1/*
2 *
3 *  Bluetooth HCI UART driver
4 *
5 *  Copyright (C) 2000-2001  Qualcomm Incorporated
6 *  Copyright (C) 2002-2003  Maxim Krasnyansky <maxk@qualcomm.com>
7 *  Copyright (C) 2004-2005  Marcel Holtmann <marcel@holtmann.org>
8 *
9 *
10 *  This program is free software; you can redistribute it and/or modify
11 *  it under the terms of the GNU General Public License as published by
12 *  the Free Software Foundation; either version 2 of the License, or
13 *  (at your option) any later version.
14 *
15 *  This program is distributed in the hope that it will be useful,
16 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
17 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18 *  GNU General Public License for more details.
19 *
20 *  You should have received a copy of the GNU General Public License
21 *  along with this program; if not, write to the Free Software
22 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
23 *
24 */
25
26#include <linux/module.h>
27
28#include <linux/kernel.h>
29#include <linux/init.h>
30#include <linux/types.h>
31#include <linux/fcntl.h>
32#include <linux/interrupt.h>
33#include <linux/ptrace.h>
34#include <linux/poll.h>
35
36#include <linux/slab.h>
37#include <linux/tty.h>
38#include <linux/errno.h>
39#include <linux/string.h>
40#include <linux/signal.h>
41#include <linux/ioctl.h>
42#include <linux/skbuff.h>
43
44#include <net/bluetooth/bluetooth.h>
45#include <net/bluetooth/hci_core.h>
46
47#include "hci_uart.h"
48
49#define VERSION "1.2"
50
51struct h4_struct {
52	unsigned long rx_state;
53	unsigned long rx_count;
54	struct sk_buff *rx_skb;
55	struct sk_buff_head txq;
56};
57
58/* H4 receiver States */
59#define H4_W4_PACKET_TYPE	0
60#define H4_W4_EVENT_HDR		1
61#define H4_W4_ACL_HDR		2
62#define H4_W4_SCO_HDR		3
63#define H4_W4_DATA		4
64
65/* Initialize protocol */
66static int h4_open(struct hci_uart *hu)
67{
68	struct h4_struct *h4;
69
70	BT_DBG("hu %p", hu);
71
72	h4 = kzalloc(sizeof(*h4), GFP_KERNEL);
73	if (!h4)
74		return -ENOMEM;
75
76	skb_queue_head_init(&h4->txq);
77
78	hu->priv = h4;
79	return 0;
80}
81
82/* Flush protocol data */
83static int h4_flush(struct hci_uart *hu)
84{
85	struct h4_struct *h4 = hu->priv;
86
87	BT_DBG("hu %p", hu);
88
89	skb_queue_purge(&h4->txq);
90
91	return 0;
92}
93
94/* Close protocol */
95static int h4_close(struct hci_uart *hu)
96{
97	struct h4_struct *h4 = hu->priv;
98
99	hu->priv = NULL;
100
101	BT_DBG("hu %p", hu);
102
103	skb_queue_purge(&h4->txq);
104
105	kfree_skb(h4->rx_skb);
106
107	hu->priv = NULL;
108	kfree(h4);
109
110	return 0;
111}
112
113/* Enqueue frame for transmittion (padding, crc, etc) */
114static int h4_enqueue(struct hci_uart *hu, struct sk_buff *skb)
115{
116	struct h4_struct *h4 = hu->priv;
117
118	BT_DBG("hu %p skb %p", hu, skb);
119
120	/* Prepend skb with frame type */
121	memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
122	skb_queue_tail(&h4->txq, skb);
123
124	return 0;
125}
126
127static inline int h4_check_data_len(struct h4_struct *h4, int len)
128{
129	register int room = skb_tailroom(h4->rx_skb);
130
131	BT_DBG("len %d room %d", len, room);
132
133	if (!len) {
134		hci_recv_frame(h4->rx_skb);
135	} else if (len > room) {
136		BT_ERR("Data length is too large");
137		kfree_skb(h4->rx_skb);
138	} else {
139		h4->rx_state = H4_W4_DATA;
140		h4->rx_count = len;
141		return len;
142	}
143
144	h4->rx_state = H4_W4_PACKET_TYPE;
145	h4->rx_skb   = NULL;
146	h4->rx_count = 0;
147
148	return 0;
149}
150
151/* Recv data */
152static int h4_recv(struct hci_uart *hu, void *data, int count)
153{
154	int ret;
155
156	ret = hci_recv_stream_fragment(hu->hdev, data, count);
157	if (ret < 0) {
158		BT_ERR("Frame Reassembly Failed");
159		return ret;
160	}
161
162	return count;
163}
164
165static struct sk_buff *h4_dequeue(struct hci_uart *hu)
166{
167	struct h4_struct *h4 = hu->priv;
168	return skb_dequeue(&h4->txq);
169}
170
171static struct hci_uart_proto h4p = {
172	.id		= HCI_UART_H4,
173	.open		= h4_open,
174	.close		= h4_close,
175	.recv		= h4_recv,
176	.enqueue	= h4_enqueue,
177	.dequeue	= h4_dequeue,
178	.flush		= h4_flush,
179};
180
181int __init h4_init(void)
182{
183	int err = hci_uart_register_proto(&h4p);
184
185	if (!err)
186		BT_INFO("HCI H4 protocol initialized");
187	else
188		BT_ERR("HCI H4 protocol registration failed");
189
190	return err;
191}
192
193int __exit h4_deinit(void)
194{
195	return hci_uart_unregister_proto(&h4p);
196}
197