drivers/nfc/st21nfca/dep.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2014  STMicroelectronics SAS. All rights reserved.
   4  */
   5
   6 #include <net/nfc/hci.h>
   7
   8 #include "st21nfca.h"
   9
  10 #define ST21NFCA_NFCIP1_INITIATOR 0x00
  11 #define ST21NFCA_NFCIP1_REQ 0xd4
  12 #define ST21NFCA_NFCIP1_RES 0xd5
  13 #define ST21NFCA_NFCIP1_ATR_REQ 0x00
  14 #define ST21NFCA_NFCIP1_ATR_RES 0x01
  15 #define ST21NFCA_NFCIP1_PSL_REQ 0x04
  16 #define ST21NFCA_NFCIP1_PSL_RES 0x05
  17 #define ST21NFCA_NFCIP1_DEP_REQ 0x06
  18 #define ST21NFCA_NFCIP1_DEP_RES 0x07
  19
  20 #define ST21NFCA_NFC_DEP_PFB_PNI(pfb)     ((pfb) & 0x03)
  21 #define ST21NFCA_NFC_DEP_PFB_TYPE(pfb) ((pfb) & 0xE0)
  22 #define ST21NFCA_NFC_DEP_PFB_IS_TIMEOUT(pfb) \
  23                                 ((pfb) & ST21NFCA_NFC_DEP_PFB_TIMEOUT_BIT)
  24 #define ST21NFCA_NFC_DEP_DID_BIT_SET(pfb) ((pfb) & 0x04)
  25 #define ST21NFCA_NFC_DEP_NAD_BIT_SET(pfb) ((pfb) & 0x08)
  26 #define ST21NFCA_NFC_DEP_PFB_TIMEOUT_BIT 0x10
  27
  28 #define ST21NFCA_NFC_DEP_PFB_IS_TIMEOUT(pfb) \
  29                                 ((pfb) & ST21NFCA_NFC_DEP_PFB_TIMEOUT_BIT)
  30
  31 #define ST21NFCA_NFC_DEP_PFB_I_PDU          0x00
  32 #define ST21NFCA_NFC_DEP_PFB_ACK_NACK_PDU   0x40
  33 #define ST21NFCA_NFC_DEP_PFB_SUPERVISOR_PDU 0x80
  34
  35 #define ST21NFCA_ATR_REQ_MIN_SIZE 17
  36 #define ST21NFCA_ATR_REQ_MAX_SIZE 65
  37 #define ST21NFCA_LR_BITS_PAYLOAD_SIZE_254B 0x30
  38 #define ST21NFCA_GB_BIT  0x02
  39
  40 #define ST21NFCA_EVT_SEND_DATA          0x10
  41 #define ST21NFCA_EVT_FIELD_ON           0x11
  42 #define ST21NFCA_EVT_CARD_DEACTIVATED   0x12
  43 #define ST21NFCA_EVT_CARD_ACTIVATED     0x13
  44 #define ST21NFCA_EVT_FIELD_OFF          0x14
  45
  46 #define ST21NFCA_EVT_CARD_F_BITRATE 0x16
  47 #define ST21NFCA_EVT_READER_F_BITRATE 0x13
  48 #define ST21NFCA_PSL_REQ_SEND_SPEED(brs) (brs & 0x38)
  49 #define ST21NFCA_PSL_REQ_RECV_SPEED(brs) (brs & 0x07)
  50 #define ST21NFCA_PP2LRI(pp) ((pp & 0x30) >> 4)
  51 #define ST21NFCA_CARD_BITRATE_212 0x01
  52 #define ST21NFCA_CARD_BITRATE_424 0x02
  53
  54 #define ST21NFCA_DEFAULT_TIMEOUT 0x0a
  55
  56
  57 #define PROTOCOL_ERR(req) pr_err("%d: ST21NFCA Protocol error: %s\n", \
  58                                  __LINE__, req)
  59
  60 struct st21nfca_atr_req {
  61         u8 length;
  62         u8 cmd0;
  63         u8 cmd1;
  64         u8 nfcid3[NFC_NFCID3_MAXSIZE];
  65         u8 did;
  66         u8 bsi;
  67         u8 bri;
  68         u8 ppi;
  69         u8 gbi[0];
  70 } __packed;
  71
  72 struct st21nfca_atr_res {
  73         u8 length;
  74         u8 cmd0;
  75         u8 cmd1;
  76         u8 nfcid3[NFC_NFCID3_MAXSIZE];
  77         u8 did;
  78         u8 bsi;
  79         u8 bri;
  80         u8 to;
  81         u8 ppi;
  82         u8 gbi[0];
  83 } __packed;
  84
  85 struct st21nfca_psl_req {
  86         u8 length;
  87         u8 cmd0;
  88         u8 cmd1;
  89         u8 did;
  90         u8 brs;
  91         u8 fsl;
  92 } __packed;
  93
  94 struct st21nfca_psl_res {
  95         u8 length;
  96         u8 cmd0;
  97         u8 cmd1;
  98         u8 did;
  99 } __packed;
 100
 101 struct st21nfca_dep_req_res {
 102         u8 length;
 103         u8 cmd0;
 104         u8 cmd1;
 105         u8 pfb;
 106         u8 did;
 107         u8 nad;
 108 } __packed;
 109
 110 static void st21nfca_tx_work(struct work_struct *work)
 111 {
 112         struct st21nfca_hci_info *info = container_of(work,
 113                                                 struct st21nfca_hci_info,
 114                                                 dep_info.tx_work);
 115
 116         struct nfc_dev *dev;
 117         struct sk_buff *skb;
 118
 119         if (info) {
 120                 dev = info->hdev->ndev;
 121                 skb = info->dep_info.tx_pending;
 122
 123                 device_lock(&dev->dev);
 124
 125                 nfc_hci_send_cmd_async(info->hdev, ST21NFCA_RF_READER_F_GATE,
 126                                 ST21NFCA_WR_XCHG_DATA, skb->data, skb->len,
 127                                 info->async_cb, info);
 128                 device_unlock(&dev->dev);
 129                 kfree_skb(skb);
 130         }
 131 }
 132
 133 static void st21nfca_im_send_pdu(struct st21nfca_hci_info *info,
 134                                                 struct sk_buff *skb)
 135 {
 136         info->dep_info.tx_pending = skb;
 137         schedule_work(&info->dep_info.tx_work);
 138 }
 139
 140 static int st21nfca_tm_send_atr_res(struct nfc_hci_dev *hdev,
 141                                     struct st21nfca_atr_req *atr_req)
 142 {
 143         struct st21nfca_atr_res *atr_res;
 144         struct sk_buff *skb;
 145         size_t gb_len;
 146         int r;
 147         struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
 148
 149         gb_len = atr_req->length - sizeof(struct st21nfca_atr_req);
 150         skb = alloc_skb(atr_req->length + 1, GFP_KERNEL);
 151         if (!skb)
 152                 return -ENOMEM;
 153
 154         skb_put(skb, sizeof(struct st21nfca_atr_res));
 155
 156         atr_res = (struct st21nfca_atr_res *)skb->data;
 157         memset(atr_res, 0, sizeof(struct st21nfca_atr_res));
 158
 159         atr_res->length = atr_req->length + 1;
 160         atr_res->cmd0 = ST21NFCA_NFCIP1_RES;
 161         atr_res->cmd1 = ST21NFCA_NFCIP1_ATR_RES;
 162
 163         memcpy(atr_res->nfcid3, atr_req->nfcid3, 6);
 164         atr_res->bsi = 0x00;
 165         atr_res->bri = 0x00;
 166         atr_res->to = ST21NFCA_DEFAULT_TIMEOUT;
 167         atr_res->ppi = ST21NFCA_LR_BITS_PAYLOAD_SIZE_254B;
 168
 169         if (gb_len) {
 170                 skb_put(skb, gb_len);
 171
 172                 atr_res->ppi |= ST21NFCA_GB_BIT;
 173                 memcpy(atr_res->gbi, atr_req->gbi, gb_len);
 174                 r = nfc_set_remote_general_bytes(hdev->ndev, atr_res->gbi,
 175                                                   gb_len);
 176                 if (r < 0)
 177                         return r;
 178         }
 179
 180         info->dep_info.curr_nfc_dep_pni = 0;
 181
 182         r = nfc_hci_send_event(hdev, ST21NFCA_RF_CARD_F_GATE,
 183                                 ST21NFCA_EVT_SEND_DATA, skb->data, skb->len);
 184         kfree_skb(skb);
 185         return r;
 186 }
 187
 188 static int st21nfca_tm_recv_atr_req(struct nfc_hci_dev *hdev,
 189                                     struct sk_buff *skb)
 190 {
 191         struct st21nfca_atr_req *atr_req;
 192         size_t gb_len;
 193         int r;
 194
 195         skb_trim(skb, skb->len - 1);
 196
 197         if (!skb->len) {
 198                 r = -EIO;
 199                 goto exit;
 200         }
 201
 202         if (skb->len < ST21NFCA_ATR_REQ_MIN_SIZE) {
 203                 r = -EPROTO;
 204                 goto exit;
 205         }
 206
 207         atr_req = (struct st21nfca_atr_req *)skb->data;
 208
 209         if (atr_req->length < sizeof(struct st21nfca_atr_req)) {
 210                 r = -EPROTO;
 211                 goto exit;
 212         }
 213
 214         r = st21nfca_tm_send_atr_res(hdev, atr_req);
 215         if (r)
 216                 goto exit;
 217
 218         gb_len = skb->len - sizeof(struct st21nfca_atr_req);
 219
 220         r = nfc_tm_activated(hdev->ndev, NFC_PROTO_NFC_DEP_MASK,
 221                               NFC_COMM_PASSIVE, atr_req->gbi, gb_len);
 222         if (r)
 223                 goto exit;
 224
 225         r = 0;
 226
 227 exit:
 228         return r;
 229 }
 230
 231 static int st21nfca_tm_send_psl_res(struct nfc_hci_dev *hdev,
 232                                     struct st21nfca_psl_req *psl_req)
 233 {
 234         struct st21nfca_psl_res *psl_res;
 235         struct sk_buff *skb;
 236         u8 bitrate[2] = {0, 0};
 237         int r;
 238
 239         skb = alloc_skb(sizeof(struct st21nfca_psl_res), GFP_KERNEL);
 240         if (!skb)
 241                 return -ENOMEM;
 242         skb_put(skb, sizeof(struct st21nfca_psl_res));
 243
 244         psl_res = (struct st21nfca_psl_res *)skb->data;
 245
 246         psl_res->length = sizeof(struct st21nfca_psl_res);
 247         psl_res->cmd0 = ST21NFCA_NFCIP1_RES;
 248         psl_res->cmd1 = ST21NFCA_NFCIP1_PSL_RES;
 249         psl_res->did = psl_req->did;
 250
 251         r = nfc_hci_send_event(hdev, ST21NFCA_RF_CARD_F_GATE,
 252                                 ST21NFCA_EVT_SEND_DATA, skb->data, skb->len);
 253         if (r < 0)
 254                 goto error;
 255
 256         /*
 257          * ST21NFCA only support P2P passive.
 258          * PSL_REQ BRS value != 0 has only a meaning to
 259          * change technology to type F.
 260          * We change to BITRATE 424Kbits.
 261          * In other case switch to BITRATE 106Kbits.
 262          */
 263         if (ST21NFCA_PSL_REQ_SEND_SPEED(psl_req->brs) &&
 264             ST21NFCA_PSL_REQ_RECV_SPEED(psl_req->brs)) {
 265                 bitrate[0] = ST21NFCA_CARD_BITRATE_424;
 266                 bitrate[1] = ST21NFCA_CARD_BITRATE_424;
 267         }
 268
 269         /* Send an event to change bitrate change event to card f */
 270         r = nfc_hci_send_event(hdev, ST21NFCA_RF_CARD_F_GATE,
 271                         ST21NFCA_EVT_CARD_F_BITRATE, bitrate, 2);
 272 error:
 273         kfree_skb(skb);
 274         return r;
 275 }
 276
 277 static int st21nfca_tm_recv_psl_req(struct nfc_hci_dev *hdev,
 278                                     struct sk_buff *skb)
 279 {
 280         struct st21nfca_psl_req *psl_req;
 281         int r;
 282
 283         skb_trim(skb, skb->len - 1);
 284
 285         if (!skb->len) {
 286                 r = -EIO;
 287                 goto exit;
 288         }
 289
 290         psl_req = (struct st21nfca_psl_req *)skb->data;
 291
 292         if (skb->len < sizeof(struct st21nfca_psl_req)) {
 293                 r = -EIO;
 294                 goto exit;
 295         }
 296
 297         r = st21nfca_tm_send_psl_res(hdev, psl_req);
 298 exit:
 299         return r;
 300 }
 301
 302 int st21nfca_tm_send_dep_res(struct nfc_hci_dev *hdev, struct sk_buff *skb)
 303 {
 304         int r;
 305         struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
 306
 307         *(u8 *)skb_push(skb, 1) = info->dep_info.curr_nfc_dep_pni;
 308         *(u8 *)skb_push(skb, 1) = ST21NFCA_NFCIP1_DEP_RES;
 309         *(u8 *)skb_push(skb, 1) = ST21NFCA_NFCIP1_RES;
 310         *(u8 *)skb_push(skb, 1) = skb->len;
 311
 312         r = nfc_hci_send_event(hdev, ST21NFCA_RF_CARD_F_GATE,
 313                         ST21NFCA_EVT_SEND_DATA, skb->data, skb->len);
 314         kfree_skb(skb);
 315
 316         return r;
 317 }
 318 EXPORT_SYMBOL(st21nfca_tm_send_dep_res);
 319
 320 static int st21nfca_tm_recv_dep_req(struct nfc_hci_dev *hdev,
 321                                     struct sk_buff *skb)
 322 {
 323         struct st21nfca_dep_req_res *dep_req;
 324         u8 size;
 325         int r;
 326         struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
 327
 328         skb_trim(skb, skb->len - 1);
 329
 330         size = 4;
 331
 332         dep_req = (struct st21nfca_dep_req_res *)skb->data;
 333         if (skb->len < size) {
 334                 r = -EIO;
 335                 goto exit;
 336         }
 337
 338         if (ST21NFCA_NFC_DEP_DID_BIT_SET(dep_req->pfb))
 339                 size++;
 340         if (ST21NFCA_NFC_DEP_NAD_BIT_SET(dep_req->pfb))
 341                 size++;
 342
 343         if (skb->len < size) {
 344                 r = -EIO;
 345                 goto exit;
 346         }
 347
 348         /* Receiving DEP_REQ - Decoding */
 349         switch (ST21NFCA_NFC_DEP_PFB_TYPE(dep_req->pfb)) {
 350         case ST21NFCA_NFC_DEP_PFB_I_PDU:
 351                 info->dep_info.curr_nfc_dep_pni =
 352                                 ST21NFCA_NFC_DEP_PFB_PNI(dep_req->pfb);
 353                 break;
 354         case ST21NFCA_NFC_DEP_PFB_ACK_NACK_PDU:
 355                 pr_err("Received a ACK/NACK PDU\n");
 356                 break;
 357         case ST21NFCA_NFC_DEP_PFB_SUPERVISOR_PDU:
 358                 pr_err("Received a SUPERVISOR PDU\n");
 359                 break;
 360         }
 361
 362         skb_pull(skb, size);
 363
 364         return nfc_tm_data_received(hdev->ndev, skb);
 365 exit:
 366         return r;
 367 }
 368
 369 static int st21nfca_tm_event_send_data(struct nfc_hci_dev *hdev,
 370                                 struct sk_buff *skb)
 371 {
 372         u8 cmd0, cmd1;
 373         int r;
 374
 375         cmd0 = skb->data[1];
 376         switch (cmd0) {
 377         case ST21NFCA_NFCIP1_REQ:
 378                 cmd1 = skb->data[2];
 379                 switch (cmd1) {
 380                 case ST21NFCA_NFCIP1_ATR_REQ:
 381                         r = st21nfca_tm_recv_atr_req(hdev, skb);
 382                         break;
 383                 case ST21NFCA_NFCIP1_PSL_REQ:
 384                         r = st21nfca_tm_recv_psl_req(hdev, skb);
 385                         break;
 386                 case ST21NFCA_NFCIP1_DEP_REQ:
 387                         r = st21nfca_tm_recv_dep_req(hdev, skb);
 388                         break;
 389                 default:
 390                         return 1;
 391                 }
 392                 break;
 393         default:
 394                 return 1;
 395         }
 396         return r;
 397 }
 398
 399 /*
 400  * Returns:
 401  * <= 0: driver handled the event, skb consumed
 402  *    1: driver does not handle the event, please do standard processing
 403  */
 404 int st21nfca_dep_event_received(struct nfc_hci_dev *hdev,
 405                                 u8 event, struct sk_buff *skb)
 406 {
 407         int r = 0;
 408         struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
 409
 410         pr_debug("dep event: %d\n", event);
 411
 412         switch (event) {
 413         case ST21NFCA_EVT_CARD_ACTIVATED:
 414                 info->dep_info.curr_nfc_dep_pni = 0;
 415                 break;
 416         case ST21NFCA_EVT_CARD_DEACTIVATED:
 417                 break;
 418         case ST21NFCA_EVT_FIELD_ON:
 419                 break;
 420         case ST21NFCA_EVT_FIELD_OFF:
 421                 break;
 422         case ST21NFCA_EVT_SEND_DATA:
 423                 r = st21nfca_tm_event_send_data(hdev, skb);
 424                 if (r < 0)
 425                         return r;
 426                 return 0;
 427         default:
 428                 nfc_err(&hdev->ndev->dev, "Unexpected event on card f gate\n");
 429                 return 1;
 430         }
 431         kfree_skb(skb);
 432         return r;
 433 }
 434 EXPORT_SYMBOL(st21nfca_dep_event_received);
 435
 436 static void st21nfca_im_send_psl_req(struct nfc_hci_dev *hdev, u8 did, u8 bsi,
 437                                      u8 bri, u8 lri)
 438 {
 439         struct sk_buff *skb;
 440         struct st21nfca_psl_req *psl_req;
 441         struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
 442
 443         skb =
 444             alloc_skb(sizeof(struct st21nfca_psl_req) + 1, GFP_KERNEL);
 445         if (!skb)
 446                 return;
 447         skb_reserve(skb, 1);
 448
 449         skb_put(skb, sizeof(struct st21nfca_psl_req));
 450         psl_req = (struct st21nfca_psl_req *) skb->data;
 451
 452         psl_req->length = sizeof(struct st21nfca_psl_req);
 453         psl_req->cmd0 = ST21NFCA_NFCIP1_REQ;
 454         psl_req->cmd1 = ST21NFCA_NFCIP1_PSL_REQ;
 455         psl_req->did = did;
 456         psl_req->brs = (0x30 & bsi << 4) | (bri & 0x03);
 457         psl_req->fsl = lri;
 458
 459         *(u8 *)skb_push(skb, 1) = info->dep_info.to | 0x10;
 460
 461         st21nfca_im_send_pdu(info, skb);
 462 }
 463
 464 #define ST21NFCA_CB_TYPE_READER_F 1
 465 static void st21nfca_im_recv_atr_res_cb(void *context, struct sk_buff *skb,
 466                                         int err)
 467 {
 468         struct st21nfca_hci_info *info = context;
 469         struct st21nfca_atr_res *atr_res;
 470         int r;
 471
 472         if (err != 0)
 473                 return;
 474
 475         if (!skb)
 476                 return;
 477
 478         switch (info->async_cb_type) {
 479         case ST21NFCA_CB_TYPE_READER_F:
 480                 skb_trim(skb, skb->len - 1);
 481                 atr_res = (struct st21nfca_atr_res *)skb->data;
 482                 r = nfc_set_remote_general_bytes(info->hdev->ndev,
 483                                 atr_res->gbi,
 484                                 skb->len - sizeof(struct st21nfca_atr_res));
 485                 if (r < 0)
 486                         return;
 487
 488                 if (atr_res->to >= 0x0e)
 489                         info->dep_info.to = 0x0e;
 490                 else
 491                         info->dep_info.to = atr_res->to + 1;
 492
 493                 info->dep_info.to |= 0x10;
 494
 495                 r = nfc_dep_link_is_up(info->hdev->ndev, info->dep_info.idx,
 496                                         NFC_COMM_PASSIVE, NFC_RF_INITIATOR);
 497                 if (r < 0)
 498                         return;
 499
 500                 info->dep_info.curr_nfc_dep_pni = 0;
 501                 if (ST21NFCA_PP2LRI(atr_res->ppi) != info->dep_info.lri)
 502                         st21nfca_im_send_psl_req(info->hdev, atr_res->did,
 503                                                 atr_res->bsi, atr_res->bri,
 504                                                 ST21NFCA_PP2LRI(atr_res->ppi));
 505                 break;
 506         default:
 507                 kfree_skb(skb);
 508                 break;
 509         }
 510 }
 511
 512 int st21nfca_im_send_atr_req(struct nfc_hci_dev *hdev, u8 *gb, size_t gb_len)
 513 {
 514         struct sk_buff *skb;
 515         struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
 516         struct st21nfca_atr_req *atr_req;
 517         struct nfc_target *target;
 518         uint size;
 519
 520         info->dep_info.to = ST21NFCA_DEFAULT_TIMEOUT;
 521         size = ST21NFCA_ATR_REQ_MIN_SIZE + gb_len;
 522         if (size > ST21NFCA_ATR_REQ_MAX_SIZE) {
 523                 PROTOCOL_ERR("14.6.1.1");
 524                 return -EINVAL;
 525         }
 526
 527         skb =
 528             alloc_skb(sizeof(struct st21nfca_atr_req) + gb_len + 1, GFP_KERNEL);
 529         if (!skb)
 530                 return -ENOMEM;
 531
 532         skb_reserve(skb, 1);
 533
 534         skb_put(skb, sizeof(struct st21nfca_atr_req));
 535
 536         atr_req = (struct st21nfca_atr_req *)skb->data;
 537         memset(atr_req, 0, sizeof(struct st21nfca_atr_req));
 538
 539         atr_req->cmd0 = ST21NFCA_NFCIP1_REQ;
 540         atr_req->cmd1 = ST21NFCA_NFCIP1_ATR_REQ;
 541         memset(atr_req->nfcid3, 0, NFC_NFCID3_MAXSIZE);
 542         target = hdev->ndev->targets;
 543
 544         if (target->sensf_res_len > 0)
 545                 memcpy(atr_req->nfcid3, target->sensf_res,
 546                                 target->sensf_res_len);
 547         else
 548                 get_random_bytes(atr_req->nfcid3, NFC_NFCID3_MAXSIZE);
 549
 550         atr_req->did = 0x0;
 551
 552         atr_req->bsi = 0x00;
 553         atr_req->bri = 0x00;
 554         atr_req->ppi = ST21NFCA_LR_BITS_PAYLOAD_SIZE_254B;
 555         if (gb_len) {
 556                 atr_req->ppi |= ST21NFCA_GB_BIT;
 557                 skb_put_data(skb, gb, gb_len);
 558         }
 559         atr_req->length = sizeof(struct st21nfca_atr_req) + hdev->gb_len;
 560
 561         *(u8 *)skb_push(skb, 1) = info->dep_info.to | 0x10; /* timeout */
 562
 563         info->async_cb_type = ST21NFCA_CB_TYPE_READER_F;
 564         info->async_cb_context = info;
 565         info->async_cb = st21nfca_im_recv_atr_res_cb;
 566         info->dep_info.bri = atr_req->bri;
 567         info->dep_info.bsi = atr_req->bsi;
 568         info->dep_info.lri = ST21NFCA_PP2LRI(atr_req->ppi);
 569
 570         return nfc_hci_send_cmd_async(hdev, ST21NFCA_RF_READER_F_GATE,
 571                                 ST21NFCA_WR_XCHG_DATA, skb->data,
 572                                 skb->len, info->async_cb, info);
 573 }
 574 EXPORT_SYMBOL(st21nfca_im_send_atr_req);
 575
 576 static void st21nfca_im_recv_dep_res_cb(void *context, struct sk_buff *skb,
 577                                         int err)
 578 {
 579         struct st21nfca_hci_info *info = context;
 580         struct st21nfca_dep_req_res *dep_res;
 581
 582         int size;
 583
 584         if (err != 0)
 585                 return;
 586
 587         if (!skb)
 588                 return;
 589
 590         switch (info->async_cb_type) {
 591         case ST21NFCA_CB_TYPE_READER_F:
 592                 dep_res = (struct st21nfca_dep_req_res *)skb->data;
 593
 594                 size = 3;
 595                 if (skb->len < size)
 596                         goto exit;
 597
 598                 if (ST21NFCA_NFC_DEP_DID_BIT_SET(dep_res->pfb))
 599                         size++;
 600                 if (ST21NFCA_NFC_DEP_NAD_BIT_SET(dep_res->pfb))
 601                         size++;
 602
 603                 if (skb->len < size)
 604                         goto exit;
 605
 606                 skb_trim(skb, skb->len - 1);
 607
 608                 /* Receiving DEP_REQ - Decoding */
 609                 switch (ST21NFCA_NFC_DEP_PFB_TYPE(dep_res->pfb)) {
 610                 case ST21NFCA_NFC_DEP_PFB_ACK_NACK_PDU:
 611                         pr_err("Received a ACK/NACK PDU\n");
 612                         /* fall through */
 613                 case ST21NFCA_NFC_DEP_PFB_I_PDU:
 614                         info->dep_info.curr_nfc_dep_pni =
 615                             ST21NFCA_NFC_DEP_PFB_PNI(dep_res->pfb + 1);
 616                         size++;
 617                         skb_pull(skb, size);
 618                         nfc_tm_data_received(info->hdev->ndev, skb);
 619                         break;
 620                 case ST21NFCA_NFC_DEP_PFB_SUPERVISOR_PDU:
 621                         pr_err("Received a SUPERVISOR PDU\n");
 622                         skb_pull(skb, size);
 623                         *(u8 *)skb_push(skb, 1) = ST21NFCA_NFCIP1_DEP_REQ;
 624                         *(u8 *)skb_push(skb, 1) = ST21NFCA_NFCIP1_REQ;
 625                         *(u8 *)skb_push(skb, 1) = skb->len;
 626                         *(u8 *)skb_push(skb, 1) = info->dep_info.to | 0x10;
 627
 628                         st21nfca_im_send_pdu(info, skb);
 629                         break;
 630                 }
 631
 632                 return;
 633         default:
 634                 break;
 635         }
 636
 637 exit:
 638         kfree_skb(skb);
 639 }
 640
 641 int st21nfca_im_send_dep_req(struct nfc_hci_dev *hdev, struct sk_buff *skb)
 642 {
 643         struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
 644
 645         info->async_cb_type = ST21NFCA_CB_TYPE_READER_F;
 646         info->async_cb_context = info;
 647         info->async_cb = st21nfca_im_recv_dep_res_cb;
 648
 649         *(u8 *)skb_push(skb, 1) = info->dep_info.curr_nfc_dep_pni;
 650         *(u8 *)skb_push(skb, 1) = ST21NFCA_NFCIP1_DEP_REQ;
 651         *(u8 *)skb_push(skb, 1) = ST21NFCA_NFCIP1_REQ;
 652         *(u8 *)skb_push(skb, 1) = skb->len;
 653
 654         *(u8 *)skb_push(skb, 1) = info->dep_info.to | 0x10;
 655
 656         return nfc_hci_send_cmd_async(hdev, ST21NFCA_RF_READER_F_GATE,
 657                                       ST21NFCA_WR_XCHG_DATA,
 658                                       skb->data, skb->len,
 659                                       info->async_cb, info);
 660 }
 661 EXPORT_SYMBOL(st21nfca_im_send_dep_req);
 662
 663 void st21nfca_dep_init(struct nfc_hci_dev *hdev)
 664 {
 665         struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
 666
 667         INIT_WORK(&info->dep_info.tx_work, st21nfca_tx_work);
 668         info->dep_info.curr_nfc_dep_pni = 0;
 669         info->dep_info.idx = 0;
 670         info->dep_info.to = ST21NFCA_DEFAULT_TIMEOUT;
 671 }
 672 EXPORT_SYMBOL(st21nfca_dep_init);
 673
 674 void st21nfca_dep_deinit(struct nfc_hci_dev *hdev)
 675 {
 676         struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
 677
 678         cancel_work_sync(&info->dep_info.tx_work);
 679 }
 680 EXPORT_SYMBOL(st21nfca_dep_deinit);