root/drivers/bluetooth/hci_h5.c

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DEFINITIONS

This source file includes following definitions.
  1. h5_link_control
  2. h5_cfg_field
  3. h5_timed_event
  4. h5_peer_reset
  5. h5_open
  6. h5_close
  7. h5_setup
  8. h5_pkt_cull
  9. h5_handle_internal_rx
  10. h5_complete_rx_pkt
  11. h5_rx_crc
  12. h5_rx_payload
  13. h5_rx_3wire_hdr
  14. h5_rx_pkt_start
  15. h5_rx_delimiter
  16. h5_unslip_one_byte
  17. h5_reset_rx
  18. h5_recv
  19. h5_enqueue
  20. h5_slip_delim
  21. h5_slip_one_byte
  22. valid_packet_type
  23. h5_prepare_pkt
  24. h5_dequeue
  25. h5_flush
  26. h5_serdev_probe
  27. h5_serdev_remove
  28. h5_serdev_suspend
  29. h5_serdev_resume
  30. h5_btrtl_setup
  31. h5_btrtl_open
  32. h5_btrtl_close
  33. h5_btrtl_suspend
  34. h5_btrtl_reprobe_worker
  35. h5_btrtl_resume
  36. h5_init
  37. h5_deinit

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

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