shscifsio.c

IXP425的BSP代码

/* shScifSio.c - Hitachi SH SCIF (Serial Communications Interface) driver */

/* Copyright 1984-2001 Wind River Systems, Inc. */

/*
modification history
--------------------
01h,06mar02,h_k  added clear overrun error for SH7615, SH7750 and SH7751 SCIF
                 (SPR #73777).
01g,02nov01,zl   corrected NULL usage and callback declaration.
01f,16nov00,zl   make BRR=0 invalid for baud rate setting.
01e,24aug99,zl   set initial baud rate
01d,29dec98,hk   changed to use smr/scr/fcr size macros for SH7750.
01c,12aug98,jmb  debugged, use FIFOs at max triggering level.
01b,10aug98,jmb  completed.
01a,31may98,jmb  derived from shScifSio.c.
*/

/*
DESCRIPTION
This is the driver for the Hitachi SH series on-chip SCIF (Serial Communication
Interface with FIFO).  It uses the SCIF in asynchronous mode only.

USAGE
A SCIF_CHAN structure is used to describe the chip. 

The BSP's sysHwInit() routine typically calls sysSerialHwInit()
which initializes all the values in the SCIF_CHAN structure (except
the SIO_DRV_FUNCS) before calling shSciDevInit().
The BSP's sysHwInit2() routine typically calls sysSerialHwInit2(), which
connects the chips interrupts via intConnect(). 

INCLUDE FILES: drv/sio/shSciSio.h drv/sio/shScifSio.h sioLib.h
*/

#include "vxWorks.h"
#include "sioLib.h"
#include "intLib.h"
#include "errnoLib.h"
#include "drv/sio/shScifSio.h"

/* external data */

IMPORT SCI_BAUD sysBaudTable[];		/* BSP specific baud-rate constants */


/* forward static declarations */

static int shScifTxStartup (SIO_CHAN * pSioChan);
static int shScifCallbackInstall (SIO_CHAN * pSioChan, int callbackType,
				 STATUS (*callback)(void *, ...), 
				 void * callbackArg);
static int shScifPollOutput (SIO_CHAN * pSioChan, char outChar);
static int shScifPollInput (SIO_CHAN * pSioChan, char * thisChar);
static int shScifIoctl (SIO_CHAN * pSioChan, int request, void * arg);
LOCAL STATUS shScifOptsSet (SCIF_CHAN * pChan, UINT options);
static STATUS dummyCallback (void);


/* local variables */

static SIO_DRV_FUNCS shSioDrvFuncs =
    {
    shScifIoctl,
    shScifTxStartup,
    shScifCallbackInstall,
    shScifPollInput,
    shScifPollOutput
    };

#define SSC_DELAY	100000

/******************************************************************************
*
* shScifDevInit - initialize a on-chip serial communication interface
*
* This routine initializes the driver
* function pointers and then resets the chip in a quiescent state.
* The BSP must have already initialized all the device addresses and the
* baudFreq fields in the SCIF_CHAN structure before passing it to
* this routine.
*
* RETURNS: N/A
*/

void shScifDevInit
    (
    SCIF_CHAN * pChan
    )
    {
    /* initialize a channel's driver function pointers */

    pChan->pDrvFuncs = &shSioDrvFuncs;


    /* install dummy driver callbacks */

    pChan->getTxChar  = dummyCallback;
    pChan->putRcvChar = dummyCallback;
    
    /* Clear and disable the FIFOs */

    *(pChan->fcr2) |= (SZ_FCR2) (SCIF_FCR2_TFRST | SCIF_FCR2_RFRST);
 
    /* Set the FIFO depth to maximum value */
    *(pChan->fcr2) |= (SZ_FCR2) (SCIF_FCR2_RTRG | SCIF_FCR2_TTRG);

    /* reset the chip to 8-none-1, no interrupts enabled */

    *(pChan->scr2) &= 0x3;  /* Keep clock bits */
    *(pChan->smr2) &= 0x3;  /* Keep clock bits */
    *(pChan->smr2) |= (SZ_SMR2)(SCI_SMR_ASYNC | SCI_SMR_8_BITS |
			    SCI_SMR_PAR_DIS | SCI_SMR_1_STOP | SCI_SMR_MP_DIS);

    pChan->options = CS8;	/* 8-bit, no parity, one stop bit */

    /* set initial baud rate */

    shScifIoctl ((SIO_CHAN *)pChan, SIO_BAUD_SET, (void *)pChan->baud);

    /* setting polled mode is one way to make the device quiet */

    shScifIoctl ((SIO_CHAN *)pChan, SIO_MODE_SET, (void *)SIO_MODE_POLL);
    }

/******************************************************************************
*
* shScifIntRcv - handle a channel's receive-character interrupt.
*
* RETURNS: N/A
*/ 

void shScifIntRcv
    (
    SCIF_CHAN * pChan			/* channel generating the interrupt */
    )
    {
    int rcvCount;
    char inChar;
    volatile UINT16 ssr = *(pChan->ssr2);

    /* Get number of bytes in FIFO 
     * The low five bits of the FIFO data register contain the
     * receive count.
     */
    
    rcvCount = *(pChan->fdr2) & 0x1f;   
    /*
     * Empty the receive FIFO a character at a time.
     */
    while (rcvCount--)
	{
	inChar = *(pChan->frdr2);			/* grab the character */

	(*(pChan->putRcvChar)) (pChan->putRcvArg, inChar);     /* hand it off */
	}

    /* Acknowledge the interrupt by clearing the receive-data-fifo full bit */

    *(pChan->ssr2) = ssr & (UINT16) ~(SCIF_SSR2_RDF | SCIF_SSR2_DR);	   
    }

/******************************************************************************
*
* shScifIntTx - handle a channels transmitter-ready interrupt.
*
* RETURNS: N/A
*/ 

void shScifIntTx
    (
    SCIF_CHAN * pChan			/* channel generating the interrupt */
    )
    {
    char outChar;
    UINT count;
    volatile UINT16 ssr = *(pChan->ssr2);

    /*
     * If there's a character to transmit then write it out, else reset
     * the transmitter.  Keep writing characters until the ring buffer
     * is empty or the FIFO is full.
     */
    if (ssr & SCIF_SSR2_TDFE)
	{
        count = SCIF_FIFO_LEN - ((*(pChan->fdr2) >> 8) & 0x0ff);
        while (count--)
            {
	    if ((*(pChan->getTxChar)) (pChan->getTxArg, &outChar) != ERROR)
	        {
	        *(pChan->sfdr2) = outChar;
	        }
	    else
	        {
	        /* no more chars to xmit now.  reset the tx int,
	         * so the SCI does not keep interrupting.
	         */
	        *(pChan->scr2) &= (SZ_SCR2)~SCI_SCR_TIE;
                break;
	        }
            }
	    *(pChan->ssr2) = ssr & (UINT16)~SCIF_SSR2_TDFE;
	}
    }

/******************************************************************************
*
* shScifIntErr - handle a channel's error interrupt.
*
* RETURNS: N/A
*/ 

void shScifIntErr
    (
    SCIF_CHAN * pChan		        /* channel generating the interrupt */
    )
    {
    volatile UINT16 ssr;
    char dummy;

    ssr = *(pChan->ssr2);

    if (ssr & SCIF_SSR2_DR)
       dummy = *(pChan->frdr2);		/* Read stray data */

    *(pChan->ssr2) = (UINT16) NULL;		/* reset errors */

    if (pChan->lsr2 != NULL)
	{
	if (*pChan->lsr2 & (UINT16)SCIF_LSR2_ORER)
	    *pChan->lsr2 &= ~(UINT16)SCIF_LSR2_ORER; /* clear overrun error */
	}

    if (pChan->ss2r2 != NULL)
	{
	if (*pChan->ss2r2 & (UINT8)SCIF_SS2R2_ORER)
	    *pChan->ss2r2 &= ~(UINT8)SCIF_SS2R2_ORER; /* clear overrun error */
	}
    }

/******************************************************************************
*
* shScifTxStartup - start the interrupt transmitter.
*
* RETURNS: OK on success, ENOSYS if the device is polled-only, or
*          EIO on hardware error.
*/

static int shScifTxStartup
    (
    SIO_CHAN * pSioChan				/* channel to start */
    )
    {
    SCIF_CHAN * pChan = (SCIF_CHAN *)pSioChan;

    *(pChan->scr2) |= (SZ_SCR2)SCI_SCR_TIE;	/* only need to enable int */

    return (OK);
    }

/******************************************************************************
*
* shScifCallbackInstall - install ISR callbacks to get/put chars.
*
* This driver allows interrupt callbacks for transmitting characters
* and receiving characters. In general, drivers may support other
* types of callbacks too.
*
* RETURNS: OK on success, or ENOSYS for an unsupported callback type.
*/ 

static int shScifCallbackInstall
    (
    SIO_CHAN * pSioChan,			/* channel */
    int        callbackType,			/* type of callback */
    STATUS     (*callback)(void *, ...),	/* callback */
    void *     callbackArg			/* parameter to callback */
    )
    {
    SCIF_CHAN * pChan = (SCIF_CHAN *)pSioChan;

    switch (callbackType)
	{
	case SIO_CALLBACK_GET_TX_CHAR:
	    pChan->getTxChar	= (STATUS (*)(void *, char *))callback;
	    pChan->getTxArg	= callbackArg;
	    return (OK);

	case SIO_CALLBACK_PUT_RCV_CHAR:
	    pChan->putRcvChar	= (STATUS (*)(void *, char *))callback;
	    pChan->putRcvArg	= callbackArg;
	    return (OK);

	default:
	    return (ENOSYS);
	}
    }

/******************************************************************************
*
* shScifPollOutput - output a character in polled mode.
*
* RETURNS: OK if a character arrived, EIO on device error, EAGAIN
*	   if the output buffer if full. ENOSYS if the device is
*          interrupt-only.
*/

static int shScifPollOutput