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166d2f6a OBC |
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 */ | |
68 | enum hcill_states_e { | |
69 | HCILL_ASLEEP, | |
70 | HCILL_ASLEEP_TO_AWAKE, | |
71 | HCILL_AWAKE, | |
72 | HCILL_AWAKE_TO_ASLEEP | |
73 | }; | |
74 | ||
75 | struct hcill_cmd { | |
76 | u8 cmd; | |
77 | } __attribute__((packed)); | |
78 | ||
79 | struct 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 | */ | |
93 | static 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); | |
117 | out: | |
118 | return err; | |
119 | } | |
120 | ||
121 | /* Initialize protocol */ | |
122 | static 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 */ | |
144 | static 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 */ | |
157 | static 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 | */ | |
183 | static 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 | */ | |
196 | static 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 | ||
231 | out: | |
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 | */ | |
241 | static 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 | ||
264 | out: | |
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 | */ | |
274 | static 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 */ | |
299 | static 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 | ||
345 | static 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 */ | |
370 | static 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 | ||
500 | static 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 | ||
506 | static 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 | ||
516 | int 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 | ||
528 | int ll_deinit(void) | |
529 | { | |
530 | return hci_uart_unregister_proto(&llp); | |
531 | } |