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         nfc_tgt.nfcid1_len = ntf->rf_tech_specific_params.nfca_poll.nfcid1_len;
 158         if (nfc_tgt.nfcid1_len > 0) {
 159                 memcpy(nfc_tgt.nfcid1,
 160                         ntf->rf_tech_specific_params.nfca_poll.nfcid1,
 161                         nfc_tgt.nfcid1_len);
 162         }
 163
 164         if (!(nfc_tgt.supported_protocols & ndev->poll_prots)) {
 165                 pr_debug("the target found does not have the desired protocol\n");
 166                 return;
 167         }
 168
 169         pr_debug("new target found,  supported_protocols 0x%x\n",
 170                  nfc_tgt.supported_protocols);
 171
 172         ndev->target_available_prots = nfc_tgt.supported_protocols;
 173         ndev->max_data_pkt_payload_size = ntf->max_data_pkt_payload_size;
 174         ndev->initial_num_credits = ntf->initial_num_credits;
 175
 176         /* set the available credits to initial value */
 177         atomic_set(&ndev->credits_cnt, ndev->initial_num_credits);
 178
 179         nfc_targets_found(ndev->nfc_dev, &nfc_tgt, 1);
 180 }
 181
 182 static void nci_rf_intf_activated_ntf_packet(struct nci_dev *ndev,
 183                                                 struct sk_buff *skb)
 184 {
 185         struct nci_rf_intf_activated_ntf ntf;
 186         __u8 *data = skb->data;
 187         int err = 0;
 188
 189         clear_bit(NCI_DISCOVERY, &ndev->flags);
 190         set_bit(NCI_POLL_ACTIVE, &ndev->flags);
 191
 192         ntf.rf_discovery_id = *data++;
 193         ntf.rf_interface = *data++;
 194         ntf.rf_protocol = *data++;
 195         ntf.activation_rf_tech_and_mode = *data++;
 196         ntf.max_data_pkt_payload_size = *data++;
 197         ntf.initial_num_credits = *data++;
 198         ntf.rf_tech_specific_params_len = *data++;
 199
 200         pr_debug("rf_discovery_id %d\n", ntf.rf_discovery_id);
 201         pr_debug("rf_interface 0x%x\n", ntf.rf_interface);
 202         pr_debug("rf_protocol 0x%x\n", ntf.rf_protocol);
 203         pr_debug("activation_rf_tech_and_mode 0x%x\n",
 204                  ntf.activation_rf_tech_and_mode);
 205         pr_debug("max_data_pkt_payload_size 0x%x\n",
 206                  ntf.max_data_pkt_payload_size);
 207         pr_debug("initial_num_credits 0x%x\n", ntf.initial_num_credits);
 208         pr_debug("rf_tech_specific_params_len %d\n",
 209                  ntf.rf_tech_specific_params_len);
 210
 211         if (ntf.rf_tech_specific_params_len > 0) {
 212                 switch (ntf.activation_rf_tech_and_mode) {
 213                 case NCI_NFC_A_PASSIVE_POLL_MODE:
 214                         data = nci_extract_rf_params_nfca_passive_poll(ndev,
 215                                 &ntf, data);
 216                         break;
 217
 218                 default:
 219                         pr_err("unsupported activation_rf_tech_and_mode 0x%x\n",
 220                                ntf.activation_rf_tech_and_mode);
 221                         return;
 222                 }
 223         }
 224
 225         ntf.data_exch_rf_tech_and_mode = *data++;
 226         ntf.data_exch_tx_bit_rate = *data++;
 227         ntf.data_exch_rx_bit_rate = *data++;
 228         ntf.activation_params_len = *data++;
 229
 230         pr_debug("data_exch_rf_tech_and_mode 0x%x\n",
 231                  ntf.data_exch_rf_tech_and_mode);
 232         pr_debug("data_exch_tx_bit_rate 0x%x\n",
 233                  ntf.data_exch_tx_bit_rate);
 234         pr_debug("data_exch_rx_bit_rate 0x%x\n",
 235                  ntf.data_exch_rx_bit_rate);
 236         pr_debug("activation_params_len %d\n",
 237                  ntf.activation_params_len);
 238
 239         if (ntf.activation_params_len > 0) {
 240                 switch (ntf.rf_interface) {
 241                 case NCI_RF_INTERFACE_ISO_DEP:
 242                         err = nci_extract_activation_params_iso_dep(ndev,
 243                                 &ntf, data);
 244                         break;
 245
 246                 case NCI_RF_INTERFACE_FRAME:
 247                         /* no activation params */
 248                         break;
 249
 250                 default:
 251                         pr_err("unsupported rf_interface 0x%x\n",
 252                                ntf.rf_interface);
 253                         return;
 254                 }
 255         }
 256
 257         if (!err)
 258                 nci_target_found(ndev, &ntf);
 259 }
 260
 261 static void nci_rf_deactivate_ntf_packet(struct nci_dev *ndev,
 262                                         struct sk_buff *skb)
 263 {
 264         struct nci_rf_deactivate_ntf *ntf = (void *) skb->data;
 265
 266         pr_debug("entry, type 0x%x, reason 0x%x\n", ntf->type, ntf->reason);
 267
 268         clear_bit(NCI_POLL_ACTIVE, &ndev->flags);
 269         ndev->target_active_prot = 0;
 270
 271         /* drop tx data queue */
 272         skb_queue_purge(&ndev->tx_q);
 273
 274         /* drop partial rx data packet */
 275         if (ndev->rx_data_reassembly) {
 276                 kfree_skb(ndev->rx_data_reassembly);
 277                 ndev->rx_data_reassembly = 0;
 278         }
 279
 280         /* complete the data exchange transaction, if exists */
 281         if (test_bit(NCI_DATA_EXCHANGE, &ndev->flags))
 282                 nci_data_exchange_complete(ndev, NULL, -EIO);
 283 }
 284
 285 void nci_ntf_packet(struct nci_dev *ndev, struct sk_buff *skb)
 286 {
 287         __u16 ntf_opcode = nci_opcode(skb->data);
 288
 289         pr_debug("NCI RX: MT=ntf, PBF=%d, GID=0x%x, OID=0x%x, plen=%d\n",
 290                  nci_pbf(skb->data),
 291                  nci_opcode_gid(ntf_opcode),
 292                  nci_opcode_oid(ntf_opcode),
 293                  nci_plen(skb->data));
 294
 295         /* strip the nci control header */
 296         skb_pull(skb, NCI_CTRL_HDR_SIZE);
 297
 298         switch (ntf_opcode) {
 299         case NCI_OP_CORE_CONN_CREDITS_NTF:
 300                 nci_core_conn_credits_ntf_packet(ndev, skb);
 301                 break;
 302
 303         case NCI_OP_CORE_INTF_ERROR_NTF:
 304                 nci_core_conn_intf_error_ntf_packet(ndev, skb);
 305                 break;
 306
 307         case NCI_OP_RF_INTF_ACTIVATED_NTF:
 308                 nci_rf_intf_activated_ntf_packet(ndev, skb);
 309                 break;
 310
 311         case NCI_OP_RF_DEACTIVATE_NTF:
 312                 nci_rf_deactivate_ntf_packet(ndev, skb);
 313                 break;
 314
 315         default:
 316                 pr_err("unknown ntf opcode 0x%x\n", ntf_opcode);
 317                 break;
 318         }
 319
 320         kfree_skb(skb);
 321 }