net/nfc/core.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2011 Instituto Nokia de Tecnologia
   4  *
   5  * Authors:
   6  *    Lauro Ramos Venancio <[email protected]>
   7  *    Aloisio Almeida Jr <[email protected]>
   8  */
   9
  10 #define pr_fmt(fmt) KBUILD_MODNAME ": %s: " fmt, __func__
  11
  12 #include <linux/init.h>
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/slab.h>
  16 #include <linux/rfkill.h>
  17 #include <linux/nfc.h>
  18
  19 #include <net/genetlink.h>
  20
  21 #include "nfc.h"
  22
  23 #define VERSION "0.1"
  24
  25 #define NFC_CHECK_PRES_FREQ_MS  2000
  26
  27 int nfc_devlist_generation;
  28 DEFINE_MUTEX(nfc_devlist_mutex);
  29
  30 /* NFC device ID bitmap */
  31 static DEFINE_IDA(nfc_index_ida);
  32
  33 int nfc_fw_download(struct nfc_dev *dev, const char *firmware_name)
  34 {
  35         int rc = 0;
  36
  37         pr_debug("%s do firmware %s\n", dev_name(&dev->dev), firmware_name);
  38
  39         device_lock(&dev->dev);
  40
  41         if (!device_is_registered(&dev->dev)) {
  42                 rc = -ENODEV;
  43                 goto error;
  44         }
  45
  46         if (dev->dev_up) {
  47                 rc = -EBUSY;
  48                 goto error;
  49         }
  50
  51         if (!dev->ops->fw_download) {
  52                 rc = -EOPNOTSUPP;
  53                 goto error;
  54         }
  55
  56         dev->fw_download_in_progress = true;
  57         rc = dev->ops->fw_download(dev, firmware_name);
  58         if (rc)
  59                 dev->fw_download_in_progress = false;
  60
  61 error:
  62         device_unlock(&dev->dev);
  63         return rc;
  64 }
  65
  66 /**
  67  * nfc_fw_download_done - inform that a firmware download was completed
  68  *
  69  * @dev: The nfc device to which firmware was downloaded
  70  * @firmware_name: The firmware filename
  71  * @result: The positive value of a standard errno value
  72  */
  73 int nfc_fw_download_done(struct nfc_dev *dev, const char *firmware_name,
  74                          u32 result)
  75 {
  76         dev->fw_download_in_progress = false;
  77
  78         return nfc_genl_fw_download_done(dev, firmware_name, result);
  79 }
  80 EXPORT_SYMBOL(nfc_fw_download_done);
  81
  82 /**
  83  * nfc_dev_up - turn on the NFC device
  84  *
  85  * @dev: The nfc device to be turned on
  86  *
  87  * The device remains up until the nfc_dev_down function is called.
  88  */
  89 int nfc_dev_up(struct nfc_dev *dev)
  90 {
  91         int rc = 0;
  92
  93         pr_debug("dev_name=%s\n", dev_name(&dev->dev));
  94
  95         device_lock(&dev->dev);
  96
  97         if (dev->rfkill && rfkill_blocked(dev->rfkill)) {
  98                 rc = -ERFKILL;
  99                 goto error;
 100         }
 101
 102         if (!device_is_registered(&dev->dev)) {
 103                 rc = -ENODEV;
 104                 goto error;
 105         }
 106
 107         if (dev->fw_download_in_progress) {
 108                 rc = -EBUSY;
 109                 goto error;
 110         }
 111
 112         if (dev->dev_up) {
 113                 rc = -EALREADY;
 114                 goto error;
 115         }
 116
 117         if (dev->ops->dev_up)
 118                 rc = dev->ops->dev_up(dev);
 119
 120         if (!rc)
 121                 dev->dev_up = true;
 122
 123         /* We have to enable the device before discovering SEs */
 124         if (dev->ops->discover_se && dev->ops->discover_se(dev))
 125                 pr_err("SE discovery failed\n");
 126
 127 error:
 128         device_unlock(&dev->dev);
 129         return rc;
 130 }
 131
 132 /**
 133  * nfc_dev_down - turn off the NFC device
 134  *
 135  * @dev: The nfc device to be turned off
 136  */
 137 int nfc_dev_down(struct nfc_dev *dev)
 138 {
 139         int rc = 0;
 140
 141         pr_debug("dev_name=%s\n", dev_name(&dev->dev));
 142
 143         device_lock(&dev->dev);
 144
 145         if (!device_is_registered(&dev->dev)) {
 146                 rc = -ENODEV;
 147                 goto error;
 148         }
 149
 150         if (!dev->dev_up) {
 151                 rc = -EALREADY;
 152                 goto error;
 153         }
 154
 155         if (dev->polling || dev->active_target) {
 156                 rc = -EBUSY;
 157                 goto error;
 158         }
 159
 160         if (dev->ops->dev_down)
 161                 dev->ops->dev_down(dev);
 162
 163         dev->dev_up = false;
 164
 165 error:
 166         device_unlock(&dev->dev);
 167         return rc;
 168 }
 169
 170 static int nfc_rfkill_set_block(void *data, bool blocked)
 171 {
 172         struct nfc_dev *dev = data;
 173
 174         pr_debug("%s blocked %d", dev_name(&dev->dev), blocked);
 175
 176         if (!blocked)
 177                 return 0;
 178
 179         nfc_dev_down(dev);
 180
 181         return 0;
 182 }
 183
 184 static const struct rfkill_ops nfc_rfkill_ops = {
 185         .set_block = nfc_rfkill_set_block,
 186 };
 187
 188 /**
 189  * nfc_start_poll - start polling for nfc targets
 190  *
 191  * @dev: The nfc device that must start polling
 192  * @protocols: bitset of nfc protocols that must be used for polling
 193  *
 194  * The device remains polling for targets until a target is found or
 195  * the nfc_stop_poll function is called.
 196  */
 197 int nfc_start_poll(struct nfc_dev *dev, u32 im_protocols, u32 tm_protocols)
 198 {
 199         int rc;
 200
 201         pr_debug("dev_name %s initiator protocols 0x%x target protocols 0x%x\n",
 202                  dev_name(&dev->dev), im_protocols, tm_protocols);
 203
 204         if (!im_protocols && !tm_protocols)
 205                 return -EINVAL;
 206
 207         device_lock(&dev->dev);
 208
 209         if (!device_is_registered(&dev->dev)) {
 210                 rc = -ENODEV;
 211                 goto error;
 212         }
 213
 214         if (!dev->dev_up) {
 215                 rc = -ENODEV;
 216                 goto error;
 217         }
 218
 219         if (dev->polling) {
 220                 rc = -EBUSY;
 221                 goto error;
 222         }
 223
 224         rc = dev->ops->start_poll(dev, im_protocols, tm_protocols);
 225         if (!rc) {
 226                 dev->polling = true;
 227                 dev->rf_mode = NFC_RF_NONE;
 228         }
 229
 230 error:
 231         device_unlock(&dev->dev);
 232         return rc;
 233 }
 234
 235 /**
 236  * nfc_stop_poll - stop polling for nfc targets
 237  *
 238  * @dev: The nfc device that must stop polling
 239  */
 240 int nfc_stop_poll(struct nfc_dev *dev)
 241 {
 242         int rc = 0;
 243
 244         pr_debug("dev_name=%s\n", dev_name(&dev->dev));
 245
 246         device_lock(&dev->dev);
 247
 248         if (!device_is_registered(&dev->dev)) {
 249                 rc = -ENODEV;
 250                 goto error;
 251         }
 252
 253         if (!dev->polling) {
 254                 rc = -EINVAL;
 255                 goto error;
 256         }
 257
 258         dev->ops->stop_poll(dev);
 259         dev->polling = false;
 260         dev->rf_mode = NFC_RF_NONE;
 261
 262 error:
 263         device_unlock(&dev->dev);
 264         return rc;
 265 }
 266
 267 static struct nfc_target *nfc_find_target(struct nfc_dev *dev, u32 target_idx)
 268 {
 269         int i;
 270
 271         for (i = 0; i < dev->n_targets; i++) {
 272                 if (dev->targets[i].idx == target_idx)
 273                         return &dev->targets[i];
 274         }
 275
 276         return NULL;
 277 }
 278
 279 int nfc_dep_link_up(struct nfc_dev *dev, int target_index, u8 comm_mode)
 280 {
 281         int rc = 0;
 282         u8 *gb;
 283         size_t gb_len;
 284         struct nfc_target *target;
 285
 286         pr_debug("dev_name=%s comm %d\n", dev_name(&dev->dev), comm_mode);
 287
 288         if (!dev->ops->dep_link_up)
 289                 return -EOPNOTSUPP;
 290
 291         device_lock(&dev->dev);
 292
 293         if (!device_is_registered(&dev->dev)) {
 294                 rc = -ENODEV;
 295                 goto error;
 296         }
 297
 298         if (dev->dep_link_up == true) {
 299                 rc = -EALREADY;
 300                 goto error;
 301         }
 302
 303         gb = nfc_llcp_general_bytes(dev, &gb_len);
 304         if (gb_len > NFC_MAX_GT_LEN) {
 305                 rc = -EINVAL;
 306                 goto error;
 307         }
 308
 309         target = nfc_find_target(dev, target_index);
 310         if (target == NULL) {
 311                 rc = -ENOTCONN;
 312                 goto error;
 313         }
 314
 315         rc = dev->ops->dep_link_up(dev, target, comm_mode, gb, gb_len);
 316         if (!rc) {
 317                 dev->active_target = target;
 318                 dev->rf_mode = NFC_RF_INITIATOR;
 319         }
 320
 321 error:
 322         device_unlock(&dev->dev);
 323         return rc;
 324 }
 325
 326 int nfc_dep_link_down(struct nfc_dev *dev)
 327 {
 328         int rc = 0;
 329
 330         pr_debug("dev_name=%s\n", dev_name(&dev->dev));
 331
 332         if (!dev->ops->dep_link_down)
 333                 return -EOPNOTSUPP;
 334
 335         device_lock(&dev->dev);
 336
 337         if (!device_is_registered(&dev->dev)) {
 338                 rc = -ENODEV;
 339                 goto error;
 340         }
 341
 342         if (dev->dep_link_up == false) {
 343                 rc = -EALREADY;
 344                 goto error;
 345         }
 346
 347         rc = dev->ops->dep_link_down(dev);
 348         if (!rc) {
 349                 dev->dep_link_up = false;
 350                 dev->active_target = NULL;
 351                 dev->rf_mode = NFC_RF_NONE;
 352                 nfc_llcp_mac_is_down(dev);
 353                 nfc_genl_dep_link_down_event(dev);
 354         }
 355
 356 error:
 357         device_unlock(&dev->dev);
 358
 359         return rc;
 360 }
 361
 362 int nfc_dep_link_is_up(struct nfc_dev *dev, u32 target_idx,
 363                        u8 comm_mode, u8 rf_mode)
 364 {
 365         dev->dep_link_up = true;
 366
 367         if (!dev->active_target && rf_mode == NFC_RF_INITIATOR) {
 368                 struct nfc_target *target;
 369
 370                 target = nfc_find_target(dev, target_idx);
 371                 if (target == NULL)
 372                         return -ENOTCONN;
 373
 374                 dev->active_target = target;
 375         }
 376
 377         dev->polling = false;
 378         dev->rf_mode = rf_mode;
 379
 380         nfc_llcp_mac_is_up(dev, target_idx, comm_mode, rf_mode);
 381
 382         return nfc_genl_dep_link_up_event(dev, target_idx, comm_mode, rf_mode);
 383 }
 384 EXPORT_SYMBOL(nfc_dep_link_is_up);
 385
 386 /**
 387  * nfc_activate_target - prepare the target for data exchange
 388  *
 389  * @dev: The nfc device that found the target
 390  * @target_idx: index of the target that must be activated
 391  * @protocol: nfc protocol that will be used for data exchange
 392  */
 393 int nfc_activate_target(struct nfc_dev *dev, u32 target_idx, u32 protocol)
 394 {
 395         int rc;
 396         struct nfc_target *target;
 397
 398         pr_debug("dev_name=%s target_idx=%u protocol=%u\n",
 399                  dev_name(&dev->dev), target_idx, protocol);
 400
 401         device_lock(&dev->dev);
 402
 403         if (!device_is_registered(&dev->dev)) {
 404                 rc = -ENODEV;
 405                 goto error;
 406         }
 407
 408         if (dev->active_target) {
 409                 rc = -EBUSY;
 410                 goto error;
 411         }
 412
 413         target = nfc_find_target(dev, target_idx);
 414         if (target == NULL) {
 415                 rc = -ENOTCONN;
 416                 goto error;
 417         }
 418
 419         rc = dev->ops->activate_target(dev, target, protocol);
 420         if (!rc) {
 421                 dev->active_target = target;
 422                 dev->rf_mode = NFC_RF_INITIATOR;
 423
 424                 if (dev->ops->check_presence && !dev->shutting_down)
 425                         mod_timer(&dev->check_pres_timer, jiffies +
 426                                   msecs_to_jiffies(NFC_CHECK_PRES_FREQ_MS));
 427         }
 428
 429 error:
 430         device_unlock(&dev->dev);
 431         return rc;
 432 }
 433
 434 /**
 435  * nfc_deactivate_target - deactivate a nfc target
 436  *
 437  * @dev: The nfc device that found the target
 438  * @target_idx: index of the target that must be deactivated
 439  */
 440 int nfc_deactivate_target(struct nfc_dev *dev, u32 target_idx, u8 mode)
 441 {
 442         int rc = 0;
 443
 444         pr_debug("dev_name=%s target_idx=%u\n",
 445                  dev_name(&dev->dev), target_idx);
 446
 447         device_lock(&dev->dev);
 448
 449         if (!device_is_registered(&dev->dev)) {
 450                 rc = -ENODEV;
 451                 goto error;
 452         }
 453
 454         if (dev->active_target == NULL) {
 455                 rc = -ENOTCONN;
 456                 goto error;
 457         }
 458
 459         if (dev->active_target->idx != target_idx) {
 460                 rc = -ENOTCONN;
 461                 goto error;
 462         }
 463
 464         if (dev->ops->check_presence)
 465                 del_timer_sync(&dev->check_pres_timer);
 466
 467         dev->ops->deactivate_target(dev, dev->active_target, mode);
 468         dev->active_target = NULL;
 469
 470 error:
 471         device_unlock(&dev->dev);
 472         return rc;
 473 }
 474
 475 /**
 476  * nfc_data_exchange - transceive data
 477  *
 478  * @dev: The nfc device that found the target
 479  * @target_idx: index of the target
 480  * @skb: data to be sent
 481  * @cb: callback called when the response is received
 482  * @cb_context: parameter for the callback function
 483  *
 484  * The user must wait for the callback before calling this function again.
 485  */
 486 int nfc_data_exchange(struct nfc_dev *dev, u32 target_idx, struct sk_buff *skb,
 487                       data_exchange_cb_t cb, void *cb_context)
 488 {
 489         int rc;
 490
 491         pr_debug("dev_name=%s target_idx=%u skb->len=%u\n",
 492                  dev_name(&dev->dev), target_idx, skb->len);
 493
 494         device_lock(&dev->dev);
 495
 496         if (!device_is_registered(&dev->dev)) {
 497                 rc = -ENODEV;
 498                 kfree_skb(skb);
 499                 goto error;
 500         }
 501
 502         if (dev->rf_mode == NFC_RF_INITIATOR && dev->active_target != NULL) {
 503                 if (dev->active_target->idx != target_idx) {
 504                         rc = -EADDRNOTAVAIL;
 505                         kfree_skb(skb);
 506                         goto error;
 507                 }
 508
 509                 if (dev->ops->check_presence)
 510                         del_timer_sync(&dev->check_pres_timer);
 511
 512                 rc = dev->ops->im_transceive(dev, dev->active_target, skb, cb,
 513                                              cb_context);
 514
 515                 if (!rc && dev->ops->check_presence && !dev->shutting_down)
 516                         mod_timer(&dev->check_pres_timer, jiffies +
 517                                   msecs_to_jiffies(NFC_CHECK_PRES_FREQ_MS));
 518         } else if (dev->rf_mode == NFC_RF_TARGET && dev->ops->tm_send != NULL) {
 519                 rc = dev->ops->tm_send(dev, skb);
 520         } else {
 521                 rc = -ENOTCONN;
 522                 kfree_skb(skb);
 523                 goto error;
 524         }
 525
 526
 527 error:
 528         device_unlock(&dev->dev);
 529         return rc;
 530 }
 531
 532 struct nfc_se *nfc_find_se(struct nfc_dev *dev, u32 se_idx)
 533 {
 534         struct nfc_se *se;
 535
 536         list_for_each_entry(se, &dev->secure_elements, list)
 537                 if (se->idx == se_idx)
 538                         return se;
 539
 540         return NULL;
 541 }
 542 EXPORT_SYMBOL(nfc_find_se);
 543
 544 int nfc_enable_se(struct nfc_dev *dev, u32 se_idx)
 545 {
 546         struct nfc_se *se;
 547         int rc;
 548
 549         pr_debug("%s se index %d\n", dev_name(&dev->dev), se_idx);
 550
 551         device_lock(&dev->dev);
 552
 553         if (!device_is_registered(&dev->dev)) {
 554                 rc = -ENODEV;
 555                 goto error;
 556         }
 557
 558         if (!dev->dev_up) {
 559                 rc = -ENODEV;
 560                 goto error;
 561         }
 562
 563         if (dev->polling) {
 564                 rc = -EBUSY;
 565                 goto error;
 566         }
 567
 568         if (!dev->ops->enable_se || !dev->ops->disable_se) {
 569                 rc = -EOPNOTSUPP;
 570                 goto error;
 571         }
 572
 573         se = nfc_find_se(dev, se_idx);
 574         if (!se) {
 575                 rc = -EINVAL;
 576                 goto error;
 577         }
 578
 579         if (se->state == NFC_SE_ENABLED) {
 580                 rc = -EALREADY;
 581                 goto error;
 582         }
 583
 584         rc = dev->ops->enable_se(dev, se_idx);
 585         if (rc >= 0)
 586                 se->state = NFC_SE_ENABLED;
 587
 588 error:
 589         device_unlock(&dev->dev);
 590         return rc;
 591 }
 592
 593 int nfc_disable_se(struct nfc_dev *dev, u32 se_idx)
 594 {
 595         struct nfc_se *se;
 596         int rc;
 597
 598         pr_debug("%s se index %d\n", dev_name(&dev->dev), se_idx);
 599
 600         device_lock(&dev->dev);
 601
 602         if (!device_is_registered(&dev->dev)) {
 603                 rc = -ENODEV;
 604                 goto error;
 605         }
 606
 607         if (!dev->dev_up) {
 608                 rc = -ENODEV;
 609                 goto error;
 610         }
 611
 612         if (!dev->ops->enable_se || !dev->ops->disable_se) {
 613                 rc = -EOPNOTSUPP;
 614                 goto error;
 615         }
 616
 617         se = nfc_find_se(dev, se_idx);
 618         if (!se) {
 619                 rc = -EINVAL;
 620                 goto error;
 621         }
 622
 623         if (se->state == NFC_SE_DISABLED) {
 624                 rc = -EALREADY;
 625                 goto error;
 626         }
 627
 628         rc = dev->ops->disable_se(dev, se_idx);
 629         if (rc >= 0)
 630                 se->state = NFC_SE_DISABLED;
 631
 632 error:
 633         device_unlock(&dev->dev);
 634         return rc;
 635 }
 636
 637 int nfc_set_remote_general_bytes(struct nfc_dev *dev, u8 *gb, u8 gb_len)
 638 {
 639         pr_debug("dev_name=%s gb_len=%d\n", dev_name(&dev->dev), gb_len);
 640
 641         return nfc_llcp_set_remote_gb(dev, gb, gb_len);
 642 }
 643 EXPORT_SYMBOL(nfc_set_remote_general_bytes);
 644
 645 u8 *nfc_get_local_general_bytes(struct nfc_dev *dev, size_t *gb_len)
 646 {
 647         pr_debug("dev_name=%s\n", dev_name(&dev->dev));
 648
 649         return nfc_llcp_general_bytes(dev, gb_len);
 650 }
 651 EXPORT_SYMBOL(nfc_get_local_general_bytes);
 652
 653 int nfc_tm_data_received(struct nfc_dev *dev, struct sk_buff *skb)
 654 {
 655         /* Only LLCP target mode for now */
 656         if (dev->dep_link_up == false) {
 657                 kfree_skb(skb);
 658                 return -ENOLINK;
 659         }
 660
 661         return nfc_llcp_data_received(dev, skb);
 662 }
 663 EXPORT_SYMBOL(nfc_tm_data_received);
 664
 665 int nfc_tm_activated(struct nfc_dev *dev, u32 protocol, u8 comm_mode,
 666                      u8 *gb, size_t gb_len)
 667 {
 668         int rc;
 669
 670         device_lock(&dev->dev);
 671
 672         dev->polling = false;
 673
 674         if (gb != NULL) {
 675                 rc = nfc_set_remote_general_bytes(dev, gb, gb_len);
 676                 if (rc < 0)
 677                         goto out;
 678         }
 679
 680         dev->rf_mode = NFC_RF_TARGET;
 681
 682         if (protocol == NFC_PROTO_NFC_DEP_MASK)
 683                 nfc_dep_link_is_up(dev, 0, comm_mode, NFC_RF_TARGET);
 684
 685         rc = nfc_genl_tm_activated(dev, protocol);
 686
 687 out:
 688         device_unlock(&dev->dev);
 689
 690         return rc;
 691 }
 692 EXPORT_SYMBOL(nfc_tm_activated);
 693
 694 int nfc_tm_deactivated(struct nfc_dev *dev)
 695 {
 696         dev->dep_link_up = false;
 697         dev->rf_mode = NFC_RF_NONE;
 698
 699         return nfc_genl_tm_deactivated(dev);
 700 }
 701 EXPORT_SYMBOL(nfc_tm_deactivated);
 702
 703 /**
 704  * nfc_alloc_send_skb - allocate a skb for data exchange responses
 705  *
 706  * @size: size to allocate
 707  */
 708 struct sk_buff *nfc_alloc_send_skb(struct nfc_dev *dev, struct sock *sk,
 709                                    unsigned int flags, unsigned int size,
 710                                    unsigned int *err)
 711 {
 712         struct sk_buff *skb;
 713         unsigned int total_size;
 714
 715         total_size = size +
 716                 dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
 717
 718         skb = sock_alloc_send_skb(sk, total_size, flags & MSG_DONTWAIT, err);
 719         if (skb)
 720                 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
 721
 722         return skb;
 723 }
 724
 725 /**
 726  * nfc_alloc_recv_skb - allocate a skb for data exchange responses
 727  *
 728  * @size: size to allocate
 729  * @gfp: gfp flags
 730  */
 731 struct sk_buff *nfc_alloc_recv_skb(unsigned int size, gfp_t gfp)
 732 {
 733         struct sk_buff *skb;
 734         unsigned int total_size;
 735
 736         total_size = size + 1;
 737         skb = alloc_skb(total_size, gfp);
 738
 739         if (skb)
 740                 skb_reserve(skb, 1);
 741
 742         return skb;
 743 }
 744 EXPORT_SYMBOL(nfc_alloc_recv_skb);
 745
 746 /**
 747  * nfc_targets_found - inform that targets were found
 748  *
 749  * @dev: The nfc device that found the targets
 750  * @targets: array of nfc targets found
 751  * @n_targets: targets array size
 752  *
 753  * The device driver must call this function when one or many nfc targets
 754  * are found. After calling this function, the device driver must stop
 755  * polling for targets.
 756  * NOTE: This function can be called with targets=NULL and n_targets=0 to
 757  * notify a driver error, meaning that the polling operation cannot complete.
 758  * IMPORTANT: this function must not be called from an atomic context.
 759  * In addition, it must also not be called from a context that would prevent
 760  * the NFC Core to call other nfc ops entry point concurrently.
 761  */
 762 int nfc_targets_found(struct nfc_dev *dev,
 763                       struct nfc_target *targets, int n_targets)
 764 {
 765         int i;
 766
 767         pr_debug("dev_name=%s n_targets=%d\n", dev_name(&dev->dev), n_targets);
 768
 769         for (i = 0; i < n_targets; i++)
 770                 targets[i].idx = dev->target_next_idx++;
 771
 772         device_lock(&dev->dev);
 773
 774         if (dev->polling == false) {
 775                 device_unlock(&dev->dev);
 776                 return 0;
 777         }
 778
 779         dev->polling = false;
 780
 781         dev->targets_generation++;
 782
 783         kfree(dev->targets);
 784         dev->targets = NULL;
 785
 786         if (targets) {
 787                 dev->targets = kmemdup(targets,
 788                                        n_targets * sizeof(struct nfc_target),
 789                                        GFP_ATOMIC);
 790
 791                 if (!dev->targets) {
 792                         dev->n_targets = 0;
 793                         device_unlock(&dev->dev);
 794                         return -ENOMEM;
 795                 }
 796         }
 797
 798         dev->n_targets = n_targets;
 799         device_unlock(&dev->dev);
 800
 801         nfc_genl_targets_found(dev);
 802
 803         return 0;
 804 }
 805 EXPORT_SYMBOL(nfc_targets_found);
 806
 807 /**
 808  * nfc_target_lost - inform that an activated target went out of field
 809  *
 810  * @dev: The nfc device that had the activated target in field
 811  * @target_idx: the nfc index of the target
 812  *
 813  * The device driver must call this function when the activated target
 814  * goes out of the field.
 815  * IMPORTANT: this function must not be called from an atomic context.
 816  * In addition, it must also not be called from a context that would prevent
 817  * the NFC Core to call other nfc ops entry point concurrently.
 818  */
 819 int nfc_target_lost(struct nfc_dev *dev, u32 target_idx)
 820 {
 821         struct nfc_target *tg;
 822         int i;
 823
 824         pr_debug("dev_name %s n_target %d\n", dev_name(&dev->dev), target_idx);
 825
 826         device_lock(&dev->dev);
 827
 828         for (i = 0; i < dev->n_targets; i++) {
 829                 tg = &dev->targets[i];
 830                 if (tg->idx == target_idx)
 831                         break;
 832         }
 833
 834         if (i == dev->n_targets) {
 835                 device_unlock(&dev->dev);
 836                 return -EINVAL;
 837         }
 838
 839         dev->targets_generation++;
 840         dev->n_targets--;
 841         dev->active_target = NULL;
 842
 843         if (dev->n_targets) {
 844                 memcpy(&dev->targets[i], &dev->targets[i + 1],
 845                        (dev->n_targets - i) * sizeof(struct nfc_target));
 846         } else {
 847                 kfree(dev->targets);
 848                 dev->targets = NULL;
 849         }
 850
 851         device_unlock(&dev->dev);
 852
 853         nfc_genl_target_lost(dev, target_idx);
 854
 855         return 0;
 856 }
 857 EXPORT_SYMBOL(nfc_target_lost);
 858
 859 inline void nfc_driver_failure(struct nfc_dev *dev, int err)
 860 {
 861         nfc_targets_found(dev, NULL, 0);
 862 }
 863 EXPORT_SYMBOL(nfc_driver_failure);
 864
 865 int nfc_add_se(struct nfc_dev *dev, u32 se_idx, u16 type)
 866 {
 867         struct nfc_se *se;
 868         int rc;
 869
 870         pr_debug("%s se index %d\n", dev_name(&dev->dev), se_idx);
 871
 872         se = nfc_find_se(dev, se_idx);
 873         if (se)
 874                 return -EALREADY;
 875
 876         se = kzalloc(sizeof(struct nfc_se), GFP_KERNEL);
 877         if (!se)
 878                 return -ENOMEM;
 879
 880         se->idx = se_idx;
 881         se->type = type;
 882         se->state = NFC_SE_DISABLED;
 883         INIT_LIST_HEAD(&se->list);
 884
 885         list_add(&se->list, &dev->secure_elements);
 886
 887         rc = nfc_genl_se_added(dev, se_idx, type);
 888         if (rc < 0) {
 889                 list_del(&se->list);
 890                 kfree(se);
 891
 892                 return rc;
 893         }
 894
 895         return 0;
 896 }
 897 EXPORT_SYMBOL(nfc_add_se);
 898
 899 int nfc_remove_se(struct nfc_dev *dev, u32 se_idx)
 900 {
 901         struct nfc_se *se, *n;
 902         int rc;
 903
 904         pr_debug("%s se index %d\n", dev_name(&dev->dev), se_idx);
 905
 906         list_for_each_entry_safe(se, n, &dev->secure_elements, list)
 907                 if (se->idx == se_idx) {
 908                         rc = nfc_genl_se_removed(dev, se_idx);
 909                         if (rc < 0)
 910                                 return rc;
 911
 912                         list_del(&se->list);
 913                         kfree(se);
 914
 915                         return 0;
 916                 }
 917
 918         return -EINVAL;
 919 }
 920 EXPORT_SYMBOL(nfc_remove_se);
 921
 922 int nfc_se_transaction(struct nfc_dev *dev, u8 se_idx,
 923                        struct nfc_evt_transaction *evt_transaction)
 924 {
 925         int rc;
 926
 927         pr_debug("transaction: %x\n", se_idx);
 928
 929         device_lock(&dev->dev);
 930
 931         if (!evt_transaction) {
 932                 rc = -EPROTO;
 933                 goto out;
 934         }
 935
 936         rc = nfc_genl_se_transaction(dev, se_idx, evt_transaction);
 937 out:
 938         device_unlock(&dev->dev);
 939         return rc;
 940 }
 941 EXPORT_SYMBOL(nfc_se_transaction);
 942
 943 int nfc_se_connectivity(struct nfc_dev *dev, u8 se_idx)
 944 {
 945         int rc;
 946
 947         pr_debug("connectivity: %x\n", se_idx);
 948
 949         device_lock(&dev->dev);
 950         rc = nfc_genl_se_connectivity(dev, se_idx);
 951         device_unlock(&dev->dev);
 952         return rc;
 953 }
 954 EXPORT_SYMBOL(nfc_se_connectivity);
 955
 956 static void nfc_release(struct device *d)
 957 {
 958         struct nfc_dev *dev = to_nfc_dev(d);
 959         struct nfc_se *se, *n;
 960
 961         pr_debug("dev_name=%s\n", dev_name(&dev->dev));
 962
 963         nfc_genl_data_exit(&dev->genl_data);
 964         kfree(dev->targets);
 965
 966         list_for_each_entry_safe(se, n, &dev->secure_elements, list) {
 967                         nfc_genl_se_removed(dev, se->idx);
 968                         list_del(&se->list);
 969                         kfree(se);
 970         }
 971
 972         ida_simple_remove(&nfc_index_ida, dev->idx);
 973
 974         kfree(dev);
 975 }
 976
 977 static void nfc_check_pres_work(struct work_struct *work)
 978 {
 979         struct nfc_dev *dev = container_of(work, struct nfc_dev,
 980                                            check_pres_work);
 981         int rc;
 982
 983         device_lock(&dev->dev);
 984
 985         if (dev->active_target && timer_pending(&dev->check_pres_timer) == 0) {
 986                 rc = dev->ops->check_presence(dev, dev->active_target);
 987                 if (rc == -EOPNOTSUPP)
 988                         goto exit;
 989                 if (rc) {
 990                         u32 active_target_idx = dev->active_target->idx;
 991                         device_unlock(&dev->dev);
 992                         nfc_target_lost(dev, active_target_idx);
 993                         return;
 994                 }
 995
 996                 if (!dev->shutting_down)
 997                         mod_timer(&dev->check_pres_timer, jiffies +
 998                                   msecs_to_jiffies(NFC_CHECK_PRES_FREQ_MS));
 999         }
1000
1001 exit:
1002         device_unlock(&dev->dev);
1003 }
1004
1005 static void nfc_check_pres_timeout(struct timer_list *t)
1006 {
1007         struct nfc_dev *dev = from_timer(dev, t, check_pres_timer);
1008
1009         schedule_work(&dev->check_pres_work);
1010 }
1011
1012 struct class nfc_class = {
1013         .name = "nfc",
1014         .dev_release = nfc_release,
1015 };
1016 EXPORT_SYMBOL(nfc_class);
1017
1018 static int match_idx(struct device *d, const void *data)
1019 {
1020         struct nfc_dev *dev = to_nfc_dev(d);
1021         const unsigned int *idx = data;
1022
1023         return dev->idx == *idx;
1024 }
1025
1026 struct nfc_dev *nfc_get_device(unsigned int idx)
1027 {
1028         struct device *d;
1029
1030         d = class_find_device(&nfc_class, NULL, &idx, match_idx);
1031         if (!d)
1032                 return NULL;
1033
1034         return to_nfc_dev(d);
1035 }
1036
1037 /**
1038  * nfc_allocate_device - allocate a new nfc device
1039  *
1040  * @ops: device operations
1041  * @supported_protocols: NFC protocols supported by the device
1042  */
1043 struct nfc_dev *nfc_allocate_device(struct nfc_ops *ops,
1044                                     u32 supported_protocols,
1045                                     int tx_headroom, int tx_tailroom)
1046 {
1047         struct nfc_dev *dev;
1048         int rc;
1049
1050         if (!ops->start_poll || !ops->stop_poll || !ops->activate_target ||
1051             !ops->deactivate_target || !ops->im_transceive)
1052                 return NULL;
1053
1054         if (!supported_protocols)
1055                 return NULL;
1056
1057         dev = kzalloc(sizeof(struct nfc_dev), GFP_KERNEL);
1058         if (!dev)
1059                 return NULL;
1060
1061         rc = ida_simple_get(&nfc_index_ida, 0, 0, GFP_KERNEL);
1062         if (rc < 0)
1063                 goto err_free_dev;
1064         dev->idx = rc;
1065
1066         dev->dev.class = &nfc_class;
1067         dev_set_name(&dev->dev, "nfc%d", dev->idx);
1068         device_initialize(&dev->dev);
1069
1070         dev->ops = ops;
1071         dev->supported_protocols = supported_protocols;
1072         dev->tx_headroom = tx_headroom;
1073         dev->tx_tailroom = tx_tailroom;
1074         INIT_LIST_HEAD(&dev->secure_elements);
1075
1076         nfc_genl_data_init(&dev->genl_data);
1077
1078         dev->rf_mode = NFC_RF_NONE;
1079
1080         /* first generation must not be 0 */
1081         dev->targets_generation = 1;
1082
1083         if (ops->check_presence) {
1084                 timer_setup(&dev->check_pres_timer, nfc_check_pres_timeout, 0);
1085                 INIT_WORK(&dev->check_pres_work, nfc_check_pres_work);
1086         }
1087
1088         return dev;
1089
1090 err_free_dev:
1091         kfree(dev);
1092
1093         return NULL;
1094 }
1095 EXPORT_SYMBOL(nfc_allocate_device);
1096
1097 /**
1098  * nfc_register_device - register a nfc device in the nfc subsystem
1099  *
1100  * @dev: The nfc device to register
1101  */
1102 int nfc_register_device(struct nfc_dev *dev)
1103 {
1104         int rc;
1105
1106         pr_debug("dev_name=%s\n", dev_name(&dev->dev));
1107
1108         mutex_lock(&nfc_devlist_mutex);
1109         nfc_devlist_generation++;
1110         rc = device_add(&dev->dev);
1111         mutex_unlock(&nfc_devlist_mutex);
1112
1113         if (rc < 0)
1114                 return rc;
1115
1116         rc = nfc_llcp_register_device(dev);
1117         if (rc)
1118                 pr_err("Could not register llcp device\n");
1119
1120         rc = nfc_genl_device_added(dev);
1121         if (rc)
1122                 pr_debug("The userspace won't be notified that the device %s was added\n",
1123                          dev_name(&dev->dev));
1124
1125         dev->rfkill = rfkill_alloc(dev_name(&dev->dev), &dev->dev,
1126                                    RFKILL_TYPE_NFC, &nfc_rfkill_ops, dev);
1127         if (dev->rfkill) {
1128                 if (rfkill_register(dev->rfkill) < 0) {
1129                         rfkill_destroy(dev->rfkill);
1130                         dev->rfkill = NULL;
1131                 }
1132         }
1133
1134         return 0;
1135 }
1136 EXPORT_SYMBOL(nfc_register_device);
1137
1138 /**
1139  * nfc_unregister_device - unregister a nfc device in the nfc subsystem
1140  *
1141  * @dev: The nfc device to unregister
1142  */
1143 void nfc_unregister_device(struct nfc_dev *dev)
1144 {
1145         int rc;
1146
1147         pr_debug("dev_name=%s\n", dev_name(&dev->dev));
1148
1149         if (dev->rfkill) {
1150                 rfkill_unregister(dev->rfkill);
1151                 rfkill_destroy(dev->rfkill);
1152         }
1153
1154         if (dev->ops->check_presence) {
1155                 device_lock(&dev->dev);
1156                 dev->shutting_down = true;
1157                 device_unlock(&dev->dev);
1158                 del_timer_sync(&dev->check_pres_timer);
1159                 cancel_work_sync(&dev->check_pres_work);
1160         }
1161
1162         rc = nfc_genl_device_removed(dev);
1163         if (rc)
1164                 pr_debug("The userspace won't be notified that the device %s "
1165                          "was removed\n", dev_name(&dev->dev));
1166
1167         nfc_llcp_unregister_device(dev);
1168
1169         mutex_lock(&nfc_devlist_mutex);
1170         nfc_devlist_generation++;
1171         device_del(&dev->dev);
1172         mutex_unlock(&nfc_devlist_mutex);
1173 }
1174 EXPORT_SYMBOL(nfc_unregister_device);
1175
1176 static int __init nfc_init(void)
1177 {
1178         int rc;
1179
1180         pr_info("NFC Core ver %s\n", VERSION);
1181
1182         rc = class_register(&nfc_class);
1183         if (rc)
1184                 return rc;
1185
1186         rc = nfc_genl_init();
1187         if (rc)
1188                 goto err_genl;
1189
1190         /* the first generation must not be 0 */
1191         nfc_devlist_generation = 1;
1192
1193         rc = rawsock_init();
1194         if (rc)
1195                 goto err_rawsock;
1196
1197         rc = nfc_llcp_init();
1198         if (rc)
1199                 goto err_llcp_sock;
1200
1201         rc = af_nfc_init();
1202         if (rc)
1203                 goto err_af_nfc;
1204
1205         return 0;
1206
1207 err_af_nfc:
1208         nfc_llcp_exit();
1209 err_llcp_sock:
1210         rawsock_exit();
1211 err_rawsock:
1212         nfc_genl_exit();
1213 err_genl:
1214         class_unregister(&nfc_class);
1215         return rc;
1216 }
1217
1218 static void __exit nfc_exit(void)
1219 {
1220         af_nfc_exit();
1221         nfc_llcp_exit();
1222         rawsock_exit();
1223         nfc_genl_exit();
1224         class_unregister(&nfc_class);
1225 }
1226
1227 subsys_initcall(nfc_init);
1228 module_exit(nfc_exit);
1229
1230 MODULE_AUTHOR("Lauro Ramos Venancio <[email protected]>");
1231 MODULE_DESCRIPTION("NFC Core ver " VERSION);
1232 MODULE_VERSION(VERSION);
1233 MODULE_LICENSE("GPL");
1234 MODULE_ALIAS_NETPROTO(PF_NFC);
1235 MODULE_ALIAS_GENL_FAMILY(NFC_GENL_NAME);