net/nfc/hci/command.c

   1 /*
   2  * Copyright (C) 2012  Intel Corporation. All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #define pr_fmt(fmt) "hci: %s: " fmt, __func__
  19
  20 #include <linux/init.h>
  21 #include <linux/kernel.h>
  22 #include <linux/sched.h>
  23 #include <linux/module.h>
  24
  25 #include <net/nfc/hci.h>
  26
  27 #include "hci.h"
  28
  29 #define MAX_FWI 4949
  30
  31 static int nfc_hci_execute_cmd_async(struct nfc_hci_dev *hdev, u8 pipe, u8 cmd,
  32                                const u8 *param, size_t param_len,
  33                                data_exchange_cb_t cb, void *cb_context)
  34 {
  35         pr_debug("exec cmd async through pipe=%d, cmd=%d, plen=%zd\n", pipe,
  36                  cmd, param_len);
  37
  38         /* TODO: Define hci cmd execution delay. Should it be the same
  39          * for all commands?
  40          */
  41         return nfc_hci_hcp_message_tx(hdev, pipe, NFC_HCI_HCP_COMMAND, cmd,
  42                                       param, param_len, cb, cb_context, MAX_FWI);
  43 }
  44
  45 /*
  46  * HCI command execution completion callback.
  47  * err will be a standard linux error (may be converted from HCI response)
  48  * skb contains the response data and must be disposed, or may be NULL if
  49  * an error occured
  50  */
  51 static void nfc_hci_execute_cb(void *context, struct sk_buff *skb, int err)
  52 {
  53         struct hcp_exec_waiter *hcp_ew = (struct hcp_exec_waiter *)context;
  54
  55         pr_debug("HCI Cmd completed with result=%d\n", err);
  56
  57         hcp_ew->exec_result = err;
  58         if (hcp_ew->exec_result == 0)
  59                 hcp_ew->result_skb = skb;
  60         else
  61                 kfree_skb(skb);
  62         hcp_ew->exec_complete = true;
  63
  64         wake_up(hcp_ew->wq);
  65 }
  66
  67 static int nfc_hci_execute_cmd(struct nfc_hci_dev *hdev, u8 pipe, u8 cmd,
  68                                const u8 *param, size_t param_len,
  69                                struct sk_buff **skb)
  70 {
  71         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(ew_wq);
  72         struct hcp_exec_waiter hcp_ew;
  73         hcp_ew.wq = &ew_wq;
  74         hcp_ew.exec_complete = false;
  75         hcp_ew.result_skb = NULL;
  76
  77         pr_debug("exec cmd sync through pipe=%d, cmd=%d, plen=%zd\n", pipe,
  78                  cmd, param_len);
  79
  80         /* TODO: Define hci cmd execution delay. Should it be the same
  81          * for all commands?
  82          */
  83         hcp_ew.exec_result = nfc_hci_hcp_message_tx(hdev, pipe,
  84                                                     NFC_HCI_HCP_COMMAND, cmd,
  85                                                     param, param_len,
  86                                                     nfc_hci_execute_cb, &hcp_ew,
  87                                                     MAX_FWI);
  88         if (hcp_ew.exec_result < 0)
  89                 return hcp_ew.exec_result;
  90
  91         wait_event(ew_wq, hcp_ew.exec_complete == true);
  92
  93         if (hcp_ew.exec_result == 0) {
  94                 if (skb)
  95                         *skb = hcp_ew.result_skb;
  96                 else
  97                         kfree_skb(hcp_ew.result_skb);
  98         }
  99
 100         return hcp_ew.exec_result;
 101 }
 102
 103 int nfc_hci_send_event(struct nfc_hci_dev *hdev, u8 gate, u8 event,
 104                        const u8 *param, size_t param_len)
 105 {
 106         u8 pipe;
 107
 108         pr_debug("%d to gate %d\n", event, gate);
 109
 110         pipe = hdev->gate2pipe[gate];
 111         if (pipe == NFC_HCI_INVALID_PIPE)
 112                 return -EADDRNOTAVAIL;
 113
 114         return nfc_hci_hcp_message_tx(hdev, pipe, NFC_HCI_HCP_EVENT, event,
 115                                       param, param_len, NULL, NULL, 0);
 116 }
 117 EXPORT_SYMBOL(nfc_hci_send_event);
 118
 119 /*
 120  * Execute an hci command sent to gate.
 121  * skb will contain response data if success. skb can be NULL if you are not
 122  * interested by the response.
 123  */
 124 int nfc_hci_send_cmd(struct nfc_hci_dev *hdev, u8 gate, u8 cmd,
 125                      const u8 *param, size_t param_len, struct sk_buff **skb)
 126 {
 127         u8 pipe;
 128
 129         pr_debug("\n");
 130
 131         pipe = hdev->gate2pipe[gate];
 132         if (pipe == NFC_HCI_INVALID_PIPE)
 133                 return -EADDRNOTAVAIL;
 134
 135         return nfc_hci_execute_cmd(hdev, pipe, cmd, param, param_len, skb);
 136 }
 137 EXPORT_SYMBOL(nfc_hci_send_cmd);
 138
 139 int nfc_hci_send_cmd_async(struct nfc_hci_dev *hdev, u8 gate, u8 cmd,
 140                            const u8 *param, size_t param_len,
 141                            data_exchange_cb_t cb, void *cb_context)
 142 {
 143         u8 pipe;
 144
 145         pr_debug("\n");
 146
 147         pipe = hdev->gate2pipe[gate];
 148         if (pipe == NFC_HCI_INVALID_PIPE)
 149                 return -EADDRNOTAVAIL;
 150
 151         return nfc_hci_execute_cmd_async(hdev, pipe, cmd, param, param_len,
 152                                          cb, cb_context);
 153 }
 154 EXPORT_SYMBOL(nfc_hci_send_cmd_async);
 155
 156 int nfc_hci_set_param(struct nfc_hci_dev *hdev, u8 gate, u8 idx,
 157                       const u8 *param, size_t param_len)
 158 {
 159         int r;
 160         u8 *tmp;
 161
 162         /* TODO ELa: reg idx must be inserted before param, but we don't want
 163          * to ask the caller to do it to keep a simpler API.
 164          * For now, just create a new temporary param buffer. This is far from
 165          * optimal though, and the plan is to modify APIs to pass idx down to
 166          * nfc_hci_hcp_message_tx where the frame is actually built, thereby
 167          * eliminating the need for the temp allocation-copy here.
 168          */
 169
 170         pr_debug("idx=%d to gate %d\n", idx, gate);
 171
 172         tmp = kmalloc(1 + param_len, GFP_KERNEL);
 173         if (tmp == NULL)
 174                 return -ENOMEM;
 175
 176         *tmp = idx;
 177         memcpy(tmp + 1, param, param_len);
 178
 179         r = nfc_hci_send_cmd(hdev, gate, NFC_HCI_ANY_SET_PARAMETER,
 180                              tmp, param_len + 1, NULL);
 181
 182         kfree(tmp);
 183
 184         return r;
 185 }
 186 EXPORT_SYMBOL(nfc_hci_set_param);
 187
 188 int nfc_hci_get_param(struct nfc_hci_dev *hdev, u8 gate, u8 idx,
 189                       struct sk_buff **skb)
 190 {
 191         pr_debug("gate=%d regidx=%d\n", gate, idx);
 192
 193         return nfc_hci_send_cmd(hdev, gate, NFC_HCI_ANY_GET_PARAMETER,
 194                                 &idx, 1, skb);
 195 }
 196 EXPORT_SYMBOL(nfc_hci_get_param);
 197
 198 static int nfc_hci_open_pipe(struct nfc_hci_dev *hdev, u8 pipe)
 199 {
 200         struct sk_buff *skb;
 201         int r;
 202
 203         pr_debug("pipe=%d\n", pipe);
 204
 205         r = nfc_hci_execute_cmd(hdev, pipe, NFC_HCI_ANY_OPEN_PIPE,
 206                                 NULL, 0, &skb);
 207         if (r == 0) {
 208                 /* dest host other than host controller will send
 209                  * number of pipes already open on this gate before
 210                  * execution. The number can be found in skb->data[0]
 211                  */
 212                 kfree_skb(skb);
 213         }
 214
 215         return r;
 216 }
 217
 218 static int nfc_hci_close_pipe(struct nfc_hci_dev *hdev, u8 pipe)
 219 {
 220         pr_debug("\n");
 221
 222         return nfc_hci_execute_cmd(hdev, pipe, NFC_HCI_ANY_CLOSE_PIPE,
 223                                    NULL, 0, NULL);
 224 }
 225
 226 static u8 nfc_hci_create_pipe(struct nfc_hci_dev *hdev, u8 dest_host,
 227                               u8 dest_gate, int *result)
 228 {
 229         struct sk_buff *skb;
 230         struct hci_create_pipe_params params;
 231         struct hci_create_pipe_resp *resp;
 232         u8 pipe;
 233
 234         pr_debug("gate=%d\n", dest_gate);
 235
 236         params.src_gate = NFC_HCI_ADMIN_GATE;
 237         params.dest_host = dest_host;
 238         params.dest_gate = dest_gate;
 239
 240         *result = nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,
 241                                       NFC_HCI_ADM_CREATE_PIPE,
 242                                       (u8 *) &params, sizeof(params), &skb);
 243         if (*result < 0)
 244                 return NFC_HCI_INVALID_PIPE;
 245
 246         resp = (struct hci_create_pipe_resp *)skb->data;
 247         pipe = resp->pipe;
 248         kfree_skb(skb);
 249
 250         pr_debug("pipe created=%d\n", pipe);
 251
 252         return pipe;
 253 }
 254
 255 static int nfc_hci_delete_pipe(struct nfc_hci_dev *hdev, u8 pipe)
 256 {
 257         pr_debug("\n");
 258
 259         return nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,
 260                                    NFC_HCI_ADM_DELETE_PIPE, &pipe, 1, NULL);
 261 }
 262
 263 static int nfc_hci_clear_all_pipes(struct nfc_hci_dev *hdev)
 264 {
 265         u8 param[2];
 266         size_t param_len = 2;
 267
 268         /* TODO: Find out what the identity reference data is
 269          * and fill param with it. HCI spec 6.1.3.5 */
 270
 271         pr_debug("\n");
 272
 273         if (test_bit(NFC_HCI_QUIRK_SHORT_CLEAR, &hdev->quirks))
 274                 param_len = 0;
 275
 276         return nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,
 277                                    NFC_HCI_ADM_CLEAR_ALL_PIPE, param, param_len,
 278                                    NULL);
 279 }
 280
 281 int nfc_hci_disconnect_gate(struct nfc_hci_dev *hdev, u8 gate)
 282 {
 283         int r;
 284         u8 pipe = hdev->gate2pipe[gate];
 285
 286         pr_debug("\n");
 287
 288         if (pipe == NFC_HCI_INVALID_PIPE)
 289                 return -EADDRNOTAVAIL;
 290
 291         r = nfc_hci_close_pipe(hdev, pipe);
 292         if (r < 0)
 293                 return r;
 294
 295         if (pipe != NFC_HCI_LINK_MGMT_PIPE && pipe != NFC_HCI_ADMIN_PIPE) {
 296                 r = nfc_hci_delete_pipe(hdev, pipe);
 297                 if (r < 0)
 298                         return r;
 299         }
 300
 301         hdev->gate2pipe[gate] = NFC_HCI_INVALID_PIPE;
 302
 303         return 0;
 304 }
 305 EXPORT_SYMBOL(nfc_hci_disconnect_gate);
 306
 307 int nfc_hci_disconnect_all_gates(struct nfc_hci_dev *hdev)
 308 {
 309         int r;
 310
 311         pr_debug("\n");
 312
 313         r = nfc_hci_clear_all_pipes(hdev);
 314         if (r < 0)
 315                 return r;
 316
 317         nfc_hci_reset_pipes(hdev);
 318
 319         return 0;
 320 }
 321 EXPORT_SYMBOL(nfc_hci_disconnect_all_gates);
 322
 323 int nfc_hci_connect_gate(struct nfc_hci_dev *hdev, u8 dest_host, u8 dest_gate,
 324                          u8 pipe)
 325 {
 326         bool pipe_created = false;
 327         int r;
 328
 329         pr_debug("\n");
 330
 331         if (pipe == NFC_HCI_DO_NOT_CREATE_PIPE)
 332                 return 0;
 333
 334         if (hdev->gate2pipe[dest_gate] != NFC_HCI_INVALID_PIPE)
 335                 return -EADDRINUSE;
 336
 337         if (pipe != NFC_HCI_INVALID_PIPE)
 338                 goto open_pipe;
 339
 340         switch (dest_gate) {
 341         case NFC_HCI_LINK_MGMT_GATE:
 342                 pipe = NFC_HCI_LINK_MGMT_PIPE;
 343                 break;
 344         case NFC_HCI_ADMIN_GATE:
 345                 pipe = NFC_HCI_ADMIN_PIPE;
 346                 break;
 347         default:
 348                 pipe = nfc_hci_create_pipe(hdev, dest_host, dest_gate, &r);
 349                 if (pipe == NFC_HCI_INVALID_PIPE)
 350                         return r;
 351                 pipe_created = true;
 352                 break;
 353         }
 354
 355 open_pipe:
 356         r = nfc_hci_open_pipe(hdev, pipe);
 357         if (r < 0) {
 358                 if (pipe_created)
 359                         if (nfc_hci_delete_pipe(hdev, pipe) < 0) {
 360                                 /* TODO: Cannot clean by deleting pipe...
 361                                  * -> inconsistent state */
 362                         }
 363                 return r;
 364         }
 365
 366         hdev->pipes[pipe].gate = dest_gate;
 367         hdev->pipes[pipe].dest_host = dest_host;
 368         hdev->gate2pipe[dest_gate] = pipe;
 369
 370         return 0;
 371 }
 372 EXPORT_SYMBOL(nfc_hci_connect_gate);