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 /* ------ LDISC part ------ */
 265 /* hci_uart_tty_open
 266  *
 267  *     Called when line discipline changed to HCI_UART.
 268  *
 269  * Arguments:
 270  *     tty    pointer to tty info structure
 271  * Return Value:
 272  *     0 if success, otherwise error code
 273  */
 274 static int hci_uart_tty_open(struct tty_struct *tty)
 275 {
 276         struct hci_uart *hu;
 277
 278         BT_DBG("tty %p", tty);
 279
 280         /* Error if the tty has no write op instead of leaving an exploitable
 281            hole */
 282         if (tty->ops->write == NULL)
 283                 return -EOPNOTSUPP;
 284
 285         hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL);
 286         if (!hu) {
 287                 BT_ERR("Can't allocate control structure");
 288                 return -ENFILE;
 289         }
 290
 291         tty->disc_data = hu;
 292         hu->tty = tty;
 293         tty->receive_room = 65536;
 294
 295         INIT_WORK(&hu->init_ready, hci_uart_init_work);
 296         INIT_WORK(&hu->write_work, hci_uart_write_work);
 297
 298         spin_lock_init(&hu->rx_lock);
 299
 300         /* Flush any pending characters in the driver and line discipline. */
 301
 302         /* FIXME: why is this needed. Note don't use ldisc_ref here as the
 303            open path is before the ldisc is referencable */
 304
 305         if (tty->ldisc->ops->flush_buffer)
 306                 tty->ldisc->ops->flush_buffer(tty);
 307         tty_driver_flush_buffer(tty);
 308
 309         return 0;
 310 }
 311
 312 /* hci_uart_tty_close()
 313  *
 314  *    Called when the line discipline is changed to something
 315  *    else, the tty is closed, or the tty detects a hangup.
 316  */
 317 static void hci_uart_tty_close(struct tty_struct *tty)
 318 {
 319         struct hci_uart *hu = (void *)tty->disc_data;
 320         struct hci_dev *hdev;
 321
 322         BT_DBG("tty %p", tty);
 323
 324         /* Detach from the tty */
 325         tty->disc_data = NULL;
 326
 327         if (!hu)
 328                 return;
 329
 330         hdev = hu->hdev;
 331         if (hdev)
 332                 hci_uart_close(hdev);
 333
 334         cancel_work_sync(&hu->write_work);
 335
 336         if (test_and_clear_bit(HCI_UART_PROTO_SET, &hu->flags)) {
 337                 if (hdev) {
 338                         if (test_bit(HCI_UART_REGISTERED, &hu->flags))
 339                                 hci_unregister_dev(hdev);
 340                         hci_free_dev(hdev);
 341                 }
 342                 hu->proto->close(hu);
 343         }
 344
 345         kfree(hu);
 346 }
 347
 348 /* hci_uart_tty_wakeup()
 349  *
 350  *    Callback for transmit wakeup. Called when low level
 351  *    device driver can accept more send data.
 352  *
 353  * Arguments:        tty    pointer to associated tty instance data
 354  * Return Value:    None
 355  */
 356 static void hci_uart_tty_wakeup(struct tty_struct *tty)
 357 {
 358         struct hci_uart *hu = (void *)tty->disc_data;
 359
 360         BT_DBG("");
 361
 362         if (!hu)
 363                 return;
 364
 365         clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 366
 367         if (tty != hu->tty)
 368                 return;
 369
 370         if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 371                 hci_uart_tx_wakeup(hu);
 372 }
 373
 374 /* hci_uart_tty_receive()
 375  *
 376  *     Called by tty low level driver when receive data is
 377  *     available.
 378  *
 379  * Arguments:  tty          pointer to tty isntance data
 380  *             data         pointer to received data
 381  *             flags        pointer to flags for data
 382  *             count        count of received data in bytes
 383  *
 384  * Return Value:    None
 385  */
 386 static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data, char *flags, int count)
 387 {
 388         struct hci_uart *hu = (void *)tty->disc_data;
 389
 390         if (!hu || tty != hu->tty)
 391                 return;
 392
 393         if (!test_bit(HCI_UART_PROTO_SET, &hu->flags))
 394                 return;
 395
 396         spin_lock(&hu->rx_lock);
 397         hu->proto->recv(hu, (void *) data, count);
 398
 399         if (hu->hdev)
 400                 hu->hdev->stat.byte_rx += count;
 401
 402         spin_unlock(&hu->rx_lock);
 403
 404         tty_unthrottle(tty);
 405 }
 406
 407 static int hci_uart_register_dev(struct hci_uart *hu)
 408 {
 409         struct hci_dev *hdev;
 410
 411         BT_DBG("");
 412
 413         /* Initialize and register HCI device */
 414         hdev = hci_alloc_dev();
 415         if (!hdev) {
 416                 BT_ERR("Can't allocate HCI device");
 417                 return -ENOMEM;
 418         }
 419
 420         hu->hdev = hdev;
 421
 422         hdev->bus = HCI_UART;
 423         hci_set_drvdata(hdev, hu);
 424
 425         hdev->open  = hci_uart_open;
 426         hdev->close = hci_uart_close;
 427         hdev->flush = hci_uart_flush;
 428         hdev->send  = hci_uart_send_frame;
 429         SET_HCIDEV_DEV(hdev, hu->tty->dev);
 430
 431         if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
 432                 set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
 433
 434         if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
 435                 set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
 436
 437         if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
 438                 hdev->dev_type = HCI_AMP;
 439         else
 440                 hdev->dev_type = HCI_BREDR;
 441
 442         if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
 443                 return 0;
 444
 445         if (hci_register_dev(hdev) < 0) {
 446                 BT_ERR("Can't register HCI device");
 447                 hci_free_dev(hdev);
 448                 return -ENODEV;
 449         }
 450
 451         set_bit(HCI_UART_REGISTERED, &hu->flags);
 452
 453         return 0;
 454 }
 455
 456 static int hci_uart_set_proto(struct hci_uart *hu, int id)
 457 {
 458         struct hci_uart_proto *p;
 459         int err;
 460
 461         p = hci_uart_get_proto(id);
 462         if (!p)
 463                 return -EPROTONOSUPPORT;
 464
 465         err = p->open(hu);
 466         if (err)
 467                 return err;
 468
 469         hu->proto = p;
 470
 471         err = hci_uart_register_dev(hu);
 472         if (err) {
 473                 p->close(hu);
 474                 return err;
 475         }
 476
 477         return 0;
 478 }
 479
 480 /* hci_uart_tty_ioctl()
 481  *
 482  *    Process IOCTL system call for the tty device.
 483  *
 484  * Arguments:
 485  *
 486  *    tty        pointer to tty instance data
 487  *    file       pointer to open file object for device
 488  *    cmd        IOCTL command code
 489  *    arg        argument for IOCTL call (cmd dependent)
 490  *
 491  * Return Value:    Command dependent
 492  */
 493 static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file * file,
 494                                         unsigned int cmd, unsigned long arg)
 495 {
 496         struct hci_uart *hu = (void *)tty->disc_data;
 497         int err = 0;
 498
 499         BT_DBG("");
 500
 501         /* Verify the status of the device */
 502         if (!hu)
 503                 return -EBADF;
 504
 505         switch (cmd) {
 506         case HCIUARTSETPROTO:
 507                 if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) {
 508                         err = hci_uart_set_proto(hu, arg);
 509                         if (err) {
 510                                 clear_bit(HCI_UART_PROTO_SET, &hu->flags);
 511                                 return err;
 512                         }
 513                 } else
 514                         return -EBUSY;
 515                 break;
 516
 517         case HCIUARTGETPROTO:
 518                 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 519                         return hu->proto->id;
 520                 return -EUNATCH;
 521
 522         case HCIUARTGETDEVICE:
 523                 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 524                         return hu->hdev->id;
 525                 return -EUNATCH;
 526
 527         case HCIUARTSETFLAGS:
 528                 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 529                         return -EBUSY;
 530                 hu->hdev_flags = arg;
 531                 break;
 532
 533         case HCIUARTGETFLAGS:
 534                 return hu->hdev_flags;
 535
 536         default:
 537                 err = n_tty_ioctl_helper(tty, file, cmd, arg);
 538                 break;
 539         }
 540
 541         return err;
 542 }
 543
 544 /*
 545  * We don't provide read/write/poll interface for user space.
 546  */
 547 static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file,
 548                                         unsigned char __user *buf, size_t nr)
 549 {
 550         return 0;
 551 }
 552
 553 static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file,
 554                                         const unsigned char *data, size_t count)
 555 {
 556         return 0;
 557 }
 558
 559 static unsigned int hci_uart_tty_poll(struct tty_struct *tty,
 560                                         struct file *filp, poll_table *wait)
 561 {
 562         return 0;
 563 }
 564
 565 static int __init hci_uart_init(void)
 566 {
 567         static struct tty_ldisc_ops hci_uart_ldisc;
 568         int err;
 569
 570         BT_INFO("HCI UART driver ver %s", VERSION);
 571
 572         /* Register the tty discipline */
 573
 574         memset(&hci_uart_ldisc, 0, sizeof (hci_uart_ldisc));
 575         hci_uart_ldisc.magic            = TTY_LDISC_MAGIC;
 576         hci_uart_ldisc.name             = "n_hci";
 577         hci_uart_ldisc.open             = hci_uart_tty_open;
 578         hci_uart_ldisc.close            = hci_uart_tty_close;
 579         hci_uart_ldisc.read             = hci_uart_tty_read;
 580         hci_uart_ldisc.write            = hci_uart_tty_write;
 581         hci_uart_ldisc.ioctl            = hci_uart_tty_ioctl;
 582         hci_uart_ldisc.poll             = hci_uart_tty_poll;
 583         hci_uart_ldisc.receive_buf      = hci_uart_tty_receive;
 584         hci_uart_ldisc.write_wakeup     = hci_uart_tty_wakeup;
 585         hci_uart_ldisc.owner            = THIS_MODULE;
 586
 587         err = tty_register_ldisc(N_HCI, &hci_uart_ldisc);
 588         if (err) {
 589                 BT_ERR("HCI line discipline registration failed. (%d)", err);
 590                 return err;
 591         }
 592
 593 #ifdef CONFIG_BT_HCIUART_H4
 594         h4_init();
 595 #endif
 596 #ifdef CONFIG_BT_HCIUART_BCSP
 597         bcsp_init();
 598 #endif
 599 #ifdef CONFIG_BT_HCIUART_LL
 600         ll_init();
 601 #endif
 602 #ifdef CONFIG_BT_HCIUART_ATH3K
 603         ath_init();
 604 #endif
 605 #ifdef CONFIG_BT_HCIUART_3WIRE
 606         h5_init();
 607 #endif
 608
 609         return 0;
 610 }
 611
 612 static void __exit hci_uart_exit(void)
 613 {
 614         int err;
 615
 616 #ifdef CONFIG_BT_HCIUART_H4
 617         h4_deinit();
 618 #endif
 619 #ifdef CONFIG_BT_HCIUART_BCSP
 620         bcsp_deinit();
 621 #endif
 622 #ifdef CONFIG_BT_HCIUART_LL
 623         ll_deinit();
 624 #endif
 625 #ifdef CONFIG_BT_HCIUART_ATH3K
 626         ath_deinit();
 627 #endif
 628 #ifdef CONFIG_BT_HCIUART_3WIRE
 629         h5_deinit();
 630 #endif
 631
 632         /* Release tty registration of line discipline */
 633         err = tty_unregister_ldisc(N_HCI);
 634         if (err)
 635                 BT_ERR("Can't unregister HCI line discipline (%d)", err);
 636 }
 637
 638 module_init(hci_uart_init);
 639 module_exit(hci_uart_exit);
 640
 641 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
 642 MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION);
 643 MODULE_VERSION(VERSION);
 644 MODULE_LICENSE("GPL");
 645 MODULE_ALIAS_LDISC(N_HCI);