net/nfc/digital_core.c

   1 /*
   2  * NFC Digital Protocol stack
   3  * Copyright (c) 2013, Intel Corporation.
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms and conditions of the GNU General Public License,
   7  * version 2, as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  */
  15
  16 #include <linux/module.h>
  17
  18 #include "digital.h"
  19
  20 #define DIGITAL_PROTO_NFCA_RF_TECH \
  21         (NFC_PROTO_JEWEL_MASK | NFC_PROTO_MIFARE_MASK)
  22
  23 struct digital_cmd {
  24         struct list_head queue;
  25
  26         u8 type;
  27         u8 pending;
  28
  29         u16 timeout;
  30         struct sk_buff *req;
  31         struct sk_buff *resp;
  32
  33         nfc_digital_cmd_complete_t cmd_cb;
  34         void *cb_context;
  35 };
  36
  37 struct sk_buff *digital_skb_alloc(struct nfc_digital_dev *ddev,
  38                                   unsigned int len)
  39 {
  40         struct sk_buff *skb;
  41
  42         skb = alloc_skb(len + ddev->tx_headroom + ddev->tx_tailroom,
  43                         GFP_KERNEL);
  44         if (skb)
  45                 skb_reserve(skb, ddev->tx_headroom);
  46
  47         return skb;
  48 }
  49
  50 static inline void digital_switch_rf(struct nfc_digital_dev *ddev, bool on)
  51 {
  52         ddev->ops->switch_rf(ddev, on);
  53 }
  54
  55 static inline void digital_abort_cmd(struct nfc_digital_dev *ddev)
  56 {
  57         ddev->ops->abort_cmd(ddev);
  58 }
  59
  60 static void digital_wq_cmd_complete(struct work_struct *work)
  61 {
  62         struct digital_cmd *cmd;
  63         struct nfc_digital_dev *ddev = container_of(work,
  64                                                     struct nfc_digital_dev,
  65                                                     cmd_complete_work);
  66
  67         mutex_lock(&ddev->cmd_lock);
  68
  69         cmd = list_first_entry_or_null(&ddev->cmd_queue, struct digital_cmd,
  70                                        queue);
  71         if (!cmd) {
  72                 mutex_unlock(&ddev->cmd_lock);
  73                 return;
  74         }
  75
  76         list_del(&cmd->queue);
  77
  78         mutex_unlock(&ddev->cmd_lock);
  79
  80         if (!IS_ERR(cmd->resp))
  81                 print_hex_dump_debug("DIGITAL RX: ", DUMP_PREFIX_NONE, 16, 1,
  82                                      cmd->resp->data, cmd->resp->len, false);
  83
  84         cmd->cmd_cb(ddev, cmd->cb_context, cmd->resp);
  85
  86         kfree(cmd);
  87
  88         schedule_work(&ddev->cmd_work);
  89 }
  90
  91 static void digital_send_cmd_complete(struct nfc_digital_dev *ddev,
  92                                       void *arg, struct sk_buff *resp)
  93 {
  94         struct digital_cmd *cmd = arg;
  95
  96         cmd->resp = resp;
  97
  98         schedule_work(&ddev->cmd_complete_work);
  99 }
 100
 101 static void digital_wq_cmd(struct work_struct *work)
 102 {
 103         int rc;
 104         struct digital_cmd *cmd;
 105         struct nfc_digital_dev *ddev = container_of(work,
 106                                                     struct nfc_digital_dev,
 107                                                     cmd_work);
 108
 109         mutex_lock(&ddev->cmd_lock);
 110
 111         cmd = list_first_entry_or_null(&ddev->cmd_queue, struct digital_cmd,
 112                                        queue);
 113         if (!cmd || cmd->pending) {
 114                 mutex_unlock(&ddev->cmd_lock);
 115                 return;
 116         }
 117
 118         mutex_unlock(&ddev->cmd_lock);
 119
 120         if (cmd->req)
 121                 print_hex_dump_debug("DIGITAL TX: ", DUMP_PREFIX_NONE, 16, 1,
 122                                      cmd->req->data, cmd->req->len, false);
 123
 124         switch (cmd->type) {
 125         case DIGITAL_CMD_IN_SEND:
 126                 rc = ddev->ops->in_send_cmd(ddev, cmd->req, cmd->timeout,
 127                                             digital_send_cmd_complete, cmd);
 128                 break;
 129         default:
 130                 PR_ERR("Unknown cmd type %d", cmd->type);
 131                 return;
 132         }
 133
 134         if (!rc)
 135                 return;
 136
 137         PR_ERR("in_send_command returned err %d", rc);
 138
 139         mutex_lock(&ddev->cmd_lock);
 140         list_del(&cmd->queue);
 141         mutex_unlock(&ddev->cmd_lock);
 142
 143         kfree_skb(cmd->req);
 144         kfree(cmd);
 145
 146         schedule_work(&ddev->cmd_work);
 147 }
 148
 149 int digital_send_cmd(struct nfc_digital_dev *ddev, u8 cmd_type,
 150                      struct sk_buff *skb, u16 timeout,
 151                      nfc_digital_cmd_complete_t cmd_cb, void *cb_context)
 152 {
 153         struct digital_cmd *cmd;
 154
 155         cmd = kzalloc(sizeof(struct digital_cmd), GFP_KERNEL);
 156         if (!cmd)
 157                 return -ENOMEM;
 158
 159         cmd->type = cmd_type;
 160         cmd->timeout = timeout;
 161         cmd->req = skb;
 162         cmd->cmd_cb = cmd_cb;
 163         cmd->cb_context = cb_context;
 164         INIT_LIST_HEAD(&cmd->queue);
 165
 166         mutex_lock(&ddev->cmd_lock);
 167         list_add_tail(&cmd->queue, &ddev->cmd_queue);
 168         mutex_unlock(&ddev->cmd_lock);
 169
 170         schedule_work(&ddev->cmd_work);
 171
 172         return 0;
 173 }
 174
 175 int digital_in_configure_hw(struct nfc_digital_dev *ddev, int type, int param)
 176 {
 177         int rc;
 178
 179         rc = ddev->ops->in_configure_hw(ddev, type, param);
 180         if (rc)
 181                 PR_ERR("in_configure_hw failed: %d", rc);
 182
 183         return rc;
 184 }
 185
 186 void digital_poll_next_tech(struct nfc_digital_dev *ddev)
 187 {
 188         digital_switch_rf(ddev, 0);
 189
 190         mutex_lock(&ddev->poll_lock);
 191
 192         if (!ddev->poll_tech_count) {
 193                 mutex_unlock(&ddev->poll_lock);
 194                 return;
 195         }
 196
 197         ddev->poll_tech_index = (ddev->poll_tech_index + 1) %
 198                                 ddev->poll_tech_count;
 199
 200         mutex_unlock(&ddev->poll_lock);
 201
 202         schedule_work(&ddev->poll_work);
 203 }
 204
 205 static void digital_wq_poll(struct work_struct *work)
 206 {
 207         int rc;
 208         struct digital_poll_tech *poll_tech;
 209         struct nfc_digital_dev *ddev = container_of(work,
 210                                                     struct nfc_digital_dev,
 211                                                     poll_work);
 212         mutex_lock(&ddev->poll_lock);
 213
 214         if (!ddev->poll_tech_count) {
 215                 mutex_unlock(&ddev->poll_lock);
 216                 return;
 217         }
 218
 219         poll_tech = &ddev->poll_techs[ddev->poll_tech_index];
 220
 221         mutex_unlock(&ddev->poll_lock);
 222
 223         rc = poll_tech->poll_func(ddev, poll_tech->rf_tech);
 224         if (rc)
 225                 digital_poll_next_tech(ddev);
 226 }
 227
 228 static void digital_add_poll_tech(struct nfc_digital_dev *ddev, u8 rf_tech,
 229                                   digital_poll_t poll_func)
 230 {
 231         struct digital_poll_tech *poll_tech;
 232
 233         if (ddev->poll_tech_count >= NFC_DIGITAL_POLL_MODE_COUNT_MAX)
 234                 return;
 235
 236         poll_tech = &ddev->poll_techs[ddev->poll_tech_count++];
 237
 238         poll_tech->rf_tech = rf_tech;
 239         poll_tech->poll_func = poll_func;
 240 }
 241
 242 /**
 243  * start_poll operation
 244  *
 245  * For every supported protocol, the corresponding polling function is added
 246  * to the table of polling technologies (ddev->poll_techs[]) using
 247  * digital_add_poll_tech().
 248  * When a polling function fails (by timeout or protocol error) the next one is
 249  * schedule by digital_poll_next_tech() on the poll workqueue (ddev->poll_work).
 250  */
 251 static int digital_start_poll(struct nfc_dev *nfc_dev, __u32 im_protocols,
 252                               __u32 tm_protocols)
 253 {
 254         struct nfc_digital_dev *ddev = nfc_get_drvdata(nfc_dev);
 255         u32 matching_im_protocols, matching_tm_protocols;
 256
 257         PR_DBG("protocols: im 0x%x, tm 0x%x, supported 0x%x", im_protocols,
 258                tm_protocols, ddev->protocols);
 259
 260         matching_im_protocols = ddev->protocols & im_protocols;
 261         matching_tm_protocols = ddev->protocols & tm_protocols;
 262
 263         if (!matching_im_protocols && !matching_tm_protocols) {
 264                 PR_ERR("No known protocol");
 265                 return -EINVAL;
 266         }
 267
 268         if (ddev->poll_tech_count) {
 269                 PR_ERR("Already polling");
 270                 return -EBUSY;
 271         }
 272
 273         if (ddev->curr_protocol) {
 274                 PR_ERR("A target is already active");
 275                 return -EBUSY;
 276         }
 277
 278         ddev->poll_tech_count = 0;
 279         ddev->poll_tech_index = 0;
 280
 281         if (matching_im_protocols & DIGITAL_PROTO_NFCA_RF_TECH)
 282                 digital_add_poll_tech(ddev, NFC_DIGITAL_RF_TECH_106A,
 283                                       digital_in_send_sens_req);
 284
 285         if (!ddev->poll_tech_count) {
 286                 PR_ERR("Unsupported protocols: im=0x%x, tm=0x%x",
 287                        matching_im_protocols, matching_tm_protocols);
 288                 return -EINVAL;
 289         }
 290
 291         schedule_work(&ddev->poll_work);
 292
 293         return 0;
 294 }
 295
 296 static void digital_stop_poll(struct nfc_dev *nfc_dev)
 297 {
 298         struct nfc_digital_dev *ddev = nfc_get_drvdata(nfc_dev);
 299
 300         mutex_lock(&ddev->poll_lock);
 301
 302         if (!ddev->poll_tech_count) {
 303                 PR_ERR("Polling operation was not running");
 304                 mutex_unlock(&ddev->poll_lock);
 305                 return;
 306         }
 307
 308         ddev->poll_tech_count = 0;
 309
 310         mutex_unlock(&ddev->poll_lock);
 311
 312         cancel_work_sync(&ddev->poll_work);
 313
 314         digital_abort_cmd(ddev);
 315 }
 316
 317 static int digital_dev_up(struct nfc_dev *nfc_dev)
 318 {
 319         struct nfc_digital_dev *ddev = nfc_get_drvdata(nfc_dev);
 320
 321         digital_switch_rf(ddev, 1);
 322
 323         return 0;
 324 }
 325
 326 static int digital_dev_down(struct nfc_dev *nfc_dev)
 327 {
 328         struct nfc_digital_dev *ddev = nfc_get_drvdata(nfc_dev);
 329
 330         digital_switch_rf(ddev, 0);
 331
 332         return 0;
 333 }
 334
 335 static int digital_dep_link_up(struct nfc_dev *nfc_dev,
 336                                struct nfc_target *target,
 337                                __u8 comm_mode, __u8 *gb, size_t gb_len)
 338 {
 339         return -EOPNOTSUPP;
 340 }
 341
 342 static int digital_dep_link_down(struct nfc_dev *nfc_dev)
 343 {
 344         return -EOPNOTSUPP;
 345 }
 346
 347 static int digital_activate_target(struct nfc_dev *nfc_dev,
 348                                    struct nfc_target *target, __u32 protocol)
 349 {
 350         return 0;
 351 }
 352
 353 static void digital_deactivate_target(struct nfc_dev *nfc_dev,
 354                                       struct nfc_target *target)
 355 {
 356         struct nfc_digital_dev *ddev = nfc_get_drvdata(nfc_dev);
 357
 358         ddev->curr_protocol = 0;
 359 }
 360
 361 static int digital_tg_send(struct nfc_dev *dev, struct sk_buff *skb)
 362 {
 363         return -EOPNOTSUPP;
 364 }
 365
 366 static int digital_in_send(struct nfc_dev *nfc_dev, struct nfc_target *target,
 367                            struct sk_buff *skb, data_exchange_cb_t cb,
 368                            void *cb_context)
 369 {
 370         return -EOPNOTSUPP;
 371 }
 372
 373 static struct nfc_ops digital_nfc_ops = {
 374         .dev_up = digital_dev_up,
 375         .dev_down = digital_dev_down,
 376         .start_poll = digital_start_poll,
 377         .stop_poll = digital_stop_poll,
 378         .dep_link_up = digital_dep_link_up,
 379         .dep_link_down = digital_dep_link_down,
 380         .activate_target = digital_activate_target,
 381         .deactivate_target = digital_deactivate_target,
 382         .tm_send = digital_tg_send,
 383         .im_transceive = digital_in_send,
 384 };
 385
 386 struct nfc_digital_dev *nfc_digital_allocate_device(struct nfc_digital_ops *ops,
 387                                             __u32 supported_protocols,
 388                                             __u32 driver_capabilities,
 389                                             int tx_headroom, int tx_tailroom)
 390 {
 391         struct nfc_digital_dev *ddev;
 392
 393         if (!ops->in_configure_hw || !ops->in_send_cmd || !ops->tg_listen ||
 394             !ops->tg_configure_hw || !ops->tg_send_cmd || !ops->abort_cmd ||
 395             !ops->switch_rf)
 396                 return NULL;
 397
 398         ddev = kzalloc(sizeof(struct nfc_digital_dev), GFP_KERNEL);
 399         if (!ddev) {
 400                 PR_ERR("kzalloc failed");
 401                 return NULL;
 402         }
 403
 404         ddev->driver_capabilities = driver_capabilities;
 405         ddev->ops = ops;
 406
 407         mutex_init(&ddev->cmd_lock);
 408         INIT_LIST_HEAD(&ddev->cmd_queue);
 409
 410         INIT_WORK(&ddev->cmd_work, digital_wq_cmd);
 411         INIT_WORK(&ddev->cmd_complete_work, digital_wq_cmd_complete);
 412
 413         mutex_init(&ddev->poll_lock);
 414         INIT_WORK(&ddev->poll_work, digital_wq_poll);
 415
 416         if (supported_protocols & NFC_PROTO_JEWEL_MASK)
 417                 ddev->protocols |= NFC_PROTO_JEWEL_MASK;
 418         if (supported_protocols & NFC_PROTO_MIFARE_MASK)
 419                 ddev->protocols |= NFC_PROTO_MIFARE_MASK;
 420
 421         ddev->tx_headroom = tx_headroom + DIGITAL_MAX_HEADER_LEN;
 422         ddev->tx_tailroom = tx_tailroom + DIGITAL_CRC_LEN;
 423
 424         ddev->nfc_dev = nfc_allocate_device(&digital_nfc_ops, ddev->protocols,
 425                                             ddev->tx_headroom,
 426                                             ddev->tx_tailroom);
 427         if (!ddev->nfc_dev) {
 428                 PR_ERR("nfc_allocate_device failed");
 429                 goto free_dev;
 430         }
 431
 432         nfc_set_drvdata(ddev->nfc_dev, ddev);
 433
 434         return ddev;
 435
 436 free_dev:
 437         kfree(ddev);
 438
 439         return NULL;
 440 }
 441 EXPORT_SYMBOL(nfc_digital_allocate_device);
 442
 443 void nfc_digital_free_device(struct nfc_digital_dev *ddev)
 444 {
 445         nfc_free_device(ddev->nfc_dev);
 446         kfree(ddev);
 447 }
 448 EXPORT_SYMBOL(nfc_digital_free_device);
 449
 450 int nfc_digital_register_device(struct nfc_digital_dev *ddev)
 451 {
 452         return nfc_register_device(ddev->nfc_dev);
 453 }
 454 EXPORT_SYMBOL(nfc_digital_register_device);
 455
 456 void nfc_digital_unregister_device(struct nfc_digital_dev *ddev)
 457 {
 458         struct digital_cmd *cmd, *n;
 459
 460         nfc_unregister_device(ddev->nfc_dev);
 461
 462         mutex_lock(&ddev->poll_lock);
 463         ddev->poll_tech_count = 0;
 464         mutex_unlock(&ddev->poll_lock);
 465
 466         cancel_work_sync(&ddev->poll_work);
 467         cancel_work_sync(&ddev->cmd_work);
 468         cancel_work_sync(&ddev->cmd_complete_work);
 469
 470         list_for_each_entry_safe(cmd, n, &ddev->cmd_queue, queue) {
 471                 list_del(&cmd->queue);
 472                 kfree(cmd);
 473         }
 474 }
 475 EXPORT_SYMBOL(nfc_digital_unregister_device);
 476
 477 MODULE_LICENSE("GPL");