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             !(rx_msg_flags & PUCAN_MSG_SELF_RECEIVE)) {
 261                 unsigned long flags;
 262
 263                 spin_lock_irqsave(&priv->echo_lock, flags);
 264                 can_get_echo_skb(priv->ndev, msg->client);
 265
 266                 /* count bytes of the echo instead of skb */
 267                 stats->tx_bytes += cf_len;
 268                 stats->tx_packets++;
 269
 270                 /* restart tx queue (a slot is free) */
 271                 netif_wake_queue(priv->ndev);
 272
 273                 spin_unlock_irqrestore(&priv->echo_lock, flags);
 274                 return 0;
 275         }
 276
 277         /* otherwise, it should be pushed into rx fifo */
 278         if (rx_msg_flags & PUCAN_MSG_EXT_DATA_LEN) {
 279                 /* CANFD frame case */
 280                 skb = alloc_canfd_skb(priv->ndev, &cf);
 281                 if (!skb)
 282                         return -ENOMEM;
 283
 284                 if (rx_msg_flags & PUCAN_MSG_BITRATE_SWITCH)
 285                         cf->flags |= CANFD_BRS;
 286
 287                 if (rx_msg_flags & PUCAN_MSG_ERROR_STATE_IND)
 288                         cf->flags |= CANFD_ESI;
 289         } else {
 290                 /* CAN 2.0 frame case */
 291                 skb = alloc_can_skb(priv->ndev, (struct can_frame **)&cf);
 292                 if (!skb)
 293                         return -ENOMEM;
 294         }
 295
 296         cf->can_id = le32_to_cpu(msg->can_id);
 297         cf->len = cf_len;
 298
 299         if (rx_msg_flags & PUCAN_MSG_EXT_ID)
 300                 cf->can_id |= CAN_EFF_FLAG;
 301
 302         if (rx_msg_flags & PUCAN_MSG_RTR)
 303                 cf->can_id |= CAN_RTR_FLAG;
 304         else
 305                 memcpy(cf->data, msg->d, cf->len);
 306
 307         stats->rx_bytes += cf->len;
 308         stats->rx_packets++;
 309
 310         netif_rx(skb);
 311
 312         return 0;
 313 }
 314
 315 /* handle rx/tx error counters notification */
 316 static int pucan_handle_error(struct peak_canfd_priv *priv,
 317                               struct pucan_error_msg *msg)
 318 {
 319         priv->bec.txerr = msg->tx_err_cnt;
 320         priv->bec.rxerr = msg->rx_err_cnt;
 321
 322         return 0;
 323 }
 324
 325 /* handle status notification */
 326 static int pucan_handle_status(struct peak_canfd_priv *priv,
 327                                struct pucan_status_msg *msg)
 328 {
 329         struct net_device *ndev = priv->ndev;
 330         struct net_device_stats *stats = &ndev->stats;
 331         struct can_frame *cf;
 332         struct sk_buff *skb;
 333
 334         /* this STATUS is the CNF of the RX_BARRIER: Tx path can be setup */
 335         if (pucan_status_is_rx_barrier(msg)) {
 336
 337                 if (priv->enable_tx_path) {
 338                         int err = priv->enable_tx_path(priv);
 339
 340                         if (err)
 341                                 return err;
 342                 }
 343
 344                 /* start network queue (echo_skb array is empty) */
 345                 netif_start_queue(ndev);
 346
 347                 return 0;
 348         }
 349
 350         skb = alloc_can_err_skb(ndev, &cf);
 351
 352         /* test state error bits according to their priority */
 353         if (pucan_status_is_busoff(msg)) {
 354                 netdev_dbg(ndev, "Bus-off entry status\n");
 355                 priv->can.state = CAN_STATE_BUS_OFF;
 356                 priv->can.can_stats.bus_off++;
 357                 can_bus_off(ndev);
 358                 if (skb)
 359                         cf->can_id |= CAN_ERR_BUSOFF;
 360
 361         } else if (pucan_status_is_passive(msg)) {
 362                 netdev_dbg(ndev, "Error passive status\n");
 363                 priv->can.state = CAN_STATE_ERROR_PASSIVE;
 364                 priv->can.can_stats.error_passive++;
 365                 if (skb) {
 366                         cf->can_id |= CAN_ERR_CRTL;
 367                         cf->data[1] = (priv->bec.txerr > priv->bec.rxerr) ?
 368                                         CAN_ERR_CRTL_TX_PASSIVE :
 369                                         CAN_ERR_CRTL_RX_PASSIVE;
 370                         cf->data[6] = priv->bec.txerr;
 371                         cf->data[7] = priv->bec.rxerr;
 372                 }
 373
 374         } else if (pucan_status_is_warning(msg)) {
 375                 netdev_dbg(ndev, "Error warning status\n");
 376                 priv->can.state = CAN_STATE_ERROR_WARNING;
 377                 priv->can.can_stats.error_warning++;
 378                 if (skb) {
 379                         cf->can_id |= CAN_ERR_CRTL;
 380                         cf->data[1] = (priv->bec.txerr > priv->bec.rxerr) ?
 381                                         CAN_ERR_CRTL_TX_WARNING :
 382                                         CAN_ERR_CRTL_RX_WARNING;
 383                         cf->data[6] = priv->bec.txerr;
 384                         cf->data[7] = priv->bec.rxerr;
 385                 }
 386
 387         } else if (priv->can.state != CAN_STATE_ERROR_ACTIVE) {
 388                 /* back to ERROR_ACTIVE */
 389                 netdev_dbg(ndev, "Error active status\n");
 390                 can_change_state(ndev, cf, CAN_STATE_ERROR_ACTIVE,
 391                                  CAN_STATE_ERROR_ACTIVE);
 392         } else {
 393                 dev_kfree_skb(skb);
 394                 return 0;
 395         }
 396
 397         if (!skb) {
 398                 stats->rx_dropped++;
 399                 return -ENOMEM;
 400         }
 401
 402         stats->rx_packets++;
 403         stats->rx_bytes += cf->can_dlc;
 404         netif_rx(skb);
 405
 406         return 0;
 407 }
 408
 409 /* handle uCAN Rx overflow notification */
 410 static int pucan_handle_cache_critical(struct peak_canfd_priv *priv)
 411 {
 412         struct net_device_stats *stats = &priv->ndev->stats;
 413         struct can_frame *cf;
 414         struct sk_buff *skb;
 415
 416         stats->rx_over_errors++;
 417         stats->rx_errors++;
 418
 419         skb = alloc_can_err_skb(priv->ndev, &cf);
 420         if (!skb) {
 421                 stats->rx_dropped++;
 422                 return -ENOMEM;
 423         }
 424
 425         cf->can_id |= CAN_ERR_CRTL;
 426         cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 427
 428         cf->data[6] = priv->bec.txerr;
 429         cf->data[7] = priv->bec.rxerr;
 430
 431         stats->rx_bytes += cf->can_dlc;
 432         stats->rx_packets++;
 433         netif_rx(skb);
 434
 435         return 0;
 436 }
 437
 438 /* handle a single uCAN message */
 439 int peak_canfd_handle_msg(struct peak_canfd_priv *priv,
 440                           struct pucan_rx_msg *msg)
 441 {
 442         u16 msg_type = le16_to_cpu(msg->type);
 443         int msg_size = le16_to_cpu(msg->size);
 444         int err;
 445
 446         if (!msg_size || !msg_type) {
 447                 /* null packet found: end of list */
 448                 goto exit;
 449         }
 450
 451         switch (msg_type) {
 452         case PUCAN_MSG_CAN_RX:
 453                 err = pucan_handle_can_rx(priv, (struct pucan_rx_msg *)msg);
 454                 break;
 455         case PUCAN_MSG_ERROR:
 456                 err = pucan_handle_error(priv, (struct pucan_error_msg *)msg);
 457                 break;
 458         case PUCAN_MSG_STATUS:
 459                 err = pucan_handle_status(priv, (struct pucan_status_msg *)msg);
 460                 break;
 461         case PUCAN_MSG_CACHE_CRITICAL:
 462                 err = pucan_handle_cache_critical(priv);
 463                 break;
 464         default:
 465                 err = 0;
 466         }
 467
 468         if (err < 0)
 469                 return err;
 470
 471 exit:
 472         return msg_size;
 473 }
 474
 475 /* handle a list of rx_count messages from rx_msg memory address */
 476 int peak_canfd_handle_msgs_list(struct peak_canfd_priv *priv,
 477                                 struct pucan_rx_msg *msg_list, int msg_count)
 478 {
 479         void *msg_ptr = msg_list;
 480         int i, msg_size = 0;
 481
 482         for (i = 0; i < msg_count; i++) {
 483                 msg_size = peak_canfd_handle_msg(priv, msg_ptr);
 484
 485                 /* a null packet can be found at the end of a list */
 486                 if (msg_size <= 0)
 487                         break;
 488
 489                 msg_ptr += ALIGN(msg_size, 4);
 490         }
 491
 492         if (msg_size < 0)
 493                 return msg_size;
 494
 495         return i;
 496 }
 497
 498 static int peak_canfd_start(struct peak_canfd_priv *priv)
 499 {
 500         int err;
 501
 502         err = pucan_clr_err_counters(priv);
 503         if (err)
 504                 goto err_exit;
 505
 506         priv->echo_idx = 0;
 507
 508         priv->bec.txerr = 0;
 509         priv->bec.rxerr = 0;
 510
 511         if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
 512                 err = pucan_set_listen_only_mode(priv);
 513         else
 514                 err = pucan_set_normal_mode(priv);
 515
 516 err_exit:
 517         return err;
 518 }
 519
 520 static void peak_canfd_stop(struct peak_canfd_priv *priv)
 521 {
 522         int err;
 523
 524         /* go back to RESET mode */
 525         err = pucan_set_reset_mode(priv);
 526         if (err) {
 527                 netdev_err(priv->ndev, "channel %u reset failed\n",
 528                            priv->index);
 529         } else {
 530                 /* abort last Tx (MUST be done in RESET mode only!) */
 531                 pucan_tx_abort(priv, PUCAN_TX_ABORT_FLUSH);
 532         }
 533 }
 534
 535 static int peak_canfd_set_mode(struct net_device *ndev, enum can_mode mode)
 536 {
 537         struct peak_canfd_priv *priv = netdev_priv(ndev);
 538
 539         switch (mode) {
 540         case CAN_MODE_START:
 541                 peak_canfd_start(priv);
 542                 netif_wake_queue(ndev);
 543                 break;
 544         default:
 545                 return -EOPNOTSUPP;
 546         }
 547
 548         return 0;
 549 }
 550
 551 static int peak_canfd_get_berr_counter(const struct net_device *ndev,
 552                                        struct can_berr_counter *bec)
 553 {
 554         struct peak_canfd_priv *priv = netdev_priv(ndev);
 555
 556         *bec = priv->bec;
 557         return 0;
 558 }
 559
 560 static int peak_canfd_open(struct net_device *ndev)
 561 {
 562         struct peak_canfd_priv *priv = netdev_priv(ndev);
 563         int i, err = 0;
 564
 565         err = open_candev(ndev);
 566         if (err) {
 567                 netdev_err(ndev, "open_candev() failed, error %d\n", err);
 568                 goto err_exit;
 569         }
 570
 571         err = pucan_set_reset_mode(priv);
 572         if (err)
 573                 goto err_close;
 574
 575         if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
 576                 if (priv->can.ctrlmode & CAN_CTRLMODE_FD_NON_ISO)
 577                         err = pucan_clr_options(priv, PUCAN_OPTION_CANDFDISO);
 578                 else
 579                         err = pucan_set_options(priv, PUCAN_OPTION_CANDFDISO);
 580
 581                 if (err)
 582                         goto err_close;
 583         }
 584
 585         /* set option: get rx/tx error counters */
 586         err = pucan_set_options(priv, PUCAN_OPTION_ERROR);
 587         if (err)
 588                 goto err_close;
 589
 590         /* accept all standard CAN ID */
 591         for (i = 0; i <= PUCAN_FLTSTD_ROW_IDX_MAX; i++)
 592                 pucan_set_std_filter(priv, i, 0xffffffff);
 593
 594         err = peak_canfd_start(priv);
 595         if (err)
 596                 goto err_close;
 597
 598         /* receiving the RB status says when Tx path is ready */
 599         err = pucan_setup_rx_barrier(priv);
 600         if (!err)
 601                 goto err_exit;
 602
 603 err_close:
 604         close_candev(ndev);
 605 err_exit:
 606         return err;
 607 }
 608
 609 static int peak_canfd_set_bittiming(struct net_device *ndev)
 610 {
 611         struct peak_canfd_priv *priv = netdev_priv(ndev);
 612
 613         return pucan_set_timing_slow(priv, &priv->can.bittiming);
 614 }
 615
 616 static int peak_canfd_set_data_bittiming(struct net_device *ndev)
 617 {
 618         struct peak_canfd_priv *priv = netdev_priv(ndev);
 619
 620         return pucan_set_timing_fast(priv, &priv->can.data_bittiming);
 621 }
 622
 623 static int peak_canfd_close(struct net_device *ndev)
 624 {
 625         struct peak_canfd_priv *priv = netdev_priv(ndev);
 626
 627         netif_stop_queue(ndev);
 628         peak_canfd_stop(priv);
 629         close_candev(ndev);
 630
 631         return 0;
 632 }
 633
 634 static netdev_tx_t peak_canfd_start_xmit(struct sk_buff *skb,
 635                                          struct net_device *ndev)
 636 {
 637         struct peak_canfd_priv *priv = netdev_priv(ndev);
 638         struct net_device_stats *stats = &ndev->stats;
 639         struct canfd_frame *cf = (struct canfd_frame *)skb->data;
 640         struct pucan_tx_msg *msg;
 641         u16 msg_size, msg_flags;
 642         unsigned long flags;
 643         bool should_stop_tx_queue;
 644         int room_left;
 645         u8 can_dlc;
 646
 647         if (can_dropped_invalid_skb(ndev, skb))
 648                 return NETDEV_TX_OK;
 649
 650         msg_size = ALIGN(sizeof(*msg) + cf->len, 4);
 651         msg = priv->alloc_tx_msg(priv, msg_size, &room_left);
 652
 653         /* should never happen except under bus-off condition and (auto-)restart
 654          * mechanism
 655          */
 656         if (!msg) {
 657                 stats->tx_dropped++;
 658                 netif_stop_queue(ndev);
 659                 return NETDEV_TX_BUSY;
 660         }
 661
 662         msg->size = cpu_to_le16(msg_size);
 663         msg->type = cpu_to_le16(PUCAN_MSG_CAN_TX);
 664         msg_flags = 0;
 665
 666         if (cf->can_id & CAN_EFF_FLAG) {
 667                 msg_flags |= PUCAN_MSG_EXT_ID;
 668                 msg->can_id = cpu_to_le32(cf->can_id & CAN_EFF_MASK);
 669         } else {
 670                 msg->can_id = cpu_to_le32(cf->can_id & CAN_SFF_MASK);
 671         }
 672
 673         if (can_is_canfd_skb(skb)) {
 674                 /* CAN FD frame format */
 675                 can_dlc = can_len2dlc(cf->len);
 676
 677                 msg_flags |= PUCAN_MSG_EXT_DATA_LEN;
 678
 679                 if (cf->flags & CANFD_BRS)
 680                         msg_flags |= PUCAN_MSG_BITRATE_SWITCH;
 681
 682                 if (cf->flags & CANFD_ESI)
 683                         msg_flags |= PUCAN_MSG_ERROR_STATE_IND;
 684         } else {
 685                 /* CAN 2.0 frame format */
 686                 can_dlc = cf->len;
 687
 688                 if (cf->can_id & CAN_RTR_FLAG)
 689                         msg_flags |= PUCAN_MSG_RTR;
 690         }
 691
 692         /* always ask loopback for echo management */
 693         msg_flags |= PUCAN_MSG_LOOPED_BACK;
 694
 695         /* set driver specific bit to differentiate with application loopback */
 696         if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
 697                 msg_flags |= PUCAN_MSG_SELF_RECEIVE;
 698
 699         msg->flags = cpu_to_le16(msg_flags);
 700         msg->channel_dlc = PUCAN_MSG_CHANNEL_DLC(priv->index, can_dlc);
 701         memcpy(msg->d, cf->data, cf->len);
 702
 703         /* struct msg client field is used as an index in the echo skbs ring */
 704         msg->client = priv->echo_idx;
 705
 706         spin_lock_irqsave(&priv->echo_lock, flags);
 707
 708         /* prepare and save echo skb in internal slot */
 709         can_put_echo_skb(skb, ndev, priv->echo_idx);
 710
 711         /* move echo index to the next slot */
 712         priv->echo_idx = (priv->echo_idx + 1) % priv->can.echo_skb_max;
 713
 714         /* if next slot is not free, stop network queue (no slot free in echo
 715          * skb ring means that the controller did not write these frames on
 716          * the bus: no need to continue).
 717          */
 718         should_stop_tx_queue = !!(priv->can.echo_skb[priv->echo_idx]);
 719
 720         /* stop network tx queue if not enough room to save one more msg too */
 721         if (priv->can.ctrlmode & CAN_CTRLMODE_FD)
 722                 should_stop_tx_queue |= (room_left <
 723                                         (sizeof(*msg) + CANFD_MAX_DLEN));
 724         else
 725                 should_stop_tx_queue |= (room_left <
 726                                         (sizeof(*msg) + CAN_MAX_DLEN));
 727
 728         if (should_stop_tx_queue)
 729                 netif_stop_queue(ndev);
 730
 731         spin_unlock_irqrestore(&priv->echo_lock, flags);
 732
 733         /* write the skb on the interface */
 734         priv->write_tx_msg(priv, msg);
 735
 736         return NETDEV_TX_OK;
 737 }
 738
 739 static const struct net_device_ops peak_canfd_netdev_ops = {
 740         .ndo_open = peak_canfd_open,
 741         .ndo_stop = peak_canfd_close,
 742         .ndo_start_xmit = peak_canfd_start_xmit,
 743         .ndo_change_mtu = can_change_mtu,
 744 };
 745
 746 struct net_device *alloc_peak_canfd_dev(int sizeof_priv, int index,
 747                                         int echo_skb_max)
 748 {
 749         struct net_device *ndev;
 750         struct peak_canfd_priv *priv;
 751
 752         /* we DO support local echo */
 753         if (echo_skb_max < 0)
 754                 echo_skb_max = PCANFD_ECHO_SKB_MAX;
 755
 756         /* allocate the candev object */
 757         ndev = alloc_candev(sizeof_priv, echo_skb_max);
 758         if (!ndev)
 759                 return NULL;
 760
 761         priv = netdev_priv(ndev);
 762
 763         /* complete now socket-can initialization side */
 764         priv->can.state = CAN_STATE_STOPPED;
 765         priv->can.bittiming_const = &peak_canfd_nominal_const;
 766         priv->can.data_bittiming_const = &peak_canfd_data_const;
 767
 768         priv->can.do_set_mode = peak_canfd_set_mode;
 769         priv->can.do_get_berr_counter = peak_canfd_get_berr_counter;
 770         priv->can.do_set_bittiming = peak_canfd_set_bittiming;
 771         priv->can.do_set_data_bittiming = peak_canfd_set_data_bittiming;
 772         priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
 773                                        CAN_CTRLMODE_LISTENONLY |
 774                                        CAN_CTRLMODE_3_SAMPLES |
 775                                        CAN_CTRLMODE_FD |
 776                                        CAN_CTRLMODE_FD_NON_ISO |
 777                                        CAN_CTRLMODE_BERR_REPORTING;
 778
 779         priv->ndev = ndev;
 780         priv->index = index;
 781         priv->cmd_len = 0;
 782         spin_lock_init(&priv->echo_lock);
 783
 784         ndev->flags |= IFF_ECHO;
 785         ndev->netdev_ops = &peak_canfd_netdev_ops;
 786         ndev->dev_id = index;
 787
 788         return ndev;
 789 }