drivers/bluetooth/hci_ll.c

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