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