net/nfc/core.c

   1 /*
   2  * Copyright (C) 2011 Instituto Nokia de Tecnologia
   3  *
   4  * Authors:
   5  *    Lauro Ramos Venancio <lauro.venancio@openbossa.org>
   6  *    Aloisio Almeida Jr <aloisio.almeida@openbossa.org>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the
  20  * Free Software Foundation, Inc.,
  21  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  22  */
  23
  24 #define pr_fmt(fmt) KBUILD_MODNAME ": %s: " fmt, __func__
  25
  26 #include <linux/init.h>
  27 #include <linux/kernel.h>
  28 #include <linux/module.h>
  29 #include <linux/slab.h>
  30 #include <linux/nfc.h>
  31
  32 #include <net/genetlink.h>
  33
  34 #include "nfc.h"
  35
  36 #define VERSION "0.1"
  37
  38 #define NFC_CHECK_PRES_FREQ_MS  2000
  39
  40 int nfc_devlist_generation;
  41 DEFINE_MUTEX(nfc_devlist_mutex);
  42
  43 /* NFC device ID bitmap */
  44 static DEFINE_IDA(nfc_index_ida);
  45
  46 /**
  47  * nfc_dev_up - turn on the NFC device
  48  *
  49  * @dev: The nfc device to be turned on
  50  *
  51  * The device remains up until the nfc_dev_down function is called.
  52  */
  53 int nfc_dev_up(struct nfc_dev *dev)
  54 {
  55         int rc = 0;
  56
  57         pr_debug("dev_name=%s\n", dev_name(&dev->dev));
  58
  59         device_lock(&dev->dev);
  60
  61         if (!device_is_registered(&dev->dev)) {
  62                 rc = -ENODEV;
  63                 goto error;
  64         }
  65
  66         if (dev->dev_up) {
  67                 rc = -EALREADY;
  68                 goto error;
  69         }
  70
  71         if (dev->ops->dev_up)
  72                 rc = dev->ops->dev_up(dev);
  73
  74         if (!rc)
  75                 dev->dev_up = true;
  76
  77 error:
  78         device_unlock(&dev->dev);
  79         return rc;
  80 }
  81
  82 /**
  83  * nfc_dev_down - turn off the NFC device
  84  *
  85  * @dev: The nfc device to be turned off
  86  */
  87 int nfc_dev_down(struct nfc_dev *dev)
  88 {
  89         int rc = 0;
  90
  91         pr_debug("dev_name=%s\n", dev_name(&dev->dev));
  92
  93         device_lock(&dev->dev);
  94
  95         if (!device_is_registered(&dev->dev)) {
  96                 rc = -ENODEV;
  97                 goto error;
  98         }
  99
 100         if (!dev->dev_up) {
 101                 rc = -EALREADY;
 102                 goto error;
 103         }
 104
 105         if (dev->polling || dev->active_target) {
 106                 rc = -EBUSY;
 107                 goto error;
 108         }
 109
 110         if (dev->ops->dev_down)
 111                 dev->ops->dev_down(dev);
 112
 113         dev->dev_up = false;
 114
 115 error:
 116         device_unlock(&dev->dev);
 117         return rc;
 118 }
 119
 120 /**
 121  * nfc_start_poll - start polling for nfc targets
 122  *
 123  * @dev: The nfc device that must start polling
 124  * @protocols: bitset of nfc protocols that must be used for polling
 125  *
 126  * The device remains polling for targets until a target is found or
 127  * the nfc_stop_poll function is called.
 128  */
 129 int nfc_start_poll(struct nfc_dev *dev, u32 im_protocols, u32 tm_protocols)
 130 {
 131         int rc;
 132
 133         pr_debug("dev_name %s initiator protocols 0x%x target protocols 0x%x\n",
 134                  dev_name(&dev->dev), im_protocols, tm_protocols);
 135
 136         if (!im_protocols && !tm_protocols)
 137                 return -EINVAL;
 138
 139         device_lock(&dev->dev);
 140
 141         if (!device_is_registered(&dev->dev)) {
 142                 rc = -ENODEV;
 143                 goto error;
 144         }
 145
 146         if (dev->polling) {
 147                 rc = -EBUSY;
 148                 goto error;
 149         }
 150
 151         rc = dev->ops->start_poll(dev, im_protocols, tm_protocols);
 152         if (!rc) {
 153                 dev->polling = true;
 154                 dev->rf_mode = NFC_RF_NONE;
 155         }
 156
 157 error:
 158         device_unlock(&dev->dev);
 159         return rc;
 160 }
 161
 162 /**
 163  * nfc_stop_poll - stop polling for nfc targets
 164  *
 165  * @dev: The nfc device that must stop polling
 166  */
 167 int nfc_stop_poll(struct nfc_dev *dev)
 168 {
 169         int rc = 0;
 170
 171         pr_debug("dev_name=%s\n", dev_name(&dev->dev));
 172
 173         device_lock(&dev->dev);
 174
 175         if (!device_is_registered(&dev->dev)) {
 176                 rc = -ENODEV;
 177                 goto error;
 178         }
 179
 180         if (!dev->polling) {
 181                 rc = -EINVAL;
 182                 goto error;
 183         }
 184
 185         dev->ops->stop_poll(dev);
 186         dev->polling = false;
 187         dev->rf_mode = NFC_RF_NONE;
 188
 189 error:
 190         device_unlock(&dev->dev);
 191         return rc;
 192 }
 193
 194 static struct nfc_target *nfc_find_target(struct nfc_dev *dev, u32 target_idx)
 195 {
 196         int i;
 197
 198         if (dev->n_targets == 0)
 199                 return NULL;
 200
 201         for (i = 0; i < dev->n_targets; i++) {
 202                 if (dev->targets[i].idx == target_idx)
 203                         return &dev->targets[i];
 204         }
 205
 206         return NULL;
 207 }
 208
 209 int nfc_dep_link_up(struct nfc_dev *dev, int target_index, u8 comm_mode)
 210 {
 211         int rc = 0;
 212         u8 *gb;
 213         size_t gb_len;
 214         struct nfc_target *target;
 215
 216         pr_debug("dev_name=%s comm %d\n", dev_name(&dev->dev), comm_mode);
 217
 218         if (!dev->ops->dep_link_up)
 219                 return -EOPNOTSUPP;
 220
 221         device_lock(&dev->dev);
 222
 223         if (!device_is_registered(&dev->dev)) {
 224                 rc = -ENODEV;
 225                 goto error;
 226         }
 227
 228         if (dev->dep_link_up == true) {
 229                 rc = -EALREADY;
 230                 goto error;
 231         }
 232
 233         gb = nfc_llcp_general_bytes(dev, &gb_len);
 234         if (gb_len > NFC_MAX_GT_LEN) {
 235                 rc = -EINVAL;
 236                 goto error;
 237         }
 238
 239         target = nfc_find_target(dev, target_index);
 240         if (target == NULL) {
 241                 rc = -ENOTCONN;
 242                 goto error;
 243         }
 244
 245         rc = dev->ops->dep_link_up(dev, target, comm_mode, gb, gb_len);
 246         if (!rc) {
 247                 dev->active_target = target;
 248                 dev->rf_mode = NFC_RF_INITIATOR;
 249         }
 250
 251 error:
 252         device_unlock(&dev->dev);
 253         return rc;
 254 }
 255
 256 int nfc_dep_link_down(struct nfc_dev *dev)
 257 {
 258         int rc = 0;
 259
 260         pr_debug("dev_name=%s\n", dev_name(&dev->dev));
 261
 262         if (!dev->ops->dep_link_down)
 263                 return -EOPNOTSUPP;
 264
 265         device_lock(&dev->dev);
 266
 267         if (!device_is_registered(&dev->dev)) {
 268                 rc = -ENODEV;
 269                 goto error;
 270         }
 271
 272         if (dev->dep_link_up == false) {
 273                 rc = -EALREADY;
 274                 goto error;
 275         }
 276
 277         rc = dev->ops->dep_link_down(dev);
 278         if (!rc) {
 279                 dev->dep_link_up = false;
 280                 dev->active_target = NULL;
 281                 dev->rf_mode = NFC_RF_NONE;
 282                 nfc_llcp_mac_is_down(dev);
 283                 nfc_genl_dep_link_down_event(dev);
 284         }
 285
 286 error:
 287         device_unlock(&dev->dev);
 288
 289         return rc;
 290 }
 291
 292 int nfc_dep_link_is_up(struct nfc_dev *dev, u32 target_idx,
 293                        u8 comm_mode, u8 rf_mode)
 294 {
 295         dev->dep_link_up = true;
 296
 297         nfc_llcp_mac_is_up(dev, target_idx, comm_mode, rf_mode);
 298
 299         return nfc_genl_dep_link_up_event(dev, target_idx, comm_mode, rf_mode);
 300 }
 301 EXPORT_SYMBOL(nfc_dep_link_is_up);
 302
 303 /**
 304  * nfc_activate_target - prepare the target for data exchange
 305  *
 306  * @dev: The nfc device that found the target
 307  * @target_idx: index of the target that must be activated
 308  * @protocol: nfc protocol that will be used for data exchange
 309  */
 310 int nfc_activate_target(struct nfc_dev *dev, u32 target_idx, u32 protocol)
 311 {
 312         int rc;
 313         struct nfc_target *target;
 314
 315         pr_debug("dev_name=%s target_idx=%u protocol=%u\n",
 316                  dev_name(&dev->dev), target_idx, protocol);
 317
 318         device_lock(&dev->dev);
 319
 320         if (!device_is_registered(&dev->dev)) {
 321                 rc = -ENODEV;
 322                 goto error;
 323         }
 324
 325         if (dev->active_target) {
 326                 rc = -EBUSY;
 327                 goto error;
 328         }
 329
 330         target = nfc_find_target(dev, target_idx);
 331         if (target == NULL) {
 332                 rc = -ENOTCONN;
 333                 goto error;
 334         }
 335
 336         rc = dev->ops->activate_target(dev, target, protocol);
 337         if (!rc) {
 338                 dev->active_target = target;
 339                 dev->rf_mode = NFC_RF_INITIATOR;
 340
 341                 if (dev->ops->check_presence && !dev->shutting_down)
 342                         mod_timer(&dev->check_pres_timer, jiffies +
 343                                   msecs_to_jiffies(NFC_CHECK_PRES_FREQ_MS));
 344         }
 345
 346 error:
 347         device_unlock(&dev->dev);
 348         return rc;
 349 }
 350
 351 /**
 352  * nfc_deactivate_target - deactivate a nfc target
 353  *
 354  * @dev: The nfc device that found the target
 355  * @target_idx: index of the target that must be deactivated
 356  */
 357 int nfc_deactivate_target(struct nfc_dev *dev, u32 target_idx)
 358 {
 359         int rc = 0;
 360
 361         pr_debug("dev_name=%s target_idx=%u\n",
 362                  dev_name(&dev->dev), target_idx);
 363
 364         device_lock(&dev->dev);
 365
 366         if (!device_is_registered(&dev->dev)) {
 367                 rc = -ENODEV;
 368                 goto error;
 369         }
 370
 371         if (dev->active_target == NULL) {
 372                 rc = -ENOTCONN;
 373                 goto error;
 374         }
 375
 376         if (dev->active_target->idx != target_idx) {
 377                 rc = -ENOTCONN;
 378                 goto error;
 379         }
 380
 381         if (dev->ops->check_presence)
 382                 del_timer_sync(&dev->check_pres_timer);
 383
 384         dev->ops->deactivate_target(dev, dev->active_target);
 385         dev->active_target = NULL;
 386
 387 error:
 388         device_unlock(&dev->dev);
 389         return rc;
 390 }
 391
 392 /**
 393  * nfc_data_exchange - transceive data
 394  *
 395  * @dev: The nfc device that found the target
 396  * @target_idx: index of the target
 397  * @skb: data to be sent
 398  * @cb: callback called when the response is received
 399  * @cb_context: parameter for the callback function
 400  *
 401  * The user must wait for the callback before calling this function again.
 402  */
 403 int nfc_data_exchange(struct nfc_dev *dev, u32 target_idx, struct sk_buff *skb,
 404                       data_exchange_cb_t cb, void *cb_context)
 405 {
 406         int rc;
 407
 408         pr_debug("dev_name=%s target_idx=%u skb->len=%u\n",
 409                  dev_name(&dev->dev), target_idx, skb->len);
 410
 411         device_lock(&dev->dev);
 412
 413         if (!device_is_registered(&dev->dev)) {
 414                 rc = -ENODEV;
 415                 kfree_skb(skb);
 416                 goto error;
 417         }
 418
 419         if (dev->rf_mode == NFC_RF_INITIATOR && dev->active_target != NULL) {
 420                 if (dev->active_target->idx != target_idx) {
 421                         rc = -EADDRNOTAVAIL;
 422                         kfree_skb(skb);
 423                         goto error;
 424                 }
 425
 426                 if (dev->ops->check_presence)
 427                         del_timer_sync(&dev->check_pres_timer);
 428
 429                 rc = dev->ops->im_transceive(dev, dev->active_target, skb, cb,
 430                                              cb_context);
 431
 432                 if (!rc && dev->ops->check_presence && !dev->shutting_down)
 433                         mod_timer(&dev->check_pres_timer, jiffies +
 434                                   msecs_to_jiffies(NFC_CHECK_PRES_FREQ_MS));
 435         } else if (dev->rf_mode == NFC_RF_TARGET && dev->ops->tm_send != NULL) {
 436                 rc = dev->ops->tm_send(dev, skb);
 437         } else {
 438                 rc = -ENOTCONN;
 439                 kfree_skb(skb);
 440                 goto error;
 441         }
 442
 443
 444 error:
 445         device_unlock(&dev->dev);
 446         return rc;
 447 }
 448
 449 int nfc_set_remote_general_bytes(struct nfc_dev *dev, u8 *gb, u8 gb_len)
 450 {
 451         pr_debug("dev_name=%s gb_len=%d\n", dev_name(&dev->dev), gb_len);
 452
 453         if (gb_len > NFC_MAX_GT_LEN)
 454                 return -EINVAL;
 455
 456         return nfc_llcp_set_remote_gb(dev, gb, gb_len);
 457 }
 458 EXPORT_SYMBOL(nfc_set_remote_general_bytes);
 459
 460 u8 *nfc_get_local_general_bytes(struct nfc_dev *dev, size_t *gb_len)
 461 {
 462         pr_debug("dev_name=%s\n", dev_name(&dev->dev));
 463
 464         return nfc_llcp_general_bytes(dev, gb_len);
 465 }
 466 EXPORT_SYMBOL(nfc_get_local_general_bytes);
 467
 468 int nfc_tm_data_received(struct nfc_dev *dev, struct sk_buff *skb)
 469 {
 470         /* Only LLCP target mode for now */
 471         if (dev->dep_link_up == false) {
 472                 kfree_skb(skb);
 473                 return -ENOLINK;
 474         }
 475
 476         return nfc_llcp_data_received(dev, skb);
 477 }
 478 EXPORT_SYMBOL(nfc_tm_data_received);
 479
 480 int nfc_tm_activated(struct nfc_dev *dev, u32 protocol, u8 comm_mode,
 481                      u8 *gb, size_t gb_len)
 482 {
 483         int rc;
 484
 485         device_lock(&dev->dev);
 486
 487         dev->polling = false;
 488
 489         if (gb != NULL) {
 490                 rc = nfc_set_remote_general_bytes(dev, gb, gb_len);
 491                 if (rc < 0)
 492                         goto out;
 493         }
 494
 495         dev->rf_mode = NFC_RF_TARGET;
 496
 497         if (protocol == NFC_PROTO_NFC_DEP_MASK)
 498                 nfc_dep_link_is_up(dev, 0, comm_mode, NFC_RF_TARGET);
 499
 500         rc = nfc_genl_tm_activated(dev, protocol);
 501
 502 out:
 503         device_unlock(&dev->dev);
 504
 505         return rc;
 506 }
 507 EXPORT_SYMBOL(nfc_tm_activated);
 508
 509 int nfc_tm_deactivated(struct nfc_dev *dev)
 510 {
 511         dev->dep_link_up = false;
 512         dev->rf_mode = NFC_RF_NONE;
 513
 514         return nfc_genl_tm_deactivated(dev);
 515 }
 516 EXPORT_SYMBOL(nfc_tm_deactivated);
 517
 518 /**
 519  * nfc_alloc_send_skb - allocate a skb for data exchange responses
 520  *
 521  * @size: size to allocate
 522  * @gfp: gfp flags
 523  */
 524 struct sk_buff *nfc_alloc_send_skb(struct nfc_dev *dev, struct sock *sk,
 525                                    unsigned int flags, unsigned int size,
 526                                    unsigned int *err)
 527 {
 528         struct sk_buff *skb;
 529         unsigned int total_size;
 530
 531         total_size = size +
 532                 dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
 533
 534         skb = sock_alloc_send_skb(sk, total_size, flags & MSG_DONTWAIT, err);
 535         if (skb)
 536                 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
 537
 538         return skb;
 539 }
 540
 541 /**
 542  * nfc_alloc_recv_skb - allocate a skb for data exchange responses
 543  *
 544  * @size: size to allocate
 545  * @gfp: gfp flags
 546  */
 547 struct sk_buff *nfc_alloc_recv_skb(unsigned int size, gfp_t gfp)
 548 {
 549         struct sk_buff *skb;
 550         unsigned int total_size;
 551
 552         total_size = size + 1;
 553         skb = alloc_skb(total_size, gfp);
 554
 555         if (skb)
 556                 skb_reserve(skb, 1);
 557
 558         return skb;
 559 }
 560 EXPORT_SYMBOL(nfc_alloc_recv_skb);
 561
 562 /**
 563  * nfc_targets_found - inform that targets were found
 564  *
 565  * @dev: The nfc device that found the targets
 566  * @targets: array of nfc targets found
 567  * @ntargets: targets array size
 568  *
 569  * The device driver must call this function when one or many nfc targets
 570  * are found. After calling this function, the device driver must stop
 571  * polling for targets.
 572  * NOTE: This function can be called with targets=NULL and n_targets=0 to
 573  * notify a driver error, meaning that the polling operation cannot complete.
 574  * IMPORTANT: this function must not be called from an atomic context.
 575  * In addition, it must also not be called from a context that would prevent
 576  * the NFC Core to call other nfc ops entry point concurrently.
 577  */
 578 int nfc_targets_found(struct nfc_dev *dev,
 579                       struct nfc_target *targets, int n_targets)
 580 {
 581         int i;
 582
 583         pr_debug("dev_name=%s n_targets=%d\n", dev_name(&dev->dev), n_targets);
 584
 585         for (i = 0; i < n_targets; i++)
 586                 targets[i].idx = dev->target_next_idx++;
 587
 588         device_lock(&dev->dev);
 589
 590         if (dev->polling == false) {
 591                 device_unlock(&dev->dev);
 592                 return 0;
 593         }
 594
 595         dev->polling = false;
 596
 597         dev->targets_generation++;
 598
 599         kfree(dev->targets);
 600         dev->targets = NULL;
 601
 602         if (targets) {
 603                 dev->targets = kmemdup(targets,
 604                                        n_targets * sizeof(struct nfc_target),
 605                                        GFP_ATOMIC);
 606
 607                 if (!dev->targets) {
 608                         dev->n_targets = 0;
 609                         device_unlock(&dev->dev);
 610                         return -ENOMEM;
 611                 }
 612         }
 613
 614         dev->n_targets = n_targets;
 615         device_unlock(&dev->dev);
 616
 617         nfc_genl_targets_found(dev);
 618
 619         return 0;
 620 }
 621 EXPORT_SYMBOL(nfc_targets_found);
 622
 623 /**
 624  * nfc_target_lost - inform that an activated target went out of field
 625  *
 626  * @dev: The nfc device that had the activated target in field
 627  * @target_idx: the nfc index of the target
 628  *
 629  * The device driver must call this function when the activated target
 630  * goes out of the field.
 631  * IMPORTANT: this function must not be called from an atomic context.
 632  * In addition, it must also not be called from a context that would prevent
 633  * the NFC Core to call other nfc ops entry point concurrently.
 634  */
 635 int nfc_target_lost(struct nfc_dev *dev, u32 target_idx)
 636 {
 637         struct nfc_target *tg;
 638         int i;
 639
 640         pr_debug("dev_name %s n_target %d\n", dev_name(&dev->dev), target_idx);
 641
 642         device_lock(&dev->dev);
 643
 644         for (i = 0; i < dev->n_targets; i++) {
 645                 tg = &dev->targets[i];
 646                 if (tg->idx == target_idx)
 647                         break;
 648         }
 649
 650         if (i == dev->n_targets) {
 651                 device_unlock(&dev->dev);
 652                 return -EINVAL;
 653         }
 654
 655         dev->targets_generation++;
 656         dev->n_targets--;
 657         dev->active_target = NULL;
 658
 659         if (dev->n_targets) {
 660                 memcpy(&dev->targets[i], &dev->targets[i + 1],
 661                        (dev->n_targets - i) * sizeof(struct nfc_target));
 662         } else {
 663                 kfree(dev->targets);
 664                 dev->targets = NULL;
 665         }
 666
 667         device_unlock(&dev->dev);
 668
 669         nfc_genl_target_lost(dev, target_idx);
 670
 671         return 0;
 672 }
 673 EXPORT_SYMBOL(nfc_target_lost);
 674
 675 inline void nfc_driver_failure(struct nfc_dev *dev, int err)
 676 {
 677         nfc_targets_found(dev, NULL, 0);
 678 }
 679 EXPORT_SYMBOL(nfc_driver_failure);
 680
 681 static void nfc_release(struct device *d)
 682 {
 683         struct nfc_dev *dev = to_nfc_dev(d);
 684
 685         pr_debug("dev_name=%s\n", dev_name(&dev->dev));
 686
 687         nfc_genl_data_exit(&dev->genl_data);
 688         kfree(dev->targets);
 689         kfree(dev);
 690 }
 691
 692 static void nfc_check_pres_work(struct work_struct *work)
 693 {
 694         struct nfc_dev *dev = container_of(work, struct nfc_dev,
 695                                            check_pres_work);
 696         int rc;
 697
 698         device_lock(&dev->dev);
 699
 700         if (dev->active_target && timer_pending(&dev->check_pres_timer) == 0) {
 701                 rc = dev->ops->check_presence(dev, dev->active_target);
 702                 if (rc == -EOPNOTSUPP)
 703                         goto exit;
 704                 if (rc) {
 705                         u32 active_target_idx = dev->active_target->idx;
 706                         device_unlock(&dev->dev);
 707                         nfc_target_lost(dev, active_target_idx);
 708                         return;
 709                 }
 710
 711                 if (!dev->shutting_down)
 712                         mod_timer(&dev->check_pres_timer, jiffies +
 713                                   msecs_to_jiffies(NFC_CHECK_PRES_FREQ_MS));
 714         }
 715
 716 exit:
 717         device_unlock(&dev->dev);
 718 }
 719
 720 static void nfc_check_pres_timeout(unsigned long data)
 721 {
 722         struct nfc_dev *dev = (struct nfc_dev *)data;
 723
 724         schedule_work(&dev->check_pres_work);
 725 }
 726
 727 struct class nfc_class = {
 728         .name = "nfc",
 729         .dev_release = nfc_release,
 730 };
 731 EXPORT_SYMBOL(nfc_class);
 732
 733 static int match_idx(struct device *d, void *data)
 734 {
 735         struct nfc_dev *dev = to_nfc_dev(d);
 736         unsigned int *idx = data;
 737
 738         return dev->idx == *idx;
 739 }
 740
 741 struct nfc_dev *nfc_get_device(unsigned int idx)
 742 {
 743         struct device *d;
 744
 745         d = class_find_device(&nfc_class, NULL, &idx, match_idx);
 746         if (!d)
 747                 return NULL;
 748
 749         return to_nfc_dev(d);
 750 }
 751
 752 /**
 753  * nfc_allocate_device - allocate a new nfc device
 754  *
 755  * @ops: device operations
 756  * @supported_protocols: NFC protocols supported by the device
 757  */
 758 struct nfc_dev *nfc_allocate_device(struct nfc_ops *ops,
 759                                     u32 supported_protocols,
 760                                     u32 supported_se,
 761                                     int tx_headroom, int tx_tailroom)
 762 {
 763         struct nfc_dev *dev;
 764
 765         if (!ops->start_poll || !ops->stop_poll || !ops->activate_target ||
 766             !ops->deactivate_target || !ops->im_transceive)
 767                 return NULL;
 768
 769         if (!supported_protocols)
 770                 return NULL;
 771
 772         dev = kzalloc(sizeof(struct nfc_dev), GFP_KERNEL);
 773         if (!dev)
 774                 return NULL;
 775
 776         dev->ops = ops;
 777         dev->supported_protocols = supported_protocols;
 778         dev->supported_se = supported_se;
 779         dev->active_se = NFC_SE_NONE;
 780         dev->tx_headroom = tx_headroom;
 781         dev->tx_tailroom = tx_tailroom;
 782
 783         nfc_genl_data_init(&dev->genl_data);
 784
 785         dev->rf_mode = NFC_RF_NONE;
 786
 787         /* first generation must not be 0 */
 788         dev->targets_generation = 1;
 789
 790         if (ops->check_presence) {
 791                 init_timer(&dev->check_pres_timer);
 792                 dev->check_pres_timer.data = (unsigned long)dev;
 793                 dev->check_pres_timer.function = nfc_check_pres_timeout;
 794
 795                 INIT_WORK(&dev->check_pres_work, nfc_check_pres_work);
 796         }
 797
 798         return dev;
 799 }
 800 EXPORT_SYMBOL(nfc_allocate_device);
 801
 802 /**
 803  * nfc_register_device - register a nfc device in the nfc subsystem
 804  *
 805  * @dev: The nfc device to register
 806  */
 807 int nfc_register_device(struct nfc_dev *dev)
 808 {
 809         int rc;
 810
 811         pr_debug("dev_name=%s\n", dev_name(&dev->dev));
 812
 813         dev->idx = ida_simple_get(&nfc_index_ida, 0, 0, GFP_KERNEL);
 814         if (dev->idx < 0)
 815                 return dev->idx;
 816
 817         dev->dev.class = &nfc_class;
 818         dev_set_name(&dev->dev, "nfc%d", dev->idx);
 819         device_initialize(&dev->dev);
 820
 821         mutex_lock(&nfc_devlist_mutex);
 822         nfc_devlist_generation++;
 823         rc = device_add(&dev->dev);
 824         mutex_unlock(&nfc_devlist_mutex);
 825
 826         if (rc < 0)
 827                 return rc;
 828
 829         rc = nfc_llcp_register_device(dev);
 830         if (rc)
 831                 pr_err("Could not register llcp device\n");
 832
 833         rc = nfc_genl_device_added(dev);
 834         if (rc)
 835                 pr_debug("The userspace won't be notified that the device %s was added\n",
 836                          dev_name(&dev->dev));
 837
 838         return 0;
 839 }
 840 EXPORT_SYMBOL(nfc_register_device);
 841
 842 /**
 843  * nfc_unregister_device - unregister a nfc device in the nfc subsystem
 844  *
 845  * @dev: The nfc device to unregister
 846  */
 847 void nfc_unregister_device(struct nfc_dev *dev)
 848 {
 849         int rc, id;
 850
 851         pr_debug("dev_name=%s\n", dev_name(&dev->dev));
 852
 853         id = dev->idx;
 854
 855         if (dev->ops->check_presence) {
 856                 device_lock(&dev->dev);
 857                 dev->shutting_down = true;
 858                 device_unlock(&dev->dev);
 859                 del_timer_sync(&dev->check_pres_timer);
 860                 cancel_work_sync(&dev->check_pres_work);
 861         }
 862
 863         rc = nfc_genl_device_removed(dev);
 864         if (rc)
 865                 pr_debug("The userspace won't be notified that the device %s "
 866                          "was removed\n", dev_name(&dev->dev));
 867
 868         nfc_llcp_unregister_device(dev);
 869
 870         mutex_lock(&nfc_devlist_mutex);
 871         nfc_devlist_generation++;
 872         device_del(&dev->dev);
 873         mutex_unlock(&nfc_devlist_mutex);
 874
 875         ida_simple_remove(&nfc_index_ida, id);
 876 }
 877 EXPORT_SYMBOL(nfc_unregister_device);
 878
 879 static int __init nfc_init(void)
 880 {
 881         int rc;
 882
 883         pr_info("NFC Core ver %s\n", VERSION);
 884
 885         rc = class_register(&nfc_class);
 886         if (rc)
 887                 return rc;
 888
 889         rc = nfc_genl_init();
 890         if (rc)
 891                 goto err_genl;
 892
 893         /* the first generation must not be 0 */
 894         nfc_devlist_generation = 1;
 895
 896         rc = rawsock_init();
 897         if (rc)
 898                 goto err_rawsock;
 899
 900         rc = nfc_llcp_init();
 901         if (rc)
 902                 goto err_llcp_sock;
 903
 904         rc = af_nfc_init();
 905         if (rc)
 906                 goto err_af_nfc;
 907
 908         return 0;
 909
 910 err_af_nfc:
 911         nfc_llcp_exit();
 912 err_llcp_sock:
 913         rawsock_exit();
 914 err_rawsock:
 915         nfc_genl_exit();
 916 err_genl:
 917         class_unregister(&nfc_class);
 918         return rc;
 919 }
 920
 921 static void __exit nfc_exit(void)
 922 {
 923         af_nfc_exit();
 924         nfc_llcp_exit();
 925         rawsock_exit();
 926         nfc_genl_exit();
 927         class_unregister(&nfc_class);
 928 }
 929
 930 subsys_initcall(nfc_init);
 931 module_exit(nfc_exit);
 932
 933 MODULE_AUTHOR("Lauro Ramos Venancio <lauro.venancio@openbossa.org>");
 934 MODULE_DESCRIPTION("NFC Core ver " VERSION);
 935 MODULE_VERSION(VERSION);
 936 MODULE_LICENSE("GPL");
 937 MODULE_ALIAS_NETPROTO(PF_NFC);
 938 MODULE_ALIAS_GENL_FAMILY(NFC_GENL_NAME);