From 03fd8d014f9871896a86534432c8757d65a576fe Mon Sep 17 00:00:00 2001 From: Jonathan Santos Date: Wed, 25 May 2011 13:54:02 -0400 Subject: Import upstream version 0.9.13 --- include/openbsc/subchan_demux.h | 101 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 101 insertions(+) create mode 100644 include/openbsc/subchan_demux.h (limited to 'include/openbsc/subchan_demux.h') diff --git a/include/openbsc/subchan_demux.h b/include/openbsc/subchan_demux.h new file mode 100644 index 000000000..da2a7f325 --- /dev/null +++ b/include/openbsc/subchan_demux.h @@ -0,0 +1,101 @@ +#ifndef _SUBCH_DEMUX_H +#define _SUBCH_DEMUX_H +/* A E1 sub-channel (de)multiplexer with TRAU frame sync */ + +/* (C) 2009 by Harald Welte + * All Rights Reserved + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU Affero General Public License as published by + * the Free Software Foundation; either version 3 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 Affero General Public License for more details. + * + * You should have received a copy of the GNU Affero General Public License + * along with this program. If not, see . + * + */ + +#include +#include + +#define NR_SUBCH 4 +#define TRAU_FRAME_SIZE 40 +#define TRAU_FRAME_BITS (TRAU_FRAME_SIZE*8) + +/***********************************************************************/ +/* DEMULTIPLEXER */ +/***********************************************************************/ + +struct demux_subch { + u_int8_t out_bitbuf[TRAU_FRAME_BITS]; + u_int16_t out_idx; /* next bit to be written in out_bitbuf */ + /* number of consecutive zeros that we have received (for sync) */ + unsigned int consecutive_zeros; + /* are we in TRAU frame sync or not? */ + unsigned int in_sync; +}; + +struct subch_demux { + /* bitmask of currently active subchannels */ + u_int8_t chan_activ; + /* one demux_subch struct for every subchannel */ + struct demux_subch subch[NR_SUBCH]; + /* callback to be called once we have received a complete + * frame on a given subchannel */ + int (*out_cb)(struct subch_demux *dmx, int ch, u_int8_t *data, int len, + void *); + /* user-provided data, transparently passed to out_cb() */ + void *data; +}; + +/* initialize one demultiplexer instance */ +int subch_demux_init(struct subch_demux *dmx); + +/* feed 'len' number of muxed bytes into the demultiplexer */ +int subch_demux_in(struct subch_demux *dmx, u_int8_t *data, int len); + +/* activate decoding/processing for one subchannel */ +int subch_demux_activate(struct subch_demux *dmx, int subch); + +/* deactivate decoding/processing for one subchannel */ +int subch_demux_deactivate(struct subch_demux *dmx, int subch); + +/***********************************************************************/ +/* MULTIPLEXER */ +/***********************************************************************/ + +/* one element in the tx_queue of a muxer sub-channel */ +struct subch_txq_entry { + struct llist_head list; + + unsigned int bit_len; /* total number of bits in 'bits' */ + unsigned int next_bit; /* next bit to be transmitted */ + + u_int8_t bits[0]; /* one bit per byte */ +}; + +struct mux_subch { + struct llist_head tx_queue; +}; + +/* structure representing one instance of the subchannel muxer */ +struct subch_mux { + struct mux_subch subch[NR_SUBCH]; +}; + +/* initialize a subchannel muxer instance */ +int subchan_mux_init(struct subch_mux *mx); + +/* request the output of 'len' multiplexed bytes */ +int subchan_mux_out(struct subch_mux *mx, u_int8_t *data, int len); + +/* enqueue some data into one sub-channel of the muxer */ +int subchan_mux_enqueue(struct subch_mux *mx, int s_nr, const u_int8_t *data, + int len); + +#endif /* _SUBCH_DEMUX_H */ -- cgit v1.2.3