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>
54 #ifndef CONFIG_BT_HCIUART_DEBUG
56 #define BT_DBG( A... )
60 #define HCILL_GO_TO_SLEEP_IND 0x30
61 #define HCILL_GO_TO_SLEEP_ACK 0x31
62 #define HCILL_WAKE_UP_IND 0x32
63 #define HCILL_WAKE_UP_ACK 0x33
65 /* HCILL receiver States */
66 #define HCILL_W4_PACKET_TYPE 0
67 #define HCILL_W4_EVENT_HDR 1
68 #define HCILL_W4_ACL_HDR 2
69 #define HCILL_W4_SCO_HDR 3
70 #define HCILL_W4_DATA 4
75 HCILL_ASLEEP_TO_AWAKE,
82 } __attribute__((packed));
85 unsigned long rx_state;
86 unsigned long rx_count;
87 struct sk_buff *rx_skb;
88 struct sk_buff_head txq;
89 spinlock_t hcill_lock; /* HCILL state lock */
90 unsigned long hcill_state; /* HCILL power state */
91 struct sk_buff_head tx_wait_q; /* HCILL wait queue */
95 * Builds and sends an HCILL command packet.
96 * These are very simple packets with only 1 cmd byte
98 static int send_hcill_cmd(u8 cmd, struct hci_uart *hu)
101 struct sk_buff *skb = NULL;
102 struct ll_struct *ll = hu->priv;
103 struct hcill_cmd *hcill_packet;
105 BT_DBG("hu %p cmd 0x%x", hu, cmd);
107 /* allocate packet */
108 skb = bt_skb_alloc(1, GFP_ATOMIC);
110 BT_ERR("cannot allocate memory for HCILL packet");
116 hcill_packet = (struct hcill_cmd *) skb_put(skb, 1);
117 hcill_packet->cmd = cmd;
118 skb->dev = (void *) hu->hdev;
121 skb_queue_tail(&ll->txq, skb);
126 /* Initialize protocol */
127 static int ll_open(struct hci_uart *hu)
129 struct ll_struct *ll;
133 ll = kzalloc(sizeof(*ll), GFP_ATOMIC);
137 skb_queue_head_init(&ll->txq);
138 skb_queue_head_init(&ll->tx_wait_q);
139 spin_lock_init(&ll->hcill_lock);
141 ll->hcill_state = HCILL_AWAKE;
148 /* Flush protocol data */
149 static int ll_flush(struct hci_uart *hu)
151 struct ll_struct *ll = hu->priv;
155 skb_queue_purge(&ll->tx_wait_q);
156 skb_queue_purge(&ll->txq);
162 static int ll_close(struct hci_uart *hu)
164 struct ll_struct *ll = hu->priv;
168 skb_queue_purge(&ll->tx_wait_q);
169 skb_queue_purge(&ll->txq);
172 kfree_skb(ll->rx_skb);
182 * internal function, which does common work of the device wake up process:
183 * 1. places all pending packets (waiting in tx_wait_q list) in txq list.
184 * 2. changes internal state to HCILL_AWAKE.
185 * Note: assumes that hcill_lock spinlock is taken,
186 * shouldn't be called otherwise!
188 static void __ll_do_awake(struct ll_struct *ll)
190 struct sk_buff *skb = NULL;
192 while ((skb = skb_dequeue(&ll->tx_wait_q)))
193 skb_queue_tail(&ll->txq, skb);
195 ll->hcill_state = HCILL_AWAKE;
199 * Called upon a wake-up-indication from the device
201 static void ll_device_want_to_wakeup(struct hci_uart *hu)
204 struct ll_struct *ll = hu->priv;
208 /* lock hcill state */
209 spin_lock_irqsave(&ll->hcill_lock, flags);
211 switch (ll->hcill_state) {
212 case HCILL_ASLEEP_TO_AWAKE:
214 * This state means that both the host and the BRF chip
215 * have simultaneously sent a wake-up-indication packet.
216 * Traditionaly, in this case, receiving a wake-up-indication
217 * was enough and an additional wake-up-ack wasn't needed.
218 * This has changed with the BRF6350, which does require an
219 * explicit wake-up-ack. Other BRF versions, which do not
220 * require an explicit ack here, do accept it, thus it is
221 * perfectly safe to always send one.
223 BT_DBG("dual wake-up-indication");
224 /* deliberate fall-through - do not add break */
226 /* acknowledge device wake up */
227 if (send_hcill_cmd(HCILL_WAKE_UP_ACK, hu) < 0) {
228 BT_ERR("cannot acknowledge device wake up");
233 /* any other state is illegal */
234 BT_ERR("received HCILL_WAKE_UP_IND in state %ld", ll->hcill_state);
238 /* send pending packets and change state to HCILL_AWAKE */
242 spin_unlock_irqrestore(&ll->hcill_lock, flags);
244 /* actually send the packets */
245 hci_uart_tx_wakeup(hu);
249 * Called upon a sleep-indication from the device
251 static void ll_device_want_to_sleep(struct hci_uart *hu)
254 struct ll_struct *ll = hu->priv;
258 /* lock hcill state */
259 spin_lock_irqsave(&ll->hcill_lock, flags);
262 if (ll->hcill_state != HCILL_AWAKE)
263 BT_ERR("ERR: HCILL_GO_TO_SLEEP_IND in state %ld", ll->hcill_state);
265 /* acknowledge device sleep */
266 if (send_hcill_cmd(HCILL_GO_TO_SLEEP_ACK, hu) < 0) {
267 BT_ERR("cannot acknowledge device sleep");
272 ll->hcill_state = HCILL_ASLEEP;
275 spin_unlock_irqrestore(&ll->hcill_lock, flags);
277 /* actually send the sleep ack packet */
278 hci_uart_tx_wakeup(hu);
282 * Called upon wake-up-acknowledgement from the device
284 static void ll_device_woke_up(struct hci_uart *hu)
287 struct ll_struct *ll = hu->priv;
291 /* lock hcill state */
292 spin_lock_irqsave(&ll->hcill_lock, flags);
295 if (ll->hcill_state != HCILL_ASLEEP_TO_AWAKE)
296 BT_ERR("received HCILL_WAKE_UP_ACK in state %ld", ll->hcill_state);
298 /* send pending packets and change state to HCILL_AWAKE */
301 spin_unlock_irqrestore(&ll->hcill_lock, flags);
303 /* actually send the packets */
304 hci_uart_tx_wakeup(hu);
307 /* Enqueue frame for transmittion (padding, crc, etc) */
308 /* may be called from two simultaneous tasklets */
309 static int ll_enqueue(struct hci_uart *hu, struct sk_buff *skb)
311 unsigned long flags = 0;
312 struct ll_struct *ll = hu->priv;
314 BT_DBG("hu %p skb %p", hu, skb);
316 /* Prepend skb with frame type */
317 memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
319 /* lock hcill state */
320 spin_lock_irqsave(&ll->hcill_lock, flags);
322 /* act according to current state */
323 switch (ll->hcill_state) {
325 BT_DBG("device awake, sending normally");
326 skb_queue_tail(&ll->txq, skb);
329 BT_DBG("device asleep, waking up and queueing packet");
330 /* save packet for later */
331 skb_queue_tail(&ll->tx_wait_q, skb);
333 if (send_hcill_cmd(HCILL_WAKE_UP_IND, hu) < 0) {
334 BT_ERR("cannot wake up device");
337 ll->hcill_state = HCILL_ASLEEP_TO_AWAKE;
339 case HCILL_ASLEEP_TO_AWAKE:
340 BT_DBG("device waking up, queueing packet");
341 /* transient state; just keep packet for later */
342 skb_queue_tail(&ll->tx_wait_q, skb);
345 BT_ERR("illegal hcill state: %ld (losing packet)", ll->hcill_state);
350 spin_unlock_irqrestore(&ll->hcill_lock, flags);
355 static inline int ll_check_data_len(struct ll_struct *ll, int len)
357 register int room = skb_tailroom(ll->rx_skb);
359 BT_DBG("len %d room %d", len, room);
362 hci_recv_frame(ll->rx_skb);
363 } else if (len > room) {
364 BT_ERR("Data length is too large");
365 kfree_skb(ll->rx_skb);
367 ll->rx_state = HCILL_W4_DATA;
372 ll->rx_state = HCILL_W4_PACKET_TYPE;
380 static int ll_recv(struct hci_uart *hu, void *data, int count)
382 struct ll_struct *ll = hu->priv;
384 struct hci_event_hdr *eh;
385 struct hci_acl_hdr *ah;
386 struct hci_sco_hdr *sh;
387 register int len, type, dlen;
389 BT_DBG("hu %p count %d rx_state %ld rx_count %ld", hu, count, ll->rx_state, ll->rx_count);
394 len = min_t(unsigned int, ll->rx_count, count);
395 memcpy(skb_put(ll->rx_skb, len), ptr, len);
396 ll->rx_count -= len; count -= len; ptr += len;
401 switch (ll->rx_state) {
403 BT_DBG("Complete data");
404 hci_recv_frame(ll->rx_skb);
406 ll->rx_state = HCILL_W4_PACKET_TYPE;
410 case HCILL_W4_EVENT_HDR:
411 eh = (struct hci_event_hdr *) ll->rx_skb->data;
413 BT_DBG("Event header: evt 0x%2.2x plen %d", eh->evt, eh->plen);
415 ll_check_data_len(ll, eh->plen);
418 case HCILL_W4_ACL_HDR:
419 ah = (struct hci_acl_hdr *) ll->rx_skb->data;
420 dlen = __le16_to_cpu(ah->dlen);
422 BT_DBG("ACL header: dlen %d", dlen);
424 ll_check_data_len(ll, dlen);
427 case HCILL_W4_SCO_HDR:
428 sh = (struct hci_sco_hdr *) ll->rx_skb->data;
430 BT_DBG("SCO header: dlen %d", sh->dlen);
432 ll_check_data_len(ll, sh->dlen);
437 /* HCILL_W4_PACKET_TYPE */
440 BT_DBG("Event packet");
441 ll->rx_state = HCILL_W4_EVENT_HDR;
442 ll->rx_count = HCI_EVENT_HDR_SIZE;
443 type = HCI_EVENT_PKT;
446 case HCI_ACLDATA_PKT:
447 BT_DBG("ACL packet");
448 ll->rx_state = HCILL_W4_ACL_HDR;
449 ll->rx_count = HCI_ACL_HDR_SIZE;
450 type = HCI_ACLDATA_PKT;
453 case HCI_SCODATA_PKT:
454 BT_DBG("SCO packet");
455 ll->rx_state = HCILL_W4_SCO_HDR;
456 ll->rx_count = HCI_SCO_HDR_SIZE;
457 type = HCI_SCODATA_PKT;
461 case HCILL_GO_TO_SLEEP_IND:
462 BT_DBG("HCILL_GO_TO_SLEEP_IND packet");
463 ll_device_want_to_sleep(hu);
467 case HCILL_GO_TO_SLEEP_ACK:
468 /* shouldn't happen */
469 BT_ERR("received HCILL_GO_TO_SLEEP_ACK (in state %ld)", ll->hcill_state);
473 case HCILL_WAKE_UP_IND:
474 BT_DBG("HCILL_WAKE_UP_IND packet");
475 ll_device_want_to_wakeup(hu);
479 case HCILL_WAKE_UP_ACK:
480 BT_DBG("HCILL_WAKE_UP_ACK packet");
481 ll_device_woke_up(hu);
486 BT_ERR("Unknown HCI packet type %2.2x", (__u8)*ptr);
487 hu->hdev->stat.err_rx++;
494 /* Allocate packet */
495 ll->rx_skb = bt_skb_alloc(HCI_MAX_FRAME_SIZE, GFP_ATOMIC);
497 BT_ERR("Can't allocate mem for new packet");
498 ll->rx_state = HCILL_W4_PACKET_TYPE;
503 ll->rx_skb->dev = (void *) hu->hdev;
504 bt_cb(ll->rx_skb)->pkt_type = type;
510 static struct sk_buff *ll_dequeue(struct hci_uart *hu)
512 struct ll_struct *ll = hu->priv;
513 return skb_dequeue(&ll->txq);
516 static struct hci_uart_proto llp = {
521 .enqueue = ll_enqueue,
522 .dequeue = ll_dequeue,
528 int err = hci_uart_register_proto(&llp);
531 BT_INFO("HCILL protocol initialized");
533 BT_ERR("HCILL protocol registration failed");
540 return hci_uart_unregister_proto(&llp);