xref: /openbmc/linux/drivers/nfc/st21nfca/dep.c (revision 6d99a79c)
1 /*
2  * Copyright (C) 2014  STMicroelectronics SAS. All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms and conditions of the GNU General Public License,
6  * version 2, as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11  * GNU General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public License
14  * along with this program; if not, see <http://www.gnu.org/licenses/>.
15  */
16 
17 #include <net/nfc/hci.h>
18 
19 #include "st21nfca.h"
20 
21 #define ST21NFCA_NFCIP1_INITIATOR 0x00
22 #define ST21NFCA_NFCIP1_REQ 0xd4
23 #define ST21NFCA_NFCIP1_RES 0xd5
24 #define ST21NFCA_NFCIP1_ATR_REQ 0x00
25 #define ST21NFCA_NFCIP1_ATR_RES 0x01
26 #define ST21NFCA_NFCIP1_PSL_REQ 0x04
27 #define ST21NFCA_NFCIP1_PSL_RES 0x05
28 #define ST21NFCA_NFCIP1_DEP_REQ 0x06
29 #define ST21NFCA_NFCIP1_DEP_RES 0x07
30 
31 #define ST21NFCA_NFC_DEP_PFB_PNI(pfb)     ((pfb) & 0x03)
32 #define ST21NFCA_NFC_DEP_PFB_TYPE(pfb) ((pfb) & 0xE0)
33 #define ST21NFCA_NFC_DEP_PFB_IS_TIMEOUT(pfb) \
34 				((pfb) & ST21NFCA_NFC_DEP_PFB_TIMEOUT_BIT)
35 #define ST21NFCA_NFC_DEP_DID_BIT_SET(pfb) ((pfb) & 0x04)
36 #define ST21NFCA_NFC_DEP_NAD_BIT_SET(pfb) ((pfb) & 0x08)
37 #define ST21NFCA_NFC_DEP_PFB_TIMEOUT_BIT 0x10
38 
39 #define ST21NFCA_NFC_DEP_PFB_IS_TIMEOUT(pfb) \
40 				((pfb) & ST21NFCA_NFC_DEP_PFB_TIMEOUT_BIT)
41 
42 #define ST21NFCA_NFC_DEP_PFB_I_PDU          0x00
43 #define ST21NFCA_NFC_DEP_PFB_ACK_NACK_PDU   0x40
44 #define ST21NFCA_NFC_DEP_PFB_SUPERVISOR_PDU 0x80
45 
46 #define ST21NFCA_ATR_REQ_MIN_SIZE 17
47 #define ST21NFCA_ATR_REQ_MAX_SIZE 65
48 #define ST21NFCA_LR_BITS_PAYLOAD_SIZE_254B 0x30
49 #define ST21NFCA_GB_BIT  0x02
50 
51 #define ST21NFCA_EVT_SEND_DATA		0x10
52 #define ST21NFCA_EVT_FIELD_ON           0x11
53 #define ST21NFCA_EVT_CARD_DEACTIVATED   0x12
54 #define ST21NFCA_EVT_CARD_ACTIVATED     0x13
55 #define ST21NFCA_EVT_FIELD_OFF          0x14
56 
57 #define ST21NFCA_EVT_CARD_F_BITRATE 0x16
58 #define ST21NFCA_EVT_READER_F_BITRATE 0x13
59 #define	ST21NFCA_PSL_REQ_SEND_SPEED(brs) (brs & 0x38)
60 #define ST21NFCA_PSL_REQ_RECV_SPEED(brs) (brs & 0x07)
61 #define ST21NFCA_PP2LRI(pp) ((pp & 0x30) >> 4)
62 #define ST21NFCA_CARD_BITRATE_212 0x01
63 #define ST21NFCA_CARD_BITRATE_424 0x02
64 
65 #define ST21NFCA_DEFAULT_TIMEOUT 0x0a
66 
67 
68 #define PROTOCOL_ERR(req) pr_err("%d: ST21NFCA Protocol error: %s\n", \
69 				 __LINE__, req)
70 
71 struct st21nfca_atr_req {
72 	u8 length;
73 	u8 cmd0;
74 	u8 cmd1;
75 	u8 nfcid3[NFC_NFCID3_MAXSIZE];
76 	u8 did;
77 	u8 bsi;
78 	u8 bri;
79 	u8 ppi;
80 	u8 gbi[0];
81 } __packed;
82 
83 struct st21nfca_atr_res {
84 	u8 length;
85 	u8 cmd0;
86 	u8 cmd1;
87 	u8 nfcid3[NFC_NFCID3_MAXSIZE];
88 	u8 did;
89 	u8 bsi;
90 	u8 bri;
91 	u8 to;
92 	u8 ppi;
93 	u8 gbi[0];
94 } __packed;
95 
96 struct st21nfca_psl_req {
97 	u8 length;
98 	u8 cmd0;
99 	u8 cmd1;
100 	u8 did;
101 	u8 brs;
102 	u8 fsl;
103 } __packed;
104 
105 struct st21nfca_psl_res {
106 	u8 length;
107 	u8 cmd0;
108 	u8 cmd1;
109 	u8 did;
110 } __packed;
111 
112 struct st21nfca_dep_req_res {
113 	u8 length;
114 	u8 cmd0;
115 	u8 cmd1;
116 	u8 pfb;
117 	u8 did;
118 	u8 nad;
119 } __packed;
120 
121 static void st21nfca_tx_work(struct work_struct *work)
122 {
123 	struct st21nfca_hci_info *info = container_of(work,
124 						struct st21nfca_hci_info,
125 						dep_info.tx_work);
126 
127 	struct nfc_dev *dev;
128 	struct sk_buff *skb;
129 
130 	if (info) {
131 		dev = info->hdev->ndev;
132 		skb = info->dep_info.tx_pending;
133 
134 		device_lock(&dev->dev);
135 
136 		nfc_hci_send_cmd_async(info->hdev, ST21NFCA_RF_READER_F_GATE,
137 				ST21NFCA_WR_XCHG_DATA, skb->data, skb->len,
138 				info->async_cb, info);
139 		device_unlock(&dev->dev);
140 		kfree_skb(skb);
141 	}
142 }
143 
144 static void st21nfca_im_send_pdu(struct st21nfca_hci_info *info,
145 						struct sk_buff *skb)
146 {
147 	info->dep_info.tx_pending = skb;
148 	schedule_work(&info->dep_info.tx_work);
149 }
150 
151 static int st21nfca_tm_send_atr_res(struct nfc_hci_dev *hdev,
152 				    struct st21nfca_atr_req *atr_req)
153 {
154 	struct st21nfca_atr_res *atr_res;
155 	struct sk_buff *skb;
156 	size_t gb_len;
157 	int r;
158 	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
159 
160 	gb_len = atr_req->length - sizeof(struct st21nfca_atr_req);
161 	skb = alloc_skb(atr_req->length + 1, GFP_KERNEL);
162 	if (!skb)
163 		return -ENOMEM;
164 
165 	skb_put(skb, sizeof(struct st21nfca_atr_res));
166 
167 	atr_res = (struct st21nfca_atr_res *)skb->data;
168 	memset(atr_res, 0, sizeof(struct st21nfca_atr_res));
169 
170 	atr_res->length = atr_req->length + 1;
171 	atr_res->cmd0 = ST21NFCA_NFCIP1_RES;
172 	atr_res->cmd1 = ST21NFCA_NFCIP1_ATR_RES;
173 
174 	memcpy(atr_res->nfcid3, atr_req->nfcid3, 6);
175 	atr_res->bsi = 0x00;
176 	atr_res->bri = 0x00;
177 	atr_res->to = ST21NFCA_DEFAULT_TIMEOUT;
178 	atr_res->ppi = ST21NFCA_LR_BITS_PAYLOAD_SIZE_254B;
179 
180 	if (gb_len) {
181 		skb_put(skb, gb_len);
182 
183 		atr_res->ppi |= ST21NFCA_GB_BIT;
184 		memcpy(atr_res->gbi, atr_req->gbi, gb_len);
185 		r = nfc_set_remote_general_bytes(hdev->ndev, atr_res->gbi,
186 						  gb_len);
187 		if (r < 0)
188 			return r;
189 	}
190 
191 	info->dep_info.curr_nfc_dep_pni = 0;
192 
193 	r = nfc_hci_send_event(hdev, ST21NFCA_RF_CARD_F_GATE,
194 				ST21NFCA_EVT_SEND_DATA, skb->data, skb->len);
195 	kfree_skb(skb);
196 	return r;
197 }
198 
199 static int st21nfca_tm_recv_atr_req(struct nfc_hci_dev *hdev,
200 				    struct sk_buff *skb)
201 {
202 	struct st21nfca_atr_req *atr_req;
203 	size_t gb_len;
204 	int r;
205 
206 	skb_trim(skb, skb->len - 1);
207 
208 	if (!skb->len) {
209 		r = -EIO;
210 		goto exit;
211 	}
212 
213 	if (skb->len < ST21NFCA_ATR_REQ_MIN_SIZE) {
214 		r = -EPROTO;
215 		goto exit;
216 	}
217 
218 	atr_req = (struct st21nfca_atr_req *)skb->data;
219 
220 	if (atr_req->length < sizeof(struct st21nfca_atr_req)) {
221 		r = -EPROTO;
222 		goto exit;
223 	}
224 
225 	r = st21nfca_tm_send_atr_res(hdev, atr_req);
226 	if (r)
227 		goto exit;
228 
229 	gb_len = skb->len - sizeof(struct st21nfca_atr_req);
230 
231 	r = nfc_tm_activated(hdev->ndev, NFC_PROTO_NFC_DEP_MASK,
232 			      NFC_COMM_PASSIVE, atr_req->gbi, gb_len);
233 	if (r)
234 		goto exit;
235 
236 	r = 0;
237 
238 exit:
239 	return r;
240 }
241 
242 static int st21nfca_tm_send_psl_res(struct nfc_hci_dev *hdev,
243 				    struct st21nfca_psl_req *psl_req)
244 {
245 	struct st21nfca_psl_res *psl_res;
246 	struct sk_buff *skb;
247 	u8 bitrate[2] = {0, 0};
248 	int r;
249 
250 	skb = alloc_skb(sizeof(struct st21nfca_psl_res), GFP_KERNEL);
251 	if (!skb)
252 		return -ENOMEM;
253 	skb_put(skb, sizeof(struct st21nfca_psl_res));
254 
255 	psl_res = (struct st21nfca_psl_res *)skb->data;
256 
257 	psl_res->length = sizeof(struct st21nfca_psl_res);
258 	psl_res->cmd0 = ST21NFCA_NFCIP1_RES;
259 	psl_res->cmd1 = ST21NFCA_NFCIP1_PSL_RES;
260 	psl_res->did = psl_req->did;
261 
262 	r = nfc_hci_send_event(hdev, ST21NFCA_RF_CARD_F_GATE,
263 				ST21NFCA_EVT_SEND_DATA, skb->data, skb->len);
264 	if (r < 0)
265 		goto error;
266 
267 	/*
268 	 * ST21NFCA only support P2P passive.
269 	 * PSL_REQ BRS value != 0 has only a meaning to
270 	 * change technology to type F.
271 	 * We change to BITRATE 424Kbits.
272 	 * In other case switch to BITRATE 106Kbits.
273 	 */
274 	if (ST21NFCA_PSL_REQ_SEND_SPEED(psl_req->brs) &&
275 	    ST21NFCA_PSL_REQ_RECV_SPEED(psl_req->brs)) {
276 		bitrate[0] = ST21NFCA_CARD_BITRATE_424;
277 		bitrate[1] = ST21NFCA_CARD_BITRATE_424;
278 	}
279 
280 	/* Send an event to change bitrate change event to card f */
281 	r = nfc_hci_send_event(hdev, ST21NFCA_RF_CARD_F_GATE,
282 			ST21NFCA_EVT_CARD_F_BITRATE, bitrate, 2);
283 error:
284 	kfree_skb(skb);
285 	return r;
286 }
287 
288 static int st21nfca_tm_recv_psl_req(struct nfc_hci_dev *hdev,
289 				    struct sk_buff *skb)
290 {
291 	struct st21nfca_psl_req *psl_req;
292 	int r;
293 
294 	skb_trim(skb, skb->len - 1);
295 
296 	if (!skb->len) {
297 		r = -EIO;
298 		goto exit;
299 	}
300 
301 	psl_req = (struct st21nfca_psl_req *)skb->data;
302 
303 	if (skb->len < sizeof(struct st21nfca_psl_req)) {
304 		r = -EIO;
305 		goto exit;
306 	}
307 
308 	r = st21nfca_tm_send_psl_res(hdev, psl_req);
309 exit:
310 	return r;
311 }
312 
313 int st21nfca_tm_send_dep_res(struct nfc_hci_dev *hdev, struct sk_buff *skb)
314 {
315 	int r;
316 	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
317 
318 	*(u8 *)skb_push(skb, 1) = info->dep_info.curr_nfc_dep_pni;
319 	*(u8 *)skb_push(skb, 1) = ST21NFCA_NFCIP1_DEP_RES;
320 	*(u8 *)skb_push(skb, 1) = ST21NFCA_NFCIP1_RES;
321 	*(u8 *)skb_push(skb, 1) = skb->len;
322 
323 	r = nfc_hci_send_event(hdev, ST21NFCA_RF_CARD_F_GATE,
324 			ST21NFCA_EVT_SEND_DATA, skb->data, skb->len);
325 	kfree_skb(skb);
326 
327 	return r;
328 }
329 EXPORT_SYMBOL(st21nfca_tm_send_dep_res);
330 
331 static int st21nfca_tm_recv_dep_req(struct nfc_hci_dev *hdev,
332 				    struct sk_buff *skb)
333 {
334 	struct st21nfca_dep_req_res *dep_req;
335 	u8 size;
336 	int r;
337 	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
338 
339 	skb_trim(skb, skb->len - 1);
340 
341 	size = 4;
342 
343 	dep_req = (struct st21nfca_dep_req_res *)skb->data;
344 	if (skb->len < size) {
345 		r = -EIO;
346 		goto exit;
347 	}
348 
349 	if (ST21NFCA_NFC_DEP_DID_BIT_SET(dep_req->pfb))
350 		size++;
351 	if (ST21NFCA_NFC_DEP_NAD_BIT_SET(dep_req->pfb))
352 		size++;
353 
354 	if (skb->len < size) {
355 		r = -EIO;
356 		goto exit;
357 	}
358 
359 	/* Receiving DEP_REQ - Decoding */
360 	switch (ST21NFCA_NFC_DEP_PFB_TYPE(dep_req->pfb)) {
361 	case ST21NFCA_NFC_DEP_PFB_I_PDU:
362 		info->dep_info.curr_nfc_dep_pni =
363 				ST21NFCA_NFC_DEP_PFB_PNI(dep_req->pfb);
364 		break;
365 	case ST21NFCA_NFC_DEP_PFB_ACK_NACK_PDU:
366 		pr_err("Received a ACK/NACK PDU\n");
367 		break;
368 	case ST21NFCA_NFC_DEP_PFB_SUPERVISOR_PDU:
369 		pr_err("Received a SUPERVISOR PDU\n");
370 		break;
371 	}
372 
373 	skb_pull(skb, size);
374 
375 	return nfc_tm_data_received(hdev->ndev, skb);
376 exit:
377 	return r;
378 }
379 
380 static int st21nfca_tm_event_send_data(struct nfc_hci_dev *hdev,
381 				struct sk_buff *skb)
382 {
383 	u8 cmd0, cmd1;
384 	int r;
385 
386 	cmd0 = skb->data[1];
387 	switch (cmd0) {
388 	case ST21NFCA_NFCIP1_REQ:
389 		cmd1 = skb->data[2];
390 		switch (cmd1) {
391 		case ST21NFCA_NFCIP1_ATR_REQ:
392 			r = st21nfca_tm_recv_atr_req(hdev, skb);
393 			break;
394 		case ST21NFCA_NFCIP1_PSL_REQ:
395 			r = st21nfca_tm_recv_psl_req(hdev, skb);
396 			break;
397 		case ST21NFCA_NFCIP1_DEP_REQ:
398 			r = st21nfca_tm_recv_dep_req(hdev, skb);
399 			break;
400 		default:
401 			return 1;
402 		}
403 	default:
404 		return 1;
405 	}
406 	return r;
407 }
408 
409 /*
410  * Returns:
411  * <= 0: driver handled the event, skb consumed
412  *    1: driver does not handle the event, please do standard processing
413  */
414 int st21nfca_dep_event_received(struct nfc_hci_dev *hdev,
415 				u8 event, struct sk_buff *skb)
416 {
417 	int r = 0;
418 	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
419 
420 	pr_debug("dep event: %d\n", event);
421 
422 	switch (event) {
423 	case ST21NFCA_EVT_CARD_ACTIVATED:
424 		info->dep_info.curr_nfc_dep_pni = 0;
425 		break;
426 	case ST21NFCA_EVT_CARD_DEACTIVATED:
427 		break;
428 	case ST21NFCA_EVT_FIELD_ON:
429 		break;
430 	case ST21NFCA_EVT_FIELD_OFF:
431 		break;
432 	case ST21NFCA_EVT_SEND_DATA:
433 		r = st21nfca_tm_event_send_data(hdev, skb);
434 		if (r < 0)
435 			return r;
436 		return 0;
437 	default:
438 		nfc_err(&hdev->ndev->dev, "Unexpected event on card f gate\n");
439 		return 1;
440 	}
441 	kfree_skb(skb);
442 	return r;
443 }
444 EXPORT_SYMBOL(st21nfca_dep_event_received);
445 
446 static void st21nfca_im_send_psl_req(struct nfc_hci_dev *hdev, u8 did, u8 bsi,
447 				     u8 bri, u8 lri)
448 {
449 	struct sk_buff *skb;
450 	struct st21nfca_psl_req *psl_req;
451 	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
452 
453 	skb =
454 	    alloc_skb(sizeof(struct st21nfca_psl_req) + 1, GFP_KERNEL);
455 	if (!skb)
456 		return;
457 	skb_reserve(skb, 1);
458 
459 	skb_put(skb, sizeof(struct st21nfca_psl_req));
460 	psl_req = (struct st21nfca_psl_req *) skb->data;
461 
462 	psl_req->length = sizeof(struct st21nfca_psl_req);
463 	psl_req->cmd0 = ST21NFCA_NFCIP1_REQ;
464 	psl_req->cmd1 = ST21NFCA_NFCIP1_PSL_REQ;
465 	psl_req->did = did;
466 	psl_req->brs = (0x30 & bsi << 4) | (bri & 0x03);
467 	psl_req->fsl = lri;
468 
469 	*(u8 *)skb_push(skb, 1) = info->dep_info.to | 0x10;
470 
471 	st21nfca_im_send_pdu(info, skb);
472 }
473 
474 #define ST21NFCA_CB_TYPE_READER_F 1
475 static void st21nfca_im_recv_atr_res_cb(void *context, struct sk_buff *skb,
476 					int err)
477 {
478 	struct st21nfca_hci_info *info = context;
479 	struct st21nfca_atr_res *atr_res;
480 	int r;
481 
482 	if (err != 0)
483 		return;
484 
485 	if (!skb)
486 		return;
487 
488 	switch (info->async_cb_type) {
489 	case ST21NFCA_CB_TYPE_READER_F:
490 		skb_trim(skb, skb->len - 1);
491 		atr_res = (struct st21nfca_atr_res *)skb->data;
492 		r = nfc_set_remote_general_bytes(info->hdev->ndev,
493 				atr_res->gbi,
494 				skb->len - sizeof(struct st21nfca_atr_res));
495 		if (r < 0)
496 			return;
497 
498 		if (atr_res->to >= 0x0e)
499 			info->dep_info.to = 0x0e;
500 		else
501 			info->dep_info.to = atr_res->to + 1;
502 
503 		info->dep_info.to |= 0x10;
504 
505 		r = nfc_dep_link_is_up(info->hdev->ndev, info->dep_info.idx,
506 					NFC_COMM_PASSIVE, NFC_RF_INITIATOR);
507 		if (r < 0)
508 			return;
509 
510 		info->dep_info.curr_nfc_dep_pni = 0;
511 		if (ST21NFCA_PP2LRI(atr_res->ppi) != info->dep_info.lri)
512 			st21nfca_im_send_psl_req(info->hdev, atr_res->did,
513 						atr_res->bsi, atr_res->bri,
514 						ST21NFCA_PP2LRI(atr_res->ppi));
515 		break;
516 	default:
517 		kfree_skb(skb);
518 		break;
519 	}
520 }
521 
522 int st21nfca_im_send_atr_req(struct nfc_hci_dev *hdev, u8 *gb, size_t gb_len)
523 {
524 	struct sk_buff *skb;
525 	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
526 	struct st21nfca_atr_req *atr_req;
527 	struct nfc_target *target;
528 	uint size;
529 
530 	info->dep_info.to = ST21NFCA_DEFAULT_TIMEOUT;
531 	size = ST21NFCA_ATR_REQ_MIN_SIZE + gb_len;
532 	if (size > ST21NFCA_ATR_REQ_MAX_SIZE) {
533 		PROTOCOL_ERR("14.6.1.1");
534 		return -EINVAL;
535 	}
536 
537 	skb =
538 	    alloc_skb(sizeof(struct st21nfca_atr_req) + gb_len + 1, GFP_KERNEL);
539 	if (!skb)
540 		return -ENOMEM;
541 
542 	skb_reserve(skb, 1);
543 
544 	skb_put(skb, sizeof(struct st21nfca_atr_req));
545 
546 	atr_req = (struct st21nfca_atr_req *)skb->data;
547 	memset(atr_req, 0, sizeof(struct st21nfca_atr_req));
548 
549 	atr_req->cmd0 = ST21NFCA_NFCIP1_REQ;
550 	atr_req->cmd1 = ST21NFCA_NFCIP1_ATR_REQ;
551 	memset(atr_req->nfcid3, 0, NFC_NFCID3_MAXSIZE);
552 	target = hdev->ndev->targets;
553 
554 	if (target->sensf_res_len > 0)
555 		memcpy(atr_req->nfcid3, target->sensf_res,
556 				target->sensf_res_len);
557 	else
558 		get_random_bytes(atr_req->nfcid3, NFC_NFCID3_MAXSIZE);
559 
560 	atr_req->did = 0x0;
561 
562 	atr_req->bsi = 0x00;
563 	atr_req->bri = 0x00;
564 	atr_req->ppi = ST21NFCA_LR_BITS_PAYLOAD_SIZE_254B;
565 	if (gb_len) {
566 		atr_req->ppi |= ST21NFCA_GB_BIT;
567 		skb_put_data(skb, gb, gb_len);
568 	}
569 	atr_req->length = sizeof(struct st21nfca_atr_req) + hdev->gb_len;
570 
571 	*(u8 *)skb_push(skb, 1) = info->dep_info.to | 0x10; /* timeout */
572 
573 	info->async_cb_type = ST21NFCA_CB_TYPE_READER_F;
574 	info->async_cb_context = info;
575 	info->async_cb = st21nfca_im_recv_atr_res_cb;
576 	info->dep_info.bri = atr_req->bri;
577 	info->dep_info.bsi = atr_req->bsi;
578 	info->dep_info.lri = ST21NFCA_PP2LRI(atr_req->ppi);
579 
580 	return nfc_hci_send_cmd_async(hdev, ST21NFCA_RF_READER_F_GATE,
581 				ST21NFCA_WR_XCHG_DATA, skb->data,
582 				skb->len, info->async_cb, info);
583 }
584 EXPORT_SYMBOL(st21nfca_im_send_atr_req);
585 
586 static void st21nfca_im_recv_dep_res_cb(void *context, struct sk_buff *skb,
587 					int err)
588 {
589 	struct st21nfca_hci_info *info = context;
590 	struct st21nfca_dep_req_res *dep_res;
591 
592 	int size;
593 
594 	if (err != 0)
595 		return;
596 
597 	if (!skb)
598 		return;
599 
600 	switch (info->async_cb_type) {
601 	case ST21NFCA_CB_TYPE_READER_F:
602 		dep_res = (struct st21nfca_dep_req_res *)skb->data;
603 
604 		size = 3;
605 		if (skb->len < size)
606 			goto exit;
607 
608 		if (ST21NFCA_NFC_DEP_DID_BIT_SET(dep_res->pfb))
609 			size++;
610 		if (ST21NFCA_NFC_DEP_NAD_BIT_SET(dep_res->pfb))
611 			size++;
612 
613 		if (skb->len < size)
614 			goto exit;
615 
616 		skb_trim(skb, skb->len - 1);
617 
618 		/* Receiving DEP_REQ - Decoding */
619 		switch (ST21NFCA_NFC_DEP_PFB_TYPE(dep_res->pfb)) {
620 		case ST21NFCA_NFC_DEP_PFB_ACK_NACK_PDU:
621 			pr_err("Received a ACK/NACK PDU\n");
622 		case ST21NFCA_NFC_DEP_PFB_I_PDU:
623 			info->dep_info.curr_nfc_dep_pni =
624 			    ST21NFCA_NFC_DEP_PFB_PNI(dep_res->pfb + 1);
625 			size++;
626 			skb_pull(skb, size);
627 			nfc_tm_data_received(info->hdev->ndev, skb);
628 			break;
629 		case ST21NFCA_NFC_DEP_PFB_SUPERVISOR_PDU:
630 			pr_err("Received a SUPERVISOR PDU\n");
631 			skb_pull(skb, size);
632 			*(u8 *)skb_push(skb, 1) = ST21NFCA_NFCIP1_DEP_REQ;
633 			*(u8 *)skb_push(skb, 1) = ST21NFCA_NFCIP1_REQ;
634 			*(u8 *)skb_push(skb, 1) = skb->len;
635 			*(u8 *)skb_push(skb, 1) = info->dep_info.to | 0x10;
636 
637 			st21nfca_im_send_pdu(info, skb);
638 			break;
639 		}
640 
641 		return;
642 	default:
643 		break;
644 	}
645 
646 exit:
647 	kfree_skb(skb);
648 }
649 
650 int st21nfca_im_send_dep_req(struct nfc_hci_dev *hdev, struct sk_buff *skb)
651 {
652 	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
653 
654 	info->async_cb_type = ST21NFCA_CB_TYPE_READER_F;
655 	info->async_cb_context = info;
656 	info->async_cb = st21nfca_im_recv_dep_res_cb;
657 
658 	*(u8 *)skb_push(skb, 1) = info->dep_info.curr_nfc_dep_pni;
659 	*(u8 *)skb_push(skb, 1) = ST21NFCA_NFCIP1_DEP_REQ;
660 	*(u8 *)skb_push(skb, 1) = ST21NFCA_NFCIP1_REQ;
661 	*(u8 *)skb_push(skb, 1) = skb->len;
662 
663 	*(u8 *)skb_push(skb, 1) = info->dep_info.to | 0x10;
664 
665 	return nfc_hci_send_cmd_async(hdev, ST21NFCA_RF_READER_F_GATE,
666 				      ST21NFCA_WR_XCHG_DATA,
667 				      skb->data, skb->len,
668 				      info->async_cb, info);
669 }
670 EXPORT_SYMBOL(st21nfca_im_send_dep_req);
671 
672 void st21nfca_dep_init(struct nfc_hci_dev *hdev)
673 {
674 	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
675 
676 	INIT_WORK(&info->dep_info.tx_work, st21nfca_tx_work);
677 	info->dep_info.curr_nfc_dep_pni = 0;
678 	info->dep_info.idx = 0;
679 	info->dep_info.to = ST21NFCA_DEFAULT_TIMEOUT;
680 }
681 EXPORT_SYMBOL(st21nfca_dep_init);
682 
683 void st21nfca_dep_deinit(struct nfc_hci_dev *hdev)
684 {
685 	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
686 
687 	cancel_work_sync(&info->dep_info.tx_work);
688 }
689 EXPORT_SYMBOL(st21nfca_dep_deinit);
690