问题描述

再次请求支援，关于字符设备驱动的程序问题，求帮找错（不好意思没点数了）

先贴代码，问题在后面

驱动函数pressure。c:

/*

功能：

外部中断4接一个人体红外感应，如果感应到有人体活动（红外模块输出高电平），如果感应不到
人体活动（红外模块输出低电平）（变量red）

外部中断8接了一个按钮开关，如果按钮开关被按下，则输出为低电平，外部中断8管脚应该低电平，
反之，高电平 （变量pre）

只有当设备感应到有人体活动同时检测到按钮开关被按下。即 red == 1，pre == 0，的时候，才打
印HELLO!!!，其他的情况，都打印MISS!!!，举例来说，就是一个凳子上 坐着一个小孩，如果检测不到
小孩在活动，同时检测到凳子没有受到来自小孩的压力的话，报警

*/
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include

volatile unsigned long *gpbcon = NULL; // nLED_2(GPB6)
volatile unsigned long *gpbdat = NULL;
volatile unsigned long *gpfcon = NULL; // EINT4 ( GPF4 )
volatile unsigned long *gpfdat = NULL;
volatile unsigned long *gpgcon = NULL; // EINT8 ( GPG0 )
volatile unsigned long *gpgdat = NULL;
//volatile unsigned long *eintmask = NULL;
//volatile unsigned long *eintpend = NULL;

unsigned int val = 0;
unsigned int red = 1;
unsigned int pre = 0;

static struct class *pressuredrv_class;
static struct class_device *pressuredrv_class_dev;

//等待队列
static DECLARE_WAIT_QUEUE_HEAD(pressure_waitq);

/* 中断事件标志, 中断服务程序将它置1，pressure_read将它清0 */
static volatile int ev_press = 0;

static irqreturn_t pressure_irq(int irq, void *dev_id)
{
if(irq == (IRQ_EINT4 | IRQ_EINT8))
{
red = s3c2410_gpio_getpin(S3C2410_GPF4) & (1 << 4) ? 1:0;
pre = s3c2410_gpio_getpin(S3C2410_GPG0) & (1 << 0) ? 1:0;

            ev_press = 1; /* 表示中断发生了 */
        wake_up_interruptible(&pressure_waitq); /* 唤醒休眠的进程 */
}
    return IRQ_RETVAL(IRQ_HANDLED); /*该返回值代表中断确实真的处理了该中断*/

}

static int pressure_open(struct inode inode, struct file *file)
{
*gpbcon &= ~(0x3<<(06*2)); / 配置GPB6为输出引脚 /

*gpbcon |= (0x1<<(06*2));
//request_irq(IRQ_EINT4, pressure_irq, IRQT_LOW, "PRESSURE", NULL); //设置外部中断4
request_irq(IRQ_EINT4, pressure_irq, IRQT_BOTHEDGE, "PRESSURE", NULL); //设置外部中断4，双边沿触发
/感应到有人体活动（红外模块输出高电平）,感应不了人体活动（红外模块输出低电平）*/
request_irq(IRQ_EINT8, pressure_irq, IRQT_BOTHEDGE, "PRESSURE", NULL); //设置外部中断8，按钮开关，如果按下，低电平，否则，高电平

    return 0;

}

static int pressure_read(struct file *file, char __user *buf, size_t size, loff_t *ppos)
{
wait_event_interruptible(pressure_waitq, ev_press);

    copy_to_user(buf, &red, 4);
    copy_to_user(buf, &pre, 4);
    ev_press = 0; 

    return 0;

}

static ssize_t pressure_write(struct file *file, const char __user *buf, size_t count, loff_t * ppos)
{
int con = 0;
copy_from_user(&con, buf, 4);
if (con == 1)
{
*gpbdat &= ~(1<<6); //亮灯报警
}
else
{
*gpbdat |= (1<<6); //灭灯
}
return 0;
}

static ssize_t pressure_close(struct inode *inode, struct file *file)
{
free_irq(IRQ_EINT4, NULL);
free_irq(IRQ_EINT8, NULL);
return 0;
}

static struct file_operations pressure_drv_fops = {
.owner = THIS_MODULE,
.open = pressure_open,
.read = pressure_read,
.write = pressure_write,

.release = pressure_close,

};

int major;
static int __init pressure_drv_init(void)
{

major = register_chrdev(0, "pressure_drv", &pressure_drv_fops);
    pressuredrv_class = class_create(THIS_MODULE, "pressure_drv");
    pressuredrv_class_dev = class_device_create(pressuredrv_class, NULL, MKDEV(major, 0), NULL, "PressureDrv");
    gpbcon = (volatile unsigned long *)ioremap(0x56000010, 16);
    gpbdat = gpbcon + 1;
    gpfcon = (volatile unsigned long *)ioremap(0x56000050, 16);
    gpfdat = gpbcon + 1;
    gpgcon = (volatile unsigned long *)ioremap(0x56000060, 16);
    gpgdat = gpgcon + 1;
    return 0;

}

static void __exit pressure_drv_exit(void)
{

unregister_chrdev(major, "pressure_drv");
class_device_unregister(pressuredrv_class_dev);
class_destroy(pressuredrv_class);
iounmap(gpbcon);
iounmap(gpfcon);
iounmap(gpgcon);
//iounmap(eintmask);
//iounmap(eintpend);
}

module_init(pressure_drv_init);
module_exit(pressure_drv_exit);

MODULE_LICENSE("GPL");

应用程序app.c：

#include
#include
#include
#include
#include
#include

int main(int argc, char **argv)
{
int fd;
int con = 0;
unsigned int val = 0;
unsigned int red = 1;
unsigned int pre = 0;

    int rc = 0;
    struct timeval tv;

    fd = open("/dev/PressureDrv",O_RDWR);
    if (fd < 0)
    {
            printf("can't open!n");
    }

    while (1)
    {
            read(fd,&red,4); //printf("red = %un",red);
            read(fd,&pre,4); //printf("pre = %un",pre);
            if ((red == 1) && (pre == 0))
            {
                    //usleep(10);
                    tv.tv_sec = 0;
                    tv.tv_usec = 10;
                    select(0, NULL, NULL, NULL, &tv);
                    if ((red == 1) && (pre == 0))
                    {
                            printf("red = %u , pre = %un",red,pre);
                            con = 0;
                            write(fd,&con,4);
                            printf("HELLO!!!n");
                            //while(!((pre == 1) && (red == 0)));
                    }
                    else
                    {
                            printf("red = %u , pre = %un",red,pre);
                            printf("MISS!!!n");
                            con = 1;
                            write(fd,&con,4);
                            //while(!((pre == 1) && (red == 0)));
                    }
            }
            else
                    {
                            printf("red = %u , pre = %un",red,pre);
                            printf("MISS!!!n");
                            con = 1;
                            write(fd,&con,4);

                    }
    }

}

现在的问题是：

能输出pre=0，red=0；pre=0，red=1；pre=1，red=0；pre=1，red=1这 4种情况分别的 HELLO 或 MISS 的情况，但是却是错乱的，
比如说，我明明没有触发 红外模块的时候，这时 red 应该为0，但是输出却是为1，
输出结果跟我实际对红外和按钮开关的操作 有很大的出入，不知道应该是哪里的问题

通过这几天，我感受到C的薄弱带来的痛苦，求点评和建议