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