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