Root/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
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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