drivers/net/caif/caif_hsi.c

   1 /*
   2  * Copyright (C) ST-Ericsson AB 2010
   3  * Contact: Sjur Brendeland / sjur.brandeland@stericsson.com
   4  * Author:  Daniel Martensson / daniel.martensson@stericsson.com
   5  *          Dmitry.Tarnyagin  / dmitry.tarnyagin@stericsson.com
   6  * License terms: GNU General Public License (GPL) version 2.
   7  */
   8
   9 #define pr_fmt(fmt) KBUILD_MODNAME fmt
  10
  11 #include <linux/init.h>
  12 #include <linux/module.h>
  13 #include <linux/device.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/netdevice.h>
  16 #include <linux/string.h>
  17 #include <linux/list.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/delay.h>
  20 #include <linux/sched.h>
  21 #include <linux/if_arp.h>
  22 #include <linux/timer.h>
  23 #include <linux/rtnetlink.h>
  24 #include <linux/pkt_sched.h>
  25 #include <net/caif/caif_layer.h>
  26 #include <net/caif/caif_hsi.h>
  27
  28 MODULE_LICENSE("GPL");
  29 MODULE_AUTHOR("Daniel Martensson<daniel.martensson@stericsson.com>");
  30 MODULE_DESCRIPTION("CAIF HSI driver");
  31
  32 /* Returns the number of padding bytes for alignment. */
  33 #define PAD_POW2(x, pow) ((((x)&((pow)-1)) == 0) ? 0 :\
  34                                 (((pow)-((x)&((pow)-1)))))
  35
  36 static int inactivity_timeout = 1000;
  37 module_param(inactivity_timeout, int, S_IRUGO | S_IWUSR);
  38 MODULE_PARM_DESC(inactivity_timeout, "Inactivity timeout on HSI, ms.");
  39
  40 static int aggregation_timeout = 1;
  41 module_param(aggregation_timeout, int, S_IRUGO | S_IWUSR);
  42 MODULE_PARM_DESC(aggregation_timeout, "Aggregation timeout on HSI, ms.");
  43
  44 /*
  45  * HSI padding options.
  46  * Warning: must be a base of 2 (& operation used) and can not be zero !
  47  */
  48 static int hsi_head_align = 4;
  49 module_param(hsi_head_align, int, S_IRUGO);
  50 MODULE_PARM_DESC(hsi_head_align, "HSI head alignment.");
  51
  52 static int hsi_tail_align = 4;
  53 module_param(hsi_tail_align, int, S_IRUGO);
  54 MODULE_PARM_DESC(hsi_tail_align, "HSI tail alignment.");
  55
  56 /*
  57  * HSI link layer flowcontrol thresholds.
  58  * Warning: A high threshold value migth increase throughput but it will at
  59  * the same time prevent channel prioritization and increase the risk of
  60  * flooding the modem. The high threshold should be above the low.
  61  */
  62 static int hsi_high_threshold = 100;
  63 module_param(hsi_high_threshold, int, S_IRUGO);
  64 MODULE_PARM_DESC(hsi_high_threshold, "HSI high threshold (FLOW OFF).");
  65
  66 static int hsi_low_threshold = 50;
  67 module_param(hsi_low_threshold, int, S_IRUGO);
  68 MODULE_PARM_DESC(hsi_low_threshold, "HSI high threshold (FLOW ON).");
  69
  70 #define ON 1
  71 #define OFF 0
  72
  73 /*
  74  * Threshold values for the HSI packet queue. Flowcontrol will be asserted
  75  * when the number of packets exceeds HIGH_WATER_MARK. It will not be
  76  * de-asserted before the number of packets drops below LOW_WATER_MARK.
  77  */
  78 #define LOW_WATER_MARK   hsi_low_threshold
  79 #define HIGH_WATER_MARK  hsi_high_threshold
  80
  81 static LIST_HEAD(cfhsi_list);
  82 static spinlock_t cfhsi_list_lock;
  83
  84 static void cfhsi_inactivity_tout(unsigned long arg)
  85 {
  86         struct cfhsi *cfhsi = (struct cfhsi *)arg;
  87
  88         dev_dbg(&cfhsi->ndev->dev, "%s.\n",
  89                 __func__);
  90
  91         /* Schedule power down work queue. */
  92         if (!test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
  93                 queue_work(cfhsi->wq, &cfhsi->wake_down_work);
  94 }
  95
  96 static void cfhsi_update_aggregation_stats(struct cfhsi *cfhsi,
  97                                            const struct sk_buff *skb,
  98                                            int direction)
  99 {
 100         struct caif_payload_info *info;
 101         int hpad, tpad, len;
 102
 103         info = (struct caif_payload_info *)&skb->cb;
 104         hpad = 1 + PAD_POW2((info->hdr_len + 1), hsi_head_align);
 105         tpad = PAD_POW2((skb->len + hpad), hsi_tail_align);
 106         len = skb->len + hpad + tpad;
 107
 108         if (direction > 0)
 109                 cfhsi->aggregation_len += len;
 110         else if (direction < 0)
 111                 cfhsi->aggregation_len -= len;
 112 }
 113
 114 static bool cfhsi_can_send_aggregate(struct cfhsi *cfhsi)
 115 {
 116         int i;
 117
 118         if (cfhsi->aggregation_timeout < 0)
 119                 return true;
 120
 121         for (i = 0; i < CFHSI_PRIO_BEBK; ++i) {
 122                 if (cfhsi->qhead[i].qlen)
 123                         return true;
 124         }
 125
 126         /* TODO: Use aggregation_len instead */
 127         if (cfhsi->qhead[CFHSI_PRIO_BEBK].qlen >= CFHSI_MAX_PKTS)
 128                 return true;
 129
 130         return false;
 131 }
 132
 133 static struct sk_buff *cfhsi_dequeue(struct cfhsi *cfhsi)
 134 {
 135         struct sk_buff *skb;
 136         int i;
 137
 138         for (i = 0; i < CFHSI_PRIO_LAST; ++i) {
 139                 skb = skb_dequeue(&cfhsi->qhead[i]);
 140                 if (skb)
 141                         break;
 142         }
 143
 144         return skb;
 145 }
 146
 147 static int cfhsi_tx_queue_len(struct cfhsi *cfhsi)
 148 {
 149         int i, len = 0;
 150         for (i = 0; i < CFHSI_PRIO_LAST; ++i)
 151                 len += skb_queue_len(&cfhsi->qhead[i]);
 152         return len;
 153 }
 154
 155 static void cfhsi_abort_tx(struct cfhsi *cfhsi)
 156 {
 157         struct sk_buff *skb;
 158
 159         for (;;) {
 160                 spin_lock_bh(&cfhsi->lock);
 161                 skb = cfhsi_dequeue(cfhsi);
 162                 if (!skb)
 163                         break;
 164
 165                 cfhsi->ndev->stats.tx_errors++;
 166                 cfhsi->ndev->stats.tx_dropped++;
 167                 cfhsi_update_aggregation_stats(cfhsi, skb, -1);
 168                 spin_unlock_bh(&cfhsi->lock);
 169                 kfree_skb(skb);
 170         }
 171         cfhsi->tx_state = CFHSI_TX_STATE_IDLE;
 172         if (!test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
 173                 mod_timer(&cfhsi->inactivity_timer,
 174                         jiffies + cfhsi->inactivity_timeout);
 175         spin_unlock_bh(&cfhsi->lock);
 176 }
 177
 178 static int cfhsi_flush_fifo(struct cfhsi *cfhsi)
 179 {
 180         char buffer[32]; /* Any reasonable value */
 181         size_t fifo_occupancy;
 182         int ret;
 183
 184         dev_dbg(&cfhsi->ndev->dev, "%s.\n",
 185                 __func__);
 186
 187         do {
 188                 ret = cfhsi->dev->cfhsi_fifo_occupancy(cfhsi->dev,
 189                                 &fifo_occupancy);
 190                 if (ret) {
 191                         dev_warn(&cfhsi->ndev->dev,
 192                                 "%s: can't get FIFO occupancy: %d.\n",
 193                                 __func__, ret);
 194                         break;
 195                 } else if (!fifo_occupancy)
 196                         /* No more data, exitting normally */
 197                         break;
 198
 199                 fifo_occupancy = min(sizeof(buffer), fifo_occupancy);
 200                 set_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits);
 201                 ret = cfhsi->dev->cfhsi_rx(buffer, fifo_occupancy,
 202                                 cfhsi->dev);
 203                 if (ret) {
 204                         clear_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits);
 205                         dev_warn(&cfhsi->ndev->dev,
 206                                 "%s: can't read data: %d.\n",
 207                                 __func__, ret);
 208                         break;
 209                 }
 210
 211                 ret = 5 * HZ;
 212                 ret = wait_event_interruptible_timeout(cfhsi->flush_fifo_wait,
 213                          !test_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits), ret);
 214
 215                 if (ret < 0) {
 216                         dev_warn(&cfhsi->ndev->dev,
 217                                 "%s: can't wait for flush complete: %d.\n",
 218                                 __func__, ret);
 219                         break;
 220                 } else if (!ret) {
 221                         ret = -ETIMEDOUT;
 222                         dev_warn(&cfhsi->ndev->dev,
 223                                 "%s: timeout waiting for flush complete.\n",
 224                                 __func__);
 225                         break;
 226                 }
 227         } while (1);
 228
 229         return ret;
 230 }
 231
 232 static int cfhsi_tx_frm(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
 233 {
 234         int nfrms = 0;
 235         int pld_len = 0;
 236         struct sk_buff *skb;
 237         u8 *pfrm = desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ;
 238
 239         skb = cfhsi_dequeue(cfhsi);
 240         if (!skb)
 241                 return 0;
 242
 243         /* Clear offset. */
 244         desc->offset = 0;
 245
 246         /* Check if we can embed a CAIF frame. */
 247         if (skb->len < CFHSI_MAX_EMB_FRM_SZ) {
 248                 struct caif_payload_info *info;
 249                 int hpad = 0;
 250                 int tpad = 0;
 251
 252                 /* Calculate needed head alignment and tail alignment. */
 253                 info = (struct caif_payload_info *)&skb->cb;
 254
 255                 hpad = 1 + PAD_POW2((info->hdr_len + 1), hsi_head_align);
 256                 tpad = PAD_POW2((skb->len + hpad), hsi_tail_align);
 257
 258                 /* Check if frame still fits with added alignment. */
 259                 if ((skb->len + hpad + tpad) <= CFHSI_MAX_EMB_FRM_SZ) {
 260                         u8 *pemb = desc->emb_frm;
 261                         desc->offset = CFHSI_DESC_SHORT_SZ;
 262                         *pemb = (u8)(hpad - 1);
 263                         pemb += hpad;
 264
 265                         /* Update network statistics. */
 266                         spin_lock_bh(&cfhsi->lock);
 267                         cfhsi->ndev->stats.tx_packets++;
 268                         cfhsi->ndev->stats.tx_bytes += skb->len;
 269                         cfhsi_update_aggregation_stats(cfhsi, skb, -1);
 270                         spin_unlock_bh(&cfhsi->lock);
 271
 272                         /* Copy in embedded CAIF frame. */
 273                         skb_copy_bits(skb, 0, pemb, skb->len);
 274
 275                         /* Consume the SKB */
 276                         consume_skb(skb);
 277                         skb = NULL;
 278                 }
 279         }
 280
 281         /* Create payload CAIF frames. */
 282         pfrm = desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ;
 283         while (nfrms < CFHSI_MAX_PKTS) {
 284                 struct caif_payload_info *info;
 285                 int hpad = 0;
 286                 int tpad = 0;
 287
 288                 if (!skb)
 289                         skb = cfhsi_dequeue(cfhsi);
 290
 291                 if (!skb)
 292                         break;
 293
 294                 /* Calculate needed head alignment and tail alignment. */
 295                 info = (struct caif_payload_info *)&skb->cb;
 296
 297                 hpad = 1 + PAD_POW2((info->hdr_len + 1), hsi_head_align);
 298                 tpad = PAD_POW2((skb->len + hpad), hsi_tail_align);
 299
 300                 /* Fill in CAIF frame length in descriptor. */
 301                 desc->cffrm_len[nfrms] = hpad + skb->len + tpad;
 302
 303                 /* Fill head padding information. */
 304                 *pfrm = (u8)(hpad - 1);
 305                 pfrm += hpad;
 306
 307                 /* Update network statistics. */
 308                 spin_lock_bh(&cfhsi->lock);
 309                 cfhsi->ndev->stats.tx_packets++;
 310                 cfhsi->ndev->stats.tx_bytes += skb->len;
 311                 cfhsi_update_aggregation_stats(cfhsi, skb, -1);
 312                 spin_unlock_bh(&cfhsi->lock);
 313
 314                 /* Copy in CAIF frame. */
 315                 skb_copy_bits(skb, 0, pfrm, skb->len);
 316
 317                 /* Update payload length. */
 318                 pld_len += desc->cffrm_len[nfrms];
 319
 320                 /* Update frame pointer. */
 321                 pfrm += skb->len + tpad;
 322
 323                 /* Consume the SKB */
 324                 consume_skb(skb);
 325                 skb = NULL;
 326
 327                 /* Update number of frames. */
 328                 nfrms++;
 329         }
 330
 331         /* Unused length fields should be zero-filled (according to SPEC). */
 332         while (nfrms < CFHSI_MAX_PKTS) {
 333                 desc->cffrm_len[nfrms] = 0x0000;
 334                 nfrms++;
 335         }
 336
 337         /* Check if we can piggy-back another descriptor. */
 338         if (cfhsi_can_send_aggregate(cfhsi))
 339                 desc->header |= CFHSI_PIGGY_DESC;
 340         else
 341                 desc->header &= ~CFHSI_PIGGY_DESC;
 342
 343         return CFHSI_DESC_SZ + pld_len;
 344 }
 345
 346 static void cfhsi_start_tx(struct cfhsi *cfhsi)
 347 {
 348         struct cfhsi_desc *desc = (struct cfhsi_desc *)cfhsi->tx_buf;
 349         int len, res;
 350
 351         dev_dbg(&cfhsi->ndev->dev, "%s.\n", __func__);
 352
 353         if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
 354                 return;
 355
 356         do {
 357                 /* Create HSI frame. */
 358                 len = cfhsi_tx_frm(desc, cfhsi);
 359                 if (!len) {
 360                         spin_lock_bh(&cfhsi->lock);
 361                         if (unlikely(cfhsi_tx_queue_len(cfhsi))) {
 362                                 spin_unlock_bh(&cfhsi->lock);
 363                                 res = -EAGAIN;
 364                                 continue;
 365                         }
 366                         cfhsi->tx_state = CFHSI_TX_STATE_IDLE;
 367                         /* Start inactivity timer. */
 368                         mod_timer(&cfhsi->inactivity_timer,
 369                                 jiffies + cfhsi->inactivity_timeout);
 370                         spin_unlock_bh(&cfhsi->lock);
 371                         break;
 372                 }
 373
 374                 /* Set up new transfer. */
 375                 res = cfhsi->dev->cfhsi_tx(cfhsi->tx_buf, len, cfhsi->dev);
 376                 if (WARN_ON(res < 0))
 377                         dev_err(&cfhsi->ndev->dev, "%s: TX error %d.\n",
 378                                 __func__, res);
 379         } while (res < 0);
 380 }
 381
 382 static void cfhsi_tx_done(struct cfhsi *cfhsi)
 383 {
 384         dev_dbg(&cfhsi->ndev->dev, "%s.\n", __func__);
 385
 386         if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
 387                 return;
 388
 389         /*
 390          * Send flow on if flow off has been previously signalled
 391          * and number of packets is below low water mark.
 392          */
 393         spin_lock_bh(&cfhsi->lock);
 394         if (cfhsi->flow_off_sent &&
 395                         cfhsi_tx_queue_len(cfhsi) <= cfhsi->q_low_mark &&
 396                         cfhsi->cfdev.flowctrl) {
 397
 398                 cfhsi->flow_off_sent = 0;
 399                 cfhsi->cfdev.flowctrl(cfhsi->ndev, ON);
 400         }
 401
 402         if (cfhsi_can_send_aggregate(cfhsi)) {
 403                 spin_unlock_bh(&cfhsi->lock);
 404                 cfhsi_start_tx(cfhsi);
 405         } else {
 406                 mod_timer(&cfhsi->aggregation_timer,
 407                         jiffies + cfhsi->aggregation_timeout);
 408                 spin_unlock_bh(&cfhsi->lock);
 409         }
 410
 411         return;
 412 }
 413
 414 static void cfhsi_tx_done_cb(struct cfhsi_drv *drv)
 415 {
 416         struct cfhsi *cfhsi;
 417
 418         cfhsi = container_of(drv, struct cfhsi, drv);
 419         dev_dbg(&cfhsi->ndev->dev, "%s.\n",
 420                 __func__);
 421
 422         if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
 423                 return;
 424         cfhsi_tx_done(cfhsi);
 425 }
 426
 427 static int cfhsi_rx_desc(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
 428 {
 429         int xfer_sz = 0;
 430         int nfrms = 0;
 431         u16 *plen = NULL;
 432         u8 *pfrm = NULL;
 433
 434         if ((desc->header & ~CFHSI_PIGGY_DESC) ||
 435                         (desc->offset > CFHSI_MAX_EMB_FRM_SZ)) {
 436                 dev_err(&cfhsi->ndev->dev, "%s: Invalid descriptor.\n",
 437                         __func__);
 438                 return -EPROTO;
 439         }
 440
 441         /* Check for embedded CAIF frame. */
 442         if (desc->offset) {
 443                 struct sk_buff *skb;
 444                 u8 *dst = NULL;
 445                 int len = 0;
 446                 pfrm = ((u8 *)desc) + desc->offset;
 447
 448                 /* Remove offset padding. */
 449                 pfrm += *pfrm + 1;
 450
 451                 /* Read length of CAIF frame (little endian). */
 452                 len = *pfrm;
 453                 len |= ((*(pfrm+1)) << 8) & 0xFF00;
 454                 len += 2;       /* Add FCS fields. */
 455
 456                 /* Sanity check length of CAIF frame. */
 457                 if (unlikely(len > CFHSI_MAX_CAIF_FRAME_SZ)) {
 458                         dev_err(&cfhsi->ndev->dev, "%s: Invalid length.\n",
 459                                 __func__);
 460                         return -EPROTO;
 461                 }
 462
 463                 /* Allocate SKB (OK even in IRQ context). */
 464                 skb = alloc_skb(len + 1, GFP_ATOMIC);
 465                 if (!skb) {
 466                         dev_err(&cfhsi->ndev->dev, "%s: Out of memory !\n",
 467                                 __func__);
 468                         return -ENOMEM;
 469                 }
 470                 caif_assert(skb != NULL);
 471
 472                 dst = skb_put(skb, len);
 473                 memcpy(dst, pfrm, len);
 474
 475                 skb->protocol = htons(ETH_P_CAIF);
 476                 skb_reset_mac_header(skb);
 477                 skb->dev = cfhsi->ndev;
 478
 479                 /*
 480                  * We are called from a arch specific platform device.
 481                  * Unfortunately we don't know what context we're
 482                  * running in.
 483                  */
 484                 if (in_interrupt())
 485                         netif_rx(skb);
 486                 else
 487                         netif_rx_ni(skb);
 488
 489                 /* Update network statistics. */
 490                 cfhsi->ndev->stats.rx_packets++;
 491                 cfhsi->ndev->stats.rx_bytes += len;
 492         }
 493
 494         /* Calculate transfer length. */
 495         plen = desc->cffrm_len;
 496         while (nfrms < CFHSI_MAX_PKTS && *plen) {
 497                 xfer_sz += *plen;
 498                 plen++;
 499                 nfrms++;
 500         }
 501
 502         /* Check for piggy-backed descriptor. */
 503         if (desc->header & CFHSI_PIGGY_DESC)
 504                 xfer_sz += CFHSI_DESC_SZ;
 505
 506         if ((xfer_sz % 4) || (xfer_sz > (CFHSI_BUF_SZ_RX - CFHSI_DESC_SZ))) {
 507                 dev_err(&cfhsi->ndev->dev,
 508                                 "%s: Invalid payload len: %d, ignored.\n",
 509                         __func__, xfer_sz);
 510                 return -EPROTO;
 511         }
 512         return xfer_sz;
 513 }
 514
 515 static int cfhsi_rx_desc_len(struct cfhsi_desc *desc)
 516 {
 517         int xfer_sz = 0;
 518         int nfrms = 0;
 519         u16 *plen;
 520
 521         if ((desc->header & ~CFHSI_PIGGY_DESC) ||
 522                         (desc->offset > CFHSI_MAX_EMB_FRM_SZ)) {
 523
 524                 pr_err("Invalid descriptor. %x %x\n", desc->header,
 525                                 desc->offset);
 526                 return -EPROTO;
 527         }
 528
 529         /* Calculate transfer length. */
 530         plen = desc->cffrm_len;
 531         while (nfrms < CFHSI_MAX_PKTS && *plen) {
 532                 xfer_sz += *plen;
 533                 plen++;
 534                 nfrms++;
 535         }
 536
 537         if (xfer_sz % 4) {
 538                 pr_err("Invalid payload len: %d, ignored.\n", xfer_sz);
 539                 return -EPROTO;
 540         }
 541         return xfer_sz;
 542 }
 543
 544 static int cfhsi_rx_pld(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
 545 {
 546         int rx_sz = 0;
 547         int nfrms = 0;
 548         u16 *plen = NULL;
 549         u8 *pfrm = NULL;
 550
 551         /* Sanity check header and offset. */
 552         if (WARN_ON((desc->header & ~CFHSI_PIGGY_DESC) ||
 553                         (desc->offset > CFHSI_MAX_EMB_FRM_SZ))) {
 554                 dev_err(&cfhsi->ndev->dev, "%s: Invalid descriptor.\n",
 555                         __func__);
 556                 return -EPROTO;
 557         }
 558
 559         /* Set frame pointer to start of payload. */
 560         pfrm = desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ;
 561         plen = desc->cffrm_len;
 562
 563         /* Skip already processed frames. */
 564         while (nfrms < cfhsi->rx_state.nfrms) {
 565                 pfrm += *plen;
 566                 rx_sz += *plen;
 567                 plen++;
 568                 nfrms++;
 569         }
 570
 571         /* Parse payload. */
 572         while (nfrms < CFHSI_MAX_PKTS && *plen) {
 573                 struct sk_buff *skb;
 574                 u8 *dst = NULL;
 575                 u8 *pcffrm = NULL;
 576                 int len = 0;
 577
 578                 /* CAIF frame starts after head padding. */
 579                 pcffrm = pfrm + *pfrm + 1;
 580
 581                 /* Read length of CAIF frame (little endian). */
 582                 len = *pcffrm;
 583                 len |= ((*(pcffrm + 1)) << 8) & 0xFF00;
 584                 len += 2;       /* Add FCS fields. */
 585
 586                 /* Sanity check length of CAIF frames. */
 587                 if (unlikely(len > CFHSI_MAX_CAIF_FRAME_SZ)) {
 588                         dev_err(&cfhsi->ndev->dev, "%s: Invalid length.\n",
 589                                 __func__);
 590                         return -EPROTO;
 591                 }
 592
 593                 /* Allocate SKB (OK even in IRQ context). */
 594                 skb = alloc_skb(len + 1, GFP_ATOMIC);
 595                 if (!skb) {
 596                         dev_err(&cfhsi->ndev->dev, "%s: Out of memory !\n",
 597                                 __func__);
 598                         cfhsi->rx_state.nfrms = nfrms;
 599                         return -ENOMEM;
 600                 }
 601                 caif_assert(skb != NULL);
 602
 603                 dst = skb_put(skb, len);
 604                 memcpy(dst, pcffrm, len);
 605
 606                 skb->protocol = htons(ETH_P_CAIF);
 607                 skb_reset_mac_header(skb);
 608                 skb->dev = cfhsi->ndev;
 609
 610                 /*
 611                  * We're called from a platform device,
 612                  * and don't know the context we're running in.
 613                  */
 614                 if (in_interrupt())
 615                         netif_rx(skb);
 616                 else
 617                         netif_rx_ni(skb);
 618
 619                 /* Update network statistics. */
 620                 cfhsi->ndev->stats.rx_packets++;
 621                 cfhsi->ndev->stats.rx_bytes += len;
 622
 623                 pfrm += *plen;
 624                 rx_sz += *plen;
 625                 plen++;
 626                 nfrms++;
 627         }
 628
 629         return rx_sz;
 630 }
 631
 632 static void cfhsi_rx_done(struct cfhsi *cfhsi)
 633 {
 634         int res;
 635         int desc_pld_len = 0, rx_len, rx_state;
 636         struct cfhsi_desc *desc = NULL;
 637         u8 *rx_ptr, *rx_buf;
 638         struct cfhsi_desc *piggy_desc = NULL;
 639
 640         desc = (struct cfhsi_desc *)cfhsi->rx_buf;
 641
 642         dev_dbg(&cfhsi->ndev->dev, "%s\n", __func__);
 643
 644         if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
 645                 return;
 646
 647         /* Update inactivity timer if pending. */
 648         spin_lock_bh(&cfhsi->lock);
 649         mod_timer_pending(&cfhsi->inactivity_timer,
 650                         jiffies + cfhsi->inactivity_timeout);
 651         spin_unlock_bh(&cfhsi->lock);
 652
 653         if (cfhsi->rx_state.state == CFHSI_RX_STATE_DESC) {
 654                 desc_pld_len = cfhsi_rx_desc_len(desc);
 655
 656                 if (desc_pld_len < 0)
 657                         goto out_of_sync;
 658
 659                 rx_buf = cfhsi->rx_buf;
 660                 rx_len = desc_pld_len;
 661                 if (desc_pld_len > 0 && (desc->header & CFHSI_PIGGY_DESC))
 662                         rx_len += CFHSI_DESC_SZ;
 663                 if (desc_pld_len == 0)
 664                         rx_buf = cfhsi->rx_flip_buf;
 665         } else {
 666                 rx_buf = cfhsi->rx_flip_buf;
 667
 668                 rx_len = CFHSI_DESC_SZ;
 669                 if (cfhsi->rx_state.pld_len > 0 &&
 670                                 (desc->header & CFHSI_PIGGY_DESC)) {
 671
 672                         piggy_desc = (struct cfhsi_desc *)
 673                                 (desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ +
 674                                                 cfhsi->rx_state.pld_len);
 675
 676                         cfhsi->rx_state.piggy_desc = true;
 677
 678                         /* Extract payload len from piggy-backed descriptor. */
 679                         desc_pld_len = cfhsi_rx_desc_len(piggy_desc);
 680                         if (desc_pld_len < 0)
 681                                 goto out_of_sync;
 682
 683                         if (desc_pld_len > 0)
 684                                 rx_len = desc_pld_len;
 685
 686                         if (desc_pld_len > 0 &&
 687                                         (piggy_desc->header & CFHSI_PIGGY_DESC))
 688                                 rx_len += CFHSI_DESC_SZ;
 689
 690                         /*
 691                          * Copy needed information from the piggy-backed
 692                          * descriptor to the descriptor in the start.
 693                          */
 694                         memcpy(rx_buf, (u8 *)piggy_desc,
 695                                         CFHSI_DESC_SHORT_SZ);
 696                         /* Mark no embedded frame here */
 697                         piggy_desc->offset = 0;
 698                         if (desc_pld_len == -EPROTO)
 699                                 goto out_of_sync;
 700                 }
 701         }
 702
 703         if (desc_pld_len) {
 704                 rx_state = CFHSI_RX_STATE_PAYLOAD;
 705                 rx_ptr = rx_buf + CFHSI_DESC_SZ;
 706         } else {
 707                 rx_state = CFHSI_RX_STATE_DESC;
 708                 rx_ptr = rx_buf;
 709                 rx_len = CFHSI_DESC_SZ;
 710         }
 711
 712         /* Initiate next read */
 713         if (test_bit(CFHSI_AWAKE, &cfhsi->bits)) {
 714                 /* Set up new transfer. */
 715                 dev_dbg(&cfhsi->ndev->dev, "%s: Start RX.\n",
 716                                 __func__);
 717
 718                 res = cfhsi->dev->cfhsi_rx(rx_ptr, rx_len,
 719                                 cfhsi->dev);
 720                 if (WARN_ON(res < 0)) {
 721                         dev_err(&cfhsi->ndev->dev, "%s: RX error %d.\n",
 722                                 __func__, res);
 723                         cfhsi->ndev->stats.rx_errors++;
 724                         cfhsi->ndev->stats.rx_dropped++;
 725                 }
 726         }
 727
 728         if (cfhsi->rx_state.state == CFHSI_RX_STATE_DESC) {
 729                 /* Extract payload from descriptor */
 730                 if (cfhsi_rx_desc(desc, cfhsi) < 0)
 731                         goto out_of_sync;
 732         } else {
 733                 /* Extract payload */
 734                 if (cfhsi_rx_pld(desc, cfhsi) < 0)
 735                         goto out_of_sync;
 736                 if (piggy_desc) {
 737                         /* Extract any payload in piggyback descriptor. */
 738                         if (cfhsi_rx_desc(piggy_desc, cfhsi) < 0)
 739                                 goto out_of_sync;
 740                 }
 741         }
 742
 743         /* Update state info */
 744         memset(&cfhsi->rx_state, 0, sizeof(cfhsi->rx_state));
 745         cfhsi->rx_state.state = rx_state;
 746         cfhsi->rx_ptr = rx_ptr;
 747         cfhsi->rx_len = rx_len;
 748         cfhsi->rx_state.pld_len = desc_pld_len;
 749         cfhsi->rx_state.piggy_desc = desc->header & CFHSI_PIGGY_DESC;
 750
 751         if (rx_buf != cfhsi->rx_buf)
 752                 swap(cfhsi->rx_buf, cfhsi->rx_flip_buf);
 753         return;
 754
 755 out_of_sync:
 756         dev_err(&cfhsi->ndev->dev, "%s: Out of sync.\n", __func__);
 757         print_hex_dump_bytes("--> ", DUMP_PREFIX_NONE,
 758                         cfhsi->rx_buf, CFHSI_DESC_SZ);
 759         schedule_work(&cfhsi->out_of_sync_work);
 760 }
 761
 762 static void cfhsi_rx_slowpath(unsigned long arg)
 763 {
 764         struct cfhsi *cfhsi = (struct cfhsi *)arg;
 765
 766         dev_dbg(&cfhsi->ndev->dev, "%s.\n",
 767                 __func__);
 768
 769         cfhsi_rx_done(cfhsi);
 770 }
 771
 772 static void cfhsi_rx_done_cb(struct cfhsi_drv *drv)
 773 {
 774         struct cfhsi *cfhsi;
 775
 776         cfhsi = container_of(drv, struct cfhsi, drv);
 777         dev_dbg(&cfhsi->ndev->dev, "%s.\n",
 778                 __func__);
 779
 780         if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
 781                 return;
 782
 783         if (test_and_clear_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits))
 784                 wake_up_interruptible(&cfhsi->flush_fifo_wait);
 785         else
 786                 cfhsi_rx_done(cfhsi);
 787 }
 788
 789 static void cfhsi_wake_up(struct work_struct *work)
 790 {
 791         struct cfhsi *cfhsi = NULL;
 792         int res;
 793         int len;
 794         long ret;
 795
 796         cfhsi = container_of(work, struct cfhsi, wake_up_work);
 797
 798         if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
 799                 return;
 800
 801         if (unlikely(test_bit(CFHSI_AWAKE, &cfhsi->bits))) {
 802                 /* It happenes when wakeup is requested by
 803                  * both ends at the same time. */
 804                 clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
 805                 clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
 806                 return;
 807         }
 808
 809         /* Activate wake line. */
 810         cfhsi->dev->cfhsi_wake_up(cfhsi->dev);
 811
 812         dev_dbg(&cfhsi->ndev->dev, "%s: Start waiting.\n",
 813                 __func__);
 814
 815         /* Wait for acknowledge. */
 816         ret = CFHSI_WAKE_TOUT;
 817         ret = wait_event_interruptible_timeout(cfhsi->wake_up_wait,
 818                                         test_and_clear_bit(CFHSI_WAKE_UP_ACK,
 819                                                         &cfhsi->bits), ret);
 820         if (unlikely(ret < 0)) {
 821                 /* Interrupted by signal. */
 822                 dev_err(&cfhsi->ndev->dev, "%s: Signalled: %ld.\n",
 823                         __func__, ret);
 824
 825                 clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
 826                 cfhsi->dev->cfhsi_wake_down(cfhsi->dev);
 827                 return;
 828         } else if (!ret) {
 829                 bool ca_wake = false;
 830                 size_t fifo_occupancy = 0;
 831
 832                 /* Wakeup timeout */
 833                 dev_dbg(&cfhsi->ndev->dev, "%s: Timeout.\n",
 834                         __func__);
 835
 836                 /* Check FIFO to check if modem has sent something. */
 837                 WARN_ON(cfhsi->dev->cfhsi_fifo_occupancy(cfhsi->dev,
 838                                         &fifo_occupancy));
 839
 840                 dev_dbg(&cfhsi->ndev->dev, "%s: Bytes in FIFO: %u.\n",
 841                                 __func__, (unsigned) fifo_occupancy);
 842
 843                 /* Check if we misssed the interrupt. */
 844                 WARN_ON(cfhsi->dev->cfhsi_get_peer_wake(cfhsi->dev,
 845                                                         &ca_wake));
 846
 847                 if (ca_wake) {
 848                         dev_err(&cfhsi->ndev->dev, "%s: CA Wake missed !.\n",
 849                                 __func__);
 850
 851                         /* Clear the CFHSI_WAKE_UP_ACK bit to prevent race. */
 852                         clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
 853
 854                         /* Continue execution. */
 855                         goto wake_ack;
 856                 }
 857
 858                 clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
 859                 cfhsi->dev->cfhsi_wake_down(cfhsi->dev);
 860                 return;
 861         }
 862 wake_ack:
 863         dev_dbg(&cfhsi->ndev->dev, "%s: Woken.\n",
 864                 __func__);
 865
 866         /* Clear power up bit. */
 867         set_bit(CFHSI_AWAKE, &cfhsi->bits);
 868         clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
 869
 870         /* Resume read operation. */
 871         dev_dbg(&cfhsi->ndev->dev, "%s: Start RX.\n", __func__);
 872         res = cfhsi->dev->cfhsi_rx(cfhsi->rx_ptr, cfhsi->rx_len, cfhsi->dev);
 873
 874         if (WARN_ON(res < 0))
 875                 dev_err(&cfhsi->ndev->dev, "%s: RX err %d.\n", __func__, res);
 876
 877         /* Clear power up acknowledment. */
 878         clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
 879
 880         spin_lock_bh(&cfhsi->lock);
 881
 882         /* Resume transmit if queues are not empty. */
 883         if (!cfhsi_tx_queue_len(cfhsi)) {
 884                 dev_dbg(&cfhsi->ndev->dev, "%s: Peer wake, start timer.\n",
 885                         __func__);
 886                 /* Start inactivity timer. */
 887                 mod_timer(&cfhsi->inactivity_timer,
 888                                 jiffies + cfhsi->inactivity_timeout);
 889                 spin_unlock_bh(&cfhsi->lock);
 890                 return;
 891         }
 892
 893         dev_dbg(&cfhsi->ndev->dev, "%s: Host wake.\n",
 894                 __func__);
 895
 896         spin_unlock_bh(&cfhsi->lock);
 897
 898         /* Create HSI frame. */
 899         len = cfhsi_tx_frm((struct cfhsi_desc *)cfhsi->tx_buf, cfhsi);
 900
 901         if (likely(len > 0)) {
 902                 /* Set up new transfer. */
 903                 res = cfhsi->dev->cfhsi_tx(cfhsi->tx_buf, len, cfhsi->dev);
 904                 if (WARN_ON(res < 0)) {
 905                         dev_err(&cfhsi->ndev->dev, "%s: TX error %d.\n",
 906                                 __func__, res);
 907                         cfhsi_abort_tx(cfhsi);
 908                 }
 909         } else {
 910                 dev_err(&cfhsi->ndev->dev,
 911                                 "%s: Failed to create HSI frame: %d.\n",
 912                                 __func__, len);
 913         }
 914 }
 915
 916 static void cfhsi_wake_down(struct work_struct *work)
 917 {
 918         long ret;
 919         struct cfhsi *cfhsi = NULL;
 920         size_t fifo_occupancy = 0;
 921         int retry = CFHSI_WAKE_TOUT;
 922
 923         cfhsi = container_of(work, struct cfhsi, wake_down_work);
 924         dev_dbg(&cfhsi->ndev->dev, "%s.\n", __func__);
 925
 926         if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
 927                 return;
 928
 929         /* Deactivate wake line. */
 930         cfhsi->dev->cfhsi_wake_down(cfhsi->dev);
 931
 932         /* Wait for acknowledge. */
 933         ret = CFHSI_WAKE_TOUT;
 934         ret = wait_event_interruptible_timeout(cfhsi->wake_down_wait,
 935                                         test_and_clear_bit(CFHSI_WAKE_DOWN_ACK,
 936                                                         &cfhsi->bits), ret);
 937         if (ret < 0) {
 938                 /* Interrupted by signal. */
 939                 dev_err(&cfhsi->ndev->dev, "%s: Signalled: %ld.\n",
 940                         __func__, ret);
 941                 return;
 942         } else if (!ret) {
 943                 bool ca_wake = true;
 944
 945                 /* Timeout */
 946                 dev_err(&cfhsi->ndev->dev, "%s: Timeout.\n", __func__);
 947
 948                 /* Check if we misssed the interrupt. */
 949                 WARN_ON(cfhsi->dev->cfhsi_get_peer_wake(cfhsi->dev,
 950                                                         &ca_wake));
 951                 if (!ca_wake)
 952                         dev_err(&cfhsi->ndev->dev, "%s: CA Wake missed !.\n",
 953                                 __func__);
 954         }
 955
 956         /* Check FIFO occupancy. */
 957         while (retry) {
 958                 WARN_ON(cfhsi->dev->cfhsi_fifo_occupancy(cfhsi->dev,
 959                                                         &fifo_occupancy));
 960
 961                 if (!fifo_occupancy)
 962                         break;
 963
 964                 set_current_state(TASK_INTERRUPTIBLE);
 965                 schedule_timeout(1);
 966                 retry--;
 967         }
 968
 969         if (!retry)
 970                 dev_err(&cfhsi->ndev->dev, "%s: FIFO Timeout.\n", __func__);
 971
 972         /* Clear AWAKE condition. */
 973         clear_bit(CFHSI_AWAKE, &cfhsi->bits);
 974
 975         /* Cancel pending RX requests. */
 976         cfhsi->dev->cfhsi_rx_cancel(cfhsi->dev);
 977
 978 }
 979
 980 static void cfhsi_out_of_sync(struct work_struct *work)
 981 {
 982         struct cfhsi *cfhsi = NULL;
 983
 984         cfhsi = container_of(work, struct cfhsi, out_of_sync_work);
 985
 986         rtnl_lock();
 987         dev_close(cfhsi->ndev);
 988         rtnl_unlock();
 989 }
 990
 991 static void cfhsi_wake_up_cb(struct cfhsi_drv *drv)
 992 {
 993         struct cfhsi *cfhsi = NULL;
 994
 995         cfhsi = container_of(drv, struct cfhsi, drv);
 996         dev_dbg(&cfhsi->ndev->dev, "%s.\n",
 997                 __func__);
 998
 999         set_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
1000         wake_up_interruptible(&cfhsi->wake_up_wait);
1001
1002         if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
1003                 return;
1004
1005         /* Schedule wake up work queue if the peer initiates. */
1006         if (!test_and_set_bit(CFHSI_WAKE_UP, &cfhsi->bits))
1007                 queue_work(cfhsi->wq, &cfhsi->wake_up_work);
1008 }
1009
1010 static void cfhsi_wake_down_cb(struct cfhsi_drv *drv)
1011 {
1012         struct cfhsi *cfhsi = NULL;
1013
1014         cfhsi = container_of(drv, struct cfhsi, drv);
1015         dev_dbg(&cfhsi->ndev->dev, "%s.\n",
1016                 __func__);
1017
1018         /* Initiating low power is only permitted by the host (us). */
1019         set_bit(CFHSI_WAKE_DOWN_ACK, &cfhsi->bits);
1020         wake_up_interruptible(&cfhsi->wake_down_wait);
1021 }
1022
1023 static void cfhsi_aggregation_tout(unsigned long arg)
1024 {
1025         struct cfhsi *cfhsi = (struct cfhsi *)arg;
1026
1027         dev_dbg(&cfhsi->ndev->dev, "%s.\n",
1028                 __func__);
1029
1030         cfhsi_start_tx(cfhsi);
1031 }
1032
1033 static int cfhsi_xmit(struct sk_buff *skb, struct net_device *dev)
1034 {
1035         struct cfhsi *cfhsi = NULL;
1036         int start_xfer = 0;
1037         int timer_active;
1038         int prio;
1039
1040         if (!dev)
1041                 return -EINVAL;
1042
1043         cfhsi = netdev_priv(dev);
1044
1045         switch (skb->priority) {
1046         case TC_PRIO_BESTEFFORT:
1047         case TC_PRIO_FILLER:
1048         case TC_PRIO_BULK:
1049                 prio = CFHSI_PRIO_BEBK;
1050                 break;
1051         case TC_PRIO_INTERACTIVE_BULK:
1052                 prio = CFHSI_PRIO_VI;
1053                 break;
1054         case TC_PRIO_INTERACTIVE:
1055                 prio = CFHSI_PRIO_VO;
1056                 break;
1057         case TC_PRIO_CONTROL:
1058         default:
1059                 prio = CFHSI_PRIO_CTL;
1060                 break;
1061         }
1062
1063         spin_lock_bh(&cfhsi->lock);
1064
1065         /* Update aggregation statistics  */
1066         cfhsi_update_aggregation_stats(cfhsi, skb, 1);
1067
1068         /* Queue the SKB */
1069         skb_queue_tail(&cfhsi->qhead[prio], skb);
1070
1071         /* Sanity check; xmit should not be called after unregister_netdev */
1072         if (WARN_ON(test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))) {
1073                 spin_unlock_bh(&cfhsi->lock);
1074                 cfhsi_abort_tx(cfhsi);
1075                 return -EINVAL;
1076         }
1077
1078         /* Send flow off if number of packets is above high water mark. */
1079         if (!cfhsi->flow_off_sent &&
1080                 cfhsi_tx_queue_len(cfhsi) > cfhsi->q_high_mark &&
1081                 cfhsi->cfdev.flowctrl) {
1082                 cfhsi->flow_off_sent = 1;
1083                 cfhsi->cfdev.flowctrl(cfhsi->ndev, OFF);
1084         }
1085
1086         if (cfhsi->tx_state == CFHSI_TX_STATE_IDLE) {
1087                 cfhsi->tx_state = CFHSI_TX_STATE_XFER;
1088                 start_xfer = 1;
1089         }
1090
1091         if (!start_xfer) {
1092                 /* Send aggregate if it is possible */
1093                 bool aggregate_ready =
1094                         cfhsi_can_send_aggregate(cfhsi) &&
1095                         del_timer(&cfhsi->aggregation_timer) > 0;
1096                 spin_unlock_bh(&cfhsi->lock);
1097                 if (aggregate_ready)
1098                         cfhsi_start_tx(cfhsi);
1099                 return 0;
1100         }
1101
1102         /* Delete inactivity timer if started. */
1103         timer_active = del_timer_sync(&cfhsi->inactivity_timer);
1104
1105         spin_unlock_bh(&cfhsi->lock);
1106
1107         if (timer_active) {
1108                 struct cfhsi_desc *desc = (struct cfhsi_desc *)cfhsi->tx_buf;
1109                 int len;
1110                 int res;
1111
1112                 /* Create HSI frame. */
1113                 len = cfhsi_tx_frm(desc, cfhsi);
1114                 WARN_ON(!len);
1115
1116                 /* Set up new transfer. */
1117                 res = cfhsi->dev->cfhsi_tx(cfhsi->tx_buf, len, cfhsi->dev);
1118                 if (WARN_ON(res < 0)) {
1119                         dev_err(&cfhsi->ndev->dev, "%s: TX error %d.\n",
1120                                 __func__, res);
1121                         cfhsi_abort_tx(cfhsi);
1122                 }
1123         } else {
1124                 /* Schedule wake up work queue if the we initiate. */
1125                 if (!test_and_set_bit(CFHSI_WAKE_UP, &cfhsi->bits))
1126                         queue_work(cfhsi->wq, &cfhsi->wake_up_work);
1127         }
1128
1129         return 0;
1130 }
1131
1132 static const struct net_device_ops cfhsi_ops;
1133
1134 static void cfhsi_setup(struct net_device *dev)
1135 {
1136         int i;
1137         struct cfhsi *cfhsi = netdev_priv(dev);
1138         dev->features = 0;
1139         dev->netdev_ops = &cfhsi_ops;
1140         dev->type = ARPHRD_CAIF;
1141         dev->flags = IFF_POINTOPOINT | IFF_NOARP;
1142         dev->mtu = CFHSI_MAX_CAIF_FRAME_SZ;
1143         dev->tx_queue_len = 0;
1144         dev->destructor = free_netdev;
1145         for (i = 0; i < CFHSI_PRIO_LAST; ++i)
1146                 skb_queue_head_init(&cfhsi->qhead[i]);
1147         cfhsi->cfdev.link_select = CAIF_LINK_HIGH_BANDW;
1148         cfhsi->cfdev.use_frag = false;
1149         cfhsi->cfdev.use_stx = false;
1150         cfhsi->cfdev.use_fcs = false;
1151         cfhsi->ndev = dev;
1152 }
1153
1154 int cfhsi_probe(struct platform_device *pdev)
1155 {
1156         struct cfhsi *cfhsi = NULL;
1157         struct net_device *ndev;
1158
1159         int res;
1160
1161         ndev = alloc_netdev(sizeof(struct cfhsi), "cfhsi%d", cfhsi_setup);
1162         if (!ndev)
1163                 return -ENODEV;
1164
1165         cfhsi = netdev_priv(ndev);
1166         cfhsi->ndev = ndev;
1167         cfhsi->pdev = pdev;
1168
1169         /* Assign the HSI device. */
1170         cfhsi->dev = pdev->dev.platform_data;
1171
1172         /* Assign the driver to this HSI device. */
1173         cfhsi->dev->drv = &cfhsi->drv;
1174
1175         /* Register network device. */
1176         res = register_netdev(ndev);
1177         if (res) {
1178                 dev_err(&ndev->dev, "%s: Registration error: %d.\n",
1179                         __func__, res);
1180                 free_netdev(ndev);
1181         }
1182         /* Add CAIF HSI device to list. */
1183         spin_lock(&cfhsi_list_lock);
1184         list_add_tail(&cfhsi->list, &cfhsi_list);
1185         spin_unlock(&cfhsi_list_lock);
1186
1187         return res;
1188 }
1189
1190 static int cfhsi_open(struct net_device *ndev)
1191 {
1192         struct cfhsi *cfhsi = netdev_priv(ndev);
1193         int res;
1194
1195         clear_bit(CFHSI_SHUTDOWN, &cfhsi->bits);
1196
1197         /* Initialize state vaiables. */
1198         cfhsi->tx_state = CFHSI_TX_STATE_IDLE;
1199         cfhsi->rx_state.state = CFHSI_RX_STATE_DESC;
1200
1201         /* Set flow info */
1202         cfhsi->flow_off_sent = 0;
1203         cfhsi->q_low_mark = LOW_WATER_MARK;
1204         cfhsi->q_high_mark = HIGH_WATER_MARK;
1205
1206
1207         /*
1208          * Allocate a TX buffer with the size of a HSI packet descriptors
1209          * and the necessary room for CAIF payload frames.
1210          */
1211         cfhsi->tx_buf = kzalloc(CFHSI_BUF_SZ_TX, GFP_KERNEL);
1212         if (!cfhsi->tx_buf) {
1213                 res = -ENODEV;
1214                 goto err_alloc_tx;
1215         }
1216
1217         /*
1218          * Allocate a RX buffer with the size of two HSI packet descriptors and
1219          * the necessary room for CAIF payload frames.
1220          */
1221         cfhsi->rx_buf = kzalloc(CFHSI_BUF_SZ_RX, GFP_KERNEL);
1222         if (!cfhsi->rx_buf) {
1223                 res = -ENODEV;
1224                 goto err_alloc_rx;
1225         }
1226
1227         cfhsi->rx_flip_buf = kzalloc(CFHSI_BUF_SZ_RX, GFP_KERNEL);
1228         if (!cfhsi->rx_flip_buf) {
1229                 res = -ENODEV;
1230                 goto err_alloc_rx_flip;
1231         }
1232
1233         /* Pre-calculate inactivity timeout. */
1234         if (inactivity_timeout != -1) {
1235                 cfhsi->inactivity_timeout =
1236                                 inactivity_timeout * HZ / 1000;
1237                 if (!cfhsi->inactivity_timeout)
1238                         cfhsi->inactivity_timeout = 1;
1239                 else if (cfhsi->inactivity_timeout > NEXT_TIMER_MAX_DELTA)
1240                         cfhsi->inactivity_timeout = NEXT_TIMER_MAX_DELTA;
1241         } else {
1242                 cfhsi->inactivity_timeout = NEXT_TIMER_MAX_DELTA;
1243         }
1244
1245         /* Initialize aggregation timeout */
1246         cfhsi->aggregation_timeout = aggregation_timeout;
1247
1248         /* Initialize recieve vaiables. */
1249         cfhsi->rx_ptr = cfhsi->rx_buf;
1250         cfhsi->rx_len = CFHSI_DESC_SZ;
1251
1252         /* Initialize spin locks. */
1253         spin_lock_init(&cfhsi->lock);
1254
1255         /* Set up the driver. */
1256         cfhsi->drv.tx_done_cb = cfhsi_tx_done_cb;
1257         cfhsi->drv.rx_done_cb = cfhsi_rx_done_cb;
1258         cfhsi->drv.wake_up_cb = cfhsi_wake_up_cb;
1259         cfhsi->drv.wake_down_cb = cfhsi_wake_down_cb;
1260
1261         /* Initialize the work queues. */
1262         INIT_WORK(&cfhsi->wake_up_work, cfhsi_wake_up);
1263         INIT_WORK(&cfhsi->wake_down_work, cfhsi_wake_down);
1264         INIT_WORK(&cfhsi->out_of_sync_work, cfhsi_out_of_sync);
1265
1266         /* Clear all bit fields. */
1267         clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
1268         clear_bit(CFHSI_WAKE_DOWN_ACK, &cfhsi->bits);
1269         clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
1270         clear_bit(CFHSI_AWAKE, &cfhsi->bits);
1271
1272         /* Create work thread. */
1273         cfhsi->wq = create_singlethread_workqueue(cfhsi->pdev->name);
1274         if (!cfhsi->wq) {
1275                 dev_err(&cfhsi->ndev->dev, "%s: Failed to create work queue.\n",
1276                         __func__);
1277                 res = -ENODEV;
1278                 goto err_create_wq;
1279         }
1280
1281         /* Initialize wait queues. */
1282         init_waitqueue_head(&cfhsi->wake_up_wait);
1283         init_waitqueue_head(&cfhsi->wake_down_wait);
1284         init_waitqueue_head(&cfhsi->flush_fifo_wait);
1285
1286         /* Setup the inactivity timer. */
1287         init_timer(&cfhsi->inactivity_timer);
1288         cfhsi->inactivity_timer.data = (unsigned long)cfhsi;
1289         cfhsi->inactivity_timer.function = cfhsi_inactivity_tout;
1290         /* Setup the slowpath RX timer. */
1291         init_timer(&cfhsi->rx_slowpath_timer);
1292         cfhsi->rx_slowpath_timer.data = (unsigned long)cfhsi;
1293         cfhsi->rx_slowpath_timer.function = cfhsi_rx_slowpath;
1294         /* Setup the aggregation timer. */
1295         init_timer(&cfhsi->aggregation_timer);
1296         cfhsi->aggregation_timer.data = (unsigned long)cfhsi;
1297         cfhsi->aggregation_timer.function = cfhsi_aggregation_tout;
1298
1299         /* Activate HSI interface. */
1300         res = cfhsi->dev->cfhsi_up(cfhsi->dev);
1301         if (res) {
1302                 dev_err(&cfhsi->ndev->dev,
1303                         "%s: can't activate HSI interface: %d.\n",
1304                         __func__, res);
1305                 goto err_activate;
1306         }
1307
1308         /* Flush FIFO */
1309         res = cfhsi_flush_fifo(cfhsi);
1310         if (res) {
1311                 dev_err(&cfhsi->ndev->dev, "%s: Can't flush FIFO: %d.\n",
1312                         __func__, res);
1313                 goto err_net_reg;
1314         }
1315         return res;
1316
1317  err_net_reg:
1318         cfhsi->dev->cfhsi_down(cfhsi->dev);
1319  err_activate:
1320         destroy_workqueue(cfhsi->wq);
1321  err_create_wq:
1322         kfree(cfhsi->rx_flip_buf);
1323  err_alloc_rx_flip:
1324         kfree(cfhsi->rx_buf);
1325  err_alloc_rx:
1326         kfree(cfhsi->tx_buf);
1327  err_alloc_tx:
1328         return res;
1329 }
1330
1331 static int cfhsi_close(struct net_device *ndev)
1332 {
1333         struct cfhsi *cfhsi = netdev_priv(ndev);
1334         u8 *tx_buf, *rx_buf, *flip_buf;
1335
1336         /* going to shutdown driver */
1337         set_bit(CFHSI_SHUTDOWN, &cfhsi->bits);
1338
1339         /* Flush workqueue */
1340         flush_workqueue(cfhsi->wq);
1341
1342         /* Delete timers if pending */
1343         del_timer_sync(&cfhsi->inactivity_timer);
1344         del_timer_sync(&cfhsi->rx_slowpath_timer);
1345         del_timer_sync(&cfhsi->aggregation_timer);
1346
1347         /* Cancel pending RX request (if any) */
1348         cfhsi->dev->cfhsi_rx_cancel(cfhsi->dev);
1349
1350         /* Destroy workqueue */
1351         destroy_workqueue(cfhsi->wq);
1352
1353         /* Store bufferes: will be freed later. */
1354         tx_buf = cfhsi->tx_buf;
1355         rx_buf = cfhsi->rx_buf;
1356         flip_buf = cfhsi->rx_flip_buf;
1357         /* Flush transmit queues. */
1358         cfhsi_abort_tx(cfhsi);
1359
1360         /* Deactivate interface */
1361         cfhsi->dev->cfhsi_down(cfhsi->dev);
1362
1363         /* Free buffers. */
1364         kfree(tx_buf);
1365         kfree(rx_buf);
1366         kfree(flip_buf);
1367         return 0;
1368 }
1369
1370 static const struct net_device_ops cfhsi_ops = {
1371         .ndo_open = cfhsi_open,
1372         .ndo_stop = cfhsi_close,
1373         .ndo_start_xmit = cfhsi_xmit
1374 };
1375
1376 int cfhsi_remove(struct platform_device *pdev)
1377 {
1378         struct list_head *list_node;
1379         struct list_head *n;
1380         struct cfhsi *cfhsi = NULL;
1381         struct cfhsi_dev *dev;
1382
1383         dev = (struct cfhsi_dev *)pdev->dev.platform_data;
1384         spin_lock(&cfhsi_list_lock);
1385         list_for_each_safe(list_node, n, &cfhsi_list) {
1386                 cfhsi = list_entry(list_node, struct cfhsi, list);
1387                 /* Find the corresponding device. */
1388                 if (cfhsi->dev == dev) {
1389                         /* Remove from list. */
1390                         list_del(list_node);
1391                         spin_unlock(&cfhsi_list_lock);
1392                         return 0;
1393                 }
1394         }
1395         spin_unlock(&cfhsi_list_lock);
1396         return -ENODEV;
1397 }
1398
1399 struct platform_driver cfhsi_plat_drv = {
1400         .probe = cfhsi_probe,
1401         .remove = cfhsi_remove,
1402         .driver = {
1403                    .name = "cfhsi",
1404                    .owner = THIS_MODULE,
1405                    },
1406 };
1407
1408 static void __exit cfhsi_exit_module(void)
1409 {
1410         struct list_head *list_node;
1411         struct list_head *n;
1412         struct cfhsi *cfhsi = NULL;
1413
1414         spin_lock(&cfhsi_list_lock);
1415         list_for_each_safe(list_node, n, &cfhsi_list) {
1416                 cfhsi = list_entry(list_node, struct cfhsi, list);
1417
1418                 /* Remove from list. */
1419                 list_del(list_node);
1420                 spin_unlock(&cfhsi_list_lock);
1421
1422                 unregister_netdevice(cfhsi->ndev);
1423
1424                 spin_lock(&cfhsi_list_lock);
1425         }
1426         spin_unlock(&cfhsi_list_lock);
1427
1428         /* Unregister platform driver. */
1429         platform_driver_unregister(&cfhsi_plat_drv);
1430 }
1431
1432 static int __init cfhsi_init_module(void)
1433 {
1434         int result;
1435
1436         /* Initialize spin lock. */
1437         spin_lock_init(&cfhsi_list_lock);
1438
1439         /* Register platform driver. */
1440         result = platform_driver_register(&cfhsi_plat_drv);
1441         if (result) {
1442                 printk(KERN_ERR "Could not register platform HSI driver: %d.\n",
1443                         result);
1444                 goto err_dev_register;
1445         }
1446
1447  err_dev_register:
1448         return result;
1449 }
1450
1451 module_init(cfhsi_init_module);
1452 module_exit(cfhsi_exit_module);