| /*! \file i460_mux.h |
| * ITU-T I.460 sub-channel multiplexer + demultiplexer */ |
| /* |
| * (C) 2020 by Harald Welte <laforge@gnumonks.org> |
| * |
| * SPDX-License-Identifier: GPL-2.0+ |
| * |
| * 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. |
| */ |
| |
| #pragma once |
| #include <stdint.h> |
| #include <osmocom/core/bits.h> |
| #include <osmocom/core/linuxlist.h> |
| #include <osmocom/core/msgb.h> |
| |
| #define OSMO_I460_NUM_SUBCHAN 8 |
| |
| /* I.460 sub-slot rate */ |
| enum osmo_i460_rate { |
| OSMO_I460_RATE_NONE, /* disabled */ |
| OSMO_I460_RATE_64k, |
| OSMO_I460_RATE_32k, |
| OSMO_I460_RATE_16k, |
| OSMO_I460_RATE_8k, |
| }; |
| |
| struct osmo_i460_subchan; |
| |
| typedef void (*out_cb_bits_t)(struct osmo_i460_subchan *schan, void *user_data, |
| const ubit_t *bits, unsigned int num_bits); |
| typedef void (*out_cb_bytes_t)(struct osmo_i460_subchan *schan, void *user_data, |
| const uint8_t *bytes, unsigned int num_bytes); |
| |
| struct osmo_i460_subchan_demux { |
| /*! bit-buffer for output bits */ |
| uint8_t *out_bitbuf; |
| /*! size of out_bitbuf in bytes */ |
| unsigned int out_bitbuf_size; |
| /*! offset of next bit to be written in out_bitbuf */ |
| unsigned int out_idx; |
| /*! callback to be called once we have received out_bitbuf_size bits */ |
| out_cb_bits_t out_cb_bits; |
| out_cb_bytes_t out_cb_bytes; |
| void *user_data; |
| }; |
| |
| typedef void (*in_cb_queue_empty_t)(struct osmo_i460_subchan *schan, void *user_data); |
| |
| struct osmo_i460_subchan_mux { |
| /*! list of to-be-transmitted message buffers */ |
| struct llist_head tx_queue; |
| in_cb_queue_empty_t in_cb_queue_empty; |
| void *user_data; |
| }; |
| |
| struct osmo_i460_subchan { |
| struct osmo_i460_timeslot *ts; /* back-pointer */ |
| enum osmo_i460_rate rate; /* 8/16/32/64k */ |
| uint8_t bit_offset; /* bit offset inside each byte of the B-channel */ |
| struct osmo_i460_subchan_demux demux; |
| struct osmo_i460_subchan_mux mux; |
| }; |
| |
| struct osmo_i460_timeslot { |
| struct osmo_i460_subchan schan[OSMO_I460_NUM_SUBCHAN]; |
| }; |
| |
| /*! description of a sub-channel; passed by caller */ |
| struct osmo_i460_schan_desc { |
| enum osmo_i460_rate rate; |
| uint8_t bit_offset; |
| struct { |
| /* size (in bits) of the internal buffer; determines granularity */ |
| size_t num_bits; |
| /*! call-back function called whenever we received num_bits */ |
| out_cb_bits_t out_cb_bits; |
| /*! out_cb_bytes call-back function called whenever we received num_bits. |
| * The user is usually expected to provide either out_cb_bits or out_cb_bytes. If only |
| * out_cb_bits is provided, output data will always be provided as unpacked bits; if only |
| * out_cb_bytes is provided, output data will always be provided as packet bits (bytes). If |
| * both are provided, it is up to the I.460 multiplex to decide if it calls either of the two, |
| * depending on what can be provided without extra conversion. */ |
| out_cb_bytes_t out_cb_bytes; |
| /* opaque user data pointer to pass to out_cb */ |
| void *user_data; |
| } demux; |
| |
| struct { |
| /* call-back function whenever the muxer requires more input data from the sub-channels, |
| * but has nothing enqueued yet. A typical function would then call osmo_i460_mux_enqueue() */ |
| in_cb_queue_empty_t in_cb_queue_empty; |
| /* opaque user data pointer to pass to in_cb */ |
| void *user_data; |
| } mux; |
| }; |
| |
| void osmo_i460_demux_in(struct osmo_i460_timeslot *ts, const uint8_t *data, size_t data_len); |
| |
| void osmo_i460_mux_enqueue(struct osmo_i460_subchan *schan, struct msgb *msg); |
| int osmo_i460_mux_out(struct osmo_i460_timeslot *ts, uint8_t *out, size_t out_len); |
| |
| void osmo_i460_ts_init(struct osmo_i460_timeslot *ts); |
| |
| struct osmo_i460_subchan * |
| osmo_i460_subchan_add(void *ctx, struct osmo_i460_timeslot *ts, const struct osmo_i460_schan_desc *chd); |
| |
| void osmo_i460_subchan_del(struct osmo_i460_subchan *schan); |
| |
| int osmo_i460_subchan_count(struct osmo_i460_timeslot *ts); |
| |
| /*! @} */ |