xref: /openbmc/linux/drivers/bluetooth/hci_h4.c (revision 275876e2)
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 /* Initialize protocol */
59 static int h4_open(struct hci_uart *hu)
60 {
61 	struct h4_struct *h4;
62 
63 	BT_DBG("hu %p", hu);
64 
65 	h4 = kzalloc(sizeof(*h4), GFP_KERNEL);
66 	if (!h4)
67 		return -ENOMEM;
68 
69 	skb_queue_head_init(&h4->txq);
70 
71 	hu->priv = h4;
72 	return 0;
73 }
74 
75 /* Flush protocol data */
76 static int h4_flush(struct hci_uart *hu)
77 {
78 	struct h4_struct *h4 = hu->priv;
79 
80 	BT_DBG("hu %p", hu);
81 
82 	skb_queue_purge(&h4->txq);
83 
84 	return 0;
85 }
86 
87 /* Close protocol */
88 static int h4_close(struct hci_uart *hu)
89 {
90 	struct h4_struct *h4 = hu->priv;
91 
92 	hu->priv = NULL;
93 
94 	BT_DBG("hu %p", hu);
95 
96 	skb_queue_purge(&h4->txq);
97 
98 	kfree_skb(h4->rx_skb);
99 
100 	hu->priv = NULL;
101 	kfree(h4);
102 
103 	return 0;
104 }
105 
106 /* Enqueue frame for transmittion (padding, crc, etc) */
107 static int h4_enqueue(struct hci_uart *hu, struct sk_buff *skb)
108 {
109 	struct h4_struct *h4 = hu->priv;
110 
111 	BT_DBG("hu %p skb %p", hu, skb);
112 
113 	/* Prepend skb with frame type */
114 	memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
115 	skb_queue_tail(&h4->txq, skb);
116 
117 	return 0;
118 }
119 
120 /* Recv data */
121 static int h4_recv(struct hci_uart *hu, void *data, int count)
122 {
123 	int ret;
124 
125 	if (!test_bit(HCI_UART_REGISTERED, &hu->flags))
126 		return -EUNATCH;
127 
128 	ret = hci_recv_stream_fragment(hu->hdev, data, count);
129 	if (ret < 0) {
130 		BT_ERR("Frame Reassembly Failed");
131 		return ret;
132 	}
133 
134 	return count;
135 }
136 
137 static struct sk_buff *h4_dequeue(struct hci_uart *hu)
138 {
139 	struct h4_struct *h4 = hu->priv;
140 	return skb_dequeue(&h4->txq);
141 }
142 
143 static struct hci_uart_proto h4p = {
144 	.id		= HCI_UART_H4,
145 	.open		= h4_open,
146 	.close		= h4_close,
147 	.recv		= h4_recv,
148 	.enqueue	= h4_enqueue,
149 	.dequeue	= h4_dequeue,
150 	.flush		= h4_flush,
151 };
152 
153 int __init h4_init(void)
154 {
155 	int err = hci_uart_register_proto(&h4p);
156 
157 	if (!err)
158 		BT_INFO("HCI H4 protocol initialized");
159 	else
160 		BT_ERR("HCI H4 protocol registration failed");
161 
162 	return err;
163 }
164 
165 int __exit h4_deinit(void)
166 {
167 	return hci_uart_unregister_proto(&h4p);
168 }
169