linux/drivers/bluetooth/hci_ldisc.c
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   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
  51static struct hci_uart_proto *hup[HCI_UART_MAX_PROTO];
  52
  53int 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
  66int 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
  79static 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
  87static 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
 107static 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
 119int 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
 132restart:
 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
 159static 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
 178int 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 */
 190static 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 */
 202static 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 */
 224static 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 */
 237static 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 */
 271static 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 */
 317static 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 */
 354static 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 */
 384static 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
 402static 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
 451static 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 */
 488static 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 */
 542static 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
 548static 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
 554static unsigned int hci_uart_tty_poll(struct tty_struct *tty,
 555                                        struct file *filp, poll_table *wait)
 556{
 557        return 0;
 558}
 559
 560static 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
 606static 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
 631module_init(hci_uart_init);
 632module_exit(hci_uart_exit);
 633
 634MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
 635MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION);
 636MODULE_VERSION(VERSION);
 637MODULE_LICENSE("GPL");
 638MODULE_ALIAS_LDISC(N_HCI);
 639
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