字符设备驱动

file fooDrv.h

#ifndef __INCfooDrv
#define __INCfooDrv
#include "vxWorks.h"
#include "sioLib.h"

STATUS fooDrv();
STATUS fooDevCreate(char *devName);
STATUS fooDelete(char *devName);
int fooOpen(DEV_HDR *pfooDevHdr, char *devName, int option, int flags);
int fooClose(int fooDevId);
int fooRead(int fooDevId, char *pBuf, int nBytes);
int fooWrite(int fooDevId, char *pBuf, int nBytes);
int fooIoctl(int fooDevId, int cmd, int arg);

#endif

/*****************************************************************************/
file fooDrv.c

#include "vxWorks.h"
#include "ioLib.h"
#include "iosLib.h"
#include "stat.h"
#include "dirent.h"
#include "memLib.h"
#include "errnoLib.h"
#include "string.h"
#include "stdlib.h"
#include "stdio.h"
#include
#include "foo.h"
#include "fooDrv.h"

typedef struct
{
    DEV_HDR devHdr;
    BOOL isOpen;
}fooDev;

LOCAL int fooDrvNum = 0;

STATUS fooDrv()
{
    /* 驱动是否已经安装过 */
    if (fooDrvNum > 0)
        return (OK);
   
    if((fooDrvNum = iosDrvInstall(fooOpen, NULL, fooOpen, fooClose,
                                  fooRead, fooWrite, fooIoctl)) == ERROR)
        return (ERROR);
   
    return (OK);
}

STATUS fooDevCreate(char *devName)
{
    fooDev *pfooDev;

    /* 检查驱动是否已经安装过 */
    if (fooDrvNum < 1)
        return (ERROR);
   
    if ((pfooDev = (fooDev *)malloc(sizeof(fooDev))) == NULL)
        return (ERROR);

    memset(pfooDev, 0x00, sizeof(fooDev));
    pfooDev->isOpen = FALSE;

    /* 添加设备 */
    if (iosDevAdd(&pfooDev->devHdr, devName, fooDrvNum) == ERROR)
    {
        free((char *)pfooDev);
        return (ERROR);
    }
   
    return (OK);
}

STATUS fooDevDelete(char *devName)
{
    DEV_HDR *pDevHdr;
    char *pNameTail;

    pDevHdr = iosDevFind(devName, &pNameTail);

    if (pDevHdr == NULL || *pNameTail != '\0')
        return (ERROR);
   
    iosDevDelete(pDevHdr);
   
    return (OK);
}

int fooOpen(DEV_HDR *pdevHdr, char *devName, int option, int flags)
{
    fooDev *pdevFd = (fooDev *)pdevHdr;
    if (pdevFd == NULL)
        return ERROR;

    if (pdevFd->isOpen == TRUE)
        return ERROR;
   
    pdevFd->isOpen = TRUE;

    /* 硬件初始化 */

    return (int) pdevFd;
}

int fooClose(int devId)
{
    fooDev *pdevFd = (fooDev *)devId;
   
    if (pdevFd == NULL)
        return (ERROR);

    pdevFd->isOpen = FALSE;

    return (OK);
}

int fooRead(int devId, char *pBuf, int nBytes)
{
    int readNum = 0;
    fooDev *pdevFd = (fooDev *)devId;
   
    if (pdevFd == NULL)
        return (ERROR);
   
    /* 读操作 */
   
    return readNum;
}

int fooWrite(int devId, char *pBuf, int nBytes)
{
    fooDev *pdevFd = (fooDev *)devId;
   
    if (pdevFd == NULL)
        return (ERROR);
   
    //写操作
   
    return nBytes;
}

int fooIoctl(int devId, int cmd, int arg)
{
    fooDev *pdevFd = (fooDev *)devId;
   
    if (pdevFd == NULL)
        return (ERROR);
   
    /* 控制操作 */
   
    return 0;
}

/*****************************************************************************/
file fooDrvTest.c
#include "selectlib.h"
#include "vxWorks.h"
#include "string.h"
#include "stdio.h"
#include "stdlib.h"
#include "ioLib.h"
#include "iosLib.h"
#include "memLib.h"
#include "errnoLib.h"
#include "string.h"

#include "fooDrv.h"

void fooDrvTest()
{
    int devFd = 0;
    char readBuf[15];
    char writeBuf[15];
    int ix = 0;
    int readNum = 0;
   
    memset(readBuf, 0, sizeof(readBuf));
    memset(writeBuf, 0, sizeof(writeBuf));
    //填充buf中的数据
   
    devFd = open("/xxx", O_RDWR, 0);
    if (devFd == ERROR )
    {
        printf("open file error\n");
        return;
    }

    write(devFd, writeBuf, sizeof(writeBuf));
    for (ix = 0; ix < 15; ix ++)
        printf("writeBuf[%d] is %x\n", ix, writeBuf[ix]);
   
    readNum = read(devFd, readBuf, sizeof(readBuf));
    printf("read %d char\n", readNum);
    for (ix = 0; ix < 15; ix ++)
        printf("readBuf[%d] is %x\n", ix, readBuf[ix]);
   
    close(devFd);
}