carlfw/src/wlan.c

   1 /*
   2  * carl9170 firmware - used by the ar9170 wireless device
   3  *
   4  * Interface to the WLAN part of the chip
   5  *
   6  * Copyright (c) 2000-2005 ZyDAS Technology Corporation
   7  * Copyright (c) 2007-2009 Atheros Communications, Inc.
   8  * Copyright    2009    Johannes Berg <johannes@sipsolutions.net>
   9  * Copyright 2009, 2010 Christian Lamparter <chunkeey@googlemail.com>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License along
  22  * with this program; if not, write to the Free Software Foundation, Inc.,
  23  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  24  */
  25
  26 #include "carl9170.h"
  27 #include "shared/phy.h"
  28 #include "hostif.h"
  29 #include "timer.h"
  30 #include "wl.h"
  31 #include "printf.h"
  32 #include "rf.h"
  33 #include "linux/ieee80211.h"
  34
  35 static void wlan_txunstuck(unsigned int queue)
  36 {
  37         set_wlan_txq_dma_addr(queue, ((uint32_t) fw.wlan.tx_queue[queue].head) | 1);
  38         wlan_trigger(BIT(queue));
  39 }
  40
  41 static void wlan_txupdate(unsigned int queue)
  42 {
  43         set_wlan_txq_dma_addr(queue, ((uint32_t) fw.wlan.tx_queue[queue].head));
  44         wlan_trigger(BIT(queue));
  45 }
  46
  47 #ifdef CONFIG_CARL9170FW_DEBUG
  48 static void wlan_dump_queue(unsigned int qidx)
  49 {
  50
  51         struct dma_desc *desc;
  52         struct carl9170_tx_superframe *super;
  53         int entries = 0;
  54
  55         __for_each_desc(desc, &fw.wlan.tx_queue[qidx]) {
  56                 super = get_super(desc);
  57                 DBG("%d: %p s:%x c:%x tl:%x ds:%x n:%p l:%p ", entries, desc,
  58                     desc->status, desc->ctrl, desc->totalLen,
  59                     desc->dataSize, desc->nextAddr, desc->lastAddr);
  60
  61                 DBG("c:%x tr:%d ri:%d l:%x m:%x p:%x fc:%x",
  62                     super->s.cookie, super->s.cnt, super->s.rix,
  63                     super->f.hdr.length, super->f.hdr.mac.set,
  64                     (unsigned int) le32_to_cpu(super->f.hdr.phy.set),
  65                     super->f.data.i3e.frame_control);
  66
  67                 entries++;
  68         }
  69
  70         desc = get_wlan_txq_addr(qidx);
  71
  72         DBG("Queue: %d: te:%d td:%d h:%p c:%p t:%p",
  73             qidx, entries, queue_len(&fw.wlan.tx_queue[qidx]),
  74             fw.wlan.tx_queue[qidx].head,
  75             desc, fw.wlan.tx_queue[qidx].terminator);
  76
  77         DBG("HW: t:%x s:%x ac:%x c:%x",
  78             (unsigned int) get(AR9170_MAC_REG_DMA_TRIGGER),
  79             (unsigned int) get(AR9170_MAC_REG_DMA_STATUS),
  80             (unsigned int) get(AR9170_MAC_REG_AMPDU_COUNT),
  81             (unsigned int) get(AR9170_MAC_REG_DMA_TXQX_ADDR_CURR));
  82 }
  83 #endif /* CONFIG_CARL9170FW_DEBUG */
  84
  85 static void wlan_send_buffered_tx_status(void)
  86 {
  87         unsigned int len;
  88
  89         while (fw.wlan.tx_status_pending) {
  90                 len = min((unsigned int)fw.wlan.tx_status_pending,
  91                           CARL9170_RSP_TX_STATUS_NUM);
  92                 len = min(len, CARL9170_TX_STATUS_NUM - fw.wlan.tx_status_head_idx);
  93
  94                 /*
  95                  * rather than memcpy each individual request into a large buffer,
  96                  * we _splice_ them all together.
  97                  *
  98                  * The only downside is however that we have to be careful around
  99                  * the edges of the tx_status_cache.
 100                  *
 101                  * Note:
 102                  * Each tx_status is about 2 bytes. However every command package
 103                  * must have a size which is a multiple of 4.
 104                  */
 105
 106                 send_cmd_to_host((len * sizeof(struct carl9170_tx_status) + 3) & ~3,
 107                                  CARL9170_RSP_TXCOMP, len, (void *)
 108                                  &fw.wlan.tx_status_cache[fw.wlan.tx_status_head_idx]);
 109
 110                 fw.wlan.tx_status_pending -= len;
 111                 fw.wlan.tx_status_head_idx += len;
 112                 fw.wlan.tx_status_head_idx %= CARL9170_TX_STATUS_NUM;
 113         }
 114 }
 115
 116 static struct carl9170_tx_status *wlan_get_tx_status_buffer(void)
 117 {
 118         struct carl9170_tx_status *tmp;
 119
 120         tmp = &fw.wlan.tx_status_cache[fw.wlan.tx_status_tail_idx++];
 121         fw.wlan.tx_status_tail_idx %= CARL9170_TX_STATUS_NUM;
 122
 123         if (fw.wlan.tx_status_pending == CARL9170_TX_STATUS_NUM)
 124                 wlan_send_buffered_tx_status();
 125
 126         fw.wlan.tx_status_pending++;
 127
 128         return tmp;
 129 }
 130
 131 /* generate _aggregated_ tx_status for the host */
 132 static void wlan_tx_complete(struct carl9170_tx_superframe *super,
 133                              bool txs)
 134 {
 135         struct carl9170_tx_status *status;
 136
 137         status = wlan_get_tx_status_buffer();
 138
 139         /*
 140          * The *unique* cookie and AC_ID is used by the driver for
 141          * frame lookup.
 142          */
 143         status->cookie = super->s.cookie;
 144         status->queue = super->s.queue;
 145
 146         /*
 147          * This field holds the number of tries of the rate in
 148          * the rate index field (rix).
 149          */
 150         status->rix = super->s.rix;
 151         status->tries = super->s.cnt;
 152         status->success = (txs) ? 1 : 0;
 153 }
 154
 155 static bool wlan_tx_consume_retry(struct carl9170_tx_superframe *super)
 156 {
 157         /* check if this was the last possible retry with this rate */
 158         if (unlikely(super->s.cnt >= super->s.ri[super->s.rix].tries)) {
 159                 /* end of the road - indicate tx failure */
 160                 if (unlikely(super->s.rix == CARL9170_TX_MAX_RETRY_RATES))
 161                         return false;
 162
 163                 /* check if there are alternative rates available */
 164                 if (!super->s.rr[super->s.rix].set)
 165                         return false;
 166
 167                 /* try next retry rate */
 168                 super->f.hdr.phy.set = super->s.rr[super->s.rix].set;
 169
 170                 /* finally - mark the old rate as USED */
 171                 super->s.rix++;
 172
 173                 /* update MAC flags */
 174                 super->f.hdr.mac.erp_prot = super->s.ri[super->s.rix].erp_prot;
 175                 super->f.hdr.mac.ampdu = super->s.ri[super->s.rix].ampdu;
 176
 177                 /* reinitialize try counter */
 178                 super->s.cnt = 1;
 179         } else {
 180                 /* just increase retry counter */
 181                 super->s.cnt++;
 182         }
 183
 184         return true;
 185 }
 186
 187 /* for all tries */
 188 static void __wlan_tx(struct dma_desc *desc)
 189 {
 190         struct carl9170_tx_superframe *super = get_super(desc);
 191 #ifdef CONFIG_CARL9170FW_NORMAL_TX_RX
 192         unsigned int queue = super->s.queue;
 193 #endif /* CONFIG_CARL9170FW_LOOPBACK */
 194
 195         if (unlikely(super->s.fill_in_tsf)) {
 196                 struct ieee80211_mgmt *mgmt = (void *) &super->f.data.i3e;
 197                 uint32_t *tsf = (uint32_t *) &mgmt->u.probe_resp.timestamp;
 198
 199                 /*
 200                  * Truth be told: this is a hack.
 201                  *
 202                  * The *real* TSF is definitely going to be higher/older.
 203                  * But this hardware emulation code is head and shoulders
 204                  * above anything a driver can possibly do.
 205                  *
 206                  * (even, if it's got an accurate atomic clock source).
 207                  */
 208
 209                 read_tsf(tsf);
 210         }
 211
 212 #if (defined CONFIG_CARL9170FW_LOOPBACK) || (defined CONFIG_CARL9170FW_DISCARD)
 213         wlan_tx_complete(super, true);
 214         unhide_super(desc);
 215 # ifdef CONFIG_CARL9170FW_LOOPBACK
 216         dma_put(&fw.pta.up_queue, desc);
 217         up_trigger();
 218 # elif CONFIG_CARL9170FW_DISCARD
 219         dma_reclaim(&fw.pta.down_queue, desc);
 220         down_trigger();
 221 # endif
 222 #else /* CONFIG_CARL9170FW_LOOPBACK */
 223
 224 # if ((defined CONFIG_CARL9170FW_DEBUG) && (defined CONFIG_CARL9170FW_PSM))
 225         BUG_ON(fw.phy.psm.state != CARL9170_PSM_WAKE);
 226 # endif /* CONFIG_CARL9170FW_DEBUG && CONFIG_CARL9170FW_PSM */
 227
 228         /* insert desc into the right queue */
 229         dma_put(&fw.wlan.tx_queue[queue], desc);
 230         wlan_trigger(BIT(queue));
 231 #endif /* CONFIG_CARL9170FW_LOOPBACK */
 232 }
 233
 234 /* prepares frame for the first transmission */
 235 static void _wlan_tx(struct dma_desc *desc)
 236 {
 237         struct carl9170_tx_superframe *super = get_super(desc);
 238
 239         if (unlikely(super->s.ampdu_commit_density)) {
 240                 set(AR9170_MAC_REG_AMPDU_DENSITY,
 241                     MOD_VAL(AR9170_MAC_AMPDU_DENSITY,
 242                             get(AR9170_MAC_REG_AMPDU_DENSITY),
 243                             super->s.ampdu_density));
 244         }
 245
 246         if (unlikely(super->s.ampdu_commit_factor)) {
 247                 set(AR9170_MAC_REG_AMPDU_FACTOR,
 248                     MOD_VAL(AR9170_MAC_AMPDU_FACTOR,
 249                             get(AR9170_MAC_REG_AMPDU_FACTOR),
 250                             8 << super->s.ampdu_factor));
 251         }
 252
 253         __wlan_tx(desc);
 254 }
 255
 256 /* propagate transmission status back to the driver */
 257 static bool wlan_tx_status(struct dma_queue *queue,
 258                            struct dma_desc *desc)
 259 {
 260         struct ar9170_tx_frame *frame = DESC_PAYLOAD(desc);
 261         struct carl9170_tx_superframe *super = get_super(desc);
 262         struct ieee80211_hdr *hdr = &super->f.data.i3e;
 263         unsigned int qidx = super->s.queue;
 264         bool txfail, success;
 265
 266         success = true;
 267
 268         if (!!(desc->ctrl & AR9170_CTRL_FAIL)) {
 269                 txfail = !!(desc->ctrl & AR9170_CTRL_TXFAIL);
 270
 271                 /* reset retry indicator flags */
 272                 desc->ctrl &= ~(AR9170_CTRL_TXFAIL | AR9170_CTRL_BAFAIL);
 273
 274                 if (wlan_tx_consume_retry(super)) {
 275                         /*
 276                          * retry for simple and aggregated 802.11 frames.
 277                          *
 278                          * Note: We must not mess up the original frame
 279                          * order.
 280                          */
 281
 282                         if (!frame->hdr.mac.ampdu) {
 283                                 /*
 284                                  * 802.11 - 7.1.3.1.5.
 285                                  * set "Retry Field" for consecutive attempts
 286                                  *
 287                                  * Note: For AMPDU see:
 288                                  * 802.11n 9.9.1.6 "Retransmit Procedures"
 289                                  */
 290
 291                                 hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_RETRY);
 292                         }
 293
 294                         if (txfail) {
 295                                 /* Normal TX Failure */
 296
 297                                 /* demise descriptor ownership back to the hardware */
 298                                 dma_rearm(desc);
 299
 300                                 /*
 301                                  * And this will get the queue going again.
 302                                  * To understand why: you have to get the HW
 303                                  * specs... But sadly I never saw them.
 304                                  */
 305                                 wlan_txunstuck(qidx);
 306
 307                                 /* abort cycle - this is necessary due to HW design */
 308                                 return false;
 309                         } else {
 310                                 /* (HT-) BlockACK failure */
 311
 312                                 /*
 313                                  * Unlink the failed attempt and put it into
 314                                  * the retry queue. The caller routine must
 315                                  * be aware of this so the frames don't get lost.
 316                                  */
 317
 318                                 dma_unlink_head(queue);
 319 #ifdef CONFIG_CARL9170FW_DELAYED_TX
 320                                 dma_put(&fw.wlan.tx_retry, desc);
 321 #else
 322                                 __wlan_tx(desc);
 323 #endif /* CONFIG_CARL9170FW_DELAYED_TX */
 324                                 return true;
 325                         }
 326                 } else {
 327                         /* out of frame attempts - discard frame */
 328                         success = false;
 329                 }
 330         }
 331
 332         dma_unlink_head(queue);
 333         if (txfail) {
 334                 /*
 335                  * Issue the queue bump,
 336                  * We need to do this in case this was the frame's last
 337                  * possible retry attempt and it unfortunately: it failed.
 338                  */
 339
 340                 wlan_txunstuck(qidx);
 341         }
 342
 343         unhide_super(desc);
 344
 345         /* update hangcheck */
 346         fw.wlan.last_tx_desc_num[qidx] = 0;
 347
 348 #ifdef CONFIG_CARL9170FW_HANDLE_BACK_REQ
 349         if (unlikely(super == (void *) &dma_mem.reserved.ba)) {
 350                 fw.wlan.ba_desc = desc;
 351                 fw.wlan.ba_desc_available = 1;
 352                 return true;
 353         }
 354 #endif /* CONFIG_CARL9170FW_HANDLE_BACK_REQ */
 355
 356         wlan_tx_complete(super, success);
 357
 358 #ifdef CONFIG_CARL9170FW_CAB_QUEUE
 359         if (unlikely(super->s.cab))
 360                 fw.wlan.cab_queue_len--;
 361 #endif /* CONFIG_CARL9170FW_CAB_QUEUE */
 362
 363         /* recycle freed descriptors */
 364         dma_reclaim(&fw.pta.down_queue, desc);
 365         down_trigger();
 366         return true;
 367 }
 368
 369 static void handle_tx_completion(void)
 370 {
 371         struct dma_desc *desc;
 372         unsigned int i;
 373
 374         for (i = 0; i < __AR9170_NUM_TX_QUEUES; i++) {
 375                 __while_desc_bits(desc, &fw.wlan.tx_queue[i], AR9170_OWN_BITS_SW) {
 376                         if (!wlan_tx_status(&fw.wlan.tx_queue[i], desc)) {
 377                                 /* termination requested. */
 378                                 break;
 379                         }
 380                 }
 381
 382 #ifdef CONFIG_CARL9170FW_DELAYED_TX
 383                 for_each_desc(desc, &fw.wlan.tx_retry)
 384                         __wlan_tx(desc);
 385
 386                 for_each_desc(desc, &fw.wlan.tx_delay[i])
 387                         _wlan_tx(desc);
 388 #endif /* CONFIG_CARL9170FW_DELAYED_TX */
 389         }
 390 }
 391
 392 void __hot wlan_tx(struct dma_desc *desc)
 393 {
 394         struct carl9170_tx_superframe *super = DESC_PAYLOAD(desc);
 395
 396         /* initialize rate control struct */
 397         super->s.rix = 0;
 398         super->s.cnt = 1;
 399         hide_super(desc);
 400
 401 #ifdef CONFIG_CARL9170FW_DELAYED_TX
 402         if (!queue_empty(&fw.wlan.tx_queue[super->s.queue])) {
 403                 dma_put(&fw.wlan.tx_delay[super->s.queue], desc);
 404                 return;
 405         }
 406 #endif /* CONFIG_CARL9170FW_DELAYED_TX */
 407
 408 #ifdef CONFIG_CARL9170FW_CAB_QUEUE
 409         if (unlikely(super->s.cab)) {
 410                 fw.wlan.cab_queue_len++;
 411                 dma_put(&fw.wlan.cab_queue, desc);
 412                 return;
 413         }
 414 #endif /* CONFIG_CARL9170FW_CAB_QUEUE */
 415
 416         _wlan_tx(desc);
 417 }
 418
 419 #ifdef CONFIG_CARL9170FW_HANDLE_BACK_REQ
 420 static void wlan_send_buffered_ba(void)
 421 {
 422         struct carl9170_tx_ba_superframe *baf = &dma_mem.reserved.ba.ba;
 423         struct ieee80211_ba *ba = (struct ieee80211_ba *) &baf->f.ba;
 424         struct carl9170_bar_ctx *ctx;
 425
 426         if (likely(fw.wlan.ba_head_idx == fw.wlan.ba_tail_idx))
 427                 return;
 428
 429         /* there's no point to continue when the ba_desc is not available. */
 430         if (!fw.wlan.ba_desc_available)
 431                 return;
 432
 433         ctx = &fw.wlan.ba_cache[fw.wlan.ba_head_idx % CONFIG_CARL9170FW_BACK_REQS_NUM];
 434         fw.wlan.ba_head_idx++;
 435
 436         /* Format BlockAck */
 437         fw.wlan.ba_desc->status = 0;
 438         fw.wlan.ba_desc->ctrl = AR9170_CTRL_FS_BIT | AR9170_CTRL_LS_BIT;
 439         fw.wlan.ba_desc_available = 0;
 440         fw.wlan.ba_desc->nextAddr = fw.wlan.ba_desc->lastAddr =
 441                 fw.wlan.ba_desc;
 442
 443         baf->s.len = fw.wlan.ba_desc->totalLen = fw.wlan.ba_desc->dataSize =
 444                 sizeof(struct carl9170_tx_superdesc) +
 445                 sizeof(struct ar9170_tx_hwdesc) +
 446                 sizeof(struct ieee80211_ba);
 447
 448         baf->s.ri[0].tries = 3;
 449         baf->s.queue = 0;
 450         baf->f.hdr.length = sizeof(struct ieee80211_ba) + FCS_LEN;
 451
 452         /* HW Duration / Backoff */
 453         baf->f.hdr.mac.backoff = 1;
 454         baf->f.hdr.mac.hw_duration = 1;
 455
 456         /* take the TX rate from the RX'd BAR */
 457         baf->f.hdr.phy.set = ctx->phy;
 458         baf->f.hdr.phy.tx_power = 29; /* 14.5 dBm */
 459
 460         /* format outgoing BA */
 461         ba->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_BACK);
 462         ba->duration = cpu_to_le16(0);
 463         memcpy(ba->ta, ctx->ta, 6);
 464         memcpy(ba->ra, ctx->ra, 6);
 465
 466         /*
 467          * Unfortunately, we cannot look into the hardware's scoreboard.
 468          * Therefore we have to proceed as described in 802.11n 9.10.7.5
 469          * and send a null BlockAck.
 470          */
 471         memset(ba->bitmap, 0x0, sizeof(ba->bitmap));
 472
 473         /*
 474          * NB:
 475          * not entirely sure if this is 100% correct?!
 476          */
 477         ba->control = ctx->control | cpu_to_le16(1);
 478         ba->start_seq_num = ctx->start_seq_num;
 479
 480         wlan_tx(fw.wlan.ba_desc);
 481 }
 482
 483 static struct carl9170_bar_ctx *wlan_get_bar_cache_buffer(void)
 484 {
 485         struct carl9170_bar_ctx *tmp;
 486
 487         /* expire oldest entry, if we ran out of ba_ctx' */
 488         if (fw.wlan.ba_head_idx + CONFIG_CARL9170FW_BACK_REQS_NUM < fw.wlan.ba_tail_idx)
 489                 fw.wlan.ba_head_idx++;
 490
 491         tmp = &fw.wlan.ba_cache[fw.wlan.ba_tail_idx % CONFIG_CARL9170FW_BACK_REQS_NUM];
 492         fw.wlan.ba_tail_idx++;
 493
 494         return tmp;
 495 }
 496
 497 static void handle_bar(struct dma_desc *desc)
 498 {
 499         struct ieee80211_hdr *hdr;
 500         struct ieee80211_bar *bar;
 501         struct carl9170_bar_ctx *ctx;
 502
 503         hdr = ar9170_get_rx_i3e(desc);
 504
 505         /* check if this is a BAR for us */
 506         if (likely(!ieee80211_is_back_req(hdr->frame_control)))
 507                 return ;
 508
 509         if (unlikely(ar9170_get_rx_macstatus_error(desc))) {
 510                 /*
 511                  * This check does a number of things:
 512                  * 1. checks if the frame is in good nick
 513                  * 2. checks if the RA (MAC) matches
 514                  */
 515                 return ;
 516         }
 517
 518         if (unlikely(ar9170_get_rx_mpdu_len(desc) <
 519             sizeof(struct ieee80211_bar))) {
 520                 /*
 521                  * Sneaky, corrupted BARs... but not with us!
 522                  */
 523
 524                 return ;
 525         }
 526
 527         bar = (void *) hdr;
 528
 529         if ((bar->control & cpu_to_le16(IEEE80211_BAR_CTRL_MULTI_TID)) ||
 530             !(bar->control & cpu_to_le16(IEEE80211_BAR_CTRL_CBMTID_COMPRESSED_BA))) {
 531                 /* not implemented yet */
 532
 533                 return ;
 534         }
 535
 536         ctx = wlan_get_bar_cache_buffer();
 537
 538         /* Brilliant! The BAR provides all necessary MACs! */
 539         memcpy(ctx->ra, bar->ta, 6);
 540         memcpy(ctx->ta, bar->ra, 6);
 541
 542         /*
 543          * NB:
 544          * not entirely sure if this is 100% correct to force the
 545          * imm ack bit or not...
 546          */
 547         ctx->control = bar->control | cpu_to_le16(1);
 548         ctx->start_seq_num = bar->start_seq_num;
 549         ctx->phy = ar9170_rx_to_phy(desc);
 550         if (unlikely(!ctx->phy)) {
 551                 /* provide a backup, in case ar9170_rx_to_phy fails */
 552                 ctx->phy = cpu_to_le32(0x2cc301);
 553         }
 554 }
 555 #endif /* CONFIG_CARL9170FW_HANDLE_BACK_REQ */
 556
 557 static void wlan_check_rx_overrun(void)
 558 {
 559         uint32_t overruns, total;
 560
 561         fw.wlan.rx_total += total = get(AR9170_MAC_REG_RX_TOTAL);
 562         fw.wlan.rx_overruns += overruns = get(AR9170_MAC_REG_RX_OVERRUN);
 563         if (unlikely(overruns)) {
 564                 if (overruns == total) {
 565                         /*
 566                          * Theoretically, it should be enough to
 567                          * trigger the WLAN RX DMA bit. But the
 568                          * original firmware wanted a reset...
 569                          */
 570                         DBG("RX Overrun");
 571                         fw.wlan.mac_reset++;
 572                 }
 573         }
 574 }
 575
 576 static void handle_rx(void)
 577 {
 578         struct dma_desc *desc;
 579
 580         for_each_desc_not_bits(desc, &fw.wlan.rx_queue, AR9170_OWN_BITS_HW) {
 581                 if (unlikely(desc->totalLen < 26 ||
 582                     desc->totalLen > CONFIG_CARL9170FW_RX_FRAME_LEN)) {
 583                         /*
 584                          * This frame is too damaged to do anything
 585                          * useful with it.
 586                          */
 587                         dma_reclaim(&fw.wlan.rx_queue, desc);
 588                         _wlan_trigger(AR9170_DMA_TRIGGER_RXQ);
 589                 } else {
 590 #ifdef CONFIG_CARL9170FW_HANDLE_BACK_REQ
 591                         handle_bar(desc);
 592 #endif /* CONFIG_CARL9170FW_HANDLE_BACK_REQ */
 593
 594                         dma_put(&fw.pta.up_queue, desc);
 595                         up_trigger();
 596                 }
 597         }
 598 }
 599
 600 #ifdef CONFIG_CARL9170FW_CAB_QUEUE
 601 static uint8_t *beacon_find_ie(uint8_t ie)
 602 {
 603         struct ieee80211_mgmt *mgmt = getp(AR9170_MAC_REG_BCN_ADDR);
 604         uint8_t *pos, *end;
 605         unsigned int len;
 606
 607         len = get(AR9170_MAC_REG_BCN_LENGTH);
 608
 609         if (len < FCS_LEN + sizeof(mgmt))
 610                 return NULL;
 611
 612         pos = mgmt->u.beacon.variable;
 613         end = (uint8_t *) ((unsigned long)mgmt + (len - FCS_LEN));
 614         while (pos < end) {
 615                 if (pos + 2 + pos[1] > end)
 616                         return NULL;
 617
 618                 if (pos[0] == ie)
 619                         return pos;
 620
 621                 pos += pos[1] + 2;
 622         }
 623
 624         return NULL;
 625 }
 626
 627 static void wlan_cab_flush_queue(void)
 628 {
 629         struct dma_desc *desc;
 630         uint8_t *_ie;
 631         struct ieee80211_tim_ie *ie;
 632
 633         /*
 634          * This prevents the code from sending new BC/MC frames
 635          * which were queued after the previous buffered traffic
 636          * has been sent out... They will have to wait until the
 637          * next DTIM beacon comes along.
 638          */
 639         if (unlikely(fw.wlan.cab_flush_trigger == CARL9170_CAB_TRIGGER_DEFER))
 640                 return ;
 641
 642         _ie = beacon_find_ie(WLAN_EID_TIM);
 643         if (unlikely(!_ie))
 644                 return ;
 645
 646         ie = (struct ieee80211_tim_ie *) &_ie[2];
 647
 648         /* Ideally, check here for == AR9170_CAB_TRIGGER_ARMED */
 649         if (fw.wlan.cab_flush_trigger) {
 650                 /* move queued frames into the main tx queues */
 651                 for_each_desc(desc, &fw.wlan.cab_queue) {
 652                         struct carl9170_tx_superframe *super = get_super(desc);
 653
 654                         if (!queue_empty(&fw.wlan.cab_queue)) {
 655                                 /*
 656                                  * Set MOREDATA flag for all,
 657                                  * but the last queued frame.
 658                                  * see: 802.11-2007 11.2.1.5 f)
 659                                  *
 660                                  * This is actually the reason to why
 661                                  * we need to prevent the reentry.
 662                                  */
 663
 664                                 super->f.data.i3e.frame_control |=
 665                                         cpu_to_le16(IEEE80211_FCTL_MOREDATA);
 666                         } else {
 667                                 super->f.data.i3e.frame_control &=
 668                                         cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
 669                         }
 670
 671                         /* ready to roll! */
 672                         _wlan_tx(desc);
 673                 }
 674         }
 675
 676         /* Transfer finished - waiting for tx status */
 677         fw.wlan.cab_flush_trigger = CARL9170_CAB_TRIGGER_DEFER;
 678 }
 679
 680 static void wlan_cab_modify_dtim_beacon(void)
 681 {
 682         uint8_t *_ie;
 683         struct ieee80211_tim_ie *ie;
 684
 685         _ie = beacon_find_ie(WLAN_EID_TIM);
 686         if (likely(_ie)) {
 687                 ie = (struct ieee80211_tim_ie *) &_ie[2];
 688
 689                 if (!queue_empty(&fw.wlan.cab_queue) && (ie->dtim_count == 0)) {
 690                         /* schedule DTIM transfer */
 691                         fw.wlan.cab_flush_trigger = CARL9170_CAB_TRIGGER_ARMED;
 692                 } else if ((fw.wlan.cab_queue_len == 0) && (fw.wlan.cab_flush_trigger)) {
 693                         /* undo all chances to the beacon structure */
 694                         ie->bitmap_ctrl &= ~0x1;
 695                         fw.wlan.cab_flush_trigger = CARL9170_CAB_TRIGGER_EMPTY;
 696                 }
 697
 698                 if (fw.wlan.cab_flush_trigger) {
 699                         /* Set the almighty Multicast Traffic Indication Bit. */
 700                         ie->bitmap_ctrl |= 0x1;
 701                 }
 702         }
 703 }
 704 #endif /* CONFIG_CARL9170FW_CAB_QUEUE */
 705
 706 static void handle_beacon_config(void)
 707 {
 708         uint32_t bcn_count;
 709
 710 #ifdef CONFIG_CARL9170FW_CAB_QUEUE
 711         /*
 712          * The application has now updated the relevant beacon data.
 713          * Now it should be the perfect time to apply the DTIM
 714          * multicast information.
 715          */
 716
 717         wlan_cab_modify_dtim_beacon();
 718 #endif /* CONFIG_CARL9170FW_CAB_QUEUE */
 719
 720         bcn_count = get(AR9170_MAC_REG_BCN_COUNT);
 721         send_cmd_to_host(4, CARL9170_RSP_BEACON_CONFIG, 0x00,
 722                          (uint8_t *) &bcn_count);
 723 }
 724
 725 static void handle_pretbtt(void)
 726 {
 727 #ifdef CONFIG_CARL9170FW_CAB_QUEUE
 728         fw.wlan.cab_flush_time = get_clock_counter();
 729 #endif /* CONFIG_CARL9170FW_CAB_QUEUE */
 730
 731 #ifdef CONFIG_CARL9170FW_PSM
 732         rf_psm();
 733
 734         send_cmd_to_host(4, CARL9170_RSP_PRETBTT, 0x00,
 735                          (uint8_t *) &fw.phy.psm.state);
 736 #else
 737         send_cmd_to_host(0, CARL9170_RSP_PRETBTT, 0x00, NULL);
 738 #endif /* CONFIG_CARL9170FW_PSM */
 739
 740 }
 741
 742 static void handle_atim(void)
 743 {
 744         send_cmd_to_host(0, CARL9170_RSP_ATIM, 0x00, NULL);
 745 }
 746
 747 #ifdef CONFIG_CARL9170FW_DEBUG
 748 static void handle_qos(void)
 749 {
 750         /*
 751          * What is the QoS Bit used for?
 752          * Is it only an indicator for TXOP & Burst, or
 753          * should we do something here?
 754          */
 755 }
 756
 757 static void handle_radar(void)
 758 {
 759         send_cmd_to_host(0, CARL9170_RSP_RADAR, 0x00, NULL);
 760 }
 761 #endif /* CONFIG_CARL9170FW_DEBUG */
 762
 763 static void wlan_janitor(void)
 764 {
 765 #ifdef CONFIG_CARL9170FW_CAB_QUEUE
 766         if (unlikely(fw.wlan.cab_flush_trigger)) {
 767                 /*
 768                  * This is hardcoded into carl9170usb driver.
 769                  *
 770                  * The driver must set the PRETBTT event to beacon_interval -
 771                  * CARL9170_PRETBTT_KUS (usually 6) Kus.
 772                  *
 773                  * But still, we can only do so much about 802.11-2007 9.3.2.1 &
 774                  * 11.2.1.6. Let's hope the current solution is adequate enough.
 775                  */
 776
 777                 if (is_after_msecs(fw.wlan.cab_flush_time,
 778                     (CARL9170_TBTT_DELTA))) {
 779                         wlan_cab_flush_queue();
 780                 }
 781         }
 782 #endif /* CONFIG_CARL9170FW_CAB_QUEUE */
 783
 784 #ifdef CONFIG_CARL9170FW_DELAYED_TX
 785         if (fw.wlan.tx_trigger) {
 786                 _wlan_trigger(fw.wlan.tx_trigger);
 787                 fw.wlan.tx_trigger = 0;
 788         }
 789 #endif /* CONFIG_CARL9170FW_DELAYED_TX */
 790
 791         wlan_send_buffered_tx_status();
 792
 793 #ifdef CONFIG_CARL9170FW_HANDLE_BACK_REQ
 794         wlan_send_buffered_ba();
 795 #endif /* CONFIG_CARL9170FW_HANDLE_BACK_REQ */
 796 }
 797
 798 void handle_wlan(void)
 799 {
 800         uint32_t intr;
 801
 802         intr = get(AR9170_MAC_REG_INT_CTRL);
 803         /* ACK Interrupt */
 804         set(AR9170_MAC_REG_INT_CTRL, intr);
 805
 806 #define HANDLER(intr, flag, func)                       \
 807         do {                                            \
 808                 if ((intr & flag) != 0) {               \
 809                         func();                         \
 810                 }                                       \
 811         } while (0)
 812
 813         HANDLER(intr, AR9170_MAC_INT_PRETBTT, handle_pretbtt);
 814
 815         HANDLER(intr, AR9170_MAC_INT_ATIM, handle_atim);
 816
 817         HANDLER(intr, AR9170_MAC_INT_RXC, handle_rx);
 818
 819         HANDLER(intr, (AR9170_MAC_INT_TXC | AR9170_MAC_INT_RETRY_FAIL),
 820                 handle_tx_completion);
 821
 822 #ifdef CONFIG_CARL9170FW_DEBUG
 823         HANDLER(intr, AR9170_MAC_INT_QOS, handle_qos);
 824
 825         HANDLER(intr, AR9170_MAC_INT_RADAR, handle_radar);
 826 #endif /* CONFIG_CARL9170FW_DEBUG */
 827
 828         HANDLER(intr, AR9170_MAC_INT_CFG_BCN, handle_beacon_config);
 829
 830         if (unlikely(intr))
 831                 DBG("Unhandled Interrupt %x\n", (unsigned int) intr);
 832
 833         wlan_janitor();
 834
 835 #undef HANDLER
 836 }
 837
 838 static void wlan_dma_bump(unsigned int qidx)
 839 {
 840         unsigned int offset = qidx;
 841         uint32_t status, trigger;
 842
 843         status = get(AR9170_MAC_REG_DMA_STATUS) >> 12;
 844         trigger = get(AR9170_MAC_REG_DMA_TRIGGER) >> 12;
 845
 846         while (offset != 0) {
 847                 status >>= 4;
 848                 trigger >>= 4;
 849                 offset--;
 850         }
 851
 852         status &= 0xf;
 853         trigger &= 0xf;
 854
 855         if ((trigger == 0xa) && (status == 0x8)) {
 856                 DBG("UNSTUCK");
 857                 wlan_txunstuck(qidx);
 858         } else {
 859                 DBG("UPDATE");
 860                 wlan_txupdate(qidx);
 861         }
 862 }
 863
 864 static void wlan_check_hang(void)
 865 {
 866         struct dma_desc *desc;
 867         unsigned int i;
 868
 869         for (i = 0; i < __AR9170_NUM_TX_QUEUES; i++) {
 870                 if (queue_empty(&fw.wlan.tx_queue[i])) {
 871                         /* Nothing to do here... move along */
 872                         continue;
 873                 }
 874
 875                 /* fetch the current DMA queue position */
 876                 desc = get_wlan_txq_addr(i);
 877
 878                 /* Stuck frame detection */
 879                 if (unlikely(desc == fw.wlan.last_tx_desc[i])) {
 880                         fw.wlan.last_tx_desc_num[i]++;
 881
 882                         if (unlikely(fw.wlan.last_tx_desc_num[i] > 6)) {
 883                                 /*
 884                                  * schedule MAC reset (aka OFF/ON => dead)
 885                                  *
 886                                  * This will almost certainly kill
 887                                  * the device for good, but it's the
 888                                  * recommended thing to do...
 889                                  */
 890
 891                                 fw.wlan.mac_reset++;
 892                         }
 893
 894 #ifdef CONFIG_CARL9170FW_DEBUG
 895                         if (unlikely(fw.wlan.last_tx_desc_num[i] > 5)) {
 896                                 /*
 897                                  * Sigh, the queue is almost certainly
 898                                  * dead. Dump the queue content to the
 899                                  * user, maybe we find out why it got
 900                                  * so stuck.
 901                                  */
 902
 903                                 wlan_dump_queue(i);
 904                         }
 905 #endif /* CONFIG_CARL9170FW_DEBUG */
 906
 907                         if (unlikely(fw.wlan.last_tx_desc_num[i] > 3)) {
 908                                 /*
 909                                  * Hrrm, bump the queue a bit.
 910                                  * maybe this will get it going again.
 911                                  */
 912
 913                                 wlan_dma_bump(i);
 914                         }
 915                 } else {
 916                         /* Nothing stuck */
 917                         fw.wlan.last_tx_desc[i] = desc;
 918                         fw.wlan.last_tx_desc_num[i] = 0;
 919                 }
 920         }
 921 }
 922
 923 /*
 924  * NB: Resetting the MAC is a two-edged sword.
 925  * On most occasions, it does what it is supposed to do.
 926  * But there is a chance that this will make it
 927  * even worse and the radio dies silently.
 928  */
 929 static void wlan_mac_reset(void)
 930 {
 931         uint32_t val;
 932         uint32_t agg_wait_counter;
 933         uint32_t agg_density;
 934         uint32_t bcn_start_addr;
 935         uint32_t rctl, rcth;
 936         uint32_t cam_mode;
 937         uint32_t ack_power;
 938         uint32_t rts_cts_tpc;
 939         unsigned int i;
 940
 941 #ifdef CONFIG_CARL9170FW_RADIO_FUNCTIONS
 942         uint32_t rx_BB;
 943 #endif /* CONFIG_CARL9170FW_RADIO_FUNCTIONS */
 944
 945         INFO("MAC RESET");
 946
 947         /* Save aggregation parameters */
 948         agg_wait_counter = get(AR9170_MAC_REG_AMPDU_FACTOR);
 949         agg_density = get(AR9170_MAC_REG_AMPDU_DENSITY);
 950
 951         bcn_start_addr = get(AR9170_MAC_REG_BCN_ADDR);
 952
 953         cam_mode = get(AR9170_MAC_REG_CAM_MODE);
 954         rctl = get(AR9170_MAC_REG_CAM_ROLL_CALL_TBL_L);
 955         rcth = get(AR9170_MAC_REG_CAM_ROLL_CALL_TBL_H);
 956
 957         ack_power = get(AR9170_MAC_REG_ACK_TPC);
 958         rts_cts_tpc = get(AR9170_MAC_REG_RTS_CTS_TPC);
 959
 960 #ifdef CONFIG_CARL9170FW_RADIO_FUNCTIONS
 961         /* 0x1c8960 write only */
 962         rx_BB = get(AR9170_PHY_REG_SWITCH_CHAIN_0);
 963 #endif /* CONFIG_CARL9170FW_RADIO_FUNCTIONS */
 964
 965         /* TX/RX must be stopped by now */
 966         val = get(AR9170_MAC_REG_POWER_STATE_CTRL);
 967
 968         val |= AR9170_MAC_POWER_STATE_CTRL_RESET;
 969
 970         /*
 971          * Manipulate CCA threshold to stop transmission
 972          *
 973          * set(AR9170_PHY_REG_CCA_THRESHOLD, 0x300);
 974          */
 975
 976         /*
 977          * check Rx state in 0(idle) 9(disable)
 978          *
 979          * chState = (get(AR9170_MAC_REG_MISC_684) >> 16) & 0xf;
 980          * while( (chState != 0) && (chState != 9)) {
 981          *      chState = (get(AR9170_MAC_REG_MISC_684) >> 16) & 0xf;
 982          * }
 983          */
 984
 985         set(AR9170_MAC_REG_POWER_STATE_CTRL, val);
 986
 987         delay(2);
 988
 989         /* Restore aggregation parameters */
 990         set(AR9170_MAC_REG_AMPDU_FACTOR, agg_wait_counter);
 991         set(AR9170_MAC_REG_AMPDU_DENSITY, agg_density);
 992
 993         set(AR9170_MAC_REG_BCN_ADDR, bcn_start_addr);
 994         set(AR9170_MAC_REG_CAM_MODE, cam_mode);
 995         set(AR9170_MAC_REG_CAM_ROLL_CALL_TBL_L, rctl);
 996         set(AR9170_MAC_REG_CAM_ROLL_CALL_TBL_H, rcth);
 997
 998         set(AR9170_MAC_REG_RTS_CTS_TPC, rts_cts_tpc);
 999         set(AR9170_MAC_REG_ACK_TPC, ack_power);
1000
1001 #ifdef CONFIG_CARL9170FW_RADIO_FUNCTIONS
1002         set(AR9170_PHY_REG_SWITCH_CHAIN_2, rx_BB);
1003 #endif /* CONFIG_CARL9170FW_RADIO_FUNCTIONS */
1004
1005         /*
1006          * Manipulate CCA threshold to resume transmission
1007          *
1008          * set(AR9170_PHY_REG_CCA_THRESHOLD, 0x0);
1009          */
1010
1011         for (i = 0; i < __AR9170_NUM_TX_QUEUES; i++) {
1012                 DBG("Q:%d l:%d h:%p t:%p\n", i, queue_len(&fw.wlan.tx_queue[i]),
1013                      fw.wlan.tx_queue[i].head, fw.wlan.tx_queue[i].terminator);
1014
1015                 set_wlan_txq_dma_addr(i, (uint32_t) fw.wlan.tx_queue[i].head);
1016
1017                 if (!queue_empty(&fw.wlan.tx_queue[i]))
1018                         wlan_trigger(BIT(i));
1019         }
1020
1021         handle_rx();
1022         set(AR9170_MAC_REG_DMA_RXQ_ADDR, (uint32_t) fw.wlan.rx_queue.head);
1023         wlan_trigger(AR9170_DMA_TRIGGER_RXQ);
1024 }
1025
1026 void __cold wlan_timer(void)
1027 {
1028         unsigned int cached_mac_reset;
1029
1030         cached_mac_reset = fw.wlan.mac_reset;
1031
1032         /* TX Queue Hang check */
1033         wlan_check_hang();
1034
1035         /* RX Overrun check */
1036         wlan_check_rx_overrun();
1037
1038         if (unlikely(fw.wlan.mac_reset >= CARL9170_MAC_RESET_RESET)) {
1039                 wlan_mac_reset();
1040                 fw.wlan.mac_reset = CARL9170_MAC_RESET_OFF;
1041         } else {
1042                 if (fw.wlan.mac_reset && cached_mac_reset == fw.wlan.mac_reset)
1043                         fw.wlan.mac_reset--;
1044         }
1045 }