drivers/net/wan/fsl_qmc_hdlc.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Freescale QMC HDLC Device Driver
   4  *
   5  * Copyright 2023 CS GROUP France
   6  *
   7  * Author: Herve Codina <herve.codina@bootlin.com>
   8  */
   9
  10 #include <linux/array_size.h>
  11 #include <linux/bug.h>
  12 #include <linux/cleanup.h>
  13 #include <linux/bitmap.h>
  14 #include <linux/dma-mapping.h>
  15 #include <linux/device.h>
  16 #include <linux/err.h>
  17 #include <linux/framer/framer.h>
  18 #include <linux/hdlc.h>
  19 #include <linux/mod_devicetable.h>
  20 #include <linux/module.h>
  21 #include <linux/mutex.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/slab.h>
  24 #include <linux/spinlock.h>
  25 #include <linux/types.h>
  26
  27 #include <soc/fsl/qe/qmc.h>
  28
  29 struct qmc_hdlc_desc {
  30         struct net_device *netdev;
  31         struct sk_buff *skb; /* NULL if the descriptor is not in use */
  32         dma_addr_t dma_addr;
  33         size_t dma_size;
  34 };
  35
  36 struct qmc_hdlc {
  37         struct device *dev;
  38         struct qmc_chan *qmc_chan;
  39         struct net_device *netdev;
  40         struct framer *framer;
  41         struct mutex carrier_lock; /* Protect carrier detection */
  42         struct notifier_block nb;
  43         bool is_crc32;
  44         spinlock_t tx_lock; /* Protect tx descriptors */
  45         struct qmc_hdlc_desc tx_descs[8];
  46         unsigned int tx_out;
  47         struct qmc_hdlc_desc rx_descs[4];
  48         u32 slot_map;
  49 };
  50
  51 static struct qmc_hdlc *netdev_to_qmc_hdlc(struct net_device *netdev)
  52 {
  53         return dev_to_hdlc(netdev)->priv;
  54 }
  55
  56 static int qmc_hdlc_framer_set_carrier(struct qmc_hdlc *qmc_hdlc)
  57 {
  58         struct framer_status framer_status;
  59         int ret;
  60
  61         if (!qmc_hdlc->framer)
  62                 return 0;
  63
  64         guard(mutex)(&qmc_hdlc->carrier_lock);
  65
  66         ret = framer_get_status(qmc_hdlc->framer, &framer_status);
  67         if (ret) {
  68                 dev_err(qmc_hdlc->dev, "get framer status failed (%d)\n", ret);
  69                 return ret;
  70         }
  71         if (framer_status.link_is_on)
  72                 netif_carrier_on(qmc_hdlc->netdev);
  73         else
  74                 netif_carrier_off(qmc_hdlc->netdev);
  75
  76         return 0;
  77 }
  78
  79 static int qmc_hdlc_framer_notifier(struct notifier_block *nb, unsigned long action,
  80                                     void *data)
  81 {
  82         struct qmc_hdlc *qmc_hdlc = container_of(nb, struct qmc_hdlc, nb);
  83         int ret;
  84
  85         if (action != FRAMER_EVENT_STATUS)
  86                 return NOTIFY_DONE;
  87
  88         ret = qmc_hdlc_framer_set_carrier(qmc_hdlc);
  89         return ret ? NOTIFY_DONE : NOTIFY_OK;
  90 }
  91
  92 static int qmc_hdlc_framer_start(struct qmc_hdlc *qmc_hdlc)
  93 {
  94         struct framer_status framer_status;
  95         int ret;
  96
  97         if (!qmc_hdlc->framer)
  98                 return 0;
  99
 100         ret = framer_power_on(qmc_hdlc->framer);
 101         if (ret) {
 102                 dev_err(qmc_hdlc->dev, "framer power-on failed (%d)\n", ret);
 103                 return ret;
 104         }
 105
 106         /* Be sure that get_status is supported */
 107         ret = framer_get_status(qmc_hdlc->framer, &framer_status);
 108         if (ret) {
 109                 dev_err(qmc_hdlc->dev, "get framer status failed (%d)\n", ret);
 110                 goto framer_power_off;
 111         }
 112
 113         qmc_hdlc->nb.notifier_call = qmc_hdlc_framer_notifier;
 114         ret = framer_notifier_register(qmc_hdlc->framer, &qmc_hdlc->nb);
 115         if (ret) {
 116                 dev_err(qmc_hdlc->dev, "framer notifier register failed (%d)\n", ret);
 117                 goto framer_power_off;
 118         }
 119
 120         return 0;
 121
 122 framer_power_off:
 123         framer_power_off(qmc_hdlc->framer);
 124         return ret;
 125 }
 126
 127 static void qmc_hdlc_framer_stop(struct qmc_hdlc *qmc_hdlc)
 128 {
 129         if (!qmc_hdlc->framer)
 130                 return;
 131
 132         framer_notifier_unregister(qmc_hdlc->framer, &qmc_hdlc->nb);
 133         framer_power_off(qmc_hdlc->framer);
 134 }
 135
 136 static int qmc_hdlc_framer_set_iface(struct qmc_hdlc *qmc_hdlc, int if_iface,
 137                                      const te1_settings *te1)
 138 {
 139         struct framer_config config;
 140         int ret;
 141
 142         if (!qmc_hdlc->framer)
 143                 return 0;
 144
 145         ret = framer_get_config(qmc_hdlc->framer, &config);
 146         if (ret)
 147                 return ret;
 148
 149         switch (if_iface) {
 150         case IF_IFACE_E1:
 151                 config.iface = FRAMER_IFACE_E1;
 152                 break;
 153         case IF_IFACE_T1:
 154                 config.iface = FRAMER_IFACE_T1;
 155                 break;
 156         default:
 157                 return -EINVAL;
 158         }
 159
 160         switch (te1->clock_type) {
 161         case CLOCK_DEFAULT:
 162                 /* Keep current value */
 163                 break;
 164         case CLOCK_EXT:
 165                 config.clock_type = FRAMER_CLOCK_EXT;
 166                 break;
 167         case CLOCK_INT:
 168                 config.clock_type = FRAMER_CLOCK_INT;
 169                 break;
 170         default:
 171                 return -EINVAL;
 172         }
 173         config.line_clock_rate = te1->clock_rate;
 174
 175         return framer_set_config(qmc_hdlc->framer, &config);
 176 }
 177
 178 static int qmc_hdlc_framer_get_iface(struct qmc_hdlc *qmc_hdlc, int *if_iface, te1_settings *te1)
 179 {
 180         struct framer_config config;
 181         int ret;
 182
 183         if (!qmc_hdlc->framer) {
 184                 *if_iface = IF_IFACE_E1;
 185                 return 0;
 186         }
 187
 188         ret = framer_get_config(qmc_hdlc->framer, &config);
 189         if (ret)
 190                 return ret;
 191
 192         switch (config.iface) {
 193         case FRAMER_IFACE_E1:
 194                 *if_iface = IF_IFACE_E1;
 195                 break;
 196         case FRAMER_IFACE_T1:
 197                 *if_iface = IF_IFACE_T1;
 198                 break;
 199         }
 200
 201         if (!te1)
 202                 return 0; /* Only iface type requested */
 203
 204         switch (config.clock_type) {
 205         case FRAMER_CLOCK_EXT:
 206                 te1->clock_type = CLOCK_EXT;
 207                 break;
 208         case FRAMER_CLOCK_INT:
 209                 te1->clock_type = CLOCK_INT;
 210                 break;
 211         default:
 212                 return -EINVAL;
 213         }
 214         te1->clock_rate = config.line_clock_rate;
 215         return 0;
 216 }
 217
 218 static int qmc_hdlc_framer_init(struct qmc_hdlc *qmc_hdlc)
 219 {
 220         int ret;
 221
 222         if (!qmc_hdlc->framer)
 223                 return 0;
 224
 225         ret = framer_init(qmc_hdlc->framer);
 226         if (ret) {
 227                 dev_err(qmc_hdlc->dev, "framer init failed (%d)\n", ret);
 228                 return ret;
 229         }
 230
 231         return 0;
 232 }
 233
 234 static void qmc_hdlc_framer_exit(struct qmc_hdlc *qmc_hdlc)
 235 {
 236         if (!qmc_hdlc->framer)
 237                 return;
 238
 239         framer_exit(qmc_hdlc->framer);
 240 }
 241
 242 static int qmc_hdlc_recv_queue(struct qmc_hdlc *qmc_hdlc, struct qmc_hdlc_desc *desc, size_t size);
 243
 244 #define QMC_HDLC_RX_ERROR_FLAGS                         \
 245         (QMC_RX_FLAG_HDLC_OVF | QMC_RX_FLAG_HDLC_UNA |  \
 246          QMC_RX_FLAG_HDLC_CRC | QMC_RX_FLAG_HDLC_ABORT)
 247
 248 static void qmc_hcld_recv_complete(void *context, size_t length, unsigned int flags)
 249 {
 250         struct qmc_hdlc_desc *desc = context;
 251         struct net_device *netdev;
 252         struct qmc_hdlc *qmc_hdlc;
 253         size_t crc_size;
 254         int ret;
 255
 256         netdev = desc->netdev;
 257         qmc_hdlc = netdev_to_qmc_hdlc(netdev);
 258
 259         dma_unmap_single(qmc_hdlc->dev, desc->dma_addr, desc->dma_size, DMA_FROM_DEVICE);
 260
 261         if (flags & QMC_HDLC_RX_ERROR_FLAGS) {
 262                 netdev->stats.rx_errors++;
 263                 if (flags & QMC_RX_FLAG_HDLC_OVF) /* Data overflow */
 264                         netdev->stats.rx_over_errors++;
 265                 if (flags & QMC_RX_FLAG_HDLC_UNA) /* bits received not multiple of 8 */
 266                         netdev->stats.rx_frame_errors++;
 267                 if (flags & QMC_RX_FLAG_HDLC_ABORT) /* Received an abort sequence */
 268                         netdev->stats.rx_frame_errors++;
 269                 if (flags & QMC_RX_FLAG_HDLC_CRC) /* CRC error */
 270                         netdev->stats.rx_crc_errors++;
 271                 kfree_skb(desc->skb);
 272                 goto re_queue;
 273         }
 274
 275         /* Discard the CRC */
 276         crc_size = qmc_hdlc->is_crc32 ? 4 : 2;
 277         if (length < crc_size) {
 278                 netdev->stats.rx_length_errors++;
 279                 kfree_skb(desc->skb);
 280                 goto re_queue;
 281         }
 282         length -= crc_size;
 283
 284         netdev->stats.rx_packets++;
 285         netdev->stats.rx_bytes += length;
 286
 287         skb_put(desc->skb, length);
 288         desc->skb->protocol = hdlc_type_trans(desc->skb, netdev);
 289         netif_rx(desc->skb);
 290
 291 re_queue:
 292         /* Re-queue a transfer using the same descriptor */
 293         ret = qmc_hdlc_recv_queue(qmc_hdlc, desc, desc->dma_size);
 294         if (ret) {
 295                 dev_err(qmc_hdlc->dev, "queue recv desc failed (%d)\n", ret);
 296                 netdev->stats.rx_errors++;
 297         }
 298 }
 299
 300 static int qmc_hdlc_recv_queue(struct qmc_hdlc *qmc_hdlc, struct qmc_hdlc_desc *desc, size_t size)
 301 {
 302         int ret;
 303
 304         desc->skb = dev_alloc_skb(size);
 305         if (!desc->skb)
 306                 return -ENOMEM;
 307
 308         desc->dma_size = size;
 309         desc->dma_addr = dma_map_single(qmc_hdlc->dev, desc->skb->data,
 310                                         desc->dma_size, DMA_FROM_DEVICE);
 311         ret = dma_mapping_error(qmc_hdlc->dev, desc->dma_addr);
 312         if (ret)
 313                 goto free_skb;
 314
 315         ret = qmc_chan_read_submit(qmc_hdlc->qmc_chan, desc->dma_addr, desc->dma_size,
 316                                    qmc_hcld_recv_complete, desc);
 317         if (ret)
 318                 goto dma_unmap;
 319
 320         return 0;
 321
 322 dma_unmap:
 323         dma_unmap_single(qmc_hdlc->dev, desc->dma_addr, desc->dma_size, DMA_FROM_DEVICE);
 324 free_skb:
 325         kfree_skb(desc->skb);
 326         desc->skb = NULL;
 327         return ret;
 328 }
 329
 330 static void qmc_hdlc_xmit_complete(void *context)
 331 {
 332         struct qmc_hdlc_desc *desc = context;
 333         struct net_device *netdev;
 334         struct qmc_hdlc *qmc_hdlc;
 335         struct sk_buff *skb;
 336
 337         netdev = desc->netdev;
 338         qmc_hdlc = netdev_to_qmc_hdlc(netdev);
 339
 340         scoped_guard(spinlock_irqsave, &qmc_hdlc->tx_lock) {
 341                 dma_unmap_single(qmc_hdlc->dev, desc->dma_addr, desc->dma_size, DMA_TO_DEVICE);
 342                 skb = desc->skb;
 343                 desc->skb = NULL; /* Release the descriptor */
 344                 if (netif_queue_stopped(netdev))
 345                         netif_wake_queue(netdev);
 346         }
 347
 348         netdev->stats.tx_packets++;
 349         netdev->stats.tx_bytes += skb->len;
 350
 351         dev_consume_skb_any(skb);
 352 }
 353
 354 static int qmc_hdlc_xmit_queue(struct qmc_hdlc *qmc_hdlc, struct qmc_hdlc_desc *desc)
 355 {
 356         int ret;
 357
 358         desc->dma_addr = dma_map_single(qmc_hdlc->dev, desc->skb->data,
 359                                         desc->dma_size, DMA_TO_DEVICE);
 360         ret = dma_mapping_error(qmc_hdlc->dev, desc->dma_addr);
 361         if (ret) {
 362                 dev_err(qmc_hdlc->dev, "failed to map skb\n");
 363                 return ret;
 364         }
 365
 366         ret = qmc_chan_write_submit(qmc_hdlc->qmc_chan, desc->dma_addr, desc->dma_size,
 367                                     qmc_hdlc_xmit_complete, desc);
 368         if (ret) {
 369                 dma_unmap_single(qmc_hdlc->dev, desc->dma_addr, desc->dma_size, DMA_TO_DEVICE);
 370                 dev_err(qmc_hdlc->dev, "qmc chan write returns %d\n", ret);
 371                 return ret;
 372         }
 373
 374         return 0;
 375 }
 376
 377 static netdev_tx_t qmc_hdlc_xmit(struct sk_buff *skb, struct net_device *netdev)
 378 {
 379         struct qmc_hdlc *qmc_hdlc = netdev_to_qmc_hdlc(netdev);
 380         struct qmc_hdlc_desc *desc;
 381         int err;
 382
 383         guard(spinlock_irqsave)(&qmc_hdlc->tx_lock);
 384
 385         desc = &qmc_hdlc->tx_descs[qmc_hdlc->tx_out];
 386         if (WARN_ONCE(desc->skb, "No tx descriptors available\n")) {
 387                 /* Should never happen.
 388                  * Previous xmit should have already stopped the queue.
 389                  */
 390                 netif_stop_queue(netdev);
 391                 return NETDEV_TX_BUSY;
 392         }
 393
 394         desc->netdev = netdev;
 395         desc->dma_size = skb->len;
 396         desc->skb = skb;
 397         err = qmc_hdlc_xmit_queue(qmc_hdlc, desc);
 398         if (err) {
 399                 desc->skb = NULL; /* Release the descriptor */
 400                 if (err == -EBUSY) {
 401                         netif_stop_queue(netdev);
 402                         return NETDEV_TX_BUSY;
 403                 }
 404                 dev_kfree_skb(skb);
 405                 netdev->stats.tx_dropped++;
 406                 return NETDEV_TX_OK;
 407         }
 408
 409         qmc_hdlc->tx_out = (qmc_hdlc->tx_out + 1) % ARRAY_SIZE(qmc_hdlc->tx_descs);
 410
 411         if (qmc_hdlc->tx_descs[qmc_hdlc->tx_out].skb)
 412                 netif_stop_queue(netdev);
 413
 414         return NETDEV_TX_OK;
 415 }
 416
 417 static int qmc_hdlc_xlate_slot_map(struct qmc_hdlc *qmc_hdlc,
 418                                    u32 slot_map, struct qmc_chan_ts_info *ts_info)
 419 {
 420         DECLARE_BITMAP(ts_mask_avail, 64);
 421         DECLARE_BITMAP(ts_mask, 64);
 422         DECLARE_BITMAP(map, 64);
 423
 424         /* Tx and Rx available masks must be identical */
 425         if (ts_info->rx_ts_mask_avail != ts_info->tx_ts_mask_avail) {
 426                 dev_err(qmc_hdlc->dev, "tx and rx available timeslots mismatch (0x%llx, 0x%llx)\n",
 427                         ts_info->rx_ts_mask_avail, ts_info->tx_ts_mask_avail);
 428                 return -EINVAL;
 429         }
 430
 431         bitmap_from_u64(ts_mask_avail, ts_info->rx_ts_mask_avail);
 432         bitmap_from_u64(map, slot_map);
 433         bitmap_scatter(ts_mask, map, ts_mask_avail, 64);
 434
 435         if (bitmap_weight(ts_mask, 64) != bitmap_weight(map, 64)) {
 436                 dev_err(qmc_hdlc->dev, "Cannot translate timeslots %64pb -> (%64pb, %64pb)\n",
 437                         map, ts_mask_avail, ts_mask);
 438                 return -EINVAL;
 439         }
 440
 441         bitmap_to_arr64(&ts_info->tx_ts_mask, ts_mask, 64);
 442         ts_info->rx_ts_mask = ts_info->tx_ts_mask;
 443         return 0;
 444 }
 445
 446 static int qmc_hdlc_xlate_ts_info(struct qmc_hdlc *qmc_hdlc,
 447                                   const struct qmc_chan_ts_info *ts_info, u32 *slot_map)
 448 {
 449         DECLARE_BITMAP(ts_mask_avail, 64);
 450         DECLARE_BITMAP(ts_mask, 64);
 451         DECLARE_BITMAP(map, 64);
 452         u32 slot_array[2];
 453
 454         /* Tx and Rx masks and available masks must be identical */
 455         if (ts_info->rx_ts_mask_avail != ts_info->tx_ts_mask_avail) {
 456                 dev_err(qmc_hdlc->dev, "tx and rx available timeslots mismatch (0x%llx, 0x%llx)\n",
 457                         ts_info->rx_ts_mask_avail, ts_info->tx_ts_mask_avail);
 458                 return -EINVAL;
 459         }
 460         if (ts_info->rx_ts_mask != ts_info->tx_ts_mask) {
 461                 dev_err(qmc_hdlc->dev, "tx and rx timeslots mismatch (0x%llx, 0x%llx)\n",
 462                         ts_info->rx_ts_mask, ts_info->tx_ts_mask);
 463                 return -EINVAL;
 464         }
 465
 466         bitmap_from_u64(ts_mask_avail, ts_info->rx_ts_mask_avail);
 467         bitmap_from_u64(ts_mask, ts_info->rx_ts_mask);
 468         bitmap_gather(map, ts_mask, ts_mask_avail, 64);
 469
 470         if (bitmap_weight(ts_mask, 64) != bitmap_weight(map, 64)) {
 471                 dev_err(qmc_hdlc->dev, "Cannot translate timeslots (%64pb, %64pb) -> %64pb\n",
 472                         ts_mask_avail, ts_mask, map);
 473                 return -EINVAL;
 474         }
 475
 476         bitmap_to_arr32(slot_array, map, 64);
 477         if (slot_array[1]) {
 478                 dev_err(qmc_hdlc->dev, "Slot map out of 32bit (%64pb, %64pb) -> %64pb\n",
 479                         ts_mask_avail, ts_mask, map);
 480                 return -EINVAL;
 481         }
 482
 483         *slot_map = slot_array[0];
 484         return 0;
 485 }
 486
 487 static int qmc_hdlc_set_iface(struct qmc_hdlc *qmc_hdlc, int if_iface, const te1_settings *te1)
 488 {
 489         struct qmc_chan_ts_info ts_info;
 490         int ret;
 491
 492         ret = qmc_chan_get_ts_info(qmc_hdlc->qmc_chan, &ts_info);
 493         if (ret) {
 494                 dev_err(qmc_hdlc->dev, "get QMC channel ts info failed %d\n", ret);
 495                 return ret;
 496         }
 497         ret = qmc_hdlc_xlate_slot_map(qmc_hdlc, te1->slot_map, &ts_info);
 498         if (ret)
 499                 return ret;
 500
 501         ret = qmc_chan_set_ts_info(qmc_hdlc->qmc_chan, &ts_info);
 502         if (ret) {
 503                 dev_err(qmc_hdlc->dev, "set QMC channel ts info failed %d\n", ret);
 504                 return ret;
 505         }
 506
 507         qmc_hdlc->slot_map = te1->slot_map;
 508
 509         ret = qmc_hdlc_framer_set_iface(qmc_hdlc, if_iface, te1);
 510         if (ret) {
 511                 dev_err(qmc_hdlc->dev, "framer set iface failed %d\n", ret);
 512                 return ret;
 513         }
 514
 515         return 0;
 516 }
 517
 518 static int qmc_hdlc_ioctl(struct net_device *netdev, struct if_settings *ifs)
 519 {
 520         struct qmc_hdlc *qmc_hdlc = netdev_to_qmc_hdlc(netdev);
 521         te1_settings te1;
 522         int ret;
 523
 524         switch (ifs->type) {
 525         case IF_GET_IFACE:
 526                 if (ifs->size < sizeof(te1)) {
 527                         /* Retrieve type only */
 528                         ret = qmc_hdlc_framer_get_iface(qmc_hdlc, &ifs->type, NULL);
 529                         if (ret)
 530                                 return ret;
 531
 532                         if (!ifs->size)
 533                                 return 0; /* only type requested */
 534
 535                         ifs->size = sizeof(te1); /* data size wanted */
 536                         return -ENOBUFS;
 537                 }
 538
 539                 memset(&te1, 0, sizeof(te1));
 540
 541                 /* Retrieve info from framer */
 542                 ret = qmc_hdlc_framer_get_iface(qmc_hdlc, &ifs->type, &te1);
 543                 if (ret)
 544                         return ret;
 545
 546                 /* Update slot_map */
 547                 te1.slot_map = qmc_hdlc->slot_map;
 548
 549                 if (copy_to_user(ifs->ifs_ifsu.te1, &te1, sizeof(te1)))
 550                         return -EFAULT;
 551                 return 0;
 552
 553         case IF_IFACE_E1:
 554         case IF_IFACE_T1:
 555                 if (!capable(CAP_NET_ADMIN))
 556                         return -EPERM;
 557
 558                 if (netdev->flags & IFF_UP)
 559                         return -EBUSY;
 560
 561                 if (copy_from_user(&te1, ifs->ifs_ifsu.te1, sizeof(te1)))
 562                         return -EFAULT;
 563
 564                 return qmc_hdlc_set_iface(qmc_hdlc, ifs->type, &te1);
 565
 566         default:
 567                 return hdlc_ioctl(netdev, ifs);
 568         }
 569 }
 570
 571 static int qmc_hdlc_open(struct net_device *netdev)
 572 {
 573         struct qmc_hdlc *qmc_hdlc = netdev_to_qmc_hdlc(netdev);
 574         struct qmc_chan_param chan_param;
 575         struct qmc_hdlc_desc *desc;
 576         int ret;
 577         int i;
 578
 579         ret = qmc_hdlc_framer_start(qmc_hdlc);
 580         if (ret)
 581                 return ret;
 582
 583         ret = hdlc_open(netdev);
 584         if (ret)
 585                 goto framer_stop;
 586
 587         /* Update carrier */
 588         qmc_hdlc_framer_set_carrier(qmc_hdlc);
 589
 590         chan_param.mode = QMC_HDLC;
 591         /* HDLC_MAX_MRU + 4 for the CRC
 592          * HDLC_MAX_MRU + 4 + 8 for the CRC and some extraspace needed by the QMC
 593          */
 594         chan_param.hdlc.max_rx_buf_size = HDLC_MAX_MRU + 4 + 8;
 595         chan_param.hdlc.max_rx_frame_size = HDLC_MAX_MRU + 4;
 596         chan_param.hdlc.is_crc32 = qmc_hdlc->is_crc32;
 597         ret = qmc_chan_set_param(qmc_hdlc->qmc_chan, &chan_param);
 598         if (ret) {
 599                 dev_err(qmc_hdlc->dev, "failed to set param (%d)\n", ret);
 600                 goto hdlc_close;
 601         }
 602
 603         /* Queue as many recv descriptors as possible */
 604         for (i = 0; i < ARRAY_SIZE(qmc_hdlc->rx_descs); i++) {
 605                 desc = &qmc_hdlc->rx_descs[i];
 606
 607                 desc->netdev = netdev;
 608                 ret = qmc_hdlc_recv_queue(qmc_hdlc, desc, chan_param.hdlc.max_rx_buf_size);
 609                 if (ret == -EBUSY && i != 0)
 610                         break; /* We use all the QMC chan capability */
 611                 if (ret)
 612                         goto free_desc;
 613         }
 614
 615         ret = qmc_chan_start(qmc_hdlc->qmc_chan, QMC_CHAN_ALL);
 616         if (ret) {
 617                 dev_err(qmc_hdlc->dev, "qmc chan start failed (%d)\n", ret);
 618                 goto free_desc;
 619         }
 620
 621         netif_start_queue(netdev);
 622
 623         return 0;
 624
 625 free_desc:
 626         qmc_chan_reset(qmc_hdlc->qmc_chan, QMC_CHAN_ALL);
 627         while (i--) {
 628                 desc = &qmc_hdlc->rx_descs[i];
 629                 dma_unmap_single(qmc_hdlc->dev, desc->dma_addr, desc->dma_size,
 630                                  DMA_FROM_DEVICE);
 631                 kfree_skb(desc->skb);
 632                 desc->skb = NULL;
 633         }
 634 hdlc_close:
 635         hdlc_close(netdev);
 636 framer_stop:
 637         qmc_hdlc_framer_stop(qmc_hdlc);
 638         return ret;
 639 }
 640
 641 static int qmc_hdlc_close(struct net_device *netdev)
 642 {
 643         struct qmc_hdlc *qmc_hdlc = netdev_to_qmc_hdlc(netdev);
 644         struct qmc_hdlc_desc *desc;
 645         int i;
 646
 647         qmc_chan_stop(qmc_hdlc->qmc_chan, QMC_CHAN_ALL);
 648         qmc_chan_reset(qmc_hdlc->qmc_chan, QMC_CHAN_ALL);
 649
 650         netif_stop_queue(netdev);
 651
 652         for (i = 0; i < ARRAY_SIZE(qmc_hdlc->tx_descs); i++) {
 653                 desc = &qmc_hdlc->tx_descs[i];
 654                 if (!desc->skb)
 655                         continue;
 656                 dma_unmap_single(qmc_hdlc->dev, desc->dma_addr, desc->dma_size,
 657                                  DMA_TO_DEVICE);
 658                 kfree_skb(desc->skb);
 659                 desc->skb = NULL;
 660         }
 661
 662         for (i = 0; i < ARRAY_SIZE(qmc_hdlc->rx_descs); i++) {
 663                 desc = &qmc_hdlc->rx_descs[i];
 664                 if (!desc->skb)
 665                         continue;
 666                 dma_unmap_single(qmc_hdlc->dev, desc->dma_addr, desc->dma_size,
 667                                  DMA_FROM_DEVICE);
 668                 kfree_skb(desc->skb);
 669                 desc->skb = NULL;
 670         }
 671
 672         hdlc_close(netdev);
 673         qmc_hdlc_framer_stop(qmc_hdlc);
 674         return 0;
 675 }
 676
 677 static int qmc_hdlc_attach(struct net_device *netdev, unsigned short encoding,
 678                            unsigned short parity)
 679 {
 680         struct qmc_hdlc *qmc_hdlc = netdev_to_qmc_hdlc(netdev);
 681
 682         if (encoding != ENCODING_NRZ)
 683                 return -EINVAL;
 684
 685         switch (parity) {
 686         case PARITY_CRC16_PR1_CCITT:
 687                 qmc_hdlc->is_crc32 = false;
 688                 break;
 689         case PARITY_CRC32_PR1_CCITT:
 690                 qmc_hdlc->is_crc32 = true;
 691                 break;
 692         default:
 693                 dev_err(qmc_hdlc->dev, "unsupported parity %u\n", parity);
 694                 return -EINVAL;
 695         }
 696
 697         return 0;
 698 }
 699
 700 static const struct net_device_ops qmc_hdlc_netdev_ops = {
 701         .ndo_open       = qmc_hdlc_open,
 702         .ndo_stop       = qmc_hdlc_close,
 703         .ndo_start_xmit = hdlc_start_xmit,
 704         .ndo_siocwandev = qmc_hdlc_ioctl,
 705 };
 706
 707 static int qmc_hdlc_probe(struct platform_device *pdev)
 708 {
 709         struct device *dev = &pdev->dev;
 710         struct qmc_chan_ts_info ts_info;
 711         struct qmc_hdlc *qmc_hdlc;
 712         struct qmc_chan_info info;
 713         hdlc_device *hdlc;
 714         int ret;
 715
 716         qmc_hdlc = devm_kzalloc(dev, sizeof(*qmc_hdlc), GFP_KERNEL);
 717         if (!qmc_hdlc)
 718                 return -ENOMEM;
 719
 720         qmc_hdlc->dev = dev;
 721         spin_lock_init(&qmc_hdlc->tx_lock);
 722         mutex_init(&qmc_hdlc->carrier_lock);
 723
 724         qmc_hdlc->qmc_chan = devm_qmc_chan_get_bychild(dev, dev->of_node);
 725         if (IS_ERR(qmc_hdlc->qmc_chan))
 726                 return dev_err_probe(dev, PTR_ERR(qmc_hdlc->qmc_chan),
 727                                      "get QMC channel failed\n");
 728
 729         ret = qmc_chan_get_info(qmc_hdlc->qmc_chan, &info);
 730         if (ret)
 731                 return dev_err_probe(dev, ret, "get QMC channel info failed\n");
 732
 733         if (info.mode != QMC_HDLC)
 734                 return dev_err_probe(dev, -EINVAL, "QMC chan mode %d is not QMC_HDLC\n",
 735                                      info.mode);
 736
 737         ret = qmc_chan_get_ts_info(qmc_hdlc->qmc_chan, &ts_info);
 738         if (ret)
 739                 return dev_err_probe(dev, ret, "get QMC channel ts info failed\n");
 740
 741         ret = qmc_hdlc_xlate_ts_info(qmc_hdlc, &ts_info, &qmc_hdlc->slot_map);
 742         if (ret)
 743                 return ret;
 744
 745         qmc_hdlc->framer = devm_framer_optional_get(dev, "fsl,framer");
 746         if (IS_ERR(qmc_hdlc->framer))
 747                 return PTR_ERR(qmc_hdlc->framer);
 748
 749         ret = qmc_hdlc_framer_init(qmc_hdlc);
 750         if (ret)
 751                 return ret;
 752
 753         qmc_hdlc->netdev = alloc_hdlcdev(qmc_hdlc);
 754         if (!qmc_hdlc->netdev) {
 755                 ret = -ENOMEM;
 756                 goto framer_exit;
 757         }
 758
 759         hdlc = dev_to_hdlc(qmc_hdlc->netdev);
 760         hdlc->attach = qmc_hdlc_attach;
 761         hdlc->xmit = qmc_hdlc_xmit;
 762         SET_NETDEV_DEV(qmc_hdlc->netdev, dev);
 763         qmc_hdlc->netdev->tx_queue_len = ARRAY_SIZE(qmc_hdlc->tx_descs);
 764         qmc_hdlc->netdev->netdev_ops = &qmc_hdlc_netdev_ops;
 765         ret = register_hdlc_device(qmc_hdlc->netdev);
 766         if (ret) {
 767                 dev_err_probe(dev, ret, "failed to register hdlc device\n");
 768                 goto free_netdev;
 769         }
 770
 771         platform_set_drvdata(pdev, qmc_hdlc);
 772         return 0;
 773
 774 free_netdev:
 775         free_netdev(qmc_hdlc->netdev);
 776 framer_exit:
 777         qmc_hdlc_framer_exit(qmc_hdlc);
 778         return ret;
 779 }
 780
 781 static void qmc_hdlc_remove(struct platform_device *pdev)
 782 {
 783         struct qmc_hdlc *qmc_hdlc = platform_get_drvdata(pdev);
 784
 785         unregister_hdlc_device(qmc_hdlc->netdev);
 786         free_netdev(qmc_hdlc->netdev);
 787         qmc_hdlc_framer_exit(qmc_hdlc);
 788 }
 789
 790 static const struct of_device_id qmc_hdlc_id_table[] = {
 791         { .compatible = "fsl,qmc-hdlc" },
 792         {} /* sentinel */
 793 };
 794 MODULE_DEVICE_TABLE(of, qmc_hdlc_id_table);
 795
 796 static struct platform_driver qmc_hdlc_driver = {
 797         .driver = {
 798                 .name = "fsl-qmc-hdlc",
 799                 .of_match_table = qmc_hdlc_id_table,
 800         },
 801         .probe = qmc_hdlc_probe,
 802         .remove = qmc_hdlc_remove,
 803 };
 804 module_platform_driver(qmc_hdlc_driver);
 805
 806 MODULE_AUTHOR("Herve Codina <herve.codina@bootlin.com>");
 807 MODULE_DESCRIPTION("QMC HDLC driver");
 808 MODULE_LICENSE("GPL");