net/nfc/digital_technology.c

   1 /*
   2  * NFC Digital Protocol stack
   3  * Copyright (c) 2013, Intel Corporation.
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms and conditions of the GNU General Public License,
   7  * version 2, as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  */
  15
  16 #define pr_fmt(fmt) "digital: %s: " fmt, __func__
  17
  18 #include "digital.h"
  19
  20 #define DIGITAL_CMD_SENS_REQ    0x26
  21 #define DIGITAL_CMD_ALL_REQ     0x52
  22 #define DIGITAL_CMD_SEL_REQ_CL1 0x93
  23 #define DIGITAL_CMD_SEL_REQ_CL2 0x95
  24 #define DIGITAL_CMD_SEL_REQ_CL3 0x97
  25
  26 #define DIGITAL_SDD_REQ_SEL_PAR 0x20
  27
  28 #define DIGITAL_SDD_RES_CT  0x88
  29 #define DIGITAL_SDD_RES_LEN 5
  30
  31 #define DIGITAL_SEL_RES_NFCID1_COMPLETE(sel_res) (!((sel_res) & 0x04))
  32 #define DIGITAL_SEL_RES_IS_T2T(sel_res) (!((sel_res) & 0x60))
  33 #define DIGITAL_SEL_RES_IS_T4T(sel_res) ((sel_res) & 0x20)
  34 #define DIGITAL_SEL_RES_IS_NFC_DEP(sel_res) ((sel_res) & 0x40)
  35
  36 #define DIGITAL_SENS_RES_IS_T1T(sens_res) (((sens_res) & 0x0C00) == 0x0C00)
  37 #define DIGITAL_SENS_RES_IS_VALID(sens_res) \
  38         ((!((sens_res) & 0x001F) && (((sens_res) & 0x0C00) == 0x0C00)) || \
  39         (((sens_res) & 0x001F) && ((sens_res) & 0x0C00) != 0x0C00))
  40
  41 #define DIGITAL_MIFARE_READ_RES_LEN 16
  42 #define DIGITAL_MIFARE_ACK_RES  0x0A
  43
  44 #define DIGITAL_CMD_SENSB_REQ                   0x05
  45 #define DIGITAL_SENSB_ADVANCED                  BIT(5)
  46 #define DIGITAL_SENSB_EXTENDED                  BIT(4)
  47 #define DIGITAL_SENSB_ALLB_REQ                  BIT(3)
  48 #define DIGITAL_SENSB_N(n)                      ((n) & 0x7)
  49
  50 #define DIGITAL_CMD_SENSB_RES                   0x50
  51
  52 #define DIGITAL_CMD_ATTRIB_REQ                  0x1D
  53 #define DIGITAL_ATTRIB_P1_TR0_DEFAULT           (0x0 << 6)
  54 #define DIGITAL_ATTRIB_P1_TR1_DEFAULT           (0x0 << 4)
  55 #define DIGITAL_ATTRIB_P1_SUPRESS_EOS           BIT(3)
  56 #define DIGITAL_ATTRIB_P1_SUPRESS_SOS           BIT(2)
  57 #define DIGITAL_ATTRIB_P2_LISTEN_POLL_1         (0x0 << 6)
  58 #define DIGITAL_ATTRIB_P2_POLL_LISTEN_1         (0x0 << 4)
  59 #define DIGITAL_ATTRIB_P2_MAX_FRAME_256         0x8
  60 #define DIGITAL_ATTRIB_P4_DID(n)                ((n) & 0xf)
  61
  62 #define DIGITAL_CMD_SENSF_REQ   0x00
  63 #define DIGITAL_CMD_SENSF_RES   0x01
  64
  65 #define DIGITAL_SENSF_RES_MIN_LENGTH 17
  66 #define DIGITAL_SENSF_RES_RD_AP_B1   0x00
  67 #define DIGITAL_SENSF_RES_RD_AP_B2   0x8F
  68
  69 #define DIGITAL_SENSF_REQ_RC_NONE 0
  70 #define DIGITAL_SENSF_REQ_RC_SC   1
  71 #define DIGITAL_SENSF_REQ_RC_AP   2
  72
  73 #define DIGITAL_CMD_ISO15693_INVENTORY_REQ      0x01
  74
  75 #define DIGITAL_ISO15693_REQ_FLAG_DATA_RATE     BIT(1)
  76 #define DIGITAL_ISO15693_REQ_FLAG_INVENTORY     BIT(2)
  77 #define DIGITAL_ISO15693_REQ_FLAG_NB_SLOTS      BIT(5)
  78 #define DIGITAL_ISO15693_RES_FLAG_ERROR         BIT(0)
  79 #define DIGITAL_ISO15693_RES_IS_VALID(flags) \
  80         (!((flags) & DIGITAL_ISO15693_RES_FLAG_ERROR))
  81
  82 #define DIGITAL_ISO_DEP_I_PCB    0x02
  83 #define DIGITAL_ISO_DEP_PNI(pni) ((pni) & 0x01)
  84
  85 #define DIGITAL_ISO_DEP_PCB_TYPE(pcb) ((pcb) & 0xC0)
  86
  87 #define DIGITAL_ISO_DEP_I_BLOCK 0x00
  88
  89 #define DIGITAL_ISO_DEP_BLOCK_HAS_DID(pcb) ((pcb) & 0x08)
  90
  91 static const u8 digital_ats_fsc[] = {
  92          16,  24,  32,  40,  48,  64,  96, 128,
  93 };
  94
  95 #define DIGITAL_ATS_FSCI(t0) ((t0) & 0x0F)
  96 #define DIGITAL_SENSB_FSCI(pi2) (((pi2) & 0xF0) >> 4)
  97 #define DIGITAL_ATS_MAX_FSC  256
  98
  99 #define DIGITAL_RATS_BYTE1 0xE0
 100 #define DIGITAL_RATS_PARAM 0x80
 101
 102 struct digital_sdd_res {
 103         u8 nfcid1[4];
 104         u8 bcc;
 105 } __packed;
 106
 107 struct digital_sel_req {
 108         u8 sel_cmd;
 109         u8 b2;
 110         u8 nfcid1[4];
 111         u8 bcc;
 112 } __packed;
 113
 114 struct digital_sensb_req {
 115         u8 cmd;
 116         u8 afi;
 117         u8 param;
 118 } __packed;
 119
 120 struct digital_sensb_res {
 121         u8 cmd;
 122         u8 nfcid0[4];
 123         u8 app_data[4];
 124         u8 proto_info[3];
 125 } __packed;
 126
 127 struct digital_attrib_req {
 128         u8 cmd;
 129         u8 nfcid0[4];
 130         u8 param1;
 131         u8 param2;
 132         u8 param3;
 133         u8 param4;
 134 } __packed;
 135
 136 struct digital_attrib_res {
 137         u8 mbli_did;
 138 } __packed;
 139
 140 struct digital_sensf_req {
 141         u8 cmd;
 142         u8 sc1;
 143         u8 sc2;
 144         u8 rc;
 145         u8 tsn;
 146 } __packed;
 147
 148 struct digital_sensf_res {
 149         u8 cmd;
 150         u8 nfcid2[8];
 151         u8 pad0[2];
 152         u8 pad1[3];
 153         u8 mrti_check;
 154         u8 mrti_update;
 155         u8 pad2;
 156         u8 rd[2];
 157 } __packed;
 158
 159 struct digital_iso15693_inv_req {
 160         u8 flags;
 161         u8 cmd;
 162         u8 mask_len;
 163         u64 mask;
 164 } __packed;
 165
 166 struct digital_iso15693_inv_res {
 167         u8 flags;
 168         u8 dsfid;
 169         u64 uid;
 170 } __packed;
 171
 172 static int digital_in_send_sdd_req(struct nfc_digital_dev *ddev,
 173                                    struct nfc_target *target);
 174
 175 int digital_in_iso_dep_pull_sod(struct nfc_digital_dev *ddev,
 176                                 struct sk_buff *skb)
 177 {
 178         u8 pcb;
 179         u8 block_type;
 180
 181         if (skb->len < 1)
 182                 return -EIO;
 183
 184         pcb = *skb->data;
 185         block_type = DIGITAL_ISO_DEP_PCB_TYPE(pcb);
 186
 187         /* No support fo R-block nor S-block */
 188         if (block_type != DIGITAL_ISO_DEP_I_BLOCK) {
 189                 pr_err("ISO_DEP R-block and S-block not supported\n");
 190                 return -EIO;
 191         }
 192
 193         if (DIGITAL_ISO_DEP_BLOCK_HAS_DID(pcb)) {
 194                 pr_err("DID field in ISO_DEP PCB not supported\n");
 195                 return -EIO;
 196         }
 197
 198         skb_pull(skb, 1);
 199
 200         return 0;
 201 }
 202
 203 int digital_in_iso_dep_push_sod(struct nfc_digital_dev *ddev,
 204                                 struct sk_buff *skb)
 205 {
 206         /*
 207          * Chaining not supported so skb->len + 1 PCB byte + 2 CRC bytes must
 208          * not be greater than remote FSC
 209          */
 210         if (skb->len + 3 > ddev->target_fsc)
 211                 return -EIO;
 212
 213         skb_push(skb, 1);
 214
 215         *skb->data = DIGITAL_ISO_DEP_I_PCB | ddev->curr_nfc_dep_pni;
 216
 217         ddev->curr_nfc_dep_pni =
 218                 DIGITAL_ISO_DEP_PNI(ddev->curr_nfc_dep_pni + 1);
 219
 220         return 0;
 221 }
 222
 223 static void digital_in_recv_ats(struct nfc_digital_dev *ddev, void *arg,
 224                                 struct sk_buff *resp)
 225 {
 226         struct nfc_target *target = arg;
 227         u8 fsdi;
 228         int rc;
 229
 230         if (IS_ERR(resp)) {
 231                 rc = PTR_ERR(resp);
 232                 resp = NULL;
 233                 goto exit;
 234         }
 235
 236         if (resp->len < 2) {
 237                 rc = -EIO;
 238                 goto exit;
 239         }
 240
 241         fsdi = DIGITAL_ATS_FSCI(resp->data[1]);
 242         if (fsdi >= 8)
 243                 ddev->target_fsc = DIGITAL_ATS_MAX_FSC;
 244         else
 245                 ddev->target_fsc = digital_ats_fsc[fsdi];
 246
 247         ddev->curr_nfc_dep_pni = 0;
 248
 249         rc = digital_target_found(ddev, target, NFC_PROTO_ISO14443);
 250
 251 exit:
 252         dev_kfree_skb(resp);
 253         kfree(target);
 254
 255         if (rc)
 256                 digital_poll_next_tech(ddev);
 257 }
 258
 259 static int digital_in_send_rats(struct nfc_digital_dev *ddev,
 260                                 struct nfc_target *target)
 261 {
 262         int rc;
 263         struct sk_buff *skb;
 264
 265         skb = digital_skb_alloc(ddev, 2);
 266         if (!skb)
 267                 return -ENOMEM;
 268
 269         *skb_put(skb, 1) = DIGITAL_RATS_BYTE1;
 270         *skb_put(skb, 1) = DIGITAL_RATS_PARAM;
 271
 272         rc = digital_in_send_cmd(ddev, skb, 30, digital_in_recv_ats,
 273                                  target);
 274         if (rc)
 275                 kfree_skb(skb);
 276
 277         return rc;
 278 }
 279
 280 static void digital_in_recv_sel_res(struct nfc_digital_dev *ddev, void *arg,
 281                                     struct sk_buff *resp)
 282 {
 283         struct nfc_target *target = arg;
 284         int rc;
 285         u8 sel_res;
 286         u8 nfc_proto;
 287
 288         if (IS_ERR(resp)) {
 289                 rc = PTR_ERR(resp);
 290                 resp = NULL;
 291                 goto exit;
 292         }
 293
 294         if (!DIGITAL_DRV_CAPS_IN_CRC(ddev)) {
 295                 rc = digital_skb_check_crc_a(resp);
 296                 if (rc) {
 297                         PROTOCOL_ERR("4.4.1.3");
 298                         goto exit;
 299                 }
 300         }
 301
 302         if (!resp->len) {
 303                 rc = -EIO;
 304                 goto exit;
 305         }
 306
 307         sel_res = resp->data[0];
 308
 309         if (!DIGITAL_SEL_RES_NFCID1_COMPLETE(sel_res)) {
 310                 rc = digital_in_send_sdd_req(ddev, target);
 311                 if (rc)
 312                         goto exit;
 313
 314                 goto exit_free_skb;
 315         }
 316
 317         target->sel_res = sel_res;
 318
 319         if (DIGITAL_SEL_RES_IS_T2T(sel_res)) {
 320                 nfc_proto = NFC_PROTO_MIFARE;
 321         } else if (DIGITAL_SEL_RES_IS_NFC_DEP(sel_res)) {
 322                 nfc_proto = NFC_PROTO_NFC_DEP;
 323         } else if (DIGITAL_SEL_RES_IS_T4T(sel_res)) {
 324                 rc = digital_in_send_rats(ddev, target);
 325                 if (rc)
 326                         goto exit;
 327                 /*
 328                  * Skip target_found and don't free it for now. This will be
 329                  * done when receiving the ATS
 330                  */
 331                 goto exit_free_skb;
 332         } else {
 333                 rc = -EOPNOTSUPP;
 334                 goto exit;
 335         }
 336
 337         rc = digital_target_found(ddev, target, nfc_proto);
 338
 339 exit:
 340         kfree(target);
 341
 342 exit_free_skb:
 343         dev_kfree_skb(resp);
 344
 345         if (rc)
 346                 digital_poll_next_tech(ddev);
 347 }
 348
 349 static int digital_in_send_sel_req(struct nfc_digital_dev *ddev,
 350                                    struct nfc_target *target,
 351                                    struct digital_sdd_res *sdd_res)
 352 {
 353         struct sk_buff *skb;
 354         struct digital_sel_req *sel_req;
 355         u8 sel_cmd;
 356         int rc;
 357
 358         skb = digital_skb_alloc(ddev, sizeof(struct digital_sel_req));
 359         if (!skb)
 360                 return -ENOMEM;
 361
 362         skb_put(skb, sizeof(struct digital_sel_req));
 363         sel_req = (struct digital_sel_req *)skb->data;
 364
 365         if (target->nfcid1_len <= 4)
 366                 sel_cmd = DIGITAL_CMD_SEL_REQ_CL1;
 367         else if (target->nfcid1_len < 10)
 368                 sel_cmd = DIGITAL_CMD_SEL_REQ_CL2;
 369         else
 370                 sel_cmd = DIGITAL_CMD_SEL_REQ_CL3;
 371
 372         sel_req->sel_cmd = sel_cmd;
 373         sel_req->b2 = 0x70;
 374         memcpy(sel_req->nfcid1, sdd_res->nfcid1, 4);
 375         sel_req->bcc = sdd_res->bcc;
 376
 377         if (DIGITAL_DRV_CAPS_IN_CRC(ddev)) {
 378                 rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
 379                                 NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A);
 380                 if (rc)
 381                         goto exit;
 382         } else {
 383                 digital_skb_add_crc_a(skb);
 384         }
 385
 386         rc = digital_in_send_cmd(ddev, skb, 30, digital_in_recv_sel_res,
 387                                  target);
 388 exit:
 389         if (rc)
 390                 kfree_skb(skb);
 391
 392         return rc;
 393 }
 394
 395 static void digital_in_recv_sdd_res(struct nfc_digital_dev *ddev, void *arg,
 396                                     struct sk_buff *resp)
 397 {
 398         struct nfc_target *target = arg;
 399         struct digital_sdd_res *sdd_res;
 400         int rc;
 401         u8 offset, size;
 402         u8 i, bcc;
 403
 404         if (IS_ERR(resp)) {
 405                 rc = PTR_ERR(resp);
 406                 resp = NULL;
 407                 goto exit;
 408         }
 409
 410         if (resp->len < DIGITAL_SDD_RES_LEN) {
 411                 PROTOCOL_ERR("4.7.2.8");
 412                 rc = -EINVAL;
 413                 goto exit;
 414         }
 415
 416         sdd_res = (struct digital_sdd_res *)resp->data;
 417
 418         for (i = 0, bcc = 0; i < 4; i++)
 419                 bcc ^= sdd_res->nfcid1[i];
 420
 421         if (bcc != sdd_res->bcc) {
 422                 PROTOCOL_ERR("4.7.2.6");
 423                 rc = -EINVAL;
 424                 goto exit;
 425         }
 426
 427         if (sdd_res->nfcid1[0] == DIGITAL_SDD_RES_CT) {
 428                 offset = 1;
 429                 size = 3;
 430         } else {
 431                 offset = 0;
 432                 size = 4;
 433         }
 434
 435         memcpy(target->nfcid1 + target->nfcid1_len, sdd_res->nfcid1 + offset,
 436                size);
 437         target->nfcid1_len += size;
 438
 439         rc = digital_in_send_sel_req(ddev, target, sdd_res);
 440
 441 exit:
 442         dev_kfree_skb(resp);
 443
 444         if (rc) {
 445                 kfree(target);
 446                 digital_poll_next_tech(ddev);
 447         }
 448 }
 449
 450 static int digital_in_send_sdd_req(struct nfc_digital_dev *ddev,
 451                                    struct nfc_target *target)
 452 {
 453         int rc;
 454         struct sk_buff *skb;
 455         u8 sel_cmd;
 456
 457         rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
 458                                      NFC_DIGITAL_FRAMING_NFCA_STANDARD);
 459         if (rc)
 460                 return rc;
 461
 462         skb = digital_skb_alloc(ddev, 2);
 463         if (!skb)
 464                 return -ENOMEM;
 465
 466         if (target->nfcid1_len == 0)
 467                 sel_cmd = DIGITAL_CMD_SEL_REQ_CL1;
 468         else if (target->nfcid1_len == 3)
 469                 sel_cmd = DIGITAL_CMD_SEL_REQ_CL2;
 470         else
 471                 sel_cmd = DIGITAL_CMD_SEL_REQ_CL3;
 472
 473         *skb_put(skb, sizeof(u8)) = sel_cmd;
 474         *skb_put(skb, sizeof(u8)) = DIGITAL_SDD_REQ_SEL_PAR;
 475
 476         return digital_in_send_cmd(ddev, skb, 30, digital_in_recv_sdd_res,
 477                                    target);
 478 }
 479
 480 static void digital_in_recv_sens_res(struct nfc_digital_dev *ddev, void *arg,
 481                                      struct sk_buff *resp)
 482 {
 483         struct nfc_target *target = NULL;
 484         int rc;
 485
 486         if (IS_ERR(resp)) {
 487                 rc = PTR_ERR(resp);
 488                 resp = NULL;
 489                 goto exit;
 490         }
 491
 492         if (resp->len < sizeof(u16)) {
 493                 rc = -EIO;
 494                 goto exit;
 495         }
 496
 497         target = kzalloc(sizeof(struct nfc_target), GFP_KERNEL);
 498         if (!target) {
 499                 rc = -ENOMEM;
 500                 goto exit;
 501         }
 502
 503         target->sens_res = __le16_to_cpu(*(__le16 *)resp->data);
 504
 505         if (!DIGITAL_SENS_RES_IS_VALID(target->sens_res)) {
 506                 PROTOCOL_ERR("4.6.3.3");
 507                 rc = -EINVAL;
 508                 goto exit;
 509         }
 510
 511         if (DIGITAL_SENS_RES_IS_T1T(target->sens_res))
 512                 rc = digital_target_found(ddev, target, NFC_PROTO_JEWEL);
 513         else
 514                 rc = digital_in_send_sdd_req(ddev, target);
 515
 516 exit:
 517         dev_kfree_skb(resp);
 518
 519         if (rc) {
 520                 kfree(target);
 521                 digital_poll_next_tech(ddev);
 522         }
 523 }
 524
 525 int digital_in_send_sens_req(struct nfc_digital_dev *ddev, u8 rf_tech)
 526 {
 527         struct sk_buff *skb;
 528         int rc;
 529
 530         rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
 531                                      NFC_DIGITAL_RF_TECH_106A);
 532         if (rc)
 533                 return rc;
 534
 535         rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
 536                                      NFC_DIGITAL_FRAMING_NFCA_SHORT);
 537         if (rc)
 538                 return rc;
 539
 540         skb = digital_skb_alloc(ddev, 1);
 541         if (!skb)
 542                 return -ENOMEM;
 543
 544         *skb_put(skb, sizeof(u8)) = DIGITAL_CMD_SENS_REQ;
 545
 546         rc = digital_in_send_cmd(ddev, skb, 30, digital_in_recv_sens_res, NULL);
 547         if (rc)
 548                 kfree_skb(skb);
 549
 550         return rc;
 551 }
 552
 553 int digital_in_recv_mifare_res(struct sk_buff *resp)
 554 {
 555         /* Successful READ command response is 16 data bytes + 2 CRC bytes long.
 556          * Since the driver can't differentiate a ACK/NACK response from a valid
 557          * READ response, the CRC calculation must be handled at digital level
 558          * even if the driver supports it for this technology.
 559          */
 560         if (resp->len == DIGITAL_MIFARE_READ_RES_LEN + DIGITAL_CRC_LEN) {
 561                 if (digital_skb_check_crc_a(resp)) {
 562                         PROTOCOL_ERR("9.4.1.2");
 563                         return -EIO;
 564                 }
 565
 566                 return 0;
 567         }
 568
 569         /* ACK response (i.e. successful WRITE). */
 570         if (resp->len == 1 && resp->data[0] == DIGITAL_MIFARE_ACK_RES) {
 571                 resp->data[0] = 0;
 572                 return 0;
 573         }
 574
 575         /* NACK and any other responses are treated as error. */
 576         return -EIO;
 577 }
 578
 579 static void digital_in_recv_attrib_res(struct nfc_digital_dev *ddev, void *arg,
 580                                        struct sk_buff *resp)
 581 {
 582         struct nfc_target *target = arg;
 583         struct digital_attrib_res *attrib_res;
 584         int rc;
 585
 586         if (IS_ERR(resp)) {
 587                 rc = PTR_ERR(resp);
 588                 resp = NULL;
 589                 goto exit;
 590         }
 591
 592         if (resp->len < sizeof(*attrib_res)) {
 593                 PROTOCOL_ERR("12.6.2");
 594                 rc = -EIO;
 595                 goto exit;
 596         }
 597
 598         attrib_res = (struct digital_attrib_res *)resp->data;
 599
 600         if (attrib_res->mbli_did & 0x0f) {
 601                 PROTOCOL_ERR("12.6.2.1");
 602                 rc = -EIO;
 603                 goto exit;
 604         }
 605
 606         rc = digital_target_found(ddev, target, NFC_PROTO_ISO14443_B);
 607
 608 exit:
 609         dev_kfree_skb(resp);
 610         kfree(target);
 611
 612         if (rc)
 613                 digital_poll_next_tech(ddev);
 614 }
 615
 616 static int digital_in_send_attrib_req(struct nfc_digital_dev *ddev,
 617                                struct nfc_target *target,
 618                                struct digital_sensb_res *sensb_res)
 619 {
 620         struct digital_attrib_req *attrib_req;
 621         struct sk_buff *skb;
 622         int rc;
 623
 624         skb = digital_skb_alloc(ddev, sizeof(*attrib_req));
 625         if (!skb)
 626                 return -ENOMEM;
 627
 628         attrib_req = (struct digital_attrib_req *)skb_put(skb,
 629                                                           sizeof(*attrib_req));
 630
 631         attrib_req->cmd = DIGITAL_CMD_ATTRIB_REQ;
 632         memcpy(attrib_req->nfcid0, sensb_res->nfcid0,
 633                sizeof(attrib_req->nfcid0));
 634         attrib_req->param1 = DIGITAL_ATTRIB_P1_TR0_DEFAULT |
 635                              DIGITAL_ATTRIB_P1_TR1_DEFAULT;
 636         attrib_req->param2 = DIGITAL_ATTRIB_P2_LISTEN_POLL_1 |
 637                              DIGITAL_ATTRIB_P2_POLL_LISTEN_1 |
 638                              DIGITAL_ATTRIB_P2_MAX_FRAME_256;
 639         attrib_req->param3 = sensb_res->proto_info[1] & 0x07;
 640         attrib_req->param4 = DIGITAL_ATTRIB_P4_DID(0);
 641
 642         rc = digital_in_send_cmd(ddev, skb, 30, digital_in_recv_attrib_res,
 643                                  target);
 644         if (rc)
 645                 kfree_skb(skb);
 646
 647         return rc;
 648 }
 649
 650 static void digital_in_recv_sensb_res(struct nfc_digital_dev *ddev, void *arg,
 651                                       struct sk_buff *resp)
 652 {
 653         struct nfc_target *target = NULL;
 654         struct digital_sensb_res *sensb_res;
 655         u8 fsci;
 656         int rc;
 657
 658         if (IS_ERR(resp)) {
 659                 rc = PTR_ERR(resp);
 660                 resp = NULL;
 661                 goto exit;
 662         }
 663
 664         if (resp->len != sizeof(*sensb_res)) {
 665                 PROTOCOL_ERR("5.6.2.1");
 666                 rc = -EIO;
 667                 goto exit;
 668         }
 669
 670         sensb_res = (struct digital_sensb_res *)resp->data;
 671
 672         if (sensb_res->cmd != DIGITAL_CMD_SENSB_RES) {
 673                 PROTOCOL_ERR("5.6.2");
 674                 rc = -EIO;
 675                 goto exit;
 676         }
 677
 678         if (!(sensb_res->proto_info[1] & BIT(0))) {
 679                 PROTOCOL_ERR("5.6.2.12");
 680                 rc = -EIO;
 681                 goto exit;
 682         }
 683
 684         if (sensb_res->proto_info[1] & BIT(3)) {
 685                 PROTOCOL_ERR("5.6.2.16");
 686                 rc = -EIO;
 687                 goto exit;
 688         }
 689
 690         fsci = DIGITAL_SENSB_FSCI(sensb_res->proto_info[1]);
 691         if (fsci >= 8)
 692                 ddev->target_fsc = DIGITAL_ATS_MAX_FSC;
 693         else
 694                 ddev->target_fsc = digital_ats_fsc[fsci];
 695
 696         target = kzalloc(sizeof(struct nfc_target), GFP_KERNEL);
 697         if (!target) {
 698                 rc = -ENOMEM;
 699                 goto exit;
 700         }
 701
 702         rc = digital_in_send_attrib_req(ddev, target, sensb_res);
 703
 704 exit:
 705         dev_kfree_skb(resp);
 706
 707         if (rc) {
 708                 kfree(target);
 709                 digital_poll_next_tech(ddev);
 710         }
 711 }
 712
 713 int digital_in_send_sensb_req(struct nfc_digital_dev *ddev, u8 rf_tech)
 714 {
 715         struct digital_sensb_req *sensb_req;
 716         struct sk_buff *skb;
 717         int rc;
 718
 719         rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
 720                                      NFC_DIGITAL_RF_TECH_106B);
 721         if (rc)
 722                 return rc;
 723
 724         rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
 725                                      NFC_DIGITAL_FRAMING_NFCB);
 726         if (rc)
 727                 return rc;
 728
 729         skb = digital_skb_alloc(ddev, sizeof(*sensb_req));
 730         if (!skb)
 731                 return -ENOMEM;
 732
 733         sensb_req = (struct digital_sensb_req *)skb_put(skb,
 734                                                         sizeof(*sensb_req));
 735
 736         sensb_req->cmd = DIGITAL_CMD_SENSB_REQ;
 737         sensb_req->afi = 0x00; /* All families and sub-families */
 738         sensb_req->param = DIGITAL_SENSB_N(0);
 739
 740         rc = digital_in_send_cmd(ddev, skb, 30, digital_in_recv_sensb_res,
 741                                  NULL);
 742         if (rc)
 743                 kfree_skb(skb);
 744
 745         return rc;
 746 }
 747
 748 static void digital_in_recv_sensf_res(struct nfc_digital_dev *ddev, void *arg,
 749                                    struct sk_buff *resp)
 750 {
 751         int rc;
 752         u8 proto;
 753         struct nfc_target target;
 754         struct digital_sensf_res *sensf_res;
 755
 756         if (IS_ERR(resp)) {
 757                 rc = PTR_ERR(resp);
 758                 resp = NULL;
 759                 goto exit;
 760         }
 761
 762         if (resp->len < DIGITAL_SENSF_RES_MIN_LENGTH) {
 763                 rc = -EIO;
 764                 goto exit;
 765         }
 766
 767         if (!DIGITAL_DRV_CAPS_IN_CRC(ddev)) {
 768                 rc = digital_skb_check_crc_f(resp);
 769                 if (rc) {
 770                         PROTOCOL_ERR("6.4.1.8");
 771                         goto exit;
 772                 }
 773         }
 774
 775         skb_pull(resp, 1);
 776
 777         memset(&target, 0, sizeof(struct nfc_target));
 778
 779         sensf_res = (struct digital_sensf_res *)resp->data;
 780
 781         memcpy(target.sensf_res, sensf_res, resp->len);
 782         target.sensf_res_len = resp->len;
 783
 784         memcpy(target.nfcid2, sensf_res->nfcid2, NFC_NFCID2_MAXSIZE);
 785         target.nfcid2_len = NFC_NFCID2_MAXSIZE;
 786
 787         if (target.nfcid2[0] == DIGITAL_SENSF_NFCID2_NFC_DEP_B1 &&
 788             target.nfcid2[1] == DIGITAL_SENSF_NFCID2_NFC_DEP_B2)
 789                 proto = NFC_PROTO_NFC_DEP;
 790         else
 791                 proto = NFC_PROTO_FELICA;
 792
 793         rc = digital_target_found(ddev, &target, proto);
 794
 795 exit:
 796         dev_kfree_skb(resp);
 797
 798         if (rc)
 799                 digital_poll_next_tech(ddev);
 800 }
 801
 802 int digital_in_send_sensf_req(struct nfc_digital_dev *ddev, u8 rf_tech)
 803 {
 804         struct digital_sensf_req *sensf_req;
 805         struct sk_buff *skb;
 806         int rc;
 807         u8 size;
 808
 809         rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH, rf_tech);
 810         if (rc)
 811                 return rc;
 812
 813         rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
 814                                      NFC_DIGITAL_FRAMING_NFCF);
 815         if (rc)
 816                 return rc;
 817
 818         size = sizeof(struct digital_sensf_req);
 819
 820         skb = digital_skb_alloc(ddev, size);
 821         if (!skb)
 822                 return -ENOMEM;
 823
 824         skb_put(skb, size);
 825
 826         sensf_req = (struct digital_sensf_req *)skb->data;
 827         sensf_req->cmd = DIGITAL_CMD_SENSF_REQ;
 828         sensf_req->sc1 = 0xFF;
 829         sensf_req->sc2 = 0xFF;
 830         sensf_req->rc = 0;
 831         sensf_req->tsn = 0;
 832
 833         *skb_push(skb, 1) = size + 1;
 834
 835         if (!DIGITAL_DRV_CAPS_IN_CRC(ddev))
 836                 digital_skb_add_crc_f(skb);
 837
 838         rc = digital_in_send_cmd(ddev, skb, 30, digital_in_recv_sensf_res,
 839                                  NULL);
 840         if (rc)
 841                 kfree_skb(skb);
 842
 843         return rc;
 844 }
 845
 846 static void digital_in_recv_iso15693_inv_res(struct nfc_digital_dev *ddev,
 847                 void *arg, struct sk_buff *resp)
 848 {
 849         struct digital_iso15693_inv_res *res;
 850         struct nfc_target *target = NULL;
 851         int rc;
 852
 853         if (IS_ERR(resp)) {
 854                 rc = PTR_ERR(resp);
 855                 resp = NULL;
 856                 goto out_free_skb;
 857         }
 858
 859         if (resp->len != sizeof(*res)) {
 860                 rc = -EIO;
 861                 goto out_free_skb;
 862         }
 863
 864         res = (struct digital_iso15693_inv_res *)resp->data;
 865
 866         if (!DIGITAL_ISO15693_RES_IS_VALID(res->flags)) {
 867                 PROTOCOL_ERR("ISO15693 - 10.3.1");
 868                 rc = -EINVAL;
 869                 goto out_free_skb;
 870         }
 871
 872         target = kzalloc(sizeof(*target), GFP_KERNEL);
 873         if (!target) {
 874                 rc = -ENOMEM;
 875                 goto out_free_skb;
 876         }
 877
 878         target->is_iso15693 = 1;
 879         target->iso15693_dsfid = res->dsfid;
 880         memcpy(target->iso15693_uid, &res->uid, sizeof(target->iso15693_uid));
 881
 882         rc = digital_target_found(ddev, target, NFC_PROTO_ISO15693);
 883
 884         kfree(target);
 885
 886 out_free_skb:
 887         dev_kfree_skb(resp);
 888
 889         if (rc)
 890                 digital_poll_next_tech(ddev);
 891 }
 892
 893 int digital_in_send_iso15693_inv_req(struct nfc_digital_dev *ddev, u8 rf_tech)
 894 {
 895         struct digital_iso15693_inv_req *req;
 896         struct sk_buff *skb;
 897         int rc;
 898
 899         rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
 900                                      NFC_DIGITAL_RF_TECH_ISO15693);
 901         if (rc)
 902                 return rc;
 903
 904         rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
 905                                      NFC_DIGITAL_FRAMING_ISO15693_INVENTORY);
 906         if (rc)
 907                 return rc;
 908
 909         skb = digital_skb_alloc(ddev, sizeof(*req));
 910         if (!skb)
 911                 return -ENOMEM;
 912
 913         skb_put(skb, sizeof(*req) - sizeof(req->mask)); /* No mask */
 914         req = (struct digital_iso15693_inv_req *)skb->data;
 915
 916         /* Single sub-carrier, high data rate, no AFI, single slot
 917          * Inventory command
 918          */
 919         req->flags = DIGITAL_ISO15693_REQ_FLAG_DATA_RATE |
 920                      DIGITAL_ISO15693_REQ_FLAG_INVENTORY |
 921                      DIGITAL_ISO15693_REQ_FLAG_NB_SLOTS;
 922         req->cmd = DIGITAL_CMD_ISO15693_INVENTORY_REQ;
 923         req->mask_len = 0;
 924
 925         rc = digital_in_send_cmd(ddev, skb, 30,
 926                                  digital_in_recv_iso15693_inv_res, NULL);
 927         if (rc)
 928                 kfree_skb(skb);
 929
 930         return rc;
 931 }
 932
 933 static int digital_tg_send_sel_res(struct nfc_digital_dev *ddev)
 934 {
 935         struct sk_buff *skb;
 936         int rc;
 937
 938         skb = digital_skb_alloc(ddev, 1);
 939         if (!skb)
 940                 return -ENOMEM;
 941
 942         *skb_put(skb, 1) = DIGITAL_SEL_RES_NFC_DEP;
 943
 944         if (!DIGITAL_DRV_CAPS_TG_CRC(ddev))
 945                 digital_skb_add_crc_a(skb);
 946
 947         rc = digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
 948                                      NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE);
 949         if (rc) {
 950                 kfree_skb(skb);
 951                 return rc;
 952         }
 953
 954         rc = digital_tg_send_cmd(ddev, skb, 300, digital_tg_recv_atr_req,
 955                                  NULL);
 956         if (rc)
 957                 kfree_skb(skb);
 958
 959         return rc;
 960 }
 961
 962 static void digital_tg_recv_sel_req(struct nfc_digital_dev *ddev, void *arg,
 963                                     struct sk_buff *resp)
 964 {
 965         int rc;
 966
 967         if (IS_ERR(resp)) {
 968                 rc = PTR_ERR(resp);
 969                 resp = NULL;
 970                 goto exit;
 971         }
 972
 973         if (!DIGITAL_DRV_CAPS_TG_CRC(ddev)) {
 974                 rc = digital_skb_check_crc_a(resp);
 975                 if (rc) {
 976                         PROTOCOL_ERR("4.4.1.3");
 977                         goto exit;
 978                 }
 979         }
 980
 981         /* Silently ignore SEL_REQ content and send a SEL_RES for NFC-DEP */
 982
 983         rc = digital_tg_send_sel_res(ddev);
 984
 985 exit:
 986         if (rc)
 987                 digital_poll_next_tech(ddev);
 988
 989         dev_kfree_skb(resp);
 990 }
 991
 992 static int digital_tg_send_sdd_res(struct nfc_digital_dev *ddev)
 993 {
 994         struct sk_buff *skb;
 995         struct digital_sdd_res *sdd_res;
 996         int rc, i;
 997
 998         skb = digital_skb_alloc(ddev, sizeof(struct digital_sdd_res));
 999         if (!skb)
1000                 return -ENOMEM;
1001
1002         skb_put(skb, sizeof(struct digital_sdd_res));
1003         sdd_res = (struct digital_sdd_res *)skb->data;
1004
1005         sdd_res->nfcid1[0] = 0x08;
1006         get_random_bytes(sdd_res->nfcid1 + 1, 3);
1007
1008         sdd_res->bcc = 0;
1009         for (i = 0; i < 4; i++)
1010                 sdd_res->bcc ^= sdd_res->nfcid1[i];
1011
1012         rc = digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
1013                                 NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A);
1014         if (rc) {
1015                 kfree_skb(skb);
1016                 return rc;
1017         }
1018
1019         rc = digital_tg_send_cmd(ddev, skb, 300, digital_tg_recv_sel_req,
1020                                  NULL);
1021         if (rc)
1022                 kfree_skb(skb);
1023
1024         return rc;
1025 }
1026
1027 static void digital_tg_recv_sdd_req(struct nfc_digital_dev *ddev, void *arg,
1028                                     struct sk_buff *resp)
1029 {
1030         u8 *sdd_req;
1031         int rc;
1032
1033         if (IS_ERR(resp)) {
1034                 rc = PTR_ERR(resp);
1035                 resp = NULL;
1036                 goto exit;
1037         }
1038
1039         sdd_req = resp->data;
1040
1041         if (resp->len < 2 || sdd_req[0] != DIGITAL_CMD_SEL_REQ_CL1 ||
1042             sdd_req[1] != DIGITAL_SDD_REQ_SEL_PAR) {
1043                 rc = -EINVAL;
1044                 goto exit;
1045         }
1046
1047         rc = digital_tg_send_sdd_res(ddev);
1048
1049 exit:
1050         if (rc)
1051                 digital_poll_next_tech(ddev);
1052
1053         dev_kfree_skb(resp);
1054 }
1055
1056 static int digital_tg_send_sens_res(struct nfc_digital_dev *ddev)
1057 {
1058         struct sk_buff *skb;
1059         u8 *sens_res;
1060         int rc;
1061
1062         skb = digital_skb_alloc(ddev, 2);
1063         if (!skb)
1064                 return -ENOMEM;
1065
1066         sens_res = skb_put(skb, 2);
1067
1068         sens_res[0] = (DIGITAL_SENS_RES_NFC_DEP >> 8) & 0xFF;
1069         sens_res[1] = DIGITAL_SENS_RES_NFC_DEP & 0xFF;
1070
1071         rc = digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
1072                                      NFC_DIGITAL_FRAMING_NFCA_STANDARD);
1073         if (rc) {
1074                 kfree_skb(skb);
1075                 return rc;
1076         }
1077
1078         rc = digital_tg_send_cmd(ddev, skb, 300, digital_tg_recv_sdd_req,
1079                                  NULL);
1080         if (rc)
1081                 kfree_skb(skb);
1082
1083         return rc;
1084 }
1085
1086 void digital_tg_recv_sens_req(struct nfc_digital_dev *ddev, void *arg,
1087                               struct sk_buff *resp)
1088 {
1089         u8 sens_req;
1090         int rc;
1091
1092         if (IS_ERR(resp)) {
1093                 rc = PTR_ERR(resp);
1094                 resp = NULL;
1095                 goto exit;
1096         }
1097
1098         sens_req = resp->data[0];
1099
1100         if (!resp->len || (sens_req != DIGITAL_CMD_SENS_REQ &&
1101             sens_req != DIGITAL_CMD_ALL_REQ)) {
1102                 rc = -EINVAL;
1103                 goto exit;
1104         }
1105
1106         rc = digital_tg_send_sens_res(ddev);
1107
1108 exit:
1109         if (rc)
1110                 digital_poll_next_tech(ddev);
1111
1112         dev_kfree_skb(resp);
1113 }
1114
1115 static void digital_tg_recv_atr_or_sensf_req(struct nfc_digital_dev *ddev,
1116                 void *arg, struct sk_buff *resp)
1117 {
1118         if (!IS_ERR(resp) && (resp->len >= 2) &&
1119                         (resp->data[1] == DIGITAL_CMD_SENSF_REQ))
1120                 digital_tg_recv_sensf_req(ddev, arg, resp);
1121         else
1122                 digital_tg_recv_atr_req(ddev, arg, resp);
1123
1124         return;
1125 }
1126
1127 static int digital_tg_send_sensf_res(struct nfc_digital_dev *ddev,
1128                               struct digital_sensf_req *sensf_req)
1129 {
1130         struct sk_buff *skb;
1131         u8 size;
1132         int rc;
1133         struct digital_sensf_res *sensf_res;
1134
1135         size = sizeof(struct digital_sensf_res);
1136
1137         if (sensf_req->rc == DIGITAL_SENSF_REQ_RC_NONE)
1138                 size -= sizeof(sensf_res->rd);
1139
1140         skb = digital_skb_alloc(ddev, size);
1141         if (!skb)
1142                 return -ENOMEM;
1143
1144         skb_put(skb, size);
1145
1146         sensf_res = (struct digital_sensf_res *)skb->data;
1147
1148         memset(sensf_res, 0, size);
1149
1150         sensf_res->cmd = DIGITAL_CMD_SENSF_RES;
1151         sensf_res->nfcid2[0] = DIGITAL_SENSF_NFCID2_NFC_DEP_B1;
1152         sensf_res->nfcid2[1] = DIGITAL_SENSF_NFCID2_NFC_DEP_B2;
1153         get_random_bytes(&sensf_res->nfcid2[2], 6);
1154
1155         switch (sensf_req->rc) {
1156         case DIGITAL_SENSF_REQ_RC_SC:
1157                 sensf_res->rd[0] = sensf_req->sc1;
1158                 sensf_res->rd[1] = sensf_req->sc2;
1159                 break;
1160         case DIGITAL_SENSF_REQ_RC_AP:
1161                 sensf_res->rd[0] = DIGITAL_SENSF_RES_RD_AP_B1;
1162                 sensf_res->rd[1] = DIGITAL_SENSF_RES_RD_AP_B2;
1163                 break;
1164         }
1165
1166         *skb_push(skb, sizeof(u8)) = size + 1;
1167
1168         if (!DIGITAL_DRV_CAPS_TG_CRC(ddev))
1169                 digital_skb_add_crc_f(skb);
1170
1171         rc = digital_tg_send_cmd(ddev, skb, 300,
1172                                  digital_tg_recv_atr_or_sensf_req, NULL);
1173         if (rc)
1174                 kfree_skb(skb);
1175
1176         return rc;
1177 }
1178
1179 void digital_tg_recv_sensf_req(struct nfc_digital_dev *ddev, void *arg,
1180                                struct sk_buff *resp)
1181 {
1182         struct digital_sensf_req *sensf_req;
1183         int rc;
1184
1185         if (IS_ERR(resp)) {
1186                 rc = PTR_ERR(resp);
1187                 resp = NULL;
1188                 goto exit;
1189         }
1190
1191         if (!DIGITAL_DRV_CAPS_TG_CRC(ddev)) {
1192                 rc = digital_skb_check_crc_f(resp);
1193                 if (rc) {
1194                         PROTOCOL_ERR("6.4.1.8");
1195                         goto exit;
1196                 }
1197         }
1198
1199         if (resp->len != sizeof(struct digital_sensf_req) + 1) {
1200                 rc = -EINVAL;
1201                 goto exit;
1202         }
1203
1204         skb_pull(resp, 1);
1205         sensf_req = (struct digital_sensf_req *)resp->data;
1206
1207         if (sensf_req->cmd != DIGITAL_CMD_SENSF_REQ) {
1208                 rc = -EINVAL;
1209                 goto exit;
1210         }
1211
1212         rc = digital_tg_send_sensf_res(ddev, sensf_req);
1213
1214 exit:
1215         if (rc)
1216                 digital_poll_next_tech(ddev);
1217
1218         dev_kfree_skb(resp);
1219 }
1220
1221 static int digital_tg_config_nfca(struct nfc_digital_dev *ddev)
1222 {
1223         int rc;
1224
1225         rc = digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
1226                                      NFC_DIGITAL_RF_TECH_106A);
1227         if (rc)
1228                 return rc;
1229
1230         return digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
1231                                        NFC_DIGITAL_FRAMING_NFCA_NFC_DEP);
1232 }
1233
1234 int digital_tg_listen_nfca(struct nfc_digital_dev *ddev, u8 rf_tech)
1235 {
1236         int rc;
1237
1238         rc = digital_tg_config_nfca(ddev);
1239         if (rc)
1240                 return rc;
1241
1242         return digital_tg_listen(ddev, 300, digital_tg_recv_sens_req, NULL);
1243 }
1244
1245 static int digital_tg_config_nfcf(struct nfc_digital_dev *ddev, u8 rf_tech)
1246 {
1247         int rc;
1248
1249         rc = digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH, rf_tech);
1250         if (rc)
1251                 return rc;
1252
1253         return digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
1254                                        NFC_DIGITAL_FRAMING_NFCF_NFC_DEP);
1255 }
1256
1257 int digital_tg_listen_nfcf(struct nfc_digital_dev *ddev, u8 rf_tech)
1258 {
1259         int rc;
1260         u8 *nfcid2;
1261
1262         rc = digital_tg_config_nfcf(ddev, rf_tech);
1263         if (rc)
1264                 return rc;
1265
1266         nfcid2 = kzalloc(NFC_NFCID2_MAXSIZE, GFP_KERNEL);
1267         if (!nfcid2)
1268                 return -ENOMEM;
1269
1270         nfcid2[0] = DIGITAL_SENSF_NFCID2_NFC_DEP_B1;
1271         nfcid2[1] = DIGITAL_SENSF_NFCID2_NFC_DEP_B2;
1272         get_random_bytes(nfcid2 + 2, NFC_NFCID2_MAXSIZE - 2);
1273
1274         return digital_tg_listen(ddev, 300, digital_tg_recv_sensf_req, nfcid2);
1275 }
1276
1277 void digital_tg_recv_md_req(struct nfc_digital_dev *ddev, void *arg,
1278                             struct sk_buff *resp)
1279 {
1280         u8 rf_tech;
1281         int rc;
1282
1283         if (IS_ERR(resp)) {
1284                 resp = NULL;
1285                 goto exit_free_skb;
1286         }
1287
1288         rc = ddev->ops->tg_get_rf_tech(ddev, &rf_tech);
1289         if (rc)
1290                 goto exit_free_skb;
1291
1292         switch (rf_tech) {
1293         case NFC_DIGITAL_RF_TECH_106A:
1294                 rc = digital_tg_config_nfca(ddev);
1295                 if (rc)
1296                         goto exit_free_skb;
1297                 digital_tg_recv_sens_req(ddev, arg, resp);
1298                 break;
1299         case NFC_DIGITAL_RF_TECH_212F:
1300         case NFC_DIGITAL_RF_TECH_424F:
1301                 rc = digital_tg_config_nfcf(ddev, rf_tech);
1302                 if (rc)
1303                         goto exit_free_skb;
1304                 digital_tg_recv_sensf_req(ddev, arg, resp);
1305                 break;
1306         default:
1307                 goto exit_free_skb;
1308         }
1309
1310         return;
1311
1312 exit_free_skb:
1313         digital_poll_next_tech(ddev);
1314         dev_kfree_skb(resp);
1315 }