2 * Copyright (c) 2000 Hellmuth Michaelis. All rights reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 *---------------------------------------------------------------------------
27 * i4b_l1lib.c - general useful L1 procedures
28 * ------------------------------------------
30 * $Id: i4b_l1lib.c,v 1.3 2000/05/29 15:41:41 hm Exp $
32 * $FreeBSD: src/sys/i4b/layer1/i4b_l1lib.c,v 1.3.2.1 2001/08/10 14:08:36 obrien Exp $
33 * $DragonFly: src/sys/net/i4b/layer1/i4b_l1lib.c,v 1.4 2003/08/07 21:17:25 dillon Exp $
35 * last edit-date: [Mon May 29 15:24:21 2000]
37 *---------------------------------------------------------------------------*/
39 #include <sys/param.h>
40 #include <sys/systm.h>
43 #include <machine/i4b_ioctl.h>
44 #include <machine/i4b_trace.h>
48 #define TEL_IDLE_MIN (BCH_MAX_DATALEN/2)
50 /*---------------------------------------------------------------------------*
51 * telephony silence detection
52 *---------------------------------------------------------------------------*/
54 i4b_l1_bchan_tel_silence(unsigned char *data, int len)
59 /* count idle bytes */
63 if((*data >= 0xaa) && (*data <= 0xac))
69 printf("i4b_l1_bchan_tel_silence: got %d silence bytes in frame\n", j);
72 if(j < (TEL_IDLE_MIN))