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

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  1 // SPDX-License-Identifier: GPL-2.0-or-later
  2 /*
  3  * Copyright (C) 2011 Instituto Nokia de Tecnologia
  4  *
  5  * Authors:
  6  *    Lauro Ramos Venancio <lauro.venancio@openbossa.org>
  7  *    Aloisio Almeida Jr <aloisio.almeida@openbossa.org>
  8  */
  9 
 10 #define pr_fmt(fmt) KBUILD_MODNAME ": %s: " fmt, __func__
 11 
 12 #include <linux/init.h>
 13 #include <linux/kernel.h>
 14 #include <linux/module.h>
 15 #include <linux/slab.h>
 16 #include <linux/rfkill.h>
 17 #include <linux/nfc.h>
 18 
 19 #include <net/genetlink.h>
 20 
 21 #include "nfc.h"
 22 
 23 #define VERSION "0.1"
 24 
 25 #define NFC_CHECK_PRES_FREQ_MS  2000
 26 
 27 int nfc_devlist_generation;
 28 DEFINE_MUTEX(nfc_devlist_mutex);
 29 
 30 /* NFC device ID bitmap */
 31 static DEFINE_IDA(nfc_index_ida);
 32 
 33 int nfc_fw_download(struct nfc_dev *dev, const char *firmware_name)
 34 {
 35         int rc = 0;
 36 
 37         pr_debug("%s do firmware %s\n", dev_name(&dev->dev), firmware_name);
 38 
 39         device_lock(&dev->dev);
 40 
 41         if (dev->shutting_down) {
 42                 rc = -ENODEV;
 43                 goto error;
 44         }
 45 
 46         if (dev->dev_up) {
 47                 rc = -EBUSY;
 48                 goto error;
 49         }
 50 
 51         if (!dev->ops->fw_download) {
 52                 rc = -EOPNOTSUPP;
 53                 goto error;
 54         }
 55 
 56         dev->fw_download_in_progress = true;
 57         rc = dev->ops->fw_download(dev, firmware_name);
 58         if (rc)
 59                 dev->fw_download_in_progress = false;
 60 
 61 error:
 62         device_unlock(&dev->dev);
 63         return rc;
 64 }
 65 
 66 /**
 67  * nfc_fw_download_done - inform that a firmware download was completed
 68  *
 69  * @dev: The nfc device to which firmware was downloaded
 70  * @firmware_name: The firmware filename
 71  * @result: The positive value of a standard errno value
 72  */
 73 int nfc_fw_download_done(struct nfc_dev *dev, const char *firmware_name,
 74                          u32 result)
 75 {
 76         dev->fw_download_in_progress = false;
 77 
 78         return nfc_genl_fw_download_done(dev, firmware_name, result);
 79 }
 80 EXPORT_SYMBOL(nfc_fw_download_done);
 81 
 82 /**
 83  * nfc_dev_up - turn on the NFC device
 84  *
 85  * @dev: The nfc device to be turned on
 86  *
 87  * The device remains up until the nfc_dev_down function is called.
 88  */
 89 int nfc_dev_up(struct nfc_dev *dev)
 90 {
 91         int rc = 0;
 92 
 93         pr_debug("dev_name=%s\n", dev_name(&dev->dev));
 94 
 95         device_lock(&dev->dev);
 96 
 97         if (dev->shutting_down) {
 98                 rc = -ENODEV;
 99                 goto error;
100         }
101 
102         if (dev->rfkill && rfkill_blocked(dev->rfkill)) {
103                 rc = -ERFKILL;
104                 goto error;
105         }
106 
107         if (dev->fw_download_in_progress) {
108                 rc = -EBUSY;
109                 goto error;
110         }
111 
112         if (dev->dev_up) {
113                 rc = -EALREADY;
114                 goto error;
115         }
116 
117         if (dev->ops->dev_up)
118                 rc = dev->ops->dev_up(dev);
119 
120         if (!rc)
121                 dev->dev_up = true;
122 
123         /* We have to enable the device before discovering SEs */
124         if (dev->ops->discover_se && dev->ops->discover_se(dev))
125                 pr_err("SE discovery failed\n");
126 
127 error:
128         device_unlock(&dev->dev);
129         return rc;
130 }
131 
132 /**
133  * nfc_dev_down - turn off the NFC device
134  *
135  * @dev: The nfc device to be turned off
136  */
137 int nfc_dev_down(struct nfc_dev *dev)
138 {
139         int rc = 0;
140 
141         pr_debug("dev_name=%s\n", dev_name(&dev->dev));
142 
143         device_lock(&dev->dev);
144 
145         if (dev->shutting_down) {
146                 rc = -ENODEV;
147                 goto error;
148         }
149 
150         if (!dev->dev_up) {
151                 rc = -EALREADY;
152                 goto error;
153         }
154 
155         if (dev->polling || dev->active_target) {
156                 rc = -EBUSY;
157                 goto error;
158         }
159 
160         if (dev->ops->dev_down)
161                 dev->ops->dev_down(dev);
162 
163         dev->dev_up = false;
164 
165 error:
166         device_unlock(&dev->dev);
167         return rc;
168 }
169 
170 static int nfc_rfkill_set_block(void *data, bool blocked)
171 {
172         struct nfc_dev *dev = data;
173 
174         pr_debug("%s blocked %d", dev_name(&dev->dev), blocked);
175 
176         if (!blocked)
177                 return 0;
178 
179         nfc_dev_down(dev);
180 
181         return 0;
182 }
183 
184 static const struct rfkill_ops nfc_rfkill_ops = {
185         .set_block = nfc_rfkill_set_block,
186 };
187 
188 /**
189  * nfc_start_poll - start polling for nfc targets
190  *
191  * @dev: The nfc device that must start polling
192  * @im_protocols: bitset of nfc initiator protocols to be used for polling
193  * @tm_protocols: bitset of nfc transport protocols to be used for polling
194  *
195  * The device remains polling for targets until a target is found or
196  * the nfc_stop_poll function is called.
197  */
198 int nfc_start_poll(struct nfc_dev *dev, u32 im_protocols, u32 tm_protocols)
199 {
200         int rc;
201 
202         pr_debug("dev_name %s initiator protocols 0x%x target protocols 0x%x\n",
203                  dev_name(&dev->dev), im_protocols, tm_protocols);
204 
205         if (!im_protocols && !tm_protocols)
206                 return -EINVAL;
207 
208         device_lock(&dev->dev);
209 
210         if (dev->shutting_down) {
211                 rc = -ENODEV;
212                 goto error;
213         }
214 
215         if (!dev->dev_up) {
216                 rc = -ENODEV;
217                 goto error;
218         }
219 
220         if (dev->polling) {
221                 rc = -EBUSY;
222                 goto error;
223         }
224 
225         rc = dev->ops->start_poll(dev, im_protocols, tm_protocols);
226         if (!rc) {
227                 dev->polling = true;
228                 dev->rf_mode = NFC_RF_NONE;
229         }
230 
231 error:
232         device_unlock(&dev->dev);
233         return rc;
234 }
235 
236 /**
237  * nfc_stop_poll - stop polling for nfc targets
238  *
239  * @dev: The nfc device that must stop polling
240  */
241 int nfc_stop_poll(struct nfc_dev *dev)
242 {
243         int rc = 0;
244 
245         pr_debug("dev_name=%s\n", dev_name(&dev->dev));
246 
247         device_lock(&dev->dev);
248 
249         if (dev->shutting_down) {
250                 rc = -ENODEV;
251                 goto error;
252         }
253 
254         if (!dev->polling) {
255                 rc = -EINVAL;
256                 goto error;
257         }
258 
259         dev->ops->stop_poll(dev);
260         dev->polling = false;
261         dev->rf_mode = NFC_RF_NONE;
262 
263 error:
264         device_unlock(&dev->dev);
265         return rc;
266 }
267 
268 static struct nfc_target *nfc_find_target(struct nfc_dev *dev, u32 target_idx)
269 {
270         int i;
271 
272         for (i = 0; i < dev->n_targets; i++) {
273                 if (dev->targets[i].idx == target_idx)
274                         return &dev->targets[i];
275         }
276 
277         return NULL;
278 }
279 
280 int nfc_dep_link_up(struct nfc_dev *dev, int target_index, u8 comm_mode)
281 {
282         int rc = 0;
283         u8 *gb;
284         size_t gb_len;
285         struct nfc_target *target;
286 
287         pr_debug("dev_name=%s comm %d\n", dev_name(&dev->dev), comm_mode);
288 
289         if (!dev->ops->dep_link_up)
290                 return -EOPNOTSUPP;
291 
292         device_lock(&dev->dev);
293 
294         if (dev->shutting_down) {
295                 rc = -ENODEV;
296                 goto error;
297         }
298 
299         if (dev->dep_link_up == true) {
300                 rc = -EALREADY;
301                 goto error;
302         }
303 
304         gb = nfc_llcp_general_bytes(dev, &gb_len);
305         if (gb_len > NFC_MAX_GT_LEN) {
306                 rc = -EINVAL;
307                 goto error;
308         }
309 
310         target = nfc_find_target(dev, target_index);
311         if (target == NULL) {
312                 rc = -ENOTCONN;
313                 goto error;
314         }
315 
316         rc = dev->ops->dep_link_up(dev, target, comm_mode, gb, gb_len);
317         if (!rc) {
318                 dev->active_target = target;
319                 dev->rf_mode = NFC_RF_INITIATOR;
320         }
321 
322 error:
323         device_unlock(&dev->dev);
324         return rc;
325 }
326 
327 int nfc_dep_link_down(struct nfc_dev *dev)
328 {
329         int rc = 0;
330 
331         pr_debug("dev_name=%s\n", dev_name(&dev->dev));
332 
333         if (!dev->ops->dep_link_down)
334                 return -EOPNOTSUPP;
335 
336         device_lock(&dev->dev);
337 
338         if (dev->shutting_down) {
339                 rc = -ENODEV;
340                 goto error;
341         }
342 
343         if (dev->dep_link_up == false) {
344                 rc = -EALREADY;
345                 goto error;
346         }
347 
348         rc = dev->ops->dep_link_down(dev);
349         if (!rc) {
350                 dev->dep_link_up = false;
351                 dev->active_target = NULL;
352                 dev->rf_mode = NFC_RF_NONE;
353                 nfc_llcp_mac_is_down(dev);
354                 nfc_genl_dep_link_down_event(dev);
355         }
356 
357 error:
358         device_unlock(&dev->dev);
359 
360         return rc;
361 }
362 
363 int nfc_dep_link_is_up(struct nfc_dev *dev, u32 target_idx,
364                        u8 comm_mode, u8 rf_mode)
365 {
366         dev->dep_link_up = true;
367 
368         if (!dev->active_target && rf_mode == NFC_RF_INITIATOR) {
369                 struct nfc_target *target;
370 
371                 target = nfc_find_target(dev, target_idx);
372                 if (target == NULL)
373                         return -ENOTCONN;
374 
375                 dev->active_target = target;
376         }
377 
378         dev->polling = false;
379         dev->rf_mode = rf_mode;
380 
381         nfc_llcp_mac_is_up(dev, target_idx, comm_mode, rf_mode);
382 
383         return nfc_genl_dep_link_up_event(dev, target_idx, comm_mode, rf_mode);
384 }
385 EXPORT_SYMBOL(nfc_dep_link_is_up);
386 
387 /**
388  * nfc_activate_target - prepare the target for data exchange
389  *
390  * @dev: The nfc device that found the target
391  * @target_idx: index of the target that must be activated
392  * @protocol: nfc protocol that will be used for data exchange
393  */
394 int nfc_activate_target(struct nfc_dev *dev, u32 target_idx, u32 protocol)
395 {
396         int rc;
397         struct nfc_target *target;
398 
399         pr_debug("dev_name=%s target_idx=%u protocol=%u\n",
400                  dev_name(&dev->dev), target_idx, protocol);
401 
402         device_lock(&dev->dev);
403 
404         if (dev->shutting_down) {
405                 rc = -ENODEV;
406                 goto error;
407         }
408 
409         if (dev->active_target) {
410                 rc = -EBUSY;
411                 goto error;
412         }
413 
414         target = nfc_find_target(dev, target_idx);
415         if (target == NULL) {
416                 rc = -ENOTCONN;
417                 goto error;
418         }
419 
420         rc = dev->ops->activate_target(dev, target, protocol);
421         if (!rc) {
422                 dev->active_target = target;
423                 dev->rf_mode = NFC_RF_INITIATOR;
424 
425                 if (dev->ops->check_presence && !dev->shutting_down)
426                         mod_timer(&dev->check_pres_timer, jiffies +
427                                   msecs_to_jiffies(NFC_CHECK_PRES_FREQ_MS));
428         }
429 
430 error:
431         device_unlock(&dev->dev);
432         return rc;
433 }
434 
435 /**
436  * nfc_deactivate_target - deactivate a nfc target
437  *
438  * @dev: The nfc device that found the target
439  * @target_idx: index of the target that must be deactivated
440  * @mode: idle or sleep?
441  */
442 int nfc_deactivate_target(struct nfc_dev *dev, u32 target_idx, u8 mode)
443 {
444         int rc = 0;
445 
446         pr_debug("dev_name=%s target_idx=%u\n",
447                  dev_name(&dev->dev), target_idx);
448 
449         device_lock(&dev->dev);
450 
451         if (dev->shutting_down) {
452                 rc = -ENODEV;
453                 goto error;
454         }
455 
456         if (dev->active_target == NULL) {
457                 rc = -ENOTCONN;
458                 goto error;
459         }
460 
461         if (dev->active_target->idx != target_idx) {
462                 rc = -ENOTCONN;
463                 goto error;
464         }
465 
466         if (dev->ops->check_presence)
467                 del_timer_sync(&dev->check_pres_timer);
468 
469         dev->ops->deactivate_target(dev, dev->active_target, mode);
470         dev->active_target = NULL;
471 
472 error:
473         device_unlock(&dev->dev);
474         return rc;
475 }
476 
477 /**
478  * nfc_data_exchange - transceive data
479  *
480  * @dev: The nfc device that found the target
481  * @target_idx: index of the target
482  * @skb: data to be sent
483  * @cb: callback called when the response is received
484  * @cb_context: parameter for the callback function
485  *
486  * The user must wait for the callback before calling this function again.
487  */
488 int nfc_data_exchange(struct nfc_dev *dev, u32 target_idx, struct sk_buff *skb,
489                       data_exchange_cb_t cb, void *cb_context)
490 {
491         int rc;
492 
493         pr_debug("dev_name=%s target_idx=%u skb->len=%u\n",
494                  dev_name(&dev->dev), target_idx, skb->len);
495 
496         device_lock(&dev->dev);
497 
498         if (dev->shutting_down) {
499                 rc = -ENODEV;
500                 kfree_skb(skb);
501                 goto error;
502         }
503 
504         if (dev->rf_mode == NFC_RF_INITIATOR && dev->active_target != NULL) {
505                 if (dev->active_target->idx != target_idx) {
506                         rc = -EADDRNOTAVAIL;
507                         kfree_skb(skb);
508                         goto error;
509                 }
510 
511                 if (dev->ops->check_presence)
512                         del_timer_sync(&dev->check_pres_timer);
513 
514                 rc = dev->ops->im_transceive(dev, dev->active_target, skb, cb,
515                                              cb_context);
516 
517                 if (!rc && dev->ops->check_presence && !dev->shutting_down)
518                         mod_timer(&dev->check_pres_timer, jiffies +
519                                   msecs_to_jiffies(NFC_CHECK_PRES_FREQ_MS));
520         } else if (dev->rf_mode == NFC_RF_TARGET && dev->ops->tm_send != NULL) {
521                 rc = dev->ops->tm_send(dev, skb);
522         } else {
523                 rc = -ENOTCONN;
524                 kfree_skb(skb);
525                 goto error;
526         }
527 
528 
529 error:
530         device_unlock(&dev->dev);
531         return rc;
532 }
533 
534 struct nfc_se *nfc_find_se(struct nfc_dev *dev, u32 se_idx)
535 {
536         struct nfc_se *se;
537 
538         list_for_each_entry(se, &dev->secure_elements, list)
539                 if (se->idx == se_idx)
540                         return se;
541 
542         return NULL;
543 }
544 EXPORT_SYMBOL(nfc_find_se);
545 
546 int nfc_enable_se(struct nfc_dev *dev, u32 se_idx)
547 {
548         struct nfc_se *se;
549         int rc;
550 
551         pr_debug("%s se index %d\n", dev_name(&dev->dev), se_idx);
552 
553         device_lock(&dev->dev);
554 
555         if (dev->shutting_down) {
556                 rc = -ENODEV;
557                 goto error;
558         }
559 
560         if (!dev->dev_up) {
561                 rc = -ENODEV;
562                 goto error;
563         }
564 
565         if (dev->polling) {
566                 rc = -EBUSY;
567                 goto error;
568         }
569 
570         if (!dev->ops->enable_se || !dev->ops->disable_se) {
571                 rc = -EOPNOTSUPP;
572                 goto error;
573         }
574 
575         se = nfc_find_se(dev, se_idx);
576         if (!se) {
577                 rc = -EINVAL;
578                 goto error;
579         }
580 
581         if (se->state == NFC_SE_ENABLED) {
582                 rc = -EALREADY;
583                 goto error;
584         }
585 
586         rc = dev->ops->enable_se(dev, se_idx);
587         if (rc >= 0)
588                 se->state = NFC_SE_ENABLED;
589 
590 error:
591         device_unlock(&dev->dev);
592         return rc;
593 }
594 
595 int nfc_disable_se(struct nfc_dev *dev, u32 se_idx)
596 {
597         struct nfc_se *se;
598         int rc;
599 
600         pr_debug("%s se index %d\n", dev_name(&dev->dev), se_idx);
601 
602         device_lock(&dev->dev);
603 
604         if (dev->shutting_down) {
605                 rc = -ENODEV;
606                 goto error;
607         }
608 
609         if (!dev->dev_up) {
610                 rc = -ENODEV;
611                 goto error;
612         }
613 
614         if (!dev->ops->enable_se || !dev->ops->disable_se) {
615                 rc = -EOPNOTSUPP;
616                 goto error;
617         }
618 
619         se = nfc_find_se(dev, se_idx);
620         if (!se) {
621                 rc = -EINVAL;
622                 goto error;
623         }
624 
625         if (se->state == NFC_SE_DISABLED) {
626                 rc = -EALREADY;
627                 goto error;
628         }
629 
630         rc = dev->ops->disable_se(dev, se_idx);
631         if (rc >= 0)
632                 se->state = NFC_SE_DISABLED;
633 
634 error:
635         device_unlock(&dev->dev);
636         return rc;
637 }
638 
639 int nfc_set_remote_general_bytes(struct nfc_dev *dev, const u8 *gb, u8 gb_len)
640 {
641         pr_debug("dev_name=%s gb_len=%d\n", dev_name(&dev->dev), gb_len);
642 
643         return nfc_llcp_set_remote_gb(dev, gb, gb_len);
644 }
645 EXPORT_SYMBOL(nfc_set_remote_general_bytes);
646 
647 u8 *nfc_get_local_general_bytes(struct nfc_dev *dev, size_t *gb_len)
648 {
649         pr_debug("dev_name=%s\n", dev_name(&dev->dev));
650 
651         return nfc_llcp_general_bytes(dev, gb_len);
652 }
653 EXPORT_SYMBOL(nfc_get_local_general_bytes);
654 
655 int nfc_tm_data_received(struct nfc_dev *dev, struct sk_buff *skb)
656 {
657         /* Only LLCP target mode for now */
658         if (dev->dep_link_up == false) {
659                 kfree_skb(skb);
660                 return -ENOLINK;
661         }
662 
663         return nfc_llcp_data_received(dev, skb);
664 }
665 EXPORT_SYMBOL(nfc_tm_data_received);
666 
667 int nfc_tm_activated(struct nfc_dev *dev, u32 protocol, u8 comm_mode,
668                      const u8 *gb, size_t gb_len)
669 {
670         int rc;
671 
672         device_lock(&dev->dev);
673 
674         dev->polling = false;
675 
676         if (gb != NULL) {
677                 rc = nfc_set_remote_general_bytes(dev, gb, gb_len);
678                 if (rc < 0)
679                         goto out;
680         }
681 
682         dev->rf_mode = NFC_RF_TARGET;
683 
684         if (protocol == NFC_PROTO_NFC_DEP_MASK)
685                 nfc_dep_link_is_up(dev, 0, comm_mode, NFC_RF_TARGET);
686 
687         rc = nfc_genl_tm_activated(dev, protocol);
688 
689 out:
690         device_unlock(&dev->dev);
691 
692         return rc;
693 }
694 EXPORT_SYMBOL(nfc_tm_activated);
695 
696 int nfc_tm_deactivated(struct nfc_dev *dev)
697 {
698         dev->dep_link_up = false;
699         dev->rf_mode = NFC_RF_NONE;
700 
701         return nfc_genl_tm_deactivated(dev);
702 }
703 EXPORT_SYMBOL(nfc_tm_deactivated);
704 
705 /**
706  * nfc_alloc_send_skb - allocate a skb for data exchange responses
707  *
708  * @dev: device sending the response
709  * @sk: socket sending the response
710  * @flags: MSG_DONTWAIT flag
711  * @size: size to allocate
712  * @err: pointer to memory to store the error code
713  */
714 struct sk_buff *nfc_alloc_send_skb(struct nfc_dev *dev, struct sock *sk,
715                                    unsigned int flags, unsigned int size,
716                                    unsigned int *err)
717 {
718         struct sk_buff *skb;
719         unsigned int total_size;
720 
721         total_size = size +
722                 dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
723 
724         skb = sock_alloc_send_skb(sk, total_size, flags & MSG_DONTWAIT, err);
725         if (skb)
726                 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
727 
728         return skb;
729 }
730 
731 /**
732  * nfc_alloc_recv_skb - allocate a skb for data exchange responses
733  *
734  * @size: size to allocate
735  * @gfp: gfp flags
736  */
737 struct sk_buff *nfc_alloc_recv_skb(unsigned int size, gfp_t gfp)
738 {
739         struct sk_buff *skb;
740         unsigned int total_size;
741 
742         total_size = size + 1;
743         skb = alloc_skb(total_size, gfp);
744 
745         if (skb)
746                 skb_reserve(skb, 1);
747 
748         return skb;
749 }
750 EXPORT_SYMBOL(nfc_alloc_recv_skb);
751 
752 /**
753  * nfc_targets_found - inform that targets were found
754  *
755  * @dev: The nfc device that found the targets
756  * @targets: array of nfc targets found
757  * @n_targets: targets array size
758  *
759  * The device driver must call this function when one or many nfc targets
760  * are found. After calling this function, the device driver must stop
761  * polling for targets.
762  * NOTE: This function can be called with targets=NULL and n_targets=0 to
763  * notify a driver error, meaning that the polling operation cannot complete.
764  * IMPORTANT: this function must not be called from an atomic context.
765  * In addition, it must also not be called from a context that would prevent
766  * the NFC Core to call other nfc ops entry point concurrently.
767  */
768 int nfc_targets_found(struct nfc_dev *dev,
769                       struct nfc_target *targets, int n_targets)
770 {
771         int i;
772 
773         pr_debug("dev_name=%s n_targets=%d\n", dev_name(&dev->dev), n_targets);
774 
775         for (i = 0; i < n_targets; i++)
776                 targets[i].idx = dev->target_next_idx++;
777 
778         device_lock(&dev->dev);
779 
780         if (dev->polling == false) {
781                 device_unlock(&dev->dev);
782                 return 0;
783         }
784 
785         dev->polling = false;
786 
787         dev->targets_generation++;
788 
789         kfree(dev->targets);
790         dev->targets = NULL;
791 
792         if (targets) {
793                 dev->targets = kmemdup(targets,
794                                        n_targets * sizeof(struct nfc_target),
795                                        GFP_ATOMIC);
796 
797                 if (!dev->targets) {
798                         dev->n_targets = 0;
799                         device_unlock(&dev->dev);
800                         return -ENOMEM;
801                 }
802         }
803 
804         dev->n_targets = n_targets;
805         device_unlock(&dev->dev);
806 
807         nfc_genl_targets_found(dev);
808 
809         return 0;
810 }
811 EXPORT_SYMBOL(nfc_targets_found);
812 
813 /**
814  * nfc_target_lost - inform that an activated target went out of field
815  *
816  * @dev: The nfc device that had the activated target in field
817  * @target_idx: the nfc index of the target
818  *
819  * The device driver must call this function when the activated target
820  * goes out of the field.
821  * IMPORTANT: this function must not be called from an atomic context.
822  * In addition, it must also not be called from a context that would prevent
823  * the NFC Core to call other nfc ops entry point concurrently.
824  */
825 int nfc_target_lost(struct nfc_dev *dev, u32 target_idx)
826 {
827         const struct nfc_target *tg;
828         int i;
829 
830         pr_debug("dev_name %s n_target %d\n", dev_name(&dev->dev), target_idx);
831 
832         device_lock(&dev->dev);
833 
834         for (i = 0; i < dev->n_targets; i++) {
835                 tg = &dev->targets[i];
836                 if (tg->idx == target_idx)
837                         break;
838         }
839 
840         if (i == dev->n_targets) {
841                 device_unlock(&dev->dev);
842                 return -EINVAL;
843         }
844 
845         dev->targets_generation++;
846         dev->n_targets--;
847         dev->active_target = NULL;
848 
849         if (dev->n_targets) {
850                 memcpy(&dev->targets[i], &dev->targets[i + 1],
851                        (dev->n_targets - i) * sizeof(struct nfc_target));
852         } else {
853                 kfree(dev->targets);
854                 dev->targets = NULL;
855         }
856 
857         device_unlock(&dev->dev);
858 
859         nfc_genl_target_lost(dev, target_idx);
860 
861         return 0;
862 }
863 EXPORT_SYMBOL(nfc_target_lost);
864 
865 inline void nfc_driver_failure(struct nfc_dev *dev, int err)
866 {
867         nfc_targets_found(dev, NULL, 0);
868 }
869 EXPORT_SYMBOL(nfc_driver_failure);
870 
871 int nfc_add_se(struct nfc_dev *dev, u32 se_idx, u16 type)
872 {
873         struct nfc_se *se;
874         int rc;
875 
876         pr_debug("%s se index %d\n", dev_name(&dev->dev), se_idx);
877 
878         se = nfc_find_se(dev, se_idx);
879         if (se)
880                 return -EALREADY;
881 
882         se = kzalloc(sizeof(struct nfc_se), GFP_KERNEL);
883         if (!se)
884                 return -ENOMEM;
885 
886         se->idx = se_idx;
887         se->type = type;
888         se->state = NFC_SE_DISABLED;
889         INIT_LIST_HEAD(&se->list);
890 
891         list_add(&se->list, &dev->secure_elements);
892 
893         rc = nfc_genl_se_added(dev, se_idx, type);
894         if (rc < 0) {
895                 list_del(&se->list);
896                 kfree(se);
897 
898                 return rc;
899         }
900 
901         return 0;
902 }
903 EXPORT_SYMBOL(nfc_add_se);
904 
905 int nfc_remove_se(struct nfc_dev *dev, u32 se_idx)
906 {
907         struct nfc_se *se, *n;
908         int rc;
909 
910         pr_debug("%s se index %d\n", dev_name(&dev->dev), se_idx);
911 
912         list_for_each_entry_safe(se, n, &dev->secure_elements, list)
913                 if (se->idx == se_idx) {
914                         rc = nfc_genl_se_removed(dev, se_idx);
915                         if (rc < 0)
916                                 return rc;
917 
918                         list_del(&se->list);
919                         kfree(se);
920 
921                         return 0;
922                 }
923 
924         return -EINVAL;
925 }
926 EXPORT_SYMBOL(nfc_remove_se);
927 
928 int nfc_se_transaction(struct nfc_dev *dev, u8 se_idx,
929                        struct nfc_evt_transaction *evt_transaction)
930 {
931         int rc;
932 
933         pr_debug("transaction: %x\n", se_idx);
934 
935         device_lock(&dev->dev);
936 
937         if (!evt_transaction) {
938                 rc = -EPROTO;
939                 goto out;
940         }
941 
942         rc = nfc_genl_se_transaction(dev, se_idx, evt_transaction);
943 out:
944         device_unlock(&dev->dev);
945         return rc;
946 }
947 EXPORT_SYMBOL(nfc_se_transaction);
948 
949 int nfc_se_connectivity(struct nfc_dev *dev, u8 se_idx)
950 {
951         int rc;
952 
953         pr_debug("connectivity: %x\n", se_idx);
954 
955         device_lock(&dev->dev);
956         rc = nfc_genl_se_connectivity(dev, se_idx);
957         device_unlock(&dev->dev);
958         return rc;
959 }
960 EXPORT_SYMBOL(nfc_se_connectivity);
961 
962 static void nfc_release(struct device *d)
963 {
964         struct nfc_dev *dev = to_nfc_dev(d);
965         struct nfc_se *se, *n;
966 
967         pr_debug("dev_name=%s\n", dev_name(&dev->dev));
968 
969         nfc_genl_data_exit(&dev->genl_data);
970         kfree(dev->targets);
971 
972         list_for_each_entry_safe(se, n, &dev->secure_elements, list) {
973                         nfc_genl_se_removed(dev, se->idx);
974                         list_del(&se->list);
975                         kfree(se);
976         }
977 
978         ida_free(&nfc_index_ida, dev->idx);
979 
980         kfree(dev);
981 }
982 
983 static void nfc_check_pres_work(struct work_struct *work)
984 {
985         struct nfc_dev *dev = container_of(work, struct nfc_dev,
986                                            check_pres_work);
987         int rc;
988 
989         device_lock(&dev->dev);
990 
991         if (dev->active_target && timer_pending(&dev->check_pres_timer) == 0) {
992                 rc = dev->ops->check_presence(dev, dev->active_target);
993                 if (rc == -EOPNOTSUPP)
994                         goto exit;
995                 if (rc) {
996                         u32 active_target_idx = dev->active_target->idx;
997                         device_unlock(&dev->dev);
998                         nfc_target_lost(dev, active_target_idx);
999                         return;
1000                 }
1001 
1002                 if (!dev->shutting_down)
1003                         mod_timer(&dev->check_pres_timer, jiffies +
1004                                   msecs_to_jiffies(NFC_CHECK_PRES_FREQ_MS));
1005         }
1006 
1007 exit:
1008         device_unlock(&dev->dev);
1009 }
1010 
1011 static void nfc_check_pres_timeout(struct timer_list *t)
1012 {
1013         struct nfc_dev *dev = from_timer(dev, t, check_pres_timer);
1014 
1015         schedule_work(&dev->check_pres_work);
1016 }
1017 
1018 const struct class nfc_class = {
1019         .name = "nfc",
1020         .dev_release = nfc_release,
1021 };
1022 EXPORT_SYMBOL(nfc_class);
1023 
1024 static int match_idx(struct device *d, const void *data)
1025 {
1026         struct nfc_dev *dev = to_nfc_dev(d);
1027         const unsigned int *idx = data;
1028 
1029         return dev->idx == *idx;
1030 }
1031 
1032 struct nfc_dev *nfc_get_device(unsigned int idx)
1033 {
1034         struct device *d;
1035 
1036         d = class_find_device(&nfc_class, NULL, &idx, match_idx);
1037         if (!d)
1038                 return NULL;
1039 
1040         return to_nfc_dev(d);
1041 }
1042 
1043 /**
1044  * nfc_allocate_device - allocate a new nfc device
1045  *
1046  * @ops: device operations
1047  * @supported_protocols: NFC protocols supported by the device
1048  * @tx_headroom: reserved space at beginning of skb
1049  * @tx_tailroom: reserved space at end of skb
1050  */
1051 struct nfc_dev *nfc_allocate_device(const struct nfc_ops *ops,
1052                                     u32 supported_protocols,
1053                                     int tx_headroom, int tx_tailroom)
1054 {
1055         struct nfc_dev *dev;
1056         int rc;
1057 
1058         if (!ops->start_poll || !ops->stop_poll || !ops->activate_target ||
1059             !ops->deactivate_target || !ops->im_transceive)
1060                 return NULL;
1061 
1062         if (!supported_protocols)
1063                 return NULL;
1064 
1065         dev = kzalloc(sizeof(struct nfc_dev), GFP_KERNEL);
1066         if (!dev)
1067                 return NULL;
1068 
1069         rc = ida_alloc(&nfc_index_ida, GFP_KERNEL);
1070         if (rc < 0)
1071                 goto err_free_dev;
1072         dev->idx = rc;
1073 
1074         dev->dev.class = &nfc_class;
1075         dev_set_name(&dev->dev, "nfc%d", dev->idx);
1076         device_initialize(&dev->dev);
1077 
1078         dev->ops = ops;
1079         dev->supported_protocols = supported_protocols;
1080         dev->tx_headroom = tx_headroom;
1081         dev->tx_tailroom = tx_tailroom;
1082         INIT_LIST_HEAD(&dev->secure_elements);
1083 
1084         nfc_genl_data_init(&dev->genl_data);
1085 
1086         dev->rf_mode = NFC_RF_NONE;
1087 
1088         /* first generation must not be 0 */
1089         dev->targets_generation = 1;
1090 
1091         if (ops->check_presence) {
1092                 timer_setup(&dev->check_pres_timer, nfc_check_pres_timeout, 0);
1093                 INIT_WORK(&dev->check_pres_work, nfc_check_pres_work);
1094         }
1095 
1096         return dev;
1097 
1098 err_free_dev:
1099         kfree(dev);
1100 
1101         return NULL;
1102 }
1103 EXPORT_SYMBOL(nfc_allocate_device);
1104 
1105 /**
1106  * nfc_register_device - register a nfc device in the nfc subsystem
1107  *
1108  * @dev: The nfc device to register
1109  */
1110 int nfc_register_device(struct nfc_dev *dev)
1111 {
1112         int rc;
1113 
1114         pr_debug("dev_name=%s\n", dev_name(&dev->dev));
1115 
1116         mutex_lock(&nfc_devlist_mutex);
1117         nfc_devlist_generation++;
1118         rc = device_add(&dev->dev);
1119         mutex_unlock(&nfc_devlist_mutex);
1120 
1121         if (rc < 0)
1122                 return rc;
1123 
1124         rc = nfc_llcp_register_device(dev);
1125         if (rc)
1126                 pr_err("Could not register llcp device\n");
1127 
1128         device_lock(&dev->dev);
1129         dev->rfkill = rfkill_alloc(dev_name(&dev->dev), &dev->dev,
1130                                    RFKILL_TYPE_NFC, &nfc_rfkill_ops, dev);
1131         if (dev->rfkill) {
1132                 if (rfkill_register(dev->rfkill) < 0) {
1133                         rfkill_destroy(dev->rfkill);
1134                         dev->rfkill = NULL;
1135                 }
1136         }
1137         dev->shutting_down = false;
1138         device_unlock(&dev->dev);
1139 
1140         rc = nfc_genl_device_added(dev);
1141         if (rc)
1142                 pr_debug("The userspace won't be notified that the device %s was added\n",
1143                          dev_name(&dev->dev));
1144 
1145         return 0;
1146 }
1147 EXPORT_SYMBOL(nfc_register_device);
1148 
1149 /**
1150  * nfc_unregister_device - unregister a nfc device in the nfc subsystem
1151  *
1152  * @dev: The nfc device to unregister
1153  */
1154 void nfc_unregister_device(struct nfc_dev *dev)
1155 {
1156         int rc;
1157 
1158         pr_debug("dev_name=%s\n", dev_name(&dev->dev));
1159 
1160         rc = nfc_genl_device_removed(dev);
1161         if (rc)
1162                 pr_debug("The userspace won't be notified that the device %s "
1163                          "was removed\n", dev_name(&dev->dev));
1164 
1165         device_lock(&dev->dev);
1166         if (dev->rfkill) {
1167                 rfkill_unregister(dev->rfkill);
1168                 rfkill_destroy(dev->rfkill);
1169                 dev->rfkill = NULL;
1170         }
1171         dev->shutting_down = true;
1172         device_unlock(&dev->dev);
1173 
1174         if (dev->ops->check_presence) {
1175                 del_timer_sync(&dev->check_pres_timer);
1176                 cancel_work_sync(&dev->check_pres_work);
1177         }
1178 
1179         nfc_llcp_unregister_device(dev);
1180 
1181         mutex_lock(&nfc_devlist_mutex);
1182         nfc_devlist_generation++;
1183         device_del(&dev->dev);
1184         mutex_unlock(&nfc_devlist_mutex);
1185 }
1186 EXPORT_SYMBOL(nfc_unregister_device);
1187 
1188 static int __init nfc_init(void)
1189 {
1190         int rc;
1191 
1192         pr_info("NFC Core ver %s\n", VERSION);
1193 
1194         rc = class_register(&nfc_class);
1195         if (rc)
1196                 return rc;
1197 
1198         rc = nfc_genl_init();
1199         if (rc)
1200                 goto err_genl;
1201 
1202         /* the first generation must not be 0 */
1203         nfc_devlist_generation = 1;
1204 
1205         rc = rawsock_init();
1206         if (rc)
1207                 goto err_rawsock;
1208 
1209         rc = nfc_llcp_init();
1210         if (rc)
1211                 goto err_llcp_sock;
1212 
1213         rc = af_nfc_init();
1214         if (rc)
1215                 goto err_af_nfc;
1216 
1217         return 0;
1218 
1219 err_af_nfc:
1220         nfc_llcp_exit();
1221 err_llcp_sock:
1222         rawsock_exit();
1223 err_rawsock:
1224         nfc_genl_exit();
1225 err_genl:
1226         class_unregister(&nfc_class);
1227         return rc;
1228 }
1229 
1230 static void __exit nfc_exit(void)
1231 {
1232         af_nfc_exit();
1233         nfc_llcp_exit();
1234         rawsock_exit();
1235         nfc_genl_exit();
1236         class_unregister(&nfc_class);
1237 }
1238 
1239 subsys_initcall(nfc_init);
1240 module_exit(nfc_exit);
1241 
1242 MODULE_AUTHOR("Lauro Ramos Venancio <lauro.venancio@openbossa.org>");
1243 MODULE_DESCRIPTION("NFC Core ver " VERSION);
1244 MODULE_VERSION(VERSION);
1245 MODULE_LICENSE("GPL");
1246 MODULE_ALIAS_NETPROTO(PF_NFC);
1247 MODULE_ALIAS_GENL_FAMILY(NFC_GENL_NAME);
1248 

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