ns16550sio.c

Vxworks的bsp软件开发包(基于wrPpmc74xx)

/* ns16550Sio.c - NS 16550 UART tty driver */

/* Copyright 1984-1997 Wind River Systems, Inc. */

#include "copyright_wrs.h"

/*
modification history
--------------------
01k,02may02,gjc  Fixing U INT int ns16550Baudset
01j,23oct01,g_h  Remove compilation warning.
01i,17sep97,dat  fixed merge problems that caused baud rate setting to fail.
01h,06mar97,dat  SPR 7899, max baud rate set to 115200.
01g,08may97,db   added hardware options and modem control(SPRs #7570, #7082).
01f,18dec95,myz  added case IIR_TIMEOUT in ns16550Int routine.
01e,28nov95,myz  fixed bugs to work at 19200 baud or above with heavy traffic.
01d,09nov95,jdi  doc: style cleanup.
01c,02nov95,myz  undo 01b fix
01b,02nov95,p_m  added test for 960CA and 960JX around access to lcr field
         in order to compile on all architectures.
01a,24oct95,myz  written from ns16550Serial.c.
*/

/*
DESCRIPTION
This is the driver for the NS16552 DUART. This device includes two universal
asynchronous receiver/transmitters, a baud rate generator, and a complete 
modem control capability. 

A NS16550_CHAN structure is used to describe the serial channel. This data 
structure is defined in ns16550Sio.h.

Only asynchronous serial operation is supported by this driver.
The default serial settings are 8 data bits, 1 stop bit, no parity, 9600
baud, and software flow control.  

USAGE
The BSP's sysHwInit() routine typically calls sysSerialHwInit(),
which creates the NS16550_CHAN structure and initializes all the values in the 
structure (except the SIO_DRV_FUNCS) before calling ns16550DevInit().
The BSP's sysHwInit2() routine typically calls sysSerialHwInit2(), which
connects the chips interrupts via intConnect() (either the single
interrupt `ns16550Int' or the three interrupts `ns16550IntWr', `ns16550IntRd',
and `ns16550IntEx').

This driver handles setting of hardware options such as parity(odd, even) and
number of data bits(5, 6, 7, 8). Hardware flow control is provided with the
handshakes RTS/CTS. The function HUPCL(hang up on last close) is available.
When hardware flow control is enabled, the signals RTS and DTR are set TRUE 
and remain set until a HUPCL is performed. 

INCLUDE FILES: drv/sio/ns16552Sio.h

*/

/* includes */

#include "vxWorks.h"
#include "intLib.h"
#include "errnoLib.h"
#include "errno.h"
#include "sioLib.h"
#include "ns16552Sio.h"

/* imports */

/* local defines       */

#ifndef SIO_HUP
#   define SIO_OPEN 0x100A
#   define SIO_HUP  0x100B
#endif

/* min/max baud rate */
 
#define NS16550_MIN_RATE 50
#define NS16550_MAX_RATE 115200

#define REG(reg, pchan) \
 (*(volatile UINT8 *)((UINT32)pchan->regs + (reg * pchan->regDelta)))
#define REGPTR(reg, pchan) \
 ((volatile UINT8 *)((UINT32)pchan->regs + (reg * pchan->regDelta)))

/* static forward declarations */

LOCAL   int     ns16550CallbackInstall (SIO_CHAN *, int, STATUS (*)(), void *);
LOCAL   STATUS  ns16550DummyCallback ();
LOCAL   void    ns16550InitChannel (NS16550_CHAN *);
LOCAL   STATUS  ns16550BaudSet (NS16550_CHAN *, UINT);
LOCAL   STATUS  ns16550ModeSet (NS16550_CHAN *, UINT);
LOCAL   STATUS  ns16550Ioctl (NS16550_CHAN *, int, int);
LOCAL   void    ns16550TxStartup (NS16550_CHAN *);
LOCAL   int     ns16550PollOutput (NS16550_CHAN *, char);
LOCAL   int     ns16550PollInput (NS16550_CHAN *, char *);
LOCAL   STATUS  ns16550OptsSet (NS16550_CHAN *, UINT);
LOCAL   STATUS  ns16550Open (NS16550_CHAN * pChan );
LOCAL   STATUS  ns16550Hup (NS16550_CHAN * pChan );

/* driver functions */

static SIO_DRV_FUNCS ns16550SioDrvFuncs =
    {
    (int (*)())ns16550Ioctl,
    (int (*)())ns16550TxStartup,
    (int (*)())ns16550CallbackInstall,
    (int (*)())ns16550PollInput,
    (int (*)(SIO_CHAN *,char))ns16550PollOutput
    };

/******************************************************************************
*
* ns16550DummyCallback - dummy callback routine.
*/

LOCAL STATUS ns16550DummyCallback (void)
    {
    return (ERROR);
    }

/******************************************************************************
*
* ns16550DevInit - intialize an NS16550 channel
*
* This routine initializes some SIO_CHAN function pointers and then resets
* the chip in a quiescent state.  Before this routine is called, the BSP
* must already have initialized all the device addresses, etc. in the
* NS16550_CHAN structure.
*
* RETURNS: N/A
*/

void ns16550DevInit
    (
    NS16550_CHAN *pChan
    )
    {
    int oldlevel = intLock ();

    /* initialize the driver function pointers in the SIO_CHAN's */

    pChan->pDrvFuncs    = &ns16550SioDrvFuncs;

    /* set the non BSP-specific constants */

    pChan->getTxChar    = ns16550DummyCallback;
    pChan->putRcvChar   = ns16550DummyCallback;
    pChan->channelMode  = SIO_MODE_INT; 
    pChan->options      = (CLOCAL | CREAD | CS8);
    pChan->mcr          = MCR_OUT2;

    /* reset the chip */

    ns16550InitChannel (pChan);

    intUnlock (oldlevel);
}

/*******************************************************************************
*
* ns16550InitChannel - initialize UART
*
* Initialize the number of data bits, parity and set the selected
* baud rate.
* Set the modem control signals if the option is selected.
*
* RETURNS: N/A
*/

LOCAL void ns16550InitChannel
    ( 
    NS16550_CHAN *pChan
    )
    {

    /* set the requested baud rate */

    ns16550BaudSet(pChan, pChan->baudRate);

    /* set the options */

    ns16550OptsSet(pChan, pChan->options);
    }

/*******************************************************************************
*
* ns16550OptsSet - set the serial options
*
* Set the channel operating mode to that specified.  All sioLib options
* are supported: CLOCAL, HUPCL, CREAD, CSIZE, PARENB, and PARODD.
* When the HUPCL option is enabled, a connection is closed on the last
* close() call and opened on each open() call.
*
* Note, this routine disables the transmitter.  The calling routine
* may have to re-enable it.
*
* RETURNS:
* Returns OK to indicate success, otherwise ERROR is returned
*/

LOCAL STATUS ns16550OptsSet
    (
    NS16550_CHAN *pChan,
    UINT options
    )
    {
    FAST int    oldlevel;   /* current interrupt level mask */

    pChan->lcr = 0; 
    pChan->mcr &= (~(MCR_RTS | MCR_DTR)); /* clear RTS and DTR bits */

    if (pChan == NULL || options & 0xffffff00)
        return ERROR;

    switch (options & CSIZE)
        {
        case CS5:
            pChan->lcr = CHAR_LEN_5;
            break;
        case CS6:
            pChan->lcr = CHAR_LEN_6;
            break;
        case CS7:
            pChan->lcr = CHAR_LEN_7;
            break;
        default:
        case CS8:
            pChan->lcr = CHAR_LEN_8;
            break;
        }
    if (options & STOPB)
        pChan->lcr |= LCR_STB;
    else
        pChan->lcr |= ONE_STOP;

    switch (options & (PARENB | PARODD))
        {
        case PARENB|PARODD:
            pChan->lcr |= LCR_PEN;
            break;
        case PARENB:
            pChan->lcr |= (LCR_PEN | LCR_EPS);
            break;
        default:
        case 0:
            pChan->lcr |= PARITY_NONE;
            break;
        }

    pChan->regs->IER = 0;

    if (!(options & CLOCAL))
        {
        /* !clocal enables hardware flow control(DTR/DSR) */

        pChan->mcr |= (MCR_DTR | MCR_RTS);
        pChan->ier &= (~TxFIFO_BIT); 
        pChan->ier |= IER_EMSI;    /* enable modem status interrupt */
        }
    else
        {
        pChan->ier &= ~IER_EMSI; /* disable modem status interrupt */
        }

    oldlevel = intLock ();

    pChan->regs->LCR = pChan->lcr;
    pChan->regs->MCR = pChan->mcr;


    /* now reset the channel mode registers */

    pChan->regs->FCR = (RxCLEAR | TxCLEAR | FIFO_ENABLE);

    if (options & CREAD)
        {
        pChan->ier |= RxFIFO_BIT;
        }
    if (pChan->channelMode == SIO_MODE_INT)
        {
        pChan->regs->IER = pChan->ier;
        }
    intUnlock (oldlevel);
    pChan->options = options;
    return OK;
    }

/*******************************************************************************
*
* ns16550Hup - hang up the modem control lines 
*
* Resets the RTS and DTR signals and clears both the receiver and
* transmitter sections.
*
* RETURNS: OK
*/

LOCAL STATUS ns16550Hup
    (
    NS16550_CHAN *pChan
    )
    {
    FAST int     oldlevel;  /* current interrupt level mask */

    oldlevel = intLock ();

    pChan->mcr &= (~(MCR_RTS | MCR_DTR));

    pChan->regs->MCR = pChan->mcr;
    pChan->regs->FCR = (RxCLEAR | TxCLEAR);

    intUnlock (oldlevel);

    return OK;
    }    

/*******************************************************************************
*
* ns16550Open - Set the modem control lines 
*
* Set the modem control lines(RTS, DTR) TRUE if not already set.  
* It also clears the receiver, transmitter and enables the fifo. 
*
* RETURNS: OK
*/

LOCAL STATUS ns16550Open
    (
    NS16550_CHAN *pChan
    )
    {
    FAST int     oldlevel;  /* current interrupt level mask */
    char mask;

    mask = pChan->regs->MCR & (MCR_RTS | MCR_DTR); 

    if (mask != (MCR_RTS | MCR_DTR))
        {    /* RTS and DTR not set yet */

        oldlevel = intLock ();

        /* set RTS and DTR TRUE */

        pChan->mcr |= (MCR_DTR | MCR_RTS); 

        pChan->regs->MCR = pChan->mcr;
        pChan->regs->FCR = (RxCLEAR | TxCLEAR | FIFO_ENABLE);

        intUnlock (oldlevel);
        }
    return OK;
    }

/******************************************************************************
*
* ns16550BaudSet - change baud rate for channel
*
* This routine sets the baud rate for the UART. The interrupts are disabled
* during chip access.
*
* RETURNS: OK
*/

LOCAL STATUS ns16550BaudSet
    (
    NS16550_CHAN *pChan,
    UINT baud
    )
    {
    int   oldlevel;

    /* disable interrupts during chip access */

    oldlevel = intLock ();

    pChan->regs->LCR  = LCR_DLAB | pChan->lcr;
    pChan->regs->DLLO = pChan->xtal/(16 * baud);
    pChan->regs->DLHI = (pChan->xtal/(16 * baud)) >> 8;
    pChan->regs->LCR  = pChan->lcr;  

    pChan->baudRate = baud;
    intUnlock (oldlevel);
    return OK;
    }

/*******************************************************************************
*
* ns16550ModeSet - change channel mode setting
*
* This driver supports both polled and interrupt modes and is capable of
* switching between modes dynamically. 
*
* If interrupt mode is desired this routine enables the channels receiver and 
* transmitter interrupts. If the modem control option is TRUE, the Tx interrupt
* is disabled if the CTS signal is FALSE. It is enabled otherwise. 
*
* If polled mode is desired the device interrupts are disabled. 
*
* RETURNS:
* Returns a status of OK if the mode was set else ERROR.
*/

LOCAL STATUS ns16550ModeSet
    (
     NS16550_CHAN *pChan,
     UINT newMode
     )
    {
    FAST int     oldlevel;  /* current interrupt level mask */
    char mask;

    if ((newMode != SIO_MODE_POLL) && (newMode != SIO_MODE_INT))
        {
        return ERROR;
        }
    oldlevel = intLock ();
    if (newMode == SIO_MODE_INT)
        {
        /* Enable appropriate interrupts */

        if (pChan->options & CLOCAL)
            {
            pChan->regs->IER = (pChan->ier | RxFIFO_BIT | TxFIFO_BIT);

            }
        else
            {
            mask = pChan->regs->MSR & MSR_CTS;

            /* if the CTS is asserted enable Tx interrupt */
            if (mask & MSR_CTS)
                pChan->ier |= TxFIFO_BIT;    /* enable Tx interrupt */
            else
                pChan->ier &= (~TxFIFO_BIT); /* disable Tx interrupt */

            pChan->regs->IER = pChan->ier;