]>
git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blob - drivers/bluetooth/hci_ll.c
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
,
77 } __attribute__((packed
));
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
;
113 skb
->dev
= (void *) hu
->hdev
;
116 skb_queue_tail(&ll
->txq
, skb
);
121 /* Initialize protocol */
122 static int ll_open(struct hci_uart
*hu
)
124 struct ll_struct
*ll
;
128 ll
= kzalloc(sizeof(*ll
), GFP_ATOMIC
);
132 skb_queue_head_init(&ll
->txq
);
133 skb_queue_head_init(&ll
->tx_wait_q
);
134 spin_lock_init(&ll
->hcill_lock
);
136 ll
->hcill_state
= HCILL_AWAKE
;
143 /* Flush protocol data */
144 static int ll_flush(struct hci_uart
*hu
)
146 struct ll_struct
*ll
= hu
->priv
;
150 skb_queue_purge(&ll
->tx_wait_q
);
151 skb_queue_purge(&ll
->txq
);
157 static int ll_close(struct hci_uart
*hu
)
159 struct ll_struct
*ll
= hu
->priv
;
163 skb_queue_purge(&ll
->tx_wait_q
);
164 skb_queue_purge(&ll
->txq
);
167 kfree_skb(ll
->rx_skb
);
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!
183 static void __ll_do_awake(struct ll_struct
*ll
)
185 struct sk_buff
*skb
= NULL
;
187 while ((skb
= skb_dequeue(&ll
->tx_wait_q
)))
188 skb_queue_tail(&ll
->txq
, skb
);
190 ll
->hcill_state
= HCILL_AWAKE
;
194 * Called upon a wake-up-indication from the device
196 static void ll_device_want_to_wakeup(struct hci_uart
*hu
)
199 struct ll_struct
*ll
= hu
->priv
;
203 /* lock hcill state */
204 spin_lock_irqsave(&ll
->hcill_lock
, flags
);
206 switch (ll
->hcill_state
) {
208 /* acknowledge device wake up */
209 if (send_hcill_cmd(HCILL_WAKE_UP_ACK
, hu
) < 0) {
210 BT_ERR("cannot acknowledge device wake up");
214 case HCILL_ASLEEP_TO_AWAKE
:
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
220 BT_DBG("dual wake-up-indication");
223 /* any other state are illegal */
224 BT_ERR("received HCILL_WAKE_UP_IND in state %ld", ll
->hcill_state
);
228 /* send pending packets and change state to HCILL_AWAKE */
232 spin_unlock_irqrestore(&ll
->hcill_lock
, flags
);
234 /* actually send the packets */
235 hci_uart_tx_wakeup(hu
);
239 * Called upon a sleep-indication from the device
241 static void ll_device_want_to_sleep(struct hci_uart
*hu
)
244 struct ll_struct
*ll
= hu
->priv
;
248 /* lock hcill state */
249 spin_lock_irqsave(&ll
->hcill_lock
, flags
);
252 if (ll
->hcill_state
!= HCILL_AWAKE
)
253 BT_ERR("ERR: HCILL_GO_TO_SLEEP_IND in state %ld", ll
->hcill_state
);
255 /* acknowledge device sleep */
256 if (send_hcill_cmd(HCILL_GO_TO_SLEEP_ACK
, hu
) < 0) {
257 BT_ERR("cannot acknowledge device sleep");
262 ll
->hcill_state
= HCILL_ASLEEP
;
265 spin_unlock_irqrestore(&ll
->hcill_lock
, flags
);
267 /* actually send the sleep ack packet */
268 hci_uart_tx_wakeup(hu
);
272 * Called upon wake-up-acknowledgement from the device
274 static void ll_device_woke_up(struct hci_uart
*hu
)
277 struct ll_struct
*ll
= hu
->priv
;
281 /* lock hcill state */
282 spin_lock_irqsave(&ll
->hcill_lock
, flags
);
285 if (ll
->hcill_state
!= HCILL_ASLEEP_TO_AWAKE
)
286 BT_ERR("received HCILL_WAKE_UP_ACK in state %ld", ll
->hcill_state
);
288 /* send pending packets and change state to HCILL_AWAKE */
291 spin_unlock_irqrestore(&ll
->hcill_lock
, flags
);
293 /* actually send the packets */
294 hci_uart_tx_wakeup(hu
);
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
)
301 unsigned long flags
= 0;
302 struct ll_struct
*ll
= hu
->priv
;
304 BT_DBG("hu %p skb %p", hu
, skb
);
306 /* Prepend skb with frame type */
307 memcpy(skb_push(skb
, 1), &bt_cb(skb
)->pkt_type
, 1);
309 /* lock hcill state */
310 spin_lock_irqsave(&ll
->hcill_lock
, flags
);
312 /* act according to current state */
313 switch (ll
->hcill_state
) {
315 BT_DBG("device awake, sending normally");
316 skb_queue_tail(&ll
->txq
, skb
);
319 BT_DBG("device asleep, waking up and queueing packet");
320 /* save packet for later */
321 skb_queue_tail(&ll
->tx_wait_q
, skb
);
323 if (send_hcill_cmd(HCILL_WAKE_UP_IND
, hu
) < 0) {
324 BT_ERR("cannot wake up device");
327 ll
->hcill_state
= HCILL_ASLEEP_TO_AWAKE
;
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
);
335 BT_ERR("illegal hcill state: %ld (losing packet)", ll
->hcill_state
);
340 spin_unlock_irqrestore(&ll
->hcill_lock
, flags
);
345 static inline int ll_check_data_len(struct ll_struct
*ll
, int len
)
347 register int room
= skb_tailroom(ll
->rx_skb
);
349 BT_DBG("len %d room %d", len
, room
);
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
);
357 ll
->rx_state
= HCILL_W4_DATA
;
362 ll
->rx_state
= HCILL_W4_PACKET_TYPE
;
370 static int ll_recv(struct hci_uart
*hu
, void *data
, int count
)
372 struct ll_struct
*ll
= hu
->priv
;
374 struct hci_event_hdr
*eh
;
375 struct hci_acl_hdr
*ah
;
376 struct hci_sco_hdr
*sh
;
377 register int len
, type
, dlen
;
379 BT_DBG("hu %p count %d rx_state %ld rx_count %ld", hu
, count
, ll
->rx_state
, 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
;
391 switch (ll
->rx_state
) {
393 BT_DBG("Complete data");
394 hci_recv_frame(ll
->rx_skb
);
396 ll
->rx_state
= HCILL_W4_PACKET_TYPE
;
400 case HCILL_W4_EVENT_HDR
:
401 eh
= (struct hci_event_hdr
*) ll
->rx_skb
->data
;
403 BT_DBG("Event header: evt 0x%2.2x plen %d", eh
->evt
, eh
->plen
);
405 ll_check_data_len(ll
, eh
->plen
);
408 case HCILL_W4_ACL_HDR
:
409 ah
= (struct hci_acl_hdr
*) ll
->rx_skb
->data
;
410 dlen
= __le16_to_cpu(ah
->dlen
);
412 BT_DBG("ACL header: dlen %d", dlen
);
414 ll_check_data_len(ll
, dlen
);
417 case HCILL_W4_SCO_HDR
:
418 sh
= (struct hci_sco_hdr
*) ll
->rx_skb
->data
;
420 BT_DBG("SCO header: dlen %d", sh
->dlen
);
422 ll_check_data_len(ll
, sh
->dlen
);
427 /* HCILL_W4_PACKET_TYPE */
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
;
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
;
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
;
451 case HCILL_GO_TO_SLEEP_IND
:
452 BT_DBG("HCILL_GO_TO_SLEEP_IND packet");
453 ll_device_want_to_sleep(hu
);
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
);
463 case HCILL_WAKE_UP_IND
:
464 BT_DBG("HCILL_WAKE_UP_IND packet");
465 ll_device_want_to_wakeup(hu
);
469 case HCILL_WAKE_UP_ACK
:
470 BT_DBG("HCILL_WAKE_UP_ACK packet");
471 ll_device_woke_up(hu
);
476 BT_ERR("Unknown HCI packet type %2.2x", (__u8
)*ptr
);
477 hu
->hdev
->stat
.err_rx
++;
484 /* Allocate packet */
485 ll
->rx_skb
= bt_skb_alloc(HCI_MAX_FRAME_SIZE
, GFP_ATOMIC
);
487 BT_ERR("Can't allocate mem for new packet");
488 ll
->rx_state
= HCILL_W4_PACKET_TYPE
;
493 ll
->rx_skb
->dev
= (void *) hu
->hdev
;
494 bt_cb(ll
->rx_skb
)->pkt_type
= type
;
500 static struct sk_buff
*ll_dequeue(struct hci_uart
*hu
)
502 struct ll_struct
*ll
= hu
->priv
;
503 return skb_dequeue(&ll
->txq
);
506 static struct hci_uart_proto llp
= {
511 .enqueue
= ll_enqueue
,
512 .dequeue
= ll_dequeue
,
518 int err
= hci_uart_register_proto(&llp
);
521 BT_INFO("HCILL protocol initialized");
523 BT_ERR("HCILL protocol registration failed");
530 return hci_uart_unregister_proto(&llp
);