cch_rcv.c

This a framework to test new ideas in transmission technology. Actual development is a LDPC-coder in

/***************************************************************************
 *    cch_rcv.c  -  Reception of the structure
 *                           -------------------
 *   begin                :  2003
 *   authors              :  ineiti
 *   emails               :  [e-mail]
 ***************************************************************************/

/***************************************************************************
 *                                Changes
 *                                -------
 * date - name - description
 * 03/01/16 - ineiti - begin
 *
 **************************************************************************/

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


/**
 *  Receives tha data-packet and checks for the CRC. If it is OK, then
 * received' is put to 1, else it is counted down.
 */

#include "spc.h"
#include "std.h"


#define DBG_LVL 0


typedef struct {
  // A pointer to the data to send
  void *data; // NULL
  // The size in bytes of the data to send
  int len; // 0
}
config_t;

typedef struct {
  // Status of the received block:
  // 1 - OK
  // 0 - nothing
  // < 0 - number of consecutive wrong blocks 
  int received;
}
stats_t;

typedef struct {
  void *data;
  int len;
}
private_t;


/*
 * The initialisation function, or constructor, 
 * is called the first time this module is instantiated.
 */

int rcv_init( swr_sdb_t *context ) {
  config_t *config;
  stats_t *stats;
  MOD_INC_USE_COUNT;
  if ( sizeof( private_t ) > 0 )
    context->private_data = swr_malloc( sizeof( private_t ) );
  swr_sdb_get_config_struct( context->id, (void**)&config );
  swr_sdb_get_stats_struct( context->id, (void**)&stats );

  config->data = NULL;
  config->len = 0;
  stats->received = 0;

  swr_sdb_free_stats_struct( context->id, (void**)&stats );
  swr_sdb_free_config_struct( context->id, (void**)&config );
  return 0;
}


/*
 * Every time modules from the outside change the value of a configuration parameter,
 * this function is called.
 */

int rcv_reconfig( swr_sdb_t *context ) {
  // Definition of variables - don't touch
  config_t *config;
  swr_sdb_get_config_struct( context->id, (void**)&config );

  private->data = config->data;
  private->len = config->len;

  // Definition - don't touch
  swr_sdb_free_config_struct( context->id, (void**)&config );
  return 0;
}


/*
 * This is the function that implements the `main method' of the class
 * Every class has got just ONE method/working-mode.
 */
int rcv_pdata( swr_sdb_t *context ) {
  stats_t *stats;
  U8 *in;
  U32 crc;

  in = buffer_in( 0 );
  if ( private->data ) {
    crc = *((U32*)in);
    in += sizeof( U32 );
    memcpy( private->data, in, private->len );

    swr_sdb_get_stats_struct( context->id, (void**)&stats );
    if ( crc == swr_crc32( private->data, private->len ) ) {
      stats->received = 1;
    } else {
      // This gives a count of how 'bad' the connection is...
      stats->received--;
    }
    swr_sdb_free_stats_struct( context->id, (void**)&stats );
  }
  return(0);
}


/*
 * This is the `destructor'.
 */
int rcv_finalize( swr_sdb_t *context ) {
  if ( sizeof( private_t ) > 0 )
    swr_free( private );
  MOD_DEC_USE_COUNT;
  return 0;
}


/*
 * This function is called upon "insmod" and is used to register the
 * different parts of the module to the SPM.
 */
swr_spc_id_t rcv_id;
int rcv_module_init(void) {
  swr_spc_desc_t *desc;

  /**
   * Get a description-part from SPM
   * Give the following parameters:
   * Input-ports, output-ports, config-params, stat-params
   */
  desc = swr_spc_get_new_desc( 1, 0, 2, 1 );
  if ( !desc ) {
    PR_DBG( 0, "Can't initialise the module. This is BAD!\n" );
    return -1;
  }

  /**
   * Define the different parts of config and stats. You have to define
   * them in the same order as they appear in the structures. The names
   * can be freely chosen.
   *
   * UM_CONFIG_{INT,DOUBLE,STRING128,POINTER}( "name" );
   * UM_STATS_{INT,DOUBLE,STRING128,POINTER,BLOCK}( "name" );
   */
  UM_CONFIG_POINTER( "data" );
  UM_CONFIG_INT( "length" );
  UM_STATS_INT( "received" );
  /**
   * The in- and outputs have also to be defined in the right order. First
   * port first. The additional flag is not used yet, but it will...
   *
   * UM_INPUT( SIG_{U8,SYMBOL_{S16,COMPLEX,MMX},SAMPLE_S12,S32}, 0 );
   * UM_OUTPUT( SIG_{U8,SYMBOL_{S16,COMPLEX,MMX},SAMPLE_S12,S32}, 0 );
   */
  UM_INPUT( SIG_U8, 0 );

  // Initialise the callback-functions. Delete the ones you don't use
  desc->fn_init              = rcv_init;
  desc->fn_reconfigure       = rcv_reconfig;
  desc->fn_process_data      = rcv_pdata;
  desc->fn_finalize          = rcv_finalize;

  // And register the module in the SPM. Change the name!
  rcv_id = swr_cdb_register_spc( &desc, "cch_rcv" );
  if ( rcv_id == SWR_SPM_INVALID_ID ) {
    swr_spc_free_desc( desc );
    PR_DBG( 0, "Couldn't register the module!\n" );
    return 1;
  }
  PR_DBG( 4, "Ready\n" );
  return 0;
}


/*
 * This is called upon rmmod
 */
void rcv_module_exit( void ) {
  PR_DBG( 4, "Freeing id: %i\n", rcv_id );
  if ( swr_cdb_unregister_spc( rcv_id ) < 0 ) {
    PR_DBG( 0, "Still in use somewhere\n" );
  }
}