| /* |
| * isdnhdlc.h -- General purpose ISDN HDLC decoder. |
| * |
| * Implementation of a HDLC decoder/encoder in software. |
| * Necessary because some ISDN devices don't have HDLC |
| * controllers. |
| * |
| * Copyright (C) |
| * 2009 Karsten Keil <keil@b1-systems.de> |
| * 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__ |
| |
| #include <stdint.h> |
| |
| struct osmo_isdnhdlc_vars { |
| int bit_shift; |
| int hdlc_bits1; |
| int data_bits; |
| int ffbit_shift; /* encoding only */ |
| int state; |
| int dstpos; |
| |
| uint16_t crc; |
| |
| uint8_t cbin; |
| uint8_t shift_reg; |
| uint8_t ffvalue; |
| |
| /* set if transferring data */ |
| uint32_t data_received:1; |
| /* set if D channel (send idle instead of flags) */ |
| uint32_t dchannel:1; |
| /* set if 56K adaptation */ |
| uint32_t do_adapt56:1; |
| /* set if in closing phase (need to send CRC + flag) */ |
| uint32_t do_closing:1; |
| /* set if data is bitreverse */ |
| uint32_t do_bitreverse:1; |
| }; |
| |
| /* Feature Flags */ |
| #define OSMO_HDLC_F_56KBIT 0x01 |
| #define OSMO_HDLC_F_DCHANNEL 0x02 |
| #define OSMO_HDLC_F_BITREVERSE 0x04 |
| |
| /* |
| The return value from isdnhdlc_decode is |
| the frame length, 0 if no complete frame was decoded, |
| or a negative error number |
| */ |
| #define OSMO_HDLC_FRAMING_ERROR 1 |
| #define OSMO_HDLC_CRC_ERROR 2 |
| #define OSMO_HDLC_LENGTH_ERROR 3 |
| |
| extern void osmo_isdnhdlc_rcv_init(struct osmo_isdnhdlc_vars *hdlc, uint32_t features); |
| |
| extern int osmo_isdnhdlc_decode(struct osmo_isdnhdlc_vars *hdlc, const uint8_t *src, |
| int slen, int *count, uint8_t *dst, int dsize); |
| |
| extern void osmo_isdnhdlc_out_init(struct osmo_isdnhdlc_vars *hdlc, uint32_t features); |
| |
| extern int osmo_isdnhdlc_encode(struct osmo_isdnhdlc_vars *hdlc, const uint8_t *src, |
| uint16_t slen, int *count, uint8_t *dst, int dsize); |
| |
| #endif /* __ISDNHDLC_H__ */ |