LXR linux/drivers/net/can/usb/peak_usb/pcan

   1/*
   2 * CAN driver for PEAK System PCAN-USB adapter
   3 * Derived from the PCAN project file driver/src/pcan_usb.c
   4 *
   5 * Copyright (C) 2003-2010 PEAK System-Technik GmbH
   6 * Copyright (C) 2011-2012 Stephane Grosjean <s.grosjean@peak-system.com>
   7 *
   8 * Many thanks to Klaus Hitschler <klaus.hitschler@gmx.de>
   9 *
  10 * This program is free software; you can redistribute it and/or modify it
  11 * under the terms of the GNU General Public License as published
  12 * by the Free Software Foundation; version 2 of the License.
  13 *
  14 * This program is distributed in the hope that it will be useful, but
  15 * WITHOUT ANY WARRANTY; without even the implied warranty of
  16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17 * General Public License for more details.
  18 */
  19#include <linux/netdevice.h>
  20#include <linux/usb.h>
  21#include <linux/module.h>
  22
  23#include <linux/can.h>
  24#include <linux/can/dev.h>
  25#include <linux/can/error.h>
  26
  27#include "pcan_usb_core.h"
  28
  29MODULE_SUPPORTED_DEVICE("PEAK-System PCAN-USB adapter");
  30
  31/* PCAN-USB Endpoints */
  32#define PCAN_USB_EP_CMDOUT              1
  33#define PCAN_USB_EP_CMDIN               (PCAN_USB_EP_CMDOUT | USB_DIR_IN)
  34#define PCAN_USB_EP_MSGOUT              2
  35#define PCAN_USB_EP_MSGIN               (PCAN_USB_EP_MSGOUT | USB_DIR_IN)
  36
  37/* PCAN-USB command struct */
  38#define PCAN_USB_CMD_FUNC               0
  39#define PCAN_USB_CMD_NUM                1
  40#define PCAN_USB_CMD_ARGS               2
  41#define PCAN_USB_CMD_ARGS_LEN           14
  42#define PCAN_USB_CMD_LEN                (PCAN_USB_CMD_ARGS + \
  43                                         PCAN_USB_CMD_ARGS_LEN)
  44
  45/* PCAN-USB command timeout (ms.) */
  46#define PCAN_USB_COMMAND_TIMEOUT        1000
  47
  48/* PCAN-USB startup timeout (ms.) */
  49#define PCAN_USB_STARTUP_TIMEOUT        10
  50
  51/* PCAN-USB rx/tx buffers size */
  52#define PCAN_USB_RX_BUFFER_SIZE         64
  53#define PCAN_USB_TX_BUFFER_SIZE         64
  54
  55#define PCAN_USB_MSG_HEADER_LEN         2
  56
  57/* PCAN-USB adapter internal clock (MHz) */
  58#define PCAN_USB_CRYSTAL_HZ             16000000
  59
  60/* PCAN-USB USB message record status/len field */
  61#define PCAN_USB_STATUSLEN_TIMESTAMP    (1 << 7)
  62#define PCAN_USB_STATUSLEN_INTERNAL     (1 << 6)
  63#define PCAN_USB_STATUSLEN_EXT_ID       (1 << 5)
  64#define PCAN_USB_STATUSLEN_RTR          (1 << 4)
  65#define PCAN_USB_STATUSLEN_DLC          (0xf)
  66
  67/* PCAN-USB error flags */
  68#define PCAN_USB_ERROR_TXFULL           0x01
  69#define PCAN_USB_ERROR_RXQOVR           0x02
  70#define PCAN_USB_ERROR_BUS_LIGHT        0x04
  71#define PCAN_USB_ERROR_BUS_HEAVY        0x08
  72#define PCAN_USB_ERROR_BUS_OFF          0x10
  73#define PCAN_USB_ERROR_RXQEMPTY         0x20
  74#define PCAN_USB_ERROR_QOVR             0x40
  75#define PCAN_USB_ERROR_TXQFULL          0x80
  76
  77/* SJA1000 modes */
  78#define SJA1000_MODE_NORMAL             0x00
  79#define SJA1000_MODE_INIT               0x01
  80
  81/*
  82 * tick duration = 42.666 us =>
  83 * (tick_number * 44739243) >> 20 ~ (tick_number * 42666) / 1000
  84 * accuracy = 10^-7
  85 */
  86#define PCAN_USB_TS_DIV_SHIFTER         20
  87#define PCAN_USB_TS_US_PER_TICK         44739243
  88
  89/* PCAN-USB messages record types */
  90#define PCAN_USB_REC_ERROR              1
  91#define PCAN_USB_REC_ANALOG             2
  92#define PCAN_USB_REC_BUSLOAD            3
  93#define PCAN_USB_REC_TS                 4
  94#define PCAN_USB_REC_BUSEVT             5
  95
  96/* private to PCAN-USB adapter */
  97struct pcan_usb {
  98        struct peak_usb_device dev;
  99        struct peak_time_ref time_ref;
 100        struct timer_list restart_timer;
 101};
 102
 103/* incoming message context for decoding */
 104struct pcan_usb_msg_context {
 105        u16 ts16;
 106        u8 prev_ts8;
 107        u8 *ptr;
 108        u8 *end;
 109        u8 rec_cnt;
 110        u8 rec_idx;
 111        u8 rec_data_idx;
 112        struct net_device *netdev;
 113        struct pcan_usb *pdev;
 114};
 115
 116/*
 117 * send a command
 118 */
 119static int pcan_usb_send_cmd(struct peak_usb_device *dev, u8 f, u8 n, u8 *p)
 120{
 121        int err;
 122        int actual_length;
 123
 124        /* usb device unregistered? */
 125        if (!(dev->state & PCAN_USB_STATE_CONNECTED))
 126                return 0;
 127
 128        dev->cmd_buf[PCAN_USB_CMD_FUNC] = f;
 129        dev->cmd_buf[PCAN_USB_CMD_NUM] = n;
 130
 131        if (p)
 132                memcpy(dev->cmd_buf + PCAN_USB_CMD_ARGS,
 133                        p, PCAN_USB_CMD_ARGS_LEN);
 134
 135        err = usb_bulk_msg(dev->udev,
 136                        usb_sndbulkpipe(dev->udev, PCAN_USB_EP_CMDOUT),
 137                        dev->cmd_buf, PCAN_USB_CMD_LEN, &actual_length,
 138                        PCAN_USB_COMMAND_TIMEOUT);
 139        if (err)
 140                netdev_err(dev->netdev,
 141                        "sending cmd f=0x%x n=0x%x failure: %d\n",
 142                        f, n, err);
 143        return err;
 144}
 145
 146/*
 147 * send a command then wait for its response
 148 */
 149static int pcan_usb_wait_rsp(struct peak_usb_device *dev, u8 f, u8 n, u8 *p)
 150{
 151        int err;
 152        int actual_length;
 153
 154        /* usb device unregistered? */
 155        if (!(dev->state & PCAN_USB_STATE_CONNECTED))
 156                return 0;
 157
 158        /* first, send command */
 159        err = pcan_usb_send_cmd(dev, f, n, NULL);
 160        if (err)
 161                return err;
 162
 163        err = usb_bulk_msg(dev->udev,
 164                usb_rcvbulkpipe(dev->udev, PCAN_USB_EP_CMDIN),
 165                dev->cmd_buf, PCAN_USB_CMD_LEN, &actual_length,
 166                PCAN_USB_COMMAND_TIMEOUT);
 167        if (err)
 168                netdev_err(dev->netdev,
 169                        "waiting rsp f=0x%x n=0x%x failure: %d\n", f, n, err);
 170        else if (p)
 171                memcpy(p, dev->cmd_buf + PCAN_USB_CMD_ARGS,
 172                        PCAN_USB_CMD_ARGS_LEN);
 173
 174        return err;
 175}
 176
 177static int pcan_usb_set_sja1000(struct peak_usb_device *dev, u8 mode)
 178{
 179        u8 args[PCAN_USB_CMD_ARGS_LEN] = {
 180                [1] = mode,
 181        };
 182
 183        return pcan_usb_send_cmd(dev, 9, 2, args);
 184}
 185
 186static int pcan_usb_set_bus(struct peak_usb_device *dev, u8 onoff)
 187{
 188        u8 args[PCAN_USB_CMD_ARGS_LEN] = {
 189                [0] = !!onoff,
 190        };
 191
 192        return pcan_usb_send_cmd(dev, 3, 2, args);
 193}
 194
 195static int pcan_usb_set_silent(struct peak_usb_device *dev, u8 onoff)
 196{
 197        u8 args[PCAN_USB_CMD_ARGS_LEN] = {
 198                [0] = !!onoff,
 199        };
 200
 201        return pcan_usb_send_cmd(dev, 3, 3, args);
 202}
 203
 204static int pcan_usb_set_ext_vcc(struct peak_usb_device *dev, u8 onoff)
 205{
 206        u8 args[PCAN_USB_CMD_ARGS_LEN] = {
 207                [0] = !!onoff,
 208        };
 209
 210        return pcan_usb_send_cmd(dev, 10, 2, args);
 211}
 212
 213/*
 214 * set bittiming value to can
 215 */
 216static int pcan_usb_set_bittiming(struct peak_usb_device *dev,
 217                                  struct can_bittiming *bt)
 218{
 219        u8 args[PCAN_USB_CMD_ARGS_LEN];
 220        u8 btr0, btr1;
 221
 222        btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
 223        btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
 224                (((bt->phase_seg2 - 1) & 0x7) << 4);
 225        if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
 226                btr1 |= 0x80;
 227
 228        netdev_info(dev->netdev, "setting BTR0=0x%02x BTR1=0x%02x\n",
 229                btr0, btr1);
 230
 231        args[0] = btr1;
 232        args[1] = btr0;
 233
 234        return pcan_usb_send_cmd(dev, 1, 2, args);
 235}
 236
 237/*
 238 * init/reset can
 239 */
 240static int pcan_usb_write_mode(struct peak_usb_device *dev, u8 onoff)
 241{
 242        int err;
 243
 244        err = pcan_usb_set_bus(dev, onoff);
 245        if (err)
 246                return err;
 247
 248        if (!onoff) {
 249                err = pcan_usb_set_sja1000(dev, SJA1000_MODE_INIT);
 250        } else {
 251                /* the PCAN-USB needs time to init */
 252                set_current_state(TASK_INTERRUPTIBLE);
 253                schedule_timeout(msecs_to_jiffies(PCAN_USB_STARTUP_TIMEOUT));
 254        }
 255
 256        return err;
 257}
 258
 259/*
 260 * handle end of waiting for the device to reset
 261 */
 262static void pcan_usb_restart(struct timer_list *t)
 263{
 264        struct pcan_usb *pdev = from_timer(pdev, t, restart_timer);
 265        struct peak_usb_device *dev = &pdev->dev;
 266
 267        /* notify candev and netdev */
 268        peak_usb_restart_complete(dev);
 269}
 270
 271/*
 272 * handle the submission of the restart urb
 273 */
 274static void pcan_usb_restart_pending(struct urb *urb)
 275{
 276        struct pcan_usb *pdev = urb->context;
 277
 278        /* the PCAN-USB needs time to restart */
 279        mod_timer(&pdev->restart_timer,
 280                        jiffies + msecs_to_jiffies(PCAN_USB_STARTUP_TIMEOUT));
 281
 282        /* can delete usb resources */
 283        peak_usb_async_complete(urb);
 284}
 285
 286/*
 287 * handle asynchronous restart
 288 */
 289static int pcan_usb_restart_async(struct peak_usb_device *dev, struct urb *urb,
 290                                  u8 *buf)
 291{
 292        struct pcan_usb *pdev = container_of(dev, struct pcan_usb, dev);
 293
 294        if (timer_pending(&pdev->restart_timer))
 295                return -EBUSY;
 296
 297        /* set bus on */
 298        buf[PCAN_USB_CMD_FUNC] = 3;
 299        buf[PCAN_USB_CMD_NUM] = 2;
 300        buf[PCAN_USB_CMD_ARGS] = 1;
 301
 302        usb_fill_bulk_urb(urb, dev->udev,
 303                        usb_sndbulkpipe(dev->udev, PCAN_USB_EP_CMDOUT),
 304                        buf, PCAN_USB_CMD_LEN,
 305                        pcan_usb_restart_pending, pdev);
 306
 307        return usb_submit_urb(urb, GFP_ATOMIC);
 308}
 309
 310/*
 311 * read serial number from device
 312 */
 313static int pcan_usb_get_serial(struct peak_usb_device *dev, u32 *serial_number)
 314{
 315        u8 args[PCAN_USB_CMD_ARGS_LEN];
 316        int err;
 317
 318        err = pcan_usb_wait_rsp(dev, 6, 1, args);
 319        if (err) {
 320                netdev_err(dev->netdev, "getting serial failure: %d\n", err);
 321        } else if (serial_number) {
 322                __le32 tmp32;
 323
 324                memcpy(&tmp32, args, 4);
 325                *serial_number = le32_to_cpu(tmp32);
 326        }
 327
 328        return err;
 329}
 330
 331/*
 332 * read device id from device
 333 */
 334static int pcan_usb_get_device_id(struct peak_usb_device *dev, u32 *device_id)
 335{
 336        u8 args[PCAN_USB_CMD_ARGS_LEN];
 337        int err;
 338
 339        err = pcan_usb_wait_rsp(dev, 4, 1, args);
 340        if (err)
 341                netdev_err(dev->netdev, "getting device id failure: %d\n", err);
 342        else if (device_id)
 343                *device_id = args[0];
 344
 345        return err;
 346}
 347
 348/*
 349 * update current time ref with received timestamp
 350 */
 351static int pcan_usb_update_ts(struct pcan_usb_msg_context *mc)
 352{
 353        __le16 tmp16;
 354
 355        if ((mc->ptr+2) > mc->end)
 356                return -EINVAL;
 357
 358        memcpy(&tmp16, mc->ptr, 2);
 359
 360        mc->ts16 = le16_to_cpu(tmp16);
 361
 362        if (mc->rec_idx > 0)
 363                peak_usb_update_ts_now(&mc->pdev->time_ref, mc->ts16);
 364        else
 365                peak_usb_set_ts_now(&mc->pdev->time_ref, mc->ts16);
 366
 367        return 0;
 368}
 369
 370/*
 371 * decode received timestamp
 372 */
 373static int pcan_usb_decode_ts(struct pcan_usb_msg_context *mc, u8 first_packet)
 374{
 375        /* only 1st packet supplies a word timestamp */
 376        if (first_packet) {
 377                __le16 tmp16;
 378
 379                if ((mc->ptr + 2) > mc->end)
 380                        return -EINVAL;
 381
 382                memcpy(&tmp16, mc->ptr, 2);
 383                mc->ptr += 2;
 384
 385                mc->ts16 = le16_to_cpu(tmp16);
 386                mc->prev_ts8 = mc->ts16 & 0x00ff;
 387        } else {
 388                u8 ts8;
 389
 390                if ((mc->ptr + 1) > mc->end)
 391                        return -EINVAL;
 392
 393                ts8 = *mc->ptr++;
 394
 395                if (ts8 < mc->prev_ts8)
 396                        mc->ts16 += 0x100;
 397
 398                mc->ts16 &= 0xff00;
 399                mc->ts16 |= ts8;
 400                mc->prev_ts8 = ts8;
 401        }
 402
 403        return 0;
 404}
 405
 406static int pcan_usb_decode_error(struct pcan_usb_msg_context *mc, u8 n,
 407                                 u8 status_len)
 408{
 409        struct sk_buff *skb;
 410        struct can_frame *cf;
 411        enum can_state new_state;
 412
 413        /* ignore this error until 1st ts received */
 414        if (n == PCAN_USB_ERROR_QOVR)
 415                if (!mc->pdev->time_ref.tick_count)
 416                        return 0;
 417
 418        new_state = mc->pdev->dev.can.state;
 419
 420        switch (mc->pdev->dev.can.state) {
 421        case CAN_STATE_ERROR_ACTIVE:
 422                if (n & PCAN_USB_ERROR_BUS_LIGHT) {
 423                        new_state = CAN_STATE_ERROR_WARNING;
 424                        break;
 425                }
 426                /* else: fall through */
 427
 428        case CAN_STATE_ERROR_WARNING:
 429                if (n & PCAN_USB_ERROR_BUS_HEAVY) {
 430                        new_state = CAN_STATE_ERROR_PASSIVE;
 431                        break;
 432                }
 433                if (n & PCAN_USB_ERROR_BUS_OFF) {
 434                        new_state = CAN_STATE_BUS_OFF;
 435                        break;
 436                }
 437                if (n & (PCAN_USB_ERROR_RXQOVR | PCAN_USB_ERROR_QOVR)) {
 438                        /*
 439                         * trick to bypass next comparison and process other
 440                         * errors
 441                         */
 442                        new_state = CAN_STATE_MAX;
 443                        break;
 444                }
 445                if ((n & PCAN_USB_ERROR_BUS_LIGHT) == 0) {
 446                        /* no error (back to active state) */
 447                        mc->pdev->dev.can.state = CAN_STATE_ERROR_ACTIVE;
 448                        return 0;
 449                }
 450                break;
 451
 452        case CAN_STATE_ERROR_PASSIVE:
 453                if (n & PCAN_USB_ERROR_BUS_OFF) {
 454                        new_state = CAN_STATE_BUS_OFF;
 455                        break;
 456                }
 457                if (n & PCAN_USB_ERROR_BUS_LIGHT) {
 458                        new_state = CAN_STATE_ERROR_WARNING;
 459                        break;
 460                }
 461                if (n & (PCAN_USB_ERROR_RXQOVR | PCAN_USB_ERROR_QOVR)) {
 462                        /*
 463                         * trick to bypass next comparison and process other
 464                         * errors
 465                         */
 466                        new_state = CAN_STATE_MAX;
 467                        break;
 468                }
 469
 470                if ((n & PCAN_USB_ERROR_BUS_HEAVY) == 0) {
 471                        /* no error (back to active state) */
 472                        mc->pdev->dev.can.state = CAN_STATE_ERROR_ACTIVE;
 473                        return 0;
 474                }
 475                break;
 476
 477        default:
 478                /* do nothing waiting for restart */
 479                return 0;
 480        }
 481
 482        /* donot post any error if current state didn't change */
 483        if (mc->pdev->dev.can.state == new_state)
 484                return 0;
 485
 486        /* allocate an skb to store the error frame */
 487        skb = alloc_can_err_skb(mc->netdev, &cf);
 488        if (!skb)
 489                return -ENOMEM;
 490
 491        switch (new_state) {
 492        case CAN_STATE_BUS_OFF:
 493                cf->can_id |= CAN_ERR_BUSOFF;
 494                mc->pdev->dev.can.can_stats.bus_off++;
 495                can_bus_off(mc->netdev);
 496                break;
 497
 498        case CAN_STATE_ERROR_PASSIVE:
 499                cf->can_id |= CAN_ERR_CRTL;
 500                cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE |
 501                               CAN_ERR_CRTL_RX_PASSIVE;
 502                mc->pdev->dev.can.can_stats.error_passive++;
 503                break;
 504
 505        case CAN_STATE_ERROR_WARNING:
 506                cf->can_id |= CAN_ERR_CRTL;
 507                cf->data[1] |= CAN_ERR_CRTL_TX_WARNING |
 508                               CAN_ERR_CRTL_RX_WARNING;
 509                mc->pdev->dev.can.can_stats.error_warning++;
 510                break;
 511
 512        default:
 513                /* CAN_STATE_MAX (trick to handle other errors) */
 514                cf->can_id |= CAN_ERR_CRTL;
 515                cf->data[1] |= CAN_ERR_CRTL_RX_OVERFLOW;
 516                mc->netdev->stats.rx_over_errors++;
 517                mc->netdev->stats.rx_errors++;
 518
 519                new_state = mc->pdev->dev.can.state;
 520                break;
 521        }
 522
 523        mc->pdev->dev.can.state = new_state;
 524
 525        if (status_len & PCAN_USB_STATUSLEN_TIMESTAMP) {
 526                struct skb_shared_hwtstamps *hwts = skb_hwtstamps(skb);
 527
 528                peak_usb_get_ts_time(&mc->pdev->time_ref, mc->ts16,
 529                                     &hwts->hwtstamp);
 530        }
 531
 532        mc->netdev->stats.rx_packets++;
 533        mc->netdev->stats.rx_bytes += cf->can_dlc;
 534        netif_rx(skb);
 535
 536        return 0;
 537}
 538
 539/*
 540 * decode non-data usb message
 541 */
 542static int pcan_usb_decode_status(struct pcan_usb_msg_context *mc,
 543                                  u8 status_len)
 544{
 545        u8 rec_len = status_len & PCAN_USB_STATUSLEN_DLC;
 546        u8 f, n;
 547        int err;
 548
 549        /* check whether function and number can be read */
 550        if ((mc->ptr + 2) > mc->end)
 551                return -EINVAL;
 552
 553        f = mc->ptr[PCAN_USB_CMD_FUNC];
 554        n = mc->ptr[PCAN_USB_CMD_NUM];
 555        mc->ptr += PCAN_USB_CMD_ARGS;
 556
 557        if (status_len & PCAN_USB_STATUSLEN_TIMESTAMP) {
 558                int err = pcan_usb_decode_ts(mc, !mc->rec_idx);
 559
 560                if (err)
 561                        return err;
 562        }
 563
 564        switch (f) {
 565        case PCAN_USB_REC_ERROR:
 566                err = pcan_usb_decode_error(mc, n, status_len);
 567                if (err)
 568                        return err;
 569                break;
 570
 571        case PCAN_USB_REC_ANALOG:
 572                /* analog values (ignored) */
 573                rec_len = 2;
 574                break;
 575
 576        case PCAN_USB_REC_BUSLOAD:
 577                /* bus load (ignored) */
 578                rec_len = 1;
 579                break;
 580
 581        case PCAN_USB_REC_TS:
 582                /* only timestamp */
 583                if (pcan_usb_update_ts(mc))
 584                        return -EINVAL;
 585                break;
 586
 587        case PCAN_USB_REC_BUSEVT:
 588                /* error frame/bus event */
 589                if (n & PCAN_USB_ERROR_TXQFULL)
 590                        netdev_dbg(mc->netdev, "device Tx queue full)\n");
 591                break;
 592        default:
 593                netdev_err(mc->netdev, "unexpected function %u\n", f);
 594                break;
 595        }
 596
 597        if ((mc->ptr + rec_len) > mc->end)
 598                return -EINVAL;
 599
 600        mc->ptr += rec_len;
 601
 602        return 0;
 603}
 604
 605/*
 606 * decode data usb message
 607 */
 608static int pcan_usb_decode_data(struct pcan_usb_msg_context *mc, u8 status_len)
 609{
 610        u8 rec_len = status_len & PCAN_USB_STATUSLEN_DLC;
 611        struct sk_buff *skb;
 612        struct can_frame *cf;
 613        struct skb_shared_hwtstamps *hwts;
 614
 615        skb = alloc_can_skb(mc->netdev, &cf);
 616        if (!skb)
 617                return -ENOMEM;
 618
 619        if (status_len & PCAN_USB_STATUSLEN_EXT_ID) {
 620                __le32 tmp32;
 621
 622                if ((mc->ptr + 4) > mc->end)
 623                        goto decode_failed;
 624
 625                memcpy(&tmp32, mc->ptr, 4);
 626                mc->ptr += 4;
 627
 628                cf->can_id = (le32_to_cpu(tmp32) >> 3) | CAN_EFF_FLAG;
 629        } else {
 630                __le16 tmp16;
 631
 632                if ((mc->ptr + 2) > mc->end)
 633                        goto decode_failed;
 634
 635                memcpy(&tmp16, mc->ptr, 2);
 636                mc->ptr += 2;
 637
 638                cf->can_id = le16_to_cpu(tmp16) >> 5;
 639        }
 640
 641        cf->can_dlc = get_can_dlc(rec_len);
 642
 643        /* first data packet timestamp is a word */
 644        if (pcan_usb_decode_ts(mc, !mc->rec_data_idx))
 645                goto decode_failed;
 646
 647        /* read data */
 648        memset(cf->data, 0x0, sizeof(cf->data));
 649        if (status_len & PCAN_USB_STATUSLEN_RTR) {
 650                cf->can_id |= CAN_RTR_FLAG;
 651        } else {
 652                if ((mc->ptr + rec_len) > mc->end)
 653                        goto decode_failed;
 654
 655                memcpy(cf->data, mc->ptr, cf->can_dlc);
 656                mc->ptr += rec_len;
 657        }
 658
 659        /* convert timestamp into kernel time */
 660        hwts = skb_hwtstamps(skb);
 661        peak_usb_get_ts_time(&mc->pdev->time_ref, mc->ts16, &hwts->hwtstamp);
 662
 663        /* update statistics */
 664        mc->netdev->stats.rx_packets++;
 665        mc->netdev->stats.rx_bytes += cf->can_dlc;
 666        /* push the skb */
 667        netif_rx(skb);
 668
 669        return 0;
 670
 671decode_failed:
 672        dev_kfree_skb(skb);
 673        return -EINVAL;
 674}
 675
 676/*
 677 * process incoming message
 678 */
 679static int pcan_usb_decode_msg(struct peak_usb_device *dev, u8 *ibuf, u32 lbuf)
 680{
 681        struct pcan_usb_msg_context mc = {
 682                .rec_cnt = ibuf[1],
 683                .ptr = ibuf + PCAN_USB_MSG_HEADER_LEN,
 684                .end = ibuf + lbuf,
 685                .netdev = dev->netdev,
 686                .pdev = container_of(dev, struct pcan_usb, dev),
 687        };
 688        int err;
 689
 690        for (err = 0; mc.rec_idx < mc.rec_cnt && !err; mc.rec_idx++) {
 691                u8 sl = *mc.ptr++;
 692
 693                /* handle status and error frames here */
 694                if (sl & PCAN_USB_STATUSLEN_INTERNAL) {
 695                        err = pcan_usb_decode_status(&mc, sl);
 696                /* handle normal can frames here */
 697                } else {
 698                        err = pcan_usb_decode_data(&mc, sl);
 699                        mc.rec_data_idx++;
 700                }
 701        }
 702
 703        return err;
 704}
 705
 706/*
 707 * process any incoming buffer
 708 */
 709static int pcan_usb_decode_buf(struct peak_usb_device *dev, struct urb *urb)
 710{
 711        int err = 0;
 712
 713        if (urb->actual_length > PCAN_USB_MSG_HEADER_LEN) {
 714                err = pcan_usb_decode_msg(dev, urb->transfer_buffer,
 715                        urb->actual_length);
 716
 717        } else if (urb->actual_length > 0) {
 718                netdev_err(dev->netdev, "usb message length error (%u)\n",
 719                        urb->actual_length);
 720                err = -EINVAL;
 721        }
 722
 723        return err;
 724}
 725
 726/*
 727 * process outgoing packet
 728 */
 729static int pcan_usb_encode_msg(struct peak_usb_device *dev, struct sk_buff *skb,
 730                               u8 *obuf, size_t *size)
 731{
 732        struct net_device *netdev = dev->netdev;
 733        struct net_device_stats *stats = &netdev->stats;
 734        struct can_frame *cf = (struct can_frame *)skb->data;
 735        u8 *pc;
 736
 737        obuf[0] = 2;
 738        obuf[1] = 1;
 739
 740        pc = obuf + PCAN_USB_MSG_HEADER_LEN;
 741
 742        /* status/len byte */
 743        *pc = cf->can_dlc;
 744        if (cf->can_id & CAN_RTR_FLAG)
 745                *pc |= PCAN_USB_STATUSLEN_RTR;
 746
 747        /* can id */
 748        if (cf->can_id & CAN_EFF_FLAG) {
 749                __le32 tmp32 = cpu_to_le32((cf->can_id & CAN_ERR_MASK) << 3);
 750
 751                *pc |= PCAN_USB_STATUSLEN_EXT_ID;
 752                memcpy(++pc, &tmp32, 4);
 753                pc += 4;
 754        } else {
 755                __le16 tmp16 = cpu_to_le16((cf->can_id & CAN_ERR_MASK) << 5);
 756
 757                memcpy(++pc, &tmp16, 2);
 758                pc += 2;
 759        }
 760
 761        /* can data */
 762        if (!(cf->can_id & CAN_RTR_FLAG)) {
 763                memcpy(pc, cf->data, cf->can_dlc);
 764                pc += cf->can_dlc;
 765        }
 766
 767        obuf[(*size)-1] = (u8)(stats->tx_packets & 0xff);
 768
 769        return 0;
 770}
 771
 772/*
 773 * start interface
 774 */
 775static int pcan_usb_start(struct peak_usb_device *dev)
 776{
 777        struct pcan_usb *pdev = container_of(dev, struct pcan_usb, dev);
 778
 779        /* number of bits used in timestamps read from adapter struct */
 780        peak_usb_init_time_ref(&pdev->time_ref, &pcan_usb);
 781
 782        /* if revision greater than 3, can put silent mode on/off */
 783        if (dev->device_rev > 3) {
 784                int err;
 785
 786                err = pcan_usb_set_silent(dev,
 787                                dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY);
 788                if (err)
 789                        return err;
 790        }
 791
 792        return pcan_usb_set_ext_vcc(dev, 0);
 793}
 794
 795static int pcan_usb_init(struct peak_usb_device *dev)
 796{
 797        struct pcan_usb *pdev = container_of(dev, struct pcan_usb, dev);
 798        u32 serial_number;
 799        int err;
 800
 801        /* initialize a timer needed to wait for hardware restart */
 802        timer_setup(&pdev->restart_timer, pcan_usb_restart, 0);
 803
 804        /*
 805         * explicit use of dev_xxx() instead of netdev_xxx() here:
 806         * information displayed are related to the device itself, not
 807         * to the canx netdevice.
 808         */
 809        err = pcan_usb_get_serial(dev, &serial_number);
 810        if (err) {
 811                dev_err(dev->netdev->dev.parent,
 812                        "unable to read %s serial number (err %d)\n",
 813                        pcan_usb.name, err);
 814                return err;
 815        }
 816
 817        dev_info(dev->netdev->dev.parent,
 818                 "PEAK-System %s adapter hwrev %u serial %08X (%u channel)\n",
 819                 pcan_usb.name, dev->device_rev, serial_number,
 820                 pcan_usb.ctrl_count);
 821
 822        return 0;
 823}
 824
 825/*
 826 * probe function for new PCAN-USB usb interface
 827 */
 828static int pcan_usb_probe(struct usb_interface *intf)
 829{
 830        struct usb_host_interface *if_desc;
 831        int i;
 832
 833        if_desc = intf->altsetting;
 834
 835        /* check interface endpoint addresses */
 836        for (i = 0; i < if_desc->desc.bNumEndpoints; i++) {
 837                struct usb_endpoint_descriptor *ep = &if_desc->endpoint[i].desc;
 838
 839                switch (ep->bEndpointAddress) {
 840                case PCAN_USB_EP_CMDOUT:
 841                case PCAN_USB_EP_CMDIN:
 842                case PCAN_USB_EP_MSGOUT:
 843                case PCAN_USB_EP_MSGIN:
 844                        break;
 845                default:
 846                        return -ENODEV;
 847                }
 848        }
 849
 850        return 0;
 851}
 852
 853/*
 854 * describe the PCAN-USB adapter
 855 */
 856static const struct can_bittiming_const pcan_usb_const = {
 857        .name = "pcan_usb",
 858        .tseg1_min = 1,
 859        .tseg1_max = 16,
 860        .tseg2_min = 1,
 861        .tseg2_max = 8,
 862        .sjw_max = 4,
 863        .brp_min = 1,
 864        .brp_max = 64,
 865        .brp_inc = 1,
 866};
 867
 868const struct peak_usb_adapter pcan_usb = {
 869        .name = "PCAN-USB",
 870        .device_id = PCAN_USB_PRODUCT_ID,
 871        .ctrl_count = 1,
 872        .ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES | CAN_CTRLMODE_LISTENONLY,
 873        .clock = {
 874                .freq = PCAN_USB_CRYSTAL_HZ / 2 ,
 875        },
 876        .bittiming_const = &pcan_usb_const,
 877
 878        /* size of device private data */
 879        .sizeof_dev_private = sizeof(struct pcan_usb),
 880
 881        /* timestamps usage */
 882        .ts_used_bits = 16,
 883        .ts_period = 24575, /* calibration period in ts. */
 884        .us_per_ts_scale = PCAN_USB_TS_US_PER_TICK, /* us=(ts*scale) */
 885        .us_per_ts_shift = PCAN_USB_TS_DIV_SHIFTER, /*  >> shift     */
 886
 887        /* give here messages in/out endpoints */
 888        .ep_msg_in = PCAN_USB_EP_MSGIN,
 889        .ep_msg_out = {PCAN_USB_EP_MSGOUT},
 890
 891        /* size of rx/tx usb buffers */
 892        .rx_buffer_size = PCAN_USB_RX_BUFFER_SIZE,
 893        .tx_buffer_size = PCAN_USB_TX_BUFFER_SIZE,
 894
 895        /* device callbacks */
 896        .intf_probe = pcan_usb_probe,
 897        .dev_init = pcan_usb_init,
 898        .dev_set_bus = pcan_usb_write_mode,
 899        .dev_set_bittiming = pcan_usb_set_bittiming,
 900        .dev_get_device_id = pcan_usb_get_device_id,
 901        .dev_decode_buf = pcan_usb_decode_buf,
 902        .dev_encode_msg = pcan_usb_encode_msg,
 903        .dev_start = pcan_usb_start,
 904        .dev_restart_async = pcan_usb_restart_async,
 905};
 906