drivers/bluetooth/hci_h5.c

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