102 lines
3.3 KiB
C
102 lines
3.3 KiB
C
#ifndef _SUBCH_DEMUX_H
|
|
#define _SUBCH_DEMUX_H
|
|
/* A E1 sub-channel (de)multiplexer with TRAU frame sync */
|
|
|
|
/* (C) 2009 by Harald Welte <laforge@gnumonks.org>
|
|
* 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 <http://www.gnu.org/licenses/>.
|
|
*
|
|
*/
|
|
|
|
#include <sys/types.h>
|
|
#include <osmocore/linuxlist.h>
|
|
|
|
#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 */
|