3 * Bluetooth HCI UART driver
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>
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.
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.
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
26 #include <linux/module.h>
28 #include <linux/kernel.h>
29 #include <linux/init.h>
30 #include <linux/sched.h>
31 #include <linux/types.h>
32 #include <linux/fcntl.h>
33 #include <linux/interrupt.h>
34 #include <linux/ptrace.h>
35 #include <linux/poll.h>
37 #include <linux/slab.h>
38 #include <linux/tty.h>
39 #include <linux/errno.h>
40 #include <linux/string.h>
41 #include <linux/signal.h>
42 #include <linux/ioctl.h>
43 #include <linux/skbuff.h>
45 #include <net/bluetooth/bluetooth.h>
46 #include <net/bluetooth/hci_core.h>
50 #ifndef CONFIG_BT_HCIUART_DEBUG
52 #define BT_DBG( A... )
58 unsigned long rx_state;
59 unsigned long rx_count;
60 struct sk_buff *rx_skb;
61 struct sk_buff_head txq;
64 /* H4 receiver States */
65 #define H4_W4_PACKET_TYPE 0
66 #define H4_W4_EVENT_HDR 1
67 #define H4_W4_ACL_HDR 2
68 #define H4_W4_SCO_HDR 3
71 /* Initialize protocol */
72 static int h4_open(struct hci_uart *hu)
78 h4 = kzalloc(sizeof(*h4), GFP_ATOMIC);
82 skb_queue_head_init(&h4->txq);
88 /* Flush protocol data */
89 static int h4_flush(struct hci_uart *hu)
91 struct h4_struct *h4 = hu->priv;
95 skb_queue_purge(&h4->txq);
101 static int h4_close(struct hci_uart *hu)
103 struct h4_struct *h4 = hu->priv;
109 skb_queue_purge(&h4->txq);
112 kfree_skb(h4->rx_skb);
120 /* Enqueue frame for transmittion (padding, crc, etc) */
121 static int h4_enqueue(struct hci_uart *hu, struct sk_buff *skb)
123 struct h4_struct *h4 = hu->priv;
125 BT_DBG("hu %p skb %p", hu, skb);
127 /* Prepend skb with frame type */
128 memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
129 skb_queue_tail(&h4->txq, skb);
134 static inline int h4_check_data_len(struct h4_struct *h4, int len)
136 register int room = skb_tailroom(h4->rx_skb);
138 BT_DBG("len %d room %d", len, room);
141 hci_recv_frame(h4->rx_skb);
142 } else if (len > room) {
143 BT_ERR("Data length is too large");
144 kfree_skb(h4->rx_skb);
146 h4->rx_state = H4_W4_DATA;
151 h4->rx_state = H4_W4_PACKET_TYPE;
159 static int h4_recv(struct hci_uart *hu, void *data, int count)
161 struct h4_struct *h4 = hu->priv;
163 struct hci_event_hdr *eh;
164 struct hci_acl_hdr *ah;
165 struct hci_sco_hdr *sh;
166 register int len, type, dlen;
168 BT_DBG("hu %p count %d rx_state %ld rx_count %ld",
169 hu, count, h4->rx_state, h4->rx_count);
174 len = min_t(unsigned int, h4->rx_count, count);
175 memcpy(skb_put(h4->rx_skb, len), ptr, len);
176 h4->rx_count -= len; count -= len; ptr += len;
181 switch (h4->rx_state) {
183 BT_DBG("Complete data");
185 hci_recv_frame(h4->rx_skb);
187 h4->rx_state = H4_W4_PACKET_TYPE;
191 case H4_W4_EVENT_HDR:
192 eh = (struct hci_event_hdr *) h4->rx_skb->data;
194 BT_DBG("Event header: evt 0x%2.2x plen %d", eh->evt, eh->plen);
196 h4_check_data_len(h4, eh->plen);
200 ah = (struct hci_acl_hdr *) h4->rx_skb->data;
201 dlen = __le16_to_cpu(ah->dlen);
203 BT_DBG("ACL header: dlen %d", dlen);
205 h4_check_data_len(h4, dlen);
209 sh = (struct hci_sco_hdr *) h4->rx_skb->data;
211 BT_DBG("SCO header: dlen %d", sh->dlen);
213 h4_check_data_len(h4, sh->dlen);
218 /* H4_W4_PACKET_TYPE */
221 BT_DBG("Event packet");
222 h4->rx_state = H4_W4_EVENT_HDR;
223 h4->rx_count = HCI_EVENT_HDR_SIZE;
224 type = HCI_EVENT_PKT;
227 case HCI_ACLDATA_PKT:
228 BT_DBG("ACL packet");
229 h4->rx_state = H4_W4_ACL_HDR;
230 h4->rx_count = HCI_ACL_HDR_SIZE;
231 type = HCI_ACLDATA_PKT;
234 case HCI_SCODATA_PKT:
235 BT_DBG("SCO packet");
236 h4->rx_state = H4_W4_SCO_HDR;
237 h4->rx_count = HCI_SCO_HDR_SIZE;
238 type = HCI_SCODATA_PKT;
242 BT_ERR("Unknown HCI packet type %2.2x", (__u8)*ptr);
243 hu->hdev->stat.err_rx++;
250 /* Allocate packet */
251 h4->rx_skb = bt_skb_alloc(HCI_MAX_FRAME_SIZE, GFP_ATOMIC);
253 BT_ERR("Can't allocate mem for new packet");
254 h4->rx_state = H4_W4_PACKET_TYPE;
259 h4->rx_skb->dev = (void *) hu->hdev;
260 bt_cb(h4->rx_skb)->pkt_type = type;
266 static struct sk_buff *h4_dequeue(struct hci_uart *hu)
268 struct h4_struct *h4 = hu->priv;
269 return skb_dequeue(&h4->txq);
272 static struct hci_uart_proto h4p = {
277 .enqueue = h4_enqueue,
278 .dequeue = h4_dequeue,
284 int err = hci_uart_register_proto(&h4p);
287 BT_INFO("HCI H4 protocol initialized");
289 BT_ERR("HCI H4 protocol registration failed");
296 return hci_uart_unregister_proto(&h4p);