drivers/isdn/hisax/st5481_hdlc.h

   1 /*
   2  * Driver for ST5481 USB ISDN modem
   3  *
   4  * Author       Frode Isaksen
   5  * Copyright    2001 by Frode Isaksen      <fisaksen@bewan.com>
   6  *              2001 by Kai Germaschewski  <kai.germaschewski@gmx.de>
   7  *
   8  * This software may be used and distributed according to the terms
   9  * of the GNU General Public License, incorporated herein by reference.
  10  *
  11  */
  12
  13 #ifndef __ST5481_HDLC_H__
  14 #define __ST5481_HDLC_H__
  15
  16 struct hdlc_vars {
  17         int bit_shift;
  18         int hdlc_bits1;
  19         int data_bits;
  20         int ffbit_shift; // encoding only
  21         int state;
  22         int dstpos;
  23
  24         int data_received:1; // set if transferring data
  25         int dchannel:1; // set if D channel (send idle instead of flags)
  26         int do_adapt56:1; // set if 56K adaptation
  27         int do_closing:1; // set if in closing phase (need to send CRC + flag
  28
  29         unsigned short crc;
  30
  31         unsigned char cbin;
  32         unsigned char shift_reg;
  33         unsigned char ffvalue;
  34
  35 };
  36
  37
  38 /*
  39   The return value from hdlc_decode is
  40   the frame length, 0 if no complete frame was decoded,
  41   or a negative error number
  42 */
  43
  44 #define HDLC_FRAMING_ERROR     1
  45 #define HDLC_CRC_ERROR         2
  46 #define HDLC_LENGTH_ERROR      3
  47
  48 void
  49 hdlc_rcv_init(struct hdlc_vars *hdlc, int do_adapt56);
  50
  51 int
  52 hdlc_decode(struct hdlc_vars *hdlc, const unsigned char *src, int slen,int *count,
  53             unsigned char *dst, int dsize);
  54
  55 void
  56 hdlc_out_init(struct hdlc_vars *hdlc,int is_d_channel,int do_adapt56);
  57
  58 int
  59 hdlc_encode(struct hdlc_vars *hdlc,const unsigned char *src,unsigned short slen,int *count,
  60             unsigned char *dst,int dsize);
  61
  62 #endif