xref: /openbmc/linux/net/nfc/hci/core.c (revision 861e10be)
1 /*
2  * Copyright (C) 2012  Intel Corporation. All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the
16  * Free Software Foundation, Inc.,
17  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18  */
19 
20 #define pr_fmt(fmt) "hci: %s: " fmt, __func__
21 
22 #include <linux/init.h>
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25 #include <linux/nfc.h>
26 
27 #include <net/nfc/nfc.h>
28 #include <net/nfc/hci.h>
29 #include <net/nfc/llc.h>
30 
31 #include "hci.h"
32 
33 /* Largest headroom needed for outgoing HCI commands */
34 #define HCI_CMDS_HEADROOM 1
35 
36 int nfc_hci_result_to_errno(u8 result)
37 {
38 	switch (result) {
39 	case NFC_HCI_ANY_OK:
40 		return 0;
41 	case NFC_HCI_ANY_E_REG_PAR_UNKNOWN:
42 		return -EOPNOTSUPP;
43 	case NFC_HCI_ANY_E_TIMEOUT:
44 		return -ETIME;
45 	default:
46 		return -1;
47 	}
48 }
49 EXPORT_SYMBOL(nfc_hci_result_to_errno);
50 
51 static void nfc_hci_msg_tx_work(struct work_struct *work)
52 {
53 	struct nfc_hci_dev *hdev = container_of(work, struct nfc_hci_dev,
54 						msg_tx_work);
55 	struct hci_msg *msg;
56 	struct sk_buff *skb;
57 	int r = 0;
58 
59 	mutex_lock(&hdev->msg_tx_mutex);
60 
61 	if (hdev->cmd_pending_msg) {
62 		if (timer_pending(&hdev->cmd_timer) == 0) {
63 			if (hdev->cmd_pending_msg->cb)
64 				hdev->cmd_pending_msg->cb(hdev->
65 							  cmd_pending_msg->
66 							  cb_context,
67 							  NULL,
68 							  -ETIME);
69 			kfree(hdev->cmd_pending_msg);
70 			hdev->cmd_pending_msg = NULL;
71 		} else {
72 			goto exit;
73 		}
74 	}
75 
76 next_msg:
77 	if (list_empty(&hdev->msg_tx_queue))
78 		goto exit;
79 
80 	msg = list_first_entry(&hdev->msg_tx_queue, struct hci_msg, msg_l);
81 	list_del(&msg->msg_l);
82 
83 	pr_debug("msg_tx_queue has a cmd to send\n");
84 	while ((skb = skb_dequeue(&msg->msg_frags)) != NULL) {
85 		r = nfc_llc_xmit_from_hci(hdev->llc, skb);
86 		if (r < 0) {
87 			kfree_skb(skb);
88 			skb_queue_purge(&msg->msg_frags);
89 			if (msg->cb)
90 				msg->cb(msg->cb_context, NULL, r);
91 			kfree(msg);
92 			break;
93 		}
94 	}
95 
96 	if (r)
97 		goto next_msg;
98 
99 	if (msg->wait_response == false) {
100 		kfree(msg);
101 		goto next_msg;
102 	}
103 
104 	hdev->cmd_pending_msg = msg;
105 	mod_timer(&hdev->cmd_timer, jiffies +
106 		  msecs_to_jiffies(hdev->cmd_pending_msg->completion_delay));
107 
108 exit:
109 	mutex_unlock(&hdev->msg_tx_mutex);
110 }
111 
112 static void nfc_hci_msg_rx_work(struct work_struct *work)
113 {
114 	struct nfc_hci_dev *hdev = container_of(work, struct nfc_hci_dev,
115 						msg_rx_work);
116 	struct sk_buff *skb;
117 	struct hcp_message *message;
118 	u8 pipe;
119 	u8 type;
120 	u8 instruction;
121 
122 	while ((skb = skb_dequeue(&hdev->msg_rx_queue)) != NULL) {
123 		pipe = skb->data[0];
124 		skb_pull(skb, NFC_HCI_HCP_PACKET_HEADER_LEN);
125 		message = (struct hcp_message *)skb->data;
126 		type = HCP_MSG_GET_TYPE(message->header);
127 		instruction = HCP_MSG_GET_CMD(message->header);
128 		skb_pull(skb, NFC_HCI_HCP_MESSAGE_HEADER_LEN);
129 
130 		nfc_hci_hcp_message_rx(hdev, pipe, type, instruction, skb);
131 	}
132 }
133 
134 static void __nfc_hci_cmd_completion(struct nfc_hci_dev *hdev, int err,
135 				     struct sk_buff *skb)
136 {
137 	del_timer_sync(&hdev->cmd_timer);
138 
139 	if (hdev->cmd_pending_msg->cb)
140 		hdev->cmd_pending_msg->cb(hdev->cmd_pending_msg->cb_context,
141 					  skb, err);
142 	else
143 		kfree_skb(skb);
144 
145 	kfree(hdev->cmd_pending_msg);
146 	hdev->cmd_pending_msg = NULL;
147 
148 	schedule_work(&hdev->msg_tx_work);
149 }
150 
151 void nfc_hci_resp_received(struct nfc_hci_dev *hdev, u8 result,
152 			   struct sk_buff *skb)
153 {
154 	mutex_lock(&hdev->msg_tx_mutex);
155 
156 	if (hdev->cmd_pending_msg == NULL) {
157 		kfree_skb(skb);
158 		goto exit;
159 	}
160 
161 	__nfc_hci_cmd_completion(hdev, nfc_hci_result_to_errno(result), skb);
162 
163 exit:
164 	mutex_unlock(&hdev->msg_tx_mutex);
165 }
166 
167 void nfc_hci_cmd_received(struct nfc_hci_dev *hdev, u8 pipe, u8 cmd,
168 			  struct sk_buff *skb)
169 {
170 	kfree_skb(skb);
171 }
172 
173 u32 nfc_hci_sak_to_protocol(u8 sak)
174 {
175 	switch (NFC_HCI_TYPE_A_SEL_PROT(sak)) {
176 	case NFC_HCI_TYPE_A_SEL_PROT_MIFARE:
177 		return NFC_PROTO_MIFARE_MASK;
178 	case NFC_HCI_TYPE_A_SEL_PROT_ISO14443:
179 		return NFC_PROTO_ISO14443_MASK;
180 	case NFC_HCI_TYPE_A_SEL_PROT_DEP:
181 		return NFC_PROTO_NFC_DEP_MASK;
182 	case NFC_HCI_TYPE_A_SEL_PROT_ISO14443_DEP:
183 		return NFC_PROTO_ISO14443_MASK | NFC_PROTO_NFC_DEP_MASK;
184 	default:
185 		return 0xffffffff;
186 	}
187 }
188 EXPORT_SYMBOL(nfc_hci_sak_to_protocol);
189 
190 int nfc_hci_target_discovered(struct nfc_hci_dev *hdev, u8 gate)
191 {
192 	struct nfc_target *targets;
193 	struct sk_buff *atqa_skb = NULL;
194 	struct sk_buff *sak_skb = NULL;
195 	struct sk_buff *uid_skb = NULL;
196 	int r;
197 
198 	pr_debug("from gate %d\n", gate);
199 
200 	targets = kzalloc(sizeof(struct nfc_target), GFP_KERNEL);
201 	if (targets == NULL)
202 		return -ENOMEM;
203 
204 	switch (gate) {
205 	case NFC_HCI_RF_READER_A_GATE:
206 		r = nfc_hci_get_param(hdev, NFC_HCI_RF_READER_A_GATE,
207 				      NFC_HCI_RF_READER_A_ATQA, &atqa_skb);
208 		if (r < 0)
209 			goto exit;
210 
211 		r = nfc_hci_get_param(hdev, NFC_HCI_RF_READER_A_GATE,
212 				      NFC_HCI_RF_READER_A_SAK, &sak_skb);
213 		if (r < 0)
214 			goto exit;
215 
216 		if (atqa_skb->len != 2 || sak_skb->len != 1) {
217 			r = -EPROTO;
218 			goto exit;
219 		}
220 
221 		targets->supported_protocols =
222 				nfc_hci_sak_to_protocol(sak_skb->data[0]);
223 		if (targets->supported_protocols == 0xffffffff) {
224 			r = -EPROTO;
225 			goto exit;
226 		}
227 
228 		targets->sens_res = be16_to_cpu(*(u16 *)atqa_skb->data);
229 		targets->sel_res = sak_skb->data[0];
230 
231 		r = nfc_hci_get_param(hdev, NFC_HCI_RF_READER_A_GATE,
232 				      NFC_HCI_RF_READER_A_UID, &uid_skb);
233 		if (r < 0)
234 			goto exit;
235 
236 		if (uid_skb->len == 0 || uid_skb->len > NFC_NFCID1_MAXSIZE) {
237 			r = -EPROTO;
238 			goto exit;
239 		}
240 
241 		memcpy(targets->nfcid1, uid_skb->data, uid_skb->len);
242 		targets->nfcid1_len = uid_skb->len;
243 
244 		if (hdev->ops->complete_target_discovered) {
245 			r = hdev->ops->complete_target_discovered(hdev, gate,
246 								  targets);
247 			if (r < 0)
248 				goto exit;
249 		}
250 		break;
251 	case NFC_HCI_RF_READER_B_GATE:
252 		targets->supported_protocols = NFC_PROTO_ISO14443_B_MASK;
253 		break;
254 	default:
255 		if (hdev->ops->target_from_gate)
256 			r = hdev->ops->target_from_gate(hdev, gate, targets);
257 		else
258 			r = -EPROTO;
259 		if (r < 0)
260 			goto exit;
261 
262 		if (hdev->ops->complete_target_discovered) {
263 			r = hdev->ops->complete_target_discovered(hdev, gate,
264 								  targets);
265 			if (r < 0)
266 				goto exit;
267 		}
268 		break;
269 	}
270 
271 	/* if driver set the new gate, we will skip the old one */
272 	if (targets->hci_reader_gate == 0x00)
273 		targets->hci_reader_gate = gate;
274 
275 	r = nfc_targets_found(hdev->ndev, targets, 1);
276 
277 exit:
278 	kfree(targets);
279 	kfree_skb(atqa_skb);
280 	kfree_skb(sak_skb);
281 	kfree_skb(uid_skb);
282 
283 	return r;
284 }
285 EXPORT_SYMBOL(nfc_hci_target_discovered);
286 
287 void nfc_hci_event_received(struct nfc_hci_dev *hdev, u8 pipe, u8 event,
288 			    struct sk_buff *skb)
289 {
290 	int r = 0;
291 	u8 gate = nfc_hci_pipe2gate(hdev, pipe);
292 
293 	if (gate == 0xff) {
294 		pr_err("Discarded event %x to unopened pipe %x\n", event, pipe);
295 		goto exit;
296 	}
297 
298 	switch (event) {
299 	case NFC_HCI_EVT_TARGET_DISCOVERED:
300 		if (skb->len < 1) {	/* no status data? */
301 			r = -EPROTO;
302 			goto exit;
303 		}
304 
305 		if (skb->data[0] == 3) {
306 			/* TODO: Multiple targets in field, none activated
307 			 * poll is supposedly stopped, but there is no
308 			 * single target to activate, so nothing to report
309 			 * up.
310 			 * if we need to restart poll, we must save the
311 			 * protocols from the initial poll and reuse here.
312 			 */
313 		}
314 
315 		if (skb->data[0] != 0) {
316 			r = -EPROTO;
317 			goto exit;
318 		}
319 
320 		r = nfc_hci_target_discovered(hdev, gate);
321 		break;
322 	default:
323 		if (hdev->ops->event_received) {
324 			hdev->ops->event_received(hdev, gate, event, skb);
325 			return;
326 		}
327 
328 		break;
329 	}
330 
331 exit:
332 	kfree_skb(skb);
333 
334 	if (r) {
335 		/* TODO: There was an error dispatching the event,
336 		 * how to propagate up to nfc core?
337 		 */
338 	}
339 }
340 
341 static void nfc_hci_cmd_timeout(unsigned long data)
342 {
343 	struct nfc_hci_dev *hdev = (struct nfc_hci_dev *)data;
344 
345 	schedule_work(&hdev->msg_tx_work);
346 }
347 
348 static int hci_dev_connect_gates(struct nfc_hci_dev *hdev, u8 gate_count,
349 				 struct nfc_hci_gate *gates)
350 {
351 	int r;
352 	while (gate_count--) {
353 		r = nfc_hci_connect_gate(hdev, NFC_HCI_HOST_CONTROLLER_ID,
354 					 gates->gate, gates->pipe);
355 		if (r < 0)
356 			return r;
357 		gates++;
358 	}
359 
360 	return 0;
361 }
362 
363 static int hci_dev_session_init(struct nfc_hci_dev *hdev)
364 {
365 	struct sk_buff *skb = NULL;
366 	int r;
367 
368 	if (hdev->init_data.gates[0].gate != NFC_HCI_ADMIN_GATE)
369 		return -EPROTO;
370 
371 	r = nfc_hci_connect_gate(hdev, NFC_HCI_HOST_CONTROLLER_ID,
372 				 hdev->init_data.gates[0].gate,
373 				 hdev->init_data.gates[0].pipe);
374 	if (r < 0)
375 		goto exit;
376 
377 	r = nfc_hci_get_param(hdev, NFC_HCI_ADMIN_GATE,
378 			      NFC_HCI_ADMIN_SESSION_IDENTITY, &skb);
379 	if (r < 0)
380 		goto disconnect_all;
381 
382 	if (skb->len && skb->len == strlen(hdev->init_data.session_id))
383 		if (memcmp(hdev->init_data.session_id, skb->data,
384 			   skb->len) == 0) {
385 			/* TODO ELa: restore gate<->pipe table from
386 			 * some TBD location.
387 			 * note: it doesn't seem possible to get the chip
388 			 * currently open gate/pipe table.
389 			 * It is only possible to obtain the supported
390 			 * gate list.
391 			 */
392 
393 			/* goto exit
394 			 * For now, always do a full initialization */
395 		}
396 
397 	r = nfc_hci_disconnect_all_gates(hdev);
398 	if (r < 0)
399 		goto exit;
400 
401 	r = hci_dev_connect_gates(hdev, hdev->init_data.gate_count,
402 				  hdev->init_data.gates);
403 	if (r < 0)
404 		goto disconnect_all;
405 
406 	r = nfc_hci_set_param(hdev, NFC_HCI_ADMIN_GATE,
407 			      NFC_HCI_ADMIN_SESSION_IDENTITY,
408 			      hdev->init_data.session_id,
409 			      strlen(hdev->init_data.session_id));
410 	if (r == 0)
411 		goto exit;
412 
413 disconnect_all:
414 	nfc_hci_disconnect_all_gates(hdev);
415 
416 exit:
417 	kfree_skb(skb);
418 
419 	return r;
420 }
421 
422 static int hci_dev_version(struct nfc_hci_dev *hdev)
423 {
424 	int r;
425 	struct sk_buff *skb;
426 
427 	r = nfc_hci_get_param(hdev, NFC_HCI_ID_MGMT_GATE,
428 			      NFC_HCI_ID_MGMT_VERSION_SW, &skb);
429 	if (r == -EOPNOTSUPP) {
430 		pr_info("Software/Hardware info not available\n");
431 		return 0;
432 	}
433 	if (r < 0)
434 		return r;
435 
436 	if (skb->len != 3) {
437 		kfree_skb(skb);
438 		return -EINVAL;
439 	}
440 
441 	hdev->sw_romlib = (skb->data[0] & 0xf0) >> 4;
442 	hdev->sw_patch = skb->data[0] & 0x0f;
443 	hdev->sw_flashlib_major = skb->data[1];
444 	hdev->sw_flashlib_minor = skb->data[2];
445 
446 	kfree_skb(skb);
447 
448 	r = nfc_hci_get_param(hdev, NFC_HCI_ID_MGMT_GATE,
449 			      NFC_HCI_ID_MGMT_VERSION_HW, &skb);
450 	if (r < 0)
451 		return r;
452 
453 	if (skb->len != 3) {
454 		kfree_skb(skb);
455 		return -EINVAL;
456 	}
457 
458 	hdev->hw_derivative = (skb->data[0] & 0xe0) >> 5;
459 	hdev->hw_version = skb->data[0] & 0x1f;
460 	hdev->hw_mpw = (skb->data[1] & 0xc0) >> 6;
461 	hdev->hw_software = skb->data[1] & 0x3f;
462 	hdev->hw_bsid = skb->data[2];
463 
464 	kfree_skb(skb);
465 
466 	pr_info("SOFTWARE INFO:\n");
467 	pr_info("RomLib         : %d\n", hdev->sw_romlib);
468 	pr_info("Patch          : %d\n", hdev->sw_patch);
469 	pr_info("FlashLib Major : %d\n", hdev->sw_flashlib_major);
470 	pr_info("FlashLib Minor : %d\n", hdev->sw_flashlib_minor);
471 	pr_info("HARDWARE INFO:\n");
472 	pr_info("Derivative     : %d\n", hdev->hw_derivative);
473 	pr_info("HW Version     : %d\n", hdev->hw_version);
474 	pr_info("#MPW           : %d\n", hdev->hw_mpw);
475 	pr_info("Software       : %d\n", hdev->hw_software);
476 	pr_info("BSID Version   : %d\n", hdev->hw_bsid);
477 
478 	return 0;
479 }
480 
481 static int hci_dev_up(struct nfc_dev *nfc_dev)
482 {
483 	struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);
484 	int r = 0;
485 
486 	if (hdev->ops->open) {
487 		r = hdev->ops->open(hdev);
488 		if (r < 0)
489 			return r;
490 	}
491 
492 	r = nfc_llc_start(hdev->llc);
493 	if (r < 0)
494 		goto exit_close;
495 
496 	r = hci_dev_session_init(hdev);
497 	if (r < 0)
498 		goto exit_llc;
499 
500 	r = nfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,
501 			       NFC_HCI_EVT_END_OPERATION, NULL, 0);
502 	if (r < 0)
503 		goto exit_llc;
504 
505 	if (hdev->ops->hci_ready) {
506 		r = hdev->ops->hci_ready(hdev);
507 		if (r < 0)
508 			goto exit_llc;
509 	}
510 
511 	r = hci_dev_version(hdev);
512 	if (r < 0)
513 		goto exit_llc;
514 
515 	return 0;
516 
517 exit_llc:
518 	nfc_llc_stop(hdev->llc);
519 
520 exit_close:
521 	if (hdev->ops->close)
522 		hdev->ops->close(hdev);
523 
524 	return r;
525 }
526 
527 static int hci_dev_down(struct nfc_dev *nfc_dev)
528 {
529 	struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);
530 
531 	nfc_llc_stop(hdev->llc);
532 
533 	if (hdev->ops->close)
534 		hdev->ops->close(hdev);
535 
536 	memset(hdev->gate2pipe, NFC_HCI_INVALID_PIPE, sizeof(hdev->gate2pipe));
537 
538 	return 0;
539 }
540 
541 static int hci_start_poll(struct nfc_dev *nfc_dev,
542 			  u32 im_protocols, u32 tm_protocols)
543 {
544 	struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);
545 
546 	if (hdev->ops->start_poll)
547 		return hdev->ops->start_poll(hdev, im_protocols, tm_protocols);
548 	else
549 		return nfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,
550 					  NFC_HCI_EVT_READER_REQUESTED,
551 					  NULL, 0);
552 }
553 
554 static void hci_stop_poll(struct nfc_dev *nfc_dev)
555 {
556 	struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);
557 
558 	nfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,
559 			   NFC_HCI_EVT_END_OPERATION, NULL, 0);
560 }
561 
562 static int hci_dep_link_up(struct nfc_dev *nfc_dev, struct nfc_target *target,
563 				__u8 comm_mode, __u8 *gb, size_t gb_len)
564 {
565 	struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);
566 
567 	if (hdev->ops->dep_link_up)
568 		return hdev->ops->dep_link_up(hdev, target, comm_mode,
569 						gb, gb_len);
570 
571 	return 0;
572 }
573 
574 static int hci_dep_link_down(struct nfc_dev *nfc_dev)
575 {
576 	struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);
577 
578 	if (hdev->ops->dep_link_down)
579 		return hdev->ops->dep_link_down(hdev);
580 
581 	return 0;
582 }
583 
584 static int hci_activate_target(struct nfc_dev *nfc_dev,
585 			       struct nfc_target *target, u32 protocol)
586 {
587 	return 0;
588 }
589 
590 static void hci_deactivate_target(struct nfc_dev *nfc_dev,
591 				  struct nfc_target *target)
592 {
593 }
594 
595 #define HCI_CB_TYPE_TRANSCEIVE 1
596 
597 static void hci_transceive_cb(void *context, struct sk_buff *skb, int err)
598 {
599 	struct nfc_hci_dev *hdev = context;
600 
601 	switch (hdev->async_cb_type) {
602 	case HCI_CB_TYPE_TRANSCEIVE:
603 		/*
604 		 * TODO: Check RF Error indicator to make sure data is valid.
605 		 * It seems that HCI cmd can complete without error, but data
606 		 * can be invalid if an RF error occured? Ignore for now.
607 		 */
608 		if (err == 0)
609 			skb_trim(skb, skb->len - 1); /* RF Err ind */
610 
611 		hdev->async_cb(hdev->async_cb_context, skb, err);
612 		break;
613 	default:
614 		if (err == 0)
615 			kfree_skb(skb);
616 		break;
617 	}
618 }
619 
620 static int hci_transceive(struct nfc_dev *nfc_dev, struct nfc_target *target,
621 			  struct sk_buff *skb, data_exchange_cb_t cb,
622 			  void *cb_context)
623 {
624 	struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);
625 	int r;
626 
627 	pr_debug("target_idx=%d\n", target->idx);
628 
629 	switch (target->hci_reader_gate) {
630 	case NFC_HCI_RF_READER_A_GATE:
631 	case NFC_HCI_RF_READER_B_GATE:
632 		if (hdev->ops->im_transceive) {
633 			r = hdev->ops->im_transceive(hdev, target, skb, cb,
634 						     cb_context);
635 			if (r <= 0)	/* handled */
636 				break;
637 		}
638 
639 		*skb_push(skb, 1) = 0;	/* CTR, see spec:10.2.2.1 */
640 
641 		hdev->async_cb_type = HCI_CB_TYPE_TRANSCEIVE;
642 		hdev->async_cb = cb;
643 		hdev->async_cb_context = cb_context;
644 
645 		r = nfc_hci_send_cmd_async(hdev, target->hci_reader_gate,
646 					   NFC_HCI_WR_XCHG_DATA, skb->data,
647 					   skb->len, hci_transceive_cb, hdev);
648 		break;
649 	default:
650 		if (hdev->ops->im_transceive) {
651 			r = hdev->ops->im_transceive(hdev, target, skb, cb,
652 						     cb_context);
653 			if (r == 1)
654 				r = -ENOTSUPP;
655 		} else {
656 			r = -ENOTSUPP;
657 		}
658 		break;
659 	}
660 
661 	kfree_skb(skb);
662 
663 	return r;
664 }
665 
666 static int hci_tm_send(struct nfc_dev *nfc_dev, struct sk_buff *skb)
667 {
668 	struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);
669 
670 	if (hdev->ops->tm_send)
671 		return hdev->ops->tm_send(hdev, skb);
672 	else
673 		return -ENOTSUPP;
674 }
675 
676 static int hci_check_presence(struct nfc_dev *nfc_dev,
677 			      struct nfc_target *target)
678 {
679 	struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);
680 
681 	if (hdev->ops->check_presence)
682 		return hdev->ops->check_presence(hdev, target);
683 
684 	return 0;
685 }
686 
687 static void nfc_hci_failure(struct nfc_hci_dev *hdev, int err)
688 {
689 	mutex_lock(&hdev->msg_tx_mutex);
690 
691 	if (hdev->cmd_pending_msg == NULL) {
692 		nfc_driver_failure(hdev->ndev, err);
693 		goto exit;
694 	}
695 
696 	__nfc_hci_cmd_completion(hdev, err, NULL);
697 
698 exit:
699 	mutex_unlock(&hdev->msg_tx_mutex);
700 }
701 
702 static void nfc_hci_llc_failure(struct nfc_hci_dev *hdev, int err)
703 {
704 	nfc_hci_failure(hdev, err);
705 }
706 
707 static void nfc_hci_recv_from_llc(struct nfc_hci_dev *hdev, struct sk_buff *skb)
708 {
709 	struct hcp_packet *packet;
710 	u8 type;
711 	u8 instruction;
712 	struct sk_buff *hcp_skb;
713 	u8 pipe;
714 	struct sk_buff *frag_skb;
715 	int msg_len;
716 
717 	packet = (struct hcp_packet *)skb->data;
718 	if ((packet->header & ~NFC_HCI_FRAGMENT) == 0) {
719 		skb_queue_tail(&hdev->rx_hcp_frags, skb);
720 		return;
721 	}
722 
723 	/* it's the last fragment. Does it need re-aggregation? */
724 	if (skb_queue_len(&hdev->rx_hcp_frags)) {
725 		pipe = packet->header & NFC_HCI_FRAGMENT;
726 		skb_queue_tail(&hdev->rx_hcp_frags, skb);
727 
728 		msg_len = 0;
729 		skb_queue_walk(&hdev->rx_hcp_frags, frag_skb) {
730 			msg_len += (frag_skb->len -
731 				    NFC_HCI_HCP_PACKET_HEADER_LEN);
732 		}
733 
734 		hcp_skb = nfc_alloc_recv_skb(NFC_HCI_HCP_PACKET_HEADER_LEN +
735 					     msg_len, GFP_KERNEL);
736 		if (hcp_skb == NULL) {
737 			nfc_hci_failure(hdev, -ENOMEM);
738 			return;
739 		}
740 
741 		*skb_put(hcp_skb, NFC_HCI_HCP_PACKET_HEADER_LEN) = pipe;
742 
743 		skb_queue_walk(&hdev->rx_hcp_frags, frag_skb) {
744 			msg_len = frag_skb->len - NFC_HCI_HCP_PACKET_HEADER_LEN;
745 			memcpy(skb_put(hcp_skb, msg_len),
746 			       frag_skb->data + NFC_HCI_HCP_PACKET_HEADER_LEN,
747 			       msg_len);
748 		}
749 
750 		skb_queue_purge(&hdev->rx_hcp_frags);
751 	} else {
752 		packet->header &= NFC_HCI_FRAGMENT;
753 		hcp_skb = skb;
754 	}
755 
756 	/* if this is a response, dispatch immediately to
757 	 * unblock waiting cmd context. Otherwise, enqueue to dispatch
758 	 * in separate context where handler can also execute command.
759 	 */
760 	packet = (struct hcp_packet *)hcp_skb->data;
761 	type = HCP_MSG_GET_TYPE(packet->message.header);
762 	if (type == NFC_HCI_HCP_RESPONSE) {
763 		pipe = packet->header;
764 		instruction = HCP_MSG_GET_CMD(packet->message.header);
765 		skb_pull(hcp_skb, NFC_HCI_HCP_PACKET_HEADER_LEN +
766 			 NFC_HCI_HCP_MESSAGE_HEADER_LEN);
767 		nfc_hci_hcp_message_rx(hdev, pipe, type, instruction, hcp_skb);
768 	} else {
769 		skb_queue_tail(&hdev->msg_rx_queue, hcp_skb);
770 		schedule_work(&hdev->msg_rx_work);
771 	}
772 }
773 
774 static struct nfc_ops hci_nfc_ops = {
775 	.dev_up = hci_dev_up,
776 	.dev_down = hci_dev_down,
777 	.start_poll = hci_start_poll,
778 	.stop_poll = hci_stop_poll,
779 	.dep_link_up = hci_dep_link_up,
780 	.dep_link_down = hci_dep_link_down,
781 	.activate_target = hci_activate_target,
782 	.deactivate_target = hci_deactivate_target,
783 	.im_transceive = hci_transceive,
784 	.tm_send = hci_tm_send,
785 	.check_presence = hci_check_presence,
786 };
787 
788 struct nfc_hci_dev *nfc_hci_allocate_device(struct nfc_hci_ops *ops,
789 					    struct nfc_hci_init_data *init_data,
790 					    u32 protocols,
791 					    const char *llc_name,
792 					    int tx_headroom,
793 					    int tx_tailroom,
794 					    int max_link_payload)
795 {
796 	struct nfc_hci_dev *hdev;
797 
798 	if (ops->xmit == NULL)
799 		return NULL;
800 
801 	if (protocols == 0)
802 		return NULL;
803 
804 	hdev = kzalloc(sizeof(struct nfc_hci_dev), GFP_KERNEL);
805 	if (hdev == NULL)
806 		return NULL;
807 
808 	hdev->llc = nfc_llc_allocate(llc_name, hdev, ops->xmit,
809 				     nfc_hci_recv_from_llc, tx_headroom,
810 				     tx_tailroom, nfc_hci_llc_failure);
811 	if (hdev->llc == NULL) {
812 		kfree(hdev);
813 		return NULL;
814 	}
815 
816 	hdev->ndev = nfc_allocate_device(&hci_nfc_ops, protocols,
817 					 tx_headroom + HCI_CMDS_HEADROOM,
818 					 tx_tailroom);
819 	if (!hdev->ndev) {
820 		nfc_llc_free(hdev->llc);
821 		kfree(hdev);
822 		return NULL;
823 	}
824 
825 	hdev->ops = ops;
826 	hdev->max_data_link_payload = max_link_payload;
827 	hdev->init_data = *init_data;
828 
829 	nfc_set_drvdata(hdev->ndev, hdev);
830 
831 	memset(hdev->gate2pipe, NFC_HCI_INVALID_PIPE, sizeof(hdev->gate2pipe));
832 
833 	return hdev;
834 }
835 EXPORT_SYMBOL(nfc_hci_allocate_device);
836 
837 void nfc_hci_free_device(struct nfc_hci_dev *hdev)
838 {
839 	nfc_free_device(hdev->ndev);
840 	nfc_llc_free(hdev->llc);
841 	kfree(hdev);
842 }
843 EXPORT_SYMBOL(nfc_hci_free_device);
844 
845 int nfc_hci_register_device(struct nfc_hci_dev *hdev)
846 {
847 	mutex_init(&hdev->msg_tx_mutex);
848 
849 	INIT_LIST_HEAD(&hdev->msg_tx_queue);
850 
851 	INIT_WORK(&hdev->msg_tx_work, nfc_hci_msg_tx_work);
852 
853 	init_timer(&hdev->cmd_timer);
854 	hdev->cmd_timer.data = (unsigned long)hdev;
855 	hdev->cmd_timer.function = nfc_hci_cmd_timeout;
856 
857 	skb_queue_head_init(&hdev->rx_hcp_frags);
858 
859 	INIT_WORK(&hdev->msg_rx_work, nfc_hci_msg_rx_work);
860 
861 	skb_queue_head_init(&hdev->msg_rx_queue);
862 
863 	return nfc_register_device(hdev->ndev);
864 }
865 EXPORT_SYMBOL(nfc_hci_register_device);
866 
867 void nfc_hci_unregister_device(struct nfc_hci_dev *hdev)
868 {
869 	struct hci_msg *msg, *n;
870 
871 	skb_queue_purge(&hdev->rx_hcp_frags);
872 	skb_queue_purge(&hdev->msg_rx_queue);
873 
874 	list_for_each_entry_safe(msg, n, &hdev->msg_tx_queue, msg_l) {
875 		list_del(&msg->msg_l);
876 		skb_queue_purge(&msg->msg_frags);
877 		kfree(msg);
878 	}
879 
880 	del_timer_sync(&hdev->cmd_timer);
881 
882 	nfc_unregister_device(hdev->ndev);
883 
884 	cancel_work_sync(&hdev->msg_tx_work);
885 	cancel_work_sync(&hdev->msg_rx_work);
886 }
887 EXPORT_SYMBOL(nfc_hci_unregister_device);
888 
889 void nfc_hci_set_clientdata(struct nfc_hci_dev *hdev, void *clientdata)
890 {
891 	hdev->clientdata = clientdata;
892 }
893 EXPORT_SYMBOL(nfc_hci_set_clientdata);
894 
895 void *nfc_hci_get_clientdata(struct nfc_hci_dev *hdev)
896 {
897 	return hdev->clientdata;
898 }
899 EXPORT_SYMBOL(nfc_hci_get_clientdata);
900 
901 void nfc_hci_driver_failure(struct nfc_hci_dev *hdev, int err)
902 {
903 	nfc_hci_failure(hdev, err);
904 }
905 EXPORT_SYMBOL(nfc_hci_driver_failure);
906 
907 void nfc_hci_recv_frame(struct nfc_hci_dev *hdev, struct sk_buff *skb)
908 {
909 	nfc_llc_rcv_from_drv(hdev->llc, skb);
910 }
911 EXPORT_SYMBOL(nfc_hci_recv_frame);
912 
913 static int __init nfc_hci_init(void)
914 {
915 	return nfc_llc_init();
916 }
917 
918 static void __exit nfc_hci_exit(void)
919 {
920 	nfc_llc_exit();
921 }
922 
923 subsys_initcall(nfc_hci_init);
924 module_exit(nfc_hci_exit);
925 
926 MODULE_LICENSE("GPL");
927 MODULE_DESCRIPTION("NFC HCI Core");
928