中断应用简单实例 - 曲径通幽论坛

#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>

#include <linux/fs.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/fcntl.h>

#include <asm/uaccess.h>
#include <asm/io.h>

#include <linux/time.h>
#include <linux/timer.h>

#include <linux/interrupt.h>

#define INT_DEV_NAME    "int_dev"
#define INT_DEV_MAJOR    240

#define INT_WRITE_ADDR        0x378
#define INT_READ_ADDR        0x379
#define INT_CTRL_ADDR        0x37A
#define    PRINT_IRQ        3
#define    PRINT_IRQ_ENABLE_MASK    0x10

#define    INT_BUFF_MAX        64

typedef struct {
    unsigned long time;
}__attribute__ ((packed)) R_INT_INFO;

R_INT_INFO intbuffer [INT_BUFF_MAX];
int intcount = 0;

/*清除缓存*/
void int_clear (void)
{
    int lp;
    for (lp = 0; lp < INT_BUFF_MAX; lp++) {
        intbuffer[lp].time = 0;
    }

    intcount = 0;
}

irqreturn_t int_interrupt (int irq, void *dev_id)
{
    printk ("come in interrupt\n");

    if (intcount < INT_BUFF_MAX) {
        intbuffer[intcount].time = get_jiffies_64();
        intcount++;
    }
    return IRQ_HANDLED;
}

int int_open (struct inode *inode, struct file *filp)
{
    set_irq_type(PRINT_IRQ, IRQ_TYPE_LEVEL_LOW);    /*设置中断为低电平触发*/

    if (!request_irq (PRINT_IRQ, int_interrupt, IRQF_DISABLED, INT_DEV_NAME, NULL)) {
        printk ("register ok\n");
        outb (PRINT_IRQ_ENABLE_MASK, INT_CTRL_ADDR);    /*使能IRQ控制*/
    }
    int_clear();

    return 0;
}

ssize_t int_read (struct file *filp, char *buf, size_t count, loff_t *f_pos)
{
    int readcount;
    char *ptrdata;
    int loop;

    readcount = count / sizeof (R_INT_INFO);    /*读以sizeof(R_INT_INFO)为单位的内容个数 */

    if (readcount > intcount)    /*读取字节数超出则读取所有现存的数据*/
        readcount = intcount;

    ptrdata = (char *) &intbuffer[0];

    for (loop = 0; loop < readcount * sizeof(R_INT_INFO); loop++) {
        printk ("loop_time = %d\n", loop);
        put_user (ptrdata[loop], (char *) &buf[loop]);    /*把中断时读取的数据写往用户空间*/
    }

    return (readcount * sizeof(R_INT_INFO));
}

ssize_t int_write (struct file *filp, const char *buf, size_t count, loff_t *f_pos)
{
    unsigned char status;
    int    loop;

    int_clear();

    for (loop = 0; loop < count; loop++) {
        get_user (status, (char *) buf);
        outb (status, INT_WRITE_ADDR);
    }

    return count;
}

int int_release (struct inode *inode, struct file *filp)
{
    outb (0x00, INT_CTRL_ADDR);    /*禁止中断*/
    free_irq (PRINT_IRQ, NULL);    /*从内核中注销中断服务函数*/

    return 0;
}

struct file_operations int_fops = {
    .owner = THIS_MODULE,
    .read = int_read,
    .write = int_write,
    .open = int_open,
    .release = int_release,
};

int int_init (void)
{
    int result;
    result = register_chrdev (INT_DEV_MAJOR, INT_DEV_NAME, &int_fops);

    if (result < 0) return result;

    return 0;
}

void int_exit (void)
{
    unregister_chrdev (INT_DEV_MAJOR, INT_DEV_NAME);
}

module_init (int_init);
module_exit (int_exit);

MODULE_LICENSE ("Dual BSD/GPL");

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>

#define DEVICE_FILENAME "/dev/int_dev"

typedef struct {
    unsigned long time;
}__attribute__ ((packed)) R_INT_INFO;

#define INT_BUFF_MAX     64

int main()
{
    int dev;
    R_INT_INFO intbuffer[INT_BUFF_MAX];
    int    intcount;
    char    buff[128];
    int    loop = 0;

    dev = open (DEVICE_FILENAME, O_RDWR | O_NDELAY);
    if (dev >= 0) {
        printf ("start...\n");

        buff[0] = 0x00;
        write (dev, buff, 1);    /*关闭LED*/
        sleep(1);

        buff[0] = 0xFF;
        write (dev, buff, 1);    /*打开LED*/
        sleep (1);

        buff[0] = 0x00;
        write (dev, buff, 1);    /*关闭LED*/
        sleep (1);

        buff[0] = 0xFF;
        write (dev, buff, 1);    /*打开LED*/

        printf ("wait...input\n");
        while (1) {
            memset (intbuffer, 0, sizeof (intbuffer));
            intcount = read (dev, (char *)&intbuffer[0], sizeof(R_INT_INFO)) / sizeof(R_INT_INFO);
            if (intcount) {
                while (intbuffer [loop].time != 0) {
                    printf ("intbuffer [%d] = %d\n", loop, intbuffer [loop]);
                    loop++;
                }
                break;
            }
        }

        printf ("input ok...\n");
        sleep (1);
        memset (intbuffer, 0, sizeof(intbuffer));

        printf ("read interrupt times\n");
        intcount = read (dev, (char *)intbuffer, sizeof(intbuffer)) / sizeof(R_INT_INFO);

        for (loop = 0; loop < intcount; loop++)
            printf ("index = %d time = %ld\n", loop, intbuffer[loop].time);

        printf ("led flashing...\n");
        for (loop = 0; loop < 5; loop++) {
            buff[0] = 0xFF;
            write (dev, buff, 1);
            sleep (1);
            buff[0] = 0x00;
            write (dev, buff, 1);
            sleep (1);
        }
        close (dev);
    } else {
        printf ("open int_dev failed\n");
     }

    return 0;
}