drivers/bluetooth/hci_ll.c

   1 /*
   2  *  Texas Instruments' Bluetooth HCILL UART protocol
   3  *
   4  *  HCILL (HCI Low Level) is a Texas Instruments' power management
   5  *  protocol extension to H4.
   6  *
   7  *  Copyright (C) 2007 Texas Instruments, Inc.
   8  *
   9  *  Written by Ohad Ben-Cohen <ohad@bencohen.org>
  10  *
  11  *  Acknowledgements:
  12  *  This file is based on hci_h4.c, which was written
  13  *  by Maxim Krasnyansky and Marcel Holtmann.
  14  *
  15  *  This program is free software; you can redistribute it and/or modify
  16  *  it under the terms of the GNU General Public License version 2
  17  *  as published by the Free Software Foundation
  18  *
  19  *  This program is distributed in the hope that it will be useful,
  20  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  *  GNU General Public License for more details.
  23  *
  24  *  You should have received a copy of the GNU General Public License
  25  *  along with this program; if not, write to the Free Software
  26  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  27  *
  28  */
  29
  30 #include <linux/module.h>
  31 #include <linux/kernel.h>
  32
  33 #include <linux/init.h>
  34 #include <linux/sched.h>
  35 #include <linux/types.h>
  36 #include <linux/fcntl.h>
  37 #include <linux/firmware.h>
  38 #include <linux/interrupt.h>
  39 #include <linux/ptrace.h>
  40 #include <linux/poll.h>
  41
  42 #include <linux/slab.h>
  43 #include <linux/errno.h>
  44 #include <linux/string.h>
  45 #include <linux/signal.h>
  46 #include <linux/ioctl.h>
  47 #include <linux/of.h>
  48 #include <linux/serdev.h>
  49 #include <linux/skbuff.h>
  50 #include <linux/ti_wilink_st.h>
  51
  52 #include <net/bluetooth/bluetooth.h>
  53 #include <net/bluetooth/hci_core.h>
  54 #include <linux/gpio/consumer.h>
  55
  56 #include "hci_uart.h"
  57
  58 /* HCILL commands */
  59 #define HCILL_GO_TO_SLEEP_IND   0x30
  60 #define HCILL_GO_TO_SLEEP_ACK   0x31
  61 #define HCILL_WAKE_UP_IND       0x32
  62 #define HCILL_WAKE_UP_ACK       0x33
  63
  64 /* HCILL receiver States */
  65 #define HCILL_W4_PACKET_TYPE    0
  66 #define HCILL_W4_EVENT_HDR      1
  67 #define HCILL_W4_ACL_HDR        2
  68 #define HCILL_W4_SCO_HDR        3
  69 #define HCILL_W4_DATA           4
  70
  71 /* HCILL states */
  72 enum hcill_states_e {
  73         HCILL_ASLEEP,
  74         HCILL_ASLEEP_TO_AWAKE,
  75         HCILL_AWAKE,
  76         HCILL_AWAKE_TO_ASLEEP
  77 };
  78
  79 struct hcill_cmd {
  80         u8 cmd;
  81 } __packed;
  82
  83 struct ll_device {
  84         struct hci_uart hu;
  85         struct serdev_device *serdev;
  86         struct gpio_desc *enable_gpio;
  87 };
  88
  89 struct ll_struct {
  90         unsigned long rx_state;
  91         unsigned long rx_count;
  92         struct sk_buff *rx_skb;
  93         struct sk_buff_head txq;
  94         spinlock_t hcill_lock;          /* HCILL state lock     */
  95         unsigned long hcill_state;      /* HCILL power state    */
  96         struct sk_buff_head tx_wait_q;  /* HCILL wait queue     */
  97 };
  98
  99 /*
 100  * Builds and sends an HCILL command packet.
 101  * These are very simple packets with only 1 cmd byte
 102  */
 103 static int send_hcill_cmd(u8 cmd, struct hci_uart *hu)
 104 {
 105         int err = 0;
 106         struct sk_buff *skb = NULL;
 107         struct ll_struct *ll = hu->priv;
 108         struct hcill_cmd *hcill_packet;
 109
 110         BT_DBG("hu %p cmd 0x%x", hu, cmd);
 111
 112         /* allocate packet */
 113         skb = bt_skb_alloc(1, GFP_ATOMIC);
 114         if (!skb) {
 115                 BT_ERR("cannot allocate memory for HCILL packet");
 116                 err = -ENOMEM;
 117                 goto out;
 118         }
 119
 120         /* prepare packet */
 121         hcill_packet = (struct hcill_cmd *) skb_put(skb, 1);
 122         hcill_packet->cmd = cmd;
 123
 124         /* send packet */
 125         skb_queue_tail(&ll->txq, skb);
 126 out:
 127         return err;
 128 }
 129
 130 /* Initialize protocol */
 131 static int ll_open(struct hci_uart *hu)
 132 {
 133         struct ll_struct *ll;
 134
 135         BT_DBG("hu %p", hu);
 136
 137         ll = kzalloc(sizeof(*ll), GFP_KERNEL);
 138         if (!ll)
 139                 return -ENOMEM;
 140
 141         skb_queue_head_init(&ll->txq);
 142         skb_queue_head_init(&ll->tx_wait_q);
 143         spin_lock_init(&ll->hcill_lock);
 144
 145         ll->hcill_state = HCILL_AWAKE;
 146
 147         hu->priv = ll;
 148
 149         if (hu->serdev)
 150                 serdev_device_open(hu->serdev);
 151
 152         return 0;
 153 }
 154
 155 /* Flush protocol data */
 156 static int ll_flush(struct hci_uart *hu)
 157 {
 158         struct ll_struct *ll = hu->priv;
 159
 160         BT_DBG("hu %p", hu);
 161
 162         skb_queue_purge(&ll->tx_wait_q);
 163         skb_queue_purge(&ll->txq);
 164
 165         return 0;
 166 }
 167
 168 /* Close protocol */
 169 static int ll_close(struct hci_uart *hu)
 170 {
 171         struct ll_struct *ll = hu->priv;
 172
 173         BT_DBG("hu %p", hu);
 174
 175         skb_queue_purge(&ll->tx_wait_q);
 176         skb_queue_purge(&ll->txq);
 177
 178         kfree_skb(ll->rx_skb);
 179
 180         if (hu->serdev) {
 181                 struct ll_device *lldev = serdev_device_get_drvdata(hu->serdev);
 182                 gpiod_set_value_cansleep(lldev->enable_gpio, 0);
 183
 184                 serdev_device_close(hu->serdev);
 185         }
 186
 187         hu->priv = NULL;
 188
 189         kfree(ll);
 190
 191         return 0;
 192 }
 193
 194 /*
 195  * internal function, which does common work of the device wake up process:
 196  * 1. places all pending packets (waiting in tx_wait_q list) in txq list.
 197  * 2. changes internal state to HCILL_AWAKE.
 198  * Note: assumes that hcill_lock spinlock is taken,
 199  * shouldn't be called otherwise!
 200  */
 201 static void __ll_do_awake(struct ll_struct *ll)
 202 {
 203         struct sk_buff *skb = NULL;
 204
 205         while ((skb = skb_dequeue(&ll->tx_wait_q)))
 206                 skb_queue_tail(&ll->txq, skb);
 207
 208         ll->hcill_state = HCILL_AWAKE;
 209 }
 210
 211 /*
 212  * Called upon a wake-up-indication from the device
 213  */
 214 static void ll_device_want_to_wakeup(struct hci_uart *hu)
 215 {
 216         unsigned long flags;
 217         struct ll_struct *ll = hu->priv;
 218
 219         BT_DBG("hu %p", hu);
 220
 221         /* lock hcill state */
 222         spin_lock_irqsave(&ll->hcill_lock, flags);
 223
 224         switch (ll->hcill_state) {
 225         case HCILL_ASLEEP_TO_AWAKE:
 226                 /*
 227                  * This state means that both the host and the BRF chip
 228                  * have simultaneously sent a wake-up-indication packet.
 229                  * Traditionally, in this case, receiving a wake-up-indication
 230                  * was enough and an additional wake-up-ack wasn't needed.
 231                  * This has changed with the BRF6350, which does require an
 232                  * explicit wake-up-ack. Other BRF versions, which do not
 233                  * require an explicit ack here, do accept it, thus it is
 234                  * perfectly safe to always send one.
 235                  */
 236                 BT_DBG("dual wake-up-indication");
 237                 /* deliberate fall-through - do not add break */
 238         case HCILL_ASLEEP:
 239                 /* acknowledge device wake up */
 240                 if (send_hcill_cmd(HCILL_WAKE_UP_ACK, hu) < 0) {
 241                         BT_ERR("cannot acknowledge device wake up");
 242                         goto out;
 243                 }
 244                 break;
 245         default:
 246                 /* any other state is illegal */
 247                 BT_ERR("received HCILL_WAKE_UP_IND in state %ld", ll->hcill_state);
 248                 break;
 249         }
 250
 251         /* send pending packets and change state to HCILL_AWAKE */
 252         __ll_do_awake(ll);
 253
 254 out:
 255         spin_unlock_irqrestore(&ll->hcill_lock, flags);
 256
 257         /* actually send the packets */
 258         hci_uart_tx_wakeup(hu);
 259 }
 260
 261 /*
 262  * Called upon a sleep-indication from the device
 263  */
 264 static void ll_device_want_to_sleep(struct hci_uart *hu)
 265 {
 266         unsigned long flags;
 267         struct ll_struct *ll = hu->priv;
 268
 269         BT_DBG("hu %p", hu);
 270
 271         /* lock hcill state */
 272         spin_lock_irqsave(&ll->hcill_lock, flags);
 273
 274         /* sanity check */
 275         if (ll->hcill_state != HCILL_AWAKE)
 276                 BT_ERR("ERR: HCILL_GO_TO_SLEEP_IND in state %ld", ll->hcill_state);
 277
 278         /* acknowledge device sleep */
 279         if (send_hcill_cmd(HCILL_GO_TO_SLEEP_ACK, hu) < 0) {
 280                 BT_ERR("cannot acknowledge device sleep");
 281                 goto out;
 282         }
 283
 284         /* update state */
 285         ll->hcill_state = HCILL_ASLEEP;
 286
 287 out:
 288         spin_unlock_irqrestore(&ll->hcill_lock, flags);
 289
 290         /* actually send the sleep ack packet */
 291         hci_uart_tx_wakeup(hu);
 292 }
 293
 294 /*
 295  * Called upon wake-up-acknowledgement from the device
 296  */
 297 static void ll_device_woke_up(struct hci_uart *hu)
 298 {
 299         unsigned long flags;
 300         struct ll_struct *ll = hu->priv;
 301
 302         BT_DBG("hu %p", hu);
 303
 304         /* lock hcill state */
 305         spin_lock_irqsave(&ll->hcill_lock, flags);
 306
 307         /* sanity check */
 308         if (ll->hcill_state != HCILL_ASLEEP_TO_AWAKE)
 309                 BT_ERR("received HCILL_WAKE_UP_ACK in state %ld", ll->hcill_state);
 310
 311         /* send pending packets and change state to HCILL_AWAKE */
 312         __ll_do_awake(ll);
 313
 314         spin_unlock_irqrestore(&ll->hcill_lock, flags);
 315
 316         /* actually send the packets */
 317         hci_uart_tx_wakeup(hu);
 318 }
 319
 320 /* Enqueue frame for transmittion (padding, crc, etc) */
 321 /* may be called from two simultaneous tasklets */
 322 static int ll_enqueue(struct hci_uart *hu, struct sk_buff *skb)
 323 {
 324         unsigned long flags = 0;
 325         struct ll_struct *ll = hu->priv;
 326
 327         BT_DBG("hu %p skb %p", hu, skb);
 328
 329         /* Prepend skb with frame type */
 330         memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);
 331
 332         /* lock hcill state */
 333         spin_lock_irqsave(&ll->hcill_lock, flags);
 334
 335         /* act according to current state */
 336         switch (ll->hcill_state) {
 337         case HCILL_AWAKE:
 338                 BT_DBG("device awake, sending normally");
 339                 skb_queue_tail(&ll->txq, skb);
 340                 break;
 341         case HCILL_ASLEEP:
 342                 BT_DBG("device asleep, waking up and queueing packet");
 343                 /* save packet for later */
 344                 skb_queue_tail(&ll->tx_wait_q, skb);
 345                 /* awake device */
 346                 if (send_hcill_cmd(HCILL_WAKE_UP_IND, hu) < 0) {
 347                         BT_ERR("cannot wake up device");
 348                         break;
 349                 }
 350                 ll->hcill_state = HCILL_ASLEEP_TO_AWAKE;
 351                 break;
 352         case HCILL_ASLEEP_TO_AWAKE:
 353                 BT_DBG("device waking up, queueing packet");
 354                 /* transient state; just keep packet for later */
 355                 skb_queue_tail(&ll->tx_wait_q, skb);
 356                 break;
 357         default:
 358                 BT_ERR("illegal hcill state: %ld (losing packet)", ll->hcill_state);
 359                 kfree_skb(skb);
 360                 break;
 361         }
 362
 363         spin_unlock_irqrestore(&ll->hcill_lock, flags);
 364
 365         return 0;
 366 }
 367
 368 static inline int ll_check_data_len(struct hci_dev *hdev, struct ll_struct *ll, int len)
 369 {
 370         int room = skb_tailroom(ll->rx_skb);
 371
 372         BT_DBG("len %d room %d", len, room);
 373
 374         if (!len) {
 375                 hci_recv_frame(hdev, ll->rx_skb);
 376         } else if (len > room) {
 377                 BT_ERR("Data length is too large");
 378                 kfree_skb(ll->rx_skb);
 379         } else {
 380                 ll->rx_state = HCILL_W4_DATA;
 381                 ll->rx_count = len;
 382                 return len;
 383         }
 384
 385         ll->rx_state = HCILL_W4_PACKET_TYPE;
 386         ll->rx_skb   = NULL;
 387         ll->rx_count = 0;
 388
 389         return 0;
 390 }
 391
 392 /* Recv data */
 393 static int ll_recv(struct hci_uart *hu, const void *data, int count)
 394 {
 395         struct ll_struct *ll = hu->priv;
 396         const char *ptr;
 397         struct hci_event_hdr *eh;
 398         struct hci_acl_hdr   *ah;
 399         struct hci_sco_hdr   *sh;
 400         int len, type, dlen;
 401
 402         BT_DBG("hu %p count %d rx_state %ld rx_count %ld", hu, count, ll->rx_state, ll->rx_count);
 403
 404         ptr = data;
 405         while (count) {
 406                 if (ll->rx_count) {
 407                         len = min_t(unsigned int, ll->rx_count, count);
 408                         memcpy(skb_put(ll->rx_skb, len), ptr, len);
 409                         ll->rx_count -= len; count -= len; ptr += len;
 410
 411                         if (ll->rx_count)
 412                                 continue;
 413
 414                         switch (ll->rx_state) {
 415                         case HCILL_W4_DATA:
 416                                 BT_DBG("Complete data");
 417                                 hci_recv_frame(hu->hdev, ll->rx_skb);
 418
 419                                 ll->rx_state = HCILL_W4_PACKET_TYPE;
 420                                 ll->rx_skb = NULL;
 421                                 continue;
 422
 423                         case HCILL_W4_EVENT_HDR:
 424                                 eh = hci_event_hdr(ll->rx_skb);
 425
 426                                 BT_DBG("Event header: evt 0x%2.2x plen %d", eh->evt, eh->plen);
 427
 428                                 ll_check_data_len(hu->hdev, ll, eh->plen);
 429                                 continue;
 430
 431                         case HCILL_W4_ACL_HDR:
 432                                 ah = hci_acl_hdr(ll->rx_skb);
 433                                 dlen = __le16_to_cpu(ah->dlen);
 434
 435                                 BT_DBG("ACL header: dlen %d", dlen);
 436
 437                                 ll_check_data_len(hu->hdev, ll, dlen);
 438                                 continue;
 439
 440                         case HCILL_W4_SCO_HDR:
 441                                 sh = hci_sco_hdr(ll->rx_skb);
 442
 443                                 BT_DBG("SCO header: dlen %d", sh->dlen);
 444
 445                                 ll_check_data_len(hu->hdev, ll, sh->dlen);
 446                                 continue;
 447                         }
 448                 }
 449
 450                 /* HCILL_W4_PACKET_TYPE */
 451                 switch (*ptr) {
 452                 case HCI_EVENT_PKT:
 453                         BT_DBG("Event packet");
 454                         ll->rx_state = HCILL_W4_EVENT_HDR;
 455                         ll->rx_count = HCI_EVENT_HDR_SIZE;
 456                         type = HCI_EVENT_PKT;
 457                         break;
 458
 459                 case HCI_ACLDATA_PKT:
 460                         BT_DBG("ACL packet");
 461                         ll->rx_state = HCILL_W4_ACL_HDR;
 462                         ll->rx_count = HCI_ACL_HDR_SIZE;
 463                         type = HCI_ACLDATA_PKT;
 464                         break;
 465
 466                 case HCI_SCODATA_PKT:
 467                         BT_DBG("SCO packet");
 468                         ll->rx_state = HCILL_W4_SCO_HDR;
 469                         ll->rx_count = HCI_SCO_HDR_SIZE;
 470                         type = HCI_SCODATA_PKT;
 471                         break;
 472
 473                 /* HCILL signals */
 474                 case HCILL_GO_TO_SLEEP_IND:
 475                         BT_DBG("HCILL_GO_TO_SLEEP_IND packet");
 476                         ll_device_want_to_sleep(hu);
 477                         ptr++; count--;
 478                         continue;
 479
 480                 case HCILL_GO_TO_SLEEP_ACK:
 481                         /* shouldn't happen */
 482                         BT_ERR("received HCILL_GO_TO_SLEEP_ACK (in state %ld)", ll->hcill_state);
 483                         ptr++; count--;
 484                         continue;
 485
 486                 case HCILL_WAKE_UP_IND:
 487                         BT_DBG("HCILL_WAKE_UP_IND packet");
 488                         ll_device_want_to_wakeup(hu);
 489                         ptr++; count--;
 490                         continue;
 491
 492                 case HCILL_WAKE_UP_ACK:
 493                         BT_DBG("HCILL_WAKE_UP_ACK packet");
 494                         ll_device_woke_up(hu);
 495                         ptr++; count--;
 496                         continue;
 497
 498                 default:
 499                         BT_ERR("Unknown HCI packet type %2.2x", (__u8)*ptr);
 500                         hu->hdev->stat.err_rx++;
 501                         ptr++; count--;
 502                         continue;
 503                 }
 504
 505                 ptr++; count--;
 506
 507                 /* Allocate packet */
 508                 ll->rx_skb = bt_skb_alloc(HCI_MAX_FRAME_SIZE, GFP_ATOMIC);
 509                 if (!ll->rx_skb) {
 510                         BT_ERR("Can't allocate mem for new packet");
 511                         ll->rx_state = HCILL_W4_PACKET_TYPE;
 512                         ll->rx_count = 0;
 513                         return -ENOMEM;
 514                 }
 515
 516                 hci_skb_pkt_type(ll->rx_skb) = type;
 517         }
 518
 519         return count;
 520 }
 521
 522 static struct sk_buff *ll_dequeue(struct hci_uart *hu)
 523 {
 524         struct ll_struct *ll = hu->priv;
 525         return skb_dequeue(&ll->txq);
 526 }
 527
 528 #if IS_ENABLED(CONFIG_SERIAL_DEV_BUS)
 529 static int read_local_version(struct hci_dev *hdev)
 530 {
 531         int err = 0;
 532         unsigned short version = 0;
 533         struct sk_buff *skb;
 534         struct hci_rp_read_local_version *ver;
 535
 536         skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL, HCI_INIT_TIMEOUT);
 537         if (IS_ERR(skb)) {
 538                 bt_dev_err(hdev, "Reading TI version information failed (%ld)",
 539                            PTR_ERR(skb));
 540                 return PTR_ERR(skb);
 541         }
 542         if (skb->len != sizeof(*ver)) {
 543                 err = -EILSEQ;
 544                 goto out;
 545         }
 546
 547         ver = (struct hci_rp_read_local_version *)skb->data;
 548         if (le16_to_cpu(ver->manufacturer) != 13) {
 549                 err = -ENODEV;
 550                 goto out;
 551         }
 552
 553         version = le16_to_cpu(ver->lmp_subver);
 554
 555 out:
 556         if (err) bt_dev_err(hdev, "Failed to read TI version info: %d", err);
 557         kfree_skb(skb);
 558         return err ? err : version;
 559 }
 560
 561 /**
 562  * download_firmware -
 563  *      internal function which parses through the .bts firmware
 564  *      script file intreprets SEND, DELAY actions only as of now
 565  */
 566 static int download_firmware(struct ll_device *lldev)
 567 {
 568         unsigned short chip, min_ver, maj_ver;
 569         int version, err, len;
 570         unsigned char *ptr, *action_ptr;
 571         unsigned char bts_scr_name[40]; /* 40 char long bts scr name? */
 572         const struct firmware *fw;
 573         struct sk_buff *skb;
 574         struct hci_command *cmd;
 575
 576         version = read_local_version(lldev->hu.hdev);
 577         if (version < 0)
 578                 return version;
 579
 580         chip = (version & 0x7C00) >> 10;
 581         min_ver = (version & 0x007F);
 582         maj_ver = (version & 0x0380) >> 7;
 583         if (version & 0x8000)
 584                 maj_ver |= 0x0008;
 585
 586         snprintf(bts_scr_name, sizeof(bts_scr_name),
 587                  "ti-connectivity/TIInit_%d.%d.%d.bts",
 588                  chip, maj_ver, min_ver);
 589
 590         err = request_firmware(&fw, bts_scr_name, &lldev->serdev->dev);
 591         if (err || !fw->data || !fw->size) {
 592                 bt_dev_err(lldev->hu.hdev, "request_firmware failed(errno %d) for %s",
 593                            err, bts_scr_name);
 594                 return -EINVAL;
 595         }
 596         ptr = (void *)fw->data;
 597         len = fw->size;
 598         /* bts_header to remove out magic number and
 599          * version
 600          */
 601         ptr += sizeof(struct bts_header);
 602         len -= sizeof(struct bts_header);
 603
 604         while (len > 0 && ptr) {
 605                 bt_dev_dbg(lldev->hu.hdev, " action size %d, type %d ",
 606                            ((struct bts_action *)ptr)->size,
 607                            ((struct bts_action *)ptr)->type);
 608
 609                 action_ptr = &(((struct bts_action *)ptr)->data[0]);
 610
 611                 switch (((struct bts_action *)ptr)->type) {
 612                 case ACTION_SEND_COMMAND:       /* action send */
 613                         bt_dev_dbg(lldev->hu.hdev, "S");
 614                         cmd = (struct hci_command *)action_ptr;
 615                         if (cmd->opcode == 0xff36) {
 616                                 /* ignore remote change
 617                                  * baud rate HCI VS command */
 618                                 bt_dev_warn(lldev->hu.hdev, "change remote baud rate command in firmware");
 619                                 break;
 620                         }
 621                         if (cmd->prefix != 1)
 622                                 bt_dev_dbg(lldev->hu.hdev, "command type %d\n", cmd->prefix);
 623
 624                         skb = __hci_cmd_sync(lldev->hu.hdev, cmd->opcode, cmd->plen, &cmd->speed, HCI_INIT_TIMEOUT);
 625                         if (IS_ERR(skb)) {
 626                                 bt_dev_err(lldev->hu.hdev, "send command failed\n");
 627                                 goto out_rel_fw;
 628                         }
 629                         kfree_skb(skb);
 630                         break;
 631                 case ACTION_WAIT_EVENT:  /* wait */
 632                         /* no need to wait as command was synchronous */
 633                         bt_dev_dbg(lldev->hu.hdev, "W");
 634                         break;
 635                 case ACTION_DELAY:      /* sleep */
 636                         bt_dev_info(lldev->hu.hdev, "sleep command in scr");
 637                         mdelay(((struct bts_action_delay *)action_ptr)->msec);
 638                         break;
 639                 }
 640                 len -= (sizeof(struct bts_action) +
 641                         ((struct bts_action *)ptr)->size);
 642                 ptr += sizeof(struct bts_action) +
 643                         ((struct bts_action *)ptr)->size;
 644         }
 645
 646 out_rel_fw:
 647         /* fw download complete */
 648         release_firmware(fw);
 649         return err;
 650 }
 651
 652 static int ll_setup(struct hci_uart *hu)
 653 {
 654         int err, retry = 3;
 655         struct ll_device *lldev;
 656         struct serdev_device *serdev = hu->serdev;
 657         u32 speed;
 658
 659         if (!serdev)
 660                 return 0;
 661
 662         lldev = serdev_device_get_drvdata(serdev);
 663
 664         serdev_device_set_flow_control(serdev, true);
 665
 666         do {
 667                 /* Configure BT_EN to HIGH state */
 668                 gpiod_set_value_cansleep(lldev->enable_gpio, 0);
 669                 msleep(5);
 670                 gpiod_set_value_cansleep(lldev->enable_gpio, 1);
 671                 msleep(100);
 672
 673                 err = download_firmware(lldev);
 674                 if (!err)
 675                         break;
 676
 677                 /* Toggle BT_EN and retry */
 678                 bt_dev_err(hu->hdev, "download firmware failed, retrying...");
 679         } while (retry--);
 680
 681         if (err)
 682                 return err;
 683
 684         /* Operational speed if any */
 685         if (hu->oper_speed)
 686                 speed = hu->oper_speed;
 687         else if (hu->proto->oper_speed)
 688                 speed = hu->proto->oper_speed;
 689         else
 690                 speed = 0;
 691
 692         if (speed) {
 693                 struct sk_buff *skb = __hci_cmd_sync(hu->hdev, 0xff36, sizeof(speed), &speed, HCI_INIT_TIMEOUT);
 694                 if (!IS_ERR(skb)) {
 695                         kfree_skb(skb);
 696                         serdev_device_set_baudrate(serdev, speed);
 697                 }
 698         }
 699
 700         return 0;
 701 }
 702
 703 static const struct hci_uart_proto llp;
 704
 705 static int hci_ti_probe(struct serdev_device *serdev)
 706 {
 707         struct hci_uart *hu;
 708         struct ll_device *lldev;
 709         u32 max_speed = 3000000;
 710
 711         lldev = devm_kzalloc(&serdev->dev, sizeof(struct ll_device), GFP_KERNEL);
 712         if (!lldev)
 713                 return -ENOMEM;
 714         hu = &lldev->hu;
 715
 716         serdev_device_set_drvdata(serdev, lldev);
 717         lldev->serdev = hu->serdev = serdev;
 718
 719         lldev->enable_gpio = devm_gpiod_get_optional(&serdev->dev, "enable", GPIOD_OUT_LOW);
 720         if (IS_ERR(lldev->enable_gpio))
 721                 return PTR_ERR(lldev->enable_gpio);
 722
 723         of_property_read_u32(serdev->dev.of_node, "max-speed", &max_speed);
 724         hci_uart_set_speeds(hu, 115200, max_speed);
 725
 726         return hci_uart_register_device(hu, &llp);
 727 }
 728
 729 static void hci_ti_remove(struct serdev_device *serdev)
 730 {
 731         struct ll_device *lldev = serdev_device_get_drvdata(serdev);
 732         struct hci_uart *hu = &lldev->hu;
 733         struct hci_dev *hdev = hu->hdev;
 734
 735         cancel_work_sync(&hu->write_work);
 736
 737         hci_unregister_dev(hdev);
 738         hci_free_dev(hdev);
 739         hu->proto->close(hu);
 740 }
 741
 742 static const struct of_device_id hci_ti_of_match[] = {
 743         { .compatible = "ti,wl1831-st" },
 744         { .compatible = "ti,wl1835-st" },
 745         { .compatible = "ti,wl1837-st" },
 746         {},
 747 };
 748 MODULE_DEVICE_TABLE(of, hci_ti_of_match);
 749
 750 static struct serdev_device_driver hci_ti_drv = {
 751         .driver         = {
 752                 .name   = "hci-ti",
 753                 .of_match_table = of_match_ptr(hci_ti_of_match),
 754         },
 755         .probe  = hci_ti_probe,
 756         .remove = hci_ti_remove,
 757 };
 758 #else
 759 #define ll_setup NULL
 760 #endif
 761
 762 static const struct hci_uart_proto llp = {
 763         .id             = HCI_UART_LL,
 764         .name           = "LL",
 765         .setup          = ll_setup,
 766         .open           = ll_open,
 767         .close          = ll_close,
 768         .recv           = ll_recv,
 769         .enqueue        = ll_enqueue,
 770         .dequeue        = ll_dequeue,
 771         .flush          = ll_flush,
 772 };
 773
 774 int __init ll_init(void)
 775 {
 776         serdev_device_driver_register(&hci_ti_drv);
 777
 778         return hci_uart_register_proto(&llp);
 779 }
 780
 781 int __exit ll_deinit(void)
 782 {
 783         serdev_device_driver_unregister(&hci_ti_drv);
 784
 785         return hci_uart_unregister_proto(&llp);
 786 }