xref: /openbmc/linux/drivers/bluetooth/hci_h4.c (revision bc000245)
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 
51 struct 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 */
66 static 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 */
83 static 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 */
95 static 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) */
114 static 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 
127 /* Recv data */
128 static int h4_recv(struct hci_uart *hu, void *data, int count)
129 {
130 	int ret;
131 
132 	if (!test_bit(HCI_UART_REGISTERED, &hu->flags))
133 		return -EUNATCH;
134 
135 	ret = hci_recv_stream_fragment(hu->hdev, data, count);
136 	if (ret < 0) {
137 		BT_ERR("Frame Reassembly Failed");
138 		return ret;
139 	}
140 
141 	return count;
142 }
143 
144 static struct sk_buff *h4_dequeue(struct hci_uart *hu)
145 {
146 	struct h4_struct *h4 = hu->priv;
147 	return skb_dequeue(&h4->txq);
148 }
149 
150 static struct hci_uart_proto h4p = {
151 	.id		= HCI_UART_H4,
152 	.open		= h4_open,
153 	.close		= h4_close,
154 	.recv		= h4_recv,
155 	.enqueue	= h4_enqueue,
156 	.dequeue	= h4_dequeue,
157 	.flush		= h4_flush,
158 };
159 
160 int __init h4_init(void)
161 {
162 	int err = hci_uart_register_proto(&h4p);
163 
164 	if (!err)
165 		BT_INFO("HCI H4 protocol initialized");
166 	else
167 		BT_ERR("HCI H4 protocol registration failed");
168 
169 	return err;
170 }
171 
172 int __exit h4_deinit(void)
173 {
174 	return hci_uart_unregister_proto(&h4p);
175 }
176