xref: /linux/net/nfc/nci/core.c (revision 25aee3debe0464f6c680173041fa3de30ec9ff54)
1 /*
2  *  The NFC Controller Interface is the communication protocol between an
3  *  NFC Controller (NFCC) and a Device Host (DH).
4  *
5  *  Copyright (C) 2011 Texas Instruments, Inc.
6  *
7  *  Written by Ilan Elias <ilane@ti.com>
8  *
9  *  Acknowledgements:
10  *  This file is based on hci_core.c, which was written
11  *  by Maxim Krasnyansky.
12  *
13  *  This program is free software; you can redistribute it and/or modify
14  *  it under the terms of the GNU General Public License version 2
15  *  as published by the Free Software Foundation
16  *
17  *  This program is distributed in the hope that it will be useful,
18  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  *  GNU General Public License for more details.
21  *
22  *  You should have received a copy of the GNU General Public License
23  *  along with this program; if not, write to the Free Software
24  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
25  *
26  */
27 
28 #define pr_fmt(fmt) KBUILD_MODNAME ": %s: " fmt, __func__
29 
30 #include <linux/module.h>
31 #include <linux/types.h>
32 #include <linux/workqueue.h>
33 #include <linux/completion.h>
34 #include <linux/export.h>
35 #include <linux/sched.h>
36 #include <linux/bitops.h>
37 #include <linux/skbuff.h>
38 
39 #include "../nfc.h"
40 #include <net/nfc/nci.h>
41 #include <net/nfc/nci_core.h>
42 #include <linux/nfc.h>
43 
44 static void nci_cmd_work(struct work_struct *work);
45 static void nci_rx_work(struct work_struct *work);
46 static void nci_tx_work(struct work_struct *work);
47 
48 /* ---- NCI requests ---- */
49 
50 void nci_req_complete(struct nci_dev *ndev, int result)
51 {
52 	if (ndev->req_status == NCI_REQ_PEND) {
53 		ndev->req_result = result;
54 		ndev->req_status = NCI_REQ_DONE;
55 		complete(&ndev->req_completion);
56 	}
57 }
58 
59 static void nci_req_cancel(struct nci_dev *ndev, int err)
60 {
61 	if (ndev->req_status == NCI_REQ_PEND) {
62 		ndev->req_result = err;
63 		ndev->req_status = NCI_REQ_CANCELED;
64 		complete(&ndev->req_completion);
65 	}
66 }
67 
68 /* Execute request and wait for completion. */
69 static int __nci_request(struct nci_dev *ndev,
70 			 void (*req)(struct nci_dev *ndev, unsigned long opt),
71 			 unsigned long opt, __u32 timeout)
72 {
73 	int rc = 0;
74 	long completion_rc;
75 
76 	ndev->req_status = NCI_REQ_PEND;
77 
78 	init_completion(&ndev->req_completion);
79 	req(ndev, opt);
80 	completion_rc =
81 		wait_for_completion_interruptible_timeout(&ndev->req_completion,
82 							  timeout);
83 
84 	pr_debug("wait_for_completion return %ld\n", completion_rc);
85 
86 	if (completion_rc > 0) {
87 		switch (ndev->req_status) {
88 		case NCI_REQ_DONE:
89 			rc = nci_to_errno(ndev->req_result);
90 			break;
91 
92 		case NCI_REQ_CANCELED:
93 			rc = -ndev->req_result;
94 			break;
95 
96 		default:
97 			rc = -ETIMEDOUT;
98 			break;
99 		}
100 	} else {
101 		pr_err("wait_for_completion_interruptible_timeout failed %ld\n",
102 		       completion_rc);
103 
104 		rc = ((completion_rc == 0) ? (-ETIMEDOUT) : (completion_rc));
105 	}
106 
107 	ndev->req_status = ndev->req_result = 0;
108 
109 	return rc;
110 }
111 
112 static inline int nci_request(struct nci_dev *ndev,
113 			      void (*req)(struct nci_dev *ndev,
114 					  unsigned long opt),
115 			      unsigned long opt, __u32 timeout)
116 {
117 	int rc;
118 
119 	if (!test_bit(NCI_UP, &ndev->flags))
120 		return -ENETDOWN;
121 
122 	/* Serialize all requests */
123 	mutex_lock(&ndev->req_lock);
124 	rc = __nci_request(ndev, req, opt, timeout);
125 	mutex_unlock(&ndev->req_lock);
126 
127 	return rc;
128 }
129 
130 static void nci_reset_req(struct nci_dev *ndev, unsigned long opt)
131 {
132 	struct nci_core_reset_cmd cmd;
133 
134 	cmd.reset_type = NCI_RESET_TYPE_RESET_CONFIG;
135 	nci_send_cmd(ndev, NCI_OP_CORE_RESET_CMD, 1, &cmd);
136 }
137 
138 static void nci_init_req(struct nci_dev *ndev, unsigned long opt)
139 {
140 	nci_send_cmd(ndev, NCI_OP_CORE_INIT_CMD, 0, NULL);
141 }
142 
143 static void nci_init_complete_req(struct nci_dev *ndev, unsigned long opt)
144 {
145 	struct nci_rf_disc_map_cmd cmd;
146 	struct disc_map_config *cfg = cmd.mapping_configs;
147 	__u8 *num = &cmd.num_mapping_configs;
148 	int i;
149 
150 	/* set rf mapping configurations */
151 	*num = 0;
152 
153 	/* by default mapping is set to NCI_RF_INTERFACE_FRAME */
154 	for (i = 0; i < ndev->num_supported_rf_interfaces; i++) {
155 		if (ndev->supported_rf_interfaces[i] ==
156 		    NCI_RF_INTERFACE_ISO_DEP) {
157 			cfg[*num].rf_protocol = NCI_RF_PROTOCOL_ISO_DEP;
158 			cfg[*num].mode = NCI_DISC_MAP_MODE_POLL |
159 				NCI_DISC_MAP_MODE_LISTEN;
160 			cfg[*num].rf_interface = NCI_RF_INTERFACE_ISO_DEP;
161 			(*num)++;
162 		} else if (ndev->supported_rf_interfaces[i] ==
163 			   NCI_RF_INTERFACE_NFC_DEP) {
164 			cfg[*num].rf_protocol = NCI_RF_PROTOCOL_NFC_DEP;
165 			cfg[*num].mode = NCI_DISC_MAP_MODE_POLL |
166 				NCI_DISC_MAP_MODE_LISTEN;
167 			cfg[*num].rf_interface = NCI_RF_INTERFACE_NFC_DEP;
168 			(*num)++;
169 		}
170 
171 		if (*num == NCI_MAX_NUM_MAPPING_CONFIGS)
172 			break;
173 	}
174 
175 	nci_send_cmd(ndev, NCI_OP_RF_DISCOVER_MAP_CMD,
176 		     (1 + ((*num) * sizeof(struct disc_map_config))), &cmd);
177 }
178 
179 static void nci_rf_discover_req(struct nci_dev *ndev, unsigned long opt)
180 {
181 	struct nci_rf_disc_cmd cmd;
182 	__u32 protocols = opt;
183 
184 	cmd.num_disc_configs = 0;
185 
186 	if ((cmd.num_disc_configs < NCI_MAX_NUM_RF_CONFIGS) &&
187 	    (protocols & NFC_PROTO_JEWEL_MASK
188 	     || protocols & NFC_PROTO_MIFARE_MASK
189 	     || protocols & NFC_PROTO_ISO14443_MASK
190 	     || protocols & NFC_PROTO_NFC_DEP_MASK)) {
191 		cmd.disc_configs[cmd.num_disc_configs].rf_tech_and_mode =
192 			NCI_NFC_A_PASSIVE_POLL_MODE;
193 		cmd.disc_configs[cmd.num_disc_configs].frequency = 1;
194 		cmd.num_disc_configs++;
195 	}
196 
197 	if ((cmd.num_disc_configs < NCI_MAX_NUM_RF_CONFIGS) &&
198 	    (protocols & NFC_PROTO_ISO14443_B_MASK)) {
199 		cmd.disc_configs[cmd.num_disc_configs].rf_tech_and_mode =
200 			NCI_NFC_B_PASSIVE_POLL_MODE;
201 		cmd.disc_configs[cmd.num_disc_configs].frequency = 1;
202 		cmd.num_disc_configs++;
203 	}
204 
205 	if ((cmd.num_disc_configs < NCI_MAX_NUM_RF_CONFIGS) &&
206 	    (protocols & NFC_PROTO_FELICA_MASK
207 	     || protocols & NFC_PROTO_NFC_DEP_MASK)) {
208 		cmd.disc_configs[cmd.num_disc_configs].rf_tech_and_mode =
209 			NCI_NFC_F_PASSIVE_POLL_MODE;
210 		cmd.disc_configs[cmd.num_disc_configs].frequency = 1;
211 		cmd.num_disc_configs++;
212 	}
213 
214 	nci_send_cmd(ndev, NCI_OP_RF_DISCOVER_CMD,
215 		     (1 + (cmd.num_disc_configs * sizeof(struct disc_config))),
216 		     &cmd);
217 }
218 
219 struct nci_rf_discover_select_param {
220 	__u8	rf_discovery_id;
221 	__u8	rf_protocol;
222 };
223 
224 static void nci_rf_discover_select_req(struct nci_dev *ndev, unsigned long opt)
225 {
226 	struct nci_rf_discover_select_param *param =
227 		(struct nci_rf_discover_select_param *)opt;
228 	struct nci_rf_discover_select_cmd cmd;
229 
230 	cmd.rf_discovery_id = param->rf_discovery_id;
231 	cmd.rf_protocol = param->rf_protocol;
232 
233 	switch (cmd.rf_protocol) {
234 	case NCI_RF_PROTOCOL_ISO_DEP:
235 		cmd.rf_interface = NCI_RF_INTERFACE_ISO_DEP;
236 		break;
237 
238 	case NCI_RF_PROTOCOL_NFC_DEP:
239 		cmd.rf_interface = NCI_RF_INTERFACE_NFC_DEP;
240 		break;
241 
242 	default:
243 		cmd.rf_interface = NCI_RF_INTERFACE_FRAME;
244 		break;
245 	}
246 
247 	nci_send_cmd(ndev, NCI_OP_RF_DISCOVER_SELECT_CMD,
248 		     sizeof(struct nci_rf_discover_select_cmd), &cmd);
249 }
250 
251 static void nci_rf_deactivate_req(struct nci_dev *ndev, unsigned long opt)
252 {
253 	struct nci_rf_deactivate_cmd cmd;
254 
255 	cmd.type = NCI_DEACTIVATE_TYPE_IDLE_MODE;
256 
257 	nci_send_cmd(ndev, NCI_OP_RF_DEACTIVATE_CMD,
258 		     sizeof(struct nci_rf_deactivate_cmd), &cmd);
259 }
260 
261 static int nci_open_device(struct nci_dev *ndev)
262 {
263 	int rc = 0;
264 
265 	mutex_lock(&ndev->req_lock);
266 
267 	if (test_bit(NCI_UP, &ndev->flags)) {
268 		rc = -EALREADY;
269 		goto done;
270 	}
271 
272 	if (ndev->ops->open(ndev)) {
273 		rc = -EIO;
274 		goto done;
275 	}
276 
277 	atomic_set(&ndev->cmd_cnt, 1);
278 
279 	set_bit(NCI_INIT, &ndev->flags);
280 
281 	rc = __nci_request(ndev, nci_reset_req, 0,
282 			   msecs_to_jiffies(NCI_RESET_TIMEOUT));
283 
284 	if (!rc) {
285 		rc = __nci_request(ndev, nci_init_req, 0,
286 				   msecs_to_jiffies(NCI_INIT_TIMEOUT));
287 	}
288 
289 	if (!rc) {
290 		rc = __nci_request(ndev, nci_init_complete_req, 0,
291 				   msecs_to_jiffies(NCI_INIT_TIMEOUT));
292 	}
293 
294 	clear_bit(NCI_INIT, &ndev->flags);
295 
296 	if (!rc) {
297 		set_bit(NCI_UP, &ndev->flags);
298 		nci_clear_target_list(ndev);
299 		atomic_set(&ndev->state, NCI_IDLE);
300 	} else {
301 		/* Init failed, cleanup */
302 		skb_queue_purge(&ndev->cmd_q);
303 		skb_queue_purge(&ndev->rx_q);
304 		skb_queue_purge(&ndev->tx_q);
305 
306 		ndev->ops->close(ndev);
307 		ndev->flags = 0;
308 	}
309 
310 done:
311 	mutex_unlock(&ndev->req_lock);
312 	return rc;
313 }
314 
315 static int nci_close_device(struct nci_dev *ndev)
316 {
317 	nci_req_cancel(ndev, ENODEV);
318 	mutex_lock(&ndev->req_lock);
319 
320 	if (!test_and_clear_bit(NCI_UP, &ndev->flags)) {
321 		del_timer_sync(&ndev->cmd_timer);
322 		del_timer_sync(&ndev->data_timer);
323 		mutex_unlock(&ndev->req_lock);
324 		return 0;
325 	}
326 
327 	/* Drop RX and TX queues */
328 	skb_queue_purge(&ndev->rx_q);
329 	skb_queue_purge(&ndev->tx_q);
330 
331 	/* Flush RX and TX wq */
332 	flush_workqueue(ndev->rx_wq);
333 	flush_workqueue(ndev->tx_wq);
334 
335 	/* Reset device */
336 	skb_queue_purge(&ndev->cmd_q);
337 	atomic_set(&ndev->cmd_cnt, 1);
338 
339 	set_bit(NCI_INIT, &ndev->flags);
340 	__nci_request(ndev, nci_reset_req, 0,
341 		      msecs_to_jiffies(NCI_RESET_TIMEOUT));
342 	clear_bit(NCI_INIT, &ndev->flags);
343 
344 	/* Flush cmd wq */
345 	flush_workqueue(ndev->cmd_wq);
346 
347 	/* After this point our queues are empty
348 	 * and no works are scheduled. */
349 	ndev->ops->close(ndev);
350 
351 	/* Clear flags */
352 	ndev->flags = 0;
353 
354 	mutex_unlock(&ndev->req_lock);
355 
356 	return 0;
357 }
358 
359 /* NCI command timer function */
360 static void nci_cmd_timer(unsigned long arg)
361 {
362 	struct nci_dev *ndev = (void *) arg;
363 
364 	atomic_set(&ndev->cmd_cnt, 1);
365 	queue_work(ndev->cmd_wq, &ndev->cmd_work);
366 }
367 
368 /* NCI data exchange timer function */
369 static void nci_data_timer(unsigned long arg)
370 {
371 	struct nci_dev *ndev = (void *) arg;
372 
373 	set_bit(NCI_DATA_EXCHANGE_TO, &ndev->flags);
374 	queue_work(ndev->rx_wq, &ndev->rx_work);
375 }
376 
377 static int nci_dev_up(struct nfc_dev *nfc_dev)
378 {
379 	struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
380 
381 	return nci_open_device(ndev);
382 }
383 
384 static int nci_dev_down(struct nfc_dev *nfc_dev)
385 {
386 	struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
387 
388 	return nci_close_device(ndev);
389 }
390 
391 static int nci_start_poll(struct nfc_dev *nfc_dev,
392 			  __u32 im_protocols, __u32 tm_protocols)
393 {
394 	struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
395 	int rc;
396 
397 	if ((atomic_read(&ndev->state) == NCI_DISCOVERY) ||
398 	    (atomic_read(&ndev->state) == NCI_W4_ALL_DISCOVERIES)) {
399 		pr_err("unable to start poll, since poll is already active\n");
400 		return -EBUSY;
401 	}
402 
403 	if (ndev->target_active_prot) {
404 		pr_err("there is an active target\n");
405 		return -EBUSY;
406 	}
407 
408 	if ((atomic_read(&ndev->state) == NCI_W4_HOST_SELECT) ||
409 	    (atomic_read(&ndev->state) == NCI_POLL_ACTIVE)) {
410 		pr_debug("target active or w4 select, implicitly deactivate\n");
411 
412 		rc = nci_request(ndev, nci_rf_deactivate_req, 0,
413 				 msecs_to_jiffies(NCI_RF_DEACTIVATE_TIMEOUT));
414 		if (rc)
415 			return -EBUSY;
416 	}
417 
418 	rc = nci_request(ndev, nci_rf_discover_req, im_protocols,
419 			 msecs_to_jiffies(NCI_RF_DISC_TIMEOUT));
420 
421 	if (!rc)
422 		ndev->poll_prots = im_protocols;
423 
424 	return rc;
425 }
426 
427 static void nci_stop_poll(struct nfc_dev *nfc_dev)
428 {
429 	struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
430 
431 	if ((atomic_read(&ndev->state) != NCI_DISCOVERY) &&
432 	    (atomic_read(&ndev->state) != NCI_W4_ALL_DISCOVERIES)) {
433 		pr_err("unable to stop poll, since poll is not active\n");
434 		return;
435 	}
436 
437 	nci_request(ndev, nci_rf_deactivate_req, 0,
438 		    msecs_to_jiffies(NCI_RF_DEACTIVATE_TIMEOUT));
439 }
440 
441 static int nci_activate_target(struct nfc_dev *nfc_dev,
442 			       struct nfc_target *target, __u32 protocol)
443 {
444 	struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
445 	struct nci_rf_discover_select_param param;
446 	struct nfc_target *nci_target = NULL;
447 	int i;
448 	int rc = 0;
449 
450 	pr_debug("target_idx %d, protocol 0x%x\n", target->idx, protocol);
451 
452 	if ((atomic_read(&ndev->state) != NCI_W4_HOST_SELECT) &&
453 	    (atomic_read(&ndev->state) != NCI_POLL_ACTIVE)) {
454 		pr_err("there is no available target to activate\n");
455 		return -EINVAL;
456 	}
457 
458 	if (ndev->target_active_prot) {
459 		pr_err("there is already an active target\n");
460 		return -EBUSY;
461 	}
462 
463 	for (i = 0; i < ndev->n_targets; i++) {
464 		if (ndev->targets[i].idx == target->idx) {
465 			nci_target = &ndev->targets[i];
466 			break;
467 		}
468 	}
469 
470 	if (!nci_target) {
471 		pr_err("unable to find the selected target\n");
472 		return -EINVAL;
473 	}
474 
475 	if (!(nci_target->supported_protocols & (1 << protocol))) {
476 		pr_err("target does not support the requested protocol 0x%x\n",
477 		       protocol);
478 		return -EINVAL;
479 	}
480 
481 	if (atomic_read(&ndev->state) == NCI_W4_HOST_SELECT) {
482 		param.rf_discovery_id = nci_target->logical_idx;
483 
484 		if (protocol == NFC_PROTO_JEWEL)
485 			param.rf_protocol = NCI_RF_PROTOCOL_T1T;
486 		else if (protocol == NFC_PROTO_MIFARE)
487 			param.rf_protocol = NCI_RF_PROTOCOL_T2T;
488 		else if (protocol == NFC_PROTO_FELICA)
489 			param.rf_protocol = NCI_RF_PROTOCOL_T3T;
490 		else if (protocol == NFC_PROTO_ISO14443 ||
491 			 protocol == NFC_PROTO_ISO14443_B)
492 			param.rf_protocol = NCI_RF_PROTOCOL_ISO_DEP;
493 		else
494 			param.rf_protocol = NCI_RF_PROTOCOL_NFC_DEP;
495 
496 		rc = nci_request(ndev, nci_rf_discover_select_req,
497 				 (unsigned long)&param,
498 				 msecs_to_jiffies(NCI_RF_DISC_SELECT_TIMEOUT));
499 	}
500 
501 	if (!rc)
502 		ndev->target_active_prot = protocol;
503 
504 	return rc;
505 }
506 
507 static void nci_deactivate_target(struct nfc_dev *nfc_dev,
508 				  struct nfc_target *target)
509 {
510 	struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
511 
512 	pr_debug("target_idx %d\n", target->idx);
513 
514 	if (!ndev->target_active_prot) {
515 		pr_err("unable to deactivate target, no active target\n");
516 		return;
517 	}
518 
519 	ndev->target_active_prot = 0;
520 
521 	if (atomic_read(&ndev->state) == NCI_POLL_ACTIVE) {
522 		nci_request(ndev, nci_rf_deactivate_req, 0,
523 			    msecs_to_jiffies(NCI_RF_DEACTIVATE_TIMEOUT));
524 	}
525 }
526 
527 static int nci_transceive(struct nfc_dev *nfc_dev, struct nfc_target *target,
528 			  struct sk_buff *skb,
529 			  data_exchange_cb_t cb, void *cb_context)
530 {
531 	struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
532 	int rc;
533 
534 	pr_debug("target_idx %d, len %d\n", target->idx, skb->len);
535 
536 	if (!ndev->target_active_prot) {
537 		pr_err("unable to exchange data, no active target\n");
538 		return -EINVAL;
539 	}
540 
541 	if (test_and_set_bit(NCI_DATA_EXCHANGE, &ndev->flags))
542 		return -EBUSY;
543 
544 	/* store cb and context to be used on receiving data */
545 	ndev->data_exchange_cb = cb;
546 	ndev->data_exchange_cb_context = cb_context;
547 
548 	rc = nci_send_data(ndev, NCI_STATIC_RF_CONN_ID, skb);
549 	if (rc)
550 		clear_bit(NCI_DATA_EXCHANGE, &ndev->flags);
551 
552 	return rc;
553 }
554 
555 static struct nfc_ops nci_nfc_ops = {
556 	.dev_up = nci_dev_up,
557 	.dev_down = nci_dev_down,
558 	.start_poll = nci_start_poll,
559 	.stop_poll = nci_stop_poll,
560 	.activate_target = nci_activate_target,
561 	.deactivate_target = nci_deactivate_target,
562 	.im_transceive = nci_transceive,
563 };
564 
565 /* ---- Interface to NCI drivers ---- */
566 
567 /**
568  * nci_allocate_device - allocate a new nci device
569  *
570  * @ops: device operations
571  * @supported_protocols: NFC protocols supported by the device
572  */
573 struct nci_dev *nci_allocate_device(struct nci_ops *ops,
574 				    __u32 supported_protocols,
575 				    int tx_headroom, int tx_tailroom)
576 {
577 	struct nci_dev *ndev;
578 
579 	pr_debug("supported_protocols 0x%x\n", supported_protocols);
580 
581 	if (!ops->open || !ops->close || !ops->send)
582 		return NULL;
583 
584 	if (!supported_protocols)
585 		return NULL;
586 
587 	ndev = kzalloc(sizeof(struct nci_dev), GFP_KERNEL);
588 	if (!ndev)
589 		return NULL;
590 
591 	ndev->ops = ops;
592 	ndev->tx_headroom = tx_headroom;
593 	ndev->tx_tailroom = tx_tailroom;
594 
595 	ndev->nfc_dev = nfc_allocate_device(&nci_nfc_ops,
596 					    supported_protocols,
597 					    tx_headroom + NCI_DATA_HDR_SIZE,
598 					    tx_tailroom);
599 	if (!ndev->nfc_dev)
600 		goto free_exit;
601 
602 	nfc_set_drvdata(ndev->nfc_dev, ndev);
603 
604 	return ndev;
605 
606 free_exit:
607 	kfree(ndev);
608 	return NULL;
609 }
610 EXPORT_SYMBOL(nci_allocate_device);
611 
612 /**
613  * nci_free_device - deallocate nci device
614  *
615  * @ndev: The nci device to deallocate
616  */
617 void nci_free_device(struct nci_dev *ndev)
618 {
619 	nfc_free_device(ndev->nfc_dev);
620 	kfree(ndev);
621 }
622 EXPORT_SYMBOL(nci_free_device);
623 
624 /**
625  * nci_register_device - register a nci device in the nfc subsystem
626  *
627  * @dev: The nci device to register
628  */
629 int nci_register_device(struct nci_dev *ndev)
630 {
631 	int rc;
632 	struct device *dev = &ndev->nfc_dev->dev;
633 	char name[32];
634 
635 	rc = nfc_register_device(ndev->nfc_dev);
636 	if (rc)
637 		goto exit;
638 
639 	ndev->flags = 0;
640 
641 	INIT_WORK(&ndev->cmd_work, nci_cmd_work);
642 	snprintf(name, sizeof(name), "%s_nci_cmd_wq", dev_name(dev));
643 	ndev->cmd_wq = create_singlethread_workqueue(name);
644 	if (!ndev->cmd_wq) {
645 		rc = -ENOMEM;
646 		goto unreg_exit;
647 	}
648 
649 	INIT_WORK(&ndev->rx_work, nci_rx_work);
650 	snprintf(name, sizeof(name), "%s_nci_rx_wq", dev_name(dev));
651 	ndev->rx_wq = create_singlethread_workqueue(name);
652 	if (!ndev->rx_wq) {
653 		rc = -ENOMEM;
654 		goto destroy_cmd_wq_exit;
655 	}
656 
657 	INIT_WORK(&ndev->tx_work, nci_tx_work);
658 	snprintf(name, sizeof(name), "%s_nci_tx_wq", dev_name(dev));
659 	ndev->tx_wq = create_singlethread_workqueue(name);
660 	if (!ndev->tx_wq) {
661 		rc = -ENOMEM;
662 		goto destroy_rx_wq_exit;
663 	}
664 
665 	skb_queue_head_init(&ndev->cmd_q);
666 	skb_queue_head_init(&ndev->rx_q);
667 	skb_queue_head_init(&ndev->tx_q);
668 
669 	setup_timer(&ndev->cmd_timer, nci_cmd_timer,
670 		    (unsigned long) ndev);
671 	setup_timer(&ndev->data_timer, nci_data_timer,
672 		    (unsigned long) ndev);
673 
674 	mutex_init(&ndev->req_lock);
675 
676 	goto exit;
677 
678 destroy_rx_wq_exit:
679 	destroy_workqueue(ndev->rx_wq);
680 
681 destroy_cmd_wq_exit:
682 	destroy_workqueue(ndev->cmd_wq);
683 
684 unreg_exit:
685 	nfc_unregister_device(ndev->nfc_dev);
686 
687 exit:
688 	return rc;
689 }
690 EXPORT_SYMBOL(nci_register_device);
691 
692 /**
693  * nci_unregister_device - unregister a nci device in the nfc subsystem
694  *
695  * @dev: The nci device to unregister
696  */
697 void nci_unregister_device(struct nci_dev *ndev)
698 {
699 	nci_close_device(ndev);
700 
701 	destroy_workqueue(ndev->cmd_wq);
702 	destroy_workqueue(ndev->rx_wq);
703 	destroy_workqueue(ndev->tx_wq);
704 
705 	nfc_unregister_device(ndev->nfc_dev);
706 }
707 EXPORT_SYMBOL(nci_unregister_device);
708 
709 /**
710  * nci_recv_frame - receive frame from NCI drivers
711  *
712  * @skb: The sk_buff to receive
713  */
714 int nci_recv_frame(struct sk_buff *skb)
715 {
716 	struct nci_dev *ndev = (struct nci_dev *) skb->dev;
717 
718 	pr_debug("len %d\n", skb->len);
719 
720 	if (!ndev || (!test_bit(NCI_UP, &ndev->flags)
721 		      && !test_bit(NCI_INIT, &ndev->flags))) {
722 		kfree_skb(skb);
723 		return -ENXIO;
724 	}
725 
726 	/* Queue frame for rx worker thread */
727 	skb_queue_tail(&ndev->rx_q, skb);
728 	queue_work(ndev->rx_wq, &ndev->rx_work);
729 
730 	return 0;
731 }
732 EXPORT_SYMBOL(nci_recv_frame);
733 
734 static int nci_send_frame(struct sk_buff *skb)
735 {
736 	struct nci_dev *ndev = (struct nci_dev *) skb->dev;
737 
738 	pr_debug("len %d\n", skb->len);
739 
740 	if (!ndev) {
741 		kfree_skb(skb);
742 		return -ENODEV;
743 	}
744 
745 	/* Get rid of skb owner, prior to sending to the driver. */
746 	skb_orphan(skb);
747 
748 	return ndev->ops->send(skb);
749 }
750 
751 /* Send NCI command */
752 int nci_send_cmd(struct nci_dev *ndev, __u16 opcode, __u8 plen, void *payload)
753 {
754 	struct nci_ctrl_hdr *hdr;
755 	struct sk_buff *skb;
756 
757 	pr_debug("opcode 0x%x, plen %d\n", opcode, plen);
758 
759 	skb = nci_skb_alloc(ndev, (NCI_CTRL_HDR_SIZE + plen), GFP_KERNEL);
760 	if (!skb) {
761 		pr_err("no memory for command\n");
762 		return -ENOMEM;
763 	}
764 
765 	hdr = (struct nci_ctrl_hdr *) skb_put(skb, NCI_CTRL_HDR_SIZE);
766 	hdr->gid = nci_opcode_gid(opcode);
767 	hdr->oid = nci_opcode_oid(opcode);
768 	hdr->plen = plen;
769 
770 	nci_mt_set((__u8 *)hdr, NCI_MT_CMD_PKT);
771 	nci_pbf_set((__u8 *)hdr, NCI_PBF_LAST);
772 
773 	if (plen)
774 		memcpy(skb_put(skb, plen), payload, plen);
775 
776 	skb->dev = (void *) ndev;
777 
778 	skb_queue_tail(&ndev->cmd_q, skb);
779 	queue_work(ndev->cmd_wq, &ndev->cmd_work);
780 
781 	return 0;
782 }
783 
784 /* ---- NCI TX Data worker thread ---- */
785 
786 static void nci_tx_work(struct work_struct *work)
787 {
788 	struct nci_dev *ndev = container_of(work, struct nci_dev, tx_work);
789 	struct sk_buff *skb;
790 
791 	pr_debug("credits_cnt %d\n", atomic_read(&ndev->credits_cnt));
792 
793 	/* Send queued tx data */
794 	while (atomic_read(&ndev->credits_cnt)) {
795 		skb = skb_dequeue(&ndev->tx_q);
796 		if (!skb)
797 			return;
798 
799 		/* Check if data flow control is used */
800 		if (atomic_read(&ndev->credits_cnt) !=
801 		    NCI_DATA_FLOW_CONTROL_NOT_USED)
802 			atomic_dec(&ndev->credits_cnt);
803 
804 		pr_debug("NCI TX: MT=data, PBF=%d, conn_id=%d, plen=%d\n",
805 			 nci_pbf(skb->data),
806 			 nci_conn_id(skb->data),
807 			 nci_plen(skb->data));
808 
809 		nci_send_frame(skb);
810 
811 		mod_timer(&ndev->data_timer,
812 			  jiffies + msecs_to_jiffies(NCI_DATA_TIMEOUT));
813 	}
814 }
815 
816 /* ----- NCI RX worker thread (data & control) ----- */
817 
818 static void nci_rx_work(struct work_struct *work)
819 {
820 	struct nci_dev *ndev = container_of(work, struct nci_dev, rx_work);
821 	struct sk_buff *skb;
822 
823 	while ((skb = skb_dequeue(&ndev->rx_q))) {
824 		/* Process frame */
825 		switch (nci_mt(skb->data)) {
826 		case NCI_MT_RSP_PKT:
827 			nci_rsp_packet(ndev, skb);
828 			break;
829 
830 		case NCI_MT_NTF_PKT:
831 			nci_ntf_packet(ndev, skb);
832 			break;
833 
834 		case NCI_MT_DATA_PKT:
835 			nci_rx_data_packet(ndev, skb);
836 			break;
837 
838 		default:
839 			pr_err("unknown MT 0x%x\n", nci_mt(skb->data));
840 			kfree_skb(skb);
841 			break;
842 		}
843 	}
844 
845 	/* check if a data exchange timout has occurred */
846 	if (test_bit(NCI_DATA_EXCHANGE_TO, &ndev->flags)) {
847 		/* complete the data exchange transaction, if exists */
848 		if (test_bit(NCI_DATA_EXCHANGE, &ndev->flags))
849 			nci_data_exchange_complete(ndev, NULL, -ETIMEDOUT);
850 
851 		clear_bit(NCI_DATA_EXCHANGE_TO, &ndev->flags);
852 	}
853 }
854 
855 /* ----- NCI TX CMD worker thread ----- */
856 
857 static void nci_cmd_work(struct work_struct *work)
858 {
859 	struct nci_dev *ndev = container_of(work, struct nci_dev, cmd_work);
860 	struct sk_buff *skb;
861 
862 	pr_debug("cmd_cnt %d\n", atomic_read(&ndev->cmd_cnt));
863 
864 	/* Send queued command */
865 	if (atomic_read(&ndev->cmd_cnt)) {
866 		skb = skb_dequeue(&ndev->cmd_q);
867 		if (!skb)
868 			return;
869 
870 		atomic_dec(&ndev->cmd_cnt);
871 
872 		pr_debug("NCI TX: MT=cmd, PBF=%d, GID=0x%x, OID=0x%x, plen=%d\n",
873 			 nci_pbf(skb->data),
874 			 nci_opcode_gid(nci_opcode(skb->data)),
875 			 nci_opcode_oid(nci_opcode(skb->data)),
876 			 nci_plen(skb->data));
877 
878 		nci_send_frame(skb);
879 
880 		mod_timer(&ndev->cmd_timer,
881 			  jiffies + msecs_to_jiffies(NCI_CMD_TIMEOUT));
882 	}
883 }
884 
885 MODULE_LICENSE("GPL");
886