drivers/net/wireless/p54/main.c

   1 /*
   2  * mac80211 glue code for mac80211 Prism54 drivers
   3  *
   4  * Copyright (c) 2006, Michael Wu <flamingice@sourmilk.net>
   5  * Copyright (c) 2007-2009, Christian Lamparter <chunkeey@web.de>
   6  * Copyright 2008, Johannes Berg <johannes@sipsolutions.net>
   7  *
   8  * Based on:
   9  * - the islsm (softmac prism54) driver, which is:
  10  *   Copyright 2004-2006 Jean-Baptiste Note <jbnote@gmail.com>, et al.
  11  * - stlc45xx driver
  12  *   Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies).
  13  *
  14  * This program is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License version 2 as
  16  * published by the Free Software Foundation.
  17  */
  18
  19 #include <linux/init.h>
  20 #include <linux/firmware.h>
  21 #include <linux/etherdevice.h>
  22
  23 #include <net/mac80211.h>
  24
  25 #include "p54.h"
  26 #include "lmac.h"
  27
  28 static int modparam_nohwcrypt;
  29 module_param_named(nohwcrypt, modparam_nohwcrypt, bool, S_IRUGO);
  30 MODULE_PARM_DESC(nohwcrypt, "Disable hardware encryption.");
  31 MODULE_AUTHOR("Michael Wu <flamingice@sourmilk.net>");
  32 MODULE_DESCRIPTION("Softmac Prism54 common code");
  33 MODULE_LICENSE("GPL");
  34 MODULE_ALIAS("prism54common");
  35
  36 static void p54_sta_notify(struct ieee80211_hw *dev, struct ieee80211_vif *vif,
  37                               enum sta_notify_cmd notify_cmd,
  38                               struct ieee80211_sta *sta)
  39 {
  40         struct p54_common *priv = dev->priv;
  41         switch (notify_cmd) {
  42         case STA_NOTIFY_ADD:
  43         case STA_NOTIFY_REMOVE:
  44                 /*
  45                  * Notify the firmware that we don't want or we don't
  46                  * need to buffer frames for this station anymore.
  47                  */
  48
  49                 p54_sta_unlock(priv, sta->addr);
  50                 break;
  51         case STA_NOTIFY_AWAKE:
  52                 /* update the firmware's filter table */
  53                 p54_sta_unlock(priv, sta->addr);
  54                 break;
  55         default:
  56                 break;
  57         }
  58 }
  59
  60 static int p54_set_tim(struct ieee80211_hw *dev, struct ieee80211_sta *sta,
  61                         bool set)
  62 {
  63         struct p54_common *priv = dev->priv;
  64
  65         return p54_update_beacon_tim(priv, sta->aid, set);
  66 }
  67
  68 u8 *p54_find_ie(struct sk_buff *skb, u8 ie)
  69 {
  70         struct ieee80211_mgmt *mgmt = (void *)skb->data;
  71         u8 *pos, *end;
  72
  73         if (skb->len <= sizeof(mgmt))
  74                 return NULL;
  75
  76         pos = (u8 *)mgmt->u.beacon.variable;
  77         end = skb->data + skb->len;
  78         while (pos < end) {
  79                 if (pos + 2 + pos[1] > end)
  80                         return NULL;
  81
  82                 if (pos[0] == ie)
  83                         return pos;
  84
  85                 pos += 2 + pos[1];
  86         }
  87         return NULL;
  88 }
  89
  90 static int p54_beacon_format_ie_tim(struct sk_buff *skb)
  91 {
  92         /*
  93          * the good excuse for this mess is ... the firmware.
  94          * The dummy TIM MUST be at the end of the beacon frame,
  95          * because it'll be overwritten!
  96          */
  97         u8 *tim;
  98         u8 dtim_len;
  99         u8 dtim_period;
 100         u8 *next;
 101
 102         tim = p54_find_ie(skb, WLAN_EID_TIM);
 103         if (!tim)
 104                 return 0;
 105
 106         dtim_len = tim[1];
 107         dtim_period = tim[3];
 108         next = tim + 2 + dtim_len;
 109
 110         if (dtim_len < 3)
 111                 return -EINVAL;
 112
 113         memmove(tim, next, skb_tail_pointer(skb) - next);
 114         tim = skb_tail_pointer(skb) - (dtim_len + 2);
 115
 116         /* add the dummy at the end */
 117         tim[0] = WLAN_EID_TIM;
 118         tim[1] = 3;
 119         tim[2] = 0;
 120         tim[3] = dtim_period;
 121         tim[4] = 0;
 122
 123         if (dtim_len > 3)
 124                 skb_trim(skb, skb->len - (dtim_len - 3));
 125
 126         return 0;
 127 }
 128
 129 static int p54_beacon_update(struct p54_common *priv,
 130                         struct ieee80211_vif *vif)
 131 {
 132         struct sk_buff *beacon;
 133         int ret;
 134
 135         beacon = ieee80211_beacon_get(priv->hw, vif);
 136         if (!beacon)
 137                 return -ENOMEM;
 138         ret = p54_beacon_format_ie_tim(beacon);
 139         if (ret)
 140                 return ret;
 141
 142         /*
 143          * During operation, the firmware takes care of beaconing.
 144          * The driver only needs to upload a new beacon template, once
 145          * the template was changed by the stack or userspace.
 146          *
 147          * LMAC API 3.2.2 also specifies that the driver does not need
 148          * to cancel the old beacon template by hand, instead the firmware
 149          * will release the previous one through the feedback mechanism.
 150          */
 151         WARN_ON(p54_tx_80211(priv->hw, beacon));
 152         priv->tsf_high32 = 0;
 153         priv->tsf_low32 = 0;
 154
 155         return 0;
 156 }
 157
 158 static int p54_start(struct ieee80211_hw *dev)
 159 {
 160         struct p54_common *priv = dev->priv;
 161         int err;
 162
 163         mutex_lock(&priv->conf_mutex);
 164         err = priv->open(dev);
 165         if (err)
 166                 goto out;
 167         P54_SET_QUEUE(priv->qos_params[0], 0x0002, 0x0003, 0x0007, 47);
 168         P54_SET_QUEUE(priv->qos_params[1], 0x0002, 0x0007, 0x000f, 94);
 169         P54_SET_QUEUE(priv->qos_params[2], 0x0003, 0x000f, 0x03ff, 0);
 170         P54_SET_QUEUE(priv->qos_params[3], 0x0007, 0x000f, 0x03ff, 0);
 171         err = p54_set_edcf(priv);
 172         if (err)
 173                 goto out;
 174
 175         memset(priv->bssid, ~0, ETH_ALEN);
 176         priv->mode = NL80211_IFTYPE_MONITOR;
 177         err = p54_setup_mac(priv);
 178         if (err) {
 179                 priv->mode = NL80211_IFTYPE_UNSPECIFIED;
 180                 goto out;
 181         }
 182
 183         ieee80211_queue_delayed_work(dev, &priv->work, 0);
 184
 185         priv->softled_state = 0;
 186         err = p54_set_leds(priv);
 187
 188 out:
 189         mutex_unlock(&priv->conf_mutex);
 190         return err;
 191 }
 192
 193 static void p54_stop(struct ieee80211_hw *dev)
 194 {
 195         struct p54_common *priv = dev->priv;
 196         int i;
 197
 198         mutex_lock(&priv->conf_mutex);
 199         priv->mode = NL80211_IFTYPE_UNSPECIFIED;
 200         priv->softled_state = 0;
 201         p54_set_leds(priv);
 202
 203         cancel_delayed_work_sync(&priv->work);
 204
 205         priv->stop(dev);
 206         skb_queue_purge(&priv->tx_pending);
 207         skb_queue_purge(&priv->tx_queue);
 208         for (i = 0; i < P54_QUEUE_NUM; i++) {
 209                 priv->tx_stats[i].count = 0;
 210                 priv->tx_stats[i].len = 0;
 211         }
 212
 213         priv->beacon_req_id = cpu_to_le32(0);
 214         priv->tsf_high32 = priv->tsf_low32 = 0;
 215         mutex_unlock(&priv->conf_mutex);
 216 }
 217
 218 static int p54_add_interface(struct ieee80211_hw *dev,
 219                              struct ieee80211_if_init_conf *conf)
 220 {
 221         struct p54_common *priv = dev->priv;
 222
 223         mutex_lock(&priv->conf_mutex);
 224         if (priv->mode != NL80211_IFTYPE_MONITOR) {
 225                 mutex_unlock(&priv->conf_mutex);
 226                 return -EOPNOTSUPP;
 227         }
 228
 229         priv->vif = conf->vif;
 230
 231         switch (conf->type) {
 232         case NL80211_IFTYPE_STATION:
 233         case NL80211_IFTYPE_ADHOC:
 234         case NL80211_IFTYPE_AP:
 235         case NL80211_IFTYPE_MESH_POINT:
 236                 priv->mode = conf->type;
 237                 break;
 238         default:
 239                 mutex_unlock(&priv->conf_mutex);
 240                 return -EOPNOTSUPP;
 241         }
 242
 243         memcpy(priv->mac_addr, conf->mac_addr, ETH_ALEN);
 244         p54_setup_mac(priv);
 245         mutex_unlock(&priv->conf_mutex);
 246         return 0;
 247 }
 248
 249 static void p54_remove_interface(struct ieee80211_hw *dev,
 250                                  struct ieee80211_if_init_conf *conf)
 251 {
 252         struct p54_common *priv = dev->priv;
 253
 254         mutex_lock(&priv->conf_mutex);
 255         priv->vif = NULL;
 256
 257         /*
 258          * LMAC API 3.2.2 states that any active beacon template must be
 259          * canceled by the driver before attempting a mode transition.
 260          */
 261         if (le32_to_cpu(priv->beacon_req_id) != 0) {
 262                 p54_tx_cancel(priv, priv->beacon_req_id);
 263                 wait_for_completion_interruptible_timeout(&priv->beacon_comp, HZ);
 264         }
 265         priv->mode = NL80211_IFTYPE_MONITOR;
 266         memset(priv->mac_addr, 0, ETH_ALEN);
 267         memset(priv->bssid, 0, ETH_ALEN);
 268         p54_setup_mac(priv);
 269         mutex_unlock(&priv->conf_mutex);
 270 }
 271
 272 static int p54_config(struct ieee80211_hw *dev, u32 changed)
 273 {
 274         int ret = 0;
 275         struct p54_common *priv = dev->priv;
 276         struct ieee80211_conf *conf = &dev->conf;
 277
 278         mutex_lock(&priv->conf_mutex);
 279         if (changed & IEEE80211_CONF_CHANGE_POWER)
 280                 priv->output_power = conf->power_level << 2;
 281         if (changed & IEEE80211_CONF_CHANGE_CHANNEL) {
 282                 ret = p54_scan(priv, P54_SCAN_EXIT, 0);
 283                 if (ret)
 284                         goto out;
 285         }
 286         if (changed & IEEE80211_CONF_CHANGE_PS) {
 287                 ret = p54_set_ps(priv);
 288                 if (ret)
 289                         goto out;
 290         }
 291
 292 out:
 293         mutex_unlock(&priv->conf_mutex);
 294         return ret;
 295 }
 296
 297 static void p54_configure_filter(struct ieee80211_hw *dev,
 298                                  unsigned int changed_flags,
 299                                  unsigned int *total_flags,
 300                                  int mc_count, struct dev_mc_list *mclist)
 301 {
 302         struct p54_common *priv = dev->priv;
 303
 304         *total_flags &= FIF_PROMISC_IN_BSS |
 305                         FIF_OTHER_BSS;
 306
 307         priv->filter_flags = *total_flags;
 308
 309         if (changed_flags & (FIF_PROMISC_IN_BSS | FIF_OTHER_BSS))
 310                 p54_setup_mac(priv);
 311 }
 312
 313 static int p54_conf_tx(struct ieee80211_hw *dev, u16 queue,
 314                        const struct ieee80211_tx_queue_params *params)
 315 {
 316         struct p54_common *priv = dev->priv;
 317         int ret;
 318
 319         mutex_lock(&priv->conf_mutex);
 320         if ((params) && !(queue > 4)) {
 321                 P54_SET_QUEUE(priv->qos_params[queue], params->aifs,
 322                         params->cw_min, params->cw_max, params->txop);
 323                 ret = p54_set_edcf(priv);
 324         } else
 325                 ret = -EINVAL;
 326         mutex_unlock(&priv->conf_mutex);
 327         return ret;
 328 }
 329
 330 static void p54_work(struct work_struct *work)
 331 {
 332         struct p54_common *priv = container_of(work, struct p54_common,
 333                                                work.work);
 334
 335         if (unlikely(priv->mode == NL80211_IFTYPE_UNSPECIFIED))
 336                 return ;
 337
 338         /*
 339          * TODO: walk through tx_queue and do the following tasks
 340          *      1. initiate bursts.
 341          *      2. cancel stuck frames / reset the device if necessary.
 342          */
 343
 344         p54_fetch_statistics(priv);
 345 }
 346
 347 static int p54_get_stats(struct ieee80211_hw *dev,
 348                          struct ieee80211_low_level_stats *stats)
 349 {
 350         struct p54_common *priv = dev->priv;
 351
 352         memcpy(stats, &priv->stats, sizeof(*stats));
 353         return 0;
 354 }
 355
 356 static int p54_get_tx_stats(struct ieee80211_hw *dev,
 357                             struct ieee80211_tx_queue_stats *stats)
 358 {
 359         struct p54_common *priv = dev->priv;
 360
 361         memcpy(stats, &priv->tx_stats[P54_QUEUE_DATA],
 362                sizeof(stats[0]) * dev->queues);
 363         return 0;
 364 }
 365
 366 static void p54_bss_info_changed(struct ieee80211_hw *dev,
 367                                  struct ieee80211_vif *vif,
 368                                  struct ieee80211_bss_conf *info,
 369                                  u32 changed)
 370 {
 371         struct p54_common *priv = dev->priv;
 372
 373         mutex_lock(&priv->conf_mutex);
 374         if (changed & BSS_CHANGED_BSSID) {
 375                 memcpy(priv->bssid, info->bssid, ETH_ALEN);
 376                 p54_setup_mac(priv);
 377         }
 378
 379         if (changed & BSS_CHANGED_BEACON) {
 380                 p54_scan(priv, P54_SCAN_EXIT, 0);
 381                 p54_setup_mac(priv);
 382                 p54_beacon_update(priv, vif);
 383                 p54_set_edcf(priv);
 384         }
 385
 386         if (changed & (BSS_CHANGED_ERP_SLOT | BSS_CHANGED_BEACON)) {
 387                 priv->use_short_slot = info->use_short_slot;
 388                 p54_set_edcf(priv);
 389         }
 390         if (changed & BSS_CHANGED_BASIC_RATES) {
 391                 if (dev->conf.channel->band == IEEE80211_BAND_5GHZ)
 392                         priv->basic_rate_mask = (info->basic_rates << 4);
 393                 else
 394                         priv->basic_rate_mask = info->basic_rates;
 395                 p54_setup_mac(priv);
 396                 if (priv->fw_var >= 0x500)
 397                         p54_scan(priv, P54_SCAN_EXIT, 0);
 398         }
 399         if (changed & BSS_CHANGED_ASSOC) {
 400                 if (info->assoc) {
 401                         priv->aid = info->aid;
 402                         priv->wakeup_timer = info->beacon_int *
 403                                              info->dtim_period * 5;
 404                         p54_setup_mac(priv);
 405                 } else {
 406                         priv->wakeup_timer = 500;
 407                         priv->aid = 0;
 408                 }
 409         }
 410
 411         mutex_unlock(&priv->conf_mutex);
 412 }
 413
 414 static int p54_set_key(struct ieee80211_hw *dev, enum set_key_cmd cmd,
 415                        struct ieee80211_vif *vif, struct ieee80211_sta *sta,
 416                        struct ieee80211_key_conf *key)
 417 {
 418         struct p54_common *priv = dev->priv;
 419         int slot, ret = 0;
 420         u8 algo = 0;
 421         u8 *addr = NULL;
 422
 423         if (modparam_nohwcrypt)
 424                 return -EOPNOTSUPP;
 425
 426         mutex_lock(&priv->conf_mutex);
 427         if (cmd == SET_KEY) {
 428                 switch (key->alg) {
 429                 case ALG_TKIP:
 430                         if (!(priv->privacy_caps & (BR_DESC_PRIV_CAP_MICHAEL |
 431                               BR_DESC_PRIV_CAP_TKIP))) {
 432                                 ret = -EOPNOTSUPP;
 433                                 goto out_unlock;
 434                         }
 435                         key->flags |= IEEE80211_KEY_FLAG_GENERATE_IV;
 436                         algo = P54_CRYPTO_TKIPMICHAEL;
 437                         break;
 438                 case ALG_WEP:
 439                         if (!(priv->privacy_caps & BR_DESC_PRIV_CAP_WEP)) {
 440                                 ret = -EOPNOTSUPP;
 441                                 goto out_unlock;
 442                         }
 443                         key->flags |= IEEE80211_KEY_FLAG_GENERATE_IV;
 444                         algo = P54_CRYPTO_WEP;
 445                         break;
 446                 case ALG_CCMP:
 447                         if (!(priv->privacy_caps & BR_DESC_PRIV_CAP_AESCCMP)) {
 448                                 ret = -EOPNOTSUPP;
 449                                 goto out_unlock;
 450                         }
 451                         key->flags |= IEEE80211_KEY_FLAG_GENERATE_IV;
 452                         algo = P54_CRYPTO_AESCCMP;
 453                         break;
 454                 default:
 455                         ret = -EOPNOTSUPP;
 456                         goto out_unlock;
 457                 }
 458                 slot = bitmap_find_free_region(priv->used_rxkeys,
 459                                                priv->rx_keycache_size, 0);
 460
 461                 if (slot < 0) {
 462                         /*
 463                          * The device supports the choosen algorithm, but the
 464                          * firmware does not provide enough key slots to store
 465                          * all of them.
 466                          * But encryption offload for outgoing frames is always
 467                          * possible, so we just pretend that the upload was
 468                          * successful and do the decryption in software.
 469                          */
 470
 471                         /* mark the key as invalid. */
 472                         key->hw_key_idx = 0xff;
 473                         goto out_unlock;
 474                 }
 475         } else {
 476                 slot = key->hw_key_idx;
 477
 478                 if (slot == 0xff) {
 479                         /* This key was not uploaded into the rx key cache. */
 480
 481                         goto out_unlock;
 482                 }
 483
 484                 bitmap_release_region(priv->used_rxkeys, slot, 0);
 485                 algo = 0;
 486         }
 487
 488         if (sta)
 489                 addr = sta->addr;
 490
 491         ret = p54_upload_key(priv, algo, slot, key->keyidx,
 492                              key->keylen, addr, key->key);
 493         if (ret) {
 494                 bitmap_release_region(priv->used_rxkeys, slot, 0);
 495                 ret = -EOPNOTSUPP;
 496                 goto out_unlock;
 497         }
 498
 499         key->hw_key_idx = slot;
 500
 501 out_unlock:
 502         mutex_unlock(&priv->conf_mutex);
 503         return ret;
 504 }
 505
 506 static const struct ieee80211_ops p54_ops = {
 507         .tx                     = p54_tx_80211,
 508         .start                  = p54_start,
 509         .stop                   = p54_stop,
 510         .add_interface          = p54_add_interface,
 511         .remove_interface       = p54_remove_interface,
 512         .set_tim                = p54_set_tim,
 513         .sta_notify             = p54_sta_notify,
 514         .set_key                = p54_set_key,
 515         .config                 = p54_config,
 516         .bss_info_changed       = p54_bss_info_changed,
 517         .configure_filter       = p54_configure_filter,
 518         .conf_tx                = p54_conf_tx,
 519         .get_stats              = p54_get_stats,
 520         .get_tx_stats           = p54_get_tx_stats
 521 };
 522
 523 struct ieee80211_hw *p54_init_common(size_t priv_data_len)
 524 {
 525         struct ieee80211_hw *dev;
 526         struct p54_common *priv;
 527
 528         dev = ieee80211_alloc_hw(priv_data_len, &p54_ops);
 529         if (!dev)
 530                 return NULL;
 531
 532         priv = dev->priv;
 533         priv->hw = dev;
 534         priv->mode = NL80211_IFTYPE_UNSPECIFIED;
 535         priv->basic_rate_mask = 0x15f;
 536         spin_lock_init(&priv->tx_stats_lock);
 537         skb_queue_head_init(&priv->tx_queue);
 538         skb_queue_head_init(&priv->tx_pending);
 539         dev->flags = IEEE80211_HW_RX_INCLUDES_FCS |
 540                      IEEE80211_HW_SIGNAL_DBM |
 541                      IEEE80211_HW_SUPPORTS_PS |
 542                      IEEE80211_HW_PS_NULLFUNC_STACK |
 543                      IEEE80211_HW_BEACON_FILTER |
 544                      IEEE80211_HW_NOISE_DBM;
 545
 546         dev->wiphy->interface_modes = BIT(NL80211_IFTYPE_STATION) |
 547                                       BIT(NL80211_IFTYPE_ADHOC) |
 548                                       BIT(NL80211_IFTYPE_AP) |
 549                                       BIT(NL80211_IFTYPE_MESH_POINT);
 550
 551         dev->channel_change_time = 1000;        /* TODO: find actual value */
 552         priv->beacon_req_id = cpu_to_le32(0);
 553         priv->tx_stats[P54_QUEUE_BEACON].limit = 1;
 554         priv->tx_stats[P54_QUEUE_FWSCAN].limit = 1;
 555         priv->tx_stats[P54_QUEUE_MGMT].limit = 3;
 556         priv->tx_stats[P54_QUEUE_CAB].limit = 3;
 557         priv->tx_stats[P54_QUEUE_DATA].limit = 5;
 558         dev->queues = 1;
 559         priv->noise = -94;
 560         /*
 561          * We support at most 8 tries no matter which rate they're at,
 562          * we cannot support max_rates * max_rate_tries as we set it
 563          * here, but setting it correctly to 4/2 or so would limit us
 564          * artificially if the RC algorithm wants just two rates, so
 565          * let's say 4/7, we'll redistribute it at TX time, see the
 566          * comments there.
 567          */
 568         dev->max_rates = 4;
 569         dev->max_rate_tries = 7;
 570         dev->extra_tx_headroom = sizeof(struct p54_hdr) + 4 +
 571                                  sizeof(struct p54_tx_data);
 572
 573         mutex_init(&priv->conf_mutex);
 574         mutex_init(&priv->eeprom_mutex);
 575         init_completion(&priv->eeprom_comp);
 576         init_completion(&priv->beacon_comp);
 577         INIT_DELAYED_WORK(&priv->work, p54_work);
 578
 579         return dev;
 580 }
 581 EXPORT_SYMBOL_GPL(p54_init_common);
 582
 583 int p54_register_common(struct ieee80211_hw *dev, struct device *pdev)
 584 {
 585         struct p54_common *priv = dev->priv;
 586         int err;
 587
 588         err = ieee80211_register_hw(dev);
 589         if (err) {
 590                 dev_err(pdev, "Cannot register device (%d).\n", err);
 591                 return err;
 592         }
 593
 594 #ifdef CONFIG_P54_LEDS
 595         err = p54_init_leds(priv);
 596         if (err)
 597                 return err;
 598 #endif /* CONFIG_P54_LEDS */
 599
 600         dev_info(pdev, "is registered as '%s'\n", wiphy_name(dev->wiphy));
 601         return 0;
 602 }
 603 EXPORT_SYMBOL_GPL(p54_register_common);
 604
 605 void p54_free_common(struct ieee80211_hw *dev)
 606 {
 607         struct p54_common *priv = dev->priv;
 608         unsigned int i;
 609
 610         for (i = 0; i < IEEE80211_NUM_BANDS; i++)
 611                 kfree(priv->band_table[i]);
 612
 613         kfree(priv->iq_autocal);
 614         kfree(priv->output_limit);
 615         kfree(priv->curve_data);
 616         kfree(priv->used_rxkeys);
 617         priv->iq_autocal = NULL;
 618         priv->output_limit = NULL;
 619         priv->curve_data = NULL;
 620         priv->used_rxkeys = NULL;
 621         ieee80211_free_hw(dev);
 622 }
 623 EXPORT_SYMBOL_GPL(p54_free_common);
 624
 625 void p54_unregister_common(struct ieee80211_hw *dev)
 626 {
 627         struct p54_common *priv = dev->priv;
 628
 629 #ifdef CONFIG_P54_LEDS
 630         p54_unregister_leds(priv);
 631 #endif /* CONFIG_P54_LEDS */
 632
 633         ieee80211_unregister_hw(dev);
 634         mutex_destroy(&priv->conf_mutex);
 635         mutex_destroy(&priv->eeprom_mutex);
 636 }
 637 EXPORT_SYMBOL_GPL(p54_unregister_common);