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                 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                 h5_reset_rx(h5);
 468                 return 0;
 469         }
 470
 471         if (h5->state != H5_ACTIVE &&
 472             H5_HDR_PKT_TYPE(hdr) != HCI_3WIRE_LINK_PKT) {
 473                 bt_dev_err(hu->hdev, "Non-link packet received in non-active state");
 474                 h5_reset_rx(h5);
 475                 return 0;
 476         }
 477
 478         h5->rx_func = h5_rx_payload;
 479         h5->rx_pending = H5_HDR_LEN(hdr);
 480
 481         return 0;
 482 }
 483
 484 static int h5_rx_pkt_start(struct hci_uart *hu, unsigned char c)
 485 {
 486         struct h5 *h5 = hu->priv;
 487
 488         if (c == SLIP_DELIMITER)
 489                 return 1;
 490
 491         h5->rx_func = h5_rx_3wire_hdr;
 492         h5->rx_pending = 4;
 493
 494         h5->rx_skb = bt_skb_alloc(H5_MAX_LEN, GFP_ATOMIC);
 495         if (!h5->rx_skb) {
 496                 bt_dev_err(hu->hdev, "Can't allocate mem for new packet");
 497                 h5_reset_rx(h5);
 498                 return -ENOMEM;
 499         }
 500
 501         h5->rx_skb->dev = (void *)hu->hdev;
 502
 503         return 0;
 504 }
 505
 506 static int h5_rx_delimiter(struct hci_uart *hu, unsigned char c)
 507 {
 508         struct h5 *h5 = hu->priv;
 509
 510         if (c == SLIP_DELIMITER)
 511                 h5->rx_func = h5_rx_pkt_start;
 512
 513         return 1;
 514 }
 515
 516 static void h5_unslip_one_byte(struct h5 *h5, unsigned char c)
 517 {
 518         const u8 delim = SLIP_DELIMITER, esc = SLIP_ESC;
 519         const u8 *byte = &c;
 520
 521         if (!test_bit(H5_RX_ESC, &h5->flags) && c == SLIP_ESC) {
 522                 set_bit(H5_RX_ESC, &h5->flags);
 523                 return;
 524         }
 525
 526         if (test_and_clear_bit(H5_RX_ESC, &h5->flags)) {
 527                 switch (c) {
 528                 case SLIP_ESC_DELIM:
 529                         byte = &delim;
 530                         break;
 531                 case SLIP_ESC_ESC:
 532                         byte = &esc;
 533                         break;
 534                 default:
 535                         BT_ERR("Invalid esc byte 0x%02hhx", c);
 536                         h5_reset_rx(h5);
 537                         return;
 538                 }
 539         }
 540
 541         skb_put_data(h5->rx_skb, byte, 1);
 542         h5->rx_pending--;
 543
 544         BT_DBG("unslipped 0x%02hhx, rx_pending %zu", *byte, h5->rx_pending);
 545 }
 546
 547 static void h5_reset_rx(struct h5 *h5)
 548 {
 549         if (h5->rx_skb) {
 550                 kfree_skb(h5->rx_skb);
 551                 h5->rx_skb = NULL;
 552         }
 553
 554         h5->rx_func = h5_rx_delimiter;
 555         h5->rx_pending = 0;
 556         clear_bit(H5_RX_ESC, &h5->flags);
 557 }
 558
 559 static int h5_recv(struct hci_uart *hu, const void *data, int count)
 560 {
 561         struct h5 *h5 = hu->priv;
 562         const unsigned char *ptr = data;
 563
 564         BT_DBG("%s pending %zu count %d", hu->hdev->name, h5->rx_pending,
 565                count);
 566
 567         while (count > 0) {
 568                 int processed;
 569
 570                 if (h5->rx_pending > 0) {
 571                         if (*ptr == SLIP_DELIMITER) {
 572                                 bt_dev_err(hu->hdev, "Too short H5 packet");
 573                                 h5_reset_rx(h5);
 574                                 continue;
 575                         }
 576
 577                         h5_unslip_one_byte(h5, *ptr);
 578
 579                         ptr++; count--;
 580                         continue;
 581                 }
 582
 583                 processed = h5->rx_func(hu, *ptr);
 584                 if (processed < 0)
 585                         return processed;
 586
 587                 ptr += processed;
 588                 count -= processed;
 589         }
 590
 591         if (hu->serdev) {
 592                 pm_runtime_get(&hu->serdev->dev);
 593                 pm_runtime_mark_last_busy(&hu->serdev->dev);
 594                 pm_runtime_put_autosuspend(&hu->serdev->dev);
 595         }
 596
 597         return 0;
 598 }
 599
 600 static int h5_enqueue(struct hci_uart *hu, struct sk_buff *skb)
 601 {
 602         struct h5 *h5 = hu->priv;
 603
 604         if (skb->len > 0xfff) {
 605                 bt_dev_err(hu->hdev, "Packet too long (%u bytes)", skb->len);
 606                 kfree_skb(skb);
 607                 return 0;
 608         }
 609
 610         if (h5->state != H5_ACTIVE) {
 611                 bt_dev_err(hu->hdev, "Ignoring HCI data in non-active state");
 612                 kfree_skb(skb);
 613                 return 0;
 614         }
 615
 616         switch (hci_skb_pkt_type(skb)) {
 617         case HCI_ACLDATA_PKT:
 618         case HCI_COMMAND_PKT:
 619                 skb_queue_tail(&h5->rel, skb);
 620                 break;
 621
 622         case HCI_SCODATA_PKT:
 623         case HCI_ISODATA_PKT:
 624                 skb_queue_tail(&h5->unrel, skb);
 625                 break;
 626
 627         default:
 628                 bt_dev_err(hu->hdev, "Unknown packet type %u", hci_skb_pkt_type(skb));
 629                 kfree_skb(skb);
 630                 break;
 631         }
 632
 633         if (hu->serdev) {
 634                 pm_runtime_get_sync(&hu->serdev->dev);
 635                 pm_runtime_mark_last_busy(&hu->serdev->dev);
 636                 pm_runtime_put_autosuspend(&hu->serdev->dev);
 637         }
 638
 639         return 0;
 640 }
 641
 642 static void h5_slip_delim(struct sk_buff *skb)
 643 {
 644         const char delim = SLIP_DELIMITER;
 645
 646         skb_put_data(skb, &delim, 1);
 647 }
 648
 649 static void h5_slip_one_byte(struct sk_buff *skb, u8 c)
 650 {
 651         const char esc_delim[2] = { SLIP_ESC, SLIP_ESC_DELIM };
 652         const char esc_esc[2] = { SLIP_ESC, SLIP_ESC_ESC };
 653
 654         switch (c) {
 655         case SLIP_DELIMITER:
 656                 skb_put_data(skb, &esc_delim, 2);
 657                 break;
 658         case SLIP_ESC:
 659                 skb_put_data(skb, &esc_esc, 2);
 660                 break;
 661         default:
 662                 skb_put_data(skb, &c, 1);
 663         }
 664 }
 665
 666 static bool valid_packet_type(u8 type)
 667 {
 668         switch (type) {
 669         case HCI_ACLDATA_PKT:
 670         case HCI_COMMAND_PKT:
 671         case HCI_SCODATA_PKT:
 672         case HCI_ISODATA_PKT:
 673         case HCI_3WIRE_LINK_PKT:
 674         case HCI_3WIRE_ACK_PKT:
 675                 return true;
 676         default:
 677                 return false;
 678         }
 679 }
 680
 681 static struct sk_buff *h5_prepare_pkt(struct hci_uart *hu, u8 pkt_type,
 682                                       const u8 *data, size_t len)
 683 {
 684         struct h5 *h5 = hu->priv;
 685         struct sk_buff *nskb;
 686         u8 hdr[4];
 687         int i;
 688
 689         if (!valid_packet_type(pkt_type)) {
 690                 bt_dev_err(hu->hdev, "Unknown packet type %u", pkt_type);
 691                 return NULL;
 692         }
 693
 694         /*
 695          * Max len of packet: (original len + 4 (H5 hdr) + 2 (crc)) * 2
 696          * (because bytes 0xc0 and 0xdb are escaped, worst case is when
 697          * the packet is all made of 0xc0 and 0xdb) + 2 (0xc0
 698          * delimiters at start and end).
 699          */
 700         nskb = alloc_skb((len + 6) * 2 + 2, GFP_ATOMIC);
 701         if (!nskb)
 702                 return NULL;
 703
 704         hci_skb_pkt_type(nskb) = pkt_type;
 705
 706         h5_slip_delim(nskb);
 707
 708         hdr[0] = h5->tx_ack << 3;
 709         clear_bit(H5_TX_ACK_REQ, &h5->flags);
 710
 711         /* Reliable packet? */
 712         if (pkt_type == HCI_ACLDATA_PKT || pkt_type == HCI_COMMAND_PKT) {
 713                 hdr[0] |= 1 << 7;
 714                 hdr[0] |= h5->tx_seq;
 715                 h5->tx_seq = (h5->tx_seq + 1) % 8;
 716         }
 717
 718         hdr[1] = pkt_type | ((len & 0x0f) << 4);
 719         hdr[2] = len >> 4;
 720         hdr[3] = ~((hdr[0] + hdr[1] + hdr[2]) & 0xff);
 721
 722         BT_DBG("%s tx: seq %u ack %u crc %u rel %u type %u len %u",
 723                hu->hdev->name, H5_HDR_SEQ(hdr), H5_HDR_ACK(hdr),
 724                H5_HDR_CRC(hdr), H5_HDR_RELIABLE(hdr), H5_HDR_PKT_TYPE(hdr),
 725                H5_HDR_LEN(hdr));
 726
 727         for (i = 0; i < 4; i++)
 728                 h5_slip_one_byte(nskb, hdr[i]);
 729
 730         for (i = 0; i < len; i++)
 731                 h5_slip_one_byte(nskb, data[i]);
 732
 733         h5_slip_delim(nskb);
 734
 735         return nskb;
 736 }
 737
 738 static struct sk_buff *h5_dequeue(struct hci_uart *hu)
 739 {
 740         struct h5 *h5 = hu->priv;
 741         unsigned long flags;
 742         struct sk_buff *skb, *nskb;
 743
 744         if (h5->sleep != H5_AWAKE) {
 745                 const unsigned char wakeup_req[] = { 0x05, 0xfa };
 746
 747                 if (h5->sleep == H5_WAKING_UP)
 748                         return NULL;
 749
 750                 h5->sleep = H5_WAKING_UP;
 751                 BT_DBG("Sending wakeup request");
 752
 753                 mod_timer(&h5->timer, jiffies + HZ / 100);
 754                 return h5_prepare_pkt(hu, HCI_3WIRE_LINK_PKT, wakeup_req, 2);
 755         }
 756
 757         skb = skb_dequeue(&h5->unrel);
 758         if (skb) {
 759                 nskb = h5_prepare_pkt(hu, hci_skb_pkt_type(skb),
 760                                       skb->data, skb->len);
 761                 if (nskb) {
 762                         kfree_skb(skb);
 763                         return nskb;
 764                 }
 765
 766                 skb_queue_head(&h5->unrel, skb);
 767                 bt_dev_err(hu->hdev, "Could not dequeue pkt because alloc_skb failed");
 768         }
 769
 770         spin_lock_irqsave_nested(&h5->unack.lock, flags, SINGLE_DEPTH_NESTING);
 771
 772         if (h5->unack.qlen >= h5->tx_win)
 773                 goto unlock;
 774
 775         skb = skb_dequeue(&h5->rel);
 776         if (skb) {
 777                 nskb = h5_prepare_pkt(hu, hci_skb_pkt_type(skb),
 778                                       skb->data, skb->len);
 779                 if (nskb) {
 780                         __skb_queue_tail(&h5->unack, skb);
 781                         mod_timer(&h5->timer, jiffies + H5_ACK_TIMEOUT);
 782                         spin_unlock_irqrestore(&h5->unack.lock, flags);
 783                         return nskb;
 784                 }
 785
 786                 skb_queue_head(&h5->rel, skb);
 787                 bt_dev_err(hu->hdev, "Could not dequeue pkt because alloc_skb failed");
 788         }
 789
 790 unlock:
 791         spin_unlock_irqrestore(&h5->unack.lock, flags);
 792
 793         if (test_bit(H5_TX_ACK_REQ, &h5->flags))
 794                 return h5_prepare_pkt(hu, HCI_3WIRE_ACK_PKT, NULL, 0);
 795
 796         return NULL;
 797 }
 798
 799 static int h5_flush(struct hci_uart *hu)
 800 {
 801         BT_DBG("hu %p", hu);
 802         return 0;
 803 }
 804
 805 static const struct hci_uart_proto h5p = {
 806         .id             = HCI_UART_3WIRE,
 807         .name           = "Three-wire (H5)",
 808         .open           = h5_open,
 809         .close          = h5_close,
 810         .setup          = h5_setup,
 811         .recv           = h5_recv,
 812         .enqueue        = h5_enqueue,
 813         .dequeue        = h5_dequeue,
 814         .flush          = h5_flush,
 815 };
 816
 817 static int h5_serdev_probe(struct serdev_device *serdev)
 818 {
 819         struct device *dev = &serdev->dev;
 820         struct h5 *h5;
 821         const struct h5_device_data *data;
 822         int err;
 823
 824         h5 = devm_kzalloc(dev, sizeof(*h5), GFP_KERNEL);
 825         if (!h5)
 826                 return -ENOMEM;
 827
 828         h5->hu = &h5->serdev_hu;
 829         h5->serdev_hu.serdev = serdev;
 830         serdev_device_set_drvdata(serdev, h5);
 831
 832         if (has_acpi_companion(dev)) {
 833                 const struct acpi_device_id *match;
 834
 835                 match = acpi_match_device(dev->driver->acpi_match_table, dev);
 836                 if (!match)
 837                         return -ENODEV;
 838
 839                 data = (const struct h5_device_data *)match->driver_data;
 840                 h5->vnd = data->vnd;
 841                 h5->id  = (char *)match->id;
 842
 843                 if (h5->vnd->acpi_gpio_map)
 844                         devm_acpi_dev_add_driver_gpios(dev,
 845                                                        h5->vnd->acpi_gpio_map);
 846         } else {
 847                 data = of_device_get_match_data(dev);
 848                 if (!data)
 849                         return -ENODEV;
 850
 851                 h5->vnd = data->vnd;
 852         }
 853
 854         if (data->driver_info & H5_INFO_WAKEUP_DISABLE)
 855                 set_bit(H5_WAKEUP_DISABLE, &h5->flags);
 856
 857         h5->enable_gpio = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_LOW);
 858         if (IS_ERR(h5->enable_gpio))
 859                 return PTR_ERR(h5->enable_gpio);
 860
 861         h5->device_wake_gpio = devm_gpiod_get_optional(dev, "device-wake",
 862                                                        GPIOD_OUT_LOW);
 863         if (IS_ERR(h5->device_wake_gpio))
 864                 return PTR_ERR(h5->device_wake_gpio);
 865
 866         err = hci_uart_register_device(&h5->serdev_hu, &h5p);
 867         if (err)
 868                 return err;
 869
 870         return 0;
 871 }
 872
 873 static void h5_serdev_remove(struct serdev_device *serdev)
 874 {
 875         struct h5 *h5 = serdev_device_get_drvdata(serdev);
 876
 877         hci_uart_unregister_device(&h5->serdev_hu);
 878 }
 879
 880 static int __maybe_unused h5_serdev_suspend(struct device *dev)
 881 {
 882         struct h5 *h5 = dev_get_drvdata(dev);
 883         int ret = 0;
 884
 885         if (h5->vnd && h5->vnd->suspend)
 886                 ret = h5->vnd->suspend(h5);
 887
 888         return ret;
 889 }
 890
 891 static int __maybe_unused h5_serdev_resume(struct device *dev)
 892 {
 893         struct h5 *h5 = dev_get_drvdata(dev);
 894         int ret = 0;
 895
 896         if (h5->vnd && h5->vnd->resume)
 897                 ret = h5->vnd->resume(h5);
 898
 899         return ret;
 900 }
 901
 902 #ifdef CONFIG_BT_HCIUART_RTL
 903 static int h5_btrtl_setup(struct h5 *h5)
 904 {
 905         struct btrtl_device_info *btrtl_dev;
 906         struct sk_buff *skb;
 907         __le32 baudrate_data;
 908         u32 device_baudrate;
 909         unsigned int controller_baudrate;
 910         bool flow_control;
 911         int err;
 912
 913         btrtl_dev = btrtl_initialize(h5->hu->hdev, h5->id);
 914         if (IS_ERR(btrtl_dev))
 915                 return PTR_ERR(btrtl_dev);
 916
 917         err = btrtl_get_uart_settings(h5->hu->hdev, btrtl_dev,
 918                                       &controller_baudrate, &device_baudrate,
 919                                       &flow_control);
 920         if (err)
 921                 goto out_free;
 922
 923         baudrate_data = cpu_to_le32(device_baudrate);
 924         skb = __hci_cmd_sync(h5->hu->hdev, 0xfc17, sizeof(baudrate_data),
 925                              &baudrate_data, HCI_INIT_TIMEOUT);
 926         if (IS_ERR(skb)) {
 927                 rtl_dev_err(h5->hu->hdev, "set baud rate command failed\n");
 928                 err = PTR_ERR(skb);
 929                 goto out_free;
 930         } else {
 931                 kfree_skb(skb);
 932         }
 933         /* Give the device some time to set up the new baudrate. */
 934         usleep_range(10000, 20000);
 935
 936         serdev_device_set_baudrate(h5->hu->serdev, controller_baudrate);
 937         serdev_device_set_flow_control(h5->hu->serdev, flow_control);
 938
 939         if (flow_control)
 940                 set_bit(H5_HW_FLOW_CONTROL, &h5->flags);
 941
 942         err = btrtl_download_firmware(h5->hu->hdev, btrtl_dev);
 943         /* Give the device some time before the hci-core sends it a reset */
 944         usleep_range(10000, 20000);
 945
 946         btrtl_set_quirks(h5->hu->hdev, btrtl_dev);
 947
 948 out_free:
 949         btrtl_free(btrtl_dev);
 950
 951         return err;
 952 }
 953
 954 static void h5_btrtl_open(struct h5 *h5)
 955 {
 956         /*
 957          * Since h5_btrtl_resume() does a device_reprobe() the suspend handling
 958          * done by the hci_suspend_notifier is not necessary; it actually causes
 959          * delays and a bunch of errors to get logged, so disable it.
 960          */
 961         if (test_bit(H5_WAKEUP_DISABLE, &h5->flags))
 962                 set_bit(HCI_UART_NO_SUSPEND_NOTIFIER, &h5->hu->flags);
 963
 964         /* Devices always start with these fixed parameters */
 965         serdev_device_set_flow_control(h5->hu->serdev, false);
 966         serdev_device_set_parity(h5->hu->serdev, SERDEV_PARITY_EVEN);
 967         serdev_device_set_baudrate(h5->hu->serdev, 115200);
 968
 969         if (!test_bit(H5_WAKEUP_DISABLE, &h5->flags)) {
 970                 pm_runtime_set_active(&h5->hu->serdev->dev);
 971                 pm_runtime_use_autosuspend(&h5->hu->serdev->dev);
 972                 pm_runtime_set_autosuspend_delay(&h5->hu->serdev->dev,
 973                                                  SUSPEND_TIMEOUT_MS);
 974                 pm_runtime_enable(&h5->hu->serdev->dev);
 975         }
 976
 977         /* The controller needs up to 500ms to wakeup */
 978         gpiod_set_value_cansleep(h5->enable_gpio, 1);
 979         gpiod_set_value_cansleep(h5->device_wake_gpio, 1);
 980         msleep(500);
 981 }
 982
 983 static void h5_btrtl_close(struct h5 *h5)
 984 {
 985         if (!test_bit(H5_WAKEUP_DISABLE, &h5->flags))
 986                 pm_runtime_disable(&h5->hu->serdev->dev);
 987
 988         gpiod_set_value_cansleep(h5->device_wake_gpio, 0);
 989         gpiod_set_value_cansleep(h5->enable_gpio, 0);
 990 }
 991
 992 /* Suspend/resume support. On many devices the RTL BT device loses power during
 993  * suspend/resume, causing it to lose its firmware and all state. So we simply
 994  * turn it off on suspend and reprobe on resume. This mirrors how RTL devices
 995  * are handled in the USB driver, where the BTUSB_WAKEUP_DISABLE is used which
 996  * also causes a reprobe on resume.
 997  */
 998 static int h5_btrtl_suspend(struct h5 *h5)
 999 {
1000         serdev_device_set_flow_control(h5->hu->serdev, false);
1001         gpiod_set_value_cansleep(h5->device_wake_gpio, 0);
1002
1003         if (test_bit(H5_WAKEUP_DISABLE, &h5->flags))
1004                 gpiod_set_value_cansleep(h5->enable_gpio, 0);
1005
1006         return 0;
1007 }
1008
1009 struct h5_btrtl_reprobe {
1010         struct device *dev;
1011         struct work_struct work;
1012 };
1013
1014 static void h5_btrtl_reprobe_worker(struct work_struct *work)
1015 {
1016         struct h5_btrtl_reprobe *reprobe =
1017                 container_of(work, struct h5_btrtl_reprobe, work);
1018         int ret;
1019
1020         ret = device_reprobe(reprobe->dev);
1021         if (ret && ret != -EPROBE_DEFER)
1022                 dev_err(reprobe->dev, "Reprobe error %d\n", ret);
1023
1024         put_device(reprobe->dev);
1025         kfree(reprobe);
1026         module_put(THIS_MODULE);
1027 }
1028
1029 static int h5_btrtl_resume(struct h5 *h5)
1030 {
1031         if (test_bit(H5_WAKEUP_DISABLE, &h5->flags)) {
1032                 struct h5_btrtl_reprobe *reprobe;
1033
1034                 reprobe = kzalloc(sizeof(*reprobe), GFP_KERNEL);
1035                 if (!reprobe)
1036                         return -ENOMEM;
1037
1038                 __module_get(THIS_MODULE);
1039
1040                 INIT_WORK(&reprobe->work, h5_btrtl_reprobe_worker);
1041                 reprobe->dev = get_device(&h5->hu->serdev->dev);
1042                 queue_work(system_long_wq, &reprobe->work);
1043         } else {
1044                 gpiod_set_value_cansleep(h5->device_wake_gpio, 1);
1045
1046                 if (test_bit(H5_HW_FLOW_CONTROL, &h5->flags))
1047                         serdev_device_set_flow_control(h5->hu->serdev, true);
1048         }
1049
1050         return 0;
1051 }
1052
1053 static const struct acpi_gpio_params btrtl_device_wake_gpios = { 0, 0, false };
1054 static const struct acpi_gpio_params btrtl_enable_gpios = { 1, 0, false };
1055 static const struct acpi_gpio_params btrtl_host_wake_gpios = { 2, 0, false };
1056 static const struct acpi_gpio_mapping acpi_btrtl_gpios[] = {
1057         { "device-wake-gpios", &btrtl_device_wake_gpios, 1 },
1058         { "enable-gpios", &btrtl_enable_gpios, 1 },
1059         { "host-wake-gpios", &btrtl_host_wake_gpios, 1 },
1060         {},
1061 };
1062
1063 static struct h5_vnd rtl_vnd = {
1064         .setup          = h5_btrtl_setup,
1065         .open           = h5_btrtl_open,
1066         .close          = h5_btrtl_close,
1067         .suspend        = h5_btrtl_suspend,
1068         .resume         = h5_btrtl_resume,
1069         .acpi_gpio_map  = acpi_btrtl_gpios,
1070 };
1071
1072 static const struct h5_device_data h5_data_rtl8822cs = {
1073         .vnd = &rtl_vnd,
1074 };
1075
1076 static const struct h5_device_data h5_data_rtl8723bs = {
1077         .driver_info = H5_INFO_WAKEUP_DISABLE,
1078         .vnd = &rtl_vnd,
1079 };
1080 #endif
1081
1082 #ifdef CONFIG_ACPI
1083 static const struct acpi_device_id h5_acpi_match[] = {
1084 #ifdef CONFIG_BT_HCIUART_RTL
1085         { "OBDA0623", (kernel_ulong_t)&h5_data_rtl8723bs },
1086         { "OBDA8723", (kernel_ulong_t)&h5_data_rtl8723bs },
1087 #endif
1088         { },
1089 };
1090 MODULE_DEVICE_TABLE(acpi, h5_acpi_match);
1091 #endif
1092
1093 static const struct dev_pm_ops h5_serdev_pm_ops = {
1094         SET_SYSTEM_SLEEP_PM_OPS(h5_serdev_suspend, h5_serdev_resume)
1095         SET_RUNTIME_PM_OPS(h5_serdev_suspend, h5_serdev_resume, NULL)
1096 };
1097
1098 static const struct of_device_id rtl_bluetooth_of_match[] = {
1099 #ifdef CONFIG_BT_HCIUART_RTL
1100         { .compatible = "realtek,rtl8822cs-bt",
1101           .data = (const void *)&h5_data_rtl8822cs },
1102         { .compatible = "realtek,rtl8723bs-bt",
1103           .data = (const void *)&h5_data_rtl8723bs },
1104         { .compatible = "realtek,rtl8723ds-bt",
1105           .data = (const void *)&h5_data_rtl8723bs },
1106 #endif
1107         { },
1108 };
1109 MODULE_DEVICE_TABLE(of, rtl_bluetooth_of_match);
1110
1111 static struct serdev_device_driver h5_serdev_driver = {
1112         .probe = h5_serdev_probe,
1113         .remove = h5_serdev_remove,
1114         .driver = {
1115                 .name = "hci_uart_h5",
1116                 .acpi_match_table = ACPI_PTR(h5_acpi_match),
1117                 .pm = &h5_serdev_pm_ops,
1118                 .of_match_table = rtl_bluetooth_of_match,
1119         },
1120 };
1121
1122 int __init h5_init(void)
1123 {
1124         serdev_device_driver_register(&h5_serdev_driver);
1125         return hci_uart_register_proto(&h5p);
1126 }
1127
1128 int __exit h5_deinit(void)
1129 {
1130         serdev_device_driver_unregister(&h5_serdev_driver);
1131         return hci_uart_unregister_proto(&h5p);
1132 }