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 /* ------- Interface to HCI layer ------ */
 160 /* Initialize device */
 161 static int hci_uart_open(struct hci_dev *hdev)
 162 {
 163         BT_DBG("%s %p", hdev->name, hdev);
 164
 165         /* Nothing to do for UART driver */
 166
 167         set_bit(HCI_RUNNING, &hdev->flags);
 168
 169         return 0;
 170 }
 171
 172 /* Reset device */
 173 static int hci_uart_flush(struct hci_dev *hdev)
 174 {
 175         struct hci_uart *hu  = hci_get_drvdata(hdev);
 176         struct tty_struct *tty = hu->tty;
 177
 178         BT_DBG("hdev %p tty %p", hdev, tty);
 179
 180         if (hu->tx_skb) {
 181                 kfree_skb(hu->tx_skb); hu->tx_skb = NULL;
 182         }
 183
 184         /* Flush any pending characters in the driver and discipline. */
 185         tty_ldisc_flush(tty);
 186         tty_driver_flush_buffer(tty);
 187
 188         if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 189                 hu->proto->flush(hu);
 190
 191         return 0;
 192 }
 193
 194 /* Close device */
 195 static int hci_uart_close(struct hci_dev *hdev)
 196 {
 197         BT_DBG("hdev %p", hdev);
 198
 199         if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
 200                 return 0;
 201
 202         hci_uart_flush(hdev);
 203         hdev->flush = NULL;
 204         return 0;
 205 }
 206
 207 /* Send frames from HCI layer */
 208 static int hci_uart_send_frame(struct sk_buff *skb)
 209 {
 210         struct hci_dev* hdev = (struct hci_dev *) skb->dev;
 211         struct hci_uart *hu;
 212
 213         if (!hdev) {
 214                 BT_ERR("Frame for unknown device (hdev=NULL)");
 215                 return -ENODEV;
 216         }
 217
 218         if (!test_bit(HCI_RUNNING, &hdev->flags))
 219                 return -EBUSY;
 220
 221         hu = hci_get_drvdata(hdev);
 222
 223         BT_DBG("%s: type %d len %d", hdev->name, bt_cb(skb)->pkt_type, skb->len);
 224
 225         hu->proto->enqueue(hu, skb);
 226
 227         hci_uart_tx_wakeup(hu);
 228
 229         return 0;
 230 }
 231
 232 /* ------ LDISC part ------ */
 233 /* hci_uart_tty_open
 234  *
 235  *     Called when line discipline changed to HCI_UART.
 236  *
 237  * Arguments:
 238  *     tty    pointer to tty info structure
 239  * Return Value:
 240  *     0 if success, otherwise error code
 241  */
 242 static int hci_uart_tty_open(struct tty_struct *tty)
 243 {
 244         struct hci_uart *hu = (void *) tty->disc_data;
 245
 246         BT_DBG("tty %p", tty);
 247
 248         /* FIXME: This btw is bogus, nothing requires the old ldisc to clear
 249            the pointer */
 250         if (hu)
 251                 return -EEXIST;
 252
 253         /* Error if the tty has no write op instead of leaving an exploitable
 254            hole */
 255         if (tty->ops->write == NULL)
 256                 return -EOPNOTSUPP;
 257
 258         if (!(hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL))) {
 259                 BT_ERR("Can't allocate control structure");
 260                 return -ENFILE;
 261         }
 262
 263         tty->disc_data = hu;
 264         hu->tty = tty;
 265         tty->receive_room = 65536;
 266
 267         spin_lock_init(&hu->rx_lock);
 268
 269         /* Flush any pending characters in the driver and line discipline. */
 270
 271         /* FIXME: why is this needed. Note don't use ldisc_ref here as the
 272            open path is before the ldisc is referencable */
 273
 274         if (tty->ldisc->ops->flush_buffer)
 275                 tty->ldisc->ops->flush_buffer(tty);
 276         tty_driver_flush_buffer(tty);
 277
 278         return 0;
 279 }
 280
 281 /* hci_uart_tty_close()
 282  *
 283  *    Called when the line discipline is changed to something
 284  *    else, the tty is closed, or the tty detects a hangup.
 285  */
 286 static void hci_uart_tty_close(struct tty_struct *tty)
 287 {
 288         struct hci_uart *hu = (void *)tty->disc_data;
 289
 290         BT_DBG("tty %p", tty);
 291
 292         /* Detach from the tty */
 293         tty->disc_data = NULL;
 294
 295         if (hu) {
 296                 struct hci_dev *hdev = hu->hdev;
 297
 298                 if (hdev)
 299                         hci_uart_close(hdev);
 300
 301                 if (test_and_clear_bit(HCI_UART_PROTO_SET, &hu->flags)) {
 302                         if (hdev) {
 303                                 hci_unregister_dev(hdev);
 304                                 hci_free_dev(hdev);
 305                         }
 306                         hu->proto->close(hu);
 307                 }
 308
 309                 kfree(hu);
 310         }
 311 }
 312
 313 /* hci_uart_tty_wakeup()
 314  *
 315  *    Callback for transmit wakeup. Called when low level
 316  *    device driver can accept more send data.
 317  *
 318  * Arguments:        tty    pointer to associated tty instance data
 319  * Return Value:    None
 320  */
 321 static void hci_uart_tty_wakeup(struct tty_struct *tty)
 322 {
 323         struct hci_uart *hu = (void *)tty->disc_data;
 324
 325         BT_DBG("");
 326
 327         if (!hu)
 328                 return;
 329
 330         clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 331
 332         if (tty != hu->tty)
 333                 return;
 334
 335         if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 336                 hci_uart_tx_wakeup(hu);
 337 }
 338
 339 /* hci_uart_tty_receive()
 340  *
 341  *     Called by tty low level driver when receive data is
 342  *     available.
 343  *
 344  * Arguments:  tty          pointer to tty isntance data
 345  *             data         pointer to received data
 346  *             flags        pointer to flags for data
 347  *             count        count of received data in bytes
 348  *
 349  * Return Value:    None
 350  */
 351 static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data, char *flags, int count)
 352 {
 353         struct hci_uart *hu = (void *)tty->disc_data;
 354
 355         if (!hu || tty != hu->tty)
 356                 return;
 357
 358         if (!test_bit(HCI_UART_PROTO_SET, &hu->flags))
 359                 return;
 360
 361         spin_lock(&hu->rx_lock);
 362         hu->proto->recv(hu, (void *) data, count);
 363         hu->hdev->stat.byte_rx += count;
 364         spin_unlock(&hu->rx_lock);
 365
 366         tty_unthrottle(tty);
 367 }
 368
 369 static int hci_uart_register_dev(struct hci_uart *hu)
 370 {
 371         struct hci_dev *hdev;
 372
 373         BT_DBG("");
 374
 375         /* Initialize and register HCI device */
 376         hdev = hci_alloc_dev();
 377         if (!hdev) {
 378                 BT_ERR("Can't allocate HCI device");
 379                 return -ENOMEM;
 380         }
 381
 382         hu->hdev = hdev;
 383
 384         hdev->bus = HCI_UART;
 385         hci_set_drvdata(hdev, hu);
 386
 387         hdev->open  = hci_uart_open;
 388         hdev->close = hci_uart_close;
 389         hdev->flush = hci_uart_flush;
 390         hdev->send  = hci_uart_send_frame;
 391         hdev->parent = hu->tty->dev;
 392
 393         if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
 394                 set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
 395
 396         if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
 397                 set_bit(HCI_QUIRK_NO_RESET, &hdev->quirks);
 398
 399         if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
 400                 hdev->dev_type = HCI_AMP;
 401         else
 402                 hdev->dev_type = HCI_BREDR;
 403
 404         if (hci_register_dev(hdev) < 0) {
 405                 BT_ERR("Can't register HCI device");
 406                 hci_free_dev(hdev);
 407                 return -ENODEV;
 408         }
 409
 410         return 0;
 411 }
 412
 413 static int hci_uart_set_proto(struct hci_uart *hu, int id)
 414 {
 415         struct hci_uart_proto *p;
 416         int err;
 417
 418         p = hci_uart_get_proto(id);
 419         if (!p)
 420                 return -EPROTONOSUPPORT;
 421
 422         err = p->open(hu);
 423         if (err)
 424                 return err;
 425
 426         hu->proto = p;
 427
 428         err = hci_uart_register_dev(hu);
 429         if (err) {
 430                 p->close(hu);
 431                 return err;
 432         }
 433
 434         return 0;
 435 }
 436
 437 /* hci_uart_tty_ioctl()
 438  *
 439  *    Process IOCTL system call for the tty device.
 440  *
 441  * Arguments:
 442  *
 443  *    tty        pointer to tty instance data
 444  *    file       pointer to open file object for device
 445  *    cmd        IOCTL command code
 446  *    arg        argument for IOCTL call (cmd dependent)
 447  *
 448  * Return Value:    Command dependent
 449  */
 450 static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file * file,
 451                                         unsigned int cmd, unsigned long arg)
 452 {
 453         struct hci_uart *hu = (void *)tty->disc_data;
 454         int err = 0;
 455
 456         BT_DBG("");
 457
 458         /* Verify the status of the device */
 459         if (!hu)
 460                 return -EBADF;
 461
 462         switch (cmd) {
 463         case HCIUARTSETPROTO:
 464                 if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) {
 465                         err = hci_uart_set_proto(hu, arg);
 466                         if (err) {
 467                                 clear_bit(HCI_UART_PROTO_SET, &hu->flags);
 468                                 return err;
 469                         }
 470                 } else
 471                         return -EBUSY;
 472                 break;
 473
 474         case HCIUARTGETPROTO:
 475                 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 476                         return hu->proto->id;
 477                 return -EUNATCH;
 478
 479         case HCIUARTGETDEVICE:
 480                 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 481                         return hu->hdev->id;
 482                 return -EUNATCH;
 483
 484         case HCIUARTSETFLAGS:
 485                 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 486                         return -EBUSY;
 487                 hu->hdev_flags = arg;
 488                 break;
 489
 490         case HCIUARTGETFLAGS:
 491                 return hu->hdev_flags;
 492
 493         default:
 494                 err = n_tty_ioctl_helper(tty, file, cmd, arg);
 495                 break;
 496         };
 497
 498         return err;
 499 }
 500
 501 /*
 502  * We don't provide read/write/poll interface for user space.
 503  */
 504 static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file,
 505                                         unsigned char __user *buf, size_t nr)
 506 {
 507         return 0;
 508 }
 509
 510 static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file,
 511                                         const unsigned char *data, size_t count)
 512 {
 513         return 0;
 514 }
 515
 516 static unsigned int hci_uart_tty_poll(struct tty_struct *tty,
 517                                         struct file *filp, poll_table *wait)
 518 {
 519         return 0;
 520 }
 521
 522 static int __init hci_uart_init(void)
 523 {
 524         static struct tty_ldisc_ops hci_uart_ldisc;
 525         int err;
 526
 527         BT_INFO("HCI UART driver ver %s", VERSION);
 528
 529         /* Register the tty discipline */
 530
 531         memset(&hci_uart_ldisc, 0, sizeof (hci_uart_ldisc));
 532         hci_uart_ldisc.magic            = TTY_LDISC_MAGIC;
 533         hci_uart_ldisc.name             = "n_hci";
 534         hci_uart_ldisc.open             = hci_uart_tty_open;
 535         hci_uart_ldisc.close            = hci_uart_tty_close;
 536         hci_uart_ldisc.read             = hci_uart_tty_read;
 537         hci_uart_ldisc.write            = hci_uart_tty_write;
 538         hci_uart_ldisc.ioctl            = hci_uart_tty_ioctl;
 539         hci_uart_ldisc.poll             = hci_uart_tty_poll;
 540         hci_uart_ldisc.receive_buf      = hci_uart_tty_receive;
 541         hci_uart_ldisc.write_wakeup     = hci_uart_tty_wakeup;
 542         hci_uart_ldisc.owner            = THIS_MODULE;
 543
 544         if ((err = tty_register_ldisc(N_HCI, &hci_uart_ldisc))) {
 545                 BT_ERR("HCI line discipline registration failed. (%d)", err);
 546                 return err;
 547         }
 548
 549 #ifdef CONFIG_BT_HCIUART_H4
 550         h4_init();
 551 #endif
 552 #ifdef CONFIG_BT_HCIUART_BCSP
 553         bcsp_init();
 554 #endif
 555 #ifdef CONFIG_BT_HCIUART_LL
 556         ll_init();
 557 #endif
 558 #ifdef CONFIG_BT_HCIUART_ATH3K
 559         ath_init();
 560 #endif
 561
 562         return 0;
 563 }
 564
 565 static void __exit hci_uart_exit(void)
 566 {
 567         int err;
 568
 569 #ifdef CONFIG_BT_HCIUART_H4
 570         h4_deinit();
 571 #endif
 572 #ifdef CONFIG_BT_HCIUART_BCSP
 573         bcsp_deinit();
 574 #endif
 575 #ifdef CONFIG_BT_HCIUART_LL
 576         ll_deinit();
 577 #endif
 578 #ifdef CONFIG_BT_HCIUART_ATH3K
 579         ath_deinit();
 580 #endif
 581
 582         /* Release tty registration of line discipline */
 583         if ((err = tty_unregister_ldisc(N_HCI)))
 584                 BT_ERR("Can't unregister HCI line discipline (%d)", err);
 585 }
 586
 587 module_init(hci_uart_init);
 588 module_exit(hci_uart_exit);
 589
 590 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
 591 MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION);
 592 MODULE_VERSION(VERSION);
 593 MODULE_LICENSE("GPL");
 594 MODULE_ALIAS_LDISC(N_HCI);