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

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * CAN driver for PEAK System PCAN-USB adapter
   4  * Derived from the PCAN project file driver/src/pcan_usb.c
   5  *
   6  * Copyright (C) 2003-2010 PEAK System-Technik GmbH
   7  * Copyright (C) 2011-2012 Stephane Grosjean <s.grosjean@peak-system.com>
   8  *
   9  * Many thanks to Klaus Hitschler <klaus.hitschler@gmx.de>
  10  */
  11 #include <linux/netdevice.h>
  12 #include <linux/usb.h>
  13 #include <linux/module.h>
  14
  15 #include <linux/can.h>
  16 #include <linux/can/dev.h>
  17 #include <linux/can/error.h>
  18
  19 #include "pcan_usb_core.h"
  20
  21 MODULE_SUPPORTED_DEVICE("PEAK-System PCAN-USB adapter");
  22
  23 /* PCAN-USB Endpoints */
  24 #define PCAN_USB_EP_CMDOUT              1
  25 #define PCAN_USB_EP_CMDIN               (PCAN_USB_EP_CMDOUT | USB_DIR_IN)
  26 #define PCAN_USB_EP_MSGOUT              2
  27 #define PCAN_USB_EP_MSGIN               (PCAN_USB_EP_MSGOUT | USB_DIR_IN)
  28
  29 /* PCAN-USB command struct */
  30 #define PCAN_USB_CMD_FUNC               0
  31 #define PCAN_USB_CMD_NUM                1
  32 #define PCAN_USB_CMD_ARGS               2
  33 #define PCAN_USB_CMD_ARGS_LEN           14
  34 #define PCAN_USB_CMD_LEN                (PCAN_USB_CMD_ARGS + \
  35                                          PCAN_USB_CMD_ARGS_LEN)
  36
  37 /* PCAN-USB commands */
  38 #define PCAN_USB_CMD_BITRATE    1
  39 #define PCAN_USB_CMD_SET_BUS    3
  40 #define PCAN_USB_CMD_DEVID      4
  41 #define PCAN_USB_CMD_SN         6
  42 #define PCAN_USB_CMD_REGISTER   9
  43 #define PCAN_USB_CMD_EXT_VCC    10
  44 #define PCAN_USB_CMD_ERR_FR     11
  45
  46 /* PCAN_USB_CMD_SET_BUS number arg */
  47 #define PCAN_USB_BUS_XCVER              2
  48 #define PCAN_USB_BUS_SILENT_MODE        3
  49
  50 /* PCAN_USB_CMD_xxx functions */
  51 #define PCAN_USB_GET            1
  52 #define PCAN_USB_SET            2
  53
  54 /* PCAN-USB command timeout (ms.) */
  55 #define PCAN_USB_COMMAND_TIMEOUT        1000
  56
  57 /* PCAN-USB startup timeout (ms.) */
  58 #define PCAN_USB_STARTUP_TIMEOUT        10
  59
  60 /* PCAN-USB rx/tx buffers size */
  61 #define PCAN_USB_RX_BUFFER_SIZE         64
  62 #define PCAN_USB_TX_BUFFER_SIZE         64
  63
  64 #define PCAN_USB_MSG_HEADER_LEN         2
  65
  66 /* PCAN-USB adapter internal clock (MHz) */
  67 #define PCAN_USB_CRYSTAL_HZ             16000000
  68
  69 /* PCAN-USB USB message record status/len field */
  70 #define PCAN_USB_STATUSLEN_TIMESTAMP    (1 << 7)
  71 #define PCAN_USB_STATUSLEN_INTERNAL     (1 << 6)
  72 #define PCAN_USB_STATUSLEN_EXT_ID       (1 << 5)
  73 #define PCAN_USB_STATUSLEN_RTR          (1 << 4)
  74 #define PCAN_USB_STATUSLEN_DLC          (0xf)
  75
  76 /* PCAN-USB error flags */
  77 #define PCAN_USB_ERROR_TXFULL           0x01
  78 #define PCAN_USB_ERROR_RXQOVR           0x02
  79 #define PCAN_USB_ERROR_BUS_LIGHT        0x04
  80 #define PCAN_USB_ERROR_BUS_HEAVY        0x08
  81 #define PCAN_USB_ERROR_BUS_OFF          0x10
  82 #define PCAN_USB_ERROR_RXQEMPTY         0x20
  83 #define PCAN_USB_ERROR_QOVR             0x40
  84 #define PCAN_USB_ERROR_TXQFULL          0x80
  85
  86 #define PCAN_USB_ERROR_BUS              (PCAN_USB_ERROR_BUS_LIGHT | \
  87                                          PCAN_USB_ERROR_BUS_HEAVY | \
  88                                          PCAN_USB_ERROR_BUS_OFF)
  89
  90 /* SJA1000 modes */
  91 #define SJA1000_MODE_NORMAL             0x00
  92 #define SJA1000_MODE_INIT               0x01
  93
  94 /*
  95  * tick duration = 42.666 us =>
  96  * (tick_number * 44739243) >> 20 ~ (tick_number * 42666) / 1000
  97  * accuracy = 10^-7
  98  */
  99 #define PCAN_USB_TS_DIV_SHIFTER         20
 100 #define PCAN_USB_TS_US_PER_TICK         44739243
 101
 102 /* PCAN-USB messages record types */
 103 #define PCAN_USB_REC_ERROR              1
 104 #define PCAN_USB_REC_ANALOG             2
 105 #define PCAN_USB_REC_BUSLOAD            3
 106 #define PCAN_USB_REC_TS                 4
 107 #define PCAN_USB_REC_BUSEVT             5
 108
 109 /* CAN bus events notifications selection mask */
 110 #define PCAN_USB_ERR_RXERR              0x02    /* ask for rxerr counter */
 111 #define PCAN_USB_ERR_TXERR              0x04    /* ask for txerr counter */
 112
 113 /* This mask generates an usb packet each time the state of the bus changes.
 114  * In other words, its interest is to know which side among rx and tx is
 115  * responsible of the change of the bus state.
 116  */
 117 #define PCAN_USB_BERR_MASK      (PCAN_USB_ERR_RXERR | PCAN_USB_ERR_TXERR)
 118
 119 /* identify bus event packets with rx/tx error counters */
 120 #define PCAN_USB_ERR_CNT                0x80
 121
 122 /* private to PCAN-USB adapter */
 123 struct pcan_usb {
 124         struct peak_usb_device dev;
 125         struct peak_time_ref time_ref;
 126         struct timer_list restart_timer;
 127         struct can_berr_counter bec;
 128 };
 129
 130 /* incoming message context for decoding */
 131 struct pcan_usb_msg_context {
 132         u16 ts16;
 133         u8 prev_ts8;
 134         u8 *ptr;
 135         u8 *end;
 136         u8 rec_cnt;
 137         u8 rec_idx;
 138         u8 rec_ts_idx;
 139         struct net_device *netdev;
 140         struct pcan_usb *pdev;
 141 };
 142
 143 /*
 144  * send a command
 145  */
 146 static int pcan_usb_send_cmd(struct peak_usb_device *dev, u8 f, u8 n, u8 *p)
 147 {
 148         int err;
 149         int actual_length;
 150
 151         /* usb device unregistered? */
 152         if (!(dev->state & PCAN_USB_STATE_CONNECTED))
 153                 return 0;
 154
 155         dev->cmd_buf[PCAN_USB_CMD_FUNC] = f;
 156         dev->cmd_buf[PCAN_USB_CMD_NUM] = n;
 157
 158         if (p)
 159                 memcpy(dev->cmd_buf + PCAN_USB_CMD_ARGS,
 160                         p, PCAN_USB_CMD_ARGS_LEN);
 161
 162         err = usb_bulk_msg(dev->udev,
 163                         usb_sndbulkpipe(dev->udev, PCAN_USB_EP_CMDOUT),
 164                         dev->cmd_buf, PCAN_USB_CMD_LEN, &actual_length,
 165                         PCAN_USB_COMMAND_TIMEOUT);
 166         if (err)
 167                 netdev_err(dev->netdev,
 168                         "sending cmd f=0x%x n=0x%x failure: %d\n",
 169                         f, n, err);
 170         return err;
 171 }
 172
 173 /*
 174  * send a command then wait for its response
 175  */
 176 static int pcan_usb_wait_rsp(struct peak_usb_device *dev, u8 f, u8 n, u8 *p)
 177 {
 178         int err;
 179         int actual_length;
 180
 181         /* usb device unregistered? */
 182         if (!(dev->state & PCAN_USB_STATE_CONNECTED))
 183                 return 0;
 184
 185         /* first, send command */
 186         err = pcan_usb_send_cmd(dev, f, n, NULL);
 187         if (err)
 188                 return err;
 189
 190         err = usb_bulk_msg(dev->udev,
 191                 usb_rcvbulkpipe(dev->udev, PCAN_USB_EP_CMDIN),
 192                 dev->cmd_buf, PCAN_USB_CMD_LEN, &actual_length,
 193                 PCAN_USB_COMMAND_TIMEOUT);
 194         if (err)
 195                 netdev_err(dev->netdev,
 196                         "waiting rsp f=0x%x n=0x%x failure: %d\n", f, n, err);
 197         else if (p)
 198                 memcpy(p, dev->cmd_buf + PCAN_USB_CMD_ARGS,
 199                         PCAN_USB_CMD_ARGS_LEN);
 200
 201         return err;
 202 }
 203
 204 static int pcan_usb_set_sja1000(struct peak_usb_device *dev, u8 mode)
 205 {
 206         u8 args[PCAN_USB_CMD_ARGS_LEN] = {
 207                 [1] = mode,
 208         };
 209
 210         return pcan_usb_send_cmd(dev, PCAN_USB_CMD_REGISTER, PCAN_USB_SET,
 211                                  args);
 212 }
 213
 214 static int pcan_usb_set_bus(struct peak_usb_device *dev, u8 onoff)
 215 {
 216         u8 args[PCAN_USB_CMD_ARGS_LEN] = {
 217                 [0] = !!onoff,
 218         };
 219
 220         return pcan_usb_send_cmd(dev, PCAN_USB_CMD_SET_BUS, PCAN_USB_BUS_XCVER,
 221                                  args);
 222 }
 223
 224 static int pcan_usb_set_silent(struct peak_usb_device *dev, u8 onoff)
 225 {
 226         u8 args[PCAN_USB_CMD_ARGS_LEN] = {
 227                 [0] = !!onoff,
 228         };
 229
 230         return pcan_usb_send_cmd(dev, PCAN_USB_CMD_SET_BUS,
 231                                  PCAN_USB_BUS_SILENT_MODE, args);
 232 }
 233
 234 /* send the cmd to be notified from bus errors */
 235 static int pcan_usb_set_err_frame(struct peak_usb_device *dev, u8 err_mask)
 236 {
 237         u8 args[PCAN_USB_CMD_ARGS_LEN] = {
 238                 [0] = err_mask,
 239         };
 240
 241         return pcan_usb_send_cmd(dev, PCAN_USB_CMD_ERR_FR, PCAN_USB_SET, args);
 242 }
 243
 244 static int pcan_usb_set_ext_vcc(struct peak_usb_device *dev, u8 onoff)
 245 {
 246         u8 args[PCAN_USB_CMD_ARGS_LEN] = {
 247                 [0] = !!onoff,
 248         };
 249
 250         return pcan_usb_send_cmd(dev, PCAN_USB_CMD_EXT_VCC, PCAN_USB_SET, args);
 251 }
 252
 253 /*
 254  * set bittiming value to can
 255  */
 256 static int pcan_usb_set_bittiming(struct peak_usb_device *dev,
 257                                   struct can_bittiming *bt)
 258 {
 259         u8 args[PCAN_USB_CMD_ARGS_LEN];
 260         u8 btr0, btr1;
 261
 262         btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
 263         btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
 264                 (((bt->phase_seg2 - 1) & 0x7) << 4);
 265         if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
 266                 btr1 |= 0x80;
 267
 268         netdev_info(dev->netdev, "setting BTR0=0x%02x BTR1=0x%02x\n",
 269                 btr0, btr1);
 270
 271         args[0] = btr1;
 272         args[1] = btr0;
 273
 274         return pcan_usb_send_cmd(dev, PCAN_USB_CMD_BITRATE, PCAN_USB_SET, args);
 275 }
 276
 277 /*
 278  * init/reset can
 279  */
 280 static int pcan_usb_write_mode(struct peak_usb_device *dev, u8 onoff)
 281 {
 282         int err;
 283
 284         err = pcan_usb_set_bus(dev, onoff);
 285         if (err)
 286                 return err;
 287
 288         if (!onoff) {
 289                 err = pcan_usb_set_sja1000(dev, SJA1000_MODE_INIT);
 290         } else {
 291                 /* the PCAN-USB needs time to init */
 292                 set_current_state(TASK_INTERRUPTIBLE);
 293                 schedule_timeout(msecs_to_jiffies(PCAN_USB_STARTUP_TIMEOUT));
 294         }
 295
 296         return err;
 297 }
 298
 299 /*
 300  * handle end of waiting for the device to reset
 301  */
 302 static void pcan_usb_restart(struct timer_list *t)
 303 {
 304         struct pcan_usb *pdev = from_timer(pdev, t, restart_timer);
 305         struct peak_usb_device *dev = &pdev->dev;
 306
 307         /* notify candev and netdev */
 308         peak_usb_restart_complete(dev);
 309 }
 310
 311 /*
 312  * handle the submission of the restart urb
 313  */
 314 static void pcan_usb_restart_pending(struct urb *urb)
 315 {
 316         struct pcan_usb *pdev = urb->context;
 317
 318         /* the PCAN-USB needs time to restart */
 319         mod_timer(&pdev->restart_timer,
 320                         jiffies + msecs_to_jiffies(PCAN_USB_STARTUP_TIMEOUT));
 321
 322         /* can delete usb resources */
 323         peak_usb_async_complete(urb);
 324 }
 325
 326 /*
 327  * handle asynchronous restart
 328  */
 329 static int pcan_usb_restart_async(struct peak_usb_device *dev, struct urb *urb,
 330                                   u8 *buf)
 331 {
 332         struct pcan_usb *pdev = container_of(dev, struct pcan_usb, dev);
 333
 334         if (timer_pending(&pdev->restart_timer))
 335                 return -EBUSY;
 336
 337         /* set bus on */
 338         buf[PCAN_USB_CMD_FUNC] = 3;
 339         buf[PCAN_USB_CMD_NUM] = 2;
 340         buf[PCAN_USB_CMD_ARGS] = 1;
 341
 342         usb_fill_bulk_urb(urb, dev->udev,
 343                         usb_sndbulkpipe(dev->udev, PCAN_USB_EP_CMDOUT),
 344                         buf, PCAN_USB_CMD_LEN,
 345                         pcan_usb_restart_pending, pdev);
 346
 347         return usb_submit_urb(urb, GFP_ATOMIC);
 348 }
 349
 350 /*
 351  * read serial number from device
 352  */
 353 static int pcan_usb_get_serial(struct peak_usb_device *dev, u32 *serial_number)
 354 {
 355         u8 args[PCAN_USB_CMD_ARGS_LEN];
 356         int err;
 357
 358         err = pcan_usb_wait_rsp(dev, PCAN_USB_CMD_SN, PCAN_USB_GET, args);
 359         if (err) {
 360                 netdev_err(dev->netdev, "getting serial failure: %d\n", err);
 361         } else if (serial_number) {
 362                 __le32 tmp32;
 363
 364                 memcpy(&tmp32, args, 4);
 365                 *serial_number = le32_to_cpu(tmp32);
 366         }
 367
 368         return err;
 369 }
 370
 371 /*
 372  * read device id from device
 373  */
 374 static int pcan_usb_get_device_id(struct peak_usb_device *dev, u32 *device_id)
 375 {
 376         u8 args[PCAN_USB_CMD_ARGS_LEN];
 377         int err;
 378
 379         err = pcan_usb_wait_rsp(dev, PCAN_USB_CMD_DEVID, PCAN_USB_GET, args);
 380         if (err)
 381                 netdev_err(dev->netdev, "getting device id failure: %d\n", err);
 382         else if (device_id)
 383                 *device_id = args[0];
 384
 385         return err;
 386 }
 387
 388 /*
 389  * update current time ref with received timestamp
 390  */
 391 static int pcan_usb_update_ts(struct pcan_usb_msg_context *mc)
 392 {
 393         __le16 tmp16;
 394
 395         if ((mc->ptr+2) > mc->end)
 396                 return -EINVAL;
 397
 398         memcpy(&tmp16, mc->ptr, 2);
 399
 400         mc->ts16 = le16_to_cpu(tmp16);
 401
 402         if (mc->rec_idx > 0)
 403                 peak_usb_update_ts_now(&mc->pdev->time_ref, mc->ts16);
 404         else
 405                 peak_usb_set_ts_now(&mc->pdev->time_ref, mc->ts16);
 406
 407         return 0;
 408 }
 409
 410 /*
 411  * decode received timestamp
 412  */
 413 static int pcan_usb_decode_ts(struct pcan_usb_msg_context *mc, u8 first_packet)
 414 {
 415         /* only 1st packet supplies a word timestamp */
 416         if (first_packet) {
 417                 __le16 tmp16;
 418
 419                 if ((mc->ptr + 2) > mc->end)
 420                         return -EINVAL;
 421
 422                 memcpy(&tmp16, mc->ptr, 2);
 423                 mc->ptr += 2;
 424
 425                 mc->ts16 = le16_to_cpu(tmp16);
 426                 mc->prev_ts8 = mc->ts16 & 0x00ff;
 427         } else {
 428                 u8 ts8;
 429
 430                 if ((mc->ptr + 1) > mc->end)
 431                         return -EINVAL;
 432
 433                 ts8 = *mc->ptr++;
 434
 435                 if (ts8 < mc->prev_ts8)
 436                         mc->ts16 += 0x100;
 437
 438                 mc->ts16 &= 0xff00;
 439                 mc->ts16 |= ts8;
 440                 mc->prev_ts8 = ts8;
 441         }
 442
 443         return 0;
 444 }
 445
 446 static int pcan_usb_decode_error(struct pcan_usb_msg_context *mc, u8 n,
 447                                  u8 status_len)
 448 {
 449         struct sk_buff *skb;
 450         struct can_frame *cf;
 451         enum can_state new_state;
 452
 453         /* ignore this error until 1st ts received */
 454         if (n == PCAN_USB_ERROR_QOVR)
 455                 if (!mc->pdev->time_ref.tick_count)
 456                         return 0;
 457
 458         new_state = mc->pdev->dev.can.state;
 459
 460         switch (mc->pdev->dev.can.state) {
 461         case CAN_STATE_ERROR_ACTIVE:
 462                 if (n & PCAN_USB_ERROR_BUS_LIGHT) {
 463                         new_state = CAN_STATE_ERROR_WARNING;
 464                         break;
 465                 }
 466                 fallthrough;
 467
 468         case CAN_STATE_ERROR_WARNING:
 469                 if (n & PCAN_USB_ERROR_BUS_HEAVY) {
 470                         new_state = CAN_STATE_ERROR_PASSIVE;
 471                         break;
 472                 }
 473                 if (n & PCAN_USB_ERROR_BUS_OFF) {
 474                         new_state = CAN_STATE_BUS_OFF;
 475                         break;
 476                 }
 477                 if (n & ~PCAN_USB_ERROR_BUS) {
 478                         /*
 479                          * trick to bypass next comparison and process other
 480                          * errors
 481                          */
 482                         new_state = CAN_STATE_MAX;
 483                         break;
 484                 }
 485                 if ((n & PCAN_USB_ERROR_BUS_LIGHT) == 0) {
 486                         /* no error (back to active state) */
 487                         new_state = CAN_STATE_ERROR_ACTIVE;
 488                         break;
 489                 }
 490                 break;
 491
 492         case CAN_STATE_ERROR_PASSIVE:
 493                 if (n & PCAN_USB_ERROR_BUS_OFF) {
 494                         new_state = CAN_STATE_BUS_OFF;
 495                         break;
 496                 }
 497                 if (n & PCAN_USB_ERROR_BUS_LIGHT) {
 498                         new_state = CAN_STATE_ERROR_WARNING;
 499                         break;
 500                 }
 501                 if (n & ~PCAN_USB_ERROR_BUS) {
 502                         /*
 503                          * trick to bypass next comparison and process other
 504                          * errors
 505                          */
 506                         new_state = CAN_STATE_MAX;
 507                         break;
 508                 }
 509
 510                 if ((n & PCAN_USB_ERROR_BUS_HEAVY) == 0) {
 511                         /* no error (back to warning state) */
 512                         new_state = CAN_STATE_ERROR_WARNING;
 513                         break;
 514                 }
 515                 break;
 516
 517         default:
 518                 /* do nothing waiting for restart */
 519                 return 0;
 520         }
 521
 522         /* donot post any error if current state didn't change */
 523         if (mc->pdev->dev.can.state == new_state)
 524                 return 0;
 525
 526         /* allocate an skb to store the error frame */
 527         skb = alloc_can_err_skb(mc->netdev, &cf);
 528         if (!skb)
 529                 return -ENOMEM;
 530
 531         switch (new_state) {
 532         case CAN_STATE_BUS_OFF:
 533                 cf->can_id |= CAN_ERR_BUSOFF;
 534                 mc->pdev->dev.can.can_stats.bus_off++;
 535                 can_bus_off(mc->netdev);
 536                 break;
 537
 538         case CAN_STATE_ERROR_PASSIVE:
 539                 cf->can_id |= CAN_ERR_CRTL;
 540                 cf->data[1] = (mc->pdev->bec.txerr > mc->pdev->bec.rxerr) ?
 541                                 CAN_ERR_CRTL_TX_PASSIVE :
 542                                 CAN_ERR_CRTL_RX_PASSIVE;
 543                 cf->data[6] = mc->pdev->bec.txerr;
 544                 cf->data[7] = mc->pdev->bec.rxerr;
 545
 546                 mc->pdev->dev.can.can_stats.error_passive++;
 547                 break;
 548
 549         case CAN_STATE_ERROR_WARNING:
 550                 cf->can_id |= CAN_ERR_CRTL;
 551                 cf->data[1] = (mc->pdev->bec.txerr > mc->pdev->bec.rxerr) ?
 552                                 CAN_ERR_CRTL_TX_WARNING :
 553                                 CAN_ERR_CRTL_RX_WARNING;
 554                 cf->data[6] = mc->pdev->bec.txerr;
 555                 cf->data[7] = mc->pdev->bec.rxerr;
 556
 557                 mc->pdev->dev.can.can_stats.error_warning++;
 558                 break;
 559
 560         case CAN_STATE_ERROR_ACTIVE:
 561                 cf->can_id |= CAN_ERR_CRTL;
 562                 cf->data[1] = CAN_ERR_CRTL_ACTIVE;
 563
 564                 /* sync local copies of rxerr/txerr counters */
 565                 mc->pdev->bec.txerr = 0;
 566                 mc->pdev->bec.rxerr = 0;
 567                 break;
 568
 569         default:
 570                 /* CAN_STATE_MAX (trick to handle other errors) */
 571                 if (n & PCAN_USB_ERROR_TXQFULL)
 572                         netdev_dbg(mc->netdev, "device Tx queue full)\n");
 573
 574                 if (n & PCAN_USB_ERROR_RXQOVR) {
 575                         netdev_dbg(mc->netdev, "data overrun interrupt\n");
 576                         cf->can_id |= CAN_ERR_CRTL;
 577                         cf->data[1] |= CAN_ERR_CRTL_RX_OVERFLOW;
 578                         mc->netdev->stats.rx_over_errors++;
 579                         mc->netdev->stats.rx_errors++;
 580                 }
 581
 582                 cf->data[6] = mc->pdev->bec.txerr;
 583                 cf->data[7] = mc->pdev->bec.rxerr;
 584
 585                 new_state = mc->pdev->dev.can.state;
 586                 break;
 587         }
 588
 589         mc->pdev->dev.can.state = new_state;
 590
 591         if (status_len & PCAN_USB_STATUSLEN_TIMESTAMP) {
 592                 struct skb_shared_hwtstamps *hwts = skb_hwtstamps(skb);
 593
 594                 peak_usb_get_ts_time(&mc->pdev->time_ref, mc->ts16,
 595                                      &hwts->hwtstamp);
 596         }
 597
 598         mc->netdev->stats.rx_packets++;
 599         mc->netdev->stats.rx_bytes += cf->len;
 600         netif_rx(skb);
 601
 602         return 0;
 603 }
 604
 605 /* decode bus event usb packet: first byte contains rxerr while 2nd one contains
 606  * txerr.
 607  */
 608 static int pcan_usb_handle_bus_evt(struct pcan_usb_msg_context *mc, u8 ir)
 609 {
 610         struct pcan_usb *pdev = mc->pdev;
 611
 612         /* acccording to the content of the packet */
 613         switch (ir) {
 614         case PCAN_USB_ERR_CNT:
 615
 616                 /* save rx/tx error counters from in the device context */
 617                 pdev->bec.rxerr = mc->ptr[0];
 618                 pdev->bec.txerr = mc->ptr[1];
 619                 break;
 620
 621         default:
 622                 /* reserved */
 623                 break;
 624         }
 625
 626         return 0;
 627 }
 628
 629 /*
 630  * decode non-data usb message
 631  */
 632 static int pcan_usb_decode_status(struct pcan_usb_msg_context *mc,
 633                                   u8 status_len)
 634 {
 635         u8 rec_len = status_len & PCAN_USB_STATUSLEN_DLC;
 636         u8 f, n;
 637         int err;
 638
 639         /* check whether function and number can be read */
 640         if ((mc->ptr + 2) > mc->end)
 641                 return -EINVAL;
 642
 643         f = mc->ptr[PCAN_USB_CMD_FUNC];
 644         n = mc->ptr[PCAN_USB_CMD_NUM];
 645         mc->ptr += PCAN_USB_CMD_ARGS;
 646
 647         if (status_len & PCAN_USB_STATUSLEN_TIMESTAMP) {
 648                 int err = pcan_usb_decode_ts(mc, !mc->rec_ts_idx);
 649
 650                 if (err)
 651                         return err;
 652
 653                 /* Next packet in the buffer will have a timestamp on a single
 654                  * byte
 655                  */
 656                 mc->rec_ts_idx++;
 657         }
 658
 659         switch (f) {
 660         case PCAN_USB_REC_ERROR:
 661                 err = pcan_usb_decode_error(mc, n, status_len);
 662                 if (err)
 663                         return err;
 664                 break;
 665
 666         case PCAN_USB_REC_ANALOG:
 667                 /* analog values (ignored) */
 668                 rec_len = 2;
 669                 break;
 670
 671         case PCAN_USB_REC_BUSLOAD:
 672                 /* bus load (ignored) */
 673                 rec_len = 1;
 674                 break;
 675
 676         case PCAN_USB_REC_TS:
 677                 /* only timestamp */
 678                 if (pcan_usb_update_ts(mc))
 679                         return -EINVAL;
 680                 break;
 681
 682         case PCAN_USB_REC_BUSEVT:
 683                 /* bus event notifications (get rxerr/txerr) */
 684                 err = pcan_usb_handle_bus_evt(mc, n);
 685                 if (err)
 686                         return err;
 687                 break;
 688         default:
 689                 netdev_err(mc->netdev, "unexpected function %u\n", f);
 690                 break;
 691         }
 692
 693         if ((mc->ptr + rec_len) > mc->end)
 694                 return -EINVAL;
 695
 696         mc->ptr += rec_len;
 697
 698         return 0;
 699 }
 700
 701 /*
 702  * decode data usb message
 703  */
 704 static int pcan_usb_decode_data(struct pcan_usb_msg_context *mc, u8 status_len)
 705 {
 706         u8 rec_len = status_len & PCAN_USB_STATUSLEN_DLC;
 707         struct sk_buff *skb;
 708         struct can_frame *cf;
 709         struct skb_shared_hwtstamps *hwts;
 710
 711         skb = alloc_can_skb(mc->netdev, &cf);
 712         if (!skb)
 713                 return -ENOMEM;
 714
 715         if (status_len & PCAN_USB_STATUSLEN_EXT_ID) {
 716                 __le32 tmp32;
 717
 718                 if ((mc->ptr + 4) > mc->end)
 719                         goto decode_failed;
 720
 721                 memcpy(&tmp32, mc->ptr, 4);
 722                 mc->ptr += 4;
 723
 724                 cf->can_id = (le32_to_cpu(tmp32) >> 3) | CAN_EFF_FLAG;
 725         } else {
 726                 __le16 tmp16;
 727
 728                 if ((mc->ptr + 2) > mc->end)
 729                         goto decode_failed;
 730
 731                 memcpy(&tmp16, mc->ptr, 2);
 732                 mc->ptr += 2;
 733
 734                 cf->can_id = le16_to_cpu(tmp16) >> 5;
 735         }
 736
 737         can_frame_set_cc_len(cf, rec_len, mc->pdev->dev.can.ctrlmode);
 738
 739         /* Only first packet timestamp is a word */
 740         if (pcan_usb_decode_ts(mc, !mc->rec_ts_idx))
 741                 goto decode_failed;
 742
 743         /* Next packet in the buffer will have a timestamp on a single byte */
 744         mc->rec_ts_idx++;
 745
 746         /* read data */
 747         memset(cf->data, 0x0, sizeof(cf->data));
 748         if (status_len & PCAN_USB_STATUSLEN_RTR) {
 749                 cf->can_id |= CAN_RTR_FLAG;
 750         } else {
 751                 if ((mc->ptr + rec_len) > mc->end)
 752                         goto decode_failed;
 753
 754                 memcpy(cf->data, mc->ptr, cf->len);
 755                 mc->ptr += rec_len;
 756         }
 757
 758         /* convert timestamp into kernel time */
 759         hwts = skb_hwtstamps(skb);
 760         peak_usb_get_ts_time(&mc->pdev->time_ref, mc->ts16, &hwts->hwtstamp);
 761
 762         /* update statistics */
 763         mc->netdev->stats.rx_packets++;
 764         mc->netdev->stats.rx_bytes += cf->len;
 765         /* push the skb */
 766         netif_rx(skb);
 767
 768         return 0;
 769
 770 decode_failed:
 771         dev_kfree_skb(skb);
 772         return -EINVAL;
 773 }
 774
 775 /*
 776  * process incoming message
 777  */
 778 static int pcan_usb_decode_msg(struct peak_usb_device *dev, u8 *ibuf, u32 lbuf)
 779 {
 780         struct pcan_usb_msg_context mc = {
 781                 .rec_cnt = ibuf[1],
 782                 .ptr = ibuf + PCAN_USB_MSG_HEADER_LEN,
 783                 .end = ibuf + lbuf,
 784                 .netdev = dev->netdev,
 785                 .pdev = container_of(dev, struct pcan_usb, dev),
 786         };
 787         int err;
 788
 789         for (err = 0; mc.rec_idx < mc.rec_cnt && !err; mc.rec_idx++) {
 790                 u8 sl = *mc.ptr++;
 791
 792                 /* handle status and error frames here */
 793                 if (sl & PCAN_USB_STATUSLEN_INTERNAL) {
 794                         err = pcan_usb_decode_status(&mc, sl);
 795                 /* handle normal can frames here */
 796                 } else {
 797                         err = pcan_usb_decode_data(&mc, sl);
 798                 }
 799         }
 800
 801         return err;
 802 }
 803
 804 /*
 805  * process any incoming buffer
 806  */
 807 static int pcan_usb_decode_buf(struct peak_usb_device *dev, struct urb *urb)
 808 {
 809         int err = 0;
 810
 811         if (urb->actual_length > PCAN_USB_MSG_HEADER_LEN) {
 812                 err = pcan_usb_decode_msg(dev, urb->transfer_buffer,
 813                         urb->actual_length);
 814
 815         } else if (urb->actual_length > 0) {
 816                 netdev_err(dev->netdev, "usb message length error (%u)\n",
 817                         urb->actual_length);
 818                 err = -EINVAL;
 819         }
 820
 821         return err;
 822 }
 823
 824 /*
 825  * process outgoing packet
 826  */
 827 static int pcan_usb_encode_msg(struct peak_usb_device *dev, struct sk_buff *skb,
 828                                u8 *obuf, size_t *size)
 829 {
 830         struct net_device *netdev = dev->netdev;
 831         struct net_device_stats *stats = &netdev->stats;
 832         struct can_frame *cf = (struct can_frame *)skb->data;
 833         u8 *pc;
 834
 835         obuf[0] = 2;
 836         obuf[1] = 1;
 837
 838         pc = obuf + PCAN_USB_MSG_HEADER_LEN;
 839
 840         /* status/len byte */
 841         *pc = can_get_cc_dlc(cf, dev->can.ctrlmode);
 842
 843         if (cf->can_id & CAN_RTR_FLAG)
 844                 *pc |= PCAN_USB_STATUSLEN_RTR;
 845
 846         /* can id */
 847         if (cf->can_id & CAN_EFF_FLAG) {
 848                 __le32 tmp32 = cpu_to_le32((cf->can_id & CAN_ERR_MASK) << 3);
 849
 850                 *pc |= PCAN_USB_STATUSLEN_EXT_ID;
 851                 memcpy(++pc, &tmp32, 4);
 852                 pc += 4;
 853         } else {
 854                 __le16 tmp16 = cpu_to_le16((cf->can_id & CAN_ERR_MASK) << 5);
 855
 856                 memcpy(++pc, &tmp16, 2);
 857                 pc += 2;
 858         }
 859
 860         /* can data */
 861         if (!(cf->can_id & CAN_RTR_FLAG)) {
 862                 memcpy(pc, cf->data, cf->len);
 863                 pc += cf->len;
 864         }
 865
 866         obuf[(*size)-1] = (u8)(stats->tx_packets & 0xff);
 867
 868         return 0;
 869 }
 870
 871 /* socket callback used to copy berr counters values received through USB */
 872 static int pcan_usb_get_berr_counter(const struct net_device *netdev,
 873                                      struct can_berr_counter *bec)
 874 {
 875         struct peak_usb_device *dev = netdev_priv(netdev);
 876         struct pcan_usb *pdev = container_of(dev, struct pcan_usb, dev);
 877
 878         *bec = pdev->bec;
 879
 880         /* must return 0 */
 881         return 0;
 882 }
 883
 884 /*
 885  * start interface
 886  */
 887 static int pcan_usb_start(struct peak_usb_device *dev)
 888 {
 889         struct pcan_usb *pdev = container_of(dev, struct pcan_usb, dev);
 890         int err;
 891
 892         /* number of bits used in timestamps read from adapter struct */
 893         peak_usb_init_time_ref(&pdev->time_ref, &pcan_usb);
 894
 895         pdev->bec.rxerr = 0;
 896         pdev->bec.txerr = 0;
 897
 898         /* be notified on error counter changes (if requested by user) */
 899         if (dev->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) {
 900                 err = pcan_usb_set_err_frame(dev, PCAN_USB_BERR_MASK);
 901                 if (err)
 902                         netdev_warn(dev->netdev,
 903                                     "Asking for BERR reporting error %u\n",
 904                                     err);
 905         }
 906
 907         /* if revision greater than 3, can put silent mode on/off */
 908         if (dev->device_rev > 3) {
 909                 err = pcan_usb_set_silent(dev,
 910                                 dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY);
 911                 if (err)
 912                         return err;
 913         }
 914
 915         return pcan_usb_set_ext_vcc(dev, 0);
 916 }
 917
 918 static int pcan_usb_init(struct peak_usb_device *dev)
 919 {
 920         struct pcan_usb *pdev = container_of(dev, struct pcan_usb, dev);
 921         u32 serial_number;
 922         int err;
 923
 924         /* initialize a timer needed to wait for hardware restart */
 925         timer_setup(&pdev->restart_timer, pcan_usb_restart, 0);
 926
 927         /*
 928          * explicit use of dev_xxx() instead of netdev_xxx() here:
 929          * information displayed are related to the device itself, not
 930          * to the canx netdevice.
 931          */
 932         err = pcan_usb_get_serial(dev, &serial_number);
 933         if (err) {
 934                 dev_err(dev->netdev->dev.parent,
 935                         "unable to read %s serial number (err %d)\n",
 936                         pcan_usb.name, err);
 937                 return err;
 938         }
 939
 940         dev_info(dev->netdev->dev.parent,
 941                  "PEAK-System %s adapter hwrev %u serial %08X (%u channel)\n",
 942                  pcan_usb.name, dev->device_rev, serial_number,
 943                  pcan_usb.ctrl_count);
 944
 945         return 0;
 946 }
 947
 948 /*
 949  * probe function for new PCAN-USB usb interface
 950  */
 951 static int pcan_usb_probe(struct usb_interface *intf)
 952 {
 953         struct usb_host_interface *if_desc;
 954         int i;
 955
 956         if_desc = intf->altsetting;
 957
 958         /* check interface endpoint addresses */
 959         for (i = 0; i < if_desc->desc.bNumEndpoints; i++) {
 960                 struct usb_endpoint_descriptor *ep = &if_desc->endpoint[i].desc;
 961
 962                 switch (ep->bEndpointAddress) {
 963                 case PCAN_USB_EP_CMDOUT:
 964                 case PCAN_USB_EP_CMDIN:
 965                 case PCAN_USB_EP_MSGOUT:
 966                 case PCAN_USB_EP_MSGIN:
 967                         break;
 968                 default:
 969                         return -ENODEV;
 970                 }
 971         }
 972
 973         return 0;
 974 }
 975
 976 /*
 977  * describe the PCAN-USB adapter
 978  */
 979 static const struct can_bittiming_const pcan_usb_const = {
 980         .name = "pcan_usb",
 981         .tseg1_min = 1,
 982         .tseg1_max = 16,
 983         .tseg2_min = 1,
 984         .tseg2_max = 8,
 985         .sjw_max = 4,
 986         .brp_min = 1,
 987         .brp_max = 64,
 988         .brp_inc = 1,
 989 };
 990
 991 const struct peak_usb_adapter pcan_usb = {
 992         .name = "PCAN-USB",
 993         .device_id = PCAN_USB_PRODUCT_ID,
 994         .ctrl_count = 1,
 995         .ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES | CAN_CTRLMODE_LISTENONLY |
 996                               CAN_CTRLMODE_BERR_REPORTING |
 997                               CAN_CTRLMODE_CC_LEN8_DLC,
 998         .clock = {
 999                 .freq = PCAN_USB_CRYSTAL_HZ / 2 ,
1000         },
1001         .bittiming_const = &pcan_usb_const,
1002
1003         /* size of device private data */
1004         .sizeof_dev_private = sizeof(struct pcan_usb),
1005
1006         /* timestamps usage */
1007         .ts_used_bits = 16,
1008         .ts_period = 24575, /* calibration period in ts. */
1009         .us_per_ts_scale = PCAN_USB_TS_US_PER_TICK, /* us=(ts*scale) */
1010         .us_per_ts_shift = PCAN_USB_TS_DIV_SHIFTER, /*  >> shift     */
1011
1012         /* give here messages in/out endpoints */
1013         .ep_msg_in = PCAN_USB_EP_MSGIN,
1014         .ep_msg_out = {PCAN_USB_EP_MSGOUT},
1015
1016         /* size of rx/tx usb buffers */
1017         .rx_buffer_size = PCAN_USB_RX_BUFFER_SIZE,
1018         .tx_buffer_size = PCAN_USB_TX_BUFFER_SIZE,
1019
1020         /* device callbacks */
1021         .intf_probe = pcan_usb_probe,
1022         .dev_init = pcan_usb_init,
1023         .dev_set_bus = pcan_usb_write_mode,
1024         .dev_set_bittiming = pcan_usb_set_bittiming,
1025         .dev_get_device_id = pcan_usb_get_device_id,
1026         .dev_decode_buf = pcan_usb_decode_buf,
1027         .dev_encode_msg = pcan_usb_encode_msg,
1028         .dev_start = pcan_usb_start,
1029         .dev_restart_async = pcan_usb_restart_async,
1030         .do_get_berr_counter = pcan_usb_get_berr_counter,
1031 };