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(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  */
 274 static 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  */
 289 static 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  */
 313 static 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  */
 334 static 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  */
 351 static 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  */
 373 static 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
 406 static 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  */
 542 static 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  */
 608 static 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
 671 decode_failed:
 672         dev_kfree_skb(skb);
 673         return -EINVAL;
 674 }
 675
 676 /*
 677  * process incoming message
 678  */
 679 static 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  */
 709 static 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  */
 729 static 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  */
 775 static 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
 795 static 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  */
 828 static 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  */
 856 static 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
 868 const 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 };