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         /* Error if the tty has no write op instead of leaving an exploitable
 483          * hole
 484          */
 485         if (tty->ops->write == NULL)
 486                 return -EOPNOTSUPP;
 487
 488         hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL);
 489         if (!hu) {
 490                 BT_ERR("Can't allocate control structure");
 491                 return -ENFILE;
 492         }
 493
 494         tty->disc_data = hu;
 495         hu->tty = tty;
 496         tty->receive_room = 65536;
 497
 498         /* disable alignment support by default */
 499         hu->alignment = 1;
 500         hu->padding = 0;
 501
 502         INIT_WORK(&hu->init_ready, hci_uart_init_work);
 503         INIT_WORK(&hu->write_work, hci_uart_write_work);
 504
 505         percpu_init_rwsem(&hu->proto_lock);
 506
 507         /* Flush any pending characters in the driver */
 508         tty_driver_flush_buffer(tty);
 509
 510         return 0;
 511 }
 512
 513 /* hci_uart_tty_close()
 514  *
 515  *    Called when the line discipline is changed to something
 516  *    else, the tty is closed, or the tty detects a hangup.
 517  */
 518 static void hci_uart_tty_close(struct tty_struct *tty)
 519 {
 520         struct hci_uart *hu = tty->disc_data;
 521         struct hci_dev *hdev;
 522
 523         BT_DBG("tty %p", tty);
 524
 525         /* Detach from the tty */
 526         tty->disc_data = NULL;
 527
 528         if (!hu)
 529                 return;
 530
 531         hdev = hu->hdev;
 532         if (hdev)
 533                 hci_uart_close(hdev);
 534
 535         if (test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
 536                 percpu_down_write(&hu->proto_lock);
 537                 clear_bit(HCI_UART_PROTO_READY, &hu->flags);
 538                 percpu_up_write(&hu->proto_lock);
 539
 540                 cancel_work_sync(&hu->init_ready);
 541                 cancel_work_sync(&hu->write_work);
 542
 543                 if (hdev) {
 544                         if (test_bit(HCI_UART_REGISTERED, &hu->flags))
 545                                 hci_unregister_dev(hdev);
 546                         hci_free_dev(hdev);
 547                 }
 548                 hu->proto->close(hu);
 549         }
 550         clear_bit(HCI_UART_PROTO_SET, &hu->flags);
 551
 552         percpu_free_rwsem(&hu->proto_lock);
 553
 554         kfree(hu);
 555 }
 556
 557 /* hci_uart_tty_wakeup()
 558  *
 559  *    Callback for transmit wakeup. Called when low level
 560  *    device driver can accept more send data.
 561  *
 562  * Arguments:        tty    pointer to associated tty instance data
 563  * Return Value:    None
 564  */
 565 static void hci_uart_tty_wakeup(struct tty_struct *tty)
 566 {
 567         struct hci_uart *hu = tty->disc_data;
 568
 569         BT_DBG("");
 570
 571         if (!hu)
 572                 return;
 573
 574         clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 575
 576         if (tty != hu->tty)
 577                 return;
 578
 579         if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
 580                 hci_uart_tx_wakeup(hu);
 581 }
 582
 583 /* hci_uart_tty_receive()
 584  *
 585  *     Called by tty low level driver when receive data is
 586  *     available.
 587  *
 588  * Arguments:  tty          pointer to tty isntance data
 589  *             data         pointer to received data
 590  *             flags        pointer to flags for data
 591  *             count        count of received data in bytes
 592  *
 593  * Return Value:    None
 594  */
 595 static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data,
 596                                  const char *flags, int count)
 597 {
 598         struct hci_uart *hu = tty->disc_data;
 599
 600         if (!hu || tty != hu->tty)
 601                 return;
 602
 603         percpu_down_read(&hu->proto_lock);
 604
 605         if (!test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
 606                 percpu_up_read(&hu->proto_lock);
 607                 return;
 608         }
 609
 610         /* It does not need a lock here as it is already protected by a mutex in
 611          * tty caller
 612          */
 613         hu->proto->recv(hu, data, count);
 614         percpu_up_read(&hu->proto_lock);
 615
 616         if (hu->hdev)
 617                 hu->hdev->stat.byte_rx += count;
 618
 619         tty_unthrottle(tty);
 620 }
 621
 622 static int hci_uart_register_dev(struct hci_uart *hu)
 623 {
 624         struct hci_dev *hdev;
 625         int err;
 626
 627         BT_DBG("");
 628
 629         /* Initialize and register HCI device */
 630         hdev = hci_alloc_dev();
 631         if (!hdev) {
 632                 BT_ERR("Can't allocate HCI device");
 633                 return -ENOMEM;
 634         }
 635
 636         hu->hdev = hdev;
 637
 638         hdev->bus = HCI_UART;
 639         hci_set_drvdata(hdev, hu);
 640
 641         /* Only when vendor specific setup callback is provided, consider
 642          * the manufacturer information valid. This avoids filling in the
 643          * value for Ericsson when nothing is specified.
 644          */
 645         if (hu->proto->setup)
 646                 hdev->manufacturer = hu->proto->manufacturer;
 647
 648         hdev->open  = hci_uart_open;
 649         hdev->close = hci_uart_close;
 650         hdev->flush = hci_uart_flush;
 651         hdev->send  = hci_uart_send_frame;
 652         hdev->setup = hci_uart_setup;
 653         SET_HCIDEV_DEV(hdev, hu->tty->dev);
 654
 655         if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
 656                 set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
 657
 658         if (test_bit(HCI_UART_EXT_CONFIG, &hu->hdev_flags))
 659                 set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
 660
 661         if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
 662                 set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
 663
 664         if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
 665                 hdev->dev_type = HCI_AMP;
 666         else
 667                 hdev->dev_type = HCI_PRIMARY;
 668
 669         /* Only call open() for the protocol after hdev is fully initialized as
 670          * open() (or a timer/workqueue it starts) may attempt to reference it.
 671          */
 672         err = hu->proto->open(hu);
 673         if (err) {
 674                 hu->hdev = NULL;
 675                 hci_free_dev(hdev);
 676                 return err;
 677         }
 678
 679         if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
 680                 return 0;
 681
 682         if (hci_register_dev(hdev) < 0) {
 683                 BT_ERR("Can't register HCI device");
 684                 hu->proto->close(hu);
 685                 hu->hdev = NULL;
 686                 hci_free_dev(hdev);
 687                 return -ENODEV;
 688         }
 689
 690         set_bit(HCI_UART_REGISTERED, &hu->flags);
 691
 692         return 0;
 693 }
 694
 695 static int hci_uart_set_proto(struct hci_uart *hu, int id)
 696 {
 697         const struct hci_uart_proto *p;
 698         int err;
 699
 700         p = hci_uart_get_proto(id);
 701         if (!p)
 702                 return -EPROTONOSUPPORT;
 703
 704         hu->proto = p;
 705
 706         err = hci_uart_register_dev(hu);
 707         if (err) {
 708                 return err;
 709         }
 710
 711         set_bit(HCI_UART_PROTO_READY, &hu->flags);
 712         return 0;
 713 }
 714
 715 static int hci_uart_set_flags(struct hci_uart *hu, unsigned long flags)
 716 {
 717         unsigned long valid_flags = BIT(HCI_UART_RAW_DEVICE) |
 718                                     BIT(HCI_UART_RESET_ON_INIT) |
 719                                     BIT(HCI_UART_CREATE_AMP) |
 720                                     BIT(HCI_UART_INIT_PENDING) |
 721                                     BIT(HCI_UART_EXT_CONFIG) |
 722                                     BIT(HCI_UART_VND_DETECT);
 723
 724         if (flags & ~valid_flags)
 725                 return -EINVAL;
 726
 727         hu->hdev_flags = flags;
 728
 729         return 0;
 730 }
 731
 732 /* hci_uart_tty_ioctl()
 733  *
 734  *    Process IOCTL system call for the tty device.
 735  *
 736  * Arguments:
 737  *
 738  *    tty        pointer to tty instance data
 739  *    file       pointer to open file object for device
 740  *    cmd        IOCTL command code
 741  *    arg        argument for IOCTL call (cmd dependent)
 742  *
 743  * Return Value:    Command dependent
 744  */
 745 static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file *file,
 746                               unsigned int cmd, unsigned long arg)
 747 {
 748         struct hci_uart *hu = tty->disc_data;
 749         int err = 0;
 750
 751         BT_DBG("");
 752
 753         /* Verify the status of the device */
 754         if (!hu)
 755                 return -EBADF;
 756
 757         switch (cmd) {
 758         case HCIUARTSETPROTO:
 759                 if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) {
 760                         err = hci_uart_set_proto(hu, arg);
 761                         if (err)
 762                                 clear_bit(HCI_UART_PROTO_SET, &hu->flags);
 763                 } else
 764                         err = -EBUSY;
 765                 break;
 766
 767         case HCIUARTGETPROTO:
 768                 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 769                         err = hu->proto->id;
 770                 else
 771                         err = -EUNATCH;
 772                 break;
 773
 774         case HCIUARTGETDEVICE:
 775                 if (test_bit(HCI_UART_REGISTERED, &hu->flags))
 776                         err = hu->hdev->id;
 777                 else
 778                         err = -EUNATCH;
 779                 break;
 780
 781         case HCIUARTSETFLAGS:
 782                 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 783                         err = -EBUSY;
 784                 else
 785                         err = hci_uart_set_flags(hu, arg);
 786                 break;
 787
 788         case HCIUARTGETFLAGS:
 789                 err = hu->hdev_flags;
 790                 break;
 791
 792         default:
 793                 err = n_tty_ioctl_helper(tty, file, cmd, arg);
 794                 break;
 795         }
 796
 797         return err;
 798 }
 799
 800 /*
 801  * We don't provide read/write/poll interface for user space.
 802  */
 803 static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file,
 804                                  unsigned char *buf, size_t nr,
 805                                  void **cookie, unsigned long offset)
 806 {
 807         return 0;
 808 }
 809
 810 static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file,
 811                                   const unsigned char *data, size_t count)
 812 {
 813         return 0;
 814 }
 815
 816 static __poll_t hci_uart_tty_poll(struct tty_struct *tty,
 817                                       struct file *filp, poll_table *wait)
 818 {
 819         return 0;
 820 }
 821
 822 static struct tty_ldisc_ops hci_uart_ldisc = {
 823         .owner          = THIS_MODULE,
 824         .num            = N_HCI,
 825         .name           = "n_hci",
 826         .open           = hci_uart_tty_open,
 827         .close          = hci_uart_tty_close,
 828         .read           = hci_uart_tty_read,
 829         .write          = hci_uart_tty_write,
 830         .ioctl          = hci_uart_tty_ioctl,
 831         .compat_ioctl   = hci_uart_tty_ioctl,
 832         .poll           = hci_uart_tty_poll,
 833         .receive_buf    = hci_uart_tty_receive,
 834         .write_wakeup   = hci_uart_tty_wakeup,
 835 };
 836
 837 static int __init hci_uart_init(void)
 838 {
 839         int err;
 840
 841         BT_INFO("HCI UART driver ver %s", VERSION);
 842
 843         /* Register the tty discipline */
 844         err = tty_register_ldisc(&hci_uart_ldisc);
 845         if (err) {
 846                 BT_ERR("HCI line discipline registration failed. (%d)", err);
 847                 return err;
 848         }
 849
 850 #ifdef CONFIG_BT_HCIUART_H4
 851         h4_init();
 852 #endif
 853 #ifdef CONFIG_BT_HCIUART_BCSP
 854         bcsp_init();
 855 #endif
 856 #ifdef CONFIG_BT_HCIUART_LL
 857         ll_init();
 858 #endif
 859 #ifdef CONFIG_BT_HCIUART_ATH3K
 860         ath_init();
 861 #endif
 862 #ifdef CONFIG_BT_HCIUART_3WIRE
 863         h5_init();
 864 #endif
 865 #ifdef CONFIG_BT_HCIUART_INTEL
 866         intel_init();
 867 #endif
 868 #ifdef CONFIG_BT_HCIUART_BCM
 869         bcm_init();
 870 #endif
 871 #ifdef CONFIG_BT_HCIUART_QCA
 872         qca_init();
 873 #endif
 874 #ifdef CONFIG_BT_HCIUART_AG6XX
 875         ag6xx_init();
 876 #endif
 877 #ifdef CONFIG_BT_HCIUART_MRVL
 878         mrvl_init();
 879 #endif
 880
 881         return 0;
 882 }
 883
 884 static void __exit hci_uart_exit(void)
 885 {
 886 #ifdef CONFIG_BT_HCIUART_H4
 887         h4_deinit();
 888 #endif
 889 #ifdef CONFIG_BT_HCIUART_BCSP
 890         bcsp_deinit();
 891 #endif
 892 #ifdef CONFIG_BT_HCIUART_LL
 893         ll_deinit();
 894 #endif
 895 #ifdef CONFIG_BT_HCIUART_ATH3K
 896         ath_deinit();
 897 #endif
 898 #ifdef CONFIG_BT_HCIUART_3WIRE
 899         h5_deinit();
 900 #endif
 901 #ifdef CONFIG_BT_HCIUART_INTEL
 902         intel_deinit();
 903 #endif
 904 #ifdef CONFIG_BT_HCIUART_BCM
 905         bcm_deinit();
 906 #endif
 907 #ifdef CONFIG_BT_HCIUART_QCA
 908         qca_deinit();
 909 #endif
 910 #ifdef CONFIG_BT_HCIUART_AG6XX
 911         ag6xx_deinit();
 912 #endif
 913 #ifdef CONFIG_BT_HCIUART_MRVL
 914         mrvl_deinit();
 915 #endif
 916
 917         tty_unregister_ldisc(&hci_uart_ldisc);
 918 }
 919
 920 module_init(hci_uart_init);
 921 module_exit(hci_uart_exit);
 922
 923 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
 924 MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION);
 925 MODULE_VERSION(VERSION);
 926 MODULE_LICENSE("GPL");
 927 MODULE_ALIAS_LDISC(N_HCI);