core.c revision 900994332675f84a9fbbb33ff089474614c7f2fe
1/* 2 * Copyright (C) 2011 Instituto Nokia de Tecnologia 3 * 4 * Authors: 5 * Lauro Ramos Venancio <lauro.venancio@openbossa.org> 6 * Aloisio Almeida Jr <aloisio.almeida@openbossa.org> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to the 20 * Free Software Foundation, Inc., 21 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 22 */ 23 24#define pr_fmt(fmt) KBUILD_MODNAME ": %s: " fmt, __func__ 25 26#include <linux/init.h> 27#include <linux/kernel.h> 28#include <linux/module.h> 29#include <linux/slab.h> 30#include <linux/nfc.h> 31 32#include "nfc.h" 33 34#define VERSION "0.1" 35 36#define NFC_CHECK_PRES_FREQ_MS 2000 37 38int nfc_devlist_generation; 39DEFINE_MUTEX(nfc_devlist_mutex); 40 41/** 42 * nfc_dev_up - turn on the NFC device 43 * 44 * @dev: The nfc device to be turned on 45 * 46 * The device remains up until the nfc_dev_down function is called. 47 */ 48int nfc_dev_up(struct nfc_dev *dev) 49{ 50 int rc = 0; 51 52 pr_debug("dev_name=%s\n", dev_name(&dev->dev)); 53 54 device_lock(&dev->dev); 55 56 if (!device_is_registered(&dev->dev)) { 57 rc = -ENODEV; 58 goto error; 59 } 60 61 if (dev->dev_up) { 62 rc = -EALREADY; 63 goto error; 64 } 65 66 if (dev->ops->dev_up) 67 rc = dev->ops->dev_up(dev); 68 69 if (!rc) 70 dev->dev_up = true; 71 72error: 73 device_unlock(&dev->dev); 74 return rc; 75} 76 77/** 78 * nfc_dev_down - turn off the NFC device 79 * 80 * @dev: The nfc device to be turned off 81 */ 82int nfc_dev_down(struct nfc_dev *dev) 83{ 84 int rc = 0; 85 86 pr_debug("dev_name=%s\n", dev_name(&dev->dev)); 87 88 device_lock(&dev->dev); 89 90 if (!device_is_registered(&dev->dev)) { 91 rc = -ENODEV; 92 goto error; 93 } 94 95 if (!dev->dev_up) { 96 rc = -EALREADY; 97 goto error; 98 } 99 100 if (dev->polling || dev->active_target) { 101 rc = -EBUSY; 102 goto error; 103 } 104 105 if (dev->ops->dev_down) 106 dev->ops->dev_down(dev); 107 108 dev->dev_up = false; 109 110error: 111 device_unlock(&dev->dev); 112 return rc; 113} 114 115/** 116 * nfc_start_poll - start polling for nfc targets 117 * 118 * @dev: The nfc device that must start polling 119 * @protocols: bitset of nfc protocols that must be used for polling 120 * 121 * The device remains polling for targets until a target is found or 122 * the nfc_stop_poll function is called. 123 */ 124int nfc_start_poll(struct nfc_dev *dev, u32 protocols) 125{ 126 int rc; 127 128 pr_debug("dev_name=%s protocols=0x%x\n", 129 dev_name(&dev->dev), protocols); 130 131 if (!protocols) 132 return -EINVAL; 133 134 device_lock(&dev->dev); 135 136 if (!device_is_registered(&dev->dev)) { 137 rc = -ENODEV; 138 goto error; 139 } 140 141 if (dev->polling) { 142 rc = -EBUSY; 143 goto error; 144 } 145 146 rc = dev->ops->start_poll(dev, protocols); 147 if (!rc) 148 dev->polling = true; 149 150error: 151 device_unlock(&dev->dev); 152 return rc; 153} 154 155/** 156 * nfc_stop_poll - stop polling for nfc targets 157 * 158 * @dev: The nfc device that must stop polling 159 */ 160int nfc_stop_poll(struct nfc_dev *dev) 161{ 162 int rc = 0; 163 164 pr_debug("dev_name=%s\n", dev_name(&dev->dev)); 165 166 device_lock(&dev->dev); 167 168 if (!device_is_registered(&dev->dev)) { 169 rc = -ENODEV; 170 goto error; 171 } 172 173 if (!dev->polling) { 174 rc = -EINVAL; 175 goto error; 176 } 177 178 dev->ops->stop_poll(dev); 179 dev->polling = false; 180 181error: 182 device_unlock(&dev->dev); 183 return rc; 184} 185 186static struct nfc_target *nfc_find_target(struct nfc_dev *dev, u32 target_idx) 187{ 188 int i; 189 190 if (dev->n_targets == 0) 191 return NULL; 192 193 for (i = 0; i < dev->n_targets ; i++) { 194 if (dev->targets[i].idx == target_idx) 195 return &dev->targets[i]; 196 } 197 198 return NULL; 199} 200 201int nfc_dep_link_up(struct nfc_dev *dev, int target_index, u8 comm_mode) 202{ 203 int rc = 0; 204 u8 *gb; 205 size_t gb_len; 206 struct nfc_target *target; 207 208 pr_debug("dev_name=%s comm %d\n", dev_name(&dev->dev), comm_mode); 209 210 if (!dev->ops->dep_link_up) 211 return -EOPNOTSUPP; 212 213 device_lock(&dev->dev); 214 215 if (!device_is_registered(&dev->dev)) { 216 rc = -ENODEV; 217 goto error; 218 } 219 220 if (dev->dep_link_up == true) { 221 rc = -EALREADY; 222 goto error; 223 } 224 225 gb = nfc_llcp_general_bytes(dev, &gb_len); 226 if (gb_len > NFC_MAX_GT_LEN) { 227 rc = -EINVAL; 228 goto error; 229 } 230 231 target = nfc_find_target(dev, target_index); 232 if (target == NULL) { 233 rc = -ENOTCONN; 234 goto error; 235 } 236 237 rc = dev->ops->dep_link_up(dev, target, comm_mode, gb, gb_len); 238 if (!rc) 239 dev->active_target = target; 240 241error: 242 device_unlock(&dev->dev); 243 return rc; 244} 245 246int nfc_dep_link_down(struct nfc_dev *dev) 247{ 248 int rc = 0; 249 250 pr_debug("dev_name=%s\n", dev_name(&dev->dev)); 251 252 if (!dev->ops->dep_link_down) 253 return -EOPNOTSUPP; 254 255 device_lock(&dev->dev); 256 257 if (!device_is_registered(&dev->dev)) { 258 rc = -ENODEV; 259 goto error; 260 } 261 262 if (dev->dep_link_up == false) { 263 rc = -EALREADY; 264 goto error; 265 } 266 267 if (dev->dep_rf_mode == NFC_RF_TARGET) { 268 rc = -EOPNOTSUPP; 269 goto error; 270 } 271 272 rc = dev->ops->dep_link_down(dev); 273 if (!rc) { 274 dev->dep_link_up = false; 275 dev->active_target = NULL; 276 nfc_llcp_mac_is_down(dev); 277 nfc_genl_dep_link_down_event(dev); 278 } 279 280error: 281 device_unlock(&dev->dev); 282 return rc; 283} 284 285int nfc_dep_link_is_up(struct nfc_dev *dev, u32 target_idx, 286 u8 comm_mode, u8 rf_mode) 287{ 288 dev->dep_link_up = true; 289 dev->dep_rf_mode = rf_mode; 290 291 nfc_llcp_mac_is_up(dev, target_idx, comm_mode, rf_mode); 292 293 return nfc_genl_dep_link_up_event(dev, target_idx, comm_mode, rf_mode); 294} 295EXPORT_SYMBOL(nfc_dep_link_is_up); 296 297/** 298 * nfc_activate_target - prepare the target for data exchange 299 * 300 * @dev: The nfc device that found the target 301 * @target_idx: index of the target that must be activated 302 * @protocol: nfc protocol that will be used for data exchange 303 */ 304int nfc_activate_target(struct nfc_dev *dev, u32 target_idx, u32 protocol) 305{ 306 int rc; 307 struct nfc_target *target; 308 309 pr_debug("dev_name=%s target_idx=%u protocol=%u\n", 310 dev_name(&dev->dev), target_idx, protocol); 311 312 device_lock(&dev->dev); 313 314 if (!device_is_registered(&dev->dev)) { 315 rc = -ENODEV; 316 goto error; 317 } 318 319 if (dev->active_target) { 320 rc = -EBUSY; 321 goto error; 322 } 323 324 target = nfc_find_target(dev, target_idx); 325 if (target == NULL) { 326 rc = -ENOTCONN; 327 goto error; 328 } 329 330 rc = dev->ops->activate_target(dev, target, protocol); 331 if (!rc) { 332 dev->active_target = target; 333 334 if (dev->ops->check_presence) 335 mod_timer(&dev->check_pres_timer, jiffies + 336 msecs_to_jiffies(NFC_CHECK_PRES_FREQ_MS)); 337 } 338 339error: 340 device_unlock(&dev->dev); 341 return rc; 342} 343 344/** 345 * nfc_deactivate_target - deactivate a nfc target 346 * 347 * @dev: The nfc device that found the target 348 * @target_idx: index of the target that must be deactivated 349 */ 350int nfc_deactivate_target(struct nfc_dev *dev, u32 target_idx) 351{ 352 int rc = 0; 353 354 pr_debug("dev_name=%s target_idx=%u\n", 355 dev_name(&dev->dev), target_idx); 356 357 device_lock(&dev->dev); 358 359 if (!device_is_registered(&dev->dev)) { 360 rc = -ENODEV; 361 goto error; 362 } 363 364 if (dev->active_target == NULL) { 365 rc = -ENOTCONN; 366 goto error; 367 } 368 369 if (dev->active_target->idx != target_idx) { 370 rc = -ENOTCONN; 371 goto error; 372 } 373 374 if (dev->ops->check_presence) 375 del_timer_sync(&dev->check_pres_timer); 376 377 dev->ops->deactivate_target(dev, dev->active_target); 378 dev->active_target = NULL; 379 380error: 381 device_unlock(&dev->dev); 382 return rc; 383} 384 385/** 386 * nfc_data_exchange - transceive data 387 * 388 * @dev: The nfc device that found the target 389 * @target_idx: index of the target 390 * @skb: data to be sent 391 * @cb: callback called when the response is received 392 * @cb_context: parameter for the callback function 393 * 394 * The user must wait for the callback before calling this function again. 395 */ 396int nfc_data_exchange(struct nfc_dev *dev, u32 target_idx, struct sk_buff *skb, 397 data_exchange_cb_t cb, void *cb_context) 398{ 399 int rc; 400 401 pr_debug("dev_name=%s target_idx=%u skb->len=%u\n", 402 dev_name(&dev->dev), target_idx, skb->len); 403 404 device_lock(&dev->dev); 405 406 if (!device_is_registered(&dev->dev)) { 407 rc = -ENODEV; 408 kfree_skb(skb); 409 goto error; 410 } 411 412 if (dev->active_target == NULL) { 413 rc = -ENOTCONN; 414 kfree_skb(skb); 415 goto error; 416 } 417 418 if (dev->active_target->idx != target_idx) { 419 rc = -EADDRNOTAVAIL; 420 kfree_skb(skb); 421 goto error; 422 } 423 424 if (dev->ops->check_presence) 425 del_timer_sync(&dev->check_pres_timer); 426 427 rc = dev->ops->data_exchange(dev, dev->active_target, skb, cb, 428 cb_context); 429 430 if (!rc && dev->ops->check_presence) 431 mod_timer(&dev->check_pres_timer, jiffies + 432 msecs_to_jiffies(NFC_CHECK_PRES_FREQ_MS)); 433 434error: 435 device_unlock(&dev->dev); 436 return rc; 437} 438 439int nfc_set_remote_general_bytes(struct nfc_dev *dev, u8 *gb, u8 gb_len) 440{ 441 pr_debug("dev_name=%s gb_len=%d\n", dev_name(&dev->dev), gb_len); 442 443 if (gb_len > NFC_MAX_GT_LEN) 444 return -EINVAL; 445 446 return nfc_llcp_set_remote_gb(dev, gb, gb_len); 447} 448EXPORT_SYMBOL(nfc_set_remote_general_bytes); 449 450/** 451 * nfc_alloc_send_skb - allocate a skb for data exchange responses 452 * 453 * @size: size to allocate 454 * @gfp: gfp flags 455 */ 456struct sk_buff *nfc_alloc_send_skb(struct nfc_dev *dev, struct sock *sk, 457 unsigned int flags, unsigned int size, 458 unsigned int *err) 459{ 460 struct sk_buff *skb; 461 unsigned int total_size; 462 463 total_size = size + 464 dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE; 465 466 skb = sock_alloc_send_skb(sk, total_size, flags & MSG_DONTWAIT, err); 467 if (skb) 468 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE); 469 470 return skb; 471} 472 473/** 474 * nfc_alloc_recv_skb - allocate a skb for data exchange responses 475 * 476 * @size: size to allocate 477 * @gfp: gfp flags 478 */ 479struct sk_buff *nfc_alloc_recv_skb(unsigned int size, gfp_t gfp) 480{ 481 struct sk_buff *skb; 482 unsigned int total_size; 483 484 total_size = size + 1; 485 skb = alloc_skb(total_size, gfp); 486 487 if (skb) 488 skb_reserve(skb, 1); 489 490 return skb; 491} 492EXPORT_SYMBOL(nfc_alloc_recv_skb); 493 494/** 495 * nfc_targets_found - inform that targets were found 496 * 497 * @dev: The nfc device that found the targets 498 * @targets: array of nfc targets found 499 * @ntargets: targets array size 500 * 501 * The device driver must call this function when one or many nfc targets 502 * are found. After calling this function, the device driver must stop 503 * polling for targets. 504 */ 505int nfc_targets_found(struct nfc_dev *dev, 506 struct nfc_target *targets, int n_targets) 507{ 508 int i; 509 510 pr_debug("dev_name=%s n_targets=%d\n", dev_name(&dev->dev), n_targets); 511 512 dev->polling = false; 513 514 for (i = 0; i < n_targets; i++) 515 targets[i].idx = dev->target_next_idx++; 516 517 spin_lock_bh(&dev->targets_lock); 518 519 dev->targets_generation++; 520 521 kfree(dev->targets); 522 dev->targets = kmemdup(targets, n_targets * sizeof(struct nfc_target), 523 GFP_ATOMIC); 524 525 if (!dev->targets) { 526 dev->n_targets = 0; 527 spin_unlock_bh(&dev->targets_lock); 528 return -ENOMEM; 529 } 530 531 dev->n_targets = n_targets; 532 spin_unlock_bh(&dev->targets_lock); 533 534 nfc_genl_targets_found(dev); 535 536 return 0; 537} 538EXPORT_SYMBOL(nfc_targets_found); 539 540int nfc_target_lost(struct nfc_dev *dev, u32 target_idx) 541{ 542 struct nfc_target *tg; 543 int i; 544 545 pr_debug("dev_name %s n_target %d\n", dev_name(&dev->dev), target_idx); 546 547 spin_lock_bh(&dev->targets_lock); 548 549 for (i = 0; i < dev->n_targets; i++) { 550 tg = &dev->targets[i]; 551 if (tg->idx == target_idx) 552 break; 553 } 554 555 if (i == dev->n_targets) { 556 spin_unlock_bh(&dev->targets_lock); 557 return -EINVAL; 558 } 559 560 dev->targets_generation++; 561 dev->n_targets--; 562 dev->active_target = NULL; 563 564 if (dev->n_targets) { 565 memcpy(&dev->targets[i], &dev->targets[i + 1], 566 (dev->n_targets - i) * sizeof(struct nfc_target)); 567 } else { 568 kfree(dev->targets); 569 dev->targets = NULL; 570 } 571 572 spin_unlock_bh(&dev->targets_lock); 573 574 nfc_genl_target_lost(dev, target_idx); 575 576 return 0; 577} 578EXPORT_SYMBOL(nfc_target_lost); 579 580static void nfc_release(struct device *d) 581{ 582 struct nfc_dev *dev = to_nfc_dev(d); 583 584 pr_debug("dev_name=%s\n", dev_name(&dev->dev)); 585 586 if (dev->ops->check_presence) { 587 del_timer_sync(&dev->check_pres_timer); 588 destroy_workqueue(dev->check_pres_wq); 589 } 590 591 nfc_genl_data_exit(&dev->genl_data); 592 kfree(dev->targets); 593 kfree(dev); 594} 595 596static void nfc_check_pres_work(struct work_struct *work) 597{ 598 struct nfc_dev *dev = container_of(work, struct nfc_dev, 599 check_pres_work); 600 int rc; 601 602 device_lock(&dev->dev); 603 604 if (dev->active_target && timer_pending(&dev->check_pres_timer) == 0) { 605 rc = dev->ops->check_presence(dev, dev->active_target); 606 if (!rc) { 607 mod_timer(&dev->check_pres_timer, jiffies + 608 msecs_to_jiffies(NFC_CHECK_PRES_FREQ_MS)); 609 } else { 610 nfc_target_lost(dev, dev->active_target->idx); 611 dev->active_target = NULL; 612 } 613 } 614 615 device_unlock(&dev->dev); 616} 617 618static void nfc_check_pres_timeout(unsigned long data) 619{ 620 struct nfc_dev *dev = (struct nfc_dev *)data; 621 622 queue_work(dev->check_pres_wq, &dev->check_pres_work); 623} 624 625struct class nfc_class = { 626 .name = "nfc", 627 .dev_release = nfc_release, 628}; 629EXPORT_SYMBOL(nfc_class); 630 631static int match_idx(struct device *d, void *data) 632{ 633 struct nfc_dev *dev = to_nfc_dev(d); 634 unsigned int *idx = data; 635 636 return dev->idx == *idx; 637} 638 639struct nfc_dev *nfc_get_device(unsigned int idx) 640{ 641 struct device *d; 642 643 d = class_find_device(&nfc_class, NULL, &idx, match_idx); 644 if (!d) 645 return NULL; 646 647 return to_nfc_dev(d); 648} 649 650/** 651 * nfc_allocate_device - allocate a new nfc device 652 * 653 * @ops: device operations 654 * @supported_protocols: NFC protocols supported by the device 655 */ 656struct nfc_dev *nfc_allocate_device(struct nfc_ops *ops, 657 u32 supported_protocols, 658 int tx_headroom, int tx_tailroom) 659{ 660 static atomic_t dev_no = ATOMIC_INIT(0); 661 struct nfc_dev *dev; 662 663 if (!ops->start_poll || !ops->stop_poll || !ops->activate_target || 664 !ops->deactivate_target || !ops->data_exchange) 665 return NULL; 666 667 if (!supported_protocols) 668 return NULL; 669 670 dev = kzalloc(sizeof(struct nfc_dev), GFP_KERNEL); 671 if (!dev) 672 return NULL; 673 674 dev->dev.class = &nfc_class; 675 dev->idx = atomic_inc_return(&dev_no) - 1; 676 dev_set_name(&dev->dev, "nfc%d", dev->idx); 677 device_initialize(&dev->dev); 678 679 dev->ops = ops; 680 dev->supported_protocols = supported_protocols; 681 dev->tx_headroom = tx_headroom; 682 dev->tx_tailroom = tx_tailroom; 683 684 spin_lock_init(&dev->targets_lock); 685 nfc_genl_data_init(&dev->genl_data); 686 687 /* first generation must not be 0 */ 688 dev->targets_generation = 1; 689 690 if (ops->check_presence) { 691 char name[32]; 692 init_timer(&dev->check_pres_timer); 693 dev->check_pres_timer.data = (unsigned long)dev; 694 dev->check_pres_timer.function = nfc_check_pres_timeout; 695 696 INIT_WORK(&dev->check_pres_work, nfc_check_pres_work); 697 snprintf(name, sizeof(name), "nfc%d_check_pres_wq", dev->idx); 698 dev->check_pres_wq = alloc_workqueue(name, WQ_NON_REENTRANT | 699 WQ_UNBOUND | 700 WQ_MEM_RECLAIM, 1); 701 if (dev->check_pres_wq == NULL) { 702 kfree(dev); 703 return NULL; 704 } 705 } 706 707 return dev; 708} 709EXPORT_SYMBOL(nfc_allocate_device); 710 711/** 712 * nfc_register_device - register a nfc device in the nfc subsystem 713 * 714 * @dev: The nfc device to register 715 */ 716int nfc_register_device(struct nfc_dev *dev) 717{ 718 int rc; 719 720 pr_debug("dev_name=%s\n", dev_name(&dev->dev)); 721 722 mutex_lock(&nfc_devlist_mutex); 723 nfc_devlist_generation++; 724 rc = device_add(&dev->dev); 725 mutex_unlock(&nfc_devlist_mutex); 726 727 if (rc < 0) 728 return rc; 729 730 rc = nfc_llcp_register_device(dev); 731 if (rc) 732 pr_err("Could not register llcp device\n"); 733 734 rc = nfc_genl_device_added(dev); 735 if (rc) 736 pr_debug("The userspace won't be notified that the device %s was added\n", 737 dev_name(&dev->dev)); 738 739 return 0; 740} 741EXPORT_SYMBOL(nfc_register_device); 742 743/** 744 * nfc_unregister_device - unregister a nfc device in the nfc subsystem 745 * 746 * @dev: The nfc device to unregister 747 */ 748void nfc_unregister_device(struct nfc_dev *dev) 749{ 750 int rc; 751 752 pr_debug("dev_name=%s\n", dev_name(&dev->dev)); 753 754 mutex_lock(&nfc_devlist_mutex); 755 nfc_devlist_generation++; 756 757 /* lock to avoid unregistering a device while an operation 758 is in progress */ 759 device_lock(&dev->dev); 760 device_del(&dev->dev); 761 device_unlock(&dev->dev); 762 763 mutex_unlock(&nfc_devlist_mutex); 764 765 nfc_llcp_unregister_device(dev); 766 767 rc = nfc_genl_device_removed(dev); 768 if (rc) 769 pr_debug("The userspace won't be notified that the device %s was removed\n", 770 dev_name(&dev->dev)); 771 772} 773EXPORT_SYMBOL(nfc_unregister_device); 774 775static int __init nfc_init(void) 776{ 777 int rc; 778 779 pr_info("NFC Core ver %s\n", VERSION); 780 781 rc = class_register(&nfc_class); 782 if (rc) 783 return rc; 784 785 rc = nfc_genl_init(); 786 if (rc) 787 goto err_genl; 788 789 /* the first generation must not be 0 */ 790 nfc_devlist_generation = 1; 791 792 rc = rawsock_init(); 793 if (rc) 794 goto err_rawsock; 795 796 rc = nfc_llcp_init(); 797 if (rc) 798 goto err_llcp_sock; 799 800 rc = af_nfc_init(); 801 if (rc) 802 goto err_af_nfc; 803 804 return 0; 805 806err_af_nfc: 807 nfc_llcp_exit(); 808err_llcp_sock: 809 rawsock_exit(); 810err_rawsock: 811 nfc_genl_exit(); 812err_genl: 813 class_unregister(&nfc_class); 814 return rc; 815} 816 817static void __exit nfc_exit(void) 818{ 819 af_nfc_exit(); 820 nfc_llcp_exit(); 821 rawsock_exit(); 822 nfc_genl_exit(); 823 class_unregister(&nfc_class); 824} 825 826subsys_initcall(nfc_init); 827module_exit(nfc_exit); 828 829MODULE_AUTHOR("Lauro Ramos Venancio <lauro.venancio@openbossa.org>"); 830MODULE_DESCRIPTION("NFC Core ver " VERSION); 831MODULE_VERSION(VERSION); 832MODULE_LICENSE("GPL"); 833