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 #include "digital.h"
  17
  18 #define DIGITAL_CMD_SENS_REQ    0x26
  19 #define DIGITAL_CMD_ALL_REQ     0x52
  20 #define DIGITAL_CMD_SEL_REQ_CL1 0x93
  21 #define DIGITAL_CMD_SEL_REQ_CL2 0x95
  22 #define DIGITAL_CMD_SEL_REQ_CL3 0x97
  23
  24 #define DIGITAL_SDD_REQ_SEL_PAR 0x20
  25
  26 #define DIGITAL_SDD_RES_CT  0x88
  27 #define DIGITAL_SDD_RES_LEN 5
  28
  29 #define DIGITAL_SEL_RES_NFCID1_COMPLETE(sel_res) (!((sel_res) & 0x04))
  30 #define DIGITAL_SEL_RES_IS_T2T(sel_res) (!((sel_res) & 0x60))
  31
  32 #define DIGITAL_SENS_RES_IS_T1T(sens_res) (((sens_res) & 0x000C) == 0x000C)
  33 #define DIGITAL_SENS_RES_IS_VALID(sens_res) \
  34         ((!((sens_res) & 0x1F00) && (((sens_res) & 0x000C) == 0x000C)) || \
  35         (((sens_res) & 0x1F00) && ((sens_res) & 0x000C) != 0x000C))
  36
  37 #define DIGITAL_MIFARE_READ_RES_LEN 16
  38 #define DIGITAL_MIFARE_ACK_RES  0x0A
  39
  40 struct digital_sdd_res {
  41         u8 nfcid1[4];
  42         u8 bcc;
  43 } __packed;
  44
  45 struct digital_sel_req {
  46         u8 sel_cmd;
  47         u8 b2;
  48         u8 nfcid1[4];
  49         u8 bcc;
  50 } __packed;
  51
  52 static int digital_in_send_sdd_req(struct nfc_digital_dev *ddev,
  53                                    struct nfc_target *target);
  54
  55 static void digital_in_recv_sel_res(struct nfc_digital_dev *ddev, void *arg,
  56                                     struct sk_buff *resp)
  57 {
  58         struct nfc_target *target = arg;
  59         int rc;
  60         u8 sel_res;
  61         u8 nfc_proto;
  62
  63         if (IS_ERR(resp)) {
  64                 rc = PTR_ERR(resp);
  65                 resp = NULL;
  66                 goto exit;
  67         }
  68
  69         if (!DIGITAL_DRV_CAPS_IN_CRC(ddev)) {
  70                 rc = digital_skb_check_crc_a(resp);
  71                 if (rc) {
  72                         PROTOCOL_ERR("4.4.1.3");
  73                         goto exit;
  74                 }
  75         }
  76
  77         if (!resp->len) {
  78                 rc = -EIO;
  79                 goto exit;
  80         }
  81
  82         sel_res = resp->data[0];
  83
  84         if (!DIGITAL_SEL_RES_NFCID1_COMPLETE(sel_res)) {
  85                 rc = digital_in_send_sdd_req(ddev, target);
  86                 if (rc)
  87                         goto exit;
  88
  89                 goto exit_free_skb;
  90         }
  91
  92         if (DIGITAL_SEL_RES_IS_T2T(sel_res)) {
  93                 nfc_proto = NFC_PROTO_MIFARE;
  94         } else {
  95                 rc = -EOPNOTSUPP;
  96                 goto exit;
  97         }
  98
  99         target->sel_res = sel_res;
 100
 101         rc = digital_target_found(ddev, target, nfc_proto);
 102
 103 exit:
 104         kfree(target);
 105
 106 exit_free_skb:
 107         dev_kfree_skb(resp);
 108
 109         if (rc)
 110                 digital_poll_next_tech(ddev);
 111 }
 112
 113 static int digital_in_send_sel_req(struct nfc_digital_dev *ddev,
 114                                    struct nfc_target *target,
 115                                    struct digital_sdd_res *sdd_res)
 116 {
 117         struct sk_buff *skb;
 118         struct digital_sel_req *sel_req;
 119         u8 sel_cmd;
 120         int rc;
 121
 122         skb = digital_skb_alloc(ddev, sizeof(struct digital_sel_req));
 123         if (!skb)
 124                 return -ENOMEM;
 125
 126         skb_put(skb, sizeof(struct digital_sel_req));
 127         sel_req = (struct digital_sel_req *)skb->data;
 128
 129         if (target->nfcid1_len <= 4)
 130                 sel_cmd = DIGITAL_CMD_SEL_REQ_CL1;
 131         else if (target->nfcid1_len < 10)
 132                 sel_cmd = DIGITAL_CMD_SEL_REQ_CL2;
 133         else
 134                 sel_cmd = DIGITAL_CMD_SEL_REQ_CL3;
 135
 136         sel_req->sel_cmd = sel_cmd;
 137         sel_req->b2 = 0x70;
 138         memcpy(sel_req->nfcid1, sdd_res->nfcid1, 4);
 139         sel_req->bcc = sdd_res->bcc;
 140
 141         if (DIGITAL_DRV_CAPS_IN_CRC(ddev)) {
 142                 rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
 143                                 NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A);
 144                 if (rc)
 145                         goto exit;
 146         } else {
 147                 digital_skb_add_crc_a(skb);
 148         }
 149
 150         rc = digital_in_send_cmd(ddev, skb, 30, digital_in_recv_sel_res,
 151                                  target);
 152 exit:
 153         if (rc)
 154                 kfree_skb(skb);
 155
 156         return rc;
 157 }
 158
 159 static void digital_in_recv_sdd_res(struct nfc_digital_dev *ddev, void *arg,
 160                                     struct sk_buff *resp)
 161 {
 162         struct nfc_target *target = arg;
 163         struct digital_sdd_res *sdd_res;
 164         int rc;
 165         u8 offset, size;
 166         u8 i, bcc;
 167
 168         if (IS_ERR(resp)) {
 169                 rc = PTR_ERR(resp);
 170                 resp = NULL;
 171                 goto exit;
 172         }
 173
 174         if (resp->len < DIGITAL_SDD_RES_LEN) {
 175                 PROTOCOL_ERR("4.7.2.8");
 176                 rc = -EINVAL;
 177                 goto exit;
 178         }
 179
 180         sdd_res = (struct digital_sdd_res *)resp->data;
 181
 182         for (i = 0, bcc = 0; i < 4; i++)
 183                 bcc ^= sdd_res->nfcid1[i];
 184
 185         if (bcc != sdd_res->bcc) {
 186                 PROTOCOL_ERR("4.7.2.6");
 187                 rc = -EINVAL;
 188                 goto exit;
 189         }
 190
 191         if (sdd_res->nfcid1[0] == DIGITAL_SDD_RES_CT) {
 192                 offset = 1;
 193                 size = 3;
 194         } else {
 195                 offset = 0;
 196                 size = 4;
 197         }
 198
 199         memcpy(target->nfcid1 + target->nfcid1_len, sdd_res->nfcid1 + offset,
 200                size);
 201         target->nfcid1_len += size;
 202
 203         rc = digital_in_send_sel_req(ddev, target, sdd_res);
 204
 205 exit:
 206         dev_kfree_skb(resp);
 207
 208         if (rc) {
 209                 kfree(target);
 210                 digital_poll_next_tech(ddev);
 211         }
 212 }
 213
 214 static int digital_in_send_sdd_req(struct nfc_digital_dev *ddev,
 215                                    struct nfc_target *target)
 216 {
 217         int rc;
 218         struct sk_buff *skb;
 219         u8 sel_cmd;
 220
 221         rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
 222                                      NFC_DIGITAL_FRAMING_NFCA_STANDARD);
 223         if (rc)
 224                 return rc;
 225
 226         skb = digital_skb_alloc(ddev, 2);
 227         if (!skb) {
 228                 PR_ERR("alloc_skb failed");
 229                 return -ENOMEM;
 230         }
 231
 232         if (target->nfcid1_len == 0)
 233                 sel_cmd = DIGITAL_CMD_SEL_REQ_CL1;
 234         else if (target->nfcid1_len == 3)
 235                 sel_cmd = DIGITAL_CMD_SEL_REQ_CL2;
 236         else
 237                 sel_cmd = DIGITAL_CMD_SEL_REQ_CL3;
 238
 239         *skb_put(skb, sizeof(u8)) = sel_cmd;
 240         *skb_put(skb, sizeof(u8)) = DIGITAL_SDD_REQ_SEL_PAR;
 241
 242         return digital_in_send_cmd(ddev, skb, 30, digital_in_recv_sdd_res,
 243                                    target);
 244 }
 245
 246 static void digital_in_recv_sens_res(struct nfc_digital_dev *ddev, void *arg,
 247                                      struct sk_buff *resp)
 248 {
 249         struct nfc_target *target = NULL;
 250         u16 sens_res;
 251         int rc;
 252
 253         if (IS_ERR(resp)) {
 254                 rc = PTR_ERR(resp);
 255                 resp = NULL;
 256                 goto exit;
 257         }
 258
 259         if (resp->len < sizeof(u16)) {
 260                 rc = -EIO;
 261                 goto exit;
 262         }
 263
 264         target = kzalloc(sizeof(struct nfc_target), GFP_KERNEL);
 265         if (!target) {
 266                 rc = -ENOMEM;
 267                 goto exit;
 268         }
 269
 270         memcpy(&target->sens_res, resp->data, sizeof(u16));
 271
 272         sens_res = be16_to_cpu(target->sens_res);
 273
 274         if (!DIGITAL_SENS_RES_IS_VALID(sens_res)) {
 275                 PROTOCOL_ERR("4.6.3.3");
 276                 rc = -EINVAL;
 277                 goto exit;
 278         }
 279
 280         if (DIGITAL_SENS_RES_IS_T1T(sens_res))
 281                 rc = digital_target_found(ddev, target, NFC_PROTO_JEWEL);
 282         else
 283                 rc = digital_in_send_sdd_req(ddev, target);
 284
 285 exit:
 286         dev_kfree_skb(resp);
 287
 288         if (rc) {
 289                 kfree(target);
 290                 digital_poll_next_tech(ddev);
 291         }
 292 }
 293
 294 int digital_in_send_sens_req(struct nfc_digital_dev *ddev, u8 rf_tech)
 295 {
 296         struct sk_buff *skb;
 297         int rc;
 298
 299         rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
 300                                      NFC_DIGITAL_RF_TECH_106A);
 301         if (rc)
 302                 return rc;
 303
 304         rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
 305                                      NFC_DIGITAL_FRAMING_NFCA_SHORT);
 306         if (rc)
 307                 return rc;
 308
 309         skb = digital_skb_alloc(ddev, 1);
 310         if (!skb)
 311                 return -ENOMEM;
 312
 313         *skb_put(skb, sizeof(u8)) = DIGITAL_CMD_SENS_REQ;
 314
 315         rc = digital_in_send_cmd(ddev, skb, 30, digital_in_recv_sens_res, NULL);
 316         if (rc)
 317                 kfree_skb(skb);
 318
 319         return rc;
 320 }
 321
 322 int digital_in_recv_mifare_res(struct sk_buff *resp)
 323 {
 324         /* Successful READ command response is 16 data bytes + 2 CRC bytes long.
 325          * Since the driver can't differentiate a ACK/NACK response from a valid
 326          * READ response, the CRC calculation must be handled at digital level
 327          * even if the driver supports it for this technology.
 328          */
 329         if (resp->len == DIGITAL_MIFARE_READ_RES_LEN + DIGITAL_CRC_LEN) {
 330                 if (digital_skb_check_crc_a(resp)) {
 331                         PROTOCOL_ERR("9.4.1.2");
 332                         return -EIO;
 333                 }
 334
 335                 return 0;
 336         }
 337
 338         /* ACK response (i.e. successful WRITE). */
 339         if (resp->len == 1 && resp->data[0] == DIGITAL_MIFARE_ACK_RES) {
 340                 resp->data[0] = 0;
 341                 return 0;
 342         }
 343
 344         /* NACK and any other responses are treated as error. */
 345         return -EIO;
 346 }