DEV_CLOSE,
  57         USB_8DEV_SET_SPEED,
  58         USB_8DEV_SET_MASK_FILTER,
  59         USB_8DEV_GET_STATUS,
  60         USB_8DEV_GET_STATISTICS,
  61         USB_8DEV_GET_SERIAL,
  62         USB_8DEV_GET_SOFTW_VER,
  63         USB_8DEV_GET_HARDW_VER,
  64         USB_8DEV_RESET_TIMESTAMP,
  65         USB_8DEV_GET_SOFTW_HARDW_VER
  66 };
  67
  68 /* command options */
  69 #define USB_8DEV_BAUD_MANUAL            0x09
  70 #define USB_8DEV_CMD_START              0x11
  71 #define USB_8DEV_CMD_END                0x22
  72
  73 #define USB_8DEV_CMD_SUCCESS            0
  74 #define USB_8DEV_CMD_ERROR              255
  75
  76 #define USB_8DEV_CMD_TIMEOUT            1000
  77
  78 /* frames */
  79 #define USB_8DEV_DATA_START             0x55
  80 #define USB_8DEV_DATA_END               0xAA
  81
  82 #define USB_8DEV_TYPE_CAN_FRAME         0
  83 #define USB_8DEV_TYPE_ERROR_FRAME       3
  84
  85 #define USB_8DEV_EXTID                  0x01
  86 #define USB_8DEV_RTR                    0x02
  87 #define USB_8DEV_ERR_FLAG               0x04
  88
  89 /* status */
  90 #define USB_8DEV_STATUSMSG_OK           0x00  /* Normal condition. */
  91 #define USB_8DEV_STATUSMSG_OVERRUN      0x01  /* Overrun occurred when sending */
  92 #define USB_8DEV_STATUSMSG_BUSLIGHT     0x02  /* Error counter has reached 96 */
  93 #define USB_8DEV_STATUSMSG_BUSHEAVY     0x03  /* Error count. has reached 128 */
  94 #define USB_8DEV_STATUSMSG_BUSOFF       0x04  /* Device is in BUSOFF */
  95 #define USB_8DEV_STATUSMSG_STUFF        0x20  /* Stuff Error */
  96 #define USB_8DEV_STATUSMSG_FORM         0x21  /* Form Error */
  97 #define USB_8DEV_STATUSMSG_ACK          0x23  /* Ack Error */
  98 #define USB_8DEV_STATUSMSG_BIT0         0x24  /* Bit1 Error */
  99 #define USB_8DEV_STATUSMSG_BIT1         0x25  /* Bit0 Error */
 100 #define USB_8DEV_STATUSMSG_CRC          0x27  /* CRC Error */
 101
 102 #define USB_8DEV_RP_MASK                0x7F  /* Mask for Receive Error Bit */
 103
 104
 105 /* table of devices that work with this driver */
 106 static const struct usb_device_id usb_8dev_table[] = {
 107         { USB_DEVICE(USB_8DEV_VENDOR_ID, USB_8DEV_PRODUCT_ID) },
 108         { }                                     /* Terminating entry */
 109 };
 110
 111 MODULE_DEVICE_TABLE(usb, usb_8dev_table);
 112
 113 struct usb_8dev_tx_urb_context {
 114         struct usb_8dev_priv *priv;
 115
 116         u32 echo_index;
 117         u8 dlc;
 118 };
 119
 120 /* Structure to hold all of our device specific stuff */
 121 struct usb_8dev_priv {
 122         struct can_priv can; /* must be the first member */
 123
 124         struct sk_buff *echo_skb[MAX_TX_URBS];
 125
 126         struct usb_device *udev;
 127         struct net_device *netdev;
 128
 129         atomic_t active_tx_urbs;
 130         struct usb_anchor tx_submitted;
 131         struct usb_8dev_tx_urb_context tx_contexts[MAX_TX_URBS];
 132
 133         struct usb_anchor rx_submitted;
 134
 135         struct can_berr_counter bec;
 136
 137         u8 *cmd_msg_buffer;
 138
 139         struct mutex usb_8dev_cmd_lock;
 140         void *rxbuf[MAX_RX_URBS];
 141         dma_addr_t rxbuf_dma[MAX_RX_URBS];
 142 };
 143
 144 /* tx frame */
 145 struct __packed usb_8dev_tx_msg {
 146         u8 begin;
 147         u8 flags;       /* RTR and EXT_ID flag */
 148         __be32 id;      /* upper 3 bits not used */
 149         u8 dlc;         /* data length code 0-8 bytes */
 150         u8 data[8];     /* 64-bit data */
 151         u8 end;
 152 };
 153
 154 /* rx frame */
 155 struct __packed usb_8dev_rx_msg {
 156         u8 begin;
 157         u8 type;                /* frame type */
 158         u8 flags;               /* RTR and EXT_ID flag */
 159         __be32 id;              /* upper 3 bits not used */
 160         u8 dlc;                 /* data length code 0-8 bytes */
 161         u8 data[8];             /* 64-bit data */
 162         __be32 timestamp;       /* 32-bit timestamp */
 163         u8 end;
 164 };
 165
 166 /* command frame */
 167 struct __packed usb_8dev_cmd_msg {
 168         u8 begin;
 169         u8 channel;     /* unknown - always 0 */
 170         u8 command;     /* command to execute */
 171         u8 opt1;        /* optional parameter / return value */
 172         u8 opt2;        /* optional parameter 2 */
 173         u8 data[10];    /* optional parameter and data */
 174         u8 end;
 175 };
 176
 177 static int usb_8dev_send_cmd_msg(struct usb_8dev_priv *priv, u8 *msg, int size)
 178 {
 179         int actual_length;
 180
 181         return usb_bulk_msg(priv->udev,
 182                             usb_sndbulkpipe(priv->udev, USB_8DEV_ENDP_CMD_TX),
 183                             msg, size, &actual_length, USB_8DEV_CMD_TIMEOUT);
 184 }
 185
 186 static int usb_8dev_wait_cmd_msg(struct usb_8dev_priv *priv, u8 *msg, int size,
 187                                 int *actual_length)
 188 {
 189         return usb_bulk_msg(priv->udev,
 190                             usb_rcvbulkpipe(priv->udev, USB_8DEV_ENDP_CMD_RX),
 191                             msg, size, actual_length, USB_8DEV_CMD_TIMEOUT);
 192 }
 193
 194 /* Send command to device and receive result.
 195  * Command was successful when opt1 = 0.
 196  */
 197 static int usb_8dev_send_cmd(struct usb_8dev_priv *priv,
 198                              struct usb_8dev_cmd_msg *out,
 199                              struct usb_8dev_cmd_msg *in)
 200 {
 201         int err;
 202         int num_bytes_read;
 203         struct net_device *netdev;
 204
 205         netdev = priv->netdev;
 206
 207         out->begin = USB_8DEV_CMD_START;
 208         out->end = USB_8DEV_CMD_END;
 209
 210         mutex_lock(&priv->usb_8dev_cmd_lock);
 211
 212         memcpy(priv->cmd_msg_buffer, out,
 213                 sizeof(struct usb_8dev_cmd_msg));
 214
 215         err = usb_8dev_send_cmd_msg(priv, priv->cmd_msg_buffer,
 216                                     sizeof(struct usb_8dev_cmd_msg));
 217         if (err < 0) {
 218                 netdev_err(netdev, "sending command message failed\n");
 219                 goto failed;
 220         }
 221
 222         err = usb_8dev_wait_cmd_msg(priv, priv->cmd_msg_buffer,
 223                                     sizeof(struct usb_8dev_cmd_msg),
 224                                     &num_bytes_read);
 225         if (err < 0) {
 226                 netdev_err(netdev, "no command message answer\n");
 227                 goto failed;
 228         }
 229
 230         memcpy(in, priv->cmd_msg_buffer, sizeof(struct usb_8dev_cmd_msg));
 231
 232         if (in->begin != USB_8DEV_CMD_START || in->end != USB_8DEV_CMD_END ||
 233                         num_bytes_read != 16 || in->opt1 != 0)
 234                 err = -EPROTO;
 235
 236 failed:
 237         mutex_unlock(&priv->usb_8dev_cmd_lock);
 238         return err;
 239 }
 240
 241 /* Send open command to device */
 242 static int usb_8dev_cmd_open(struct usb_8dev_priv *priv)
 243 {
 244         struct can_bittiming *bt = &priv->can.bittiming;
 245         struct usb_8dev_cmd_msg outmsg;
 246         struct usb_8dev_cmd_msg inmsg;
 247         u32 ctrlmode = priv->can.ctrlmode;
 248         u32 flags = USB_8DEV_STATUS_FRAME;
 249         __be32 beflags;
 250         __be16 bebrp;
 251
 252         memset(&outmsg, 0, sizeof(outmsg));
 253         outmsg.command = USB_8DEV_OPEN;
 254         outmsg.opt1 = USB_8DEV_BAUD_MANUAL;
 255         outmsg.data[0] = bt->prop_seg + bt->phase_seg1;
 256         outmsg.data[1] = bt->phase_seg2;
 257         outmsg.data[2] = bt->sjw;
 258
 259         /* BRP */
 260         bebrp = cpu_to_be16((u16)bt->brp);
 261         memcpy(&outmsg.data[3], &bebrp, sizeof(bebrp));
 262
 263         /* flags */
 264         if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
 265                 flags |= USB_8DEV_LOOPBACK;
 266         if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
 267                 flags |= USB_8DEV_SILENT;
 268         if (ctrlmode & CAN_CTRLMODE_ONE_SHOT)
 269                 flags |= USB_8DEV_DISABLE_AUTO_RESTRANS;
 270
 271         beflags = cpu_to_be32(flags);
 272         memcpy(&outmsg.data[5], &beflags, sizeof(beflags));
 273
 274         return usb_8dev_send_cmd(priv, &outmsg, &inmsg);
 275 }
 276
 277 /* Send close command to device */
 278 static int usb_8dev_cmd_close(struct usb_8dev_priv *priv)
 279 {
 280         struct usb_8dev_cmd_msg inmsg;
 281         struct usb_8dev_cmd_msg outmsg = {
 282                 .channel = 0,
 283                 .command = USB_8DEV_CLOSE,
 284                 .opt1 = 0,
 285                 .opt2 = 0
 286         };
 287
 288         return usb_8dev_send_cmd(priv, &outmsg, &inmsg);
 289 }
 290
 291 /* Get firmware and hardware version */
 292 static int usb_8dev_cmd_version(struct usb_8dev_priv *priv, u32 *res)
 293 {
 294         struct usb_8dev_cmd_msg inmsg;
 295         struct usb_8dev_cmd_msg outmsg = {
 296                 .channel = 0,
 297                 .command = USB_8DEV_GET_SOFTW_HARDW_VER,
 298                 .opt1 = 0,
 299                 .opt2 = 0
 300         };
 301
 302         int err = usb_8dev_send_cmd(priv, &outmsg, &inmsg);
 303         if (err)
 304                 return err;
 305
 306         *res = be32_to_cpup((__be32 *)inmsg.data);
 307
 308         return err;
 309 }
 310
 311 /* Set network device mode
 312  *
 313  * Maybe we should leave this function empty, because the device
 314  * set mode variable with open command.
 315  */
 316 static int usb_8dev_set_mode(struct net_device *netdev, enum can_mode mode)
 317 {
 318         struct usb_8dev_priv *priv = netdev_priv(netdev);
 319         int err = 0;
 320
 321         switch (mode) {
 322         case CAN_MODE_START:
 323                 err = usb_8dev_cmd_open(priv);
 324                 if (err)
 325                         netdev_warn(netdev, "couldn't start device");
 326                 break;
 327
 328         default:
 329                 return -EOPNOTSUPP;
 330         }
 331
 332         return err;
 333 }
 334
 335 /* Read error/status frames */
 336 static void usb_8dev_rx_err_msg(struct usb_8dev_priv *priv,
 337                                 struct usb_8dev_rx_msg *msg)
 338 {
 339         struct can_frame *cf;
 340         struct sk_buff *skb;
 341         struct net_device_stats *stats = &priv->netdev->stats;
 342
 343         /* Error message:
 344          * byte 0: Status
 345          * byte 1: bit   7: Receive Passive
 346          * byte 1: bit 0-6: Receive Error Counter
 347          * byte 2: Transmit Error Counter
 348          * byte 3: Always 0 (maybe reserved for future use)
 349          */
 350
 351         u8 state = msg->data[0];
 352         u8 rxerr = msg->data[1] & USB_8DEV_RP_MASK;
 353         u8 txerr = msg->data[2];
 354         int rx_errors = 0;
 355         int tx_errors = 0;
 356
 357         skb = alloc_can_err_skb(priv->netdev, &cf);
 358         if (!skb)
 359                 return;
 360
 361         switch (state) {
 362         case USB_8DEV_STATUSMSG_OK:
 363                 priv->can.state = CAN_STATE_ERROR_ACTIVE;
 364                 cf->can_id |= CAN_ERR_PROT;
 365                 cf->data[2] = CAN_ERR_PROT_ACTIVE;
 366                 break;
 367         case USB_8DEV_STATUSMSG_BUSOFF:
 368                 priv->can.state = CAN_STATE_BUS_OFF;
 369                 cf->can_id |= CAN_ERR_BUSOFF;
 370                 priv->can.can_stats.bus_off++;
 371                 can_bus_off(priv->netdev);
 372                 break;
 373         case USB_8DEV_STATUSMSG_OVERRUN:
 374         case USB_8DEV_STATUSMSG_BUSLIGHT:
 375         case USB_8DEV_STATUSMSG_BUSHEAVY:
 376                 cf->can_id |= CAN_ERR_CRTL;
 377                 break;
 378         default:
 379                 priv->can.state = CAN_STATE_ERROR_WARNING;
 380                 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
 381                 priv->can.can_stats.bus_error++;
 382                 break;
 383         }
 384
 385         switch (state) {
 386         case USB_8DEV_STATUSMSG_OK:
 387         case USB_8DEV_STATUSMSG_BUSOFF:
 388                 break;
 389         case USB_8DEV_STATUSMSG_ACK:
 390                 cf->can_id |= CAN_ERR_ACK;
 391                 tx_errors = 1;
 392                 break;
 393         case USB_8DEV_STATUSMSG_CRC:
 394                 cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
 395                 rx_errors = 1;
 396                 break;
 397         case USB_8DEV_STATUSMSG_BIT0:
 398                 cf->data[2] |= CAN_ERR_PROT_BIT0;
 399                 tx_errors = 1;
 400                 break;
 401         case USB_8DEV_STATUSMSG_BIT1:
 402                 cf->data[2] |= CAN_ERR_PROT_BIT1;
 403                 tx_errors = 1;
 404                 break;
 405         case USB_8DEV_STATUSMSG_FORM:
 406                 cf->data[2] |= CAN_ERR_PROT_FORM;
 407                 rx_errors = 1;
 408                 break;
 409         case USB_8DEV_STATUSMSG_STUFF:
 410                 cf->data[2] |= CAN_ERR_PROT_STUFF;
 411                 rx_errors = 1;
 412                 break;
 413         case USB_8DEV_STATUSMSG_OVERRUN:
 414                 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 415                 stats->rx_over_errors++;
 416                 rx_errors = 1;
 417                 break;
 418         case USB_8DEV_STATUSMSG_BUSLIGHT:
 419                 priv->can.state = CAN_STATE_ERROR_WARNING;
 420                 cf->data[1] = (txerr > rxerr) ?
 421                         CAN_ERR_CRTL_TX_WARNING :
 422                         CAN_ERR_CRTL_RX_WARNING;
 423                 priv->can.can_stats.error_warning++;
 424                 break;
 425         case USB_8DEV_STATUSMSG_BUSHEAVY:
 426                 priv->can.state = CAN_STATE_ERROR_PASSIVE;
 427                 cf->data[1] = (txerr > rxerr) ?
 428                         CAN_ERR_CRTL_TX_PASSIVE :
 429                         CAN_ERR_CRTL_RX_PASSIVE;
 430                 priv->can.can_stats.error_passive++;
 431                 break;
 432         default:
 433                 netdev_warn(priv->netdev,
 434                             "Unknown status/error message (%d)\n", state);
 435                 break;
 436         }
 437
 438         if (tx_errors) {
 439                 cf->data[2] |= CAN_ERR_PROT_TX;
 440                 stats->tx_errors++;
 441         }
 442
 443         if (rx_errors)
 444                 stats->rx_errors++;
 445
 446         cf->data[6] = txerr;
 447         cf->data[7] = rxerr;
 448
 449         priv->bec.txerr = txerr;
 450         priv->bec.rxerr = rxerr;
 451
 452         stats->rx_packets++;
 453         stats->rx_bytes += cf->len;
 454         netif_rx(skb);
 455 }
 456
 457 /* Read data and status frames */
 458 static void usb_8dev_rx_can_msg(struct usb_8dev_priv *priv,
 459                                 struct usb_8dev_rx_msg *msg)
 460 {
 461         struct can_frame *cf;
 462         struct sk_buff *skb;
 463         struct net_device_stats *stats = &priv->netdev->stats;
 464
 465         if (msg->type == USB_8DEV_TYPE_ERROR_FRAME &&
 466                    msg->flags == USB_8DEV_ERR_FLAG) {
 467                 usb_8dev_rx_err_msg(priv, msg);
 468         } else if (msg->type == USB_8DEV_TYPE_CAN_FRAME) {
 469                 skb = alloc_can_skb(priv->netdev, &cf);
 470                 if (!skb)
 471                         return;
 472
 473                 cf->can_id = be32_to_cpu(msg->id);
 474                 can_frame_set_cc_len(cf, msg->dlc & 0xF, priv->can.ctrlmode);
 475
 476                 if (msg->flags & USB_8DEV_EXTID)
 477                         cf->can_id |= CAN_EFF_FLAG;
 478
 479                 if (msg->flags & USB_8DEV_RTR)
 480                         cf->can_id |= CAN_RTR_FLAG;
 481                 else
 482                         memcpy(cf->data, msg->data, cf->len);
 483
 484                 stats->rx_packets++;
 485                 stats->rx_bytes += cf->len;
 486                 netif_rx(skb);
 487
 488                 can_led_event(priv->netdev, CAN_LED_EVENT_RX);
 489         } else {
 490                 netdev_warn(priv->netdev, "frame type %d unknown",
 491                          msg->type);
 492         }
 493
 494 }
 495
 496 /* Callback for reading data from device
 497  *
 498  * Check urb status, call read function and resubmit urb read operation.
 499  */
 500 static void usb_8dev_read_bulk_callback(struct urb *urb)
 501 {
 502         struct usb_8dev_priv *priv = urb->context;
 503         struct net_device *netdev;
 504         int retval;
 505         int pos = 0;
 506
 507         netdev = priv->netdev;
 508
 509         if (!netif_device_present(netdev))
 510                 return;
 511
 512         switch (urb->status) {
 513         case 0: /* success */
 514                 break;
 515
 516         case -ENOENT:
 517         case -EPIPE:
 518         case -EPROTO:
 519         case -ESHUTDOWN:
 520                 return;
 521
 522         default:
 523                 netdev_info(netdev, "Rx URB aborted (%d)\n",
 524                          urb->status);
 525                 goto resubmit_urb;
 526         }
 527
 528         while (pos < urb->actual_length) {
 529                 struct usb_8dev_rx_msg *msg;
 530
 531                 if (pos + sizeof(struct usb_8dev_rx_msg) > urb->actual_length) {
 532                         netdev_err(priv->netdev, "format error\n");
 533                         break;
 534                 }
 535
 536                 msg = (struct usb_8dev_rx_msg *)(urb->transfer_buffer + pos);
 537                 usb_8dev_rx_can_msg(priv, msg);
 538
 539                 pos += sizeof(struct usb_8dev_rx_msg);
 540         }
 541
 542 resubmit_urb:
 543         usb_fill_bulk_urb(urb, priv->udev,
 544                           usb_rcvbulkpipe(priv->udev, USB_8DEV_ENDP_DATA_RX),
 545                           urb->transfer_buffer, RX_BUFFER_SIZE,
 546                           usb_8dev_read_bulk_callback, priv);
 547
 548         retval = usb_submit_urb(urb, GFP_ATOMIC);
 549
 550         if (retval == -ENODEV)
 551                 netif_device_detach(netdev);
 552         else if (retval)
 553                 netdev_err(netdev,
 554                         "failed resubmitting read bulk urb: %d\n", retval);
 555 }
 556
 557 /* Callback handler for write operations
 558  *
 559  * Free allocated buffers, check transmit status and
 560  * calculate statistic.
 561  */
 562 static void usb_8dev_write_bulk_callback(struct urb *urb)
 563 {
 564         struct usb_8dev_tx_urb_context *context = urb->context;
 565         struct usb_8dev_priv *priv;
 566         struct net_device *netdev;
 567
 568         BUG_ON(!context);
 569
 570         priv = context->priv;
 571         netdev = priv->netdev;
 572
 573         /* free up our allocated buffer */
 574         usb_free_coherent(urb->dev, urb->transfer_buffer_length,
 575                           urb->transfer_buffer, urb->transfer_dma);
 576
 577         atomic_dec(&priv->active_tx_urbs);
 578
 579         if (!netif_device_present(netdev))
 580                 return;
 581
 582         if (urb->status)
 583                 netdev_info(netdev, "Tx URB aborted (%d)\n",
 584                          urb->status);
 585
 586         netdev->stats.tx_packets++;
 587         netdev->stats.tx_bytes += context->dlc;
 588
 589         can_get_echo_skb(netdev, context->echo_index, NULL);
 590
 591         can_led_event(netdev, CAN_LED_EVENT_TX);
 592
 593         /* Release context */
 594         context->echo_index = MAX_TX_URBS;
 595
 596         netif_wake_queue(netdev);
 597 }
 598
 599 /* Send data to device */
 600 static netdev_tx_t usb_8dev_start_xmit(struct sk_buff *skb,
 601                                       struct net_device *netdev)
 602 {
 603         struct usb_8dev_priv *priv = netdev_priv(netdev);
 604         struct net_device_stats *stats = &netdev->stats;
 605         struct can_frame *cf = (struct can_frame *) skb->data;
 606         struct usb_8dev_tx_msg *msg;
 607         struct urb *urb;
 608         struct usb_8dev_tx_urb_context *context = NULL;
 609         u8 *buf;
 610         int i, err;
 611         size_t size = sizeof(struct usb_8dev_tx_msg);
 612
 613         if (can_dropped_invalid_skb(netdev, skb))
 614                 return NETDEV_TX_OK;
 615
 616         /* create a URB, and a buffer for it, and copy the data to the URB */
 617         urb = usb_alloc_urb(0, GFP_ATOMIC);
 618         if (!urb)
 619                 goto nomem;
 620
 621         buf = usb_alloc_coherent(priv->udev, size, GFP_ATOMIC,
 622                                  &urb->transfer_dma);
 623         if (!buf) {
 624                 netdev_err(netdev, "No memory left for USB buffer\n");
 625                 goto nomembuf;
 626         }
 627
 628         memset(buf, 0, size);
 629
 630         msg = (struct usb_8dev_tx_msg *)buf;
 631         msg->begin = USB_8DEV_DATA_START;
 632         msg->flags = 0x00;
 633
 634         if (cf->can_id & CAN_RTR_FLAG)
 635                 msg->flags |= USB_8DEV_RTR;
 636
 637         if (cf->can_id & CAN_EFF_FLAG)
 638                 msg->flags |= USB_8DEV_EXTID;
 639
 640         msg->id = cpu_to_be32(cf->can_id & CAN_ERR_MASK);
 641         msg->dlc = can_get_cc_dlc(cf, priv->can.ctrlmode);
 642         memcpy(msg->data, cf->data, cf->len);
 643         msg->end = USB_8DEV_DATA_END;
 644
 645         for (i = 0; i < MAX_TX_URBS; i++) {
 646                 if (priv->tx_contexts[i].echo_index == MAX_TX_URBS) {
 647                         context = &priv->tx_contexts[i];
 648                         break;
 649                 }
 650         }
 651
 652         /* May never happen! When this happens we'd more URBs in flight as
 653          * allowed (MAX_TX_URBS).
 654          */
 655         if (!context)
 656                 goto nofreecontext;
 657
 658         context->priv = priv;
 659         context->echo_index = i;
 660         context->dlc = cf->len;
 661
 662         usb_fill_bulk_urb(urb, priv->udev,
 663                           usb_sndbulkpipe(priv->udev, USB_8DEV_ENDP_DATA_TX),
 664                           buf, size, usb_8dev_write_bulk_callback, context);
 665         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 666         usb_anchor_urb(urb, &priv->tx_submitted);
 667
 668         can_put_echo_skb(skb, netdev, context->echo_index, 0);
 669
 670         atomic_inc(&priv->active_tx_urbs);
 671
 672         err = usb_submit_urb(urb, GFP_ATOMIC);
 673         if (unlikely(err))
 674                 goto failed;
 675         else if (atomic_read(&priv->active_tx_urbs) >= MAX_TX_URBS)
 676                 /* Slow down tx path */
 677                 netif_stop_queue(netdev);
 678
 679         /* Release our reference to this URB, the USB core will eventually free
 680          * it entirely.
 681          */
 682         usb_free_urb(urb);
 683
 684         return NETDEV_TX_OK;
 685
 686 nofreecontext:
 687         usb_free_coherent(priv->udev, size, buf, urb->transfer_dma);
 688         usb_free_urb(urb);
 689
 690         netdev_warn(netdev, "couldn't find free context");
 691
 692         return NETDEV_TX_BUSY;
 693
 694 failed:
 695         can_free_echo_skb(netdev, context->echo_index, NULL);
 696
 697         usb_unanchor_urb(urb);
 698         usb_free_coherent(priv->udev, size, buf, urb->transfer_dma);
 699
 700         atomic_dec(&priv->active_tx_urbs);
 701
 702         if (err == -ENODEV)
 703                 netif_device_detach(netdev);
 704         else
 705                 netdev_warn(netdev, "failed tx_urb %d\n", err);
 706
 707 nomembuf:
 708         usb_free_urb(urb);
 709
 710 nomem:
 711         dev_kfree_skb(skb);
 712         stats->tx_dropped++;
 713
 714         return NETDEV_TX_OK;
 715 }
 716
 717 static int usb_8dev_get_berr_counter(const struct net_device *netdev,
 718                                      struct can_berr_counter *bec)
 719 {
 720         struct usb_8dev_priv *priv = netdev_priv(netdev);
 721
 722         bec->txerr = priv->bec.txerr;
 723         bec->rxerr = priv->bec.rxerr;
 724
 725         return 0;
 726 }
 727
 728 /* Start USB device */
 729 static int usb_8dev_start(struct usb_8dev_priv *priv)
 730 {
 731         struct net_device *netdev = priv->netdev;
 732         int err, i;
 733
 734         for (i = 0; i < MAX_RX_URBS; i++) {
 735                 struct urb *urb = NULL;
 736                 u8 *buf;
 737                 dma_addr_t buf_dma;
 738
 739                 /* create a URB, and a buffer for it */
 740                 urb = usb_alloc_urb(0, GFP_KERNEL);
 741                 if (!urb) {
 742                         err = -ENOMEM;
 743                         break;
 744                 }
 745
 746                 buf = usb_alloc_coherent(priv->udev, RX_BUFFER_SIZE, GFP_KERNEL,
 747                                          &buf_dma);
 748                 if (!buf) {
 749                         netdev_err(netdev, "No memory left for USB buffer\n");
 750                         usb_free_urb(urb);
 751                         err = -ENOMEM;
 752                         break;
 753                 }
 754
 755                 urb->transfer_dma = buf_dma;
 756
 757                 usb_fill_bulk_urb(urb, priv->udev,
 758                                   usb_rcvbulkpipe(priv->udev,
 759                                                   USB_8DEV_ENDP_DATA_RX),
 760                                   buf, RX_BUFFER_SIZE,
 761                                   usb_8dev_read_bulk_callback, priv);
 762                 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 763                 usb_anchor_urb(urb, &priv->rx_submitted);
 764
 765                 err = usb_submit_urb(urb, GFP_KERNEL);
 766                 if (err) {
 767                         usb_unanchor_urb(urb);
 768                         usb_free_coherent(priv->udev, RX_BUFFER_SIZE, buf,
 769                                           urb->transfer_dma);
 770                         usb_free_urb(urb);
 771                         break;
 772                 }
 773
 774                 priv->rxbuf[i] = buf;
 775                 priv->rxbuf_dma[i] = buf_dma;
 776
 777                 /* Drop reference, USB core will take care of freeing it */
 778                 usb_free_urb(urb);
 779         }
 780
 781         /* Did we submit any URBs */
 782         if (i == 0) {
 783                 netdev_warn(netdev, "couldn't setup read URBs\n");
 784                 return err;
 785         }
 786
 787         /* Warn if we've couldn't transmit all the URBs */
 788         if (i < MAX_RX_URBS)
 789                 netdev_warn(netdev, "rx performance may be slow\n");
 790
 791         err = usb_8dev_cmd_open(priv);
 792         if (err)
 793                 goto failed;
 794
 795         priv->can.state = CAN_STATE_ERROR_ACTIVE;
 796
 797         return 0;
 798
 799 failed:
 800         if (err == -ENODEV)
 801                 netif_device_detach(priv->netdev);
 802
 803         netdev_warn(netdev, "couldn't submit control: %d\n", err);
 804
 805         return err;
 806 }
 807
 808 /* Open USB device */
 809 static int usb_8dev_open(struct net_device *netdev)
 810 {
 811         struct usb_8dev_priv *priv = netdev_priv(netdev);
 812         int err;
 813
 814         /* common open */
 815         err = open_candev(netdev);
 816         if (err)
 817                 return err;
 818
 819         can_led_event(netdev, CAN_LED_EVENT_OPEN);
 820
 821         /* finally start device */
 822         err = usb_8dev_start(priv);
 823         if (err) {
 824                 if (err == -ENODEV)
 825                         netif_device_detach(priv->netdev);
 826
 827                 netdev_warn(netdev, "couldn't start device: %d\n",
 828                          err);
 829
 830                 close_candev(netdev);
 831
 832                 return err;
 833         }
 834
 835         netif_start_queue(netdev);
 836
 837         return 0;
 838 }
 839
 840 static void unlink_all_urbs(struct usb_8dev_priv *priv)
 841 {
 842         int i;
 843
 844         usb_kill_anchored_urbs(&priv->rx_submitted);
 845
 846         for (i = 0; i < MAX_RX_URBS; ++i)
 847                 usb_free_coherent(priv->udev, RX_BUFFER_SIZE,
 848                                   priv->rxbuf[i], priv->rxbuf_dma[i]);
 849
 850         usb_kill_anchored_urbs(&priv->tx_submitted);
 851         atomic_set(&priv->active_tx_urbs, 0);
 852
 853         for (i = 0; i < MAX_TX_URBS; i++)
 854                 priv->tx_contexts[i].echo_index = MAX_TX_URBS;
 855 }
 856
 857 /* Close USB device */
 858 static int usb_8dev_close(struct net_device *netdev)
 859 {
 860         struct usb_8dev_priv *priv = netdev_priv(netdev);
 861         int err = 0;
 862
 863         /* Send CLOSE command to CAN controller */
 864         err = usb_8dev_cmd_close(priv);
 865         if (err)
 866                 netdev_warn(netdev, "couldn't stop device");
 867
 868         priv->can.state = CAN_STATE_STOPPED;
 869
 870         netif_stop_queue(netdev);
 871
 872         /* Stop polling */
 873         unlink_all_urbs(priv);
 874
 875         close_candev(netdev);
 876
 877         can_led_event(netdev, CAN_LED_EVENT_STOP);
 878
 879         return err;
 880 }
 881
 882 static const struct net_device_ops usb_8dev_netdev_ops = {
 883         .ndo_open = usb_8dev_open,
 884         .ndo_stop = usb_8dev_close,
 885         .ndo_start_xmit = usb_8dev_start_xmit,
 886         .ndo_change_mtu = can_change_mtu,
 887 };
 888
 889 static const struct can_bittiming_const usb_8dev_bittiming_const = {
 890         .name = "usb_8dev",
 891         .tseg1_min = 1,
 892         .tseg1_max = 16,
 893         .tseg2_min = 1,
 894         .tseg2_max = 8,
 895         .sjw_max = 4,
 896         .brp_min = 1,
 897         .brp_max = 1024,
 898         .brp_inc = 1,
 899 };
 900
 901 /* Probe USB device
 902  *
 903  * Check device and firmware.
 904  * Set supported modes and bittiming constants.
 905  * Allocate some memory.
 906  */
 907 static int usb_8dev_probe(struct usb_interface *intf,
 908                          const struct usb_device_id *id)
 909 {
 910         struct net_device *netdev;
 911         struct usb_8dev_priv *priv;
 912         int i, err = -ENOMEM;
 913         u32 version;
 914         char buf[18];
 915         struct usb_device *usbdev = interface_to_usbdev(intf);
 916
 917         /* product id looks strange, better we also check iProduct string */
 918         if (usb_string(usbdev, usbdev->descriptor.iProduct, buf,
 919                        sizeof(buf)) > 0 && strcmp(buf, "USB2CAN converter")) {
 920                 dev_info(&usbdev->dev, "ignoring: not an USB2CAN converter\n");
 921                 return -ENODEV;
 922         }
 923
 924         netdev = alloc_candev(sizeof(struct usb_8dev_priv), MAX_TX_URBS);
 925         if (!netdev) {
 926                 dev_err(&intf->dev, "Couldn't alloc candev\n");
 927                 return -ENOMEM;
 928         }
 929
 930         priv = netdev_priv(netdev);
 931
 932         priv->udev = usbdev;
 933         priv->netdev = netdev;
 934
 935         priv->can.state = CAN_STATE_STOPPED;
 936         priv->can.clock.freq = USB_8DEV_ABP_CLOCK;
 937         priv->can.bittiming_const = &usb_8dev_bittiming_const;
 938         priv->can.do_set_mode = usb_8dev_set_mode;
 939         priv->can.do_get_berr_counter = usb_8dev_get_berr_counter;
 940         priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
 941                                       CAN_CTRLMODE_LISTENONLY |
 942                                       CAN_CTRLMODE_ONE_SHOT |
 943                                       CAN_CTRLMODE_CC_LEN8_DLC;
 944
 945         netdev->netdev_ops = &usb_8dev_netdev_ops;
 946
 947         netdev->flags |= IFF_ECHO; /* we support local echo */
 948
 949         init_usb_anchor(&priv->rx_submitted);
 950
 951         init_usb_anchor(&priv->tx_submitted);
 952         atomic_set(&priv->active_tx_urbs, 0);
 953
 954         for (i = 0; i < MAX_TX_URBS; i++)
 955                 priv->tx_contexts[i].echo_index = MAX_TX_URBS;
 956
 957         priv->cmd_msg_buffer = devm_kzalloc(&intf->dev, sizeof(struct usb_8dev_cmd_msg),
 958                                             GFP_KERNEL);
 959         if (!priv->cmd_msg_buffer)
 960                 goto cleanup_candev;
 961
 962         usb_set_intfdata(intf, priv);
 963
 964         SET_NETDEV_DEV(netdev, &intf->dev);
 965
 966         mutex_init(&priv->usb_8dev_cmd_lock);
 967
 968         err = register_candev(netdev);
 969         if (err) {
 970                 netdev_err(netdev,
 971                         "couldn't register CAN device: %d\n", err);
 972                 goto cleanup_candev;
 973         }
 974
 975         err = usb_8dev_cmd_version(priv, &version);
 976         if (err) {
 977                 netdev_err(netdev, "can't get firmware version\n");
 978                 goto cleanup_unregister_candev;
 979         } else {
 980                 netdev_info(netdev,
 981                          "firmware: %d.%d, hardware: %d.%d\n",
 982                          (version>>24) & 0xff, (version>>16) & 0xff,
 983                          (version>>8) & 0xff, version & 0xff);
 984         }
 985
 986         devm_can_led_init(netdev);
 987
 988         return 0;
 989
 990 cleanup_unregister_candev:
 991         unregister_netdev(priv->netdev);
 992
 993 cleanup_candev:
 994         free_candev(netdev);
 995
 996         return err;
 997
 998 }
 999
1000 /* Called by the usb core when driver is unloaded or device is removed */
1001 static void usb_8dev_disconnect(struct usb_interface *intf)
1002 {
1003         struct usb_8dev_priv *priv = usb_get_intfdata(intf);
1004
1005         usb_set_intfdata(intf, NULL);
1006
1007         if (priv) {
1008                 netdev_info(priv->netdev, "device disconnected\n");
1009
1010                 unregister_netdev(priv->netdev);
1011                 unlink_all_urbs(priv);
1012                 free_candev(priv->netdev);
1013         }
1014
1015 }
1016
1017 static struct usb_driver usb_8dev_driver = {
1018         .name =         "usb_8dev",
1019         .probe =        usb_8dev_probe,
1020         .disconnect =   usb_8dev_disconnect,
1021         .id_table =     usb_8dev_table,
1022 };
1023
1024 module_usb_driver(usb_8dev_driver);
1025
1026 MODULE_AUTHOR("Bernd Krumboeck <[email protected]>");
1027 MODULE_DESCRIPTION("CAN driver for 8 devices USB2CAN interfaces");
1028 MODULE_LICENSE("GPL v2");