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/config.h>
27 #include <linux/module.h>
28
29 #include <linux/kernel.h>
30 #include <linux/init.h>
31 #include <linux/sched.h>
32 #include <linux/types.h>
33 #include <linux/fcntl.h>
34 #include <linux/interrupt.h>
35 #include <linux/ptrace.h>
36 #include <linux/poll.h>
37
38 #include <linux/slab.h>
39 #include <linux/tty.h>
40 #include <linux/errno.h>
41 #include <linux/string.h>
42 #include <linux/signal.h>
43 #include <linux/ioctl.h>
44 #include <linux/skbuff.h>
45
46 #include <net/bluetooth/bluetooth.h>
47 #include <net/bluetooth/hci_core.h>
48
49 #include "hci_uart.h"
50
51 #ifndef CONFIG_BT_HCIUART_DEBUG
52 #undef BT_DBG
53 #define BT_DBG( A... )
54 #endif
55
56 #define VERSION "1.2"
57
58 struct h4_struct {
59 unsigned long rx_state;
60 unsigned long rx_count;
61 struct sk_buff *rx_skb;
62 struct sk_buff_head txq;
63 };
64
65 /* H4 receiver States */
66 #define H4_W4_PACKET_TYPE 0
67 #define H4_W4_EVENT_HDR 1
68 #define H4_W4_ACL_HDR 2
69 #define H4_W4_SCO_HDR 3
70 #define H4_W4_DATA 4
71
72 /* Initialize protocol */
73 static int h4_open(struct hci_uart *hu)
74 {
75 struct h4_struct *h4;
76
77 BT_DBG("hu %p", hu);
78
79 h4 = kzalloc(sizeof(*h4), GFP_ATOMIC);
80 if (!h4)
81 return -ENOMEM;
82
83 skb_queue_head_init(&h4->txq);
84
85 hu->priv = h4;
86 return 0;
87 }
88
89 /* Flush protocol data */
90 static int h4_flush(struct hci_uart *hu)
91 {
92 struct h4_struct *h4 = hu->priv;
93
94 BT_DBG("hu %p", hu);
95
96 skb_queue_purge(&h4->txq);
97
98 return 0;
99 }
100
101 /* Close protocol */
102 static int h4_close(struct hci_uart *hu)
103 {
104 struct h4_struct *h4 = hu->priv;
105
106 hu->priv = NULL;
107
108 BT_DBG("hu %p", hu);
109
110 skb_queue_purge(&h4->txq);
111
112 if (h4->rx_skb)
113 kfree_skb(h4->rx_skb);
114
115 hu->priv = NULL;
116 kfree(h4);
117
118 return 0;
119 }
120
121 /* Enqueue frame for transmittion (padding, crc, etc) */
122 static int h4_enqueue(struct hci_uart *hu, struct sk_buff *skb)
123 {
124 struct h4_struct *h4 = hu->priv;
125
126 BT_DBG("hu %p skb %p", hu, skb);
127
128 /* Prepend skb with frame type */
129 memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
130 skb_queue_tail(&h4->txq, skb);
131
132 return 0;
133 }
134
135 static inline int h4_check_data_len(struct h4_struct *h4, int len)
136 {
137 register int room = skb_tailroom(h4->rx_skb);
138
139 BT_DBG("len %d room %d", len, room);
140
141 if (!len) {
142 hci_recv_frame(h4->rx_skb);
143 } else if (len > room) {
144 BT_ERR("Data length is too large");
145 kfree_skb(h4->rx_skb);
146 } else {
147 h4->rx_state = H4_W4_DATA;
148 h4->rx_count = len;
149 return len;
150 }
151
152 h4->rx_state = H4_W4_PACKET_TYPE;
153 h4->rx_skb = NULL;
154 h4->rx_count = 0;
155
156 return 0;
157 }
158
159 /* Recv data */
160 static int h4_recv(struct hci_uart *hu, void *data, int count)
161 {
162 struct h4_struct *h4 = hu->priv;
163 register char *ptr;
164 struct hci_event_hdr *eh;
165 struct hci_acl_hdr *ah;
166 struct hci_sco_hdr *sh;
167 register int len, type, dlen;
168
169 BT_DBG("hu %p count %d rx_state %ld rx_count %ld",
170 hu, count, h4->rx_state, h4->rx_count);
171
172 ptr = data;
173 while (count) {
174 if (h4->rx_count) {
175 len = min_t(unsigned int, h4->rx_count, count);
176 memcpy(skb_put(h4->rx_skb, len), ptr, len);
177 h4->rx_count -= len; count -= len; ptr += len;
178
179 if (h4->rx_count)
180 continue;
181
182 switch (h4->rx_state) {
183 case H4_W4_DATA:
184 BT_DBG("Complete data");
185
186 hci_recv_frame(h4->rx_skb);
187
188 h4->rx_state = H4_W4_PACKET_TYPE;
189 h4->rx_skb = NULL;
190 continue;
191
192 case H4_W4_EVENT_HDR:
193 eh = (struct hci_event_hdr *) h4->rx_skb->data;
194
195 BT_DBG("Event header: evt 0x%2.2x plen %d", eh->evt, eh->plen);
196
197 h4_check_data_len(h4, eh->plen);
198 continue;
199
200 case H4_W4_ACL_HDR:
201 ah = (struct hci_acl_hdr *) h4->rx_skb->data;
202 dlen = __le16_to_cpu(ah->dlen);
203
204 BT_DBG("ACL header: dlen %d", dlen);
205
206 h4_check_data_len(h4, dlen);
207 continue;
208
209 case H4_W4_SCO_HDR:
210 sh = (struct hci_sco_hdr *) h4->rx_skb->data;
211
212 BT_DBG("SCO header: dlen %d", sh->dlen);
213
214 h4_check_data_len(h4, sh->dlen);
215 continue;
216 }
217 }
218
219 /* H4_W4_PACKET_TYPE */
220 switch (*ptr) {
221 case HCI_EVENT_PKT:
222 BT_DBG("Event packet");
223 h4->rx_state = H4_W4_EVENT_HDR;
224 h4->rx_count = HCI_EVENT_HDR_SIZE;
225 type = HCI_EVENT_PKT;
226 break;
227
228 case HCI_ACLDATA_PKT:
229 BT_DBG("ACL packet");
230 h4->rx_state = H4_W4_ACL_HDR;
231 h4->rx_count = HCI_ACL_HDR_SIZE;
232 type = HCI_ACLDATA_PKT;
233 break;
234
235 case HCI_SCODATA_PKT:
236 BT_DBG("SCO packet");
237 h4->rx_state = H4_W4_SCO_HDR;
238 h4->rx_count = HCI_SCO_HDR_SIZE;
239 type = HCI_SCODATA_PKT;
240 break;
241
242 default:
243 BT_ERR("Unknown HCI packet type %2.2x", (__u8)*ptr);
244 hu->hdev->stat.err_rx++;
245 ptr++; count--;
246 continue;
247 };
248
249 ptr++; count--;
250
251 /* Allocate packet */
252 h4->rx_skb = bt_skb_alloc(HCI_MAX_FRAME_SIZE, GFP_ATOMIC);
253 if (!h4->rx_skb) {
254 BT_ERR("Can't allocate mem for new packet");
255 h4->rx_state = H4_W4_PACKET_TYPE;
256 h4->rx_count = 0;
257 return 0;
258 }
259
260 h4->rx_skb->dev = (void *) hu->hdev;
261 bt_cb(h4->rx_skb)->pkt_type = type;
262 }
263
264 return count;
265 }
266
267 static struct sk_buff *h4_dequeue(struct hci_uart *hu)
268 {
269 struct h4_struct *h4 = hu->priv;
270 return skb_dequeue(&h4->txq);
271 }
272
273 static struct hci_uart_proto h4p = {
274 .id = HCI_UART_H4,
275 .open = h4_open,
276 .close = h4_close,
277 .recv = h4_recv,
278 .enqueue = h4_enqueue,
279 .dequeue = h4_dequeue,
280 .flush = h4_flush,
281 };
282
283 int h4_init(void)
284 {
285 int err = hci_uart_register_proto(&h4p);
286
287 if (!err)
288 BT_INFO("HCI H4 protocol initialized");
289 else
290 BT_ERR("HCI H4 protocol registration failed");
291
292 return err;
293 }
294
295 int h4_deinit(void)
296 {
297 return hci_uart_unregister_proto(&h4p);
298 }
299
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