view src/cs/layer1/gtt_include/ctm/ctm_transmitter.h @ 220:0ed36de51973

ABB semaphore protection overhaul The ABB semaphone protection logic that came with TCS211 from TI was broken in several ways: * Some semaphore-protected functions were called from Application_Initialize() context. NU_Obtain_Semaphore() called with NU_SUSPEND fails with NU_INVALID_SUSPEND in this context, but the return value wasn't checked, and NU_Release_Semaphore() would be called unconditionally at the end. The latter call would increment the semaphore count past 1, making the semaphore no longer binary and thus no longer effective for resource protection. The fix is to check the return value from NU_Obtain_Semaphore() and skip the NU_Release_Semaphore() call if the semaphore wasn't properly obtained. * Some SPI hardware manipulation was being done before entering the semaphore- protected critical section. The fix is to reorder the code: first obtain the semaphore, then do everything else. * In the corner case of L1/DSP recovery, l1_abb_power_on() would call some non-semaphore-protected ABB & SPI init functions. The fix is to skip those calls in the case of recovery. * A few additional corner cases existed, all of which are fixed by making ABB semaphore protection 100% consistent for all ABB functions and code paths. There is still one remaining problem of priority inversion: suppose a low- priority task calls an ABB function, and some medium-priority task just happens to preempt right in the middle of that semaphore-protected ABB operation. Then the high-priority SPI task is locked out for a non-deterministic time until that medium-priority task finishes its work and goes back to sleep. This priority inversion problem remains outstanding for now.
author Mychaela Falconia <falcon@freecalypso.org>
date Mon, 26 Apr 2021 20:55:25 +0000
parents 4e78acac3d88
children
line wrap: on
line source

/*
*******************************************************************************
*
*      COPYRIGHT (C) 2000 BY ERICSSON EUROLAB DEUTSCHLAND GmbH
*      90411 NUERNBERG, GERMANY, Tel Int + 49 911 5217 100
*
*      The program(s) may be used and/or copied only with the
*      written permission from Ericsson or in accordance
*      with the terms and conditions stipulated in the agreement or
*      contract under which the program(s) have been supplied.
*
*******************************************************************************
*
*      File             : ctm_transmitter.h
*      Author           : EEDN/RV Matthias Doerbecker
*      Tested Platforms : Sun Solaris, Windows NT 4.0
*      Description      : header file for ctm_transmitter.c
*
*      Changes since October 13, 2000:
*      - added reset function reset_ctm_transmitter()
*
*      $Log: $
*
*******************************************************************************
*/
#ifndef ctm_transmitter_h
#define ctm_transmitter_h "$Id: $"

/*
*******************************************************************************
*                         INCLUDE FILES
*******************************************************************************
*/

#include "ctm_typedefs.h"
#include "ctm_defines.h"
#include "init_interleaver.h"
#include "tonemod.h"
#include "conv_poly.h"
#include "fifo.h"

/* ******************************************************************/
/* Type definitions for variables that contain all states of the    */
/* CTM Transmitter                                                  */
/* ******************************************************************/

typedef struct {
  BOOL      burstActive;
  WORD16    cntIdleSymbols;
  WORD16    cntEncBitsInCurrentBlock;
  WORD16    cntTXBitsInCurrentBlock;

  /* vectors (not to be allocated) */
  WORD16    resync_sequence[RESYNC_SEQ_LENGTH];
  
#if (NUM_MUTE_ROWS>0)
  WORD16    mutePositions[intlvB*NUM_MUTE_ROWS];
#else
  WORD16    mutePositions[1];
#endif
  
  fifo_state_t         fifo_state;
  fifo_state_t         octet_fifo_state;
  interleaver_state_t  diag_int_state;
  conv_encoder_t       conv_enc_state;
} tx_state_t;

     

/***********************************************************************/
/* init_ctm_transmitter()                                              */
/* **********************                                              */
/* Initialization of the CTM Transmitter                               */
/*                                                                     */
/* output vaiables:                                                    */
/* tx_state :   pointer to a variable of tx_state_t containing the     */
/*              initialized states of the receiver                     */
/***********************************************************************/

void init_ctm_transmitter(tx_state_t* tx_state);
/*
 ***********************************************************************
 * Shutdown_ctm_transmitter()                                          *
 * **********************                                              *
 * Shutdown of the Cellular Text Telephone Modem transmitter and       *
 * deallocate memory used by the CTM Tx buffers.                       *
 *                                                                     *
 * Input variables:                                                    *
 * tx_state :   pointer to a variable of tx_state_t containing the     *
 *              initialized states of the transmitter.                 *
 ***********************************************************************
*/
void Shutdown_ctm_transmitter(tx_state_t* tx_state);

/*
 ***********************************************************************
 * reset_ctm_transmitter()                                             *
 * **********************                                              *
 * Reset of the Cellular Text Telephone Modem transmitter, state       *
 * machines and buffer pointers.                                       *
 *                                                                     *
 * Input variables:                                                    *
 * tx_state :   pointer to a variable of tx_state_t containing the     *
 *              initialized states of the transmitter.                 *
 ***********************************************************************
*/
void reset_ctm_transmitter(tx_state_t* tx_state);


/***********************************************************************/
/* ctm_transmitter()                                                   */
/* *****************                                                   */
/* Runs the Cellular Text Telephone Modem (CTM) Transmitter for a      */
/* block of 160 output samples, representing 8 gross bits.             */
/* The bits, which are modulated into tones, are taken from an         */
/* internal fifo buffer. If the fifo buffer is empty, zero-valued      */
/* samples are generated. The fifo buffer is filled with               */
/* channel-encoded and interlaeved bits, which are generated           */
/* internally by coding the actual input character.  With each call of */
/* this function one or less input characters can be coded. If there   */
/* is no character to for transmission, one of the following code has  */
/* be used:                                                            */
/* - 0xFFFF:  indicates that there is no character to transmit and     */
/*            that the transmitter should stay in idle mode, if it is  */
/*            currently already in idle mode. If the transmitter is    */
/*            NOT in idle mode, it might generate <IDLE> symbols in    */
/*            to keep an active burst running. The CTM burst is        */
/*            terminated if five <IDLE> symbols have been generated    */
/*            consecutevely.                                           */
/*                                                                     */
/* - 0xFFFE:  although there is no character to transmit, a CTM burst  */
/*            is initiated in order to signalize to the far-end side   */
/*            that CTM is supported. The burst starts with the <IDLE>  */
/*            symbol and will be contiued with <IDLE> symbols if there */
/*            are no regular characters handed over during the next    */
/*            calls of this function. The CTM burst is terminated if   */
/*            five <IDLE> symbols have been transmitted consecutevely. */
/*                                                                     */
/* In order to avoid an overflow of the internal fifo buffer, the      */
/* variable *ptrNumBitsStillToModulate should be checked before        */
/* calling this function.                                              */
/*                                                                     */
/* input variables:                                                    */
/* ucsCode                    UCS code of the character                */
/*                            or one of the codes 0xFFFF or 0xFFFE     */
/* sineOutput                 must be false in regular mode; if true,  */
/*                            a pure sine output signal is generated   */
/* output variables:                                                   */
/* txToneVec                  output signal (vector  of 160 samples)   */
/* input/output variables:                                             */
/* tx_state                   pointer to the variable containing the   */
/*                            transmitter states                       */
/***********************************************************************/

void ctm_transmitter(UWORD16   ucsCode, 
                     fifo_state_t*  ctmCodeOutputVec,
                     tx_state_t* tx_state );

#endif