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 static void wlan_dma_bump(unsigned int qidx)
  48 {
  49         unsigned int offset = qidx;
  50         uint32_t status, trigger;
  51
  52         status = get(AR9170_MAC_REG_DMA_STATUS) >> 12;
  53         trigger = get(AR9170_MAC_REG_DMA_TRIGGER) >> 12;
  54
  55         while (offset != 0) {
  56                 status >>= 4;
  57                 trigger >>= 4;
  58                 offset--;
  59         }
  60
  61         status &= 0xf;
  62         trigger &= 0xf;
  63
  64         if ((trigger == 0xa) && (status == 0x8)) {
  65                 DBG("UNSTUCK");
  66                 wlan_txunstuck(qidx);
  67         } else {
  68                 DBG("UPDATE");
  69                 wlan_txupdate(qidx);
  70         }
  71 }
  72
  73 #ifdef CONFIG_CARL9170FW_DEBUG
  74 static void wlan_dump_queue(unsigned int qidx)
  75 {
  76
  77         struct dma_desc *desc;
  78         struct carl9170_tx_superframe *super;
  79         int entries = 0;
  80
  81         __for_each_desc(desc, &fw.wlan.tx_queue[qidx]) {
  82                 super = get_super(desc);
  83                 DBG("%d: %p s:%x c:%x tl:%x ds:%x n:%p l:%p ", entries, desc,
  84                     desc->status, desc->ctrl, desc->totalLen,
  85                     desc->dataSize, desc->nextAddr, desc->lastAddr);
  86
  87                 DBG("c:%x tr:%d ri:%d l:%x m:%x p:%x fc:%x",
  88                     super->s.cookie, super->s.cnt, super->s.rix,
  89                     super->f.hdr.length, super->f.hdr.mac.set,
  90                     (unsigned int) le32_to_cpu(super->f.hdr.phy.set),
  91                     super->f.data.i3e.frame_control);
  92
  93                 entries++;
  94         }
  95
  96         desc = get_wlan_txq_addr(qidx);
  97
  98         DBG("Queue: %d: te:%d td:%d h:%p c:%p t:%p",
  99             qidx, entries, queue_len(&fw.wlan.tx_queue[qidx]),
 100             fw.wlan.tx_queue[qidx].head,
 101             desc, fw.wlan.tx_queue[qidx].terminator);
 102
 103         DBG("HW: t:%x s:%x ac:%x c:%x",
 104             (unsigned int) get(AR9170_MAC_REG_DMA_TRIGGER),
 105             (unsigned int) get(AR9170_MAC_REG_DMA_STATUS),
 106             (unsigned int) get(AR9170_MAC_REG_AMPDU_COUNT),
 107             (unsigned int) get(AR9170_MAC_REG_DMA_TXQX_ADDR_CURR));
 108 }
 109 #endif /* CONFIG_CARL9170FW_DEBUG */
 110
 111 static void wlan_send_buffered_tx_status(void)
 112 {
 113         unsigned int len;
 114
 115         while (fw.wlan.tx_status_pending) {
 116                 len = min((unsigned int)fw.wlan.tx_status_pending,
 117                           CARL9170_RSP_TX_STATUS_NUM);
 118                 len = min(len, CARL9170_TX_STATUS_NUM - fw.wlan.tx_status_head_idx);
 119
 120                 /*
 121                  * rather than memcpy each individual request into a large buffer,
 122                  * we _splice_ them all together.
 123                  *
 124                  * The only downside is however that we have to be careful around
 125                  * the edges of the tx_status_cache.
 126                  *
 127                  * Note:
 128                  * Each tx_status is about 2 bytes. However every command package
 129                  * must have a size which is a multiple of 4.
 130                  */
 131
 132                 send_cmd_to_host((len * sizeof(struct carl9170_tx_status) + 3) & ~3,
 133                                  CARL9170_RSP_TXCOMP, len, (void *)
 134                                  &fw.wlan.tx_status_cache[fw.wlan.tx_status_head_idx]);
 135
 136                 fw.wlan.tx_status_pending -= len;
 137                 fw.wlan.tx_status_head_idx += len;
 138                 fw.wlan.tx_status_head_idx %= CARL9170_TX_STATUS_NUM;
 139         }
 140 }
 141
 142 static struct carl9170_tx_status *wlan_get_tx_status_buffer(void)
 143 {
 144         struct carl9170_tx_status *tmp;
 145
 146         tmp = &fw.wlan.tx_status_cache[fw.wlan.tx_status_tail_idx++];
 147         fw.wlan.tx_status_tail_idx %= CARL9170_TX_STATUS_NUM;
 148
 149         if (fw.wlan.tx_status_pending == CARL9170_TX_STATUS_NUM)
 150                 wlan_send_buffered_tx_status();
 151
 152         fw.wlan.tx_status_pending++;
 153
 154         return tmp;
 155 }
 156
 157 /* generate _aggregated_ tx_status for the host */
 158 static void wlan_tx_complete(struct carl9170_tx_superframe *super,
 159                              bool txs)
 160 {
 161         struct carl9170_tx_status *status;
 162
 163         status = wlan_get_tx_status_buffer();
 164
 165         /*
 166          * The *unique* cookie and AC_ID is used by the driver for
 167          * frame lookup.
 168          */
 169         status->cookie = super->s.cookie;
 170         status->queue = super->s.queue;
 171
 172         /*
 173          * This field holds the number of tries of the rate in
 174          * the rate index field (rix).
 175          */
 176         status->rix = super->s.rix;
 177         status->tries = super->s.cnt;
 178         status->success = (txs) ? 1 : 0;
 179 }
 180
 181 static bool wlan_tx_consume_retry(struct carl9170_tx_superframe *super)
 182 {
 183         /* check if this was the last possible retry with this rate */
 184         if (unlikely(super->s.cnt >= super->s.tries[super->s.rix])) {
 185                 /* end of the road - indicate tx failure */
 186                 if (unlikely(super->s.rix == CARL9170_TX_MAX_RETRY_RATES))
 187                         return false;
 188
 189                 /* check if there are alternative rates available */
 190                 if (!super->s.rr[super->s.rix].set)
 191                         return false;
 192
 193                 /* try next retry rate */
 194                 super->f.hdr.phy.set = super->s.rr[super->s.rix].set;
 195
 196                 /* finally - mark the old rate as USED */
 197                 super->s.rix++;
 198
 199                 /* reinitialize try counter */
 200                 super->s.cnt = 1;
 201         } else {
 202                 /* just increase retry counter */
 203                 super->s.cnt++;
 204         }
 205
 206         return true;
 207 }
 208
 209 /* for all tries */
 210 static void __wlan_tx(struct dma_desc *desc)
 211 {
 212         struct carl9170_tx_superframe *super = get_super(desc);
 213 #ifdef CONFIG_CARL9170FW_NORMAL_TX_RX
 214         unsigned int queue = super->s.queue;
 215 #endif /* CONFIG_CARL9170FW_LOOPBACK */
 216
 217         if (unlikely(super->s.fill_in_tsf)) {
 218                 struct ieee80211_mgmt *mgmt = (void *) &super->f.data.i3e;
 219                 uint32_t *tsf = (uint32_t *) &mgmt->u.probe_resp.timestamp;
 220
 221                 /*
 222                  * Truth be told: this is a hack.
 223                  *
 224                  * The *real* TSF is definitely going to be higher/older.
 225                  * But this hardware emulation code is head and shoulders
 226                  * above anything a driver can possibly do.
 227                  *
 228                  * (even, if it's got an accurate atomic clock source).
 229                  */
 230
 231                 read_tsf(tsf);
 232         }
 233
 234 #if (defined CONFIG_CARL9170FW_LOOPBACK) || (defined CONFIG_CARL9170FW_DISCARD)
 235         wlan_tx_complete(super, true);
 236         unhide_super(desc);
 237 # ifdef CONFIG_CARL9170FW_LOOPBACK
 238         dma_put(&fw.pta.up_queue, desc);
 239         up_trigger();
 240 # elif CONFIG_CARL9170FW_DISCARD
 241         dma_reclaim(&fw.pta.down_queue, desc);
 242         down_trigger();
 243 # endif
 244 #else /* CONFIG_CARL9170FW_LOOPBACK */
 245
 246 # if ((defined CONFIG_CARL9170FW_DEBUG) && (defined CONFIG_CARL9170FW_PSM))
 247         BUG_ON(fw.phy.psm.state != CARL9170_PSM_WAKE);
 248 # endif /* CONFIG_CARL9170FW_DEBUG && CONFIG_CARL9170FW_PSM */
 249
 250         /* insert desc into the right queue */
 251         dma_put(&fw.wlan.tx_queue[queue], desc);
 252         wlan_trigger(BIT(queue));
 253 #endif /* CONFIG_CARL9170FW_LOOPBACK */
 254 }
 255
 256 /* prepares frame for the first transmission */
 257 static void _wlan_tx(struct dma_desc *desc)
 258 {
 259         struct carl9170_tx_superframe *super = get_super(desc);
 260
 261         if (unlikely(super->s.ampdu_commit_density)) {
 262                 set(AR9170_MAC_REG_AMPDU_DENSITY,
 263                     MOD_VAL(AR9170_MAC_AMPDU_DENSITY,
 264                             get(AR9170_MAC_REG_AMPDU_DENSITY),
 265                             super->s.ampdu_density));
 266         }
 267
 268         if (unlikely(super->s.ampdu_commit_factor)) {
 269                 set(AR9170_MAC_REG_AMPDU_FACTOR,
 270                     MOD_VAL(AR9170_MAC_AMPDU_FACTOR,
 271                             get(AR9170_MAC_REG_AMPDU_FACTOR),
 272                             8 << super->s.ampdu_factor));
 273         }
 274
 275         __wlan_tx(desc);
 276 }
 277
 278 /* propagate transmission status back to the driver */
 279 static bool wlan_tx_status(struct dma_queue *queue,
 280                            struct dma_desc *desc)
 281 {
 282         struct ar9170_tx_frame *frame = DESC_PAYLOAD(desc);
 283         struct carl9170_tx_superframe *super = get_super(desc);
 284         struct ieee80211_hdr *hdr = &super->f.data.i3e;
 285         unsigned int qidx = super->s.queue;
 286         bool txfail, success;
 287
 288         success = true;
 289
 290         if (!!(desc->ctrl & AR9170_CTRL_FAIL_MASK)) {
 291                 txfail = !!(desc->ctrl & AR9170_CTRL_TXFAIL);
 292
 293                 /* reset retry indicator flags */
 294                 desc->ctrl &= ~(AR9170_CTRL_TXFAIL | AR9170_CTRL_BAFAIL);
 295
 296                 if (wlan_tx_consume_retry(super)) {
 297                         /*
 298                          * retry for simple and aggregated 802.11 frames.
 299                          *
 300                          * Note: We must not mess up the original frame
 301                          * order.
 302                          */
 303
 304                         if (!frame->hdr.mac.ampdu) {
 305                                 /*
 306                                  * 802.11 - 7.1.3.1.5.
 307                                  * set "Retry Field" for consecutive attempts
 308                                  *
 309                                  * Note: For AMPDU see:
 310                                  * 802.11n 9.9.1.6 "Retransmit Procedures"
 311                                  */
 312
 313                                 hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_RETRY);
 314                         }
 315
 316                         if (txfail) {
 317                                 /* Normal TX Failure */
 318
 319                                 /* demise descriptor ownership back to the hardware */
 320                                 dma_rearm(desc);
 321
 322                                 /*
 323                                  * And this will get the queue going again.
 324                                  * To understand why: you have to get the HW
 325                                  * specs... But sadly I never saw them.
 326                                  */
 327                                 wlan_txunstuck(qidx);
 328
 329                                 /* abort cycle - this is necessary due to HW design */
 330                                 return false;
 331                         } else {
 332                                 /* (HT-) BlockACK failure */
 333
 334                                 /*
 335                                  * Unlink the failed attempt and put it into
 336                                  * the retry queue. The caller routine must
 337                                  * be aware of this so the frames don't get lost.
 338                                  */
 339
 340                                 dma_unlink_head(queue);
 341 #ifdef CONFIG_CARL9170FW_DELAYED_TX
 342                                 dma_put(&fw.wlan.tx_retry, desc);
 343 #else
 344                                 __wlan_tx(desc);
 345 #endif /* CONFIG_CARL9170FW_DELAYED_TX */
 346                                 return true;
 347                         }
 348                 } else {
 349                         /* out of frame attempts - discard frame */
 350                         success = false;
 351                 }
 352         }
 353
 354         dma_unlink_head(queue);
 355         if (txfail) {
 356                 /*
 357                  * Issue the queue bump,
 358                  * We need to do this in case this was the frame's last
 359                  * possible retry attempt and it unfortunately: it failed.
 360                  */
 361
 362                 wlan_txunstuck(qidx);
 363         }
 364
 365         unhide_super(desc);
 366
 367         /* update hangcheck */
 368         fw.wlan.last_tx_desc_num[qidx] = 0;
 369
 370 #ifdef CONFIG_CARL9170FW_HANDLE_BACK_REQ
 371         if (unlikely(super == (void *) &dma_mem.reserved.ba)) {
 372                 fw.wlan.ba_desc = desc;
 373                 fw.wlan.ba_desc_available = 1;
 374                 return true;
 375         }
 376 #endif /* CONFIG_CARL9170FW_HANDLE_BACK_REQ */
 377
 378         wlan_tx_complete(super, success);
 379
 380 #ifdef CONFIG_CARL9170FW_CAB_QUEUE
 381         if (unlikely(super->s.cab))
 382                 fw.wlan.cab_queue_len--;
 383 #endif /* CONFIG_CARL9170FW_CAB_QUEUE */
 384
 385         /* recycle freed descriptors */
 386         dma_reclaim(&fw.pta.down_queue, desc);
 387         down_trigger();
 388         return true;
 389 }
 390
 391 static void handle_tx_completion(void)
 392 {
 393         struct dma_desc *desc;
 394         unsigned int i;
 395
 396         for (i = 0; i < __AR9170_NUM_TX_QUEUES; i++) {
 397                 __while_desc_bits(desc, &fw.wlan.tx_queue[i], AR9170_OWN_BITS_SW) {
 398                         if (!wlan_tx_status(&fw.wlan.tx_queue[i], desc)) {
 399                                 /* termination requested. */
 400                                 break;
 401                         }
 402                 }
 403
 404 #ifdef CONFIG_CARL9170FW_DELAYED_TX
 405                 for_each_desc(desc, &fw.wlan.tx_retry)
 406                         __wlan_tx(desc);
 407
 408                 for_each_desc(desc, &fw.wlan.tx_delay[i])
 409                         _wlan_tx(desc);
 410 #endif /* CONFIG_CARL9170FW_DELAYED_TX */
 411         }
 412 }
 413
 414 void __hot wlan_tx(struct dma_desc *desc)
 415 {
 416         struct carl9170_tx_superframe *super = DESC_PAYLOAD(desc);
 417
 418         /* initialize rate control struct */
 419         super->s.rix = 0;
 420         super->s.cnt = 1;
 421         hide_super(desc);
 422
 423 #ifdef CONFIG_CARL9170FW_DELAYED_TX
 424         if (!queue_empty(&fw.wlan.tx_queue[super->s.queue])) {
 425                 dma_put(&fw.wlan.tx_delay[super->s.queue], desc);
 426                 return;
 427         }
 428 #endif /* CONFIG_CARL9170FW_DELAYED_TX */
 429
 430 #ifdef CONFIG_CARL9170FW_CAB_QUEUE
 431         if (unlikely(super->s.cab)) {
 432                 fw.wlan.cab_queue_len++;
 433                 dma_put(&fw.wlan.cab_queue, desc);
 434                 return;
 435         }
 436 #endif /* CONFIG_CARL9170FW_CAB_QUEUE */
 437
 438         _wlan_tx(desc);
 439 }
 440
 441 #ifdef CONFIG_CARL9170FW_HANDLE_BACK_REQ
 442 static void wlan_send_buffered_ba(void)
 443 {
 444         struct carl9170_tx_ba_superframe *baf = &dma_mem.reserved.ba.ba;
 445         struct ieee80211_ba *ba = (struct ieee80211_ba *) &baf->f.ba;
 446         struct carl9170_bar_ctx *ctx;
 447
 448         if (likely(fw.wlan.ba_head_idx == fw.wlan.ba_tail_idx))
 449                 return;
 450
 451         /* there's no point to continue when the ba_desc is not available. */
 452         if (!fw.wlan.ba_desc_available)
 453                 return;
 454
 455         ctx = &fw.wlan.ba_cache[fw.wlan.ba_head_idx % CONFIG_CARL9170FW_BACK_REQS_NUM];
 456         fw.wlan.ba_head_idx++;
 457
 458         /* Format BlockAck */
 459         fw.wlan.ba_desc->status = 0;
 460         fw.wlan.ba_desc->ctrl = AR9170_CTRL_FS_BIT | AR9170_CTRL_LS_BIT;
 461         fw.wlan.ba_desc_available = 0;
 462         fw.wlan.ba_desc->nextAddr = fw.wlan.ba_desc->lastAddr =
 463                 fw.wlan.ba_desc;
 464
 465         baf->s.len = fw.wlan.ba_desc->totalLen = fw.wlan.ba_desc->dataSize =
 466                 sizeof(struct carl9170_tx_superdesc) +
 467                 sizeof(struct ar9170_tx_hwdesc) +
 468                 sizeof(struct ieee80211_ba);
 469
 470         baf->s.tries[0] = 3;
 471         baf->s.queue = 0;
 472         baf->f.hdr.length = sizeof(struct ieee80211_ba) + FCS_LEN;
 473
 474         /* HW Duration / Backoff */
 475         baf->f.hdr.mac.backoff = 1;
 476         baf->f.hdr.mac.hw_duration = 1;
 477
 478         /* take the TX rate from the RX'd BAR */
 479         baf->f.hdr.phy.set = ctx->phy;
 480         baf->f.hdr.phy.tx_power = 29; /* 14.5 dBm */
 481
 482         /* format outgoing BA */
 483         ba->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_BACK);
 484         ba->duration = cpu_to_le16(0);
 485         memcpy(ba->ta, ctx->ta, 6);
 486         memcpy(ba->ra, ctx->ra, 6);
 487
 488         /*
 489          * Unfortunately, we cannot look into the hardware's scoreboard.
 490          * Therefore we have to proceed as described in 802.11n 9.10.7.5
 491          * and send a null BlockAck.
 492          */
 493         memset(ba->bitmap, 0x0, sizeof(ba->bitmap));
 494
 495         /*
 496          * NB:
 497          * not entirely sure if this is 100% correct?!
 498          */
 499         ba->control = ctx->control | cpu_to_le16(1);
 500         ba->start_seq_num = ctx->start_seq_num;
 501
 502         wlan_tx(fw.wlan.ba_desc);
 503 }
 504
 505 static struct carl9170_bar_ctx *wlan_get_bar_cache_buffer(void)
 506 {
 507         struct carl9170_bar_ctx *tmp;
 508
 509         /* expire oldest entry, if we ran out of ba_ctx' */
 510         if (fw.wlan.ba_head_idx + CONFIG_CARL9170FW_BACK_REQS_NUM < fw.wlan.ba_tail_idx)
 511                 fw.wlan.ba_head_idx++;
 512
 513         tmp = &fw.wlan.ba_cache[fw.wlan.ba_tail_idx % CONFIG_CARL9170FW_BACK_REQS_NUM];
 514         fw.wlan.ba_tail_idx++;
 515
 516         return tmp;
 517 }
 518
 519 static void handle_bar(struct dma_desc *desc)
 520 {
 521         struct ieee80211_hdr *hdr;
 522         struct ieee80211_bar *bar;
 523         struct carl9170_bar_ctx *ctx;
 524
 525         hdr = ar9170_get_rx_i3e(desc);
 526
 527         /* check if this is a BAR for us */
 528         if (likely(!ieee80211_is_back_req(hdr->frame_control)))
 529                 return ;
 530
 531         if (unlikely(ar9170_get_rx_macstatus_error(desc))) {
 532                 /*
 533                  * This check does a number of things:
 534                  * 1. checks if the frame is in good nick
 535                  * 2. checks if the RA (MAC) matches
 536                  */
 537                 return ;
 538         }
 539
 540         if (unlikely(ar9170_get_rx_mpdu_len(desc) <
 541             sizeof(struct ieee80211_bar))) {
 542                 /*
 543                  * Sneaky, corrupted BARs... but not with us!
 544                  */
 545
 546                 return ;
 547         }
 548
 549         bar = (void *) hdr;
 550
 551         if ((bar->control & cpu_to_le16(IEEE80211_BAR_CTRL_MULTI_TID)) ||
 552             !(bar->control & cpu_to_le16(IEEE80211_BAR_CTRL_CBMTID_COMPRESSED_BA))) {
 553                 /* not implemented yet */
 554
 555                 return ;
 556         }
 557
 558         ctx = wlan_get_bar_cache_buffer();
 559
 560         /* Brilliant! The BAR provides all necessary MACs! */
 561         memcpy(ctx->ra, bar->ta, 6);
 562         memcpy(ctx->ta, bar->ra, 6);
 563
 564         /*
 565          * NB:
 566          * not entirely sure if this is 100% correct to force the
 567          * imm ack bit or not...
 568          */
 569         ctx->control = bar->control | cpu_to_le16(1);
 570         ctx->start_seq_num = bar->start_seq_num;
 571         ctx->phy = ar9170_rx_to_phy(desc);
 572         if (unlikely(!ctx->phy)) {
 573                 /* provide a backup, in case ar9170_rx_to_phy fails */
 574                 ctx->phy = cpu_to_le32(0x2cc301);
 575         }
 576 }
 577 #endif /* CONFIG_CARL9170FW_HANDLE_BACK_REQ */
 578
 579 static void wlan_check_rx_overrun(void)
 580 {
 581         uint32_t overruns, total;
 582
 583         fw.wlan.rx_total += total = get(AR9170_MAC_REG_RX_TOTAL);
 584         fw.wlan.rx_overruns += overruns = get(AR9170_MAC_REG_RX_OVERRUN);
 585         if (unlikely(overruns)) {
 586                 if (overruns == total) {
 587                         DBG("RX Overrun");
 588                         fw.wlan.mac_reset++;
 589                 }
 590         }
 591 }
 592
 593 static void handle_rx(void)
 594 {
 595         struct dma_desc *desc;
 596
 597         wlan_check_rx_overrun();
 598
 599         for_each_desc_not_bits(desc, &fw.wlan.rx_queue, AR9170_OWN_BITS_HW) {
 600                 if (unlikely(desc->totalLen < 26 ||
 601                     desc->totalLen > CONFIG_CARL9170FW_RX_FRAME_LEN)) {
 602                         /*
 603                          * This frame is too damaged to do anything
 604                          * useful with it.
 605                          */
 606                         dma_reclaim(&fw.wlan.rx_queue, desc);
 607                         _wlan_trigger(AR9170_DMA_TRIGGER_RXQ);
 608                 } else {
 609 #ifdef CONFIG_CARL9170FW_HANDLE_BACK_REQ
 610                         handle_bar(desc);
 611 #endif /* CONFIG_CARL9170FW_HANDLE_BACK_REQ */
 612
 613                         dma_put(&fw.pta.up_queue, desc);
 614                         up_trigger();
 615                 }
 616         }
 617 }
 618
 619 #ifdef CONFIG_CARL9170FW_CAB_QUEUE
 620 static uint8_t *beacon_find_ie(uint8_t ie)
 621 {
 622         struct ieee80211_mgmt *mgmt = getp(AR9170_MAC_REG_BCN_ADDR);
 623         uint8_t *pos, *end;
 624         unsigned int len;
 625
 626         len = get(AR9170_MAC_REG_BCN_LENGTH);
 627
 628         if (len < FCS_LEN + sizeof(mgmt))
 629                 return NULL;
 630
 631         pos = mgmt->u.beacon.variable;
 632         end = (uint8_t *) ((unsigned long)mgmt + (len - FCS_LEN));
 633         while (pos < end) {
 634                 if (pos + 2 + pos[1] > end)
 635                         return NULL;
 636
 637                 if (pos[0] == ie)
 638                         return pos;
 639
 640                 pos += pos[1] + 2;
 641         }
 642
 643         return NULL;
 644 }
 645
 646 static void wlan_cab_flush_queue(void)
 647 {
 648         struct dma_desc *desc;
 649         uint8_t *_ie;
 650         struct ieee80211_tim_ie *ie;
 651
 652         /*
 653          * This prevents the code from sending new BC/MC frames
 654          * which were queued after the previous buffered traffic
 655          * has been sent out... They will have to wait until the
 656          * next DTIM beacon comes along.
 657          */
 658         if (unlikely(fw.wlan.cab_flush_trigger == CARL9170_CAB_TRIGGER_DEFER))
 659                 return ;
 660
 661         _ie = beacon_find_ie(WLAN_EID_TIM);
 662         if (unlikely(!_ie))
 663                 return ;
 664
 665         ie = (struct ieee80211_tim_ie *) &_ie[2];
 666
 667         /* Ideally, check here for == AR9170_CAB_TRIGGER_ARMED */
 668         if (fw.wlan.cab_flush_trigger) {
 669                 /* move queued frames into the main tx queues */
 670                 for_each_desc(desc, &fw.wlan.cab_queue) {
 671                         struct carl9170_tx_superframe *super = get_super(desc);
 672
 673                         if (!queue_empty(&fw.wlan.cab_queue)) {
 674                                 /*
 675                                  * Set MOREDATA flag for all,
 676                                  * but the last queued frame.
 677                                  * see: 802.11-2007 11.2.1.5 f)
 678                                  *
 679                                  * This is actually the reason to why
 680                                  * we need to prevent the reentry.
 681                                  */
 682
 683                                 super->f.data.i3e.frame_control |=
 684                                         cpu_to_le16(IEEE80211_FCTL_MOREDATA);
 685                         } else {
 686                                 super->f.data.i3e.frame_control &=
 687                                         cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
 688                         }
 689
 690                         /* ready to roll! */
 691                         _wlan_tx(desc);
 692                 }
 693         }
 694
 695         /* Transfer finished - waiting for tx status */
 696         fw.wlan.cab_flush_trigger = CARL9170_CAB_TRIGGER_DEFER;
 697 }
 698
 699 static void wlan_cab_modify_dtim_beacon(void)
 700 {
 701         uint8_t *_ie;
 702         struct ieee80211_tim_ie *ie;
 703
 704         _ie = beacon_find_ie(WLAN_EID_TIM);
 705         if (likely(_ie)) {
 706                 ie = (struct ieee80211_tim_ie *) &_ie[2];
 707
 708                 if (!queue_empty(&fw.wlan.cab_queue) && (ie->dtim_count == 0)) {
 709                         /* schedule DTIM transfer */
 710                         fw.wlan.cab_flush_trigger = CARL9170_CAB_TRIGGER_ARMED;
 711                 } else if ((fw.wlan.cab_queue_len == 0) && (fw.wlan.cab_flush_trigger)) {
 712                         /* undo all chances to the beacon structure */
 713                         ie->bitmap_ctrl &= ~0x1;
 714                         fw.wlan.cab_flush_trigger = CARL9170_CAB_TRIGGER_EMPTY;
 715                 }
 716
 717                 if (fw.wlan.cab_flush_trigger) {
 718                         /* Set the almighty Multicast Traffic Indication Bit. */
 719                         ie->bitmap_ctrl |= 0x1;
 720                 }
 721         }
 722 }
 723 #endif /* CONFIG_CARL9170FW_CAB_QUEUE */
 724
 725 static void handle_beacon_config(void)
 726 {
 727         uint32_t bcn_count;
 728
 729 #ifdef CONFIG_CARL9170FW_CAB_QUEUE
 730         /*
 731          * The application has now updated the relevant beacon data.
 732          * Now it should be the perfect time to apply the DTIM
 733          * multicast information.
 734          */
 735
 736         wlan_cab_modify_dtim_beacon();
 737 #endif /* CONFIG_CARL9170FW_CAB_QUEUE */
 738
 739         bcn_count = get(AR9170_MAC_REG_BCN_COUNT);
 740         send_cmd_to_host(4, CARL9170_RSP_BEACON_CONFIG, 0x00,
 741                          (uint8_t *) &bcn_count);
 742 }
 743
 744 static void handle_pretbtt(void)
 745 {
 746 #ifdef CONFIG_CARL9170FW_CAB_QUEUE
 747         fw.wlan.cab_flush_time = get_clock_counter();
 748 #endif /* CONFIG_CARL9170FW_CAB_QUEUE */
 749
 750 #ifdef CONFIG_CARL9170FW_PSM
 751         rf_psm();
 752
 753         send_cmd_to_host(4, CARL9170_RSP_PRETBTT, 0x00,
 754                          (uint8_t *) &fw.phy.psm.state);
 755 #else
 756         send_cmd_to_host(0, CARL9170_RSP_PRETBTT, 0x00, NULL);
 757 #endif /* CONFIG_CARL9170FW_PSM */
 758
 759 }
 760
 761 static void handle_atim(void)
 762 {
 763         send_cmd_to_host(0, CARL9170_RSP_ATIM, 0x00, NULL);
 764 }
 765
 766 #ifdef CONFIG_CARL9170FW_DEBUG
 767 static void handle_qos(void)
 768 {
 769         /*
 770          * What is the QoS Bit used for?
 771          * Is it only an indicator for TXOP & Burst, or
 772          * should we do something here?
 773          */
 774 }
 775
 776 static void handle_radar(void)
 777 {
 778         send_cmd_to_host(0, CARL9170_RSP_RADAR, 0x00, NULL);
 779 }
 780 #endif /* CONFIG_CARL9170FW_DEBUG */
 781
 782 static void wlan_janitor(void)
 783 {
 784 #ifdef CONFIG_CARL9170FW_CAB_QUEUE
 785         if (unlikely(fw.wlan.cab_flush_trigger)) {
 786                 /*
 787                  * This is hardcoded into carl9170usb driver.
 788                  *
 789                  * The driver must set the PRETBTT event to beacon_interval -
 790                  * CARL9170_PRETBTT_KUS (usually 6) Kus.
 791                  *
 792                  * But still, we can only do so much about 802.11-2007 9.3.2.1 &
 793                  * 11.2.1.6. Let's hope the current solution is adequate enough.
 794                  */
 795
 796                 if (is_after_msecs(fw.wlan.cab_flush_time,
 797                     (CARL9170_TBTT_DELTA))) {
 798                         wlan_cab_flush_queue();
 799                 }
 800         }
 801 #endif /* CONFIG_CARL9170FW_CAB_QUEUE */
 802
 803 #ifdef CONFIG_CARL9170FW_DELAYED_TX
 804         if (fw.wlan.tx_trigger) {
 805                 _wlan_trigger(fw.wlan.tx_trigger);
 806                 fw.wlan.tx_trigger = 0;
 807         }
 808 #endif /* CONFIG_CARL9170FW_DELAYED_TX */
 809
 810         wlan_send_buffered_tx_status();
 811
 812 #ifdef CONFIG_CARL9170FW_HANDLE_BACK_REQ
 813         wlan_send_buffered_ba();
 814 #endif /* CONFIG_CARL9170FW_HANDLE_BACK_REQ */
 815 }
 816
 817 void handle_wlan(void)
 818 {
 819         uint32_t intr;
 820
 821         intr = get(AR9170_MAC_REG_INT_CTRL);
 822         /* ACK Interrupt */
 823         set(AR9170_MAC_REG_INT_CTRL, intr);
 824
 825 #define HANDLER(intr, flag, func)                       \
 826         do {                                            \
 827                 if ((intr & flag) != 0) {               \
 828                         func();                         \
 829                 }                                       \
 830         } while (0)
 831
 832         HANDLER(intr, AR9170_MAC_INT_PRETBTT, handle_pretbtt);
 833
 834         HANDLER(intr, AR9170_MAC_INT_ATIM, handle_atim);
 835
 836         HANDLER(intr, AR9170_MAC_INT_RXC, handle_rx);
 837
 838         HANDLER(intr, (AR9170_MAC_INT_TXC | AR9170_MAC_INT_RETRY_FAIL),
 839                 handle_tx_completion);
 840
 841 #ifdef CONFIG_CARL9170FW_DEBUG
 842         HANDLER(intr, AR9170_MAC_INT_QOS, handle_qos);
 843
 844         HANDLER(intr, AR9170_MAC_INT_RADAR, handle_radar);
 845 #endif /* CONFIG_CARL9170FW_DEBUG */
 846
 847         HANDLER(intr, AR9170_MAC_INT_CFG_BCN, handle_beacon_config);
 848
 849         if (unlikely(intr))
 850                 DBG("Unhandled Interrupt %x\n", (unsigned int) intr);
 851
 852         wlan_janitor();
 853
 854 #undef HANDLER
 855 }
 856
 857 static void wlan_check_hang(void)
 858 {
 859         struct dma_desc *desc;
 860         unsigned int i;
 861
 862         for (i = 0; i < __AR9170_NUM_TX_QUEUES; i++) {
 863                 if (queue_empty(&fw.wlan.tx_queue[i])) {
 864                         /* Nothing to do here... move along */
 865                         continue;
 866                 }
 867
 868                 /* fetch the current DMA queue position */
 869                 desc = get_wlan_txq_addr(i);
 870
 871                 /* Stuck frame detection */
 872                 if (unlikely(desc == fw.wlan.last_tx_desc[i])) {
 873                         fw.wlan.last_tx_desc_num[i]++;
 874
 875                         if (unlikely(fw.wlan.last_tx_desc_num[i] > 6)) {
 876                                 /*
 877                                  * schedule MAC reset (aka OFF/ON => dead)
 878                                  *
 879                                  * This will almost certainly kill
 880                                  * the device for good, but it's the
 881                                  * recommended thing to do...
 882                                  */
 883
 884                                 fw.wlan.mac_reset++;
 885                         }
 886
 887 #ifdef CONFIG_CARL9170FW_DEBUG
 888                         if (unlikely(fw.wlan.last_tx_desc_num[i] > 5)) {
 889                                 /*
 890                                  * Sigh, the queue is almost certainly
 891                                  * dead. Dump the queue content to the
 892                                  * user, maybe we find out why it got
 893                                  * so stuck.
 894                                  */
 895
 896                                 wlan_dump_queue(i);
 897                         }
 898 #endif /* CONFIG_CARL9170FW_DEBUG */
 899
 900                         if (unlikely(fw.wlan.last_tx_desc_num[i] > 3)) {
 901                                 /*
 902                                  * Hrrm, bump the queue a bit.
 903                                  * maybe this will get it going again.
 904                                  */
 905
 906                                 wlan_dma_bump(i);
 907                         }
 908                 } else {
 909                         /* Nothing stuck */
 910                         fw.wlan.last_tx_desc[i] = desc;
 911                         fw.wlan.last_tx_desc_num[i] = 0;
 912                 }
 913         }
 914 }
 915
 916 /*
 917  * NB: Resetting the MAC is a two-edged sword.
 918  * On most occasions, it does what it is supposed to do.
 919  * But there is a chance that this will make it
 920  * even worse and the radio dies silently.
 921  */
 922 static void wlan_mac_reset(void)
 923 {
 924         uint32_t val;
 925         uint32_t agg_wait_counter;
 926         uint32_t agg_density;
 927         uint32_t bcn_start_addr;
 928         uint32_t rctl, rcth;
 929         uint32_t cam_mode;
 930         uint32_t ack_power;
 931         uint32_t rts_cts_tpc;
 932         unsigned int i;
 933
 934 #ifdef CONFIG_CARL9170FW_RADIO_FUNCTIONS
 935         uint32_t rx_BB;
 936 #endif /* CONFIG_CARL9170FW_RADIO_FUNCTIONS */
 937
 938         ERR("MAC RESET");
 939
 940         /* Save aggregation parameters */
 941         agg_wait_counter = get(AR9170_MAC_REG_AMPDU_FACTOR);
 942         agg_density = get(AR9170_MAC_REG_AMPDU_DENSITY);
 943
 944         bcn_start_addr = get(AR9170_MAC_REG_BCN_ADDR);
 945
 946         cam_mode = get(AR9170_MAC_REG_CAM_MODE);
 947         rctl = get(AR9170_MAC_REG_CAM_ROLL_CALL_TBL_L);
 948         rcth = get(AR9170_MAC_REG_CAM_ROLL_CALL_TBL_H);
 949
 950         ack_power = get(AR9170_MAC_REG_ACK_TPC);
 951         rts_cts_tpc = get(AR9170_MAC_REG_RTS_CTS_TPC);
 952
 953 #ifdef CONFIG_CARL9170FW_RADIO_FUNCTIONS
 954         /* 0x1c8960 write only */
 955         rx_BB = get(AR9170_PHY_REG_SWITCH_CHAIN_0);
 956 #endif /* CONFIG_CARL9170FW_RADIO_FUNCTIONS */
 957
 958         /* TX/RX must be stopped by now */
 959         val = get(AR9170_MAC_REG_POWER_STATE_CTRL);
 960
 961         val |= AR9170_MAC_POWER_STATE_CTRL_RESET;
 962
 963         /*
 964          * Manipulate CCA threshold to stop transmission
 965          *
 966          * set(AR9170_PHY_REG_CCA_THRESHOLD, 0x300);
 967          */
 968
 969         /*
 970          * check Rx state in 0(idle) 9(disable)
 971          *
 972          * chState = (get(AR9170_MAC_REG_MISC_684) >> 16) & 0xf;
 973          * while( (chState != 0) && (chState != 9)) {
 974          *      chState = (get(AR9170_MAC_REG_MISC_684) >> 16) & 0xf;
 975          * }
 976          */
 977
 978         set(AR9170_MAC_REG_POWER_STATE_CTRL, val);
 979
 980         delay(2);
 981
 982         /* Restore aggregation parameters */
 983         set(AR9170_MAC_REG_AMPDU_FACTOR, agg_wait_counter);
 984         set(AR9170_MAC_REG_AMPDU_DENSITY, agg_density);
 985
 986         set(AR9170_MAC_REG_BCN_ADDR, bcn_start_addr);
 987         set(AR9170_MAC_REG_CAM_MODE, cam_mode);
 988         set(AR9170_MAC_REG_CAM_ROLL_CALL_TBL_L, rctl);
 989         set(AR9170_MAC_REG_CAM_ROLL_CALL_TBL_H, rcth);
 990
 991         set(AR9170_MAC_REG_RTS_CTS_TPC, rts_cts_tpc);
 992         set(AR9170_MAC_REG_ACK_TPC, ack_power);
 993
 994 #ifdef CONFIG_CARL9170FW_RADIO_FUNCTIONS
 995         set(AR9170_PHY_REG_SWITCH_CHAIN_2, rx_BB);
 996 #endif /* CONFIG_CARL9170FW_RADIO_FUNCTIONS */
 997
 998         /*
 999          * Manipulate CCA threshold to resume transmission
1000          *
1001          * set(AR9170_PHY_REG_CCA_THRESHOLD, 0x0);
1002          */
1003
1004         for (i = 0; i < __AR9170_NUM_TX_QUEUES; i++) {
1005                 DBG("Q:%d l:%d h:%p t:%p\n", i, queue_len(&fw.wlan.tx_queue[i]),
1006                      fw.wlan.tx_queue[i].head, fw.wlan.tx_queue[i].terminator);
1007
1008                 set_wlan_txq_dma_addr(i, (uint32_t) fw.wlan.tx_queue[i].head);
1009
1010                 if (!queue_empty(&fw.wlan.tx_queue[i]))
1011                         wlan_trigger(BIT(i));
1012         }
1013
1014         handle_rx();
1015         set(AR9170_MAC_REG_DMA_RXQ_ADDR, (uint32_t) fw.wlan.rx_queue.head);
1016         wlan_trigger(AR9170_DMA_TRIGGER_RXQ);
1017 }
1018
1019 void __cold wlan_timer(void)
1020 {
1021         unsigned int cached_mac_reset;
1022
1023         cached_mac_reset = fw.wlan.mac_reset;
1024
1025         /* TX Queue Hang check */
1026         wlan_check_hang();
1027
1028         /* RX Overrun check */
1029         wlan_check_rx_overrun();
1030
1031         if (unlikely(fw.wlan.mac_reset >= CARL9170_MAC_RESET_RESET)) {
1032                 wlan_mac_reset();
1033                 fw.wlan.mac_reset = CARL9170_MAC_RESET_OFF;
1034         } else {
1035                 if (fw.wlan.mac_reset && cached_mac_reset == fw.wlan.mac_reset)
1036                         fw.wlan.mac_reset--;
1037         }
1038 }