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