[Bluetooth] Add UART driver for Texas Instruments' BRF63xx chips
[linux-2.6.git] / drivers / bluetooth / hci_ll.c
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 }