xref: /linux/net/nfc/nci/core.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
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 struct nci_set_config_param {
180 	__u8	id;
181 	size_t	len;
182 	__u8	*val;
183 };
184 
185 static void nci_set_config_req(struct nci_dev *ndev, unsigned long opt)
186 {
187 	struct nci_set_config_param *param = (struct nci_set_config_param *)opt;
188 	struct nci_core_set_config_cmd cmd;
189 
190 	BUG_ON(param->len > NCI_MAX_PARAM_LEN);
191 
192 	cmd.num_params = 1;
193 	cmd.param.id = param->id;
194 	cmd.param.len = param->len;
195 	memcpy(cmd.param.val, param->val, param->len);
196 
197 	nci_send_cmd(ndev, NCI_OP_CORE_SET_CONFIG_CMD, (3 + param->len), &cmd);
198 }
199 
200 static void nci_rf_discover_req(struct nci_dev *ndev, unsigned long opt)
201 {
202 	struct nci_rf_disc_cmd cmd;
203 	__u32 protocols = opt;
204 
205 	cmd.num_disc_configs = 0;
206 
207 	if ((cmd.num_disc_configs < NCI_MAX_NUM_RF_CONFIGS) &&
208 	    (protocols & NFC_PROTO_JEWEL_MASK ||
209 	     protocols & NFC_PROTO_MIFARE_MASK ||
210 	     protocols & NFC_PROTO_ISO14443_MASK ||
211 	     protocols & NFC_PROTO_NFC_DEP_MASK)) {
212 		cmd.disc_configs[cmd.num_disc_configs].rf_tech_and_mode =
213 			NCI_NFC_A_PASSIVE_POLL_MODE;
214 		cmd.disc_configs[cmd.num_disc_configs].frequency = 1;
215 		cmd.num_disc_configs++;
216 	}
217 
218 	if ((cmd.num_disc_configs < NCI_MAX_NUM_RF_CONFIGS) &&
219 	    (protocols & NFC_PROTO_ISO14443_B_MASK)) {
220 		cmd.disc_configs[cmd.num_disc_configs].rf_tech_and_mode =
221 			NCI_NFC_B_PASSIVE_POLL_MODE;
222 		cmd.disc_configs[cmd.num_disc_configs].frequency = 1;
223 		cmd.num_disc_configs++;
224 	}
225 
226 	if ((cmd.num_disc_configs < NCI_MAX_NUM_RF_CONFIGS) &&
227 	    (protocols & NFC_PROTO_FELICA_MASK ||
228 	     protocols & NFC_PROTO_NFC_DEP_MASK)) {
229 		cmd.disc_configs[cmd.num_disc_configs].rf_tech_and_mode =
230 			NCI_NFC_F_PASSIVE_POLL_MODE;
231 		cmd.disc_configs[cmd.num_disc_configs].frequency = 1;
232 		cmd.num_disc_configs++;
233 	}
234 
235 	nci_send_cmd(ndev, NCI_OP_RF_DISCOVER_CMD,
236 		     (1 + (cmd.num_disc_configs * sizeof(struct disc_config))),
237 		     &cmd);
238 }
239 
240 struct nci_rf_discover_select_param {
241 	__u8	rf_discovery_id;
242 	__u8	rf_protocol;
243 };
244 
245 static void nci_rf_discover_select_req(struct nci_dev *ndev, unsigned long opt)
246 {
247 	struct nci_rf_discover_select_param *param =
248 		(struct nci_rf_discover_select_param *)opt;
249 	struct nci_rf_discover_select_cmd cmd;
250 
251 	cmd.rf_discovery_id = param->rf_discovery_id;
252 	cmd.rf_protocol = param->rf_protocol;
253 
254 	switch (cmd.rf_protocol) {
255 	case NCI_RF_PROTOCOL_ISO_DEP:
256 		cmd.rf_interface = NCI_RF_INTERFACE_ISO_DEP;
257 		break;
258 
259 	case NCI_RF_PROTOCOL_NFC_DEP:
260 		cmd.rf_interface = NCI_RF_INTERFACE_NFC_DEP;
261 		break;
262 
263 	default:
264 		cmd.rf_interface = NCI_RF_INTERFACE_FRAME;
265 		break;
266 	}
267 
268 	nci_send_cmd(ndev, NCI_OP_RF_DISCOVER_SELECT_CMD,
269 		     sizeof(struct nci_rf_discover_select_cmd), &cmd);
270 }
271 
272 static void nci_rf_deactivate_req(struct nci_dev *ndev, unsigned long opt)
273 {
274 	struct nci_rf_deactivate_cmd cmd;
275 
276 	cmd.type = NCI_DEACTIVATE_TYPE_IDLE_MODE;
277 
278 	nci_send_cmd(ndev, NCI_OP_RF_DEACTIVATE_CMD,
279 		     sizeof(struct nci_rf_deactivate_cmd), &cmd);
280 }
281 
282 static int nci_open_device(struct nci_dev *ndev)
283 {
284 	int rc = 0;
285 
286 	mutex_lock(&ndev->req_lock);
287 
288 	if (test_bit(NCI_UP, &ndev->flags)) {
289 		rc = -EALREADY;
290 		goto done;
291 	}
292 
293 	if (ndev->ops->open(ndev)) {
294 		rc = -EIO;
295 		goto done;
296 	}
297 
298 	atomic_set(&ndev->cmd_cnt, 1);
299 
300 	set_bit(NCI_INIT, &ndev->flags);
301 
302 	rc = __nci_request(ndev, nci_reset_req, 0,
303 			   msecs_to_jiffies(NCI_RESET_TIMEOUT));
304 
305 	if (!rc) {
306 		rc = __nci_request(ndev, nci_init_req, 0,
307 				   msecs_to_jiffies(NCI_INIT_TIMEOUT));
308 	}
309 
310 	if (!rc) {
311 		rc = __nci_request(ndev, nci_init_complete_req, 0,
312 				   msecs_to_jiffies(NCI_INIT_TIMEOUT));
313 	}
314 
315 	clear_bit(NCI_INIT, &ndev->flags);
316 
317 	if (!rc) {
318 		set_bit(NCI_UP, &ndev->flags);
319 		nci_clear_target_list(ndev);
320 		atomic_set(&ndev->state, NCI_IDLE);
321 	} else {
322 		/* Init failed, cleanup */
323 		skb_queue_purge(&ndev->cmd_q);
324 		skb_queue_purge(&ndev->rx_q);
325 		skb_queue_purge(&ndev->tx_q);
326 
327 		ndev->ops->close(ndev);
328 		ndev->flags = 0;
329 	}
330 
331 done:
332 	mutex_unlock(&ndev->req_lock);
333 	return rc;
334 }
335 
336 static int nci_close_device(struct nci_dev *ndev)
337 {
338 	nci_req_cancel(ndev, ENODEV);
339 	mutex_lock(&ndev->req_lock);
340 
341 	if (!test_and_clear_bit(NCI_UP, &ndev->flags)) {
342 		del_timer_sync(&ndev->cmd_timer);
343 		del_timer_sync(&ndev->data_timer);
344 		mutex_unlock(&ndev->req_lock);
345 		return 0;
346 	}
347 
348 	/* Drop RX and TX queues */
349 	skb_queue_purge(&ndev->rx_q);
350 	skb_queue_purge(&ndev->tx_q);
351 
352 	/* Flush RX and TX wq */
353 	flush_workqueue(ndev->rx_wq);
354 	flush_workqueue(ndev->tx_wq);
355 
356 	/* Reset device */
357 	skb_queue_purge(&ndev->cmd_q);
358 	atomic_set(&ndev->cmd_cnt, 1);
359 
360 	set_bit(NCI_INIT, &ndev->flags);
361 	__nci_request(ndev, nci_reset_req, 0,
362 		      msecs_to_jiffies(NCI_RESET_TIMEOUT));
363 	clear_bit(NCI_INIT, &ndev->flags);
364 
365 	/* Flush cmd wq */
366 	flush_workqueue(ndev->cmd_wq);
367 
368 	/* After this point our queues are empty
369 	 * and no works are scheduled. */
370 	ndev->ops->close(ndev);
371 
372 	/* Clear flags */
373 	ndev->flags = 0;
374 
375 	mutex_unlock(&ndev->req_lock);
376 
377 	return 0;
378 }
379 
380 /* NCI command timer function */
381 static void nci_cmd_timer(unsigned long arg)
382 {
383 	struct nci_dev *ndev = (void *) arg;
384 
385 	atomic_set(&ndev->cmd_cnt, 1);
386 	queue_work(ndev->cmd_wq, &ndev->cmd_work);
387 }
388 
389 /* NCI data exchange timer function */
390 static void nci_data_timer(unsigned long arg)
391 {
392 	struct nci_dev *ndev = (void *) arg;
393 
394 	set_bit(NCI_DATA_EXCHANGE_TO, &ndev->flags);
395 	queue_work(ndev->rx_wq, &ndev->rx_work);
396 }
397 
398 static int nci_dev_up(struct nfc_dev *nfc_dev)
399 {
400 	struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
401 
402 	return nci_open_device(ndev);
403 }
404 
405 static int nci_dev_down(struct nfc_dev *nfc_dev)
406 {
407 	struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
408 
409 	return nci_close_device(ndev);
410 }
411 
412 static int nci_set_local_general_bytes(struct nfc_dev *nfc_dev)
413 {
414 	struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
415 	struct nci_set_config_param param;
416 	__u8 local_gb[NFC_MAX_GT_LEN];
417 	int i;
418 
419 	param.val = nfc_get_local_general_bytes(nfc_dev, &param.len);
420 	if ((param.val == NULL) || (param.len == 0))
421 		return 0;
422 
423 	if (param.len > NFC_MAX_GT_LEN)
424 		return -EINVAL;
425 
426 	for (i = 0; i < param.len; i++)
427 		local_gb[param.len-1-i] = param.val[i];
428 
429 	param.id = NCI_PN_ATR_REQ_GEN_BYTES;
430 	param.val = local_gb;
431 
432 	return nci_request(ndev, nci_set_config_req, (unsigned long)&param,
433 			   msecs_to_jiffies(NCI_SET_CONFIG_TIMEOUT));
434 }
435 
436 static int nci_start_poll(struct nfc_dev *nfc_dev,
437 			  __u32 im_protocols, __u32 tm_protocols)
438 {
439 	struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
440 	int rc;
441 
442 	if ((atomic_read(&ndev->state) == NCI_DISCOVERY) ||
443 	    (atomic_read(&ndev->state) == NCI_W4_ALL_DISCOVERIES)) {
444 		pr_err("unable to start poll, since poll is already active\n");
445 		return -EBUSY;
446 	}
447 
448 	if (ndev->target_active_prot) {
449 		pr_err("there is an active target\n");
450 		return -EBUSY;
451 	}
452 
453 	if ((atomic_read(&ndev->state) == NCI_W4_HOST_SELECT) ||
454 	    (atomic_read(&ndev->state) == NCI_POLL_ACTIVE)) {
455 		pr_debug("target active or w4 select, implicitly deactivate\n");
456 
457 		rc = nci_request(ndev, nci_rf_deactivate_req, 0,
458 				 msecs_to_jiffies(NCI_RF_DEACTIVATE_TIMEOUT));
459 		if (rc)
460 			return -EBUSY;
461 	}
462 
463 	if (im_protocols & NFC_PROTO_NFC_DEP_MASK) {
464 		rc = nci_set_local_general_bytes(nfc_dev);
465 		if (rc) {
466 			pr_err("failed to set local general bytes\n");
467 			return rc;
468 		}
469 	}
470 
471 	rc = nci_request(ndev, nci_rf_discover_req, im_protocols,
472 			 msecs_to_jiffies(NCI_RF_DISC_TIMEOUT));
473 
474 	if (!rc)
475 		ndev->poll_prots = im_protocols;
476 
477 	return rc;
478 }
479 
480 static void nci_stop_poll(struct nfc_dev *nfc_dev)
481 {
482 	struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
483 
484 	if ((atomic_read(&ndev->state) != NCI_DISCOVERY) &&
485 	    (atomic_read(&ndev->state) != NCI_W4_ALL_DISCOVERIES)) {
486 		pr_err("unable to stop poll, since poll is not active\n");
487 		return;
488 	}
489 
490 	nci_request(ndev, nci_rf_deactivate_req, 0,
491 		    msecs_to_jiffies(NCI_RF_DEACTIVATE_TIMEOUT));
492 }
493 
494 static int nci_activate_target(struct nfc_dev *nfc_dev,
495 			       struct nfc_target *target, __u32 protocol)
496 {
497 	struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
498 	struct nci_rf_discover_select_param param;
499 	struct nfc_target *nci_target = NULL;
500 	int i;
501 	int rc = 0;
502 
503 	pr_debug("target_idx %d, protocol 0x%x\n", target->idx, protocol);
504 
505 	if ((atomic_read(&ndev->state) != NCI_W4_HOST_SELECT) &&
506 	    (atomic_read(&ndev->state) != NCI_POLL_ACTIVE)) {
507 		pr_err("there is no available target to activate\n");
508 		return -EINVAL;
509 	}
510 
511 	if (ndev->target_active_prot) {
512 		pr_err("there is already an active target\n");
513 		return -EBUSY;
514 	}
515 
516 	for (i = 0; i < ndev->n_targets; i++) {
517 		if (ndev->targets[i].idx == target->idx) {
518 			nci_target = &ndev->targets[i];
519 			break;
520 		}
521 	}
522 
523 	if (!nci_target) {
524 		pr_err("unable to find the selected target\n");
525 		return -EINVAL;
526 	}
527 
528 	if (!(nci_target->supported_protocols & (1 << protocol))) {
529 		pr_err("target does not support the requested protocol 0x%x\n",
530 		       protocol);
531 		return -EINVAL;
532 	}
533 
534 	if (atomic_read(&ndev->state) == NCI_W4_HOST_SELECT) {
535 		param.rf_discovery_id = nci_target->logical_idx;
536 
537 		if (protocol == NFC_PROTO_JEWEL)
538 			param.rf_protocol = NCI_RF_PROTOCOL_T1T;
539 		else if (protocol == NFC_PROTO_MIFARE)
540 			param.rf_protocol = NCI_RF_PROTOCOL_T2T;
541 		else if (protocol == NFC_PROTO_FELICA)
542 			param.rf_protocol = NCI_RF_PROTOCOL_T3T;
543 		else if (protocol == NFC_PROTO_ISO14443 ||
544 			 protocol == NFC_PROTO_ISO14443_B)
545 			param.rf_protocol = NCI_RF_PROTOCOL_ISO_DEP;
546 		else
547 			param.rf_protocol = NCI_RF_PROTOCOL_NFC_DEP;
548 
549 		rc = nci_request(ndev, nci_rf_discover_select_req,
550 				 (unsigned long)&param,
551 				 msecs_to_jiffies(NCI_RF_DISC_SELECT_TIMEOUT));
552 	}
553 
554 	if (!rc)
555 		ndev->target_active_prot = protocol;
556 
557 	return rc;
558 }
559 
560 static void nci_deactivate_target(struct nfc_dev *nfc_dev,
561 				  struct nfc_target *target)
562 {
563 	struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
564 
565 	pr_debug("entry\n");
566 
567 	if (!ndev->target_active_prot) {
568 		pr_err("unable to deactivate target, no active target\n");
569 		return;
570 	}
571 
572 	ndev->target_active_prot = 0;
573 
574 	if (atomic_read(&ndev->state) == NCI_POLL_ACTIVE) {
575 		nci_request(ndev, nci_rf_deactivate_req, 0,
576 			    msecs_to_jiffies(NCI_RF_DEACTIVATE_TIMEOUT));
577 	}
578 }
579 
580 static int nci_dep_link_up(struct nfc_dev *nfc_dev, struct nfc_target *target,
581 			   __u8 comm_mode, __u8 *gb, size_t gb_len)
582 {
583 	struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
584 	int rc;
585 
586 	pr_debug("target_idx %d, comm_mode %d\n", target->idx, comm_mode);
587 
588 	rc = nci_activate_target(nfc_dev, target, NFC_PROTO_NFC_DEP);
589 	if (rc)
590 		return rc;
591 
592 	rc = nfc_set_remote_general_bytes(nfc_dev, ndev->remote_gb,
593 					  ndev->remote_gb_len);
594 	if (!rc)
595 		rc = nfc_dep_link_is_up(nfc_dev, target->idx, NFC_COMM_PASSIVE,
596 					NFC_RF_INITIATOR);
597 
598 	return rc;
599 }
600 
601 static int nci_dep_link_down(struct nfc_dev *nfc_dev)
602 {
603 	pr_debug("entry\n");
604 
605 	nci_deactivate_target(nfc_dev, NULL);
606 
607 	return 0;
608 }
609 
610 
611 static int nci_transceive(struct nfc_dev *nfc_dev, struct nfc_target *target,
612 			  struct sk_buff *skb,
613 			  data_exchange_cb_t cb, void *cb_context)
614 {
615 	struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
616 	int rc;
617 
618 	pr_debug("target_idx %d, len %d\n", target->idx, skb->len);
619 
620 	if (!ndev->target_active_prot) {
621 		pr_err("unable to exchange data, no active target\n");
622 		return -EINVAL;
623 	}
624 
625 	if (test_and_set_bit(NCI_DATA_EXCHANGE, &ndev->flags))
626 		return -EBUSY;
627 
628 	/* store cb and context to be used on receiving data */
629 	ndev->data_exchange_cb = cb;
630 	ndev->data_exchange_cb_context = cb_context;
631 
632 	rc = nci_send_data(ndev, NCI_STATIC_RF_CONN_ID, skb);
633 	if (rc)
634 		clear_bit(NCI_DATA_EXCHANGE, &ndev->flags);
635 
636 	return rc;
637 }
638 
639 static struct nfc_ops nci_nfc_ops = {
640 	.dev_up = nci_dev_up,
641 	.dev_down = nci_dev_down,
642 	.start_poll = nci_start_poll,
643 	.stop_poll = nci_stop_poll,
644 	.dep_link_up = nci_dep_link_up,
645 	.dep_link_down = nci_dep_link_down,
646 	.activate_target = nci_activate_target,
647 	.deactivate_target = nci_deactivate_target,
648 	.im_transceive = nci_transceive,
649 };
650 
651 /* ---- Interface to NCI drivers ---- */
652 
653 /**
654  * nci_allocate_device - allocate a new nci device
655  *
656  * @ops: device operations
657  * @supported_protocols: NFC protocols supported by the device
658  */
659 struct nci_dev *nci_allocate_device(struct nci_ops *ops,
660 				    __u32 supported_protocols,
661 				    int tx_headroom, int tx_tailroom)
662 {
663 	struct nci_dev *ndev;
664 
665 	pr_debug("supported_protocols 0x%x\n", supported_protocols);
666 
667 	if (!ops->open || !ops->close || !ops->send)
668 		return NULL;
669 
670 	if (!supported_protocols)
671 		return NULL;
672 
673 	ndev = kzalloc(sizeof(struct nci_dev), GFP_KERNEL);
674 	if (!ndev)
675 		return NULL;
676 
677 	ndev->ops = ops;
678 	ndev->tx_headroom = tx_headroom;
679 	ndev->tx_tailroom = tx_tailroom;
680 
681 	ndev->nfc_dev = nfc_allocate_device(&nci_nfc_ops,
682 					    supported_protocols,
683 					    tx_headroom + NCI_DATA_HDR_SIZE,
684 					    tx_tailroom);
685 	if (!ndev->nfc_dev)
686 		goto free_exit;
687 
688 	nfc_set_drvdata(ndev->nfc_dev, ndev);
689 
690 	return ndev;
691 
692 free_exit:
693 	kfree(ndev);
694 	return NULL;
695 }
696 EXPORT_SYMBOL(nci_allocate_device);
697 
698 /**
699  * nci_free_device - deallocate nci device
700  *
701  * @ndev: The nci device to deallocate
702  */
703 void nci_free_device(struct nci_dev *ndev)
704 {
705 	nfc_free_device(ndev->nfc_dev);
706 	kfree(ndev);
707 }
708 EXPORT_SYMBOL(nci_free_device);
709 
710 /**
711  * nci_register_device - register a nci device in the nfc subsystem
712  *
713  * @dev: The nci device to register
714  */
715 int nci_register_device(struct nci_dev *ndev)
716 {
717 	int rc;
718 	struct device *dev = &ndev->nfc_dev->dev;
719 	char name[32];
720 
721 	rc = nfc_register_device(ndev->nfc_dev);
722 	if (rc)
723 		goto exit;
724 
725 	ndev->flags = 0;
726 
727 	INIT_WORK(&ndev->cmd_work, nci_cmd_work);
728 	snprintf(name, sizeof(name), "%s_nci_cmd_wq", dev_name(dev));
729 	ndev->cmd_wq = create_singlethread_workqueue(name);
730 	if (!ndev->cmd_wq) {
731 		rc = -ENOMEM;
732 		goto unreg_exit;
733 	}
734 
735 	INIT_WORK(&ndev->rx_work, nci_rx_work);
736 	snprintf(name, sizeof(name), "%s_nci_rx_wq", dev_name(dev));
737 	ndev->rx_wq = create_singlethread_workqueue(name);
738 	if (!ndev->rx_wq) {
739 		rc = -ENOMEM;
740 		goto destroy_cmd_wq_exit;
741 	}
742 
743 	INIT_WORK(&ndev->tx_work, nci_tx_work);
744 	snprintf(name, sizeof(name), "%s_nci_tx_wq", dev_name(dev));
745 	ndev->tx_wq = create_singlethread_workqueue(name);
746 	if (!ndev->tx_wq) {
747 		rc = -ENOMEM;
748 		goto destroy_rx_wq_exit;
749 	}
750 
751 	skb_queue_head_init(&ndev->cmd_q);
752 	skb_queue_head_init(&ndev->rx_q);
753 	skb_queue_head_init(&ndev->tx_q);
754 
755 	setup_timer(&ndev->cmd_timer, nci_cmd_timer,
756 		    (unsigned long) ndev);
757 	setup_timer(&ndev->data_timer, nci_data_timer,
758 		    (unsigned long) ndev);
759 
760 	mutex_init(&ndev->req_lock);
761 
762 	goto exit;
763 
764 destroy_rx_wq_exit:
765 	destroy_workqueue(ndev->rx_wq);
766 
767 destroy_cmd_wq_exit:
768 	destroy_workqueue(ndev->cmd_wq);
769 
770 unreg_exit:
771 	nfc_unregister_device(ndev->nfc_dev);
772 
773 exit:
774 	return rc;
775 }
776 EXPORT_SYMBOL(nci_register_device);
777 
778 /**
779  * nci_unregister_device - unregister a nci device in the nfc subsystem
780  *
781  * @dev: The nci device to unregister
782  */
783 void nci_unregister_device(struct nci_dev *ndev)
784 {
785 	nci_close_device(ndev);
786 
787 	destroy_workqueue(ndev->cmd_wq);
788 	destroy_workqueue(ndev->rx_wq);
789 	destroy_workqueue(ndev->tx_wq);
790 
791 	nfc_unregister_device(ndev->nfc_dev);
792 }
793 EXPORT_SYMBOL(nci_unregister_device);
794 
795 /**
796  * nci_recv_frame - receive frame from NCI drivers
797  *
798  * @skb: The sk_buff to receive
799  */
800 int nci_recv_frame(struct sk_buff *skb)
801 {
802 	struct nci_dev *ndev = (struct nci_dev *) skb->dev;
803 
804 	pr_debug("len %d\n", skb->len);
805 
806 	if (!ndev || (!test_bit(NCI_UP, &ndev->flags) &&
807 	    !test_bit(NCI_INIT, &ndev->flags))) {
808 		kfree_skb(skb);
809 		return -ENXIO;
810 	}
811 
812 	/* Queue frame for rx worker thread */
813 	skb_queue_tail(&ndev->rx_q, skb);
814 	queue_work(ndev->rx_wq, &ndev->rx_work);
815 
816 	return 0;
817 }
818 EXPORT_SYMBOL(nci_recv_frame);
819 
820 static int nci_send_frame(struct sk_buff *skb)
821 {
822 	struct nci_dev *ndev = (struct nci_dev *) skb->dev;
823 
824 	pr_debug("len %d\n", skb->len);
825 
826 	if (!ndev) {
827 		kfree_skb(skb);
828 		return -ENODEV;
829 	}
830 
831 	/* Get rid of skb owner, prior to sending to the driver. */
832 	skb_orphan(skb);
833 
834 	return ndev->ops->send(skb);
835 }
836 
837 /* Send NCI command */
838 int nci_send_cmd(struct nci_dev *ndev, __u16 opcode, __u8 plen, void *payload)
839 {
840 	struct nci_ctrl_hdr *hdr;
841 	struct sk_buff *skb;
842 
843 	pr_debug("opcode 0x%x, plen %d\n", opcode, plen);
844 
845 	skb = nci_skb_alloc(ndev, (NCI_CTRL_HDR_SIZE + plen), GFP_KERNEL);
846 	if (!skb) {
847 		pr_err("no memory for command\n");
848 		return -ENOMEM;
849 	}
850 
851 	hdr = (struct nci_ctrl_hdr *) skb_put(skb, NCI_CTRL_HDR_SIZE);
852 	hdr->gid = nci_opcode_gid(opcode);
853 	hdr->oid = nci_opcode_oid(opcode);
854 	hdr->plen = plen;
855 
856 	nci_mt_set((__u8 *)hdr, NCI_MT_CMD_PKT);
857 	nci_pbf_set((__u8 *)hdr, NCI_PBF_LAST);
858 
859 	if (plen)
860 		memcpy(skb_put(skb, plen), payload, plen);
861 
862 	skb->dev = (void *) ndev;
863 
864 	skb_queue_tail(&ndev->cmd_q, skb);
865 	queue_work(ndev->cmd_wq, &ndev->cmd_work);
866 
867 	return 0;
868 }
869 
870 /* ---- NCI TX Data worker thread ---- */
871 
872 static void nci_tx_work(struct work_struct *work)
873 {
874 	struct nci_dev *ndev = container_of(work, struct nci_dev, tx_work);
875 	struct sk_buff *skb;
876 
877 	pr_debug("credits_cnt %d\n", atomic_read(&ndev->credits_cnt));
878 
879 	/* Send queued tx data */
880 	while (atomic_read(&ndev->credits_cnt)) {
881 		skb = skb_dequeue(&ndev->tx_q);
882 		if (!skb)
883 			return;
884 
885 		/* Check if data flow control is used */
886 		if (atomic_read(&ndev->credits_cnt) !=
887 		    NCI_DATA_FLOW_CONTROL_NOT_USED)
888 			atomic_dec(&ndev->credits_cnt);
889 
890 		pr_debug("NCI TX: MT=data, PBF=%d, conn_id=%d, plen=%d\n",
891 			 nci_pbf(skb->data),
892 			 nci_conn_id(skb->data),
893 			 nci_plen(skb->data));
894 
895 		nci_send_frame(skb);
896 
897 		mod_timer(&ndev->data_timer,
898 			  jiffies + msecs_to_jiffies(NCI_DATA_TIMEOUT));
899 	}
900 }
901 
902 /* ----- NCI RX worker thread (data & control) ----- */
903 
904 static void nci_rx_work(struct work_struct *work)
905 {
906 	struct nci_dev *ndev = container_of(work, struct nci_dev, rx_work);
907 	struct sk_buff *skb;
908 
909 	while ((skb = skb_dequeue(&ndev->rx_q))) {
910 		/* Process frame */
911 		switch (nci_mt(skb->data)) {
912 		case NCI_MT_RSP_PKT:
913 			nci_rsp_packet(ndev, skb);
914 			break;
915 
916 		case NCI_MT_NTF_PKT:
917 			nci_ntf_packet(ndev, skb);
918 			break;
919 
920 		case NCI_MT_DATA_PKT:
921 			nci_rx_data_packet(ndev, skb);
922 			break;
923 
924 		default:
925 			pr_err("unknown MT 0x%x\n", nci_mt(skb->data));
926 			kfree_skb(skb);
927 			break;
928 		}
929 	}
930 
931 	/* check if a data exchange timout has occurred */
932 	if (test_bit(NCI_DATA_EXCHANGE_TO, &ndev->flags)) {
933 		/* complete the data exchange transaction, if exists */
934 		if (test_bit(NCI_DATA_EXCHANGE, &ndev->flags))
935 			nci_data_exchange_complete(ndev, NULL, -ETIMEDOUT);
936 
937 		clear_bit(NCI_DATA_EXCHANGE_TO, &ndev->flags);
938 	}
939 }
940 
941 /* ----- NCI TX CMD worker thread ----- */
942 
943 static void nci_cmd_work(struct work_struct *work)
944 {
945 	struct nci_dev *ndev = container_of(work, struct nci_dev, cmd_work);
946 	struct sk_buff *skb;
947 
948 	pr_debug("cmd_cnt %d\n", atomic_read(&ndev->cmd_cnt));
949 
950 	/* Send queued command */
951 	if (atomic_read(&ndev->cmd_cnt)) {
952 		skb = skb_dequeue(&ndev->cmd_q);
953 		if (!skb)
954 			return;
955 
956 		atomic_dec(&ndev->cmd_cnt);
957 
958 		pr_debug("NCI TX: MT=cmd, PBF=%d, GID=0x%x, OID=0x%x, plen=%d\n",
959 			 nci_pbf(skb->data),
960 			 nci_opcode_gid(nci_opcode(skb->data)),
961 			 nci_opcode_oid(nci_opcode(skb->data)),
962 			 nci_plen(skb->data));
963 
964 		nci_send_frame(skb);
965 
966 		mod_timer(&ndev->cmd_timer,
967 			  jiffies + msecs_to_jiffies(NCI_CMD_TIMEOUT));
968 	}
969 }
970 
971 MODULE_LICENSE("GPL");
972