aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/bluetooth/hci_h4.c
blob: 2fcd8b387d694b74130956fe836b5c211dbee20a (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
/*
 *
 *  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/module.h>

#include <linux/kernel.h>
#include <linux/init.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"

#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);

	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)
{
	int ret;

	ret = hci_recv_stream_fragment(hu->hdev, data, count);
	if (ret < 0) {
		BT_ERR("Frame Reassembly Failed");
		return ret;
	}

	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 __init 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 __exit h4_deinit(void)
{
	return hci_uart_unregister_proto(&h4p);
}