2 * Texas Instruments' Bluetooth HCILL UART protocol
4 * HCILL (HCI Low Level) is a Texas Instruments' power management
5 * protocol extension to H4.
7 * Copyright (C) 2007 Texas Instruments, Inc.
9 * Written by Ohad Ben-Cohen <ohad@bencohen.org>
12 * This file is based on hci_h4.c, which was written
13 * by Maxim Krasnyansky and Marcel Holtmann.
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
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.
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
30 #include <linux/module.h>
31 #include <linux/kernel.h>
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>
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>
49 #include <net/bluetooth/bluetooth.h>
50 #include <net/bluetooth/hci_core.h>
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
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
70 HCILL_ASLEEP_TO_AWAKE
,
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 */
90 * Builds and sends an HCILL command packet.
91 * These are very simple packets with only 1 cmd byte
93 static int send_hcill_cmd(u8 cmd
, struct hci_uart
*hu
)
96 struct sk_buff
*skb
= NULL
;
97 struct ll_struct
*ll
= hu
->priv
;
98 struct hcill_cmd
*hcill_packet
;
100 BT_DBG("hu %p cmd 0x%x", hu
, cmd
);
102 /* allocate packet */
103 skb
= bt_skb_alloc(1, GFP_ATOMIC
);
105 BT_ERR("cannot allocate memory for HCILL packet");
111 hcill_packet
= (struct hcill_cmd
*) skb_put(skb
, 1);
112 hcill_packet
->cmd
= cmd
;
115 skb_queue_tail(&ll
->txq
, skb
);
120 /* Initialize protocol */
121 static int ll_open(struct hci_uart
*hu
)
123 struct ll_struct
*ll
;
127 ll
= kzalloc(sizeof(*ll
), GFP_KERNEL
);
131 skb_queue_head_init(&ll
->txq
);
132 skb_queue_head_init(&ll
->tx_wait_q
);
133 spin_lock_init(&ll
->hcill_lock
);
135 ll
->hcill_state
= HCILL_AWAKE
;
142 /* Flush protocol data */
143 static int ll_flush(struct hci_uart
*hu
)
145 struct ll_struct
*ll
= hu
->priv
;
149 skb_queue_purge(&ll
->tx_wait_q
);
150 skb_queue_purge(&ll
->txq
);
156 static int ll_close(struct hci_uart
*hu
)
158 struct ll_struct
*ll
= hu
->priv
;
162 skb_queue_purge(&ll
->tx_wait_q
);
163 skb_queue_purge(&ll
->txq
);
165 kfree_skb(ll
->rx_skb
);
175 * internal function, which does common work of the device wake up process:
176 * 1. places all pending packets (waiting in tx_wait_q list) in txq list.
177 * 2. changes internal state to HCILL_AWAKE.
178 * Note: assumes that hcill_lock spinlock is taken,
179 * shouldn't be called otherwise!
181 static void __ll_do_awake(struct ll_struct
*ll
)
183 struct sk_buff
*skb
= NULL
;
185 while ((skb
= skb_dequeue(&ll
->tx_wait_q
)))
186 skb_queue_tail(&ll
->txq
, skb
);
188 ll
->hcill_state
= HCILL_AWAKE
;
192 * Called upon a wake-up-indication from the device
194 static void ll_device_want_to_wakeup(struct hci_uart
*hu
)
197 struct ll_struct
*ll
= hu
->priv
;
201 /* lock hcill state */
202 spin_lock_irqsave(&ll
->hcill_lock
, flags
);
204 switch (ll
->hcill_state
) {
205 case HCILL_ASLEEP_TO_AWAKE
:
207 * This state means that both the host and the BRF chip
208 * have simultaneously sent a wake-up-indication packet.
209 * Traditionally, in this case, receiving a wake-up-indication
210 * was enough and an additional wake-up-ack wasn't needed.
211 * This has changed with the BRF6350, which does require an
212 * explicit wake-up-ack. Other BRF versions, which do not
213 * require an explicit ack here, do accept it, thus it is
214 * perfectly safe to always send one.
216 BT_DBG("dual wake-up-indication");
217 /* deliberate fall-through - do not add break */
219 /* acknowledge device wake up */
220 if (send_hcill_cmd(HCILL_WAKE_UP_ACK
, hu
) < 0) {
221 BT_ERR("cannot acknowledge device wake up");
226 /* any other state is illegal */
227 BT_ERR("received HCILL_WAKE_UP_IND in state %ld", ll
->hcill_state
);
231 /* send pending packets and change state to HCILL_AWAKE */
235 spin_unlock_irqrestore(&ll
->hcill_lock
, flags
);
237 /* actually send the packets */
238 hci_uart_tx_wakeup(hu
);
242 * Called upon a sleep-indication from the device
244 static void ll_device_want_to_sleep(struct hci_uart
*hu
)
247 struct ll_struct
*ll
= hu
->priv
;
251 /* lock hcill state */
252 spin_lock_irqsave(&ll
->hcill_lock
, flags
);
255 if (ll
->hcill_state
!= HCILL_AWAKE
)
256 BT_ERR("ERR: HCILL_GO_TO_SLEEP_IND in state %ld", ll
->hcill_state
);
258 /* acknowledge device sleep */
259 if (send_hcill_cmd(HCILL_GO_TO_SLEEP_ACK
, hu
) < 0) {
260 BT_ERR("cannot acknowledge device sleep");
265 ll
->hcill_state
= HCILL_ASLEEP
;
268 spin_unlock_irqrestore(&ll
->hcill_lock
, flags
);
270 /* actually send the sleep ack packet */
271 hci_uart_tx_wakeup(hu
);
275 * Called upon wake-up-acknowledgement from the device
277 static void ll_device_woke_up(struct hci_uart
*hu
)
280 struct ll_struct
*ll
= hu
->priv
;
284 /* lock hcill state */
285 spin_lock_irqsave(&ll
->hcill_lock
, flags
);
288 if (ll
->hcill_state
!= HCILL_ASLEEP_TO_AWAKE
)
289 BT_ERR("received HCILL_WAKE_UP_ACK in state %ld", ll
->hcill_state
);
291 /* send pending packets and change state to HCILL_AWAKE */
294 spin_unlock_irqrestore(&ll
->hcill_lock
, flags
);
296 /* actually send the packets */
297 hci_uart_tx_wakeup(hu
);
300 /* Enqueue frame for transmittion (padding, crc, etc) */
301 /* may be called from two simultaneous tasklets */
302 static int ll_enqueue(struct hci_uart
*hu
, struct sk_buff
*skb
)
304 unsigned long flags
= 0;
305 struct ll_struct
*ll
= hu
->priv
;
307 BT_DBG("hu %p skb %p", hu
, skb
);
309 /* Prepend skb with frame type */
310 memcpy(skb_push(skb
, 1), &hci_skb_pkt_type(skb
), 1);
312 /* lock hcill state */
313 spin_lock_irqsave(&ll
->hcill_lock
, flags
);
315 /* act according to current state */
316 switch (ll
->hcill_state
) {
318 BT_DBG("device awake, sending normally");
319 skb_queue_tail(&ll
->txq
, skb
);
322 BT_DBG("device asleep, waking up and queueing packet");
323 /* save packet for later */
324 skb_queue_tail(&ll
->tx_wait_q
, skb
);
326 if (send_hcill_cmd(HCILL_WAKE_UP_IND
, hu
) < 0) {
327 BT_ERR("cannot wake up device");
330 ll
->hcill_state
= HCILL_ASLEEP_TO_AWAKE
;
332 case HCILL_ASLEEP_TO_AWAKE
:
333 BT_DBG("device waking up, queueing packet");
334 /* transient state; just keep packet for later */
335 skb_queue_tail(&ll
->tx_wait_q
, skb
);
338 BT_ERR("illegal hcill state: %ld (losing packet)", ll
->hcill_state
);
343 spin_unlock_irqrestore(&ll
->hcill_lock
, flags
);
348 static inline int ll_check_data_len(struct hci_dev
*hdev
, struct ll_struct
*ll
, int len
)
350 int room
= skb_tailroom(ll
->rx_skb
);
352 BT_DBG("len %d room %d", len
, room
);
355 hci_recv_frame(hdev
, ll
->rx_skb
);
356 } else if (len
> room
) {
357 BT_ERR("Data length is too large");
358 kfree_skb(ll
->rx_skb
);
360 ll
->rx_state
= HCILL_W4_DATA
;
365 ll
->rx_state
= HCILL_W4_PACKET_TYPE
;
373 static int ll_recv(struct hci_uart
*hu
, const void *data
, int count
)
375 struct ll_struct
*ll
= hu
->priv
;
377 struct hci_event_hdr
*eh
;
378 struct hci_acl_hdr
*ah
;
379 struct hci_sco_hdr
*sh
;
382 BT_DBG("hu %p count %d rx_state %ld rx_count %ld", hu
, count
, ll
->rx_state
, ll
->rx_count
);
387 len
= min_t(unsigned int, ll
->rx_count
, count
);
388 memcpy(skb_put(ll
->rx_skb
, len
), ptr
, len
);
389 ll
->rx_count
-= len
; count
-= len
; ptr
+= len
;
394 switch (ll
->rx_state
) {
396 BT_DBG("Complete data");
397 hci_recv_frame(hu
->hdev
, ll
->rx_skb
);
399 ll
->rx_state
= HCILL_W4_PACKET_TYPE
;
403 case HCILL_W4_EVENT_HDR
:
404 eh
= hci_event_hdr(ll
->rx_skb
);
406 BT_DBG("Event header: evt 0x%2.2x plen %d", eh
->evt
, eh
->plen
);
408 ll_check_data_len(hu
->hdev
, ll
, eh
->plen
);
411 case HCILL_W4_ACL_HDR
:
412 ah
= hci_acl_hdr(ll
->rx_skb
);
413 dlen
= __le16_to_cpu(ah
->dlen
);
415 BT_DBG("ACL header: dlen %d", dlen
);
417 ll_check_data_len(hu
->hdev
, ll
, dlen
);
420 case HCILL_W4_SCO_HDR
:
421 sh
= hci_sco_hdr(ll
->rx_skb
);
423 BT_DBG("SCO header: dlen %d", sh
->dlen
);
425 ll_check_data_len(hu
->hdev
, ll
, sh
->dlen
);
430 /* HCILL_W4_PACKET_TYPE */
433 BT_DBG("Event packet");
434 ll
->rx_state
= HCILL_W4_EVENT_HDR
;
435 ll
->rx_count
= HCI_EVENT_HDR_SIZE
;
436 type
= HCI_EVENT_PKT
;
439 case HCI_ACLDATA_PKT
:
440 BT_DBG("ACL packet");
441 ll
->rx_state
= HCILL_W4_ACL_HDR
;
442 ll
->rx_count
= HCI_ACL_HDR_SIZE
;
443 type
= HCI_ACLDATA_PKT
;
446 case HCI_SCODATA_PKT
:
447 BT_DBG("SCO packet");
448 ll
->rx_state
= HCILL_W4_SCO_HDR
;
449 ll
->rx_count
= HCI_SCO_HDR_SIZE
;
450 type
= HCI_SCODATA_PKT
;
454 case HCILL_GO_TO_SLEEP_IND
:
455 BT_DBG("HCILL_GO_TO_SLEEP_IND packet");
456 ll_device_want_to_sleep(hu
);
460 case HCILL_GO_TO_SLEEP_ACK
:
461 /* shouldn't happen */
462 BT_ERR("received HCILL_GO_TO_SLEEP_ACK (in state %ld)", ll
->hcill_state
);
466 case HCILL_WAKE_UP_IND
:
467 BT_DBG("HCILL_WAKE_UP_IND packet");
468 ll_device_want_to_wakeup(hu
);
472 case HCILL_WAKE_UP_ACK
:
473 BT_DBG("HCILL_WAKE_UP_ACK packet");
474 ll_device_woke_up(hu
);
479 BT_ERR("Unknown HCI packet type %2.2x", (__u8
)*ptr
);
480 hu
->hdev
->stat
.err_rx
++;
487 /* Allocate packet */
488 ll
->rx_skb
= bt_skb_alloc(HCI_MAX_FRAME_SIZE
, GFP_ATOMIC
);
490 BT_ERR("Can't allocate mem for new packet");
491 ll
->rx_state
= HCILL_W4_PACKET_TYPE
;
496 hci_skb_pkt_type(ll
->rx_skb
) = type
;
502 static struct sk_buff
*ll_dequeue(struct hci_uart
*hu
)
504 struct ll_struct
*ll
= hu
->priv
;
505 return skb_dequeue(&ll
->txq
);
508 static const struct hci_uart_proto llp
= {
514 .enqueue
= ll_enqueue
,
515 .dequeue
= ll_dequeue
,
519 int __init
ll_init(void)
521 return hci_uart_register_proto(&llp
);
524 int __exit
ll_deinit(void)
526 return hci_uart_unregister_proto(&llp
);
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