drivers/net/can/peak_canfd/peak_canfd.c

   1 /*
   2  * Copyright (C) 2007, 2011 Wolfgang Grandegger <wg@grandegger.com>
   3  * Copyright (C) 2012 Stephane Grosjean <s.grosjean@peak-system.com>
   4  *
   5  * Copyright (C) 2016  PEAK System-Technik GmbH
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the version 2 of the GNU General Public License
   9  * as published by the Free Software Foundation
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU General Public License for more details.
  15  */
  16
  17 #include <linux/can.h>
  18 #include <linux/can/dev.h>
  19
  20 #include "peak_canfd_user.h"
  21
  22 /* internal IP core cache size (used as default echo skbs max number) */
  23 #define PCANFD_ECHO_SKB_MAX             24
  24
  25 /* bittiming ranges of the PEAK-System PC CAN-FD interfaces */
  26 static const struct can_bittiming_const peak_canfd_nominal_const = {
  27         .name = "peak_canfd",
  28         .tseg1_min = 1,
  29         .tseg1_max = (1 << PUCAN_TSLOW_TSGEG1_BITS),
  30         .tseg2_min = 1,
  31         .tseg2_max = (1 << PUCAN_TSLOW_TSGEG2_BITS),
  32         .sjw_max = (1 << PUCAN_TSLOW_SJW_BITS),
  33         .brp_min = 1,
  34         .brp_max = (1 << PUCAN_TSLOW_BRP_BITS),
  35         .brp_inc = 1,
  36 };
  37
  38 static const struct can_bittiming_const peak_canfd_data_const = {
  39         .name = "peak_canfd",
  40         .tseg1_min = 1,
  41         .tseg1_max = (1 << PUCAN_TFAST_TSGEG1_BITS),
  42         .tseg2_min = 1,
  43         .tseg2_max = (1 << PUCAN_TFAST_TSGEG2_BITS),
  44         .sjw_max = (1 << PUCAN_TFAST_SJW_BITS),
  45         .brp_min = 1,
  46         .brp_max = (1 << PUCAN_TFAST_BRP_BITS),
  47         .brp_inc = 1,
  48 };
  49
  50 static struct peak_canfd_priv *pucan_init_cmd(struct peak_canfd_priv *priv)
  51 {
  52         priv->cmd_len = 0;
  53         return priv;
  54 }
  55
  56 static void *pucan_add_cmd(struct peak_canfd_priv *priv, int cmd_op)
  57 {
  58         struct pucan_command *cmd;
  59
  60         if (priv->cmd_len + sizeof(*cmd) > priv->cmd_maxlen)
  61                 return NULL;
  62
  63         cmd = priv->cmd_buffer + priv->cmd_len;
  64
  65         /* reset all unused bit to default */
  66         memset(cmd, 0, sizeof(*cmd));
  67
  68         cmd->opcode_channel = pucan_cmd_opcode_channel(priv->index, cmd_op);
  69         priv->cmd_len += sizeof(*cmd);
  70
  71         return cmd;
  72 }
  73
  74 static int pucan_write_cmd(struct peak_canfd_priv *priv)
  75 {
  76         int err;
  77
  78         if (priv->pre_cmd) {
  79                 err = priv->pre_cmd(priv);
  80                 if (err)
  81                         return err;
  82         }
  83
  84         err = priv->write_cmd(priv);
  85         if (err)
  86                 return err;
  87
  88         if (priv->post_cmd)
  89                 err = priv->post_cmd(priv);
  90
  91         return err;
  92 }
  93
  94 /* uCAN commands interface functions */
  95 static int pucan_set_reset_mode(struct peak_canfd_priv *priv)
  96 {
  97         pucan_add_cmd(pucan_init_cmd(priv), PUCAN_CMD_RESET_MODE);
  98         return pucan_write_cmd(priv);
  99 }
 100
 101 static int pucan_set_normal_mode(struct peak_canfd_priv *priv)
 102 {
 103         int err;
 104
 105         pucan_add_cmd(pucan_init_cmd(priv), PUCAN_CMD_NORMAL_MODE);
 106         err = pucan_write_cmd(priv);
 107         if (!err)
 108                 priv->can.state = CAN_STATE_ERROR_ACTIVE;
 109
 110         return err;
 111 }
 112
 113 static int pucan_set_listen_only_mode(struct peak_canfd_priv *priv)
 114 {
 115         int err;
 116
 117         pucan_add_cmd(pucan_init_cmd(priv), PUCAN_CMD_LISTEN_ONLY_MODE);
 118         err = pucan_write_cmd(priv);
 119         if (!err)
 120                 priv->can.state = CAN_STATE_ERROR_ACTIVE;
 121
 122         return err;
 123 }
 124
 125 static int pucan_set_timing_slow(struct peak_canfd_priv *priv,
 126                                  const struct can_bittiming *pbt)
 127 {
 128         struct pucan_timing_slow *cmd;
 129
 130         cmd = pucan_add_cmd(pucan_init_cmd(priv), PUCAN_CMD_TIMING_SLOW);
 131
 132         cmd->sjw_t = PUCAN_TSLOW_SJW_T(pbt->sjw - 1,
 133                                 priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES);
 134         cmd->tseg1 = PUCAN_TSLOW_TSEG1(pbt->prop_seg + pbt->phase_seg1 - 1);
 135         cmd->tseg2 = PUCAN_TSLOW_TSEG2(pbt->phase_seg2 - 1);
 136         cmd->brp = cpu_to_le16(PUCAN_TSLOW_BRP(pbt->brp - 1));
 137
 138         cmd->ewl = 96;  /* default */
 139
 140         netdev_dbg(priv->ndev,
 141                    "nominal: brp=%u tseg1=%u tseg2=%u sjw=%u\n",
 142                    le16_to_cpu(cmd->brp), cmd->tseg1, cmd->tseg2, cmd->sjw_t);
 143
 144         return pucan_write_cmd(priv);
 145 }
 146
 147 static int pucan_set_timing_fast(struct peak_canfd_priv *priv,
 148                                  const struct can_bittiming *pbt)
 149 {
 150         struct pucan_timing_fast *cmd;
 151
 152         cmd = pucan_add_cmd(pucan_init_cmd(priv), PUCAN_CMD_TIMING_FAST);
 153
 154         cmd->sjw = PUCAN_TFAST_SJW(pbt->sjw - 1);
 155         cmd->tseg1 = PUCAN_TFAST_TSEG1(pbt->prop_seg + pbt->phase_seg1 - 1);
 156         cmd->tseg2 = PUCAN_TFAST_TSEG2(pbt->phase_seg2 - 1);
 157         cmd->brp = cpu_to_le16(PUCAN_TFAST_BRP(pbt->brp - 1));
 158
 159         netdev_dbg(priv->ndev,
 160                    "data: brp=%u tseg1=%u tseg2=%u sjw=%u\n",
 161                    le16_to_cpu(cmd->brp), cmd->tseg1, cmd->tseg2, cmd->sjw);
 162
 163         return pucan_write_cmd(priv);
 164 }
 165
 166 static int pucan_set_std_filter(struct peak_canfd_priv *priv, u8 row, u32 mask)
 167 {
 168         struct pucan_std_filter *cmd;
 169
 170         cmd = pucan_add_cmd(pucan_init_cmd(priv), PUCAN_CMD_SET_STD_FILTER);
 171
 172         /* all the 11-bits CAN ID values are represented by one bit in a
 173          * 64 rows array of 32 bits: the upper 6 bits of the CAN ID select the
 174          * row while the lowest 5 bits select the bit in that row.
 175          *
 176          * bit  filter
 177          * 1    passed
 178          * 0    discarded
 179          */
 180
 181         /* select the row */
 182         cmd->idx = row;
 183
 184         /* set/unset bits in the row */
 185         cmd->mask = cpu_to_le32(mask);
 186
 187         return pucan_write_cmd(priv);
 188 }
 189
 190 static int pucan_tx_abort(struct peak_canfd_priv *priv, u16 flags)
 191 {
 192         struct pucan_tx_abort *cmd;
 193
 194         cmd = pucan_add_cmd(pucan_init_cmd(priv), PUCAN_CMD_TX_ABORT);
 195
 196         cmd->flags = cpu_to_le16(flags);
 197
 198         return pucan_write_cmd(priv);
 199 }
 200
 201 static int pucan_clr_err_counters(struct peak_canfd_priv *priv)
 202 {
 203         struct pucan_wr_err_cnt *cmd;
 204
 205         cmd = pucan_add_cmd(pucan_init_cmd(priv), PUCAN_CMD_WR_ERR_CNT);
 206
 207         cmd->sel_mask = cpu_to_le16(PUCAN_WRERRCNT_TE | PUCAN_WRERRCNT_RE);
 208         cmd->tx_counter = 0;
 209         cmd->rx_counter = 0;
 210
 211         return pucan_write_cmd(priv);
 212 }
 213
 214 static int pucan_set_options(struct peak_canfd_priv *priv, u16 opt_mask)
 215 {
 216         struct pucan_options *cmd;
 217
 218         cmd = pucan_add_cmd(pucan_init_cmd(priv), PUCAN_CMD_SET_EN_OPTION);
 219
 220         cmd->options = cpu_to_le16(opt_mask);
 221
 222         return pucan_write_cmd(priv);
 223 }
 224
 225 static int pucan_clr_options(struct peak_canfd_priv *priv, u16 opt_mask)
 226 {
 227         struct pucan_options *cmd;
 228
 229         cmd = pucan_add_cmd(pucan_init_cmd(priv), PUCAN_CMD_CLR_DIS_OPTION);
 230
 231         cmd->options = cpu_to_le16(opt_mask);
 232
 233         return pucan_write_cmd(priv);
 234 }
 235
 236 static int pucan_setup_rx_barrier(struct peak_canfd_priv *priv)
 237 {
 238         pucan_add_cmd(pucan_init_cmd(priv), PUCAN_CMD_RX_BARRIER);
 239
 240         return pucan_write_cmd(priv);
 241 }
 242
 243 /* handle the reception of one CAN frame */
 244 static int pucan_handle_can_rx(struct peak_canfd_priv *priv,
 245                                struct pucan_rx_msg *msg)
 246 {
 247         struct net_device_stats *stats = &priv->ndev->stats;
 248         struct canfd_frame *cf;
 249         struct sk_buff *skb;
 250         const u16 rx_msg_flags = le16_to_cpu(msg->flags);
 251         u8 cf_len;
 252
 253         if (rx_msg_flags & PUCAN_MSG_EXT_DATA_LEN)
 254                 cf_len = can_dlc2len(get_canfd_dlc(pucan_msg_get_dlc(msg)));
 255         else
 256                 cf_len = get_can_dlc(pucan_msg_get_dlc(msg));
 257
 258         /* if this frame is an echo, */
 259         if (rx_msg_flags & PUCAN_MSG_LOOPED_BACK) {
 260                 unsigned long flags;
 261
 262                 spin_lock_irqsave(&priv->echo_lock, flags);
 263                 can_get_echo_skb(priv->ndev, msg->client);
 264
 265                 /* count bytes of the echo instead of skb */
 266                 stats->tx_bytes += cf_len;
 267                 stats->tx_packets++;
 268
 269                 /* restart tx queue (a slot is free) */
 270                 netif_wake_queue(priv->ndev);
 271
 272                 spin_unlock_irqrestore(&priv->echo_lock, flags);
 273
 274                 /* if this frame is only an echo, stop here. Otherwise,
 275                  * continue to push this application self-received frame into
 276                  * its own rx queue.
 277                  */
 278                 if (!(rx_msg_flags & PUCAN_MSG_SELF_RECEIVE))
 279                         return 0;
 280         }
 281
 282         /* otherwise, it should be pushed into rx fifo */
 283         if (rx_msg_flags & PUCAN_MSG_EXT_DATA_LEN) {
 284                 /* CANFD frame case */
 285                 skb = alloc_canfd_skb(priv->ndev, &cf);
 286                 if (!skb)
 287                         return -ENOMEM;
 288
 289                 if (rx_msg_flags & PUCAN_MSG_BITRATE_SWITCH)
 290                         cf->flags |= CANFD_BRS;
 291
 292                 if (rx_msg_flags & PUCAN_MSG_ERROR_STATE_IND)
 293                         cf->flags |= CANFD_ESI;
 294         } else {
 295                 /* CAN 2.0 frame case */
 296                 skb = alloc_can_skb(priv->ndev, (struct can_frame **)&cf);
 297                 if (!skb)
 298                         return -ENOMEM;
 299         }
 300
 301         cf->can_id = le32_to_cpu(msg->can_id);
 302         cf->len = cf_len;
 303
 304         if (rx_msg_flags & PUCAN_MSG_EXT_ID)
 305                 cf->can_id |= CAN_EFF_FLAG;
 306
 307         if (rx_msg_flags & PUCAN_MSG_RTR)
 308                 cf->can_id |= CAN_RTR_FLAG;
 309         else
 310                 memcpy(cf->data, msg->d, cf->len);
 311
 312         stats->rx_bytes += cf->len;
 313         stats->rx_packets++;
 314
 315         netif_rx(skb);
 316
 317         return 0;
 318 }
 319
 320 /* handle rx/tx error counters notification */
 321 static int pucan_handle_error(struct peak_canfd_priv *priv,
 322                               struct pucan_error_msg *msg)
 323 {
 324         priv->bec.txerr = msg->tx_err_cnt;
 325         priv->bec.rxerr = msg->rx_err_cnt;
 326
 327         return 0;
 328 }
 329
 330 /* handle status notification */
 331 static int pucan_handle_status(struct peak_canfd_priv *priv,
 332                                struct pucan_status_msg *msg)
 333 {
 334         struct net_device *ndev = priv->ndev;
 335         struct net_device_stats *stats = &ndev->stats;
 336         struct can_frame *cf;
 337         struct sk_buff *skb;
 338
 339         /* this STATUS is the CNF of the RX_BARRIER: Tx path can be setup */
 340         if (pucan_status_is_rx_barrier(msg)) {
 341
 342                 if (priv->enable_tx_path) {
 343                         int err = priv->enable_tx_path(priv);
 344
 345                         if (err)
 346                                 return err;
 347                 }
 348
 349                 /* wake network queue up (echo_skb array is empty) */
 350                 netif_wake_queue(ndev);
 351
 352                 return 0;
 353         }
 354
 355         skb = alloc_can_err_skb(ndev, &cf);
 356
 357         /* test state error bits according to their priority */
 358         if (pucan_status_is_busoff(msg)) {
 359                 netdev_dbg(ndev, "Bus-off entry status\n");
 360                 priv->can.state = CAN_STATE_BUS_OFF;
 361                 priv->can.can_stats.bus_off++;
 362                 can_bus_off(ndev);
 363                 if (skb)
 364                         cf->can_id |= CAN_ERR_BUSOFF;
 365
 366         } else if (pucan_status_is_passive(msg)) {
 367                 netdev_dbg(ndev, "Error passive status\n");
 368                 priv->can.state = CAN_STATE_ERROR_PASSIVE;
 369                 priv->can.can_stats.error_passive++;
 370                 if (skb) {
 371                         cf->can_id |= CAN_ERR_CRTL;
 372                         cf->data[1] = (priv->bec.txerr > priv->bec.rxerr) ?
 373                                         CAN_ERR_CRTL_TX_PASSIVE :
 374                                         CAN_ERR_CRTL_RX_PASSIVE;
 375                         cf->data[6] = priv->bec.txerr;
 376                         cf->data[7] = priv->bec.rxerr;
 377                 }
 378
 379         } else if (pucan_status_is_warning(msg)) {
 380                 netdev_dbg(ndev, "Error warning status\n");
 381                 priv->can.state = CAN_STATE_ERROR_WARNING;
 382                 priv->can.can_stats.error_warning++;
 383                 if (skb) {
 384                         cf->can_id |= CAN_ERR_CRTL;
 385                         cf->data[1] = (priv->bec.txerr > priv->bec.rxerr) ?
 386                                         CAN_ERR_CRTL_TX_WARNING :
 387                                         CAN_ERR_CRTL_RX_WARNING;
 388                         cf->data[6] = priv->bec.txerr;
 389                         cf->data[7] = priv->bec.rxerr;
 390                 }
 391
 392         } else if (priv->can.state != CAN_STATE_ERROR_ACTIVE) {
 393                 /* back to ERROR_ACTIVE */
 394                 netdev_dbg(ndev, "Error active status\n");
 395                 can_change_state(ndev, cf, CAN_STATE_ERROR_ACTIVE,
 396                                  CAN_STATE_ERROR_ACTIVE);
 397         } else {
 398                 dev_kfree_skb(skb);
 399                 return 0;
 400         }
 401
 402         if (!skb) {
 403                 stats->rx_dropped++;
 404                 return -ENOMEM;
 405         }
 406
 407         stats->rx_packets++;
 408         stats->rx_bytes += cf->can_dlc;
 409         netif_rx(skb);
 410
 411         return 0;
 412 }
 413
 414 /* handle uCAN Rx overflow notification */
 415 static int pucan_handle_cache_critical(struct peak_canfd_priv *priv)
 416 {
 417         struct net_device_stats *stats = &priv->ndev->stats;
 418         struct can_frame *cf;
 419         struct sk_buff *skb;
 420
 421         stats->rx_over_errors++;
 422         stats->rx_errors++;
 423
 424         skb = alloc_can_err_skb(priv->ndev, &cf);
 425         if (!skb) {
 426                 stats->rx_dropped++;
 427                 return -ENOMEM;
 428         }
 429
 430         cf->can_id |= CAN_ERR_CRTL;
 431         cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 432
 433         cf->data[6] = priv->bec.txerr;
 434         cf->data[7] = priv->bec.rxerr;
 435
 436         stats->rx_bytes += cf->can_dlc;
 437         stats->rx_packets++;
 438         netif_rx(skb);
 439
 440         return 0;
 441 }
 442
 443 /* handle a single uCAN message */
 444 int peak_canfd_handle_msg(struct peak_canfd_priv *priv,
 445                           struct pucan_rx_msg *msg)
 446 {
 447         u16 msg_type = le16_to_cpu(msg->type);
 448         int msg_size = le16_to_cpu(msg->size);
 449         int err;
 450
 451         if (!msg_size || !msg_type) {
 452                 /* null packet found: end of list */
 453                 goto exit;
 454         }
 455
 456         switch (msg_type) {
 457         case PUCAN_MSG_CAN_RX:
 458                 err = pucan_handle_can_rx(priv, (struct pucan_rx_msg *)msg);
 459                 break;
 460         case PUCAN_MSG_ERROR:
 461                 err = pucan_handle_error(priv, (struct pucan_error_msg *)msg);
 462                 break;
 463         case PUCAN_MSG_STATUS:
 464                 err = pucan_handle_status(priv, (struct pucan_status_msg *)msg);
 465                 break;
 466         case PUCAN_MSG_CACHE_CRITICAL:
 467                 err = pucan_handle_cache_critical(priv);
 468                 break;
 469         default:
 470                 err = 0;
 471         }
 472
 473         if (err < 0)
 474                 return err;
 475
 476 exit:
 477         return msg_size;
 478 }
 479
 480 /* handle a list of rx_count messages from rx_msg memory address */
 481 int peak_canfd_handle_msgs_list(struct peak_canfd_priv *priv,
 482                                 struct pucan_rx_msg *msg_list, int msg_count)
 483 {
 484         void *msg_ptr = msg_list;
 485         int i, msg_size = 0;
 486
 487         for (i = 0; i < msg_count; i++) {
 488                 msg_size = peak_canfd_handle_msg(priv, msg_ptr);
 489
 490                 /* a null packet can be found at the end of a list */
 491                 if (msg_size <= 0)
 492                         break;
 493
 494                 msg_ptr += ALIGN(msg_size, 4);
 495         }
 496
 497         if (msg_size < 0)
 498                 return msg_size;
 499
 500         return i;
 501 }
 502
 503 static int peak_canfd_start(struct peak_canfd_priv *priv)
 504 {
 505         int err;
 506
 507         err = pucan_clr_err_counters(priv);
 508         if (err)
 509                 goto err_exit;
 510
 511         priv->echo_idx = 0;
 512
 513         priv->bec.txerr = 0;
 514         priv->bec.rxerr = 0;
 515
 516         if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
 517                 err = pucan_set_listen_only_mode(priv);
 518         else
 519                 err = pucan_set_normal_mode(priv);
 520
 521 err_exit:
 522         return err;
 523 }
 524
 525 static void peak_canfd_stop(struct peak_canfd_priv *priv)
 526 {
 527         int err;
 528
 529         /* go back to RESET mode */
 530         err = pucan_set_reset_mode(priv);
 531         if (err) {
 532                 netdev_err(priv->ndev, "channel %u reset failed\n",
 533                            priv->index);
 534         } else {
 535                 /* abort last Tx (MUST be done in RESET mode only!) */
 536                 pucan_tx_abort(priv, PUCAN_TX_ABORT_FLUSH);
 537         }
 538 }
 539
 540 static int peak_canfd_set_mode(struct net_device *ndev, enum can_mode mode)
 541 {
 542         struct peak_canfd_priv *priv = netdev_priv(ndev);
 543
 544         switch (mode) {
 545         case CAN_MODE_START:
 546                 peak_canfd_start(priv);
 547                 netif_wake_queue(ndev);
 548                 break;
 549         default:
 550                 return -EOPNOTSUPP;
 551         }
 552
 553         return 0;
 554 }
 555
 556 static int peak_canfd_get_berr_counter(const struct net_device *ndev,
 557                                        struct can_berr_counter *bec)
 558 {
 559         struct peak_canfd_priv *priv = netdev_priv(ndev);
 560
 561         *bec = priv->bec;
 562         return 0;
 563 }
 564
 565 static int peak_canfd_open(struct net_device *ndev)
 566 {
 567         struct peak_canfd_priv *priv = netdev_priv(ndev);
 568         int i, err = 0;
 569
 570         err = open_candev(ndev);
 571         if (err) {
 572                 netdev_err(ndev, "open_candev() failed, error %d\n", err);
 573                 goto err_exit;
 574         }
 575
 576         err = pucan_set_reset_mode(priv);
 577         if (err)
 578                 goto err_close;
 579
 580         if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
 581                 if (priv->can.ctrlmode & CAN_CTRLMODE_FD_NON_ISO)
 582                         err = pucan_clr_options(priv, PUCAN_OPTION_CANDFDISO);
 583                 else
 584                         err = pucan_set_options(priv, PUCAN_OPTION_CANDFDISO);
 585
 586                 if (err)
 587                         goto err_close;
 588         }
 589
 590         /* set option: get rx/tx error counters */
 591         err = pucan_set_options(priv, PUCAN_OPTION_ERROR);
 592         if (err)
 593                 goto err_close;
 594
 595         /* accept all standard CAN ID */
 596         for (i = 0; i <= PUCAN_FLTSTD_ROW_IDX_MAX; i++)
 597                 pucan_set_std_filter(priv, i, 0xffffffff);
 598
 599         err = peak_canfd_start(priv);
 600         if (err)
 601                 goto err_close;
 602
 603         /* receiving the RB status says when Tx path is ready */
 604         err = pucan_setup_rx_barrier(priv);
 605         if (!err)
 606                 goto err_exit;
 607
 608 err_close:
 609         close_candev(ndev);
 610 err_exit:
 611         return err;
 612 }
 613
 614 static int peak_canfd_set_bittiming(struct net_device *ndev)
 615 {
 616         struct peak_canfd_priv *priv = netdev_priv(ndev);
 617
 618         return pucan_set_timing_slow(priv, &priv->can.bittiming);
 619 }
 620
 621 static int peak_canfd_set_data_bittiming(struct net_device *ndev)
 622 {
 623         struct peak_canfd_priv *priv = netdev_priv(ndev);
 624
 625         return pucan_set_timing_fast(priv, &priv->can.data_bittiming);
 626 }
 627
 628 static int peak_canfd_close(struct net_device *ndev)
 629 {
 630         struct peak_canfd_priv *priv = netdev_priv(ndev);
 631
 632         netif_stop_queue(ndev);
 633         peak_canfd_stop(priv);
 634         close_candev(ndev);
 635
 636         return 0;
 637 }
 638
 639 static netdev_tx_t peak_canfd_start_xmit(struct sk_buff *skb,
 640                                          struct net_device *ndev)
 641 {
 642         struct peak_canfd_priv *priv = netdev_priv(ndev);
 643         struct net_device_stats *stats = &ndev->stats;
 644         struct canfd_frame *cf = (struct canfd_frame *)skb->data;
 645         struct pucan_tx_msg *msg;
 646         u16 msg_size, msg_flags;
 647         unsigned long flags;
 648         bool should_stop_tx_queue;
 649         int room_left;
 650         u8 can_dlc;
 651
 652         if (can_dropped_invalid_skb(ndev, skb))
 653                 return NETDEV_TX_OK;
 654
 655         msg_size = ALIGN(sizeof(*msg) + cf->len, 4);
 656         msg = priv->alloc_tx_msg(priv, msg_size, &room_left);
 657
 658         /* should never happen except under bus-off condition and (auto-)restart
 659          * mechanism
 660          */
 661         if (!msg) {
 662                 stats->tx_dropped++;
 663                 netif_stop_queue(ndev);
 664                 return NETDEV_TX_BUSY;
 665         }
 666
 667         msg->size = cpu_to_le16(msg_size);
 668         msg->type = cpu_to_le16(PUCAN_MSG_CAN_TX);
 669         msg_flags = 0;
 670
 671         if (cf->can_id & CAN_EFF_FLAG) {
 672                 msg_flags |= PUCAN_MSG_EXT_ID;
 673                 msg->can_id = cpu_to_le32(cf->can_id & CAN_EFF_MASK);
 674         } else {
 675                 msg->can_id = cpu_to_le32(cf->can_id & CAN_SFF_MASK);
 676         }
 677
 678         if (can_is_canfd_skb(skb)) {
 679                 /* CAN FD frame format */
 680                 can_dlc = can_len2dlc(cf->len);
 681
 682                 msg_flags |= PUCAN_MSG_EXT_DATA_LEN;
 683
 684                 if (cf->flags & CANFD_BRS)
 685                         msg_flags |= PUCAN_MSG_BITRATE_SWITCH;
 686
 687                 if (cf->flags & CANFD_ESI)
 688                         msg_flags |= PUCAN_MSG_ERROR_STATE_IND;
 689         } else {
 690                 /* CAN 2.0 frame format */
 691                 can_dlc = cf->len;
 692
 693                 if (cf->can_id & CAN_RTR_FLAG)
 694                         msg_flags |= PUCAN_MSG_RTR;
 695         }
 696
 697         /* always ask loopback for echo management */
 698         msg_flags |= PUCAN_MSG_LOOPED_BACK;
 699
 700         /* set driver specific bit to differentiate with application loopback */
 701         if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
 702                 msg_flags |= PUCAN_MSG_SELF_RECEIVE;
 703
 704         msg->flags = cpu_to_le16(msg_flags);
 705         msg->channel_dlc = PUCAN_MSG_CHANNEL_DLC(priv->index, can_dlc);
 706         memcpy(msg->d, cf->data, cf->len);
 707
 708         /* struct msg client field is used as an index in the echo skbs ring */
 709         msg->client = priv->echo_idx;
 710
 711         spin_lock_irqsave(&priv->echo_lock, flags);
 712
 713         /* prepare and save echo skb in internal slot */
 714         can_put_echo_skb(skb, ndev, priv->echo_idx);
 715
 716         /* move echo index to the next slot */
 717         priv->echo_idx = (priv->echo_idx + 1) % priv->can.echo_skb_max;
 718
 719         /* if next slot is not free, stop network queue (no slot free in echo
 720          * skb ring means that the controller did not write these frames on
 721          * the bus: no need to continue).
 722          */
 723         should_stop_tx_queue = !!(priv->can.echo_skb[priv->echo_idx]);
 724
 725         /* stop network tx queue if not enough room to save one more msg too */
 726         if (priv->can.ctrlmode & CAN_CTRLMODE_FD)
 727                 should_stop_tx_queue |= (room_left <
 728                                         (sizeof(*msg) + CANFD_MAX_DLEN));
 729         else
 730                 should_stop_tx_queue |= (room_left <
 731                                         (sizeof(*msg) + CAN_MAX_DLEN));
 732
 733         if (should_stop_tx_queue)
 734                 netif_stop_queue(ndev);
 735
 736         spin_unlock_irqrestore(&priv->echo_lock, flags);
 737
 738         /* write the skb on the interface */
 739         priv->write_tx_msg(priv, msg);
 740
 741         return NETDEV_TX_OK;
 742 }
 743
 744 static const struct net_device_ops peak_canfd_netdev_ops = {
 745         .ndo_open = peak_canfd_open,
 746         .ndo_stop = peak_canfd_close,
 747         .ndo_start_xmit = peak_canfd_start_xmit,
 748         .ndo_change_mtu = can_change_mtu,
 749 };
 750
 751 struct net_device *alloc_peak_canfd_dev(int sizeof_priv, int index,
 752                                         int echo_skb_max)
 753 {
 754         struct net_device *ndev;
 755         struct peak_canfd_priv *priv;
 756
 757         /* we DO support local echo */
 758         if (echo_skb_max < 0)
 759                 echo_skb_max = PCANFD_ECHO_SKB_MAX;
 760
 761         /* allocate the candev object */
 762         ndev = alloc_candev(sizeof_priv, echo_skb_max);
 763         if (!ndev)
 764                 return NULL;
 765
 766         priv = netdev_priv(ndev);
 767
 768         /* complete now socket-can initialization side */
 769         priv->can.state = CAN_STATE_STOPPED;
 770         priv->can.bittiming_const = &peak_canfd_nominal_const;
 771         priv->can.data_bittiming_const = &peak_canfd_data_const;
 772
 773         priv->can.do_set_mode = peak_canfd_set_mode;
 774         priv->can.do_get_berr_counter = peak_canfd_get_berr_counter;
 775         priv->can.do_set_bittiming = peak_canfd_set_bittiming;
 776         priv->can.do_set_data_bittiming = peak_canfd_set_data_bittiming;
 777         priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
 778                                        CAN_CTRLMODE_LISTENONLY |
 779                                        CAN_CTRLMODE_3_SAMPLES |
 780                                        CAN_CTRLMODE_FD |
 781                                        CAN_CTRLMODE_FD_NON_ISO |
 782                                        CAN_CTRLMODE_BERR_REPORTING;
 783
 784         priv->ndev = ndev;
 785         priv->index = index;
 786         priv->cmd_len = 0;
 787         spin_lock_init(&priv->echo_lock);
 788
 789         ndev->flags |= IFF_ECHO;
 790         ndev->netdev_ops = &peak_canfd_netdev_ops;
 791         ndev->dev_id = index;
 792
 793         return ndev;
 794 }