net/nfc/nci/ntf.c

   1 /*
   2  *  The NFC Controller Interface is the communication protocol between an
   3  *  NFC Controller (NFCC) and a Device Host (DH).
   4  *
   5  *  Copyright (C) 2011 Texas Instruments, Inc.
   6  *
   7  *  Written by Ilan Elias <ilane@ti.com>
   8  *
   9  *  Acknowledgements:
  10  *  This file is based on hci_event.c, which was written
  11  *  by Maxim Krasnyansky.
  12  *
  13  *  This program is free software; you can redistribute it and/or modify
  14  *  it under the terms of the GNU General Public License version 2
  15  *  as published by the Free Software Foundation
  16  *
  17  *  This program is distributed in the hope that it will be useful,
  18  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  *  GNU General Public License for more details.
  21  *
  22  *  You should have received a copy of the GNU General Public License
  23  *  along with this program; if not, write to the Free Software
  24  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  25  *
  26  */
  27
  28 #define pr_fmt(fmt) KBUILD_MODNAME ": %s: " fmt, __func__
  29
  30 #include <linux/types.h>
  31 #include <linux/interrupt.h>
  32 #include <linux/bitops.h>
  33 #include <linux/skbuff.h>
  34
  35 #include "../nfc.h"
  36 #include <net/nfc/nci.h>
  37 #include <net/nfc/nci_core.h>
  38 #include <linux/nfc.h>
  39
  40 /* Handle NCI Notification packets */
  41
  42 static void nci_core_conn_credits_ntf_packet(struct nci_dev *ndev,
  43                                                 struct sk_buff *skb)
  44 {
  45         struct nci_core_conn_credit_ntf *ntf = (void *) skb->data;
  46         int i;
  47
  48         pr_debug("num_entries %d\n", ntf->num_entries);
  49
  50         if (ntf->num_entries > NCI_MAX_NUM_CONN)
  51                 ntf->num_entries = NCI_MAX_NUM_CONN;
  52
  53         /* update the credits */
  54         for (i = 0; i < ntf->num_entries; i++) {
  55                 ntf->conn_entries[i].conn_id =
  56                         nci_conn_id(&ntf->conn_entries[i].conn_id);
  57
  58                 pr_debug("entry[%d]: conn_id %d, credits %d\n",
  59                          i, ntf->conn_entries[i].conn_id,
  60                          ntf->conn_entries[i].credits);
  61
  62                 if (ntf->conn_entries[i].conn_id == NCI_STATIC_RF_CONN_ID) {
  63                         /* found static rf connection */
  64                         atomic_add(ntf->conn_entries[i].credits,
  65                                 &ndev->credits_cnt);
  66                 }
  67         }
  68
  69         /* trigger the next tx */
  70         if (!skb_queue_empty(&ndev->tx_q))
  71                 queue_work(ndev->tx_wq, &ndev->tx_work);
  72 }
  73
  74 static void nci_core_conn_intf_error_ntf_packet(struct nci_dev *ndev,
  75                                                 struct sk_buff *skb)
  76 {
  77         struct nci_core_intf_error_ntf *ntf = (void *) skb->data;
  78
  79         ntf->conn_id = nci_conn_id(&ntf->conn_id);
  80
  81         pr_debug("status 0x%x, conn_id %d\n", ntf->status, ntf->conn_id);
  82
  83         /* complete the data exchange transaction, if exists */
  84         if (test_bit(NCI_DATA_EXCHANGE, &ndev->flags))
  85                 nci_data_exchange_complete(ndev, NULL, -EIO);
  86 }
  87
  88 static __u8 *nci_extract_rf_params_nfca_passive_poll(struct nci_dev *ndev,
  89                         struct nci_rf_intf_activated_ntf *ntf, __u8 *data)
  90 {
  91         struct rf_tech_specific_params_nfca_poll *nfca_poll;
  92
  93         nfca_poll = &ntf->rf_tech_specific_params.nfca_poll;
  94
  95         nfca_poll->sens_res = __le16_to_cpu(*((__u16 *)data));
  96         data += 2;
  97
  98         nfca_poll->nfcid1_len = *data++;
  99
 100         pr_debug("sens_res 0x%x, nfcid1_len %d\n",
 101                  nfca_poll->sens_res, nfca_poll->nfcid1_len);
 102
 103         memcpy(nfca_poll->nfcid1, data, nfca_poll->nfcid1_len);
 104         data += nfca_poll->nfcid1_len;
 105
 106         nfca_poll->sel_res_len = *data++;
 107
 108         if (nfca_poll->sel_res_len != 0)
 109                 nfca_poll->sel_res = *data++;
 110
 111         pr_debug("sel_res_len %d, sel_res 0x%x\n",
 112                  nfca_poll->sel_res_len,
 113                  nfca_poll->sel_res);
 114
 115         return data;
 116 }
 117
 118 static int nci_extract_activation_params_iso_dep(struct nci_dev *ndev,
 119                         struct nci_rf_intf_activated_ntf *ntf, __u8 *data)
 120 {
 121         struct activation_params_nfca_poll_iso_dep *nfca_poll;
 122
 123         switch (ntf->activation_rf_tech_and_mode) {
 124         case NCI_NFC_A_PASSIVE_POLL_MODE:
 125                 nfca_poll = &ntf->activation_params.nfca_poll_iso_dep;
 126                 nfca_poll->rats_res_len = *data++;
 127                 if (nfca_poll->rats_res_len > 0) {
 128                         memcpy(nfca_poll->rats_res,
 129                                 data,
 130                                 nfca_poll->rats_res_len);
 131                 }
 132                 break;
 133
 134         default:
 135                 pr_err("unsupported activation_rf_tech_and_mode 0x%x\n",
 136                        ntf->activation_rf_tech_and_mode);
 137                 return -EPROTO;
 138         }
 139
 140         return 0;
 141 }
 142
 143 static void nci_target_found(struct nci_dev *ndev,
 144                                 struct nci_rf_intf_activated_ntf *ntf)
 145 {
 146         struct nfc_target nfc_tgt;
 147
 148         if (ntf->rf_protocol == NCI_RF_PROTOCOL_T2T)    /* T2T MifareUL */
 149                 nfc_tgt.supported_protocols = NFC_PROTO_MIFARE_MASK;
 150         else if (ntf->rf_protocol == NCI_RF_PROTOCOL_ISO_DEP)   /* 4A */
 151                 nfc_tgt.supported_protocols = NFC_PROTO_ISO14443_MASK;
 152         else
 153                 nfc_tgt.supported_protocols = 0;
 154
 155         nfc_tgt.sens_res = ntf->rf_tech_specific_params.nfca_poll.sens_res;
 156         nfc_tgt.sel_res = ntf->rf_tech_specific_params.nfca_poll.sel_res;
 157
 158         if (!(nfc_tgt.supported_protocols & ndev->poll_prots)) {
 159                 pr_debug("the target found does not have the desired protocol\n");
 160                 return;
 161         }
 162
 163         pr_debug("new target found,  supported_protocols 0x%x\n",
 164                  nfc_tgt.supported_protocols);
 165
 166         ndev->target_available_prots = nfc_tgt.supported_protocols;
 167         ndev->max_data_pkt_payload_size = ntf->max_data_pkt_payload_size;
 168         ndev->initial_num_credits = ntf->initial_num_credits;
 169
 170         /* set the available credits to initial value */
 171         atomic_set(&ndev->credits_cnt, ndev->initial_num_credits);
 172
 173         nfc_targets_found(ndev->nfc_dev, &nfc_tgt, 1);
 174 }
 175
 176 static void nci_rf_intf_activated_ntf_packet(struct nci_dev *ndev,
 177                                                 struct sk_buff *skb)
 178 {
 179         struct nci_rf_intf_activated_ntf ntf;
 180         __u8 *data = skb->data;
 181         int err = 0;
 182
 183         clear_bit(NCI_DISCOVERY, &ndev->flags);
 184         set_bit(NCI_POLL_ACTIVE, &ndev->flags);
 185
 186         ntf.rf_discovery_id = *data++;
 187         ntf.rf_interface = *data++;
 188         ntf.rf_protocol = *data++;
 189         ntf.activation_rf_tech_and_mode = *data++;
 190         ntf.max_data_pkt_payload_size = *data++;
 191         ntf.initial_num_credits = *data++;
 192         ntf.rf_tech_specific_params_len = *data++;
 193
 194         pr_debug("rf_discovery_id %d\n", ntf.rf_discovery_id);
 195         pr_debug("rf_interface 0x%x\n", ntf.rf_interface);
 196         pr_debug("rf_protocol 0x%x\n", ntf.rf_protocol);
 197         pr_debug("activation_rf_tech_and_mode 0x%x\n",
 198                  ntf.activation_rf_tech_and_mode);
 199         pr_debug("max_data_pkt_payload_size 0x%x\n",
 200                  ntf.max_data_pkt_payload_size);
 201         pr_debug("initial_num_credits 0x%x\n", ntf.initial_num_credits);
 202         pr_debug("rf_tech_specific_params_len %d\n",
 203                  ntf.rf_tech_specific_params_len);
 204
 205         if (ntf.rf_tech_specific_params_len > 0) {
 206                 switch (ntf.activation_rf_tech_and_mode) {
 207                 case NCI_NFC_A_PASSIVE_POLL_MODE:
 208                         data = nci_extract_rf_params_nfca_passive_poll(ndev,
 209                                 &ntf, data);
 210                         break;
 211
 212                 default:
 213                         pr_err("unsupported activation_rf_tech_and_mode 0x%x\n",
 214                                ntf.activation_rf_tech_and_mode);
 215                         return;
 216                 }
 217         }
 218
 219         ntf.data_exch_rf_tech_and_mode = *data++;
 220         ntf.data_exch_tx_bit_rate = *data++;
 221         ntf.data_exch_rx_bit_rate = *data++;
 222         ntf.activation_params_len = *data++;
 223
 224         pr_debug("data_exch_rf_tech_and_mode 0x%x\n",
 225                  ntf.data_exch_rf_tech_and_mode);
 226         pr_debug("data_exch_tx_bit_rate 0x%x\n",
 227                  ntf.data_exch_tx_bit_rate);
 228         pr_debug("data_exch_rx_bit_rate 0x%x\n",
 229                  ntf.data_exch_rx_bit_rate);
 230         pr_debug("activation_params_len %d\n",
 231                  ntf.activation_params_len);
 232
 233         if (ntf.activation_params_len > 0) {
 234                 switch (ntf.rf_interface) {
 235                 case NCI_RF_INTERFACE_ISO_DEP:
 236                         err = nci_extract_activation_params_iso_dep(ndev,
 237                                 &ntf, data);
 238                         break;
 239
 240                 case NCI_RF_INTERFACE_FRAME:
 241                         /* no activation params */
 242                         break;
 243
 244                 default:
 245                         pr_err("unsupported rf_interface 0x%x\n",
 246                                ntf.rf_interface);
 247                         return;
 248                 }
 249         }
 250
 251         if (!err)
 252                 nci_target_found(ndev, &ntf);
 253 }
 254
 255 static void nci_rf_deactivate_ntf_packet(struct nci_dev *ndev,
 256                                         struct sk_buff *skb)
 257 {
 258         struct nci_rf_deactivate_ntf *ntf = (void *) skb->data;
 259
 260         pr_debug("entry, type 0x%x, reason 0x%x\n", ntf->type, ntf->reason);
 261
 262         clear_bit(NCI_POLL_ACTIVE, &ndev->flags);
 263         ndev->target_active_prot = 0;
 264
 265         /* drop tx data queue */
 266         skb_queue_purge(&ndev->tx_q);
 267
 268         /* drop partial rx data packet */
 269         if (ndev->rx_data_reassembly) {
 270                 kfree_skb(ndev->rx_data_reassembly);
 271                 ndev->rx_data_reassembly = 0;
 272         }
 273
 274         /* complete the data exchange transaction, if exists */
 275         if (test_bit(NCI_DATA_EXCHANGE, &ndev->flags))
 276                 nci_data_exchange_complete(ndev, NULL, -EIO);
 277 }
 278
 279 void nci_ntf_packet(struct nci_dev *ndev, struct sk_buff *skb)
 280 {
 281         __u16 ntf_opcode = nci_opcode(skb->data);
 282
 283         pr_debug("NCI RX: MT=ntf, PBF=%d, GID=0x%x, OID=0x%x, plen=%d\n",
 284                  nci_pbf(skb->data),
 285                  nci_opcode_gid(ntf_opcode),
 286                  nci_opcode_oid(ntf_opcode),
 287                  nci_plen(skb->data));
 288
 289         /* strip the nci control header */
 290         skb_pull(skb, NCI_CTRL_HDR_SIZE);
 291
 292         switch (ntf_opcode) {
 293         case NCI_OP_CORE_CONN_CREDITS_NTF:
 294                 nci_core_conn_credits_ntf_packet(ndev, skb);
 295                 break;
 296
 297         case NCI_OP_CORE_INTF_ERROR_NTF:
 298                 nci_core_conn_intf_error_ntf_packet(ndev, skb);
 299                 break;
 300
 301         case NCI_OP_RF_INTF_ACTIVATED_NTF:
 302                 nci_rf_intf_activated_ntf_packet(ndev, skb);
 303                 break;
 304
 305         case NCI_OP_RF_DEACTIVATE_NTF:
 306                 nci_rf_deactivate_ntf_packet(ndev, skb);
 307                 break;
 308
 309         default:
 310                 pr_err("unknown ntf opcode 0x%x\n", ntf_opcode);
 311                 break;
 312         }
 313
 314         kfree_skb(skb);
 315 }