ogrt_inout.c

The OpenGPSRec receiver software runs on the real time operating system RTAI-Linux. It compiles with

/* ************************************************************************ 
   *                                                                      *
   *                            OpenGPS Receiver                          *
   *                                                                      *
   * -------------------------------------------------------------------- *
   *                                                                      *
   *    Module:   ogrt_inout.c                                            *
   *                                                                      *
   *   Version:   0.1                                                     *
   *                                                                      *
   *      Date:   01.12.03                                                *
   *                                                                      *
   *    Author:   C. Kelley, G. Beyerle                                   *
   *                                                                      *
   * -------------------------------------------------------------------- *
   *                                                                      *
   * Copyright (C) 2001-2003  C. Kelley, G. Beyerle                       *
   *                                                                      *
   * 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.                         *
   *                                                                      *
   * You should have received a copy of the GNU General Public License    *
   * along with this program; if not, write to the Free Software          *
   * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.            *
   *                                                                      *
   * -------------------------------------------------------------------- *
   *                                                                      *
   * OpenGPS is based on Clifford Kelley's OpenSourceGPS distribution.    *
   * The OpenSourceGPS distribution can be obtained from                  *
   *             http://www.home.earthlink.net/~cwkelley                  *
   *                                                                      *
   * -------------------------------------------------------------------- *
   *                                                                      *
   *              Real-time process - input/output functions              *
   *                                                                      *
   ************************************************************************ */

/* ******************************* changes ********************************

   01.12.03 - separate input/output function from ogrt_proc.c

   ************************************************************************ */

/***********************************************************************
  GPS RECEIVER (GPSRCVR) Ver. 1.02
  12 Channel All-in-View GPS Receiver Program based on 
  Mitel GP2021 chipset
  Clifford Kelley [e-mail]
  Copyright (c) 1996-2002 Clifford Kelley.  All Rights Reserved.
  This LICENSE must be included with the OGR code.
***********************************************************************/

/*
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:

      CONDITIONS

1. Redistributions of GPSRCVR source code must retain the above copyright
notice, this list of conditions, and the following disclaimer.

2. Redistributions in binary form must contain the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.

3. All modifications to the source code must be clearly marked as
such.  Binary redistributions based on modified source code must be
clearly marked as modified versions in the documentation and/or other
materials provided with the distribution.

4. Notice must be given of the location of the availability of the
unmodified current source code, e.g.,
  http://www.Kelley.com/
or
  ftp://ftp.Kelley.com
in the documentation and/or other materials provided with the
distribution.

5. All advertising and published materials mentioning features or use
of this software must display the following acknowledgment:  "This
product includes software developed by Clifford Kelley and other
contributors."

6. The name of Clifford Kelley may not be used to endorse or promote
products derived from this software without specific prior written
permission.

      DISCLAIMER

This software is provided by Clifford Kelley and contributors "as is" and
any expressed or implied warranties, including, but not limited to, the
implied warranties of merchantability and fitness for a particular
purpose are disclaimed.  In no event shall Clifford Kelley or
contributors be liable for any direct, indirect, incidental, special,
exemplary, or consequential damages (including, but not limited to,
procurement of substitute goods or services; loss of use, data, or
profits; or business interruption) however caused and on any theory of
liability, whether in contract, strict liability, or tort (including
negligence or otherwise) arising in any way out of the use of this
software, even if advised of the possibility of such damage.
*/

/* ------------------------------- includes ------------------------------- */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>

#include <rtai.h>
#include <rtai_sched.h>
#include <rtai_fifos.h>
#include <rtai_shm.h>

#include  "port.h"
#include  "ogr_defines.h"
#include  "ogr_structs.h"

#include  "ogrt_defines.h"
#include  "ogrt_prototypes.h"

#include  "ogrt_globals.h"

MODULE_LICENSE( "GPL");

/* ------------------------------ local variables ------------------------- */

/* ------------------------------ prototypes ------------------------------ */

/* ------------------------------ procedures ------------------------------ */

/* ------------------------------------------------------------------------- *
FUNCTION writefifo_navdata()

RETURNS
  none

PARAMETERS
  ch  : channel number

PURPOSE
  tell user land of nav bit
* ------------------------------------------------------------------------- */

inline void writefifo_navbit( INT16 ch, INT16 bit)
{
  signed char chr, buf[MSG_MAX_LEN];
  unsigned char len;

//  write to FIFO: channel number / nav bit
  chr = MSG_NAVBIT;
  memcpy( buf, &chr, sizeof( char));
  len = MSG_NAVBIT_LEN;
  memcpy( buf+1, &len, sizeof( char));

  chr = (char) ch;
  memcpy( buf+2, &chr, sizeof( char));
  chr = (char)((Preamble_Found[ch] > 0) ? bit : ~bit & 0x1);
//  bit 1 of chr indicates start of TLM (bit 1 ends at 20 ms offset)
  if ( Chan[ch].ms_count == 20)
    chr = ( 0x2 | chr);
  memcpy( buf+3, &chr, sizeof( char));

  rtf_put( FIFO_NAVBIT, buf, len+2);

  return;
}

/* ------------------------------------------------------------------------- *
FUNCTION writefifo_navdata()

RETURNS
  none

PARAMETERS

PURPOSE
  communicate to user land
* ------------------------------------------------------------------------- */

inline void writefifo_navdata( void)
{
  UINT16 ch;
  char chr, len, buf[MSG_MAX_LEN];
  unsigned long tow_1s;

  for ( ch=0; ch<NOFCHN; ch++)
  {

/*
*  field 'epoch' provides elapsed time up to 1 sec
*  take full seconds from 'tow' and millisecond counter 'ms_count'
*/
//  alternative:  tow_1s = Chan[ch].tow_HOW + ((Chan[ch].ms_count + 4800) % 6000 + 1200) / 1000;
    tow_1s = Chan[ch].tow + Chan[ch].ms_count / 1000;

//  assemble message and send to user proc

    chr = MSG_PSIRANGE;
    memcpy( buf, &chr, sizeof( char));
    len = MSG_PSIRANGE_LEN;   // length of message not counting header
    memcpy( buf+1, &len, sizeof( char));

    memcpy( buf+2,  &ch, sizeof( INT16));
    memcpy( buf+4,  &Chan[ch].epoch, sizeof( INT16));
    memcpy( buf+6,  &Chan[ch].code_phase, sizeof( INT16));
    memcpy( buf+8,  &Chan[ch].code_dco_phase, sizeof( INT16));
    memcpy( buf+10, &Chan[ch].carr_dco_phase, sizeof( INT16));
    memcpy( buf+12, &Chan[ch].carr_cycle_lo, sizeof( INT16));
    memcpy( buf+14, &Chan[ch].carr_cycle_hi, sizeof( INT16));
    memcpy( buf+16, &RT_Ctrl->tow_tic_count, sizeof( long));
    memcpy( buf+20, &tow_1s, sizeof( long));

    rtf_put( FIFO_NAVBIT, buf, len+2);

//        rt_printk( "OGRT_PROC: wrote %d bytes to fifo.\n", len+2);

  }  // --- for ( ch=0; ch<NOFCHN; ch++) ---
  return;
}


/* ------------------------------------------------------------------------- *
FUNCTION writefifo_corrdata()

RETURNS
  none

PARAMETERS
  ch  : channel number

PURPOSE
  save correlator data to file
* ------------------------------------------------------------------------- */

inline void writefifo_corrdata( INT16 ch, INT16 leadch)
{
  char buf[64];

//  #include <rtai_sched.h>
//  RTIME rt;
//  rt = rt_get_time_ns();
//  rt = rt_get_cpu_time_ns();
//
//  rtf_put( 1, &rt, sizeof( long long));

  memcpy( buf,    &RT_Ctrl->tow_tic_count, sizeof( long));
  memcpy( buf+ 4, &Chan[ch].i_prompt_20ms, sizeof( long));
  memcpy( buf+ 8, &Chan[ch].i_dith_20ms, sizeof( long));
  memcpy( buf+12, &Chan[ch].q_prompt_20ms, sizeof( long));
  memcpy( buf+16, &Chan[ch].q_dith_20ms, sizeof( long));
  memcpy( buf+20, &ch, sizeof( INT16));
  memcpy( buf+22, &Chan[ch].carr_cycle_lo, sizeof( INT16));
  memcpy( buf+24, &Chan[ch].carr_cycle_hi, sizeof( INT16));
  memcpy( buf+26, &Chan[ch].carr_dco_phase, sizeof( INT16));
  memcpy( buf+28, &Chan[ch].code_phase, sizeof( INT16));
  memcpy( buf+30, &Chan[ch].code_dco_phase, sizeof( INT16));

  rtf_put( FIFO_IQDUMP, buf, 32);

  return;
}


/* ------------------------------------------------------------------------- *
FUNCTION fill_channelinfo_ringbuffer()

RETURNS
  none

PARAMETERS

PURPOSE
  save amplitude and phase data to ring buffer -> gpsplot
* ------------------------------------------------------------------------- */
void fill_channelinfo_ringbuffer( void)
{
  INT16    idx, ch;
  CHN_INFO Chn_Info;

  if ( !Chn_RBuf)
    return;

/* next element is written to 'Chn_RBuf->ch_head' */
  idx = Chn_RBuf->ch_head;

//  rt_printk( "OGRT_INOUT: (1) Chn_RBuf->ch_head = %d\n", Chn_RBuf->ch_head);

  if ( idx < 0)
    idx = 0;

//         i_prompt_20ms,    // I prompt avg'ed over 20 ms
//         q_prompt_20ms,    // Q prompt avg'ed over 20 ms
//         i_dith_20ms,      // I dither avg'ed over 20 ms
//         q_dith_20ms,      // Q dither avg'ed over 20 ms  

  for ( ch=0; ch<NOFCHN; ch++)
  {
    Chn_Info.ch             = ch;
    Chn_Info.car_frq        = Chan[ch].car_frq;
    Chn_Info.cod_frq        = Chan[ch].cod_frq;
    Chn_Info.missed         = Chan[ch].missed;
    Chn_Info.code_phase     = Chan[ch].code_phase;     // code phase: 0,...,2046 halfchips
    Chn_Info.code_dco_phase = Chan[ch].code_dco_phase; // code frc. phs: 0,...,1023, 1024 = halfchip
    Chn_Info.i_prompt       = Chan[ch].i_prompt;
    Chn_Info.q_prompt       = Chan[ch].q_prompt;
    Chn_Info.i_dith         = Chan[ch].i_dith;
    Chn_Info.q_dith         = Chan[ch].q_dith;
    Chn_Info.prn            = Chan[ch].prn;
    Chn_Info.i_prompt_20ms  = Chan[ch].i_prompt_20ms;
    Chn_Info.q_prompt_20ms  = Chan[ch].q_prompt_20ms;
    Chn_Info.i_dith_20ms    = Chan[ch].i_dith_20ms;
    Chn_Info.q_dith_20ms    = Chan[ch].q_dith_20ms;
    Chn_Info.sourceSel      = 0;

    Chn_RBuf->chan[idx] = Chn_Info;
    idx = (idx + 1) % CHN_RBUF_LEN;
  }
  
  Chn_RBuf->ch_head  = idx;
  Chn_RBuf->leadch   = RT_Ctrl->leadch;
  Chn_RBuf->watchdog += 1;      

//  rt_printk( "OGRT_INOUT: (2) Chn_RBuf->ch_head = %d\n", Chn_RBuf->ch_head);
  
  return;
}

/* ------------------------------- end of file ---------------------------- */