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 static inline int h4_check_data_len(struct h4_struct *h4, int len) 128 { 129 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 */ 152 static 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 } 164 165 static struct sk_buff *h4_dequeue(struct hci_uart *hu) 166 { 167 struct h4_struct *h4 = hu->priv; 168 return skb_dequeue(&h4->txq); 169 } 170 171 static 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 }; 180 181 int __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 } 192 193 int __exit h4_deinit(void) 194 { 195 return hci_uart_unregister_proto(&h4p); 196 } 197