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 int nfc_devlist_generation; 37 DEFINE_MUTEX(nfc_devlist_mutex); 38 39 /** 40 * nfc_dev_up - turn on the NFC device 41 * 42 * @dev: The nfc device to be turned on 43 * 44 * The device remains up until the nfc_dev_down function is called. 45 */ 46 int nfc_dev_up(struct nfc_dev *dev) 47 { 48 int rc = 0; 49 50 pr_debug("dev_name=%s\n", dev_name(&dev->dev)); 51 52 device_lock(&dev->dev); 53 54 if (!device_is_registered(&dev->dev)) { 55 rc = -ENODEV; 56 goto error; 57 } 58 59 if (dev->dev_up) { 60 rc = -EALREADY; 61 goto error; 62 } 63 64 if (dev->ops->dev_up) 65 rc = dev->ops->dev_up(dev); 66 67 if (!rc) 68 dev->dev_up = true; 69 70 error: 71 device_unlock(&dev->dev); 72 return rc; 73 } 74 75 /** 76 * nfc_dev_down - turn off the NFC device 77 * 78 * @dev: The nfc device to be turned off 79 */ 80 int nfc_dev_down(struct nfc_dev *dev) 81 { 82 int rc = 0; 83 84 pr_debug("dev_name=%s\n", dev_name(&dev->dev)); 85 86 device_lock(&dev->dev); 87 88 if (!device_is_registered(&dev->dev)) { 89 rc = -ENODEV; 90 goto error; 91 } 92 93 if (!dev->dev_up) { 94 rc = -EALREADY; 95 goto error; 96 } 97 98 if (dev->polling || dev->remote_activated) { 99 rc = -EBUSY; 100 goto error; 101 } 102 103 if (dev->ops->dev_down) 104 dev->ops->dev_down(dev); 105 106 dev->dev_up = false; 107 108 error: 109 device_unlock(&dev->dev); 110 return rc; 111 } 112 113 /** 114 * nfc_start_poll - start polling for nfc targets 115 * 116 * @dev: The nfc device that must start polling 117 * @protocols: bitset of nfc protocols that must be used for polling 118 * 119 * The device remains polling for targets until a target is found or 120 * the nfc_stop_poll function is called. 121 */ 122 int nfc_start_poll(struct nfc_dev *dev, u32 protocols) 123 { 124 int rc; 125 126 pr_debug("dev_name=%s protocols=0x%x\n", 127 dev_name(&dev->dev), protocols); 128 129 if (!protocols) 130 return -EINVAL; 131 132 device_lock(&dev->dev); 133 134 if (!device_is_registered(&dev->dev)) { 135 rc = -ENODEV; 136 goto error; 137 } 138 139 if (dev->polling) { 140 rc = -EBUSY; 141 goto error; 142 } 143 144 rc = dev->ops->start_poll(dev, protocols); 145 if (!rc) 146 dev->polling = true; 147 148 error: 149 device_unlock(&dev->dev); 150 return rc; 151 } 152 153 /** 154 * nfc_stop_poll - stop polling for nfc targets 155 * 156 * @dev: The nfc device that must stop polling 157 */ 158 int nfc_stop_poll(struct nfc_dev *dev) 159 { 160 int rc = 0; 161 162 pr_debug("dev_name=%s\n", dev_name(&dev->dev)); 163 164 device_lock(&dev->dev); 165 166 if (!device_is_registered(&dev->dev)) { 167 rc = -ENODEV; 168 goto error; 169 } 170 171 if (!dev->polling) { 172 rc = -EINVAL; 173 goto error; 174 } 175 176 dev->ops->stop_poll(dev); 177 dev->polling = false; 178 179 error: 180 device_unlock(&dev->dev); 181 return rc; 182 } 183 184 int nfc_dep_link_up(struct nfc_dev *dev, int target_index, 185 u8 comm_mode, u8 rf_mode) 186 { 187 int rc = 0; 188 189 pr_debug("dev_name=%s comm:%d rf:%d\n", 190 dev_name(&dev->dev), comm_mode, rf_mode); 191 192 if (!dev->ops->dep_link_up) 193 return -EOPNOTSUPP; 194 195 device_lock(&dev->dev); 196 197 if (!device_is_registered(&dev->dev)) { 198 rc = -ENODEV; 199 goto error; 200 } 201 202 if (dev->dep_link_up == true) { 203 rc = -EALREADY; 204 goto error; 205 } 206 207 rc = dev->ops->dep_link_up(dev, target_index, comm_mode, rf_mode); 208 209 error: 210 device_unlock(&dev->dev); 211 return rc; 212 } 213 214 int nfc_dep_link_down(struct nfc_dev *dev) 215 { 216 int rc = 0; 217 218 pr_debug("dev_name=%s\n", dev_name(&dev->dev)); 219 220 if (!dev->ops->dep_link_down) 221 return -EOPNOTSUPP; 222 223 device_lock(&dev->dev); 224 225 if (!device_is_registered(&dev->dev)) { 226 rc = -ENODEV; 227 goto error; 228 } 229 230 if (dev->dep_link_up == false) { 231 rc = -EALREADY; 232 goto error; 233 } 234 235 if (dev->dep_rf_mode == NFC_RF_TARGET) { 236 rc = -EOPNOTSUPP; 237 goto error; 238 } 239 240 rc = dev->ops->dep_link_down(dev); 241 if (!rc) { 242 dev->dep_link_up = false; 243 nfc_llcp_mac_is_down(dev); 244 nfc_genl_dep_link_down_event(dev); 245 } 246 247 error: 248 device_unlock(&dev->dev); 249 return rc; 250 } 251 252 int nfc_dep_link_is_up(struct nfc_dev *dev, u32 target_idx, 253 u8 comm_mode, u8 rf_mode) 254 { 255 dev->dep_link_up = true; 256 dev->dep_rf_mode = rf_mode; 257 258 nfc_llcp_mac_is_up(dev, target_idx, comm_mode, rf_mode); 259 260 return nfc_genl_dep_link_up_event(dev, target_idx, comm_mode, rf_mode); 261 } 262 EXPORT_SYMBOL(nfc_dep_link_is_up); 263 264 /** 265 * nfc_activate_target - prepare the target for data exchange 266 * 267 * @dev: The nfc device that found the target 268 * @target_idx: index of the target that must be activated 269 * @protocol: nfc protocol that will be used for data exchange 270 */ 271 int nfc_activate_target(struct nfc_dev *dev, u32 target_idx, u32 protocol) 272 { 273 int rc; 274 275 pr_debug("dev_name=%s target_idx=%u protocol=%u\n", 276 dev_name(&dev->dev), target_idx, protocol); 277 278 device_lock(&dev->dev); 279 280 if (!device_is_registered(&dev->dev)) { 281 rc = -ENODEV; 282 goto error; 283 } 284 285 rc = dev->ops->activate_target(dev, target_idx, protocol); 286 if (!rc) 287 dev->remote_activated = true; 288 289 error: 290 device_unlock(&dev->dev); 291 return rc; 292 } 293 294 /** 295 * nfc_deactivate_target - deactivate a nfc target 296 * 297 * @dev: The nfc device that found the target 298 * @target_idx: index of the target that must be deactivated 299 */ 300 int nfc_deactivate_target(struct nfc_dev *dev, u32 target_idx) 301 { 302 int rc = 0; 303 304 pr_debug("dev_name=%s target_idx=%u\n", 305 dev_name(&dev->dev), target_idx); 306 307 device_lock(&dev->dev); 308 309 if (!device_is_registered(&dev->dev)) { 310 rc = -ENODEV; 311 goto error; 312 } 313 314 dev->ops->deactivate_target(dev, target_idx); 315 dev->remote_activated = false; 316 317 error: 318 device_unlock(&dev->dev); 319 return rc; 320 } 321 322 /** 323 * nfc_data_exchange - transceive data 324 * 325 * @dev: The nfc device that found the target 326 * @target_idx: index of the target 327 * @skb: data to be sent 328 * @cb: callback called when the response is received 329 * @cb_context: parameter for the callback function 330 * 331 * The user must wait for the callback before calling this function again. 332 */ 333 int nfc_data_exchange(struct nfc_dev *dev, u32 target_idx, 334 struct sk_buff *skb, 335 data_exchange_cb_t cb, 336 void *cb_context) 337 { 338 int rc; 339 340 pr_debug("dev_name=%s target_idx=%u skb->len=%u\n", 341 dev_name(&dev->dev), target_idx, skb->len); 342 343 device_lock(&dev->dev); 344 345 if (!device_is_registered(&dev->dev)) { 346 rc = -ENODEV; 347 kfree_skb(skb); 348 goto error; 349 } 350 351 rc = dev->ops->data_exchange(dev, target_idx, skb, cb, cb_context); 352 353 error: 354 device_unlock(&dev->dev); 355 return rc; 356 } 357 358 int nfc_set_remote_general_bytes(struct nfc_dev *dev, u8 *gb, u8 gb_len) 359 { 360 pr_debug("dev_name=%s gb_len=%d\n", 361 dev_name(&dev->dev), gb_len); 362 363 if (gb_len > NFC_MAX_GT_LEN) 364 return -EINVAL; 365 366 return nfc_llcp_set_remote_gb(dev, gb, gb_len); 367 } 368 EXPORT_SYMBOL(nfc_set_remote_general_bytes); 369 370 u8 *nfc_get_local_general_bytes(struct nfc_dev *dev, u8 *gt_len) 371 { 372 return nfc_llcp_general_bytes(dev, gt_len); 373 } 374 EXPORT_SYMBOL(nfc_get_local_general_bytes); 375 376 /** 377 * nfc_alloc_send_skb - allocate a skb for data exchange responses 378 * 379 * @size: size to allocate 380 * @gfp: gfp flags 381 */ 382 struct sk_buff *nfc_alloc_send_skb(struct nfc_dev *dev, struct sock *sk, 383 unsigned int flags, unsigned int size, 384 unsigned int *err) 385 { 386 struct sk_buff *skb; 387 unsigned int total_size; 388 389 total_size = size + 390 dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE; 391 392 skb = sock_alloc_send_skb(sk, total_size, flags & MSG_DONTWAIT, err); 393 if (skb) 394 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE); 395 396 return skb; 397 } 398 399 /** 400 * nfc_alloc_recv_skb - allocate a skb for data exchange responses 401 * 402 * @size: size to allocate 403 * @gfp: gfp flags 404 */ 405 struct sk_buff *nfc_alloc_recv_skb(unsigned int size, gfp_t gfp) 406 { 407 struct sk_buff *skb; 408 unsigned int total_size; 409 410 total_size = size + 1; 411 skb = alloc_skb(total_size, gfp); 412 413 if (skb) 414 skb_reserve(skb, 1); 415 416 return skb; 417 } 418 EXPORT_SYMBOL(nfc_alloc_recv_skb); 419 420 /** 421 * nfc_targets_found - inform that targets were found 422 * 423 * @dev: The nfc device that found the targets 424 * @targets: array of nfc targets found 425 * @ntargets: targets array size 426 * 427 * The device driver must call this function when one or many nfc targets 428 * are found. After calling this function, the device driver must stop 429 * polling for targets. 430 */ 431 int nfc_targets_found(struct nfc_dev *dev, struct nfc_target *targets, 432 int n_targets) 433 { 434 int i; 435 436 pr_debug("dev_name=%s n_targets=%d\n", dev_name(&dev->dev), n_targets); 437 438 dev->polling = false; 439 440 for (i = 0; i < n_targets; i++) 441 targets[i].idx = dev->target_idx++; 442 443 spin_lock_bh(&dev->targets_lock); 444 445 dev->targets_generation++; 446 447 kfree(dev->targets); 448 dev->targets = kmemdup(targets, n_targets * sizeof(struct nfc_target), 449 GFP_ATOMIC); 450 451 if (!dev->targets) { 452 dev->n_targets = 0; 453 spin_unlock_bh(&dev->targets_lock); 454 return -ENOMEM; 455 } 456 457 dev->n_targets = n_targets; 458 spin_unlock_bh(&dev->targets_lock); 459 460 nfc_genl_targets_found(dev); 461 462 return 0; 463 } 464 EXPORT_SYMBOL(nfc_targets_found); 465 466 static void nfc_release(struct device *d) 467 { 468 struct nfc_dev *dev = to_nfc_dev(d); 469 470 pr_debug("dev_name=%s\n", dev_name(&dev->dev)); 471 472 nfc_genl_data_exit(&dev->genl_data); 473 kfree(dev->targets); 474 kfree(dev); 475 } 476 477 struct class nfc_class = { 478 .name = "nfc", 479 .dev_release = nfc_release, 480 }; 481 EXPORT_SYMBOL(nfc_class); 482 483 static int match_idx(struct device *d, void *data) 484 { 485 struct nfc_dev *dev = to_nfc_dev(d); 486 unsigned *idx = data; 487 488 return dev->idx == *idx; 489 } 490 491 struct nfc_dev *nfc_get_device(unsigned idx) 492 { 493 struct device *d; 494 495 d = class_find_device(&nfc_class, NULL, &idx, match_idx); 496 if (!d) 497 return NULL; 498 499 return to_nfc_dev(d); 500 } 501 502 /** 503 * nfc_allocate_device - allocate a new nfc device 504 * 505 * @ops: device operations 506 * @supported_protocols: NFC protocols supported by the device 507 */ 508 struct nfc_dev *nfc_allocate_device(struct nfc_ops *ops, 509 u32 supported_protocols, 510 int tx_headroom, 511 int tx_tailroom) 512 { 513 static atomic_t dev_no = ATOMIC_INIT(0); 514 struct nfc_dev *dev; 515 516 if (!ops->start_poll || !ops->stop_poll || !ops->activate_target || 517 !ops->deactivate_target || !ops->data_exchange) 518 return NULL; 519 520 if (!supported_protocols) 521 return NULL; 522 523 dev = kzalloc(sizeof(struct nfc_dev), GFP_KERNEL); 524 if (!dev) 525 return NULL; 526 527 dev->dev.class = &nfc_class; 528 dev->idx = atomic_inc_return(&dev_no) - 1; 529 dev_set_name(&dev->dev, "nfc%d", dev->idx); 530 device_initialize(&dev->dev); 531 532 dev->ops = ops; 533 dev->supported_protocols = supported_protocols; 534 dev->tx_headroom = tx_headroom; 535 dev->tx_tailroom = tx_tailroom; 536 537 spin_lock_init(&dev->targets_lock); 538 nfc_genl_data_init(&dev->genl_data); 539 540 /* first generation must not be 0 */ 541 dev->targets_generation = 1; 542 543 return dev; 544 } 545 EXPORT_SYMBOL(nfc_allocate_device); 546 547 /** 548 * nfc_register_device - register a nfc device in the nfc subsystem 549 * 550 * @dev: The nfc device to register 551 */ 552 int nfc_register_device(struct nfc_dev *dev) 553 { 554 int rc; 555 556 pr_debug("dev_name=%s\n", dev_name(&dev->dev)); 557 558 mutex_lock(&nfc_devlist_mutex); 559 nfc_devlist_generation++; 560 rc = device_add(&dev->dev); 561 mutex_unlock(&nfc_devlist_mutex); 562 563 if (rc < 0) 564 return rc; 565 566 rc = nfc_llcp_register_device(dev); 567 if (rc) 568 pr_err("Could not register llcp device\n"); 569 570 rc = nfc_genl_device_added(dev); 571 if (rc) 572 pr_debug("The userspace won't be notified that the device %s was added\n", 573 dev_name(&dev->dev)); 574 575 return 0; 576 } 577 EXPORT_SYMBOL(nfc_register_device); 578 579 /** 580 * nfc_unregister_device - unregister a nfc device in the nfc subsystem 581 * 582 * @dev: The nfc device to unregister 583 */ 584 void nfc_unregister_device(struct nfc_dev *dev) 585 { 586 int rc; 587 588 pr_debug("dev_name=%s\n", dev_name(&dev->dev)); 589 590 mutex_lock(&nfc_devlist_mutex); 591 nfc_devlist_generation++; 592 593 /* lock to avoid unregistering a device while an operation 594 is in progress */ 595 device_lock(&dev->dev); 596 device_del(&dev->dev); 597 device_unlock(&dev->dev); 598 599 mutex_unlock(&nfc_devlist_mutex); 600 601 nfc_llcp_unregister_device(dev); 602 603 rc = nfc_genl_device_removed(dev); 604 if (rc) 605 pr_debug("The userspace won't be notified that the device %s was removed\n", 606 dev_name(&dev->dev)); 607 608 } 609 EXPORT_SYMBOL(nfc_unregister_device); 610 611 static int __init nfc_init(void) 612 { 613 int rc; 614 615 pr_info("NFC Core ver %s\n", VERSION); 616 617 rc = class_register(&nfc_class); 618 if (rc) 619 return rc; 620 621 rc = nfc_genl_init(); 622 if (rc) 623 goto err_genl; 624 625 /* the first generation must not be 0 */ 626 nfc_devlist_generation = 1; 627 628 rc = rawsock_init(); 629 if (rc) 630 goto err_rawsock; 631 632 rc = nfc_llcp_init(); 633 if (rc) 634 goto err_llcp_sock; 635 636 rc = af_nfc_init(); 637 if (rc) 638 goto err_af_nfc; 639 640 return 0; 641 642 err_af_nfc: 643 nfc_llcp_exit(); 644 err_llcp_sock: 645 rawsock_exit(); 646 err_rawsock: 647 nfc_genl_exit(); 648 err_genl: 649 class_unregister(&nfc_class); 650 return rc; 651 } 652 653 static void __exit nfc_exit(void) 654 { 655 af_nfc_exit(); 656 nfc_llcp_exit(); 657 rawsock_exit(); 658 nfc_genl_exit(); 659 class_unregister(&nfc_class); 660 } 661 662 subsys_initcall(nfc_init); 663 module_exit(nfc_exit); 664 665 MODULE_AUTHOR("Lauro Ramos Venancio <lauro.venancio@openbossa.org>"); 666 MODULE_DESCRIPTION("NFC Core ver " VERSION); 667 MODULE_VERSION(VERSION); 668 MODULE_LICENSE("GPL"); 669