linux/drivers/bluetooth/hci_ll.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *  Texas Instruments' Bluetooth HCILL UART protocol
   4 *
   5 *  HCILL (HCI Low Level) is a Texas Instruments' power management
   6 *  protocol extension to H4.
   7 *
   8 *  Copyright (C) 2007 Texas Instruments, Inc.
   9 *
  10 *  Written by Ohad Ben-Cohen <ohad@bencohen.org>
  11 *
  12 *  Acknowledgements:
  13 *  This file is based on hci_h4.c, which was written
  14 *  by Maxim Krasnyansky and Marcel Holtmann.
  15 */
  16
  17#include <linux/module.h>
  18#include <linux/kernel.h>
  19
  20#include <linux/init.h>
  21#include <linux/sched.h>
  22#include <linux/types.h>
  23#include <linux/fcntl.h>
  24#include <linux/firmware.h>
  25#include <linux/interrupt.h>
  26#include <linux/ptrace.h>
  27#include <linux/poll.h>
  28
  29#include <linux/slab.h>
  30#include <linux/errno.h>
  31#include <linux/string.h>
  32#include <linux/signal.h>
  33#include <linux/ioctl.h>
  34#include <linux/of.h>
  35#include <linux/serdev.h>
  36#include <linux/skbuff.h>
  37#include <linux/ti_wilink_st.h>
  38#include <linux/clk.h>
  39
  40#include <net/bluetooth/bluetooth.h>
  41#include <net/bluetooth/hci_core.h>
  42#include <linux/gpio/consumer.h>
  43#include <linux/nvmem-consumer.h>
  44
  45#include "hci_uart.h"
  46
  47/* Vendor-specific HCI commands */
  48#define HCI_VS_WRITE_BD_ADDR                    0xfc06
  49#define HCI_VS_UPDATE_UART_HCI_BAUDRATE         0xff36
  50
  51/* HCILL commands */
  52#define HCILL_GO_TO_SLEEP_IND   0x30
  53#define HCILL_GO_TO_SLEEP_ACK   0x31
  54#define HCILL_WAKE_UP_IND       0x32
  55#define HCILL_WAKE_UP_ACK       0x33
  56
  57/* HCILL states */
  58enum hcill_states_e {
  59        HCILL_ASLEEP,
  60        HCILL_ASLEEP_TO_AWAKE,
  61        HCILL_AWAKE,
  62        HCILL_AWAKE_TO_ASLEEP
  63};
  64
  65struct ll_device {
  66        struct hci_uart hu;
  67        struct serdev_device *serdev;
  68        struct gpio_desc *enable_gpio;
  69        struct clk *ext_clk;
  70        bdaddr_t bdaddr;
  71};
  72
  73struct ll_struct {
  74        struct sk_buff *rx_skb;
  75        struct sk_buff_head txq;
  76        spinlock_t hcill_lock;          /* HCILL state lock     */
  77        unsigned long hcill_state;      /* HCILL power state    */
  78        struct sk_buff_head tx_wait_q;  /* HCILL wait queue     */
  79};
  80
  81/*
  82 * Builds and sends an HCILL command packet.
  83 * These are very simple packets with only 1 cmd byte
  84 */
  85static int send_hcill_cmd(u8 cmd, struct hci_uart *hu)
  86{
  87        int err = 0;
  88        struct sk_buff *skb = NULL;
  89        struct ll_struct *ll = hu->priv;
  90
  91        BT_DBG("hu %p cmd 0x%x", hu, cmd);
  92
  93        /* allocate packet */
  94        skb = bt_skb_alloc(1, GFP_ATOMIC);
  95        if (!skb) {
  96                BT_ERR("cannot allocate memory for HCILL packet");
  97                err = -ENOMEM;
  98                goto out;
  99        }
 100
 101        /* prepare packet */
 102        skb_put_u8(skb, cmd);
 103
 104        /* send packet */
 105        skb_queue_tail(&ll->txq, skb);
 106out:
 107        return err;
 108}
 109
 110/* Initialize protocol */
 111static int ll_open(struct hci_uart *hu)
 112{
 113        struct ll_struct *ll;
 114
 115        BT_DBG("hu %p", hu);
 116
 117        ll = kzalloc(sizeof(*ll), GFP_KERNEL);
 118        if (!ll)
 119                return -ENOMEM;
 120
 121        skb_queue_head_init(&ll->txq);
 122        skb_queue_head_init(&ll->tx_wait_q);
 123        spin_lock_init(&ll->hcill_lock);
 124
 125        ll->hcill_state = HCILL_AWAKE;
 126
 127        hu->priv = ll;
 128
 129        if (hu->serdev) {
 130                struct ll_device *lldev = serdev_device_get_drvdata(hu->serdev);
 131
 132                if (!IS_ERR(lldev->ext_clk))
 133                        clk_prepare_enable(lldev->ext_clk);
 134        }
 135
 136        return 0;
 137}
 138
 139/* Flush protocol data */
 140static int ll_flush(struct hci_uart *hu)
 141{
 142        struct ll_struct *ll = hu->priv;
 143
 144        BT_DBG("hu %p", hu);
 145
 146        skb_queue_purge(&ll->tx_wait_q);
 147        skb_queue_purge(&ll->txq);
 148
 149        return 0;
 150}
 151
 152/* Close protocol */
 153static int ll_close(struct hci_uart *hu)
 154{
 155        struct ll_struct *ll = hu->priv;
 156
 157        BT_DBG("hu %p", hu);
 158
 159        skb_queue_purge(&ll->tx_wait_q);
 160        skb_queue_purge(&ll->txq);
 161
 162        kfree_skb(ll->rx_skb);
 163
 164        if (hu->serdev) {
 165                struct ll_device *lldev = serdev_device_get_drvdata(hu->serdev);
 166
 167                gpiod_set_value_cansleep(lldev->enable_gpio, 0);
 168
 169                clk_disable_unprepare(lldev->ext_clk);
 170        }
 171
 172        hu->priv = NULL;
 173
 174        kfree(ll);
 175
 176        return 0;
 177}
 178
 179/*
 180 * internal function, which does common work of the device wake up process:
 181 * 1. places all pending packets (waiting in tx_wait_q list) in txq list.
 182 * 2. changes internal state to HCILL_AWAKE.
 183 * Note: assumes that hcill_lock spinlock is taken,
 184 * shouldn't be called otherwise!
 185 */
 186static void __ll_do_awake(struct ll_struct *ll)
 187{
 188        struct sk_buff *skb = NULL;
 189
 190        while ((skb = skb_dequeue(&ll->tx_wait_q)))
 191                skb_queue_tail(&ll->txq, skb);
 192
 193        ll->hcill_state = HCILL_AWAKE;
 194}
 195
 196/*
 197 * Called upon a wake-up-indication from the device
 198 */
 199static void ll_device_want_to_wakeup(struct hci_uart *hu)
 200{
 201        unsigned long flags;
 202        struct ll_struct *ll = hu->priv;
 203
 204        BT_DBG("hu %p", hu);
 205
 206        /* lock hcill state */
 207        spin_lock_irqsave(&ll->hcill_lock, flags);
 208
 209        switch (ll->hcill_state) {
 210        case HCILL_ASLEEP_TO_AWAKE:
 211                /*
 212                 * This state means that both the host and the BRF chip
 213                 * have simultaneously sent a wake-up-indication packet.
 214                 * Traditionally, in this case, receiving a wake-up-indication
 215                 * was enough and an additional wake-up-ack wasn't needed.
 216                 * This has changed with the BRF6350, which does require an
 217                 * explicit wake-up-ack. Other BRF versions, which do not
 218                 * require an explicit ack here, do accept it, thus it is
 219                 * perfectly safe to always send one.
 220                 */
 221                BT_DBG("dual wake-up-indication");
 222                fallthrough;
 223        case HCILL_ASLEEP:
 224                /* acknowledge device wake up */
 225                if (send_hcill_cmd(HCILL_WAKE_UP_ACK, hu) < 0) {
 226                        BT_ERR("cannot acknowledge device wake up");
 227                        goto out;
 228                }
 229                break;
 230        default:
 231                /* any other state is illegal */
 232                BT_ERR("received HCILL_WAKE_UP_IND in state %ld",
 233                       ll->hcill_state);
 234                break;
 235        }
 236
 237        /* send pending packets and change state to HCILL_AWAKE */
 238        __ll_do_awake(ll);
 239
 240out:
 241        spin_unlock_irqrestore(&ll->hcill_lock, flags);
 242
 243        /* actually send the packets */
 244        hci_uart_tx_wakeup(hu);
 245}
 246
 247/*
 248 * Called upon a sleep-indication from the device
 249 */
 250static void ll_device_want_to_sleep(struct hci_uart *hu)
 251{
 252        unsigned long flags;
 253        struct ll_struct *ll = hu->priv;
 254
 255        BT_DBG("hu %p", hu);
 256
 257        /* lock hcill state */
 258        spin_lock_irqsave(&ll->hcill_lock, flags);
 259
 260        /* sanity check */
 261        if (ll->hcill_state != HCILL_AWAKE)
 262                BT_ERR("ERR: HCILL_GO_TO_SLEEP_IND in state %ld",
 263                       ll->hcill_state);
 264
 265        /* acknowledge device sleep */
 266        if (send_hcill_cmd(HCILL_GO_TO_SLEEP_ACK, hu) < 0) {
 267                BT_ERR("cannot acknowledge device sleep");
 268                goto out;
 269        }
 270
 271        /* update state */
 272        ll->hcill_state = HCILL_ASLEEP;
 273
 274out:
 275        spin_unlock_irqrestore(&ll->hcill_lock, flags);
 276
 277        /* actually send the sleep ack packet */
 278        hci_uart_tx_wakeup(hu);
 279}
 280
 281/*
 282 * Called upon wake-up-acknowledgement from the device
 283 */
 284static void ll_device_woke_up(struct hci_uart *hu)
 285{
 286        unsigned long flags;
 287        struct ll_struct *ll = hu->priv;
 288
 289        BT_DBG("hu %p", hu);
 290
 291        /* lock hcill state */
 292        spin_lock_irqsave(&ll->hcill_lock, flags);
 293
 294        /* sanity check */
 295        if (ll->hcill_state != HCILL_ASLEEP_TO_AWAKE)
 296                BT_ERR("received HCILL_WAKE_UP_ACK in state %ld",
 297                       ll->hcill_state);
 298
 299        /* send pending packets and change state to HCILL_AWAKE */
 300        __ll_do_awake(ll);
 301
 302        spin_unlock_irqrestore(&ll->hcill_lock, flags);
 303
 304        /* actually send the packets */
 305        hci_uart_tx_wakeup(hu);
 306}
 307
 308/* Enqueue frame for transmittion (padding, crc, etc) */
 309/* may be called from two simultaneous tasklets */
 310static int ll_enqueue(struct hci_uart *hu, struct sk_buff *skb)
 311{
 312        unsigned long flags = 0;
 313        struct ll_struct *ll = hu->priv;
 314
 315        BT_DBG("hu %p skb %p", hu, skb);
 316
 317        /* Prepend skb with frame type */
 318        memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);
 319
 320        /* lock hcill state */
 321        spin_lock_irqsave(&ll->hcill_lock, flags);
 322
 323        /* act according to current state */
 324        switch (ll->hcill_state) {
 325        case HCILL_AWAKE:
 326                BT_DBG("device awake, sending normally");
 327                skb_queue_tail(&ll->txq, skb);
 328                break;
 329        case HCILL_ASLEEP:
 330                BT_DBG("device asleep, waking up and queueing packet");
 331                /* save packet for later */
 332                skb_queue_tail(&ll->tx_wait_q, skb);
 333                /* awake device */
 334                if (send_hcill_cmd(HCILL_WAKE_UP_IND, hu) < 0) {
 335                        BT_ERR("cannot wake up device");
 336                        break;
 337                }
 338                ll->hcill_state = HCILL_ASLEEP_TO_AWAKE;
 339                break;
 340        case HCILL_ASLEEP_TO_AWAKE:
 341                BT_DBG("device waking up, queueing packet");
 342                /* transient state; just keep packet for later */
 343                skb_queue_tail(&ll->tx_wait_q, skb);
 344                break;
 345        default:
 346                BT_ERR("illegal hcill state: %ld (losing packet)",
 347                       ll->hcill_state);
 348                kfree_skb(skb);
 349                break;
 350        }
 351
 352        spin_unlock_irqrestore(&ll->hcill_lock, flags);
 353
 354        return 0;
 355}
 356
 357static int ll_recv_frame(struct hci_dev *hdev, struct sk_buff *skb)
 358{
 359        struct hci_uart *hu = hci_get_drvdata(hdev);
 360        struct ll_struct *ll = hu->priv;
 361
 362        switch (hci_skb_pkt_type(skb)) {
 363        case HCILL_GO_TO_SLEEP_IND:
 364                BT_DBG("HCILL_GO_TO_SLEEP_IND packet");
 365                ll_device_want_to_sleep(hu);
 366                break;
 367        case HCILL_GO_TO_SLEEP_ACK:
 368                /* shouldn't happen */
 369                bt_dev_err(hdev, "received HCILL_GO_TO_SLEEP_ACK in state %ld",
 370                           ll->hcill_state);
 371                break;
 372        case HCILL_WAKE_UP_IND:
 373                BT_DBG("HCILL_WAKE_UP_IND packet");
 374                ll_device_want_to_wakeup(hu);
 375                break;
 376        case HCILL_WAKE_UP_ACK:
 377                BT_DBG("HCILL_WAKE_UP_ACK packet");
 378                ll_device_woke_up(hu);
 379                break;
 380        }
 381
 382        kfree_skb(skb);
 383        return 0;
 384}
 385
 386#define LL_RECV_SLEEP_IND \
 387        .type = HCILL_GO_TO_SLEEP_IND, \
 388        .hlen = 0, \
 389        .loff = 0, \
 390        .lsize = 0, \
 391        .maxlen = 0
 392
 393#define LL_RECV_SLEEP_ACK \
 394        .type = HCILL_GO_TO_SLEEP_ACK, \
 395        .hlen = 0, \
 396        .loff = 0, \
 397        .lsize = 0, \
 398        .maxlen = 0
 399
 400#define LL_RECV_WAKE_IND \
 401        .type = HCILL_WAKE_UP_IND, \
 402        .hlen = 0, \
 403        .loff = 0, \
 404        .lsize = 0, \
 405        .maxlen = 0
 406
 407#define LL_RECV_WAKE_ACK \
 408        .type = HCILL_WAKE_UP_ACK, \
 409        .hlen = 0, \
 410        .loff = 0, \
 411        .lsize = 0, \
 412        .maxlen = 0
 413
 414static const struct h4_recv_pkt ll_recv_pkts[] = {
 415        { H4_RECV_ACL,       .recv = hci_recv_frame },
 416        { H4_RECV_SCO,       .recv = hci_recv_frame },
 417        { H4_RECV_EVENT,     .recv = hci_recv_frame },
 418        { LL_RECV_SLEEP_IND, .recv = ll_recv_frame  },
 419        { LL_RECV_SLEEP_ACK, .recv = ll_recv_frame  },
 420        { LL_RECV_WAKE_IND,  .recv = ll_recv_frame  },
 421        { LL_RECV_WAKE_ACK,  .recv = ll_recv_frame  },
 422};
 423
 424/* Recv data */
 425static int ll_recv(struct hci_uart *hu, const void *data, int count)
 426{
 427        struct ll_struct *ll = hu->priv;
 428
 429        if (!test_bit(HCI_UART_REGISTERED, &hu->flags))
 430                return -EUNATCH;
 431
 432        ll->rx_skb = h4_recv_buf(hu->hdev, ll->rx_skb, data, count,
 433                                 ll_recv_pkts, ARRAY_SIZE(ll_recv_pkts));
 434        if (IS_ERR(ll->rx_skb)) {
 435                int err = PTR_ERR(ll->rx_skb);
 436                bt_dev_err(hu->hdev, "Frame reassembly failed (%d)", err);
 437                ll->rx_skb = NULL;
 438                return err;
 439        }
 440
 441        return count;
 442}
 443
 444static struct sk_buff *ll_dequeue(struct hci_uart *hu)
 445{
 446        struct ll_struct *ll = hu->priv;
 447
 448        return skb_dequeue(&ll->txq);
 449}
 450
 451#if IS_ENABLED(CONFIG_SERIAL_DEV_BUS)
 452static int read_local_version(struct hci_dev *hdev)
 453{
 454        int err = 0;
 455        unsigned short version = 0;
 456        struct sk_buff *skb;
 457        struct hci_rp_read_local_version *ver;
 458
 459        skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
 460                             HCI_INIT_TIMEOUT);
 461        if (IS_ERR(skb)) {
 462                bt_dev_err(hdev, "Reading TI version information failed (%ld)",
 463                           PTR_ERR(skb));
 464                return PTR_ERR(skb);
 465        }
 466        if (skb->len != sizeof(*ver)) {
 467                err = -EILSEQ;
 468                goto out;
 469        }
 470
 471        ver = (struct hci_rp_read_local_version *)skb->data;
 472        if (le16_to_cpu(ver->manufacturer) != 13) {
 473                err = -ENODEV;
 474                goto out;
 475        }
 476
 477        version = le16_to_cpu(ver->lmp_subver);
 478
 479out:
 480        if (err)
 481                bt_dev_err(hdev, "Failed to read TI version info: %d", err);
 482        kfree_skb(skb);
 483        return err ? err : version;
 484}
 485
 486static int send_command_from_firmware(struct ll_device *lldev,
 487                                      struct hci_command *cmd)
 488{
 489        struct sk_buff *skb;
 490
 491        if (cmd->opcode == HCI_VS_UPDATE_UART_HCI_BAUDRATE) {
 492                /* ignore remote change
 493                 * baud rate HCI VS command
 494                 */
 495                bt_dev_warn(lldev->hu.hdev,
 496                            "change remote baud rate command in firmware");
 497                return 0;
 498        }
 499        if (cmd->prefix != 1)
 500                bt_dev_dbg(lldev->hu.hdev, "command type %d", cmd->prefix);
 501
 502        skb = __hci_cmd_sync(lldev->hu.hdev, cmd->opcode, cmd->plen,
 503                             &cmd->speed, HCI_INIT_TIMEOUT);
 504        if (IS_ERR(skb)) {
 505                bt_dev_err(lldev->hu.hdev, "send command failed");
 506                return PTR_ERR(skb);
 507        }
 508        kfree_skb(skb);
 509        return 0;
 510}
 511
 512/**
 513 * download_firmware -
 514 *      internal function which parses through the .bts firmware
 515 *      script file intreprets SEND, DELAY actions only as of now
 516 */
 517static int download_firmware(struct ll_device *lldev)
 518{
 519        unsigned short chip, min_ver, maj_ver;
 520        int version, err, len;
 521        unsigned char *ptr, *action_ptr;
 522        unsigned char bts_scr_name[40]; /* 40 char long bts scr name? */
 523        const struct firmware *fw;
 524        struct hci_command *cmd;
 525
 526        version = read_local_version(lldev->hu.hdev);
 527        if (version < 0)
 528                return version;
 529
 530        chip = (version & 0x7C00) >> 10;
 531        min_ver = (version & 0x007F);
 532        maj_ver = (version & 0x0380) >> 7;
 533        if (version & 0x8000)
 534                maj_ver |= 0x0008;
 535
 536        snprintf(bts_scr_name, sizeof(bts_scr_name),
 537                 "ti-connectivity/TIInit_%d.%d.%d.bts",
 538                 chip, maj_ver, min_ver);
 539
 540        err = request_firmware(&fw, bts_scr_name, &lldev->serdev->dev);
 541        if (err || !fw->data || !fw->size) {
 542                bt_dev_err(lldev->hu.hdev, "request_firmware failed(errno %d) for %s",
 543                           err, bts_scr_name);
 544                return -EINVAL;
 545        }
 546        ptr = (void *)fw->data;
 547        len = fw->size;
 548        /* bts_header to remove out magic number and
 549         * version
 550         */
 551        ptr += sizeof(struct bts_header);
 552        len -= sizeof(struct bts_header);
 553
 554        while (len > 0 && ptr) {
 555                bt_dev_dbg(lldev->hu.hdev, " action size %d, type %d ",
 556                           ((struct bts_action *)ptr)->size,
 557                           ((struct bts_action *)ptr)->type);
 558
 559                action_ptr = &(((struct bts_action *)ptr)->data[0]);
 560
 561                switch (((struct bts_action *)ptr)->type) {
 562                case ACTION_SEND_COMMAND:       /* action send */
 563                        bt_dev_dbg(lldev->hu.hdev, "S");
 564                        cmd = (struct hci_command *)action_ptr;
 565                        err = send_command_from_firmware(lldev, cmd);
 566                        if (err)
 567                                goto out_rel_fw;
 568                        break;
 569                case ACTION_WAIT_EVENT:  /* wait */
 570                        /* no need to wait as command was synchronous */
 571                        bt_dev_dbg(lldev->hu.hdev, "W");
 572                        break;
 573                case ACTION_DELAY:      /* sleep */
 574                        bt_dev_info(lldev->hu.hdev, "sleep command in scr");
 575                        msleep(((struct bts_action_delay *)action_ptr)->msec);
 576                        break;
 577                }
 578                len -= (sizeof(struct bts_action) +
 579                        ((struct bts_action *)ptr)->size);
 580                ptr += sizeof(struct bts_action) +
 581                        ((struct bts_action *)ptr)->size;
 582        }
 583
 584out_rel_fw:
 585        /* fw download complete */
 586        release_firmware(fw);
 587        return err;
 588}
 589
 590static int ll_set_bdaddr(struct hci_dev *hdev, const bdaddr_t *bdaddr)
 591{
 592        bdaddr_t bdaddr_swapped;
 593        struct sk_buff *skb;
 594
 595        /* HCI_VS_WRITE_BD_ADDR (at least on a CC2560A chip) expects the BD
 596         * address to be MSB first, but bdaddr_t has the convention of being
 597         * LSB first.
 598         */
 599        baswap(&bdaddr_swapped, bdaddr);
 600        skb = __hci_cmd_sync(hdev, HCI_VS_WRITE_BD_ADDR, sizeof(bdaddr_t),
 601                             &bdaddr_swapped, HCI_INIT_TIMEOUT);
 602        if (!IS_ERR(skb))
 603                kfree_skb(skb);
 604
 605        return PTR_ERR_OR_ZERO(skb);
 606}
 607
 608static int ll_setup(struct hci_uart *hu)
 609{
 610        int err, retry = 3;
 611        struct ll_device *lldev;
 612        struct serdev_device *serdev = hu->serdev;
 613        u32 speed;
 614
 615        if (!serdev)
 616                return 0;
 617
 618        lldev = serdev_device_get_drvdata(serdev);
 619
 620        hu->hdev->set_bdaddr = ll_set_bdaddr;
 621
 622        serdev_device_set_flow_control(serdev, true);
 623
 624        do {
 625                /* Reset the Bluetooth device */
 626                gpiod_set_value_cansleep(lldev->enable_gpio, 0);
 627                msleep(5);
 628                gpiod_set_value_cansleep(lldev->enable_gpio, 1);
 629                mdelay(100);
 630                err = serdev_device_wait_for_cts(serdev, true, 200);
 631                if (err) {
 632                        bt_dev_err(hu->hdev, "Failed to get CTS");
 633                        return err;
 634                }
 635
 636                err = download_firmware(lldev);
 637                if (!err)
 638                        break;
 639
 640                /* Toggle BT_EN and retry */
 641                bt_dev_err(hu->hdev, "download firmware failed, retrying...");
 642        } while (retry--);
 643
 644        if (err)
 645                return err;
 646
 647        /* Set BD address if one was specified at probe */
 648        if (!bacmp(&lldev->bdaddr, BDADDR_NONE)) {
 649                /* This means that there was an error getting the BD address
 650                 * during probe, so mark the device as having a bad address.
 651                 */
 652                set_bit(HCI_QUIRK_INVALID_BDADDR, &hu->hdev->quirks);
 653        } else if (bacmp(&lldev->bdaddr, BDADDR_ANY)) {
 654                err = ll_set_bdaddr(hu->hdev, &lldev->bdaddr);
 655                if (err)
 656                        set_bit(HCI_QUIRK_INVALID_BDADDR, &hu->hdev->quirks);
 657        }
 658
 659        /* Operational speed if any */
 660        if (hu->oper_speed)
 661                speed = hu->oper_speed;
 662        else if (hu->proto->oper_speed)
 663                speed = hu->proto->oper_speed;
 664        else
 665                speed = 0;
 666
 667        if (speed) {
 668                __le32 speed_le = cpu_to_le32(speed);
 669                struct sk_buff *skb;
 670
 671                skb = __hci_cmd_sync(hu->hdev, HCI_VS_UPDATE_UART_HCI_BAUDRATE,
 672                                     sizeof(speed_le), &speed_le,
 673                                     HCI_INIT_TIMEOUT);
 674                if (!IS_ERR(skb)) {
 675                        kfree_skb(skb);
 676                        serdev_device_set_baudrate(serdev, speed);
 677                }
 678        }
 679
 680        return 0;
 681}
 682
 683static const struct hci_uart_proto llp;
 684
 685static int hci_ti_probe(struct serdev_device *serdev)
 686{
 687        struct hci_uart *hu;
 688        struct ll_device *lldev;
 689        struct nvmem_cell *bdaddr_cell;
 690        u32 max_speed = 3000000;
 691
 692        lldev = devm_kzalloc(&serdev->dev, sizeof(struct ll_device), GFP_KERNEL);
 693        if (!lldev)
 694                return -ENOMEM;
 695        hu = &lldev->hu;
 696
 697        serdev_device_set_drvdata(serdev, lldev);
 698        lldev->serdev = hu->serdev = serdev;
 699
 700        lldev->enable_gpio = devm_gpiod_get_optional(&serdev->dev,
 701                                                     "enable",
 702                                                     GPIOD_OUT_LOW);
 703        if (IS_ERR(lldev->enable_gpio))
 704                return PTR_ERR(lldev->enable_gpio);
 705
 706        lldev->ext_clk = devm_clk_get(&serdev->dev, "ext_clock");
 707        if (IS_ERR(lldev->ext_clk) && PTR_ERR(lldev->ext_clk) != -ENOENT)
 708                return PTR_ERR(lldev->ext_clk);
 709
 710        of_property_read_u32(serdev->dev.of_node, "max-speed", &max_speed);
 711        hci_uart_set_speeds(hu, 115200, max_speed);
 712
 713        /* optional BD address from nvram */
 714        bdaddr_cell = nvmem_cell_get(&serdev->dev, "bd-address");
 715        if (IS_ERR(bdaddr_cell)) {
 716                int err = PTR_ERR(bdaddr_cell);
 717
 718                if (err == -EPROBE_DEFER)
 719                        return err;
 720
 721                /* ENOENT means there is no matching nvmem cell and ENOSYS
 722                 * means that nvmem is not enabled in the kernel configuration.
 723                 */
 724                if (err != -ENOENT && err != -ENOSYS) {
 725                        /* If there was some other error, give userspace a
 726                         * chance to fix the problem instead of failing to load
 727                         * the driver. Using BDADDR_NONE as a flag that is
 728                         * tested later in the setup function.
 729                         */
 730                        dev_warn(&serdev->dev,
 731                                 "Failed to get \"bd-address\" nvmem cell (%d)\n",
 732                                 err);
 733                        bacpy(&lldev->bdaddr, BDADDR_NONE);
 734                }
 735        } else {
 736                bdaddr_t *bdaddr;
 737                size_t len;
 738
 739                bdaddr = nvmem_cell_read(bdaddr_cell, &len);
 740                nvmem_cell_put(bdaddr_cell);
 741                if (IS_ERR(bdaddr)) {
 742                        dev_err(&serdev->dev, "Failed to read nvmem bd-address\n");
 743                        return PTR_ERR(bdaddr);
 744                }
 745                if (len != sizeof(bdaddr_t)) {
 746                        dev_err(&serdev->dev, "Invalid nvmem bd-address length\n");
 747                        kfree(bdaddr);
 748                        return -EINVAL;
 749                }
 750
 751                /* As per the device tree bindings, the value from nvmem is
 752                 * expected to be MSB first, but in the kernel it is expected
 753                 * that bdaddr_t is LSB first.
 754                 */
 755                baswap(&lldev->bdaddr, bdaddr);
 756                kfree(bdaddr);
 757        }
 758
 759        return hci_uart_register_device(hu, &llp);
 760}
 761
 762static void hci_ti_remove(struct serdev_device *serdev)
 763{
 764        struct ll_device *lldev = serdev_device_get_drvdata(serdev);
 765
 766        hci_uart_unregister_device(&lldev->hu);
 767}
 768
 769static const struct of_device_id hci_ti_of_match[] = {
 770        { .compatible = "ti,cc2560" },
 771        { .compatible = "ti,wl1271-st" },
 772        { .compatible = "ti,wl1273-st" },
 773        { .compatible = "ti,wl1281-st" },
 774        { .compatible = "ti,wl1283-st" },
 775        { .compatible = "ti,wl1285-st" },
 776        { .compatible = "ti,wl1801-st" },
 777        { .compatible = "ti,wl1805-st" },
 778        { .compatible = "ti,wl1807-st" },
 779        { .compatible = "ti,wl1831-st" },
 780        { .compatible = "ti,wl1835-st" },
 781        { .compatible = "ti,wl1837-st" },
 782        {},
 783};
 784MODULE_DEVICE_TABLE(of, hci_ti_of_match);
 785
 786static struct serdev_device_driver hci_ti_drv = {
 787        .driver         = {
 788                .name   = "hci-ti",
 789                .of_match_table = of_match_ptr(hci_ti_of_match),
 790        },
 791        .probe  = hci_ti_probe,
 792        .remove = hci_ti_remove,
 793};
 794#else
 795#define ll_setup NULL
 796#endif
 797
 798static const struct hci_uart_proto llp = {
 799        .id             = HCI_UART_LL,
 800        .name           = "LL",
 801        .setup          = ll_setup,
 802        .open           = ll_open,
 803        .close          = ll_close,
 804        .recv           = ll_recv,
 805        .enqueue        = ll_enqueue,
 806        .dequeue        = ll_dequeue,
 807        .flush          = ll_flush,
 808};
 809
 810int __init ll_init(void)
 811{
 812        serdev_device_driver_register(&hci_ti_drv);
 813
 814        return hci_uart_register_proto(&llp);
 815}
 816
 817int __exit ll_deinit(void)
 818{
 819        serdev_device_driver_unregister(&hci_ti_drv);
 820
 821        return hci_uart_unregister_proto(&llp);
 822}
 823