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 #include <linux/types.h>
  29 #include <linux/interrupt.h>
  30 #include <linux/bitops.h>
  31 #include <linux/skbuff.h>
  32
  33 #include "../nfc.h"
  34 #include <net/nfc/nci.h>
  35 #include <net/nfc/nci_core.h>
  36 #include <linux/nfc.h>
  37
  38 /* Handle NCI Notification packets */
  39
  40 static void nci_core_conn_credits_ntf_packet(struct nci_dev *ndev,
  41                                                 struct sk_buff *skb)
  42 {
  43         struct nci_core_conn_credit_ntf *ntf = (void *) skb->data;
  44         int i;
  45
  46         nfc_dbg("entry, num_entries %d", ntf->num_entries);
  47
  48         if (ntf->num_entries > NCI_MAX_NUM_CONN)
  49                 ntf->num_entries = NCI_MAX_NUM_CONN;
  50
  51         /* update the credits */
  52         for (i = 0; i < ntf->num_entries; i++) {
  53                 nfc_dbg("entry[%d]: conn_id %d, credits %d", i,
  54                         ntf->conn_entries[i].conn_id,
  55                         ntf->conn_entries[i].credits);
  56
  57                 if (ntf->conn_entries[i].conn_id == NCI_STATIC_RF_CONN_ID) {
  58                         /* found static rf connection */
  59                         atomic_add(ntf->conn_entries[i].credits,
  60                                 &ndev->credits_cnt);
  61                 }
  62         }
  63
  64         /* trigger the next tx */
  65         if (!skb_queue_empty(&ndev->tx_q))
  66                 queue_work(ndev->tx_wq, &ndev->tx_work);
  67 }
  68
  69 static __u8 *nci_extract_rf_params_nfca_passive_poll(struct nci_dev *ndev,
  70                         struct nci_rf_intf_activated_ntf *ntf, __u8 *data)
  71 {
  72         struct rf_tech_specific_params_nfca_poll *nfca_poll;
  73
  74         nfca_poll = &ntf->rf_tech_specific_params.nfca_poll;
  75
  76         nfca_poll->sens_res = __le16_to_cpu(*((__u16 *)data));
  77         data += 2;
  78
  79         nfca_poll->nfcid1_len = *data++;
  80
  81         nfc_dbg("sens_res 0x%x, nfcid1_len %d",
  82                 nfca_poll->sens_res,
  83                 nfca_poll->nfcid1_len);
  84
  85         memcpy(nfca_poll->nfcid1, data, nfca_poll->nfcid1_len);
  86         data += nfca_poll->nfcid1_len;
  87
  88         nfca_poll->sel_res_len = *data++;
  89
  90         if (nfca_poll->sel_res_len != 0)
  91                 nfca_poll->sel_res = *data++;
  92
  93         nfc_dbg("sel_res_len %d, sel_res 0x%x",
  94                 nfca_poll->sel_res_len,
  95                 nfca_poll->sel_res);
  96
  97         return data;
  98 }
  99
 100 static int nci_extract_activation_params_iso_dep(struct nci_dev *ndev,
 101                         struct nci_rf_intf_activated_ntf *ntf, __u8 *data)
 102 {
 103         struct activation_params_nfca_poll_iso_dep *nfca_poll;
 104
 105         switch (ntf->activation_rf_tech_and_mode) {
 106         case NCI_NFC_A_PASSIVE_POLL_MODE:
 107                 nfca_poll = &ntf->activation_params.nfca_poll_iso_dep;
 108                 nfca_poll->rats_res_len = *data++;
 109                 if (nfca_poll->rats_res_len > 0) {
 110                         memcpy(nfca_poll->rats_res,
 111                                 data,
 112                                 nfca_poll->rats_res_len);
 113                 }
 114                 break;
 115
 116         default:
 117                 nfc_err("unsupported activation_rf_tech_and_mode 0x%x",
 118                         ntf->activation_rf_tech_and_mode);
 119                 return -EPROTO;
 120         }
 121
 122         return 0;
 123 }
 124
 125 static void nci_target_found(struct nci_dev *ndev,
 126                                 struct nci_rf_intf_activated_ntf *ntf)
 127 {
 128         struct nfc_target nfc_tgt;
 129
 130         if (ntf->rf_protocol == NCI_RF_PROTOCOL_T2T)    /* T2T MifareUL */
 131                 nfc_tgt.supported_protocols = NFC_PROTO_MIFARE_MASK;
 132         else if (ntf->rf_protocol == NCI_RF_PROTOCOL_ISO_DEP)   /* 4A */
 133                 nfc_tgt.supported_protocols = NFC_PROTO_ISO14443_MASK;
 134         else
 135                 nfc_tgt.supported_protocols = 0;
 136
 137         nfc_tgt.sens_res = ntf->rf_tech_specific_params.nfca_poll.sens_res;
 138         nfc_tgt.sel_res = ntf->rf_tech_specific_params.nfca_poll.sel_res;
 139
 140         if (!(nfc_tgt.supported_protocols & ndev->poll_prots)) {
 141                 nfc_dbg("the target found does not have the desired protocol");
 142                 return;
 143         }
 144
 145         nfc_dbg("new target found,  supported_protocols 0x%x",
 146                 nfc_tgt.supported_protocols);
 147
 148         ndev->target_available_prots = nfc_tgt.supported_protocols;
 149
 150         nfc_targets_found(ndev->nfc_dev, &nfc_tgt, 1);
 151 }
 152
 153 static void nci_rf_intf_activated_ntf_packet(struct nci_dev *ndev,
 154                                                 struct sk_buff *skb)
 155 {
 156         struct nci_rf_intf_activated_ntf ntf;
 157         __u8 *data = skb->data;
 158         int err = 0;
 159
 160         clear_bit(NCI_DISCOVERY, &ndev->flags);
 161         set_bit(NCI_POLL_ACTIVE, &ndev->flags);
 162
 163         ntf.rf_discovery_id = *data++;
 164         ntf.rf_interface_type = *data++;
 165         ntf.rf_protocol = *data++;
 166         ntf.activation_rf_tech_and_mode = *data++;
 167         ntf.rf_tech_specific_params_len = *data++;
 168
 169         nfc_dbg("rf_discovery_id %d", ntf.rf_discovery_id);
 170         nfc_dbg("rf_interface_type 0x%x", ntf.rf_interface_type);
 171         nfc_dbg("rf_protocol 0x%x", ntf.rf_protocol);
 172         nfc_dbg("activation_rf_tech_and_mode 0x%x",
 173                 ntf.activation_rf_tech_and_mode);
 174         nfc_dbg("rf_tech_specific_params_len %d",
 175                 ntf.rf_tech_specific_params_len);
 176
 177         if (ntf.rf_tech_specific_params_len > 0) {
 178                 switch (ntf.activation_rf_tech_and_mode) {
 179                 case NCI_NFC_A_PASSIVE_POLL_MODE:
 180                         data = nci_extract_rf_params_nfca_passive_poll(ndev,
 181                                 &ntf, data);
 182                         break;
 183
 184                 default:
 185                         nfc_err("unsupported activation_rf_tech_and_mode 0x%x",
 186                                 ntf.activation_rf_tech_and_mode);
 187                         return;
 188                 }
 189         }
 190
 191         ntf.data_exch_rf_tech_and_mode = *data++;
 192         ntf.data_exch_tx_bit_rate = *data++;
 193         ntf.data_exch_rx_bit_rate = *data++;
 194         ntf.activation_params_len = *data++;
 195
 196         nfc_dbg("data_exch_rf_tech_and_mode 0x%x",
 197                 ntf.data_exch_rf_tech_and_mode);
 198         nfc_dbg("data_exch_tx_bit_rate 0x%x",
 199                 ntf.data_exch_tx_bit_rate);
 200         nfc_dbg("data_exch_rx_bit_rate 0x%x",
 201                 ntf.data_exch_rx_bit_rate);
 202         nfc_dbg("activation_params_len %d",
 203                 ntf.activation_params_len);
 204
 205         if (ntf.activation_params_len > 0) {
 206                 switch (ntf.rf_interface_type) {
 207                 case NCI_RF_INTERFACE_ISO_DEP:
 208                         err = nci_extract_activation_params_iso_dep(ndev,
 209                                 &ntf, data);
 210                         break;
 211
 212                 case NCI_RF_INTERFACE_FRAME:
 213                         /* no activation params */
 214                         break;
 215
 216                 default:
 217                         nfc_err("unsupported rf_interface_type 0x%x",
 218                                 ntf.rf_interface_type);
 219                         return;
 220                 }
 221         }
 222
 223         if (!err)
 224                 nci_target_found(ndev, &ntf);
 225 }
 226
 227 static void nci_rf_deactivate_ntf_packet(struct nci_dev *ndev,
 228                                         struct sk_buff *skb)
 229 {
 230         struct nci_rf_deactivate_ntf *ntf = (void *) skb->data;
 231
 232         nfc_dbg("entry, type 0x%x, reason 0x%x", ntf->type, ntf->reason);
 233
 234         clear_bit(NCI_POLL_ACTIVE, &ndev->flags);
 235         ndev->target_active_prot = 0;
 236
 237         /* drop tx data queue */
 238         skb_queue_purge(&ndev->tx_q);
 239
 240         /* drop partial rx data packet */
 241         if (ndev->rx_data_reassembly) {
 242                 kfree_skb(ndev->rx_data_reassembly);
 243                 ndev->rx_data_reassembly = 0;
 244         }
 245
 246         /* set the available credits to initial value */
 247         atomic_set(&ndev->credits_cnt, ndev->initial_num_credits);
 248
 249         /* complete the data exchange transaction, if exists */
 250         if (test_bit(NCI_DATA_EXCHANGE, &ndev->flags))
 251                 nci_data_exchange_complete(ndev, NULL, -EIO);
 252 }
 253
 254 void nci_ntf_packet(struct nci_dev *ndev, struct sk_buff *skb)
 255 {
 256         __u16 ntf_opcode = nci_opcode(skb->data);
 257
 258         nfc_dbg("NCI RX: MT=ntf, PBF=%d, GID=0x%x, OID=0x%x, plen=%d",
 259                         nci_pbf(skb->data),
 260                         nci_opcode_gid(ntf_opcode),
 261                         nci_opcode_oid(ntf_opcode),
 262                         nci_plen(skb->data));
 263
 264         /* strip the nci control header */
 265         skb_pull(skb, NCI_CTRL_HDR_SIZE);
 266
 267         switch (ntf_opcode) {
 268         case NCI_OP_CORE_CONN_CREDITS_NTF:
 269                 nci_core_conn_credits_ntf_packet(ndev, skb);
 270                 break;
 271
 272         case NCI_OP_RF_INTF_ACTIVATED_NTF:
 273                 nci_rf_intf_activated_ntf_packet(ndev, skb);
 274                 break;
 275
 276         case NCI_OP_RF_DEACTIVATE_NTF:
 277                 nci_rf_deactivate_ntf_packet(ndev, skb);
 278                 break;
 279
 280         default:
 281                 nfc_err("unknown ntf opcode 0x%x", ntf_opcode);
 282                 break;
 283         }
 284
 285         kfree_skb(skb);
 286 }