summaryrefslogtreecommitdiffstats
path: root/drivers/bluetooth/hci_h4.c
blob: 4804d474dc8735d4a2365258385551134134c616 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
/*
 *
 *  Bluetooth HCI UART driver
 *
 *  Copyright (C) 2000-2001  Qualcomm Incorporated
 *  Copyright (C) 2002-2003  Maxim Krasnyansky <maxk@qualcomm.com>
 *  Copyright (C) 2004-2005  Marcel Holtmann <marcel@holtmann.org>
 *
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#include <linux/config.h>
#include <linux/module.h>

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/interrupt.h>
#include <linux/ptrace.h>
#include <linux/poll.h>

#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/signal.h>
#include <linux/ioctl.h>
#include <linux/skbuff.h>

#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci_core.h>

#include "hci_uart.h"

#ifndef CONFIG_BT_HCIUART_DEBUG
#undef  BT_DBG
#define BT_DBG( A... )
#endif

#define VERSION "1.2"

struct h4_struct {
	unsigned long rx_state;
	unsigned long rx_count;
	struct sk_buff *rx_skb;
	struct sk_buff_head txq;
};

/* H4 receiver States */
#define H4_W4_PACKET_TYPE	0
#define H4_W4_EVENT_HDR		1
#define H4_W4_ACL_HDR		2
#define H4_W4_SCO_HDR		3
#define H4_W4_DATA		4

/* Initialize protocol */
static int h4_open(struct hci_uart *hu)
{
	struct h4_struct *h4;

	BT_DBG("hu %p", hu);

	h4 = kzalloc(sizeof(*h4), GFP_ATOMIC);
	if (!h4)
		return -ENOMEM;

	skb_queue_head_init(&h4->txq);

	hu->priv = h4;
	return 0;
}

/* Flush protocol data */
static int h4_flush(struct hci_uart *hu)
{
	struct h4_struct *h4 = hu->priv;

	BT_DBG("hu %p", hu);

	skb_queue_purge(&h4->txq);

	return 0;
}

/* Close protocol */
static int h4_close(struct hci_uart *hu)
{
	struct h4_struct *h4 = hu->priv;

	hu->priv = NULL;

	BT_DBG("hu %p", hu);

	skb_queue_purge(&h4->txq);

	if (h4->rx_skb)
		kfree_skb(h4->rx_skb);

	hu->priv = NULL;
	kfree(h4);

	return 0;
}

/* Enqueue frame for transmittion (padding, crc, etc) */
static int h4_enqueue(struct hci_uart *hu, struct sk_buff *skb)
{
	struct h4_struct *h4 = hu->priv;

	BT_DBG("hu %p skb %p", hu, skb);

	/* Prepend skb with frame type */
	memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
	skb_queue_tail(&h4->txq, skb);

	return 0;
}

static inline int h4_check_data_len(struct h4_struct *h4, int len)
{
	register int room = skb_tailroom(h4->rx_skb);

	BT_DBG("len %d room %d", len, room);

	if (!len) {
		hci_recv_frame(h4->rx_skb);
	} else if (len > room) {
		BT_ERR("Data length is too large");
		kfree_skb(h4->rx_skb);
	} else {
		h4->rx_state = H4_W4_DATA;
		h4->rx_count = len;
		return len;
	}

	h4->rx_state = H4_W4_PACKET_TYPE;
	h4->rx_skb   = NULL;
	h4->rx_count = 0;

	return 0;
}

/* Recv data */
static int h4_recv(struct hci_uart *hu, void *data, int count)
{
	struct h4_struct *h4 = hu->priv;
	register char *ptr;
	struct hci_event_hdr *eh;
	struct hci_acl_hdr   *ah;
	struct hci_sco_hdr   *sh;
	register int len, type, dlen;

	BT_DBG("hu %p count %d rx_state %ld rx_count %ld", 
			hu, count, h4->rx_state, h4->rx_count);

	ptr = data;
	while (count) {
		if (h4->rx_count) {
			len = min_t(unsigned int, h4->rx_count, count);
			memcpy(skb_put(h4->rx_skb, len), ptr, len);
			h4->rx_count -= len; count -= len; ptr += len;

			if (h4->rx_count)
				continue;

			switch (h4->rx_state) {
			case H4_W4_DATA:
				BT_DBG("Complete data");

				hci_recv_frame(h4->rx_skb);

				h4->rx_state = H4_W4_PACKET_TYPE;
				h4->rx_skb = NULL;
				continue;

			case H4_W4_EVENT_HDR:
				eh = (struct hci_event_hdr *) h4->rx_skb->data;

				BT_DBG("Event header: evt 0x%2.2x plen %d", eh->evt, eh->plen);

				h4_check_data_len(h4, eh->plen);
				continue;

			case H4_W4_ACL_HDR:
				ah = (struct hci_acl_hdr *) h4->rx_skb->data;
				dlen = __le16_to_cpu(ah->dlen);

				BT_DBG("ACL header: dlen %d", dlen);

				h4_check_data_len(h4, dlen);
				continue;

			case H4_W4_SCO_HDR:
				sh = (struct hci_sco_hdr *) h4->rx_skb->data;

				BT_DBG("SCO header: dlen %d", sh->dlen);

				h4_check_data_len(h4, sh->dlen);
				continue;
			}
		}

		/* H4_W4_PACKET_TYPE */
		switch (*ptr) {
		case HCI_EVENT_PKT:
			BT_DBG("Event packet");
			h4->rx_state = H4_W4_EVENT_HDR;
			h4->rx_count = HCI_EVENT_HDR_SIZE;
			type = HCI_EVENT_PKT;
			break;

		case HCI_ACLDATA_PKT:
			BT_DBG("ACL packet");
			h4->rx_state = H4_W4_ACL_HDR;
			h4->rx_count = HCI_ACL_HDR_SIZE;
			type = HCI_ACLDATA_PKT;
			break;

		case HCI_SCODATA_PKT:
			BT_DBG("SCO packet");
			h4->rx_state = H4_W4_SCO_HDR;
			h4->rx_count = HCI_SCO_HDR_SIZE;
			type = HCI_SCODATA_PKT;
			break;

		default:
			BT_ERR("Unknown HCI packet type %2.2x", (__u8)*ptr);
			hu->hdev->stat.err_rx++;
			ptr++; count--;
			continue;
		};

		ptr++; count--;

		/* Allocate packet */
		h4->rx_skb = bt_skb_alloc(HCI_MAX_FRAME_SIZE, GFP_ATOMIC);
		if (!h4->rx_skb) {
			BT_ERR("Can't allocate mem for new packet");
			h4->rx_state = H4_W4_PACKET_TYPE;
			h4->rx_count = 0;
			return 0;
		}

		h4->rx_skb->dev = (void *) hu->hdev;
		bt_cb(h4->rx_skb)->pkt_type = type;
	}

	return count;
}

static struct sk_buff *h4_dequeue(struct hci_uart *hu)
{
	struct h4_struct *h4 = hu->priv;
	return skb_dequeue(&h4->txq);
}

static struct hci_uart_proto h4p = {
	.id		= HCI_UART_H4,
	.open		= h4_open,
	.close		= h4_close,
	.recv		= h4_recv,
	.enqueue	= h4_enqueue,
	.dequeue	= h4_dequeue,
	.flush		= h4_flush,
};

int h4_init(void)
{
	int err = hci_uart_register_proto(&h4p);

	if (!err)
		BT_INFO("HCI H4 protocol initialized");
	else
		BT_ERR("HCI H4 protocol registration failed");

	return err;
}

int h4_deinit(void)
{
	return hci_uart_unregister_proto(&h4p);
}
OpenPOWER on IntegriCloud