xref: /openbmc/linux/net/nfc/digital_technology.c (revision 8730046c)
1 /*
2  * NFC Digital Protocol stack
3  * Copyright (c) 2013, Intel Corporation.
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms and conditions of the GNU General Public License,
7  * version 2, as published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  *
14  */
15 
16 #define pr_fmt(fmt) "digital: %s: " fmt, __func__
17 
18 #include "digital.h"
19 
20 #define DIGITAL_CMD_SENS_REQ    0x26
21 #define DIGITAL_CMD_ALL_REQ     0x52
22 #define DIGITAL_CMD_SEL_REQ_CL1 0x93
23 #define DIGITAL_CMD_SEL_REQ_CL2 0x95
24 #define DIGITAL_CMD_SEL_REQ_CL3 0x97
25 
26 #define DIGITAL_SDD_REQ_SEL_PAR 0x20
27 
28 #define DIGITAL_SDD_RES_CT  0x88
29 #define DIGITAL_SDD_RES_LEN 5
30 
31 #define DIGITAL_SEL_RES_NFCID1_COMPLETE(sel_res) (!((sel_res) & 0x04))
32 #define DIGITAL_SEL_RES_IS_T2T(sel_res) (!((sel_res) & 0x60))
33 #define DIGITAL_SEL_RES_IS_T4T(sel_res) ((sel_res) & 0x20)
34 #define DIGITAL_SEL_RES_IS_NFC_DEP(sel_res) ((sel_res) & 0x40)
35 
36 #define DIGITAL_SENS_RES_IS_T1T(sens_res) (((sens_res) & 0x0C00) == 0x0C00)
37 #define DIGITAL_SENS_RES_IS_VALID(sens_res) \
38 	((!((sens_res) & 0x001F) && (((sens_res) & 0x0C00) == 0x0C00)) || \
39 	(((sens_res) & 0x001F) && ((sens_res) & 0x0C00) != 0x0C00))
40 
41 #define DIGITAL_MIFARE_READ_RES_LEN 16
42 #define DIGITAL_MIFARE_ACK_RES	0x0A
43 
44 #define DIGITAL_CMD_SENSB_REQ			0x05
45 #define DIGITAL_SENSB_ADVANCED			BIT(5)
46 #define DIGITAL_SENSB_EXTENDED			BIT(4)
47 #define DIGITAL_SENSB_ALLB_REQ			BIT(3)
48 #define DIGITAL_SENSB_N(n)			((n) & 0x7)
49 
50 #define DIGITAL_CMD_SENSB_RES			0x50
51 
52 #define DIGITAL_CMD_ATTRIB_REQ			0x1D
53 #define DIGITAL_ATTRIB_P1_TR0_DEFAULT		(0x0 << 6)
54 #define DIGITAL_ATTRIB_P1_TR1_DEFAULT		(0x0 << 4)
55 #define DIGITAL_ATTRIB_P1_SUPRESS_EOS		BIT(3)
56 #define DIGITAL_ATTRIB_P1_SUPRESS_SOS		BIT(2)
57 #define DIGITAL_ATTRIB_P2_LISTEN_POLL_1		(0x0 << 6)
58 #define DIGITAL_ATTRIB_P2_POLL_LISTEN_1		(0x0 << 4)
59 #define DIGITAL_ATTRIB_P2_MAX_FRAME_256		0x8
60 #define DIGITAL_ATTRIB_P4_DID(n)		((n) & 0xf)
61 
62 #define DIGITAL_CMD_SENSF_REQ	0x00
63 #define DIGITAL_CMD_SENSF_RES	0x01
64 
65 #define DIGITAL_SENSF_RES_MIN_LENGTH 17
66 #define DIGITAL_SENSF_RES_RD_AP_B1   0x00
67 #define DIGITAL_SENSF_RES_RD_AP_B2   0x8F
68 
69 #define DIGITAL_SENSF_REQ_RC_NONE 0
70 #define DIGITAL_SENSF_REQ_RC_SC   1
71 #define DIGITAL_SENSF_REQ_RC_AP   2
72 
73 #define DIGITAL_CMD_ISO15693_INVENTORY_REQ	0x01
74 
75 #define DIGITAL_ISO15693_REQ_FLAG_DATA_RATE	BIT(1)
76 #define DIGITAL_ISO15693_REQ_FLAG_INVENTORY	BIT(2)
77 #define DIGITAL_ISO15693_REQ_FLAG_NB_SLOTS	BIT(5)
78 #define DIGITAL_ISO15693_RES_FLAG_ERROR		BIT(0)
79 #define DIGITAL_ISO15693_RES_IS_VALID(flags) \
80 	(!((flags) & DIGITAL_ISO15693_RES_FLAG_ERROR))
81 
82 #define DIGITAL_ISO_DEP_I_PCB	 0x02
83 #define DIGITAL_ISO_DEP_PNI(pni) ((pni) & 0x01)
84 
85 #define DIGITAL_ISO_DEP_PCB_TYPE(pcb) ((pcb) & 0xC0)
86 
87 #define DIGITAL_ISO_DEP_I_BLOCK 0x00
88 
89 #define DIGITAL_ISO_DEP_BLOCK_HAS_DID(pcb) ((pcb) & 0x08)
90 
91 static const u8 digital_ats_fsc[] = {
92 	 16,  24,  32,  40,  48,  64,  96, 128,
93 };
94 
95 #define DIGITAL_ATS_FSCI(t0) ((t0) & 0x0F)
96 #define DIGITAL_SENSB_FSCI(pi2) (((pi2) & 0xF0) >> 4)
97 #define DIGITAL_ATS_MAX_FSC  256
98 
99 #define DIGITAL_RATS_BYTE1 0xE0
100 #define DIGITAL_RATS_PARAM 0x80
101 
102 struct digital_sdd_res {
103 	u8 nfcid1[4];
104 	u8 bcc;
105 } __packed;
106 
107 struct digital_sel_req {
108 	u8 sel_cmd;
109 	u8 b2;
110 	u8 nfcid1[4];
111 	u8 bcc;
112 } __packed;
113 
114 struct digital_sensb_req {
115 	u8 cmd;
116 	u8 afi;
117 	u8 param;
118 } __packed;
119 
120 struct digital_sensb_res {
121 	u8 cmd;
122 	u8 nfcid0[4];
123 	u8 app_data[4];
124 	u8 proto_info[3];
125 } __packed;
126 
127 struct digital_attrib_req {
128 	u8 cmd;
129 	u8 nfcid0[4];
130 	u8 param1;
131 	u8 param2;
132 	u8 param3;
133 	u8 param4;
134 } __packed;
135 
136 struct digital_attrib_res {
137 	u8 mbli_did;
138 } __packed;
139 
140 struct digital_sensf_req {
141 	u8 cmd;
142 	u8 sc1;
143 	u8 sc2;
144 	u8 rc;
145 	u8 tsn;
146 } __packed;
147 
148 struct digital_sensf_res {
149 	u8 cmd;
150 	u8 nfcid2[8];
151 	u8 pad0[2];
152 	u8 pad1[3];
153 	u8 mrti_check;
154 	u8 mrti_update;
155 	u8 pad2;
156 	u8 rd[2];
157 } __packed;
158 
159 struct digital_iso15693_inv_req {
160 	u8 flags;
161 	u8 cmd;
162 	u8 mask_len;
163 	u64 mask;
164 } __packed;
165 
166 struct digital_iso15693_inv_res {
167 	u8 flags;
168 	u8 dsfid;
169 	u64 uid;
170 } __packed;
171 
172 static int digital_in_send_sdd_req(struct nfc_digital_dev *ddev,
173 				   struct nfc_target *target);
174 
175 int digital_in_iso_dep_pull_sod(struct nfc_digital_dev *ddev,
176 				struct sk_buff *skb)
177 {
178 	u8 pcb;
179 	u8 block_type;
180 
181 	if (skb->len < 1)
182 		return -EIO;
183 
184 	pcb = *skb->data;
185 	block_type = DIGITAL_ISO_DEP_PCB_TYPE(pcb);
186 
187 	/* No support fo R-block nor S-block */
188 	if (block_type != DIGITAL_ISO_DEP_I_BLOCK) {
189 		pr_err("ISO_DEP R-block and S-block not supported\n");
190 		return -EIO;
191 	}
192 
193 	if (DIGITAL_ISO_DEP_BLOCK_HAS_DID(pcb)) {
194 		pr_err("DID field in ISO_DEP PCB not supported\n");
195 		return -EIO;
196 	}
197 
198 	skb_pull(skb, 1);
199 
200 	return 0;
201 }
202 
203 int digital_in_iso_dep_push_sod(struct nfc_digital_dev *ddev,
204 				struct sk_buff *skb)
205 {
206 	/*
207 	 * Chaining not supported so skb->len + 1 PCB byte + 2 CRC bytes must
208 	 * not be greater than remote FSC
209 	 */
210 	if (skb->len + 3 > ddev->target_fsc)
211 		return -EIO;
212 
213 	skb_push(skb, 1);
214 
215 	*skb->data = DIGITAL_ISO_DEP_I_PCB | ddev->curr_nfc_dep_pni;
216 
217 	ddev->curr_nfc_dep_pni =
218 		DIGITAL_ISO_DEP_PNI(ddev->curr_nfc_dep_pni + 1);
219 
220 	return 0;
221 }
222 
223 static void digital_in_recv_ats(struct nfc_digital_dev *ddev, void *arg,
224 				struct sk_buff *resp)
225 {
226 	struct nfc_target *target = arg;
227 	u8 fsdi;
228 	int rc;
229 
230 	if (IS_ERR(resp)) {
231 		rc = PTR_ERR(resp);
232 		resp = NULL;
233 		goto exit;
234 	}
235 
236 	if (resp->len < 2) {
237 		rc = -EIO;
238 		goto exit;
239 	}
240 
241 	fsdi = DIGITAL_ATS_FSCI(resp->data[1]);
242 	if (fsdi >= 8)
243 		ddev->target_fsc = DIGITAL_ATS_MAX_FSC;
244 	else
245 		ddev->target_fsc = digital_ats_fsc[fsdi];
246 
247 	ddev->curr_nfc_dep_pni = 0;
248 
249 	rc = digital_target_found(ddev, target, NFC_PROTO_ISO14443);
250 
251 exit:
252 	dev_kfree_skb(resp);
253 	kfree(target);
254 
255 	if (rc)
256 		digital_poll_next_tech(ddev);
257 }
258 
259 static int digital_in_send_rats(struct nfc_digital_dev *ddev,
260 				struct nfc_target *target)
261 {
262 	int rc;
263 	struct sk_buff *skb;
264 
265 	skb = digital_skb_alloc(ddev, 2);
266 	if (!skb)
267 		return -ENOMEM;
268 
269 	*skb_put(skb, 1) = DIGITAL_RATS_BYTE1;
270 	*skb_put(skb, 1) = DIGITAL_RATS_PARAM;
271 
272 	rc = digital_in_send_cmd(ddev, skb, 30, digital_in_recv_ats,
273 				 target);
274 	if (rc)
275 		kfree_skb(skb);
276 
277 	return rc;
278 }
279 
280 static void digital_in_recv_sel_res(struct nfc_digital_dev *ddev, void *arg,
281 				    struct sk_buff *resp)
282 {
283 	struct nfc_target *target = arg;
284 	int rc;
285 	u8 sel_res;
286 	u8 nfc_proto;
287 
288 	if (IS_ERR(resp)) {
289 		rc = PTR_ERR(resp);
290 		resp = NULL;
291 		goto exit;
292 	}
293 
294 	if (!DIGITAL_DRV_CAPS_IN_CRC(ddev)) {
295 		rc = digital_skb_check_crc_a(resp);
296 		if (rc) {
297 			PROTOCOL_ERR("4.4.1.3");
298 			goto exit;
299 		}
300 	}
301 
302 	if (!resp->len) {
303 		rc = -EIO;
304 		goto exit;
305 	}
306 
307 	sel_res = resp->data[0];
308 
309 	if (!DIGITAL_SEL_RES_NFCID1_COMPLETE(sel_res)) {
310 		rc = digital_in_send_sdd_req(ddev, target);
311 		if (rc)
312 			goto exit;
313 
314 		goto exit_free_skb;
315 	}
316 
317 	target->sel_res = sel_res;
318 
319 	if (DIGITAL_SEL_RES_IS_T2T(sel_res)) {
320 		nfc_proto = NFC_PROTO_MIFARE;
321 	} else if (DIGITAL_SEL_RES_IS_NFC_DEP(sel_res)) {
322 		nfc_proto = NFC_PROTO_NFC_DEP;
323 	} else if (DIGITAL_SEL_RES_IS_T4T(sel_res)) {
324 		rc = digital_in_send_rats(ddev, target);
325 		if (rc)
326 			goto exit;
327 		/*
328 		 * Skip target_found and don't free it for now. This will be
329 		 * done when receiving the ATS
330 		 */
331 		goto exit_free_skb;
332 	} else {
333 		rc = -EOPNOTSUPP;
334 		goto exit;
335 	}
336 
337 	rc = digital_target_found(ddev, target, nfc_proto);
338 
339 exit:
340 	kfree(target);
341 
342 exit_free_skb:
343 	dev_kfree_skb(resp);
344 
345 	if (rc)
346 		digital_poll_next_tech(ddev);
347 }
348 
349 static int digital_in_send_sel_req(struct nfc_digital_dev *ddev,
350 				   struct nfc_target *target,
351 				   struct digital_sdd_res *sdd_res)
352 {
353 	struct sk_buff *skb;
354 	struct digital_sel_req *sel_req;
355 	u8 sel_cmd;
356 	int rc;
357 
358 	skb = digital_skb_alloc(ddev, sizeof(struct digital_sel_req));
359 	if (!skb)
360 		return -ENOMEM;
361 
362 	skb_put(skb, sizeof(struct digital_sel_req));
363 	sel_req = (struct digital_sel_req *)skb->data;
364 
365 	if (target->nfcid1_len <= 4)
366 		sel_cmd = DIGITAL_CMD_SEL_REQ_CL1;
367 	else if (target->nfcid1_len < 10)
368 		sel_cmd = DIGITAL_CMD_SEL_REQ_CL2;
369 	else
370 		sel_cmd = DIGITAL_CMD_SEL_REQ_CL3;
371 
372 	sel_req->sel_cmd = sel_cmd;
373 	sel_req->b2 = 0x70;
374 	memcpy(sel_req->nfcid1, sdd_res->nfcid1, 4);
375 	sel_req->bcc = sdd_res->bcc;
376 
377 	if (DIGITAL_DRV_CAPS_IN_CRC(ddev)) {
378 		rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
379 				NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A);
380 		if (rc)
381 			goto exit;
382 	} else {
383 		digital_skb_add_crc_a(skb);
384 	}
385 
386 	rc = digital_in_send_cmd(ddev, skb, 30, digital_in_recv_sel_res,
387 				 target);
388 exit:
389 	if (rc)
390 		kfree_skb(skb);
391 
392 	return rc;
393 }
394 
395 static void digital_in_recv_sdd_res(struct nfc_digital_dev *ddev, void *arg,
396 				    struct sk_buff *resp)
397 {
398 	struct nfc_target *target = arg;
399 	struct digital_sdd_res *sdd_res;
400 	int rc;
401 	u8 offset, size;
402 	u8 i, bcc;
403 
404 	if (IS_ERR(resp)) {
405 		rc = PTR_ERR(resp);
406 		resp = NULL;
407 		goto exit;
408 	}
409 
410 	if (resp->len < DIGITAL_SDD_RES_LEN) {
411 		PROTOCOL_ERR("4.7.2.8");
412 		rc = -EINVAL;
413 		goto exit;
414 	}
415 
416 	sdd_res = (struct digital_sdd_res *)resp->data;
417 
418 	for (i = 0, bcc = 0; i < 4; i++)
419 		bcc ^= sdd_res->nfcid1[i];
420 
421 	if (bcc != sdd_res->bcc) {
422 		PROTOCOL_ERR("4.7.2.6");
423 		rc = -EINVAL;
424 		goto exit;
425 	}
426 
427 	if (sdd_res->nfcid1[0] == DIGITAL_SDD_RES_CT) {
428 		offset = 1;
429 		size = 3;
430 	} else {
431 		offset = 0;
432 		size = 4;
433 	}
434 
435 	memcpy(target->nfcid1 + target->nfcid1_len, sdd_res->nfcid1 + offset,
436 	       size);
437 	target->nfcid1_len += size;
438 
439 	rc = digital_in_send_sel_req(ddev, target, sdd_res);
440 
441 exit:
442 	dev_kfree_skb(resp);
443 
444 	if (rc) {
445 		kfree(target);
446 		digital_poll_next_tech(ddev);
447 	}
448 }
449 
450 static int digital_in_send_sdd_req(struct nfc_digital_dev *ddev,
451 				   struct nfc_target *target)
452 {
453 	int rc;
454 	struct sk_buff *skb;
455 	u8 sel_cmd;
456 
457 	rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
458 				     NFC_DIGITAL_FRAMING_NFCA_STANDARD);
459 	if (rc)
460 		return rc;
461 
462 	skb = digital_skb_alloc(ddev, 2);
463 	if (!skb)
464 		return -ENOMEM;
465 
466 	if (target->nfcid1_len == 0)
467 		sel_cmd = DIGITAL_CMD_SEL_REQ_CL1;
468 	else if (target->nfcid1_len == 3)
469 		sel_cmd = DIGITAL_CMD_SEL_REQ_CL2;
470 	else
471 		sel_cmd = DIGITAL_CMD_SEL_REQ_CL3;
472 
473 	*skb_put(skb, sizeof(u8)) = sel_cmd;
474 	*skb_put(skb, sizeof(u8)) = DIGITAL_SDD_REQ_SEL_PAR;
475 
476 	return digital_in_send_cmd(ddev, skb, 30, digital_in_recv_sdd_res,
477 				   target);
478 }
479 
480 static void digital_in_recv_sens_res(struct nfc_digital_dev *ddev, void *arg,
481 				     struct sk_buff *resp)
482 {
483 	struct nfc_target *target = NULL;
484 	int rc;
485 
486 	if (IS_ERR(resp)) {
487 		rc = PTR_ERR(resp);
488 		resp = NULL;
489 		goto exit;
490 	}
491 
492 	if (resp->len < sizeof(u16)) {
493 		rc = -EIO;
494 		goto exit;
495 	}
496 
497 	target = kzalloc(sizeof(struct nfc_target), GFP_KERNEL);
498 	if (!target) {
499 		rc = -ENOMEM;
500 		goto exit;
501 	}
502 
503 	target->sens_res = __le16_to_cpu(*(__le16 *)resp->data);
504 
505 	if (!DIGITAL_SENS_RES_IS_VALID(target->sens_res)) {
506 		PROTOCOL_ERR("4.6.3.3");
507 		rc = -EINVAL;
508 		goto exit;
509 	}
510 
511 	if (DIGITAL_SENS_RES_IS_T1T(target->sens_res))
512 		rc = digital_target_found(ddev, target, NFC_PROTO_JEWEL);
513 	else
514 		rc = digital_in_send_sdd_req(ddev, target);
515 
516 exit:
517 	dev_kfree_skb(resp);
518 
519 	if (rc) {
520 		kfree(target);
521 		digital_poll_next_tech(ddev);
522 	}
523 }
524 
525 int digital_in_send_sens_req(struct nfc_digital_dev *ddev, u8 rf_tech)
526 {
527 	struct sk_buff *skb;
528 	int rc;
529 
530 	rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
531 				     NFC_DIGITAL_RF_TECH_106A);
532 	if (rc)
533 		return rc;
534 
535 	rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
536 				     NFC_DIGITAL_FRAMING_NFCA_SHORT);
537 	if (rc)
538 		return rc;
539 
540 	skb = digital_skb_alloc(ddev, 1);
541 	if (!skb)
542 		return -ENOMEM;
543 
544 	*skb_put(skb, sizeof(u8)) = DIGITAL_CMD_SENS_REQ;
545 
546 	rc = digital_in_send_cmd(ddev, skb, 30, digital_in_recv_sens_res, NULL);
547 	if (rc)
548 		kfree_skb(skb);
549 
550 	return rc;
551 }
552 
553 int digital_in_recv_mifare_res(struct sk_buff *resp)
554 {
555 	/* Successful READ command response is 16 data bytes + 2 CRC bytes long.
556 	 * Since the driver can't differentiate a ACK/NACK response from a valid
557 	 * READ response, the CRC calculation must be handled at digital level
558 	 * even if the driver supports it for this technology.
559 	 */
560 	if (resp->len == DIGITAL_MIFARE_READ_RES_LEN + DIGITAL_CRC_LEN) {
561 		if (digital_skb_check_crc_a(resp)) {
562 			PROTOCOL_ERR("9.4.1.2");
563 			return -EIO;
564 		}
565 
566 		return 0;
567 	}
568 
569 	/* ACK response (i.e. successful WRITE). */
570 	if (resp->len == 1 && resp->data[0] == DIGITAL_MIFARE_ACK_RES) {
571 		resp->data[0] = 0;
572 		return 0;
573 	}
574 
575 	/* NACK and any other responses are treated as error. */
576 	return -EIO;
577 }
578 
579 static void digital_in_recv_attrib_res(struct nfc_digital_dev *ddev, void *arg,
580 				       struct sk_buff *resp)
581 {
582 	struct nfc_target *target = arg;
583 	struct digital_attrib_res *attrib_res;
584 	int rc;
585 
586 	if (IS_ERR(resp)) {
587 		rc = PTR_ERR(resp);
588 		resp = NULL;
589 		goto exit;
590 	}
591 
592 	if (resp->len < sizeof(*attrib_res)) {
593 		PROTOCOL_ERR("12.6.2");
594 		rc = -EIO;
595 		goto exit;
596 	}
597 
598 	attrib_res = (struct digital_attrib_res *)resp->data;
599 
600 	if (attrib_res->mbli_did & 0x0f) {
601 		PROTOCOL_ERR("12.6.2.1");
602 		rc = -EIO;
603 		goto exit;
604 	}
605 
606 	rc = digital_target_found(ddev, target, NFC_PROTO_ISO14443_B);
607 
608 exit:
609 	dev_kfree_skb(resp);
610 	kfree(target);
611 
612 	if (rc)
613 		digital_poll_next_tech(ddev);
614 }
615 
616 static int digital_in_send_attrib_req(struct nfc_digital_dev *ddev,
617 			       struct nfc_target *target,
618 			       struct digital_sensb_res *sensb_res)
619 {
620 	struct digital_attrib_req *attrib_req;
621 	struct sk_buff *skb;
622 	int rc;
623 
624 	skb = digital_skb_alloc(ddev, sizeof(*attrib_req));
625 	if (!skb)
626 		return -ENOMEM;
627 
628 	attrib_req = (struct digital_attrib_req *)skb_put(skb,
629 							  sizeof(*attrib_req));
630 
631 	attrib_req->cmd = DIGITAL_CMD_ATTRIB_REQ;
632 	memcpy(attrib_req->nfcid0, sensb_res->nfcid0,
633 	       sizeof(attrib_req->nfcid0));
634 	attrib_req->param1 = DIGITAL_ATTRIB_P1_TR0_DEFAULT |
635 			     DIGITAL_ATTRIB_P1_TR1_DEFAULT;
636 	attrib_req->param2 = DIGITAL_ATTRIB_P2_LISTEN_POLL_1 |
637 			     DIGITAL_ATTRIB_P2_POLL_LISTEN_1 |
638 			     DIGITAL_ATTRIB_P2_MAX_FRAME_256;
639 	attrib_req->param3 = sensb_res->proto_info[1] & 0x07;
640 	attrib_req->param4 = DIGITAL_ATTRIB_P4_DID(0);
641 
642 	rc = digital_in_send_cmd(ddev, skb, 30, digital_in_recv_attrib_res,
643 				 target);
644 	if (rc)
645 		kfree_skb(skb);
646 
647 	return rc;
648 }
649 
650 static void digital_in_recv_sensb_res(struct nfc_digital_dev *ddev, void *arg,
651 				      struct sk_buff *resp)
652 {
653 	struct nfc_target *target = NULL;
654 	struct digital_sensb_res *sensb_res;
655 	u8 fsci;
656 	int rc;
657 
658 	if (IS_ERR(resp)) {
659 		rc = PTR_ERR(resp);
660 		resp = NULL;
661 		goto exit;
662 	}
663 
664 	if (resp->len != sizeof(*sensb_res)) {
665 		PROTOCOL_ERR("5.6.2.1");
666 		rc = -EIO;
667 		goto exit;
668 	}
669 
670 	sensb_res = (struct digital_sensb_res *)resp->data;
671 
672 	if (sensb_res->cmd != DIGITAL_CMD_SENSB_RES) {
673 		PROTOCOL_ERR("5.6.2");
674 		rc = -EIO;
675 		goto exit;
676 	}
677 
678 	if (!(sensb_res->proto_info[1] & BIT(0))) {
679 		PROTOCOL_ERR("5.6.2.12");
680 		rc = -EIO;
681 		goto exit;
682 	}
683 
684 	if (sensb_res->proto_info[1] & BIT(3)) {
685 		PROTOCOL_ERR("5.6.2.16");
686 		rc = -EIO;
687 		goto exit;
688 	}
689 
690 	fsci = DIGITAL_SENSB_FSCI(sensb_res->proto_info[1]);
691 	if (fsci >= 8)
692 		ddev->target_fsc = DIGITAL_ATS_MAX_FSC;
693 	else
694 		ddev->target_fsc = digital_ats_fsc[fsci];
695 
696 	target = kzalloc(sizeof(struct nfc_target), GFP_KERNEL);
697 	if (!target) {
698 		rc = -ENOMEM;
699 		goto exit;
700 	}
701 
702 	rc = digital_in_send_attrib_req(ddev, target, sensb_res);
703 
704 exit:
705 	dev_kfree_skb(resp);
706 
707 	if (rc) {
708 		kfree(target);
709 		digital_poll_next_tech(ddev);
710 	}
711 }
712 
713 int digital_in_send_sensb_req(struct nfc_digital_dev *ddev, u8 rf_tech)
714 {
715 	struct digital_sensb_req *sensb_req;
716 	struct sk_buff *skb;
717 	int rc;
718 
719 	rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
720 				     NFC_DIGITAL_RF_TECH_106B);
721 	if (rc)
722 		return rc;
723 
724 	rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
725 				     NFC_DIGITAL_FRAMING_NFCB);
726 	if (rc)
727 		return rc;
728 
729 	skb = digital_skb_alloc(ddev, sizeof(*sensb_req));
730 	if (!skb)
731 		return -ENOMEM;
732 
733 	sensb_req = (struct digital_sensb_req *)skb_put(skb,
734 							sizeof(*sensb_req));
735 
736 	sensb_req->cmd = DIGITAL_CMD_SENSB_REQ;
737 	sensb_req->afi = 0x00; /* All families and sub-families */
738 	sensb_req->param = DIGITAL_SENSB_N(0);
739 
740 	rc = digital_in_send_cmd(ddev, skb, 30, digital_in_recv_sensb_res,
741 				 NULL);
742 	if (rc)
743 		kfree_skb(skb);
744 
745 	return rc;
746 }
747 
748 static void digital_in_recv_sensf_res(struct nfc_digital_dev *ddev, void *arg,
749 				   struct sk_buff *resp)
750 {
751 	int rc;
752 	u8 proto;
753 	struct nfc_target target;
754 	struct digital_sensf_res *sensf_res;
755 
756 	if (IS_ERR(resp)) {
757 		rc = PTR_ERR(resp);
758 		resp = NULL;
759 		goto exit;
760 	}
761 
762 	if (resp->len < DIGITAL_SENSF_RES_MIN_LENGTH) {
763 		rc = -EIO;
764 		goto exit;
765 	}
766 
767 	if (!DIGITAL_DRV_CAPS_IN_CRC(ddev)) {
768 		rc = digital_skb_check_crc_f(resp);
769 		if (rc) {
770 			PROTOCOL_ERR("6.4.1.8");
771 			goto exit;
772 		}
773 	}
774 
775 	skb_pull(resp, 1);
776 
777 	memset(&target, 0, sizeof(struct nfc_target));
778 
779 	sensf_res = (struct digital_sensf_res *)resp->data;
780 
781 	memcpy(target.sensf_res, sensf_res, resp->len);
782 	target.sensf_res_len = resp->len;
783 
784 	memcpy(target.nfcid2, sensf_res->nfcid2, NFC_NFCID2_MAXSIZE);
785 	target.nfcid2_len = NFC_NFCID2_MAXSIZE;
786 
787 	if (target.nfcid2[0] == DIGITAL_SENSF_NFCID2_NFC_DEP_B1 &&
788 	    target.nfcid2[1] == DIGITAL_SENSF_NFCID2_NFC_DEP_B2)
789 		proto = NFC_PROTO_NFC_DEP;
790 	else
791 		proto = NFC_PROTO_FELICA;
792 
793 	rc = digital_target_found(ddev, &target, proto);
794 
795 exit:
796 	dev_kfree_skb(resp);
797 
798 	if (rc)
799 		digital_poll_next_tech(ddev);
800 }
801 
802 int digital_in_send_sensf_req(struct nfc_digital_dev *ddev, u8 rf_tech)
803 {
804 	struct digital_sensf_req *sensf_req;
805 	struct sk_buff *skb;
806 	int rc;
807 	u8 size;
808 
809 	rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH, rf_tech);
810 	if (rc)
811 		return rc;
812 
813 	rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
814 				     NFC_DIGITAL_FRAMING_NFCF);
815 	if (rc)
816 		return rc;
817 
818 	size = sizeof(struct digital_sensf_req);
819 
820 	skb = digital_skb_alloc(ddev, size);
821 	if (!skb)
822 		return -ENOMEM;
823 
824 	skb_put(skb, size);
825 
826 	sensf_req = (struct digital_sensf_req *)skb->data;
827 	sensf_req->cmd = DIGITAL_CMD_SENSF_REQ;
828 	sensf_req->sc1 = 0xFF;
829 	sensf_req->sc2 = 0xFF;
830 	sensf_req->rc = 0;
831 	sensf_req->tsn = 0;
832 
833 	*skb_push(skb, 1) = size + 1;
834 
835 	if (!DIGITAL_DRV_CAPS_IN_CRC(ddev))
836 		digital_skb_add_crc_f(skb);
837 
838 	rc = digital_in_send_cmd(ddev, skb, 30, digital_in_recv_sensf_res,
839 				 NULL);
840 	if (rc)
841 		kfree_skb(skb);
842 
843 	return rc;
844 }
845 
846 static void digital_in_recv_iso15693_inv_res(struct nfc_digital_dev *ddev,
847 		void *arg, struct sk_buff *resp)
848 {
849 	struct digital_iso15693_inv_res *res;
850 	struct nfc_target *target = NULL;
851 	int rc;
852 
853 	if (IS_ERR(resp)) {
854 		rc = PTR_ERR(resp);
855 		resp = NULL;
856 		goto out_free_skb;
857 	}
858 
859 	if (resp->len != sizeof(*res)) {
860 		rc = -EIO;
861 		goto out_free_skb;
862 	}
863 
864 	res = (struct digital_iso15693_inv_res *)resp->data;
865 
866 	if (!DIGITAL_ISO15693_RES_IS_VALID(res->flags)) {
867 		PROTOCOL_ERR("ISO15693 - 10.3.1");
868 		rc = -EINVAL;
869 		goto out_free_skb;
870 	}
871 
872 	target = kzalloc(sizeof(*target), GFP_KERNEL);
873 	if (!target) {
874 		rc = -ENOMEM;
875 		goto out_free_skb;
876 	}
877 
878 	target->is_iso15693 = 1;
879 	target->iso15693_dsfid = res->dsfid;
880 	memcpy(target->iso15693_uid, &res->uid, sizeof(target->iso15693_uid));
881 
882 	rc = digital_target_found(ddev, target, NFC_PROTO_ISO15693);
883 
884 	kfree(target);
885 
886 out_free_skb:
887 	dev_kfree_skb(resp);
888 
889 	if (rc)
890 		digital_poll_next_tech(ddev);
891 }
892 
893 int digital_in_send_iso15693_inv_req(struct nfc_digital_dev *ddev, u8 rf_tech)
894 {
895 	struct digital_iso15693_inv_req *req;
896 	struct sk_buff *skb;
897 	int rc;
898 
899 	rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
900 				     NFC_DIGITAL_RF_TECH_ISO15693);
901 	if (rc)
902 		return rc;
903 
904 	rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
905 				     NFC_DIGITAL_FRAMING_ISO15693_INVENTORY);
906 	if (rc)
907 		return rc;
908 
909 	skb = digital_skb_alloc(ddev, sizeof(*req));
910 	if (!skb)
911 		return -ENOMEM;
912 
913 	skb_put(skb, sizeof(*req) - sizeof(req->mask)); /* No mask */
914 	req = (struct digital_iso15693_inv_req *)skb->data;
915 
916 	/* Single sub-carrier, high data rate, no AFI, single slot
917 	 * Inventory command
918 	 */
919 	req->flags = DIGITAL_ISO15693_REQ_FLAG_DATA_RATE |
920 		     DIGITAL_ISO15693_REQ_FLAG_INVENTORY |
921 		     DIGITAL_ISO15693_REQ_FLAG_NB_SLOTS;
922 	req->cmd = DIGITAL_CMD_ISO15693_INVENTORY_REQ;
923 	req->mask_len = 0;
924 
925 	rc = digital_in_send_cmd(ddev, skb, 30,
926 				 digital_in_recv_iso15693_inv_res, NULL);
927 	if (rc)
928 		kfree_skb(skb);
929 
930 	return rc;
931 }
932 
933 static int digital_tg_send_sel_res(struct nfc_digital_dev *ddev)
934 {
935 	struct sk_buff *skb;
936 	int rc;
937 
938 	skb = digital_skb_alloc(ddev, 1);
939 	if (!skb)
940 		return -ENOMEM;
941 
942 	*skb_put(skb, 1) = DIGITAL_SEL_RES_NFC_DEP;
943 
944 	if (!DIGITAL_DRV_CAPS_TG_CRC(ddev))
945 		digital_skb_add_crc_a(skb);
946 
947 	rc = digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
948 				     NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE);
949 	if (rc) {
950 		kfree_skb(skb);
951 		return rc;
952 	}
953 
954 	rc = digital_tg_send_cmd(ddev, skb, 300, digital_tg_recv_atr_req,
955 				 NULL);
956 	if (rc)
957 		kfree_skb(skb);
958 
959 	return rc;
960 }
961 
962 static void digital_tg_recv_sel_req(struct nfc_digital_dev *ddev, void *arg,
963 				    struct sk_buff *resp)
964 {
965 	int rc;
966 
967 	if (IS_ERR(resp)) {
968 		rc = PTR_ERR(resp);
969 		resp = NULL;
970 		goto exit;
971 	}
972 
973 	if (!DIGITAL_DRV_CAPS_TG_CRC(ddev)) {
974 		rc = digital_skb_check_crc_a(resp);
975 		if (rc) {
976 			PROTOCOL_ERR("4.4.1.3");
977 			goto exit;
978 		}
979 	}
980 
981 	/* Silently ignore SEL_REQ content and send a SEL_RES for NFC-DEP */
982 
983 	rc = digital_tg_send_sel_res(ddev);
984 
985 exit:
986 	if (rc)
987 		digital_poll_next_tech(ddev);
988 
989 	dev_kfree_skb(resp);
990 }
991 
992 static int digital_tg_send_sdd_res(struct nfc_digital_dev *ddev)
993 {
994 	struct sk_buff *skb;
995 	struct digital_sdd_res *sdd_res;
996 	int rc, i;
997 
998 	skb = digital_skb_alloc(ddev, sizeof(struct digital_sdd_res));
999 	if (!skb)
1000 		return -ENOMEM;
1001 
1002 	skb_put(skb, sizeof(struct digital_sdd_res));
1003 	sdd_res = (struct digital_sdd_res *)skb->data;
1004 
1005 	sdd_res->nfcid1[0] = 0x08;
1006 	get_random_bytes(sdd_res->nfcid1 + 1, 3);
1007 
1008 	sdd_res->bcc = 0;
1009 	for (i = 0; i < 4; i++)
1010 		sdd_res->bcc ^= sdd_res->nfcid1[i];
1011 
1012 	rc = digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
1013 				NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A);
1014 	if (rc) {
1015 		kfree_skb(skb);
1016 		return rc;
1017 	}
1018 
1019 	rc = digital_tg_send_cmd(ddev, skb, 300, digital_tg_recv_sel_req,
1020 				 NULL);
1021 	if (rc)
1022 		kfree_skb(skb);
1023 
1024 	return rc;
1025 }
1026 
1027 static void digital_tg_recv_sdd_req(struct nfc_digital_dev *ddev, void *arg,
1028 				    struct sk_buff *resp)
1029 {
1030 	u8 *sdd_req;
1031 	int rc;
1032 
1033 	if (IS_ERR(resp)) {
1034 		rc = PTR_ERR(resp);
1035 		resp = NULL;
1036 		goto exit;
1037 	}
1038 
1039 	sdd_req = resp->data;
1040 
1041 	if (resp->len < 2 || sdd_req[0] != DIGITAL_CMD_SEL_REQ_CL1 ||
1042 	    sdd_req[1] != DIGITAL_SDD_REQ_SEL_PAR) {
1043 		rc = -EINVAL;
1044 		goto exit;
1045 	}
1046 
1047 	rc = digital_tg_send_sdd_res(ddev);
1048 
1049 exit:
1050 	if (rc)
1051 		digital_poll_next_tech(ddev);
1052 
1053 	dev_kfree_skb(resp);
1054 }
1055 
1056 static int digital_tg_send_sens_res(struct nfc_digital_dev *ddev)
1057 {
1058 	struct sk_buff *skb;
1059 	u8 *sens_res;
1060 	int rc;
1061 
1062 	skb = digital_skb_alloc(ddev, 2);
1063 	if (!skb)
1064 		return -ENOMEM;
1065 
1066 	sens_res = skb_put(skb, 2);
1067 
1068 	sens_res[0] = (DIGITAL_SENS_RES_NFC_DEP >> 8) & 0xFF;
1069 	sens_res[1] = DIGITAL_SENS_RES_NFC_DEP & 0xFF;
1070 
1071 	rc = digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
1072 				     NFC_DIGITAL_FRAMING_NFCA_STANDARD);
1073 	if (rc) {
1074 		kfree_skb(skb);
1075 		return rc;
1076 	}
1077 
1078 	rc = digital_tg_send_cmd(ddev, skb, 300, digital_tg_recv_sdd_req,
1079 				 NULL);
1080 	if (rc)
1081 		kfree_skb(skb);
1082 
1083 	return rc;
1084 }
1085 
1086 void digital_tg_recv_sens_req(struct nfc_digital_dev *ddev, void *arg,
1087 			      struct sk_buff *resp)
1088 {
1089 	u8 sens_req;
1090 	int rc;
1091 
1092 	if (IS_ERR(resp)) {
1093 		rc = PTR_ERR(resp);
1094 		resp = NULL;
1095 		goto exit;
1096 	}
1097 
1098 	sens_req = resp->data[0];
1099 
1100 	if (!resp->len || (sens_req != DIGITAL_CMD_SENS_REQ &&
1101 	    sens_req != DIGITAL_CMD_ALL_REQ)) {
1102 		rc = -EINVAL;
1103 		goto exit;
1104 	}
1105 
1106 	rc = digital_tg_send_sens_res(ddev);
1107 
1108 exit:
1109 	if (rc)
1110 		digital_poll_next_tech(ddev);
1111 
1112 	dev_kfree_skb(resp);
1113 }
1114 
1115 static void digital_tg_recv_atr_or_sensf_req(struct nfc_digital_dev *ddev,
1116 		void *arg, struct sk_buff *resp)
1117 {
1118 	if (!IS_ERR(resp) && (resp->len >= 2) &&
1119 			(resp->data[1] == DIGITAL_CMD_SENSF_REQ))
1120 		digital_tg_recv_sensf_req(ddev, arg, resp);
1121 	else
1122 		digital_tg_recv_atr_req(ddev, arg, resp);
1123 
1124 	return;
1125 }
1126 
1127 static int digital_tg_send_sensf_res(struct nfc_digital_dev *ddev,
1128 			      struct digital_sensf_req *sensf_req)
1129 {
1130 	struct sk_buff *skb;
1131 	u8 size;
1132 	int rc;
1133 	struct digital_sensf_res *sensf_res;
1134 
1135 	size = sizeof(struct digital_sensf_res);
1136 
1137 	if (sensf_req->rc == DIGITAL_SENSF_REQ_RC_NONE)
1138 		size -= sizeof(sensf_res->rd);
1139 
1140 	skb = digital_skb_alloc(ddev, size);
1141 	if (!skb)
1142 		return -ENOMEM;
1143 
1144 	skb_put(skb, size);
1145 
1146 	sensf_res = (struct digital_sensf_res *)skb->data;
1147 
1148 	memset(sensf_res, 0, size);
1149 
1150 	sensf_res->cmd = DIGITAL_CMD_SENSF_RES;
1151 	sensf_res->nfcid2[0] = DIGITAL_SENSF_NFCID2_NFC_DEP_B1;
1152 	sensf_res->nfcid2[1] = DIGITAL_SENSF_NFCID2_NFC_DEP_B2;
1153 	get_random_bytes(&sensf_res->nfcid2[2], 6);
1154 
1155 	switch (sensf_req->rc) {
1156 	case DIGITAL_SENSF_REQ_RC_SC:
1157 		sensf_res->rd[0] = sensf_req->sc1;
1158 		sensf_res->rd[1] = sensf_req->sc2;
1159 		break;
1160 	case DIGITAL_SENSF_REQ_RC_AP:
1161 		sensf_res->rd[0] = DIGITAL_SENSF_RES_RD_AP_B1;
1162 		sensf_res->rd[1] = DIGITAL_SENSF_RES_RD_AP_B2;
1163 		break;
1164 	}
1165 
1166 	*skb_push(skb, sizeof(u8)) = size + 1;
1167 
1168 	if (!DIGITAL_DRV_CAPS_TG_CRC(ddev))
1169 		digital_skb_add_crc_f(skb);
1170 
1171 	rc = digital_tg_send_cmd(ddev, skb, 300,
1172 				 digital_tg_recv_atr_or_sensf_req, NULL);
1173 	if (rc)
1174 		kfree_skb(skb);
1175 
1176 	return rc;
1177 }
1178 
1179 void digital_tg_recv_sensf_req(struct nfc_digital_dev *ddev, void *arg,
1180 			       struct sk_buff *resp)
1181 {
1182 	struct digital_sensf_req *sensf_req;
1183 	int rc;
1184 
1185 	if (IS_ERR(resp)) {
1186 		rc = PTR_ERR(resp);
1187 		resp = NULL;
1188 		goto exit;
1189 	}
1190 
1191 	if (!DIGITAL_DRV_CAPS_TG_CRC(ddev)) {
1192 		rc = digital_skb_check_crc_f(resp);
1193 		if (rc) {
1194 			PROTOCOL_ERR("6.4.1.8");
1195 			goto exit;
1196 		}
1197 	}
1198 
1199 	if (resp->len != sizeof(struct digital_sensf_req) + 1) {
1200 		rc = -EINVAL;
1201 		goto exit;
1202 	}
1203 
1204 	skb_pull(resp, 1);
1205 	sensf_req = (struct digital_sensf_req *)resp->data;
1206 
1207 	if (sensf_req->cmd != DIGITAL_CMD_SENSF_REQ) {
1208 		rc = -EINVAL;
1209 		goto exit;
1210 	}
1211 
1212 	rc = digital_tg_send_sensf_res(ddev, sensf_req);
1213 
1214 exit:
1215 	if (rc)
1216 		digital_poll_next_tech(ddev);
1217 
1218 	dev_kfree_skb(resp);
1219 }
1220 
1221 static int digital_tg_config_nfca(struct nfc_digital_dev *ddev)
1222 {
1223 	int rc;
1224 
1225 	rc = digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
1226 				     NFC_DIGITAL_RF_TECH_106A);
1227 	if (rc)
1228 		return rc;
1229 
1230 	return digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
1231 				       NFC_DIGITAL_FRAMING_NFCA_NFC_DEP);
1232 }
1233 
1234 int digital_tg_listen_nfca(struct nfc_digital_dev *ddev, u8 rf_tech)
1235 {
1236 	int rc;
1237 
1238 	rc = digital_tg_config_nfca(ddev);
1239 	if (rc)
1240 		return rc;
1241 
1242 	return digital_tg_listen(ddev, 300, digital_tg_recv_sens_req, NULL);
1243 }
1244 
1245 static int digital_tg_config_nfcf(struct nfc_digital_dev *ddev, u8 rf_tech)
1246 {
1247 	int rc;
1248 
1249 	rc = digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH, rf_tech);
1250 	if (rc)
1251 		return rc;
1252 
1253 	return digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
1254 				       NFC_DIGITAL_FRAMING_NFCF_NFC_DEP);
1255 }
1256 
1257 int digital_tg_listen_nfcf(struct nfc_digital_dev *ddev, u8 rf_tech)
1258 {
1259 	int rc;
1260 
1261 	rc = digital_tg_config_nfcf(ddev, rf_tech);
1262 	if (rc)
1263 		return rc;
1264 
1265 	return digital_tg_listen(ddev, 300, digital_tg_recv_sensf_req, NULL);
1266 }
1267 
1268 void digital_tg_recv_md_req(struct nfc_digital_dev *ddev, void *arg,
1269 			    struct sk_buff *resp)
1270 {
1271 	u8 rf_tech;
1272 	int rc;
1273 
1274 	if (IS_ERR(resp)) {
1275 		resp = NULL;
1276 		goto exit_free_skb;
1277 	}
1278 
1279 	rc = ddev->ops->tg_get_rf_tech(ddev, &rf_tech);
1280 	if (rc)
1281 		goto exit_free_skb;
1282 
1283 	switch (rf_tech) {
1284 	case NFC_DIGITAL_RF_TECH_106A:
1285 		rc = digital_tg_config_nfca(ddev);
1286 		if (rc)
1287 			goto exit_free_skb;
1288 		digital_tg_recv_sens_req(ddev, arg, resp);
1289 		break;
1290 	case NFC_DIGITAL_RF_TECH_212F:
1291 	case NFC_DIGITAL_RF_TECH_424F:
1292 		rc = digital_tg_config_nfcf(ddev, rf_tech);
1293 		if (rc)
1294 			goto exit_free_skb;
1295 		digital_tg_recv_sensf_req(ddev, arg, resp);
1296 		break;
1297 	default:
1298 		goto exit_free_skb;
1299 	}
1300 
1301 	return;
1302 
1303 exit_free_skb:
1304 	digital_poll_next_tech(ddev);
1305 	dev_kfree_skb(resp);
1306 }
1307