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TOMOYO Linux Cross Reference
Linux/net/nfc/core.c

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  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);
982 

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