xref: /linux/net/nfc/nci/core.c (revision 2d87650a3bf1b80f7d0d150ee1af3f8a89e5b7aa)
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, see <http://www.gnu.org/licenses/>.
24  *
25  */
26 
27 #define pr_fmt(fmt) KBUILD_MODNAME ": %s: " fmt, __func__
28 
29 #include <linux/module.h>
30 #include <linux/types.h>
31 #include <linux/workqueue.h>
32 #include <linux/completion.h>
33 #include <linux/export.h>
34 #include <linux/sched.h>
35 #include <linux/bitops.h>
36 #include <linux/skbuff.h>
37 
38 #include "../nfc.h"
39 #include <net/nfc/nci.h>
40 #include <net/nfc/nci_core.h>
41 #include <linux/nfc.h>
42 
43 static void nci_cmd_work(struct work_struct *work);
44 static void nci_rx_work(struct work_struct *work);
45 static void nci_tx_work(struct work_struct *work);
46 
47 /* ---- NCI requests ---- */
48 
49 void nci_req_complete(struct nci_dev *ndev, int result)
50 {
51 	if (ndev->req_status == NCI_REQ_PEND) {
52 		ndev->req_result = result;
53 		ndev->req_status = NCI_REQ_DONE;
54 		complete(&ndev->req_completion);
55 	}
56 }
57 
58 static void nci_req_cancel(struct nci_dev *ndev, int err)
59 {
60 	if (ndev->req_status == NCI_REQ_PEND) {
61 		ndev->req_result = err;
62 		ndev->req_status = NCI_REQ_CANCELED;
63 		complete(&ndev->req_completion);
64 	}
65 }
66 
67 /* Execute request and wait for completion. */
68 static int __nci_request(struct nci_dev *ndev,
69 			 void (*req)(struct nci_dev *ndev, unsigned long opt),
70 			 unsigned long opt, __u32 timeout)
71 {
72 	int rc = 0;
73 	long completion_rc;
74 
75 	ndev->req_status = NCI_REQ_PEND;
76 
77 	init_completion(&ndev->req_completion);
78 	req(ndev, opt);
79 	completion_rc =
80 		wait_for_completion_interruptible_timeout(&ndev->req_completion,
81 							  timeout);
82 
83 	pr_debug("wait_for_completion return %ld\n", completion_rc);
84 
85 	if (completion_rc > 0) {
86 		switch (ndev->req_status) {
87 		case NCI_REQ_DONE:
88 			rc = nci_to_errno(ndev->req_result);
89 			break;
90 
91 		case NCI_REQ_CANCELED:
92 			rc = -ndev->req_result;
93 			break;
94 
95 		default:
96 			rc = -ETIMEDOUT;
97 			break;
98 		}
99 	} else {
100 		pr_err("wait_for_completion_interruptible_timeout failed %ld\n",
101 		       completion_rc);
102 
103 		rc = ((completion_rc == 0) ? (-ETIMEDOUT) : (completion_rc));
104 	}
105 
106 	ndev->req_status = ndev->req_result = 0;
107 
108 	return rc;
109 }
110 
111 static inline int nci_request(struct nci_dev *ndev,
112 			      void (*req)(struct nci_dev *ndev,
113 					  unsigned long opt),
114 			      unsigned long opt, __u32 timeout)
115 {
116 	int rc;
117 
118 	if (!test_bit(NCI_UP, &ndev->flags))
119 		return -ENETDOWN;
120 
121 	/* Serialize all requests */
122 	mutex_lock(&ndev->req_lock);
123 	rc = __nci_request(ndev, req, opt, timeout);
124 	mutex_unlock(&ndev->req_lock);
125 
126 	return rc;
127 }
128 
129 static void nci_reset_req(struct nci_dev *ndev, unsigned long opt)
130 {
131 	struct nci_core_reset_cmd cmd;
132 
133 	cmd.reset_type = NCI_RESET_TYPE_RESET_CONFIG;
134 	nci_send_cmd(ndev, NCI_OP_CORE_RESET_CMD, 1, &cmd);
135 }
136 
137 static void nci_init_req(struct nci_dev *ndev, unsigned long opt)
138 {
139 	nci_send_cmd(ndev, NCI_OP_CORE_INIT_CMD, 0, NULL);
140 }
141 
142 static void nci_init_complete_req(struct nci_dev *ndev, unsigned long opt)
143 {
144 	struct nci_rf_disc_map_cmd cmd;
145 	struct disc_map_config *cfg = cmd.mapping_configs;
146 	__u8 *num = &cmd.num_mapping_configs;
147 	int i;
148 
149 	/* set rf mapping configurations */
150 	*num = 0;
151 
152 	/* by default mapping is set to NCI_RF_INTERFACE_FRAME */
153 	for (i = 0; i < ndev->num_supported_rf_interfaces; i++) {
154 		if (ndev->supported_rf_interfaces[i] ==
155 		    NCI_RF_INTERFACE_ISO_DEP) {
156 			cfg[*num].rf_protocol = NCI_RF_PROTOCOL_ISO_DEP;
157 			cfg[*num].mode = NCI_DISC_MAP_MODE_POLL |
158 				NCI_DISC_MAP_MODE_LISTEN;
159 			cfg[*num].rf_interface = NCI_RF_INTERFACE_ISO_DEP;
160 			(*num)++;
161 		} else if (ndev->supported_rf_interfaces[i] ==
162 			   NCI_RF_INTERFACE_NFC_DEP) {
163 			cfg[*num].rf_protocol = NCI_RF_PROTOCOL_NFC_DEP;
164 			cfg[*num].mode = NCI_DISC_MAP_MODE_POLL |
165 				NCI_DISC_MAP_MODE_LISTEN;
166 			cfg[*num].rf_interface = NCI_RF_INTERFACE_NFC_DEP;
167 			(*num)++;
168 		}
169 
170 		if (*num == NCI_MAX_NUM_MAPPING_CONFIGS)
171 			break;
172 	}
173 
174 	nci_send_cmd(ndev, NCI_OP_RF_DISCOVER_MAP_CMD,
175 		     (1 + ((*num) * sizeof(struct disc_map_config))), &cmd);
176 }
177 
178 struct nci_set_config_param {
179 	__u8	id;
180 	size_t	len;
181 	__u8	*val;
182 };
183 
184 static void nci_set_config_req(struct nci_dev *ndev, unsigned long opt)
185 {
186 	struct nci_set_config_param *param = (struct nci_set_config_param *)opt;
187 	struct nci_core_set_config_cmd cmd;
188 
189 	BUG_ON(param->len > NCI_MAX_PARAM_LEN);
190 
191 	cmd.num_params = 1;
192 	cmd.param.id = param->id;
193 	cmd.param.len = param->len;
194 	memcpy(cmd.param.val, param->val, param->len);
195 
196 	nci_send_cmd(ndev, NCI_OP_CORE_SET_CONFIG_CMD, (3 + param->len), &cmd);
197 }
198 
199 static void nci_rf_discover_req(struct nci_dev *ndev, unsigned long opt)
200 {
201 	struct nci_rf_disc_cmd cmd;
202 	__u32 protocols = opt;
203 
204 	cmd.num_disc_configs = 0;
205 
206 	if ((cmd.num_disc_configs < NCI_MAX_NUM_RF_CONFIGS) &&
207 	    (protocols & NFC_PROTO_JEWEL_MASK ||
208 	     protocols & NFC_PROTO_MIFARE_MASK ||
209 	     protocols & NFC_PROTO_ISO14443_MASK ||
210 	     protocols & NFC_PROTO_NFC_DEP_MASK)) {
211 		cmd.disc_configs[cmd.num_disc_configs].rf_tech_and_mode =
212 			NCI_NFC_A_PASSIVE_POLL_MODE;
213 		cmd.disc_configs[cmd.num_disc_configs].frequency = 1;
214 		cmd.num_disc_configs++;
215 	}
216 
217 	if ((cmd.num_disc_configs < NCI_MAX_NUM_RF_CONFIGS) &&
218 	    (protocols & NFC_PROTO_ISO14443_B_MASK)) {
219 		cmd.disc_configs[cmd.num_disc_configs].rf_tech_and_mode =
220 			NCI_NFC_B_PASSIVE_POLL_MODE;
221 		cmd.disc_configs[cmd.num_disc_configs].frequency = 1;
222 		cmd.num_disc_configs++;
223 	}
224 
225 	if ((cmd.num_disc_configs < NCI_MAX_NUM_RF_CONFIGS) &&
226 	    (protocols & NFC_PROTO_FELICA_MASK ||
227 	     protocols & NFC_PROTO_NFC_DEP_MASK)) {
228 		cmd.disc_configs[cmd.num_disc_configs].rf_tech_and_mode =
229 			NCI_NFC_F_PASSIVE_POLL_MODE;
230 		cmd.disc_configs[cmd.num_disc_configs].frequency = 1;
231 		cmd.num_disc_configs++;
232 	}
233 
234 	nci_send_cmd(ndev, NCI_OP_RF_DISCOVER_CMD,
235 		     (1 + (cmd.num_disc_configs * sizeof(struct disc_config))),
236 		     &cmd);
237 }
238 
239 struct nci_rf_discover_select_param {
240 	__u8	rf_discovery_id;
241 	__u8	rf_protocol;
242 };
243 
244 static void nci_rf_discover_select_req(struct nci_dev *ndev, unsigned long opt)
245 {
246 	struct nci_rf_discover_select_param *param =
247 		(struct nci_rf_discover_select_param *)opt;
248 	struct nci_rf_discover_select_cmd cmd;
249 
250 	cmd.rf_discovery_id = param->rf_discovery_id;
251 	cmd.rf_protocol = param->rf_protocol;
252 
253 	switch (cmd.rf_protocol) {
254 	case NCI_RF_PROTOCOL_ISO_DEP:
255 		cmd.rf_interface = NCI_RF_INTERFACE_ISO_DEP;
256 		break;
257 
258 	case NCI_RF_PROTOCOL_NFC_DEP:
259 		cmd.rf_interface = NCI_RF_INTERFACE_NFC_DEP;
260 		break;
261 
262 	default:
263 		cmd.rf_interface = NCI_RF_INTERFACE_FRAME;
264 		break;
265 	}
266 
267 	nci_send_cmd(ndev, NCI_OP_RF_DISCOVER_SELECT_CMD,
268 		     sizeof(struct nci_rf_discover_select_cmd), &cmd);
269 }
270 
271 static void nci_rf_deactivate_req(struct nci_dev *ndev, unsigned long opt)
272 {
273 	struct nci_rf_deactivate_cmd cmd;
274 
275 	cmd.type = NCI_DEACTIVATE_TYPE_IDLE_MODE;
276 
277 	nci_send_cmd(ndev, NCI_OP_RF_DEACTIVATE_CMD,
278 		     sizeof(struct nci_rf_deactivate_cmd), &cmd);
279 }
280 
281 static int nci_open_device(struct nci_dev *ndev)
282 {
283 	int rc = 0;
284 
285 	mutex_lock(&ndev->req_lock);
286 
287 	if (test_bit(NCI_UP, &ndev->flags)) {
288 		rc = -EALREADY;
289 		goto done;
290 	}
291 
292 	if (ndev->ops->open(ndev)) {
293 		rc = -EIO;
294 		goto done;
295 	}
296 
297 	atomic_set(&ndev->cmd_cnt, 1);
298 
299 	set_bit(NCI_INIT, &ndev->flags);
300 
301 	rc = __nci_request(ndev, nci_reset_req, 0,
302 			   msecs_to_jiffies(NCI_RESET_TIMEOUT));
303 
304 	if (!rc) {
305 		rc = __nci_request(ndev, nci_init_req, 0,
306 				   msecs_to_jiffies(NCI_INIT_TIMEOUT));
307 	}
308 
309 	if (!rc) {
310 		rc = __nci_request(ndev, nci_init_complete_req, 0,
311 				   msecs_to_jiffies(NCI_INIT_TIMEOUT));
312 	}
313 
314 	clear_bit(NCI_INIT, &ndev->flags);
315 
316 	if (!rc) {
317 		set_bit(NCI_UP, &ndev->flags);
318 		nci_clear_target_list(ndev);
319 		atomic_set(&ndev->state, NCI_IDLE);
320 	} else {
321 		/* Init failed, cleanup */
322 		skb_queue_purge(&ndev->cmd_q);
323 		skb_queue_purge(&ndev->rx_q);
324 		skb_queue_purge(&ndev->tx_q);
325 
326 		ndev->ops->close(ndev);
327 		ndev->flags = 0;
328 	}
329 
330 done:
331 	mutex_unlock(&ndev->req_lock);
332 	return rc;
333 }
334 
335 static int nci_close_device(struct nci_dev *ndev)
336 {
337 	nci_req_cancel(ndev, ENODEV);
338 	mutex_lock(&ndev->req_lock);
339 
340 	if (!test_and_clear_bit(NCI_UP, &ndev->flags)) {
341 		del_timer_sync(&ndev->cmd_timer);
342 		del_timer_sync(&ndev->data_timer);
343 		mutex_unlock(&ndev->req_lock);
344 		return 0;
345 	}
346 
347 	/* Drop RX and TX queues */
348 	skb_queue_purge(&ndev->rx_q);
349 	skb_queue_purge(&ndev->tx_q);
350 
351 	/* Flush RX and TX wq */
352 	flush_workqueue(ndev->rx_wq);
353 	flush_workqueue(ndev->tx_wq);
354 
355 	/* Reset device */
356 	skb_queue_purge(&ndev->cmd_q);
357 	atomic_set(&ndev->cmd_cnt, 1);
358 
359 	set_bit(NCI_INIT, &ndev->flags);
360 	__nci_request(ndev, nci_reset_req, 0,
361 		      msecs_to_jiffies(NCI_RESET_TIMEOUT));
362 	clear_bit(NCI_INIT, &ndev->flags);
363 
364 	/* Flush cmd wq */
365 	flush_workqueue(ndev->cmd_wq);
366 
367 	/* After this point our queues are empty
368 	 * and no works are scheduled. */
369 	ndev->ops->close(ndev);
370 
371 	/* Clear flags */
372 	ndev->flags = 0;
373 
374 	mutex_unlock(&ndev->req_lock);
375 
376 	return 0;
377 }
378 
379 /* NCI command timer function */
380 static void nci_cmd_timer(unsigned long arg)
381 {
382 	struct nci_dev *ndev = (void *) arg;
383 
384 	atomic_set(&ndev->cmd_cnt, 1);
385 	queue_work(ndev->cmd_wq, &ndev->cmd_work);
386 }
387 
388 /* NCI data exchange timer function */
389 static void nci_data_timer(unsigned long arg)
390 {
391 	struct nci_dev *ndev = (void *) arg;
392 
393 	set_bit(NCI_DATA_EXCHANGE_TO, &ndev->flags);
394 	queue_work(ndev->rx_wq, &ndev->rx_work);
395 }
396 
397 static int nci_dev_up(struct nfc_dev *nfc_dev)
398 {
399 	struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
400 
401 	return nci_open_device(ndev);
402 }
403 
404 static int nci_dev_down(struct nfc_dev *nfc_dev)
405 {
406 	struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
407 
408 	return nci_close_device(ndev);
409 }
410 
411 static int nci_set_local_general_bytes(struct nfc_dev *nfc_dev)
412 {
413 	struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
414 	struct nci_set_config_param param;
415 	__u8 local_gb[NFC_MAX_GT_LEN];
416 	int i;
417 
418 	param.val = nfc_get_local_general_bytes(nfc_dev, &param.len);
419 	if ((param.val == NULL) || (param.len == 0))
420 		return 0;
421 
422 	if (param.len > NFC_MAX_GT_LEN)
423 		return -EINVAL;
424 
425 	for (i = 0; i < param.len; i++)
426 		local_gb[param.len-1-i] = param.val[i];
427 
428 	param.id = NCI_PN_ATR_REQ_GEN_BYTES;
429 	param.val = local_gb;
430 
431 	return nci_request(ndev, nci_set_config_req, (unsigned long)&param,
432 			   msecs_to_jiffies(NCI_SET_CONFIG_TIMEOUT));
433 }
434 
435 static int nci_start_poll(struct nfc_dev *nfc_dev,
436 			  __u32 im_protocols, __u32 tm_protocols)
437 {
438 	struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
439 	int rc;
440 
441 	if ((atomic_read(&ndev->state) == NCI_DISCOVERY) ||
442 	    (atomic_read(&ndev->state) == NCI_W4_ALL_DISCOVERIES)) {
443 		pr_err("unable to start poll, since poll is already active\n");
444 		return -EBUSY;
445 	}
446 
447 	if (ndev->target_active_prot) {
448 		pr_err("there is an active target\n");
449 		return -EBUSY;
450 	}
451 
452 	if ((atomic_read(&ndev->state) == NCI_W4_HOST_SELECT) ||
453 	    (atomic_read(&ndev->state) == NCI_POLL_ACTIVE)) {
454 		pr_debug("target active or w4 select, implicitly deactivate\n");
455 
456 		rc = nci_request(ndev, nci_rf_deactivate_req, 0,
457 				 msecs_to_jiffies(NCI_RF_DEACTIVATE_TIMEOUT));
458 		if (rc)
459 			return -EBUSY;
460 	}
461 
462 	if (im_protocols & NFC_PROTO_NFC_DEP_MASK) {
463 		rc = nci_set_local_general_bytes(nfc_dev);
464 		if (rc) {
465 			pr_err("failed to set local general bytes\n");
466 			return rc;
467 		}
468 	}
469 
470 	rc = nci_request(ndev, nci_rf_discover_req, im_protocols,
471 			 msecs_to_jiffies(NCI_RF_DISC_TIMEOUT));
472 
473 	if (!rc)
474 		ndev->poll_prots = im_protocols;
475 
476 	return rc;
477 }
478 
479 static void nci_stop_poll(struct nfc_dev *nfc_dev)
480 {
481 	struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
482 
483 	if ((atomic_read(&ndev->state) != NCI_DISCOVERY) &&
484 	    (atomic_read(&ndev->state) != NCI_W4_ALL_DISCOVERIES)) {
485 		pr_err("unable to stop poll, since poll is not active\n");
486 		return;
487 	}
488 
489 	nci_request(ndev, nci_rf_deactivate_req, 0,
490 		    msecs_to_jiffies(NCI_RF_DEACTIVATE_TIMEOUT));
491 }
492 
493 static int nci_activate_target(struct nfc_dev *nfc_dev,
494 			       struct nfc_target *target, __u32 protocol)
495 {
496 	struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
497 	struct nci_rf_discover_select_param param;
498 	struct nfc_target *nci_target = NULL;
499 	int i;
500 	int rc = 0;
501 
502 	pr_debug("target_idx %d, protocol 0x%x\n", target->idx, protocol);
503 
504 	if ((atomic_read(&ndev->state) != NCI_W4_HOST_SELECT) &&
505 	    (atomic_read(&ndev->state) != NCI_POLL_ACTIVE)) {
506 		pr_err("there is no available target to activate\n");
507 		return -EINVAL;
508 	}
509 
510 	if (ndev->target_active_prot) {
511 		pr_err("there is already an active target\n");
512 		return -EBUSY;
513 	}
514 
515 	for (i = 0; i < ndev->n_targets; i++) {
516 		if (ndev->targets[i].idx == target->idx) {
517 			nci_target = &ndev->targets[i];
518 			break;
519 		}
520 	}
521 
522 	if (!nci_target) {
523 		pr_err("unable to find the selected target\n");
524 		return -EINVAL;
525 	}
526 
527 	if (!(nci_target->supported_protocols & (1 << protocol))) {
528 		pr_err("target does not support the requested protocol 0x%x\n",
529 		       protocol);
530 		return -EINVAL;
531 	}
532 
533 	if (atomic_read(&ndev->state) == NCI_W4_HOST_SELECT) {
534 		param.rf_discovery_id = nci_target->logical_idx;
535 
536 		if (protocol == NFC_PROTO_JEWEL)
537 			param.rf_protocol = NCI_RF_PROTOCOL_T1T;
538 		else if (protocol == NFC_PROTO_MIFARE)
539 			param.rf_protocol = NCI_RF_PROTOCOL_T2T;
540 		else if (protocol == NFC_PROTO_FELICA)
541 			param.rf_protocol = NCI_RF_PROTOCOL_T3T;
542 		else if (protocol == NFC_PROTO_ISO14443 ||
543 			 protocol == NFC_PROTO_ISO14443_B)
544 			param.rf_protocol = NCI_RF_PROTOCOL_ISO_DEP;
545 		else
546 			param.rf_protocol = NCI_RF_PROTOCOL_NFC_DEP;
547 
548 		rc = nci_request(ndev, nci_rf_discover_select_req,
549 				 (unsigned long)&param,
550 				 msecs_to_jiffies(NCI_RF_DISC_SELECT_TIMEOUT));
551 	}
552 
553 	if (!rc)
554 		ndev->target_active_prot = protocol;
555 
556 	return rc;
557 }
558 
559 static void nci_deactivate_target(struct nfc_dev *nfc_dev,
560 				  struct nfc_target *target)
561 {
562 	struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
563 
564 	pr_debug("entry\n");
565 
566 	if (!ndev->target_active_prot) {
567 		pr_err("unable to deactivate target, no active target\n");
568 		return;
569 	}
570 
571 	ndev->target_active_prot = 0;
572 
573 	if (atomic_read(&ndev->state) == NCI_POLL_ACTIVE) {
574 		nci_request(ndev, nci_rf_deactivate_req, 0,
575 			    msecs_to_jiffies(NCI_RF_DEACTIVATE_TIMEOUT));
576 	}
577 }
578 
579 static int nci_dep_link_up(struct nfc_dev *nfc_dev, struct nfc_target *target,
580 			   __u8 comm_mode, __u8 *gb, size_t gb_len)
581 {
582 	struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
583 	int rc;
584 
585 	pr_debug("target_idx %d, comm_mode %d\n", target->idx, comm_mode);
586 
587 	rc = nci_activate_target(nfc_dev, target, NFC_PROTO_NFC_DEP);
588 	if (rc)
589 		return rc;
590 
591 	rc = nfc_set_remote_general_bytes(nfc_dev, ndev->remote_gb,
592 					  ndev->remote_gb_len);
593 	if (!rc)
594 		rc = nfc_dep_link_is_up(nfc_dev, target->idx, NFC_COMM_PASSIVE,
595 					NFC_RF_INITIATOR);
596 
597 	return rc;
598 }
599 
600 static int nci_dep_link_down(struct nfc_dev *nfc_dev)
601 {
602 	pr_debug("entry\n");
603 
604 	nci_deactivate_target(nfc_dev, NULL);
605 
606 	return 0;
607 }
608 
609 
610 static int nci_transceive(struct nfc_dev *nfc_dev, struct nfc_target *target,
611 			  struct sk_buff *skb,
612 			  data_exchange_cb_t cb, void *cb_context)
613 {
614 	struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
615 	int rc;
616 
617 	pr_debug("target_idx %d, len %d\n", target->idx, skb->len);
618 
619 	if (!ndev->target_active_prot) {
620 		pr_err("unable to exchange data, no active target\n");
621 		return -EINVAL;
622 	}
623 
624 	if (test_and_set_bit(NCI_DATA_EXCHANGE, &ndev->flags))
625 		return -EBUSY;
626 
627 	/* store cb and context to be used on receiving data */
628 	ndev->data_exchange_cb = cb;
629 	ndev->data_exchange_cb_context = cb_context;
630 
631 	rc = nci_send_data(ndev, NCI_STATIC_RF_CONN_ID, skb);
632 	if (rc)
633 		clear_bit(NCI_DATA_EXCHANGE, &ndev->flags);
634 
635 	return rc;
636 }
637 
638 static int nci_enable_se(struct nfc_dev *nfc_dev, u32 se_idx)
639 {
640 	return 0;
641 }
642 
643 static int nci_disable_se(struct nfc_dev *nfc_dev, u32 se_idx)
644 {
645 	return 0;
646 }
647 
648 static int nci_discover_se(struct nfc_dev *nfc_dev)
649 {
650 	return 0;
651 }
652 
653 static struct nfc_ops nci_nfc_ops = {
654 	.dev_up = nci_dev_up,
655 	.dev_down = nci_dev_down,
656 	.start_poll = nci_start_poll,
657 	.stop_poll = nci_stop_poll,
658 	.dep_link_up = nci_dep_link_up,
659 	.dep_link_down = nci_dep_link_down,
660 	.activate_target = nci_activate_target,
661 	.deactivate_target = nci_deactivate_target,
662 	.im_transceive = nci_transceive,
663 	.enable_se = nci_enable_se,
664 	.disable_se = nci_disable_se,
665 	.discover_se = nci_discover_se,
666 };
667 
668 /* ---- Interface to NCI drivers ---- */
669 
670 /**
671  * nci_allocate_device - allocate a new nci device
672  *
673  * @ops: device operations
674  * @supported_protocols: NFC protocols supported by the device
675  */
676 struct nci_dev *nci_allocate_device(struct nci_ops *ops,
677 				    __u32 supported_protocols,
678 				    int tx_headroom, int tx_tailroom)
679 {
680 	struct nci_dev *ndev;
681 
682 	pr_debug("supported_protocols 0x%x\n", supported_protocols);
683 
684 	if (!ops->open || !ops->close || !ops->send)
685 		return NULL;
686 
687 	if (!supported_protocols)
688 		return NULL;
689 
690 	ndev = kzalloc(sizeof(struct nci_dev), GFP_KERNEL);
691 	if (!ndev)
692 		return NULL;
693 
694 	ndev->ops = ops;
695 	ndev->tx_headroom = tx_headroom;
696 	ndev->tx_tailroom = tx_tailroom;
697 
698 	ndev->nfc_dev = nfc_allocate_device(&nci_nfc_ops,
699 					    supported_protocols,
700 					    tx_headroom + NCI_DATA_HDR_SIZE,
701 					    tx_tailroom);
702 	if (!ndev->nfc_dev)
703 		goto free_exit;
704 
705 	nfc_set_drvdata(ndev->nfc_dev, ndev);
706 
707 	return ndev;
708 
709 free_exit:
710 	kfree(ndev);
711 	return NULL;
712 }
713 EXPORT_SYMBOL(nci_allocate_device);
714 
715 /**
716  * nci_free_device - deallocate nci device
717  *
718  * @ndev: The nci device to deallocate
719  */
720 void nci_free_device(struct nci_dev *ndev)
721 {
722 	nfc_free_device(ndev->nfc_dev);
723 	kfree(ndev);
724 }
725 EXPORT_SYMBOL(nci_free_device);
726 
727 /**
728  * nci_register_device - register a nci device in the nfc subsystem
729  *
730  * @dev: The nci device to register
731  */
732 int nci_register_device(struct nci_dev *ndev)
733 {
734 	int rc;
735 	struct device *dev = &ndev->nfc_dev->dev;
736 	char name[32];
737 
738 	rc = nfc_register_device(ndev->nfc_dev);
739 	if (rc)
740 		goto exit;
741 
742 	ndev->flags = 0;
743 
744 	INIT_WORK(&ndev->cmd_work, nci_cmd_work);
745 	snprintf(name, sizeof(name), "%s_nci_cmd_wq", dev_name(dev));
746 	ndev->cmd_wq = create_singlethread_workqueue(name);
747 	if (!ndev->cmd_wq) {
748 		rc = -ENOMEM;
749 		goto unreg_exit;
750 	}
751 
752 	INIT_WORK(&ndev->rx_work, nci_rx_work);
753 	snprintf(name, sizeof(name), "%s_nci_rx_wq", dev_name(dev));
754 	ndev->rx_wq = create_singlethread_workqueue(name);
755 	if (!ndev->rx_wq) {
756 		rc = -ENOMEM;
757 		goto destroy_cmd_wq_exit;
758 	}
759 
760 	INIT_WORK(&ndev->tx_work, nci_tx_work);
761 	snprintf(name, sizeof(name), "%s_nci_tx_wq", dev_name(dev));
762 	ndev->tx_wq = create_singlethread_workqueue(name);
763 	if (!ndev->tx_wq) {
764 		rc = -ENOMEM;
765 		goto destroy_rx_wq_exit;
766 	}
767 
768 	skb_queue_head_init(&ndev->cmd_q);
769 	skb_queue_head_init(&ndev->rx_q);
770 	skb_queue_head_init(&ndev->tx_q);
771 
772 	setup_timer(&ndev->cmd_timer, nci_cmd_timer,
773 		    (unsigned long) ndev);
774 	setup_timer(&ndev->data_timer, nci_data_timer,
775 		    (unsigned long) ndev);
776 
777 	mutex_init(&ndev->req_lock);
778 
779 	goto exit;
780 
781 destroy_rx_wq_exit:
782 	destroy_workqueue(ndev->rx_wq);
783 
784 destroy_cmd_wq_exit:
785 	destroy_workqueue(ndev->cmd_wq);
786 
787 unreg_exit:
788 	nfc_unregister_device(ndev->nfc_dev);
789 
790 exit:
791 	return rc;
792 }
793 EXPORT_SYMBOL(nci_register_device);
794 
795 /**
796  * nci_unregister_device - unregister a nci device in the nfc subsystem
797  *
798  * @dev: The nci device to unregister
799  */
800 void nci_unregister_device(struct nci_dev *ndev)
801 {
802 	nci_close_device(ndev);
803 
804 	destroy_workqueue(ndev->cmd_wq);
805 	destroy_workqueue(ndev->rx_wq);
806 	destroy_workqueue(ndev->tx_wq);
807 
808 	nfc_unregister_device(ndev->nfc_dev);
809 }
810 EXPORT_SYMBOL(nci_unregister_device);
811 
812 /**
813  * nci_recv_frame - receive frame from NCI drivers
814  *
815  * @ndev: The nci device
816  * @skb: The sk_buff to receive
817  */
818 int nci_recv_frame(struct nci_dev *ndev, struct sk_buff *skb)
819 {
820 	pr_debug("len %d\n", skb->len);
821 
822 	if (!ndev || (!test_bit(NCI_UP, &ndev->flags) &&
823 	    !test_bit(NCI_INIT, &ndev->flags))) {
824 		kfree_skb(skb);
825 		return -ENXIO;
826 	}
827 
828 	/* Queue frame for rx worker thread */
829 	skb_queue_tail(&ndev->rx_q, skb);
830 	queue_work(ndev->rx_wq, &ndev->rx_work);
831 
832 	return 0;
833 }
834 EXPORT_SYMBOL(nci_recv_frame);
835 
836 static int nci_send_frame(struct nci_dev *ndev, struct sk_buff *skb)
837 {
838 	pr_debug("len %d\n", skb->len);
839 
840 	if (!ndev) {
841 		kfree_skb(skb);
842 		return -ENODEV;
843 	}
844 
845 	/* Get rid of skb owner, prior to sending to the driver. */
846 	skb_orphan(skb);
847 
848 	return ndev->ops->send(ndev, skb);
849 }
850 
851 /* Send NCI command */
852 int nci_send_cmd(struct nci_dev *ndev, __u16 opcode, __u8 plen, void *payload)
853 {
854 	struct nci_ctrl_hdr *hdr;
855 	struct sk_buff *skb;
856 
857 	pr_debug("opcode 0x%x, plen %d\n", opcode, plen);
858 
859 	skb = nci_skb_alloc(ndev, (NCI_CTRL_HDR_SIZE + plen), GFP_KERNEL);
860 	if (!skb) {
861 		pr_err("no memory for command\n");
862 		return -ENOMEM;
863 	}
864 
865 	hdr = (struct nci_ctrl_hdr *) skb_put(skb, NCI_CTRL_HDR_SIZE);
866 	hdr->gid = nci_opcode_gid(opcode);
867 	hdr->oid = nci_opcode_oid(opcode);
868 	hdr->plen = plen;
869 
870 	nci_mt_set((__u8 *)hdr, NCI_MT_CMD_PKT);
871 	nci_pbf_set((__u8 *)hdr, NCI_PBF_LAST);
872 
873 	if (plen)
874 		memcpy(skb_put(skb, plen), payload, plen);
875 
876 	skb_queue_tail(&ndev->cmd_q, skb);
877 	queue_work(ndev->cmd_wq, &ndev->cmd_work);
878 
879 	return 0;
880 }
881 
882 /* ---- NCI TX Data worker thread ---- */
883 
884 static void nci_tx_work(struct work_struct *work)
885 {
886 	struct nci_dev *ndev = container_of(work, struct nci_dev, tx_work);
887 	struct sk_buff *skb;
888 
889 	pr_debug("credits_cnt %d\n", atomic_read(&ndev->credits_cnt));
890 
891 	/* Send queued tx data */
892 	while (atomic_read(&ndev->credits_cnt)) {
893 		skb = skb_dequeue(&ndev->tx_q);
894 		if (!skb)
895 			return;
896 
897 		/* Check if data flow control is used */
898 		if (atomic_read(&ndev->credits_cnt) !=
899 		    NCI_DATA_FLOW_CONTROL_NOT_USED)
900 			atomic_dec(&ndev->credits_cnt);
901 
902 		pr_debug("NCI TX: MT=data, PBF=%d, conn_id=%d, plen=%d\n",
903 			 nci_pbf(skb->data),
904 			 nci_conn_id(skb->data),
905 			 nci_plen(skb->data));
906 
907 		nci_send_frame(ndev, skb);
908 
909 		mod_timer(&ndev->data_timer,
910 			  jiffies + msecs_to_jiffies(NCI_DATA_TIMEOUT));
911 	}
912 }
913 
914 /* ----- NCI RX worker thread (data & control) ----- */
915 
916 static void nci_rx_work(struct work_struct *work)
917 {
918 	struct nci_dev *ndev = container_of(work, struct nci_dev, rx_work);
919 	struct sk_buff *skb;
920 
921 	while ((skb = skb_dequeue(&ndev->rx_q))) {
922 		/* Process frame */
923 		switch (nci_mt(skb->data)) {
924 		case NCI_MT_RSP_PKT:
925 			nci_rsp_packet(ndev, skb);
926 			break;
927 
928 		case NCI_MT_NTF_PKT:
929 			nci_ntf_packet(ndev, skb);
930 			break;
931 
932 		case NCI_MT_DATA_PKT:
933 			nci_rx_data_packet(ndev, skb);
934 			break;
935 
936 		default:
937 			pr_err("unknown MT 0x%x\n", nci_mt(skb->data));
938 			kfree_skb(skb);
939 			break;
940 		}
941 	}
942 
943 	/* check if a data exchange timout has occurred */
944 	if (test_bit(NCI_DATA_EXCHANGE_TO, &ndev->flags)) {
945 		/* complete the data exchange transaction, if exists */
946 		if (test_bit(NCI_DATA_EXCHANGE, &ndev->flags))
947 			nci_data_exchange_complete(ndev, NULL, -ETIMEDOUT);
948 
949 		clear_bit(NCI_DATA_EXCHANGE_TO, &ndev->flags);
950 	}
951 }
952 
953 /* ----- NCI TX CMD worker thread ----- */
954 
955 static void nci_cmd_work(struct work_struct *work)
956 {
957 	struct nci_dev *ndev = container_of(work, struct nci_dev, cmd_work);
958 	struct sk_buff *skb;
959 
960 	pr_debug("cmd_cnt %d\n", atomic_read(&ndev->cmd_cnt));
961 
962 	/* Send queued command */
963 	if (atomic_read(&ndev->cmd_cnt)) {
964 		skb = skb_dequeue(&ndev->cmd_q);
965 		if (!skb)
966 			return;
967 
968 		atomic_dec(&ndev->cmd_cnt);
969 
970 		pr_debug("NCI TX: MT=cmd, PBF=%d, GID=0x%x, OID=0x%x, plen=%d\n",
971 			 nci_pbf(skb->data),
972 			 nci_opcode_gid(nci_opcode(skb->data)),
973 			 nci_opcode_oid(nci_opcode(skb->data)),
974 			 nci_plen(skb->data));
975 
976 		nci_send_frame(ndev, skb);
977 
978 		mod_timer(&ndev->cmd_timer,
979 			  jiffies + msecs_to_jiffies(NCI_CMD_TIMEOUT));
980 	}
981 }
982 
983 MODULE_LICENSE("GPL");
984