drivers/net/can/usb/peak_usb/pcan_usb.c

   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
  29 MODULE_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 */
  97 struct 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 */
 104 struct 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  */
 119 static 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  */
 149 static 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
 177 static 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
 186 static 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
 195 static 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
 204 static 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  */
 216 static 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  */
 240 static 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  */
 262 static void pcan_usb_restart(unsigned long arg)
 263 {
 264         /* notify candev and netdev */
 265         peak_usb_restart_complete((struct peak_usb_device *)arg);
 266 }
 267
 268 /*
 269  * handle the submission of the restart urb
 270  */
 271 static void pcan_usb_restart_pending(struct urb *urb)
 272 {
 273         struct pcan_usb *pdev = urb->context;
 274
 275         /* the PCAN-USB needs time to restart */
 276         mod_timer(&pdev->restart_timer,
 277                         jiffies + msecs_to_jiffies(PCAN_USB_STARTUP_TIMEOUT));
 278
 279         /* can delete usb resources */
 280         peak_usb_async_complete(urb);
 281 }
 282
 283 /*
 284  * handle asynchronous restart
 285  */
 286 static int pcan_usb_restart_async(struct peak_usb_device *dev, struct urb *urb,
 287                                   u8 *buf)
 288 {
 289         struct pcan_usb *pdev = container_of(dev, struct pcan_usb, dev);
 290
 291         if (timer_pending(&pdev->restart_timer))
 292                 return -EBUSY;
 293
 294         /* set bus on */
 295         buf[PCAN_USB_CMD_FUNC] = 3;
 296         buf[PCAN_USB_CMD_NUM] = 2;
 297         buf[PCAN_USB_CMD_ARGS] = 1;
 298
 299         usb_fill_bulk_urb(urb, dev->udev,
 300                         usb_sndbulkpipe(dev->udev, PCAN_USB_EP_CMDOUT),
 301                         buf, PCAN_USB_CMD_LEN,
 302                         pcan_usb_restart_pending, pdev);
 303
 304         return usb_submit_urb(urb, GFP_ATOMIC);
 305 }
 306
 307 /*
 308  * read serial number from device
 309  */
 310 static int pcan_usb_get_serial(struct peak_usb_device *dev, u32 *serial_number)
 311 {
 312         u8 args[PCAN_USB_CMD_ARGS_LEN];
 313         int err;
 314
 315         err = pcan_usb_wait_rsp(dev, 6, 1, args);
 316         if (err) {
 317                 netdev_err(dev->netdev, "getting serial failure: %d\n", err);
 318         } else if (serial_number) {
 319                 __le32 tmp32;
 320
 321                 memcpy(&tmp32, args, 4);
 322                 *serial_number = le32_to_cpu(tmp32);
 323         }
 324
 325         return err;
 326 }
 327
 328 /*
 329  * read device id from device
 330  */
 331 static int pcan_usb_get_device_id(struct peak_usb_device *dev, u32 *device_id)
 332 {
 333         u8 args[PCAN_USB_CMD_ARGS_LEN];
 334         int err;
 335
 336         err = pcan_usb_wait_rsp(dev, 4, 1, args);
 337         if (err)
 338                 netdev_err(dev->netdev, "getting device id failure: %d\n", err);
 339         else if (device_id)
 340                 *device_id = args[0];
 341
 342         return err;
 343 }
 344
 345 /*
 346  * update current time ref with received timestamp
 347  */
 348 static int pcan_usb_update_ts(struct pcan_usb_msg_context *mc)
 349 {
 350         __le16 tmp16;
 351
 352         if ((mc->ptr+2) > mc->end)
 353                 return -EINVAL;
 354
 355         memcpy(&tmp16, mc->ptr, 2);
 356
 357         mc->ts16 = le16_to_cpu(tmp16);
 358
 359         if (mc->rec_idx > 0)
 360                 peak_usb_update_ts_now(&mc->pdev->time_ref, mc->ts16);
 361         else
 362                 peak_usb_set_ts_now(&mc->pdev->time_ref, mc->ts16);
 363
 364         return 0;
 365 }
 366
 367 /*
 368  * decode received timestamp
 369  */
 370 static int pcan_usb_decode_ts(struct pcan_usb_msg_context *mc, u8 first_packet)
 371 {
 372         /* only 1st packet supplies a word timestamp */
 373         if (first_packet) {
 374                 __le16 tmp16;
 375
 376                 if ((mc->ptr + 2) > mc->end)
 377                         return -EINVAL;
 378
 379                 memcpy(&tmp16, mc->ptr, 2);
 380                 mc->ptr += 2;
 381
 382                 mc->ts16 = le16_to_cpu(tmp16);
 383                 mc->prev_ts8 = mc->ts16 & 0x00ff;
 384         } else {
 385                 u8 ts8;
 386
 387                 if ((mc->ptr + 1) > mc->end)
 388                         return -EINVAL;
 389
 390                 ts8 = *mc->ptr++;
 391
 392                 if (ts8 < mc->prev_ts8)
 393                         mc->ts16 += 0x100;
 394
 395                 mc->ts16 &= 0xff00;
 396                 mc->ts16 |= ts8;
 397                 mc->prev_ts8 = ts8;
 398         }
 399
 400         return 0;
 401 }
 402
 403 static int pcan_usb_decode_error(struct pcan_usb_msg_context *mc, u8 n,
 404                                  u8 status_len)
 405 {
 406         struct sk_buff *skb;
 407         struct can_frame *cf;
 408         struct timeval tv;
 409         enum can_state new_state;
 410
 411         /* ignore this error until 1st ts received */
 412         if (n == PCAN_USB_ERROR_QOVR)
 413                 if (!mc->pdev->time_ref.tick_count)
 414                         return 0;
 415
 416         new_state = mc->pdev->dev.can.state;
 417
 418         switch (mc->pdev->dev.can.state) {
 419         case CAN_STATE_ERROR_ACTIVE:
 420                 if (n & PCAN_USB_ERROR_BUS_LIGHT) {
 421                         new_state = CAN_STATE_ERROR_WARNING;
 422                         break;
 423                 }
 424
 425         case CAN_STATE_ERROR_WARNING:
 426                 if (n & PCAN_USB_ERROR_BUS_HEAVY) {
 427                         new_state = CAN_STATE_ERROR_PASSIVE;
 428                         break;
 429                 }
 430                 if (n & PCAN_USB_ERROR_BUS_OFF) {
 431                         new_state = CAN_STATE_BUS_OFF;
 432                         break;
 433                 }
 434                 if (n & (PCAN_USB_ERROR_RXQOVR | PCAN_USB_ERROR_QOVR)) {
 435                         /*
 436                          * trick to bypass next comparison and process other
 437                          * errors
 438                          */
 439                         new_state = CAN_STATE_MAX;
 440                         break;
 441                 }
 442                 if ((n & PCAN_USB_ERROR_BUS_LIGHT) == 0) {
 443                         /* no error (back to active state) */
 444                         mc->pdev->dev.can.state = CAN_STATE_ERROR_ACTIVE;
 445                         return 0;
 446                 }
 447                 break;
 448
 449         case CAN_STATE_ERROR_PASSIVE:
 450                 if (n & PCAN_USB_ERROR_BUS_OFF) {
 451                         new_state = CAN_STATE_BUS_OFF;
 452                         break;
 453                 }
 454                 if (n & PCAN_USB_ERROR_BUS_LIGHT) {
 455                         new_state = CAN_STATE_ERROR_WARNING;
 456                         break;
 457                 }
 458                 if (n & (PCAN_USB_ERROR_RXQOVR | PCAN_USB_ERROR_QOVR)) {
 459                         /*
 460                          * trick to bypass next comparison and process other
 461                          * errors
 462                          */
 463                         new_state = CAN_STATE_MAX;
 464                         break;
 465                 }
 466
 467                 if ((n & PCAN_USB_ERROR_BUS_HEAVY) == 0) {
 468                         /* no error (back to active state) */
 469                         mc->pdev->dev.can.state = CAN_STATE_ERROR_ACTIVE;
 470                         return 0;
 471                 }
 472                 break;
 473
 474         default:
 475                 /* do nothing waiting for restart */
 476                 return 0;
 477         }
 478
 479         /* donot post any error if current state didn't change */
 480         if (mc->pdev->dev.can.state == new_state)
 481                 return 0;
 482
 483         /* allocate an skb to store the error frame */
 484         skb = alloc_can_err_skb(mc->netdev, &cf);
 485         if (!skb)
 486                 return -ENOMEM;
 487
 488         switch (new_state) {
 489         case CAN_STATE_BUS_OFF:
 490                 cf->can_id |= CAN_ERR_BUSOFF;
 491                 mc->pdev->dev.can.can_stats.bus_off++;
 492                 can_bus_off(mc->netdev);
 493                 break;
 494
 495         case CAN_STATE_ERROR_PASSIVE:
 496                 cf->can_id |= CAN_ERR_CRTL;
 497                 cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE |
 498                                CAN_ERR_CRTL_RX_PASSIVE;
 499                 mc->pdev->dev.can.can_stats.error_passive++;
 500                 break;
 501
 502         case CAN_STATE_ERROR_WARNING:
 503                 cf->can_id |= CAN_ERR_CRTL;
 504                 cf->data[1] |= CAN_ERR_CRTL_TX_WARNING |
 505                                CAN_ERR_CRTL_RX_WARNING;
 506                 mc->pdev->dev.can.can_stats.error_warning++;
 507                 break;
 508
 509         default:
 510                 /* CAN_STATE_MAX (trick to handle other errors) */
 511                 cf->can_id |= CAN_ERR_CRTL;
 512                 cf->data[1] |= CAN_ERR_CRTL_RX_OVERFLOW;
 513                 mc->netdev->stats.rx_over_errors++;
 514                 mc->netdev->stats.rx_errors++;
 515
 516                 new_state = mc->pdev->dev.can.state;
 517                 break;
 518         }
 519
 520         mc->pdev->dev.can.state = new_state;
 521
 522         if (status_len & PCAN_USB_STATUSLEN_TIMESTAMP) {
 523                 struct skb_shared_hwtstamps *hwts = skb_hwtstamps(skb);
 524
 525                 peak_usb_get_ts_tv(&mc->pdev->time_ref, mc->ts16, &tv);
 526                 hwts->hwtstamp = timeval_to_ktime(tv);
 527         }
 528
 529         mc->netdev->stats.rx_packets++;
 530         mc->netdev->stats.rx_bytes += cf->can_dlc;
 531         netif_rx(skb);
 532
 533         return 0;
 534 }
 535
 536 /*
 537  * decode non-data usb message
 538  */
 539 static int pcan_usb_decode_status(struct pcan_usb_msg_context *mc,
 540                                   u8 status_len)
 541 {
 542         u8 rec_len = status_len & PCAN_USB_STATUSLEN_DLC;
 543         u8 f, n;
 544         int err;
 545
 546         /* check whether function and number can be read */
 547         if ((mc->ptr + 2) > mc->end)
 548                 return -EINVAL;
 549
 550         f = mc->ptr[PCAN_USB_CMD_FUNC];
 551         n = mc->ptr[PCAN_USB_CMD_NUM];
 552         mc->ptr += PCAN_USB_CMD_ARGS;
 553
 554         if (status_len & PCAN_USB_STATUSLEN_TIMESTAMP) {
 555                 int err = pcan_usb_decode_ts(mc, !mc->rec_idx);
 556
 557                 if (err)
 558                         return err;
 559         }
 560
 561         switch (f) {
 562         case PCAN_USB_REC_ERROR:
 563                 err = pcan_usb_decode_error(mc, n, status_len);
 564                 if (err)
 565                         return err;
 566                 break;
 567
 568         case PCAN_USB_REC_ANALOG:
 569                 /* analog values (ignored) */
 570                 rec_len = 2;
 571                 break;
 572
 573         case PCAN_USB_REC_BUSLOAD:
 574                 /* bus load (ignored) */
 575                 rec_len = 1;
 576                 break;
 577
 578         case PCAN_USB_REC_TS:
 579                 /* only timestamp */
 580                 if (pcan_usb_update_ts(mc))
 581                         return -EINVAL;
 582                 break;
 583
 584         case PCAN_USB_REC_BUSEVT:
 585                 /* error frame/bus event */
 586                 if (n & PCAN_USB_ERROR_TXQFULL)
 587                         netdev_dbg(mc->netdev, "device Tx queue full)\n");
 588                 break;
 589         default:
 590                 netdev_err(mc->netdev, "unexpected function %u\n", f);
 591                 break;
 592         }
 593
 594         if ((mc->ptr + rec_len) > mc->end)
 595                 return -EINVAL;
 596
 597         mc->ptr += rec_len;
 598
 599         return 0;
 600 }
 601
 602 /*
 603  * decode data usb message
 604  */
 605 static int pcan_usb_decode_data(struct pcan_usb_msg_context *mc, u8 status_len)
 606 {
 607         u8 rec_len = status_len & PCAN_USB_STATUSLEN_DLC;
 608         struct sk_buff *skb;
 609         struct can_frame *cf;
 610         struct timeval tv;
 611         struct skb_shared_hwtstamps *hwts;
 612
 613         skb = alloc_can_skb(mc->netdev, &cf);
 614         if (!skb)
 615                 return -ENOMEM;
 616
 617         if (status_len & PCAN_USB_STATUSLEN_EXT_ID) {
 618                 __le32 tmp32;
 619
 620                 if ((mc->ptr + 4) > mc->end)
 621                         goto decode_failed;
 622
 623                 memcpy(&tmp32, mc->ptr, 4);
 624                 mc->ptr += 4;
 625
 626                 cf->can_id = (le32_to_cpu(tmp32) >> 3) | CAN_EFF_FLAG;
 627         } else {
 628                 __le16 tmp16;
 629
 630                 if ((mc->ptr + 2) > mc->end)
 631                         goto decode_failed;
 632
 633                 memcpy(&tmp16, mc->ptr, 2);
 634                 mc->ptr += 2;
 635
 636                 cf->can_id = le16_to_cpu(tmp16) >> 5;
 637         }
 638
 639         cf->can_dlc = get_can_dlc(rec_len);
 640
 641         /* first data packet timestamp is a word */
 642         if (pcan_usb_decode_ts(mc, !mc->rec_data_idx))
 643                 goto decode_failed;
 644
 645         /* read data */
 646         memset(cf->data, 0x0, sizeof(cf->data));
 647         if (status_len & PCAN_USB_STATUSLEN_RTR) {
 648                 cf->can_id |= CAN_RTR_FLAG;
 649         } else {
 650                 if ((mc->ptr + rec_len) > mc->end)
 651                         goto decode_failed;
 652
 653                 memcpy(cf->data, mc->ptr, cf->can_dlc);
 654                 mc->ptr += rec_len;
 655         }
 656
 657         /* convert timestamp into kernel time */
 658         peak_usb_get_ts_tv(&mc->pdev->time_ref, mc->ts16, &tv);
 659         hwts = skb_hwtstamps(skb);
 660         hwts->hwtstamp = timeval_to_ktime(tv);
 661
 662         /* update statistics */
 663         mc->netdev->stats.rx_packets++;
 664         mc->netdev->stats.rx_bytes += cf->can_dlc;
 665         /* push the skb */
 666         netif_rx(skb);
 667
 668         return 0;
 669
 670 decode_failed:
 671         dev_kfree_skb(skb);
 672         return -EINVAL;
 673 }
 674
 675 /*
 676  * process incoming message
 677  */
 678 static int pcan_usb_decode_msg(struct peak_usb_device *dev, u8 *ibuf, u32 lbuf)
 679 {
 680         struct pcan_usb_msg_context mc = {
 681                 .rec_cnt = ibuf[1],
 682                 .ptr = ibuf + PCAN_USB_MSG_HEADER_LEN,
 683                 .end = ibuf + lbuf,
 684                 .netdev = dev->netdev,
 685                 .pdev = container_of(dev, struct pcan_usb, dev),
 686         };
 687         int err;
 688
 689         for (err = 0; mc.rec_idx < mc.rec_cnt && !err; mc.rec_idx++) {
 690                 u8 sl = *mc.ptr++;
 691
 692                 /* handle status and error frames here */
 693                 if (sl & PCAN_USB_STATUSLEN_INTERNAL) {
 694                         err = pcan_usb_decode_status(&mc, sl);
 695                 /* handle normal can frames here */
 696                 } else {
 697                         err = pcan_usb_decode_data(&mc, sl);
 698                         mc.rec_data_idx++;
 699                 }
 700         }
 701
 702         return err;
 703 }
 704
 705 /*
 706  * process any incoming buffer
 707  */
 708 static int pcan_usb_decode_buf(struct peak_usb_device *dev, struct urb *urb)
 709 {
 710         int err = 0;
 711
 712         if (urb->actual_length > PCAN_USB_MSG_HEADER_LEN) {
 713                 err = pcan_usb_decode_msg(dev, urb->transfer_buffer,
 714                         urb->actual_length);
 715
 716         } else if (urb->actual_length > 0) {
 717                 netdev_err(dev->netdev, "usb message length error (%u)\n",
 718                         urb->actual_length);
 719                 err = -EINVAL;
 720         }
 721
 722         return err;
 723 }
 724
 725 /*
 726  * process outgoing packet
 727  */
 728 static int pcan_usb_encode_msg(struct peak_usb_device *dev, struct sk_buff *skb,
 729                                u8 *obuf, size_t *size)
 730 {
 731         struct net_device *netdev = dev->netdev;
 732         struct net_device_stats *stats = &netdev->stats;
 733         struct can_frame *cf = (struct can_frame *)skb->data;
 734         u8 *pc;
 735
 736         obuf[0] = 2;
 737         obuf[1] = 1;
 738
 739         pc = obuf + PCAN_USB_MSG_HEADER_LEN;
 740
 741         /* status/len byte */
 742         *pc = cf->can_dlc;
 743         if (cf->can_id & CAN_RTR_FLAG)
 744                 *pc |= PCAN_USB_STATUSLEN_RTR;
 745
 746         /* can id */
 747         if (cf->can_id & CAN_EFF_FLAG) {
 748                 __le32 tmp32 = cpu_to_le32((cf->can_id & CAN_ERR_MASK) << 3);
 749
 750                 *pc |= PCAN_USB_STATUSLEN_EXT_ID;
 751                 memcpy(++pc, &tmp32, 4);
 752                 pc += 4;
 753         } else {
 754                 __le16 tmp16 = cpu_to_le16((cf->can_id & CAN_ERR_MASK) << 5);
 755
 756                 memcpy(++pc, &tmp16, 2);
 757                 pc += 2;
 758         }
 759
 760         /* can data */
 761         if (!(cf->can_id & CAN_RTR_FLAG)) {
 762                 memcpy(pc, cf->data, cf->can_dlc);
 763                 pc += cf->can_dlc;
 764         }
 765
 766         obuf[(*size)-1] = (u8)(stats->tx_packets & 0xff);
 767
 768         return 0;
 769 }
 770
 771 /*
 772  * start interface
 773  */
 774 static int pcan_usb_start(struct peak_usb_device *dev)
 775 {
 776         struct pcan_usb *pdev = container_of(dev, struct pcan_usb, dev);
 777
 778         /* number of bits used in timestamps read from adapter struct */
 779         peak_usb_init_time_ref(&pdev->time_ref, &pcan_usb);
 780
 781         /* if revision greater than 3, can put silent mode on/off */
 782         if (dev->device_rev > 3) {
 783                 int err;
 784
 785                 err = pcan_usb_set_silent(dev,
 786                                 dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY);
 787                 if (err)
 788                         return err;
 789         }
 790
 791         return pcan_usb_set_ext_vcc(dev, 0);
 792 }
 793
 794 static int pcan_usb_init(struct peak_usb_device *dev)
 795 {
 796         struct pcan_usb *pdev = container_of(dev, struct pcan_usb, dev);
 797         u32 serial_number;
 798         int err;
 799
 800         /* initialize a timer needed to wait for hardware restart */
 801         init_timer(&pdev->restart_timer);
 802         pdev->restart_timer.function = pcan_usb_restart;
 803         pdev->restart_timer.data = (unsigned long)dev;
 804
 805         /*
 806          * explicit use of dev_xxx() instead of netdev_xxx() here:
 807          * information displayed are related to the device itself, not
 808          * to the canx netdevice.
 809          */
 810         err = pcan_usb_get_serial(dev, &serial_number);
 811         if (err) {
 812                 dev_err(dev->netdev->dev.parent,
 813                         "unable to read %s serial number (err %d)\n",
 814                         pcan_usb.name, err);
 815                 return err;
 816         }
 817
 818         dev_info(dev->netdev->dev.parent,
 819                  "PEAK-System %s adapter hwrev %u serial %08X (%u channel)\n",
 820                  pcan_usb.name, dev->device_rev, serial_number,
 821                  pcan_usb.ctrl_count);
 822
 823         return 0;
 824 }
 825
 826 /*
 827  * probe function for new PCAN-USB usb interface
 828  */
 829 static int pcan_usb_probe(struct usb_interface *intf)
 830 {
 831         struct usb_host_interface *if_desc;
 832         int i;
 833
 834         if_desc = intf->altsetting;
 835
 836         /* check interface endpoint addresses */
 837         for (i = 0; i < if_desc->desc.bNumEndpoints; i++) {
 838                 struct usb_endpoint_descriptor *ep = &if_desc->endpoint[i].desc;
 839
 840                 switch (ep->bEndpointAddress) {
 841                 case PCAN_USB_EP_CMDOUT:
 842                 case PCAN_USB_EP_CMDIN:
 843                 case PCAN_USB_EP_MSGOUT:
 844                 case PCAN_USB_EP_MSGIN:
 845                         break;
 846                 default:
 847                         return -ENODEV;
 848                 }
 849         }
 850
 851         return 0;
 852 }
 853
 854 /*
 855  * describe the PCAN-USB adapter
 856  */
 857 static const struct can_bittiming_const pcan_usb_const = {
 858         .name = "pcan_usb",
 859         .tseg1_min = 1,
 860         .tseg1_max = 16,
 861         .tseg2_min = 1,
 862         .tseg2_max = 8,
 863         .sjw_max = 4,
 864         .brp_min = 1,
 865         .brp_max = 64,
 866         .brp_inc = 1,
 867 };
 868
 869 const struct peak_usb_adapter pcan_usb = {
 870         .name = "PCAN-USB",
 871         .device_id = PCAN_USB_PRODUCT_ID,
 872         .ctrl_count = 1,
 873         .ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES | CAN_CTRLMODE_LISTENONLY,
 874         .clock = {
 875                 .freq = PCAN_USB_CRYSTAL_HZ / 2 ,
 876         },
 877         .bittiming_const = &pcan_usb_const,
 878
 879         /* size of device private data */
 880         .sizeof_dev_private = sizeof(struct pcan_usb),
 881
 882         /* timestamps usage */
 883         .ts_used_bits = 16,
 884         .ts_period = 24575, /* calibration period in ts. */
 885         .us_per_ts_scale = PCAN_USB_TS_US_PER_TICK, /* us=(ts*scale) */
 886         .us_per_ts_shift = PCAN_USB_TS_DIV_SHIFTER, /*  >> shift     */
 887
 888         /* give here messages in/out endpoints */
 889         .ep_msg_in = PCAN_USB_EP_MSGIN,
 890         .ep_msg_out = {PCAN_USB_EP_MSGOUT},
 891
 892         /* size of rx/tx usb buffers */
 893         .rx_buffer_size = PCAN_USB_RX_BUFFER_SIZE,
 894         .tx_buffer_size = PCAN_USB_TX_BUFFER_SIZE,
 895
 896         /* device callbacks */
 897         .intf_probe = pcan_usb_probe,
 898         .dev_init = pcan_usb_init,
 899         .dev_set_bus = pcan_usb_write_mode,
 900         .dev_set_bittiming = pcan_usb_set_bittiming,
 901         .dev_get_device_id = pcan_usb_get_device_id,
 902         .dev_decode_buf = pcan_usb_decode_buf,
 903         .dev_encode_msg = pcan_usb_encode_msg,
 904         .dev_start = pcan_usb_start,
 905         .dev_restart_async = pcan_usb_restart_async,
 906 };