source: svn/newcon3bcm2_21bu/magnum/syslib/pvrlib/bpvrlib_p_ringmgr.c @ 22

/***************************************************************************
 *     Copyright (c) 2002, Broadcom Corporation
 *     All Rights Reserved
 *     Confidential Property of Broadcom Corporation
 *
 *  THIS SOFTWARE MAY ONLY BE USED SUBJECT TO AN EXECUTED SOFTWARE LICENSE
 *  AGREEMENT  BETWEEN THE USER AND BROADCOM.  YOU HAVE NO RIGHT TO USE OR
 *  EXPLOIT THIS MATERIAL EXCEPT SUBJECT TO THE TERMS OF SUCH AN AGREEMENT.
 *
 * $brcm_Workfile: bpvrlib_p_ringmgr.c $
 * $brcm_Revision: Hydra_Software_Devel/5 $
 * $brcm_Date: 1/21/04 4:43p $
 *
 * Module Description:
 * 
 * This module implements a generic ring buffer in software.
 * It includes function that allow the user add and remove data
 * from the ring buffer.  It supports notication of buffer
 * full to not full, and buffer empty to not empty states through
 * the use of callbacks.  It supports blocking function
 * calls when requesting to add and requesting to remove data
 * from the ring buffer.  It supports a programmable buffer
 * address and size, and does not actually require accessing any
 * memory inside the specified buffer.
 *
 * Revision History:
 *
 * $brcm_Log: /vobs/magnum/syslib/pvrlib/bpvrlib_p_ringmgr.c $
 * 
 * Hydra_Software_Devel/5   1/21/04 4:43p marcusk
 * PR8927: Fixed to work with latest version of XPT porting interface.
 * Validate channel number.
 * 
 * Hydra_Software_Devel/4   12/12/03 2:03p dlwin
 * PR 8970: Change naming convention to conform to Magnum
 * 
 * Hydra_Software_Devel/3   12/10/03 2:25p marcusk
 * PR8927: Record syslib now compiles.
 * 
 * Hydra_Software_Devel/2   12/10/03 11:07a marcusk
 * PR 8927: Initial magnum version (not compiled yet)
 * 
 * Irvine_HDDemo_Devel\26   6/25/02 12:57p marcusk
 * Fixed detection of buffer full condition.
 * 
 * Irvine_HDDemo_Devel\25   5/17/02 9:47a marcusk
 * Added "" around BRCM_DBG_MODULE to support new debug routines.
 *
 ***************************************************************************/
#include "bstd.h"
#include "bkni.h"
#include "bpvrlib_p_ringmgr.h"

BDBG_MODULE(BPVRlib_RingMgr);

BERR_Code BPVRlib_P_RingMgr_Open( 
                                BPVRlib_P_RingMgr_Handle *rbmgr,                        /* [out] returns context */
                                uint32_t channel,                                                       /* returned as parameter by callback functions */
                                BPVRlib_P_RingMgrCb emptyToNotEmptyCb,  /* optional callback function to be called when the ring buffer transitions from empty to not empty */
                                BPVRlib_P_RingMgrCb fullToNotFullCb,            /* optional callback function to be called when the ring buffer transitions from full to not full */
                                uint8_t *p_bfr,                                                 /* pointer to the buffer that the ring buffer manager should use */
                                size_t bfrSize                                                  /* the size of the buffer described by the p_bfr pointer */
                                )
{
        BERR_Code err = BERR_SUCCESS;
        
        *rbmgr = BKNI_Malloc( sizeof( BPVRlib_P_RingMgr_Impl ) );
        if( !*rbmgr )
        {
                err = BERR_TRACE(BERR_OUT_OF_SYSTEM_MEMORY);
                BDBG_ERR(("Unable to allocate ring buffer manager."));
                goto done;
        }

        /* This variable must be set to init the rpbmgr */
        (*rbmgr)->channel                       = channel;
        (*rbmgr)->emptyToNotEmptyCb= emptyToNotEmptyCb;
        (*rbmgr)->fullToNotFullCb       = fullToNotFullCb;
        (*rbmgr)->bufferSize            = bfrSize;
        (*rbmgr)->p_bfr                         = p_bfr;

        err = BKNI_CreateEvent(&((*rbmgr)->notifyEvent));
        if( err != BERR_SUCCESS )
        {
                BKNI_Free( *rbmgr );
                goto done;
        }
        BPVRlib_P_RingMgr_Reset( *rbmgr );

done:
        return err;
}

void BPVRlib_P_RingMgr_Reset( 
                        BPVRlib_P_RingMgr_Handle rbmgr                          /* handle of ring buffer manager */
                        )
{
        /* Assign the proper channel */
        rbmgr->resetInProgress  = 1;
        rbmgr->abortInProgress  = 0;
        rbmgr->writeOffset              = 0;
        rbmgr->writeWrapCount   = 0;
        rbmgr->readOffset               = 0;
        rbmgr->readWrapCount    = 0;
        rbmgr->hwWriteOffset    = 0;
        rbmgr->hwWriteWrapCount = 0;
        BKNI_SetEvent(rbmgr->notifyEvent);
}

void BPVRlib_P_RingMgr_Close( 
                        BPVRlib_P_RingMgr_Handle rbmgr                          /* handle of ring buffer manager */
                        )
{
        BKNI_DestroyEvent(rbmgr->notifyEvent);
        BKNI_Free( rbmgr );
}

BERR_Code BPVRlib_P_RingMgr_AddDataRequest( 
                        BPVRlib_P_RingMgr_Handle rbmgr,         /* handle of ring buffer manager */
                        uint8_t **pp_bfr,                                               /* returns pointer of starting buffer address of free space */
                        size_t *p_count,                                        /* returns size of the free space (in bytes) */
                        bool block,                                                     /* false (do not block), true (block until free space is available) */
                        uint32_t timeout                                                /* max num of msec to block */
                        )
{
        BERR_Code err = BERR_SUCCESS;

        BDBG_MSG(("Request to add data to ring buffer with %s", block?"block":"no block"));

        rbmgr->resetInProgress = 0;
        *pp_bfr = (uint8_t *)rbmgr->p_bfr + rbmgr->writeOffset;

        while( 1 )
        {
                if( rbmgr->writeOffset == rbmgr->readOffset )
                {
                        if( rbmgr->writeWrapCount == rbmgr->readWrapCount )
                        {
                                *p_count = rbmgr->bufferSize - rbmgr->writeOffset;
                        }
                        else
                        {
                                *p_count = 0;
                        }
                }
                else if( rbmgr->writeOffset > rbmgr->readOffset )
                {
                        *p_count = rbmgr->bufferSize - rbmgr->writeOffset;
                }
                else if( rbmgr->writeOffset < rbmgr->readOffset )
                {
                        *p_count = rbmgr->readOffset - rbmgr->writeOffset;
                }

                if( *p_count == 0 && block )
                {
                        BDBG_MSG(("Ring buffer full.  Waiting %ld for read offset to be updated", timeout));
                        err = BKNI_WaitForEvent( rbmgr->notifyEvent, timeout );

                        if( err != BERR_SUCCESS || rbmgr->resetInProgress || rbmgr->abortInProgress )
                        {
                                err = BERR_TRACE(BERR_TIMEOUT);
                                break;
                        }
                }
                else
                {
                        break;
                }
        }

        return err;
}

BERR_Code BPVRlib_P_RingMgr_UpdateWritePointer( 
                        BPVRlib_P_RingMgr_Handle rbmgr,         /* handle of ring buffer manager */
                        size_t count                                            /* number of bytes to increment the write pointer */
                        )
{
        BERR_Code err = BERR_SUCCESS;
        bool empty = false;

        if( rbmgr->resetInProgress )
        {
                err = BERR_TRACE(BERR_UNKNOWN);
                BDBG_WRN(("Reset or timeout occurred: rpbmgr_UpdateWritePointer"));
                goto done;
        }

        BDBG_MSG(("Incrementing write pointer by %ld bytes", count));

        if( (rbmgr->writeOffset == rbmgr->readOffset)
                && (rbmgr->writeWrapCount == rbmgr->readWrapCount) )
        {
                empty = true;
        }

        if( (rbmgr->writeOffset+count) > rbmgr->bufferSize )
        {
                err = BERR_TRACE(BERR_INVALID_PARAMETER);
                BDBG_ERR(("FATAL ERROR: Attempt to overflow ring buffer by %ld bytes!", (rbmgr->writeOffset+count)-rbmgr->bufferSize));
                goto done;
        }

        rbmgr->writeOffset += count;
        if( rbmgr->writeOffset >= rbmgr->bufferSize )
        {
                rbmgr->writeWrapCount++;
                rbmgr->writeOffset -= rbmgr->bufferSize;
        }
                
        BKNI_SetEvent( rbmgr->notifyEvent );

        if( empty )
        {
                if( rbmgr->emptyToNotEmptyCb )
                        (*rbmgr->emptyToNotEmptyCb)( rbmgr->channel );
        }

done:
        return err;
}

BERR_Code BPVRlib_P_RingMgr_RemoveDataRequest( 
                        BPVRlib_P_RingMgr_Handle rbmgr,                         /* handle of ring buffer manager */
                        uint8_t **pp_bfr,                               /* returns pointer of starting buffer address of valid data */
                        size_t *p_count,                        /* returns size of the valid data (in bytes) */
                        bool block,                                     /* false (do not block), true (block until free space is available) */
                        uint32_t timeout                                /* max num of msec to block */
                        )

{
        BERR_Code err = BERR_SUCCESS;

        BDBG_MSG(("Requesting to remove data from ring buffer with %s", block?"block":"no block"));

        *pp_bfr = (uint8_t *)rbmgr->p_bfr + rbmgr->readOffset;

        while( 1 )
        {
                if( rbmgr->writeOffset == rbmgr->readOffset )
                {
                        if( rbmgr->readWrapCount == rbmgr->writeWrapCount )
                        {
                                *p_count = 0;
                        }
                        else
                        {
                                *p_count = rbmgr->bufferSize - rbmgr->readOffset;
                        }
                }
                else if( rbmgr->writeOffset > rbmgr->readOffset )
                {
                        *p_count = rbmgr->writeOffset - rbmgr->readOffset;
                }
                else if( rbmgr->writeOffset < rbmgr->readOffset )
                {
                        *p_count = rbmgr->bufferSize - rbmgr->readOffset;
                }

                if( *p_count == 0 && block )
                {
                        BDBG_MSG(("Ring buffer empty.  Waiting %ld for write offset to be updated", timeout));
                        err = BKNI_WaitForEvent( rbmgr->notifyEvent, timeout);

                        if( err != BERR_SUCCESS || rbmgr->resetInProgress || rbmgr->abortInProgress )
                        {
                                err = BERR_TRACE(BERR_TIMEOUT);
                                break;
                        }
                }
                else
                {
                        break;
                }
        }

        return err;
}

BERR_Code BPVRlib_P_RingMgr_UpdateReadPointer( 
                        BPVRlib_P_RingMgr_Handle rbmgr,         /* handle of ring buffer manager */
                        size_t count                                            /* number of bytes to increment the read pointer */
                        )
{
        BERR_Code err = BERR_SUCCESS;
        bool full = false;

        if( rbmgr->resetInProgress )
        {
                BDBG_WRN(("Reset or timeout occurred: rpbmgr_UpdateReadPointer"));
                err = BERR_TRACE(BERR_UNKNOWN);
                goto done;
        }

        BDBG_MSG(("Incrementing read pointer by %ld bytes", count));

        if( (rbmgr->writeOffset == rbmgr->readOffset)
                && (rbmgr->writeWrapCount != rbmgr->readWrapCount) )
        {
                full = true;
        }

        if( (rbmgr->readOffset+count) > rbmgr->bufferSize )
        {
                BDBG_ERR(("FATAL ERROR: Attempt to overflow ring buffer by %ld bytes!", (rbmgr->readOffset+count)-rbmgr->bufferSize));
                err = BERR_TRACE(BERR_INVALID_PARAMETER);
                goto done;
        }

        rbmgr->readOffset += count;
        if( rbmgr->readOffset >= rbmgr->bufferSize )
        {
                rbmgr->readWrapCount++;
                rbmgr->readOffset -= rbmgr->bufferSize;
        }

        BKNI_SetEvent( rbmgr->notifyEvent );

        if( full )
        {
                if( rbmgr->fullToNotFullCb )
                        (*rbmgr->fullToNotFullCb)( rbmgr->channel );
        }

done:
        return err;
}

void BPVRlib_P_RingMgr_GetNumFreeBytes( 
                        BPVRlib_P_RingMgr_Handle rbmgr,         /* handle of ring buffer manager */
                        size_t *p_numFreeBytes                          /* returns number of bytes available in ring buffer */
                        )
{
        if( rbmgr->writeOffset == rbmgr->readOffset )
        {
                if( rbmgr->readWrapCount == rbmgr->writeWrapCount )
                {
                        *p_numFreeBytes = rbmgr->bufferSize;
                }
                else
                {
                        *p_numFreeBytes = 0;
                }
        }
        else if( rbmgr->writeOffset < rbmgr->readOffset )
        {
                *p_numFreeBytes = rbmgr->readOffset - rbmgr->writeOffset;
        }
        else if( rbmgr->writeOffset > rbmgr->readOffset )
        {
                *p_numFreeBytes = rbmgr->bufferSize - rbmgr->writeOffset;
                *p_numFreeBytes += rbmgr->readOffset;
        }
        else
        {
                BDBG_ERR(("FATAL ERROR: This should not be possible!"));
        }
}

void BPVRlib_P_RingMgr_Abort( 
                        BPVRlib_P_RingMgr_Handle rbmgr                          /* handle of ring buffer manager */
                        )
{
        /* This function differs from a reset only in that it
         * doesn't reset any of the data pointers
         */
        rbmgr->abortInProgress = true;

        BKNI_SetEvent(rbmgr->notifyEvent);
}

void BPVRlib_P_RingMgr_GetHwWriteDifference( 
                        BPVRlib_P_RingMgr_Handle rbmgr,         /* handle of ring buffer manager */
                        uint8_t **pp_bfr,                                               /* returns pointer of starting buffer address of data that needs to be added into hardware */
                        size_t *p_count                                         /* returns size of the data that needs to be added into hardware */
                        )
{
        *p_count = 0;

        *pp_bfr = (uint8_t *)rbmgr->p_bfr + rbmgr->hwWriteOffset;

        if( rbmgr->hwWriteOffset == rbmgr->writeOffset )
        {
                if( rbmgr->hwWriteWrapCount == rbmgr->writeWrapCount )
                {
                        *p_count = 0;
                }
                else
                {
                        *p_count = rbmgr->bufferSize - rbmgr->hwWriteOffset;
                }
        }
        else
        {
                if( rbmgr->hwWriteOffset > rbmgr->writeOffset )
                {
                        *p_count = rbmgr->bufferSize - rbmgr->hwWriteOffset;
                }
                else
                {
                        *p_count = rbmgr->writeOffset - rbmgr->hwWriteOffset;
                }
        }
}       

void BPVRlib_P_RingMgr_UpdateHwWriteCount( 
                        BPVRlib_P_RingMgr_Handle rbmgr, /* handle of ring buffer manager */
                        size_t count                                    /* number of bytes to increment the hw write pointer */
                        )
{
        rbmgr->hwWriteOffset += count;

        if( rbmgr->hwWriteOffset >= rbmgr->bufferSize )
        {
                rbmgr->hwWriteWrapCount++;
                rbmgr->hwWriteOffset -= rbmgr->bufferSize;
        }
}