linux/drivers/net/can/usb/usb_8dev.c
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   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 */
  47enum 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 */
  64enum 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 */
 117static const struct usb_device_id usb_8dev_table[] = {
 118        { USB_DEVICE(USB_8DEV_VENDOR_ID, USB_8DEV_PRODUCT_ID) },
 119        { }                                     /* Terminating entry */
 120};
 121
 122MODULE_DEVICE_TABLE(usb, usb_8dev_table);
 123
 124struct 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 */
 132struct 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 */
 155struct __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 */
 165struct __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 */
 177struct __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
 187static 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
 196static 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 */
 207static 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
 246failed:
 247        mutex_unlock(&priv->usb_8dev_cmd_lock);
 248        return err;
 249}
 250
 251/* Send open command to device */
 252static 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 */
 288static 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 */
 302static 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 */
 326static 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 */
 346static 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[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
 405                rx_errors = 1;
 406                break;
 407        case USB_8DEV_STATUSMSG_BIT0:
 408                cf->data[2] |= CAN_ERR_PROT_BIT0;
 409                tx_errors = 1;
 410                break;
 411        case USB_8DEV_STATUSMSG_BIT1:
 412                cf->data[2] |= CAN_ERR_PROT_BIT1;
 413                tx_errors = 1;
 414                break;
 415        case USB_8DEV_STATUSMSG_FORM:
 416                cf->data[2] |= CAN_ERR_PROT_FORM;
 417                rx_errors = 1;
 418                break;
 419        case USB_8DEV_STATUSMSG_STUFF:
 420                cf->data[2] |= CAN_ERR_PROT_STUFF;
 421                rx_errors = 1;
 422                break;
 423        case USB_8DEV_STATUSMSG_OVERRUN:
 424                cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 425                stats->rx_over_errors++;
 426                rx_errors = 1;
 427                break;
 428        case USB_8DEV_STATUSMSG_BUSLIGHT:
 429                priv->can.state = CAN_STATE_ERROR_WARNING;
 430                cf->data[1] = (txerr > rxerr) ?
 431                        CAN_ERR_CRTL_TX_WARNING :
 432                        CAN_ERR_CRTL_RX_WARNING;
 433                priv->can.can_stats.error_warning++;
 434                break;
 435        case USB_8DEV_STATUSMSG_BUSHEAVY:
 436                priv->can.state = CAN_STATE_ERROR_PASSIVE;
 437                cf->data[1] = (txerr > rxerr) ?
 438                        CAN_ERR_CRTL_TX_PASSIVE :
 439                        CAN_ERR_CRTL_RX_PASSIVE;
 440                priv->can.can_stats.error_passive++;
 441                break;
 442        default:
 443                netdev_warn(priv->netdev,
 444                            "Unknown status/error message (%d)\n", state);
 445                break;
 446        }
 447
 448        if (tx_errors) {
 449                cf->data[2] |= CAN_ERR_PROT_TX;
 450                stats->tx_errors++;
 451        }
 452
 453        if (rx_errors)
 454                stats->rx_errors++;
 455
 456        cf->data[6] = txerr;
 457        cf->data[7] = rxerr;
 458
 459        priv->bec.txerr = txerr;
 460        priv->bec.rxerr = rxerr;
 461
 462        stats->rx_packets++;
 463        stats->rx_bytes += cf->can_dlc;
 464        netif_rx(skb);
 465}
 466
 467/* Read data and status frames */
 468static void usb_8dev_rx_can_msg(struct usb_8dev_priv *priv,
 469                                struct usb_8dev_rx_msg *msg)
 470{
 471        struct can_frame *cf;
 472        struct sk_buff *skb;
 473        struct net_device_stats *stats = &priv->netdev->stats;
 474
 475        if (msg->type == USB_8DEV_TYPE_ERROR_FRAME &&
 476                   msg->flags == USB_8DEV_ERR_FLAG) {
 477                usb_8dev_rx_err_msg(priv, msg);
 478        } else if (msg->type == USB_8DEV_TYPE_CAN_FRAME) {
 479                skb = alloc_can_skb(priv->netdev, &cf);
 480                if (!skb)
 481                        return;
 482
 483                cf->can_id = be32_to_cpu(msg->id);
 484                cf->can_dlc = get_can_dlc(msg->dlc & 0xF);
 485
 486                if (msg->flags & USB_8DEV_EXTID)
 487                        cf->can_id |= CAN_EFF_FLAG;
 488
 489                if (msg->flags & USB_8DEV_RTR)
 490                        cf->can_id |= CAN_RTR_FLAG;
 491                else
 492                        memcpy(cf->data, msg->data, cf->can_dlc);
 493
 494                stats->rx_packets++;
 495                stats->rx_bytes += cf->can_dlc;
 496                netif_rx(skb);
 497
 498                can_led_event(priv->netdev, CAN_LED_EVENT_RX);
 499        } else {
 500                netdev_warn(priv->netdev, "frame type %d unknown",
 501                         msg->type);
 502        }
 503
 504}
 505
 506/* Callback for reading data from device
 507 *
 508 * Check urb status, call read function and resubmit urb read operation.
 509 */
 510static void usb_8dev_read_bulk_callback(struct urb *urb)
 511{
 512        struct usb_8dev_priv *priv = urb->context;
 513        struct net_device *netdev;
 514        int retval;
 515        int pos = 0;
 516
 517        netdev = priv->netdev;
 518
 519        if (!netif_device_present(netdev))
 520                return;
 521
 522        switch (urb->status) {
 523        case 0: /* success */
 524                break;
 525
 526        case -ENOENT:
 527        case -ESHUTDOWN:
 528                return;
 529
 530        default:
 531                netdev_info(netdev, "Rx URB aborted (%d)\n",
 532                         urb->status);
 533                goto resubmit_urb;
 534        }
 535
 536        while (pos < urb->actual_length) {
 537                struct usb_8dev_rx_msg *msg;
 538
 539                if (pos + sizeof(struct usb_8dev_rx_msg) > urb->actual_length) {
 540                        netdev_err(priv->netdev, "format error\n");
 541                        break;
 542                }
 543
 544                msg = (struct usb_8dev_rx_msg *)(urb->transfer_buffer + pos);
 545                usb_8dev_rx_can_msg(priv, msg);
 546
 547                pos += sizeof(struct usb_8dev_rx_msg);
 548        }
 549
 550resubmit_urb:
 551        usb_fill_bulk_urb(urb, priv->udev,
 552                          usb_rcvbulkpipe(priv->udev, USB_8DEV_ENDP_DATA_RX),
 553                          urb->transfer_buffer, RX_BUFFER_SIZE,
 554                          usb_8dev_read_bulk_callback, priv);
 555
 556        retval = usb_submit_urb(urb, GFP_ATOMIC);
 557
 558        if (retval == -ENODEV)
 559                netif_device_detach(netdev);
 560        else if (retval)
 561                netdev_err(netdev,
 562                        "failed resubmitting read bulk urb: %d\n", retval);
 563}
 564
 565/* Callback handler for write operations
 566 *
 567 * Free allocated buffers, check transmit status and
 568 * calculate statistic.
 569 */
 570static void usb_8dev_write_bulk_callback(struct urb *urb)
 571{
 572        struct usb_8dev_tx_urb_context *context = urb->context;
 573        struct usb_8dev_priv *priv;
 574        struct net_device *netdev;
 575
 576        BUG_ON(!context);
 577
 578        priv = context->priv;
 579        netdev = priv->netdev;
 580
 581        /* free up our allocated buffer */
 582        usb_free_coherent(urb->dev, urb->transfer_buffer_length,
 583                          urb->transfer_buffer, urb->transfer_dma);
 584
 585        atomic_dec(&priv->active_tx_urbs);
 586
 587        if (!netif_device_present(netdev))
 588                return;
 589
 590        if (urb->status)
 591                netdev_info(netdev, "Tx URB aborted (%d)\n",
 592                         urb->status);
 593
 594        netdev->stats.tx_packets++;
 595        netdev->stats.tx_bytes += context->dlc;
 596
 597        can_get_echo_skb(netdev, context->echo_index);
 598
 599        can_led_event(netdev, CAN_LED_EVENT_TX);
 600
 601        /* Release context */
 602        context->echo_index = MAX_TX_URBS;
 603
 604        netif_wake_queue(netdev);
 605}
 606
 607/* Send data to device */
 608static netdev_tx_t usb_8dev_start_xmit(struct sk_buff *skb,
 609                                      struct net_device *netdev)
 610{
 611        struct usb_8dev_priv *priv = netdev_priv(netdev);
 612        struct net_device_stats *stats = &netdev->stats;
 613        struct can_frame *cf = (struct can_frame *) skb->data;
 614        struct usb_8dev_tx_msg *msg;
 615        struct urb *urb;
 616        struct usb_8dev_tx_urb_context *context = NULL;
 617        u8 *buf;
 618        int i, err;
 619        size_t size = sizeof(struct usb_8dev_tx_msg);
 620
 621        if (can_dropped_invalid_skb(netdev, skb))
 622                return NETDEV_TX_OK;
 623
 624        /* create a URB, and a buffer for it, and copy the data to the URB */
 625        urb = usb_alloc_urb(0, GFP_ATOMIC);
 626        if (!urb) {
 627                netdev_err(netdev, "No memory left for URBs\n");
 628                goto nomem;
 629        }
 630
 631        buf = usb_alloc_coherent(priv->udev, size, GFP_ATOMIC,
 632                                 &urb->transfer_dma);
 633        if (!buf) {
 634                netdev_err(netdev, "No memory left for USB buffer\n");
 635                goto nomembuf;
 636        }
 637
 638        memset(buf, 0, size);
 639
 640        msg = (struct usb_8dev_tx_msg *)buf;
 641        msg->begin = USB_8DEV_DATA_START;
 642        msg->flags = 0x00;
 643
 644        if (cf->can_id & CAN_RTR_FLAG)
 645                msg->flags |= USB_8DEV_RTR;
 646
 647        if (cf->can_id & CAN_EFF_FLAG)
 648                msg->flags |= USB_8DEV_EXTID;
 649
 650        msg->id = cpu_to_be32(cf->can_id & CAN_ERR_MASK);
 651        msg->dlc = cf->can_dlc;
 652        memcpy(msg->data, cf->data, cf->can_dlc);
 653        msg->end = USB_8DEV_DATA_END;
 654
 655        for (i = 0; i < MAX_TX_URBS; i++) {
 656                if (priv->tx_contexts[i].echo_index == MAX_TX_URBS) {
 657                        context = &priv->tx_contexts[i];
 658                        break;
 659                }
 660        }
 661
 662        /* May never happen! When this happens we'd more URBs in flight as
 663         * allowed (MAX_TX_URBS).
 664         */
 665        if (!context)
 666                goto nofreecontext;
 667
 668        context->priv = priv;
 669        context->echo_index = i;
 670        context->dlc = cf->can_dlc;
 671
 672        usb_fill_bulk_urb(urb, priv->udev,
 673                          usb_sndbulkpipe(priv->udev, USB_8DEV_ENDP_DATA_TX),
 674                          buf, size, usb_8dev_write_bulk_callback, context);
 675        urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 676        usb_anchor_urb(urb, &priv->tx_submitted);
 677
 678        can_put_echo_skb(skb, netdev, context->echo_index);
 679
 680        atomic_inc(&priv->active_tx_urbs);
 681
 682        err = usb_submit_urb(urb, GFP_ATOMIC);
 683        if (unlikely(err))
 684                goto failed;
 685        else if (atomic_read(&priv->active_tx_urbs) >= MAX_TX_URBS)
 686                /* Slow down tx path */
 687                netif_stop_queue(netdev);
 688
 689        /* Release our reference to this URB, the USB core will eventually free
 690         * it entirely.
 691         */
 692        usb_free_urb(urb);
 693
 694        return NETDEV_TX_OK;
 695
 696nofreecontext:
 697        usb_free_coherent(priv->udev, size, buf, urb->transfer_dma);
 698        usb_free_urb(urb);
 699
 700        netdev_warn(netdev, "couldn't find free context");
 701
 702        return NETDEV_TX_BUSY;
 703
 704failed:
 705        can_free_echo_skb(netdev, context->echo_index);
 706
 707        usb_unanchor_urb(urb);
 708        usb_free_coherent(priv->udev, size, buf, urb->transfer_dma);
 709
 710        atomic_dec(&priv->active_tx_urbs);
 711
 712        if (err == -ENODEV)
 713                netif_device_detach(netdev);
 714        else
 715                netdev_warn(netdev, "failed tx_urb %d\n", err);
 716
 717nomembuf:
 718        usb_free_urb(urb);
 719
 720nomem:
 721        dev_kfree_skb(skb);
 722        stats->tx_dropped++;
 723
 724        return NETDEV_TX_OK;
 725}
 726
 727static 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 */
 739static 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
 748                /* create a URB, and a buffer for it */
 749                urb = usb_alloc_urb(0, GFP_KERNEL);
 750                if (!urb) {
 751                        netdev_err(netdev, "No memory left for URBs\n");
 752                        err = -ENOMEM;
 753                        break;
 754                }
 755
 756                buf = usb_alloc_coherent(priv->udev, RX_BUFFER_SIZE, GFP_KERNEL,
 757                                         &urb->transfer_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                usb_fill_bulk_urb(urb, priv->udev,
 766                                  usb_rcvbulkpipe(priv->udev,
 767                                                  USB_8DEV_ENDP_DATA_RX),
 768                                  buf, RX_BUFFER_SIZE,
 769                                  usb_8dev_read_bulk_callback, priv);
 770                urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 771                usb_anchor_urb(urb, &priv->rx_submitted);
 772
 773                err = usb_submit_urb(urb, GFP_KERNEL);
 774                if (err) {
 775                        usb_unanchor_urb(urb);
 776                        usb_free_coherent(priv->udev, RX_BUFFER_SIZE, buf,
 777                                          urb->transfer_dma);
 778                        usb_free_urb(urb);
 779                        break;
 780                }
 781
 782                /* Drop reference, USB core will take care of freeing it */
 783                usb_free_urb(urb);
 784        }
 785
 786        /* Did we submit any URBs */
 787        if (i == 0) {
 788                netdev_warn(netdev, "couldn't setup read URBs\n");
 789                return err;
 790        }
 791
 792        /* Warn if we've couldn't transmit all the URBs */
 793        if (i < MAX_RX_URBS)
 794                netdev_warn(netdev, "rx performance may be slow\n");
 795
 796        err = usb_8dev_cmd_open(priv);
 797        if (err)
 798                goto failed;
 799
 800        priv->can.state = CAN_STATE_ERROR_ACTIVE;
 801
 802        return 0;
 803
 804failed:
 805        if (err == -ENODEV)
 806                netif_device_detach(priv->netdev);
 807
 808        netdev_warn(netdev, "couldn't submit control: %d\n", err);
 809
 810        return err;
 811}
 812
 813/* Open USB device */
 814static int usb_8dev_open(struct net_device *netdev)
 815{
 816        struct usb_8dev_priv *priv = netdev_priv(netdev);
 817        int err;
 818
 819        /* common open */
 820        err = open_candev(netdev);
 821        if (err)
 822                return err;
 823
 824        can_led_event(netdev, CAN_LED_EVENT_OPEN);
 825
 826        /* finally start device */
 827        err = usb_8dev_start(priv);
 828        if (err) {
 829                if (err == -ENODEV)
 830                        netif_device_detach(priv->netdev);
 831
 832                netdev_warn(netdev, "couldn't start device: %d\n",
 833                         err);
 834
 835                close_candev(netdev);
 836
 837                return err;
 838        }
 839
 840        netif_start_queue(netdev);
 841
 842        return 0;
 843}
 844
 845static void unlink_all_urbs(struct usb_8dev_priv *priv)
 846{
 847        int i;
 848
 849        usb_kill_anchored_urbs(&priv->rx_submitted);
 850
 851        usb_kill_anchored_urbs(&priv->tx_submitted);
 852        atomic_set(&priv->active_tx_urbs, 0);
 853
 854        for (i = 0; i < MAX_TX_URBS; i++)
 855                priv->tx_contexts[i].echo_index = MAX_TX_URBS;
 856}
 857
 858/* Close USB device */
 859static int usb_8dev_close(struct net_device *netdev)
 860{
 861        struct usb_8dev_priv *priv = netdev_priv(netdev);
 862        int err = 0;
 863
 864        /* Send CLOSE command to CAN controller */
 865        err = usb_8dev_cmd_close(priv);
 866        if (err)
 867                netdev_warn(netdev, "couldn't stop device");
 868
 869        priv->can.state = CAN_STATE_STOPPED;
 870
 871        netif_stop_queue(netdev);
 872
 873        /* Stop polling */
 874        unlink_all_urbs(priv);
 875
 876        close_candev(netdev);
 877
 878        can_led_event(netdev, CAN_LED_EVENT_STOP);
 879
 880        return err;
 881}
 882
 883static const struct net_device_ops usb_8dev_netdev_ops = {
 884        .ndo_open = usb_8dev_open,
 885        .ndo_stop = usb_8dev_close,
 886        .ndo_start_xmit = usb_8dev_start_xmit,
 887        .ndo_change_mtu = can_change_mtu,
 888};
 889
 890static const struct can_bittiming_const usb_8dev_bittiming_const = {
 891        .name = "usb_8dev",
 892        .tseg1_min = 1,
 893        .tseg1_max = 16,
 894        .tseg2_min = 1,
 895        .tseg2_max = 8,
 896        .sjw_max = 4,
 897        .brp_min = 1,
 898        .brp_max = 1024,
 899        .brp_inc = 1,
 900};
 901
 902/* Probe USB device
 903 *
 904 * Check device and firmware.
 905 * Set supported modes and bittiming constants.
 906 * Allocate some memory.
 907 */
 908static int usb_8dev_probe(struct usb_interface *intf,
 909                         const struct usb_device_id *id)
 910{
 911        struct net_device *netdev;
 912        struct usb_8dev_priv *priv;
 913        int i, err = -ENOMEM;
 914        u32 version;
 915        char buf[18];
 916        struct usb_device *usbdev = interface_to_usbdev(intf);
 917
 918        /* product id looks strange, better we also check iProduct string */
 919        if (usb_string(usbdev, usbdev->descriptor.iProduct, buf,
 920                       sizeof(buf)) > 0 && strcmp(buf, "USB2CAN converter")) {
 921                dev_info(&usbdev->dev, "ignoring: not an USB2CAN converter\n");
 922                return -ENODEV;
 923        }
 924
 925        netdev = alloc_candev(sizeof(struct usb_8dev_priv), MAX_TX_URBS);
 926        if (!netdev) {
 927                dev_err(&intf->dev, "Couldn't alloc candev\n");
 928                return -ENOMEM;
 929        }
 930
 931        priv = netdev_priv(netdev);
 932
 933        priv->udev = usbdev;
 934        priv->netdev = netdev;
 935
 936        priv->can.state = CAN_STATE_STOPPED;
 937        priv->can.clock.freq = USB_8DEV_ABP_CLOCK;
 938        priv->can.bittiming_const = &usb_8dev_bittiming_const;
 939        priv->can.do_set_mode = usb_8dev_set_mode;
 940        priv->can.do_get_berr_counter = usb_8dev_get_berr_counter;
 941        priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
 942                                      CAN_CTRLMODE_LISTENONLY |
 943                                      CAN_CTRLMODE_ONE_SHOT;
 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 = kzalloc(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_cmd_msg_buffer;
 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
 990cleanup_unregister_candev:
 991        unregister_netdev(priv->netdev);
 992
 993cleanup_cmd_msg_buffer:
 994        kfree(priv->cmd_msg_buffer);
 995
 996cleanup_candev:
 997        free_candev(netdev);
 998
 999        return err;
1000
1001}
1002
1003/* Called by the usb core when driver is unloaded or device is removed */
1004static void usb_8dev_disconnect(struct usb_interface *intf)
1005{
1006        struct usb_8dev_priv *priv = usb_get_intfdata(intf);
1007
1008        usb_set_intfdata(intf, NULL);
1009
1010        if (priv) {
1011                netdev_info(priv->netdev, "device disconnected\n");
1012
1013                unregister_netdev(priv->netdev);
1014                free_candev(priv->netdev);
1015
1016                unlink_all_urbs(priv);
1017        }
1018
1019}
1020
1021static struct usb_driver usb_8dev_driver = {
1022        .name =         "usb_8dev",
1023        .probe =        usb_8dev_probe,
1024        .disconnect =   usb_8dev_disconnect,
1025        .id_table =     usb_8dev_table,
1026};
1027
1028module_usb_driver(usb_8dev_driver);
1029
1030MODULE_AUTHOR("Bernd Krumboeck <krumboeck@universalnet.at>");
1031MODULE_DESCRIPTION("CAN driver for 8 devices USB2CAN interfaces");
1032MODULE_LICENSE("GPL v2");
1033
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