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_device.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                 kfree_skb(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                 h5_link_control(hu, conf_req, 3);
 361         } else if (memcmp(data, conf_rsp, 2) == 0) {
 362                 if (H5_HDR_LEN(hdr) > 2)
 363                         h5->tx_win = (data[2] & 0x07);
 364                 BT_DBG("Three-wire init complete. tx_win %u", h5->tx_win);
 365                 h5->state = H5_ACTIVE;
 366                 hci_uart_init_ready(hu);
 367                 return;
 368         } else if (memcmp(data, sleep_req, 2) == 0) {
 369                 BT_DBG("Peer went to sleep");
 370                 h5->sleep = H5_SLEEPING;
 371                 return;
 372         } else if (memcmp(data, woken_req, 2) == 0) {
 373                 BT_DBG("Peer woke up");
 374                 h5->sleep = H5_AWAKE;
 375         } else if (memcmp(data, wakeup_req, 2) == 0) {
 376                 BT_DBG("Peer requested wakeup");
 377                 h5_link_control(hu, woken_req, 2);
 378                 h5->sleep = H5_AWAKE;
 379         } else {
 380                 BT_DBG("Link Control: 0x%02hhx 0x%02hhx", data[0], data[1]);
 381                 return;
 382         }
 383
 384         hci_uart_tx_wakeup(hu);
 385 }
 386
 387 static void h5_complete_rx_pkt(struct hci_uart *hu)
 388 {
 389         struct h5 *h5 = hu->priv;
 390         const unsigned char *hdr = h5->rx_skb->data;
 391
 392         if (H5_HDR_RELIABLE(hdr)) {
 393                 h5->tx_ack = (h5->tx_ack + 1) % 8;
 394                 set_bit(H5_TX_ACK_REQ, &h5->flags);
 395                 hci_uart_tx_wakeup(hu);
 396         }
 397
 398         h5->rx_ack = H5_HDR_ACK(hdr);
 399
 400         h5_pkt_cull(h5);
 401
 402         switch (H5_HDR_PKT_TYPE(hdr)) {
 403         case HCI_EVENT_PKT:
 404         case HCI_ACLDATA_PKT:
 405         case HCI_SCODATA_PKT:
 406         case HCI_ISODATA_PKT:
 407                 hci_skb_pkt_type(h5->rx_skb) = H5_HDR_PKT_TYPE(hdr);
 408
 409                 /* Remove Three-wire header */
 410                 skb_pull(h5->rx_skb, 4);
 411
 412                 hci_recv_frame(hu->hdev, h5->rx_skb);
 413                 h5->rx_skb = NULL;
 414
 415                 break;
 416
 417         default:
 418                 h5_handle_internal_rx(hu);
 419                 break;
 420         }
 421
 422         h5_reset_rx(h5);
 423 }
 424
 425 static int h5_rx_crc(struct hci_uart *hu, unsigned char c)
 426 {
 427         h5_complete_rx_pkt(hu);
 428
 429         return 0;
 430 }
 431
 432 static int h5_rx_payload(struct hci_uart *hu, unsigned char c)
 433 {
 434         struct h5 *h5 = hu->priv;
 435         const unsigned char *hdr = h5->rx_skb->data;
 436
 437         if (H5_HDR_CRC(hdr)) {
 438                 h5->rx_func = h5_rx_crc;
 439                 h5->rx_pending = 2;
 440         } else {
 441                 h5_complete_rx_pkt(hu);
 442         }
 443
 444         return 0;
 445 }
 446
 447 static int h5_rx_3wire_hdr(struct hci_uart *hu, unsigned char c)
 448 {
 449         struct h5 *h5 = hu->priv;
 450         const unsigned char *hdr = h5->rx_skb->data;
 451
 452         BT_DBG("%s rx: seq %u ack %u crc %u rel %u type %u len %u",
 453                hu->hdev->name, H5_HDR_SEQ(hdr), H5_HDR_ACK(hdr),
 454                H5_HDR_CRC(hdr), H5_HDR_RELIABLE(hdr), H5_HDR_PKT_TYPE(hdr),
 455                H5_HDR_LEN(hdr));
 456
 457         if (((hdr[0] + hdr[1] + hdr[2] + hdr[3]) & 0xff) != 0xff) {
 458                 bt_dev_err(hu->hdev, "Invalid header checksum");
 459                 h5_reset_rx(h5);
 460                 return 0;
 461         }
 462
 463         if (H5_HDR_RELIABLE(hdr) && H5_HDR_SEQ(hdr) != h5->tx_ack) {
 464                 bt_dev_err(hu->hdev, "Out-of-order packet arrived (%u != %u)",
 465                            H5_HDR_SEQ(hdr), h5->tx_ack);
 466                 h5_reset_rx(h5);
 467                 return 0;
 468         }
 469
 470         if (h5->state != H5_ACTIVE &&
 471             H5_HDR_PKT_TYPE(hdr) != HCI_3WIRE_LINK_PKT) {
 472                 bt_dev_err(hu->hdev, "Non-link packet received in non-active state");
 473                 h5_reset_rx(h5);
 474                 return 0;
 475         }
 476
 477         h5->rx_func = h5_rx_payload;
 478         h5->rx_pending = H5_HDR_LEN(hdr);
 479
 480         return 0;
 481 }
 482
 483 static int h5_rx_pkt_start(struct hci_uart *hu, unsigned char c)
 484 {
 485         struct h5 *h5 = hu->priv;
 486
 487         if (c == SLIP_DELIMITER)
 488                 return 1;
 489
 490         h5->rx_func = h5_rx_3wire_hdr;
 491         h5->rx_pending = 4;
 492
 493         h5->rx_skb = bt_skb_alloc(H5_MAX_LEN, GFP_ATOMIC);
 494         if (!h5->rx_skb) {
 495                 bt_dev_err(hu->hdev, "Can't allocate mem for new packet");
 496                 h5_reset_rx(h5);
 497                 return -ENOMEM;
 498         }
 499
 500         h5->rx_skb->dev = (void *)hu->hdev;
 501
 502         return 0;
 503 }
 504
 505 static int h5_rx_delimiter(struct hci_uart *hu, unsigned char c)
 506 {
 507         struct h5 *h5 = hu->priv;
 508
 509         if (c == SLIP_DELIMITER)
 510                 h5->rx_func = h5_rx_pkt_start;
 511
 512         return 1;
 513 }
 514
 515 static void h5_unslip_one_byte(struct h5 *h5, unsigned char c)
 516 {
 517         const u8 delim = SLIP_DELIMITER, esc = SLIP_ESC;
 518         const u8 *byte = &c;
 519
 520         if (!test_bit(H5_RX_ESC, &h5->flags) && c == SLIP_ESC) {
 521                 set_bit(H5_RX_ESC, &h5->flags);
 522                 return;
 523         }
 524
 525         if (test_and_clear_bit(H5_RX_ESC, &h5->flags)) {
 526                 switch (c) {
 527                 case SLIP_ESC_DELIM:
 528                         byte = &delim;
 529                         break;
 530                 case SLIP_ESC_ESC:
 531                         byte = &esc;
 532                         break;
 533                 default:
 534                         BT_ERR("Invalid esc byte 0x%02hhx", c);
 535                         h5_reset_rx(h5);
 536                         return;
 537                 }
 538         }
 539
 540         skb_put_data(h5->rx_skb, byte, 1);
 541         h5->rx_pending--;
 542
 543         BT_DBG("unslipped 0x%02hhx, rx_pending %zu", *byte, h5->rx_pending);
 544 }
 545
 546 static void h5_reset_rx(struct h5 *h5)
 547 {
 548         if (h5->rx_skb) {
 549                 kfree_skb(h5->rx_skb);
 550                 h5->rx_skb = NULL;
 551         }
 552
 553         h5->rx_func = h5_rx_delimiter;
 554         h5->rx_pending = 0;
 555         clear_bit(H5_RX_ESC, &h5->flags);
 556 }
 557
 558 static int h5_recv(struct hci_uart *hu, const void *data, int count)
 559 {
 560         struct h5 *h5 = hu->priv;
 561         const unsigned char *ptr = data;
 562
 563         BT_DBG("%s pending %zu count %d", hu->hdev->name, h5->rx_pending,
 564                count);
 565
 566         while (count > 0) {
 567                 int processed;
 568
 569                 if (h5->rx_pending > 0) {
 570                         if (*ptr == SLIP_DELIMITER) {
 571                                 bt_dev_err(hu->hdev, "Too short H5 packet");
 572                                 h5_reset_rx(h5);
 573                                 continue;
 574                         }
 575
 576                         h5_unslip_one_byte(h5, *ptr);
 577
 578                         ptr++; count--;
 579                         continue;
 580                 }
 581
 582                 processed = h5->rx_func(hu, *ptr);
 583                 if (processed < 0)
 584                         return processed;
 585
 586                 ptr += processed;
 587                 count -= processed;
 588         }
 589
 590         if (hu->serdev) {
 591                 pm_runtime_get(&hu->serdev->dev);
 592                 pm_runtime_mark_last_busy(&hu->serdev->dev);
 593                 pm_runtime_put_autosuspend(&hu->serdev->dev);
 594         }
 595
 596         return 0;
 597 }
 598
 599 static int h5_enqueue(struct hci_uart *hu, struct sk_buff *skb)
 600 {
 601         struct h5 *h5 = hu->priv;
 602
 603         if (skb->len > 0xfff) {
 604                 bt_dev_err(hu->hdev, "Packet too long (%u bytes)", skb->len);
 605                 kfree_skb(skb);
 606                 return 0;
 607         }
 608
 609         if (h5->state != H5_ACTIVE) {
 610                 bt_dev_err(hu->hdev, "Ignoring HCI data in non-active state");
 611                 kfree_skb(skb);
 612                 return 0;
 613         }
 614
 615         switch (hci_skb_pkt_type(skb)) {
 616         case HCI_ACLDATA_PKT:
 617         case HCI_COMMAND_PKT:
 618                 skb_queue_tail(&h5->rel, skb);
 619                 break;
 620
 621         case HCI_SCODATA_PKT:
 622         case HCI_ISODATA_PKT:
 623                 skb_queue_tail(&h5->unrel, skb);
 624                 break;
 625
 626         default:
 627                 bt_dev_err(hu->hdev, "Unknown packet type %u", hci_skb_pkt_type(skb));
 628                 kfree_skb(skb);
 629                 break;
 630         }
 631
 632         pm_runtime_get_sync(&hu->serdev->dev);
 633         pm_runtime_mark_last_busy(&hu->serdev->dev);
 634         pm_runtime_put_autosuspend(&hu->serdev->dev);
 635
 636         return 0;
 637 }
 638
 639 static void h5_slip_delim(struct sk_buff *skb)
 640 {
 641         const char delim = SLIP_DELIMITER;
 642
 643         skb_put_data(skb, &delim, 1);
 644 }
 645
 646 static void h5_slip_one_byte(struct sk_buff *skb, u8 c)
 647 {
 648         const char esc_delim[2] = { SLIP_ESC, SLIP_ESC_DELIM };
 649         const char esc_esc[2] = { SLIP_ESC, SLIP_ESC_ESC };
 650
 651         switch (c) {
 652         case SLIP_DELIMITER:
 653                 skb_put_data(skb, &esc_delim, 2);
 654                 break;
 655         case SLIP_ESC:
 656                 skb_put_data(skb, &esc_esc, 2);
 657                 break;
 658         default:
 659                 skb_put_data(skb, &c, 1);
 660         }
 661 }
 662
 663 static bool valid_packet_type(u8 type)
 664 {
 665         switch (type) {
 666         case HCI_ACLDATA_PKT:
 667         case HCI_COMMAND_PKT:
 668         case HCI_SCODATA_PKT:
 669         case HCI_ISODATA_PKT:
 670         case HCI_3WIRE_LINK_PKT:
 671         case HCI_3WIRE_ACK_PKT:
 672                 return true;
 673         default:
 674                 return false;
 675         }
 676 }
 677
 678 static struct sk_buff *h5_prepare_pkt(struct hci_uart *hu, u8 pkt_type,
 679                                       const u8 *data, size_t len)
 680 {
 681         struct h5 *h5 = hu->priv;
 682         struct sk_buff *nskb;
 683         u8 hdr[4];
 684         int i;
 685
 686         if (!valid_packet_type(pkt_type)) {
 687                 bt_dev_err(hu->hdev, "Unknown packet type %u", pkt_type);
 688                 return NULL;
 689         }
 690
 691         /*
 692          * Max len of packet: (original len + 4 (H5 hdr) + 2 (crc)) * 2
 693          * (because bytes 0xc0 and 0xdb are escaped, worst case is when
 694          * the packet is all made of 0xc0 and 0xdb) + 2 (0xc0
 695          * delimiters at start and end).
 696          */
 697         nskb = alloc_skb((len + 6) * 2 + 2, GFP_ATOMIC);
 698         if (!nskb)
 699                 return NULL;
 700
 701         hci_skb_pkt_type(nskb) = pkt_type;
 702
 703         h5_slip_delim(nskb);
 704
 705         hdr[0] = h5->tx_ack << 3;
 706         clear_bit(H5_TX_ACK_REQ, &h5->flags);
 707
 708         /* Reliable packet? */
 709         if (pkt_type == HCI_ACLDATA_PKT || pkt_type == HCI_COMMAND_PKT) {
 710                 hdr[0] |= 1 << 7;
 711                 hdr[0] |= h5->tx_seq;
 712                 h5->tx_seq = (h5->tx_seq + 1) % 8;
 713         }
 714
 715         hdr[1] = pkt_type | ((len & 0x0f) << 4);
 716         hdr[2] = len >> 4;
 717         hdr[3] = ~((hdr[0] + hdr[1] + hdr[2]) & 0xff);
 718
 719         BT_DBG("%s tx: seq %u ack %u crc %u rel %u type %u len %u",
 720                hu->hdev->name, H5_HDR_SEQ(hdr), H5_HDR_ACK(hdr),
 721                H5_HDR_CRC(hdr), H5_HDR_RELIABLE(hdr), H5_HDR_PKT_TYPE(hdr),
 722                H5_HDR_LEN(hdr));
 723
 724         for (i = 0; i < 4; i++)
 725                 h5_slip_one_byte(nskb, hdr[i]);
 726
 727         for (i = 0; i < len; i++)
 728                 h5_slip_one_byte(nskb, data[i]);
 729
 730         h5_slip_delim(nskb);
 731
 732         return nskb;
 733 }
 734
 735 static struct sk_buff *h5_dequeue(struct hci_uart *hu)
 736 {
 737         struct h5 *h5 = hu->priv;
 738         unsigned long flags;
 739         struct sk_buff *skb, *nskb;
 740
 741         if (h5->sleep != H5_AWAKE) {
 742                 const unsigned char wakeup_req[] = { 0x05, 0xfa };
 743
 744                 if (h5->sleep == H5_WAKING_UP)
 745                         return NULL;
 746
 747                 h5->sleep = H5_WAKING_UP;
 748                 BT_DBG("Sending wakeup request");
 749
 750                 mod_timer(&h5->timer, jiffies + HZ / 100);
 751                 return h5_prepare_pkt(hu, HCI_3WIRE_LINK_PKT, wakeup_req, 2);
 752         }
 753
 754         skb = skb_dequeue(&h5->unrel);
 755         if (skb) {
 756                 nskb = h5_prepare_pkt(hu, hci_skb_pkt_type(skb),
 757                                       skb->data, skb->len);
 758                 if (nskb) {
 759                         kfree_skb(skb);
 760                         return nskb;
 761                 }
 762
 763                 skb_queue_head(&h5->unrel, skb);
 764                 bt_dev_err(hu->hdev, "Could not dequeue pkt because alloc_skb failed");
 765         }
 766
 767         spin_lock_irqsave_nested(&h5->unack.lock, flags, SINGLE_DEPTH_NESTING);
 768
 769         if (h5->unack.qlen >= h5->tx_win)
 770                 goto unlock;
 771
 772         skb = skb_dequeue(&h5->rel);
 773         if (skb) {
 774                 nskb = h5_prepare_pkt(hu, hci_skb_pkt_type(skb),
 775                                       skb->data, skb->len);
 776                 if (nskb) {
 777                         __skb_queue_tail(&h5->unack, skb);
 778                         mod_timer(&h5->timer, jiffies + H5_ACK_TIMEOUT);
 779                         spin_unlock_irqrestore(&h5->unack.lock, flags);
 780                         return nskb;
 781                 }
 782
 783                 skb_queue_head(&h5->rel, skb);
 784                 bt_dev_err(hu->hdev, "Could not dequeue pkt because alloc_skb failed");
 785         }
 786
 787 unlock:
 788         spin_unlock_irqrestore(&h5->unack.lock, flags);
 789
 790         if (test_bit(H5_TX_ACK_REQ, &h5->flags))
 791                 return h5_prepare_pkt(hu, HCI_3WIRE_ACK_PKT, NULL, 0);
 792
 793         return NULL;
 794 }
 795
 796 static int h5_flush(struct hci_uart *hu)
 797 {
 798         BT_DBG("hu %p", hu);
 799         return 0;
 800 }
 801
 802 static const struct hci_uart_proto h5p = {
 803         .id             = HCI_UART_3WIRE,
 804         .name           = "Three-wire (H5)",
 805         .open           = h5_open,
 806         .close          = h5_close,
 807         .setup          = h5_setup,
 808         .recv           = h5_recv,
 809         .enqueue        = h5_enqueue,
 810         .dequeue        = h5_dequeue,
 811         .flush          = h5_flush,
 812 };
 813
 814 static int h5_serdev_probe(struct serdev_device *serdev)
 815 {
 816         struct device *dev = &serdev->dev;
 817         struct h5 *h5;
 818         const struct h5_device_data *data;
 819
 820         h5 = devm_kzalloc(dev, sizeof(*h5), GFP_KERNEL);
 821         if (!h5)
 822                 return -ENOMEM;
 823
 824         h5->hu = &h5->serdev_hu;
 825         h5->serdev_hu.serdev = serdev;
 826         serdev_device_set_drvdata(serdev, h5);
 827
 828         if (has_acpi_companion(dev)) {
 829                 const struct acpi_device_id *match;
 830
 831                 match = acpi_match_device(dev->driver->acpi_match_table, dev);
 832                 if (!match)
 833                         return -ENODEV;
 834
 835                 data = (const struct h5_device_data *)match->driver_data;
 836                 h5->vnd = data->vnd;
 837                 h5->id  = (char *)match->id;
 838
 839                 if (h5->vnd->acpi_gpio_map)
 840                         devm_acpi_dev_add_driver_gpios(dev,
 841                                                        h5->vnd->acpi_gpio_map);
 842         } else {
 843                 data = of_device_get_match_data(dev);
 844                 if (!data)
 845                         return -ENODEV;
 846
 847                 h5->vnd = data->vnd;
 848         }
 849
 850         if (data->driver_info & H5_INFO_WAKEUP_DISABLE)
 851                 set_bit(H5_WAKEUP_DISABLE, &h5->flags);
 852
 853         h5->enable_gpio = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_LOW);
 854         if (IS_ERR(h5->enable_gpio))
 855                 return PTR_ERR(h5->enable_gpio);
 856
 857         h5->device_wake_gpio = devm_gpiod_get_optional(dev, "device-wake",
 858                                                        GPIOD_OUT_LOW);
 859         if (IS_ERR(h5->device_wake_gpio))
 860                 return PTR_ERR(h5->device_wake_gpio);
 861
 862         return hci_uart_register_device(&h5->serdev_hu, &h5p);
 863 }
 864
 865 static void h5_serdev_remove(struct serdev_device *serdev)
 866 {
 867         struct h5 *h5 = serdev_device_get_drvdata(serdev);
 868
 869         hci_uart_unregister_device(&h5->serdev_hu);
 870 }
 871
 872 static int __maybe_unused h5_serdev_suspend(struct device *dev)
 873 {
 874         struct h5 *h5 = dev_get_drvdata(dev);
 875         int ret = 0;
 876
 877         if (h5->vnd && h5->vnd->suspend)
 878                 ret = h5->vnd->suspend(h5);
 879
 880         return ret;
 881 }
 882
 883 static int __maybe_unused h5_serdev_resume(struct device *dev)
 884 {
 885         struct h5 *h5 = dev_get_drvdata(dev);
 886         int ret = 0;
 887
 888         if (h5->vnd && h5->vnd->resume)
 889                 ret = h5->vnd->resume(h5);
 890
 891         return ret;
 892 }
 893
 894 #ifdef CONFIG_BT_HCIUART_RTL
 895 static int h5_btrtl_setup(struct h5 *h5)
 896 {
 897         struct btrtl_device_info *btrtl_dev;
 898         struct sk_buff *skb;
 899         __le32 baudrate_data;
 900         u32 device_baudrate;
 901         unsigned int controller_baudrate;
 902         bool flow_control;
 903         int err;
 904
 905         btrtl_dev = btrtl_initialize(h5->hu->hdev, h5->id);
 906         if (IS_ERR(btrtl_dev))
 907                 return PTR_ERR(btrtl_dev);
 908
 909         err = btrtl_get_uart_settings(h5->hu->hdev, btrtl_dev,
 910                                       &controller_baudrate, &device_baudrate,
 911                                       &flow_control);
 912         if (err)
 913                 goto out_free;
 914
 915         baudrate_data = cpu_to_le32(device_baudrate);
 916         skb = __hci_cmd_sync(h5->hu->hdev, 0xfc17, sizeof(baudrate_data),
 917                              &baudrate_data, HCI_INIT_TIMEOUT);
 918         if (IS_ERR(skb)) {
 919                 rtl_dev_err(h5->hu->hdev, "set baud rate command failed\n");
 920                 err = PTR_ERR(skb);
 921                 goto out_free;
 922         } else {
 923                 kfree_skb(skb);
 924         }
 925         /* Give the device some time to set up the new baudrate. */
 926         usleep_range(10000, 20000);
 927
 928         serdev_device_set_baudrate(h5->hu->serdev, controller_baudrate);
 929         serdev_device_set_flow_control(h5->hu->serdev, flow_control);
 930
 931         if (flow_control)
 932                 set_bit(H5_HW_FLOW_CONTROL, &h5->flags);
 933
 934         err = btrtl_download_firmware(h5->hu->hdev, btrtl_dev);
 935         /* Give the device some time before the hci-core sends it a reset */
 936         usleep_range(10000, 20000);
 937
 938         btrtl_set_quirks(h5->hu->hdev, btrtl_dev);
 939
 940 out_free:
 941         btrtl_free(btrtl_dev);
 942
 943         return err;
 944 }
 945
 946 static void h5_btrtl_open(struct h5 *h5)
 947 {
 948         /*
 949          * Since h5_btrtl_resume() does a device_reprobe() the suspend handling
 950          * done by the hci_suspend_notifier is not necessary; it actually causes
 951          * delays and a bunch of errors to get logged, so disable it.
 952          */
 953         if (test_bit(H5_WAKEUP_DISABLE, &h5->flags))
 954                 set_bit(HCI_UART_NO_SUSPEND_NOTIFIER, &h5->hu->flags);
 955
 956         /* Devices always start with these fixed parameters */
 957         serdev_device_set_flow_control(h5->hu->serdev, false);
 958         serdev_device_set_parity(h5->hu->serdev, SERDEV_PARITY_EVEN);
 959         serdev_device_set_baudrate(h5->hu->serdev, 115200);
 960
 961         if (!test_bit(H5_WAKEUP_DISABLE, &h5->flags)) {
 962                 pm_runtime_set_active(&h5->hu->serdev->dev);
 963                 pm_runtime_use_autosuspend(&h5->hu->serdev->dev);
 964                 pm_runtime_set_autosuspend_delay(&h5->hu->serdev->dev,
 965                                                  SUSPEND_TIMEOUT_MS);
 966                 pm_runtime_enable(&h5->hu->serdev->dev);
 967         }
 968
 969         /* The controller needs up to 500ms to wakeup */
 970         gpiod_set_value_cansleep(h5->enable_gpio, 1);
 971         gpiod_set_value_cansleep(h5->device_wake_gpio, 1);
 972         msleep(500);
 973 }
 974
 975 static void h5_btrtl_close(struct h5 *h5)
 976 {
 977         if (!test_bit(H5_WAKEUP_DISABLE, &h5->flags))
 978                 pm_runtime_disable(&h5->hu->serdev->dev);
 979
 980         gpiod_set_value_cansleep(h5->device_wake_gpio, 0);
 981         gpiod_set_value_cansleep(h5->enable_gpio, 0);
 982 }
 983
 984 /* Suspend/resume support. On many devices the RTL BT device loses power during
 985  * suspend/resume, causing it to lose its firmware and all state. So we simply
 986  * turn it off on suspend and reprobe on resume. This mirrors how RTL devices
 987  * are handled in the USB driver, where the BTUSB_WAKEUP_DISABLE is used which
 988  * also causes a reprobe on resume.
 989  */
 990 static int h5_btrtl_suspend(struct h5 *h5)
 991 {
 992         serdev_device_set_flow_control(h5->hu->serdev, false);
 993         gpiod_set_value_cansleep(h5->device_wake_gpio, 0);
 994
 995         if (test_bit(H5_WAKEUP_DISABLE, &h5->flags))
 996                 gpiod_set_value_cansleep(h5->enable_gpio, 0);
 997
 998         return 0;
 999 }
1000
1001 struct h5_btrtl_reprobe {
1002         struct device *dev;
1003         struct work_struct work;
1004 };
1005
1006 static void h5_btrtl_reprobe_worker(struct work_struct *work)
1007 {
1008         struct h5_btrtl_reprobe *reprobe =
1009                 container_of(work, struct h5_btrtl_reprobe, work);
1010         int ret;
1011
1012         ret = device_reprobe(reprobe->dev);
1013         if (ret && ret != -EPROBE_DEFER)
1014                 dev_err(reprobe->dev, "Reprobe error %d\n", ret);
1015
1016         put_device(reprobe->dev);
1017         kfree(reprobe);
1018         module_put(THIS_MODULE);
1019 }
1020
1021 static int h5_btrtl_resume(struct h5 *h5)
1022 {
1023         if (test_bit(H5_WAKEUP_DISABLE, &h5->flags)) {
1024                 struct h5_btrtl_reprobe *reprobe;
1025
1026                 reprobe = kzalloc(sizeof(*reprobe), GFP_KERNEL);
1027                 if (!reprobe)
1028                         return -ENOMEM;
1029
1030                 __module_get(THIS_MODULE);
1031
1032                 INIT_WORK(&reprobe->work, h5_btrtl_reprobe_worker);
1033                 reprobe->dev = get_device(&h5->hu->serdev->dev);
1034                 queue_work(system_long_wq, &reprobe->work);
1035         } else {
1036                 gpiod_set_value_cansleep(h5->device_wake_gpio, 1);
1037
1038                 if (test_bit(H5_HW_FLOW_CONTROL, &h5->flags))
1039                         serdev_device_set_flow_control(h5->hu->serdev, true);
1040         }
1041
1042         return 0;
1043 }
1044
1045 static const struct acpi_gpio_params btrtl_device_wake_gpios = { 0, 0, false };
1046 static const struct acpi_gpio_params btrtl_enable_gpios = { 1, 0, false };
1047 static const struct acpi_gpio_params btrtl_host_wake_gpios = { 2, 0, false };
1048 static const struct acpi_gpio_mapping acpi_btrtl_gpios[] = {
1049         { "device-wake-gpios", &btrtl_device_wake_gpios, 1 },
1050         { "enable-gpios", &btrtl_enable_gpios, 1 },
1051         { "host-wake-gpios", &btrtl_host_wake_gpios, 1 },
1052         {},
1053 };
1054
1055 static struct h5_vnd rtl_vnd = {
1056         .setup          = h5_btrtl_setup,
1057         .open           = h5_btrtl_open,
1058         .close          = h5_btrtl_close,
1059         .suspend        = h5_btrtl_suspend,
1060         .resume         = h5_btrtl_resume,
1061         .acpi_gpio_map  = acpi_btrtl_gpios,
1062 };
1063
1064 static const struct h5_device_data h5_data_rtl8822cs = {
1065         .vnd = &rtl_vnd,
1066 };
1067
1068 static const struct h5_device_data h5_data_rtl8723bs = {
1069         .driver_info = H5_INFO_WAKEUP_DISABLE,
1070         .vnd = &rtl_vnd,
1071 };
1072 #endif
1073
1074 #ifdef CONFIG_ACPI
1075 static const struct acpi_device_id h5_acpi_match[] = {
1076 #ifdef CONFIG_BT_HCIUART_RTL
1077         { "OBDA0623", (kernel_ulong_t)&h5_data_rtl8723bs },
1078         { "OBDA8723", (kernel_ulong_t)&h5_data_rtl8723bs },
1079 #endif
1080         { },
1081 };
1082 MODULE_DEVICE_TABLE(acpi, h5_acpi_match);
1083 #endif
1084
1085 static const struct dev_pm_ops h5_serdev_pm_ops = {
1086         SET_SYSTEM_SLEEP_PM_OPS(h5_serdev_suspend, h5_serdev_resume)
1087         SET_RUNTIME_PM_OPS(h5_serdev_suspend, h5_serdev_resume, NULL)
1088 };
1089
1090 static const struct of_device_id rtl_bluetooth_of_match[] = {
1091 #ifdef CONFIG_BT_HCIUART_RTL
1092         { .compatible = "realtek,rtl8822cs-bt",
1093           .data = (const void *)&h5_data_rtl8822cs },
1094         { .compatible = "realtek,rtl8723bs-bt",
1095           .data = (const void *)&h5_data_rtl8723bs },
1096         { .compatible = "realtek,rtl8723ds-bt",
1097           .data = (const void *)&h5_data_rtl8723bs },
1098 #endif
1099         { },
1100 };
1101 MODULE_DEVICE_TABLE(of, rtl_bluetooth_of_match);
1102
1103 static struct serdev_device_driver h5_serdev_driver = {
1104         .probe = h5_serdev_probe,
1105         .remove = h5_serdev_remove,
1106         .driver = {
1107                 .name = "hci_uart_h5",
1108                 .acpi_match_table = ACPI_PTR(h5_acpi_match),
1109                 .pm = &h5_serdev_pm_ops,
1110                 .of_match_table = rtl_bluetooth_of_match,
1111         },
1112 };
1113
1114 int __init h5_init(void)
1115 {
1116         serdev_device_driver_register(&h5_serdev_driver);
1117         return hci_uart_register_proto(&h5p);
1118 }
1119
1120 int __exit h5_deinit(void)
1121 {
1122         serdev_device_driver_unregister(&h5_serdev_driver);
1123         return hci_uart_unregister_proto(&h5p);
1124 }