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Diffstat (limited to 'drivers/bluetooth/hci_ll.c')
-rw-r--r--drivers/bluetooth/hci_ll.c531
1 files changed, 531 insertions, 0 deletions
diff --git a/drivers/bluetooth/hci_ll.c b/drivers/bluetooth/hci_ll.c
new file mode 100644
index 000000000000..8c3e62a17b4a
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+++ b/drivers/bluetooth/hci_ll.c
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1/*
2 * Texas Instruments' Bluetooth HCILL UART protocol
3 *
4 * HCILL (HCI Low Level) is a Texas Instruments' power management
5 * protocol extension to H4.
6 *
7 * Copyright (C) 2007 Texas Instruments, Inc.
8 *
9 * Written by Ohad Ben-Cohen <ohad@bencohen.org>
10 *
11 * Acknowledgements:
12 * This file is based on hci_h4.c, which was written
13 * by Maxim Krasnyansky and Marcel Holtmann.
14 *
15 * This program is free software; you can redistribute it and/or modify
16 * it under the terms of the GNU General Public License version 2
17 * as published by the Free Software Foundation
18 *
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License
25 * along with this program; if not, write to the Free Software
26 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
27 *
28 */
29
30#include <linux/module.h>
31#include <linux/kernel.h>
32
33#include <linux/init.h>
34#include <linux/sched.h>
35#include <linux/types.h>
36#include <linux/fcntl.h>
37#include <linux/interrupt.h>
38#include <linux/ptrace.h>
39#include <linux/poll.h>
40
41#include <linux/slab.h>
42#include <linux/tty.h>
43#include <linux/errno.h>
44#include <linux/string.h>
45#include <linux/signal.h>
46#include <linux/ioctl.h>
47#include <linux/skbuff.h>
48
49#include <net/bluetooth/bluetooth.h>
50#include <net/bluetooth/hci_core.h>
51
52#include "hci_uart.h"
53
54/* HCILL commands */
55#define HCILL_GO_TO_SLEEP_IND 0x30
56#define HCILL_GO_TO_SLEEP_ACK 0x31
57#define HCILL_WAKE_UP_IND 0x32
58#define HCILL_WAKE_UP_ACK 0x33
59
60/* HCILL receiver States */
61#define HCILL_W4_PACKET_TYPE 0
62#define HCILL_W4_EVENT_HDR 1
63#define HCILL_W4_ACL_HDR 2
64#define HCILL_W4_SCO_HDR 3
65#define HCILL_W4_DATA 4
66
67/* HCILL states */
68enum hcill_states_e {
69 HCILL_ASLEEP,
70 HCILL_ASLEEP_TO_AWAKE,
71 HCILL_AWAKE,
72 HCILL_AWAKE_TO_ASLEEP
73};
74
75struct hcill_cmd {
76 u8 cmd;
77} __attribute__((packed));
78
79struct ll_struct {
80 unsigned long rx_state;
81 unsigned long rx_count;
82 struct sk_buff *rx_skb;
83 struct sk_buff_head txq;
84 spinlock_t hcill_lock; /* HCILL state lock */
85 unsigned long hcill_state; /* HCILL power state */
86 struct sk_buff_head tx_wait_q; /* HCILL wait queue */
87};
88
89/*
90 * Builds and sends an HCILL command packet.
91 * These are very simple packets with only 1 cmd byte
92 */
93static int send_hcill_cmd(u8 cmd, struct hci_uart *hu)
94{
95 int err = 0;
96 struct sk_buff *skb = NULL;
97 struct ll_struct *ll = hu->priv;
98 struct hcill_cmd *hcill_packet;
99
100 BT_DBG("hu %p cmd 0x%x", hu, cmd);
101
102 /* allocate packet */
103 skb = bt_skb_alloc(1, GFP_ATOMIC);
104 if (!skb) {
105 BT_ERR("cannot allocate memory for HCILL packet");
106 err = -ENOMEM;
107 goto out;
108 }
109
110 /* prepare packet */
111 hcill_packet = (struct hcill_cmd *) skb_put(skb, 1);
112 hcill_packet->cmd = cmd;
113 skb->dev = (void *) hu->hdev;
114
115 /* send packet */
116 skb_queue_tail(&ll->txq, skb);
117out:
118 return err;
119}
120
121/* Initialize protocol */
122static int ll_open(struct hci_uart *hu)
123{
124 struct ll_struct *ll;
125
126 BT_DBG("hu %p", hu);
127
128 ll = kzalloc(sizeof(*ll), GFP_ATOMIC);
129 if (!ll)
130 return -ENOMEM;
131
132 skb_queue_head_init(&ll->txq);
133 skb_queue_head_init(&ll->tx_wait_q);
134 spin_lock_init(&ll->hcill_lock);
135
136 ll->hcill_state = HCILL_AWAKE;
137
138 hu->priv = ll;
139
140 return 0;
141}
142
143/* Flush protocol data */
144static int ll_flush(struct hci_uart *hu)
145{
146 struct ll_struct *ll = hu->priv;
147
148 BT_DBG("hu %p", hu);
149
150 skb_queue_purge(&ll->tx_wait_q);
151 skb_queue_purge(&ll->txq);
152
153 return 0;
154}
155
156/* Close protocol */
157static int ll_close(struct hci_uart *hu)
158{
159 struct ll_struct *ll = hu->priv;
160
161 BT_DBG("hu %p", hu);
162
163 skb_queue_purge(&ll->tx_wait_q);
164 skb_queue_purge(&ll->txq);
165
166 if (ll->rx_skb)
167 kfree_skb(ll->rx_skb);
168
169 hu->priv = NULL;
170
171 kfree(ll);
172
173 return 0;
174}
175
176/*
177 * internal function, which does common work of the device wake up process:
178 * 1. places all pending packets (waiting in tx_wait_q list) in txq list.
179 * 2. changes internal state to HCILL_AWAKE.
180 * Note: assumes that hcill_lock spinlock is taken,
181 * shouldn't be called otherwise!
182 */
183static void __ll_do_awake(struct ll_struct *ll)
184{
185 struct sk_buff *skb = NULL;
186
187 while ((skb = skb_dequeue(&ll->tx_wait_q)))
188 skb_queue_tail(&ll->txq, skb);
189
190 ll->hcill_state = HCILL_AWAKE;
191}
192
193/*
194 * Called upon a wake-up-indication from the device
195 */
196static void ll_device_want_to_wakeup(struct hci_uart *hu)
197{
198 unsigned long flags;
199 struct ll_struct *ll = hu->priv;
200
201 BT_DBG("hu %p", hu);
202
203 /* lock hcill state */
204 spin_lock_irqsave(&ll->hcill_lock, flags);
205
206 switch (ll->hcill_state) {
207 case HCILL_ASLEEP:
208 /* acknowledge device wake up */
209 if (send_hcill_cmd(HCILL_WAKE_UP_ACK, hu) < 0) {
210 BT_ERR("cannot acknowledge device wake up");
211 goto out;
212 }
213 break;
214 case HCILL_ASLEEP_TO_AWAKE:
215 /*
216 * this state means that a wake-up-indication
217 * is already on its way to the device,
218 * and will serve as the required wake-up-ack
219 */
220 BT_DBG("dual wake-up-indication");
221 break;
222 default:
223 /* any other state are illegal */
224 BT_ERR("received HCILL_WAKE_UP_IND in state %ld", ll->hcill_state);
225 break;
226 }
227
228 /* send pending packets and change state to HCILL_AWAKE */
229 __ll_do_awake(ll);
230
231out:
232 spin_unlock_irqrestore(&ll->hcill_lock, flags);
233
234 /* actually send the packets */
235 hci_uart_tx_wakeup(hu);
236}
237
238/*
239 * Called upon a sleep-indication from the device
240 */
241static void ll_device_want_to_sleep(struct hci_uart *hu)
242{
243 unsigned long flags;
244 struct ll_struct *ll = hu->priv;
245
246 BT_DBG("hu %p", hu);
247
248 /* lock hcill state */
249 spin_lock_irqsave(&ll->hcill_lock, flags);
250
251 /* sanity check */
252 if (ll->hcill_state != HCILL_AWAKE)
253 BT_ERR("ERR: HCILL_GO_TO_SLEEP_IND in state %ld", ll->hcill_state);
254
255 /* acknowledge device sleep */
256 if (send_hcill_cmd(HCILL_GO_TO_SLEEP_ACK, hu) < 0) {
257 BT_ERR("cannot acknowledge device sleep");
258 goto out;
259 }
260
261 /* update state */
262 ll->hcill_state = HCILL_ASLEEP;
263
264out:
265 spin_unlock_irqrestore(&ll->hcill_lock, flags);
266
267 /* actually send the sleep ack packet */
268 hci_uart_tx_wakeup(hu);
269}
270
271/*
272 * Called upon wake-up-acknowledgement from the device
273 */
274static void ll_device_woke_up(struct hci_uart *hu)
275{
276 unsigned long flags;
277 struct ll_struct *ll = hu->priv;
278
279 BT_DBG("hu %p", hu);
280
281 /* lock hcill state */
282 spin_lock_irqsave(&ll->hcill_lock, flags);
283
284 /* sanity check */
285 if (ll->hcill_state != HCILL_ASLEEP_TO_AWAKE)
286 BT_ERR("received HCILL_WAKE_UP_ACK in state %ld", ll->hcill_state);
287
288 /* send pending packets and change state to HCILL_AWAKE */
289 __ll_do_awake(ll);
290
291 spin_unlock_irqrestore(&ll->hcill_lock, flags);
292
293 /* actually send the packets */
294 hci_uart_tx_wakeup(hu);
295}
296
297/* Enqueue frame for transmittion (padding, crc, etc) */
298/* may be called from two simultaneous tasklets */
299static int ll_enqueue(struct hci_uart *hu, struct sk_buff *skb)
300{
301 unsigned long flags = 0;
302 struct ll_struct *ll = hu->priv;
303
304 BT_DBG("hu %p skb %p", hu, skb);
305
306 /* Prepend skb with frame type */
307 memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
308
309 /* lock hcill state */
310 spin_lock_irqsave(&ll->hcill_lock, flags);
311
312 /* act according to current state */
313 switch (ll->hcill_state) {
314 case HCILL_AWAKE:
315 BT_DBG("device awake, sending normally");
316 skb_queue_tail(&ll->txq, skb);
317 break;
318 case HCILL_ASLEEP:
319 BT_DBG("device asleep, waking up and queueing packet");
320 /* save packet for later */
321 skb_queue_tail(&ll->tx_wait_q, skb);
322 /* awake device */
323 if (send_hcill_cmd(HCILL_WAKE_UP_IND, hu) < 0) {
324 BT_ERR("cannot wake up device");
325 break;
326 }
327 ll->hcill_state = HCILL_ASLEEP_TO_AWAKE;
328 break;
329 case HCILL_ASLEEP_TO_AWAKE:
330 BT_DBG("device waking up, queueing packet");
331 /* transient state; just keep packet for later */
332 skb_queue_tail(&ll->tx_wait_q, skb);
333 break;
334 default:
335 BT_ERR("illegal hcill state: %ld (losing packet)", ll->hcill_state);
336 kfree_skb(skb);
337 break;
338 }
339
340 spin_unlock_irqrestore(&ll->hcill_lock, flags);
341
342 return 0;
343}
344
345static inline int ll_check_data_len(struct ll_struct *ll, int len)
346{
347 register int room = skb_tailroom(ll->rx_skb);
348
349 BT_DBG("len %d room %d", len, room);
350
351 if (!len) {
352 hci_recv_frame(ll->rx_skb);
353 } else if (len > room) {
354 BT_ERR("Data length is too large");
355 kfree_skb(ll->rx_skb);
356 } else {
357 ll->rx_state = HCILL_W4_DATA;
358 ll->rx_count = len;
359 return len;
360 }
361
362 ll->rx_state = HCILL_W4_PACKET_TYPE;
363 ll->rx_skb = NULL;
364 ll->rx_count = 0;
365
366 return 0;
367}
368
369/* Recv data */
370static int ll_recv(struct hci_uart *hu, void *data, int count)
371{
372 struct ll_struct *ll = hu->priv;
373 register char *ptr;
374 struct hci_event_hdr *eh;
375 struct hci_acl_hdr *ah;
376 struct hci_sco_hdr *sh;
377 register int len, type, dlen;
378
379 BT_DBG("hu %p count %d rx_state %ld rx_count %ld", hu, count, ll->rx_state, ll->rx_count);
380
381 ptr = data;
382 while (count) {
383 if (ll->rx_count) {
384 len = min_t(unsigned int, ll->rx_count, count);
385 memcpy(skb_put(ll->rx_skb, len), ptr, len);
386 ll->rx_count -= len; count -= len; ptr += len;
387
388 if (ll->rx_count)
389 continue;
390
391 switch (ll->rx_state) {
392 case HCILL_W4_DATA:
393 BT_DBG("Complete data");
394 hci_recv_frame(ll->rx_skb);
395
396 ll->rx_state = HCILL_W4_PACKET_TYPE;
397 ll->rx_skb = NULL;
398 continue;
399
400 case HCILL_W4_EVENT_HDR:
401 eh = (struct hci_event_hdr *) ll->rx_skb->data;
402
403 BT_DBG("Event header: evt 0x%2.2x plen %d", eh->evt, eh->plen);
404
405 ll_check_data_len(ll, eh->plen);
406 continue;
407
408 case HCILL_W4_ACL_HDR:
409 ah = (struct hci_acl_hdr *) ll->rx_skb->data;
410 dlen = __le16_to_cpu(ah->dlen);
411
412 BT_DBG("ACL header: dlen %d", dlen);
413
414 ll_check_data_len(ll, dlen);
415 continue;
416
417 case HCILL_W4_SCO_HDR:
418 sh = (struct hci_sco_hdr *) ll->rx_skb->data;
419
420 BT_DBG("SCO header: dlen %d", sh->dlen);
421
422 ll_check_data_len(ll, sh->dlen);
423 continue;
424 }
425 }
426
427 /* HCILL_W4_PACKET_TYPE */
428 switch (*ptr) {
429 case HCI_EVENT_PKT:
430 BT_DBG("Event packet");
431 ll->rx_state = HCILL_W4_EVENT_HDR;
432 ll->rx_count = HCI_EVENT_HDR_SIZE;
433 type = HCI_EVENT_PKT;
434 break;
435
436 case HCI_ACLDATA_PKT:
437 BT_DBG("ACL packet");
438 ll->rx_state = HCILL_W4_ACL_HDR;
439 ll->rx_count = HCI_ACL_HDR_SIZE;
440 type = HCI_ACLDATA_PKT;
441 break;
442
443 case HCI_SCODATA_PKT:
444 BT_DBG("SCO packet");
445 ll->rx_state = HCILL_W4_SCO_HDR;
446 ll->rx_count = HCI_SCO_HDR_SIZE;
447 type = HCI_SCODATA_PKT;
448 break;
449
450 /* HCILL signals */
451 case HCILL_GO_TO_SLEEP_IND:
452 BT_DBG("HCILL_GO_TO_SLEEP_IND packet");
453 ll_device_want_to_sleep(hu);
454 ptr++; count--;
455 continue;
456
457 case HCILL_GO_TO_SLEEP_ACK:
458 /* shouldn't happen */
459 BT_ERR("received HCILL_GO_TO_SLEEP_ACK (in state %ld)", ll->hcill_state);
460 ptr++; count--;
461 continue;
462
463 case HCILL_WAKE_UP_IND:
464 BT_DBG("HCILL_WAKE_UP_IND packet");
465 ll_device_want_to_wakeup(hu);
466 ptr++; count--;
467 continue;
468
469 case HCILL_WAKE_UP_ACK:
470 BT_DBG("HCILL_WAKE_UP_ACK packet");
471 ll_device_woke_up(hu);
472 ptr++; count--;
473 continue;
474
475 default:
476 BT_ERR("Unknown HCI packet type %2.2x", (__u8)*ptr);
477 hu->hdev->stat.err_rx++;
478 ptr++; count--;
479 continue;
480 };
481
482 ptr++; count--;
483
484 /* Allocate packet */
485 ll->rx_skb = bt_skb_alloc(HCI_MAX_FRAME_SIZE, GFP_ATOMIC);
486 if (!ll->rx_skb) {
487 BT_ERR("Can't allocate mem for new packet");
488 ll->rx_state = HCILL_W4_PACKET_TYPE;
489 ll->rx_count = 0;
490 return 0;
491 }
492
493 ll->rx_skb->dev = (void *) hu->hdev;
494 bt_cb(ll->rx_skb)->pkt_type = type;
495 }
496
497 return count;
498}
499
500static struct sk_buff *ll_dequeue(struct hci_uart *hu)
501{
502 struct ll_struct *ll = hu->priv;
503 return skb_dequeue(&ll->txq);
504}
505
506static struct hci_uart_proto llp = {
507 .id = HCI_UART_LL,
508 .open = ll_open,
509 .close = ll_close,
510 .recv = ll_recv,
511 .enqueue = ll_enqueue,
512 .dequeue = ll_dequeue,
513 .flush = ll_flush,
514};
515
516int ll_init(void)
517{
518 int err = hci_uart_register_proto(&llp);
519
520 if (!err)
521 BT_INFO("HCILL protocol initialized");
522 else
523 BT_ERR("HCILL protocol registration failed");
524
525 return err;
526}
527
528int ll_deinit(void)
529{
530 return hci_uart_unregister_proto(&llp);
531}
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