iicdirection.c

用于TM1300/PNX1300系列DSP（主要用于视频处理）的设备库的源码

/*
 * Copyright (c) 1995 - 1999 by TriMedia Technologies. 
 *
 * +------------------------------------------------------------------+
 * | This software is furnished under a license and may only be used  |
 * | and copied in accordance with the terms and conditions of  such  |
 * | a license and with the inclusion of this copyright notice. This  |
 * | software or any other copies of this software may not be provided|
 * | or otherwise made available to any other person.  The ownership  |
 * | and title of this software is not transferred.                   |
 * |                                                                  |
 * | The information in this software is subject  to change without   |
 * | any  prior notice and should not be construed as a commitment by |
 * | TriMedia Technologies.                                           |
 * |                                                                  |
 * | this code and information is provided "as is" without any        |
 * | warranty of any kind, either expressed or implied, including but |
 * | not limited to the implied warranties of merchantability and/or  |
 * | fitness for any particular purpose.                              |
 * +------------------------------------------------------------------+
 *
 *  Module name             : iicDirection.c    1.3
 *
 *  Last update             : 18:43:41 - 00/11/09
 *
 *
 */

#include <tmlib/tmtypes.h>
#include <tmlib/dprintf.h>
#include <tmlib/AppSem.h>
#include <tm1/tmLibdevErr.h>
#include <tm1/tmAssert.h>

#include "iicDirection.h"

static struct _AppSem_Semaphore  directionLock = _AppSem_INITIALISED_SEM; 
static Bool                      initialized   = False;
static directionSwitchFunction_t switchFunc    = Null;
static UInt32                    defaultDirection = 0;

extern tmLibdevErr_t iicDirectionInit(piicDirectionParam_t params)
{
    DP(("iicDirectionInit\n"));

    tmAssert(params, TMLIBDEV_ERR_NULL_PARAMETER);
    tmAssert(params->directionSwitchFunction, TMLIBDEV_ERR_NULL_PARAMETER);

    switchFunc       = params->directionSwitchFunction;
    defaultDirection = params->defaultDirection;

    initialized = True;

    return TMLIBDEV_OK;
}

extern tmLibdevErr_t iicDirectionSelect(UInt direction)
{
    tmLibdevErr_t err;

    DP(("iicDirectionSelect\n"));

    if (!initialized)
        return TMLIBDEV_OK;

    AppSem_P(&directionLock);

    err = switchFunc(direction);
    if (err != TMLIBDEV_OK)
        AppSem_V(&directionLock);

    return err;
}

extern tmLibdevErr_t iicDirectionUnSelect(UInt direction)
{
    tmLibdevErr_t err;

    DP(("iicDirectionUnSelect\n"));

    if (!initialized)
        return TMLIBDEV_OK;

    err = switchFunc(defaultDirection);

    AppSem_V(&directionLock);

    return err;
}