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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * NFC Digital Protocol stack
   4 * Copyright (c) 2013, Intel Corporation.
   5 */
   6
   7#define pr_fmt(fmt) "digital: %s: " fmt, __func__
   8
   9#include "digital.h"
  10
  11#define DIGITAL_NFC_DEP_N_RETRY_NACK	2
  12#define DIGITAL_NFC_DEP_N_RETRY_ATN	2
  13
  14#define DIGITAL_NFC_DEP_FRAME_DIR_OUT 0xD4
  15#define DIGITAL_NFC_DEP_FRAME_DIR_IN  0xD5
  16
  17#define DIGITAL_NFC_DEP_NFCA_SOD_SB   0xF0
  18
  19#define DIGITAL_CMD_ATR_REQ 0x00
  20#define DIGITAL_CMD_ATR_RES 0x01
  21#define DIGITAL_CMD_PSL_REQ 0x04
  22#define DIGITAL_CMD_PSL_RES 0x05
  23#define DIGITAL_CMD_DEP_REQ 0x06
  24#define DIGITAL_CMD_DEP_RES 0x07
  25
  26#define DIGITAL_ATR_REQ_MIN_SIZE 16
  27#define DIGITAL_ATR_REQ_MAX_SIZE 64
  28
  29#define DIGITAL_ATR_RES_TO_WT(s)	((s) & 0xF)
  30
  31#define DIGITAL_DID_MAX	14
  32
  33#define DIGITAL_PAYLOAD_SIZE_MAX	254
  34#define DIGITAL_PAYLOAD_BITS_TO_PP(s)	(((s) & 0x3) << 4)
  35#define DIGITAL_PAYLOAD_PP_TO_BITS(s)	(((s) >> 4) & 0x3)
  36#define DIGITAL_PAYLOAD_BITS_TO_FSL(s)	((s) & 0x3)
  37#define DIGITAL_PAYLOAD_FSL_TO_BITS(s)	((s) & 0x3)
  38
  39#define DIGITAL_GB_BIT	0x02
  40
  41#define DIGITAL_NFC_DEP_PFB_TYPE(pfb) ((pfb) & 0xE0)
  42
  43#define DIGITAL_NFC_DEP_PFB_TIMEOUT_BIT 0x10
  44#define DIGITAL_NFC_DEP_PFB_MI_BIT	0x10
  45#define DIGITAL_NFC_DEP_PFB_NACK_BIT	0x10
  46#define DIGITAL_NFC_DEP_PFB_DID_BIT	0x04
  47
  48#define DIGITAL_NFC_DEP_PFB_IS_TIMEOUT(pfb) \
  49				((pfb) & DIGITAL_NFC_DEP_PFB_TIMEOUT_BIT)
  50#define DIGITAL_NFC_DEP_MI_BIT_SET(pfb)  ((pfb) & DIGITAL_NFC_DEP_PFB_MI_BIT)
  51#define DIGITAL_NFC_DEP_NACK_BIT_SET(pfb) ((pfb) & DIGITAL_NFC_DEP_PFB_NACK_BIT)
  52#define DIGITAL_NFC_DEP_NAD_BIT_SET(pfb) ((pfb) & 0x08)
  53#define DIGITAL_NFC_DEP_DID_BIT_SET(pfb) ((pfb) & DIGITAL_NFC_DEP_PFB_DID_BIT)
  54#define DIGITAL_NFC_DEP_PFB_PNI(pfb)     ((pfb) & 0x03)
  55
  56#define DIGITAL_NFC_DEP_RTOX_VALUE(data) ((data) & 0x3F)
  57#define DIGITAL_NFC_DEP_RTOX_MAX	 59
  58
  59#define DIGITAL_NFC_DEP_PFB_I_PDU          0x00
  60#define DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU   0x40
  61#define DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU 0x80
  62
  63struct digital_atr_req {
  64	u8 dir;
  65	u8 cmd;
  66	u8 nfcid3[10];
  67	u8 did;
  68	u8 bs;
  69	u8 br;
  70	u8 pp;
  71	u8 gb[];
  72} __packed;
  73
  74struct digital_atr_res {
  75	u8 dir;
  76	u8 cmd;
  77	u8 nfcid3[10];
  78	u8 did;
  79	u8 bs;
  80	u8 br;
  81	u8 to;
  82	u8 pp;
  83	u8 gb[];
  84} __packed;
  85
  86struct digital_psl_req {
  87	u8 dir;
  88	u8 cmd;
  89	u8 did;
  90	u8 brs;
  91	u8 fsl;
  92} __packed;
  93
  94struct digital_psl_res {
  95	u8 dir;
  96	u8 cmd;
  97	u8 did;
  98} __packed;
  99
 100struct digital_dep_req_res {
 101	u8 dir;
 102	u8 cmd;
 103	u8 pfb;
 104} __packed;
 105
 106static void digital_in_recv_dep_res(struct nfc_digital_dev *ddev, void *arg,
 107				    struct sk_buff *resp);
 108static void digital_tg_recv_dep_req(struct nfc_digital_dev *ddev, void *arg,
 109				    struct sk_buff *resp);
 110
 111static const u8 digital_payload_bits_map[4] = {
 112	[0] = 64,
 113	[1] = 128,
 114	[2] = 192,
 115	[3] = 254
 116};
 117
 118/* Response Waiting Time for ATR_RES PDU in ms
 119 *
 120 * RWT(ATR_RES) = RWT(nfcdep,activation) + dRWT(nfcdep) + dT(nfcdep,initiator)
 121 *
 122 * with:
 123 *  RWT(nfcdep,activation) = 4096 * 2^12 / f(c) s
 124 *  dRWT(nfcdep) = 16 / f(c) s
 125 *  dT(nfcdep,initiator) = 100 ms
 126 *  f(c) = 13560000 Hz
 127 */
 128#define DIGITAL_ATR_RES_RWT 1337
 129
 130/* Response Waiting Time for other DEP PDUs in ms
 131 *
 132 * max_rwt = rwt + dRWT(nfcdep) + dT(nfcdep,initiator)
 133 *
 134 * with:
 135 *  rwt = (256 * 16 / f(c)) * 2^wt s
 136 *  dRWT(nfcdep) = 16 / f(c) s
 137 *  dT(nfcdep,initiator) = 100 ms
 138 *  f(c) = 13560000 Hz
 139 *  0 <= wt <= 14 (given by the target by the TO field of ATR_RES response)
 140 */
 141#define DIGITAL_NFC_DEP_IN_MAX_WT 14
 142#define DIGITAL_NFC_DEP_TG_MAX_WT 14
 143static const u16 digital_rwt_map[DIGITAL_NFC_DEP_IN_MAX_WT + 1] = {
 144	100,  101,  101,  102,  105,
 145	110,  119,  139,  177,  255,
 146	409,  719, 1337, 2575, 5049,
 147};
 148
 149static u8 digital_payload_bits_to_size(u8 payload_bits)
 150{
 151	if (payload_bits >= ARRAY_SIZE(digital_payload_bits_map))
 152		return 0;
 153
 154	return digital_payload_bits_map[payload_bits];
 155}
 156
 157static u8 digital_payload_size_to_bits(u8 payload_size)
 158{
 159	int i;
 160
 161	for (i = 0; i < ARRAY_SIZE(digital_payload_bits_map); i++)
 162		if (digital_payload_bits_map[i] == payload_size)
 163			return i;
 164
 165	return 0xff;
 166}
 167
 168static void digital_skb_push_dep_sod(struct nfc_digital_dev *ddev,
 169				     struct sk_buff *skb)
 170{
 171	skb_push(skb, sizeof(u8));
 172
 173	skb->data[0] = skb->len;
 174
 175	if (ddev->curr_rf_tech == NFC_DIGITAL_RF_TECH_106A)
 176		*(u8 *)skb_push(skb, sizeof(u8)) = DIGITAL_NFC_DEP_NFCA_SOD_SB;
 177}
 178
 179static int digital_skb_pull_dep_sod(struct nfc_digital_dev *ddev,
 180				    struct sk_buff *skb)
 181{
 182	u8 size;
 183
 184	if (skb->len < 2)
 185		return -EIO;
 186
 187	if (ddev->curr_rf_tech == NFC_DIGITAL_RF_TECH_106A)
 188		skb_pull(skb, sizeof(u8));
 189
 190	size = skb->data[0];
 191	if (size != skb->len)
 192		return -EIO;
 193
 194	skb_pull(skb, sizeof(u8));
 195
 196	return 0;
 197}
 198
 199static struct sk_buff *
 200digital_send_dep_data_prep(struct nfc_digital_dev *ddev, struct sk_buff *skb,
 201			   struct digital_dep_req_res *dep_req_res,
 202			   struct digital_data_exch *data_exch)
 203{
 204	struct sk_buff *new_skb;
 205
 206	if (skb->len > ddev->remote_payload_max) {
 207		dep_req_res->pfb |= DIGITAL_NFC_DEP_PFB_MI_BIT;
 208
 209		new_skb = digital_skb_alloc(ddev, ddev->remote_payload_max);
 210		if (!new_skb) {
 211			kfree_skb(ddev->chaining_skb);
 212			ddev->chaining_skb = NULL;
 213
 214			return ERR_PTR(-ENOMEM);
 215		}
 216
 217		skb_put_data(new_skb, skb->data, ddev->remote_payload_max);
 218		skb_pull(skb, ddev->remote_payload_max);
 219
 220		ddev->chaining_skb = skb;
 221		ddev->data_exch = data_exch;
 222	} else {
 223		ddev->chaining_skb = NULL;
 224		new_skb = skb;
 225	}
 226
 227	return new_skb;
 228}
 229
 230static struct sk_buff *
 231digital_recv_dep_data_gather(struct nfc_digital_dev *ddev, u8 pfb,
 232			     struct sk_buff *resp,
 233			     int (*send_ack)(struct nfc_digital_dev *ddev,
 234					     struct digital_data_exch
 235							     *data_exch),
 236			     struct digital_data_exch *data_exch)
 237{
 238	struct sk_buff *new_skb;
 239	int rc;
 240
 241	if (DIGITAL_NFC_DEP_MI_BIT_SET(pfb) && (!ddev->chaining_skb)) {
 242		ddev->chaining_skb =
 243			nfc_alloc_recv_skb(8 * ddev->local_payload_max,
 244					   GFP_KERNEL);
 245		if (!ddev->chaining_skb) {
 246			rc = -ENOMEM;
 247			goto error;
 248		}
 249	}
 250
 251	if (ddev->chaining_skb) {
 252		if (resp->len > skb_tailroom(ddev->chaining_skb)) {
 253			new_skb = skb_copy_expand(ddev->chaining_skb,
 254						  skb_headroom(
 255							  ddev->chaining_skb),
 256						  8 * ddev->local_payload_max,
 257						  GFP_KERNEL);
 258			if (!new_skb) {
 259				rc = -ENOMEM;
 260				goto error;
 261			}
 262
 263			kfree_skb(ddev->chaining_skb);
 264			ddev->chaining_skb = new_skb;
 265		}
 266
 267		skb_put_data(ddev->chaining_skb, resp->data, resp->len);
 268
 269		kfree_skb(resp);
 270		resp = NULL;
 271
 272		if (DIGITAL_NFC_DEP_MI_BIT_SET(pfb)) {
 273			rc = send_ack(ddev, data_exch);
 274			if (rc)
 275				goto error;
 276
 277			return NULL;
 278		}
 279
 280		resp = ddev->chaining_skb;
 281		ddev->chaining_skb = NULL;
 282	}
 283
 284	return resp;
 285
 286error:
 287	kfree_skb(resp);
 288
 289	kfree_skb(ddev->chaining_skb);
 290	ddev->chaining_skb = NULL;
 291
 292	return ERR_PTR(rc);
 293}
 294
 295static void digital_in_recv_psl_res(struct nfc_digital_dev *ddev, void *arg,
 296				    struct sk_buff *resp)
 297{
 298	struct nfc_target *target = arg;
 299	struct digital_psl_res *psl_res;
 300	int rc;
 301
 302	if (IS_ERR(resp)) {
 303		rc = PTR_ERR(resp);
 304		resp = NULL;
 305		goto exit;
 306	}
 307
 308	rc = ddev->skb_check_crc(resp);
 309	if (rc) {
 310		PROTOCOL_ERR("14.4.1.6");
 311		goto exit;
 312	}
 313
 314	rc = digital_skb_pull_dep_sod(ddev, resp);
 315	if (rc) {
 316		PROTOCOL_ERR("14.4.1.2");
 317		goto exit;
 318	}
 319
 320	psl_res = (struct digital_psl_res *)resp->data;
 321
 322	if ((resp->len != sizeof(*psl_res)) ||
 323	    (psl_res->dir != DIGITAL_NFC_DEP_FRAME_DIR_IN) ||
 324	    (psl_res->cmd != DIGITAL_CMD_PSL_RES)) {
 325		rc = -EIO;
 326		goto exit;
 327	}
 328
 329	rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
 330				     NFC_DIGITAL_RF_TECH_424F);
 331	if (rc)
 332		goto exit;
 333
 334	rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
 335				     NFC_DIGITAL_FRAMING_NFCF_NFC_DEP);
 336	if (rc)
 337		goto exit;
 338
 339	if (!DIGITAL_DRV_CAPS_IN_CRC(ddev) &&
 340	    (ddev->curr_rf_tech == NFC_DIGITAL_RF_TECH_106A)) {
 341		ddev->skb_add_crc = digital_skb_add_crc_f;
 342		ddev->skb_check_crc = digital_skb_check_crc_f;
 343	}
 344
 345	ddev->curr_rf_tech = NFC_DIGITAL_RF_TECH_424F;
 346
 347	nfc_dep_link_is_up(ddev->nfc_dev, target->idx, NFC_COMM_ACTIVE,
 348			   NFC_RF_INITIATOR);
 349
 350	ddev->curr_nfc_dep_pni = 0;
 351
 352exit:
 353	dev_kfree_skb(resp);
 354
 355	if (rc)
 356		ddev->curr_protocol = 0;
 357}
 358
 359static int digital_in_send_psl_req(struct nfc_digital_dev *ddev,
 360				   struct nfc_target *target)
 361{
 362	struct sk_buff *skb;
 363	struct digital_psl_req *psl_req;
 364	int rc;
 365	u8 payload_size, payload_bits;
 366
 367	skb = digital_skb_alloc(ddev, sizeof(*psl_req));
 368	if (!skb)
 369		return -ENOMEM;
 370
 371	skb_put(skb, sizeof(*psl_req));
 372
 373	psl_req = (struct digital_psl_req *)skb->data;
 374
 375	psl_req->dir = DIGITAL_NFC_DEP_FRAME_DIR_OUT;
 376	psl_req->cmd = DIGITAL_CMD_PSL_REQ;
 377	psl_req->did = 0;
 378	psl_req->brs = (0x2 << 3) | 0x2; /* 424F both directions */
 379
 380	payload_size = min(ddev->local_payload_max, ddev->remote_payload_max);
 381	payload_bits = digital_payload_size_to_bits(payload_size);
 382	psl_req->fsl = DIGITAL_PAYLOAD_BITS_TO_FSL(payload_bits);
 383
 384	ddev->local_payload_max = payload_size;
 385	ddev->remote_payload_max = payload_size;
 386
 387	digital_skb_push_dep_sod(ddev, skb);
 388
 389	ddev->skb_add_crc(skb);
 390
 391	rc = digital_in_send_cmd(ddev, skb, ddev->dep_rwt,
 392				 digital_in_recv_psl_res, target);
 393	if (rc)
 394		kfree_skb(skb);
 395
 396	return rc;
 397}
 398
 399static void digital_in_recv_atr_res(struct nfc_digital_dev *ddev, void *arg,
 400				 struct sk_buff *resp)
 401{
 402	struct nfc_target *target = arg;
 403	struct digital_atr_res *atr_res;
 404	u8 gb_len, payload_bits;
 405	u8 wt;
 406	int rc;
 407
 408	if (IS_ERR(resp)) {
 409		rc = PTR_ERR(resp);
 410		resp = NULL;
 411		goto exit;
 412	}
 413
 414	rc = ddev->skb_check_crc(resp);
 415	if (rc) {
 416		PROTOCOL_ERR("14.4.1.6");
 417		goto exit;
 418	}
 419
 420	rc = digital_skb_pull_dep_sod(ddev, resp);
 421	if (rc) {
 422		PROTOCOL_ERR("14.4.1.2");
 423		goto exit;
 424	}
 425
 426	if (resp->len < sizeof(struct digital_atr_res)) {
 427		rc = -EIO;
 428		goto exit;
 429	}
 430
 431	gb_len = resp->len - sizeof(struct digital_atr_res);
 432
 433	atr_res = (struct digital_atr_res *)resp->data;
 434
 435	wt = DIGITAL_ATR_RES_TO_WT(atr_res->to);
 436	if (wt > DIGITAL_NFC_DEP_IN_MAX_WT)
 437		wt = DIGITAL_NFC_DEP_IN_MAX_WT;
 438	ddev->dep_rwt = digital_rwt_map[wt];
 439
 440	payload_bits = DIGITAL_PAYLOAD_PP_TO_BITS(atr_res->pp);
 441	ddev->remote_payload_max = digital_payload_bits_to_size(payload_bits);
 442
 443	if (!ddev->remote_payload_max) {
 444		rc = -EINVAL;
 445		goto exit;
 446	}
 447
 448	rc = nfc_set_remote_general_bytes(ddev->nfc_dev, atr_res->gb, gb_len);
 449	if (rc)
 450		goto exit;
 451
 452	if ((ddev->protocols & NFC_PROTO_FELICA_MASK) &&
 453	    (ddev->curr_rf_tech != NFC_DIGITAL_RF_TECH_424F)) {
 454		rc = digital_in_send_psl_req(ddev, target);
 455		if (!rc)
 456			goto exit;
 457	}
 458
 459	rc = nfc_dep_link_is_up(ddev->nfc_dev, target->idx, NFC_COMM_ACTIVE,
 460				NFC_RF_INITIATOR);
 461
 462	ddev->curr_nfc_dep_pni = 0;
 463
 464exit:
 465	dev_kfree_skb(resp);
 466
 467	if (rc)
 468		ddev->curr_protocol = 0;
 469}
 470
 471int digital_in_send_atr_req(struct nfc_digital_dev *ddev,
 472			    struct nfc_target *target, __u8 comm_mode, __u8 *gb,
 473			    size_t gb_len)
 474{
 475	struct sk_buff *skb;
 476	struct digital_atr_req *atr_req;
 477	uint size;
 478	int rc;
 479	u8 payload_bits;
 480
 481	size = DIGITAL_ATR_REQ_MIN_SIZE + gb_len;
 482
 483	if (size > DIGITAL_ATR_REQ_MAX_SIZE) {
 484		PROTOCOL_ERR("14.6.1.1");
 485		return -EINVAL;
 486	}
 487
 488	skb = digital_skb_alloc(ddev, size);
 489	if (!skb)
 490		return -ENOMEM;
 491
 492	skb_put(skb, sizeof(struct digital_atr_req));
 493
 494	atr_req = (struct digital_atr_req *)skb->data;
 495	memset(atr_req, 0, sizeof(struct digital_atr_req));
 496
 497	atr_req->dir = DIGITAL_NFC_DEP_FRAME_DIR_OUT;
 498	atr_req->cmd = DIGITAL_CMD_ATR_REQ;
 499	if (target->nfcid2_len)
 500		memcpy(atr_req->nfcid3, target->nfcid2, NFC_NFCID2_MAXSIZE);
 501	else
 502		get_random_bytes(atr_req->nfcid3, NFC_NFCID3_MAXSIZE);
 503
 504	atr_req->did = 0;
 505	atr_req->bs = 0;
 506	atr_req->br = 0;
 507
 508	ddev->local_payload_max = DIGITAL_PAYLOAD_SIZE_MAX;
 509	payload_bits = digital_payload_size_to_bits(ddev->local_payload_max);
 510	atr_req->pp = DIGITAL_PAYLOAD_BITS_TO_PP(payload_bits);
 511
 512	if (gb_len) {
 513		atr_req->pp |= DIGITAL_GB_BIT;
 514		skb_put_data(skb, gb, gb_len);
 515	}
 516
 517	digital_skb_push_dep_sod(ddev, skb);
 518
 519	ddev->skb_add_crc(skb);
 520
 521	rc = digital_in_send_cmd(ddev, skb, DIGITAL_ATR_RES_RWT,
 522				 digital_in_recv_atr_res, target);
 523	if (rc)
 524		kfree_skb(skb);
 525
 526	return rc;
 527}
 528
 529static int digital_in_send_ack(struct nfc_digital_dev *ddev,
 530			       struct digital_data_exch *data_exch)
 531{
 532	struct digital_dep_req_res *dep_req;
 533	struct sk_buff *skb;
 534	int rc;
 535
 536	skb = digital_skb_alloc(ddev, 1);
 537	if (!skb)
 538		return -ENOMEM;
 539
 540	skb_push(skb, sizeof(struct digital_dep_req_res));
 541
 542	dep_req = (struct digital_dep_req_res *)skb->data;
 543
 544	dep_req->dir = DIGITAL_NFC_DEP_FRAME_DIR_OUT;
 545	dep_req->cmd = DIGITAL_CMD_DEP_REQ;
 546	dep_req->pfb = DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU |
 547		       ddev->curr_nfc_dep_pni;
 548
 549	digital_skb_push_dep_sod(ddev, skb);
 550
 551	ddev->skb_add_crc(skb);
 552
 553	ddev->saved_skb = pskb_copy(skb, GFP_KERNEL);
 554
 555	rc = digital_in_send_cmd(ddev, skb, ddev->dep_rwt,
 556				 digital_in_recv_dep_res, data_exch);
 557	if (rc) {
 558		kfree_skb(skb);
 559		kfree_skb(ddev->saved_skb);
 560		ddev->saved_skb = NULL;
 561	}
 562
 563	return rc;
 564}
 565
 566static int digital_in_send_nack(struct nfc_digital_dev *ddev,
 567				struct digital_data_exch *data_exch)
 568{
 569	struct digital_dep_req_res *dep_req;
 570	struct sk_buff *skb;
 571	int rc;
 572
 573	skb = digital_skb_alloc(ddev, 1);
 574	if (!skb)
 575		return -ENOMEM;
 576
 577	skb_push(skb, sizeof(struct digital_dep_req_res));
 578
 579	dep_req = (struct digital_dep_req_res *)skb->data;
 580
 581	dep_req->dir = DIGITAL_NFC_DEP_FRAME_DIR_OUT;
 582	dep_req->cmd = DIGITAL_CMD_DEP_REQ;
 583	dep_req->pfb = DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU |
 584		       DIGITAL_NFC_DEP_PFB_NACK_BIT | ddev->curr_nfc_dep_pni;
 585
 586	digital_skb_push_dep_sod(ddev, skb);
 587
 588	ddev->skb_add_crc(skb);
 589
 590	rc = digital_in_send_cmd(ddev, skb, ddev->dep_rwt,
 591				 digital_in_recv_dep_res, data_exch);
 592	if (rc)
 593		kfree_skb(skb);
 594
 595	return rc;
 596}
 597
 598static int digital_in_send_atn(struct nfc_digital_dev *ddev,
 599			       struct digital_data_exch *data_exch)
 600{
 601	struct digital_dep_req_res *dep_req;
 602	struct sk_buff *skb;
 603	int rc;
 604
 605	skb = digital_skb_alloc(ddev, 1);
 606	if (!skb)
 607		return -ENOMEM;
 608
 609	skb_push(skb, sizeof(struct digital_dep_req_res));
 610
 611	dep_req = (struct digital_dep_req_res *)skb->data;
 612
 613	dep_req->dir = DIGITAL_NFC_DEP_FRAME_DIR_OUT;
 614	dep_req->cmd = DIGITAL_CMD_DEP_REQ;
 615	dep_req->pfb = DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU;
 616
 617	digital_skb_push_dep_sod(ddev, skb);
 618
 619	ddev->skb_add_crc(skb);
 620
 621	rc = digital_in_send_cmd(ddev, skb, ddev->dep_rwt,
 622				 digital_in_recv_dep_res, data_exch);
 623	if (rc)
 624		kfree_skb(skb);
 625
 626	return rc;
 627}
 628
 629static int digital_in_send_rtox(struct nfc_digital_dev *ddev,
 630				struct digital_data_exch *data_exch, u8 rtox)
 631{
 632	struct digital_dep_req_res *dep_req;
 633	struct sk_buff *skb;
 634	int rc;
 635	u16 rwt_int;
 636
 637	rwt_int = ddev->dep_rwt * rtox;
 638	if (rwt_int > digital_rwt_map[DIGITAL_NFC_DEP_IN_MAX_WT])
 639		rwt_int = digital_rwt_map[DIGITAL_NFC_DEP_IN_MAX_WT];
 640
 641	skb = digital_skb_alloc(ddev, 1);
 642	if (!skb)
 643		return -ENOMEM;
 644
 645	skb_put_u8(skb, rtox);
 646
 647	skb_push(skb, sizeof(struct digital_dep_req_res));
 648
 649	dep_req = (struct digital_dep_req_res *)skb->data;
 650
 651	dep_req->dir = DIGITAL_NFC_DEP_FRAME_DIR_OUT;
 652	dep_req->cmd = DIGITAL_CMD_DEP_REQ;
 653	dep_req->pfb = DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU |
 654		       DIGITAL_NFC_DEP_PFB_TIMEOUT_BIT;
 655
 656	digital_skb_push_dep_sod(ddev, skb);
 657
 658	ddev->skb_add_crc(skb);
 659
 660	rc = digital_in_send_cmd(ddev, skb, rwt_int,
 661				 digital_in_recv_dep_res, data_exch);
 662	if (rc)
 663		kfree_skb(skb);
 664
 665	return rc;
 666}
 667
 668static int digital_in_send_saved_skb(struct nfc_digital_dev *ddev,
 669				     struct digital_data_exch *data_exch)
 670{
 671	int rc;
 672
 673	if (!ddev->saved_skb)
 674		return -EINVAL;
 675
 676	skb_get(ddev->saved_skb);
 677
 678	rc = digital_in_send_cmd(ddev, ddev->saved_skb, ddev->dep_rwt,
 679				 digital_in_recv_dep_res, data_exch);
 680	if (rc)
 681		kfree_skb(ddev->saved_skb);
 682
 683	return rc;
 684}
 685
 686static void digital_in_recv_dep_res(struct nfc_digital_dev *ddev, void *arg,
 687				    struct sk_buff *resp)
 688{
 689	struct digital_data_exch *data_exch = arg;
 690	struct digital_dep_req_res *dep_res;
 691	u8 pfb;
 692	uint size;
 693	int rc;
 694	u8 rtox;
 695
 696	if (IS_ERR(resp)) {
 697		rc = PTR_ERR(resp);
 698		resp = NULL;
 699
 700		if ((rc == -EIO || (rc == -ETIMEDOUT && ddev->nack_count)) &&
 701		    (ddev->nack_count++ < DIGITAL_NFC_DEP_N_RETRY_NACK)) {
 702			ddev->atn_count = 0;
 703
 704			rc = digital_in_send_nack(ddev, data_exch);
 705			if (rc)
 706				goto error;
 707
 708			return;
 709		} else if ((rc == -ETIMEDOUT) &&
 710			   (ddev->atn_count++ < DIGITAL_NFC_DEP_N_RETRY_ATN)) {
 711			ddev->nack_count = 0;
 712
 713			rc = digital_in_send_atn(ddev, data_exch);
 714			if (rc)
 715				goto error;
 716
 717			return;
 718		}
 719
 720		goto exit;
 721	}
 722
 723	rc = digital_skb_pull_dep_sod(ddev, resp);
 724	if (rc) {
 725		PROTOCOL_ERR("14.4.1.2");
 726		goto exit;
 727	}
 728
 729	rc = ddev->skb_check_crc(resp);
 730	if (rc) {
 731		if ((resp->len >= 4) &&
 732		    (ddev->nack_count++ < DIGITAL_NFC_DEP_N_RETRY_NACK)) {
 733			ddev->atn_count = 0;
 734
 735			rc = digital_in_send_nack(ddev, data_exch);
 736			if (rc)
 737				goto error;
 738
 739			kfree_skb(resp);
 740
 741			return;
 742		}
 743
 744		PROTOCOL_ERR("14.4.1.6");
 745		goto error;
 746	}
 747
 748	ddev->atn_count = 0;
 749	ddev->nack_count = 0;
 750
 751	if (resp->len > ddev->local_payload_max) {
 752		rc = -EMSGSIZE;
 753		goto exit;
 754	}
 755
 756	size = sizeof(struct digital_dep_req_res);
 757	dep_res = (struct digital_dep_req_res *)resp->data;
 758
 759	if (resp->len < size || dep_res->dir != DIGITAL_NFC_DEP_FRAME_DIR_IN ||
 760	    dep_res->cmd != DIGITAL_CMD_DEP_RES) {
 761		rc = -EIO;
 762		goto error;
 763	}
 764
 765	pfb = dep_res->pfb;
 766
 767	if (DIGITAL_NFC_DEP_DID_BIT_SET(pfb)) {
 768		PROTOCOL_ERR("14.8.2.1");
 769		rc = -EIO;
 770		goto error;
 771	}
 772
 773	if (DIGITAL_NFC_DEP_NAD_BIT_SET(pfb)) {
 774		rc = -EIO;
 775		goto exit;
 776	}
 777
 778	if (size > resp->len) {
 779		rc = -EIO;
 780		goto error;
 781	}
 782
 783	skb_pull(resp, size);
 784
 785	switch (DIGITAL_NFC_DEP_PFB_TYPE(pfb)) {
 786	case DIGITAL_NFC_DEP_PFB_I_PDU:
 787		if (DIGITAL_NFC_DEP_PFB_PNI(pfb) != ddev->curr_nfc_dep_pni) {
 788			PROTOCOL_ERR("14.12.3.3");
 789			rc = -EIO;
 790			goto error;
 791		}
 792
 793		ddev->curr_nfc_dep_pni =
 794			DIGITAL_NFC_DEP_PFB_PNI(ddev->curr_nfc_dep_pni + 1);
 795
 796		kfree_skb(ddev->saved_skb);
 797		ddev->saved_skb = NULL;
 798
 799		resp = digital_recv_dep_data_gather(ddev, pfb, resp,
 800						    digital_in_send_ack,
 801						    data_exch);
 802		if (IS_ERR(resp)) {
 803			rc = PTR_ERR(resp);
 804			resp = NULL;
 805			goto error;
 806		}
 807
 808		/* If resp is NULL then we're still chaining so return and
 809		 * wait for the next part of the PDU.  Else, the PDU is
 810		 * complete so pass it up.
 811		 */
 812		if (!resp)
 813			return;
 814
 815		rc = 0;
 816		break;
 817
 818	case DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU:
 819		if (DIGITAL_NFC_DEP_NACK_BIT_SET(pfb)) {
 820			PROTOCOL_ERR("14.12.4.5");
 821			rc = -EIO;
 822			goto exit;
 823		}
 824
 825		if (DIGITAL_NFC_DEP_PFB_PNI(pfb) != ddev->curr_nfc_dep_pni) {
 826			PROTOCOL_ERR("14.12.3.3");
 827			rc = -EIO;
 828			goto exit;
 829		}
 830
 831		ddev->curr_nfc_dep_pni =
 832			DIGITAL_NFC_DEP_PFB_PNI(ddev->curr_nfc_dep_pni + 1);
 833
 834		if (!ddev->chaining_skb) {
 835			PROTOCOL_ERR("14.12.4.3");
 836			rc = -EIO;
 837			goto exit;
 838		}
 839
 840		/* The initiator has received a valid ACK. Free the last sent
 841		 * PDU and keep on sending chained skb.
 842		 */
 843		kfree_skb(ddev->saved_skb);
 844		ddev->saved_skb = NULL;
 845
 846		rc = digital_in_send_dep_req(ddev, NULL,
 847					     ddev->chaining_skb,
 848					     ddev->data_exch);
 849		if (rc)
 850			goto error;
 851
 852		goto free_resp;
 853
 854	case DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU:
 855		if (!DIGITAL_NFC_DEP_PFB_IS_TIMEOUT(pfb)) { /* ATN */
 856			rc = digital_in_send_saved_skb(ddev, data_exch);
 857			if (rc)
 858				goto error;
 859
 860			goto free_resp;
 861		}
 862
 863		if (ddev->atn_count || ddev->nack_count) {
 864			PROTOCOL_ERR("14.12.4.4");
 865			rc = -EIO;
 866			goto error;
 867		}
 868
 869		rtox = DIGITAL_NFC_DEP_RTOX_VALUE(resp->data[0]);
 870		if (!rtox || rtox > DIGITAL_NFC_DEP_RTOX_MAX) {
 871			PROTOCOL_ERR("14.8.4.1");
 872			rc = -EIO;
 873			goto error;
 874		}
 875
 876		rc = digital_in_send_rtox(ddev, data_exch, rtox);
 877		if (rc)
 878			goto error;
 879
 880		goto free_resp;
 881	}
 882
 883exit:
 884	data_exch->cb(data_exch->cb_context, resp, rc);
 885
 886error:
 887	kfree(data_exch);
 888
 889	kfree_skb(ddev->chaining_skb);
 890	ddev->chaining_skb = NULL;
 891
 892	kfree_skb(ddev->saved_skb);
 893	ddev->saved_skb = NULL;
 894
 895	if (rc)
 896		kfree_skb(resp);
 897
 898	return;
 899
 900free_resp:
 901	dev_kfree_skb(resp);
 902}
 903
 904int digital_in_send_dep_req(struct nfc_digital_dev *ddev,
 905			    struct nfc_target *target, struct sk_buff *skb,
 906			    struct digital_data_exch *data_exch)
 907{
 908	struct digital_dep_req_res *dep_req;
 909	struct sk_buff *chaining_skb, *tmp_skb;
 910	int rc;
 911
 912	skb_push(skb, sizeof(struct digital_dep_req_res));
 913
 914	dep_req = (struct digital_dep_req_res *)skb->data;
 915
 916	dep_req->dir = DIGITAL_NFC_DEP_FRAME_DIR_OUT;
 917	dep_req->cmd = DIGITAL_CMD_DEP_REQ;
 918	dep_req->pfb = ddev->curr_nfc_dep_pni;
 919
 920	ddev->atn_count = 0;
 921	ddev->nack_count = 0;
 922
 923	chaining_skb = ddev->chaining_skb;
 924
 925	tmp_skb = digital_send_dep_data_prep(ddev, skb, dep_req, data_exch);
 926	if (IS_ERR(tmp_skb))
 927		return PTR_ERR(tmp_skb);
 928
 929	digital_skb_push_dep_sod(ddev, tmp_skb);
 930
 931	ddev->skb_add_crc(tmp_skb);
 932
 933	ddev->saved_skb = pskb_copy(tmp_skb, GFP_KERNEL);
 934
 935	rc = digital_in_send_cmd(ddev, tmp_skb, ddev->dep_rwt,
 936				 digital_in_recv_dep_res, data_exch);
 937	if (rc) {
 938		if (tmp_skb != skb)
 939			kfree_skb(tmp_skb);
 940
 941		kfree_skb(chaining_skb);
 942		ddev->chaining_skb = NULL;
 943
 944		kfree_skb(ddev->saved_skb);
 945		ddev->saved_skb = NULL;
 946	}
 947
 948	return rc;
 949}
 950
 951static void digital_tg_set_rf_tech(struct nfc_digital_dev *ddev, u8 rf_tech)
 952{
 953	ddev->curr_rf_tech = rf_tech;
 954
 955	ddev->skb_add_crc = digital_skb_add_crc_none;
 956	ddev->skb_check_crc = digital_skb_check_crc_none;
 957
 958	if (DIGITAL_DRV_CAPS_TG_CRC(ddev))
 959		return;
 960
 961	switch (ddev->curr_rf_tech) {
 962	case NFC_DIGITAL_RF_TECH_106A:
 963		ddev->skb_add_crc = digital_skb_add_crc_a;
 964		ddev->skb_check_crc = digital_skb_check_crc_a;
 965		break;
 966
 967	case NFC_DIGITAL_RF_TECH_212F:
 968	case NFC_DIGITAL_RF_TECH_424F:
 969		ddev->skb_add_crc = digital_skb_add_crc_f;
 970		ddev->skb_check_crc = digital_skb_check_crc_f;
 971		break;
 972
 973	default:
 974		break;
 975	}
 976}
 977
 978static int digital_tg_send_ack(struct nfc_digital_dev *ddev,
 979			       struct digital_data_exch *data_exch)
 980{
 981	struct digital_dep_req_res *dep_res;
 982	struct sk_buff *skb;
 983	int rc;
 984
 985	skb = digital_skb_alloc(ddev, 1);
 986	if (!skb)
 987		return -ENOMEM;
 988
 989	skb_push(skb, sizeof(struct digital_dep_req_res));
 990
 991	dep_res = (struct digital_dep_req_res *)skb->data;
 992
 993	dep_res->dir = DIGITAL_NFC_DEP_FRAME_DIR_IN;
 994	dep_res->cmd = DIGITAL_CMD_DEP_RES;
 995	dep_res->pfb = DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU |
 996		       ddev->curr_nfc_dep_pni;
 997
 998	if (ddev->did) {
 999		dep_res->pfb |= DIGITAL_NFC_DEP_PFB_DID_BIT;
1000
1001		skb_put_data(skb, &ddev->did, sizeof(ddev->did));
1002	}
1003
1004	ddev->curr_nfc_dep_pni =
1005		DIGITAL_NFC_DEP_PFB_PNI(ddev->curr_nfc_dep_pni + 1);
1006
1007	digital_skb_push_dep_sod(ddev, skb);
1008
1009	ddev->skb_add_crc(skb);
1010
1011	ddev->saved_skb = pskb_copy(skb, GFP_KERNEL);
1012
1013	rc = digital_tg_send_cmd(ddev, skb, 1500, digital_tg_recv_dep_req,
1014				 data_exch);
1015	if (rc) {
1016		kfree_skb(skb);
1017		kfree_skb(ddev->saved_skb);
1018		ddev->saved_skb = NULL;
1019	}
1020
1021	return rc;
1022}
1023
1024static int digital_tg_send_atn(struct nfc_digital_dev *ddev)
1025{
1026	struct digital_dep_req_res *dep_res;
1027	struct sk_buff *skb;
1028	int rc;
1029
1030	skb = digital_skb_alloc(ddev, 1);
1031	if (!skb)
1032		return -ENOMEM;
1033
1034	skb_push(skb, sizeof(struct digital_dep_req_res));
1035
1036	dep_res = (struct digital_dep_req_res *)skb->data;
1037
1038	dep_res->dir = DIGITAL_NFC_DEP_FRAME_DIR_IN;
1039	dep_res->cmd = DIGITAL_CMD_DEP_RES;
1040	dep_res->pfb = DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU;
1041
1042	if (ddev->did) {
1043		dep_res->pfb |= DIGITAL_NFC_DEP_PFB_DID_BIT;
1044
1045		skb_put_data(skb, &ddev->did, sizeof(ddev->did));
1046	}
1047
1048	digital_skb_push_dep_sod(ddev, skb);
1049
1050	ddev->skb_add_crc(skb);
1051
1052	rc = digital_tg_send_cmd(ddev, skb, 1500, digital_tg_recv_dep_req,
1053				 NULL);
1054	if (rc)
1055		kfree_skb(skb);
1056
1057	return rc;
1058}
1059
1060static int digital_tg_send_saved_skb(struct nfc_digital_dev *ddev)
1061{
1062	int rc;
1063
1064	if (!ddev->saved_skb)
1065		return -EINVAL;
1066
1067	skb_get(ddev->saved_skb);
1068
1069	rc = digital_tg_send_cmd(ddev, ddev->saved_skb, 1500,
1070				 digital_tg_recv_dep_req, NULL);
1071	if (rc)
1072		kfree_skb(ddev->saved_skb);
1073
1074	return rc;
1075}
1076
1077static void digital_tg_recv_dep_req(struct nfc_digital_dev *ddev, void *arg,
1078				    struct sk_buff *resp)
1079{
1080	int rc;
1081	struct digital_dep_req_res *dep_req;
1082	u8 pfb;
1083	size_t size;
1084
1085	if (IS_ERR(resp)) {
1086		rc = PTR_ERR(resp);
1087		resp = NULL;
1088		goto exit;
1089	}
1090
1091	rc = ddev->skb_check_crc(resp);
1092	if (rc) {
1093		PROTOCOL_ERR("14.4.1.6");
1094		goto exit;
1095	}
1096
1097	rc = digital_skb_pull_dep_sod(ddev, resp);
1098	if (rc) {
1099		PROTOCOL_ERR("14.4.1.2");
1100		goto exit;
1101	}
1102
1103	if (resp->len > ddev->local_payload_max) {
1104		rc = -EMSGSIZE;
1105		goto exit;
1106	}
1107
1108	size = sizeof(struct digital_dep_req_res);
1109	dep_req = (struct digital_dep_req_res *)resp->data;
1110
1111	if (resp->len < size || dep_req->dir != DIGITAL_NFC_DEP_FRAME_DIR_OUT ||
1112	    dep_req->cmd != DIGITAL_CMD_DEP_REQ) {
1113		rc = -EIO;
1114		goto exit;
1115	}
1116
1117	pfb = dep_req->pfb;
1118
1119	if (DIGITAL_NFC_DEP_DID_BIT_SET(pfb)) {
1120		if (ddev->did && (ddev->did == resp->data[3])) {
1121			size++;
1122		} else {
1123			rc = -EIO;
1124			goto exit;
1125		}
1126	} else if (ddev->did) {
1127		rc = -EIO;
1128		goto exit;
1129	}
1130
1131	if (DIGITAL_NFC_DEP_NAD_BIT_SET(pfb)) {
1132		rc = -EIO;
1133		goto exit;
1134	}
1135
1136	if (size > resp->len) {
1137		rc = -EIO;
1138		goto exit;
1139	}
1140
1141	skb_pull(resp, size);
1142
1143	switch (DIGITAL_NFC_DEP_PFB_TYPE(pfb)) {
1144	case DIGITAL_NFC_DEP_PFB_I_PDU:
1145		pr_debug("DIGITAL_NFC_DEP_PFB_I_PDU\n");
1146
1147		if (ddev->atn_count) {
1148			/* The target has received (and replied to) at least one
1149			 * ATN DEP_REQ.
1150			 */
1151			ddev->atn_count = 0;
1152
1153			/* pni of resp PDU equal to the target current pni - 1
1154			 * means resp is the previous DEP_REQ PDU received from
1155			 * the initiator so the target replies with saved_skb
1156			 * which is the previous DEP_RES saved in
1157			 * digital_tg_send_dep_res().
1158			 */
1159			if (DIGITAL_NFC_DEP_PFB_PNI(pfb) ==
1160			  DIGITAL_NFC_DEP_PFB_PNI(ddev->curr_nfc_dep_pni - 1)) {
1161				rc = digital_tg_send_saved_skb(ddev);
1162				if (rc)
1163					goto exit;
1164
1165				goto free_resp;
1166			}
1167
1168			/* atn_count > 0 and PDU pni != curr_nfc_dep_pni - 1
1169			 * means the target probably did not received the last
1170			 * DEP_REQ PDU sent by the initiator. The target
1171			 * fallbacks to normal processing then.
1172			 */
1173		}
1174
1175		if (DIGITAL_NFC_DEP_PFB_PNI(pfb) != ddev->curr_nfc_dep_pni) {
1176			PROTOCOL_ERR("14.12.3.4");
1177			rc = -EIO;
1178			goto exit;
1179		}
1180
1181		kfree_skb(ddev->saved_skb);
1182		ddev->saved_skb = NULL;
1183
1184		resp = digital_recv_dep_data_gather(ddev, pfb, resp,
1185						    digital_tg_send_ack, NULL);
1186		if (IS_ERR(resp)) {
1187			rc = PTR_ERR(resp);
1188			resp = NULL;
1189			goto exit;
1190		}
1191
1192		/* If resp is NULL then we're still chaining so return and
1193		 * wait for the next part of the PDU.  Else, the PDU is
1194		 * complete so pass it up.
1195		 */
1196		if (!resp)
1197			return;
1198
1199		rc = 0;
1200		break;
1201	case DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU:
1202		if (DIGITAL_NFC_DEP_NACK_BIT_SET(pfb)) { /* NACK */
1203			if (DIGITAL_NFC_DEP_PFB_PNI(pfb + 1) !=
1204						ddev->curr_nfc_dep_pni) {
1205				rc = -EIO;
1206				goto exit;
1207			}
1208
1209			ddev->atn_count = 0;
1210
1211			rc = digital_tg_send_saved_skb(ddev);
1212			if (rc)
1213				goto exit;
1214
1215			goto free_resp;
1216		}
1217
1218		/* ACK */
1219		if (ddev->atn_count) {
1220			/* The target has previously received one or more ATN
1221			 * PDUs.
1222			 */
1223			ddev->atn_count = 0;
1224
1225			/* If the ACK PNI is equal to the target PNI - 1 means
1226			 * that the initiator did not receive the previous PDU
1227			 * sent by the target so re-send it.
1228			 */
1229			if (DIGITAL_NFC_DEP_PFB_PNI(pfb + 1) ==
1230						ddev->curr_nfc_dep_pni) {
1231				rc = digital_tg_send_saved_skb(ddev);
1232				if (rc)
1233					goto exit;
1234
1235				goto free_resp;
1236			}
1237
1238			/* Otherwise, the target did not receive the previous
1239			 * ACK PDU from the initiator. Fallback to normal
1240			 * processing of chained PDU then.
1241			 */
1242		}
1243
1244		/* Keep on sending chained PDU */
1245		if (!ddev->chaining_skb ||
1246		    DIGITAL_NFC_DEP_PFB_PNI(pfb) !=
1247					ddev->curr_nfc_dep_pni) {
1248			rc = -EIO;
1249			goto exit;
1250		}
1251
1252		kfree_skb(ddev->saved_skb);
1253		ddev->saved_skb = NULL;
1254
1255		rc = digital_tg_send_dep_res(ddev, ddev->chaining_skb);
1256		if (rc)
1257			goto exit;
1258
1259		goto free_resp;
1260	case DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU:
1261		if (DIGITAL_NFC_DEP_PFB_IS_TIMEOUT(pfb)) {
1262			rc = -EINVAL;
1263			goto exit;
1264		}
1265
1266		rc = digital_tg_send_atn(ddev);
1267		if (rc)
1268			goto exit;
1269
1270		ddev->atn_count++;
1271
1272		goto free_resp;
1273	}
1274
1275	rc = nfc_tm_data_received(ddev->nfc_dev, resp);
1276	if (rc)
1277		resp = NULL;
1278
1279exit:
1280	kfree_skb(ddev->chaining_skb);
1281	ddev->chaining_skb = NULL;
1282
1283	ddev->atn_count = 0;
1284
1285	kfree_skb(ddev->saved_skb);
1286	ddev->saved_skb = NULL;
1287
1288	if (rc)
1289		kfree_skb(resp);
1290
1291	return;
1292
1293free_resp:
1294	dev_kfree_skb(resp);
1295}
1296
1297int digital_tg_send_dep_res(struct nfc_digital_dev *ddev, struct sk_buff *skb)
1298{
1299	struct digital_dep_req_res *dep_res;
1300	struct sk_buff *chaining_skb, *tmp_skb;
1301	int rc;
1302
1303	skb_push(skb, sizeof(struct digital_dep_req_res));
1304
1305	dep_res = (struct digital_dep_req_res *)skb->data;
1306
1307	dep_res->dir = DIGITAL_NFC_DEP_FRAME_DIR_IN;
1308	dep_res->cmd = DIGITAL_CMD_DEP_RES;
1309	dep_res->pfb = ddev->curr_nfc_dep_pni;
1310
1311	if (ddev->did) {
1312		dep_res->pfb |= DIGITAL_NFC_DEP_PFB_DID_BIT;
1313
1314		skb_put_data(skb, &ddev->did, sizeof(ddev->did));
1315	}
1316
1317	ddev->curr_nfc_dep_pni =
1318		DIGITAL_NFC_DEP_PFB_PNI(ddev->curr_nfc_dep_pni + 1);
1319
1320	chaining_skb = ddev->chaining_skb;
1321
1322	tmp_skb = digital_send_dep_data_prep(ddev, skb, dep_res, NULL);
1323	if (IS_ERR(tmp_skb))
1324		return PTR_ERR(tmp_skb);
1325
1326	digital_skb_push_dep_sod(ddev, tmp_skb);
1327
1328	ddev->skb_add_crc(tmp_skb);
1329
1330	ddev->saved_skb = pskb_copy(tmp_skb, GFP_KERNEL);
1331
1332	rc = digital_tg_send_cmd(ddev, tmp_skb, 1500, digital_tg_recv_dep_req,
1333				 NULL);
1334	if (rc) {
1335		if (tmp_skb != skb)
1336			kfree_skb(tmp_skb);
1337
1338		kfree_skb(chaining_skb);
1339		ddev->chaining_skb = NULL;
1340
1341		kfree_skb(ddev->saved_skb);
1342		ddev->saved_skb = NULL;
1343	}
1344
1345	return rc;
1346}
1347
1348static void digital_tg_send_psl_res_complete(struct nfc_digital_dev *ddev,
1349					     void *arg, struct sk_buff *resp)
1350{
1351	u8 rf_tech = (unsigned long)arg;
1352
1353	if (IS_ERR(resp))
1354		return;
1355
1356	digital_tg_set_rf_tech(ddev, rf_tech);
1357
1358	digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH, rf_tech);
1359
1360	digital_tg_listen(ddev, 1500, digital_tg_recv_dep_req, NULL);
1361
1362	dev_kfree_skb(resp);
1363}
1364
1365static int digital_tg_send_psl_res(struct nfc_digital_dev *ddev, u8 did,
1366				   u8 rf_tech)
1367{
1368	struct digital_psl_res *psl_res;
1369	struct sk_buff *skb;
1370	int rc;
1371
1372	skb = digital_skb_alloc(ddev, sizeof(struct digital_psl_res));
1373	if (!skb)
1374		return -ENOMEM;
1375
1376	skb_put(skb, sizeof(struct digital_psl_res));
1377
1378	psl_res = (struct digital_psl_res *)skb->data;
1379
1380	psl_res->dir = DIGITAL_NFC_DEP_FRAME_DIR_IN;
1381	psl_res->cmd = DIGITAL_CMD_PSL_RES;
1382	psl_res->did = did;
1383
1384	digital_skb_push_dep_sod(ddev, skb);
1385
1386	ddev->skb_add_crc(skb);
1387
1388	ddev->curr_nfc_dep_pni = 0;
1389
1390	rc = digital_tg_send_cmd(ddev, skb, 0, digital_tg_send_psl_res_complete,
1391				 (void *)(unsigned long)rf_tech);
1392	if (rc)
1393		kfree_skb(skb);
1394
1395	return rc;
1396}
1397
1398static void digital_tg_recv_psl_req(struct nfc_digital_dev *ddev, void *arg,
1399				    struct sk_buff *resp)
1400{
1401	int rc;
1402	struct digital_psl_req *psl_req;
1403	u8 rf_tech;
1404	u8 dsi, payload_size, payload_bits;
1405
1406	if (IS_ERR(resp)) {
1407		rc = PTR_ERR(resp);
1408		resp = NULL;
1409		goto exit;
1410	}
1411
1412	rc = ddev->skb_check_crc(resp);
1413	if (rc) {
1414		PROTOCOL_ERR("14.4.1.6");
1415		goto exit;
1416	}
1417
1418	rc = digital_skb_pull_dep_sod(ddev, resp);
1419	if (rc) {
1420		PROTOCOL_ERR("14.4.1.2");
1421		goto exit;
1422	}
1423
1424	psl_req = (struct digital_psl_req *)resp->data;
1425
1426	if (resp->len != sizeof(struct digital_psl_req) ||
1427	    psl_req->dir != DIGITAL_NFC_DEP_FRAME_DIR_OUT ||
1428	    psl_req->cmd != DIGITAL_CMD_PSL_REQ) {
1429		rc = -EIO;
1430		goto exit;
1431	}
1432
1433	dsi = (psl_req->brs >> 3) & 0x07;
1434	switch (dsi) {
1435	case 0:
1436		rf_tech = NFC_DIGITAL_RF_TECH_106A;
1437		break;
1438	case 1:
1439		rf_tech = NFC_DIGITAL_RF_TECH_212F;
1440		break;
1441	case 2:
1442		rf_tech = NFC_DIGITAL_RF_TECH_424F;
1443		break;
1444	default:
1445		pr_err("Unsupported dsi value %d\n", dsi);
1446		goto exit;
1447	}
1448
1449	payload_bits = DIGITAL_PAYLOAD_FSL_TO_BITS(psl_req->fsl);
1450	payload_size = digital_payload_bits_to_size(payload_bits);
1451
1452	if (!payload_size || (payload_size > min(ddev->local_payload_max,
1453						 ddev->remote_payload_max))) {
1454		rc = -EINVAL;
1455		goto exit;
1456	}
1457
1458	ddev->local_payload_max = payload_size;
1459	ddev->remote_payload_max = payload_size;
1460
1461	rc = digital_tg_send_psl_res(ddev, psl_req->did, rf_tech);
1462
1463exit:
1464	kfree_skb(resp);
1465}
1466
1467static void digital_tg_send_atr_res_complete(struct nfc_digital_dev *ddev,
1468					     void *arg, struct sk_buff *resp)
1469{
1470	int offset;
1471
1472	if (IS_ERR(resp)) {
1473		digital_poll_next_tech(ddev);
1474		return;
1475	}
1476
1477	offset = 2;
1478	if (resp->data[0] == DIGITAL_NFC_DEP_NFCA_SOD_SB)
1479		offset++;
1480
1481	ddev->atn_count = 0;
1482
1483	if (resp->data[offset] == DIGITAL_CMD_PSL_REQ)
1484		digital_tg_recv_psl_req(ddev, arg, resp);
1485	else
1486		digital_tg_recv_dep_req(ddev, arg, resp);
1487}
1488
1489static int digital_tg_send_atr_res(struct nfc_digital_dev *ddev,
1490				   struct digital_atr_req *atr_req)
1491{
1492	struct digital_atr_res *atr_res;
1493	struct sk_buff *skb;
1494	u8 *gb, payload_bits;
1495	size_t gb_len;
1496	int rc;
1497
1498	gb = nfc_get_local_general_bytes(ddev->nfc_dev, &gb_len);
1499	if (!gb)
1500		gb_len = 0;
1501
1502	skb = digital_skb_alloc(ddev, sizeof(struct digital_atr_res) + gb_len);
1503	if (!skb)
1504		return -ENOMEM;
1505
1506	skb_put(skb, sizeof(struct digital_atr_res));
1507	atr_res = (struct digital_atr_res *)skb->data;
1508
1509	memset(atr_res, 0, sizeof(struct digital_atr_res));
1510
1511	atr_res->dir = DIGITAL_NFC_DEP_FRAME_DIR_IN;
1512	atr_res->cmd = DIGITAL_CMD_ATR_RES;
1513	memcpy(atr_res->nfcid3, atr_req->nfcid3, sizeof(atr_req->nfcid3));
1514	atr_res->to = DIGITAL_NFC_DEP_TG_MAX_WT;
1515
1516	ddev->local_payload_max = DIGITAL_PAYLOAD_SIZE_MAX;
1517	payload_bits = digital_payload_size_to_bits(ddev->local_payload_max);
1518	atr_res->pp = DIGITAL_PAYLOAD_BITS_TO_PP(payload_bits);
1519
1520	if (gb_len) {
1521		skb_put(skb, gb_len);
1522
1523		atr_res->pp |= DIGITAL_GB_BIT;
1524		memcpy(atr_res->gb, gb, gb_len);
1525	}
1526
1527	digital_skb_push_dep_sod(ddev, skb);
1528
1529	ddev->skb_add_crc(skb);
1530
1531	ddev->curr_nfc_dep_pni = 0;
1532
1533	rc = digital_tg_send_cmd(ddev, skb, 999,
1534				 digital_tg_send_atr_res_complete, NULL);
1535	if (rc)
1536		kfree_skb(skb);
1537
1538	return rc;
1539}
1540
1541void digital_tg_recv_atr_req(struct nfc_digital_dev *ddev, void *arg,
1542			     struct sk_buff *resp)
1543{
1544	int rc;
1545	struct digital_atr_req *atr_req;
1546	size_t gb_len, min_size;
1547	u8 poll_tech_count, payload_bits;
1548
1549	if (IS_ERR(resp)) {
1550		rc = PTR_ERR(resp);
1551		resp = NULL;
1552		goto exit;
1553	}
1554
1555	if (!resp->len) {
1556		rc = -EIO;
1557		goto exit;
1558	}
1559
1560	if (resp->data[0] == DIGITAL_NFC_DEP_NFCA_SOD_SB) {
1561		min_size = DIGITAL_ATR_REQ_MIN_SIZE + 2;
1562		digital_tg_set_rf_tech(ddev, NFC_DIGITAL_RF_TECH_106A);
1563	} else {
1564		min_size = DIGITAL_ATR_REQ_MIN_SIZE + 1;
1565		digital_tg_set_rf_tech(ddev, NFC_DIGITAL_RF_TECH_212F);
1566	}
1567
1568	if (resp->len < min_size) {
1569		rc = -EIO;
1570		goto exit;
1571	}
1572
1573	ddev->curr_protocol = NFC_PROTO_NFC_DEP_MASK;
1574
1575	rc = ddev->skb_check_crc(resp);
1576	if (rc) {
1577		PROTOCOL_ERR("14.4.1.6");
1578		goto exit;
1579	}
1580
1581	rc = digital_skb_pull_dep_sod(ddev, resp);
1582	if (rc) {
1583		PROTOCOL_ERR("14.4.1.2");
1584		goto exit;
1585	}
1586
1587	atr_req = (struct digital_atr_req *)resp->data;
1588
1589	if (atr_req->dir != DIGITAL_NFC_DEP_FRAME_DIR_OUT ||
1590	    atr_req->cmd != DIGITAL_CMD_ATR_REQ ||
1591	    atr_req->did > DIGITAL_DID_MAX) {
1592		rc = -EINVAL;
1593		goto exit;
1594	}
1595
1596	payload_bits = DIGITAL_PAYLOAD_PP_TO_BITS(atr_req->pp);
1597	ddev->remote_payload_max = digital_payload_bits_to_size(payload_bits);
1598
1599	if (!ddev->remote_payload_max) {
1600		rc = -EINVAL;
1601		goto exit;
1602	}
1603
1604	ddev->did = atr_req->did;
1605
1606	rc = digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
1607				     NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED);
1608	if (rc)
1609		goto exit;
1610
1611	rc = digital_tg_send_atr_res(ddev, atr_req);
1612	if (rc)
1613		goto exit;
1614
1615	gb_len = resp->len - sizeof(struct digital_atr_req);
1616
1617	poll_tech_count = ddev->poll_tech_count;
1618	ddev->poll_tech_count = 0;
1619
1620	rc = nfc_tm_activated(ddev->nfc_dev, NFC_PROTO_NFC_DEP_MASK,
1621			      NFC_COMM_PASSIVE, atr_req->gb, gb_len);
1622	if (rc) {
1623		ddev->poll_tech_count = poll_tech_count;
1624		goto exit;
1625	}
1626
1627	rc = 0;
1628exit:
1629	if (rc)
1630		digital_poll_next_tech(ddev);
1631
1632	dev_kfree_skb(resp);
1633}