xref: /openbmc/linux/net/nfc/nci/core.c (revision 767f19ae)
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, rc = 0;
418 
419 	param.val = nfc_get_local_general_bytes(nfc_dev, &param.len);
420 	if ((param.val == NULL) || (param.len == 0))
421 		return rc;
422 
423 	if (param.len > NCI_MAX_PARAM_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 	rc = nci_request(ndev, nci_set_config_req, (unsigned long)&param,
433 			 msecs_to_jiffies(NCI_SET_CONFIG_TIMEOUT));
434 
435 	return rc;
436 }
437 
438 static int nci_start_poll(struct nfc_dev *nfc_dev,
439 			  __u32 im_protocols, __u32 tm_protocols)
440 {
441 	struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
442 	int rc;
443 
444 	if ((atomic_read(&ndev->state) == NCI_DISCOVERY) ||
445 	    (atomic_read(&ndev->state) == NCI_W4_ALL_DISCOVERIES)) {
446 		pr_err("unable to start poll, since poll is already active\n");
447 		return -EBUSY;
448 	}
449 
450 	if (ndev->target_active_prot) {
451 		pr_err("there is an active target\n");
452 		return -EBUSY;
453 	}
454 
455 	if ((atomic_read(&ndev->state) == NCI_W4_HOST_SELECT) ||
456 	    (atomic_read(&ndev->state) == NCI_POLL_ACTIVE)) {
457 		pr_debug("target active or w4 select, implicitly deactivate\n");
458 
459 		rc = nci_request(ndev, nci_rf_deactivate_req, 0,
460 				 msecs_to_jiffies(NCI_RF_DEACTIVATE_TIMEOUT));
461 		if (rc)
462 			return -EBUSY;
463 	}
464 
465 	if (im_protocols & NFC_PROTO_NFC_DEP_MASK) {
466 		rc = nci_set_local_general_bytes(nfc_dev);
467 		if (rc) {
468 			pr_err("failed to set local general bytes\n");
469 			return rc;
470 		}
471 	}
472 
473 	rc = nci_request(ndev, nci_rf_discover_req, im_protocols,
474 			 msecs_to_jiffies(NCI_RF_DISC_TIMEOUT));
475 
476 	if (!rc)
477 		ndev->poll_prots = im_protocols;
478 
479 	return rc;
480 }
481 
482 static void nci_stop_poll(struct nfc_dev *nfc_dev)
483 {
484 	struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
485 
486 	if ((atomic_read(&ndev->state) != NCI_DISCOVERY) &&
487 	    (atomic_read(&ndev->state) != NCI_W4_ALL_DISCOVERIES)) {
488 		pr_err("unable to stop poll, since poll is not active\n");
489 		return;
490 	}
491 
492 	nci_request(ndev, nci_rf_deactivate_req, 0,
493 		    msecs_to_jiffies(NCI_RF_DEACTIVATE_TIMEOUT));
494 }
495 
496 static int nci_activate_target(struct nfc_dev *nfc_dev,
497 			       struct nfc_target *target, __u32 protocol)
498 {
499 	struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
500 	struct nci_rf_discover_select_param param;
501 	struct nfc_target *nci_target = NULL;
502 	int i;
503 	int rc = 0;
504 
505 	pr_debug("target_idx %d, protocol 0x%x\n", target->idx, protocol);
506 
507 	if ((atomic_read(&ndev->state) != NCI_W4_HOST_SELECT) &&
508 	    (atomic_read(&ndev->state) != NCI_POLL_ACTIVE)) {
509 		pr_err("there is no available target to activate\n");
510 		return -EINVAL;
511 	}
512 
513 	if (ndev->target_active_prot) {
514 		pr_err("there is already an active target\n");
515 		return -EBUSY;
516 	}
517 
518 	for (i = 0; i < ndev->n_targets; i++) {
519 		if (ndev->targets[i].idx == target->idx) {
520 			nci_target = &ndev->targets[i];
521 			break;
522 		}
523 	}
524 
525 	if (!nci_target) {
526 		pr_err("unable to find the selected target\n");
527 		return -EINVAL;
528 	}
529 
530 	if (!(nci_target->supported_protocols & (1 << protocol))) {
531 		pr_err("target does not support the requested protocol 0x%x\n",
532 		       protocol);
533 		return -EINVAL;
534 	}
535 
536 	if (atomic_read(&ndev->state) == NCI_W4_HOST_SELECT) {
537 		param.rf_discovery_id = nci_target->logical_idx;
538 
539 		if (protocol == NFC_PROTO_JEWEL)
540 			param.rf_protocol = NCI_RF_PROTOCOL_T1T;
541 		else if (protocol == NFC_PROTO_MIFARE)
542 			param.rf_protocol = NCI_RF_PROTOCOL_T2T;
543 		else if (protocol == NFC_PROTO_FELICA)
544 			param.rf_protocol = NCI_RF_PROTOCOL_T3T;
545 		else if (protocol == NFC_PROTO_ISO14443 ||
546 			 protocol == NFC_PROTO_ISO14443_B)
547 			param.rf_protocol = NCI_RF_PROTOCOL_ISO_DEP;
548 		else
549 			param.rf_protocol = NCI_RF_PROTOCOL_NFC_DEP;
550 
551 		rc = nci_request(ndev, nci_rf_discover_select_req,
552 				 (unsigned long)&param,
553 				 msecs_to_jiffies(NCI_RF_DISC_SELECT_TIMEOUT));
554 	}
555 
556 	if (!rc)
557 		ndev->target_active_prot = protocol;
558 
559 	return rc;
560 }
561 
562 static void nci_deactivate_target(struct nfc_dev *nfc_dev,
563 				  struct nfc_target *target)
564 {
565 	struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
566 
567 	pr_debug("entry\n");
568 
569 	if (!ndev->target_active_prot) {
570 		pr_err("unable to deactivate target, no active target\n");
571 		return;
572 	}
573 
574 	ndev->target_active_prot = 0;
575 
576 	if (atomic_read(&ndev->state) == NCI_POLL_ACTIVE) {
577 		nci_request(ndev, nci_rf_deactivate_req, 0,
578 			    msecs_to_jiffies(NCI_RF_DEACTIVATE_TIMEOUT));
579 	}
580 }
581 
582 
583 static int nci_dep_link_up(struct nfc_dev *nfc_dev, struct nfc_target *target,
584 			   __u8 comm_mode, __u8 *gb, size_t gb_len)
585 {
586 	struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
587 	int rc;
588 
589 	pr_debug("target_idx %d, comm_mode %d\n", target->idx, comm_mode);
590 
591 	rc = nci_activate_target(nfc_dev, target, NFC_PROTO_NFC_DEP);
592 	if (rc)
593 		return rc;
594 
595 	rc = nfc_set_remote_general_bytes(nfc_dev, ndev->remote_gb,
596 					  ndev->remote_gb_len);
597 	if (!rc)
598 		rc = nfc_dep_link_is_up(nfc_dev, target->idx, NFC_COMM_PASSIVE,
599 					NFC_RF_INITIATOR);
600 
601 	return rc;
602 }
603 
604 static int nci_dep_link_down(struct nfc_dev *nfc_dev)
605 {
606 	pr_debug("entry\n");
607 
608 	nci_deactivate_target(nfc_dev, NULL);
609 
610 	return 0;
611 }
612 
613 
614 static int nci_transceive(struct nfc_dev *nfc_dev, struct nfc_target *target,
615 			  struct sk_buff *skb,
616 			  data_exchange_cb_t cb, void *cb_context)
617 {
618 	struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
619 	int rc;
620 
621 	pr_debug("target_idx %d, len %d\n", target->idx, skb->len);
622 
623 	if (!ndev->target_active_prot) {
624 		pr_err("unable to exchange data, no active target\n");
625 		return -EINVAL;
626 	}
627 
628 	if (test_and_set_bit(NCI_DATA_EXCHANGE, &ndev->flags))
629 		return -EBUSY;
630 
631 	/* store cb and context to be used on receiving data */
632 	ndev->data_exchange_cb = cb;
633 	ndev->data_exchange_cb_context = cb_context;
634 
635 	rc = nci_send_data(ndev, NCI_STATIC_RF_CONN_ID, skb);
636 	if (rc)
637 		clear_bit(NCI_DATA_EXCHANGE, &ndev->flags);
638 
639 	return rc;
640 }
641 
642 static struct nfc_ops nci_nfc_ops = {
643 	.dev_up = nci_dev_up,
644 	.dev_down = nci_dev_down,
645 	.start_poll = nci_start_poll,
646 	.stop_poll = nci_stop_poll,
647 	.dep_link_up = nci_dep_link_up,
648 	.dep_link_down = nci_dep_link_down,
649 	.activate_target = nci_activate_target,
650 	.deactivate_target = nci_deactivate_target,
651 	.im_transceive = nci_transceive,
652 };
653 
654 /* ---- Interface to NCI drivers ---- */
655 
656 /**
657  * nci_allocate_device - allocate a new nci device
658  *
659  * @ops: device operations
660  * @supported_protocols: NFC protocols supported by the device
661  */
662 struct nci_dev *nci_allocate_device(struct nci_ops *ops,
663 				    __u32 supported_protocols,
664 				    int tx_headroom, int tx_tailroom)
665 {
666 	struct nci_dev *ndev;
667 
668 	pr_debug("supported_protocols 0x%x\n", supported_protocols);
669 
670 	if (!ops->open || !ops->close || !ops->send)
671 		return NULL;
672 
673 	if (!supported_protocols)
674 		return NULL;
675 
676 	ndev = kzalloc(sizeof(struct nci_dev), GFP_KERNEL);
677 	if (!ndev)
678 		return NULL;
679 
680 	ndev->ops = ops;
681 	ndev->tx_headroom = tx_headroom;
682 	ndev->tx_tailroom = tx_tailroom;
683 
684 	ndev->nfc_dev = nfc_allocate_device(&nci_nfc_ops,
685 					    supported_protocols,
686 					    tx_headroom + NCI_DATA_HDR_SIZE,
687 					    tx_tailroom);
688 	if (!ndev->nfc_dev)
689 		goto free_exit;
690 
691 	nfc_set_drvdata(ndev->nfc_dev, ndev);
692 
693 	return ndev;
694 
695 free_exit:
696 	kfree(ndev);
697 	return NULL;
698 }
699 EXPORT_SYMBOL(nci_allocate_device);
700 
701 /**
702  * nci_free_device - deallocate nci device
703  *
704  * @ndev: The nci device to deallocate
705  */
706 void nci_free_device(struct nci_dev *ndev)
707 {
708 	nfc_free_device(ndev->nfc_dev);
709 	kfree(ndev);
710 }
711 EXPORT_SYMBOL(nci_free_device);
712 
713 /**
714  * nci_register_device - register a nci device in the nfc subsystem
715  *
716  * @dev: The nci device to register
717  */
718 int nci_register_device(struct nci_dev *ndev)
719 {
720 	int rc;
721 	struct device *dev = &ndev->nfc_dev->dev;
722 	char name[32];
723 
724 	rc = nfc_register_device(ndev->nfc_dev);
725 	if (rc)
726 		goto exit;
727 
728 	ndev->flags = 0;
729 
730 	INIT_WORK(&ndev->cmd_work, nci_cmd_work);
731 	snprintf(name, sizeof(name), "%s_nci_cmd_wq", dev_name(dev));
732 	ndev->cmd_wq = create_singlethread_workqueue(name);
733 	if (!ndev->cmd_wq) {
734 		rc = -ENOMEM;
735 		goto unreg_exit;
736 	}
737 
738 	INIT_WORK(&ndev->rx_work, nci_rx_work);
739 	snprintf(name, sizeof(name), "%s_nci_rx_wq", dev_name(dev));
740 	ndev->rx_wq = create_singlethread_workqueue(name);
741 	if (!ndev->rx_wq) {
742 		rc = -ENOMEM;
743 		goto destroy_cmd_wq_exit;
744 	}
745 
746 	INIT_WORK(&ndev->tx_work, nci_tx_work);
747 	snprintf(name, sizeof(name), "%s_nci_tx_wq", dev_name(dev));
748 	ndev->tx_wq = create_singlethread_workqueue(name);
749 	if (!ndev->tx_wq) {
750 		rc = -ENOMEM;
751 		goto destroy_rx_wq_exit;
752 	}
753 
754 	skb_queue_head_init(&ndev->cmd_q);
755 	skb_queue_head_init(&ndev->rx_q);
756 	skb_queue_head_init(&ndev->tx_q);
757 
758 	setup_timer(&ndev->cmd_timer, nci_cmd_timer,
759 		    (unsigned long) ndev);
760 	setup_timer(&ndev->data_timer, nci_data_timer,
761 		    (unsigned long) ndev);
762 
763 	mutex_init(&ndev->req_lock);
764 
765 	goto exit;
766 
767 destroy_rx_wq_exit:
768 	destroy_workqueue(ndev->rx_wq);
769 
770 destroy_cmd_wq_exit:
771 	destroy_workqueue(ndev->cmd_wq);
772 
773 unreg_exit:
774 	nfc_unregister_device(ndev->nfc_dev);
775 
776 exit:
777 	return rc;
778 }
779 EXPORT_SYMBOL(nci_register_device);
780 
781 /**
782  * nci_unregister_device - unregister a nci device in the nfc subsystem
783  *
784  * @dev: The nci device to unregister
785  */
786 void nci_unregister_device(struct nci_dev *ndev)
787 {
788 	nci_close_device(ndev);
789 
790 	destroy_workqueue(ndev->cmd_wq);
791 	destroy_workqueue(ndev->rx_wq);
792 	destroy_workqueue(ndev->tx_wq);
793 
794 	nfc_unregister_device(ndev->nfc_dev);
795 }
796 EXPORT_SYMBOL(nci_unregister_device);
797 
798 /**
799  * nci_recv_frame - receive frame from NCI drivers
800  *
801  * @skb: The sk_buff to receive
802  */
803 int nci_recv_frame(struct sk_buff *skb)
804 {
805 	struct nci_dev *ndev = (struct nci_dev *) skb->dev;
806 
807 	pr_debug("len %d\n", skb->len);
808 
809 	if (!ndev || (!test_bit(NCI_UP, &ndev->flags)
810 		      && !test_bit(NCI_INIT, &ndev->flags))) {
811 		kfree_skb(skb);
812 		return -ENXIO;
813 	}
814 
815 	/* Queue frame for rx worker thread */
816 	skb_queue_tail(&ndev->rx_q, skb);
817 	queue_work(ndev->rx_wq, &ndev->rx_work);
818 
819 	return 0;
820 }
821 EXPORT_SYMBOL(nci_recv_frame);
822 
823 static int nci_send_frame(struct sk_buff *skb)
824 {
825 	struct nci_dev *ndev = (struct nci_dev *) skb->dev;
826 
827 	pr_debug("len %d\n", skb->len);
828 
829 	if (!ndev) {
830 		kfree_skb(skb);
831 		return -ENODEV;
832 	}
833 
834 	/* Get rid of skb owner, prior to sending to the driver. */
835 	skb_orphan(skb);
836 
837 	return ndev->ops->send(skb);
838 }
839 
840 /* Send NCI command */
841 int nci_send_cmd(struct nci_dev *ndev, __u16 opcode, __u8 plen, void *payload)
842 {
843 	struct nci_ctrl_hdr *hdr;
844 	struct sk_buff *skb;
845 
846 	pr_debug("opcode 0x%x, plen %d\n", opcode, plen);
847 
848 	skb = nci_skb_alloc(ndev, (NCI_CTRL_HDR_SIZE + plen), GFP_KERNEL);
849 	if (!skb) {
850 		pr_err("no memory for command\n");
851 		return -ENOMEM;
852 	}
853 
854 	hdr = (struct nci_ctrl_hdr *) skb_put(skb, NCI_CTRL_HDR_SIZE);
855 	hdr->gid = nci_opcode_gid(opcode);
856 	hdr->oid = nci_opcode_oid(opcode);
857 	hdr->plen = plen;
858 
859 	nci_mt_set((__u8 *)hdr, NCI_MT_CMD_PKT);
860 	nci_pbf_set((__u8 *)hdr, NCI_PBF_LAST);
861 
862 	if (plen)
863 		memcpy(skb_put(skb, plen), payload, plen);
864 
865 	skb->dev = (void *) ndev;
866 
867 	skb_queue_tail(&ndev->cmd_q, skb);
868 	queue_work(ndev->cmd_wq, &ndev->cmd_work);
869 
870 	return 0;
871 }
872 
873 /* ---- NCI TX Data worker thread ---- */
874 
875 static void nci_tx_work(struct work_struct *work)
876 {
877 	struct nci_dev *ndev = container_of(work, struct nci_dev, tx_work);
878 	struct sk_buff *skb;
879 
880 	pr_debug("credits_cnt %d\n", atomic_read(&ndev->credits_cnt));
881 
882 	/* Send queued tx data */
883 	while (atomic_read(&ndev->credits_cnt)) {
884 		skb = skb_dequeue(&ndev->tx_q);
885 		if (!skb)
886 			return;
887 
888 		/* Check if data flow control is used */
889 		if (atomic_read(&ndev->credits_cnt) !=
890 		    NCI_DATA_FLOW_CONTROL_NOT_USED)
891 			atomic_dec(&ndev->credits_cnt);
892 
893 		pr_debug("NCI TX: MT=data, PBF=%d, conn_id=%d, plen=%d\n",
894 			 nci_pbf(skb->data),
895 			 nci_conn_id(skb->data),
896 			 nci_plen(skb->data));
897 
898 		nci_send_frame(skb);
899 
900 		mod_timer(&ndev->data_timer,
901 			  jiffies + msecs_to_jiffies(NCI_DATA_TIMEOUT));
902 	}
903 }
904 
905 /* ----- NCI RX worker thread (data & control) ----- */
906 
907 static void nci_rx_work(struct work_struct *work)
908 {
909 	struct nci_dev *ndev = container_of(work, struct nci_dev, rx_work);
910 	struct sk_buff *skb;
911 
912 	while ((skb = skb_dequeue(&ndev->rx_q))) {
913 		/* Process frame */
914 		switch (nci_mt(skb->data)) {
915 		case NCI_MT_RSP_PKT:
916 			nci_rsp_packet(ndev, skb);
917 			break;
918 
919 		case NCI_MT_NTF_PKT:
920 			nci_ntf_packet(ndev, skb);
921 			break;
922 
923 		case NCI_MT_DATA_PKT:
924 			nci_rx_data_packet(ndev, skb);
925 			break;
926 
927 		default:
928 			pr_err("unknown MT 0x%x\n", nci_mt(skb->data));
929 			kfree_skb(skb);
930 			break;
931 		}
932 	}
933 
934 	/* check if a data exchange timout has occurred */
935 	if (test_bit(NCI_DATA_EXCHANGE_TO, &ndev->flags)) {
936 		/* complete the data exchange transaction, if exists */
937 		if (test_bit(NCI_DATA_EXCHANGE, &ndev->flags))
938 			nci_data_exchange_complete(ndev, NULL, -ETIMEDOUT);
939 
940 		clear_bit(NCI_DATA_EXCHANGE_TO, &ndev->flags);
941 	}
942 }
943 
944 /* ----- NCI TX CMD worker thread ----- */
945 
946 static void nci_cmd_work(struct work_struct *work)
947 {
948 	struct nci_dev *ndev = container_of(work, struct nci_dev, cmd_work);
949 	struct sk_buff *skb;
950 
951 	pr_debug("cmd_cnt %d\n", atomic_read(&ndev->cmd_cnt));
952 
953 	/* Send queued command */
954 	if (atomic_read(&ndev->cmd_cnt)) {
955 		skb = skb_dequeue(&ndev->cmd_q);
956 		if (!skb)
957 			return;
958 
959 		atomic_dec(&ndev->cmd_cnt);
960 
961 		pr_debug("NCI TX: MT=cmd, PBF=%d, GID=0x%x, OID=0x%x, plen=%d\n",
962 			 nci_pbf(skb->data),
963 			 nci_opcode_gid(nci_opcode(skb->data)),
964 			 nci_opcode_oid(nci_opcode(skb->data)),
965 			 nci_plen(skb->data));
966 
967 		nci_send_frame(skb);
968 
969 		mod_timer(&ndev->cmd_timer,
970 			  jiffies + msecs_to_jiffies(NCI_CMD_TIMEOUT));
971 	}
972 }
973 
974 MODULE_LICENSE("GPL");
975