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                 spin_unlock_irqrestore(&priv->echo_lock, flags);
 266
 267                 /* count bytes of the echo instead of skb */
 268                 stats->tx_bytes += cf_len;
 269                 stats->tx_packets++;
 270
 271                 /* restart tx queue (a slot is free) */
 272                 netif_wake_queue(priv->ndev);
 273
 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                 unsigned long flags;
 337
 338                 if (priv->enable_tx_path) {
 339                         int err = priv->enable_tx_path(priv);
 340
 341                         if (err)
 342                                 return err;
 343                 }
 344
 345                 /* restart network queue only if echo skb array is free */
 346                 spin_lock_irqsave(&priv->echo_lock, flags);
 347
 348                 if (!priv->can.echo_skb[priv->echo_idx]) {
 349                         spin_unlock_irqrestore(&priv->echo_lock, flags);
 350
 351                         netif_wake_queue(ndev);
 352                 } else {
 353                         spin_unlock_irqrestore(&priv->echo_lock, flags);
 354                 }
 355
 356                 return 0;
 357         }
 358
 359         skb = alloc_can_err_skb(ndev, &cf);
 360
 361         /* test state error bits according to their priority */
 362         if (pucan_status_is_busoff(msg)) {
 363                 netdev_dbg(ndev, "Bus-off entry status\n");
 364                 priv->can.state = CAN_STATE_BUS_OFF;
 365                 priv->can.can_stats.bus_off++;
 366                 can_bus_off(ndev);
 367                 if (skb)
 368                         cf->can_id |= CAN_ERR_BUSOFF;
 369
 370         } else if (pucan_status_is_passive(msg)) {
 371                 netdev_dbg(ndev, "Error passive status\n");
 372                 priv->can.state = CAN_STATE_ERROR_PASSIVE;
 373                 priv->can.can_stats.error_passive++;
 374                 if (skb) {
 375                         cf->can_id |= CAN_ERR_CRTL;
 376                         cf->data[1] = (priv->bec.txerr > priv->bec.rxerr) ?
 377                                         CAN_ERR_CRTL_TX_PASSIVE :
 378                                         CAN_ERR_CRTL_RX_PASSIVE;
 379                         cf->data[6] = priv->bec.txerr;
 380                         cf->data[7] = priv->bec.rxerr;
 381                 }
 382
 383         } else if (pucan_status_is_warning(msg)) {
 384                 netdev_dbg(ndev, "Error warning status\n");
 385                 priv->can.state = CAN_STATE_ERROR_WARNING;
 386                 priv->can.can_stats.error_warning++;
 387                 if (skb) {
 388                         cf->can_id |= CAN_ERR_CRTL;
 389                         cf->data[1] = (priv->bec.txerr > priv->bec.rxerr) ?
 390                                         CAN_ERR_CRTL_TX_WARNING :
 391                                         CAN_ERR_CRTL_RX_WARNING;
 392                         cf->data[6] = priv->bec.txerr;
 393                         cf->data[7] = priv->bec.rxerr;
 394                 }
 395
 396         } else if (priv->can.state != CAN_STATE_ERROR_ACTIVE) {
 397                 /* back to ERROR_ACTIVE */
 398                 netdev_dbg(ndev, "Error active status\n");
 399                 can_change_state(ndev, cf, CAN_STATE_ERROR_ACTIVE,
 400                                  CAN_STATE_ERROR_ACTIVE);
 401         } else {
 402                 dev_kfree_skb(skb);
 403                 return 0;
 404         }
 405
 406         if (!skb) {
 407                 stats->rx_dropped++;
 408                 return -ENOMEM;
 409         }
 410
 411         stats->rx_packets++;
 412         stats->rx_bytes += cf->can_dlc;
 413         netif_rx(skb);
 414
 415         return 0;
 416 }
 417
 418 /* handle uCAN Rx overflow notification */
 419 static int pucan_handle_cache_critical(struct peak_canfd_priv *priv)
 420 {
 421         struct net_device_stats *stats = &priv->ndev->stats;
 422         struct can_frame *cf;
 423         struct sk_buff *skb;
 424
 425         stats->rx_over_errors++;
 426         stats->rx_errors++;
 427
 428         skb = alloc_can_err_skb(priv->ndev, &cf);
 429         if (!skb) {
 430                 stats->rx_dropped++;
 431                 return -ENOMEM;
 432         }
 433
 434         cf->can_id |= CAN_ERR_CRTL;
 435         cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 436
 437         cf->data[6] = priv->bec.txerr;
 438         cf->data[7] = priv->bec.rxerr;
 439
 440         stats->rx_bytes += cf->can_dlc;
 441         stats->rx_packets++;
 442         netif_rx(skb);
 443
 444         return 0;
 445 }
 446
 447 /* handle a single uCAN message */
 448 int peak_canfd_handle_msg(struct peak_canfd_priv *priv,
 449                           struct pucan_rx_msg *msg)
 450 {
 451         u16 msg_type = le16_to_cpu(msg->type);
 452         int msg_size = le16_to_cpu(msg->size);
 453         int err;
 454
 455         if (!msg_size || !msg_type) {
 456                 /* null packet found: end of list */
 457                 goto exit;
 458         }
 459
 460         switch (msg_type) {
 461         case PUCAN_MSG_CAN_RX:
 462                 err = pucan_handle_can_rx(priv, (struct pucan_rx_msg *)msg);
 463                 break;
 464         case PUCAN_MSG_ERROR:
 465                 err = pucan_handle_error(priv, (struct pucan_error_msg *)msg);
 466                 break;
 467         case PUCAN_MSG_STATUS:
 468                 err = pucan_handle_status(priv, (struct pucan_status_msg *)msg);
 469                 break;
 470         case PUCAN_MSG_CACHE_CRITICAL:
 471                 err = pucan_handle_cache_critical(priv);
 472                 break;
 473         default:
 474                 err = 0;
 475         }
 476
 477         if (err < 0)
 478                 return err;
 479
 480 exit:
 481         return msg_size;
 482 }
 483
 484 /* handle a list of rx_count messages from rx_msg memory address */
 485 int peak_canfd_handle_msgs_list(struct peak_canfd_priv *priv,
 486                                 struct pucan_rx_msg *msg_list, int msg_count)
 487 {
 488         void *msg_ptr = msg_list;
 489         int i, msg_size = 0;
 490
 491         for (i = 0; i < msg_count; i++) {
 492                 msg_size = peak_canfd_handle_msg(priv, msg_ptr);
 493
 494                 /* a null packet can be found at the end of a list */
 495                 if (msg_size <= 0)
 496                         break;
 497
 498                 msg_ptr += msg_size;
 499         }
 500
 501         if (msg_size < 0)
 502                 return msg_size;
 503
 504         return i;
 505 }
 506
 507 static int peak_canfd_start(struct peak_canfd_priv *priv)
 508 {
 509         int err;
 510
 511         err = pucan_clr_err_counters(priv);
 512         if (err)
 513                 goto err_exit;
 514
 515         priv->echo_idx = 0;
 516
 517         priv->bec.txerr = 0;
 518         priv->bec.rxerr = 0;
 519
 520         if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
 521                 err = pucan_set_listen_only_mode(priv);
 522         else
 523                 err = pucan_set_normal_mode(priv);
 524
 525 err_exit:
 526         return err;
 527 }
 528
 529 static void peak_canfd_stop(struct peak_canfd_priv *priv)
 530 {
 531         int err;
 532
 533         /* go back to RESET mode */
 534         err = pucan_set_reset_mode(priv);
 535         if (err) {
 536                 netdev_err(priv->ndev, "channel %u reset failed\n",
 537                            priv->index);
 538         } else {
 539                 /* abort last Tx (MUST be done in RESET mode only!) */
 540                 pucan_tx_abort(priv, PUCAN_TX_ABORT_FLUSH);
 541         }
 542 }
 543
 544 static int peak_canfd_set_mode(struct net_device *ndev, enum can_mode mode)
 545 {
 546         struct peak_canfd_priv *priv = netdev_priv(ndev);
 547
 548         switch (mode) {
 549         case CAN_MODE_START:
 550                 peak_canfd_start(priv);
 551                 netif_wake_queue(ndev);
 552                 break;
 553         default:
 554                 return -EOPNOTSUPP;
 555         }
 556
 557         return 0;
 558 }
 559
 560 static int peak_canfd_get_berr_counter(const struct net_device *ndev,
 561                                        struct can_berr_counter *bec)
 562 {
 563         struct peak_canfd_priv *priv = netdev_priv(ndev);
 564
 565         *bec = priv->bec;
 566         return 0;
 567 }
 568
 569 static int peak_canfd_open(struct net_device *ndev)
 570 {
 571         struct peak_canfd_priv *priv = netdev_priv(ndev);
 572         int i, err = 0;
 573
 574         err = open_candev(ndev);
 575         if (err) {
 576                 netdev_err(ndev, "open_candev() failed, error %d\n", err);
 577                 goto err_exit;
 578         }
 579
 580         err = pucan_set_reset_mode(priv);
 581         if (err)
 582                 goto err_close;
 583
 584         if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
 585                 if (priv->can.ctrlmode & CAN_CTRLMODE_FD_NON_ISO)
 586                         err = pucan_clr_options(priv, PUCAN_OPTION_CANDFDISO);
 587                 else
 588                         err = pucan_set_options(priv, PUCAN_OPTION_CANDFDISO);
 589
 590                 if (err)
 591                         goto err_close;
 592         }
 593
 594         /* set option: get rx/tx error counters */
 595         err = pucan_set_options(priv, PUCAN_OPTION_ERROR);
 596         if (err)
 597                 goto err_close;
 598
 599         /* accept all standard CAN ID */
 600         for (i = 0; i <= PUCAN_FLTSTD_ROW_IDX_MAX; i++)
 601                 pucan_set_std_filter(priv, i, 0xffffffff);
 602
 603         err = peak_canfd_start(priv);
 604         if (err)
 605                 goto err_close;
 606
 607         /* receiving the RB status says when Tx path is ready */
 608         err = pucan_setup_rx_barrier(priv);
 609         if (!err)
 610                 goto err_exit;
 611
 612 err_close:
 613         close_candev(ndev);
 614 err_exit:
 615         return err;
 616 }
 617
 618 static int peak_canfd_set_bittiming(struct net_device *ndev)
 619 {
 620         struct peak_canfd_priv *priv = netdev_priv(ndev);
 621
 622         return pucan_set_timing_slow(priv, &priv->can.bittiming);
 623 }
 624
 625 static int peak_canfd_set_data_bittiming(struct net_device *ndev)
 626 {
 627         struct peak_canfd_priv *priv = netdev_priv(ndev);
 628
 629         return pucan_set_timing_fast(priv, &priv->can.data_bittiming);
 630 }
 631
 632 static int peak_canfd_close(struct net_device *ndev)
 633 {
 634         struct peak_canfd_priv *priv = netdev_priv(ndev);
 635
 636         netif_stop_queue(ndev);
 637         peak_canfd_stop(priv);
 638         close_candev(ndev);
 639
 640         return 0;
 641 }
 642
 643 static netdev_tx_t peak_canfd_start_xmit(struct sk_buff *skb,
 644                                          struct net_device *ndev)
 645 {
 646         struct peak_canfd_priv *priv = netdev_priv(ndev);
 647         struct net_device_stats *stats = &ndev->stats;
 648         struct canfd_frame *cf = (struct canfd_frame *)skb->data;
 649         struct pucan_tx_msg *msg;
 650         u16 msg_size, msg_flags;
 651         unsigned long flags;
 652         bool should_stop_tx_queue;
 653         int room_left;
 654         u8 can_dlc;
 655
 656         if (can_dropped_invalid_skb(ndev, skb))
 657                 return NETDEV_TX_OK;
 658
 659         msg_size = ALIGN(sizeof(*msg) + cf->len, 4);
 660         msg = priv->alloc_tx_msg(priv, msg_size, &room_left);
 661
 662         /* should never happen except under bus-off condition and (auto-)restart
 663          * mechanism
 664          */
 665         if (!msg) {
 666                 stats->tx_dropped++;
 667                 netif_stop_queue(ndev);
 668                 return NETDEV_TX_BUSY;
 669         }
 670
 671         msg->size = cpu_to_le16(msg_size);
 672         msg->type = cpu_to_le16(PUCAN_MSG_CAN_TX);
 673         msg_flags = 0;
 674
 675         if (cf->can_id & CAN_EFF_FLAG) {
 676                 msg_flags |= PUCAN_MSG_EXT_ID;
 677                 msg->can_id = cpu_to_le32(cf->can_id & CAN_EFF_MASK);
 678         } else {
 679                 msg->can_id = cpu_to_le32(cf->can_id & CAN_SFF_MASK);
 680         }
 681
 682         if (can_is_canfd_skb(skb)) {
 683                 /* CAN FD frame format */
 684                 can_dlc = can_len2dlc(cf->len);
 685
 686                 msg_flags |= PUCAN_MSG_EXT_DATA_LEN;
 687
 688                 if (cf->flags & CANFD_BRS)
 689                         msg_flags |= PUCAN_MSG_BITRATE_SWITCH;
 690
 691                 if (cf->flags & CANFD_ESI)
 692                         msg_flags |= PUCAN_MSG_ERROR_STATE_IND;
 693         } else {
 694                 /* CAN 2.0 frame format */
 695                 can_dlc = cf->len;
 696
 697                 if (cf->can_id & CAN_RTR_FLAG)
 698                         msg_flags |= PUCAN_MSG_RTR;
 699         }
 700
 701         /* always ask loopback for echo management */
 702         msg_flags |= PUCAN_MSG_LOOPED_BACK;
 703
 704         /* set driver specific bit to differentiate with application loopback */
 705         if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
 706                 msg_flags |= PUCAN_MSG_SELF_RECEIVE;
 707
 708         msg->flags = cpu_to_le16(msg_flags);
 709         msg->channel_dlc = PUCAN_MSG_CHANNEL_DLC(priv->index, can_dlc);
 710         memcpy(msg->d, cf->data, cf->len);
 711
 712         /* struct msg client field is used as an index in the echo skbs ring */
 713         msg->client = priv->echo_idx;
 714
 715         spin_lock_irqsave(&priv->echo_lock, flags);
 716
 717         /* prepare and save echo skb in internal slot */
 718         can_put_echo_skb(skb, ndev, priv->echo_idx);
 719
 720         /* move echo index to the next slot */
 721         priv->echo_idx = (priv->echo_idx + 1) % priv->can.echo_skb_max;
 722
 723         /* if next slot is not free, stop network queue (no slot free in echo
 724          * skb ring means that the controller did not write these frames on
 725          * the bus: no need to continue).
 726          */
 727         should_stop_tx_queue = !!(priv->can.echo_skb[priv->echo_idx]);
 728
 729         spin_unlock_irqrestore(&priv->echo_lock, flags);
 730
 731         /* write the skb on the interface */
 732         priv->write_tx_msg(priv, msg);
 733
 734         /* stop network tx queue if not enough room to save one more msg too */
 735         if (priv->can.ctrlmode & CAN_CTRLMODE_FD)
 736                 should_stop_tx_queue |= (room_left <
 737                                         (sizeof(*msg) + CANFD_MAX_DLEN));
 738         else
 739                 should_stop_tx_queue |= (room_left <
 740                                         (sizeof(*msg) + CAN_MAX_DLEN));
 741
 742         if (should_stop_tx_queue)
 743                 netif_stop_queue(ndev);
 744
 745         return NETDEV_TX_OK;
 746 }
 747
 748 static const struct net_device_ops peak_canfd_netdev_ops = {
 749         .ndo_open = peak_canfd_open,
 750         .ndo_stop = peak_canfd_close,
 751         .ndo_start_xmit = peak_canfd_start_xmit,
 752         .ndo_change_mtu = can_change_mtu,
 753 };
 754
 755 struct net_device *alloc_peak_canfd_dev(int sizeof_priv, int index,
 756                                         int echo_skb_max)
 757 {
 758         struct net_device *ndev;
 759         struct peak_canfd_priv *priv;
 760
 761         /* we DO support local echo */
 762         if (echo_skb_max < 0)
 763                 echo_skb_max = PCANFD_ECHO_SKB_MAX;
 764
 765         /* allocate the candev object */
 766         ndev = alloc_candev(sizeof_priv, echo_skb_max);
 767         if (!ndev)
 768                 return NULL;
 769
 770         priv = netdev_priv(ndev);
 771
 772         /* complete now socket-can initialization side */
 773         priv->can.state = CAN_STATE_STOPPED;
 774         priv->can.bittiming_const = &peak_canfd_nominal_const;
 775         priv->can.data_bittiming_const = &peak_canfd_data_const;
 776
 777         priv->can.do_set_mode = peak_canfd_set_mode;
 778         priv->can.do_get_berr_counter = peak_canfd_get_berr_counter;
 779         priv->can.do_set_bittiming = peak_canfd_set_bittiming;
 780         priv->can.do_set_data_bittiming = peak_canfd_set_data_bittiming;
 781         priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
 782                                        CAN_CTRLMODE_LISTENONLY |
 783                                        CAN_CTRLMODE_3_SAMPLES |
 784                                        CAN_CTRLMODE_FD |
 785                                        CAN_CTRLMODE_FD_NON_ISO |
 786                                        CAN_CTRLMODE_BERR_REPORTING;
 787
 788         priv->ndev = ndev;
 789         priv->index = index;
 790         priv->cmd_len = 0;
 791         spin_lock_init(&priv->echo_lock);
 792
 793         ndev->flags |= IFF_ECHO;
 794         ndev->netdev_ops = &peak_canfd_netdev_ops;
 795         ndev->dev_id = index;
 796
 797         return ndev;
 798 }