linux/net/nfc/digital_dep.c
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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}
1634