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