piodrv.c

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#include "pioDrv.h"

IMPORT DAADIO daadio;
IMPORT PIO pio;
LOCAL int pioDrvNum = ERROR;

STATUS pioDrv(base, intLevel, intVector)
    char *   base;
    int      intLevel;
    int      intVector;
    {
    int pioClose(), pioRead(), pioWrite(), pioIoctl();
    int pioOpen();

    if (daadio.initialized == FALSE)
        {
        if (daadioInit(base, intLevel, intVector) == ERROR)
            return (ERROR);
        }
    if (pio.initialized == FALSE)
        { 
        if (pioInit(0) == ERROR)
            return (ERROR);
        }
    if (pioDrvNum == ERROR)
        {
        if((pioDrvNum = iosDrvInstall(pioOpen, 0, pioOpen,
            pioClose, pioRead, pioWrite, pioIoctl)) == ERROR)
            return (ERROR);
        }
    return (OK);
    }

STATUS pioDevCreate(name, port, mode)
    char *    name;
    int       port;
    BOOL      mode;
    {
    PIO_DEV *        pPioDev;
    UINT8            portBit;
    UINT8 *          pOutputEnablePort;    
    UINT8 *          pPort;    

    if (pioDrvNum == ERROR)
        {
        printf ("pioDrv() must be called first\n");
        return (ERROR);
        }
    if (port < PORT_A || port >= PIO_MAX_PORTS)
        {
        printf ("Invalid port number: %d\n", port);
        return (ERROR);
        }

    /* Initialize the port: clear the port register, if output
     * port set the corresponding bit in the output enable register
     * (otherwise, reset it), and update the mode field in the
     * PIO data structure.
     */
    pOutputEnablePort = (UINT8 *) daadio.baseAddr + 
                        PIO_OUTPUT_ENABLE_OFFSET;
    portBit = 1 << port;
    if (semTake (pio.mutexSem, WAIT_FOREVER) == ERROR)
        return (ERROR);
    if (mode)
        {
        pPort = (UINT8 *) daadio.baseAddr + PIO_PORT_NUM_TO_OFF(port);
        *pPort = (UINT8) 0;
        *pOutputEnablePort |= portBit;
        }
    else
        *pOutputEnablePort &= ~portBit;
    if (semGive (pio.mutexSem) == ERROR)
        return (ERROR);

    if ((pPioDev = (PIO_DEV *) malloc (sizeof (PIO_DEV))) == NULL)
        return (ERROR);
    bzero ((char *)pPioDev, sizeof (PIO_DEV));
    pPioDev->port = port;
    return (iosDevAdd(&pPioDev->devHdr, name, pioDrvNum));
    }



int pioOpen(pDevHdr, name, mode)
    DEV_HDR * pDevHdr;
    char *name;
    int mode;
    {
    PIO_DEV *    pDev = (PIO_DEV *) pDevHdr;
    PIO_CH  *    pCh;
    int port = pDev->port;
    int channel;


    /* skip leading front slash */
    while (*name == '/')
        name++;

    channel = *name - 0x30;
    if (channel < 0 || channel >= PIO_MAX_CHANNELS_PER_PORT)
        {
        printf ("pioOpen: Invalid channel: %d\n", channel);
        return (ERROR);
        }

    if ((pCh = (PIO_CH *) malloc (sizeof (PIO_CH))) == NULL)
        return (ERROR);
    pCh->pDev = pDev;
    pCh->channel = channel;
    
    return ((int)pCh);
    }

STATUS pioClose (devId)
    int    devId;
    {
    free ((void *) devId);
    return (OK);
    }

pioRead(devId, buf, nBytes)
    int devId;
    char *buf;
    int nBytes;
    {
    PIO_CH *  pCh = (PIO_CH *)devId;
    BOOL      value;

    if ((value = pioGet (pCh->pDev->port, pCh->channel)) == ERROR)
        return (ERROR);

    *buf = (char) value;
    return (1);
    }

pioWrite(devId, buf, nBytes)
    int devId;
    char *buf;
    int nBytes;
    {
    PIO_CH *pCh = (PIO_CH *) devId;

    if (nBytes == 0)
        return (0);
    if (pioSet (pCh->pDev->port, pCh->channel, (BOOL) *buf) == ERROR)
        return (ERROR);

    return (1);
    }

pioIoctl(devId, cmd, arg)
    int devId;
    int cmd, arg;
    {
    PIO_CH *pCh = (PIO_CH *) devId;
    int status;
    int channel = pCh->channel;
    int port = pCh->pDev->port;
    UINT8 *        pOutputEnablePort;

    pOutputEnablePort = (UINT8 *) daadio.baseAddr + 
                        PIO_OUTPUT_ENABLE_OFFSET;
    switch (cmd)
        {
        case IS_ON:
            status = pioGet (port, channel);
            if (arg)
                *(int *)arg = status;
            break;
        case IS_OFF:
            status = !pioGet (port, channel);
            if (arg)
                *(int *)arg = status;
            break;
        case IS_INPUT:
            status = ((*pOutputEnablePort & (1 << port)) == 0) ? TRUE : FALSE ;
            if (arg)
                *(int *)arg = status;
            break;
        case IS_OUTPUT:
            status = (*pOutputEnablePort & (1 << port)) ? TRUE : FALSE ;
            if (arg)
                *(int *)arg = status;
            break;
        case TURN_ON:
            status = pioSet (port, channel, ON);
            break;
        case TURN_OFF:
            status = pioSet (port, channel, OFF);
            break;
        case GET_CHANNEL:
            status = channel;
            if (arg)
                *(int *)arg = status;
            break;
        case SET_TO_ARG:
            status = pioSet (port, channel, (BOOL) arg);
            break;
        default:
            errnoSet (S_ioLib_UNKNOWN_REQUEST);
            status = ERROR;
            break;
        }
    return (status);
    }