1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * 4 * Bluetooth HCI Three-wire UART driver 5 * 6 * Copyright (C) 2012 Intel Corporation 7 */ 8 9 #include <linux/acpi.h> 10 #include <linux/bitrev.h> 11 #include <linux/crc-ccitt.h> 12 #include <linux/errno.h> 13 #include <linux/gpio/consumer.h> 14 #include <linux/kernel.h> 15 #include <linux/of.h> 16 #include <linux/pm_runtime.h> 17 #include <linux/serdev.h> 18 #include <linux/skbuff.h> 19 20 #include <net/bluetooth/bluetooth.h> 21 #include <net/bluetooth/hci_core.h> 22 23 #include "btrtl.h" 24 #include "hci_uart.h" 25 26 #define SUSPEND_TIMEOUT_MS 6000 27 28 #define HCI_3WIRE_ACK_PKT 0 29 #define HCI_3WIRE_LINK_PKT 15 30 31 /* Sliding window size */ 32 #define H5_TX_WIN_MAX 4 33 34 #define H5_ACK_TIMEOUT msecs_to_jiffies(250) 35 #define H5_SYNC_TIMEOUT msecs_to_jiffies(100) 36 37 /* 38 * Maximum Three-wire packet: 39 * 4 byte header + max value for 12-bit length + 2 bytes for CRC 40 */ 41 #define H5_MAX_LEN (4 + 0xfff + 2) 42 43 /* Convenience macros for reading Three-wire header values */ 44 #define H5_HDR_SEQ(hdr) ((hdr)[0] & 0x07) 45 #define H5_HDR_ACK(hdr) (((hdr)[0] >> 3) & 0x07) 46 #define H5_HDR_CRC(hdr) (((hdr)[0] >> 6) & 0x01) 47 #define H5_HDR_RELIABLE(hdr) (((hdr)[0] >> 7) & 0x01) 48 #define H5_HDR_PKT_TYPE(hdr) ((hdr)[1] & 0x0f) 49 #define H5_HDR_LEN(hdr) ((((hdr)[1] >> 4) & 0x0f) + ((hdr)[2] << 4)) 50 51 #define SLIP_DELIMITER 0xc0 52 #define SLIP_ESC 0xdb 53 #define SLIP_ESC_DELIM 0xdc 54 #define SLIP_ESC_ESC 0xdd 55 56 /* H5 state flags */ 57 enum { 58 H5_RX_ESC, /* SLIP escape mode */ 59 H5_TX_ACK_REQ, /* Pending ack to send */ 60 H5_WAKEUP_DISABLE, /* Device cannot wake host */ 61 H5_HW_FLOW_CONTROL, /* Use HW flow control */ 62 H5_CRC, /* Use CRC */ 63 }; 64 65 struct h5 { 66 /* Must be the first member, hci_serdev.c expects this. */ 67 struct hci_uart serdev_hu; 68 69 struct sk_buff_head unack; /* Unack'ed packets queue */ 70 struct sk_buff_head rel; /* Reliable packets queue */ 71 struct sk_buff_head unrel; /* Unreliable packets queue */ 72 73 unsigned long flags; 74 75 struct sk_buff *rx_skb; /* Receive buffer */ 76 size_t rx_pending; /* Expecting more bytes */ 77 u8 rx_ack; /* Last ack number received */ 78 79 int (*rx_func)(struct hci_uart *hu, u8 c); 80 81 struct timer_list timer; /* Retransmission timer */ 82 struct hci_uart *hu; /* Parent HCI UART */ 83 84 u8 tx_seq; /* Next seq number to send */ 85 u8 tx_ack; /* Next ack number to send */ 86 u8 tx_win; /* Sliding window size */ 87 88 enum { 89 H5_UNINITIALIZED, 90 H5_INITIALIZED, 91 H5_ACTIVE, 92 } state; 93 94 enum { 95 H5_AWAKE, 96 H5_SLEEPING, 97 H5_WAKING_UP, 98 } sleep; 99 100 const struct h5_vnd *vnd; 101 const char *id; 102 103 struct gpio_desc *enable_gpio; 104 struct gpio_desc *device_wake_gpio; 105 }; 106 107 enum h5_driver_info { 108 H5_INFO_WAKEUP_DISABLE = BIT(0), 109 }; 110 111 struct h5_vnd { 112 int (*setup)(struct h5 *h5); 113 void (*open)(struct h5 *h5); 114 void (*close)(struct h5 *h5); 115 int (*suspend)(struct h5 *h5); 116 int (*resume)(struct h5 *h5); 117 const struct acpi_gpio_mapping *acpi_gpio_map; 118 int sizeof_priv; 119 }; 120 121 struct h5_device_data { 122 uint32_t driver_info; 123 struct h5_vnd *vnd; 124 }; 125 126 static void h5_reset_rx(struct h5 *h5); 127 128 static void h5_link_control(struct hci_uart *hu, const void *data, size_t len) 129 { 130 struct h5 *h5 = hu->priv; 131 struct sk_buff *nskb; 132 133 nskb = alloc_skb(3, GFP_ATOMIC); 134 if (!nskb) 135 return; 136 137 hci_skb_pkt_type(nskb) = HCI_3WIRE_LINK_PKT; 138 139 skb_put_data(nskb, data, len); 140 141 skb_queue_tail(&h5->unrel, nskb); 142 } 143 144 static u8 h5_cfg_field(struct h5 *h5) 145 { 146 /* Sliding window size (first 3 bits) and CRC request (fifth bit). */ 147 return (h5->tx_win & 0x07) | 0x10; 148 } 149 150 static void h5_timed_event(struct timer_list *t) 151 { 152 const unsigned char sync_req[] = { 0x01, 0x7e }; 153 unsigned char conf_req[3] = { 0x03, 0xfc }; 154 struct h5 *h5 = timer_container_of(h5, t, timer); 155 struct hci_uart *hu = h5->hu; 156 struct sk_buff *skb; 157 unsigned long flags; 158 159 BT_DBG("%s", hu->hdev->name); 160 161 if (h5->state == H5_UNINITIALIZED) 162 h5_link_control(hu, sync_req, sizeof(sync_req)); 163 164 if (h5->state == H5_INITIALIZED) { 165 conf_req[2] = h5_cfg_field(h5); 166 h5_link_control(hu, conf_req, sizeof(conf_req)); 167 } 168 169 if (h5->state != H5_ACTIVE) { 170 mod_timer(&h5->timer, jiffies + H5_SYNC_TIMEOUT); 171 goto wakeup; 172 } 173 174 if (h5->sleep != H5_AWAKE) { 175 h5->sleep = H5_SLEEPING; 176 goto wakeup; 177 } 178 179 BT_DBG("hu %p retransmitting %u pkts", hu, h5->unack.qlen); 180 181 spin_lock_irqsave_nested(&h5->unack.lock, flags, SINGLE_DEPTH_NESTING); 182 183 while ((skb = __skb_dequeue_tail(&h5->unack)) != NULL) { 184 h5->tx_seq = (h5->tx_seq - 1) & 0x07; 185 skb_queue_head(&h5->rel, skb); 186 } 187 188 spin_unlock_irqrestore(&h5->unack.lock, flags); 189 190 wakeup: 191 hci_uart_tx_wakeup(hu); 192 } 193 194 static void h5_peer_reset(struct hci_uart *hu) 195 { 196 struct h5 *h5 = hu->priv; 197 198 bt_dev_err(hu->hdev, "Peer device has reset"); 199 200 h5->state = H5_UNINITIALIZED; 201 202 timer_delete(&h5->timer); 203 204 skb_queue_purge(&h5->rel); 205 skb_queue_purge(&h5->unrel); 206 skb_queue_purge(&h5->unack); 207 208 h5->tx_seq = 0; 209 h5->tx_ack = 0; 210 211 /* Send reset request to upper stack */ 212 hci_reset_dev(hu->hdev); 213 } 214 215 static int h5_open(struct hci_uart *hu) 216 { 217 struct h5 *h5; 218 219 BT_DBG("hu %p", hu); 220 221 if (hu->serdev) { 222 h5 = serdev_device_get_drvdata(hu->serdev); 223 } else { 224 h5 = kzalloc_obj(*h5); 225 if (!h5) 226 return -ENOMEM; 227 } 228 229 hu->priv = h5; 230 h5->hu = hu; 231 232 skb_queue_head_init(&h5->unack); 233 skb_queue_head_init(&h5->rel); 234 skb_queue_head_init(&h5->unrel); 235 236 h5_reset_rx(h5); 237 238 timer_setup(&h5->timer, h5_timed_event, 0); 239 240 h5->tx_win = H5_TX_WIN_MAX; 241 242 if (h5->vnd && h5->vnd->open) 243 h5->vnd->open(h5); 244 245 set_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags); 246 247 /* 248 * Wait one jiffy because the UART layer won't set HCI_UART_PROTO_READY, 249 * which allows us to send link packets, until this function returns. 250 */ 251 mod_timer(&h5->timer, jiffies + 1); 252 253 return 0; 254 } 255 256 static int h5_close(struct hci_uart *hu) 257 { 258 struct h5 *h5 = hu->priv; 259 260 timer_delete_sync(&h5->timer); 261 262 skb_queue_purge(&h5->unack); 263 skb_queue_purge(&h5->rel); 264 skb_queue_purge(&h5->unrel); 265 266 kfree_skb(h5->rx_skb); 267 h5->rx_skb = NULL; 268 269 if (h5->vnd && h5->vnd->close) 270 h5->vnd->close(h5); 271 272 if (!hu->serdev) 273 kfree(h5); 274 275 hu->priv = NULL; 276 return 0; 277 } 278 279 static int h5_setup(struct hci_uart *hu) 280 { 281 struct h5 *h5 = hu->priv; 282 283 if (h5->vnd && h5->vnd->setup) 284 return h5->vnd->setup(h5); 285 286 return 0; 287 } 288 289 static void h5_pkt_cull(struct h5 *h5) 290 { 291 struct sk_buff *skb, *tmp; 292 unsigned long flags; 293 int i, to_remove; 294 u8 seq; 295 296 spin_lock_irqsave(&h5->unack.lock, flags); 297 298 to_remove = skb_queue_len(&h5->unack); 299 if (to_remove == 0) 300 goto unlock; 301 302 seq = h5->tx_seq; 303 304 while (to_remove > 0) { 305 if (h5->rx_ack == seq) 306 break; 307 308 to_remove--; 309 seq = (seq - 1) & 0x07; 310 } 311 312 if (seq != h5->rx_ack) 313 BT_ERR("Controller acked invalid packet"); 314 315 i = 0; 316 skb_queue_walk_safe(&h5->unack, skb, tmp) { 317 if (i++ >= to_remove) 318 break; 319 320 __skb_unlink(skb, &h5->unack); 321 dev_kfree_skb_irq(skb); 322 } 323 324 if (skb_queue_empty(&h5->unack)) 325 timer_delete(&h5->timer); 326 327 unlock: 328 spin_unlock_irqrestore(&h5->unack.lock, flags); 329 } 330 331 static void h5_handle_internal_rx(struct hci_uart *hu) 332 { 333 struct h5 *h5 = hu->priv; 334 const unsigned char sync_req[] = { 0x01, 0x7e }; 335 const unsigned char sync_rsp[] = { 0x02, 0x7d }; 336 unsigned char conf_req[3] = { 0x03, 0xfc }; 337 const unsigned char conf_rsp[] = { 0x04, 0x7b }; 338 const unsigned char wakeup_req[] = { 0x05, 0xfa }; 339 const unsigned char woken_req[] = { 0x06, 0xf9 }; 340 const unsigned char sleep_req[] = { 0x07, 0x78 }; 341 const unsigned char *hdr = h5->rx_skb->data; 342 const unsigned char *data = &h5->rx_skb->data[4]; 343 344 BT_DBG("%s", hu->hdev->name); 345 346 if (H5_HDR_PKT_TYPE(hdr) != HCI_3WIRE_LINK_PKT) 347 return; 348 349 if (H5_HDR_LEN(hdr) < 2) 350 return; 351 352 conf_req[2] = h5_cfg_field(h5); 353 354 if (memcmp(data, sync_req, 2) == 0) { 355 if (h5->state == H5_ACTIVE) 356 h5_peer_reset(hu); 357 h5_link_control(hu, sync_rsp, 2); 358 } else if (memcmp(data, sync_rsp, 2) == 0) { 359 if (h5->state == H5_ACTIVE) 360 h5_peer_reset(hu); 361 h5->state = H5_INITIALIZED; 362 h5_link_control(hu, conf_req, 3); 363 } else if (memcmp(data, conf_req, 2) == 0) { 364 h5_link_control(hu, conf_rsp, 2); 365 h5_link_control(hu, conf_req, 3); 366 } else if (memcmp(data, conf_rsp, 2) == 0) { 367 if (H5_HDR_LEN(hdr) > 2) { 368 h5->tx_win = (data[2] & 0x07); 369 assign_bit(H5_CRC, &h5->flags, data[2] & 0x10); 370 } 371 BT_DBG("Three-wire init complete. tx_win %u", h5->tx_win); 372 h5->state = H5_ACTIVE; 373 hci_uart_init_ready(hu); 374 return; 375 } else if (memcmp(data, sleep_req, 2) == 0) { 376 BT_DBG("Peer went to sleep"); 377 h5->sleep = H5_SLEEPING; 378 return; 379 } else if (memcmp(data, woken_req, 2) == 0) { 380 BT_DBG("Peer woke up"); 381 h5->sleep = H5_AWAKE; 382 } else if (memcmp(data, wakeup_req, 2) == 0) { 383 BT_DBG("Peer requested wakeup"); 384 h5_link_control(hu, woken_req, 2); 385 h5->sleep = H5_AWAKE; 386 } else { 387 BT_DBG("Link Control: 0x%02hhx 0x%02hhx", data[0], data[1]); 388 return; 389 } 390 391 hci_uart_tx_wakeup(hu); 392 } 393 394 static void h5_complete_rx_pkt(struct hci_uart *hu) 395 { 396 struct h5 *h5 = hu->priv; 397 const unsigned char *hdr = h5->rx_skb->data; 398 399 if (H5_HDR_RELIABLE(hdr)) { 400 h5->tx_ack = (h5->tx_ack + 1) % 8; 401 set_bit(H5_TX_ACK_REQ, &h5->flags); 402 hci_uart_tx_wakeup(hu); 403 } 404 405 h5->rx_ack = H5_HDR_ACK(hdr); 406 407 h5_pkt_cull(h5); 408 409 switch (H5_HDR_PKT_TYPE(hdr)) { 410 case HCI_EVENT_PKT: 411 case HCI_ACLDATA_PKT: 412 case HCI_SCODATA_PKT: 413 case HCI_ISODATA_PKT: 414 hci_skb_pkt_type(h5->rx_skb) = H5_HDR_PKT_TYPE(hdr); 415 416 /* Remove Three-wire header */ 417 skb_pull(h5->rx_skb, 4); 418 419 hci_recv_frame(hu->hdev, h5->rx_skb); 420 h5->rx_skb = NULL; 421 422 break; 423 424 default: 425 h5_handle_internal_rx(hu); 426 break; 427 } 428 429 h5_reset_rx(h5); 430 } 431 432 static int h5_rx_crc(struct hci_uart *hu, unsigned char c) 433 { 434 struct h5 *h5 = hu->priv; 435 const unsigned char *hdr = h5->rx_skb->data; 436 u16 crc; 437 __be16 crc_be; 438 439 crc = crc_ccitt(0xffff, hdr, 4 + H5_HDR_LEN(hdr)); 440 crc = bitrev16(crc); 441 442 crc_be = cpu_to_be16(crc); 443 444 if (memcmp(&crc_be, hdr + 4 + H5_HDR_LEN(hdr), 2) != 0) { 445 bt_dev_err(hu->hdev, "Received packet with invalid CRC"); 446 h5_reset_rx(h5); 447 } else { 448 /* Remove CRC bytes */ 449 skb_trim(h5->rx_skb, 4 + H5_HDR_LEN(hdr)); 450 h5_complete_rx_pkt(hu); 451 } 452 453 return 0; 454 } 455 456 static int h5_rx_payload(struct hci_uart *hu, unsigned char c) 457 { 458 struct h5 *h5 = hu->priv; 459 const unsigned char *hdr = h5->rx_skb->data; 460 461 if (H5_HDR_CRC(hdr)) { 462 h5->rx_func = h5_rx_crc; 463 h5->rx_pending = 2; 464 } else { 465 h5_complete_rx_pkt(hu); 466 } 467 468 return 0; 469 } 470 471 static int h5_rx_3wire_hdr(struct hci_uart *hu, unsigned char c) 472 { 473 struct h5 *h5 = hu->priv; 474 const unsigned char *hdr = h5->rx_skb->data; 475 476 BT_DBG("%s rx: seq %u ack %u crc %u rel %u type %u len %u", 477 hu->hdev->name, H5_HDR_SEQ(hdr), H5_HDR_ACK(hdr), 478 H5_HDR_CRC(hdr), H5_HDR_RELIABLE(hdr), H5_HDR_PKT_TYPE(hdr), 479 H5_HDR_LEN(hdr)); 480 481 if (((hdr[0] + hdr[1] + hdr[2] + hdr[3]) & 0xff) != 0xff) { 482 bt_dev_err(hu->hdev, "Invalid header checksum"); 483 h5_reset_rx(h5); 484 return 0; 485 } 486 487 if (H5_HDR_RELIABLE(hdr) && H5_HDR_SEQ(hdr) != h5->tx_ack) { 488 bt_dev_err(hu->hdev, "Out-of-order packet arrived (%u != %u)", 489 H5_HDR_SEQ(hdr), h5->tx_ack); 490 set_bit(H5_TX_ACK_REQ, &h5->flags); 491 hci_uart_tx_wakeup(hu); 492 h5_reset_rx(h5); 493 return 0; 494 } 495 496 if (h5->state != H5_ACTIVE && 497 H5_HDR_PKT_TYPE(hdr) != HCI_3WIRE_LINK_PKT) { 498 bt_dev_err(hu->hdev, "Non-link packet received in non-active state"); 499 h5_reset_rx(h5); 500 return 0; 501 } 502 503 h5->rx_func = h5_rx_payload; 504 h5->rx_pending = H5_HDR_LEN(hdr); 505 506 return 0; 507 } 508 509 static int h5_rx_pkt_start(struct hci_uart *hu, unsigned char c) 510 { 511 struct h5 *h5 = hu->priv; 512 513 if (c == SLIP_DELIMITER) 514 return 1; 515 516 h5->rx_func = h5_rx_3wire_hdr; 517 h5->rx_pending = 4; 518 519 h5->rx_skb = bt_skb_alloc(H5_MAX_LEN, GFP_ATOMIC); 520 if (!h5->rx_skb) { 521 bt_dev_err(hu->hdev, "Can't allocate mem for new packet"); 522 h5_reset_rx(h5); 523 return -ENOMEM; 524 } 525 526 h5->rx_skb->dev = (void *)hu->hdev; 527 528 return 0; 529 } 530 531 static int h5_rx_delimiter(struct hci_uart *hu, unsigned char c) 532 { 533 struct h5 *h5 = hu->priv; 534 535 if (c == SLIP_DELIMITER) 536 h5->rx_func = h5_rx_pkt_start; 537 538 return 1; 539 } 540 541 static void h5_unslip_one_byte(struct h5 *h5, unsigned char c) 542 { 543 const u8 delim = SLIP_DELIMITER, esc = SLIP_ESC; 544 const u8 *byte = &c; 545 546 if (test_bit(H5_RX_ESC, &h5->flags)) { 547 clear_bit(H5_RX_ESC, &h5->flags); 548 switch (c) { 549 case SLIP_ESC_DELIM: 550 byte = &delim; 551 break; 552 case SLIP_ESC_ESC: 553 byte = &esc; 554 break; 555 default: 556 BT_ERR("Invalid esc byte 0x%02hhx", c); 557 h5_reset_rx(h5); 558 return; 559 } 560 } else if (c == SLIP_ESC) { 561 set_bit(H5_RX_ESC, &h5->flags); 562 return; 563 } 564 565 skb_put_data(h5->rx_skb, byte, 1); 566 h5->rx_pending--; 567 568 BT_DBG("unslipped 0x%02hhx, rx_pending %zu", *byte, h5->rx_pending); 569 } 570 571 static void h5_reset_rx(struct h5 *h5) 572 { 573 if (h5->rx_skb) { 574 kfree_skb(h5->rx_skb); 575 h5->rx_skb = NULL; 576 } 577 578 h5->rx_func = h5_rx_delimiter; 579 h5->rx_pending = 0; 580 clear_bit(H5_RX_ESC, &h5->flags); 581 clear_bit(H5_CRC, &h5->flags); 582 } 583 584 static int h5_recv(struct hci_uart *hu, const void *data, int count) 585 { 586 struct h5 *h5 = hu->priv; 587 const unsigned char *ptr = data; 588 589 if (!h5) 590 return -ENODEV; 591 592 BT_DBG("%s pending %zu count %d", hu->hdev->name, h5->rx_pending, 593 count); 594 595 while (count > 0) { 596 int processed; 597 598 if (h5->rx_pending > 0) { 599 if (*ptr == SLIP_DELIMITER) { 600 bt_dev_err(hu->hdev, "Too short H5 packet"); 601 h5_reset_rx(h5); 602 continue; 603 } 604 605 h5_unslip_one_byte(h5, *ptr); 606 607 ptr++; count--; 608 continue; 609 } 610 611 processed = h5->rx_func(hu, *ptr); 612 if (processed < 0) 613 return processed; 614 615 ptr += processed; 616 count -= processed; 617 } 618 619 if (hu->serdev) { 620 pm_runtime_get(&hu->serdev->dev); 621 pm_runtime_put_autosuspend(&hu->serdev->dev); 622 } 623 624 return 0; 625 } 626 627 static int h5_enqueue(struct hci_uart *hu, struct sk_buff *skb) 628 { 629 struct h5 *h5 = hu->priv; 630 631 if (skb->len > 0xfff) { 632 bt_dev_err(hu->hdev, "Packet too long (%u bytes)", skb->len); 633 kfree_skb(skb); 634 return 0; 635 } 636 637 if (h5->state != H5_ACTIVE) { 638 bt_dev_err(hu->hdev, "Ignoring HCI data in non-active state"); 639 kfree_skb(skb); 640 return 0; 641 } 642 643 switch (hci_skb_pkt_type(skb)) { 644 case HCI_ACLDATA_PKT: 645 case HCI_COMMAND_PKT: 646 skb_queue_tail(&h5->rel, skb); 647 break; 648 649 case HCI_SCODATA_PKT: 650 case HCI_ISODATA_PKT: 651 skb_queue_tail(&h5->unrel, skb); 652 break; 653 654 default: 655 bt_dev_err(hu->hdev, "Unknown packet type %u", hci_skb_pkt_type(skb)); 656 kfree_skb(skb); 657 break; 658 } 659 660 if (hu->serdev) { 661 pm_runtime_get_sync(&hu->serdev->dev); 662 pm_runtime_put_autosuspend(&hu->serdev->dev); 663 } 664 665 return 0; 666 } 667 668 static void h5_slip_delim(struct sk_buff *skb) 669 { 670 const char delim = SLIP_DELIMITER; 671 672 skb_put_data(skb, &delim, 1); 673 } 674 675 static void h5_slip_one_byte(struct sk_buff *skb, u8 c) 676 { 677 const char esc_delim[2] = { SLIP_ESC, SLIP_ESC_DELIM }; 678 const char esc_esc[2] = { SLIP_ESC, SLIP_ESC_ESC }; 679 680 switch (c) { 681 case SLIP_DELIMITER: 682 skb_put_data(skb, &esc_delim, 2); 683 break; 684 case SLIP_ESC: 685 skb_put_data(skb, &esc_esc, 2); 686 break; 687 default: 688 skb_put_data(skb, &c, 1); 689 } 690 } 691 692 static bool valid_packet_type(u8 type) 693 { 694 switch (type) { 695 case HCI_ACLDATA_PKT: 696 case HCI_COMMAND_PKT: 697 case HCI_SCODATA_PKT: 698 case HCI_ISODATA_PKT: 699 case HCI_3WIRE_LINK_PKT: 700 case HCI_3WIRE_ACK_PKT: 701 return true; 702 default: 703 return false; 704 } 705 } 706 707 static struct sk_buff *h5_prepare_pkt(struct hci_uart *hu, u8 pkt_type, 708 const u8 *data, size_t len) 709 { 710 struct h5 *h5 = hu->priv; 711 struct sk_buff *nskb; 712 u8 hdr[4]; 713 u16 crc; 714 int i; 715 716 if (!valid_packet_type(pkt_type)) { 717 bt_dev_err(hu->hdev, "Unknown packet type %u", pkt_type); 718 return NULL; 719 } 720 721 /* 722 * Max len of packet: (original len + 4 (H5 hdr) + 2 (crc)) * 2 723 * (because bytes 0xc0 and 0xdb are escaped, worst case is when 724 * the packet is all made of 0xc0 and 0xdb) + 2 (0xc0 725 * delimiters at start and end). 726 */ 727 nskb = alloc_skb((len + 6) * 2 + 2, GFP_ATOMIC); 728 if (!nskb) 729 return NULL; 730 731 hci_skb_pkt_type(nskb) = pkt_type; 732 733 h5_slip_delim(nskb); 734 735 hdr[0] = h5->tx_ack << 3; 736 clear_bit(H5_TX_ACK_REQ, &h5->flags); 737 738 /* Reliable packet? */ 739 if (pkt_type == HCI_ACLDATA_PKT || pkt_type == HCI_COMMAND_PKT) { 740 hdr[0] |= 1 << 7; 741 hdr[0] |= (test_bit(H5_CRC, &h5->flags) && 1) << 6; 742 hdr[0] |= h5->tx_seq; 743 h5->tx_seq = (h5->tx_seq + 1) % 8; 744 } 745 746 hdr[1] = pkt_type | ((len & 0x0f) << 4); 747 hdr[2] = len >> 4; 748 hdr[3] = ~((hdr[0] + hdr[1] + hdr[2]) & 0xff); 749 750 BT_DBG("%s tx: seq %u ack %u crc %u rel %u type %u len %u", 751 hu->hdev->name, H5_HDR_SEQ(hdr), H5_HDR_ACK(hdr), 752 H5_HDR_CRC(hdr), H5_HDR_RELIABLE(hdr), H5_HDR_PKT_TYPE(hdr), 753 H5_HDR_LEN(hdr)); 754 755 for (i = 0; i < 4; i++) 756 h5_slip_one_byte(nskb, hdr[i]); 757 758 for (i = 0; i < len; i++) 759 h5_slip_one_byte(nskb, data[i]); 760 761 if (H5_HDR_CRC(hdr)) { 762 crc = crc_ccitt(0xffff, hdr, 4); 763 crc = crc_ccitt(crc, data, len); 764 crc = bitrev16(crc); 765 766 h5_slip_one_byte(nskb, (crc >> 8) & 0xff); 767 h5_slip_one_byte(nskb, crc & 0xff); 768 } 769 770 h5_slip_delim(nskb); 771 772 return nskb; 773 } 774 775 static struct sk_buff *h5_dequeue(struct hci_uart *hu) 776 { 777 struct h5 *h5 = hu->priv; 778 unsigned long flags; 779 struct sk_buff *skb, *nskb; 780 781 if (h5->sleep != H5_AWAKE) { 782 const unsigned char wakeup_req[] = { 0x05, 0xfa }; 783 784 if (h5->sleep == H5_WAKING_UP) 785 return NULL; 786 787 h5->sleep = H5_WAKING_UP; 788 BT_DBG("Sending wakeup request"); 789 790 mod_timer(&h5->timer, jiffies + HZ / 100); 791 return h5_prepare_pkt(hu, HCI_3WIRE_LINK_PKT, wakeup_req, 2); 792 } 793 794 skb = skb_dequeue(&h5->unrel); 795 if (skb) { 796 nskb = h5_prepare_pkt(hu, hci_skb_pkt_type(skb), 797 skb->data, skb->len); 798 if (nskb) { 799 kfree_skb(skb); 800 return nskb; 801 } 802 803 skb_queue_head(&h5->unrel, skb); 804 bt_dev_err(hu->hdev, "Could not dequeue pkt because alloc_skb failed"); 805 } 806 807 spin_lock_irqsave_nested(&h5->unack.lock, flags, SINGLE_DEPTH_NESTING); 808 809 if (h5->unack.qlen >= h5->tx_win) 810 goto unlock; 811 812 skb = skb_dequeue(&h5->rel); 813 if (skb) { 814 nskb = h5_prepare_pkt(hu, hci_skb_pkt_type(skb), 815 skb->data, skb->len); 816 if (nskb) { 817 __skb_queue_tail(&h5->unack, skb); 818 mod_timer(&h5->timer, jiffies + H5_ACK_TIMEOUT); 819 spin_unlock_irqrestore(&h5->unack.lock, flags); 820 return nskb; 821 } 822 823 skb_queue_head(&h5->rel, skb); 824 bt_dev_err(hu->hdev, "Could not dequeue pkt because alloc_skb failed"); 825 } 826 827 unlock: 828 spin_unlock_irqrestore(&h5->unack.lock, flags); 829 830 if (test_bit(H5_TX_ACK_REQ, &h5->flags)) 831 return h5_prepare_pkt(hu, HCI_3WIRE_ACK_PKT, NULL, 0); 832 833 return NULL; 834 } 835 836 static int h5_flush(struct hci_uart *hu) 837 { 838 BT_DBG("hu %p", hu); 839 return 0; 840 } 841 842 static const struct hci_uart_proto h5p = { 843 .id = HCI_UART_3WIRE, 844 .name = "Three-wire (H5)", 845 .open = h5_open, 846 .close = h5_close, 847 .setup = h5_setup, 848 .recv = h5_recv, 849 .enqueue = h5_enqueue, 850 .dequeue = h5_dequeue, 851 .flush = h5_flush, 852 }; 853 854 static int h5_serdev_probe(struct serdev_device *serdev) 855 { 856 struct device *dev = &serdev->dev; 857 struct h5 *h5; 858 const struct h5_device_data *data; 859 860 h5 = devm_kzalloc(dev, sizeof(*h5), GFP_KERNEL); 861 if (!h5) 862 return -ENOMEM; 863 864 h5->hu = &h5->serdev_hu; 865 h5->serdev_hu.serdev = serdev; 866 serdev_device_set_drvdata(serdev, h5); 867 868 if (has_acpi_companion(dev)) { 869 const struct acpi_device_id *match; 870 871 match = acpi_match_device(dev->driver->acpi_match_table, dev); 872 if (!match) 873 return -ENODEV; 874 875 data = (const struct h5_device_data *)match->driver_data; 876 h5->vnd = data->vnd; 877 h5->id = (char *)match->id; 878 879 if (h5->vnd->acpi_gpio_map) 880 devm_acpi_dev_add_driver_gpios(dev, 881 h5->vnd->acpi_gpio_map); 882 } else { 883 data = of_device_get_match_data(dev); 884 if (!data) 885 return -ENODEV; 886 887 h5->vnd = data->vnd; 888 } 889 890 if (data->driver_info & H5_INFO_WAKEUP_DISABLE) 891 set_bit(H5_WAKEUP_DISABLE, &h5->flags); 892 893 h5->enable_gpio = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_LOW); 894 if (IS_ERR(h5->enable_gpio)) 895 return PTR_ERR(h5->enable_gpio); 896 897 h5->device_wake_gpio = devm_gpiod_get_optional(dev, "device-wake", 898 GPIOD_OUT_LOW); 899 if (IS_ERR(h5->device_wake_gpio)) 900 return PTR_ERR(h5->device_wake_gpio); 901 902 return hci_uart_register_device_priv(&h5->serdev_hu, &h5p, 903 h5->vnd->sizeof_priv); 904 } 905 906 static void h5_serdev_remove(struct serdev_device *serdev) 907 { 908 struct h5 *h5 = serdev_device_get_drvdata(serdev); 909 910 hci_uart_unregister_device(&h5->serdev_hu); 911 } 912 913 static int __maybe_unused h5_serdev_suspend(struct device *dev) 914 { 915 struct h5 *h5 = dev_get_drvdata(dev); 916 int ret = 0; 917 918 if (h5->vnd && h5->vnd->suspend) 919 ret = h5->vnd->suspend(h5); 920 921 return ret; 922 } 923 924 static int __maybe_unused h5_serdev_resume(struct device *dev) 925 { 926 struct h5 *h5 = dev_get_drvdata(dev); 927 int ret = 0; 928 929 if (h5->vnd && h5->vnd->resume) 930 ret = h5->vnd->resume(h5); 931 932 return ret; 933 } 934 935 #ifdef CONFIG_BT_HCIUART_RTL 936 static int h5_btrtl_setup(struct h5 *h5) 937 { 938 struct btrtl_device_info *btrtl_dev; 939 struct sk_buff *skb; 940 __le32 baudrate_data; 941 u32 device_baudrate; 942 unsigned int controller_baudrate; 943 bool flow_control; 944 int err; 945 946 btrtl_dev = btrtl_initialize(h5->hu->hdev, h5->id); 947 if (IS_ERR(btrtl_dev)) 948 return PTR_ERR(btrtl_dev); 949 950 err = btrtl_get_uart_settings(h5->hu->hdev, btrtl_dev, 951 &controller_baudrate, &device_baudrate, 952 &flow_control); 953 if (err) 954 goto out_free; 955 956 baudrate_data = cpu_to_le32(device_baudrate); 957 skb = __hci_cmd_sync(h5->hu->hdev, 0xfc17, sizeof(baudrate_data), 958 &baudrate_data, HCI_INIT_TIMEOUT); 959 if (IS_ERR(skb)) { 960 rtl_dev_err(h5->hu->hdev, "set baud rate command failed\n"); 961 err = PTR_ERR(skb); 962 goto out_free; 963 } else { 964 kfree_skb(skb); 965 } 966 /* Give the device some time to set up the new baudrate. */ 967 usleep_range(10000, 20000); 968 969 serdev_device_set_baudrate(h5->hu->serdev, controller_baudrate); 970 serdev_device_set_flow_control(h5->hu->serdev, flow_control); 971 972 if (flow_control) 973 set_bit(H5_HW_FLOW_CONTROL, &h5->flags); 974 975 err = btrtl_download_firmware(h5->hu->hdev, btrtl_dev); 976 /* Give the device some time before the hci-core sends it a reset */ 977 usleep_range(10000, 20000); 978 if (err) 979 goto out_free; 980 981 btrtl_set_quirks(h5->hu->hdev, btrtl_dev); 982 983 out_free: 984 btrtl_free(btrtl_dev); 985 986 return err; 987 } 988 989 static void h5_btrtl_open(struct h5 *h5) 990 { 991 /* 992 * Since h5_btrtl_resume() does a device_reprobe() the suspend handling 993 * done by the hci_suspend_notifier is not necessary; it actually causes 994 * delays and a bunch of errors to get logged, so disable it. 995 */ 996 if (test_bit(H5_WAKEUP_DISABLE, &h5->flags)) 997 set_bit(HCI_UART_NO_SUSPEND_NOTIFIER, &h5->hu->flags); 998 999 /* Devices always start with these fixed parameters */ 1000 serdev_device_set_flow_control(h5->hu->serdev, false); 1001 serdev_device_set_parity(h5->hu->serdev, SERDEV_PARITY_EVEN); 1002 serdev_device_set_baudrate(h5->hu->serdev, 115200); 1003 1004 if (!test_bit(H5_WAKEUP_DISABLE, &h5->flags)) { 1005 pm_runtime_set_active(&h5->hu->serdev->dev); 1006 pm_runtime_use_autosuspend(&h5->hu->serdev->dev); 1007 pm_runtime_set_autosuspend_delay(&h5->hu->serdev->dev, 1008 SUSPEND_TIMEOUT_MS); 1009 pm_runtime_enable(&h5->hu->serdev->dev); 1010 } 1011 1012 /* The controller needs reset to startup */ 1013 gpiod_set_value_cansleep(h5->enable_gpio, 0); 1014 gpiod_set_value_cansleep(h5->device_wake_gpio, 0); 1015 msleep(100); 1016 1017 /* The controller needs up to 500ms to wakeup */ 1018 gpiod_set_value_cansleep(h5->enable_gpio, 1); 1019 gpiod_set_value_cansleep(h5->device_wake_gpio, 1); 1020 msleep(500); 1021 } 1022 1023 static void h5_btrtl_close(struct h5 *h5) 1024 { 1025 if (!test_bit(H5_WAKEUP_DISABLE, &h5->flags)) { 1026 pm_runtime_dont_use_autosuspend(&h5->hu->serdev->dev); 1027 pm_runtime_disable(&h5->hu->serdev->dev); 1028 } 1029 1030 gpiod_set_value_cansleep(h5->device_wake_gpio, 0); 1031 gpiod_set_value_cansleep(h5->enable_gpio, 0); 1032 } 1033 1034 /* Suspend/resume support. On many devices the RTL BT device loses power during 1035 * suspend/resume, causing it to lose its firmware and all state. So we simply 1036 * turn it off on suspend and reprobe on resume. This mirrors how RTL devices 1037 * are handled in the USB driver, where the BTUSB_WAKEUP_DISABLE is used which 1038 * also causes a reprobe on resume. 1039 */ 1040 static int h5_btrtl_suspend(struct h5 *h5) 1041 { 1042 serdev_device_set_flow_control(h5->hu->serdev, false); 1043 gpiod_set_value_cansleep(h5->device_wake_gpio, 0); 1044 1045 if (test_bit(H5_WAKEUP_DISABLE, &h5->flags)) 1046 gpiod_set_value_cansleep(h5->enable_gpio, 0); 1047 1048 return 0; 1049 } 1050 1051 struct h5_btrtl_reprobe { 1052 struct device *dev; 1053 struct work_struct work; 1054 }; 1055 1056 static void h5_btrtl_reprobe_worker(struct work_struct *work) 1057 { 1058 struct h5_btrtl_reprobe *reprobe = 1059 container_of(work, struct h5_btrtl_reprobe, work); 1060 int ret; 1061 1062 ret = device_reprobe(reprobe->dev); 1063 if (ret && ret != -EPROBE_DEFER) 1064 dev_err(reprobe->dev, "Reprobe error %d\n", ret); 1065 1066 put_device(reprobe->dev); 1067 kfree(reprobe); 1068 module_put(THIS_MODULE); 1069 } 1070 1071 static int h5_btrtl_resume(struct h5 *h5) 1072 { 1073 if (test_bit(H5_WAKEUP_DISABLE, &h5->flags)) { 1074 struct h5_btrtl_reprobe *reprobe; 1075 1076 reprobe = kzalloc_obj(*reprobe); 1077 if (!reprobe) 1078 return -ENOMEM; 1079 1080 __module_get(THIS_MODULE); 1081 1082 INIT_WORK(&reprobe->work, h5_btrtl_reprobe_worker); 1083 reprobe->dev = get_device(&h5->hu->serdev->dev); 1084 queue_work(system_long_wq, &reprobe->work); 1085 } else { 1086 gpiod_set_value_cansleep(h5->device_wake_gpio, 1); 1087 1088 if (test_bit(H5_HW_FLOW_CONTROL, &h5->flags)) 1089 serdev_device_set_flow_control(h5->hu->serdev, true); 1090 } 1091 1092 return 0; 1093 } 1094 1095 static const struct acpi_gpio_params btrtl_device_wake_gpios = { 0, 0, false }; 1096 static const struct acpi_gpio_params btrtl_enable_gpios = { 1, 0, false }; 1097 static const struct acpi_gpio_params btrtl_host_wake_gpios = { 2, 0, false }; 1098 static const struct acpi_gpio_mapping acpi_btrtl_gpios[] = { 1099 { "device-wake-gpios", &btrtl_device_wake_gpios, 1 }, 1100 { "enable-gpios", &btrtl_enable_gpios, 1 }, 1101 { "host-wake-gpios", &btrtl_host_wake_gpios, 1 }, 1102 {}, 1103 }; 1104 1105 static struct h5_vnd rtl_vnd = { 1106 .setup = h5_btrtl_setup, 1107 .open = h5_btrtl_open, 1108 .close = h5_btrtl_close, 1109 .suspend = h5_btrtl_suspend, 1110 .resume = h5_btrtl_resume, 1111 .acpi_gpio_map = acpi_btrtl_gpios, 1112 .sizeof_priv = sizeof(struct btrealtek_data), 1113 }; 1114 1115 static const struct h5_device_data h5_data_rtl8822cs = { 1116 .vnd = &rtl_vnd, 1117 }; 1118 1119 static const struct h5_device_data h5_data_rtl8723bs = { 1120 .driver_info = H5_INFO_WAKEUP_DISABLE, 1121 .vnd = &rtl_vnd, 1122 }; 1123 #endif 1124 1125 #ifdef CONFIG_ACPI 1126 static const struct acpi_device_id h5_acpi_match[] = { 1127 #ifdef CONFIG_BT_HCIUART_RTL 1128 { .id = "OBDA0623", .driver_data = (kernel_ulong_t)&h5_data_rtl8723bs }, 1129 { .id = "OBDA8723", .driver_data = (kernel_ulong_t)&h5_data_rtl8723bs }, 1130 #endif 1131 { } 1132 }; 1133 MODULE_DEVICE_TABLE(acpi, h5_acpi_match); 1134 #endif 1135 1136 static const struct dev_pm_ops h5_serdev_pm_ops = { 1137 SET_SYSTEM_SLEEP_PM_OPS(h5_serdev_suspend, h5_serdev_resume) 1138 SET_RUNTIME_PM_OPS(h5_serdev_suspend, h5_serdev_resume, NULL) 1139 }; 1140 1141 static const struct of_device_id rtl_bluetooth_of_match[] = { 1142 #ifdef CONFIG_BT_HCIUART_RTL 1143 { .compatible = "realtek,rtl8822cs-bt", 1144 .data = (const void *)&h5_data_rtl8822cs }, 1145 { .compatible = "realtek,rtl8723bs-bt", 1146 .data = (const void *)&h5_data_rtl8723bs }, 1147 { .compatible = "realtek,rtl8723cs-bt", 1148 .data = (const void *)&h5_data_rtl8723bs }, 1149 { .compatible = "realtek,rtl8723ds-bt", 1150 .data = (const void *)&h5_data_rtl8723bs }, 1151 #endif 1152 { }, 1153 }; 1154 MODULE_DEVICE_TABLE(of, rtl_bluetooth_of_match); 1155 1156 static struct serdev_device_driver h5_serdev_driver = { 1157 .probe = h5_serdev_probe, 1158 .remove = h5_serdev_remove, 1159 .driver = { 1160 .name = "hci_uart_h5", 1161 .acpi_match_table = ACPI_PTR(h5_acpi_match), 1162 .pm = &h5_serdev_pm_ops, 1163 .of_match_table = rtl_bluetooth_of_match, 1164 }, 1165 }; 1166 1167 int __init h5_init(void) 1168 { 1169 serdev_device_driver_register(&h5_serdev_driver); 1170 return hci_uart_register_proto(&h5p); 1171 } 1172 1173 int __exit h5_deinit(void) 1174 { 1175 serdev_device_driver_unregister(&h5_serdev_driver); 1176 return hci_uart_unregister_proto(&h5p); 1177 } 1178