| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * isdnhdlc.h -- General purpose ISDN HDLC decoder. |
| 3 | * |
| 4 | * Implementation of a HDLC decoder/encoder in software. |
| 5 | * Neccessary because some ISDN devices don't have HDLC |
| 6 | * controllers. Also included: a bit reversal table. |
| 7 | * |
| 8 | *Copyright (C) 2002 Wolfgang Mües <wolfgang@iksw-muees.de> |
| 9 | * 2001 Frode Isaksen <fisaksen@bewan.com> |
| 10 | * 2001 Kai Germaschewski <kai.germaschewski@gmx.de> |
| 11 | * |
| 12 | * This program is free software; you can redistribute it and/or modify |
| 13 | * it under the terms of the GNU General Public License as published by |
| 14 | * the Free Software Foundation; either version 2 of the License, or |
| 15 | * (at your option) any later version. |
| 16 | * |
| 17 | * This program is distributed in the hope that it will be useful, |
| 18 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 20 | * GNU General Public License for more details. |
| 21 | * |
| 22 | * You should have received a copy of the GNU General Public License |
| 23 | * along with this program; if not, write to the Free Software |
| 24 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
| 25 | */ |
| 26 | |
| 27 | #ifndef __ISDNHDLC_H__ |
| 28 | #define __ISDNHDLC_H__ |
| 29 | |
| 30 | struct isdnhdlc_vars { |
| 31 | int bit_shift; |
| 32 | int hdlc_bits1; |
| 33 | int data_bits; |
| 34 | int ffbit_shift; // encoding only |
| 35 | int state; |
| 36 | int dstpos; |
| 37 | |
| 38 | unsigned short crc; |
| 39 | |
| 40 | unsigned char cbin; |
| 41 | unsigned char shift_reg; |
| 42 | unsigned char ffvalue; |
| 43 | |
| 44 | int data_received:1; // set if transferring data |
| 45 | int dchannel:1; // set if D channel (send idle instead of flags) |
| 46 | int do_adapt56:1; // set if 56K adaptation |
| 47 | int do_closing:1; // set if in closing phase (need to send CRC + flag |
| 48 | }; |
| 49 | |
| 50 | |
| 51 | /* |
| 52 | The return value from isdnhdlc_decode is |
| 53 | the frame length, 0 if no complete frame was decoded, |
| 54 | or a negative error number |
| 55 | */ |
| 56 | #define HDLC_FRAMING_ERROR 1 |
| 57 | #define HDLC_CRC_ERROR 2 |
| 58 | #define HDLC_LENGTH_ERROR 3 |
| 59 | |
| 60 | extern const unsigned char isdnhdlc_bit_rev_tab[256]; |
| 61 | |
| 62 | extern void isdnhdlc_rcv_init (struct isdnhdlc_vars *hdlc, int do_adapt56); |
| 63 | |
| 64 | extern int isdnhdlc_decode (struct isdnhdlc_vars *hdlc, const unsigned char *src, int slen,int *count, |
| 65 | unsigned char *dst, int dsize); |
| 66 | |
| 67 | extern void isdnhdlc_out_init (struct isdnhdlc_vars *hdlc,int is_d_channel,int do_adapt56); |
| 68 | |
| 69 | extern int isdnhdlc_encode (struct isdnhdlc_vars *hdlc,const unsigned char *src,unsigned short slen,int *count, |
| 70 | unsigned char *dst,int dsize); |
| 71 | |
| 72 | #endif /* __ISDNHDLC_H__ */ |