drivers/bluetooth/hci_ldisc.c

   1 /*
   2  *
   3  *  Bluetooth HCI UART driver
   4  *
   5  *  Copyright (C) 2000-2001  Qualcomm Incorporated
   6  *  Copyright (C) 2002-2003  Maxim Krasnyansky <maxk@qualcomm.com>
   7  *  Copyright (C) 2004-2005  Marcel Holtmann <marcel@holtmann.org>
   8  *
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License as published by
  12  *  the Free Software Foundation; either version 2 of the License, or
  13  *  (at your option) any later version.
  14  *
  15  *  This program is distributed in the hope that it will be useful,
  16  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  *  GNU General Public License for more details.
  19  *
  20  *  You should have received a copy of the GNU General Public License
  21  *  along with this program; if not, write to the Free Software
  22  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  23  *
  24  */
  25
  26 #include <linux/module.h>
  27
  28 #include <linux/kernel.h>
  29 #include <linux/init.h>
  30 #include <linux/types.h>
  31 #include <linux/fcntl.h>
  32 #include <linux/interrupt.h>
  33 #include <linux/ptrace.h>
  34 #include <linux/poll.h>
  35
  36 #include <linux/slab.h>
  37 #include <linux/tty.h>
  38 #include <linux/errno.h>
  39 #include <linux/string.h>
  40 #include <linux/signal.h>
  41 #include <linux/ioctl.h>
  42 #include <linux/skbuff.h>
  43
  44 #include <net/bluetooth/bluetooth.h>
  45 #include <net/bluetooth/hci_core.h>
  46
  47 #include "hci_uart.h"
  48
  49 #define VERSION "2.2"
  50
  51 static struct hci_uart_proto *hup[HCI_UART_MAX_PROTO];
  52
  53 int hci_uart_register_proto(struct hci_uart_proto *p)
  54 {
  55         if (p->id >= HCI_UART_MAX_PROTO)
  56                 return -EINVAL;
  57
  58         if (hup[p->id])
  59                 return -EEXIST;
  60
  61         hup[p->id] = p;
  62
  63         return 0;
  64 }
  65
  66 int hci_uart_unregister_proto(struct hci_uart_proto *p)
  67 {
  68         if (p->id >= HCI_UART_MAX_PROTO)
  69                 return -EINVAL;
  70
  71         if (!hup[p->id])
  72                 return -EINVAL;
  73
  74         hup[p->id] = NULL;
  75
  76         return 0;
  77 }
  78
  79 static struct hci_uart_proto *hci_uart_get_proto(unsigned int id)
  80 {
  81         if (id >= HCI_UART_MAX_PROTO)
  82                 return NULL;
  83
  84         return hup[id];
  85 }
  86
  87 static inline void hci_uart_tx_complete(struct hci_uart *hu, int pkt_type)
  88 {
  89         struct hci_dev *hdev = hu->hdev;
  90
  91         /* Update HCI stat counters */
  92         switch (pkt_type) {
  93         case HCI_COMMAND_PKT:
  94                 hdev->stat.cmd_tx++;
  95                 break;
  96
  97         case HCI_ACLDATA_PKT:
  98                 hdev->stat.acl_tx++;
  99                 break;
 100
 101         case HCI_SCODATA_PKT:
 102                 hdev->stat.sco_tx++;
 103                 break;
 104         }
 105 }
 106
 107 static inline struct sk_buff *hci_uart_dequeue(struct hci_uart *hu)
 108 {
 109         struct sk_buff *skb = hu->tx_skb;
 110
 111         if (!skb)
 112                 skb = hu->proto->dequeue(hu);
 113         else
 114                 hu->tx_skb = NULL;
 115
 116         return skb;
 117 }
 118
 119 int hci_uart_tx_wakeup(struct hci_uart *hu)
 120 {
 121         if (test_and_set_bit(HCI_UART_SENDING, &hu->tx_state)) {
 122                 set_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
 123                 return 0;
 124         }
 125
 126         BT_DBG("");
 127
 128         schedule_work(&hu->write_work);
 129
 130         return 0;
 131 }
 132
 133 static void hci_uart_write_work(struct work_struct *work)
 134 {
 135         struct hci_uart *hu = container_of(work, struct hci_uart, write_work);
 136         struct tty_struct *tty = hu->tty;
 137         struct hci_dev *hdev = hu->hdev;
 138         struct sk_buff *skb;
 139
 140         /* REVISIT: should we cope with bad skbs or ->write() returning
 141          * and error value ?
 142          */
 143
 144 restart:
 145         clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
 146
 147         while ((skb = hci_uart_dequeue(hu))) {
 148                 int len;
 149
 150                 set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 151                 len = tty->ops->write(tty, skb->data, skb->len);
 152                 hdev->stat.byte_tx += len;
 153
 154                 skb_pull(skb, len);
 155                 if (skb->len) {
 156                         hu->tx_skb = skb;
 157                         break;
 158                 }
 159
 160                 hci_uart_tx_complete(hu, bt_cb(skb)->pkt_type);
 161                 kfree_skb(skb);
 162         }
 163
 164         if (test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state))
 165                 goto restart;
 166
 167         clear_bit(HCI_UART_SENDING, &hu->tx_state);
 168 }
 169
 170 static void hci_uart_init_work(struct work_struct *work)
 171 {
 172         struct hci_uart *hu = container_of(work, struct hci_uart, init_ready);
 173         int err;
 174
 175         if (!test_and_clear_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
 176                 return;
 177
 178         err = hci_register_dev(hu->hdev);
 179         if (err < 0) {
 180                 BT_ERR("Can't register HCI device");
 181                 hci_free_dev(hu->hdev);
 182                 hu->hdev = NULL;
 183                 hu->proto->close(hu);
 184         }
 185
 186         set_bit(HCI_UART_REGISTERED, &hu->flags);
 187 }
 188
 189 int hci_uart_init_ready(struct hci_uart *hu)
 190 {
 191         if (!test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
 192                 return -EALREADY;
 193
 194         schedule_work(&hu->init_ready);
 195
 196         return 0;
 197 }
 198
 199 /* ------- Interface to HCI layer ------ */
 200 /* Initialize device */
 201 static int hci_uart_open(struct hci_dev *hdev)
 202 {
 203         BT_DBG("%s %p", hdev->name, hdev);
 204
 205         /* Nothing to do for UART driver */
 206
 207         set_bit(HCI_RUNNING, &hdev->flags);
 208
 209         return 0;
 210 }
 211
 212 /* Reset device */
 213 static int hci_uart_flush(struct hci_dev *hdev)
 214 {
 215         struct hci_uart *hu  = hci_get_drvdata(hdev);
 216         struct tty_struct *tty = hu->tty;
 217
 218         BT_DBG("hdev %p tty %p", hdev, tty);
 219
 220         if (hu->tx_skb) {
 221                 kfree_skb(hu->tx_skb); hu->tx_skb = NULL;
 222         }
 223
 224         /* Flush any pending characters in the driver and discipline. */
 225         tty_ldisc_flush(tty);
 226         tty_driver_flush_buffer(tty);
 227
 228         if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 229                 hu->proto->flush(hu);
 230
 231         return 0;
 232 }
 233
 234 /* Close device */
 235 static int hci_uart_close(struct hci_dev *hdev)
 236 {
 237         BT_DBG("hdev %p", hdev);
 238
 239         if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
 240                 return 0;
 241
 242         hci_uart_flush(hdev);
 243         hdev->flush = NULL;
 244         return 0;
 245 }
 246
 247 /* Send frames from HCI layer */
 248 static int hci_uart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
 249 {
 250         struct hci_uart *hu = hci_get_drvdata(hdev);
 251
 252         if (!test_bit(HCI_RUNNING, &hdev->flags))
 253                 return -EBUSY;
 254
 255         BT_DBG("%s: type %d len %d", hdev->name, bt_cb(skb)->pkt_type, skb->len);
 256
 257         hu->proto->enqueue(hu, skb);
 258
 259         hci_uart_tx_wakeup(hu);
 260
 261         return 0;
 262 }
 263
 264 static int hci_uart_setup(struct hci_dev *hdev)
 265 {
 266         struct hci_uart *hu = hci_get_drvdata(hdev);
 267
 268         if (hu->proto->setup)
 269                 return hu->proto->setup(hu);
 270
 271         return 0;
 272 }
 273
 274 /* ------ LDISC part ------ */
 275 /* hci_uart_tty_open
 276  *
 277  *     Called when line discipline changed to HCI_UART.
 278  *
 279  * Arguments:
 280  *     tty    pointer to tty info structure
 281  * Return Value:
 282  *     0 if success, otherwise error code
 283  */
 284 static int hci_uart_tty_open(struct tty_struct *tty)
 285 {
 286         struct hci_uart *hu;
 287
 288         BT_DBG("tty %p", tty);
 289
 290         /* Error if the tty has no write op instead of leaving an exploitable
 291            hole */
 292         if (tty->ops->write == NULL)
 293                 return -EOPNOTSUPP;
 294
 295         hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL);
 296         if (!hu) {
 297                 BT_ERR("Can't allocate control structure");
 298                 return -ENFILE;
 299         }
 300
 301         tty->disc_data = hu;
 302         hu->tty = tty;
 303         tty->receive_room = 65536;
 304
 305         INIT_WORK(&hu->init_ready, hci_uart_init_work);
 306         INIT_WORK(&hu->write_work, hci_uart_write_work);
 307
 308         spin_lock_init(&hu->rx_lock);
 309
 310         /* Flush any pending characters in the driver and line discipline. */
 311
 312         /* FIXME: why is this needed. Note don't use ldisc_ref here as the
 313            open path is before the ldisc is referencable */
 314
 315         if (tty->ldisc->ops->flush_buffer)
 316                 tty->ldisc->ops->flush_buffer(tty);
 317         tty_driver_flush_buffer(tty);
 318
 319         return 0;
 320 }
 321
 322 /* hci_uart_tty_close()
 323  *
 324  *    Called when the line discipline is changed to something
 325  *    else, the tty is closed, or the tty detects a hangup.
 326  */
 327 static void hci_uart_tty_close(struct tty_struct *tty)
 328 {
 329         struct hci_uart *hu = (void *)tty->disc_data;
 330         struct hci_dev *hdev;
 331
 332         BT_DBG("tty %p", tty);
 333
 334         /* Detach from the tty */
 335         tty->disc_data = NULL;
 336
 337         if (!hu)
 338                 return;
 339
 340         hdev = hu->hdev;
 341         if (hdev)
 342                 hci_uart_close(hdev);
 343
 344         cancel_work_sync(&hu->write_work);
 345
 346         if (test_and_clear_bit(HCI_UART_PROTO_SET, &hu->flags)) {
 347                 if (hdev) {
 348                         if (test_bit(HCI_UART_REGISTERED, &hu->flags))
 349                                 hci_unregister_dev(hdev);
 350                         hci_free_dev(hdev);
 351                 }
 352                 hu->proto->close(hu);
 353         }
 354
 355         kfree(hu);
 356 }
 357
 358 /* hci_uart_tty_wakeup()
 359  *
 360  *    Callback for transmit wakeup. Called when low level
 361  *    device driver can accept more send data.
 362  *
 363  * Arguments:        tty    pointer to associated tty instance data
 364  * Return Value:    None
 365  */
 366 static void hci_uart_tty_wakeup(struct tty_struct *tty)
 367 {
 368         struct hci_uart *hu = (void *)tty->disc_data;
 369
 370         BT_DBG("");
 371
 372         if (!hu)
 373                 return;
 374
 375         clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 376
 377         if (tty != hu->tty)
 378                 return;
 379
 380         if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 381                 hci_uart_tx_wakeup(hu);
 382 }
 383
 384 /* hci_uart_tty_receive()
 385  *
 386  *     Called by tty low level driver when receive data is
 387  *     available.
 388  *
 389  * Arguments:  tty          pointer to tty isntance data
 390  *             data         pointer to received data
 391  *             flags        pointer to flags for data
 392  *             count        count of received data in bytes
 393  *
 394  * Return Value:    None
 395  */
 396 static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data, char *flags, int count)
 397 {
 398         struct hci_uart *hu = (void *)tty->disc_data;
 399
 400         if (!hu || tty != hu->tty)
 401                 return;
 402
 403         if (!test_bit(HCI_UART_PROTO_SET, &hu->flags))
 404                 return;
 405
 406         spin_lock(&hu->rx_lock);
 407         hu->proto->recv(hu, (void *) data, count);
 408
 409         if (hu->hdev)
 410                 hu->hdev->stat.byte_rx += count;
 411
 412         spin_unlock(&hu->rx_lock);
 413
 414         tty_unthrottle(tty);
 415 }
 416
 417 static int hci_uart_register_dev(struct hci_uart *hu)
 418 {
 419         struct hci_dev *hdev;
 420
 421         BT_DBG("");
 422
 423         /* Initialize and register HCI device */
 424         hdev = hci_alloc_dev();
 425         if (!hdev) {
 426                 BT_ERR("Can't allocate HCI device");
 427                 return -ENOMEM;
 428         }
 429
 430         hu->hdev = hdev;
 431
 432         hdev->bus = HCI_UART;
 433         hci_set_drvdata(hdev, hu);
 434
 435         hdev->open  = hci_uart_open;
 436         hdev->close = hci_uart_close;
 437         hdev->flush = hci_uart_flush;
 438         hdev->send  = hci_uart_send_frame;
 439         hdev->setup = hci_uart_setup;
 440         SET_HCIDEV_DEV(hdev, hu->tty->dev);
 441
 442         if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
 443                 set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
 444
 445         if (test_bit(HCI_UART_EXT_CONFIG, &hu->hdev_flags))
 446                 set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
 447
 448         if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
 449                 set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
 450
 451         if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
 452                 hdev->dev_type = HCI_AMP;
 453         else
 454                 hdev->dev_type = HCI_BREDR;
 455
 456         if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
 457                 return 0;
 458
 459         if (hci_register_dev(hdev) < 0) {
 460                 BT_ERR("Can't register HCI device");
 461                 hci_free_dev(hdev);
 462                 return -ENODEV;
 463         }
 464
 465         set_bit(HCI_UART_REGISTERED, &hu->flags);
 466
 467         return 0;
 468 }
 469
 470 static int hci_uart_set_proto(struct hci_uart *hu, int id)
 471 {
 472         struct hci_uart_proto *p;
 473         int err;
 474
 475         p = hci_uart_get_proto(id);
 476         if (!p)
 477                 return -EPROTONOSUPPORT;
 478
 479         err = p->open(hu);
 480         if (err)
 481                 return err;
 482
 483         hu->proto = p;
 484
 485         err = hci_uart_register_dev(hu);
 486         if (err) {
 487                 p->close(hu);
 488                 return err;
 489         }
 490
 491         return 0;
 492 }
 493
 494 static int hci_uart_set_flags(struct hci_uart *hu, unsigned long flags)
 495 {
 496         unsigned long valid_flags = BIT(HCI_UART_RAW_DEVICE) |
 497                                     BIT(HCI_UART_RESET_ON_INIT) |
 498                                     BIT(HCI_UART_CREATE_AMP) |
 499                                     BIT(HCI_UART_INIT_PENDING) |
 500                                     BIT(HCI_UART_EXT_CONFIG);
 501
 502         if (flags & ~valid_flags)
 503                 return -EINVAL;
 504
 505         hu->hdev_flags = flags;
 506
 507         return 0;
 508 }
 509
 510 /* hci_uart_tty_ioctl()
 511  *
 512  *    Process IOCTL system call for the tty device.
 513  *
 514  * Arguments:
 515  *
 516  *    tty        pointer to tty instance data
 517  *    file       pointer to open file object for device
 518  *    cmd        IOCTL command code
 519  *    arg        argument for IOCTL call (cmd dependent)
 520  *
 521  * Return Value:    Command dependent
 522  */
 523 static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file * file,
 524                                         unsigned int cmd, unsigned long arg)
 525 {
 526         struct hci_uart *hu = (void *)tty->disc_data;
 527         int err = 0;
 528
 529         BT_DBG("");
 530
 531         /* Verify the status of the device */
 532         if (!hu)
 533                 return -EBADF;
 534
 535         switch (cmd) {
 536         case HCIUARTSETPROTO:
 537                 if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) {
 538                         err = hci_uart_set_proto(hu, arg);
 539                         if (err) {
 540                                 clear_bit(HCI_UART_PROTO_SET, &hu->flags);
 541                                 return err;
 542                         }
 543                 } else
 544                         return -EBUSY;
 545                 break;
 546
 547         case HCIUARTGETPROTO:
 548                 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 549                         return hu->proto->id;
 550                 return -EUNATCH;
 551
 552         case HCIUARTGETDEVICE:
 553                 if (test_bit(HCI_UART_REGISTERED, &hu->flags))
 554                         return hu->hdev->id;
 555                 return -EUNATCH;
 556
 557         case HCIUARTSETFLAGS:
 558                 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 559                         return -EBUSY;
 560                 err = hci_uart_set_flags(hu, arg);
 561                 if (err)
 562                         return err;
 563                 break;
 564
 565         case HCIUARTGETFLAGS:
 566                 return hu->hdev_flags;
 567
 568         default:
 569                 err = n_tty_ioctl_helper(tty, file, cmd, arg);
 570                 break;
 571         }
 572
 573         return err;
 574 }
 575
 576 /*
 577  * We don't provide read/write/poll interface for user space.
 578  */
 579 static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file,
 580                                         unsigned char __user *buf, size_t nr)
 581 {
 582         return 0;
 583 }
 584
 585 static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file,
 586                                         const unsigned char *data, size_t count)
 587 {
 588         return 0;
 589 }
 590
 591 static unsigned int hci_uart_tty_poll(struct tty_struct *tty,
 592                                         struct file *filp, poll_table *wait)
 593 {
 594         return 0;
 595 }
 596
 597 static int __init hci_uart_init(void)
 598 {
 599         static struct tty_ldisc_ops hci_uart_ldisc;
 600         int err;
 601
 602         BT_INFO("HCI UART driver ver %s", VERSION);
 603
 604         /* Register the tty discipline */
 605
 606         memset(&hci_uart_ldisc, 0, sizeof (hci_uart_ldisc));
 607         hci_uart_ldisc.magic            = TTY_LDISC_MAGIC;
 608         hci_uart_ldisc.name             = "n_hci";
 609         hci_uart_ldisc.open             = hci_uart_tty_open;
 610         hci_uart_ldisc.close            = hci_uart_tty_close;
 611         hci_uart_ldisc.read             = hci_uart_tty_read;
 612         hci_uart_ldisc.write            = hci_uart_tty_write;
 613         hci_uart_ldisc.ioctl            = hci_uart_tty_ioctl;
 614         hci_uart_ldisc.poll             = hci_uart_tty_poll;
 615         hci_uart_ldisc.receive_buf      = hci_uart_tty_receive;
 616         hci_uart_ldisc.write_wakeup     = hci_uart_tty_wakeup;
 617         hci_uart_ldisc.owner            = THIS_MODULE;
 618
 619         err = tty_register_ldisc(N_HCI, &hci_uart_ldisc);
 620         if (err) {
 621                 BT_ERR("HCI line discipline registration failed. (%d)", err);
 622                 return err;
 623         }
 624
 625 #ifdef CONFIG_BT_HCIUART_H4
 626         h4_init();
 627 #endif
 628 #ifdef CONFIG_BT_HCIUART_BCSP
 629         bcsp_init();
 630 #endif
 631 #ifdef CONFIG_BT_HCIUART_LL
 632         ll_init();
 633 #endif
 634 #ifdef CONFIG_BT_HCIUART_ATH3K
 635         ath_init();
 636 #endif
 637 #ifdef CONFIG_BT_HCIUART_3WIRE
 638         h5_init();
 639 #endif
 640
 641         return 0;
 642 }
 643
 644 static void __exit hci_uart_exit(void)
 645 {
 646         int err;
 647
 648 #ifdef CONFIG_BT_HCIUART_H4
 649         h4_deinit();
 650 #endif
 651 #ifdef CONFIG_BT_HCIUART_BCSP
 652         bcsp_deinit();
 653 #endif
 654 #ifdef CONFIG_BT_HCIUART_LL
 655         ll_deinit();
 656 #endif
 657 #ifdef CONFIG_BT_HCIUART_ATH3K
 658         ath_deinit();
 659 #endif
 660 #ifdef CONFIG_BT_HCIUART_3WIRE
 661         h5_deinit();
 662 #endif
 663
 664         /* Release tty registration of line discipline */
 665         err = tty_unregister_ldisc(N_HCI);
 666         if (err)
 667                 BT_ERR("Can't unregister HCI line discipline (%d)", err);
 668 }
 669
 670 module_init(hci_uart_init);
 671 module_exit(hci_uart_exit);
 672
 673 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
 674 MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION);
 675 MODULE_VERSION(VERSION);
 676 MODULE_LICENSE("GPL");
 677 MODULE_ALIAS_LDISC(N_HCI);