drivers/bluetooth/hci_ldisc.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *
   4  *  Bluetooth HCI UART driver
   5  *
   6  *  Copyright (C) 2000-2001  Qualcomm Incorporated
   7  *  Copyright (C) 2002-2003  Maxim Krasnyansky <maxk@qualcomm.com>
   8  *  Copyright (C) 2004-2005  Marcel Holtmann <marcel@holtmann.org>
   9  */
  10
  11 #include <linux/module.h>
  12
  13 #include <linux/kernel.h>
  14 #include <linux/init.h>
  15 #include <linux/types.h>
  16 #include <linux/fcntl.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/ptrace.h>
  19 #include <linux/poll.h>
  20
  21 #include <linux/slab.h>
  22 #include <linux/tty.h>
  23 #include <linux/errno.h>
  24 #include <linux/string.h>
  25 #include <linux/signal.h>
  26 #include <linux/ioctl.h>
  27 #include <linux/skbuff.h>
  28 #include <linux/firmware.h>
  29 #include <linux/serdev.h>
  30
  31 #include <net/bluetooth/bluetooth.h>
  32 #include <net/bluetooth/hci_core.h>
  33
  34 #include "btintel.h"
  35 #include "btbcm.h"
  36 #include "hci_uart.h"
  37
  38 #define VERSION "2.3"
  39
  40 static const struct hci_uart_proto *hup[HCI_UART_MAX_PROTO];
  41
  42 int hci_uart_register_proto(const struct hci_uart_proto *p)
  43 {
  44         if (p->id >= HCI_UART_MAX_PROTO)
  45                 return -EINVAL;
  46
  47         if (hup[p->id])
  48                 return -EEXIST;
  49
  50         hup[p->id] = p;
  51
  52         BT_INFO("HCI UART protocol %s registered", p->name);
  53
  54         return 0;
  55 }
  56
  57 int hci_uart_unregister_proto(const struct hci_uart_proto *p)
  58 {
  59         if (p->id >= HCI_UART_MAX_PROTO)
  60                 return -EINVAL;
  61
  62         if (!hup[p->id])
  63                 return -EINVAL;
  64
  65         hup[p->id] = NULL;
  66
  67         return 0;
  68 }
  69
  70 static const struct hci_uart_proto *hci_uart_get_proto(unsigned int id)
  71 {
  72         if (id >= HCI_UART_MAX_PROTO)
  73                 return NULL;
  74
  75         return hup[id];
  76 }
  77
  78 static inline void hci_uart_tx_complete(struct hci_uart *hu, int pkt_type)
  79 {
  80         struct hci_dev *hdev = hu->hdev;
  81
  82         /* Update HCI stat counters */
  83         switch (pkt_type) {
  84         case HCI_COMMAND_PKT:
  85                 hdev->stat.cmd_tx++;
  86                 break;
  87
  88         case HCI_ACLDATA_PKT:
  89                 hdev->stat.acl_tx++;
  90                 break;
  91
  92         case HCI_SCODATA_PKT:
  93                 hdev->stat.sco_tx++;
  94                 break;
  95         }
  96 }
  97
  98 static inline struct sk_buff *hci_uart_dequeue(struct hci_uart *hu)
  99 {
 100         struct sk_buff *skb = hu->tx_skb;
 101
 102         if (!skb) {
 103                 percpu_down_read(&hu->proto_lock);
 104
 105                 if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
 106                         skb = hu->proto->dequeue(hu);
 107
 108                 percpu_up_read(&hu->proto_lock);
 109         } else {
 110                 hu->tx_skb = NULL;
 111         }
 112
 113         return skb;
 114 }
 115
 116 int hci_uart_tx_wakeup(struct hci_uart *hu)
 117 {
 118         /* This may be called in an IRQ context, so we can't sleep. Therefore
 119          * we try to acquire the lock only, and if that fails we assume the
 120          * tty is being closed because that is the only time the write lock is
 121          * acquired. If, however, at some point in the future the write lock
 122          * is also acquired in other situations, then this must be revisited.
 123          */
 124         if (!percpu_down_read_trylock(&hu->proto_lock))
 125                 return 0;
 126
 127         if (!test_bit(HCI_UART_PROTO_READY, &hu->flags))
 128                 goto no_schedule;
 129
 130         set_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
 131         if (test_and_set_bit(HCI_UART_SENDING, &hu->tx_state))
 132                 goto no_schedule;
 133
 134         BT_DBG("");
 135
 136         schedule_work(&hu->write_work);
 137
 138 no_schedule:
 139         percpu_up_read(&hu->proto_lock);
 140
 141         return 0;
 142 }
 143 EXPORT_SYMBOL_GPL(hci_uart_tx_wakeup);
 144
 145 static void hci_uart_write_work(struct work_struct *work)
 146 {
 147         struct hci_uart *hu = container_of(work, struct hci_uart, write_work);
 148         struct tty_struct *tty = hu->tty;
 149         struct hci_dev *hdev = hu->hdev;
 150         struct sk_buff *skb;
 151
 152         /* REVISIT: should we cope with bad skbs or ->write() returning
 153          * and error value ?
 154          */
 155
 156 restart:
 157         clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
 158
 159         while ((skb = hci_uart_dequeue(hu))) {
 160                 int len;
 161
 162                 set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 163                 len = tty->ops->write(tty, skb->data, skb->len);
 164                 hdev->stat.byte_tx += len;
 165
 166                 skb_pull(skb, len);
 167                 if (skb->len) {
 168                         hu->tx_skb = skb;
 169                         break;
 170                 }
 171
 172                 hci_uart_tx_complete(hu, hci_skb_pkt_type(skb));
 173                 kfree_skb(skb);
 174         }
 175
 176         clear_bit(HCI_UART_SENDING, &hu->tx_state);
 177         if (test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state))
 178                 goto restart;
 179
 180         wake_up_bit(&hu->tx_state, HCI_UART_SENDING);
 181 }
 182
 183 void hci_uart_init_work(struct work_struct *work)
 184 {
 185         struct hci_uart *hu = container_of(work, struct hci_uart, init_ready);
 186         int err;
 187         struct hci_dev *hdev;
 188
 189         if (!test_and_clear_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
 190                 return;
 191
 192         err = hci_register_dev(hu->hdev);
 193         if (err < 0) {
 194                 BT_ERR("Can't register HCI device");
 195                 clear_bit(HCI_UART_PROTO_READY, &hu->flags);
 196                 hu->proto->close(hu);
 197                 hdev = hu->hdev;
 198                 hu->hdev = NULL;
 199                 hci_free_dev(hdev);
 200                 return;
 201         }
 202
 203         set_bit(HCI_UART_REGISTERED, &hu->flags);
 204 }
 205
 206 int hci_uart_init_ready(struct hci_uart *hu)
 207 {
 208         if (!test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
 209                 return -EALREADY;
 210
 211         schedule_work(&hu->init_ready);
 212
 213         return 0;
 214 }
 215
 216 int hci_uart_wait_until_sent(struct hci_uart *hu)
 217 {
 218         return wait_on_bit_timeout(&hu->tx_state, HCI_UART_SENDING,
 219                                    TASK_INTERRUPTIBLE,
 220                                    msecs_to_jiffies(2000));
 221 }
 222
 223 /* ------- Interface to HCI layer ------ */
 224 /* Reset device */
 225 static int hci_uart_flush(struct hci_dev *hdev)
 226 {
 227         struct hci_uart *hu  = hci_get_drvdata(hdev);
 228         struct tty_struct *tty = hu->tty;
 229
 230         BT_DBG("hdev %p tty %p", hdev, tty);
 231
 232         if (hu->tx_skb) {
 233                 kfree_skb(hu->tx_skb); hu->tx_skb = NULL;
 234         }
 235
 236         /* Flush any pending characters in the driver and discipline. */
 237         tty_ldisc_flush(tty);
 238         tty_driver_flush_buffer(tty);
 239
 240         percpu_down_read(&hu->proto_lock);
 241
 242         if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
 243                 hu->proto->flush(hu);
 244
 245         percpu_up_read(&hu->proto_lock);
 246
 247         return 0;
 248 }
 249
 250 /* Initialize device */
 251 static int hci_uart_open(struct hci_dev *hdev)
 252 {
 253         BT_DBG("%s %p", hdev->name, hdev);
 254
 255         /* Undo clearing this from hci_uart_close() */
 256         hdev->flush = hci_uart_flush;
 257
 258         return 0;
 259 }
 260
 261 /* Close device */
 262 static int hci_uart_close(struct hci_dev *hdev)
 263 {
 264         BT_DBG("hdev %p", hdev);
 265
 266         hci_uart_flush(hdev);
 267         hdev->flush = NULL;
 268         return 0;
 269 }
 270
 271 /* Send frames from HCI layer */
 272 static int hci_uart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
 273 {
 274         struct hci_uart *hu = hci_get_drvdata(hdev);
 275
 276         BT_DBG("%s: type %d len %d", hdev->name, hci_skb_pkt_type(skb),
 277                skb->len);
 278
 279         percpu_down_read(&hu->proto_lock);
 280
 281         if (!test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
 282                 percpu_up_read(&hu->proto_lock);
 283                 return -EUNATCH;
 284         }
 285
 286         hu->proto->enqueue(hu, skb);
 287         percpu_up_read(&hu->proto_lock);
 288
 289         hci_uart_tx_wakeup(hu);
 290
 291         return 0;
 292 }
 293
 294 /* Check the underlying device or tty has flow control support */
 295 bool hci_uart_has_flow_control(struct hci_uart *hu)
 296 {
 297         /* serdev nodes check if the needed operations are present */
 298         if (hu->serdev)
 299                 return true;
 300
 301         if (hu->tty->driver->ops->tiocmget && hu->tty->driver->ops->tiocmset)
 302                 return true;
 303
 304         return false;
 305 }
 306
 307 /* Flow control or un-flow control the device */
 308 void hci_uart_set_flow_control(struct hci_uart *hu, bool enable)
 309 {
 310         struct tty_struct *tty = hu->tty;
 311         struct ktermios ktermios;
 312         int status;
 313         unsigned int set = 0;
 314         unsigned int clear = 0;
 315
 316         if (hu->serdev) {
 317                 serdev_device_set_flow_control(hu->serdev, !enable);
 318                 serdev_device_set_rts(hu->serdev, !enable);
 319                 return;
 320         }
 321
 322         if (enable) {
 323                 /* Disable hardware flow control */
 324                 ktermios = tty->termios;
 325                 ktermios.c_cflag &= ~CRTSCTS;
 326                 status = tty_set_termios(tty, &ktermios);
 327                 BT_DBG("Disabling hardware flow control: %s",
 328                        status ? "failed" : "success");
 329
 330                 /* Clear RTS to prevent the device from sending */
 331                 /* Most UARTs need OUT2 to enable interrupts */
 332                 status = tty->driver->ops->tiocmget(tty);
 333                 BT_DBG("Current tiocm 0x%x", status);
 334
 335                 set &= ~(TIOCM_OUT2 | TIOCM_RTS);
 336                 clear = ~set;
 337                 set &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
 338                        TIOCM_OUT2 | TIOCM_LOOP;
 339                 clear &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
 340                          TIOCM_OUT2 | TIOCM_LOOP;
 341                 status = tty->driver->ops->tiocmset(tty, set, clear);
 342                 BT_DBG("Clearing RTS: %s", status ? "failed" : "success");
 343         } else {
 344                 /* Set RTS to allow the device to send again */
 345                 status = tty->driver->ops->tiocmget(tty);
 346                 BT_DBG("Current tiocm 0x%x", status);
 347
 348                 set |= (TIOCM_OUT2 | TIOCM_RTS);
 349                 clear = ~set;
 350                 set &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
 351                        TIOCM_OUT2 | TIOCM_LOOP;
 352                 clear &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
 353                          TIOCM_OUT2 | TIOCM_LOOP;
 354                 status = tty->driver->ops->tiocmset(tty, set, clear);
 355                 BT_DBG("Setting RTS: %s", status ? "failed" : "success");
 356
 357                 /* Re-enable hardware flow control */
 358                 ktermios = tty->termios;
 359                 ktermios.c_cflag |= CRTSCTS;
 360                 status = tty_set_termios(tty, &ktermios);
 361                 BT_DBG("Enabling hardware flow control: %s",
 362                        status ? "failed" : "success");
 363         }
 364 }
 365
 366 void hci_uart_set_speeds(struct hci_uart *hu, unsigned int init_speed,
 367                          unsigned int oper_speed)
 368 {
 369         hu->init_speed = init_speed;
 370         hu->oper_speed = oper_speed;
 371 }
 372
 373 void hci_uart_set_baudrate(struct hci_uart *hu, unsigned int speed)
 374 {
 375         struct tty_struct *tty = hu->tty;
 376         struct ktermios ktermios;
 377
 378         ktermios = tty->termios;
 379         ktermios.c_cflag &= ~CBAUD;
 380         tty_termios_encode_baud_rate(&ktermios, speed, speed);
 381
 382         /* tty_set_termios() return not checked as it is always 0 */
 383         tty_set_termios(tty, &ktermios);
 384
 385         BT_DBG("%s: New tty speeds: %d/%d", hu->hdev->name,
 386                tty->termios.c_ispeed, tty->termios.c_ospeed);
 387 }
 388
 389 static int hci_uart_setup(struct hci_dev *hdev)
 390 {
 391         struct hci_uart *hu = hci_get_drvdata(hdev);
 392         struct hci_rp_read_local_version *ver;
 393         struct sk_buff *skb;
 394         unsigned int speed;
 395         int err;
 396
 397         /* Init speed if any */
 398         if (hu->init_speed)
 399                 speed = hu->init_speed;
 400         else if (hu->proto->init_speed)
 401                 speed = hu->proto->init_speed;
 402         else
 403                 speed = 0;
 404
 405         if (speed)
 406                 hci_uart_set_baudrate(hu, speed);
 407
 408         /* Operational speed if any */
 409         if (hu->oper_speed)
 410                 speed = hu->oper_speed;
 411         else if (hu->proto->oper_speed)
 412                 speed = hu->proto->oper_speed;
 413         else
 414                 speed = 0;
 415
 416         if (hu->proto->set_baudrate && speed) {
 417                 err = hu->proto->set_baudrate(hu, speed);
 418                 if (!err)
 419                         hci_uart_set_baudrate(hu, speed);
 420         }
 421
 422         if (hu->proto->setup)
 423                 return hu->proto->setup(hu);
 424
 425         if (!test_bit(HCI_UART_VND_DETECT, &hu->hdev_flags))
 426                 return 0;
 427
 428         skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
 429                              HCI_INIT_TIMEOUT);
 430         if (IS_ERR(skb)) {
 431                 BT_ERR("%s: Reading local version information failed (%ld)",
 432                        hdev->name, PTR_ERR(skb));
 433                 return 0;
 434         }
 435
 436         if (skb->len != sizeof(*ver)) {
 437                 BT_ERR("%s: Event length mismatch for version information",
 438                        hdev->name);
 439                 goto done;
 440         }
 441
 442         ver = (struct hci_rp_read_local_version *)skb->data;
 443
 444         switch (le16_to_cpu(ver->manufacturer)) {
 445 #ifdef CONFIG_BT_HCIUART_INTEL
 446         case 2:
 447                 hdev->set_bdaddr = btintel_set_bdaddr;
 448                 btintel_check_bdaddr(hdev);
 449                 break;
 450 #endif
 451 #ifdef CONFIG_BT_HCIUART_BCM
 452         case 15:
 453                 hdev->set_bdaddr = btbcm_set_bdaddr;
 454                 btbcm_check_bdaddr(hdev);
 455                 break;
 456 #endif
 457         default:
 458                 break;
 459         }
 460
 461 done:
 462         kfree_skb(skb);
 463         return 0;
 464 }
 465
 466 /* ------ LDISC part ------ */
 467 /* hci_uart_tty_open
 468  *
 469  *     Called when line discipline changed to HCI_UART.
 470  *
 471  * Arguments:
 472  *     tty    pointer to tty info structure
 473  * Return Value:
 474  *     0 if success, otherwise error code
 475  */
 476 static int hci_uart_tty_open(struct tty_struct *tty)
 477 {
 478         struct hci_uart *hu;
 479
 480         BT_DBG("tty %p", tty);
 481
 482         if (!capable(CAP_NET_ADMIN))
 483                 return -EPERM;
 484
 485         /* Error if the tty has no write op instead of leaving an exploitable
 486          * hole
 487          */
 488         if (tty->ops->write == NULL)
 489                 return -EOPNOTSUPP;
 490
 491         hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL);
 492         if (!hu) {
 493                 BT_ERR("Can't allocate control structure");
 494                 return -ENFILE;
 495         }
 496         if (percpu_init_rwsem(&hu->proto_lock)) {
 497                 BT_ERR("Can't allocate semaphore structure");
 498                 kfree(hu);
 499                 return -ENOMEM;
 500         }
 501
 502         tty->disc_data = hu;
 503         hu->tty = tty;
 504         tty->receive_room = 65536;
 505
 506         /* disable alignment support by default */
 507         hu->alignment = 1;
 508         hu->padding = 0;
 509
 510         INIT_WORK(&hu->init_ready, hci_uart_init_work);
 511         INIT_WORK(&hu->write_work, hci_uart_write_work);
 512
 513         /* Flush any pending characters in the driver */
 514         tty_driver_flush_buffer(tty);
 515
 516         return 0;
 517 }
 518
 519 /* hci_uart_tty_close()
 520  *
 521  *    Called when the line discipline is changed to something
 522  *    else, the tty is closed, or the tty detects a hangup.
 523  */
 524 static void hci_uart_tty_close(struct tty_struct *tty)
 525 {
 526         struct hci_uart *hu = tty->disc_data;
 527         struct hci_dev *hdev;
 528
 529         BT_DBG("tty %p", tty);
 530
 531         /* Detach from the tty */
 532         tty->disc_data = NULL;
 533
 534         if (!hu)
 535                 return;
 536
 537         hdev = hu->hdev;
 538         if (hdev)
 539                 hci_uart_close(hdev);
 540
 541         if (test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
 542                 percpu_down_write(&hu->proto_lock);
 543                 clear_bit(HCI_UART_PROTO_READY, &hu->flags);
 544                 percpu_up_write(&hu->proto_lock);
 545
 546                 cancel_work_sync(&hu->init_ready);
 547                 cancel_work_sync(&hu->write_work);
 548
 549                 if (hdev) {
 550                         if (test_bit(HCI_UART_REGISTERED, &hu->flags))
 551                                 hci_unregister_dev(hdev);
 552                         hci_free_dev(hdev);
 553                 }
 554                 hu->proto->close(hu);
 555         }
 556         clear_bit(HCI_UART_PROTO_SET, &hu->flags);
 557
 558         percpu_free_rwsem(&hu->proto_lock);
 559
 560         kfree(hu);
 561 }
 562
 563 /* hci_uart_tty_wakeup()
 564  *
 565  *    Callback for transmit wakeup. Called when low level
 566  *    device driver can accept more send data.
 567  *
 568  * Arguments:        tty    pointer to associated tty instance data
 569  * Return Value:    None
 570  */
 571 static void hci_uart_tty_wakeup(struct tty_struct *tty)
 572 {
 573         struct hci_uart *hu = tty->disc_data;
 574
 575         BT_DBG("");
 576
 577         if (!hu)
 578                 return;
 579
 580         clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 581
 582         if (tty != hu->tty)
 583                 return;
 584
 585         if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
 586                 hci_uart_tx_wakeup(hu);
 587 }
 588
 589 /* hci_uart_tty_receive()
 590  *
 591  *     Called by tty low level driver when receive data is
 592  *     available.
 593  *
 594  * Arguments:  tty          pointer to tty isntance data
 595  *             data         pointer to received data
 596  *             flags        pointer to flags for data
 597  *             count        count of received data in bytes
 598  *
 599  * Return Value:    None
 600  */
 601 static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data,
 602                                  const char *flags, int count)
 603 {
 604         struct hci_uart *hu = tty->disc_data;
 605
 606         if (!hu || tty != hu->tty)
 607                 return;
 608
 609         percpu_down_read(&hu->proto_lock);
 610
 611         if (!test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
 612                 percpu_up_read(&hu->proto_lock);
 613                 return;
 614         }
 615
 616         /* It does not need a lock here as it is already protected by a mutex in
 617          * tty caller
 618          */
 619         hu->proto->recv(hu, data, count);
 620         percpu_up_read(&hu->proto_lock);
 621
 622         if (hu->hdev)
 623                 hu->hdev->stat.byte_rx += count;
 624
 625         tty_unthrottle(tty);
 626 }
 627
 628 static int hci_uart_register_dev(struct hci_uart *hu)
 629 {
 630         struct hci_dev *hdev;
 631         int err;
 632
 633         BT_DBG("");
 634
 635         /* Initialize and register HCI device */
 636         hdev = hci_alloc_dev();
 637         if (!hdev) {
 638                 BT_ERR("Can't allocate HCI device");
 639                 return -ENOMEM;
 640         }
 641
 642         hu->hdev = hdev;
 643
 644         hdev->bus = HCI_UART;
 645         hci_set_drvdata(hdev, hu);
 646
 647         /* Only when vendor specific setup callback is provided, consider
 648          * the manufacturer information valid. This avoids filling in the
 649          * value for Ericsson when nothing is specified.
 650          */
 651         if (hu->proto->setup)
 652                 hdev->manufacturer = hu->proto->manufacturer;
 653
 654         hdev->open  = hci_uart_open;
 655         hdev->close = hci_uart_close;
 656         hdev->flush = hci_uart_flush;
 657         hdev->send  = hci_uart_send_frame;
 658         hdev->setup = hci_uart_setup;
 659         SET_HCIDEV_DEV(hdev, hu->tty->dev);
 660
 661         if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
 662                 set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
 663
 664         if (test_bit(HCI_UART_EXT_CONFIG, &hu->hdev_flags))
 665                 set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
 666
 667         if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
 668                 set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
 669
 670         if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
 671                 hdev->dev_type = HCI_AMP;
 672         else
 673                 hdev->dev_type = HCI_PRIMARY;
 674
 675         /* Only call open() for the protocol after hdev is fully initialized as
 676          * open() (or a timer/workqueue it starts) may attempt to reference it.
 677          */
 678         err = hu->proto->open(hu);
 679         if (err) {
 680                 hu->hdev = NULL;
 681                 hci_free_dev(hdev);
 682                 return err;
 683         }
 684
 685         if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
 686                 return 0;
 687
 688         if (hci_register_dev(hdev) < 0) {
 689                 BT_ERR("Can't register HCI device");
 690                 hu->proto->close(hu);
 691                 hu->hdev = NULL;
 692                 hci_free_dev(hdev);
 693                 return -ENODEV;
 694         }
 695
 696         set_bit(HCI_UART_REGISTERED, &hu->flags);
 697
 698         return 0;
 699 }
 700
 701 static int hci_uart_set_proto(struct hci_uart *hu, int id)
 702 {
 703         const struct hci_uart_proto *p;
 704         int err;
 705
 706         p = hci_uart_get_proto(id);
 707         if (!p)
 708                 return -EPROTONOSUPPORT;
 709
 710         hu->proto = p;
 711
 712         err = hci_uart_register_dev(hu);
 713         if (err) {
 714                 return err;
 715         }
 716
 717         set_bit(HCI_UART_PROTO_READY, &hu->flags);
 718         return 0;
 719 }
 720
 721 static int hci_uart_set_flags(struct hci_uart *hu, unsigned long flags)
 722 {
 723         unsigned long valid_flags = BIT(HCI_UART_RAW_DEVICE) |
 724                                     BIT(HCI_UART_RESET_ON_INIT) |
 725                                     BIT(HCI_UART_CREATE_AMP) |
 726                                     BIT(HCI_UART_INIT_PENDING) |
 727                                     BIT(HCI_UART_EXT_CONFIG) |
 728                                     BIT(HCI_UART_VND_DETECT);
 729
 730         if (flags & ~valid_flags)
 731                 return -EINVAL;
 732
 733         hu->hdev_flags = flags;
 734
 735         return 0;
 736 }
 737
 738 /* hci_uart_tty_ioctl()
 739  *
 740  *    Process IOCTL system call for the tty device.
 741  *
 742  * Arguments:
 743  *
 744  *    tty        pointer to tty instance data
 745  *    cmd        IOCTL command code
 746  *    arg        argument for IOCTL call (cmd dependent)
 747  *
 748  * Return Value:    Command dependent
 749  */
 750 static int hci_uart_tty_ioctl(struct tty_struct *tty, unsigned int cmd,
 751                               unsigned long arg)
 752 {
 753         struct hci_uart *hu = tty->disc_data;
 754         int err = 0;
 755
 756         BT_DBG("");
 757
 758         /* Verify the status of the device */
 759         if (!hu)
 760                 return -EBADF;
 761
 762         switch (cmd) {
 763         case HCIUARTSETPROTO:
 764                 if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) {
 765                         err = hci_uart_set_proto(hu, arg);
 766                         if (err)
 767                                 clear_bit(HCI_UART_PROTO_SET, &hu->flags);
 768                 } else
 769                         err = -EBUSY;
 770                 break;
 771
 772         case HCIUARTGETPROTO:
 773                 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 774                         err = hu->proto->id;
 775                 else
 776                         err = -EUNATCH;
 777                 break;
 778
 779         case HCIUARTGETDEVICE:
 780                 if (test_bit(HCI_UART_REGISTERED, &hu->flags))
 781                         err = hu->hdev->id;
 782                 else
 783                         err = -EUNATCH;
 784                 break;
 785
 786         case HCIUARTSETFLAGS:
 787                 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 788                         err = -EBUSY;
 789                 else
 790                         err = hci_uart_set_flags(hu, arg);
 791                 break;
 792
 793         case HCIUARTGETFLAGS:
 794                 err = hu->hdev_flags;
 795                 break;
 796
 797         default:
 798                 err = n_tty_ioctl_helper(tty, cmd, arg);
 799                 break;
 800         }
 801
 802         return err;
 803 }
 804
 805 /*
 806  * We don't provide read/write/poll interface for user space.
 807  */
 808 static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file,
 809                                  unsigned char *buf, size_t nr,
 810                                  void **cookie, unsigned long offset)
 811 {
 812         return 0;
 813 }
 814
 815 static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file,
 816                                   const unsigned char *data, size_t count)
 817 {
 818         return 0;
 819 }
 820
 821 static __poll_t hci_uart_tty_poll(struct tty_struct *tty,
 822                                       struct file *filp, poll_table *wait)
 823 {
 824         return 0;
 825 }
 826
 827 static struct tty_ldisc_ops hci_uart_ldisc = {
 828         .owner          = THIS_MODULE,
 829         .num            = N_HCI,
 830         .name           = "n_hci",
 831         .open           = hci_uart_tty_open,
 832         .close          = hci_uart_tty_close,
 833         .read           = hci_uart_tty_read,
 834         .write          = hci_uart_tty_write,
 835         .ioctl          = hci_uart_tty_ioctl,
 836         .compat_ioctl   = hci_uart_tty_ioctl,
 837         .poll           = hci_uart_tty_poll,
 838         .receive_buf    = hci_uart_tty_receive,
 839         .write_wakeup   = hci_uart_tty_wakeup,
 840 };
 841
 842 static int __init hci_uart_init(void)
 843 {
 844         int err;
 845
 846         BT_INFO("HCI UART driver ver %s", VERSION);
 847
 848         /* Register the tty discipline */
 849         err = tty_register_ldisc(&hci_uart_ldisc);
 850         if (err) {
 851                 BT_ERR("HCI line discipline registration failed. (%d)", err);
 852                 return err;
 853         }
 854
 855 #ifdef CONFIG_BT_HCIUART_H4
 856         h4_init();
 857 #endif
 858 #ifdef CONFIG_BT_HCIUART_BCSP
 859         bcsp_init();
 860 #endif
 861 #ifdef CONFIG_BT_HCIUART_LL
 862         ll_init();
 863 #endif
 864 #ifdef CONFIG_BT_HCIUART_ATH3K
 865         ath_init();
 866 #endif
 867 #ifdef CONFIG_BT_HCIUART_3WIRE
 868         h5_init();
 869 #endif
 870 #ifdef CONFIG_BT_HCIUART_INTEL
 871         intel_init();
 872 #endif
 873 #ifdef CONFIG_BT_HCIUART_BCM
 874         bcm_init();
 875 #endif
 876 #ifdef CONFIG_BT_HCIUART_QCA
 877         qca_init();
 878 #endif
 879 #ifdef CONFIG_BT_HCIUART_AG6XX
 880         ag6xx_init();
 881 #endif
 882 #ifdef CONFIG_BT_HCIUART_MRVL
 883         mrvl_init();
 884 #endif
 885
 886         return 0;
 887 }
 888
 889 static void __exit hci_uart_exit(void)
 890 {
 891 #ifdef CONFIG_BT_HCIUART_H4
 892         h4_deinit();
 893 #endif
 894 #ifdef CONFIG_BT_HCIUART_BCSP
 895         bcsp_deinit();
 896 #endif
 897 #ifdef CONFIG_BT_HCIUART_LL
 898         ll_deinit();
 899 #endif
 900 #ifdef CONFIG_BT_HCIUART_ATH3K
 901         ath_deinit();
 902 #endif
 903 #ifdef CONFIG_BT_HCIUART_3WIRE
 904         h5_deinit();
 905 #endif
 906 #ifdef CONFIG_BT_HCIUART_INTEL
 907         intel_deinit();
 908 #endif
 909 #ifdef CONFIG_BT_HCIUART_BCM
 910         bcm_deinit();
 911 #endif
 912 #ifdef CONFIG_BT_HCIUART_QCA
 913         qca_deinit();
 914 #endif
 915 #ifdef CONFIG_BT_HCIUART_AG6XX
 916         ag6xx_deinit();
 917 #endif
 918 #ifdef CONFIG_BT_HCIUART_MRVL
 919         mrvl_deinit();
 920 #endif
 921
 922         tty_unregister_ldisc(&hci_uart_ldisc);
 923 }
 924
 925 module_init(hci_uart_init);
 926 module_exit(hci_uart_exit);
 927
 928 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
 929 MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION);
 930 MODULE_VERSION(VERSION);
 931 MODULE_LICENSE("GPL");
 932 MODULE_ALIAS_LDISC(N_HCI);