emul.c

软件无线电的平台

/***************************************************************************
           emul.c  -  Emulator for the hardware-layer
                            -------------------
    begin                :  2002
    authors              :  Linus Gasser
    emails               :  [e-mail]
 ***************************************************************************/

/***************************************************************************
                                 Changes
                                 -------
 date - name - description
 02-10-14 - ineiti- begin
 02-12-11 - ineiti - copy Sender to Receiver by default
 02-12-12 - ineiti - rip out everything already in antenna
 
 **************************************************************************/

/***************************************************************************
 *                                                                         *
 *   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.                                   *
 *                                                                         *
 ***************************************************************************/


/**
 * A very simple, flat-channel simulator. Works only with one process.
 */


#define DBG_LVL 3

#include "system.h"
#include "debugging.h"
#include "memory.h"
#include "sdb.h"
#include "antenna.h"


swr_ant_param_t *params[ MAX_ANTENNAS ];
int antennas;

/**
 * @short Initialises an antenna's channel
 */
int swr_ant_ch_init( swr_ant_param_t *p ) {
  if ( antennas < MAX_ANTENNAS ){
    params[ antennas ] = p;
    params[ antennas ]->rx_tx_delay = 0;
    params[ antennas ]->slot_length = 20;
    return antennas++;
  } else {
    PR_DBG( 0, "Asking for too many antennas\n" );
    return -1;
  }
}

/**
 * @short Deletes an antenna's channel
 */
void swr_ant_ch_free( int nbr_ant ) {
  if ( !antennas ){
    PR_DBG( 0, "There are no antennas to be freed\n" );
  }
  if ( nbr_ant != --antennas ){
    PR_DBG( 0, "Out of order freeing.\n" );
  }
}

/**
 * @short Starts the channel
 */
void swr_ant_ch_start( void ) {
  // Well, there's nothing to do, really ;)
}

/**
 * @short Stops the channel
 */
void swr_ant_ch_stop( void ) {
}

/**
 * @short IOs the antenna
 */
int swr_ant_ch_io( int block ) {
  swr_ant_param_t *p;
  int pos_tx, pos_rx, pos;
  short int *buf_rx, *buf_tx;
  int nbr_ant;
  
  for ( nbr_ant=0; nbr_ant<antennas; nbr_ant++ ){
    p = params[ nbr_ant ];
    PR_DBG( 4, "Copying block %i with length %i\n", block, p->slot_length );
    pos_tx = ( block % p->frame_blocks ) * DAQ_DMA_BLOCK_SIZE_BYTES;
    block += p->slot_length;
    pos_rx = ( block % p->frame_blocks ) * DAQ_DMA_BLOCK_SIZE_BYTES;

    // Copy the transmitted part to the emission signal to the
    // received part.
    buf_rx = p->addr_rx + pos_rx;
    buf_tx = p->addr_tx + pos_tx;
    for ( pos = 0; pos < p->slot_length * DAQ_DMA_BLOCK_SIZE_SAMPLES; pos++ ){
      buf_rx[pos] = buf_tx[pos] / 16;
    }
  }

  return 1000;
}


int swr_ant_ch_reconfig( int nbr_ant ){
  return 0;
}


int swr_emul_init( void ){
  antennas = 0;
  return 0;
}


void swr_emul_exit( void ){
  if ( antennas > 0 ){
    PR_DBG( 0, "Hmm, still some antennas left...\n" );
  }
}


module_init( swr_emul_init );
module_exit( swr_emul_exit );

EXPORT_SYMBOL(swr_ant_ch_init);
EXPORT_SYMBOL(swr_ant_ch_free);
EXPORT_SYMBOL(swr_ant_ch_start);
EXPORT_SYMBOL(swr_ant_ch_stop);
EXPORT_SYMBOL(swr_ant_ch_io);
EXPORT_SYMBOL(swr_ant_ch_reconfig);