00001 /* 00002 * SpanDSP - a series of DSP components for telephony 00003 * 00004 * async.h - Asynchronous serial bit stream encoding and decoding 00005 * 00006 * Written by Steve Underwood <steveu@coppice.org> 00007 * 00008 * Copyright (C) 2003 Steve Underwood 00009 * 00010 * All rights reserved. 00011 * 00012 * This program is free software; you can redistribute it and/or modify 00013 * it under the terms of the GNU Lesser General Public License version 2.1, 00014 * as published by the Free Software Foundation. 00015 * 00016 * This program is distributed in the hope that it will be useful, 00017 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00018 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00019 * GNU Lesser General Public License for more details. 00020 * 00021 * You should have received a copy of the GNU Lesser General Public 00022 * License along with this program; if not, write to the Free Software 00023 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 00024 * 00025 * $Id: async.h,v 1.25 2009/04/23 14:12:34 steveu Exp $ 00026 */ 00027 00028 /*! \file */ 00029 00030 /*! \page async_page Asynchronous bit stream processing 00031 \section async_page_sec_1 What does it do? 00032 The asynchronous serial bit stream processing module provides 00033 generation and decoding facilities for most asynchronous data 00034 formats. It supports: 00035 - 1 or 2 stop bits. 00036 - Odd, even or no parity. 00037 - 5, 6, 7, or 8 bit characters. 00038 - V.14 rate adaption. 00039 The input to this module is a bit stream. This means any symbol synchronisation 00040 and decoding must occur before data is fed to this module. 00041 00042 \section async_page_sec_2 The transmitter 00043 ???. 00044 00045 \section async_page_sec_3 The receiver 00046 ???. 00047 */ 00048 00049 #if !defined(_SPANDSP_ASYNC_H_) 00050 #define _SPANDSP_ASYNC_H_ 00051 00052 /*! Special "bit" values for the bitstream put and get functions, and the signal status functions. */ 00053 enum 00054 { 00055 /*! \brief The carrier signal has dropped. */ 00056 SIG_STATUS_CARRIER_DOWN = -1, 00057 /*! \brief The carrier signal is up. This merely indicates that carrier 00058 energy has been seen. It is not an indication that the carrier is either 00059 valid, or of the expected type. */ 00060 SIG_STATUS_CARRIER_UP = -2, 00061 /*! \brief The modem is training. This is an early indication that the 00062 signal seems to be of the right type. This may be needed in time critical 00063 applications, like T.38, to forward an early indication of what is happening 00064 on the wire. */ 00065 SIG_STATUS_TRAINING_IN_PROGRESS = -3, 00066 /*! \brief The modem has trained, and is ready for data exchange. */ 00067 SIG_STATUS_TRAINING_SUCCEEDED = -4, 00068 /*! \brief The modem has failed to train. */ 00069 SIG_STATUS_TRAINING_FAILED = -5, 00070 /*! \brief Packet framing (e.g. HDLC framing) is OK. */ 00071 SIG_STATUS_FRAMING_OK = -6, 00072 /*! \brief The data stream has ended. */ 00073 SIG_STATUS_END_OF_DATA = -7, 00074 /*! \brief An abort signal (e.g. an HDLC abort) has been received. */ 00075 SIG_STATUS_ABORT = -8, 00076 /*! \brief A break signal (e.g. an async break) has been received. */ 00077 SIG_STATUS_BREAK = -9, 00078 /*! \brief A modem has completed its task, and shut down. */ 00079 SIG_STATUS_SHUTDOWN_COMPLETE = -10, 00080 /*! \brief Regular octet report for things like HDLC to the MTP standards. */ 00081 SIG_STATUS_OCTET_REPORT = -11, 00082 /*! \brief Notification that a modem has detected signal quality degradation. */ 00083 SIG_STATUS_POOR_SIGNAL_QUALITY = -12, 00084 /*! \brief Notification that a modem retrain has occurred. */ 00085 SIG_STATUS_MODEM_RETRAIN_OCCURRED = -13 00086 }; 00087 00088 /*! Message put function for data pumps */ 00089 typedef void (*put_msg_func_t)(void *user_data, const uint8_t *msg, int len); 00090 00091 /*! Message get function for data pumps */ 00092 typedef int (*get_msg_func_t)(void *user_data, uint8_t *msg, int max_len); 00093 00094 /*! Byte put function for data pumps */ 00095 typedef void (*put_byte_func_t)(void *user_data, int byte); 00096 00097 /*! Byte get function for data pumps */ 00098 typedef int (*get_byte_func_t)(void *user_data); 00099 00100 /*! Bit put function for data pumps */ 00101 typedef void (*put_bit_func_t)(void *user_data, int bit); 00102 00103 /*! Bit get function for data pumps */ 00104 typedef int (*get_bit_func_t)(void *user_data); 00105 00106 /*! Completion callback function for tx data pumps */ 00107 typedef void (*modem_tx_status_func_t)(void *user_data, int status); 00108 00109 /*! Completion callback function for rx data pumps */ 00110 typedef void (*modem_rx_status_func_t)(void *user_data, int status); 00111 00112 enum 00113 { 00114 /*! No parity bit should be used */ 00115 ASYNC_PARITY_NONE = 0, 00116 /*! An even parity bit will exist, after the data bits */ 00117 ASYNC_PARITY_EVEN, 00118 /*! An odd parity bit will exist, after the data bits */ 00119 ASYNC_PARITY_ODD 00120 }; 00121 00122 /*! 00123 Asynchronous data transmit descriptor. This defines the state of a single 00124 working instance of a byte to asynchronous serial converter, for use 00125 in FSK modems. 00126 */ 00127 typedef struct async_tx_state_s async_tx_state_t; 00128 00129 /*! 00130 Asynchronous data receive descriptor. This defines the state of a single 00131 working instance of an asynchronous serial to byte converter, for use 00132 in FSK modems. 00133 */ 00134 typedef struct async_rx_state_s async_rx_state_t; 00135 00136 #if defined(__cplusplus) 00137 extern "C" 00138 { 00139 #endif 00140 00141 /*! Convert a signal status to a short text description. 00142 \brief Convert a signal status to a short text description. 00143 \param status The modem signal status. 00144 \return A pointer to the description. */ 00145 SPAN_DECLARE(const char *) signal_status_to_str(int status); 00146 00147 /*! Initialise an asynchronous data transmit context. 00148 \brief Initialise an asynchronous data transmit context. 00149 \param s The transmitter context. 00150 \param data_bits The number of data bit. 00151 \param parity_bits The type of parity. 00152 \param stop_bits The number of stop bits. 00153 \param use_v14 TRUE if V.14 rate adaption processing should be used. 00154 \param get_byte The callback routine used to get the data to be transmitted. 00155 \param user_data An opaque pointer. 00156 \return A pointer to the initialised context, or NULL if there was a problem. */ 00157 SPAN_DECLARE(async_tx_state_t *) async_tx_init(async_tx_state_t *s, 00158 int data_bits, 00159 int parity_bits, 00160 int stop_bits, 00161 int use_v14, 00162 get_byte_func_t get_byte, 00163 void *user_data); 00164 00165 SPAN_DECLARE(int) async_tx_release(async_tx_state_t *s); 00166 00167 SPAN_DECLARE(int) async_tx_free(async_tx_state_t *s); 00168 00169 /*! Get the next bit of a transmitted serial bit stream. 00170 \brief Get the next bit of a transmitted serial bit stream. 00171 \param user_data An opaque point which must point to a transmitter context. 00172 \return the next bit, or PUTBIT_END_OF_DATA to indicate the data stream has ended. */ 00173 SPAN_DECLARE_NONSTD(int) async_tx_get_bit(void *user_data); 00174 00175 /*! Initialise an asynchronous data receiver context. 00176 \brief Initialise an asynchronous data receiver context. 00177 \param s The receiver context. 00178 \param data_bits The number of data bits. 00179 \param parity_bits The type of parity. 00180 \param stop_bits The number of stop bits. 00181 \param use_v14 TRUE if V.14 rate adaption processing should be used. 00182 \param put_byte The callback routine used to put the received data. 00183 \param user_data An opaque pointer. 00184 \return A pointer to the initialised context, or NULL if there was a problem. */ 00185 SPAN_DECLARE(async_rx_state_t *) async_rx_init(async_rx_state_t *s, 00186 int data_bits, 00187 int parity_bits, 00188 int stop_bits, 00189 int use_v14, 00190 put_byte_func_t put_byte, 00191 void *user_data); 00192 00193 SPAN_DECLARE(int) async_rx_release(async_rx_state_t *s); 00194 00195 SPAN_DECLARE(int) async_rx_free(async_rx_state_t *s); 00196 00197 /*! Accept a bit from a received serial bit stream 00198 \brief Accept a bit from a received serial bit stream 00199 \param user_data An opaque point which must point to a receiver context. 00200 \param bit The new bit. Some special values are supported for this field. 00201 - SIG_STATUS_CARRIER_UP 00202 - SIG_STATUS_CARRIER_DOWN 00203 - SIG_STATUS_TRAINING_SUCCEEDED 00204 - SIG_STATUS_TRAINING_FAILED 00205 - SIG_STATUS_END_OF_DATA */ 00206 SPAN_DECLARE_NONSTD(void) async_rx_put_bit(void *user_data, int bit); 00207 00208 #if defined(__cplusplus) 00209 } 00210 #endif 00211 00212 #endif 00213 /*- End of file ------------------------------------------------------------*/