linux-imx

/* $Id: isdn_v110.c,v 1.1.2.2 2004/01/12 22:37:19 keil Exp $

 *

 * Linux ISDN subsystem, V.110 related functions (linklevel).

 *

 * Copyright by Thomas Pfeiffer (pfeiffer@pds.de)

 *

 * This software may be used and distributed according to the terms

 * of the GNU General Public License, incorporated herein by reference.

 *

 */

​

#include <linux/string.h>

#include <linux/kernel.h>

#include <linux/slab.h>

#include <linux/mm.h>

#include <linux/delay.h>

​

#include <linux/isdn.h>

#include "isdn_v110.h"

​

#undef ISDN_V110_DEBUG

​

char *isdn_v110_revision = "$Revision: 1.1.2.2 $";

​

#define V110_38400 255

#define V110_19200  15

#define V110_9600    3

​

/*

 * The following data are precoded matrices, online and offline matrix

 * for 9600, 19200 und 38400, respectively

 */

static unsigned char V110_OnMatrix_9600[] =

{0xfc, 0xfc, 0xfc, 0xfc, 0xff, 0xff, 0xff, 0xfd, 0xff, 0xff,

 0xff, 0xfd, 0xff, 0xff, 0xff, 0xfd, 0xff, 0xff, 0xff, 0xfd,

 0xfd, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfd, 0xff, 0xff,

 0xff, 0xfd, 0xff, 0xff, 0xff, 0xfd, 0xff, 0xff, 0xff, 0xfd};

​

static unsigned char V110_OffMatrix_9600[] =

{0xfc, 0xfc, 0xfc, 0xfc, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

 0xfd, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff};

​

static unsigned char V110_OnMatrix_19200[] =

{0xf0, 0xf0, 0xff, 0xf7, 0xff, 0xf7, 0xff, 0xf7, 0xff, 0xf7,

 0xfd, 0xff, 0xff, 0xf7, 0xff, 0xf7, 0xff, 0xf7, 0xff, 0xf7};

​

static unsigned char V110_OffMatrix_19200[] =

{0xf0, 0xf0, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

 0xfd, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff};

​

static unsigned char V110_OnMatrix_38400[] =

{0x00, 0x7f, 0x7f, 0x7f, 0x7f, 0xfd, 0x7f, 0x7f, 0x7f, 0x7f};

​

static unsigned char V110_OffMatrix_38400[] =

{0x00, 0xff, 0xff, 0xff, 0xff, 0xfd, 0xff, 0xff, 0xff, 0xff};

​

/*

 * FlipBits reorders sequences of keylen bits in one byte.

 * E.g. source order 7654321 will be converted to 45670123 when keylen = 4,

 * and to 67452301 when keylen = 2. This is necessary because ordering on

 * the isdn line is the other way.

 */

static inline unsigned char

FlipBits(unsigned char c, int keylen)

{

    unsigned char b = c;

    unsigned char bit = 128;

    int i;

    int j;

    int hunks = (8 / keylen);

​

    c = 0;

    for (i = 0; i < hunks; i++) {

        for (j = 0; j < keylen; j++) {

            if (b & (bit >> j))

                c |= bit >> (keylen - j - 1);

        }

        bit >>= keylen;

    }

    return c;

}

​

​

/* isdn_v110_open allocates and initializes private V.110 data

 * structures and returns a pointer to these.

 */

static isdn_v110_stream *

isdn_v110_open(unsigned char key, int hdrlen, int maxsize)

{

    int i;