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
  96 static const u16 crc_table[] = {
  97         0x0000, 0x1081, 0x2102, 0x3183,
  98         0x4204, 0x5285, 0x6306, 0x7387,
  99         0x8408, 0x9489, 0xa50a, 0xb58b,
 100         0xc60c, 0xd68d, 0xe70e, 0xf78f
 101 };
 102
 103 /* Initialise the crc calculator */
 104 #define BCSP_CRC_INIT(x) x = 0xffff
 105
 106 /* Update crc with next data byte
 107  *
 108  * Implementation note
 109  *     The data byte is treated as two nibbles.  The crc is generated
 110  *     in reverse, i.e., bits are fed into the register from the top.
 111  */
 112 static void bcsp_crc_update(u16 *crc, u8 d)
 113 {
 114         u16 reg = *crc;
 115
 116         reg = (reg >> 4) ^ crc_table[(reg ^ d) & 0x000f];
 117         reg = (reg >> 4) ^ crc_table[(reg ^ (d >> 4)) & 0x000f];
 118
 119         *crc = reg;
 120 }
 121
 122 /* ---- BCSP core ---- */
 123
 124 static void bcsp_slip_msgdelim(struct sk_buff *skb)
 125 {
 126         const char pkt_delim = 0xc0;
 127
 128         memcpy(skb_put(skb, 1), &pkt_delim, 1);
 129 }
 130
 131 static void bcsp_slip_one_byte(struct sk_buff *skb, u8 c)
 132 {
 133         const char esc_c0[2] = { 0xdb, 0xdc };
 134         const char esc_db[2] = { 0xdb, 0xdd };
 135
 136         switch (c) {
 137         case 0xc0:
 138                 memcpy(skb_put(skb, 2), &esc_c0, 2);
 139                 break;
 140         case 0xdb:
 141                 memcpy(skb_put(skb, 2), &esc_db, 2);
 142                 break;
 143         default:
 144                 memcpy(skb_put(skb, 1), &c, 1);
 145         }
 146 }
 147
 148 static int bcsp_enqueue(struct hci_uart *hu, struct sk_buff *skb)
 149 {
 150         struct bcsp_struct *bcsp = hu->priv;
 151
 152         if (skb->len > 0xFFF) {
 153                 BT_ERR("Packet too long");
 154                 kfree_skb(skb);
 155                 return 0;
 156         }
 157
 158         switch (hci_skb_pkt_type(skb)) {
 159         case HCI_ACLDATA_PKT:
 160         case HCI_COMMAND_PKT:
 161                 skb_queue_tail(&bcsp->rel, skb);
 162                 break;
 163
 164         case HCI_SCODATA_PKT:
 165                 skb_queue_tail(&bcsp->unrel, skb);
 166                 break;
 167
 168         default:
 169                 BT_ERR("Unknown packet type");
 170                 kfree_skb(skb);
 171                 break;
 172         }
 173
 174         return 0;
 175 }
 176
 177 static struct sk_buff *bcsp_prepare_pkt(struct bcsp_struct *bcsp, u8 *data,
 178                                         int len, int pkt_type)
 179 {
 180         struct sk_buff *nskb;
 181         u8 hdr[4], chan;
 182         u16 BCSP_CRC_INIT(bcsp_txmsg_crc);
 183         int rel, i;
 184
 185         switch (pkt_type) {
 186         case HCI_ACLDATA_PKT:
 187                 chan = 6;       /* BCSP ACL channel */
 188                 rel = 1;        /* reliable channel */
 189                 break;
 190         case HCI_COMMAND_PKT:
 191                 chan = 5;       /* BCSP cmd/evt channel */
 192                 rel = 1;        /* reliable channel */
 193                 break;
 194         case HCI_SCODATA_PKT:
 195                 chan = 7;       /* BCSP SCO channel */
 196                 rel = 0;        /* unreliable channel */
 197                 break;
 198         case BCSP_LE_PKT:
 199                 chan = 1;       /* BCSP LE channel */
 200                 rel = 0;        /* unreliable channel */
 201                 break;
 202         case BCSP_ACK_PKT:
 203                 chan = 0;       /* BCSP internal channel */
 204                 rel = 0;        /* unreliable channel */
 205                 break;
 206         default:
 207                 BT_ERR("Unknown packet type");
 208                 return NULL;
 209         }
 210
 211         if (hciextn && chan == 5) {
 212                 __le16 opcode = ((struct hci_command_hdr *)data)->opcode;
 213
 214                 /* Vendor specific commands */
 215                 if (hci_opcode_ogf(__le16_to_cpu(opcode)) == 0x3f) {
 216                         u8 desc = *(data + HCI_COMMAND_HDR_SIZE);
 217
 218                         if ((desc & 0xf0) == 0xc0) {
 219                                 data += HCI_COMMAND_HDR_SIZE + 1;
 220                                 len  -= HCI_COMMAND_HDR_SIZE + 1;
 221                                 chan = desc & 0x0f;
 222                         }
 223                 }
 224         }
 225
 226         /* Max len of packet: (original len +4(bcsp hdr) +2(crc))*2
 227          * (because bytes 0xc0 and 0xdb are escaped, worst case is
 228          * when the packet is all made of 0xc0 and 0xdb :) )
 229          * + 2 (0xc0 delimiters at start and end).
 230          */
 231
 232         nskb = alloc_skb((len + 6) * 2 + 2, GFP_ATOMIC);
 233         if (!nskb)
 234                 return NULL;
 235
 236         hci_skb_pkt_type(nskb) = pkt_type;
 237
 238         bcsp_slip_msgdelim(nskb);
 239
 240         hdr[0] = bcsp->rxseq_txack << 3;
 241         bcsp->txack_req = 0;
 242         BT_DBG("We request packet no %u to card", bcsp->rxseq_txack);
 243
 244         if (rel) {
 245                 hdr[0] |= 0x80 + bcsp->msgq_txseq;
 246                 BT_DBG("Sending packet with seqno %u", bcsp->msgq_txseq);
 247                 bcsp->msgq_txseq = (bcsp->msgq_txseq + 1) & 0x07;
 248         }
 249
 250         if (bcsp->use_crc)
 251                 hdr[0] |= 0x40;
 252
 253         hdr[1] = ((len << 4) & 0xff) | chan;
 254         hdr[2] = len >> 4;
 255         hdr[3] = ~(hdr[0] + hdr[1] + hdr[2]);
 256
 257         /* Put BCSP header */
 258         for (i = 0; i < 4; i++) {
 259                 bcsp_slip_one_byte(nskb, hdr[i]);
 260
 261                 if (bcsp->use_crc)
 262                         bcsp_crc_update(&bcsp_txmsg_crc, hdr[i]);
 263         }
 264
 265         /* Put payload */
 266         for (i = 0; i < len; i++) {
 267                 bcsp_slip_one_byte(nskb, data[i]);
 268
 269                 if (bcsp->use_crc)
 270                         bcsp_crc_update(&bcsp_txmsg_crc, data[i]);
 271         }
 272
 273         /* Put CRC */
 274         if (bcsp->use_crc) {
 275                 bcsp_txmsg_crc = bitrev16(bcsp_txmsg_crc);
 276                 bcsp_slip_one_byte(nskb, (u8)((bcsp_txmsg_crc >> 8) & 0x00ff));
 277                 bcsp_slip_one_byte(nskb, (u8)(bcsp_txmsg_crc & 0x00ff));
 278         }
 279
 280         bcsp_slip_msgdelim(nskb);
 281         return nskb;
 282 }
 283
 284 /* This is a rewrite of pkt_avail in ABCSP */
 285 static struct sk_buff *bcsp_dequeue(struct hci_uart *hu)
 286 {
 287         struct bcsp_struct *bcsp = hu->priv;
 288         unsigned long flags;
 289         struct sk_buff *skb;
 290
 291         /* First of all, check for unreliable messages in the queue,
 292          * since they have priority
 293          */
 294
 295         skb = skb_dequeue(&bcsp->unrel);
 296         if (skb != NULL) {
 297                 struct sk_buff *nskb;
 298
 299                 nskb = bcsp_prepare_pkt(bcsp, skb->data, skb->len,
 300                                         hci_skb_pkt_type(skb));
 301                 if (nskb) {
 302                         kfree_skb(skb);
 303                         return nskb;
 304                 } else {
 305                         skb_queue_head(&bcsp->unrel, skb);
 306                         BT_ERR("Could not dequeue pkt because alloc_skb failed");
 307                 }
 308         }
 309
 310         /* Now, try to send a reliable pkt. We can only send a
 311          * reliable packet if the number of packets sent but not yet ack'ed
 312          * is < than the winsize
 313          */
 314
 315         spin_lock_irqsave_nested(&bcsp->unack.lock, flags, SINGLE_DEPTH_NESTING);
 316
 317         if (bcsp->unack.qlen < BCSP_TXWINSIZE) {
 318                 skb = skb_dequeue(&bcsp->rel);
 319                 if (skb != NULL) {
 320                         struct sk_buff *nskb;
 321
 322                         nskb = bcsp_prepare_pkt(bcsp, skb->data, skb->len,
 323                                                 hci_skb_pkt_type(skb));
 324                         if (nskb) {
 325                                 __skb_queue_tail(&bcsp->unack, skb);
 326                                 mod_timer(&bcsp->tbcsp, jiffies + HZ / 4);
 327                                 spin_unlock_irqrestore(&bcsp->unack.lock, flags);
 328                                 return nskb;
 329                         } else {
 330                                 skb_queue_head(&bcsp->rel, skb);
 331                                 BT_ERR("Could not dequeue pkt because alloc_skb failed");
 332                         }
 333                 }
 334         }
 335
 336         spin_unlock_irqrestore(&bcsp->unack.lock, flags);
 337
 338         /* We could not send a reliable packet, either because there are
 339          * none or because there are too many unack'ed pkts. Did we receive
 340          * any packets we have not acknowledged yet ?
 341          */
 342
 343         if (bcsp->txack_req) {
 344                 /* if so, craft an empty ACK pkt and send it on BCSP unreliable
 345                  * channel 0
 346                  */
 347                 struct sk_buff *nskb = bcsp_prepare_pkt(bcsp, NULL, 0, BCSP_ACK_PKT);
 348                 return nskb;
 349         }
 350
 351         /* We have nothing to send */
 352         return NULL;
 353 }
 354
 355 static int bcsp_flush(struct hci_uart *hu)
 356 {
 357         BT_DBG("hu %p", hu);
 358         return 0;
 359 }
 360
 361 /* Remove ack'ed packets */
 362 static void bcsp_pkt_cull(struct bcsp_struct *bcsp)
 363 {
 364         struct sk_buff *skb, *tmp;
 365         unsigned long flags;
 366         int i, pkts_to_be_removed;
 367         u8 seqno;
 368
 369         spin_lock_irqsave(&bcsp->unack.lock, flags);
 370
 371         pkts_to_be_removed = skb_queue_len(&bcsp->unack);
 372         seqno = bcsp->msgq_txseq;
 373
 374         while (pkts_to_be_removed) {
 375                 if (bcsp->rxack == seqno)
 376                         break;
 377                 pkts_to_be_removed--;
 378                 seqno = (seqno - 1) & 0x07;
 379         }
 380
 381         if (bcsp->rxack != seqno)
 382                 BT_ERR("Peer acked invalid packet");
 383
 384         BT_DBG("Removing %u pkts out of %u, up to seqno %u",
 385                pkts_to_be_removed, skb_queue_len(&bcsp->unack),
 386                (seqno - 1) & 0x07);
 387
 388         i = 0;
 389         skb_queue_walk_safe(&bcsp->unack, skb, tmp) {
 390                 if (i >= pkts_to_be_removed)
 391                         break;
 392                 i++;
 393
 394                 __skb_unlink(skb, &bcsp->unack);
 395                 kfree_skb(skb);
 396         }
 397
 398         if (skb_queue_empty(&bcsp->unack))
 399                 del_timer(&bcsp->tbcsp);
 400
 401         spin_unlock_irqrestore(&bcsp->unack.lock, flags);
 402
 403         if (i != pkts_to_be_removed)
 404                 BT_ERR("Removed only %u out of %u pkts", i, pkts_to_be_removed);
 405 }
 406
 407 /* Handle BCSP link-establishment packets. When we
 408  * detect a "sync" packet, symptom that the BT module has reset,
 409  * we do nothing :) (yet)
 410  */
 411 static void bcsp_handle_le_pkt(struct hci_uart *hu)
 412 {
 413         struct bcsp_struct *bcsp = hu->priv;
 414         u8 conf_pkt[4]     = { 0xad, 0xef, 0xac, 0xed };
 415         u8 conf_rsp_pkt[4] = { 0xde, 0xad, 0xd0, 0xd0 };
 416         u8 sync_pkt[4]     = { 0xda, 0xdc, 0xed, 0xed };
 417
 418         /* spot "conf" pkts and reply with a "conf rsp" pkt */
 419         if (bcsp->rx_skb->data[1] >> 4 == 4 && bcsp->rx_skb->data[2] == 0 &&
 420             !memcmp(&bcsp->rx_skb->data[4], conf_pkt, 4)) {
 421                 struct sk_buff *nskb = alloc_skb(4, GFP_ATOMIC);
 422
 423                 BT_DBG("Found a LE conf pkt");
 424                 if (!nskb)
 425                         return;
 426                 memcpy(skb_put(nskb, 4), conf_rsp_pkt, 4);
 427                 hci_skb_pkt_type(nskb) = BCSP_LE_PKT;
 428
 429                 skb_queue_head(&bcsp->unrel, nskb);
 430                 hci_uart_tx_wakeup(hu);
 431         }
 432         /* Spot "sync" pkts. If we find one...disaster! */
 433         else if (bcsp->rx_skb->data[1] >> 4 == 4 && bcsp->rx_skb->data[2] == 0 &&
 434                  !memcmp(&bcsp->rx_skb->data[4], sync_pkt, 4)) {
 435                 BT_ERR("Found a LE sync pkt, card has reset");
 436         }
 437 }
 438
 439 static inline void bcsp_unslip_one_byte(struct bcsp_struct *bcsp, unsigned char byte)
 440 {
 441         const u8 c0 = 0xc0, db = 0xdb;
 442
 443         switch (bcsp->rx_esc_state) {
 444         case BCSP_ESCSTATE_NOESC:
 445                 switch (byte) {
 446                 case 0xdb:
 447                         bcsp->rx_esc_state = BCSP_ESCSTATE_ESC;
 448                         break;
 449                 default:
 450                         memcpy(skb_put(bcsp->rx_skb, 1), &byte, 1);
 451                         if ((bcsp->rx_skb->data[0] & 0x40) != 0 &&
 452                             bcsp->rx_state != BCSP_W4_CRC)
 453                                 bcsp_crc_update(&bcsp->message_crc, byte);
 454                         bcsp->rx_count--;
 455                 }
 456                 break;
 457
 458         case BCSP_ESCSTATE_ESC:
 459                 switch (byte) {
 460                 case 0xdc:
 461                         memcpy(skb_put(bcsp->rx_skb, 1), &c0, 1);
 462                         if ((bcsp->rx_skb->data[0] & 0x40) != 0 &&
 463                             bcsp->rx_state != BCSP_W4_CRC)
 464                                 bcsp_crc_update(&bcsp->message_crc, 0xc0);
 465                         bcsp->rx_esc_state = BCSP_ESCSTATE_NOESC;
 466                         bcsp->rx_count--;
 467                         break;
 468
 469                 case 0xdd:
 470                         memcpy(skb_put(bcsp->rx_skb, 1), &db, 1);
 471                         if ((bcsp->rx_skb->data[0] & 0x40) != 0 &&
 472                             bcsp->rx_state != BCSP_W4_CRC)
 473                                 bcsp_crc_update(&bcsp->message_crc, 0xdb);
 474                         bcsp->rx_esc_state = BCSP_ESCSTATE_NOESC;
 475                         bcsp->rx_count--;
 476                         break;
 477
 478                 default:
 479                         BT_ERR("Invalid byte %02x after esc byte", byte);
 480                         kfree_skb(bcsp->rx_skb);
 481                         bcsp->rx_skb = NULL;
 482                         bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
 483                         bcsp->rx_count = 0;
 484                 }
 485         }
 486 }
 487
 488 static void bcsp_complete_rx_pkt(struct hci_uart *hu)
 489 {
 490         struct bcsp_struct *bcsp = hu->priv;
 491         int pass_up = 0;
 492
 493         if (bcsp->rx_skb->data[0] & 0x80) {     /* reliable pkt */
 494                 BT_DBG("Received seqno %u from card", bcsp->rxseq_txack);
 495
 496                 /* check the rx sequence number is as expected */
 497                 if ((bcsp->rx_skb->data[0] & 0x07) == bcsp->rxseq_txack) {
 498                         bcsp->rxseq_txack++;
 499                         bcsp->rxseq_txack %= 0x8;
 500                 } else {
 501                         /* handle re-transmitted packet or
 502                          * when packet was missed
 503                          */
 504                         BT_ERR("Out-of-order packet arrived, got %u expected %u",
 505                                bcsp->rx_skb->data[0] & 0x07, bcsp->rxseq_txack);
 506
 507                         /* do not process out-of-order packet payload */
 508                         pass_up = 2;
 509                 }
 510
 511                 /* send current txack value to all received reliable packets */
 512                 bcsp->txack_req = 1;
 513
 514                 /* If needed, transmit an ack pkt */
 515                 hci_uart_tx_wakeup(hu);
 516         }
 517
 518         bcsp->rxack = (bcsp->rx_skb->data[0] >> 3) & 0x07;
 519         BT_DBG("Request for pkt %u from card", bcsp->rxack);
 520
 521         /* handle received ACK indications,
 522          * including those from out-of-order packets
 523          */
 524         bcsp_pkt_cull(bcsp);
 525
 526         if (pass_up != 2) {
 527                 if ((bcsp->rx_skb->data[1] & 0x0f) == 6 &&
 528                     (bcsp->rx_skb->data[0] & 0x80)) {
 529                         hci_skb_pkt_type(bcsp->rx_skb) = HCI_ACLDATA_PKT;
 530                         pass_up = 1;
 531                 } else if ((bcsp->rx_skb->data[1] & 0x0f) == 5 &&
 532                            (bcsp->rx_skb->data[0] & 0x80)) {
 533                         hci_skb_pkt_type(bcsp->rx_skb) = HCI_EVENT_PKT;
 534                         pass_up = 1;
 535                 } else if ((bcsp->rx_skb->data[1] & 0x0f) == 7) {
 536                         hci_skb_pkt_type(bcsp->rx_skb) = HCI_SCODATA_PKT;
 537                         pass_up = 1;
 538                 } else if ((bcsp->rx_skb->data[1] & 0x0f) == 1 &&
 539                            !(bcsp->rx_skb->data[0] & 0x80)) {
 540                         bcsp_handle_le_pkt(hu);
 541                         pass_up = 0;
 542                 } else {
 543                         pass_up = 0;
 544                 }
 545         }
 546
 547         if (pass_up == 0) {
 548                 struct hci_event_hdr hdr;
 549                 u8 desc = (bcsp->rx_skb->data[1] & 0x0f);
 550
 551                 if (desc != 0 && desc != 1) {
 552                         if (hciextn) {
 553                                 desc |= 0xc0;
 554                                 skb_pull(bcsp->rx_skb, 4);
 555                                 memcpy(skb_push(bcsp->rx_skb, 1), &desc, 1);
 556
 557                                 hdr.evt = 0xff;
 558                                 hdr.plen = bcsp->rx_skb->len;
 559                                 memcpy(skb_push(bcsp->rx_skb, HCI_EVENT_HDR_SIZE), &hdr, HCI_EVENT_HDR_SIZE);
 560                                 hci_skb_pkt_type(bcsp->rx_skb) = HCI_EVENT_PKT;
 561
 562                                 hci_recv_frame(hu->hdev, bcsp->rx_skb);
 563                         } else {
 564                                 BT_ERR("Packet for unknown channel (%u %s)",
 565                                        bcsp->rx_skb->data[1] & 0x0f,
 566                                        bcsp->rx_skb->data[0] & 0x80 ?
 567                                        "reliable" : "unreliable");
 568                                 kfree_skb(bcsp->rx_skb);
 569                         }
 570                 } else
 571                         kfree_skb(bcsp->rx_skb);
 572         } else if (pass_up == 1) {
 573                 /* Pull out BCSP hdr */
 574                 skb_pull(bcsp->rx_skb, 4);
 575
 576                 hci_recv_frame(hu->hdev, bcsp->rx_skb);
 577         } else {
 578                 /* ignore packet payload of already ACKed re-transmitted
 579                  * packets or when a packet was missed in the BCSP window
 580                  */
 581                 kfree_skb(bcsp->rx_skb);
 582         }
 583
 584         bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
 585         bcsp->rx_skb = NULL;
 586 }
 587
 588 static u16 bscp_get_crc(struct bcsp_struct *bcsp)
 589 {
 590         return get_unaligned_be16(&bcsp->rx_skb->data[bcsp->rx_skb->len - 2]);
 591 }
 592
 593 /* Recv data */
 594 static int bcsp_recv(struct hci_uart *hu, const void *data, int count)
 595 {
 596         struct bcsp_struct *bcsp = hu->priv;
 597         const unsigned char *ptr;
 598
 599         BT_DBG("hu %p count %d rx_state %d rx_count %ld",
 600                hu, count, bcsp->rx_state, bcsp->rx_count);
 601
 602         ptr = data;
 603         while (count) {
 604                 if (bcsp->rx_count) {
 605                         if (*ptr == 0xc0) {
 606                                 BT_ERR("Short BCSP packet");
 607                                 kfree_skb(bcsp->rx_skb);
 608                                 bcsp->rx_state = BCSP_W4_PKT_START;
 609                                 bcsp->rx_count = 0;
 610                         } else
 611                                 bcsp_unslip_one_byte(bcsp, *ptr);
 612
 613                         ptr++; count--;
 614                         continue;
 615                 }
 616
 617                 switch (bcsp->rx_state) {
 618                 case BCSP_W4_BCSP_HDR:
 619                         if ((0xff & (u8)~(bcsp->rx_skb->data[0] + bcsp->rx_skb->data[1] +
 620                             bcsp->rx_skb->data[2])) != bcsp->rx_skb->data[3]) {
 621                                 BT_ERR("Error in BCSP hdr checksum");
 622                                 kfree_skb(bcsp->rx_skb);
 623                                 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
 624                                 bcsp->rx_count = 0;
 625                                 continue;
 626                         }
 627                         bcsp->rx_state = BCSP_W4_DATA;
 628                         bcsp->rx_count = (bcsp->rx_skb->data[1] >> 4) +
 629                                         (bcsp->rx_skb->data[2] << 4);   /* May be 0 */
 630                         continue;
 631
 632                 case BCSP_W4_DATA:
 633                         if (bcsp->rx_skb->data[0] & 0x40) {     /* pkt with crc */
 634                                 bcsp->rx_state = BCSP_W4_CRC;
 635                                 bcsp->rx_count = 2;
 636                         } else
 637                                 bcsp_complete_rx_pkt(hu);
 638                         continue;
 639
 640                 case BCSP_W4_CRC:
 641                         if (bitrev16(bcsp->message_crc) != bscp_get_crc(bcsp)) {
 642                                 BT_ERR("Checksum failed: computed %04x received %04x",
 643                                        bitrev16(bcsp->message_crc),
 644                                        bscp_get_crc(bcsp));
 645
 646                                 kfree_skb(bcsp->rx_skb);
 647                                 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
 648                                 bcsp->rx_count = 0;
 649                                 continue;
 650                         }
 651                         skb_trim(bcsp->rx_skb, bcsp->rx_skb->len - 2);
 652                         bcsp_complete_rx_pkt(hu);
 653                         continue;
 654
 655                 case BCSP_W4_PKT_DELIMITER:
 656                         switch (*ptr) {
 657                         case 0xc0:
 658                                 bcsp->rx_state = BCSP_W4_PKT_START;
 659                                 break;
 660                         default:
 661                                 /*BT_ERR("Ignoring byte %02x", *ptr);*/
 662                                 break;
 663                         }
 664                         ptr++; count--;
 665                         break;
 666
 667                 case BCSP_W4_PKT_START:
 668                         switch (*ptr) {
 669                         case 0xc0:
 670                                 ptr++; count--;
 671                                 break;
 672
 673                         default:
 674                                 bcsp->rx_state = BCSP_W4_BCSP_HDR;
 675                                 bcsp->rx_count = 4;
 676                                 bcsp->rx_esc_state = BCSP_ESCSTATE_NOESC;
 677                                 BCSP_CRC_INIT(bcsp->message_crc);
 678
 679                                 /* Do not increment ptr or decrement count
 680                                  * Allocate packet. Max len of a BCSP pkt=
 681                                  * 0xFFF (payload) +4 (header) +2 (crc)
 682                                  */
 683
 684                                 bcsp->rx_skb = bt_skb_alloc(0x1005, GFP_ATOMIC);
 685                                 if (!bcsp->rx_skb) {
 686                                         BT_ERR("Can't allocate mem for new packet");
 687                                         bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
 688                                         bcsp->rx_count = 0;
 689                                         return 0;
 690                                 }
 691                                 break;
 692                         }
 693                         break;
 694                 }
 695         }
 696         return count;
 697 }
 698
 699         /* Arrange to retransmit all messages in the relq. */
 700 static void bcsp_timed_event(unsigned long arg)
 701 {
 702         struct hci_uart *hu = (struct hci_uart *)arg;
 703         struct bcsp_struct *bcsp = hu->priv;
 704         struct sk_buff *skb;
 705         unsigned long flags;
 706
 707         BT_DBG("hu %p retransmitting %u pkts", hu, bcsp->unack.qlen);
 708
 709         spin_lock_irqsave_nested(&bcsp->unack.lock, flags, SINGLE_DEPTH_NESTING);
 710
 711         while ((skb = __skb_dequeue_tail(&bcsp->unack)) != NULL) {
 712                 bcsp->msgq_txseq = (bcsp->msgq_txseq - 1) & 0x07;
 713                 skb_queue_head(&bcsp->rel, skb);
 714         }
 715
 716         spin_unlock_irqrestore(&bcsp->unack.lock, flags);
 717
 718         hci_uart_tx_wakeup(hu);
 719 }
 720
 721 static int bcsp_open(struct hci_uart *hu)
 722 {
 723         struct bcsp_struct *bcsp;
 724
 725         BT_DBG("hu %p", hu);
 726
 727         bcsp = kzalloc(sizeof(*bcsp), GFP_KERNEL);
 728         if (!bcsp)
 729                 return -ENOMEM;
 730
 731         hu->priv = bcsp;
 732         skb_queue_head_init(&bcsp->unack);
 733         skb_queue_head_init(&bcsp->rel);
 734         skb_queue_head_init(&bcsp->unrel);
 735
 736         setup_timer(&bcsp->tbcsp, bcsp_timed_event, (u_long)hu);
 737
 738         bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
 739
 740         if (txcrc)
 741                 bcsp->use_crc = 1;
 742
 743         return 0;
 744 }
 745
 746 static int bcsp_close(struct hci_uart *hu)
 747 {
 748         struct bcsp_struct *bcsp = hu->priv;
 749
 750         del_timer_sync(&bcsp->tbcsp);
 751
 752         hu->priv = NULL;
 753
 754         BT_DBG("hu %p", hu);
 755
 756         skb_queue_purge(&bcsp->unack);
 757         skb_queue_purge(&bcsp->rel);
 758         skb_queue_purge(&bcsp->unrel);
 759
 760         kfree(bcsp);
 761         return 0;
 762 }
 763
 764 static const struct hci_uart_proto bcsp = {
 765         .id             = HCI_UART_BCSP,
 766         .name           = "BCSP",
 767         .open           = bcsp_open,
 768         .close          = bcsp_close,
 769         .enqueue        = bcsp_enqueue,
 770         .dequeue        = bcsp_dequeue,
 771         .recv           = bcsp_recv,
 772         .flush          = bcsp_flush
 773 };
 774
 775 int __init bcsp_init(void)
 776 {
 777         return hci_uart_register_proto(&bcsp);
 778 }
 779
 780 int __exit bcsp_deinit(void)
 781 {
 782         return hci_uart_unregister_proto(&bcsp);
 783 }
 784
 785 module_param(txcrc, bool, 0644);
 786 MODULE_PARM_DESC(txcrc, "Transmit CRC with every BCSP packet");
 787
 788 module_param(hciextn, bool, 0644);
 789 MODULE_PARM_DESC(hciextn, "Convert HCI Extensions into BCSP packets");