diff options
Diffstat (limited to 'include/linux/isdn')
| -rw-r--r-- | include/linux/isdn/hdlc.h | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/include/linux/isdn/hdlc.h b/include/linux/isdn/hdlc.h new file mode 100644 index 00000000000..cf0a95a2401 --- /dev/null +++ b/include/linux/isdn/hdlc.h @@ -0,0 +1,70 @@ +/* + * isdnhdlc.h -- General purpose ISDN HDLC decoder. + * + * Implementation of a HDLC decoder/encoder in software. + * Neccessary because some ISDN devices don't have HDLC + * controllers. Also included: a bit reversal table. + * + *Copyright (C) 2002 Wolfgang Mües <wolfgang@iksw-muees.de> + * 2001 Frode Isaksen <fisaksen@bewan.com> + * 2001 Kai Germaschewski <kai.germaschewski@gmx.de> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#ifndef __ISDNHDLC_H__ +#define __ISDNHDLC_H__ + +struct isdnhdlc_vars { + int bit_shift; + int hdlc_bits1; + int data_bits; + int ffbit_shift; // encoding only + int state; + int dstpos; + + unsigned short crc; + + unsigned char cbin; + unsigned char shift_reg; + unsigned char ffvalue; + + unsigned int data_received:1; // set if transferring data + unsigned int dchannel:1; // set if D channel (send idle instead of flags) + unsigned int do_adapt56:1; // set if 56K adaptation + unsigned int do_closing:1; // set if in closing phase (need to send CRC + flag +}; + + +/* + The return value from isdnhdlc_decode is + the frame length, 0 if no complete frame was decoded, + or a negative error number +*/ +#define HDLC_FRAMING_ERROR 1 +#define HDLC_CRC_ERROR 2 +#define HDLC_LENGTH_ERROR 3 + +extern void isdnhdlc_rcv_init (struct isdnhdlc_vars *hdlc, int do_adapt56); + +extern int isdnhdlc_decode (struct isdnhdlc_vars *hdlc, const unsigned char *src, int slen,int *count, + unsigned char *dst, int dsize); + +extern void isdnhdlc_out_init (struct isdnhdlc_vars *hdlc,int is_d_channel,int do_adapt56); + +extern int isdnhdlc_encode (struct isdnhdlc_vars *hdlc,const unsigned char *src,unsigned short slen,int *count, + unsigned char *dst,int dsize); + +#endif /* __ISDNHDLC_H__ */ |