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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  */
nfc_dev_up(struct nfc_dev * dev)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  */
nfc_dev_down(struct nfc_dev * dev)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 
nfc_rfkill_set_block(void * data,bool blocked)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  */
nfc_start_poll(struct nfc_dev * dev,u32 im_protocols,u32 tm_protocols)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  */
nfc_stop_poll(struct nfc_dev * dev)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 
nfc_find_target(struct nfc_dev * dev,u32 target_idx)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 
nfc_dep_link_up(struct nfc_dev * dev,int target_index,u8 comm_mode)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 
nfc_dep_link_down(struct nfc_dev * dev)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 
nfc_dep_link_is_up(struct nfc_dev * dev,u32 target_idx,u8 comm_mode,u8 rf_mode)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  */
nfc_activate_target(struct nfc_dev * dev,u32 target_idx,u32 protocol)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  */
nfc_deactivate_target(struct nfc_dev * dev,u32 target_idx)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  */
nfc_data_exchange(struct nfc_dev * dev,u32 target_idx,struct sk_buff * skb,data_exchange_cb_t cb,void * cb_context)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 
nfc_set_remote_general_bytes(struct nfc_dev * dev,u8 * gb,u8 gb_len)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 
nfc_get_local_general_bytes(struct nfc_dev * dev,size_t * gb_len)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 
nfc_tm_data_received(struct nfc_dev * dev,struct sk_buff * skb)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 
nfc_tm_activated(struct nfc_dev * dev,u32 protocol,u8 comm_mode,u8 * gb,size_t gb_len)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 
nfc_tm_deactivated(struct nfc_dev * dev)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  */
nfc_alloc_send_skb(struct nfc_dev * dev,struct sock * sk,unsigned int flags,unsigned int size,unsigned int * err)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  */
nfc_alloc_recv_skb(unsigned int size,gfp_t gfp)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  */
nfc_targets_found(struct nfc_dev * dev,struct nfc_target * targets,int n_targets)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  */
nfc_target_lost(struct nfc_dev * dev,u32 target_idx)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 
nfc_driver_failure(struct nfc_dev * dev,int err)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 
nfc_release(struct device * d)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 
nfc_check_pres_work(struct work_struct * work)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 
nfc_check_pres_timeout(unsigned long data)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 
match_idx(struct device * d,const void * data)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 
nfc_get_device(unsigned int idx)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  */
nfc_allocate_device(struct nfc_ops * ops,u32 supported_protocols,u32 supported_se,int tx_headroom,int tx_tailroom)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  */
nfc_register_device(struct nfc_dev * dev)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  */
nfc_unregister_device(struct nfc_dev * dev)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 
nfc_init(void)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 
nfc_exit(void)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