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