xref: /linux/net/nfc/core.c (revision 48dea9a700c8728cc31a1dd44588b97578de86ee)
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 (!device_is_registered(&dev->dev)) {
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->rfkill && rfkill_blocked(dev->rfkill)) {
98 		rc = -ERFKILL;
99 		goto error;
100 	}
101 
102 	if (!device_is_registered(&dev->dev)) {
103 		rc = -ENODEV;
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 (!device_is_registered(&dev->dev)) {
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  * @protocols: bitset of nfc protocols that must be used for polling
193  *
194  * The device remains polling for targets until a target is found or
195  * the nfc_stop_poll function is called.
196  */
197 int nfc_start_poll(struct nfc_dev *dev, u32 im_protocols, u32 tm_protocols)
198 {
199 	int rc;
200 
201 	pr_debug("dev_name %s initiator protocols 0x%x target protocols 0x%x\n",
202 		 dev_name(&dev->dev), im_protocols, tm_protocols);
203 
204 	if (!im_protocols && !tm_protocols)
205 		return -EINVAL;
206 
207 	device_lock(&dev->dev);
208 
209 	if (!device_is_registered(&dev->dev)) {
210 		rc = -ENODEV;
211 		goto error;
212 	}
213 
214 	if (!dev->dev_up) {
215 		rc = -ENODEV;
216 		goto error;
217 	}
218 
219 	if (dev->polling) {
220 		rc = -EBUSY;
221 		goto error;
222 	}
223 
224 	rc = dev->ops->start_poll(dev, im_protocols, tm_protocols);
225 	if (!rc) {
226 		dev->polling = true;
227 		dev->rf_mode = NFC_RF_NONE;
228 	}
229 
230 error:
231 	device_unlock(&dev->dev);
232 	return rc;
233 }
234 
235 /**
236  * nfc_stop_poll - stop polling for nfc targets
237  *
238  * @dev: The nfc device that must stop polling
239  */
240 int nfc_stop_poll(struct nfc_dev *dev)
241 {
242 	int rc = 0;
243 
244 	pr_debug("dev_name=%s\n", dev_name(&dev->dev));
245 
246 	device_lock(&dev->dev);
247 
248 	if (!device_is_registered(&dev->dev)) {
249 		rc = -ENODEV;
250 		goto error;
251 	}
252 
253 	if (!dev->polling) {
254 		rc = -EINVAL;
255 		goto error;
256 	}
257 
258 	dev->ops->stop_poll(dev);
259 	dev->polling = false;
260 	dev->rf_mode = NFC_RF_NONE;
261 
262 error:
263 	device_unlock(&dev->dev);
264 	return rc;
265 }
266 
267 static struct nfc_target *nfc_find_target(struct nfc_dev *dev, u32 target_idx)
268 {
269 	int i;
270 
271 	for (i = 0; i < dev->n_targets; i++) {
272 		if (dev->targets[i].idx == target_idx)
273 			return &dev->targets[i];
274 	}
275 
276 	return NULL;
277 }
278 
279 int nfc_dep_link_up(struct nfc_dev *dev, int target_index, u8 comm_mode)
280 {
281 	int rc = 0;
282 	u8 *gb;
283 	size_t gb_len;
284 	struct nfc_target *target;
285 
286 	pr_debug("dev_name=%s comm %d\n", dev_name(&dev->dev), comm_mode);
287 
288 	if (!dev->ops->dep_link_up)
289 		return -EOPNOTSUPP;
290 
291 	device_lock(&dev->dev);
292 
293 	if (!device_is_registered(&dev->dev)) {
294 		rc = -ENODEV;
295 		goto error;
296 	}
297 
298 	if (dev->dep_link_up == true) {
299 		rc = -EALREADY;
300 		goto error;
301 	}
302 
303 	gb = nfc_llcp_general_bytes(dev, &gb_len);
304 	if (gb_len > NFC_MAX_GT_LEN) {
305 		rc = -EINVAL;
306 		goto error;
307 	}
308 
309 	target = nfc_find_target(dev, target_index);
310 	if (target == NULL) {
311 		rc = -ENOTCONN;
312 		goto error;
313 	}
314 
315 	rc = dev->ops->dep_link_up(dev, target, comm_mode, gb, gb_len);
316 	if (!rc) {
317 		dev->active_target = target;
318 		dev->rf_mode = NFC_RF_INITIATOR;
319 	}
320 
321 error:
322 	device_unlock(&dev->dev);
323 	return rc;
324 }
325 
326 int nfc_dep_link_down(struct nfc_dev *dev)
327 {
328 	int rc = 0;
329 
330 	pr_debug("dev_name=%s\n", dev_name(&dev->dev));
331 
332 	if (!dev->ops->dep_link_down)
333 		return -EOPNOTSUPP;
334 
335 	device_lock(&dev->dev);
336 
337 	if (!device_is_registered(&dev->dev)) {
338 		rc = -ENODEV;
339 		goto error;
340 	}
341 
342 	if (dev->dep_link_up == false) {
343 		rc = -EALREADY;
344 		goto error;
345 	}
346 
347 	rc = dev->ops->dep_link_down(dev);
348 	if (!rc) {
349 		dev->dep_link_up = false;
350 		dev->active_target = NULL;
351 		dev->rf_mode = NFC_RF_NONE;
352 		nfc_llcp_mac_is_down(dev);
353 		nfc_genl_dep_link_down_event(dev);
354 	}
355 
356 error:
357 	device_unlock(&dev->dev);
358 
359 	return rc;
360 }
361 
362 int nfc_dep_link_is_up(struct nfc_dev *dev, u32 target_idx,
363 		       u8 comm_mode, u8 rf_mode)
364 {
365 	dev->dep_link_up = true;
366 
367 	if (!dev->active_target && rf_mode == NFC_RF_INITIATOR) {
368 		struct nfc_target *target;
369 
370 		target = nfc_find_target(dev, target_idx);
371 		if (target == NULL)
372 			return -ENOTCONN;
373 
374 		dev->active_target = target;
375 	}
376 
377 	dev->polling = false;
378 	dev->rf_mode = rf_mode;
379 
380 	nfc_llcp_mac_is_up(dev, target_idx, comm_mode, rf_mode);
381 
382 	return nfc_genl_dep_link_up_event(dev, target_idx, comm_mode, rf_mode);
383 }
384 EXPORT_SYMBOL(nfc_dep_link_is_up);
385 
386 /**
387  * nfc_activate_target - prepare the target for data exchange
388  *
389  * @dev: The nfc device that found the target
390  * @target_idx: index of the target that must be activated
391  * @protocol: nfc protocol that will be used for data exchange
392  */
393 int nfc_activate_target(struct nfc_dev *dev, u32 target_idx, u32 protocol)
394 {
395 	int rc;
396 	struct nfc_target *target;
397 
398 	pr_debug("dev_name=%s target_idx=%u protocol=%u\n",
399 		 dev_name(&dev->dev), target_idx, protocol);
400 
401 	device_lock(&dev->dev);
402 
403 	if (!device_is_registered(&dev->dev)) {
404 		rc = -ENODEV;
405 		goto error;
406 	}
407 
408 	if (dev->active_target) {
409 		rc = -EBUSY;
410 		goto error;
411 	}
412 
413 	target = nfc_find_target(dev, target_idx);
414 	if (target == NULL) {
415 		rc = -ENOTCONN;
416 		goto error;
417 	}
418 
419 	rc = dev->ops->activate_target(dev, target, protocol);
420 	if (!rc) {
421 		dev->active_target = target;
422 		dev->rf_mode = NFC_RF_INITIATOR;
423 
424 		if (dev->ops->check_presence && !dev->shutting_down)
425 			mod_timer(&dev->check_pres_timer, jiffies +
426 				  msecs_to_jiffies(NFC_CHECK_PRES_FREQ_MS));
427 	}
428 
429 error:
430 	device_unlock(&dev->dev);
431 	return rc;
432 }
433 
434 /**
435  * nfc_deactivate_target - deactivate a nfc target
436  *
437  * @dev: The nfc device that found the target
438  * @target_idx: index of the target that must be deactivated
439  */
440 int nfc_deactivate_target(struct nfc_dev *dev, u32 target_idx, u8 mode)
441 {
442 	int rc = 0;
443 
444 	pr_debug("dev_name=%s target_idx=%u\n",
445 		 dev_name(&dev->dev), target_idx);
446 
447 	device_lock(&dev->dev);
448 
449 	if (!device_is_registered(&dev->dev)) {
450 		rc = -ENODEV;
451 		goto error;
452 	}
453 
454 	if (dev->active_target == NULL) {
455 		rc = -ENOTCONN;
456 		goto error;
457 	}
458 
459 	if (dev->active_target->idx != target_idx) {
460 		rc = -ENOTCONN;
461 		goto error;
462 	}
463 
464 	if (dev->ops->check_presence)
465 		del_timer_sync(&dev->check_pres_timer);
466 
467 	dev->ops->deactivate_target(dev, dev->active_target, mode);
468 	dev->active_target = NULL;
469 
470 error:
471 	device_unlock(&dev->dev);
472 	return rc;
473 }
474 
475 /**
476  * nfc_data_exchange - transceive data
477  *
478  * @dev: The nfc device that found the target
479  * @target_idx: index of the target
480  * @skb: data to be sent
481  * @cb: callback called when the response is received
482  * @cb_context: parameter for the callback function
483  *
484  * The user must wait for the callback before calling this function again.
485  */
486 int nfc_data_exchange(struct nfc_dev *dev, u32 target_idx, struct sk_buff *skb,
487 		      data_exchange_cb_t cb, void *cb_context)
488 {
489 	int rc;
490 
491 	pr_debug("dev_name=%s target_idx=%u skb->len=%u\n",
492 		 dev_name(&dev->dev), target_idx, skb->len);
493 
494 	device_lock(&dev->dev);
495 
496 	if (!device_is_registered(&dev->dev)) {
497 		rc = -ENODEV;
498 		kfree_skb(skb);
499 		goto error;
500 	}
501 
502 	if (dev->rf_mode == NFC_RF_INITIATOR && dev->active_target != NULL) {
503 		if (dev->active_target->idx != target_idx) {
504 			rc = -EADDRNOTAVAIL;
505 			kfree_skb(skb);
506 			goto error;
507 		}
508 
509 		if (dev->ops->check_presence)
510 			del_timer_sync(&dev->check_pres_timer);
511 
512 		rc = dev->ops->im_transceive(dev, dev->active_target, skb, cb,
513 					     cb_context);
514 
515 		if (!rc && dev->ops->check_presence && !dev->shutting_down)
516 			mod_timer(&dev->check_pres_timer, jiffies +
517 				  msecs_to_jiffies(NFC_CHECK_PRES_FREQ_MS));
518 	} else if (dev->rf_mode == NFC_RF_TARGET && dev->ops->tm_send != NULL) {
519 		rc = dev->ops->tm_send(dev, skb);
520 	} else {
521 		rc = -ENOTCONN;
522 		kfree_skb(skb);
523 		goto error;
524 	}
525 
526 
527 error:
528 	device_unlock(&dev->dev);
529 	return rc;
530 }
531 
532 struct nfc_se *nfc_find_se(struct nfc_dev *dev, u32 se_idx)
533 {
534 	struct nfc_se *se;
535 
536 	list_for_each_entry(se, &dev->secure_elements, list)
537 		if (se->idx == se_idx)
538 			return se;
539 
540 	return NULL;
541 }
542 EXPORT_SYMBOL(nfc_find_se);
543 
544 int nfc_enable_se(struct nfc_dev *dev, u32 se_idx)
545 {
546 	struct nfc_se *se;
547 	int rc;
548 
549 	pr_debug("%s se index %d\n", dev_name(&dev->dev), se_idx);
550 
551 	device_lock(&dev->dev);
552 
553 	if (!device_is_registered(&dev->dev)) {
554 		rc = -ENODEV;
555 		goto error;
556 	}
557 
558 	if (!dev->dev_up) {
559 		rc = -ENODEV;
560 		goto error;
561 	}
562 
563 	if (dev->polling) {
564 		rc = -EBUSY;
565 		goto error;
566 	}
567 
568 	if (!dev->ops->enable_se || !dev->ops->disable_se) {
569 		rc = -EOPNOTSUPP;
570 		goto error;
571 	}
572 
573 	se = nfc_find_se(dev, se_idx);
574 	if (!se) {
575 		rc = -EINVAL;
576 		goto error;
577 	}
578 
579 	if (se->state == NFC_SE_ENABLED) {
580 		rc = -EALREADY;
581 		goto error;
582 	}
583 
584 	rc = dev->ops->enable_se(dev, se_idx);
585 	if (rc >= 0)
586 		se->state = NFC_SE_ENABLED;
587 
588 error:
589 	device_unlock(&dev->dev);
590 	return rc;
591 }
592 
593 int nfc_disable_se(struct nfc_dev *dev, u32 se_idx)
594 {
595 	struct nfc_se *se;
596 	int rc;
597 
598 	pr_debug("%s se index %d\n", dev_name(&dev->dev), se_idx);
599 
600 	device_lock(&dev->dev);
601 
602 	if (!device_is_registered(&dev->dev)) {
603 		rc = -ENODEV;
604 		goto error;
605 	}
606 
607 	if (!dev->dev_up) {
608 		rc = -ENODEV;
609 		goto error;
610 	}
611 
612 	if (!dev->ops->enable_se || !dev->ops->disable_se) {
613 		rc = -EOPNOTSUPP;
614 		goto error;
615 	}
616 
617 	se = nfc_find_se(dev, se_idx);
618 	if (!se) {
619 		rc = -EINVAL;
620 		goto error;
621 	}
622 
623 	if (se->state == NFC_SE_DISABLED) {
624 		rc = -EALREADY;
625 		goto error;
626 	}
627 
628 	rc = dev->ops->disable_se(dev, se_idx);
629 	if (rc >= 0)
630 		se->state = NFC_SE_DISABLED;
631 
632 error:
633 	device_unlock(&dev->dev);
634 	return rc;
635 }
636 
637 int nfc_set_remote_general_bytes(struct nfc_dev *dev, u8 *gb, u8 gb_len)
638 {
639 	pr_debug("dev_name=%s gb_len=%d\n", dev_name(&dev->dev), gb_len);
640 
641 	return nfc_llcp_set_remote_gb(dev, gb, gb_len);
642 }
643 EXPORT_SYMBOL(nfc_set_remote_general_bytes);
644 
645 u8 *nfc_get_local_general_bytes(struct nfc_dev *dev, size_t *gb_len)
646 {
647 	pr_debug("dev_name=%s\n", dev_name(&dev->dev));
648 
649 	return nfc_llcp_general_bytes(dev, gb_len);
650 }
651 EXPORT_SYMBOL(nfc_get_local_general_bytes);
652 
653 int nfc_tm_data_received(struct nfc_dev *dev, struct sk_buff *skb)
654 {
655 	/* Only LLCP target mode for now */
656 	if (dev->dep_link_up == false) {
657 		kfree_skb(skb);
658 		return -ENOLINK;
659 	}
660 
661 	return nfc_llcp_data_received(dev, skb);
662 }
663 EXPORT_SYMBOL(nfc_tm_data_received);
664 
665 int nfc_tm_activated(struct nfc_dev *dev, u32 protocol, u8 comm_mode,
666 		     u8 *gb, size_t gb_len)
667 {
668 	int rc;
669 
670 	device_lock(&dev->dev);
671 
672 	dev->polling = false;
673 
674 	if (gb != NULL) {
675 		rc = nfc_set_remote_general_bytes(dev, gb, gb_len);
676 		if (rc < 0)
677 			goto out;
678 	}
679 
680 	dev->rf_mode = NFC_RF_TARGET;
681 
682 	if (protocol == NFC_PROTO_NFC_DEP_MASK)
683 		nfc_dep_link_is_up(dev, 0, comm_mode, NFC_RF_TARGET);
684 
685 	rc = nfc_genl_tm_activated(dev, protocol);
686 
687 out:
688 	device_unlock(&dev->dev);
689 
690 	return rc;
691 }
692 EXPORT_SYMBOL(nfc_tm_activated);
693 
694 int nfc_tm_deactivated(struct nfc_dev *dev)
695 {
696 	dev->dep_link_up = false;
697 	dev->rf_mode = NFC_RF_NONE;
698 
699 	return nfc_genl_tm_deactivated(dev);
700 }
701 EXPORT_SYMBOL(nfc_tm_deactivated);
702 
703 /**
704  * nfc_alloc_send_skb - allocate a skb for data exchange responses
705  *
706  * @size: size to allocate
707  */
708 struct sk_buff *nfc_alloc_send_skb(struct nfc_dev *dev, struct sock *sk,
709 				   unsigned int flags, unsigned int size,
710 				   unsigned int *err)
711 {
712 	struct sk_buff *skb;
713 	unsigned int total_size;
714 
715 	total_size = size +
716 		dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
717 
718 	skb = sock_alloc_send_skb(sk, total_size, flags & MSG_DONTWAIT, err);
719 	if (skb)
720 		skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
721 
722 	return skb;
723 }
724 
725 /**
726  * nfc_alloc_recv_skb - allocate a skb for data exchange responses
727  *
728  * @size: size to allocate
729  * @gfp: gfp flags
730  */
731 struct sk_buff *nfc_alloc_recv_skb(unsigned int size, gfp_t gfp)
732 {
733 	struct sk_buff *skb;
734 	unsigned int total_size;
735 
736 	total_size = size + 1;
737 	skb = alloc_skb(total_size, gfp);
738 
739 	if (skb)
740 		skb_reserve(skb, 1);
741 
742 	return skb;
743 }
744 EXPORT_SYMBOL(nfc_alloc_recv_skb);
745 
746 /**
747  * nfc_targets_found - inform that targets were found
748  *
749  * @dev: The nfc device that found the targets
750  * @targets: array of nfc targets found
751  * @n_targets: targets array size
752  *
753  * The device driver must call this function when one or many nfc targets
754  * are found. After calling this function, the device driver must stop
755  * polling for targets.
756  * NOTE: This function can be called with targets=NULL and n_targets=0 to
757  * notify a driver error, meaning that the polling operation cannot complete.
758  * IMPORTANT: this function must not be called from an atomic context.
759  * In addition, it must also not be called from a context that would prevent
760  * the NFC Core to call other nfc ops entry point concurrently.
761  */
762 int nfc_targets_found(struct nfc_dev *dev,
763 		      struct nfc_target *targets, int n_targets)
764 {
765 	int i;
766 
767 	pr_debug("dev_name=%s n_targets=%d\n", dev_name(&dev->dev), n_targets);
768 
769 	for (i = 0; i < n_targets; i++)
770 		targets[i].idx = dev->target_next_idx++;
771 
772 	device_lock(&dev->dev);
773 
774 	if (dev->polling == false) {
775 		device_unlock(&dev->dev);
776 		return 0;
777 	}
778 
779 	dev->polling = false;
780 
781 	dev->targets_generation++;
782 
783 	kfree(dev->targets);
784 	dev->targets = NULL;
785 
786 	if (targets) {
787 		dev->targets = kmemdup(targets,
788 				       n_targets * sizeof(struct nfc_target),
789 				       GFP_ATOMIC);
790 
791 		if (!dev->targets) {
792 			dev->n_targets = 0;
793 			device_unlock(&dev->dev);
794 			return -ENOMEM;
795 		}
796 	}
797 
798 	dev->n_targets = n_targets;
799 	device_unlock(&dev->dev);
800 
801 	nfc_genl_targets_found(dev);
802 
803 	return 0;
804 }
805 EXPORT_SYMBOL(nfc_targets_found);
806 
807 /**
808  * nfc_target_lost - inform that an activated target went out of field
809  *
810  * @dev: The nfc device that had the activated target in field
811  * @target_idx: the nfc index of the target
812  *
813  * The device driver must call this function when the activated target
814  * goes out of the field.
815  * IMPORTANT: this function must not be called from an atomic context.
816  * In addition, it must also not be called from a context that would prevent
817  * the NFC Core to call other nfc ops entry point concurrently.
818  */
819 int nfc_target_lost(struct nfc_dev *dev, u32 target_idx)
820 {
821 	struct nfc_target *tg;
822 	int i;
823 
824 	pr_debug("dev_name %s n_target %d\n", dev_name(&dev->dev), target_idx);
825 
826 	device_lock(&dev->dev);
827 
828 	for (i = 0; i < dev->n_targets; i++) {
829 		tg = &dev->targets[i];
830 		if (tg->idx == target_idx)
831 			break;
832 	}
833 
834 	if (i == dev->n_targets) {
835 		device_unlock(&dev->dev);
836 		return -EINVAL;
837 	}
838 
839 	dev->targets_generation++;
840 	dev->n_targets--;
841 	dev->active_target = NULL;
842 
843 	if (dev->n_targets) {
844 		memcpy(&dev->targets[i], &dev->targets[i + 1],
845 		       (dev->n_targets - i) * sizeof(struct nfc_target));
846 	} else {
847 		kfree(dev->targets);
848 		dev->targets = NULL;
849 	}
850 
851 	device_unlock(&dev->dev);
852 
853 	nfc_genl_target_lost(dev, target_idx);
854 
855 	return 0;
856 }
857 EXPORT_SYMBOL(nfc_target_lost);
858 
859 inline void nfc_driver_failure(struct nfc_dev *dev, int err)
860 {
861 	nfc_targets_found(dev, NULL, 0);
862 }
863 EXPORT_SYMBOL(nfc_driver_failure);
864 
865 int nfc_add_se(struct nfc_dev *dev, u32 se_idx, u16 type)
866 {
867 	struct nfc_se *se;
868 	int rc;
869 
870 	pr_debug("%s se index %d\n", dev_name(&dev->dev), se_idx);
871 
872 	se = nfc_find_se(dev, se_idx);
873 	if (se)
874 		return -EALREADY;
875 
876 	se = kzalloc(sizeof(struct nfc_se), GFP_KERNEL);
877 	if (!se)
878 		return -ENOMEM;
879 
880 	se->idx = se_idx;
881 	se->type = type;
882 	se->state = NFC_SE_DISABLED;
883 	INIT_LIST_HEAD(&se->list);
884 
885 	list_add(&se->list, &dev->secure_elements);
886 
887 	rc = nfc_genl_se_added(dev, se_idx, type);
888 	if (rc < 0) {
889 		list_del(&se->list);
890 		kfree(se);
891 
892 		return rc;
893 	}
894 
895 	return 0;
896 }
897 EXPORT_SYMBOL(nfc_add_se);
898 
899 int nfc_remove_se(struct nfc_dev *dev, u32 se_idx)
900 {
901 	struct nfc_se *se, *n;
902 	int rc;
903 
904 	pr_debug("%s se index %d\n", dev_name(&dev->dev), se_idx);
905 
906 	list_for_each_entry_safe(se, n, &dev->secure_elements, list)
907 		if (se->idx == se_idx) {
908 			rc = nfc_genl_se_removed(dev, se_idx);
909 			if (rc < 0)
910 				return rc;
911 
912 			list_del(&se->list);
913 			kfree(se);
914 
915 			return 0;
916 		}
917 
918 	return -EINVAL;
919 }
920 EXPORT_SYMBOL(nfc_remove_se);
921 
922 int nfc_se_transaction(struct nfc_dev *dev, u8 se_idx,
923 		       struct nfc_evt_transaction *evt_transaction)
924 {
925 	int rc;
926 
927 	pr_debug("transaction: %x\n", se_idx);
928 
929 	device_lock(&dev->dev);
930 
931 	if (!evt_transaction) {
932 		rc = -EPROTO;
933 		goto out;
934 	}
935 
936 	rc = nfc_genl_se_transaction(dev, se_idx, evt_transaction);
937 out:
938 	device_unlock(&dev->dev);
939 	return rc;
940 }
941 EXPORT_SYMBOL(nfc_se_transaction);
942 
943 int nfc_se_connectivity(struct nfc_dev *dev, u8 se_idx)
944 {
945 	int rc;
946 
947 	pr_debug("connectivity: %x\n", se_idx);
948 
949 	device_lock(&dev->dev);
950 	rc = nfc_genl_se_connectivity(dev, se_idx);
951 	device_unlock(&dev->dev);
952 	return rc;
953 }
954 EXPORT_SYMBOL(nfc_se_connectivity);
955 
956 static void nfc_release(struct device *d)
957 {
958 	struct nfc_dev *dev = to_nfc_dev(d);
959 	struct nfc_se *se, *n;
960 
961 	pr_debug("dev_name=%s\n", dev_name(&dev->dev));
962 
963 	nfc_genl_data_exit(&dev->genl_data);
964 	kfree(dev->targets);
965 
966 	list_for_each_entry_safe(se, n, &dev->secure_elements, list) {
967 			nfc_genl_se_removed(dev, se->idx);
968 			list_del(&se->list);
969 			kfree(se);
970 	}
971 
972 	ida_simple_remove(&nfc_index_ida, dev->idx);
973 
974 	kfree(dev);
975 }
976 
977 static void nfc_check_pres_work(struct work_struct *work)
978 {
979 	struct nfc_dev *dev = container_of(work, struct nfc_dev,
980 					   check_pres_work);
981 	int rc;
982 
983 	device_lock(&dev->dev);
984 
985 	if (dev->active_target && timer_pending(&dev->check_pres_timer) == 0) {
986 		rc = dev->ops->check_presence(dev, dev->active_target);
987 		if (rc == -EOPNOTSUPP)
988 			goto exit;
989 		if (rc) {
990 			u32 active_target_idx = dev->active_target->idx;
991 			device_unlock(&dev->dev);
992 			nfc_target_lost(dev, active_target_idx);
993 			return;
994 		}
995 
996 		if (!dev->shutting_down)
997 			mod_timer(&dev->check_pres_timer, jiffies +
998 				  msecs_to_jiffies(NFC_CHECK_PRES_FREQ_MS));
999 	}
1000 
1001 exit:
1002 	device_unlock(&dev->dev);
1003 }
1004 
1005 static void nfc_check_pres_timeout(struct timer_list *t)
1006 {
1007 	struct nfc_dev *dev = from_timer(dev, t, check_pres_timer);
1008 
1009 	schedule_work(&dev->check_pres_work);
1010 }
1011 
1012 struct class nfc_class = {
1013 	.name = "nfc",
1014 	.dev_release = nfc_release,
1015 };
1016 EXPORT_SYMBOL(nfc_class);
1017 
1018 static int match_idx(struct device *d, const void *data)
1019 {
1020 	struct nfc_dev *dev = to_nfc_dev(d);
1021 	const unsigned int *idx = data;
1022 
1023 	return dev->idx == *idx;
1024 }
1025 
1026 struct nfc_dev *nfc_get_device(unsigned int idx)
1027 {
1028 	struct device *d;
1029 
1030 	d = class_find_device(&nfc_class, NULL, &idx, match_idx);
1031 	if (!d)
1032 		return NULL;
1033 
1034 	return to_nfc_dev(d);
1035 }
1036 
1037 /**
1038  * nfc_allocate_device - allocate a new nfc device
1039  *
1040  * @ops: device operations
1041  * @supported_protocols: NFC protocols supported by the device
1042  */
1043 struct nfc_dev *nfc_allocate_device(struct nfc_ops *ops,
1044 				    u32 supported_protocols,
1045 				    int tx_headroom, int tx_tailroom)
1046 {
1047 	struct nfc_dev *dev;
1048 	int rc;
1049 
1050 	if (!ops->start_poll || !ops->stop_poll || !ops->activate_target ||
1051 	    !ops->deactivate_target || !ops->im_transceive)
1052 		return NULL;
1053 
1054 	if (!supported_protocols)
1055 		return NULL;
1056 
1057 	dev = kzalloc(sizeof(struct nfc_dev), GFP_KERNEL);
1058 	if (!dev)
1059 		return NULL;
1060 
1061 	rc = ida_simple_get(&nfc_index_ida, 0, 0, GFP_KERNEL);
1062 	if (rc < 0)
1063 		goto err_free_dev;
1064 	dev->idx = rc;
1065 
1066 	dev->dev.class = &nfc_class;
1067 	dev_set_name(&dev->dev, "nfc%d", dev->idx);
1068 	device_initialize(&dev->dev);
1069 
1070 	dev->ops = ops;
1071 	dev->supported_protocols = supported_protocols;
1072 	dev->tx_headroom = tx_headroom;
1073 	dev->tx_tailroom = tx_tailroom;
1074 	INIT_LIST_HEAD(&dev->secure_elements);
1075 
1076 	nfc_genl_data_init(&dev->genl_data);
1077 
1078 	dev->rf_mode = NFC_RF_NONE;
1079 
1080 	/* first generation must not be 0 */
1081 	dev->targets_generation = 1;
1082 
1083 	if (ops->check_presence) {
1084 		timer_setup(&dev->check_pres_timer, nfc_check_pres_timeout, 0);
1085 		INIT_WORK(&dev->check_pres_work, nfc_check_pres_work);
1086 	}
1087 
1088 	return dev;
1089 
1090 err_free_dev:
1091 	kfree(dev);
1092 
1093 	return NULL;
1094 }
1095 EXPORT_SYMBOL(nfc_allocate_device);
1096 
1097 /**
1098  * nfc_register_device - register a nfc device in the nfc subsystem
1099  *
1100  * @dev: The nfc device to register
1101  */
1102 int nfc_register_device(struct nfc_dev *dev)
1103 {
1104 	int rc;
1105 
1106 	pr_debug("dev_name=%s\n", dev_name(&dev->dev));
1107 
1108 	mutex_lock(&nfc_devlist_mutex);
1109 	nfc_devlist_generation++;
1110 	rc = device_add(&dev->dev);
1111 	mutex_unlock(&nfc_devlist_mutex);
1112 
1113 	if (rc < 0)
1114 		return rc;
1115 
1116 	rc = nfc_llcp_register_device(dev);
1117 	if (rc)
1118 		pr_err("Could not register llcp device\n");
1119 
1120 	rc = nfc_genl_device_added(dev);
1121 	if (rc)
1122 		pr_debug("The userspace won't be notified that the device %s was added\n",
1123 			 dev_name(&dev->dev));
1124 
1125 	dev->rfkill = rfkill_alloc(dev_name(&dev->dev), &dev->dev,
1126 				   RFKILL_TYPE_NFC, &nfc_rfkill_ops, dev);
1127 	if (dev->rfkill) {
1128 		if (rfkill_register(dev->rfkill) < 0) {
1129 			rfkill_destroy(dev->rfkill);
1130 			dev->rfkill = NULL;
1131 		}
1132 	}
1133 
1134 	return 0;
1135 }
1136 EXPORT_SYMBOL(nfc_register_device);
1137 
1138 /**
1139  * nfc_unregister_device - unregister a nfc device in the nfc subsystem
1140  *
1141  * @dev: The nfc device to unregister
1142  */
1143 void nfc_unregister_device(struct nfc_dev *dev)
1144 {
1145 	int rc;
1146 
1147 	pr_debug("dev_name=%s\n", dev_name(&dev->dev));
1148 
1149 	if (dev->rfkill) {
1150 		rfkill_unregister(dev->rfkill);
1151 		rfkill_destroy(dev->rfkill);
1152 	}
1153 
1154 	if (dev->ops->check_presence) {
1155 		device_lock(&dev->dev);
1156 		dev->shutting_down = true;
1157 		device_unlock(&dev->dev);
1158 		del_timer_sync(&dev->check_pres_timer);
1159 		cancel_work_sync(&dev->check_pres_work);
1160 	}
1161 
1162 	rc = nfc_genl_device_removed(dev);
1163 	if (rc)
1164 		pr_debug("The userspace won't be notified that the device %s "
1165 			 "was removed\n", dev_name(&dev->dev));
1166 
1167 	nfc_llcp_unregister_device(dev);
1168 
1169 	mutex_lock(&nfc_devlist_mutex);
1170 	nfc_devlist_generation++;
1171 	device_del(&dev->dev);
1172 	mutex_unlock(&nfc_devlist_mutex);
1173 }
1174 EXPORT_SYMBOL(nfc_unregister_device);
1175 
1176 static int __init nfc_init(void)
1177 {
1178 	int rc;
1179 
1180 	pr_info("NFC Core ver %s\n", VERSION);
1181 
1182 	rc = class_register(&nfc_class);
1183 	if (rc)
1184 		return rc;
1185 
1186 	rc = nfc_genl_init();
1187 	if (rc)
1188 		goto err_genl;
1189 
1190 	/* the first generation must not be 0 */
1191 	nfc_devlist_generation = 1;
1192 
1193 	rc = rawsock_init();
1194 	if (rc)
1195 		goto err_rawsock;
1196 
1197 	rc = nfc_llcp_init();
1198 	if (rc)
1199 		goto err_llcp_sock;
1200 
1201 	rc = af_nfc_init();
1202 	if (rc)
1203 		goto err_af_nfc;
1204 
1205 	return 0;
1206 
1207 err_af_nfc:
1208 	nfc_llcp_exit();
1209 err_llcp_sock:
1210 	rawsock_exit();
1211 err_rawsock:
1212 	nfc_genl_exit();
1213 err_genl:
1214 	class_unregister(&nfc_class);
1215 	return rc;
1216 }
1217 
1218 static void __exit nfc_exit(void)
1219 {
1220 	af_nfc_exit();
1221 	nfc_llcp_exit();
1222 	rawsock_exit();
1223 	nfc_genl_exit();
1224 	class_unregister(&nfc_class);
1225 }
1226 
1227 subsys_initcall(nfc_init);
1228 module_exit(nfc_exit);
1229 
1230 MODULE_AUTHOR("Lauro Ramos Venancio <lauro.venancio@openbossa.org>");
1231 MODULE_DESCRIPTION("NFC Core ver " VERSION);
1232 MODULE_VERSION(VERSION);
1233 MODULE_LICENSE("GPL");
1234 MODULE_ALIAS_NETPROTO(PF_NFC);
1235 MODULE_ALIAS_GENL_FAMILY(NFC_GENL_NAME);
1236