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TOMOYO Linux Cross Reference
Linux/net/nfc/digital_dep.c

Version: ~ [ linux-5.4.2 ] ~ [ linux-5.3.15 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.88 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.158 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.206 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.206 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.78 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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_REQ_RES_HEADROOM        2 /* SoD: [SB (NFC-A)] + LEN */
 42 #define DIGITAL_NFC_DEP_REQ_RES_TAILROOM        2 /* EoD: 2-byte CRC */
 43 
 44 #define DIGITAL_NFC_DEP_PFB_TYPE(pfb) ((pfb) & 0xE0)
 45 
 46 #define DIGITAL_NFC_DEP_PFB_TIMEOUT_BIT 0x10
 47 #define DIGITAL_NFC_DEP_PFB_MI_BIT      0x10
 48 #define DIGITAL_NFC_DEP_PFB_NACK_BIT    0x10
 49 #define DIGITAL_NFC_DEP_PFB_DID_BIT     0x04
 50 
 51 #define DIGITAL_NFC_DEP_PFB_IS_TIMEOUT(pfb) \
 52                                 ((pfb) & DIGITAL_NFC_DEP_PFB_TIMEOUT_BIT)
 53 #define DIGITAL_NFC_DEP_MI_BIT_SET(pfb)  ((pfb) & DIGITAL_NFC_DEP_PFB_MI_BIT)
 54 #define DIGITAL_NFC_DEP_NACK_BIT_SET(pfb) ((pfb) & DIGITAL_NFC_DEP_PFB_NACK_BIT)
 55 #define DIGITAL_NFC_DEP_NAD_BIT_SET(pfb) ((pfb) & 0x08)
 56 #define DIGITAL_NFC_DEP_DID_BIT_SET(pfb) ((pfb) & DIGITAL_NFC_DEP_PFB_DID_BIT)
 57 #define DIGITAL_NFC_DEP_PFB_PNI(pfb)     ((pfb) & 0x03)
 58 
 59 #define DIGITAL_NFC_DEP_RTOX_VALUE(data) ((data) & 0x3F)
 60 #define DIGITAL_NFC_DEP_RTOX_MAX         59
 61 
 62 #define DIGITAL_NFC_DEP_PFB_I_PDU          0x00
 63 #define DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU   0x40
 64 #define DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU 0x80
 65 
 66 struct digital_atr_req {
 67         u8 dir;
 68         u8 cmd;
 69         u8 nfcid3[10];
 70         u8 did;
 71         u8 bs;
 72         u8 br;
 73         u8 pp;
 74         u8 gb[0];
 75 } __packed;
 76 
 77 struct digital_atr_res {
 78         u8 dir;
 79         u8 cmd;
 80         u8 nfcid3[10];
 81         u8 did;
 82         u8 bs;
 83         u8 br;
 84         u8 to;
 85         u8 pp;
 86         u8 gb[0];
 87 } __packed;
 88 
 89 struct digital_psl_req {
 90         u8 dir;
 91         u8 cmd;
 92         u8 did;
 93         u8 brs;
 94         u8 fsl;
 95 } __packed;
 96 
 97 struct digital_psl_res {
 98         u8 dir;
 99         u8 cmd;
100         u8 did;
101 } __packed;
102 
103 struct digital_dep_req_res {
104         u8 dir;
105         u8 cmd;
106         u8 pfb;
107 } __packed;
108 
109 static void digital_in_recv_dep_res(struct nfc_digital_dev *ddev, void *arg,
110                                     struct sk_buff *resp);
111 static void digital_tg_recv_dep_req(struct nfc_digital_dev *ddev, void *arg,
112                                     struct sk_buff *resp);
113 
114 static const u8 digital_payload_bits_map[4] = {
115         [0] = 64,
116         [1] = 128,
117         [2] = 192,
118         [3] = 254
119 };
120 
121 /* Response Waiting Time for ATR_RES PDU in ms
122  *
123  * RWT(ATR_RES) = RWT(nfcdep,activation) + dRWT(nfcdep) + dT(nfcdep,initiator)
124  *
125  * with:
126  *  RWT(nfcdep,activation) = 4096 * 2^12 / f(c) s
127  *  dRWT(nfcdep) = 16 / f(c) s
128  *  dT(nfcdep,initiator) = 100 ms
129  *  f(c) = 13560000 Hz
130  */
131 #define DIGITAL_ATR_RES_RWT 1337
132 
133 /* Response Waiting Time for other DEP PDUs in ms
134  *
135  * max_rwt = rwt + dRWT(nfcdep) + dT(nfcdep,initiator)
136  *
137  * with:
138  *  rwt = (256 * 16 / f(c)) * 2^wt s
139  *  dRWT(nfcdep) = 16 / f(c) s
140  *  dT(nfcdep,initiator) = 100 ms
141  *  f(c) = 13560000 Hz
142  *  0 <= wt <= 14 (given by the target by the TO field of ATR_RES response)
143  */
144 #define DIGITAL_NFC_DEP_IN_MAX_WT 14
145 #define DIGITAL_NFC_DEP_TG_MAX_WT 14
146 static const u16 digital_rwt_map[DIGITAL_NFC_DEP_IN_MAX_WT + 1] = {
147         100,  101,  101,  102,  105,
148         110,  119,  139,  177,  255,
149         409,  719, 1337, 2575, 5049,
150 };
151 
152 static u8 digital_payload_bits_to_size(u8 payload_bits)
153 {
154         if (payload_bits >= ARRAY_SIZE(digital_payload_bits_map))
155                 return 0;
156 
157         return digital_payload_bits_map[payload_bits];
158 }
159 
160 static u8 digital_payload_size_to_bits(u8 payload_size)
161 {
162         int i;
163 
164         for (i = 0; i < ARRAY_SIZE(digital_payload_bits_map); i++)
165                 if (digital_payload_bits_map[i] == payload_size)
166                         return i;
167 
168         return 0xff;
169 }
170 
171 static void digital_skb_push_dep_sod(struct nfc_digital_dev *ddev,
172                                      struct sk_buff *skb)
173 {
174         skb_push(skb, sizeof(u8));
175 
176         skb->data[0] = skb->len;
177 
178         if (ddev->curr_rf_tech == NFC_DIGITAL_RF_TECH_106A)
179                 *(u8 *)skb_push(skb, sizeof(u8)) = DIGITAL_NFC_DEP_NFCA_SOD_SB;
180 }
181 
182 static int digital_skb_pull_dep_sod(struct nfc_digital_dev *ddev,
183                                     struct sk_buff *skb)
184 {
185         u8 size;
186 
187         if (skb->len < 2)
188                 return -EIO;
189 
190         if (ddev->curr_rf_tech == NFC_DIGITAL_RF_TECH_106A)
191                 skb_pull(skb, sizeof(u8));
192 
193         size = skb->data[0];
194         if (size != skb->len)
195                 return -EIO;
196 
197         skb_pull(skb, sizeof(u8));
198 
199         return 0;
200 }
201 
202 static struct sk_buff *
203 digital_send_dep_data_prep(struct nfc_digital_dev *ddev, struct sk_buff *skb,
204                            struct digital_dep_req_res *dep_req_res,
205                            struct digital_data_exch *data_exch)
206 {
207         struct sk_buff *new_skb;
208 
209         if (skb->len > ddev->remote_payload_max) {
210                 dep_req_res->pfb |= DIGITAL_NFC_DEP_PFB_MI_BIT;
211 
212                 new_skb = digital_skb_alloc(ddev, ddev->remote_payload_max);
213                 if (!new_skb) {
214                         kfree_skb(ddev->chaining_skb);
215                         ddev->chaining_skb = NULL;
216 
217                         return ERR_PTR(-ENOMEM);
218                 }
219 
220                 skb_put_data(new_skb, skb->data, ddev->remote_payload_max);
221                 skb_pull(skb, ddev->remote_payload_max);
222 
223                 ddev->chaining_skb = skb;
224                 ddev->data_exch = data_exch;
225         } else {
226                 ddev->chaining_skb = NULL;
227                 new_skb = skb;
228         }
229 
230         return new_skb;
231 }
232 
233 static struct sk_buff *
234 digital_recv_dep_data_gather(struct nfc_digital_dev *ddev, u8 pfb,
235                              struct sk_buff *resp,
236                              int (*send_ack)(struct nfc_digital_dev *ddev,
237                                              struct digital_data_exch
238                                                              *data_exch),
239                              struct digital_data_exch *data_exch)
240 {
241         struct sk_buff *new_skb;
242         int rc;
243 
244         if (DIGITAL_NFC_DEP_MI_BIT_SET(pfb) && (!ddev->chaining_skb)) {
245                 ddev->chaining_skb =
246                         nfc_alloc_recv_skb(8 * ddev->local_payload_max,
247                                            GFP_KERNEL);
248                 if (!ddev->chaining_skb) {
249                         rc = -ENOMEM;
250                         goto error;
251                 }
252         }
253 
254         if (ddev->chaining_skb) {
255                 if (resp->len > skb_tailroom(ddev->chaining_skb)) {
256                         new_skb = skb_copy_expand(ddev->chaining_skb,
257                                                   skb_headroom(
258                                                           ddev->chaining_skb),
259                                                   8 * ddev->local_payload_max,
260                                                   GFP_KERNEL);
261                         if (!new_skb) {
262                                 rc = -ENOMEM;
263                                 goto error;
264                         }
265 
266                         kfree_skb(ddev->chaining_skb);
267                         ddev->chaining_skb = new_skb;
268                 }
269 
270                 skb_put_data(ddev->chaining_skb, resp->data, resp->len);
271 
272                 kfree_skb(resp);
273                 resp = NULL;
274 
275                 if (DIGITAL_NFC_DEP_MI_BIT_SET(pfb)) {
276                         rc = send_ack(ddev, data_exch);
277                         if (rc)
278                                 goto error;
279 
280                         return NULL;
281                 }
282 
283                 resp = ddev->chaining_skb;
284                 ddev->chaining_skb = NULL;
285         }
286 
287         return resp;
288 
289 error:
290         kfree_skb(resp);
291 
292         kfree_skb(ddev->chaining_skb);
293         ddev->chaining_skb = NULL;
294 
295         return ERR_PTR(rc);
296 }
297 
298 static void digital_in_recv_psl_res(struct nfc_digital_dev *ddev, void *arg,
299                                     struct sk_buff *resp)
300 {
301         struct nfc_target *target = arg;
302         struct digital_psl_res *psl_res;
303         int rc;
304 
305         if (IS_ERR(resp)) {
306                 rc = PTR_ERR(resp);
307                 resp = NULL;
308                 goto exit;
309         }
310 
311         rc = ddev->skb_check_crc(resp);
312         if (rc) {
313                 PROTOCOL_ERR("14.4.1.6");
314                 goto exit;
315         }
316 
317         rc = digital_skb_pull_dep_sod(ddev, resp);
318         if (rc) {
319                 PROTOCOL_ERR("14.4.1.2");
320                 goto exit;
321         }
322 
323         psl_res = (struct digital_psl_res *)resp->data;
324 
325         if ((resp->len != sizeof(*psl_res)) ||
326             (psl_res->dir != DIGITAL_NFC_DEP_FRAME_DIR_IN) ||
327             (psl_res->cmd != DIGITAL_CMD_PSL_RES)) {
328                 rc = -EIO;
329                 goto exit;
330         }
331 
332         rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
333                                      NFC_DIGITAL_RF_TECH_424F);
334         if (rc)
335                 goto exit;
336 
337         rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
338                                      NFC_DIGITAL_FRAMING_NFCF_NFC_DEP);
339         if (rc)
340                 goto exit;
341 
342         if (!DIGITAL_DRV_CAPS_IN_CRC(ddev) &&
343             (ddev->curr_rf_tech == NFC_DIGITAL_RF_TECH_106A)) {
344                 ddev->skb_add_crc = digital_skb_add_crc_f;
345                 ddev->skb_check_crc = digital_skb_check_crc_f;
346         }
347 
348         ddev->curr_rf_tech = NFC_DIGITAL_RF_TECH_424F;
349 
350         nfc_dep_link_is_up(ddev->nfc_dev, target->idx, NFC_COMM_ACTIVE,
351                            NFC_RF_INITIATOR);
352 
353         ddev->curr_nfc_dep_pni = 0;
354 
355 exit:
356         dev_kfree_skb(resp);
357 
358         if (rc)
359                 ddev->curr_protocol = 0;
360 }
361 
362 static int digital_in_send_psl_req(struct nfc_digital_dev *ddev,
363                                    struct nfc_target *target)
364 {
365         struct sk_buff *skb;
366         struct digital_psl_req *psl_req;
367         int rc;
368         u8 payload_size, payload_bits;
369 
370         skb = digital_skb_alloc(ddev, sizeof(*psl_req));
371         if (!skb)
372                 return -ENOMEM;
373 
374         skb_put(skb, sizeof(*psl_req));
375 
376         psl_req = (struct digital_psl_req *)skb->data;
377 
378         psl_req->dir = DIGITAL_NFC_DEP_FRAME_DIR_OUT;
379         psl_req->cmd = DIGITAL_CMD_PSL_REQ;
380         psl_req->did = 0;
381         psl_req->brs = (0x2 << 3) | 0x2; /* 424F both directions */
382 
383         payload_size = min(ddev->local_payload_max, ddev->remote_payload_max);
384         payload_bits = digital_payload_size_to_bits(payload_size);
385         psl_req->fsl = DIGITAL_PAYLOAD_BITS_TO_FSL(payload_bits);
386 
387         ddev->local_payload_max = payload_size;
388         ddev->remote_payload_max = payload_size;
389 
390         digital_skb_push_dep_sod(ddev, skb);
391 
392         ddev->skb_add_crc(skb);
393 
394         rc = digital_in_send_cmd(ddev, skb, ddev->dep_rwt,
395                                  digital_in_recv_psl_res, target);
396         if (rc)
397                 kfree_skb(skb);
398 
399         return rc;
400 }
401 
402 static void digital_in_recv_atr_res(struct nfc_digital_dev *ddev, void *arg,
403                                  struct sk_buff *resp)
404 {
405         struct nfc_target *target = arg;
406         struct digital_atr_res *atr_res;
407         u8 gb_len, payload_bits;
408         u8 wt;
409         int rc;
410 
411         if (IS_ERR(resp)) {
412                 rc = PTR_ERR(resp);
413                 resp = NULL;
414                 goto exit;
415         }
416 
417         rc = ddev->skb_check_crc(resp);
418         if (rc) {
419                 PROTOCOL_ERR("14.4.1.6");
420                 goto exit;
421         }
422 
423         rc = digital_skb_pull_dep_sod(ddev, resp);
424         if (rc) {
425                 PROTOCOL_ERR("14.4.1.2");
426                 goto exit;
427         }
428 
429         if (resp->len < sizeof(struct digital_atr_res)) {
430                 rc = -EIO;
431                 goto exit;
432         }
433 
434         gb_len = resp->len - sizeof(struct digital_atr_res);
435 
436         atr_res = (struct digital_atr_res *)resp->data;
437 
438         wt = DIGITAL_ATR_RES_TO_WT(atr_res->to);
439         if (wt > DIGITAL_NFC_DEP_IN_MAX_WT)
440                 wt = DIGITAL_NFC_DEP_IN_MAX_WT;
441         ddev->dep_rwt = digital_rwt_map[wt];
442 
443         payload_bits = DIGITAL_PAYLOAD_PP_TO_BITS(atr_res->pp);
444         ddev->remote_payload_max = digital_payload_bits_to_size(payload_bits);
445 
446         if (!ddev->remote_payload_max) {
447                 rc = -EINVAL;
448                 goto exit;
449         }
450 
451         rc = nfc_set_remote_general_bytes(ddev->nfc_dev, atr_res->gb, gb_len);
452         if (rc)
453                 goto exit;
454 
455         if ((ddev->protocols & NFC_PROTO_FELICA_MASK) &&
456             (ddev->curr_rf_tech != NFC_DIGITAL_RF_TECH_424F)) {
457                 rc = digital_in_send_psl_req(ddev, target);
458                 if (!rc)
459                         goto exit;
460         }
461 
462         rc = nfc_dep_link_is_up(ddev->nfc_dev, target->idx, NFC_COMM_ACTIVE,
463                                 NFC_RF_INITIATOR);
464 
465         ddev->curr_nfc_dep_pni = 0;
466 
467 exit:
468         dev_kfree_skb(resp);
469 
470         if (rc)
471                 ddev->curr_protocol = 0;
472 }
473 
474 int digital_in_send_atr_req(struct nfc_digital_dev *ddev,
475                             struct nfc_target *target, __u8 comm_mode, __u8 *gb,
476                             size_t gb_len)
477 {
478         struct sk_buff *skb;
479         struct digital_atr_req *atr_req;
480         uint size;
481         int rc;
482         u8 payload_bits;
483 
484         size = DIGITAL_ATR_REQ_MIN_SIZE + gb_len;
485 
486         if (size > DIGITAL_ATR_REQ_MAX_SIZE) {
487                 PROTOCOL_ERR("14.6.1.1");
488                 return -EINVAL;
489         }
490 
491         skb = digital_skb_alloc(ddev, size);
492         if (!skb)
493                 return -ENOMEM;
494 
495         skb_put(skb, sizeof(struct digital_atr_req));
496 
497         atr_req = (struct digital_atr_req *)skb->data;
498         memset(atr_req, 0, sizeof(struct digital_atr_req));
499 
500         atr_req->dir = DIGITAL_NFC_DEP_FRAME_DIR_OUT;
501         atr_req->cmd = DIGITAL_CMD_ATR_REQ;
502         if (target->nfcid2_len)
503                 memcpy(atr_req->nfcid3, target->nfcid2, NFC_NFCID2_MAXSIZE);
504         else
505                 get_random_bytes(atr_req->nfcid3, NFC_NFCID3_MAXSIZE);
506 
507         atr_req->did = 0;
508         atr_req->bs = 0;
509         atr_req->br = 0;
510 
511         ddev->local_payload_max = DIGITAL_PAYLOAD_SIZE_MAX;
512         payload_bits = digital_payload_size_to_bits(ddev->local_payload_max);
513         atr_req->pp = DIGITAL_PAYLOAD_BITS_TO_PP(payload_bits);
514 
515         if (gb_len) {
516                 atr_req->pp |= DIGITAL_GB_BIT;
517                 skb_put_data(skb, gb, gb_len);
518         }
519 
520         digital_skb_push_dep_sod(ddev, skb);
521 
522         ddev->skb_add_crc(skb);
523 
524         rc = digital_in_send_cmd(ddev, skb, DIGITAL_ATR_RES_RWT,
525                                  digital_in_recv_atr_res, target);
526         if (rc)
527                 kfree_skb(skb);
528 
529         return rc;
530 }
531 
532 static int digital_in_send_ack(struct nfc_digital_dev *ddev,
533                                struct digital_data_exch *data_exch)
534 {
535         struct digital_dep_req_res *dep_req;
536         struct sk_buff *skb;
537         int rc;
538 
539         skb = digital_skb_alloc(ddev, 1);
540         if (!skb)
541                 return -ENOMEM;
542 
543         skb_push(skb, sizeof(struct digital_dep_req_res));
544 
545         dep_req = (struct digital_dep_req_res *)skb->data;
546 
547         dep_req->dir = DIGITAL_NFC_DEP_FRAME_DIR_OUT;
548         dep_req->cmd = DIGITAL_CMD_DEP_REQ;
549         dep_req->pfb = DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU |
550                        ddev->curr_nfc_dep_pni;
551 
552         digital_skb_push_dep_sod(ddev, skb);
553 
554         ddev->skb_add_crc(skb);
555 
556         ddev->saved_skb = pskb_copy(skb, GFP_KERNEL);
557 
558         rc = digital_in_send_cmd(ddev, skb, ddev->dep_rwt,
559                                  digital_in_recv_dep_res, data_exch);
560         if (rc) {
561                 kfree_skb(skb);
562                 kfree_skb(ddev->saved_skb);
563                 ddev->saved_skb = NULL;
564         }
565 
566         return rc;
567 }
568 
569 static int digital_in_send_nack(struct nfc_digital_dev *ddev,
570                                 struct digital_data_exch *data_exch)
571 {
572         struct digital_dep_req_res *dep_req;
573         struct sk_buff *skb;
574         int rc;
575 
576         skb = digital_skb_alloc(ddev, 1);
577         if (!skb)
578                 return -ENOMEM;
579 
580         skb_push(skb, sizeof(struct digital_dep_req_res));
581 
582         dep_req = (struct digital_dep_req_res *)skb->data;
583 
584         dep_req->dir = DIGITAL_NFC_DEP_FRAME_DIR_OUT;
585         dep_req->cmd = DIGITAL_CMD_DEP_REQ;
586         dep_req->pfb = DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU |
587                        DIGITAL_NFC_DEP_PFB_NACK_BIT | ddev->curr_nfc_dep_pni;
588 
589         digital_skb_push_dep_sod(ddev, skb);
590 
591         ddev->skb_add_crc(skb);
592 
593         rc = digital_in_send_cmd(ddev, skb, ddev->dep_rwt,
594                                  digital_in_recv_dep_res, data_exch);
595         if (rc)
596                 kfree_skb(skb);
597 
598         return rc;
599 }
600 
601 static int digital_in_send_atn(struct nfc_digital_dev *ddev,
602                                struct digital_data_exch *data_exch)
603 {
604         struct digital_dep_req_res *dep_req;
605         struct sk_buff *skb;
606         int rc;
607 
608         skb = digital_skb_alloc(ddev, 1);
609         if (!skb)
610                 return -ENOMEM;
611 
612         skb_push(skb, sizeof(struct digital_dep_req_res));
613 
614         dep_req = (struct digital_dep_req_res *)skb->data;
615 
616         dep_req->dir = DIGITAL_NFC_DEP_FRAME_DIR_OUT;
617         dep_req->cmd = DIGITAL_CMD_DEP_REQ;
618         dep_req->pfb = DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU;
619 
620         digital_skb_push_dep_sod(ddev, skb);
621 
622         ddev->skb_add_crc(skb);
623 
624         rc = digital_in_send_cmd(ddev, skb, ddev->dep_rwt,
625                                  digital_in_recv_dep_res, data_exch);
626         if (rc)
627                 kfree_skb(skb);
628 
629         return rc;
630 }
631 
632 static int digital_in_send_rtox(struct nfc_digital_dev *ddev,
633                                 struct digital_data_exch *data_exch, u8 rtox)
634 {
635         struct digital_dep_req_res *dep_req;
636         struct sk_buff *skb;
637         int rc;
638         u16 rwt_int;
639 
640         rwt_int = ddev->dep_rwt * rtox;
641         if (rwt_int > digital_rwt_map[DIGITAL_NFC_DEP_IN_MAX_WT])
642                 rwt_int = digital_rwt_map[DIGITAL_NFC_DEP_IN_MAX_WT];
643 
644         skb = digital_skb_alloc(ddev, 1);
645         if (!skb)
646                 return -ENOMEM;
647 
648         skb_put_u8(skb, rtox);
649 
650         skb_push(skb, sizeof(struct digital_dep_req_res));
651 
652         dep_req = (struct digital_dep_req_res *)skb->data;
653 
654         dep_req->dir = DIGITAL_NFC_DEP_FRAME_DIR_OUT;
655         dep_req->cmd = DIGITAL_CMD_DEP_REQ;
656         dep_req->pfb = DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU |
657                        DIGITAL_NFC_DEP_PFB_TIMEOUT_BIT;
658 
659         digital_skb_push_dep_sod(ddev, skb);
660 
661         ddev->skb_add_crc(skb);
662 
663         rc = digital_in_send_cmd(ddev, skb, rwt_int,
664                                  digital_in_recv_dep_res, data_exch);
665         if (rc)
666                 kfree_skb(skb);
667 
668         return rc;
669 }
670 
671 static int digital_in_send_saved_skb(struct nfc_digital_dev *ddev,
672                                      struct digital_data_exch *data_exch)
673 {
674         int rc;
675 
676         if (!ddev->saved_skb)
677                 return -EINVAL;
678 
679         skb_get(ddev->saved_skb);
680 
681         rc = digital_in_send_cmd(ddev, ddev->saved_skb, ddev->dep_rwt,
682                                  digital_in_recv_dep_res, data_exch);
683         if (rc)
684                 kfree_skb(ddev->saved_skb);
685 
686         return rc;
687 }
688 
689 static void digital_in_recv_dep_res(struct nfc_digital_dev *ddev, void *arg,
690                                     struct sk_buff *resp)
691 {
692         struct digital_data_exch *data_exch = arg;
693         struct digital_dep_req_res *dep_res;
694         u8 pfb;
695         uint size;
696         int rc;
697         u8 rtox;
698 
699         if (IS_ERR(resp)) {
700                 rc = PTR_ERR(resp);
701                 resp = NULL;
702 
703                 if ((rc == -EIO || (rc == -ETIMEDOUT && ddev->nack_count)) &&
704                     (ddev->nack_count++ < DIGITAL_NFC_DEP_N_RETRY_NACK)) {
705                         ddev->atn_count = 0;
706 
707                         rc = digital_in_send_nack(ddev, data_exch);
708                         if (rc)
709                                 goto error;
710 
711                         return;
712                 } else if ((rc == -ETIMEDOUT) &&
713                            (ddev->atn_count++ < DIGITAL_NFC_DEP_N_RETRY_ATN)) {
714                         ddev->nack_count = 0;
715 
716                         rc = digital_in_send_atn(ddev, data_exch);
717                         if (rc)
718                                 goto error;
719 
720                         return;
721                 }
722 
723                 goto exit;
724         }
725 
726         rc = digital_skb_pull_dep_sod(ddev, resp);
727         if (rc) {
728                 PROTOCOL_ERR("14.4.1.2");
729                 goto exit;
730         }
731 
732         rc = ddev->skb_check_crc(resp);
733         if (rc) {
734                 if ((resp->len >= 4) &&
735                     (ddev->nack_count++ < DIGITAL_NFC_DEP_N_RETRY_NACK)) {
736                         ddev->atn_count = 0;
737 
738                         rc = digital_in_send_nack(ddev, data_exch);
739                         if (rc)
740                                 goto error;
741 
742                         kfree_skb(resp);
743 
744                         return;
745                 }
746 
747                 PROTOCOL_ERR("14.4.1.6");
748                 goto error;
749         }
750 
751         ddev->atn_count = 0;
752         ddev->nack_count = 0;
753 
754         if (resp->len > ddev->local_payload_max) {
755                 rc = -EMSGSIZE;
756                 goto exit;
757         }
758 
759         size = sizeof(struct digital_dep_req_res);
760         dep_res = (struct digital_dep_req_res *)resp->data;
761 
762         if (resp->len < size || dep_res->dir != DIGITAL_NFC_DEP_FRAME_DIR_IN ||
763             dep_res->cmd != DIGITAL_CMD_DEP_RES) {
764                 rc = -EIO;
765                 goto error;
766         }
767 
768         pfb = dep_res->pfb;
769 
770         if (DIGITAL_NFC_DEP_DID_BIT_SET(pfb)) {
771                 PROTOCOL_ERR("14.8.2.1");
772                 rc = -EIO;
773                 goto error;
774         }
775 
776         if (DIGITAL_NFC_DEP_NAD_BIT_SET(pfb)) {
777                 rc = -EIO;
778                 goto exit;
779         }
780 
781         if (size > resp->len) {
782                 rc = -EIO;
783                 goto error;
784         }
785 
786         skb_pull(resp, size);
787 
788         switch (DIGITAL_NFC_DEP_PFB_TYPE(pfb)) {
789         case DIGITAL_NFC_DEP_PFB_I_PDU:
790                 if (DIGITAL_NFC_DEP_PFB_PNI(pfb) != ddev->curr_nfc_dep_pni) {
791                         PROTOCOL_ERR("14.12.3.3");
792                         rc = -EIO;
793                         goto error;
794                 }
795 
796                 ddev->curr_nfc_dep_pni =
797                         DIGITAL_NFC_DEP_PFB_PNI(ddev->curr_nfc_dep_pni + 1);
798 
799                 kfree_skb(ddev->saved_skb);
800                 ddev->saved_skb = NULL;
801 
802                 resp = digital_recv_dep_data_gather(ddev, pfb, resp,
803                                                     digital_in_send_ack,
804                                                     data_exch);
805                 if (IS_ERR(resp)) {
806                         rc = PTR_ERR(resp);
807                         resp = NULL;
808                         goto error;
809                 }
810 
811                 /* If resp is NULL then we're still chaining so return and
812                  * wait for the next part of the PDU.  Else, the PDU is
813                  * complete so pass it up.
814                  */
815                 if (!resp)
816                         return;
817 
818                 rc = 0;
819                 break;
820 
821         case DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU:
822                 if (DIGITAL_NFC_DEP_NACK_BIT_SET(pfb)) {
823                         PROTOCOL_ERR("14.12.4.5");
824                         rc = -EIO;
825                         goto exit;
826                 }
827 
828                 if (DIGITAL_NFC_DEP_PFB_PNI(pfb) != ddev->curr_nfc_dep_pni) {
829                         PROTOCOL_ERR("14.12.3.3");
830                         rc = -EIO;
831                         goto exit;
832                 }
833 
834                 ddev->curr_nfc_dep_pni =
835                         DIGITAL_NFC_DEP_PFB_PNI(ddev->curr_nfc_dep_pni + 1);
836 
837                 if (!ddev->chaining_skb) {
838                         PROTOCOL_ERR("14.12.4.3");
839                         rc = -EIO;
840                         goto exit;
841                 }
842 
843                 /* The initiator has received a valid ACK. Free the last sent
844                  * PDU and keep on sending chained skb.
845                  */
846                 kfree_skb(ddev->saved_skb);
847                 ddev->saved_skb = NULL;
848 
849                 rc = digital_in_send_dep_req(ddev, NULL,
850                                              ddev->chaining_skb,
851                                              ddev->data_exch);
852                 if (rc)
853                         goto error;
854 
855                 goto free_resp;
856 
857         case DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU:
858                 if (!DIGITAL_NFC_DEP_PFB_IS_TIMEOUT(pfb)) { /* ATN */
859                         rc = digital_in_send_saved_skb(ddev, data_exch);
860                         if (rc)
861                                 goto error;
862 
863                         goto free_resp;
864                 }
865 
866                 if (ddev->atn_count || ddev->nack_count) {
867                         PROTOCOL_ERR("14.12.4.4");
868                         rc = -EIO;
869                         goto error;
870                 }
871 
872                 rtox = DIGITAL_NFC_DEP_RTOX_VALUE(resp->data[0]);
873                 if (!rtox || rtox > DIGITAL_NFC_DEP_RTOX_MAX) {
874                         PROTOCOL_ERR("14.8.4.1");
875                         rc = -EIO;
876                         goto error;
877                 }
878 
879                 rc = digital_in_send_rtox(ddev, data_exch, rtox);
880                 if (rc)
881                         goto error;
882 
883                 goto free_resp;
884         }
885 
886 exit:
887         data_exch->cb(data_exch->cb_context, resp, rc);
888 
889 error:
890         kfree(data_exch);
891 
892         kfree_skb(ddev->chaining_skb);
893         ddev->chaining_skb = NULL;
894 
895         kfree_skb(ddev->saved_skb);
896         ddev->saved_skb = NULL;
897 
898         if (rc)
899                 kfree_skb(resp);
900 
901         return;
902 
903 free_resp:
904         dev_kfree_skb(resp);
905 }
906 
907 int digital_in_send_dep_req(struct nfc_digital_dev *ddev,
908                             struct nfc_target *target, struct sk_buff *skb,
909                             struct digital_data_exch *data_exch)
910 {
911         struct digital_dep_req_res *dep_req;
912         struct sk_buff *chaining_skb, *tmp_skb;
913         int rc;
914 
915         skb_push(skb, sizeof(struct digital_dep_req_res));
916 
917         dep_req = (struct digital_dep_req_res *)skb->data;
918 
919         dep_req->dir = DIGITAL_NFC_DEP_FRAME_DIR_OUT;
920         dep_req->cmd = DIGITAL_CMD_DEP_REQ;
921         dep_req->pfb = ddev->curr_nfc_dep_pni;
922 
923         ddev->atn_count = 0;
924         ddev->nack_count = 0;
925 
926         chaining_skb = ddev->chaining_skb;
927 
928         tmp_skb = digital_send_dep_data_prep(ddev, skb, dep_req, data_exch);
929         if (IS_ERR(tmp_skb))
930                 return PTR_ERR(tmp_skb);
931 
932         digital_skb_push_dep_sod(ddev, tmp_skb);
933 
934         ddev->skb_add_crc(tmp_skb);
935 
936         ddev->saved_skb = pskb_copy(tmp_skb, GFP_KERNEL);
937 
938         rc = digital_in_send_cmd(ddev, tmp_skb, ddev->dep_rwt,
939                                  digital_in_recv_dep_res, data_exch);
940         if (rc) {
941                 if (tmp_skb != skb)
942                         kfree_skb(tmp_skb);
943 
944                 kfree_skb(chaining_skb);
945                 ddev->chaining_skb = NULL;
946 
947                 kfree_skb(ddev->saved_skb);
948                 ddev->saved_skb = NULL;
949         }
950 
951         return rc;
952 }
953 
954 static void digital_tg_set_rf_tech(struct nfc_digital_dev *ddev, u8 rf_tech)
955 {
956         ddev->curr_rf_tech = rf_tech;
957 
958         ddev->skb_add_crc = digital_skb_add_crc_none;
959         ddev->skb_check_crc = digital_skb_check_crc_none;
960 
961         if (DIGITAL_DRV_CAPS_TG_CRC(ddev))
962                 return;
963 
964         switch (ddev->curr_rf_tech) {
965         case NFC_DIGITAL_RF_TECH_106A:
966                 ddev->skb_add_crc = digital_skb_add_crc_a;
967                 ddev->skb_check_crc = digital_skb_check_crc_a;
968                 break;
969 
970         case NFC_DIGITAL_RF_TECH_212F:
971         case NFC_DIGITAL_RF_TECH_424F:
972                 ddev->skb_add_crc = digital_skb_add_crc_f;
973                 ddev->skb_check_crc = digital_skb_check_crc_f;
974                 break;
975 
976         default:
977                 break;
978         }
979 }
980 
981 static int digital_tg_send_ack(struct nfc_digital_dev *ddev,
982                                struct digital_data_exch *data_exch)
983 {
984         struct digital_dep_req_res *dep_res;
985         struct sk_buff *skb;
986         int rc;
987 
988         skb = digital_skb_alloc(ddev, 1);
989         if (!skb)
990                 return -ENOMEM;
991 
992         skb_push(skb, sizeof(struct digital_dep_req_res));
993 
994         dep_res = (struct digital_dep_req_res *)skb->data;
995 
996         dep_res->dir = DIGITAL_NFC_DEP_FRAME_DIR_IN;
997         dep_res->cmd = DIGITAL_CMD_DEP_RES;
998         dep_res->pfb = DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU |
999                        ddev->curr_nfc_dep_pni;
1000 
1001         if (ddev->did) {
1002                 dep_res->pfb |= DIGITAL_NFC_DEP_PFB_DID_BIT;
1003 
1004                 skb_put_data(skb, &ddev->did, sizeof(ddev->did));
1005         }
1006 
1007         ddev->curr_nfc_dep_pni =
1008                 DIGITAL_NFC_DEP_PFB_PNI(ddev->curr_nfc_dep_pni + 1);
1009 
1010         digital_skb_push_dep_sod(ddev, skb);
1011 
1012         ddev->skb_add_crc(skb);
1013 
1014         ddev->saved_skb = pskb_copy(skb, GFP_KERNEL);
1015 
1016         rc = digital_tg_send_cmd(ddev, skb, 1500, digital_tg_recv_dep_req,
1017                                  data_exch);
1018         if (rc) {
1019                 kfree_skb(skb);
1020                 kfree_skb(ddev->saved_skb);
1021                 ddev->saved_skb = NULL;
1022         }
1023 
1024         return rc;
1025 }
1026 
1027 static int digital_tg_send_atn(struct nfc_digital_dev *ddev)
1028 {
1029         struct digital_dep_req_res *dep_res;
1030         struct sk_buff *skb;
1031         int rc;
1032 
1033         skb = digital_skb_alloc(ddev, 1);
1034         if (!skb)
1035                 return -ENOMEM;
1036 
1037         skb_push(skb, sizeof(struct digital_dep_req_res));
1038 
1039         dep_res = (struct digital_dep_req_res *)skb->data;
1040 
1041         dep_res->dir = DIGITAL_NFC_DEP_FRAME_DIR_IN;
1042         dep_res->cmd = DIGITAL_CMD_DEP_RES;
1043         dep_res->pfb = DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU;
1044 
1045         if (ddev->did) {
1046                 dep_res->pfb |= DIGITAL_NFC_DEP_PFB_DID_BIT;
1047 
1048                 skb_put_data(skb, &ddev->did, sizeof(ddev->did));
1049         }
1050 
1051         digital_skb_push_dep_sod(ddev, skb);
1052 
1053         ddev->skb_add_crc(skb);
1054 
1055         rc = digital_tg_send_cmd(ddev, skb, 1500, digital_tg_recv_dep_req,
1056                                  NULL);
1057         if (rc)
1058                 kfree_skb(skb);
1059 
1060         return rc;
1061 }
1062 
1063 static int digital_tg_send_saved_skb(struct nfc_digital_dev *ddev)
1064 {
1065         int rc;
1066 
1067         if (!ddev->saved_skb)
1068                 return -EINVAL;
1069 
1070         skb_get(ddev->saved_skb);
1071 
1072         rc = digital_tg_send_cmd(ddev, ddev->saved_skb, 1500,
1073                                  digital_tg_recv_dep_req, NULL);
1074         if (rc)
1075                 kfree_skb(ddev->saved_skb);
1076 
1077         return rc;
1078 }
1079 
1080 static void digital_tg_recv_dep_req(struct nfc_digital_dev *ddev, void *arg,
1081                                     struct sk_buff *resp)
1082 {
1083         int rc;
1084         struct digital_dep_req_res *dep_req;
1085         u8 pfb;
1086         size_t size;
1087 
1088         if (IS_ERR(resp)) {
1089                 rc = PTR_ERR(resp);
1090                 resp = NULL;
1091                 goto exit;
1092         }
1093 
1094         rc = ddev->skb_check_crc(resp);
1095         if (rc) {
1096                 PROTOCOL_ERR("14.4.1.6");
1097                 goto exit;
1098         }
1099 
1100         rc = digital_skb_pull_dep_sod(ddev, resp);
1101         if (rc) {
1102                 PROTOCOL_ERR("14.4.1.2");
1103                 goto exit;
1104         }
1105 
1106         if (resp->len > ddev->local_payload_max) {
1107                 rc = -EMSGSIZE;
1108                 goto exit;
1109         }
1110 
1111         size = sizeof(struct digital_dep_req_res);
1112         dep_req = (struct digital_dep_req_res *)resp->data;
1113 
1114         if (resp->len < size || dep_req->dir != DIGITAL_NFC_DEP_FRAME_DIR_OUT ||
1115             dep_req->cmd != DIGITAL_CMD_DEP_REQ) {
1116                 rc = -EIO;
1117                 goto exit;
1118         }
1119 
1120         pfb = dep_req->pfb;
1121 
1122         if (DIGITAL_NFC_DEP_DID_BIT_SET(pfb)) {
1123                 if (ddev->did && (ddev->did == resp->data[3])) {
1124                         size++;
1125                 } else {
1126                         rc = -EIO;
1127                         goto exit;
1128                 }
1129         } else if (ddev->did) {
1130                 rc = -EIO;
1131                 goto exit;
1132         }
1133 
1134         if (DIGITAL_NFC_DEP_NAD_BIT_SET(pfb)) {
1135                 rc = -EIO;
1136                 goto exit;
1137         }
1138 
1139         if (size > resp->len) {
1140                 rc = -EIO;
1141                 goto exit;
1142         }
1143 
1144         skb_pull(resp, size);
1145 
1146         switch (DIGITAL_NFC_DEP_PFB_TYPE(pfb)) {
1147         case DIGITAL_NFC_DEP_PFB_I_PDU:
1148                 pr_debug("DIGITAL_NFC_DEP_PFB_I_PDU\n");
1149 
1150                 if (ddev->atn_count) {
1151                         /* The target has received (and replied to) at least one
1152                          * ATN DEP_REQ.
1153                          */
1154                         ddev->atn_count = 0;
1155 
1156                         /* pni of resp PDU equal to the target current pni - 1
1157                          * means resp is the previous DEP_REQ PDU received from
1158                          * the initiator so the target replies with saved_skb
1159                          * which is the previous DEP_RES saved in
1160                          * digital_tg_send_dep_res().
1161                          */
1162                         if (DIGITAL_NFC_DEP_PFB_PNI(pfb) ==
1163                           DIGITAL_NFC_DEP_PFB_PNI(ddev->curr_nfc_dep_pni - 1)) {
1164                                 rc = digital_tg_send_saved_skb(ddev);
1165                                 if (rc)
1166                                         goto exit;
1167 
1168                                 goto free_resp;
1169                         }
1170 
1171                         /* atn_count > 0 and PDU pni != curr_nfc_dep_pni - 1
1172                          * means the target probably did not received the last
1173                          * DEP_REQ PDU sent by the initiator. The target
1174                          * fallbacks to normal processing then.
1175                          */
1176                 }
1177 
1178                 if (DIGITAL_NFC_DEP_PFB_PNI(pfb) != ddev->curr_nfc_dep_pni) {
1179                         PROTOCOL_ERR("14.12.3.4");
1180                         rc = -EIO;
1181                         goto exit;
1182                 }
1183 
1184                 kfree_skb(ddev->saved_skb);
1185                 ddev->saved_skb = NULL;
1186 
1187                 resp = digital_recv_dep_data_gather(ddev, pfb, resp,
1188                                                     digital_tg_send_ack, NULL);
1189                 if (IS_ERR(resp)) {
1190                         rc = PTR_ERR(resp);
1191                         resp = NULL;
1192                         goto exit;
1193                 }
1194 
1195                 /* If resp is NULL then we're still chaining so return and
1196                  * wait for the next part of the PDU.  Else, the PDU is
1197                  * complete so pass it up.
1198                  */
1199                 if (!resp)
1200                         return;
1201 
1202                 rc = 0;
1203                 break;
1204         case DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU:
1205                 if (DIGITAL_NFC_DEP_NACK_BIT_SET(pfb)) { /* NACK */
1206                         if (DIGITAL_NFC_DEP_PFB_PNI(pfb + 1) !=
1207                                                 ddev->curr_nfc_dep_pni) {
1208                                 rc = -EIO;
1209                                 goto exit;
1210                         }
1211 
1212                         ddev->atn_count = 0;
1213 
1214                         rc = digital_tg_send_saved_skb(ddev);
1215                         if (rc)
1216                                 goto exit;
1217 
1218                         goto free_resp;
1219                 }
1220 
1221                 /* ACK */
1222                 if (ddev->atn_count) {
1223                         /* The target has previously recevied one or more ATN
1224                          * PDUs.
1225                          */
1226                         ddev->atn_count = 0;
1227 
1228                         /* If the ACK PNI is equal to the target PNI - 1 means
1229                          * that the initiator did not receive the previous PDU
1230                          * sent by the target so re-send it.
1231                          */
1232                         if (DIGITAL_NFC_DEP_PFB_PNI(pfb + 1) ==
1233                                                 ddev->curr_nfc_dep_pni) {
1234                                 rc = digital_tg_send_saved_skb(ddev);
1235                                 if (rc)
1236                                         goto exit;
1237 
1238                                 goto free_resp;
1239                         }
1240 
1241                         /* Otherwise, the target did not receive the previous
1242                          * ACK PDU from the initiator. Fallback to normal
1243                          * processing of chained PDU then.
1244                          */
1245                 }
1246 
1247                 /* Keep on sending chained PDU */
1248                 if (!ddev->chaining_skb ||
1249                     DIGITAL_NFC_DEP_PFB_PNI(pfb) !=
1250                                         ddev->curr_nfc_dep_pni) {
1251                         rc = -EIO;
1252                         goto exit;
1253                 }
1254 
1255                 kfree_skb(ddev->saved_skb);
1256                 ddev->saved_skb = NULL;
1257 
1258                 rc = digital_tg_send_dep_res(ddev, ddev->chaining_skb);
1259                 if (rc)
1260                         goto exit;
1261 
1262                 goto free_resp;
1263         case DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU:
1264                 if (DIGITAL_NFC_DEP_PFB_IS_TIMEOUT(pfb)) {
1265                         rc = -EINVAL;
1266                         goto exit;
1267                 }
1268 
1269                 rc = digital_tg_send_atn(ddev);
1270                 if (rc)
1271                         goto exit;
1272 
1273                 ddev->atn_count++;
1274 
1275                 goto free_resp;
1276         }
1277 
1278         rc = nfc_tm_data_received(ddev->nfc_dev, resp);
1279 
1280 exit:
1281         kfree_skb(ddev->chaining_skb);
1282         ddev->chaining_skb = NULL;
1283 
1284         ddev->atn_count = 0;
1285 
1286         kfree_skb(ddev->saved_skb);
1287         ddev->saved_skb = NULL;
1288 
1289         if (rc)
1290                 kfree_skb(resp);
1291 
1292         return;
1293 
1294 free_resp:
1295         dev_kfree_skb(resp);
1296 }
1297 
1298 int digital_tg_send_dep_res(struct nfc_digital_dev *ddev, struct sk_buff *skb)
1299 {
1300         struct digital_dep_req_res *dep_res;
1301         struct sk_buff *chaining_skb, *tmp_skb;
1302         int rc;
1303 
1304         skb_push(skb, sizeof(struct digital_dep_req_res));
1305 
1306         dep_res = (struct digital_dep_req_res *)skb->data;
1307 
1308         dep_res->dir = DIGITAL_NFC_DEP_FRAME_DIR_IN;
1309         dep_res->cmd = DIGITAL_CMD_DEP_RES;
1310         dep_res->pfb = ddev->curr_nfc_dep_pni;
1311 
1312         if (ddev->did) {
1313                 dep_res->pfb |= DIGITAL_NFC_DEP_PFB_DID_BIT;
1314 
1315                 skb_put_data(skb, &ddev->did, sizeof(ddev->did));
1316         }
1317 
1318         ddev->curr_nfc_dep_pni =
1319                 DIGITAL_NFC_DEP_PFB_PNI(ddev->curr_nfc_dep_pni + 1);
1320 
1321         chaining_skb = ddev->chaining_skb;
1322 
1323         tmp_skb = digital_send_dep_data_prep(ddev, skb, dep_res, NULL);
1324         if (IS_ERR(tmp_skb))
1325                 return PTR_ERR(tmp_skb);
1326 
1327         digital_skb_push_dep_sod(ddev, tmp_skb);
1328 
1329         ddev->skb_add_crc(tmp_skb);
1330 
1331         ddev->saved_skb = pskb_copy(tmp_skb, GFP_KERNEL);
1332 
1333         rc = digital_tg_send_cmd(ddev, tmp_skb, 1500, digital_tg_recv_dep_req,
1334                                  NULL);
1335         if (rc) {
1336                 if (tmp_skb != skb)
1337                         kfree_skb(tmp_skb);
1338 
1339                 kfree_skb(chaining_skb);
1340                 ddev->chaining_skb = NULL;
1341 
1342                 kfree_skb(ddev->saved_skb);
1343                 ddev->saved_skb = NULL;
1344         }
1345 
1346         return rc;
1347 }
1348 
1349 static void digital_tg_send_psl_res_complete(struct nfc_digital_dev *ddev,
1350                                              void *arg, struct sk_buff *resp)
1351 {
1352         u8 rf_tech = (unsigned long)arg;
1353 
1354         if (IS_ERR(resp))
1355                 return;
1356 
1357         digital_tg_set_rf_tech(ddev, rf_tech);
1358 
1359         digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH, rf_tech);
1360 
1361         digital_tg_listen(ddev, 1500, digital_tg_recv_dep_req, NULL);
1362 
1363         dev_kfree_skb(resp);
1364 }
1365 
1366 static int digital_tg_send_psl_res(struct nfc_digital_dev *ddev, u8 did,
1367                                    u8 rf_tech)
1368 {
1369         struct digital_psl_res *psl_res;
1370         struct sk_buff *skb;
1371         int rc;
1372 
1373         skb = digital_skb_alloc(ddev, sizeof(struct digital_psl_res));
1374         if (!skb)
1375                 return -ENOMEM;
1376 
1377         skb_put(skb, sizeof(struct digital_psl_res));
1378 
1379         psl_res = (struct digital_psl_res *)skb->data;
1380 
1381         psl_res->dir = DIGITAL_NFC_DEP_FRAME_DIR_IN;
1382         psl_res->cmd = DIGITAL_CMD_PSL_RES;
1383         psl_res->did = did;
1384 
1385         digital_skb_push_dep_sod(ddev, skb);
1386 
1387         ddev->skb_add_crc(skb);
1388 
1389         ddev->curr_nfc_dep_pni = 0;
1390 
1391         rc = digital_tg_send_cmd(ddev, skb, 0, digital_tg_send_psl_res_complete,
1392                                  (void *)(unsigned long)rf_tech);
1393         if (rc)
1394                 kfree_skb(skb);
1395 
1396         return rc;
1397 }
1398 
1399 static void digital_tg_recv_psl_req(struct nfc_digital_dev *ddev, void *arg,
1400                                     struct sk_buff *resp)
1401 {
1402         int rc;
1403         struct digital_psl_req *psl_req;
1404         u8 rf_tech;
1405         u8 dsi, payload_size, payload_bits;
1406 
1407         if (IS_ERR(resp)) {
1408                 rc = PTR_ERR(resp);
1409                 resp = NULL;
1410                 goto exit;
1411         }
1412 
1413         rc = ddev->skb_check_crc(resp);
1414         if (rc) {
1415                 PROTOCOL_ERR("14.4.1.6");
1416                 goto exit;
1417         }
1418 
1419         rc = digital_skb_pull_dep_sod(ddev, resp);
1420         if (rc) {
1421                 PROTOCOL_ERR("14.4.1.2");
1422                 goto exit;
1423         }
1424 
1425         psl_req = (struct digital_psl_req *)resp->data;
1426 
1427         if (resp->len != sizeof(struct digital_psl_req) ||
1428             psl_req->dir != DIGITAL_NFC_DEP_FRAME_DIR_OUT ||
1429             psl_req->cmd != DIGITAL_CMD_PSL_REQ) {
1430                 rc = -EIO;
1431                 goto exit;
1432         }
1433 
1434         dsi = (psl_req->brs >> 3) & 0x07;
1435         switch (dsi) {
1436         case 0:
1437                 rf_tech = NFC_DIGITAL_RF_TECH_106A;
1438                 break;
1439         case 1:
1440                 rf_tech = NFC_DIGITAL_RF_TECH_212F;
1441                 break;
1442         case 2:
1443                 rf_tech = NFC_DIGITAL_RF_TECH_424F;
1444                 break;
1445         default:
1446                 pr_err("Unsupported dsi value %d\n", dsi);
1447                 goto exit;
1448         }
1449 
1450         payload_bits = DIGITAL_PAYLOAD_FSL_TO_BITS(psl_req->fsl);
1451         payload_size = digital_payload_bits_to_size(payload_bits);
1452 
1453         if (!payload_size || (payload_size > min(ddev->local_payload_max,
1454                                                  ddev->remote_payload_max))) {
1455                 rc = -EINVAL;
1456                 goto exit;
1457         }
1458 
1459         ddev->local_payload_max = payload_size;
1460         ddev->remote_payload_max = payload_size;
1461 
1462         rc = digital_tg_send_psl_res(ddev, psl_req->did, rf_tech);
1463 
1464 exit:
1465         kfree_skb(resp);
1466 }
1467 
1468 static void digital_tg_send_atr_res_complete(struct nfc_digital_dev *ddev,
1469                                              void *arg, struct sk_buff *resp)
1470 {
1471         int offset;
1472 
1473         if (IS_ERR(resp)) {
1474                 digital_poll_next_tech(ddev);
1475                 return;
1476         }
1477 
1478         offset = 2;
1479         if (resp->data[0] == DIGITAL_NFC_DEP_NFCA_SOD_SB)
1480                 offset++;
1481 
1482         ddev->atn_count = 0;
1483 
1484         if (resp->data[offset] == DIGITAL_CMD_PSL_REQ)
1485                 digital_tg_recv_psl_req(ddev, arg, resp);
1486         else
1487                 digital_tg_recv_dep_req(ddev, arg, resp);
1488 }
1489 
1490 static int digital_tg_send_atr_res(struct nfc_digital_dev *ddev,
1491                                    struct digital_atr_req *atr_req)
1492 {
1493         struct digital_atr_res *atr_res;
1494         struct sk_buff *skb;
1495         u8 *gb, payload_bits;
1496         size_t gb_len;
1497         int rc;
1498 
1499         gb = nfc_get_local_general_bytes(ddev->nfc_dev, &gb_len);
1500         if (!gb)
1501                 gb_len = 0;
1502 
1503         skb = digital_skb_alloc(ddev, sizeof(struct digital_atr_res) + gb_len);
1504         if (!skb)
1505                 return -ENOMEM;
1506 
1507         skb_put(skb, sizeof(struct digital_atr_res));
1508         atr_res = (struct digital_atr_res *)skb->data;
1509 
1510         memset(atr_res, 0, sizeof(struct digital_atr_res));
1511 
1512         atr_res->dir = DIGITAL_NFC_DEP_FRAME_DIR_IN;
1513         atr_res->cmd = DIGITAL_CMD_ATR_RES;
1514         memcpy(atr_res->nfcid3, atr_req->nfcid3, sizeof(atr_req->nfcid3));
1515         atr_res->to = DIGITAL_NFC_DEP_TG_MAX_WT;
1516 
1517         ddev->local_payload_max = DIGITAL_PAYLOAD_SIZE_MAX;
1518         payload_bits = digital_payload_size_to_bits(ddev->local_payload_max);
1519         atr_res->pp = DIGITAL_PAYLOAD_BITS_TO_PP(payload_bits);
1520 
1521         if (gb_len) {
1522                 skb_put(skb, gb_len);
1523 
1524                 atr_res->pp |= DIGITAL_GB_BIT;
1525                 memcpy(atr_res->gb, gb, gb_len);
1526         }
1527 
1528         digital_skb_push_dep_sod(ddev, skb);
1529 
1530         ddev->skb_add_crc(skb);
1531 
1532         ddev->curr_nfc_dep_pni = 0;
1533 
1534         rc = digital_tg_send_cmd(ddev, skb, 999,
1535                                  digital_tg_send_atr_res_complete, NULL);
1536         if (rc)
1537                 kfree_skb(skb);
1538 
1539         return rc;
1540 }
1541 
1542 void digital_tg_recv_atr_req(struct nfc_digital_dev *ddev, void *arg,
1543                              struct sk_buff *resp)
1544 {
1545         int rc;
1546         struct digital_atr_req *atr_req;
1547         size_t gb_len, min_size;
1548         u8 poll_tech_count, payload_bits;
1549 
1550         if (IS_ERR(resp)) {
1551                 rc = PTR_ERR(resp);
1552                 resp = NULL;
1553                 goto exit;
1554         }
1555 
1556         if (!resp->len) {
1557                 rc = -EIO;
1558                 goto exit;
1559         }
1560 
1561         if (resp->data[0] == DIGITAL_NFC_DEP_NFCA_SOD_SB) {
1562                 min_size = DIGITAL_ATR_REQ_MIN_SIZE + 2;
1563                 digital_tg_set_rf_tech(ddev, NFC_DIGITAL_RF_TECH_106A);
1564         } else {
1565                 min_size = DIGITAL_ATR_REQ_MIN_SIZE + 1;
1566                 digital_tg_set_rf_tech(ddev, NFC_DIGITAL_RF_TECH_212F);
1567         }
1568 
1569         if (resp->len < min_size) {
1570                 rc = -EIO;
1571                 goto exit;
1572         }
1573 
1574         ddev->curr_protocol = NFC_PROTO_NFC_DEP_MASK;
1575 
1576         rc = ddev->skb_check_crc(resp);
1577         if (rc) {
1578                 PROTOCOL_ERR("14.4.1.6");
1579                 goto exit;
1580         }
1581 
1582         rc = digital_skb_pull_dep_sod(ddev, resp);
1583         if (rc) {
1584                 PROTOCOL_ERR("14.4.1.2");
1585                 goto exit;
1586         }
1587 
1588         atr_req = (struct digital_atr_req *)resp->data;
1589 
1590         if (atr_req->dir != DIGITAL_NFC_DEP_FRAME_DIR_OUT ||
1591             atr_req->cmd != DIGITAL_CMD_ATR_REQ ||
1592             atr_req->did > DIGITAL_DID_MAX) {
1593                 rc = -EINVAL;
1594                 goto exit;
1595         }
1596 
1597         payload_bits = DIGITAL_PAYLOAD_PP_TO_BITS(atr_req->pp);
1598         ddev->remote_payload_max = digital_payload_bits_to_size(payload_bits);
1599 
1600         if (!ddev->remote_payload_max) {
1601                 rc = -EINVAL;
1602                 goto exit;
1603         }
1604 
1605         ddev->did = atr_req->did;
1606 
1607         rc = digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
1608                                      NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED);
1609         if (rc)
1610                 goto exit;
1611 
1612         rc = digital_tg_send_atr_res(ddev, atr_req);
1613         if (rc)
1614                 goto exit;
1615 
1616         gb_len = resp->len - sizeof(struct digital_atr_req);
1617 
1618         poll_tech_count = ddev->poll_tech_count;
1619         ddev->poll_tech_count = 0;
1620 
1621         rc = nfc_tm_activated(ddev->nfc_dev, NFC_PROTO_NFC_DEP_MASK,
1622                               NFC_COMM_PASSIVE, atr_req->gb, gb_len);
1623         if (rc) {
1624                 ddev->poll_tech_count = poll_tech_count;
1625                 goto exit;
1626         }
1627 
1628         rc = 0;
1629 exit:
1630         if (rc)
1631                 digital_poll_next_tech(ddev);
1632 
1633         dev_kfree_skb(resp);
1634 }
1635 

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