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         struct nfc_se *se;
 559         int rc;
 560
 561         pr_debug("%s se index %d\n", dev_name(&dev->dev), se_idx);
 562
 563         device_lock(&dev->dev);
 564
 565         if (!device_is_registered(&dev->dev)) {
 566                 rc = -ENODEV;
 567                 goto error;
 568         }
 569
 570         if (!dev->dev_up) {
 571                 rc = -ENODEV;
 572                 goto error;
 573         }
 574
 575         if (dev->polling) {
 576                 rc = -EBUSY;
 577                 goto error;
 578         }
 579
 580         if (!dev->ops->enable_se || !dev->ops->disable_se) {
 581                 rc = -EOPNOTSUPP;
 582                 goto error;
 583         }
 584
 585         se = nfc_find_se(dev, se_idx);
 586         if (!se) {
 587                 rc = -EINVAL;
 588                 goto error;
 589         }
 590
 591         if (se->state == NFC_SE_ENABLED) {
 592                 rc = -EALREADY;
 593                 goto error;
 594         }
 595
 596         rc = dev->ops->enable_se(dev, se_idx);
 597         if (rc >= 0)
 598                 se->state = NFC_SE_ENABLED;
 599
 600 error:
 601         device_unlock(&dev->dev);
 602         return rc;
 603 }
 604
 605 int nfc_disable_se(struct nfc_dev *dev, u32 se_idx)
 606 {
 607
 608         struct nfc_se *se;
 609         int rc;
 610
 611         pr_debug("%s se index %d\n", dev_name(&dev->dev), se_idx);
 612
 613         device_lock(&dev->dev);
 614
 615         if (!device_is_registered(&dev->dev)) {
 616                 rc = -ENODEV;
 617                 goto error;
 618         }
 619
 620         if (!dev->dev_up) {
 621                 rc = -ENODEV;
 622                 goto error;
 623         }
 624
 625         if (!dev->ops->enable_se || !dev->ops->disable_se) {
 626                 rc = -EOPNOTSUPP;
 627                 goto error;
 628         }
 629
 630         se = nfc_find_se(dev, se_idx);
 631         if (!se) {
 632                 rc = -EINVAL;
 633                 goto error;
 634         }
 635
 636         if (se->state == NFC_SE_DISABLED) {
 637                 rc = -EALREADY;
 638                 goto error;
 639         }
 640
 641         rc = dev->ops->disable_se(dev, se_idx);
 642         if (rc >= 0)
 643                 se->state = NFC_SE_DISABLED;
 644
 645 error:
 646         device_unlock(&dev->dev);
 647         return rc;
 648 }
 649
 650 int nfc_set_remote_general_bytes(struct nfc_dev *dev, u8 *gb, u8 gb_len)
 651 {
 652         pr_debug("dev_name=%s gb_len=%d\n", dev_name(&dev->dev), gb_len);
 653
 654         return nfc_llcp_set_remote_gb(dev, gb, gb_len);
 655 }
 656 EXPORT_SYMBOL(nfc_set_remote_general_bytes);
 657
 658 u8 *nfc_get_local_general_bytes(struct nfc_dev *dev, size_t *gb_len)
 659 {
 660         pr_debug("dev_name=%s\n", dev_name(&dev->dev));
 661
 662         return nfc_llcp_general_bytes(dev, gb_len);
 663 }
 664 EXPORT_SYMBOL(nfc_get_local_general_bytes);
 665
 666 int nfc_tm_data_received(struct nfc_dev *dev, struct sk_buff *skb)
 667 {
 668         /* Only LLCP target mode for now */
 669         if (dev->dep_link_up == false) {
 670                 kfree_skb(skb);
 671                 return -ENOLINK;
 672         }
 673
 674         return nfc_llcp_data_received(dev, skb);
 675 }
 676 EXPORT_SYMBOL(nfc_tm_data_received);
 677
 678 int nfc_tm_activated(struct nfc_dev *dev, u32 protocol, u8 comm_mode,
 679                      u8 *gb, size_t gb_len)
 680 {
 681         int rc;
 682
 683         device_lock(&dev->dev);
 684
 685         dev->polling = false;
 686
 687         if (gb != NULL) {
 688                 rc = nfc_set_remote_general_bytes(dev, gb, gb_len);
 689                 if (rc < 0)
 690                         goto out;
 691         }
 692
 693         dev->rf_mode = NFC_RF_TARGET;
 694
 695         if (protocol == NFC_PROTO_NFC_DEP_MASK)
 696                 nfc_dep_link_is_up(dev, 0, comm_mode, NFC_RF_TARGET);
 697
 698         rc = nfc_genl_tm_activated(dev, protocol);
 699
 700 out:
 701         device_unlock(&dev->dev);
 702
 703         return rc;
 704 }
 705 EXPORT_SYMBOL(nfc_tm_activated);
 706
 707 int nfc_tm_deactivated(struct nfc_dev *dev)
 708 {
 709         dev->dep_link_up = false;
 710         dev->rf_mode = NFC_RF_NONE;
 711
 712         return nfc_genl_tm_deactivated(dev);
 713 }
 714 EXPORT_SYMBOL(nfc_tm_deactivated);
 715
 716 /**
 717  * nfc_alloc_send_skb - allocate a skb for data exchange responses
 718  *
 719  * @size: size to allocate
 720  * @gfp: gfp flags
 721  */
 722 struct sk_buff *nfc_alloc_send_skb(struct nfc_dev *dev, struct sock *sk,
 723                                    unsigned int flags, unsigned int size,
 724                                    unsigned int *err)
 725 {
 726         struct sk_buff *skb;
 727         unsigned int total_size;
 728
 729         total_size = size +
 730                 dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
 731
 732         skb = sock_alloc_send_skb(sk, total_size, flags & MSG_DONTWAIT, err);
 733         if (skb)
 734                 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
 735
 736         return skb;
 737 }
 738
 739 /**
 740  * nfc_alloc_recv_skb - allocate a skb for data exchange responses
 741  *
 742  * @size: size to allocate
 743  * @gfp: gfp flags
 744  */
 745 struct sk_buff *nfc_alloc_recv_skb(unsigned int size, gfp_t gfp)
 746 {
 747         struct sk_buff *skb;
 748         unsigned int total_size;
 749
 750         total_size = size + 1;
 751         skb = alloc_skb(total_size, gfp);
 752
 753         if (skb)
 754                 skb_reserve(skb, 1);
 755
 756         return skb;
 757 }
 758 EXPORT_SYMBOL(nfc_alloc_recv_skb);
 759
 760 /**
 761  * nfc_targets_found - inform that targets were found
 762  *
 763  * @dev: The nfc device that found the targets
 764  * @targets: array of nfc targets found
 765  * @ntargets: targets array size
 766  *
 767  * The device driver must call this function when one or many nfc targets
 768  * are found. After calling this function, the device driver must stop
 769  * polling for targets.
 770  * NOTE: This function can be called with targets=NULL and n_targets=0 to
 771  * notify a driver error, meaning that the polling operation cannot complete.
 772  * IMPORTANT: this function must not be called from an atomic context.
 773  * In addition, it must also not be called from a context that would prevent
 774  * the NFC Core to call other nfc ops entry point concurrently.
 775  */
 776 int nfc_targets_found(struct nfc_dev *dev,
 777                       struct nfc_target *targets, int n_targets)
 778 {
 779         int i;
 780
 781         pr_debug("dev_name=%s n_targets=%d\n", dev_name(&dev->dev), n_targets);
 782
 783         for (i = 0; i < n_targets; i++)
 784                 targets[i].idx = dev->target_next_idx++;
 785
 786         device_lock(&dev->dev);
 787
 788         if (dev->polling == false) {
 789                 device_unlock(&dev->dev);
 790                 return 0;
 791         }
 792
 793         dev->polling = false;
 794
 795         dev->targets_generation++;
 796
 797         kfree(dev->targets);
 798         dev->targets = NULL;
 799
 800         if (targets) {
 801                 dev->targets = kmemdup(targets,
 802                                        n_targets * sizeof(struct nfc_target),
 803                                        GFP_ATOMIC);
 804
 805                 if (!dev->targets) {
 806                         dev->n_targets = 0;
 807                         device_unlock(&dev->dev);
 808                         return -ENOMEM;
 809                 }
 810         }
 811
 812         dev->n_targets = n_targets;
 813         device_unlock(&dev->dev);
 814
 815         nfc_genl_targets_found(dev);
 816
 817         return 0;
 818 }
 819 EXPORT_SYMBOL(nfc_targets_found);
 820
 821 /**
 822  * nfc_target_lost - inform that an activated target went out of field
 823  *
 824  * @dev: The nfc device that had the activated target in field
 825  * @target_idx: the nfc index of the target
 826  *
 827  * The device driver must call this function when the activated target
 828  * goes out of the field.
 829  * IMPORTANT: this function must not be called from an atomic context.
 830  * In addition, it must also not be called from a context that would prevent
 831  * the NFC Core to call other nfc ops entry point concurrently.
 832  */
 833 int nfc_target_lost(struct nfc_dev *dev, u32 target_idx)
 834 {
 835         struct nfc_target *tg;
 836         int i;
 837
 838         pr_debug("dev_name %s n_target %d\n", dev_name(&dev->dev), target_idx);
 839
 840         device_lock(&dev->dev);
 841
 842         for (i = 0; i < dev->n_targets; i++) {
 843                 tg = &dev->targets[i];
 844                 if (tg->idx == target_idx)
 845                         break;
 846         }
 847
 848         if (i == dev->n_targets) {
 849                 device_unlock(&dev->dev);
 850                 return -EINVAL;
 851         }
 852
 853         dev->targets_generation++;
 854         dev->n_targets--;
 855         dev->active_target = NULL;
 856
 857         if (dev->n_targets) {
 858                 memcpy(&dev->targets[i], &dev->targets[i + 1],
 859                        (dev->n_targets - i) * sizeof(struct nfc_target));
 860         } else {
 861                 kfree(dev->targets);
 862                 dev->targets = NULL;
 863         }
 864
 865         device_unlock(&dev->dev);
 866
 867         nfc_genl_target_lost(dev, target_idx);
 868
 869         return 0;
 870 }
 871 EXPORT_SYMBOL(nfc_target_lost);
 872
 873 inline void nfc_driver_failure(struct nfc_dev *dev, int err)
 874 {
 875         nfc_targets_found(dev, NULL, 0);
 876 }
 877 EXPORT_SYMBOL(nfc_driver_failure);
 878
 879 int nfc_add_se(struct nfc_dev *dev, u32 se_idx, u16 type)
 880 {
 881         struct nfc_se *se;
 882         int rc;
 883
 884         pr_debug("%s se index %d\n", dev_name(&dev->dev), se_idx);
 885
 886         se = nfc_find_se(dev, se_idx);
 887         if (se)
 888                 return -EALREADY;
 889
 890         se = kzalloc(sizeof(struct nfc_se), GFP_KERNEL);
 891         if (!se)
 892                 return -ENOMEM;
 893
 894         se->idx = se_idx;
 895         se->type = type;
 896         se->state = NFC_SE_DISABLED;
 897         INIT_LIST_HEAD(&se->list);
 898
 899         list_add(&se->list, &dev->secure_elements);
 900
 901         rc = nfc_genl_se_added(dev, se_idx, type);
 902         if (rc < 0) {
 903                 list_del(&se->list);
 904                 kfree(se);
 905
 906                 return rc;
 907         }
 908
 909         return 0;
 910 }
 911 EXPORT_SYMBOL(nfc_add_se);
 912
 913 int nfc_remove_se(struct nfc_dev *dev, u32 se_idx)
 914 {
 915         struct nfc_se *se, *n;
 916         int rc;
 917
 918         pr_debug("%s se index %d\n", dev_name(&dev->dev), se_idx);
 919
 920         list_for_each_entry_safe(se, n, &dev->secure_elements, list)
 921                 if (se->idx == se_idx) {
 922                         rc = nfc_genl_se_removed(dev, se_idx);
 923                         if (rc < 0)
 924                                 return rc;
 925
 926                         list_del(&se->list);
 927                         kfree(se);
 928
 929                         return 0;
 930                 }
 931
 932         return -EINVAL;
 933 }
 934 EXPORT_SYMBOL(nfc_remove_se);
 935
 936 static void nfc_release(struct device *d)
 937 {
 938         struct nfc_dev *dev = to_nfc_dev(d);
 939         struct nfc_se *se, *n;
 940
 941         pr_debug("dev_name=%s\n", dev_name(&dev->dev));
 942
 943         nfc_genl_data_exit(&dev->genl_data);
 944         kfree(dev->targets);
 945
 946         list_for_each_entry_safe(se, n, &dev->secure_elements, list) {
 947                         nfc_genl_se_removed(dev, se->idx);
 948                         list_del(&se->list);
 949                         kfree(se);
 950         }
 951
 952         kfree(dev);
 953 }
 954
 955 static void nfc_check_pres_work(struct work_struct *work)
 956 {
 957         struct nfc_dev *dev = container_of(work, struct nfc_dev,
 958                                            check_pres_work);
 959         int rc;
 960
 961         device_lock(&dev->dev);
 962
 963         if (dev->active_target && timer_pending(&dev->check_pres_timer) == 0) {
 964                 rc = dev->ops->check_presence(dev, dev->active_target);
 965                 if (rc == -EOPNOTSUPP)
 966                         goto exit;
 967                 if (rc) {
 968                         u32 active_target_idx = dev->active_target->idx;
 969                         device_unlock(&dev->dev);
 970                         nfc_target_lost(dev, active_target_idx);
 971                         return;
 972                 }
 973
 974                 if (!dev->shutting_down)
 975                         mod_timer(&dev->check_pres_timer, jiffies +
 976                                   msecs_to_jiffies(NFC_CHECK_PRES_FREQ_MS));
 977         }
 978
 979 exit:
 980         device_unlock(&dev->dev);
 981 }
 982
 983 static void nfc_check_pres_timeout(unsigned long data)
 984 {
 985         struct nfc_dev *dev = (struct nfc_dev *)data;
 986
 987         schedule_work(&dev->check_pres_work);
 988 }
 989
 990 struct class nfc_class = {
 991         .name = "nfc",
 992         .dev_release = nfc_release,
 993 };
 994 EXPORT_SYMBOL(nfc_class);
 995
 996 static int match_idx(struct device *d, const void *data)
 997 {
 998         struct nfc_dev *dev = to_nfc_dev(d);
 999         const unsigned int *idx = data;
1000
1001         return dev->idx == *idx;
1002 }
1003
1004 struct nfc_dev *nfc_get_device(unsigned int idx)
1005 {
1006         struct device *d;
1007
1008         d = class_find_device(&nfc_class, NULL, &idx, match_idx);
1009         if (!d)
1010                 return NULL;
1011
1012         return to_nfc_dev(d);
1013 }
1014
1015 /**
1016  * nfc_allocate_device - allocate a new nfc device
1017  *
1018  * @ops: device operations
1019  * @supported_protocols: NFC protocols supported by the device
1020  */
1021 struct nfc_dev *nfc_allocate_device(struct nfc_ops *ops,
1022                                     u32 supported_protocols,
1023                                     int tx_headroom, int tx_tailroom)
1024 {
1025         struct nfc_dev *dev;
1026
1027         if (!ops->start_poll || !ops->stop_poll || !ops->activate_target ||
1028             !ops->deactivate_target || !ops->im_transceive)
1029                 return NULL;
1030
1031         if (!supported_protocols)
1032                 return NULL;
1033
1034         dev = kzalloc(sizeof(struct nfc_dev), GFP_KERNEL);
1035         if (!dev)
1036                 return NULL;
1037
1038         dev->ops = ops;
1039         dev->supported_protocols = supported_protocols;
1040         dev->tx_headroom = tx_headroom;
1041         dev->tx_tailroom = tx_tailroom;
1042         INIT_LIST_HEAD(&dev->secure_elements);
1043
1044         nfc_genl_data_init(&dev->genl_data);
1045
1046         dev->rf_mode = NFC_RF_NONE;
1047
1048         /* first generation must not be 0 */
1049         dev->targets_generation = 1;
1050
1051         if (ops->check_presence) {
1052                 init_timer(&dev->check_pres_timer);
1053                 dev->check_pres_timer.data = (unsigned long)dev;
1054                 dev->check_pres_timer.function = nfc_check_pres_timeout;
1055
1056                 INIT_WORK(&dev->check_pres_work, nfc_check_pres_work);
1057         }
1058
1059         return dev;
1060 }
1061 EXPORT_SYMBOL(nfc_allocate_device);
1062
1063 /**
1064  * nfc_register_device - register a nfc device in the nfc subsystem
1065  *
1066  * @dev: The nfc device to register
1067  */
1068 int nfc_register_device(struct nfc_dev *dev)
1069 {
1070         int rc;
1071
1072         pr_debug("dev_name=%s\n", dev_name(&dev->dev));
1073
1074         dev->idx = ida_simple_get(&nfc_index_ida, 0, 0, GFP_KERNEL);
1075         if (dev->idx < 0)
1076                 return dev->idx;
1077
1078         dev->dev.class = &nfc_class;
1079         dev_set_name(&dev->dev, "nfc%d", dev->idx);
1080         device_initialize(&dev->dev);
1081
1082         mutex_lock(&nfc_devlist_mutex);
1083         nfc_devlist_generation++;
1084         rc = device_add(&dev->dev);
1085         mutex_unlock(&nfc_devlist_mutex);
1086
1087         if (rc < 0)
1088                 return rc;
1089
1090         rc = nfc_llcp_register_device(dev);
1091         if (rc)
1092                 pr_err("Could not register llcp device\n");
1093
1094         rc = nfc_genl_device_added(dev);
1095         if (rc)
1096                 pr_debug("The userspace won't be notified that the device %s was added\n",
1097                          dev_name(&dev->dev));
1098
1099         dev->rfkill = rfkill_alloc(dev_name(&dev->dev), &dev->dev,
1100                                    RFKILL_TYPE_NFC, &nfc_rfkill_ops, dev);
1101         if (dev->rfkill) {
1102                 if (rfkill_register(dev->rfkill) < 0) {
1103                         rfkill_destroy(dev->rfkill);
1104                         dev->rfkill = NULL;
1105                 }
1106         }
1107
1108         return 0;
1109 }
1110 EXPORT_SYMBOL(nfc_register_device);
1111
1112 /**
1113  * nfc_unregister_device - unregister a nfc device in the nfc subsystem
1114  *
1115  * @dev: The nfc device to unregister
1116  */
1117 void nfc_unregister_device(struct nfc_dev *dev)
1118 {
1119         int rc, id;
1120
1121         pr_debug("dev_name=%s\n", dev_name(&dev->dev));
1122
1123         id = dev->idx;
1124
1125         if (dev->rfkill) {
1126                 rfkill_unregister(dev->rfkill);
1127                 rfkill_destroy(dev->rfkill);
1128         }
1129
1130         if (dev->ops->check_presence) {
1131                 device_lock(&dev->dev);
1132                 dev->shutting_down = true;
1133                 device_unlock(&dev->dev);
1134                 del_timer_sync(&dev->check_pres_timer);
1135                 cancel_work_sync(&dev->check_pres_work);
1136         }
1137
1138         rc = nfc_genl_device_removed(dev);
1139         if (rc)
1140                 pr_debug("The userspace won't be notified that the device %s "
1141                          "was removed\n", dev_name(&dev->dev));
1142
1143         nfc_llcp_unregister_device(dev);
1144
1145         mutex_lock(&nfc_devlist_mutex);
1146         nfc_devlist_generation++;
1147         device_del(&dev->dev);
1148         mutex_unlock(&nfc_devlist_mutex);
1149
1150         ida_simple_remove(&nfc_index_ida, id);
1151 }
1152 EXPORT_SYMBOL(nfc_unregister_device);
1153
1154 static int __init nfc_init(void)
1155 {
1156         int rc;
1157
1158         pr_info("NFC Core ver %s\n", VERSION);
1159
1160         rc = class_register(&nfc_class);
1161         if (rc)
1162                 return rc;
1163
1164         rc = nfc_genl_init();
1165         if (rc)
1166                 goto err_genl;
1167
1168         /* the first generation must not be 0 */
1169         nfc_devlist_generation = 1;
1170
1171         rc = rawsock_init();
1172         if (rc)
1173                 goto err_rawsock;
1174
1175         rc = nfc_llcp_init();
1176         if (rc)
1177                 goto err_llcp_sock;
1178
1179         rc = af_nfc_init();
1180         if (rc)
1181                 goto err_af_nfc;
1182
1183         return 0;
1184
1185 err_af_nfc:
1186         nfc_llcp_exit();
1187 err_llcp_sock:
1188         rawsock_exit();
1189 err_rawsock:
1190         nfc_genl_exit();
1191 err_genl:
1192         class_unregister(&nfc_class);
1193         return rc;
1194 }
1195
1196 static void __exit nfc_exit(void)
1197 {
1198         af_nfc_exit();
1199         nfc_llcp_exit();
1200         rawsock_exit();
1201         nfc_genl_exit();
1202         class_unregister(&nfc_class);
1203 }
1204
1205 subsys_initcall(nfc_init);
1206 module_exit(nfc_exit);
1207
1208 MODULE_AUTHOR("Lauro Ramos Venancio <lauro.venancio@openbossa.org>");
1209 MODULE_DESCRIPTION("NFC Core ver " VERSION);
1210 MODULE_VERSION(VERSION);
1211 MODULE_LICENSE("GPL");
1212 MODULE_ALIAS_NETPROTO(PF_NFC);
1213 MODULE_ALIAS_GENL_FAMILY(NFC_GENL_NAME);