linux/drivers/bluetooth/hci_h5.c
<<
>>
Prefs
   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/of_device.h>
  15#include <linux/serdev.h>
  16#include <linux/skbuff.h>
  17
  18#include <net/bluetooth/bluetooth.h>
  19#include <net/bluetooth/hci_core.h>
  20
  21#include "btrtl.h"
  22#include "hci_uart.h"
  23
  24#define HCI_3WIRE_ACK_PKT       0
  25#define HCI_3WIRE_LINK_PKT      15
  26
  27/* Sliding window size */
  28#define H5_TX_WIN_MAX           4
  29
  30#define H5_ACK_TIMEOUT  msecs_to_jiffies(250)
  31#define H5_SYNC_TIMEOUT msecs_to_jiffies(100)
  32
  33/*
  34 * Maximum Three-wire packet:
  35 *     4 byte header + max value for 12-bit length + 2 bytes for CRC
  36 */
  37#define H5_MAX_LEN (4 + 0xfff + 2)
  38
  39/* Convenience macros for reading Three-wire header values */
  40#define H5_HDR_SEQ(hdr)         ((hdr)[0] & 0x07)
  41#define H5_HDR_ACK(hdr)         (((hdr)[0] >> 3) & 0x07)
  42#define H5_HDR_CRC(hdr)         (((hdr)[0] >> 6) & 0x01)
  43#define H5_HDR_RELIABLE(hdr)    (((hdr)[0] >> 7) & 0x01)
  44#define H5_HDR_PKT_TYPE(hdr)    ((hdr)[1] & 0x0f)
  45#define H5_HDR_LEN(hdr)         ((((hdr)[1] >> 4) & 0x0f) + ((hdr)[2] << 4))
  46
  47#define SLIP_DELIMITER  0xc0
  48#define SLIP_ESC        0xdb
  49#define SLIP_ESC_DELIM  0xdc
  50#define SLIP_ESC_ESC    0xdd
  51
  52/* H5 state flags */
  53enum {
  54        H5_RX_ESC,      /* SLIP escape mode */
  55        H5_TX_ACK_REQ,  /* Pending ack to send */
  56};
  57
  58struct h5 {
  59        /* Must be the first member, hci_serdev.c expects this. */
  60        struct hci_uart         serdev_hu;
  61
  62        struct sk_buff_head     unack;          /* Unack'ed packets queue */
  63        struct sk_buff_head     rel;            /* Reliable packets queue */
  64        struct sk_buff_head     unrel;          /* Unreliable packets queue */
  65
  66        unsigned long           flags;
  67
  68        struct sk_buff          *rx_skb;        /* Receive buffer */
  69        size_t                  rx_pending;     /* Expecting more bytes */
  70        u8                      rx_ack;         /* Last ack number received */
  71
  72        int                     (*rx_func)(struct hci_uart *hu, u8 c);
  73
  74        struct timer_list       timer;          /* Retransmission timer */
  75        struct hci_uart         *hu;            /* Parent HCI UART */
  76
  77        u8                      tx_seq;         /* Next seq number to send */
  78        u8                      tx_ack;         /* Next ack number to send */
  79        u8                      tx_win;         /* Sliding window size */
  80
  81        enum {
  82                H5_UNINITIALIZED,
  83                H5_INITIALIZED,
  84                H5_ACTIVE,
  85        } state;
  86
  87        enum {
  88                H5_AWAKE,
  89                H5_SLEEPING,
  90                H5_WAKING_UP,
  91        } sleep;
  92
  93        const struct h5_vnd *vnd;
  94        const char *id;
  95
  96        struct gpio_desc *enable_gpio;
  97        struct gpio_desc *device_wake_gpio;
  98};
  99
 100struct h5_vnd {
 101        int (*setup)(struct h5 *h5);
 102        void (*open)(struct h5 *h5);
 103        void (*close)(struct h5 *h5);
 104        int (*suspend)(struct h5 *h5);
 105        int (*resume)(struct h5 *h5);
 106        const struct acpi_gpio_mapping *acpi_gpio_map;
 107};
 108
 109static void h5_reset_rx(struct h5 *h5);
 110
 111static void h5_link_control(struct hci_uart *hu, const void *data, size_t len)
 112{
 113        struct h5 *h5 = hu->priv;
 114        struct sk_buff *nskb;
 115
 116        nskb = alloc_skb(3, GFP_ATOMIC);
 117        if (!nskb)
 118                return;
 119
 120        hci_skb_pkt_type(nskb) = HCI_3WIRE_LINK_PKT;
 121
 122        skb_put_data(nskb, data, len);
 123
 124        skb_queue_tail(&h5->unrel, nskb);
 125}
 126
 127static u8 h5_cfg_field(struct h5 *h5)
 128{
 129        /* Sliding window size (first 3 bits) */
 130        return h5->tx_win & 0x07;
 131}
 132
 133static void h5_timed_event(struct timer_list *t)
 134{
 135        const unsigned char sync_req[] = { 0x01, 0x7e };
 136        unsigned char conf_req[3] = { 0x03, 0xfc };
 137        struct h5 *h5 = from_timer(h5, t, timer);
 138        struct hci_uart *hu = h5->hu;
 139        struct sk_buff *skb;
 140        unsigned long flags;
 141
 142        BT_DBG("%s", hu->hdev->name);
 143
 144        if (h5->state == H5_UNINITIALIZED)
 145                h5_link_control(hu, sync_req, sizeof(sync_req));
 146
 147        if (h5->state == H5_INITIALIZED) {
 148                conf_req[2] = h5_cfg_field(h5);
 149                h5_link_control(hu, conf_req, sizeof(conf_req));
 150        }
 151
 152        if (h5->state != H5_ACTIVE) {
 153                mod_timer(&h5->timer, jiffies + H5_SYNC_TIMEOUT);
 154                goto wakeup;
 155        }
 156
 157        if (h5->sleep != H5_AWAKE) {
 158                h5->sleep = H5_SLEEPING;
 159                goto wakeup;
 160        }
 161
 162        BT_DBG("hu %p retransmitting %u pkts", hu, h5->unack.qlen);
 163
 164        spin_lock_irqsave_nested(&h5->unack.lock, flags, SINGLE_DEPTH_NESTING);
 165
 166        while ((skb = __skb_dequeue_tail(&h5->unack)) != NULL) {
 167                h5->tx_seq = (h5->tx_seq - 1) & 0x07;
 168                skb_queue_head(&h5->rel, skb);
 169        }
 170
 171        spin_unlock_irqrestore(&h5->unack.lock, flags);
 172
 173wakeup:
 174        hci_uart_tx_wakeup(hu);
 175}
 176
 177static void h5_peer_reset(struct hci_uart *hu)
 178{
 179        struct h5 *h5 = hu->priv;
 180
 181        bt_dev_err(hu->hdev, "Peer device has reset");
 182
 183        h5->state = H5_UNINITIALIZED;
 184
 185        del_timer(&h5->timer);
 186
 187        skb_queue_purge(&h5->rel);
 188        skb_queue_purge(&h5->unrel);
 189        skb_queue_purge(&h5->unack);
 190
 191        h5->tx_seq = 0;
 192        h5->tx_ack = 0;
 193
 194        /* Send reset request to upper stack */
 195        hci_reset_dev(hu->hdev);
 196}
 197
 198static int h5_open(struct hci_uart *hu)
 199{
 200        struct h5 *h5;
 201        const unsigned char sync[] = { 0x01, 0x7e };
 202
 203        BT_DBG("hu %p", hu);
 204
 205        if (hu->serdev) {
 206                h5 = serdev_device_get_drvdata(hu->serdev);
 207        } else {
 208                h5 = kzalloc(sizeof(*h5), GFP_KERNEL);
 209                if (!h5)
 210                        return -ENOMEM;
 211        }
 212
 213        hu->priv = h5;
 214        h5->hu = hu;
 215
 216        skb_queue_head_init(&h5->unack);
 217        skb_queue_head_init(&h5->rel);
 218        skb_queue_head_init(&h5->unrel);
 219
 220        h5_reset_rx(h5);
 221
 222        timer_setup(&h5->timer, h5_timed_event, 0);
 223
 224        h5->tx_win = H5_TX_WIN_MAX;
 225
 226        if (h5->vnd && h5->vnd->open)
 227                h5->vnd->open(h5);
 228
 229        set_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags);
 230
 231        /* Send initial sync request */
 232        h5_link_control(hu, sync, sizeof(sync));
 233        mod_timer(&h5->timer, jiffies + H5_SYNC_TIMEOUT);
 234
 235        return 0;
 236}
 237
 238static int h5_close(struct hci_uart *hu)
 239{
 240        struct h5 *h5 = hu->priv;
 241
 242        del_timer_sync(&h5->timer);
 243
 244        skb_queue_purge(&h5->unack);
 245        skb_queue_purge(&h5->rel);
 246        skb_queue_purge(&h5->unrel);
 247
 248        kfree_skb(h5->rx_skb);
 249        h5->rx_skb = NULL;
 250
 251        if (h5->vnd && h5->vnd->close)
 252                h5->vnd->close(h5);
 253
 254        if (!hu->serdev)
 255                kfree(h5);
 256
 257        return 0;
 258}
 259
 260static int h5_setup(struct hci_uart *hu)
 261{
 262        struct h5 *h5 = hu->priv;
 263
 264        if (h5->vnd && h5->vnd->setup)
 265                return h5->vnd->setup(h5);
 266
 267        return 0;
 268}
 269
 270static void h5_pkt_cull(struct h5 *h5)
 271{
 272        struct sk_buff *skb, *tmp;
 273        unsigned long flags;
 274        int i, to_remove;
 275        u8 seq;
 276
 277        spin_lock_irqsave(&h5->unack.lock, flags);
 278
 279        to_remove = skb_queue_len(&h5->unack);
 280        if (to_remove == 0)
 281                goto unlock;
 282
 283        seq = h5->tx_seq;
 284
 285        while (to_remove > 0) {
 286                if (h5->rx_ack == seq)
 287                        break;
 288
 289                to_remove--;
 290                seq = (seq - 1) & 0x07;
 291        }
 292
 293        if (seq != h5->rx_ack)
 294                BT_ERR("Controller acked invalid packet");
 295
 296        i = 0;
 297        skb_queue_walk_safe(&h5->unack, skb, tmp) {
 298                if (i++ >= to_remove)
 299                        break;
 300
 301                __skb_unlink(skb, &h5->unack);
 302                kfree_skb(skb);
 303        }
 304
 305        if (skb_queue_empty(&h5->unack))
 306                del_timer(&h5->timer);
 307
 308unlock:
 309        spin_unlock_irqrestore(&h5->unack.lock, flags);
 310}
 311
 312static void h5_handle_internal_rx(struct hci_uart *hu)
 313{
 314        struct h5 *h5 = hu->priv;
 315        const unsigned char sync_req[] = { 0x01, 0x7e };
 316        const unsigned char sync_rsp[] = { 0x02, 0x7d };
 317        unsigned char conf_req[3] = { 0x03, 0xfc };
 318        const unsigned char conf_rsp[] = { 0x04, 0x7b };
 319        const unsigned char wakeup_req[] = { 0x05, 0xfa };
 320        const unsigned char woken_req[] = { 0x06, 0xf9 };
 321        const unsigned char sleep_req[] = { 0x07, 0x78 };
 322        const unsigned char *hdr = h5->rx_skb->data;
 323        const unsigned char *data = &h5->rx_skb->data[4];
 324
 325        BT_DBG("%s", hu->hdev->name);
 326
 327        if (H5_HDR_PKT_TYPE(hdr) != HCI_3WIRE_LINK_PKT)
 328                return;
 329
 330        if (H5_HDR_LEN(hdr) < 2)
 331                return;
 332
 333        conf_req[2] = h5_cfg_field(h5);
 334
 335        if (memcmp(data, sync_req, 2) == 0) {
 336                if (h5->state == H5_ACTIVE)
 337                        h5_peer_reset(hu);
 338                h5_link_control(hu, sync_rsp, 2);
 339        } else if (memcmp(data, sync_rsp, 2) == 0) {
 340                if (h5->state == H5_ACTIVE)
 341                        h5_peer_reset(hu);
 342                h5->state = H5_INITIALIZED;
 343                h5_link_control(hu, conf_req, 3);
 344        } else if (memcmp(data, conf_req, 2) == 0) {
 345                h5_link_control(hu, conf_rsp, 2);
 346                h5_link_control(hu, conf_req, 3);
 347        } else if (memcmp(data, conf_rsp, 2) == 0) {
 348                if (H5_HDR_LEN(hdr) > 2)
 349                        h5->tx_win = (data[2] & 0x07);
 350                BT_DBG("Three-wire init complete. tx_win %u", h5->tx_win);
 351                h5->state = H5_ACTIVE;
 352                hci_uart_init_ready(hu);
 353                return;
 354        } else if (memcmp(data, sleep_req, 2) == 0) {
 355                BT_DBG("Peer went to sleep");
 356                h5->sleep = H5_SLEEPING;
 357                return;
 358        } else if (memcmp(data, woken_req, 2) == 0) {
 359                BT_DBG("Peer woke up");
 360                h5->sleep = H5_AWAKE;
 361        } else if (memcmp(data, wakeup_req, 2) == 0) {
 362                BT_DBG("Peer requested wakeup");
 363                h5_link_control(hu, woken_req, 2);
 364                h5->sleep = H5_AWAKE;
 365        } else {
 366                BT_DBG("Link Control: 0x%02hhx 0x%02hhx", data[0], data[1]);
 367                return;
 368        }
 369
 370        hci_uart_tx_wakeup(hu);
 371}
 372
 373static void h5_complete_rx_pkt(struct hci_uart *hu)
 374{
 375        struct h5 *h5 = hu->priv;
 376        const unsigned char *hdr = h5->rx_skb->data;
 377
 378        if (H5_HDR_RELIABLE(hdr)) {
 379                h5->tx_ack = (h5->tx_ack + 1) % 8;
 380                set_bit(H5_TX_ACK_REQ, &h5->flags);
 381                hci_uart_tx_wakeup(hu);
 382        }
 383
 384        h5->rx_ack = H5_HDR_ACK(hdr);
 385
 386        h5_pkt_cull(h5);
 387
 388        switch (H5_HDR_PKT_TYPE(hdr)) {
 389        case HCI_EVENT_PKT:
 390        case HCI_ACLDATA_PKT:
 391        case HCI_SCODATA_PKT:
 392        case HCI_ISODATA_PKT:
 393                hci_skb_pkt_type(h5->rx_skb) = H5_HDR_PKT_TYPE(hdr);
 394
 395                /* Remove Three-wire header */
 396                skb_pull(h5->rx_skb, 4);
 397
 398                hci_recv_frame(hu->hdev, h5->rx_skb);
 399                h5->rx_skb = NULL;
 400
 401                break;
 402
 403        default:
 404                h5_handle_internal_rx(hu);
 405                break;
 406        }
 407
 408        h5_reset_rx(h5);
 409}
 410
 411static int h5_rx_crc(struct hci_uart *hu, unsigned char c)
 412{
 413        h5_complete_rx_pkt(hu);
 414
 415        return 0;
 416}
 417
 418static int h5_rx_payload(struct hci_uart *hu, unsigned char c)
 419{
 420        struct h5 *h5 = hu->priv;
 421        const unsigned char *hdr = h5->rx_skb->data;
 422
 423        if (H5_HDR_CRC(hdr)) {
 424                h5->rx_func = h5_rx_crc;
 425                h5->rx_pending = 2;
 426        } else {
 427                h5_complete_rx_pkt(hu);
 428        }
 429
 430        return 0;
 431}
 432
 433static int h5_rx_3wire_hdr(struct hci_uart *hu, unsigned char c)
 434{
 435        struct h5 *h5 = hu->priv;
 436        const unsigned char *hdr = h5->rx_skb->data;
 437
 438        BT_DBG("%s rx: seq %u ack %u crc %u rel %u type %u len %u",
 439               hu->hdev->name, H5_HDR_SEQ(hdr), H5_HDR_ACK(hdr),
 440               H5_HDR_CRC(hdr), H5_HDR_RELIABLE(hdr), H5_HDR_PKT_TYPE(hdr),
 441               H5_HDR_LEN(hdr));
 442
 443        if (((hdr[0] + hdr[1] + hdr[2] + hdr[3]) & 0xff) != 0xff) {
 444                bt_dev_err(hu->hdev, "Invalid header checksum");
 445                h5_reset_rx(h5);
 446                return 0;
 447        }
 448
 449        if (H5_HDR_RELIABLE(hdr) && H5_HDR_SEQ(hdr) != h5->tx_ack) {
 450                bt_dev_err(hu->hdev, "Out-of-order packet arrived (%u != %u)",
 451                           H5_HDR_SEQ(hdr), h5->tx_ack);
 452                h5_reset_rx(h5);
 453                return 0;
 454        }
 455
 456        if (h5->state != H5_ACTIVE &&
 457            H5_HDR_PKT_TYPE(hdr) != HCI_3WIRE_LINK_PKT) {
 458                bt_dev_err(hu->hdev, "Non-link packet received in non-active state");
 459                h5_reset_rx(h5);
 460                return 0;
 461        }
 462
 463        h5->rx_func = h5_rx_payload;
 464        h5->rx_pending = H5_HDR_LEN(hdr);
 465
 466        return 0;
 467}
 468
 469static int h5_rx_pkt_start(struct hci_uart *hu, unsigned char c)
 470{
 471        struct h5 *h5 = hu->priv;
 472
 473        if (c == SLIP_DELIMITER)
 474                return 1;
 475
 476        h5->rx_func = h5_rx_3wire_hdr;
 477        h5->rx_pending = 4;
 478
 479        h5->rx_skb = bt_skb_alloc(H5_MAX_LEN, GFP_ATOMIC);
 480        if (!h5->rx_skb) {
 481                bt_dev_err(hu->hdev, "Can't allocate mem for new packet");
 482                h5_reset_rx(h5);
 483                return -ENOMEM;
 484        }
 485
 486        h5->rx_skb->dev = (void *)hu->hdev;
 487
 488        return 0;
 489}
 490
 491static int h5_rx_delimiter(struct hci_uart *hu, unsigned char c)
 492{
 493        struct h5 *h5 = hu->priv;
 494
 495        if (c == SLIP_DELIMITER)
 496                h5->rx_func = h5_rx_pkt_start;
 497
 498        return 1;
 499}
 500
 501static void h5_unslip_one_byte(struct h5 *h5, unsigned char c)
 502{
 503        const u8 delim = SLIP_DELIMITER, esc = SLIP_ESC;
 504        const u8 *byte = &c;
 505
 506        if (!test_bit(H5_RX_ESC, &h5->flags) && c == SLIP_ESC) {
 507                set_bit(H5_RX_ESC, &h5->flags);
 508                return;
 509        }
 510
 511        if (test_and_clear_bit(H5_RX_ESC, &h5->flags)) {
 512                switch (c) {
 513                case SLIP_ESC_DELIM:
 514                        byte = &delim;
 515                        break;
 516                case SLIP_ESC_ESC:
 517                        byte = &esc;
 518                        break;
 519                default:
 520                        BT_ERR("Invalid esc byte 0x%02hhx", c);
 521                        h5_reset_rx(h5);
 522                        return;
 523                }
 524        }
 525
 526        skb_put_data(h5->rx_skb, byte, 1);
 527        h5->rx_pending--;
 528
 529        BT_DBG("unslipped 0x%02hhx, rx_pending %zu", *byte, h5->rx_pending);
 530}
 531
 532static void h5_reset_rx(struct h5 *h5)
 533{
 534        if (h5->rx_skb) {
 535                kfree_skb(h5->rx_skb);
 536                h5->rx_skb = NULL;
 537        }
 538
 539        h5->rx_func = h5_rx_delimiter;
 540        h5->rx_pending = 0;
 541        clear_bit(H5_RX_ESC, &h5->flags);
 542}
 543
 544static int h5_recv(struct hci_uart *hu, const void *data, int count)
 545{
 546        struct h5 *h5 = hu->priv;
 547        const unsigned char *ptr = data;
 548
 549        BT_DBG("%s pending %zu count %d", hu->hdev->name, h5->rx_pending,
 550               count);
 551
 552        while (count > 0) {
 553                int processed;
 554
 555                if (h5->rx_pending > 0) {
 556                        if (*ptr == SLIP_DELIMITER) {
 557                                bt_dev_err(hu->hdev, "Too short H5 packet");
 558                                h5_reset_rx(h5);
 559                                continue;
 560                        }
 561
 562                        h5_unslip_one_byte(h5, *ptr);
 563
 564                        ptr++; count--;
 565                        continue;
 566                }
 567
 568                processed = h5->rx_func(hu, *ptr);
 569                if (processed < 0)
 570                        return processed;
 571
 572                ptr += processed;
 573                count -= processed;
 574        }
 575
 576        return 0;
 577}
 578
 579static int h5_enqueue(struct hci_uart *hu, struct sk_buff *skb)
 580{
 581        struct h5 *h5 = hu->priv;
 582
 583        if (skb->len > 0xfff) {
 584                bt_dev_err(hu->hdev, "Packet too long (%u bytes)", skb->len);
 585                kfree_skb(skb);
 586                return 0;
 587        }
 588
 589        if (h5->state != H5_ACTIVE) {
 590                bt_dev_err(hu->hdev, "Ignoring HCI data in non-active state");
 591                kfree_skb(skb);
 592                return 0;
 593        }
 594
 595        switch (hci_skb_pkt_type(skb)) {
 596        case HCI_ACLDATA_PKT:
 597        case HCI_COMMAND_PKT:
 598                skb_queue_tail(&h5->rel, skb);
 599                break;
 600
 601        case HCI_SCODATA_PKT:
 602        case HCI_ISODATA_PKT:
 603                skb_queue_tail(&h5->unrel, skb);
 604                break;
 605
 606        default:
 607                bt_dev_err(hu->hdev, "Unknown packet type %u", hci_skb_pkt_type(skb));
 608                kfree_skb(skb);
 609                break;
 610        }
 611
 612        return 0;
 613}
 614
 615static void h5_slip_delim(struct sk_buff *skb)
 616{
 617        const char delim = SLIP_DELIMITER;
 618
 619        skb_put_data(skb, &delim, 1);
 620}
 621
 622static void h5_slip_one_byte(struct sk_buff *skb, u8 c)
 623{
 624        const char esc_delim[2] = { SLIP_ESC, SLIP_ESC_DELIM };
 625        const char esc_esc[2] = { SLIP_ESC, SLIP_ESC_ESC };
 626
 627        switch (c) {
 628        case SLIP_DELIMITER:
 629                skb_put_data(skb, &esc_delim, 2);
 630                break;
 631        case SLIP_ESC:
 632                skb_put_data(skb, &esc_esc, 2);
 633                break;
 634        default:
 635                skb_put_data(skb, &c, 1);
 636        }
 637}
 638
 639static bool valid_packet_type(u8 type)
 640{
 641        switch (type) {
 642        case HCI_ACLDATA_PKT:
 643        case HCI_COMMAND_PKT:
 644        case HCI_SCODATA_PKT:
 645        case HCI_ISODATA_PKT:
 646        case HCI_3WIRE_LINK_PKT:
 647        case HCI_3WIRE_ACK_PKT:
 648                return true;
 649        default:
 650                return false;
 651        }
 652}
 653
 654static struct sk_buff *h5_prepare_pkt(struct hci_uart *hu, u8 pkt_type,
 655                                      const u8 *data, size_t len)
 656{
 657        struct h5 *h5 = hu->priv;
 658        struct sk_buff *nskb;
 659        u8 hdr[4];
 660        int i;
 661
 662        if (!valid_packet_type(pkt_type)) {
 663                bt_dev_err(hu->hdev, "Unknown packet type %u", pkt_type);
 664                return NULL;
 665        }
 666
 667        /*
 668         * Max len of packet: (original len + 4 (H5 hdr) + 2 (crc)) * 2
 669         * (because bytes 0xc0 and 0xdb are escaped, worst case is when
 670         * the packet is all made of 0xc0 and 0xdb) + 2 (0xc0
 671         * delimiters at start and end).
 672         */
 673        nskb = alloc_skb((len + 6) * 2 + 2, GFP_ATOMIC);
 674        if (!nskb)
 675                return NULL;
 676
 677        hci_skb_pkt_type(nskb) = pkt_type;
 678
 679        h5_slip_delim(nskb);
 680
 681        hdr[0] = h5->tx_ack << 3;
 682        clear_bit(H5_TX_ACK_REQ, &h5->flags);
 683
 684        /* Reliable packet? */
 685        if (pkt_type == HCI_ACLDATA_PKT || pkt_type == HCI_COMMAND_PKT) {
 686                hdr[0] |= 1 << 7;
 687                hdr[0] |= h5->tx_seq;
 688                h5->tx_seq = (h5->tx_seq + 1) % 8;
 689        }
 690
 691        hdr[1] = pkt_type | ((len & 0x0f) << 4);
 692        hdr[2] = len >> 4;
 693        hdr[3] = ~((hdr[0] + hdr[1] + hdr[2]) & 0xff);
 694
 695        BT_DBG("%s tx: seq %u ack %u crc %u rel %u type %u len %u",
 696               hu->hdev->name, H5_HDR_SEQ(hdr), H5_HDR_ACK(hdr),
 697               H5_HDR_CRC(hdr), H5_HDR_RELIABLE(hdr), H5_HDR_PKT_TYPE(hdr),
 698               H5_HDR_LEN(hdr));
 699
 700        for (i = 0; i < 4; i++)
 701                h5_slip_one_byte(nskb, hdr[i]);
 702
 703        for (i = 0; i < len; i++)
 704                h5_slip_one_byte(nskb, data[i]);
 705
 706        h5_slip_delim(nskb);
 707
 708        return nskb;
 709}
 710
 711static struct sk_buff *h5_dequeue(struct hci_uart *hu)
 712{
 713        struct h5 *h5 = hu->priv;
 714        unsigned long flags;
 715        struct sk_buff *skb, *nskb;
 716
 717        if (h5->sleep != H5_AWAKE) {
 718                const unsigned char wakeup_req[] = { 0x05, 0xfa };
 719
 720                if (h5->sleep == H5_WAKING_UP)
 721                        return NULL;
 722
 723                h5->sleep = H5_WAKING_UP;
 724                BT_DBG("Sending wakeup request");
 725
 726                mod_timer(&h5->timer, jiffies + HZ / 100);
 727                return h5_prepare_pkt(hu, HCI_3WIRE_LINK_PKT, wakeup_req, 2);
 728        }
 729
 730        skb = skb_dequeue(&h5->unrel);
 731        if (skb) {
 732                nskb = h5_prepare_pkt(hu, hci_skb_pkt_type(skb),
 733                                      skb->data, skb->len);
 734                if (nskb) {
 735                        kfree_skb(skb);
 736                        return nskb;
 737                }
 738
 739                skb_queue_head(&h5->unrel, skb);
 740                bt_dev_err(hu->hdev, "Could not dequeue pkt because alloc_skb failed");
 741        }
 742
 743        spin_lock_irqsave_nested(&h5->unack.lock, flags, SINGLE_DEPTH_NESTING);
 744
 745        if (h5->unack.qlen >= h5->tx_win)
 746                goto unlock;
 747
 748        skb = skb_dequeue(&h5->rel);
 749        if (skb) {
 750                nskb = h5_prepare_pkt(hu, hci_skb_pkt_type(skb),
 751                                      skb->data, skb->len);
 752                if (nskb) {
 753                        __skb_queue_tail(&h5->unack, skb);
 754                        mod_timer(&h5->timer, jiffies + H5_ACK_TIMEOUT);
 755                        spin_unlock_irqrestore(&h5->unack.lock, flags);
 756                        return nskb;
 757                }
 758
 759                skb_queue_head(&h5->rel, skb);
 760                bt_dev_err(hu->hdev, "Could not dequeue pkt because alloc_skb failed");
 761        }
 762
 763unlock:
 764        spin_unlock_irqrestore(&h5->unack.lock, flags);
 765
 766        if (test_bit(H5_TX_ACK_REQ, &h5->flags))
 767                return h5_prepare_pkt(hu, HCI_3WIRE_ACK_PKT, NULL, 0);
 768
 769        return NULL;
 770}
 771
 772static int h5_flush(struct hci_uart *hu)
 773{
 774        BT_DBG("hu %p", hu);
 775        return 0;
 776}
 777
 778static const struct hci_uart_proto h5p = {
 779        .id             = HCI_UART_3WIRE,
 780        .name           = "Three-wire (H5)",
 781        .open           = h5_open,
 782        .close          = h5_close,
 783        .setup          = h5_setup,
 784        .recv           = h5_recv,
 785        .enqueue        = h5_enqueue,
 786        .dequeue        = h5_dequeue,
 787        .flush          = h5_flush,
 788};
 789
 790static int h5_serdev_probe(struct serdev_device *serdev)
 791{
 792        struct device *dev = &serdev->dev;
 793        struct h5 *h5;
 794
 795        h5 = devm_kzalloc(dev, sizeof(*h5), GFP_KERNEL);
 796        if (!h5)
 797                return -ENOMEM;
 798
 799        h5->hu = &h5->serdev_hu;
 800        h5->serdev_hu.serdev = serdev;
 801        serdev_device_set_drvdata(serdev, h5);
 802
 803        if (has_acpi_companion(dev)) {
 804                const struct acpi_device_id *match;
 805
 806                match = acpi_match_device(dev->driver->acpi_match_table, dev);
 807                if (!match)
 808                        return -ENODEV;
 809
 810                h5->vnd = (const struct h5_vnd *)match->driver_data;
 811                h5->id  = (char *)match->id;
 812
 813                if (h5->vnd->acpi_gpio_map)
 814                        devm_acpi_dev_add_driver_gpios(dev,
 815                                                       h5->vnd->acpi_gpio_map);
 816        } else {
 817                const void *data;
 818
 819                data = of_device_get_match_data(dev);
 820                if (!data)
 821                        return -ENODEV;
 822
 823                h5->vnd = (const struct h5_vnd *)data;
 824        }
 825
 826
 827        h5->enable_gpio = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_LOW);
 828        if (IS_ERR(h5->enable_gpio))
 829                return PTR_ERR(h5->enable_gpio);
 830
 831        h5->device_wake_gpio = devm_gpiod_get_optional(dev, "device-wake",
 832                                                       GPIOD_OUT_LOW);
 833        if (IS_ERR(h5->device_wake_gpio))
 834                return PTR_ERR(h5->device_wake_gpio);
 835
 836        return hci_uart_register_device(&h5->serdev_hu, &h5p);
 837}
 838
 839static void h5_serdev_remove(struct serdev_device *serdev)
 840{
 841        struct h5 *h5 = serdev_device_get_drvdata(serdev);
 842
 843        hci_uart_unregister_device(&h5->serdev_hu);
 844}
 845
 846static int __maybe_unused h5_serdev_suspend(struct device *dev)
 847{
 848        struct h5 *h5 = dev_get_drvdata(dev);
 849        int ret = 0;
 850
 851        if (h5->vnd && h5->vnd->suspend)
 852                ret = h5->vnd->suspend(h5);
 853
 854        return ret;
 855}
 856
 857static int __maybe_unused h5_serdev_resume(struct device *dev)
 858{
 859        struct h5 *h5 = dev_get_drvdata(dev);
 860        int ret = 0;
 861
 862        if (h5->vnd && h5->vnd->resume)
 863                ret = h5->vnd->resume(h5);
 864
 865        return ret;
 866}
 867
 868#ifdef CONFIG_BT_HCIUART_RTL
 869static int h5_btrtl_setup(struct h5 *h5)
 870{
 871        struct btrtl_device_info *btrtl_dev;
 872        struct sk_buff *skb;
 873        __le32 baudrate_data;
 874        u32 device_baudrate;
 875        unsigned int controller_baudrate;
 876        bool flow_control;
 877        int err;
 878
 879        btrtl_dev = btrtl_initialize(h5->hu->hdev, h5->id);
 880        if (IS_ERR(btrtl_dev))
 881                return PTR_ERR(btrtl_dev);
 882
 883        err = btrtl_get_uart_settings(h5->hu->hdev, btrtl_dev,
 884                                      &controller_baudrate, &device_baudrate,
 885                                      &flow_control);
 886        if (err)
 887                goto out_free;
 888
 889        baudrate_data = cpu_to_le32(device_baudrate);
 890        skb = __hci_cmd_sync(h5->hu->hdev, 0xfc17, sizeof(baudrate_data),
 891                             &baudrate_data, HCI_INIT_TIMEOUT);
 892        if (IS_ERR(skb)) {
 893                rtl_dev_err(h5->hu->hdev, "set baud rate command failed\n");
 894                err = PTR_ERR(skb);
 895                goto out_free;
 896        } else {
 897                kfree_skb(skb);
 898        }
 899        /* Give the device some time to set up the new baudrate. */
 900        usleep_range(10000, 20000);
 901
 902        serdev_device_set_baudrate(h5->hu->serdev, controller_baudrate);
 903        serdev_device_set_flow_control(h5->hu->serdev, flow_control);
 904
 905        err = btrtl_download_firmware(h5->hu->hdev, btrtl_dev);
 906        /* Give the device some time before the hci-core sends it a reset */
 907        usleep_range(10000, 20000);
 908
 909        /* Enable controller to do both LE scan and BR/EDR inquiry
 910         * simultaneously.
 911         */
 912        set_bit(HCI_QUIRK_SIMULTANEOUS_DISCOVERY, &h5->hu->hdev->quirks);
 913
 914out_free:
 915        btrtl_free(btrtl_dev);
 916
 917        return err;
 918}
 919
 920static void h5_btrtl_open(struct h5 *h5)
 921{
 922        /* Devices always start with these fixed parameters */
 923        serdev_device_set_flow_control(h5->hu->serdev, false);
 924        serdev_device_set_parity(h5->hu->serdev, SERDEV_PARITY_EVEN);
 925        serdev_device_set_baudrate(h5->hu->serdev, 115200);
 926
 927        /* The controller needs up to 500ms to wakeup */
 928        gpiod_set_value_cansleep(h5->enable_gpio, 1);
 929        gpiod_set_value_cansleep(h5->device_wake_gpio, 1);
 930        msleep(500);
 931}
 932
 933static void h5_btrtl_close(struct h5 *h5)
 934{
 935        gpiod_set_value_cansleep(h5->device_wake_gpio, 0);
 936        gpiod_set_value_cansleep(h5->enable_gpio, 0);
 937}
 938
 939/* Suspend/resume support. On many devices the RTL BT device loses power during
 940 * suspend/resume, causing it to lose its firmware and all state. So we simply
 941 * turn it off on suspend and reprobe on resume.  This mirrors how RTL devices
 942 * are handled in the USB driver, where the USB_QUIRK_RESET_RESUME is used which
 943 * also causes a reprobe on resume.
 944 */
 945static int h5_btrtl_suspend(struct h5 *h5)
 946{
 947        serdev_device_set_flow_control(h5->hu->serdev, false);
 948        gpiod_set_value_cansleep(h5->device_wake_gpio, 0);
 949        gpiod_set_value_cansleep(h5->enable_gpio, 0);
 950        return 0;
 951}
 952
 953struct h5_btrtl_reprobe {
 954        struct device *dev;
 955        struct work_struct work;
 956};
 957
 958static void h5_btrtl_reprobe_worker(struct work_struct *work)
 959{
 960        struct h5_btrtl_reprobe *reprobe =
 961                container_of(work, struct h5_btrtl_reprobe, work);
 962        int ret;
 963
 964        ret = device_reprobe(reprobe->dev);
 965        if (ret && ret != -EPROBE_DEFER)
 966                dev_err(reprobe->dev, "Reprobe error %d\n", ret);
 967
 968        put_device(reprobe->dev);
 969        kfree(reprobe);
 970        module_put(THIS_MODULE);
 971}
 972
 973static int h5_btrtl_resume(struct h5 *h5)
 974{
 975        struct h5_btrtl_reprobe *reprobe;
 976
 977        reprobe = kzalloc(sizeof(*reprobe), GFP_KERNEL);
 978        if (!reprobe)
 979                return -ENOMEM;
 980
 981        __module_get(THIS_MODULE);
 982
 983        INIT_WORK(&reprobe->work, h5_btrtl_reprobe_worker);
 984        reprobe->dev = get_device(&h5->hu->serdev->dev);
 985        queue_work(system_long_wq, &reprobe->work);
 986        return 0;
 987}
 988
 989static const struct acpi_gpio_params btrtl_device_wake_gpios = { 0, 0, false };
 990static const struct acpi_gpio_params btrtl_enable_gpios = { 1, 0, false };
 991static const struct acpi_gpio_params btrtl_host_wake_gpios = { 2, 0, false };
 992static const struct acpi_gpio_mapping acpi_btrtl_gpios[] = {
 993        { "device-wake-gpios", &btrtl_device_wake_gpios, 1 },
 994        { "enable-gpios", &btrtl_enable_gpios, 1 },
 995        { "host-wake-gpios", &btrtl_host_wake_gpios, 1 },
 996        {},
 997};
 998
 999static struct h5_vnd rtl_vnd = {
1000        .setup          = h5_btrtl_setup,
1001        .open           = h5_btrtl_open,
1002        .close          = h5_btrtl_close,
1003        .suspend        = h5_btrtl_suspend,
1004        .resume         = h5_btrtl_resume,
1005        .acpi_gpio_map  = acpi_btrtl_gpios,
1006};
1007#endif
1008
1009#ifdef CONFIG_ACPI
1010static const struct acpi_device_id h5_acpi_match[] = {
1011#ifdef CONFIG_BT_HCIUART_RTL
1012        { "OBDA0623", (kernel_ulong_t)&rtl_vnd },
1013        { "OBDA8723", (kernel_ulong_t)&rtl_vnd },
1014#endif
1015        { },
1016};
1017MODULE_DEVICE_TABLE(acpi, h5_acpi_match);
1018#endif
1019
1020static const struct dev_pm_ops h5_serdev_pm_ops = {
1021        SET_SYSTEM_SLEEP_PM_OPS(h5_serdev_suspend, h5_serdev_resume)
1022};
1023
1024static const struct of_device_id rtl_bluetooth_of_match[] = {
1025#ifdef CONFIG_BT_HCIUART_RTL
1026        { .compatible = "realtek,rtl8822cs-bt",
1027          .data = (const void *)&rtl_vnd },
1028        { .compatible = "realtek,rtl8723bs-bt",
1029          .data = (const void *)&rtl_vnd },
1030        { .compatible = "realtek,rtl8723ds-bt",
1031          .data = (const void *)&rtl_vnd },
1032#endif
1033        { },
1034};
1035MODULE_DEVICE_TABLE(of, rtl_bluetooth_of_match);
1036
1037static struct serdev_device_driver h5_serdev_driver = {
1038        .probe = h5_serdev_probe,
1039        .remove = h5_serdev_remove,
1040        .driver = {
1041                .name = "hci_uart_h5",
1042                .acpi_match_table = ACPI_PTR(h5_acpi_match),
1043                .pm = &h5_serdev_pm_ops,
1044                .of_match_table = rtl_bluetooth_of_match,
1045        },
1046};
1047
1048int __init h5_init(void)
1049{
1050        serdev_device_driver_register(&h5_serdev_driver);
1051        return hci_uart_register_proto(&h5p);
1052}
1053
1054int __exit h5_deinit(void)
1055{
1056        serdev_device_driver_unregister(&h5_serdev_driver);
1057        return hci_uart_unregister_proto(&h5p);
1058}
1059