1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * 4 * Bluetooth HCI UART driver 5 * 6 * Copyright (C) 2002-2003 Fabrizio Gennari <fabrizio.gennari@philips.com> 7 * Copyright (C) 2004-2005 Marcel Holtmann <marcel@holtmann.org> 8 */ 9 10 #include <linux/module.h> 11 12 #include <linux/kernel.h> 13 #include <linux/init.h> 14 #include <linux/types.h> 15 #include <linux/fcntl.h> 16 #include <linux/interrupt.h> 17 #include <linux/ptrace.h> 18 #include <linux/poll.h> 19 20 #include <linux/slab.h> 21 #include <linux/tty.h> 22 #include <linux/errno.h> 23 #include <linux/string.h> 24 #include <linux/signal.h> 25 #include <linux/ioctl.h> 26 #include <linux/skbuff.h> 27 #include <linux/bitrev.h> 28 #include <linux/unaligned.h> 29 30 #include <net/bluetooth/bluetooth.h> 31 #include <net/bluetooth/hci_core.h> 32 33 #include "hci_uart.h" 34 35 static bool txcrc = true; 36 static bool hciextn = true; 37 38 #define BCSP_TXWINSIZE 4 39 40 #define BCSP_ACK_PKT 0x05 41 #define BCSP_LE_PKT 0x06 42 43 struct bcsp_struct { 44 struct sk_buff_head unack; /* Unack'ed packets queue */ 45 struct sk_buff_head rel; /* Reliable packets queue */ 46 struct sk_buff_head unrel; /* Unreliable packets queue */ 47 48 unsigned long rx_count; 49 struct sk_buff *rx_skb; 50 u8 rxseq_txack; /* rxseq == txack. */ 51 u8 rxack; /* Last packet sent by us that the peer ack'ed */ 52 struct timer_list tbcsp; 53 struct hci_uart *hu; 54 55 enum { 56 BCSP_W4_PKT_DELIMITER, 57 BCSP_W4_PKT_START, 58 BCSP_W4_BCSP_HDR, 59 BCSP_W4_DATA, 60 BCSP_W4_CRC 61 } rx_state; 62 63 enum { 64 BCSP_ESCSTATE_NOESC, 65 BCSP_ESCSTATE_ESC 66 } rx_esc_state; 67 68 u8 use_crc; 69 u16 message_crc; 70 u8 txack_req; /* Do we need to send ack's to the peer? */ 71 72 /* Reliable packet sequence number - used to assign seq to each rel pkt. */ 73 u8 msgq_txseq; 74 }; 75 76 /* ---- BCSP CRC calculation ---- */ 77 78 /* Table for calculating CRC for polynomial 0x1021, LSB processed first, 79 * initial value 0xffff, bits shifted in reverse order. 80 */ 81 82 static const u16 crc_table[] = { 83 0x0000, 0x1081, 0x2102, 0x3183, 84 0x4204, 0x5285, 0x6306, 0x7387, 85 0x8408, 0x9489, 0xa50a, 0xb58b, 86 0xc60c, 0xd68d, 0xe70e, 0xf78f 87 }; 88 89 /* Initialise the crc calculator */ 90 #define BCSP_CRC_INIT(x) x = 0xffff 91 92 /* Update crc with next data byte 93 * 94 * Implementation note 95 * The data byte is treated as two nibbles. The crc is generated 96 * in reverse, i.e., bits are fed into the register from the top. 97 */ 98 static void bcsp_crc_update(u16 *crc, u8 d) 99 { 100 u16 reg = *crc; 101 102 reg = (reg >> 4) ^ crc_table[(reg ^ d) & 0x000f]; 103 reg = (reg >> 4) ^ crc_table[(reg ^ (d >> 4)) & 0x000f]; 104 105 *crc = reg; 106 } 107 108 /* ---- BCSP core ---- */ 109 110 static void bcsp_slip_msgdelim(struct sk_buff *skb) 111 { 112 const char pkt_delim = 0xc0; 113 114 skb_put_data(skb, &pkt_delim, 1); 115 } 116 117 static void bcsp_slip_one_byte(struct sk_buff *skb, u8 c) 118 { 119 const char esc_c0[2] = { 0xdb, 0xdc }; 120 const char esc_db[2] = { 0xdb, 0xdd }; 121 122 switch (c) { 123 case 0xc0: 124 skb_put_data(skb, &esc_c0, 2); 125 break; 126 case 0xdb: 127 skb_put_data(skb, &esc_db, 2); 128 break; 129 default: 130 skb_put_data(skb, &c, 1); 131 } 132 } 133 134 static int bcsp_enqueue(struct hci_uart *hu, struct sk_buff *skb) 135 { 136 struct bcsp_struct *bcsp = hu->priv; 137 138 if (skb->len > 0xFFF) { 139 BT_ERR("Packet too long"); 140 kfree_skb(skb); 141 return 0; 142 } 143 144 switch (hci_skb_pkt_type(skb)) { 145 case HCI_ACLDATA_PKT: 146 case HCI_COMMAND_PKT: 147 skb_queue_tail(&bcsp->rel, skb); 148 break; 149 150 case HCI_SCODATA_PKT: 151 skb_queue_tail(&bcsp->unrel, skb); 152 break; 153 154 default: 155 BT_ERR("Unknown packet type"); 156 kfree_skb(skb); 157 break; 158 } 159 160 return 0; 161 } 162 163 static struct sk_buff *bcsp_prepare_pkt(struct bcsp_struct *bcsp, u8 *data, 164 int len, int pkt_type) 165 { 166 struct sk_buff *nskb; 167 u8 hdr[4], chan; 168 u16 BCSP_CRC_INIT(bcsp_txmsg_crc); 169 int rel, i; 170 171 switch (pkt_type) { 172 case HCI_ACLDATA_PKT: 173 chan = 6; /* BCSP ACL channel */ 174 rel = 1; /* reliable channel */ 175 break; 176 case HCI_COMMAND_PKT: 177 chan = 5; /* BCSP cmd/evt channel */ 178 rel = 1; /* reliable channel */ 179 break; 180 case HCI_SCODATA_PKT: 181 chan = 7; /* BCSP SCO channel */ 182 rel = 0; /* unreliable channel */ 183 break; 184 case BCSP_LE_PKT: 185 chan = 1; /* BCSP LE channel */ 186 rel = 0; /* unreliable channel */ 187 break; 188 case BCSP_ACK_PKT: 189 chan = 0; /* BCSP internal channel */ 190 rel = 0; /* unreliable channel */ 191 break; 192 default: 193 BT_ERR("Unknown packet type"); 194 return NULL; 195 } 196 197 if (hciextn && chan == 5 && len > HCI_COMMAND_HDR_SIZE) { 198 __le16 opcode = ((struct hci_command_hdr *)data)->opcode; 199 200 /* Vendor specific commands */ 201 if (hci_opcode_ogf(__le16_to_cpu(opcode)) == 0x3f) { 202 u8 desc = *(data + HCI_COMMAND_HDR_SIZE); 203 204 if ((desc & 0xf0) == 0xc0) { 205 data += HCI_COMMAND_HDR_SIZE + 1; 206 len -= HCI_COMMAND_HDR_SIZE + 1; 207 chan = desc & 0x0f; 208 } 209 } 210 } 211 212 /* Max len of packet: (original len +4(bcsp hdr) +2(crc))*2 213 * (because bytes 0xc0 and 0xdb are escaped, worst case is 214 * when the packet is all made of 0xc0 and 0xdb :) ) 215 * + 2 (0xc0 delimiters at start and end). 216 */ 217 218 nskb = alloc_skb((len + 6) * 2 + 2, GFP_ATOMIC); 219 if (!nskb) 220 return NULL; 221 222 hci_skb_pkt_type(nskb) = pkt_type; 223 224 bcsp_slip_msgdelim(nskb); 225 226 hdr[0] = bcsp->rxseq_txack << 3; 227 bcsp->txack_req = 0; 228 BT_DBG("We request packet no %u to card", bcsp->rxseq_txack); 229 230 if (rel) { 231 hdr[0] |= 0x80 + bcsp->msgq_txseq; 232 BT_DBG("Sending packet with seqno %u", bcsp->msgq_txseq); 233 bcsp->msgq_txseq = (bcsp->msgq_txseq + 1) & 0x07; 234 } 235 236 if (bcsp->use_crc) 237 hdr[0] |= 0x40; 238 239 hdr[1] = ((len << 4) & 0xff) | chan; 240 hdr[2] = len >> 4; 241 hdr[3] = ~(hdr[0] + hdr[1] + hdr[2]); 242 243 /* Put BCSP header */ 244 for (i = 0; i < 4; i++) { 245 bcsp_slip_one_byte(nskb, hdr[i]); 246 247 if (bcsp->use_crc) 248 bcsp_crc_update(&bcsp_txmsg_crc, hdr[i]); 249 } 250 251 /* Put payload */ 252 for (i = 0; i < len; i++) { 253 bcsp_slip_one_byte(nskb, data[i]); 254 255 if (bcsp->use_crc) 256 bcsp_crc_update(&bcsp_txmsg_crc, data[i]); 257 } 258 259 /* Put CRC */ 260 if (bcsp->use_crc) { 261 bcsp_txmsg_crc = bitrev16(bcsp_txmsg_crc); 262 bcsp_slip_one_byte(nskb, (u8)((bcsp_txmsg_crc >> 8) & 0x00ff)); 263 bcsp_slip_one_byte(nskb, (u8)(bcsp_txmsg_crc & 0x00ff)); 264 } 265 266 bcsp_slip_msgdelim(nskb); 267 return nskb; 268 } 269 270 /* This is a rewrite of pkt_avail in ABCSP */ 271 static struct sk_buff *bcsp_dequeue(struct hci_uart *hu) 272 { 273 struct bcsp_struct *bcsp = hu->priv; 274 unsigned long flags; 275 struct sk_buff *skb; 276 277 /* First of all, check for unreliable messages in the queue, 278 * since they have priority 279 */ 280 281 skb = skb_dequeue(&bcsp->unrel); 282 if (skb != NULL) { 283 struct sk_buff *nskb; 284 285 nskb = bcsp_prepare_pkt(bcsp, skb->data, skb->len, 286 hci_skb_pkt_type(skb)); 287 if (nskb) { 288 kfree_skb(skb); 289 return nskb; 290 } else { 291 skb_queue_head(&bcsp->unrel, skb); 292 BT_ERR("Could not dequeue pkt because alloc_skb failed"); 293 } 294 } 295 296 /* Now, try to send a reliable pkt. We can only send a 297 * reliable packet if the number of packets sent but not yet ack'ed 298 * is < than the winsize 299 */ 300 301 spin_lock_irqsave_nested(&bcsp->unack.lock, flags, SINGLE_DEPTH_NESTING); 302 303 if (bcsp->unack.qlen < BCSP_TXWINSIZE) { 304 skb = skb_dequeue(&bcsp->rel); 305 if (skb != NULL) { 306 struct sk_buff *nskb; 307 308 nskb = bcsp_prepare_pkt(bcsp, skb->data, skb->len, 309 hci_skb_pkt_type(skb)); 310 if (nskb) { 311 __skb_queue_tail(&bcsp->unack, skb); 312 mod_timer(&bcsp->tbcsp, jiffies + HZ / 4); 313 spin_unlock_irqrestore(&bcsp->unack.lock, flags); 314 return nskb; 315 } else { 316 skb_queue_head(&bcsp->rel, skb); 317 BT_ERR("Could not dequeue pkt because alloc_skb failed"); 318 } 319 } 320 } 321 322 spin_unlock_irqrestore(&bcsp->unack.lock, flags); 323 324 /* We could not send a reliable packet, either because there are 325 * none or because there are too many unack'ed pkts. Did we receive 326 * any packets we have not acknowledged yet ? 327 */ 328 329 if (bcsp->txack_req) { 330 /* if so, craft an empty ACK pkt and send it on BCSP unreliable 331 * channel 0 332 */ 333 struct sk_buff *nskb = bcsp_prepare_pkt(bcsp, NULL, 0, BCSP_ACK_PKT); 334 return nskb; 335 } 336 337 /* We have nothing to send */ 338 return NULL; 339 } 340 341 static int bcsp_flush(struct hci_uart *hu) 342 { 343 BT_DBG("hu %p", hu); 344 return 0; 345 } 346 347 /* Remove ack'ed packets */ 348 static void bcsp_pkt_cull(struct bcsp_struct *bcsp) 349 { 350 struct sk_buff *skb, *tmp; 351 unsigned long flags; 352 int i, pkts_to_be_removed; 353 u8 seqno; 354 355 spin_lock_irqsave(&bcsp->unack.lock, flags); 356 357 pkts_to_be_removed = skb_queue_len(&bcsp->unack); 358 seqno = bcsp->msgq_txseq; 359 360 while (pkts_to_be_removed) { 361 if (bcsp->rxack == seqno) 362 break; 363 pkts_to_be_removed--; 364 seqno = (seqno - 1) & 0x07; 365 } 366 367 if (bcsp->rxack != seqno) 368 BT_ERR("Peer acked invalid packet"); 369 370 BT_DBG("Removing %u pkts out of %u, up to seqno %u", 371 pkts_to_be_removed, skb_queue_len(&bcsp->unack), 372 (seqno - 1) & 0x07); 373 374 i = 0; 375 skb_queue_walk_safe(&bcsp->unack, skb, tmp) { 376 if (i >= pkts_to_be_removed) 377 break; 378 i++; 379 380 __skb_unlink(skb, &bcsp->unack); 381 dev_kfree_skb_irq(skb); 382 } 383 384 if (skb_queue_empty(&bcsp->unack)) 385 timer_delete(&bcsp->tbcsp); 386 387 spin_unlock_irqrestore(&bcsp->unack.lock, flags); 388 389 if (i != pkts_to_be_removed) 390 BT_ERR("Removed only %u out of %u pkts", i, pkts_to_be_removed); 391 } 392 393 /* Handle BCSP link-establishment packets. When we 394 * detect a "sync" packet, symptom that the BT module has reset, 395 * we do nothing :) (yet) 396 */ 397 static void bcsp_handle_le_pkt(struct hci_uart *hu) 398 { 399 struct bcsp_struct *bcsp = hu->priv; 400 u8 conf_pkt[4] = { 0xad, 0xef, 0xac, 0xed }; 401 u8 conf_rsp_pkt[4] = { 0xde, 0xad, 0xd0, 0xd0 }; 402 u8 sync_pkt[4] = { 0xda, 0xdc, 0xed, 0xed }; 403 404 /* spot "conf" pkts and reply with a "conf rsp" pkt */ 405 if (bcsp->rx_skb->len < 8) 406 return; 407 408 if (bcsp->rx_skb->data[1] >> 4 == 4 && bcsp->rx_skb->data[2] == 0 && 409 !memcmp(&bcsp->rx_skb->data[4], conf_pkt, 4)) { 410 struct sk_buff *nskb = alloc_skb(4, GFP_ATOMIC); 411 412 BT_DBG("Found a LE conf pkt"); 413 if (!nskb) 414 return; 415 skb_put_data(nskb, conf_rsp_pkt, 4); 416 hci_skb_pkt_type(nskb) = BCSP_LE_PKT; 417 418 skb_queue_head(&bcsp->unrel, nskb); 419 hci_uart_tx_wakeup(hu); 420 } 421 /* Spot "sync" pkts. If we find one...disaster! */ 422 else if (bcsp->rx_skb->data[1] >> 4 == 4 && bcsp->rx_skb->data[2] == 0 && 423 !memcmp(&bcsp->rx_skb->data[4], sync_pkt, 4)) { 424 BT_ERR("Found a LE sync pkt, card has reset"); 425 } 426 } 427 428 static inline void bcsp_unslip_one_byte(struct bcsp_struct *bcsp, unsigned char byte) 429 { 430 const u8 c0 = 0xc0, db = 0xdb; 431 432 switch (bcsp->rx_esc_state) { 433 case BCSP_ESCSTATE_NOESC: 434 switch (byte) { 435 case 0xdb: 436 bcsp->rx_esc_state = BCSP_ESCSTATE_ESC; 437 break; 438 default: 439 skb_put_data(bcsp->rx_skb, &byte, 1); 440 if ((bcsp->rx_skb->data[0] & 0x40) != 0 && 441 bcsp->rx_state != BCSP_W4_CRC) 442 bcsp_crc_update(&bcsp->message_crc, byte); 443 bcsp->rx_count--; 444 } 445 break; 446 447 case BCSP_ESCSTATE_ESC: 448 switch (byte) { 449 case 0xdc: 450 skb_put_data(bcsp->rx_skb, &c0, 1); 451 if ((bcsp->rx_skb->data[0] & 0x40) != 0 && 452 bcsp->rx_state != BCSP_W4_CRC) 453 bcsp_crc_update(&bcsp->message_crc, 0xc0); 454 bcsp->rx_esc_state = BCSP_ESCSTATE_NOESC; 455 bcsp->rx_count--; 456 break; 457 458 case 0xdd: 459 skb_put_data(bcsp->rx_skb, &db, 1); 460 if ((bcsp->rx_skb->data[0] & 0x40) != 0 && 461 bcsp->rx_state != BCSP_W4_CRC) 462 bcsp_crc_update(&bcsp->message_crc, 0xdb); 463 bcsp->rx_esc_state = BCSP_ESCSTATE_NOESC; 464 bcsp->rx_count--; 465 break; 466 467 default: 468 BT_ERR("Invalid byte %02x after esc byte", byte); 469 kfree_skb(bcsp->rx_skb); 470 bcsp->rx_skb = NULL; 471 bcsp->rx_state = BCSP_W4_PKT_DELIMITER; 472 bcsp->rx_count = 0; 473 } 474 } 475 } 476 477 static void bcsp_complete_rx_pkt(struct hci_uart *hu) 478 { 479 struct bcsp_struct *bcsp = hu->priv; 480 int pass_up = 0; 481 482 if (bcsp->rx_skb->data[0] & 0x80) { /* reliable pkt */ 483 BT_DBG("Received seqno %u from card", bcsp->rxseq_txack); 484 485 /* check the rx sequence number is as expected */ 486 if ((bcsp->rx_skb->data[0] & 0x07) == bcsp->rxseq_txack) { 487 bcsp->rxseq_txack++; 488 bcsp->rxseq_txack %= 0x8; 489 } else { 490 /* handle re-transmitted packet or 491 * when packet was missed 492 */ 493 BT_ERR("Out-of-order packet arrived, got %u expected %u", 494 bcsp->rx_skb->data[0] & 0x07, bcsp->rxseq_txack); 495 496 /* do not process out-of-order packet payload */ 497 pass_up = 2; 498 } 499 500 /* send current txack value to all received reliable packets */ 501 bcsp->txack_req = 1; 502 503 /* If needed, transmit an ack pkt */ 504 hci_uart_tx_wakeup(hu); 505 } 506 507 bcsp->rxack = (bcsp->rx_skb->data[0] >> 3) & 0x07; 508 BT_DBG("Request for pkt %u from card", bcsp->rxack); 509 510 /* handle received ACK indications, 511 * including those from out-of-order packets 512 */ 513 bcsp_pkt_cull(bcsp); 514 515 if (pass_up != 2) { 516 if ((bcsp->rx_skb->data[1] & 0x0f) == 6 && 517 (bcsp->rx_skb->data[0] & 0x80)) { 518 hci_skb_pkt_type(bcsp->rx_skb) = HCI_ACLDATA_PKT; 519 pass_up = 1; 520 } else if ((bcsp->rx_skb->data[1] & 0x0f) == 5 && 521 (bcsp->rx_skb->data[0] & 0x80)) { 522 hci_skb_pkt_type(bcsp->rx_skb) = HCI_EVENT_PKT; 523 pass_up = 1; 524 } else if ((bcsp->rx_skb->data[1] & 0x0f) == 7) { 525 hci_skb_pkt_type(bcsp->rx_skb) = HCI_SCODATA_PKT; 526 pass_up = 1; 527 } else if ((bcsp->rx_skb->data[1] & 0x0f) == 1 && 528 !(bcsp->rx_skb->data[0] & 0x80)) { 529 bcsp_handle_le_pkt(hu); 530 pass_up = 0; 531 } else { 532 pass_up = 0; 533 } 534 } 535 536 if (pass_up == 0) { 537 struct hci_event_hdr hdr; 538 u8 desc = (bcsp->rx_skb->data[1] & 0x0f); 539 540 if (desc != 0 && desc != 1) { 541 if (hciextn) { 542 desc |= 0xc0; 543 skb_pull(bcsp->rx_skb, 4); 544 memcpy(skb_push(bcsp->rx_skb, 1), &desc, 1); 545 546 hdr.evt = 0xff; 547 hdr.plen = bcsp->rx_skb->len; 548 memcpy(skb_push(bcsp->rx_skb, HCI_EVENT_HDR_SIZE), &hdr, HCI_EVENT_HDR_SIZE); 549 hci_skb_pkt_type(bcsp->rx_skb) = HCI_EVENT_PKT; 550 551 hci_recv_frame(hu->hdev, bcsp->rx_skb); 552 } else { 553 BT_ERR("Packet for unknown channel (%u %s)", 554 bcsp->rx_skb->data[1] & 0x0f, 555 bcsp->rx_skb->data[0] & 0x80 ? 556 "reliable" : "unreliable"); 557 kfree_skb(bcsp->rx_skb); 558 } 559 } else 560 kfree_skb(bcsp->rx_skb); 561 } else if (pass_up == 1) { 562 /* Pull out BCSP hdr */ 563 skb_pull(bcsp->rx_skb, 4); 564 565 hci_recv_frame(hu->hdev, bcsp->rx_skb); 566 } else { 567 /* ignore packet payload of already ACKed re-transmitted 568 * packets or when a packet was missed in the BCSP window 569 */ 570 kfree_skb(bcsp->rx_skb); 571 } 572 573 bcsp->rx_state = BCSP_W4_PKT_DELIMITER; 574 bcsp->rx_skb = NULL; 575 } 576 577 static u16 bscp_get_crc(struct bcsp_struct *bcsp) 578 { 579 return get_unaligned_be16(&bcsp->rx_skb->data[bcsp->rx_skb->len - 2]); 580 } 581 582 /* Recv data */ 583 static int bcsp_recv(struct hci_uart *hu, const void *data, int count) 584 { 585 struct bcsp_struct *bcsp = hu->priv; 586 const unsigned char *ptr; 587 588 if (!test_bit(HCI_UART_REGISTERED, &hu->flags)) 589 return -EUNATCH; 590 591 if (!bcsp) 592 return -ENODEV; 593 594 BT_DBG("hu %p count %d rx_state %d rx_count %ld", 595 hu, count, bcsp->rx_state, bcsp->rx_count); 596 597 ptr = data; 598 while (count) { 599 if (bcsp->rx_count) { 600 if (*ptr == 0xc0) { 601 BT_ERR("Short BCSP packet"); 602 kfree_skb(bcsp->rx_skb); 603 bcsp->rx_skb = NULL; 604 bcsp->rx_state = BCSP_W4_PKT_START; 605 bcsp->rx_count = 0; 606 } else 607 bcsp_unslip_one_byte(bcsp, *ptr); 608 609 ptr++; count--; 610 continue; 611 } 612 613 switch (bcsp->rx_state) { 614 case BCSP_W4_BCSP_HDR: 615 if ((0xff & (u8)~(bcsp->rx_skb->data[0] + bcsp->rx_skb->data[1] + 616 bcsp->rx_skb->data[2])) != bcsp->rx_skb->data[3]) { 617 BT_ERR("Error in BCSP hdr checksum"); 618 kfree_skb(bcsp->rx_skb); 619 bcsp->rx_skb = NULL; 620 bcsp->rx_state = BCSP_W4_PKT_DELIMITER; 621 bcsp->rx_count = 0; 622 continue; 623 } 624 bcsp->rx_state = BCSP_W4_DATA; 625 bcsp->rx_count = (bcsp->rx_skb->data[1] >> 4) + 626 (bcsp->rx_skb->data[2] << 4); /* May be 0 */ 627 continue; 628 629 case BCSP_W4_DATA: 630 if (bcsp->rx_skb->data[0] & 0x40) { /* pkt with crc */ 631 bcsp->rx_state = BCSP_W4_CRC; 632 bcsp->rx_count = 2; 633 } else 634 bcsp_complete_rx_pkt(hu); 635 continue; 636 637 case BCSP_W4_CRC: 638 if (bitrev16(bcsp->message_crc) != bscp_get_crc(bcsp)) { 639 BT_ERR("Checksum failed: computed %04x received %04x", 640 bitrev16(bcsp->message_crc), 641 bscp_get_crc(bcsp)); 642 643 kfree_skb(bcsp->rx_skb); 644 bcsp->rx_skb = NULL; 645 bcsp->rx_state = BCSP_W4_PKT_DELIMITER; 646 bcsp->rx_count = 0; 647 continue; 648 } 649 skb_trim(bcsp->rx_skb, bcsp->rx_skb->len - 2); 650 bcsp_complete_rx_pkt(hu); 651 continue; 652 653 case BCSP_W4_PKT_DELIMITER: 654 switch (*ptr) { 655 case 0xc0: 656 bcsp->rx_state = BCSP_W4_PKT_START; 657 break; 658 default: 659 /*BT_ERR("Ignoring byte %02x", *ptr);*/ 660 break; 661 } 662 ptr++; count--; 663 break; 664 665 case BCSP_W4_PKT_START: 666 switch (*ptr) { 667 case 0xc0: 668 ptr++; count--; 669 break; 670 671 default: 672 bcsp->rx_state = BCSP_W4_BCSP_HDR; 673 bcsp->rx_count = 4; 674 bcsp->rx_esc_state = BCSP_ESCSTATE_NOESC; 675 BCSP_CRC_INIT(bcsp->message_crc); 676 677 /* Do not increment ptr or decrement count 678 * Allocate packet. Max len of a BCSP pkt= 679 * 0xFFF (payload) +4 (header) +2 (crc) 680 */ 681 682 bcsp->rx_skb = bt_skb_alloc(0x1005, GFP_ATOMIC); 683 if (!bcsp->rx_skb) { 684 BT_ERR("Can't allocate mem for new packet"); 685 bcsp->rx_state = BCSP_W4_PKT_DELIMITER; 686 bcsp->rx_count = 0; 687 return 0; 688 } 689 break; 690 } 691 break; 692 } 693 } 694 return count; 695 } 696 697 /* Arrange to retransmit all messages in the relq. */ 698 static void bcsp_timed_event(struct timer_list *t) 699 { 700 struct bcsp_struct *bcsp = timer_container_of(bcsp, t, tbcsp); 701 struct hci_uart *hu = bcsp->hu; 702 struct sk_buff *skb; 703 unsigned long flags; 704 705 BT_DBG("hu %p retransmitting %u pkts", hu, bcsp->unack.qlen); 706 707 spin_lock_irqsave_nested(&bcsp->unack.lock, flags, SINGLE_DEPTH_NESTING); 708 709 while ((skb = __skb_dequeue_tail(&bcsp->unack)) != NULL) { 710 bcsp->msgq_txseq = (bcsp->msgq_txseq - 1) & 0x07; 711 skb_queue_head(&bcsp->rel, skb); 712 } 713 714 spin_unlock_irqrestore(&bcsp->unack.lock, flags); 715 716 hci_uart_tx_wakeup(hu); 717 } 718 719 static int bcsp_open(struct hci_uart *hu) 720 { 721 struct bcsp_struct *bcsp; 722 723 BT_DBG("hu %p", hu); 724 725 bcsp = kzalloc_obj(*bcsp); 726 if (!bcsp) 727 return -ENOMEM; 728 729 hu->priv = bcsp; 730 bcsp->hu = hu; 731 skb_queue_head_init(&bcsp->unack); 732 skb_queue_head_init(&bcsp->rel); 733 skb_queue_head_init(&bcsp->unrel); 734 735 timer_setup(&bcsp->tbcsp, bcsp_timed_event, 0); 736 737 bcsp->rx_state = BCSP_W4_PKT_DELIMITER; 738 739 if (txcrc) 740 bcsp->use_crc = 1; 741 742 return 0; 743 } 744 745 static int bcsp_close(struct hci_uart *hu) 746 { 747 struct bcsp_struct *bcsp = hu->priv; 748 749 timer_shutdown_sync(&bcsp->tbcsp); 750 751 hu->priv = NULL; 752 753 BT_DBG("hu %p", hu); 754 755 skb_queue_purge(&bcsp->unack); 756 skb_queue_purge(&bcsp->rel); 757 skb_queue_purge(&bcsp->unrel); 758 759 if (bcsp->rx_skb) { 760 kfree_skb(bcsp->rx_skb); 761 bcsp->rx_skb = NULL; 762 } 763 764 kfree(bcsp); 765 return 0; 766 } 767 768 static const struct hci_uart_proto bcsp = { 769 .id = HCI_UART_BCSP, 770 .name = "BCSP", 771 .open = bcsp_open, 772 .close = bcsp_close, 773 .enqueue = bcsp_enqueue, 774 .dequeue = bcsp_dequeue, 775 .recv = bcsp_recv, 776 .flush = bcsp_flush 777 }; 778 779 int __init bcsp_init(void) 780 { 781 return hci_uart_register_proto(&bcsp); 782 } 783 784 int __exit bcsp_deinit(void) 785 { 786 return hci_uart_unregister_proto(&bcsp); 787 } 788 789 module_param(txcrc, bool, 0644); 790 MODULE_PARM_DESC(txcrc, "Transmit CRC with every BCSP packet"); 791 792 module_param(hciextn, bool, 0644); 793 MODULE_PARM_DESC(hciextn, "Convert HCI Extensions into BCSP packets"); 794