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         struct tty_struct *tty = hu->tty;
 122         struct hci_dev *hdev = hu->hdev;
 123         struct sk_buff *skb;
 124
 125         if (test_and_set_bit(HCI_UART_SENDING, &hu->tx_state)) {
 126                 set_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
 127                 return 0;
 128         }
 129
 130         BT_DBG("");
 131
 132 restart:
 133         clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
 134
 135         while ((skb = hci_uart_dequeue(hu))) {
 136                 int len;
 137
 138                 set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 139                 len = tty->ops->write(tty, skb->data, skb->len);
 140                 hdev->stat.byte_tx += len;
 141
 142                 skb_pull(skb, len);
 143                 if (skb->len) {
 144                         hu->tx_skb = skb;
 145                         break;
 146                 }
 147
 148                 hci_uart_tx_complete(hu, bt_cb(skb)->pkt_type);
 149                 kfree_skb(skb);
 150         }
 151
 152         if (test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state))
 153                 goto restart;
 154
 155         clear_bit(HCI_UART_SENDING, &hu->tx_state);
 156         return 0;
 157 }
 158
 159 static void hci_uart_init_work(struct work_struct *work)
 160 {
 161         struct hci_uart *hu = container_of(work, struct hci_uart, init_ready);
 162         int err;
 163
 164         if (!test_and_clear_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
 165                 return;
 166
 167         err = hci_register_dev(hu->hdev);
 168         if (err < 0) {
 169                 BT_ERR("Can't register HCI device");
 170                 hci_free_dev(hu->hdev);
 171                 hu->hdev = NULL;
 172                 hu->proto->close(hu);
 173         }
 174
 175         set_bit(HCI_UART_REGISTERED, &hu->flags);
 176 }
 177
 178 int hci_uart_init_ready(struct hci_uart *hu)
 179 {
 180         if (!test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
 181                 return -EALREADY;
 182
 183         schedule_work(&hu->init_ready);
 184
 185         return 0;
 186 }
 187
 188 /* ------- Interface to HCI layer ------ */
 189 /* Initialize device */
 190 static int hci_uart_open(struct hci_dev *hdev)
 191 {
 192         BT_DBG("%s %p", hdev->name, hdev);
 193
 194         /* Nothing to do for UART driver */
 195
 196         set_bit(HCI_RUNNING, &hdev->flags);
 197
 198         return 0;
 199 }
 200
 201 /* Reset device */
 202 static int hci_uart_flush(struct hci_dev *hdev)
 203 {
 204         struct hci_uart *hu  = hci_get_drvdata(hdev);
 205         struct tty_struct *tty = hu->tty;
 206
 207         BT_DBG("hdev %p tty %p", hdev, tty);
 208
 209         if (hu->tx_skb) {
 210                 kfree_skb(hu->tx_skb); hu->tx_skb = NULL;
 211         }
 212
 213         /* Flush any pending characters in the driver and discipline. */
 214         tty_ldisc_flush(tty);
 215         tty_driver_flush_buffer(tty);
 216
 217         if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 218                 hu->proto->flush(hu);
 219
 220         return 0;
 221 }
 222
 223 /* Close device */
 224 static int hci_uart_close(struct hci_dev *hdev)
 225 {
 226         BT_DBG("hdev %p", hdev);
 227
 228         if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
 229                 return 0;
 230
 231         hci_uart_flush(hdev);
 232         hdev->flush = NULL;
 233         return 0;
 234 }
 235
 236 /* Send frames from HCI layer */
 237 static int hci_uart_send_frame(struct sk_buff *skb)
 238 {
 239         struct hci_dev* hdev = (struct hci_dev *) skb->dev;
 240         struct hci_uart *hu;
 241
 242         if (!hdev) {
 243                 BT_ERR("Frame for unknown device (hdev=NULL)");
 244                 return -ENODEV;
 245         }
 246
 247         if (!test_bit(HCI_RUNNING, &hdev->flags))
 248                 return -EBUSY;
 249
 250         hu = hci_get_drvdata(hdev);
 251
 252         BT_DBG("%s: type %d len %d", hdev->name, bt_cb(skb)->pkt_type, skb->len);
 253
 254         hu->proto->enqueue(hu, skb);
 255
 256         hci_uart_tx_wakeup(hu);
 257
 258         return 0;
 259 }
 260
 261 /* ------ LDISC part ------ */
 262 /* hci_uart_tty_open
 263  *
 264  *     Called when line discipline changed to HCI_UART.
 265  *
 266  * Arguments:
 267  *     tty    pointer to tty info structure
 268  * Return Value:
 269  *     0 if success, otherwise error code
 270  */
 271 static int hci_uart_tty_open(struct tty_struct *tty)
 272 {
 273         struct hci_uart *hu = (void *) tty->disc_data;
 274
 275         BT_DBG("tty %p", tty);
 276
 277         /* FIXME: This btw is bogus, nothing requires the old ldisc to clear
 278            the pointer */
 279         if (hu)
 280                 return -EEXIST;
 281
 282         /* Error if the tty has no write op instead of leaving an exploitable
 283            hole */
 284         if (tty->ops->write == NULL)
 285                 return -EOPNOTSUPP;
 286
 287         if (!(hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL))) {
 288                 BT_ERR("Can't allocate control structure");
 289                 return -ENFILE;
 290         }
 291
 292         tty->disc_data = hu;
 293         hu->tty = tty;
 294         tty->receive_room = 65536;
 295
 296         INIT_WORK(&hu->init_ready, hci_uart_init_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         if (test_and_clear_bit(HCI_UART_PROTO_SET, &hu->flags)) {
 335                 if (hdev) {
 336                         if (test_bit(HCI_UART_REGISTERED, &hu->flags))
 337                                 hci_unregister_dev(hdev);
 338                         hci_free_dev(hdev);
 339                 }
 340                 hu->proto->close(hu);
 341         }
 342
 343         kfree(hu);
 344 }
 345
 346 /* hci_uart_tty_wakeup()
 347  *
 348  *    Callback for transmit wakeup. Called when low level
 349  *    device driver can accept more send data.
 350  *
 351  * Arguments:        tty    pointer to associated tty instance data
 352  * Return Value:    None
 353  */
 354 static void hci_uart_tty_wakeup(struct tty_struct *tty)
 355 {
 356         struct hci_uart *hu = (void *)tty->disc_data;
 357
 358         BT_DBG("");
 359
 360         if (!hu)
 361                 return;
 362
 363         clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 364
 365         if (tty != hu->tty)
 366                 return;
 367
 368         if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 369                 hci_uart_tx_wakeup(hu);
 370 }
 371
 372 /* hci_uart_tty_receive()
 373  *
 374  *     Called by tty low level driver when receive data is
 375  *     available.
 376  *
 377  * Arguments:  tty          pointer to tty isntance data
 378  *             data         pointer to received data
 379  *             flags        pointer to flags for data
 380  *             count        count of received data in bytes
 381  *
 382  * Return Value:    None
 383  */
 384 static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data, char *flags, int count)
 385 {
 386         struct hci_uart *hu = (void *)tty->disc_data;
 387
 388         if (!hu || tty != hu->tty)
 389                 return;
 390
 391         if (!test_bit(HCI_UART_PROTO_SET, &hu->flags))
 392                 return;
 393
 394         spin_lock(&hu->rx_lock);
 395         hu->proto->recv(hu, (void *) data, count);
 396         hu->hdev->stat.byte_rx += count;
 397         spin_unlock(&hu->rx_lock);
 398
 399         tty_unthrottle(tty);
 400 }
 401
 402 static int hci_uart_register_dev(struct hci_uart *hu)
 403 {
 404         struct hci_dev *hdev;
 405
 406         BT_DBG("");
 407
 408         /* Initialize and register HCI device */
 409         hdev = hci_alloc_dev();
 410         if (!hdev) {
 411                 BT_ERR("Can't allocate HCI device");
 412                 return -ENOMEM;
 413         }
 414
 415         hu->hdev = hdev;
 416
 417         hdev->bus = HCI_UART;
 418         hci_set_drvdata(hdev, hu);
 419
 420         hdev->open  = hci_uart_open;
 421         hdev->close = hci_uart_close;
 422         hdev->flush = hci_uart_flush;
 423         hdev->send  = hci_uart_send_frame;
 424         SET_HCIDEV_DEV(hdev, hu->tty->dev);
 425
 426         if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
 427                 set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
 428
 429         if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
 430                 set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
 431
 432         if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
 433                 hdev->dev_type = HCI_AMP;
 434         else
 435                 hdev->dev_type = HCI_BREDR;
 436
 437         if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
 438                 return 0;
 439
 440         if (hci_register_dev(hdev) < 0) {
 441                 BT_ERR("Can't register HCI device");
 442                 hci_free_dev(hdev);
 443                 return -ENODEV;
 444         }
 445
 446         set_bit(HCI_UART_REGISTERED, &hu->flags);
 447
 448         return 0;
 449 }
 450
 451 static int hci_uart_set_proto(struct hci_uart *hu, int id)
 452 {
 453         struct hci_uart_proto *p;
 454         int err;
 455
 456         p = hci_uart_get_proto(id);
 457         if (!p)
 458                 return -EPROTONOSUPPORT;
 459
 460         err = p->open(hu);
 461         if (err)
 462                 return err;
 463
 464         hu->proto = p;
 465
 466         err = hci_uart_register_dev(hu);
 467         if (err) {
 468                 p->close(hu);
 469                 return err;
 470         }
 471
 472         return 0;
 473 }
 474
 475 /* hci_uart_tty_ioctl()
 476  *
 477  *    Process IOCTL system call for the tty device.
 478  *
 479  * Arguments:
 480  *
 481  *    tty        pointer to tty instance data
 482  *    file       pointer to open file object for device
 483  *    cmd        IOCTL command code
 484  *    arg        argument for IOCTL call (cmd dependent)
 485  *
 486  * Return Value:    Command dependent
 487  */
 488 static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file * file,
 489                                         unsigned int cmd, unsigned long arg)
 490 {
 491         struct hci_uart *hu = (void *)tty->disc_data;
 492         int err = 0;
 493
 494         BT_DBG("");
 495
 496         /* Verify the status of the device */
 497         if (!hu)
 498                 return -EBADF;
 499
 500         switch (cmd) {
 501         case HCIUARTSETPROTO:
 502                 if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) {
 503                         err = hci_uart_set_proto(hu, arg);
 504                         if (err) {
 505                                 clear_bit(HCI_UART_PROTO_SET, &hu->flags);
 506                                 return err;
 507                         }
 508                 } else
 509                         return -EBUSY;
 510                 break;
 511
 512         case HCIUARTGETPROTO:
 513                 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 514                         return hu->proto->id;
 515                 return -EUNATCH;
 516
 517         case HCIUARTGETDEVICE:
 518                 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 519                         return hu->hdev->id;
 520                 return -EUNATCH;
 521
 522         case HCIUARTSETFLAGS:
 523                 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 524                         return -EBUSY;
 525                 hu->hdev_flags = arg;
 526                 break;
 527
 528         case HCIUARTGETFLAGS:
 529                 return hu->hdev_flags;
 530
 531         default:
 532                 err = n_tty_ioctl_helper(tty, file, cmd, arg);
 533                 break;
 534         };
 535
 536         return err;
 537 }
 538
 539 /*
 540  * We don't provide read/write/poll interface for user space.
 541  */
 542 static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file,
 543                                         unsigned char __user *buf, size_t nr)
 544 {
 545         return 0;
 546 }
 547
 548 static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file,
 549                                         const unsigned char *data, size_t count)
 550 {
 551         return 0;
 552 }
 553
 554 static unsigned int hci_uart_tty_poll(struct tty_struct *tty,
 555                                         struct file *filp, poll_table *wait)
 556 {
 557         return 0;
 558 }
 559
 560 static int __init hci_uart_init(void)
 561 {
 562         static struct tty_ldisc_ops hci_uart_ldisc;
 563         int err;
 564
 565         BT_INFO("HCI UART driver ver %s", VERSION);
 566
 567         /* Register the tty discipline */
 568
 569         memset(&hci_uart_ldisc, 0, sizeof (hci_uart_ldisc));
 570         hci_uart_ldisc.magic            = TTY_LDISC_MAGIC;
 571         hci_uart_ldisc.name             = "n_hci";
 572         hci_uart_ldisc.open             = hci_uart_tty_open;
 573         hci_uart_ldisc.close            = hci_uart_tty_close;
 574         hci_uart_ldisc.read             = hci_uart_tty_read;
 575         hci_uart_ldisc.write            = hci_uart_tty_write;
 576         hci_uart_ldisc.ioctl            = hci_uart_tty_ioctl;
 577         hci_uart_ldisc.poll             = hci_uart_tty_poll;
 578         hci_uart_ldisc.receive_buf      = hci_uart_tty_receive;
 579         hci_uart_ldisc.write_wakeup     = hci_uart_tty_wakeup;
 580         hci_uart_ldisc.owner            = THIS_MODULE;
 581
 582         if ((err = tty_register_ldisc(N_HCI, &hci_uart_ldisc))) {
 583                 BT_ERR("HCI line discipline registration failed. (%d)", err);
 584                 return err;
 585         }
 586
 587 #ifdef CONFIG_BT_HCIUART_H4
 588         h4_init();
 589 #endif
 590 #ifdef CONFIG_BT_HCIUART_BCSP
 591         bcsp_init();
 592 #endif
 593 #ifdef CONFIG_BT_HCIUART_LL
 594         ll_init();
 595 #endif
 596 #ifdef CONFIG_BT_HCIUART_ATH3K
 597         ath_init();
 598 #endif
 599 #ifdef CONFIG_BT_HCIUART_3WIRE
 600         h5_init();
 601 #endif
 602
 603         return 0;
 604 }
 605
 606 static void __exit hci_uart_exit(void)
 607 {
 608         int err;
 609
 610 #ifdef CONFIG_BT_HCIUART_H4
 611         h4_deinit();
 612 #endif
 613 #ifdef CONFIG_BT_HCIUART_BCSP
 614         bcsp_deinit();
 615 #endif
 616 #ifdef CONFIG_BT_HCIUART_LL
 617         ll_deinit();
 618 #endif
 619 #ifdef CONFIG_BT_HCIUART_ATH3K
 620         ath_deinit();
 621 #endif
 622 #ifdef CONFIG_BT_HCIUART_3WIRE
 623         h5_deinit();
 624 #endif
 625
 626         /* Release tty registration of line discipline */
 627         if ((err = tty_unregister_ldisc(N_HCI)))
 628                 BT_ERR("Can't unregister HCI line discipline (%d)", err);
 629 }
 630
 631 module_init(hci_uart_init);
 632 module_exit(hci_uart_exit);
 633
 634 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
 635 MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION);
 636 MODULE_VERSION(VERSION);
 637 MODULE_LICENSE("GPL");
 638 MODULE_ALIAS_LDISC(N_HCI);