drivers/bluetooth/hci_bcsp.c

   1 /*
   2  *
   3  *  Bluetooth HCI UART driver
   4  *
   5  *  Copyright (C) 2002-2003  Fabrizio Gennari <fabrizio.gennari@philips.com>
   6  *  Copyright (C) 2004-2005  Marcel Holtmann <marcel@holtmann.org>
   7  *
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License as published by
  11  *  the Free Software Foundation; either version 2 of the License, or
  12  *  (at your option) any later version.
  13  *
  14  *  This program is distributed in the hope that it will be useful,
  15  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  *  GNU General Public License for more details.
  18  *
  19  *  You should have received a copy of the GNU General Public License
  20  *  along with this program; if not, write to the Free Software
  21  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  22  *
  23  */
  24
  25 #include <linux/module.h>
  26
  27 #include <linux/kernel.h>
  28 #include <linux/init.h>
  29 #include <linux/types.h>
  30 #include <linux/fcntl.h>
  31 #include <linux/interrupt.h>
  32 #include <linux/ptrace.h>
  33 #include <linux/poll.h>
  34
  35 #include <linux/slab.h>
  36 #include <linux/tty.h>
  37 #include <linux/errno.h>
  38 #include <linux/string.h>
  39 #include <linux/signal.h>
  40 #include <linux/ioctl.h>
  41 #include <linux/skbuff.h>
  42 #include <linux/bitrev.h>
  43 #include <asm/unaligned.h>
  44
  45 #include <net/bluetooth/bluetooth.h>
  46 #include <net/bluetooth/hci_core.h>
  47
  48 #include "hci_uart.h"
  49
  50 static bool txcrc = true;
  51 static bool hciextn = true;
  52
  53 #define BCSP_TXWINSIZE  4
  54
  55 #define BCSP_ACK_PKT    0x05
  56 #define BCSP_LE_PKT     0x06
  57
  58 struct bcsp_struct {
  59         struct sk_buff_head unack;      /* Unack'ed packets queue */
  60         struct sk_buff_head rel;        /* Reliable packets queue */
  61         struct sk_buff_head unrel;      /* Unreliable packets queue */
  62
  63         unsigned long rx_count;
  64         struct  sk_buff *rx_skb;
  65         u8      rxseq_txack;            /* rxseq == txack. */
  66         u8      rxack;                  /* Last packet sent by us that the peer ack'ed */
  67         struct  timer_list tbcsp;
  68
  69         enum {
  70                 BCSP_W4_PKT_DELIMITER,
  71                 BCSP_W4_PKT_START,
  72                 BCSP_W4_BCSP_HDR,
  73                 BCSP_W4_DATA,
  74                 BCSP_W4_CRC
  75         } rx_state;
  76
  77         enum {
  78                 BCSP_ESCSTATE_NOESC,
  79                 BCSP_ESCSTATE_ESC
  80         } rx_esc_state;
  81
  82         u8      use_crc;
  83         u16     message_crc;
  84         u8      txack_req;              /* Do we need to send ack's to the peer? */
  85
  86         /* Reliable packet sequence number - used to assign seq to each rel pkt. */
  87         u8      msgq_txseq;
  88 };
  89
  90 /* ---- BCSP CRC calculation ---- */
  91
  92 /* Table for calculating CRC for polynomial 0x1021, LSB processed first,
  93 initial value 0xffff, bits shifted in reverse order. */
  94
  95 static const u16 crc_table[] = {
  96         0x0000, 0x1081, 0x2102, 0x3183,
  97         0x4204, 0x5285, 0x6306, 0x7387,
  98         0x8408, 0x9489, 0xa50a, 0xb58b,
  99         0xc60c, 0xd68d, 0xe70e, 0xf78f
 100 };
 101
 102 /* Initialise the crc calculator */
 103 #define BCSP_CRC_INIT(x) x = 0xffff
 104
 105 /* Update crc with next data byte
 106  *
 107  * Implementation note
 108  *     The data byte is treated as two nibbles.  The crc is generated
 109  *     in reverse, i.e., bits are fed into the register from the top.
 110  */
 111 static void bcsp_crc_update(u16 *crc, u8 d)
 112 {
 113         u16 reg = *crc;
 114
 115         reg = (reg >> 4) ^ crc_table[(reg ^ d) & 0x000f];
 116         reg = (reg >> 4) ^ crc_table[(reg ^ (d >> 4)) & 0x000f];
 117
 118         *crc = reg;
 119 }
 120
 121 /* ---- BCSP core ---- */
 122
 123 static void bcsp_slip_msgdelim(struct sk_buff *skb)
 124 {
 125         const char pkt_delim = 0xc0;
 126
 127         memcpy(skb_put(skb, 1), &pkt_delim, 1);
 128 }
 129
 130 static void bcsp_slip_one_byte(struct sk_buff *skb, u8 c)
 131 {
 132         const char esc_c0[2] = { 0xdb, 0xdc };
 133         const char esc_db[2] = { 0xdb, 0xdd };
 134
 135         switch (c) {
 136         case 0xc0:
 137                 memcpy(skb_put(skb, 2), &esc_c0, 2);
 138                 break;
 139         case 0xdb:
 140                 memcpy(skb_put(skb, 2), &esc_db, 2);
 141                 break;
 142         default:
 143                 memcpy(skb_put(skb, 1), &c, 1);
 144         }
 145 }
 146
 147 static int bcsp_enqueue(struct hci_uart *hu, struct sk_buff *skb)
 148 {
 149         struct bcsp_struct *bcsp = hu->priv;
 150
 151         if (skb->len > 0xFFF) {
 152                 BT_ERR("Packet too long");
 153                 kfree_skb(skb);
 154                 return 0;
 155         }
 156
 157         switch (hci_skb_pkt_type(skb)) {
 158         case HCI_ACLDATA_PKT:
 159         case HCI_COMMAND_PKT:
 160                 skb_queue_tail(&bcsp->rel, skb);
 161                 break;
 162
 163         case HCI_SCODATA_PKT:
 164                 skb_queue_tail(&bcsp->unrel, skb);
 165                 break;
 166
 167         default:
 168                 BT_ERR("Unknown packet type");
 169                 kfree_skb(skb);
 170                 break;
 171         }
 172
 173         return 0;
 174 }
 175
 176 static struct sk_buff *bcsp_prepare_pkt(struct bcsp_struct *bcsp, u8 *data,
 177                 int len, int pkt_type)
 178 {
 179         struct sk_buff *nskb;
 180         u8 hdr[4], chan;
 181         u16 BCSP_CRC_INIT(bcsp_txmsg_crc);
 182         int rel, i;
 183
 184         switch (pkt_type) {
 185         case HCI_ACLDATA_PKT:
 186                 chan = 6;       /* BCSP ACL channel */
 187                 rel = 1;        /* reliable channel */
 188                 break;
 189         case HCI_COMMAND_PKT:
 190                 chan = 5;       /* BCSP cmd/evt channel */
 191                 rel = 1;        /* reliable channel */
 192                 break;
 193         case HCI_SCODATA_PKT:
 194                 chan = 7;       /* BCSP SCO channel */
 195                 rel = 0;        /* unreliable channel */
 196                 break;
 197         case BCSP_LE_PKT:
 198                 chan = 1;       /* BCSP LE channel */
 199                 rel = 0;        /* unreliable channel */
 200                 break;
 201         case BCSP_ACK_PKT:
 202                 chan = 0;       /* BCSP internal channel */
 203                 rel = 0;        /* unreliable channel */
 204                 break;
 205         default:
 206                 BT_ERR("Unknown packet type");
 207                 return NULL;
 208         }
 209
 210         if (hciextn && chan == 5) {
 211                 __le16 opcode = ((struct hci_command_hdr *)data)->opcode;
 212
 213                 /* Vendor specific commands */
 214                 if (hci_opcode_ogf(__le16_to_cpu(opcode)) == 0x3f) {
 215                         u8 desc = *(data + HCI_COMMAND_HDR_SIZE);
 216                         if ((desc & 0xf0) == 0xc0) {
 217                                 data += HCI_COMMAND_HDR_SIZE + 1;
 218                                 len  -= HCI_COMMAND_HDR_SIZE + 1;
 219                                 chan = desc & 0x0f;
 220                         }
 221                 }
 222         }
 223
 224         /* Max len of packet: (original len +4(bcsp hdr) +2(crc))*2
 225          * (because bytes 0xc0 and 0xdb are escaped, worst case is
 226          * when the packet is all made of 0xc0 and 0xdb :) )
 227          * + 2 (0xc0 delimiters at start and end).
 228          */
 229
 230         nskb = alloc_skb((len + 6) * 2 + 2, GFP_ATOMIC);
 231         if (!nskb)
 232                 return NULL;
 233
 234         hci_skb_pkt_type(nskb) = pkt_type;
 235
 236         bcsp_slip_msgdelim(nskb);
 237
 238         hdr[0] = bcsp->rxseq_txack << 3;
 239         bcsp->txack_req = 0;
 240         BT_DBG("We request packet no %u to card", bcsp->rxseq_txack);
 241
 242         if (rel) {
 243                 hdr[0] |= 0x80 + bcsp->msgq_txseq;
 244                 BT_DBG("Sending packet with seqno %u", bcsp->msgq_txseq);
 245                 bcsp->msgq_txseq = (bcsp->msgq_txseq + 1) & 0x07;
 246         }
 247
 248         if (bcsp->use_crc)
 249                 hdr[0] |= 0x40;
 250
 251         hdr[1] = ((len << 4) & 0xff) | chan;
 252         hdr[2] = len >> 4;
 253         hdr[3] = ~(hdr[0] + hdr[1] + hdr[2]);
 254
 255         /* Put BCSP header */
 256         for (i = 0; i < 4; i++) {
 257                 bcsp_slip_one_byte(nskb, hdr[i]);
 258
 259                 if (bcsp->use_crc)
 260                         bcsp_crc_update(&bcsp_txmsg_crc, hdr[i]);
 261         }
 262
 263         /* Put payload */
 264         for (i = 0; i < len; i++) {
 265                 bcsp_slip_one_byte(nskb, data[i]);
 266
 267                 if (bcsp->use_crc)
 268                         bcsp_crc_update(&bcsp_txmsg_crc, data[i]);
 269         }
 270
 271         /* Put CRC */
 272         if (bcsp->use_crc) {
 273                 bcsp_txmsg_crc = bitrev16(bcsp_txmsg_crc);
 274                 bcsp_slip_one_byte(nskb, (u8) ((bcsp_txmsg_crc >> 8) & 0x00ff));
 275                 bcsp_slip_one_byte(nskb, (u8) (bcsp_txmsg_crc & 0x00ff));
 276         }
 277
 278         bcsp_slip_msgdelim(nskb);
 279         return nskb;
 280 }
 281
 282 /* This is a rewrite of pkt_avail in ABCSP */
 283 static struct sk_buff *bcsp_dequeue(struct hci_uart *hu)
 284 {
 285         struct bcsp_struct *bcsp = hu->priv;
 286         unsigned long flags;
 287         struct sk_buff *skb;
 288
 289         /* First of all, check for unreliable messages in the queue,
 290            since they have priority */
 291
 292         skb = skb_dequeue(&bcsp->unrel);
 293         if (skb != NULL) {
 294                 struct sk_buff *nskb;
 295
 296                 nskb = bcsp_prepare_pkt(bcsp, skb->data, skb->len,
 297                                         hci_skb_pkt_type(skb));
 298                 if (nskb) {
 299                         kfree_skb(skb);
 300                         return nskb;
 301                 } else {
 302                         skb_queue_head(&bcsp->unrel, skb);
 303                         BT_ERR("Could not dequeue pkt because alloc_skb failed");
 304                 }
 305         }
 306
 307         /* Now, try to send a reliable pkt. We can only send a
 308          * reliable packet if the number of packets sent but not yet ack'ed
 309          * is < than the winsize
 310          */
 311
 312         spin_lock_irqsave_nested(&bcsp->unack.lock, flags, SINGLE_DEPTH_NESTING);
 313
 314         if (bcsp->unack.qlen < BCSP_TXWINSIZE) {
 315                 skb = skb_dequeue(&bcsp->rel);
 316                 if (skb != NULL) {
 317                         struct sk_buff *nskb;
 318
 319                         nskb = bcsp_prepare_pkt(bcsp, skb->data, skb->len,
 320                                                 hci_skb_pkt_type(skb));
 321                         if (nskb) {
 322                                 __skb_queue_tail(&bcsp->unack, skb);
 323                                 mod_timer(&bcsp->tbcsp, jiffies + HZ / 4);
 324                                 spin_unlock_irqrestore(&bcsp->unack.lock, flags);
 325                                 return nskb;
 326                         } else {
 327                                 skb_queue_head(&bcsp->rel, skb);
 328                                 BT_ERR("Could not dequeue pkt because alloc_skb failed");
 329                         }
 330                 }
 331         }
 332
 333         spin_unlock_irqrestore(&bcsp->unack.lock, flags);
 334
 335         /* We could not send a reliable packet, either because there are
 336          * none or because there are too many unack'ed pkts. Did we receive
 337          * any packets we have not acknowledged yet ?
 338          */
 339
 340         if (bcsp->txack_req) {
 341                 /* if so, craft an empty ACK pkt and send it on BCSP unreliable
 342                  * channel 0
 343                  */
 344                 struct sk_buff *nskb = bcsp_prepare_pkt(bcsp, NULL, 0, BCSP_ACK_PKT);
 345                 return nskb;
 346         }
 347
 348         /* We have nothing to send */
 349         return NULL;
 350 }
 351
 352 static int bcsp_flush(struct hci_uart *hu)
 353 {
 354         BT_DBG("hu %p", hu);
 355         return 0;
 356 }
 357
 358 /* Remove ack'ed packets */
 359 static void bcsp_pkt_cull(struct bcsp_struct *bcsp)
 360 {
 361         struct sk_buff *skb, *tmp;
 362         unsigned long flags;
 363         int i, pkts_to_be_removed;
 364         u8 seqno;
 365
 366         spin_lock_irqsave(&bcsp->unack.lock, flags);
 367
 368         pkts_to_be_removed = skb_queue_len(&bcsp->unack);
 369         seqno = bcsp->msgq_txseq;
 370
 371         while (pkts_to_be_removed) {
 372                 if (bcsp->rxack == seqno)
 373                         break;
 374                 pkts_to_be_removed--;
 375                 seqno = (seqno - 1) & 0x07;
 376         }
 377
 378         if (bcsp->rxack != seqno)
 379                 BT_ERR("Peer acked invalid packet");
 380
 381         BT_DBG("Removing %u pkts out of %u, up to seqno %u",
 382                pkts_to_be_removed, skb_queue_len(&bcsp->unack),
 383                (seqno - 1) & 0x07);
 384
 385         i = 0;
 386         skb_queue_walk_safe(&bcsp->unack, skb, tmp) {
 387                 if (i >= pkts_to_be_removed)
 388                         break;
 389                 i++;
 390
 391                 __skb_unlink(skb, &bcsp->unack);
 392                 kfree_skb(skb);
 393         }
 394
 395         if (skb_queue_empty(&bcsp->unack))
 396                 del_timer(&bcsp->tbcsp);
 397
 398         spin_unlock_irqrestore(&bcsp->unack.lock, flags);
 399
 400         if (i != pkts_to_be_removed)
 401                 BT_ERR("Removed only %u out of %u pkts", i, pkts_to_be_removed);
 402 }
 403
 404 /* Handle BCSP link-establishment packets. When we
 405  * detect a "sync" packet, symptom that the BT module has reset,
 406  * we do nothing :) (yet)
 407  */
 408 static void bcsp_handle_le_pkt(struct hci_uart *hu)
 409 {
 410         struct bcsp_struct *bcsp = hu->priv;
 411         u8 conf_pkt[4]     = { 0xad, 0xef, 0xac, 0xed };
 412         u8 conf_rsp_pkt[4] = { 0xde, 0xad, 0xd0, 0xd0 };
 413         u8 sync_pkt[4]     = { 0xda, 0xdc, 0xed, 0xed };
 414
 415         /* spot "conf" pkts and reply with a "conf rsp" pkt */
 416         if (bcsp->rx_skb->data[1] >> 4 == 4 && bcsp->rx_skb->data[2] == 0 &&
 417                         !memcmp(&bcsp->rx_skb->data[4], conf_pkt, 4)) {
 418                 struct sk_buff *nskb = alloc_skb(4, GFP_ATOMIC);
 419
 420                 BT_DBG("Found a LE conf pkt");
 421                 if (!nskb)
 422                         return;
 423                 memcpy(skb_put(nskb, 4), conf_rsp_pkt, 4);
 424                 hci_skb_pkt_type(nskb) = BCSP_LE_PKT;
 425
 426                 skb_queue_head(&bcsp->unrel, nskb);
 427                 hci_uart_tx_wakeup(hu);
 428         }
 429         /* Spot "sync" pkts. If we find one...disaster! */
 430         else if (bcsp->rx_skb->data[1] >> 4 == 4 && bcsp->rx_skb->data[2] == 0 &&
 431                         !memcmp(&bcsp->rx_skb->data[4], sync_pkt, 4)) {
 432                 BT_ERR("Found a LE sync pkt, card has reset");
 433         }
 434 }
 435
 436 static inline void bcsp_unslip_one_byte(struct bcsp_struct *bcsp, unsigned char byte)
 437 {
 438         const u8 c0 = 0xc0, db = 0xdb;
 439
 440         switch (bcsp->rx_esc_state) {
 441         case BCSP_ESCSTATE_NOESC:
 442                 switch (byte) {
 443                 case 0xdb:
 444                         bcsp->rx_esc_state = BCSP_ESCSTATE_ESC;
 445                         break;
 446                 default:
 447                         memcpy(skb_put(bcsp->rx_skb, 1), &byte, 1);
 448                         if ((bcsp->rx_skb->data[0] & 0x40) != 0 &&
 449                                         bcsp->rx_state != BCSP_W4_CRC)
 450                                 bcsp_crc_update(&bcsp->message_crc, byte);
 451                         bcsp->rx_count--;
 452                 }
 453                 break;
 454
 455         case BCSP_ESCSTATE_ESC:
 456                 switch (byte) {
 457                 case 0xdc:
 458                         memcpy(skb_put(bcsp->rx_skb, 1), &c0, 1);
 459                         if ((bcsp->rx_skb->data[0] & 0x40) != 0 &&
 460                                         bcsp->rx_state != BCSP_W4_CRC)
 461                                 bcsp_crc_update(&bcsp->message_crc, 0xc0);
 462                         bcsp->rx_esc_state = BCSP_ESCSTATE_NOESC;
 463                         bcsp->rx_count--;
 464                         break;
 465
 466                 case 0xdd:
 467                         memcpy(skb_put(bcsp->rx_skb, 1), &db, 1);
 468                         if ((bcsp->rx_skb->data[0] & 0x40) != 0 &&
 469                                         bcsp->rx_state != BCSP_W4_CRC)
 470                                 bcsp_crc_update(&bcsp->message_crc, 0xdb);
 471                         bcsp->rx_esc_state = BCSP_ESCSTATE_NOESC;
 472                         bcsp->rx_count--;
 473                         break;
 474
 475                 default:
 476                         BT_ERR("Invalid byte %02x after esc byte", byte);
 477                         kfree_skb(bcsp->rx_skb);
 478                         bcsp->rx_skb = NULL;
 479                         bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
 480                         bcsp->rx_count = 0;
 481                 }
 482         }
 483 }
 484
 485 static void bcsp_complete_rx_pkt(struct hci_uart *hu)
 486 {
 487         struct bcsp_struct *bcsp = hu->priv;
 488         int pass_up;
 489
 490         if (bcsp->rx_skb->data[0] & 0x80) {     /* reliable pkt */
 491                 BT_DBG("Received seqno %u from card", bcsp->rxseq_txack);
 492                 bcsp->rxseq_txack++;
 493                 bcsp->rxseq_txack %= 0x8;
 494                 bcsp->txack_req    = 1;
 495
 496                 /* If needed, transmit an ack pkt */
 497                 hci_uart_tx_wakeup(hu);
 498         }
 499
 500         bcsp->rxack = (bcsp->rx_skb->data[0] >> 3) & 0x07;
 501         BT_DBG("Request for pkt %u from card", bcsp->rxack);
 502
 503         bcsp_pkt_cull(bcsp);
 504         if ((bcsp->rx_skb->data[1] & 0x0f) == 6 &&
 505                         bcsp->rx_skb->data[0] & 0x80) {
 506                 hci_skb_pkt_type(bcsp->rx_skb) = HCI_ACLDATA_PKT;
 507                 pass_up = 1;
 508         } else if ((bcsp->rx_skb->data[1] & 0x0f) == 5 &&
 509                         bcsp->rx_skb->data[0] & 0x80) {
 510                 hci_skb_pkt_type(bcsp->rx_skb) = HCI_EVENT_PKT;
 511                 pass_up = 1;
 512         } else if ((bcsp->rx_skb->data[1] & 0x0f) == 7) {
 513                 hci_skb_pkt_type(bcsp->rx_skb) = HCI_SCODATA_PKT;
 514                 pass_up = 1;
 515         } else if ((bcsp->rx_skb->data[1] & 0x0f) == 1 &&
 516                         !(bcsp->rx_skb->data[0] & 0x80)) {
 517                 bcsp_handle_le_pkt(hu);
 518                 pass_up = 0;
 519         } else
 520                 pass_up = 0;
 521
 522         if (!pass_up) {
 523                 struct hci_event_hdr hdr;
 524                 u8 desc = (bcsp->rx_skb->data[1] & 0x0f);
 525
 526                 if (desc != 0 && desc != 1) {
 527                         if (hciextn) {
 528                                 desc |= 0xc0;
 529                                 skb_pull(bcsp->rx_skb, 4);
 530                                 memcpy(skb_push(bcsp->rx_skb, 1), &desc, 1);
 531
 532                                 hdr.evt = 0xff;
 533                                 hdr.plen = bcsp->rx_skb->len;
 534                                 memcpy(skb_push(bcsp->rx_skb, HCI_EVENT_HDR_SIZE), &hdr, HCI_EVENT_HDR_SIZE);
 535                                 hci_skb_pkt_type(bcsp->rx_skb) = HCI_EVENT_PKT;
 536
 537                                 hci_recv_frame(hu->hdev, bcsp->rx_skb);
 538                         } else {
 539                                 BT_ERR("Packet for unknown channel (%u %s)",
 540                                         bcsp->rx_skb->data[1] & 0x0f,
 541                                         bcsp->rx_skb->data[0] & 0x80 ?
 542                                         "reliable" : "unreliable");
 543                                 kfree_skb(bcsp->rx_skb);
 544                         }
 545                 } else
 546                         kfree_skb(bcsp->rx_skb);
 547         } else {
 548                 /* Pull out BCSP hdr */
 549                 skb_pull(bcsp->rx_skb, 4);
 550
 551                 hci_recv_frame(hu->hdev, bcsp->rx_skb);
 552         }
 553
 554         bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
 555         bcsp->rx_skb = NULL;
 556 }
 557
 558 static u16 bscp_get_crc(struct bcsp_struct *bcsp)
 559 {
 560         return get_unaligned_be16(&bcsp->rx_skb->data[bcsp->rx_skb->len - 2]);
 561 }
 562
 563 /* Recv data */
 564 static int bcsp_recv(struct hci_uart *hu, const void *data, int count)
 565 {
 566         struct bcsp_struct *bcsp = hu->priv;
 567         const unsigned char *ptr;
 568
 569         BT_DBG("hu %p count %d rx_state %d rx_count %ld",
 570                 hu, count, bcsp->rx_state, bcsp->rx_count);
 571
 572         ptr = data;
 573         while (count) {
 574                 if (bcsp->rx_count) {
 575                         if (*ptr == 0xc0) {
 576                                 BT_ERR("Short BCSP packet");
 577                                 kfree_skb(bcsp->rx_skb);
 578                                 bcsp->rx_state = BCSP_W4_PKT_START;
 579                                 bcsp->rx_count = 0;
 580                         } else
 581                                 bcsp_unslip_one_byte(bcsp, *ptr);
 582
 583                         ptr++; count--;
 584                         continue;
 585                 }
 586
 587                 switch (bcsp->rx_state) {
 588                 case BCSP_W4_BCSP_HDR:
 589                         if ((0xff & (u8) ~ (bcsp->rx_skb->data[0] + bcsp->rx_skb->data[1] +
 590                                         bcsp->rx_skb->data[2])) != bcsp->rx_skb->data[3]) {
 591                                 BT_ERR("Error in BCSP hdr checksum");
 592                                 kfree_skb(bcsp->rx_skb);
 593                                 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
 594                                 bcsp->rx_count = 0;
 595                                 continue;
 596                         }
 597                         if (bcsp->rx_skb->data[0] & 0x80        /* reliable pkt */
 598                                                 && (bcsp->rx_skb->data[0] & 0x07) != bcsp->rxseq_txack) {
 599                                 BT_ERR("Out-of-order packet arrived, got %u expected %u",
 600                                         bcsp->rx_skb->data[0] & 0x07, bcsp->rxseq_txack);
 601
 602                                 kfree_skb(bcsp->rx_skb);
 603                                 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
 604                                 bcsp->rx_count = 0;
 605                                 continue;
 606                         }
 607                         bcsp->rx_state = BCSP_W4_DATA;
 608                         bcsp->rx_count = (bcsp->rx_skb->data[1] >> 4) +
 609                                         (bcsp->rx_skb->data[2] << 4);   /* May be 0 */
 610                         continue;
 611
 612                 case BCSP_W4_DATA:
 613                         if (bcsp->rx_skb->data[0] & 0x40) {     /* pkt with crc */
 614                                 bcsp->rx_state = BCSP_W4_CRC;
 615                                 bcsp->rx_count = 2;
 616                         } else
 617                                 bcsp_complete_rx_pkt(hu);
 618                         continue;
 619
 620                 case BCSP_W4_CRC:
 621                         if (bitrev16(bcsp->message_crc) != bscp_get_crc(bcsp)) {
 622                                 BT_ERR("Checksum failed: computed %04x received %04x",
 623                                         bitrev16(bcsp->message_crc),
 624                                         bscp_get_crc(bcsp));
 625
 626                                 kfree_skb(bcsp->rx_skb);
 627                                 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
 628                                 bcsp->rx_count = 0;
 629                                 continue;
 630                         }
 631                         skb_trim(bcsp->rx_skb, bcsp->rx_skb->len - 2);
 632                         bcsp_complete_rx_pkt(hu);
 633                         continue;
 634
 635                 case BCSP_W4_PKT_DELIMITER:
 636                         switch (*ptr) {
 637                         case 0xc0:
 638                                 bcsp->rx_state = BCSP_W4_PKT_START;
 639                                 break;
 640                         default:
 641                                 /*BT_ERR("Ignoring byte %02x", *ptr);*/
 642                                 break;
 643                         }
 644                         ptr++; count--;
 645                         break;
 646
 647                 case BCSP_W4_PKT_START:
 648                         switch (*ptr) {
 649                         case 0xc0:
 650                                 ptr++; count--;
 651                                 break;
 652
 653                         default:
 654                                 bcsp->rx_state = BCSP_W4_BCSP_HDR;
 655                                 bcsp->rx_count = 4;
 656                                 bcsp->rx_esc_state = BCSP_ESCSTATE_NOESC;
 657                                 BCSP_CRC_INIT(bcsp->message_crc);
 658
 659                                 /* Do not increment ptr or decrement count
 660                                  * Allocate packet. Max len of a BCSP pkt=
 661                                  * 0xFFF (payload) +4 (header) +2 (crc)
 662                                  */
 663
 664                                 bcsp->rx_skb = bt_skb_alloc(0x1005, GFP_ATOMIC);
 665                                 if (!bcsp->rx_skb) {
 666                                         BT_ERR("Can't allocate mem for new packet");
 667                                         bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
 668                                         bcsp->rx_count = 0;
 669                                         return 0;
 670                                 }
 671                                 break;
 672                         }
 673                         break;
 674                 }
 675         }
 676         return count;
 677 }
 678
 679         /* Arrange to retransmit all messages in the relq. */
 680 static void bcsp_timed_event(unsigned long arg)
 681 {
 682         struct hci_uart *hu = (struct hci_uart *) arg;
 683         struct bcsp_struct *bcsp = hu->priv;
 684         struct sk_buff *skb;
 685         unsigned long flags;
 686
 687         BT_DBG("hu %p retransmitting %u pkts", hu, bcsp->unack.qlen);
 688
 689         spin_lock_irqsave_nested(&bcsp->unack.lock, flags, SINGLE_DEPTH_NESTING);
 690
 691         while ((skb = __skb_dequeue_tail(&bcsp->unack)) != NULL) {
 692                 bcsp->msgq_txseq = (bcsp->msgq_txseq - 1) & 0x07;
 693                 skb_queue_head(&bcsp->rel, skb);
 694         }
 695
 696         spin_unlock_irqrestore(&bcsp->unack.lock, flags);
 697
 698         hci_uart_tx_wakeup(hu);
 699 }
 700
 701 static int bcsp_open(struct hci_uart *hu)
 702 {
 703         struct bcsp_struct *bcsp;
 704
 705         BT_DBG("hu %p", hu);
 706
 707         bcsp = kzalloc(sizeof(*bcsp), GFP_KERNEL);
 708         if (!bcsp)
 709                 return -ENOMEM;
 710
 711         hu->priv = bcsp;
 712         skb_queue_head_init(&bcsp->unack);
 713         skb_queue_head_init(&bcsp->rel);
 714         skb_queue_head_init(&bcsp->unrel);
 715
 716         init_timer(&bcsp->tbcsp);
 717         bcsp->tbcsp.function = bcsp_timed_event;
 718         bcsp->tbcsp.data     = (u_long) hu;
 719
 720         bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
 721
 722         if (txcrc)
 723                 bcsp->use_crc = 1;
 724
 725         return 0;
 726 }
 727
 728 static int bcsp_close(struct hci_uart *hu)
 729 {
 730         struct bcsp_struct *bcsp = hu->priv;
 731
 732         del_timer_sync(&bcsp->tbcsp);
 733
 734         hu->priv = NULL;
 735
 736         BT_DBG("hu %p", hu);
 737
 738         skb_queue_purge(&bcsp->unack);
 739         skb_queue_purge(&bcsp->rel);
 740         skb_queue_purge(&bcsp->unrel);
 741
 742         kfree(bcsp);
 743         return 0;
 744 }
 745
 746 static const struct hci_uart_proto bcsp = {
 747         .id             = HCI_UART_BCSP,
 748         .name           = "BCSP",
 749         .open           = bcsp_open,
 750         .close          = bcsp_close,
 751         .enqueue        = bcsp_enqueue,
 752         .dequeue        = bcsp_dequeue,
 753         .recv           = bcsp_recv,
 754         .flush          = bcsp_flush
 755 };
 756
 757 int __init bcsp_init(void)
 758 {
 759         return hci_uart_register_proto(&bcsp);
 760 }
 761
 762 int __exit bcsp_deinit(void)
 763 {
 764         return hci_uart_unregister_proto(&bcsp);
 765 }
 766
 767 module_param(txcrc, bool, 0644);
 768 MODULE_PARM_DESC(txcrc, "Transmit CRC with every BCSP packet");
 769
 770 module_param(hciextn, bool, 0644);
 771 MODULE_PARM_DESC(hciextn, "Convert HCI Extensions into BCSP packets");