1 /* 2 * 3 * Bluetooth HCI Three-wire UART driver 4 * 5 * Copyright (C) 2012 Intel Corporation 6 * 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to the Free Software 20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 21 * 22 */ 23 24 #include <linux/kernel.h> 25 #include <linux/errno.h> 26 #include <linux/skbuff.h> 27 28 #include <net/bluetooth/bluetooth.h> 29 #include <net/bluetooth/hci_core.h> 30 31 #include "hci_uart.h" 32 33 #define HCI_3WIRE_ACK_PKT 0 34 #define HCI_3WIRE_LINK_PKT 15 35 36 /* Sliding window size */ 37 #define H5_TX_WIN_MAX 4 38 39 #define H5_ACK_TIMEOUT msecs_to_jiffies(250) 40 #define H5_SYNC_TIMEOUT msecs_to_jiffies(100) 41 42 /* 43 * Maximum Three-wire packet: 44 * 4 byte header + max value for 12-bit length + 2 bytes for CRC 45 */ 46 #define H5_MAX_LEN (4 + 0xfff + 2) 47 48 /* Convenience macros for reading Three-wire header values */ 49 #define H5_HDR_SEQ(hdr) ((hdr)[0] & 0x07) 50 #define H5_HDR_ACK(hdr) (((hdr)[0] >> 3) & 0x07) 51 #define H5_HDR_CRC(hdr) (((hdr)[0] >> 6) & 0x01) 52 #define H5_HDR_RELIABLE(hdr) (((hdr)[0] >> 7) & 0x01) 53 #define H5_HDR_PKT_TYPE(hdr) ((hdr)[1] & 0x0f) 54 #define H5_HDR_LEN(hdr) ((((hdr)[1] >> 4) & 0x0f) + ((hdr)[2] << 4)) 55 56 #define SLIP_DELIMITER 0xc0 57 #define SLIP_ESC 0xdb 58 #define SLIP_ESC_DELIM 0xdc 59 #define SLIP_ESC_ESC 0xdd 60 61 /* H5 state flags */ 62 enum { 63 H5_RX_ESC, /* SLIP escape mode */ 64 H5_TX_ACK_REQ, /* Pending ack to send */ 65 }; 66 67 struct h5 { 68 struct sk_buff_head unack; /* Unack'ed packets queue */ 69 struct sk_buff_head rel; /* Reliable packets queue */ 70 struct sk_buff_head unrel; /* Unreliable packets queue */ 71 72 unsigned long flags; 73 74 struct sk_buff *rx_skb; /* Receive buffer */ 75 size_t rx_pending; /* Expecting more bytes */ 76 u8 rx_ack; /* Last ack number received */ 77 78 int (*rx_func)(struct hci_uart *hu, u8 c); 79 80 struct timer_list timer; /* Retransmission timer */ 81 82 u8 tx_seq; /* Next seq number to send */ 83 u8 tx_ack; /* Next ack number to send */ 84 u8 tx_win; /* Sliding window size */ 85 86 enum { 87 H5_UNINITIALIZED, 88 H5_INITIALIZED, 89 H5_ACTIVE, 90 } state; 91 92 enum { 93 H5_AWAKE, 94 H5_SLEEPING, 95 H5_WAKING_UP, 96 } sleep; 97 }; 98 99 static void h5_reset_rx(struct h5 *h5); 100 101 static void h5_link_control(struct hci_uart *hu, const void *data, size_t len) 102 { 103 struct h5 *h5 = hu->priv; 104 struct sk_buff *nskb; 105 106 nskb = alloc_skb(3, GFP_ATOMIC); 107 if (!nskb) 108 return; 109 110 hci_skb_pkt_type(nskb) = HCI_3WIRE_LINK_PKT; 111 112 skb_put_data(nskb, data, len); 113 114 skb_queue_tail(&h5->unrel, nskb); 115 } 116 117 static u8 h5_cfg_field(struct h5 *h5) 118 { 119 /* Sliding window size (first 3 bits) */ 120 return h5->tx_win & 0x07; 121 } 122 123 static void h5_timed_event(unsigned long arg) 124 { 125 const unsigned char sync_req[] = { 0x01, 0x7e }; 126 unsigned char conf_req[3] = { 0x03, 0xfc }; 127 struct hci_uart *hu = (struct hci_uart *)arg; 128 struct h5 *h5 = hu->priv; 129 struct sk_buff *skb; 130 unsigned long flags; 131 132 BT_DBG("%s", hu->hdev->name); 133 134 if (h5->state == H5_UNINITIALIZED) 135 h5_link_control(hu, sync_req, sizeof(sync_req)); 136 137 if (h5->state == H5_INITIALIZED) { 138 conf_req[2] = h5_cfg_field(h5); 139 h5_link_control(hu, conf_req, sizeof(conf_req)); 140 } 141 142 if (h5->state != H5_ACTIVE) { 143 mod_timer(&h5->timer, jiffies + H5_SYNC_TIMEOUT); 144 goto wakeup; 145 } 146 147 if (h5->sleep != H5_AWAKE) { 148 h5->sleep = H5_SLEEPING; 149 goto wakeup; 150 } 151 152 BT_DBG("hu %p retransmitting %u pkts", hu, h5->unack.qlen); 153 154 spin_lock_irqsave_nested(&h5->unack.lock, flags, SINGLE_DEPTH_NESTING); 155 156 while ((skb = __skb_dequeue_tail(&h5->unack)) != NULL) { 157 h5->tx_seq = (h5->tx_seq - 1) & 0x07; 158 skb_queue_head(&h5->rel, skb); 159 } 160 161 spin_unlock_irqrestore(&h5->unack.lock, flags); 162 163 wakeup: 164 hci_uart_tx_wakeup(hu); 165 } 166 167 static void h5_peer_reset(struct hci_uart *hu) 168 { 169 struct h5 *h5 = hu->priv; 170 171 BT_ERR("Peer device has reset"); 172 173 h5->state = H5_UNINITIALIZED; 174 175 del_timer(&h5->timer); 176 177 skb_queue_purge(&h5->rel); 178 skb_queue_purge(&h5->unrel); 179 skb_queue_purge(&h5->unack); 180 181 h5->tx_seq = 0; 182 h5->tx_ack = 0; 183 184 /* Send reset request to upper stack */ 185 hci_reset_dev(hu->hdev); 186 } 187 188 static int h5_open(struct hci_uart *hu) 189 { 190 struct h5 *h5; 191 const unsigned char sync[] = { 0x01, 0x7e }; 192 193 BT_DBG("hu %p", hu); 194 195 h5 = kzalloc(sizeof(*h5), GFP_KERNEL); 196 if (!h5) 197 return -ENOMEM; 198 199 hu->priv = h5; 200 201 skb_queue_head_init(&h5->unack); 202 skb_queue_head_init(&h5->rel); 203 skb_queue_head_init(&h5->unrel); 204 205 h5_reset_rx(h5); 206 207 setup_timer(&h5->timer, h5_timed_event, (unsigned long)hu); 208 209 h5->tx_win = H5_TX_WIN_MAX; 210 211 set_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags); 212 213 /* Send initial sync request */ 214 h5_link_control(hu, sync, sizeof(sync)); 215 mod_timer(&h5->timer, jiffies + H5_SYNC_TIMEOUT); 216 217 return 0; 218 } 219 220 static int h5_close(struct hci_uart *hu) 221 { 222 struct h5 *h5 = hu->priv; 223 224 del_timer_sync(&h5->timer); 225 226 skb_queue_purge(&h5->unack); 227 skb_queue_purge(&h5->rel); 228 skb_queue_purge(&h5->unrel); 229 230 kfree(h5); 231 232 return 0; 233 } 234 235 static void h5_pkt_cull(struct h5 *h5) 236 { 237 struct sk_buff *skb, *tmp; 238 unsigned long flags; 239 int i, to_remove; 240 u8 seq; 241 242 spin_lock_irqsave(&h5->unack.lock, flags); 243 244 to_remove = skb_queue_len(&h5->unack); 245 if (to_remove == 0) 246 goto unlock; 247 248 seq = h5->tx_seq; 249 250 while (to_remove > 0) { 251 if (h5->rx_ack == seq) 252 break; 253 254 to_remove--; 255 seq = (seq - 1) & 0x07; 256 } 257 258 if (seq != h5->rx_ack) 259 BT_ERR("Controller acked invalid packet"); 260 261 i = 0; 262 skb_queue_walk_safe(&h5->unack, skb, tmp) { 263 if (i++ >= to_remove) 264 break; 265 266 __skb_unlink(skb, &h5->unack); 267 kfree_skb(skb); 268 } 269 270 if (skb_queue_empty(&h5->unack)) 271 del_timer(&h5->timer); 272 273 unlock: 274 spin_unlock_irqrestore(&h5->unack.lock, flags); 275 } 276 277 static void h5_handle_internal_rx(struct hci_uart *hu) 278 { 279 struct h5 *h5 = hu->priv; 280 const unsigned char sync_req[] = { 0x01, 0x7e }; 281 const unsigned char sync_rsp[] = { 0x02, 0x7d }; 282 unsigned char conf_req[3] = { 0x03, 0xfc }; 283 const unsigned char conf_rsp[] = { 0x04, 0x7b }; 284 const unsigned char wakeup_req[] = { 0x05, 0xfa }; 285 const unsigned char woken_req[] = { 0x06, 0xf9 }; 286 const unsigned char sleep_req[] = { 0x07, 0x78 }; 287 const unsigned char *hdr = h5->rx_skb->data; 288 const unsigned char *data = &h5->rx_skb->data[4]; 289 290 BT_DBG("%s", hu->hdev->name); 291 292 if (H5_HDR_PKT_TYPE(hdr) != HCI_3WIRE_LINK_PKT) 293 return; 294 295 if (H5_HDR_LEN(hdr) < 2) 296 return; 297 298 conf_req[2] = h5_cfg_field(h5); 299 300 if (memcmp(data, sync_req, 2) == 0) { 301 if (h5->state == H5_ACTIVE) 302 h5_peer_reset(hu); 303 h5_link_control(hu, sync_rsp, 2); 304 } else if (memcmp(data, sync_rsp, 2) == 0) { 305 if (h5->state == H5_ACTIVE) 306 h5_peer_reset(hu); 307 h5->state = H5_INITIALIZED; 308 h5_link_control(hu, conf_req, 3); 309 } else if (memcmp(data, conf_req, 2) == 0) { 310 h5_link_control(hu, conf_rsp, 2); 311 h5_link_control(hu, conf_req, 3); 312 } else if (memcmp(data, conf_rsp, 2) == 0) { 313 if (H5_HDR_LEN(hdr) > 2) 314 h5->tx_win = (data[2] & 0x07); 315 BT_DBG("Three-wire init complete. tx_win %u", h5->tx_win); 316 h5->state = H5_ACTIVE; 317 hci_uart_init_ready(hu); 318 return; 319 } else if (memcmp(data, sleep_req, 2) == 0) { 320 BT_DBG("Peer went to sleep"); 321 h5->sleep = H5_SLEEPING; 322 return; 323 } else if (memcmp(data, woken_req, 2) == 0) { 324 BT_DBG("Peer woke up"); 325 h5->sleep = H5_AWAKE; 326 } else if (memcmp(data, wakeup_req, 2) == 0) { 327 BT_DBG("Peer requested wakeup"); 328 h5_link_control(hu, woken_req, 2); 329 h5->sleep = H5_AWAKE; 330 } else { 331 BT_DBG("Link Control: 0x%02hhx 0x%02hhx", data[0], data[1]); 332 return; 333 } 334 335 hci_uart_tx_wakeup(hu); 336 } 337 338 static void h5_complete_rx_pkt(struct hci_uart *hu) 339 { 340 struct h5 *h5 = hu->priv; 341 const unsigned char *hdr = h5->rx_skb->data; 342 343 if (H5_HDR_RELIABLE(hdr)) { 344 h5->tx_ack = (h5->tx_ack + 1) % 8; 345 set_bit(H5_TX_ACK_REQ, &h5->flags); 346 hci_uart_tx_wakeup(hu); 347 } 348 349 h5->rx_ack = H5_HDR_ACK(hdr); 350 351 h5_pkt_cull(h5); 352 353 switch (H5_HDR_PKT_TYPE(hdr)) { 354 case HCI_EVENT_PKT: 355 case HCI_ACLDATA_PKT: 356 case HCI_SCODATA_PKT: 357 hci_skb_pkt_type(h5->rx_skb) = H5_HDR_PKT_TYPE(hdr); 358 359 /* Remove Three-wire header */ 360 skb_pull(h5->rx_skb, 4); 361 362 hci_recv_frame(hu->hdev, h5->rx_skb); 363 h5->rx_skb = NULL; 364 365 break; 366 367 default: 368 h5_handle_internal_rx(hu); 369 break; 370 } 371 372 h5_reset_rx(h5); 373 } 374 375 static int h5_rx_crc(struct hci_uart *hu, unsigned char c) 376 { 377 h5_complete_rx_pkt(hu); 378 379 return 0; 380 } 381 382 static int h5_rx_payload(struct hci_uart *hu, unsigned char c) 383 { 384 struct h5 *h5 = hu->priv; 385 const unsigned char *hdr = h5->rx_skb->data; 386 387 if (H5_HDR_CRC(hdr)) { 388 h5->rx_func = h5_rx_crc; 389 h5->rx_pending = 2; 390 } else { 391 h5_complete_rx_pkt(hu); 392 } 393 394 return 0; 395 } 396 397 static int h5_rx_3wire_hdr(struct hci_uart *hu, unsigned char c) 398 { 399 struct h5 *h5 = hu->priv; 400 const unsigned char *hdr = h5->rx_skb->data; 401 402 BT_DBG("%s rx: seq %u ack %u crc %u rel %u type %u len %u", 403 hu->hdev->name, H5_HDR_SEQ(hdr), H5_HDR_ACK(hdr), 404 H5_HDR_CRC(hdr), H5_HDR_RELIABLE(hdr), H5_HDR_PKT_TYPE(hdr), 405 H5_HDR_LEN(hdr)); 406 407 if (((hdr[0] + hdr[1] + hdr[2] + hdr[3]) & 0xff) != 0xff) { 408 BT_ERR("Invalid header checksum"); 409 h5_reset_rx(h5); 410 return 0; 411 } 412 413 if (H5_HDR_RELIABLE(hdr) && H5_HDR_SEQ(hdr) != h5->tx_ack) { 414 BT_ERR("Out-of-order packet arrived (%u != %u)", 415 H5_HDR_SEQ(hdr), h5->tx_ack); 416 h5_reset_rx(h5); 417 return 0; 418 } 419 420 if (h5->state != H5_ACTIVE && 421 H5_HDR_PKT_TYPE(hdr) != HCI_3WIRE_LINK_PKT) { 422 BT_ERR("Non-link packet received in non-active state"); 423 h5_reset_rx(h5); 424 return 0; 425 } 426 427 h5->rx_func = h5_rx_payload; 428 h5->rx_pending = H5_HDR_LEN(hdr); 429 430 return 0; 431 } 432 433 static int h5_rx_pkt_start(struct hci_uart *hu, unsigned char c) 434 { 435 struct h5 *h5 = hu->priv; 436 437 if (c == SLIP_DELIMITER) 438 return 1; 439 440 h5->rx_func = h5_rx_3wire_hdr; 441 h5->rx_pending = 4; 442 443 h5->rx_skb = bt_skb_alloc(H5_MAX_LEN, GFP_ATOMIC); 444 if (!h5->rx_skb) { 445 BT_ERR("Can't allocate mem for new packet"); 446 h5_reset_rx(h5); 447 return -ENOMEM; 448 } 449 450 h5->rx_skb->dev = (void *)hu->hdev; 451 452 return 0; 453 } 454 455 static int h5_rx_delimiter(struct hci_uart *hu, unsigned char c) 456 { 457 struct h5 *h5 = hu->priv; 458 459 if (c == SLIP_DELIMITER) 460 h5->rx_func = h5_rx_pkt_start; 461 462 return 1; 463 } 464 465 static void h5_unslip_one_byte(struct h5 *h5, unsigned char c) 466 { 467 const u8 delim = SLIP_DELIMITER, esc = SLIP_ESC; 468 const u8 *byte = &c; 469 470 if (!test_bit(H5_RX_ESC, &h5->flags) && c == SLIP_ESC) { 471 set_bit(H5_RX_ESC, &h5->flags); 472 return; 473 } 474 475 if (test_and_clear_bit(H5_RX_ESC, &h5->flags)) { 476 switch (c) { 477 case SLIP_ESC_DELIM: 478 byte = &delim; 479 break; 480 case SLIP_ESC_ESC: 481 byte = &esc; 482 break; 483 default: 484 BT_ERR("Invalid esc byte 0x%02hhx", c); 485 h5_reset_rx(h5); 486 return; 487 } 488 } 489 490 skb_put_data(h5->rx_skb, byte, 1); 491 h5->rx_pending--; 492 493 BT_DBG("unsliped 0x%02hhx, rx_pending %zu", *byte, h5->rx_pending); 494 } 495 496 static void h5_reset_rx(struct h5 *h5) 497 { 498 if (h5->rx_skb) { 499 kfree_skb(h5->rx_skb); 500 h5->rx_skb = NULL; 501 } 502 503 h5->rx_func = h5_rx_delimiter; 504 h5->rx_pending = 0; 505 clear_bit(H5_RX_ESC, &h5->flags); 506 } 507 508 static int h5_recv(struct hci_uart *hu, const void *data, int count) 509 { 510 struct h5 *h5 = hu->priv; 511 const unsigned char *ptr = data; 512 513 BT_DBG("%s pending %zu count %d", hu->hdev->name, h5->rx_pending, 514 count); 515 516 while (count > 0) { 517 int processed; 518 519 if (h5->rx_pending > 0) { 520 if (*ptr == SLIP_DELIMITER) { 521 BT_ERR("Too short H5 packet"); 522 h5_reset_rx(h5); 523 continue; 524 } 525 526 h5_unslip_one_byte(h5, *ptr); 527 528 ptr++; count--; 529 continue; 530 } 531 532 processed = h5->rx_func(hu, *ptr); 533 if (processed < 0) 534 return processed; 535 536 ptr += processed; 537 count -= processed; 538 } 539 540 return 0; 541 } 542 543 static int h5_enqueue(struct hci_uart *hu, struct sk_buff *skb) 544 { 545 struct h5 *h5 = hu->priv; 546 547 if (skb->len > 0xfff) { 548 BT_ERR("Packet too long (%u bytes)", skb->len); 549 kfree_skb(skb); 550 return 0; 551 } 552 553 if (h5->state != H5_ACTIVE) { 554 BT_ERR("Ignoring HCI data in non-active state"); 555 kfree_skb(skb); 556 return 0; 557 } 558 559 switch (hci_skb_pkt_type(skb)) { 560 case HCI_ACLDATA_PKT: 561 case HCI_COMMAND_PKT: 562 skb_queue_tail(&h5->rel, skb); 563 break; 564 565 case HCI_SCODATA_PKT: 566 skb_queue_tail(&h5->unrel, skb); 567 break; 568 569 default: 570 BT_ERR("Unknown packet type %u", hci_skb_pkt_type(skb)); 571 kfree_skb(skb); 572 break; 573 } 574 575 return 0; 576 } 577 578 static void h5_slip_delim(struct sk_buff *skb) 579 { 580 const char delim = SLIP_DELIMITER; 581 582 skb_put_data(skb, &delim, 1); 583 } 584 585 static void h5_slip_one_byte(struct sk_buff *skb, u8 c) 586 { 587 const char esc_delim[2] = { SLIP_ESC, SLIP_ESC_DELIM }; 588 const char esc_esc[2] = { SLIP_ESC, SLIP_ESC_ESC }; 589 590 switch (c) { 591 case SLIP_DELIMITER: 592 skb_put_data(skb, &esc_delim, 2); 593 break; 594 case SLIP_ESC: 595 skb_put_data(skb, &esc_esc, 2); 596 break; 597 default: 598 skb_put_data(skb, &c, 1); 599 } 600 } 601 602 static bool valid_packet_type(u8 type) 603 { 604 switch (type) { 605 case HCI_ACLDATA_PKT: 606 case HCI_COMMAND_PKT: 607 case HCI_SCODATA_PKT: 608 case HCI_3WIRE_LINK_PKT: 609 case HCI_3WIRE_ACK_PKT: 610 return true; 611 default: 612 return false; 613 } 614 } 615 616 static struct sk_buff *h5_prepare_pkt(struct hci_uart *hu, u8 pkt_type, 617 const u8 *data, size_t len) 618 { 619 struct h5 *h5 = hu->priv; 620 struct sk_buff *nskb; 621 u8 hdr[4]; 622 int i; 623 624 if (!valid_packet_type(pkt_type)) { 625 BT_ERR("Unknown packet type %u", pkt_type); 626 return NULL; 627 } 628 629 /* 630 * Max len of packet: (original len + 4 (H5 hdr) + 2 (crc)) * 2 631 * (because bytes 0xc0 and 0xdb are escaped, worst case is when 632 * the packet is all made of 0xc0 and 0xdb) + 2 (0xc0 633 * delimiters at start and end). 634 */ 635 nskb = alloc_skb((len + 6) * 2 + 2, GFP_ATOMIC); 636 if (!nskb) 637 return NULL; 638 639 hci_skb_pkt_type(nskb) = pkt_type; 640 641 h5_slip_delim(nskb); 642 643 hdr[0] = h5->tx_ack << 3; 644 clear_bit(H5_TX_ACK_REQ, &h5->flags); 645 646 /* Reliable packet? */ 647 if (pkt_type == HCI_ACLDATA_PKT || pkt_type == HCI_COMMAND_PKT) { 648 hdr[0] |= 1 << 7; 649 hdr[0] |= h5->tx_seq; 650 h5->tx_seq = (h5->tx_seq + 1) % 8; 651 } 652 653 hdr[1] = pkt_type | ((len & 0x0f) << 4); 654 hdr[2] = len >> 4; 655 hdr[3] = ~((hdr[0] + hdr[1] + hdr[2]) & 0xff); 656 657 BT_DBG("%s tx: seq %u ack %u crc %u rel %u type %u len %u", 658 hu->hdev->name, H5_HDR_SEQ(hdr), H5_HDR_ACK(hdr), 659 H5_HDR_CRC(hdr), H5_HDR_RELIABLE(hdr), H5_HDR_PKT_TYPE(hdr), 660 H5_HDR_LEN(hdr)); 661 662 for (i = 0; i < 4; i++) 663 h5_slip_one_byte(nskb, hdr[i]); 664 665 for (i = 0; i < len; i++) 666 h5_slip_one_byte(nskb, data[i]); 667 668 h5_slip_delim(nskb); 669 670 return nskb; 671 } 672 673 static struct sk_buff *h5_dequeue(struct hci_uart *hu) 674 { 675 struct h5 *h5 = hu->priv; 676 unsigned long flags; 677 struct sk_buff *skb, *nskb; 678 679 if (h5->sleep != H5_AWAKE) { 680 const unsigned char wakeup_req[] = { 0x05, 0xfa }; 681 682 if (h5->sleep == H5_WAKING_UP) 683 return NULL; 684 685 h5->sleep = H5_WAKING_UP; 686 BT_DBG("Sending wakeup request"); 687 688 mod_timer(&h5->timer, jiffies + HZ / 100); 689 return h5_prepare_pkt(hu, HCI_3WIRE_LINK_PKT, wakeup_req, 2); 690 } 691 692 skb = skb_dequeue(&h5->unrel); 693 if (skb) { 694 nskb = h5_prepare_pkt(hu, hci_skb_pkt_type(skb), 695 skb->data, skb->len); 696 if (nskb) { 697 kfree_skb(skb); 698 return nskb; 699 } 700 701 skb_queue_head(&h5->unrel, skb); 702 BT_ERR("Could not dequeue pkt because alloc_skb failed"); 703 } 704 705 spin_lock_irqsave_nested(&h5->unack.lock, flags, SINGLE_DEPTH_NESTING); 706 707 if (h5->unack.qlen >= h5->tx_win) 708 goto unlock; 709 710 skb = skb_dequeue(&h5->rel); 711 if (skb) { 712 nskb = h5_prepare_pkt(hu, hci_skb_pkt_type(skb), 713 skb->data, skb->len); 714 if (nskb) { 715 __skb_queue_tail(&h5->unack, skb); 716 mod_timer(&h5->timer, jiffies + H5_ACK_TIMEOUT); 717 spin_unlock_irqrestore(&h5->unack.lock, flags); 718 return nskb; 719 } 720 721 skb_queue_head(&h5->rel, skb); 722 BT_ERR("Could not dequeue pkt because alloc_skb failed"); 723 } 724 725 unlock: 726 spin_unlock_irqrestore(&h5->unack.lock, flags); 727 728 if (test_bit(H5_TX_ACK_REQ, &h5->flags)) 729 return h5_prepare_pkt(hu, HCI_3WIRE_ACK_PKT, NULL, 0); 730 731 return NULL; 732 } 733 734 static int h5_flush(struct hci_uart *hu) 735 { 736 BT_DBG("hu %p", hu); 737 return 0; 738 } 739 740 static const struct hci_uart_proto h5p = { 741 .id = HCI_UART_3WIRE, 742 .name = "Three-wire (H5)", 743 .open = h5_open, 744 .close = h5_close, 745 .recv = h5_recv, 746 .enqueue = h5_enqueue, 747 .dequeue = h5_dequeue, 748 .flush = h5_flush, 749 }; 750 751 int __init h5_init(void) 752 { 753 return hci_uart_register_proto(&h5p); 754 } 755 756 int __exit h5_deinit(void) 757 { 758 return hci_uart_unregister_proto(&h5p); 759 } 760