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 ": " fmt
  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         nfc_dbg("entry, num_entries %d", 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                 nfc_dbg("entry[%d]: conn_id %d, credits %d", i,
  56                         ntf->conn_entries[i].conn_id,
  57                         ntf->conn_entries[i].credits);
  58
  59                 if (ntf->conn_entries[i].conn_id == NCI_STATIC_RF_CONN_ID) {
  60                         /* found static rf connection */
  61                         atomic_add(ntf->conn_entries[i].credits,
  62                                 &ndev->credits_cnt);
  63                 }
  64         }
  65
  66         /* trigger the next tx */
  67         if (!skb_queue_empty(&ndev->tx_q))
  68                 queue_work(ndev->tx_wq, &ndev->tx_work);
  69 }
  70
  71 static __u8 *nci_extract_rf_params_nfca_passive_poll(struct nci_dev *ndev,
  72                         struct nci_rf_intf_activated_ntf *ntf, __u8 *data)
  73 {
  74         struct rf_tech_specific_params_nfca_poll *nfca_poll;
  75
  76         nfca_poll = &ntf->rf_tech_specific_params.nfca_poll;
  77
  78         nfca_poll->sens_res = __le16_to_cpu(*((__u16 *)data));
  79         data += 2;
  80
  81         nfca_poll->nfcid1_len = *data++;
  82
  83         nfc_dbg("sens_res 0x%x, nfcid1_len %d",
  84                 nfca_poll->sens_res,
  85                 nfca_poll->nfcid1_len);
  86
  87         memcpy(nfca_poll->nfcid1, data, nfca_poll->nfcid1_len);
  88         data += nfca_poll->nfcid1_len;
  89
  90         nfca_poll->sel_res_len = *data++;
  91
  92         if (nfca_poll->sel_res_len != 0)
  93                 nfca_poll->sel_res = *data++;
  94
  95         nfc_dbg("sel_res_len %d, sel_res 0x%x",
  96                 nfca_poll->sel_res_len,
  97                 nfca_poll->sel_res);
  98
  99         return data;
 100 }
 101
 102 static int nci_extract_activation_params_iso_dep(struct nci_dev *ndev,
 103                         struct nci_rf_intf_activated_ntf *ntf, __u8 *data)
 104 {
 105         struct activation_params_nfca_poll_iso_dep *nfca_poll;
 106
 107         switch (ntf->activation_rf_tech_and_mode) {
 108         case NCI_NFC_A_PASSIVE_POLL_MODE:
 109                 nfca_poll = &ntf->activation_params.nfca_poll_iso_dep;
 110                 nfca_poll->rats_res_len = *data++;
 111                 if (nfca_poll->rats_res_len > 0) {
 112                         memcpy(nfca_poll->rats_res,
 113                                 data,
 114                                 nfca_poll->rats_res_len);
 115                 }
 116                 break;
 117
 118         default:
 119                 pr_err("unsupported activation_rf_tech_and_mode 0x%x\n",
 120                        ntf->activation_rf_tech_and_mode);
 121                 return -EPROTO;
 122         }
 123
 124         return 0;
 125 }
 126
 127 static void nci_target_found(struct nci_dev *ndev,
 128                                 struct nci_rf_intf_activated_ntf *ntf)
 129 {
 130         struct nfc_target nfc_tgt;
 131
 132         if (ntf->rf_protocol == NCI_RF_PROTOCOL_T2T)    /* T2T MifareUL */
 133                 nfc_tgt.supported_protocols = NFC_PROTO_MIFARE_MASK;
 134         else if (ntf->rf_protocol == NCI_RF_PROTOCOL_ISO_DEP)   /* 4A */
 135                 nfc_tgt.supported_protocols = NFC_PROTO_ISO14443_MASK;
 136         else
 137                 nfc_tgt.supported_protocols = 0;
 138
 139         nfc_tgt.sens_res = ntf->rf_tech_specific_params.nfca_poll.sens_res;
 140         nfc_tgt.sel_res = ntf->rf_tech_specific_params.nfca_poll.sel_res;
 141
 142         if (!(nfc_tgt.supported_protocols & ndev->poll_prots)) {
 143                 nfc_dbg("the target found does not have the desired protocol");
 144                 return;
 145         }
 146
 147         nfc_dbg("new target found,  supported_protocols 0x%x",
 148                 nfc_tgt.supported_protocols);
 149
 150         ndev->target_available_prots = nfc_tgt.supported_protocols;
 151
 152         nfc_targets_found(ndev->nfc_dev, &nfc_tgt, 1);
 153 }
 154
 155 static void nci_rf_intf_activated_ntf_packet(struct nci_dev *ndev,
 156                                                 struct sk_buff *skb)
 157 {
 158         struct nci_rf_intf_activated_ntf ntf;
 159         __u8 *data = skb->data;
 160         int err = 0;
 161
 162         clear_bit(NCI_DISCOVERY, &ndev->flags);
 163         set_bit(NCI_POLL_ACTIVE, &ndev->flags);
 164
 165         ntf.rf_discovery_id = *data++;
 166         ntf.rf_interface_type = *data++;
 167         ntf.rf_protocol = *data++;
 168         ntf.activation_rf_tech_and_mode = *data++;
 169         ntf.rf_tech_specific_params_len = *data++;
 170
 171         nfc_dbg("rf_discovery_id %d", ntf.rf_discovery_id);
 172         nfc_dbg("rf_interface_type 0x%x", ntf.rf_interface_type);
 173         nfc_dbg("rf_protocol 0x%x", ntf.rf_protocol);
 174         nfc_dbg("activation_rf_tech_and_mode 0x%x",
 175                 ntf.activation_rf_tech_and_mode);
 176         nfc_dbg("rf_tech_specific_params_len %d",
 177                 ntf.rf_tech_specific_params_len);
 178
 179         if (ntf.rf_tech_specific_params_len > 0) {
 180                 switch (ntf.activation_rf_tech_and_mode) {
 181                 case NCI_NFC_A_PASSIVE_POLL_MODE:
 182                         data = nci_extract_rf_params_nfca_passive_poll(ndev,
 183                                 &ntf, data);
 184                         break;
 185
 186                 default:
 187                         pr_err("unsupported activation_rf_tech_and_mode 0x%x\n",
 188                                ntf.activation_rf_tech_and_mode);
 189                         return;
 190                 }
 191         }
 192
 193         ntf.data_exch_rf_tech_and_mode = *data++;
 194         ntf.data_exch_tx_bit_rate = *data++;
 195         ntf.data_exch_rx_bit_rate = *data++;
 196         ntf.activation_params_len = *data++;
 197
 198         nfc_dbg("data_exch_rf_tech_and_mode 0x%x",
 199                 ntf.data_exch_rf_tech_and_mode);
 200         nfc_dbg("data_exch_tx_bit_rate 0x%x",
 201                 ntf.data_exch_tx_bit_rate);
 202         nfc_dbg("data_exch_rx_bit_rate 0x%x",
 203                 ntf.data_exch_rx_bit_rate);
 204         nfc_dbg("activation_params_len %d",
 205                 ntf.activation_params_len);
 206
 207         if (ntf.activation_params_len > 0) {
 208                 switch (ntf.rf_interface_type) {
 209                 case NCI_RF_INTERFACE_ISO_DEP:
 210                         err = nci_extract_activation_params_iso_dep(ndev,
 211                                 &ntf, data);
 212                         break;
 213
 214                 case NCI_RF_INTERFACE_FRAME:
 215                         /* no activation params */
 216                         break;
 217
 218                 default:
 219                         pr_err("unsupported rf_interface_type 0x%x\n",
 220                                ntf.rf_interface_type);
 221                         return;
 222                 }
 223         }
 224
 225         if (!err)
 226                 nci_target_found(ndev, &ntf);
 227 }
 228
 229 static void nci_rf_deactivate_ntf_packet(struct nci_dev *ndev,
 230                                         struct sk_buff *skb)
 231 {
 232         struct nci_rf_deactivate_ntf *ntf = (void *) skb->data;
 233
 234         nfc_dbg("entry, type 0x%x, reason 0x%x", ntf->type, ntf->reason);
 235
 236         clear_bit(NCI_POLL_ACTIVE, &ndev->flags);
 237         ndev->target_active_prot = 0;
 238
 239         /* drop tx data queue */
 240         skb_queue_purge(&ndev->tx_q);
 241
 242         /* drop partial rx data packet */
 243         if (ndev->rx_data_reassembly) {
 244                 kfree_skb(ndev->rx_data_reassembly);
 245                 ndev->rx_data_reassembly = 0;
 246         }
 247
 248         /* set the available credits to initial value */
 249         atomic_set(&ndev->credits_cnt, ndev->initial_num_credits);
 250
 251         /* complete the data exchange transaction, if exists */
 252         if (test_bit(NCI_DATA_EXCHANGE, &ndev->flags))
 253                 nci_data_exchange_complete(ndev, NULL, -EIO);
 254 }
 255
 256 void nci_ntf_packet(struct nci_dev *ndev, struct sk_buff *skb)
 257 {
 258         __u16 ntf_opcode = nci_opcode(skb->data);
 259
 260         nfc_dbg("NCI RX: MT=ntf, PBF=%d, GID=0x%x, OID=0x%x, plen=%d",
 261                         nci_pbf(skb->data),
 262                         nci_opcode_gid(ntf_opcode),
 263                         nci_opcode_oid(ntf_opcode),
 264                         nci_plen(skb->data));
 265
 266         /* strip the nci control header */
 267         skb_pull(skb, NCI_CTRL_HDR_SIZE);
 268
 269         switch (ntf_opcode) {
 270         case NCI_OP_CORE_CONN_CREDITS_NTF:
 271                 nci_core_conn_credits_ntf_packet(ndev, skb);
 272                 break;
 273
 274         case NCI_OP_RF_INTF_ACTIVATED_NTF:
 275                 nci_rf_intf_activated_ntf_packet(ndev, skb);
 276                 break;
 277
 278         case NCI_OP_RF_DEACTIVATE_NTF:
 279                 nci_rf_deactivate_ntf_packet(ndev, skb);
 280                 break;
 281
 282         default:
 283                 pr_err("unknown ntf opcode 0x%x\n", ntf_opcode);
 284                 break;
 285         }
 286
 287         kfree_skb(skb);
 288 }