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